WO2015072241A1

WO2015072241A1 - Photoelectric conversion element module and method for manufacturing photoelectric conversion element module

Info

Publication number: WO2015072241A1
Application number: PCT/JP2014/076461
Authority: WO
Inventors: 大介新延; 坂井　裕一
Original assignee: 三菱電機株式会社
Priority date: 2013-11-15
Filing date: 2014-10-02
Publication date: 2015-05-21
Also published as: JPWO2015072241A1

Abstract

A back-connection type photoelectric conversion element comprises, on the back surface: a linear electrode (12) that serves as a first element electrode; and a collector electrode (14) and a current extraction electrode (15), which serve as a second element electrode. The extraction electrode of the second element electrode is arranged so as to have a portion intersecting with the second element electrode in the middle part thereof. The first and second element electrodes are arranged side by side so as not to overlap each other on the back surface, and a plurality of back-connection type photoelectric conversion elements are connected by means of an inter-element connector (30) that is configured of a main body part (32) and an inter-element connection part (31). The main body part (32) is selectively and directly connected to the first element electrode, while having an adhesive layer (26) that serves as an insulating layer interposed between itself and the second element electrode. The main body part (32) covers the whole back surface of the photoelectric conversion element other than a part of the second electrode. The inter-element connection part (31) is connected to the main body part (32) and is connected to the second element electrode of an adjacent photoelectric conversion element, while being arranged along the current extraction electrode (15), which is the extraction electrode of the second element electrode. Due to this configuration, there can be obtained a photoelectric conversion element module which can be manufactured easily and has excellent photoelectric conversion efficiency.

Description

Photoelectric conversion element module and method for manufacturing photoelectric conversion element module

The present invention relates to a photoelectric conversion element module and a method for manufacturing the photoelectric conversion element module, and more particularly to an inter-element connection structure.

Conventionally, a plurality of light receiving elements having a positive electrode and a negative electrode provided on the non-light-receiving surface side are provided side by side without providing an electrode on the light-receiving surface side, and the positive electrode of one light receiving element and the negative electrode of the adjacent light receiving element are interconnected. There is disclosed a light receiving element module connected by an inter-element connection body called as a so-called element connecting body. Hereinafter, the light receiving element may be referred to as an element or a photoelectric conversion element.

In the light receiving element module, in order to electrically connect the positive electrode formed on the back surface of the first light receiving element and the negative electrode formed on the back surface of the adjacent second light receiving element, an interelement connection body is generally used. Are connected. The connection method using the inter-element connection body is not only for the light receiving element, but also for all photoelectric conversion elements in which a positive electrode and a negative electrode are provided as element electrodes on the non-light-receiving surface or non-light-emitting surface side without providing an electrode on the light-receiving or light-emitting surface side. Applicable. In the photoelectric conversion element, since there is no electrode on the light receiving surface or the light emitting surface of the light receiving element, a light receiving area and a light emitting area can be secured. Further, the inter-element connection body does not cover the light receiving surface of the light receiving element. Therefore, the shape of the inter-element connection body and the element electrode can be increased, and the resistance for collecting current in the light receiving element and the resistance for connecting the elements can be reduced. Therefore, there is an advantage that the conversion efficiency between light and electricity, that is, the photoelectric conversion efficiency is excellent.

As the inter-element connection body, generally, an entire surface of a highly conductive metal such as a copper (Cu) foil is coated with solder. In the connection of the inter-element connection body, the inter-element connection body is placed on the positive electrode or the negative electrode, which is an element electrode made of a metal such as silver (Ag), and heated, and the inter-element connection body and the element electrode are partially or over the entire length. And are connected by a conductive member such as solder.

As a back connection type light receiving element module, for example, as in Patent Document 1, a large number of elongated linear electrodes called grid electrodes are collectively connected to a bus electrode or a current extraction electrode at the end of the element. Some of the current extraction electrodes are interconnected using inter-element connectors. In the light receiving element module, a large number of elongated linear electrodes collect power generation current to the end of the element, and current flows from the end to the adjacent element through the inter-element connector.

Also, as in Patent Document 2, for example, a solar cell element in which positive and negative grid electrodes are formed in a two-layer structure on an element via an insulating layer to form an element electrode has been proposed. In the above structure, the electrode area per projected area of the element can be increased as compared with Patent Document 1, and as a result of the increase in the electrode area, the current collecting resistance with respect to the received light current is reduced, and the power loss due to the resistance can be reduced. it can.

In addition to this, the current collecting resistance can be reduced by increasing the thickness or height of the element electrode, but the warpage of the element increases due to the difference in thermal expansion coefficient between the element and the electrode material. However, it has been difficult to increase the thickness of the device electrode. On the other hand, for example, as in Patent Document 3, a resin sheet in which a metal electrode having a pattern equivalent to the positive electrode and the negative electrode on the back surface of the element is provided on the element on which the device electrode including the positive electrode and the negative electrode is formed on the back surface of the element. A light receiving element module is also disclosed in which element electrodes between a plurality of elements are connected using metal electrodes on a resin sheet as inter-element connectors and current extraction electrodes.

Further, for example, as in Patent Document 4, an element electrode composed of a positive electrode and a negative electrode is formed on the back surface of a cell of a light receiving element in a two-layer structure, and an inter-element connection line overlaps the element electrode and is disposed over the entire element. A solar cell module is also disclosed in which the current collecting resistance with respect to the photocurrent is reduced by increasing the total area of the element electrodes, and the power loss due to the resistance is reduced.

In the element structure of Patent Document 1, a large number of elongated linear electrodes collect generated current up to the end of the element, and are connected together to the bus electrode or current extraction electrode at the end of the element. Then, the inter-element connection body is connected to the bus electrode or the current extraction electrode, and a current flows to the adjacent element through the inter-element connection body. However, in the structure of the element, it is necessary to collect the generated current to the end of the element by the linear electrode, and there is a problem that the resistance loss at the time of current collection is relatively large. The above problem is particularly remarkable in a solar cell having a large element area. Further, in Patent Document 1, since the positional relationship between the positive electrode and the negative electrode on the plane is constant, a string formed by a plurality of elements is created, and a portion that connects the strings, that is, a folded portion of the string It is necessary to arrange and connect a conductor between the strings at the (end portion). Therefore, the ratio of the area of the part other than the element occupying the module area is increased, and resistance between the strings is added, so that there is a problem that the photoelectric conversion efficiency as a module cannot be improved. In addition, since the element electrode is formed directly on the semiconductor substrate, there is a problem that the metal diffuses in the semiconductor substrate depending on the type of electrode metal constituting the element electrode or the element structure, and the photoelectric conversion efficiency is lowered.

In Patent Document 2, the positive and negative electrodes of the element are formed in two layers, and the structure is complicated. Therefore, in manufacturing the device, the number of processes and time are required, and although one electrode covers the entire back surface of the device, it is difficult to increase the thickness of the electrode on the device to sufficiently reduce the current collecting resistance. There is a problem that power loss due to resistance cannot be made sufficiently small. In addition, in the structure of the element, it is necessary to collect the generated current by the electrode on the element up to the end of the element when modularizing, and there is a problem that the resistance loss at the time of current collection is relatively large. In addition, since the element electrode is formed directly on the semiconductor substrate, there is a problem in that the metal diffuses into the semiconductor substrate depending on the electrode metal or element structure constituting the element electrode, thereby reducing the photoelectric conversion efficiency. In addition, when the thickness of the element electrode formed directly on the element increases, warpage occurs in the light receiving element with the inter-element connection body due to the difference in thermal expansion coefficient between the metal inter-element connection body and the light receiving element substrate. There has been a problem that it cannot be sealed in a planar shape without damaging the element. In particular, when a metal electrode formed by firing a paste containing a commonly used glass component is used as an element electrode, a high temperature is required during firing, and increasing the electrode area and thickness increases warping of the element. There was a problem. The cause of this warpage is caused not only by the element electrode and the element substrate, but also by the difference in the coefficient of thermal expansion between the inter-element connector and the element substrate.

In Patent Document 3, a resin film in which a metal pattern is formed is used as an inter-element connection without forming a current extraction electrode and a bus electrode on the element. It was necessary to align with the electrode on the element. Therefore, in the module structure of Patent Document 3, the interval necessary for preventing a short circuit between the positive electrode and the negative electrode is not only the positional accuracy between the element electrode and the semiconductor substrate, but also the alignment accuracy between the element and the resin film. Also depends.

Furthermore, in Patent Document 4, since the positive and negative electrodes are formed on the back surface of the light receiving element in a two-layer structure, and the inter-element connector overlaps the element electrode and is disposed on the entire element, current collection for photocurrent is performed. Resistance is reduced. However, in Patent Document 4, since one row of element electrodes and one inter-element connection body need to correspond one-to-one, it is necessary to adjust the interval between the inter-element connection bodies to the inter-electrode pitch. The electrode pitch is preferably smaller than the diffusion length of minority carriers in the semiconductor element substrate. For example, in the case of a silicon substrate, although it depends on the specific resistance, it is about 2 mm or less. Therefore, when using a substrate having a size of about 150 mm square, it is necessary to arrange about 70 inter-element connection bodies accurately and connect them to the element electrodes so that adjacent inter-element connection bodies do not contact each other. Furthermore, there is a problem that it is necessary to insulate from the electrode of the other polarity, many alignment steps occur, and it is difficult to align and layout the element electrodes of the positive electrode and the negative electrode.

Further, as a connection method between an element such as a light receiving element and an inter-element connection body, a prior art document such as Patent Document 5 and Patent Document 6 includes a method in which a metal material is melted and connected by a heating means such as a laser. Is also disclosed.

Patent Document 7 also proposes a light receiving element in which a first electrical contact and a second electrical contact that are insulated and separated by a passivation film are provided on one surface side of a wafer.

Furthermore, Patent Documents 8 and 9 also propose a light receiving element module using a wiring board in which a wiring corresponding to the element electrode is formed for the back surface taking type light receiving element.

Moreover, in patent document 10, after installing fixing resin in at least one between the electrodes of a photovoltaic cell, and between the wiring of a wiring sheet, fixing resin is made into the 1st hardening state, Then, the joining member containing an electroconductive substance is used. A method of manufacturing a solar cell with a wiring sheet is also proposed in which the solar cell and the wiring sheet are superposed to soften the fixed resin in the first cured state and re-cured into the second cured state. ing.

For example, Non-Patent Document 1 proposes a structure in which an electrode having the other polarity is directly contacted with a semiconductor substrate through a thin inorganic insulating layer formed on the semiconductor substrate on a semiconductor layer having one polarity. Yes.

Japanese translation of PCT publication 2010-521811 JP 2001-189475 A JP 2010-245399 A JP 2009-206366 A US 2004-2004062 Specification International Publication No. 2012-171968 Specification Special table 2008-519438 JP 2011-151262 A JP 2012-151240 A JP 2012-99569 A International Publication No. 2008-1113741 Specification JP 2012-28806 A

As described above, in the conventional element structure, since the distance from the current collecting portion such as the grid electrode and the linear electrode to the current extraction portion is relatively long, the resistance loss is large and the thickness of the element electrode is necessary. There is. When the thickness of the element electrode or inter-element connection body is large, the warpage of the light receiving element increases due to the difference in thermal expansion coefficient between the element electrode and inter-element connection body and the light receiving element substrate. In the back connection type light receiving element module in which the electrode is formed, the warp of the light receiving element is particularly large, and there is a problem that the element string cannot be sealed in a planar shape.

In addition, when the current collecting electrode is thick and the distance between the positive and negative current collecting electrodes is wide, the distance that carriers flow in the plane in the device before reaching the current collecting electrode becomes longer, increasing the current collecting resistance or the carrier. The current collection efficiency decreases due to the deactivation, and the power generation efficiency decreases. Therefore, it is necessary to narrow the electrode interval or electrode width, and when forming positive and negative electrodes separately, it is necessary to improve the positional accuracy of both.

In the structure in which the electrode metal is directly formed on an insulating film such as a passivation film on the element substrate, the metal is electrically short-circuited with the element substrate through the pinhole of the passivation film, or the metal diffuses into the element substrate. Thus, there is a problem that it acts as a recombination center and a loss occurs in photoelectric conversion efficiency.

Also, since it is necessary to insulate between the positive and negative electrodes, there is a gap between the positive and negative electrodes. Since there is no gap between the positive and negative electrodes that reflects light, part of the light incident on the gap is transmitted through the element and escapes, resulting in poor light utilization efficiency and loss in photoelectric conversion efficiency. There was a problem that caused.

The present invention has been made in view of the above, and an object thereof is to obtain a photoelectric conversion element module that is excellent in photoelectric conversion efficiency and easy to manufacture.

In order to solve the above-described problems and achieve the object, a photoelectric conversion element module according to the present invention includes a back connection type photoelectric conversion element having first and second element electrodes having different polarities on the back side from a conductive plate. And connected by an inter-element connector. The first and second element electrodes are arranged in a plane, and the second element electrode includes a current extraction electrode connected to the inter-element connection portion and a plurality of current collecting electrodes connected to the current extraction electrode. The current collecting electrode of the element electrode has a portion that intersects and connects with the inter-element connection portion on the back surface of the semiconductor substrate, and the first element electrode has a plurality of regions separated by the inter-element connection portion. . The body part of the inter-element connection body has a plate shape, and the width of the body part is wider than the width of the inter-element connection part, and is in contact with the second element electrode on the back surface of the photoelectric conversion element through an insulating layer. Is electrically insulated from the first element electrode, and the inter-element connection portion of the inter-element connection body electrically connected to the main body is adjacent to the second element electrode of the adjacent element. Directly connected to the current extraction electrode.

According to the present invention, a photoelectric conversion element module that is excellent in photoelectric conversion efficiency and easy to manufacture can be obtained.

FIG. 3 is a plan view of the light receiving element module according to the first embodiment when viewed from the light receiving surface side, and a module forming member such as a sealing material is omitted for easy understanding. It is the top view which looked at the light receiving element module by Embodiment 1 from the back surface side, and module forming members, such as a sealing material, are omitted for easy understanding FIG. 2 is a perspective view schematically showing a positional relationship between a light receiving element and an inter-element connection body constituting the light receiving element module used in Embodiment 1, and shows a state before connecting the inter-element connection body between the element and the inter-element connection; The figure which shows the state which looked at the light receiving element connected to the body from the back side 2A and 2B are diagrams of a light receiving element with an inter-element connection body used in Embodiment 1 as viewed from the back side, where FIG. 1A is a plan view, FIG. 1B is a cross-sectional view taken along line CD in FIGS. 1C is a cross-sectional view taken along the line EF in FIGS. 1 and 2, and FIG. 4D is a cross-sectional view taken along the line GH in FIGS. 1 and 2 for easy understanding. Module forming members such as are omitted The figure which shows the pattern of the contact bonding layer in the light receiving element module of Embodiment 1. 2 is a diagram illustrating an inter-element connection body used in the light-receiving element module according to Embodiment 1, wherein (a) is a plan view, (b) is a cross-sectional view taken along line IJ in (a), and (c) is ( It is KL sectional drawing of a), (b), (c) shows the state in which the adhesive layer was formed in order to facilitate understanding It is a figure which shows an example of the positional relationship of the light receiving element of Embodiment 1, and an adhesive layer, (a) is a top view, (b) is the light receiving element of (a), and the connection between elements of an interelement connection body The top view which shows the state which mounted | wore the mounting | wearing part, (c) is a top view which shows the state which mounted | wore the light receiving element of (b) with the main-body part of the connection element between elements further. The figure which shows arrangement | positioning of the connection body between elements used in Embodiment 1. FIG. 3 is a cross-sectional view showing the light-receiving element module according to the first embodiment, and shows a cross section AB in FIGS. It is the top view which looked at the light receiving element module by Embodiment 2 from the back surface side, and module forming members, such as a sealing material, are omitted for easy understanding The perspective view which shows typically the positional relationship with the light receiving element which comprises the light receiving element module used in Embodiment 2, and an inter-element connection body, The state before connecting an inter-element connection body is set to an element and an inter-element connection body. The figure which shows the state which looked at the connected light receiving element from the back side FIG. 6 is a diagram illustrating an inter-element connection body used in the light-receiving element module according to Embodiment 2, wherein (a) is a plan view, (b) is a cross-sectional view taken along line IJ in (a), and (c) is ( KL sectional view of a), (d) is an M ₁ -N ₁ sectional view of (a), and (e) is an M ₂ -N ₂ sectional view of (a). Sectional drawing which shows the light receiving element module of Embodiment 2. FIG. 6 is a diagram showing a modification of the inter-element connection body used in the light receiving element module according to Embodiment 2, wherein (a) is a plan view, (b) is a cross-sectional view taken along line IJ in (a), and (c). (A) is a KL sectional view, (d) is an M ₁ -N ₁ sectional view of (a), and (e) is an M ₂ -N ₂ sectional view of (a). The figure which shows the modification of the light receiving element with a connection body between elements The figure which shows the modification of the light receiving element with a connection body between elements The perspective view which shows the modification of the connection body between elements used in

Embodiment

1,2. The figure which shows the modification of the connection body between elements used in

Embodiment

1,2. It is a figure which shows the light receiving element of Embodiment 3, (a) is sectional drawing, (b) is the principal part enlarged view of (a), (c) is the principal part enlarged view of (a). Sectional drawing which shows the modification of a light receiving element Sectional drawing which shows the modification of a light receiving element Sectional drawing which shows the modification of a light receiving element Sectional drawing which shows the modification of a light receiving element The top view which showed the light receiving element with the connection body between elements of Embodiment 4 from the back side It is the figure which showed the light receiving element of Embodiment 4 from the back side, (a) is a top view, (b) is the state which the element connection part of the element connection body connected to the current extraction electrode in (a). Plan view 25A is a cross-sectional view of a light receiving element with an inter-element connection body according to a fourth embodiment, where FIG. 25A is a cross-sectional view corresponding to the position of a line segment 6A-6B in FIG. 25A, and FIG. (A) A sectional view corresponding to the position of the line segment 6C-6D in FIG. 25, (c) is a sectional view corresponding to the position of the line segment 6E-6F in FIG. The top view which showed from the back side the light-receiving element with the connection body between elements used as the modification of Embodiment 4 The top view which showed from the back side the light-receiving element with the connection body between elements used as the modification of Embodiment 4 Plan view on the element back surface side showing the pattern of the conductive region on the element surface of the element used in the fourth embodiment, in which the electrode on the semiconductor substrate has the opposite polarity to the conductive region in the semiconductor substrate under the electrode The top view which looked at the element of Embodiment 4 from the element back surface side Sectional view of the light-receiving element module according to Embodiment 4 corresponding to the 6A-6B portion of FIG.

Embodiments of a photoelectric conversion element module and a method for manufacturing a photoelectric conversion element module according to the present invention will be described below with reference to the drawings. In addition, this invention is not limited to the following description, In the range which does not deviate from the summary of this invention, it can change suitably. In the drawings, the scale of each member may be different from the actual scale for easy understanding. The same applies between the drawings. Furthermore, the same components in the embodiments are denoted by the same reference numerals, and the components described in one embodiment are not described in detail in another embodiment. In this embodiment, a light receiving element is described as an example of a photoelectric conversion element. However, various light emitting elements such as a light emitting element using a direct transition type GaAs as a semiconductor substrate and having a double heterojunction structure at a junction are also described. Applicable.

Embodiment 1 FIG.
1 and 2 are plan views of the light receiving element module according to Embodiment 1 as viewed from the light receiving surface side and the back surface side. FIG. 3 is a perspective view schematically showing a positional relationship between a light receiving element and an inter-element connection body constituting the light receiving element module. As shown in FIGS. 1 and 2, the light receiving element module 1 according to the first embodiment is configured by connecting back connection type light receiving elements 10a to 10f in series. Here, when each light receiving element is identified by the position of each light receiving element, it is set to 10a to 10f, and the light receiving element alone is collectively referred to as 10. The light receiving elements 10 are electrically connected by an inter-element connection body 30 made of a conductive plate to form a linear element row, that is, a string, and an element composed of a main body portion 32 and an inter-element connection portion 31 between the strings. It is electrically connected by the inter-connection body 30.

FIG. 4 (a) shows a plan view of the light receiving element with an inter-element connection body used in Embodiment 1, as viewed from the back side. 4B is a cross-sectional view taken along the line CD of FIGS. 1 and 2, FIG. 4C is a cross-sectional view taken along the line EF of FIGS. 1 and 2, and FIG. 4D is a cross-sectional view taken along the lines of FIGS. FIG. In FIG. 4, module forming members such as inter-element connectors and sealing materials are omitted for easy understanding. In the present embodiment, among the element electrodes formed on the back surface of the light receiving element 10, a plurality of current collecting electrodes 14 and the back surface of the light receiving element 10 are arranged such that the second element electrode, which is a positive electrode, is arranged in parallel at regular intervals. It is composed of two current extraction electrodes 15 having intersections in the same plane, and an inter-element connection portion 31 is mounted along the two current extraction electrodes 15. The main body portion 32 is in direct contact with the linear electrode 12 constituting the first element electrode which is a negative electrode, which is disposed in a plane without having an overlapping portion overlapping the second element electrode. ing.

That is, except for the region where the plurality of current collecting electrodes 14 and the two current extraction electrodes 15 cross-connected thereto are formed, and separated from the current collection electrode 14 and the current extraction electrode 15, the entire back surface A first element electrode is formed on the element to constitute an element electrode. The main body 32 is widely distributed and connected to the entire surface of the linear electrode 12 and the main body 32 by the electrical connection body 21 while being insulated from the element electrodes other than the linear electrodes 12. The pattern arrangement of the element electrode and the inter-element connection body 30 reduces the current collection distance on the inter-element connection body 30 and the element electrode, and increases the light absorptance by reflection of the element transmitted light by the main body 32 or the like. Can do. In the light receiving element 10 in the present embodiment, the current extraction electrode 15 is formed on the non-light-receiving surface side and an electrode shadow by the current extraction electrode 15 cannot be formed. Therefore, it is preferable that the number of the current extraction electrodes 15 is large. From the viewpoint of productivity, it is better that the number is smaller, so that the number can be 4-16, for example. In the following, the element electrode refers to an electrode formed on the light receiving element 10 such as the linear electrode 12, the current extraction electrode of the linear electrode 12, the current collecting electrode 14, the current extraction electrode 15 of the current collecting electrode 14, and the like. To do. In the present embodiment, the first and second element electrodes having two polarities constitute a single-layer structure and do not have overlapping portions, but are arranged in a plane.

The light receiving element 10 of the present embodiment does not have the current extraction electrode of the linear electrode 12 which is the first element electrode. Further, the current collecting electrode 14 in the second element electrode which is an element electrode having a polarity that is not directly connected to the main body portion 32 of the inter-element connector 30 is connected to the current extraction electrodes 15 that are cross-connected to each other. The current extraction electrode 15 is directly connected to the inter-element connection portion 31 of the inter-element connector 30. On the other hand, the first element electrode divided by the discontinuous part by the second element electrode is directly connected to the main body part 32 of the inter-element connector 30.

With the above configuration, on the second element electrode side, current is efficiently collected by the highly conductive inter-element connection portion 31 and the current extraction electrode 15, so that most of the current collecting resistance between the elements is the collecting electrode 14. The distance from the current extraction electrode 15 to the current extraction electrode 15 is sufficient. Similar to the back electrode of the light receiving element having electrodes on both sides, the current extraction electrode 15 is distributed at the position where the surface of the element is divided. Therefore, the current collecting distance in the element electrode is the same as the passivation film on both sides. It is equivalent to the current collection distance of the back surface electrode of the light receiving element which has an element electrode. This means that the current collecting distance is at most about half or less than that of a conventional back-connected light receiving element having a current extraction electrode at the end of the element. If the conductor resistance of the element electrode is not different from the usual, it is half. It means that the current collecting resistance can be less than about.

Furthermore, the present embodiment relates to a back connection type light receiving element. Since the electrode shadow area does not increase even if the electrode area increases, the number of current extraction electrodes 15 and inter-element connection portions 31 can be arbitrarily increased. . Accordingly, by increasing the number of current extraction electrodes 15 and inter-element connection portions 31 to n, the current collection distance and the current collection resistance can be reduced to about ½ n, and the current collection distance in the element electrode having a large resistance can be reduced. It has the effect that it can be made shorter than the back surface electrode of the light receiving element which has an electrode on both surfaces normally.

On the other hand, since the first element electrode side is directly connected to the main body 32 of the inter-element connector 30, the current collecting resistance by the element electrode is only the thickness of the first element electrode, and the resistance is greatly reduced. It becomes possible to do. Note that the current collecting resistance can be significantly reduced by adjusting the area ratio of the area occupied by the first and second element electrodes on the back surface of the element so that the wiring resistance between them is as small as possible. Since the width of the main body is wider than the width of the inter-element connection portion, it can be directly connected to a wider range of the first element electrodes and the current collecting resistance can be reduced.

In addition, since the width of the body part of the inter-element connection body is wide, the thickness can be reduced while keeping the conductor resistance of the inter-element connection body low, so the difference in coefficient of thermal expansion between the element substrate and the inter-element part The advantage is that the warpage of the element due to the above can be reduced, the strength of the element can be kept high, and damage can be prevented. The same applies to the inter-element connection section. With the configuration of the present embodiment, the number of inter-element connection sections can be increased, and as a result, the projected area of the inter-element connection section with respect to the elements can be increased. It is possible to reduce the warpage of the device, to keep the strength of the device high, and to prevent breakage. Compared with the element where the inter-element connection body is connected to both sides, in the back connection type element module where the inter-element connection body is connected to only one surface, the thermal expansion coefficient difference between the element substrate and the inter-element connection body Although the warp is large, the warp can be reduced by using the structure of this embodiment. Here, the direct connection means an electrical connection with a low resistance such as a connection through a conductive adhesive layer such as a solder layer or a connection by welding, or a close connection by electrostatic bonding. And

1 and 2, in the light receiving element 10 at the end of the connected element row, the current lead line 38 is connected to the light receiving element 10, and although not shown, the light receiving element row is sealed with the sealing material 22. ing. The sealing structure will be described later. The semiconductor substrate 11 is covered with the front-side main surface material 23 on the outer side of the sealing material 22 as shown in the cross section AB of FIGS. 1 and 2 in FIG. A part of the two current lead lines 38 exits the sealing material 22 and the back side main surface material 25 from the holes formed in the back side main surface material 25 and the back surface side sealing material 22. It becomes a state. The current lead line 38 coming out from the sealing material 22 is connected to a conductor in the junction box so that it can be taken out of the light receiving element module 1 through a cable connected to the junction box. In FIGS. 1 and 2, the frame and the junction box are not shown for easy viewing.

In the following, first, the structure of the light receiving element module 1 in which the light receiving elements 10 are connected by the interelement connecting bodies 30 will be described, then the structure of the light receiving elements 10 will be described, and the interelement connecting bodies 30 for connecting the light receiving elements 10 to each other. The structure of will be described.

As shown in FIGS. 1 to 3, the light receiving element module 1 according to the present embodiment includes light receiving elements 10a to 10f and an inter-element connection body 30 that connects the light receiving elements 10a to 10f. The inter-element connector 30 is connected to the back connection type light receiving elements 10a to 10f having the first and second element electrodes on the back side, and the main body 32 covers almost the entire back surface of the light receiving elements 10a to 10f. And an inter-element connection portion 31 connected to the main body portion 32 and connected to the second element electrode of the adjacent light receiving element. The linear electrodes 12 as the first element electrodes and the collecting electrodes 14 as the second element electrodes of the light receiving elements 10a to 10f include parallel portions arranged alternately so as to be parallel to each other at a constant interval. . The second element electrode includes a current extraction electrode 15 that intersects the parallel collecting electrode 14. It is preferable that the main body 32 is formed of a light reflector having high reflectivity with respect to light transmitted through the light receiving element 10 on the surface of the portion other than the connection point or the connection region with the first element electrode of the light receiving element 10. The main body 32 is selectively connected directly to the linear electrode 12 that is the first element electrode of the light receiving elements 10a to 10f, and is an insulating layer for the current collecting electrode 14 that is the second element electrode. It arrange | positions through the contact bonding layer 26. FIG. Then, as will be described later, the scattering particles are dispersed in the adhesive layer 26. Thereby, in addition to the reflection by the main body 32, the reflection portion is constituted by the adhesive layer 26 between the main body 32 and the light receiving elements 10a to 10f, and the first element electrode including the linear electrode 12 and the current collecting electrode 14 are provided. Reflected light is incident on the light receiving elements 10a to 10f through the gap between the second element electrodes provided with the photoelectric conversion efficiency. FIG. 5 shows the shape of the adhesive layer 26 in the module state.

In the light receiving element with an inter-element connection body according to the present embodiment, as shown in FIGS. 3 and 4 (a) to (d), the inter-element connection portion 31 is connected to the main body portion 32 and is adjacent thereto. It is connected to a current extraction electrode 15 that is a second element electrode of the light receiving element 10. The second element electrode intersects with the current collecting electrode 14 at both ends of the line segment of the current collecting electrode 14 at a length of about 1/4 of the line segment, that is, on the current collecting electrode 14. Since the current extraction electrode 15 is arranged so as to have a crossing portion with respect to the current electrode 14, the current collection distance from the second element electrode to the inter-element connector is extremely short, and the current collection is performed efficiently. Electricity is made. Further, the main body 32 is selectively connected directly to the linear electrode 12 and is disposed on the current collecting electrode 14 via an adhesive layer 26 that is an insulating layer, except for the slit S portion. Cover the entire back side. In addition, the current extraction electrode 15 divides the linear electrode 12 as the first element electrode at two locations in the longitudinal direction of the linear electrode 12, and is arranged so as to intersect the longitudinal direction of the current extraction electrode 15 at the division portion. Has been. As described above, although the linear electrode 12 is divided, the current collecting distance to the inter-element connector 30 is the thickness of the linear electrode 12 because it is in direct contact with the main body 32 of the inter-element connector 30. It is only a part, almost equal to 0, and the conductive resistance is very low.

As shown in FIG. 3 and FIG. 4A, the light receiving element 10 of the first embodiment is a thin plate-like pn junction having a rectangular planar shape and a thickness of, for example, 0.05 to 0.5 mm. The semiconductor substrate 11 is provided. The rectangle here means a quadrangular shape having two sets of parallel sides perpendicular to each other. In particular, in the light receiving element 10 using a single crystal, when forming a rectangular substrate from a cylindrical single crystal ingot, in order to reduce a portion that is cut off from a circle to a rectangle and is wasted, as shown in FIG. In many cases, a substrate having a shape in which a part of the corner is cut off is used. Those that are slightly deformed, including the above shapes, are also included in the rectangle. In the figure, an example of a shape in which a part of a square corner is cut off is shown, but a rectangular shape may be formed by dividing this into half.

As shown in FIGS. 4A to 4D, in the region on the back surface side of the light receiving element 10, a linear electrode 12 as an element electrode of one polarity, a collecting electrode 14 as an electrode of the other polarity, A current extraction electrode 15 of the current collecting electrode 14 is formed. A part of the linear electrode 12 is electrically connected to the substrate through an opening of a passivation film (not shown) of the element substrate, but the other part of the electrode is in contact with the passivation film and reflects light transmitted through the element. Therefore, the material of the linear electrode 12 mainly includes a material having a high light reflectance in a wide wavelength range of metals such as aluminum (Al), nickel, tin, copper, silver, gold, a mixture thereof, and an alloy. It is preferable to use a metallic material to form a reflective metal layer. By laminating a barrier layer that suppresses the reaction with the metal material or the reflective metal layer as the second layer on the reflective metal layer, the electric conduction in the linear electrode 12 can be improved. As a material for suppressing the reaction, metals such as nickel, tin, copper, silver, titanium tungsten (TiW), mixtures and alloys of the above materials, and laminates of the above materials can be used. The material constituting the element electrode itself may include additives such as a resin component or a glass component in addition to metal, and a conductive adhesive may be used. In addition to the element electrode constituent material, for example, in the case of a light receiving element in which a semiconductor junction is formed by heterojunction of amorphous silicon and single crystal silicon, a translucent electrode formed by a translucent conductive film such as indium oxide And a laminate of metal layers such as aluminum, silver, and gold may be used.

As the outermost layer of the laminated body of the linear electrodes 12, it is preferable to use a material suitable for connecting to the inter-element connector 30 when modularizing. For example, when the element and the inter-element connector 30 are connected using solder, it is preferable to use a metal having solder bonding properties such as copper, tin, and silver.

The linear electrode 12 and the current collecting electrode 14 of the first embodiment are electrodes that collect electric charges generated by photocarrier generation from the semiconductor substrate 11 and collect current, and are arranged at appropriate intervals. The pattern of the linear electrode 12 is a junction formed by doping, a heterojunction, or a straight line extending in a certain direction with a width of about 0.05 to 1 mm, for example. The shape portions are arranged in parallel with the direction orthogonal to the extending direction of the electrodes with a period of 0.2 to 2.5 mm to constitute a parallel portion. The pattern of the collector electrode 14 also varies depending on the element structure, such as whether it is a junction formed by impurity doping or a heterojunction, but for example, a linear shape extending in a certain direction with a width of about 0.2 to 2 mm The portions are arranged in parallel with a direction orthogonal to the extending direction of the electrodes with a period of 0.2 to 2.5 mm to constitute a parallel portion. The widths of the linear electrode 12, the current collecting electrode 14, and the current extraction electrode 15, which are element electrodes, need not be the same, and are designed according to the current collecting distance or the minority carrier diffusion length of the substrate.

Further, the collecting electrodes 14 are widely distributed on the back surface side and have a function of collecting current to the current extracting electrode 15. The current collecting electrode 14 can be composed of, for example, a material mainly composed of a conductor such as aluminum, silver, copper, nickel, tin, a mixture thereof, an alloy, and a laminate thereof. The current extraction electrode 15 is connected to the current collecting electrode 14 of one polarity, and functions as a current extraction electrode that extracts the current collected by the current collecting electrode 14 to the outside of the light receiving element 10. The current extraction electrode 15 may be formed in a separate process, but is often formed in the same process as the current collecting electrode 14, and similarly contains mainly aluminum, silver, copper, nickel, and tin. It is preferably made of a metal material and a laminate of metal materials. The electrodes such as the current extraction electrode 15 may contain additives such as glass frit and resin. The current collected by the current collecting electrode 14 is taken out to the outside of the element through the current extracting electrode 15 and the inter-element connector 30.

The electrode height of the electrodes may be the same height among the linear electrode 12, the current collecting electrode 14, and the current extraction electrode 15, but a case where the height is different in the first embodiment will be described. When there is a current extraction electrode having the same polarity as that of the linear electrode 12, the current extraction electrode has the same height as the linear electrode. When the heights of the linear electrode 12 and the current collecting electrode 14 and the current extraction electrode 15 are different, the height of the electrode of the linear electrode 12 in FIGS. 4 (a) to 4 (d) is the current extraction. Although it depends on the number of electrodes 15, it is preferably about 10 to 100 μm. The height of the collector electrode 14 and the current extraction electrode 15 is preferably about 5 to 50 μm.

In addition, although the case where it forms in the thin linear form as the linear electrode 12 is shown here, it does not need to be linear and may be an electrode group formed by separating a plurality of dotted electrodes. Further, in the structure of the present embodiment, since the main body portion 32 of the inter-element connector 30 and the linear electrode 12 can be directly connected, there is no need to provide a current extraction electrode on the first element electrode side. Also good. Alternatively, a current extraction electrode connected to the first element electrode side, that is, the linear electrode 12 of one polarity may be separately provided. In this case, the current extraction electrode is connected to the main body 32 of the inter-element connector 30 and functions to extract the current collected by the linear electrode 12 to the outside of the light receiving element 10.

The term “intersecting” includes that in which the inter-element connection portion 31 is arranged so as to intersect the point-like electrode or the current collecting electrode when the point-like electrode group is viewed as a line. For example, a collection of point-like electrodes exists as the current extraction electrode 15 so as to have an intersection with the linear current collection electrode 14, covers the current extraction electrode 15, and contacts the linear current collection electrode 14. Thus, the inter-element connection portion 31 of the inter-element connector 30 may be formed. Moreover, the linear electrode 12 may also have a dot shape, and the light transmitting electrode may be a flat metal electrode formed on the light transmitting electrode. Further, the current collecting electrode 14 may not be orthogonal to the current extraction electrode 15 or the inter-element connection body 31, and the inter-element connection body 30 arranged approximately in parallel with the direction in which the string extends, There should be a pattern in which there is an electrode for collecting current on the device up to the connection body 30. Also, the second element electrode side does not have to be formed separately from the current collecting electrode 14 as the current extraction electrode 15, and the pattern of the entire element electrode is the first element electrode and the second element electrode having different polarities. It is sufficient that they are separated.

In addition to this, the element electrode may have a laminated structure of a translucent conductive film and a metal electrode which are insulated between the negative electrode and the positive electrode and formed on the entire surface excluding the inter-electrode region. A translucent electrode such as indium oxide may be formed on the outermost layer on the non-light-receiving surface side on the passivation film such as an amorphous silicon film on the semiconductor element, and one electrode portion and the other electrode portion A structure in which indium oxides are electrically separated from each other can be obtained. A linear electrode 12, a collecting electrode 14, and a current extraction electrode 15 are formed on the respective laminated films of the translucent conductive layer and the impurity-doped amorphous silicon film. On the other hand, an n-type amorphous silicon film as a passivation film on the light receiving surface side, and an amorphous silicon nitride film or a high refractive index film such as titanium dioxide formed as a reflection preventing film by a thin film process such as sputtering or CVD. Are stacked.

In the light receiving element 10 of the present embodiment, it is necessary to make the minority carrier diffusion length longer than the distance between the element electrodes in order to increase the current extraction efficiency. Therefore, it is preferable that the element surface is inactivated, that is, passivated. As an example of an element structure in which the element surface is inactivated, a heterojunction solar produced by an amorphous silicon film formed on a single crystal silicon substrate and a semiconductor material such as microcrystalline silicon, gallium arsenide, or aluminum gallium arsenide Examples thereof include a battery, or a single crystal silicon solar cell that is passivated with a passivation film such as a silicon oxide film, a silicon nitride film, or aluminum oxide. Although the element structure is not particularly limited, for example, in the case of a light receiving element using a heterojunction, as the semiconductor substrate 11, an intrinsic amorphous silicon film having a thickness of about 5 nm is formed on both surfaces of a single crystal n-type silicon substrate. Further, a p-type amorphous silicon film and an n-type amorphous silicon film are laminated on one surface of the single crystal n-type silicon substrate on which an intrinsic amorphous silicon film is formed. In the case of a light receiving element using a heterojunction, a p-type amorphous silicon film is formed on an electrode portion of one polarity, for example, a portion where the current collecting electrode 14 and the current extraction electrode 15 are formed, and a linear electrode which is an electrode portion of the other polarity An n-type amorphous silicon film is formed in a portion where 12 is formed. The electrodes can be electrically insulated, and an intrinsic amorphous silicon film or an insulating film such as a silicon oxide film can be formed between the p layer and the n layer. Translucent electrodes that are insulated from each other are formed on the p layer and the n layer, and a current collecting electrode 14, a current extraction electrode 15, and a linear electrode 12 are formed on the translucent electrode, respectively. . The semiconductor junction region formed on the surface of the light receiving element 10 may be formed by impurity element implantation called thermal diffusion of impurities or ion implantation. A passivation film is formed on the surface of the semiconductor substrate 11, but the description is omitted in the drawings of this specification except when attention is paid to the passivation film, and only the semiconductor substrate 11 is described in the drawing. ing.

In addition, the light receiving element 10 of the present embodiment may be a light receiving element using not only a heterojunction but also a homojunction formed by diffusing a dopant. For example, single crystal n-type silicon is used as the semiconductor substrate 11, and the collector electrode 14 and the current extraction electrode 15 that are in contact with a p-type semiconductor region formed by thermal diffusion of boron are used as positive electrodes, and phosphorus is thermally diffused. The linear electrode 12 in contact with the n-type semiconductor region thus formed operates as a negative electrode. By using the configuration of the present embodiment for a back-connected light receiving element having such a heterojunction or a homojunction, the separation distance or pitch of the p-type semiconductor region can be made finer, and the hole diffusion length is rate-limiting. As a result, the carrier movement distance to the p-type semiconductor region can be reduced, and the carrier collection efficiency in the device can be further increased.

On the other hand, when a p-type substrate is used, the separation distance between the semiconductor substrate 11 and the n-type semiconductor region forming the pn junction is small in order to reduce the distance of carrier movement in the p-type substrate where the electrons are rate-limiting. It is preferable to make it small.

Further, in the present embodiment, the inter-element connector 30 is connected to the current extraction electrode 15 as shown in FIGS. 6A to 6C, FIGS. 7A to 7C, and FIG. An inter-element connection portion 31 and a main body portion 32 that covers the entire back surface of the light receiving element 10, abuts against the linear electrode 12, and is separated from the current collecting electrode 14 via an adhesive layer 26. It is configured. The main body portion 32 has a complementary shape to the inter-element connection portion 31 and covers the entire back surface of the element substrate except the region where the inter-element connection portion 31 is arranged and its periphery and the vicinity of the outer periphery of the element substrate. Since the width | variety of the main-body part of the connection body 30 is wide, even if there is no thickness, resistance can fully be reduced. The width of the main body is wider than the inter-element connection portion in the inter-element region. 6 (b) and 6 (c) are the IJ cross-sectional view and the KL cross-sectional view of FIG. 6 (a), respectively, in which a part of the module is taken out by one repeating unit of the string. FIG. 6C shows the adhesive layer 26. The inter-element connection portion 31 formed integrally with the main body portion 32 is composed of a flexible conductive foil, and on the one hand, one of the element electrodes, for example, a linear electrode which is a first element electrode 12 and the current extraction electrode 15 are selectively connected to each other, and are in contact with the current extraction electrode 15 that is the second element electrode of the adjacent light receiving element 10. The current collecting electrode 14 as the second element electrode is also formed in a stripe shape at a constant interval, that is, in a linear shape spaced apart in parallel, and has two current extraction electrodes 15 intersecting the current collecting electrode 14. The inter-element connection portion 31 is in contact with the current extraction electrode 15. Therefore, since the short-distance connection is made to the inter-element connection portion 31 having a low resistance in the substrate in-plane direction, the current collection distance of the second element electrode can be reduced, and the current collection resistance can be reduced. .

5 and 7A to 7C, the current extraction electrode 15 is exposed from the opening of the adhesive layer 26 in the vicinity of the second electrode from the element end of the current collecting electrode 14, that is, from the upper part in each figure. The drawings are described so that regions to be formed are formed. However, in reality, depending on the number of current extraction electrodes 15 on the element, when the element substrate is 156 mm square, a region corresponding to the current extraction electrode 15 is formed from a portion of about 5 to 50 mm from the end of the element substrate. Is done.

The length range of the current extraction electrode 15 is determined mainly by the conductor resistance of the current extraction electrode 15. Regarding the length of the inter-element connection portion 31 of the inter-element connection body 30, the inter-element connection portion 31 of the inter-element connection body 30 generally has a lower resistance than the current extraction electrode 15. From the viewpoint, it is preferable that the connection length between the inter-element connection portion 31 and the current extraction electrode 15 is long. On the other hand, it does not have to be as long as the element. When the number of current extraction electrodes 15 is large, the electrode cross-sectional area is large, and the resistance is sufficiently low, the inter-element connection portion 31 can be shortened. When the inter-element connection portion 31 is shortened, the warpage of the element with the inter-element connection body due to the difference in thermal expansion coefficient between the element substrate and the inter-element connection portion 31 can be reduced. The fact that the actual connection length between the inter-element connection portion 31 of the inter-element connection body 30 and the current extraction electrode 15 is not limited to the illustration is the same in the present embodiment as well as the following embodiments. .

The main body portion 32 has a slit S having a shape corresponding to the inter-element connection portion 31 and has a complementary shape with the inter-element connection portion 31. Since the inter-element connection portion 31 of the adjacent inter-element connection body 30 is disposed in the slit S of the main body portion 32, not only positioning is easy, but also a step is reduced. By applying the adhesive layer 26 made of an insulating resin to the side surface of the inter-element connection portion 31 in advance, a short circuit with the main body portion 32 of the adjacent inter-element connection body 30 can be prevented. 7A to 7C between the current extraction electrode 15 and the light receiving element 10 excluding the connection point between the main body 32 and the linear electrode 12 and the main body 32 of the inter-element connector 30. As shown, an adhesive layer 26 made of an insulating resin is filled. On the other hand, as shown in FIG. 4C, FIG. 4D, and FIG. 7B, in this embodiment, the adhesive layer 26 is formed on the module back surface side of the inter-element connection portion 31. However, the inter-element connector 31 may be sealed by covering it with the adhesive layer 26. Further, the adhesive layer 26 made of an insulating resin may have light scattering particles. FIG. 8 shows an example of a pattern shape when the inter-element connector 30 is formed by punching. The inter-element connection portion 31 and the main body portion 32 are complementary.

Therefore, in the light receiving element module 1 in which the back connection type light receiving elements 10a to 10f are connected using the inter-element connection body 30, at least the linear electrode 12 which is the first element electrode on the light receiving elements 10a to 10f. Are widely distributed on the main surface of the light receiving element and are connected to the main body portion 32 which is a planar shape portion of the inter-element connector 30 over the entire area of the semiconductor substrate 11.

According to the inter-element connector 30, the light receiving element 10, and the light receiving element module 1 of the present embodiment, the inter-element connecting portion 31 intersects one of the element electrodes, for example, the current collecting electrode 14 that is the second element electrode. Are connected selectively along the current extraction electrode 15 of the second polarity element electrode. Therefore, as compared with the case where the current extraction electrode portion is only at the end portion of the element substrate as in Patent Document 1, the second element electrode that is the element electrode connected to the semiconductor substrate 11 is connected to the element connection element 30. Since the connection distance to the connection portion 31 is short and a conductor having the same or similar area as the light receiving elements 10a to 10f can be used, resistance loss is small. Further, when a conductor having a resistance equivalent to that of a foil is formed on the element, it takes cost and time, and it is difficult to increase the cross-sectional area of the electrode to reduce the resistance. This is particularly advantageous in that the current collection distance can be reduced. In addition, the transmitted light that has passed through the light receiving elements 10a to 10f can be reflected and re-entered to the light receiving element 1, so that the light transmission loss can be reduced and the light receiving element module 1 having a high power generation output with respect to the installation area can be obtained. it can.

In the present embodiment, the inter-element connection body 30 is formed of a metal conductive plate, that is, a continuous body, and has the same or similar size as the inter-element connection portion 31 that connects the elements and the light receiving element 10. And it is comprised from the main-body part 32 which is a planar conductor part connected to the back surface side of the light receiving element 10 of an equivalent shape. The inter-element connection body 30 can be manufactured very easily, for example, by punching a copper foil. Since the inter-element connector 30 of the present embodiment is formed from a base material obtained by simply cutting a metal, for example, an element in which a positive electrode and a negative electrode are insulated from each other and sandwiched between resin sheets as in Patent Document 3 It can be manufactured at a lower cost than an inter-connection body. A low resistance conductive plate such as copper or aluminum is preferably used as the substrate, and a conductive adhesive layer such as solder plating is formed on the substrate. Here, copper foil is used as the body portion 32 of the inter-element connection body 30 having flexibility and the inter-element connection section 31 of the inter-element connection body 30, but in the first embodiment, the integrated structure is continuous. It may not be a metal foil. For example, a metal film deposited on a polyimide film, a metal particle-containing resin, a metal particle group formed by drying a printing paste, a film to which a metal sintered body is connected, or a conductor such as a foil Can be used as the main body portion 32 and the inter-element connection portion 31.

Further, the inter-element connection portion 31 and the main body portion 32 may be configured from different parts. When the inter-element connection portion 31 and the main body portion 32 are formed as separate structures, the inter-element connection portion 31 and the main body portion 32 are connected via the electric connection body 21 or the second electric connection body made of another material. Is done. In the case where the inter-element connection body 30 is formed as a separate structure of the main body part 32 for light reflection and the inter-element connection part 31, it is easy to manufacture, and the same element as the inside of the string at the string end of the module It has the advantage that an inter-connector can be used. Further, if the inter-element connection body 30 is formed as a separate structure of the main body portion 32 for light reflection and the inter-element connection section 31, different materials can be used, and the strength of the element with the inter-element connection body can be increased. Conductivity, connectivity, and light utilization efficiency can be improved.

Moreover, since the height by which the first element electrode of the light receiving element protrudes toward the inter-element connection body than the second element electrode can be adjusted as necessary, the height difference between the first and second element electrodes can be adjusted. Thus, the connection portion between the element electrode and the main body portion 32 of the inter-element connection body 30 and the insulating portion between the inter-element connection section 31 can be separated, and in the substrate plane when the inter-element connection body 30 is connected to the element This has the advantage that precise alignment in the direction of several hundreds of micrometers is unnecessary.

The main body portion 32 of the inter-element connection body 30 may be formed of a conductive foil, for example, a copper foil flat plate, or may be used by pressing the flat plate in advance to form a concavo-convex shape. When the main body portion 32 has an uneven shape, the main body 32 of the interelement connection body 30 in the portion of the other collector electrode 14 and current extraction electrode 15 with respect to the main body portion 32 of the portion roughly corresponding to the one linear electrode 12. The portion 32 becomes a recessed shape, that is, a concave portion, and the portion corresponding to the linear electrode 12 becomes a relatively protruding shape, that is, a convex portion. Here, the convex part on the inter-element connector 30 side means protruding from the element substrate, and the concave part means being further away from the element substrate. The convex part and the concave part do not necessarily have to be formed corresponding to the positions of the linear electrode 12 and the collecting electrode 14, respectively, and if the concave and convex interval is formed narrower than the element electrode pitch, the protruding linear shape It can be set as the structure where the convex part of the main-body part 32 is connected with respect to the electrode 12, This eliminates the need for precise alignment.

Further, the size of the main body portion 32 of the inter-element connector 30 is such that it can cover the outer peripheral portion of the linear electrode 12 on the element of FIG. The end portion of the body portion 32 of the body 30 is fixed, and the bondability can be improved. Therefore, in FIG. 4A, the linear electrode 12 has an electrode pattern that comes outside the collecting electrode 14. In addition to the pattern of FIG. 4A, the linear electrode 12 may be formed so as to further surround the inner side of the outer periphery of the element substrate.

(Connection method between element connection body and element electrode)
In connection between the inter-element connection body 30 and the element electrode, the light receiving element 10 has the linear electrode 12 as the first element electrode and the collector electrode 14 as the second element electrode on the same surface, that is, the negative electrode Therefore, it is necessary to insulate between the electrodes. For insulation between the electrodes, a gap may be used as an insulating layer between the main body 32 and the collecting electrode 14, but in order to improve the reliability, FIG. 4 (a) to FIG. As shown in d), an adhesive layer 26 is formed so as to mainly cover the current collecting electrode 14 except for only a part of the current extraction electrode 15 of the light receiving element and to expose most of the linear electrode 12 to the outside. . The adhesive layer 26 may partially overlap the linear electrode 12. For example, when the main body portion 32 has irregularities, it may be formed between the convex portion and the linear electrode 12 as long as it is a concave portion and part of the main body portion 32 in the connection portion with the linear electrode 12. When forming the adhesive layer 26, the adhesive layer 26 is formed thicker than a predetermined gap between the main body 32 and the semiconductor substrate 11, and the main body 32 is pressed against the semiconductor substrate 11 after the adhesive layer 26 is formed. A method of spreading the adhesive layer 26 in the lateral direction can be used. When the above method is used, the width of the adhesive layer 26 is formed to be narrower than the line width of the current collecting electrode 14, spreads when the main body 32 is connected, and has a shape as shown in FIG.

As described above, in order to provide a high adhesive strength between the light receiving element 10 and the inter-element connector 30 and to insulate between the collector electrode 14 and the main body 32 of the inter-element connector 30, the inter-element connection Main portions other than the soldered portion between the body 30 and the light receiving element 10 are bonded by the adhesive layer 26. Specifically, resin such as ethylene vinyl acetate (EVA), epoxy containing filler, polyimide, or the like can be used. However, it is possible to reflect the light transmitted through the element by the inter-element connector and to enter the element again. It is preferable to use one that does not absorb the element transmitted light. For the above purpose, the adhesive layer 26 may have a light reflection or light scattering function. As the adhesive layer 26, ethylene vinyl acetate containing a high concentration of inorganic particles such as titanium dioxide particles of about several hundred nm can be used. The size of the inorganic particles used here is preferably smaller than about half of the distance between the current collecting electrode 14 and the inter-element connection body 30 after the light receiving element 10 and the inter-element connection body 30 are connected. In order to impart the property, it is preferable to set the particle size to be about half the wavelength of the light to be scattered.

Here, an example in which the adhesive layer 26 connects the inter-element connection body 30 and the light receiving element 10 is described, but the adhesive layer 26 must adhere between the inter-element connection body 30 and the light receiving element 10 without any gap. For example, in order to enhance insulation, the adhesive layer 26 may cover the element electrode, but may not be in contact with the main body 32 of the inter-element connection body. The main body part 32 of 30 may be covered but may not be in contact with the element electrode.

As a method for forming the adhesive layer 26, an epoxy resin precursor is applied in advance to the back surface side of the light receiving element 10, except for the linear electrode 12, and bonded to the main body portion 32 of the interelement connection body 30. Heat and cool. Then, by melting the solder once to electrically connect the main body portion 32 of the inter-element connector 30 and the linear electrode 12 on the light receiving element, the epoxy resin as the adhesive layer 26 is polymerized and cured, whereby the element The main body portion 32 of the inter-connection body 30 and the light receiving element 10a can be bonded. When the main body 32 and the light receiving element 10a are bonded by polymerizing and curing the epoxy resin, the polymerization temperature of the precursor of the adhesive layer 26 or the softening point of the insulating resin is the same as the melting point of the electrical connector 21 or The same or higher is preferable. In order to make the melting point of the electrical connection body 21 higher than the softening point of the insulating resin constituting the adhesive layer 26, a solder such as a bismuth solder that melts at a relatively low temperature is used as the electrical connection body 21. As the adhesive layer 26, an insulating resin such as a resin reinforced with a reinforcing agent such as polyimide or glass fiber is preferably used. Moreover, in the said process, a thing with a viscosity and low fluidity is preferable as an epoxy resin precursor. Further, as described in Patent Document 10, for example, a method of curing the adhesive layer in two steps is also applicable.

In addition to the above method, for example, heating is performed while bonding the main body portion 32 of the inter-element connection body 30 that does not have the electrical connection body 21 and the back surface side of the light receiving element 10 on which the solder layer is formed on the linear electrode 12. Thereafter, the body portion 32 of the inter-element connector 30 and the light receiving element 10a can be bonded by cooling. When bonding, first, the solder is once melted to electrically connect the main body portion 32 of the inter-element connector 30 and the linear electrode 12 on the element. And after supplying an epoxy resin precursor between the main-body part 32 and the element back surface of the interelement connection body 30 bonded together using a capillary phenomenon, it heats again, and an epoxy monomer is superposed | polymerized and hardened. In the case where the epoxy resin precursor is supplied after being bonded by soldering and heated to be polymerized again, it is preferable that the melting point of the electrical connection body 21 is equal to or higher than the polymerization temperature or softening point of the adhesive layer 26. Moreover, as an epoxy precursor in said case, a thing with a low viscosity and high fluidity | liquidity is preferable. Further, the adhesive layer 26 may be cured in advance before connecting the inter-element connector 30. In the above case, the adhesive layer 26 is bonded to the current collecting electrode 14 out of the element substrate and the element electrode. Thus, the linear electrode 12 and the main body 32 of the inter-element connector 30 are not bonded. As the heat source used for the connection, a contact heat source such as a hot plate, a non-contact heat source such as an air heater, a laser, or an infrared lamp can be used.

By making the adhesive layer 26 have the above-described structure, the electrical connection between the linear electrode 12 and the body portion 32 of the inter-element connector 30 is not disturbed, while the current collecting electrode 14 and the body portion 32 of the inter-element connector 30 are Can keep the insulation between.

When maintaining the insulation between the current collecting electrode 14 and the main body portion 32 of the inter-element connector 30, the current collecting electrode 14 is mainly covered as the adhesive layer 26, and the linear electrode 12 and the current extraction electrode 15 are large. A resin film having a shape that does not cover the portion can also be used as a material. Alternatively, a resin having a shape equivalent to that of the current collecting electrode 14 is applied and dried on the main body 32 of the inter-element connector 30 in advance, and a solder paste is applied to a portion other than the resin application region. It is good also as the electrical connection body 21 of the linear electrode 12 and the inter-element connection body 30 on the back surface. When different materials are used for the electrical connection body 21 between the linear electrode 12 on the back surface and the inter-element connection body 30 and the electrical connection body between the current lead line 38 and the inter-element connection body 30, the linear electrode 12 and the inter-element connection body 30 and subsequent steps, the melting point of the electrical connection body 33 used in subsequent processes such as the process of connecting the current lead line 38 to the main body 32 of the inter-element connection body 30 is the same as that of the linear electrode 12. A lower one than the melting point of the electrical connection body 21 used in the connection step with the inter-element connection body 30 is preferable because it does not cause a positional shift accompanying remelting of the electrical connection body 21.

In addition, when a plurality of electrical connection bodies having different melting points are used, for example, when the inter-element connection portion 31 and the main body portion 32 of adjacent elements are formed from different members, the inter-element connection body 32 and the linear connection body are formed. The connection with the electrode 12 is performed using an electrical connection body having a high melting temperature, and when the string is formed after the connection, the inter-element connection portion 31 of the inter-element connection body 30, the current extraction electrode 15, and the adjacent one. For the connection between the inter-element connection portion 31 of the inter-element connection body 30 of the element and the main body portion 32, it is preferable to use an electric connection body having a lower melting temperature so as not to cause misalignment. The combination of high and low melting temperatures depending on the location of the electrical connector may be reversed from the above according to the order of manufacture. On the other hand, when the adhesive layer 26 is bonded prior to the electrical connection body, the flow temperature or melting temperature of the adhesive layer 26 is preferably higher than the melting point of the electrical connection body 21. By making the flow temperature or melting temperature of the adhesive layer 26 higher than the melting point of the electrical connector 21, it is possible to prevent the flow, remelting, etc. from occurring by keeping the adhesive layer 26 below the melting temperature in the bonding step. it can.

Moreover, as the electrical connection body 21, specifically, a silver-silver solder, a conductive adhesive, and a conductive tape can be used. In the first embodiment, the electrical connection body 21 is formed on almost the entire surface of one side of the inter-element connection body 30 (FIGS. 4 (b) to 4 (d)), but the inter-element connection body itself is like a tin foil. As a low melting point metal, it may also serve as an electrical connector. When covering the entire surface on the element side of the inter-element connector 30 or the entire surface of both surfaces, the electrical connector 21 is preferably made of a material having as high a light reflectance as possible. When the reflectance of the inter-element connection body 30 is higher than the reflectance of the electrical connection body 21, the electrical connection body 21 is formed only at a portion where the element electrode and the inter-element connection body 30 are connected between the electrodes. It is preferable. The portion where the electrodes are connected mainly refers to the overlapping portion of the inter-element connector 30, the current extraction electrode 15 and the linear electrode 12.

As described above, the main body portion 32 and the inter-element connection portion 31 of the inter-element connector 30 shown in FIGS. 6A to 6C are connected to the element electrode on the back surface of the light-receiving element. The light receiving element with an inter-element connection body having the back surface shown in FIG. As shown in FIG. 2, the end portion of the linear electrode 12 should be visible from the slit S of the main body portion 32, but is omitted in FIG. 7C. Further, in FIG. 7C, the element part with the inter-element connection body seen through the main body part 32 is drawn, and the main body part 32 of the inter-element connection body 30 is a region where the main body part 32 is arranged by a dotted line. It is shown. In the structure having the slits S as in the present embodiment, the element electrode forming portion is externally covered when the linear electrode 12 and the current extraction electrode 15 are covered with the metal of the main body portion 32 or the resin made of the adhesive layer 26. This is preferable because the intrusion of moisture is reduced and the reliability and durability are improved. As a modification, unlike the example shown in FIG. 2, the linear electrode 12 and the current extraction electrode 15 which are element electrodes are hidden by the main body 32 and the adhesive layer 26 and are not exposed on the surface of the light receiving element 10. It may be. In FIG. 7C, the position of the main body portion 32 of the inter-element connection body 30 is indicated by a dotted line, and the main body portion 32 itself of the inter-element connection body 30 is transmitted to describe the structure on the back side of the element. .

In the first embodiment, the inter-element connection body 30 can be manufactured, for example, by punching a copper foil. The main body portion 32 and the inter-element connection portion 31 do not have to be integrally formed. The inter-element connection portion 31 and the main body portion 32 are formed of different members, and solder or conductive adhesive It may be connected later by, for example. For example, a metal film deposited on a polyimide film, a resin containing metal particles, a metal fine particle group formed by drying a printing paste, or a film or foil in which a metal sintered body is connected in the same pattern shape as the element electrode The inter-element connection body 30 is integrally formed using the conductor. Alternatively, the inter-element connection portion 31 and the main body portion 32 may be formed in the same manner and connected later with solder or a conductive adhesive.

The thickness of the inter-element connection body 30 can be set to 0.01 to 1 mm, for example. In addition, after the inter-element connection body 30 is integrally formed by punching, the inter-element connection portion 31 or the main body portion 32 may be thinned by punching or rolling.

In addition, although the description of the concavo-convex portion of the main body portion 32 of the inter-element connector 30 shown in FIGS. 6A, 6B, and 6C is omitted, in practice this embodiment In the first embodiment, the main body portion 32 of the inter-element connector 30 may have an uneven portion or a cutout portion other than the through hole and the slit S. When the main body portion 32 of the inter-element connection body 30 has a through hole, a slit, or other cutout portion, by supplying the adhesive layer 26 in a fluid state at a temperature lower than the melting temperature of the electrical connection body 21, Since the adhesive layer 26 enters between the body portion 32 of the inter-element connector 30 through the through hole, slit, or cutout formed in the body portion 32 of the inter-element connector 30, there is an advantage that it is easy to encapsulate. is there.

Moreover, when the main-body part 32 of the connection body 30 between elements has an uneven | corrugated | grooved part, as shown in FIG.20 and FIG.21 mentioned later, all the convex parts of the connection body 30 between elements are connected with the linear electrode 12. FIG. It is not necessary, and it is sufficient that at least one convex part is in contact with the linear electrode 12 connected to the element. Therefore, depending on the cross section to be seen, the convex parts of all the main body parts 32 may be connected to the linear electrode 12 and the element. It may not be connected to the inter-connection body 30. FIG. 20 shows an element electrode in which an electrical connection body 21 made of a solder plating layer by selective plating is formed. The solder plating layer is selectively formed only on the surface of the device electrode exposed on the surface by electrolytic plating. FIG. 21 shows a structure in which an electrical connection body 21 made of a solder plating layer is formed on the entire surface of the main body portion 32 of the inter-element connection body 30.

In the manufacture of the light-receiving element module 1 according to the first embodiment, the light-receiving element 10 having the first and second element electrodes is formed on the back side, and the inter-element connection body 30 is selectively and directly connected to the first element electrode. In addition to being connected, the second element electrode is mounted via an insulating layer so as to be disposed via an insulating adhesive layer. As shown in FIGS. 1, 2, and 7 (c), a linear electrode 12 that is a first element electrode and a second element electrode are provided on the back side of the semiconductor substrate 11 that constitutes the light receiving element 10. A current collecting electrode 14 and a current extraction electrode 15 are formed. The inter-element connection portion 31 of the inter-element connection body 30 is connected to the current extraction electrode 15 formed on the back surface of the light receiving element 10 via the electric connection body 21, and the main body portion 32 is different from the light receiving element 10. By being connected to the linear electrode 12 formed on the back surface side of the element 10, electrical connection between two adjacent light receiving elements 10 is achieved, and an element string is formed.

By connecting the light receiving elements 10 using the inter-element connection body 30, as shown in FIGS. 1 and 2, a string in which the

light receiving elements

10a, 10b, and 10c are linearly connected is formed. The linear string formed by the

light receiving elements

10a, 10b, and 10c and the linear string formed by the

light receiving elements

10d, 10e, and 10f are connected by solder or a conductive adhesive, so that FIG. The element arrangement of the light receiving element module 1 in which the two string rows shown in 2 are connected in series is formed.

The

light receiving elements

10 a and 10 f serving as the terminal portions of the light receiving element module 1 are connected to a current drawing line 38 for extracting current from the light receiving element module 1.

In addition, since the module current lead wire 38 is connected to the terminal portion of the element constituting the module by solder or conductive adhesive, the shape of the inter-element connection body 30 of the

light receiving elements

10a and 10f is different from that of the other light receiving elements 10b to 10b. The shape is different from that of 10e.

In the light receiving element 10a, the current extraction line 38 is connected to the current extraction electrode 15 portion, and in the light receiving element 10f, the current extraction line 38 is connected to the main body portion 32 of the inter-element connection body 30 through the electric connection body 21, thereby enabling external connection. ing. Further, in the present embodiment, the positional relationship between the main body portion 32 of the inter-element connection body 30 and the inter-element connection portion 31 of the inter-element connection body 30 is different between the string end and the inside of the string.

Then, after forming the string, resin sealing is performed. As shown in the cross-sectional view of FIG. 9, sheet-like sealing material 22 such as an ethylene vinyl acetate resin sheet is provided on the front surface side and the back surface side of the light receiving element array including the two rows of strings illustrated in FIGS. 1 and 2. The surface side main surface material 23 such as glass is bonded to the front surface side, that is, the light receiving surface side through the sealing material 22, and the back surface side main surface such as a weather-resistant polyethylene terephthalate resin sheet is bonded to the back surface side. The face material 25 is bonded.

In FIG. 9, the case where the back surface of the element substrate is flat is described, but the connection portion of the substrate itself with the linear electrode 12 and the vicinity of the connection portion protrude from the current collecting electrode 14 and the current extraction electrode 15. It is good also as a structure to do. When the connection portion between the element substrate and the linear electrode 12 and the element substrate in the vicinity of the connection portion project from the connection portion between the element substrate and the current collecting electrode 14 and the current extraction electrode 15, The height difference between the polarity electrode and the other polarity electrode is increased by the height difference on the substrate.

Further, the structure sandwiched between the front-side main surface material 23 and the back-side main surface material 25 is supported by a frame made of a reinforcing body such as a metal, and the current lead line 38 is formed between the sealing material 22 and the back-side main surface material 25. The light receiving element module 1 is configured by taking the structure from the cut through the junction box to the back surface.

The light-receiving element module structure shown in FIGS. 1, 2, and 9 can be obtained by sealing the light-receiving surface side and the back surface side of the element string row created as described above with a sealing material and a main surface material. It becomes.

Although not shown in FIGS. 1 and 2, a sheet-like ethylene vinyl acetate resin or the like is sealed on the front side and back side of the light receiving element array composed of two rows of strings shown in FIGS. 1 and 2. A stop material 22 is disposed, and a front-side main surface material 23 such as glass is disposed on the front surface side through the sealing material 22, and a back-surface side main material such as a weather-resistant polyethylene terephthalate resin sheet is disposed on the back surface side. A face material 25 is disposed.

In the case of the back connection type light receiving element described in the first embodiment, it is necessary to use a substrate having a long lifetime, and an n substrate is suitable as the silicon substrate. In the present embodiment, the collector electrode 14 and the current extraction electrode 15 that are the second element electrodes are positive electrodes, and the area of the second element electrode is that of the linear electrode 12 that is the first element electrode. It is larger than the area. In the case of the above structure, when the recombination in the p-layer region is not too large than the recombination in the n-layer region, the minority carriers are transferred to the pn junction when the area of the pn junction is larger than the area of the nn ⁺ junction. The rate of arrival and contribution to power generation is increased, and therefore the current extraction efficiency and power generation efficiency are increased.

In addition, by using a reflective layer for the first and second element electrodes, the reflector is formed directly on the substrate, so that the light utilization efficiency is increased. Since the inter-element connection body 30 can be formed of separate parts for the connection area between the reflector and the electrical connection body, materials suitable for each can be used, and the element electrode having excellent reflectivity and connectivity And an element having an element electrode. Here, the reflective layer includes not only a layer made of a reflective material but also a scattering layer.

In addition, if the first element electrode protrudes toward the main body 32 of the inter-element connector 30 compared to the second element electrode, a precise difference can be obtained by providing a difference in height between the element electrodes. The main body 32 can be connected only to the element electrode of one polarity without requiring alignment.

Further, since there is no overlap between the elements of the inter-element connection body 30, the insulation is high, the thickness of the laminated portion of the inter-element connection body 30 is small, bending and warping are small, and the strength of the elements and strings is high. Can keep. In addition, a light receiving element module having a small current collecting resistance and excellent photoelectric conversion efficiency and power generation output can be obtained.

Furthermore, in the present embodiment, the slit S of the main body portion 32 and the inter-element connection portion 31 have a complementary shape, so that the main body portion 32 has the shape of the inter-element connection portion 31 of the inter-element connection body 30. Is cut out to form a slit S. The inter-element connection body 30 is attached to the light receiving element while the main body portion 32 has the slit S. As shown in FIGS. 8 and 9, the inter-element connection portion 31 enters the slit S so that the inter-element connection is achieved. The portion 31 and the main body portion 32 are structured not to overlap. Therefore, there is an advantage that the insulating property between the inter-element connection portion 31 and the main body portion 32 is excellent without performing precise alignment. In addition, when the inter-element connection portion 31 and the main body portion 32 are stacked as in the second embodiment, it is necessary to form the adhesive layer 26 between the inter-element connection portion 31 and the main body portion 32. . Note that the current collection resistance between the elements can be further reduced by reducing the interval Q between the main body portions 32 in FIG. 8 within a range in which the reliability can be maintained.

Also, as shown in FIGS. 8 and 9, the slit S of the main body and the inter-element connection part 31 are formed so as to have a complementary shape, so that there is little waste of material, and it is accurately formed by punching. can do. In mounting, as described above, alignment is unnecessary and connection is possible by connecting the inter-element connector 30 to one of the electrodes in a self-aligning manner, so that no margin is required. The distance between the electrodes can be reduced. Therefore, according to the first embodiment, it is possible to obtain a photoelectric conversion element module such as a light receiving element module that is excellent in conversion efficiency and highly reliable without causing a short circuit. In order to increase the current extraction efficiency, the minority carrier diffusion length must be longer than the distance between the device electrodes. Conversely, the electrode pitch of the device electrodes is smaller than the minority carrier diffusion length in the semiconductor device substrate. Is preferred. Therefore, an example of the electrode pitch in the case of a silicon substrate is about 1 mm. When a substrate having a size of about 150 mm square is used, it is necessary to align the inter-element connector 30 with high accuracy with respect to about 300 element electrodes having two polarities. There is a problem that it is necessary to arrange the electrodes with high precision so that they do not contact each other and to be connected to the electrode of the other electrode, and to insulate from the electrode of the other polarity, which requires cost and time. For example, if an alignment mark is placed on the element for high-precision alignment, it is necessary to introduce a process for forming the alignment mark. If the alignment mark is formed of a silver electrode, silver is required for the alignment mark. In addition, the cost of the apparatus is increased by having a highly accurate alignment mechanism. In addition, the photoelectric conversion efficiency may decrease at the alignment mark portion.

Furthermore, by arranging the current extraction electrode 15 so as to be parallel to the string extending direction, the linear electrode 12 and the current collecting electrode 14 are orthogonal to the string. Therefore, the distance that the element electrode on the element electrode extends to the inter-element connection body 30 that runs parallel to the string is 1 / 2n of the element size, and the current collecting resistance on the element electrode is reduced. Here, n is the number of buses, that is, current extraction electrodes. By rotating the element 90 degrees at the end of the string, an inter-string connector is not necessary, and the area occupied by the module other than the element can be reduced, and a module excellent in power generation per area can be obtained.

In general, a light receiving element module composed of a plurality of light receiving elements electrically connects elements with a metal inter-element connection body. However, the heat between the metal inter-element connection body and the element electrode and the light receiving element substrate is not limited. Due to the difference in the expansion coefficient, the light receiving element with the inter-element connection body may be warped. When the thickness of the inter-element connection body and the element electrode formed directly on the element increases, the light reception with the inter-element connection body is caused by the difference in thermal expansion coefficient between the metal inter-element connection body and the element electrode and the light receiving element substrate. The element is warped, and it is difficult to seal the element in a planar shape without damaging the element. In particular, when a metal electrode formed by firing a paste containing a commonly used glass component is used as an element electrode, a high temperature is required during firing, and increasing the electrode area and thickness increases warping of the element. . In particular, in a light receiving element module formed by sealing a back connection type element in which an inter-element connection body is connected to only one side of the element, the inter-element inter-connection bodies on both sides are similar to a light receiving element having electrodes on both sides. Therefore, the warpage of the light-receiving element with the inter-element connection body is particularly large, which may make it difficult to seal the element string in a planar shape.

Such a warpage problem is extremely serious in the back connection type element. To reduce warpage, it is necessary to reduce the connection area between the element substrate and the element electrode and reduce the thickness of the inter-element connection body and the element electrode. However, if the thickness is reduced, the resistance between the inter-element connection body and the element electrode increases. To do. Further, when the width of the device electrode is wider than the diffusion length of minority carriers, the carrier collection efficiency decreases. However, according to the configuration of the present embodiment, the layout of the element electrodes is highly flexible, the number of element electrode buses and the number of inter-element connection portions 31 of the inter-element connection body 30 can be arbitrarily set, and the number Can increase the area of the body part of the inter-element connection body, the inter-element connection part of the inter-element connection body, and the current extraction electrode without increasing the width of the current extraction electrode, that is, the bus electrode. The thickness of the connection body can be reduced. As a result, the current collecting resistance can be lowered and the warpage of the element can be reduced. In the case where an electrode is formed on the element, the warpage increases according to the size of the element, the thermal expansion coefficient of the electrode, the ratio of the plate thickness, the Young's modulus, and the temperature. The warping is reduced by making the element electrode as thin as possible so that the inter-element connector can collect current. Since the connection temperature of the inter-element connection body is low and the width of the main body portion is wide in this embodiment mode, it can be made thinner than a general inter-element connection body and warpage can be reduced.

In addition, a silver electrode having high rarity is often used as a device electrode as a metal having high conductivity in a solar cell. However, if the structure of the present invention is used, it is difficult to be affected by an increase in resistance of the device electrode. The conductivity may be low. Therefore, materials other than silver can be used, and the amount of metal used for the device electrode can be reduced. As described above, since the amount of metal used for the device electrode can be reduced, it is possible to reduce the amount of silver to be used when manufacturing a solar cell, and it is possible to save resources and reduce costs. Have.

Furthermore, in the first embodiment, the inter-element connection portion 31 and the main body portion 32 are formed to have the same thickness. However, for example, in FIG. Alternatively, the main body 32 may be thin. It is possible to easily process the main body 32 by thinning it by a method such as punching.

According to the present invention, the first element electrode is directly connected to the main body of the inter-element connector made of a conductive plate, so that the current collection distance on the element is substantially zero, and the second element electrode is the intermediate portion. In this case, the extraction electrodes are arranged so as to have crossing portions and the inter-element connection portions are connected along the extraction electrodes, thereby reducing the current collection distance on the elements. Thereby, current collection resistance and the curvature of an element can be reduced significantly, and there exists an effect that the light receiving element module excellent in the electric power generation output with respect to an installation area can be obtained. Further, the time required for the production is short, and various electrode materials can be used, and a low-resistance electrode can be obtained by a low cost and simple method.

In the above embodiment, the element electrodes are arranged in a plane and the second element electrodes are crossed. However, the current extraction electrode 15 or the inter-element connection portion 31 of one electrode is connected to the current collecting electrode 14. It is good also as a structure made to cross | intersect. In the conventional light receiving element module, it is necessary to match the positions and the number of the current extraction electrodes and the inter-element connection portions of both poles, but according to the above configuration, the current extraction electrode 15 and the inter-element connection portion 31 between the two poles, It is not necessary to match the number and position of the current extraction electrodes of the other polarity electrode, and the resistance in the element electrode portion can be reduced. This is an effect obtained by making the electrodes of two polarities into a layer structure and crossing the current extraction electrode 15 or the inter-element connection portion 31 of one electrode with the current collecting electrode 14.

Embodiment 2. FIG.
FIG. 10 is a plan view of the light receiving element module according to the second embodiment as viewed from the back side. FIG. 11 is a perspective view schematically showing a positional relationship between a light receiving element and an inter-element connection body constituting the light receiving element module used in the second embodiment. FIG. 12A is a plan view showing an inter-element connection body used in the light receiving element module according to Embodiment 2, and FIG. 12B, FIG. 12C, FIG. 12D, and FIG. These are the IJ sectional view, KL sectional view, M ₁ -N ₁ sectional view, and M ₂ -N ₂ sectional view of FIG. The M ₁ -N ₁ cross-sectional view shows a cross section through the portion where the collecting electrode 14 exists, and the M ₂ -N ₂ cross-sectional view shows a cross section through the portion where the linear electrode 12 exists. Here, the inter-element connection body in the module state is taken out by one repeating unit of the string, and in FIG. 12 (b), FIG. 12 (c), FIG. 12 (d), and FIG. The adhesive layer 26 is shown so that the positional relationship of the adhesive layer 26 when the connection body 30 and the element are connected can be understood. In FIG. 10, the illustration of the frame and the junction box is omitted for easy viewing. 12 (a) to 12 (e) are diagrams schematically showing electrode patterns, and the actual number of electrodes is larger than that of the drawings.

The inter-element connection body 30 of the present embodiment, like the inter-element connection body 30 of the light-receiving element module described in the first embodiment, has a back connection type light reception having first and second element electrodes on the back surface side. The elements 10a to 10f are connected. The inter-element connection portion 31 is made of a flexible conductor foil. And as shown in FIG.12 (b), the main-body part 32 which covers the whole back surface of a light receiving element, and the element connection part connected to the back surface of the main body part 32, and connected to the 2nd element electrode of an adjacent light receiving element. 31. The main body 32 of the inter-element connection body 30 and the inter-element connection section 31 are connected by an electrical connection body. When connecting the main body part 32 of the inter-element connection body 30 and the inter-element connection part 31, they may be directly connected by spot welding, thermocompression bonding or the like without using an electrical connection body.

Further, in the present embodiment, the main body 32 does not have a slit S, that is, a notch, and differs from the first embodiment in that it covers the entire semiconductor substrate 11 constituting the light receiving element 10. Furthermore, the point that the main-body part 32 and the inter-element connection part 31 of the inter-element connection body 30 are comprised from two separate components differs. Other parts are the same as those in the first embodiment, and the description thereof is omitted here. Here, FIG. 12A is a view of the inter-element connection body 30 as viewed from the back side, and the inter-element connection portion 31 is connected to the back surface of the main body portion 32. Compared with the case where the inter-element connection portion 31 is closer to the element side than the main body portion 32, the inter-element connection portion 31, the current extraction electrode 15, and the inter-element connection portion 31 are located closer to the back side of the module than the main body portion 32. Can prevent short circuit.

In the IJ cross section of FIG. 12B and the M ₁ -N ₁ cross section of FIG. 12D, the adhesive layer 26 exists on the light receiving surface side of the main body 32 of the inter-element connector 30, and the inter-element connection The body portion 32 of the body 30 and the inter-element connection portion 31 are insulated. On the other hand, the portion other than O _{31 in the} KL cross section shown in FIG. 12C and the M ₁ -N ₁ cross section in FIG. 12E has a portion where the insulating layer 26 does not exist selectively. The portion where the insulating layer 26 is not provided on the light receiving surface side of the main body 32 of the inter-element connector 30 is connected to the linear electrode 12 that is an element electrode via the electrical connector 21. 12 (d) and 12 (e), the inter-element connection portion 31 connected to the adjacent light receiving element is located at the concave portion O ₃₁ , and is insulated from the main body portion 32 of the inter-element connection body 30 by the insulating layer 26. Is done.

Then, the inter-element connection portion 31 connected to the main body portion 32 selectively connected to the linear electrode 12 (and current extraction electrode) which is one of the element electrodes is connected to the second light receiving element 10 of the adjacent light receiving element 10. This is in contact with the current extraction electrode 15 which is an element electrode. The collector electrode 14 as the second element electrode is also formed in a stripe shape, that is, a linear shape at a constant interval, and has two current extraction electrodes 15 that intersect the collector electrode 14. Since the inter-element connection portion 31 is in contact with the current extraction electrode 15, the current collection distance of the second element electrode can be reduced, so that the current collection resistance can be reduced.

Also in the present embodiment, as in the light receiving element module of the first embodiment, resin sealing is performed, and a light receiving element module whose sectional view is shown in FIG. 13 is obtained. In the second embodiment, as shown in FIG. 13, the main body portion 32 of the inter-element connection body 30 and a part of the inter-element connection section 31 of the adjacent inter-element connection body 30 are located on the light receiving element 10. , And a portion stacked on the element and electrically connected. Therefore, in the case of the second embodiment, the laminated structure portion of the inter-element connection portion 31 of the inter-element connection body 30 -the main body portion 32 of the inter-element connection body 30 -the inter-element connection portion 31 of the inter-element connection body 30 is formed. Come out. When including the laminated structure of the main body part 32 and the inter-element connection part 31, as much as the length of the part where the inter-element connection part 31 is laminated in the α part in FIG. The length of the connection between the current extraction electrode 15 and the inter-element connection portion 31 is increased, and the horizontal distance from the current collecting electrode 14 to the inter-element connection portion 31 of the inter-element connection body 30 is shortened. This has the advantage that the current collecting resistance on the device electrode at the end can be reduced.

In the first embodiment, in the portion of the current extraction electrode 15, the inter-element connection portion 31 of the inter-element connection body 30 has a structure that does not overlap the main body portion 32 of the inter-element connection body 30 on the same element. In the second embodiment, the inter-element connection portion 31 overlaps the main body portion 32. That is, the inter-element connection portion 31 of the inter-element connection body 30 is connected to almost the entire current extraction electrode 15, and the main body portion 32 of the inter-element connection body 30 is formed on the back side of the same element via the adhesive layer 26. Further, the inter-element connection portion 31 is stacked on the partial region on the back side of the main body portion 32 via the electrical connection body 33. When the inter-element connection portion 31 is laminated on the main body portion 32, the main body portion 32 is formed in the laminated portion with the inter-element connection portion 31 on the current extraction electrode 15, as shown by β and γ portions in FIG. The shape protrudes from the main body portion 32 other than the laminated portion to the element back side, that is, the non-light receiving surface side of the module.

In the case of a structure having a portion where the inter-element connection portion 31 on the same element and the main body portion 32 of the inter-element connection body 30 overlap with the adhesive layer 26 sandwiched as in the second embodiment, the inter-element connection portion 31 and The connection length with the current extraction electrode 15 can be increased, and the current collection resistance at the current collection electrode 14 and the current extraction electrode 15 is reduced. Specifically, in the portion α in FIG. 13, the inter-element connection portion 31 is connected over the entire area of the current extraction electrode 15, and the inter-element connection portion 31 extends to the α portion as compared with the case where only the current extraction electrode 15 is provided. Accordingly, the current collecting resistance can be made smaller than that of the element module of the first embodiment.

On the other hand, the overlapping portion is a factor that causes a short circuit when, for example, the electrical connection body 21 has a protruding portion. Therefore, it is preferable to reduce the overlap depending on the material of the electrical connection body 21, as in the first embodiment. When it has a notch part, an overlap part can be reduced. Further, in the first embodiment, there is no inter-element connection portion 31 of the inter-element connection body 30 at the portion where the main body portion 32 and the current extraction electrode 15 overlap, so that the elements are not connected to each other. Therefore, the inter-element connection portion 31 and the planar main body portion 32 do not overlap each other, and the insulation is improved.

The inter-element connection portion 31, the main body portion 32, the linear electrode 12, and the current extraction electrode 15 of the inter-element connection body 30 are connected by an electrical connection body. In the second embodiment, as shown in FIG. 13, between the back side of the main body portion 32 of the inter-element connection body 30 and the inter-element connection section 31, and between the current extraction electrode 15 and the inter-element connection body 30. The inter-connection portion 31 is connected by a second electrical connection body 33, and the back side of the main body portion 32 of the inter-element connection body 30 and the linear electrode 12 are connected by an electrical connection body 21.

As the electrical connection body 21 and the electrical connection body 33, the same material or different ones may be used. Furthermore, the inter-element connection section 31, the main body section 32, and the wire of the inter-element connection body 30 may be used. Different electrical connectors may be formed in all the portions of the electrode 12 and the current extraction electrode 15. Further, as a combination of parts using different electrical connection bodies 21 and electrical connection bodies 33, for example, between the main body portion 32 of the electrical connection body 30 and the linear electrode 12 and between the current extraction electrode 15 and the inter-element connection portion 31. The electrical connection body 21 may be used for the connection part, and the electrical connection body 33 may be used for the connection part between the element connection part 31 and the main body part 32 of the electrical connection body. You may combine arbitrarily with a body. It is also possible to form the electrical connection body 33 in the most part of the inter-element connection portion 31 and form the electrical connection body 21 only in the portion connected to the main body portion 32 of the inter-element connection body 30.

The melting temperatures of the

electrical connection bodies

21 and 33 may be different so that the element electrodes and the inter-element connection bodies 31 do not come off during heating to connect the elements to form a string. In this case, the electrical connection body 33 has a lower melting temperature than the electrical connection body 21. When each part is connected by the electrical connection body, the electrical connection body 21 is first melted at a high temperature to connect the current extraction electrode 15 and the inter-element connection section 31, and the inter-element connection section 31 and the main body section 32. Then, the former electrical connection is performed during the latter heating by connecting the main body 32 and the linear electrode 12 by heating at a temperature at which the electrical connection body 33 melts without melting the electrical connection body 21. Since the connection part by the body 21 can hold a place without melting, there is an advantage that it is easy to create a string. The combination of the location where the electrical connector is used and the melting temperature may be reversed according to the order of manufacture. As the electrical connection body, tin silver solder, tin bismuth solder, metal tin solder or the like can be used.

According to the light receiving element module 1 of the present embodiment, since the main body portion 32 of the inter-element connection body 30 covers the entire surface of the light receiving element, the reflection by the main body portion 32 can be achieved even if the adhesive layer 26 is not particularly scattering. Thus, sufficient light absorption in the element is realized. Therefore, since the main body surface of the portion other than the connection point of the light receiving element 10 to the first element electrode, that is, the connection region, only needs to be formed of a light reflector having high reflectivity with respect to the light transmitted through the light receiving element. Is also simplified. Reflected light enters the light receiving elements 10a to 10f through the gap between the linear electrode 12 as the first element electrode and the collecting electrode 14 as the second element electrode, and the photoelectric conversion efficiency can be increased. In particular, it is effective when the back surface side of the element such as the back side main surface material 25 uses a material having low light reflectivity, such as a black material, for the purpose of blackening the appearance of the light receiving element module.

Modification 1
In the configuration of the second embodiment in which the inter-element connection portion 31 and the main body portion 32 of the inter-element connection body 30 are made of different members, the inter-element connection is shown in FIGS. 14 (a) to 14 (c). As shown in Modification 1 of the connection body, the slit S may be formed in the main body portion 32 so as to coincide with the inter-element connection portion 31. FIG. 14A is a plan view showing an inter-element connection body used in the light-receiving element module according to Embodiment 2, and FIGS. 14B, 14C, 14D, and 14E. These are the IJ sectional view, KL sectional view, M ₁ -N ₁ sectional view, and M ₂ -N ₂ sectional view of FIG. 14 (a). The M ₁ -N ₁ sectional view shows a portion where the collecting electrode 14 exists. The M ₂ -N ₂ sectional view is a portion showing a portion where the linear electrode 12 exists. 14 (a) to 14 (e) show the inter-element connection body 30 in a module state in which one repeating unit of the string is taken out, and descriptions of peripheral members such as a module sealing material and a light receiving element are omitted. However, in FIGS. 14 (b), 14 (c), 14 (d), and 14 (e), the positional relationship of the adhesive layer 26 when the inter-element connector 30 and the element are connected is known. Thus, the adhesive layer 26 is described. Specifically, in the M ₁ -N ₁ cross section of FIG. 14D, the linear electrode 12 which is the other of the element electrodes in the portion not having the adhesive layer 26 indicated by the O ₁₂ portion is the inter-element connector. In the cross section M ₂ -N ₂ of FIG. 14E, the current collecting electrode 14 is one of the element electrodes by the adhesive layer 26 between the elements. 14C. In the KL cross section of FIG. 14C, the collector electrode 14 is insulated from the main body 32 of the inter-element connection body by the adhesive layer 26 in the portion having the adhesive layer 26. On the other hand, the linear electrode 12 is connected to the body portion 32 of the inter-element connection body via the electrical connection body 21 in a portion where the adhesive layer 26 is not provided. Since it is the same as that of the said Embodiment 2 except the slit S being formed, although description is abbreviate | omitted here, the same code | symbol was attached | subjected to the same site | part. In the case of the first modification, the inter-element connection portion 31 of the inter-element connector 30 is connected to almost the entire current extraction electrode 15 connected to the current collecting electrode 14, and the adhesive layer 26 is interposed on the back side on the same element. A main body portion 32 of the inter-element connection body 30 is formed, and the inter-element connection portion 31 is laminated on a part of the back surface side of the main body portion 32 via the electric connection body 33. 14A to 14E, the device electrodes are not shown.

Compared to the case where the inter-element connection portion 31, the main body portion 32, and the adjacent inter-element connection portion 31 are stacked as shown in FIG. 13, the inter-element connection portion 31, the main body portion 32, When adjacent inter-element connection portions 31 are not stacked, the γ portion, which is a stacked portion in FIG. 13, disappears, and the inter-element connection portion 31 is stacked with the main body portion 32 only in the vicinity of the α portion. Note that, in the structure having the inter-element connection body 30 having the slits of the modified example 1, the inter-element connection section 31 of the inter-element connection body 30 and the main body section 32 of the inter-element connection body 30 are made of different parts. The same as in the first embodiment. For this reason, according to the structure of the modification 1 shown in FIG. 14, another member or the thing of different thickness can be used for the element connection part 31 and the main-body part 32 of the element connection body 30. In addition to the effect of the second aspect, the configuration close to that of FIG. 9 can reduce the portion corresponding to the β portion in FIG. 13 in which the main body portion 32 protrudes to the module back side, thereby maintaining flatness. Insulation can be improved.

Furthermore, since the inter-element connection portion 31 and the main body portion 32 are formed of different members, unlike the first embodiment, an inter-element connection body having a shape different from that of the inter-element connection body inside the string is provided at the end of the string. It has the advantage that it is not necessary to use it. Moreover, after connecting the main-body part 32, the inter-element connection part 31 can be connected, and as the process of connecting the main-body part 32 which is the element back part of the inter-element connection body 30 to an element, and the process of forming a string There is an advantage that the step of connecting the inter-element connection portion 31 of the inter-element connection body 30 to the element is easily performed separately.

Further, in the second embodiment, since the main body 32 and the inter-element connection portion 31 are configured from different parts, the material and the plate thickness can be appropriately selected. The inter-element connection portion 31 may have a lower resistance than the main body portion. In order to achieve low resistance, it is preferable to increase the plate thickness or to use a material having a small specific resistance. As the inter-element connection portion 31 of the inter-element connection body 30, a copper flat plate having a thickness of 0.2 mm and a width of about 1 mm to 2 mm is used, and the main body portion 32 of the inter-element connection body 30 is 0.02 mm in thickness and the same as the element. It is possible to use a copper foil of a certain size punched into a slit S shape.

In addition, when forming the main-body part 32 and the inter-element connection part 31 with the same member, a cut part is made and a cut part is formed by raising the part of the cut part. It is formed. In the case of forming with a separate member, the cut-and-raised portion may be cut and raised and molded along the main body portion, or may be in an upright state.

Modification 2
Hereinafter, modifications of the first and second embodiments will be described. First, the element electrode pattern can be appropriately changed in any of the structures of the first and second embodiments other than the pattern shown in FIG. 4A. For example, as shown in FIGS. It can be a pattern. That is, in the case of the element electrode structure shown in FIGS. 15 and 16, the current extraction electrode 15 of one polarity does not cross the element and the current extraction electrode 13 of the other polarity is formed. In the case of the light receiving element having the element electrode structure of the modified example 2, when the module is formed, the element connection portion 31 of the element connection body 30 on one side of the adjacent elements is connected to the current extraction electrode 15. The The inter-element connection portion 31 of the inter-element connection body 30 on the other adjacent side is connected to the main body portion 32 of the inter-element connection body 30 that covers the current extraction electrode 13 and the current collecting electrode 14. Accordingly, the inter-element connection portions 31 of the two adjacent inter-element connection bodies 30 are not stacked. 15 and 16, the main body portion 32 of the inter-element connector 30 is directly connected to the element in a wide area without the adhesive layer 26, and the current extraction electrode 15 on one polarity Since the inter-element connection portion 31 is directly connected, the adhesion between the inter-element connection body 30 and the element electrode can be improved, and a light receiving element module having excellent reliability can be obtained. Further, there is no inter-element connection portion 31 of the inter-element connection body 30 in the portion of the current extraction electrode 13, and the main body portion 32 of the inter-element connection body 30 is connected to the other linear electrode 12 in the portion of the current extraction electrode 13. Therefore, it is not necessary to bend the main body portion 32 of the inter-element connector 30 so as to protrude toward the back side of the module on the electrodes at the end portions of the elements as in the first embodiment. Therefore, there is an advantage that the connection between the main body portion 32 of the inter-element connector 30 and the semiconductor substrate 11 as the element substrate is facilitated.

Further, in any of the electrode patterns described above, the outer peripheral portion is surrounded by the linear electrode 12 so that the main body portion 32 of the inter-element connector 30 at the element end can be fixed to the element. This is not the case when a layer having good adhesion between the layer 26 and the main body portion 32 of the inter-element connector 30 is used, and the current collecting electrode 14 can be arranged on the outermost periphery. Can reach the outermost periphery to increase the charge collection efficiency at the end of the device.

In any of the above electrode patterns, the current extraction electrode 15 has a continuous linear shape. However, the current extraction electrode 15 does not have to be continuously formed. For example, island-shaped electrodes are separated and intermittent. It may be formed. Even in the case where the island-shaped electrodes are intermittently formed, the inter-element connection portion 31 of the inter-element connector 30 is connected to each island-shaped electrode portion, so that conduction between the island-shaped electrodes separated from each other is achieved. Can be taken. In the case where the island-shaped electrode is intermittently formed, the amount of electrode material used can be reduced.

Modification 3
Further, the main body portion 32 of the inter-element connection body 30 is formed by pressing a conductive foil, for example, a copper foil in advance so as to have an uneven shape, thereby improving the adhesion with the element electrode of the light receiving element or warping of the element. Can be reduced. As a modification, it may be formed into a concave-convex shape having a concave portion 32R and a convex portion 32P that intersect with the element electrode as shown in a perspective view in FIG. 17 at an angle, for example, 45 degrees. . The main body 32 is electrically connected to the linear electrode 12 and the current extraction electrode of one electrode through the electric connection body 21, and is insulated from the current collecting electrode 14 of the other electrode by the adhesive layer 26.

In addition to the above configuration, the main body portion 32 of the inter-element connection body 30 in the portion of the current collecting electrode 14 and the current extraction electrode 15 corresponds to the module light receiving portion with respect to the main body portion 32 corresponding to the one linear electrode 12. A concave portion having a shape recessed with respect to the surface side may be formed, and a convex portion having a shape protruding relatively to the module light-receiving surface side may be provided in a portion corresponding to the linear electrode 12.

The body portion 32 of the inter-element connector 30 preferably has a convex portion indicated by 32P and a concave portion indicated by 32R in FIG. 17, and uses a flexible conductor. A flexible conductor is used as the main body portion 32 of the inter-element connector 30, and the conductor is not directly fixed to the light receiving element 10 in a portion other than a part of the electrically connected region. As a result, the main body portion 32 of the inter-element connector 30 is deformed in a portion not connected to the light-receiving element 10, and light reception caused by a difference in thermal expansion coefficient between the light-receiving element substrate and the main body portion 32 of the inter-element connector 30. The deformation of the element 10 and the stress on the light receiving element 10 can be relaxed. As described above, there is an effect that the light receiving element 10 and the light receiving element module 1 with an inter-element connection body that have less warpage of the light receiving element 10 and excellent in strength, long-term reliability, and productivity can be obtained. The adhesive layer 26 functions as an insulating layer for the inter-element connection body 30, and relaxes stress by fixing the space between the light receiving element 10 and the inter-element connection body 30 and functioning as a deformable layer. It also functions as a layer. In addition to the structure shown in FIG. 17, the pattern of the convex portion of the main body portion 32 of the inter-element connector 30 can be a shape in which the concave and convex portions on the stripe intersect. The uneven portions can be formed with a pitch of 0.1 to 5 mm, for example.

In FIG. 4B, FIG. 4C, and FIG. 4D, the description of the concave and convex portions of the main body portion 32 of the inter-element connector 30 is omitted. It is preferable to use the connection body 30 having the concavo-

convex portions

32R and 32P because warpage of the element can be reduced. The main body 32 may be formed into a flat plate shape, and irregularities may be formed in the joining process with the light receiving element. Further, as shown in FIG. 19A described later, it is preferable from the viewpoint of reducing the wiring resistance that all the convex portions 32P of the inter-element connector 30 are connected to the linear electrode 12. However, it is not necessary that all the protrusions 32P of the inter-element connector 30 are connected to the linear electrode 12, and at least one connection point is generated with respect to the continuous linear electrode 12 on the element. Therefore, depending on the cross section taken, the linear electrode 12 and the convex part 32P of the main body part 32 of the inter-element connector 30 may not correspond one-to-one.

In order to make the main body 32 of the inter-element connector 30 flexible, the conductivity may be lowered by reducing the thickness of the main body 32. When the photoelectric conversion efficiency decreases due to resistance loss when current flows from the light receiving element 10 to the adjacent light receiving element 10 due to a decrease in conductivity of the main body 32, although not shown, the main body 32 of the inter-element connector 30 is not shown. It is also possible to laminate a conductor as an outer portion on the non-light receiving surface side. By laminating the conductor on the main body 32, the outer portion functions as a conductor, and a decrease in photoelectric conversion efficiency when the element is modularized can be suppressed.

Modification 4
Further, in the first and second embodiments, the inter-element connection portions 31 are constituted by two per string. However, as shown in FIG. 18, four inter-element connection portions 31 are formed. The number of connection portions 31 may be larger. A larger number of bus electrodes, that is, current extraction electrodes has an advantage that the current collection distance of the current collecting electrode 14 is shortened and the current collecting resistance can be reduced. In order to increase the current extraction efficiency, it is necessary to make the distance between the device electrodes longer than the minority carrier diffusion length, and make the bus width, that is, the current extraction electrode width narrower than the minority carrier diffusion length in the semiconductor element substrate. It is preferable. Accordingly, an example of the electrode width in the case of an n-type silicon substrate having a specific resistance of about 1-10 Ω · cm is preferably about 1.5 mm or less. Further, in order to reduce the warpage of the element, when the melting temperature of the electrical connection body 21 is about 300 ° C., the thickness of the inter-element connection portion 31 of the inter-element connection body 30 is equal to or less than that of the semiconductor element substrate. Is preferred.

Further, in this modification, the main body portion 32 of the inter-element connection body 30 and the linear electrode 12 of the light receiving element 10 are connected by the electrical connection body 21, and the inter-element connection section 31 of the inter-element connection body 30 and the inter-element connection. The main body portion 32 that is the element back portion of the connection body 30, the inter-element connection portion 31 of the inter-element connection body 30, and the current extraction electrode 15 are connected by an electric connection body 33. In FIG. 18, the

inter-element connectors

21 and 33 are not shown. The melting temperature or bonding temperature of the electrical connecting

members

21 and 33 is set so that the inter-element connecting portion 31 between the element electrode and the inter-element connecting body does not come off during heating or bonding to connect the elements to form a string. May be different. In order to prevent the element electrode and the main body part 32 from being detached from the element electrode when heating is performed to connect the elements to form a string, the electric connection for connecting the element connection part 31 and the current extraction electrode 15 is performed. The connecting body 33 has a lower melting temperature or bonding temperature. As the electrical connection body 33, a conductive connection member such as tin-silver solder, tin bismuth solder, or a conductive adhesive can be used. As the material of the electrical connection body 33, the lower the temperature required for forming the electrical connection body part, the light receiving element when the temperature is lowered to room temperature after joining the connection body and the element back part of the inter-element connection body 30 The stress to the main body 32 is reduced, and therefore a light receiving element module with less warpage of the light receiving element 10 and excellent strength and long-term reliability can be obtained, which is more preferable. Note that the combination of the location where the electrical connection body is used and the melting temperature may be reversed according to the order of manufacture.

As described above, in FIGS. 3 and 4 (a), 7 (a), 7 (b), 7 (c), 11, 15, 16, and 18, the linear electrode 12, the current collecting electrode 14, and the adhesive layer are used. Although only about 10 are described in the X direction, 26 is a diagram schematically described, and the number of electrodes may be different from the actual one.

Embodiment 3 FIG.
Next, as a third embodiment of the present invention, another example of a light receiving element with an inter-element connector will be described. As a light receiving element used in the first and second embodiments and the modification thereof, a light receiving element having a junction formed by impurity doping may be used in addition to the heterojunction light receiving element. As the structure of the light receiving element, a light receiving element as shown in FIGS. 19A to 19C can be used. Although it is preferable to have unevenness called texture on the light receiving surface side of the substrate, the unevenness of the substrate is omitted in FIGS. 19A to 19C of this embodiment. 19A is a cross-sectional view of a light receiving element with an inter-element connection body according to the present embodiment, and FIG. 19B is an enlarged cross-sectional view of a portion A in FIG. 19A. c) is an enlarged sectional view of a portion B in FIG.

In the light receiving element 10 with the inter-element connection body of the present embodiment, a linear electrode 12 as a first element electrode and a collecting electrode 14 as a second element electrode are formed on the first passivation film 18a. A contact with the element substrate is formed in the first opening 12h and the second opening 14h, and the linear electrode 12 is formed so as to protrude from the collecting electrode 14. And the linear electrode 12 contact | abuts to the linear electrode 12 in the convex part 32P of the main-body part 32 of the inter-element connection body 30, and achieves an electrical connection directly. On the other hand, the current collecting electrode 14 abuts on the main body 32 through the adhesive layer 26 to achieve mechanical connection. In the cross sections shown in FIGS. 19A to 19C, the inter-element connection portion 31 cannot be seen, but the inter-element connection portion 31 is connected to the current extraction electrode 15 in the same manner as shown in FIG. Abutting and connected. As the semiconductor substrate 11, a single crystal n-type silicon substrate is used, and the light receiving surface of the semiconductor substrate 11 has an n-type doped region 17 which is an n-type diffusion layer formed by phosphorus diffusion as a surface electric field layer 17S. A third passivation film 18c made of an amorphous silicon nitride film is formed by laminating a silicon oxide film and the second passivation film 18b as the second passivation film 18b that also serves as an antireflection film on the surface side. On the back surface side, a p-type doped region 16 formed by phosphorus diffusion and p-type doped region 16 is formed in a portion of the substrate corresponding to the positive electrode and negative electrode of the element electrode. Except for the connection point between the device electrode and the device substrate, almost the entire surface including the surfaces of the n-type doped region 17 and the p-type doped region 16 is covered with the first passivation film 18a. As the first passivation film 18a, a stacked body of a silicon oxide film and an amorphous silicon nitride film is used. In part of the n-type doped region 17 and the p-type doped region 16, the first opening 12h and the second opening 14h are formed in the first passivation film 18a, and the metal electrode is connected to the n-type doped region 17 and the p-type. The contact with the doped region 16 serves to extract current from the substrate.

In the light receiving element shown in FIGS. 19 (a) to 19 (c), the first and

second openings

12h and 14h of the negative electrode and the positive electrode are on the same cross section, but the pitch between the openings is actually different. Therefore, the openings of the positive electrode and the negative electrode are not always formed depending on the element cross section. Further, the unevenness of the main body 32 of the inter-element connector 30 may not be formed at the same interval as the electrode pitch. Further, not all the protrusions 32P of the inter-element connector 30 need to be connected to the element electrodes, and if one connection point is generated with respect to the continuous linear electrode 12 on the element. Good.

Electrodes such as the linear electrode 12, the collecting electrode 14 and the current extraction electrode 15 are formed of a multilayer film as shown in FIGS. 19 (a) to 19 (c). Here, the p-type doped region 16 is formed on the electrode portion of one polarity, for example, the portion where the current extraction electrode 15 of the collecting electrode 14 and the collecting electrode 14 is formed, and the linear electrode 12 which is the other polarity electrode portion. An n-type doped region 17 is formed. As shown in FIG. 19C, the linear electrode 12 that is an element electrode has a four-layer structure of a negative electrode first layer 12a, a negative electrode second layer 12b, a negative electrode third layer 12c, and a negative electrode fourth layer 12d. The Further, as shown in FIG. 19B, the current collecting electrode 14 and the current extraction electrode 15 have a three-layer structure of a positive electrode first layer 14a, a positive electrode second layer 14b, and a positive electrode third layer 14c. In both the positive electrode and the negative electrode, aluminum having low contact resistance and high reflectivity is directly formed on the substrate, and titanium tungsten (TiW), copper, silver, tin, or the like is laminated on the aluminum. As described above, both the positive electrode and the negative electrode are formed with aluminum having high reflectivity directly on the substrate, so that the reflectivity is extremely good. In actual manufacturing, for example, aluminum of about 40 nm is formed on the back surface of the element as a reflective layer by vapor deposition or the like, and heated to about 400 ° C. in a nitrogen gas atmosphere containing about 3% of hydrogen to form aluminum and silicon. The contact resistance with the substrate can be reduced. And an electrode can be created by laminating other metal electrodes on the aluminum layer by thin film formation such as vapor deposition and electroplating.

In the third embodiment, the linear electrode 12 is a negative electrode, and the current collecting electrode 14 and the current extraction electrode 15 are positive electrodes. The negative electrode is connected to n-type doped region 17 and the positive electrode is connected to p-type doped region 16. In FIG. 19A to FIG. 19C, the width of the p-type doped region 16 is larger than the width of the n-type doped region 17. As described in the first embodiment, when the surface passivation effect on the p-type doped region 16 and the n-type doped region 17 is the same, the area of the pn junction is larger than the area of the n ⁺ n junction, Although the photogenerated carrier reaches the pn junction and contributes to the power generation, there is an effect that the reverse may be possible depending on the combination of the passivation films. For example, when a material having a low passivation ability for the p layer, such as SiO ₂ , is used as the passivation film, the area of the p-type doped region may be preferably small. When the area of the p-type doped region 16 is preferably small, the p-type doped region 16 may be on the linear electrode 12 side.

Since the element electrode formed in the element has a positive electrode and a negative electrode on the same surface of the element, it is preferable to take a structure that ensures insulation between the positive and negative electrodes. In order to ensure insulation between the positive and negative electrodes, the current collector electrode 14 of the element electrode shown in FIG. 19A is mainly covered with an adhesive layer 26 which is an insulating layer, and the linear electrode 12 and Insulated. The insulating layer may include a void containing gas, but in the third embodiment, the adhesive layer 26 is formed so that most of the linear electrode 12 is exposed to the outside and mainly covers the collecting electrode 14. In the module state, as shown in FIG. 19A, the current collecting electrode 14 and the body portion 32 of the inter-element connection body 30 are mainly insulated, and most of the linear electrodes 12 are inter-element connection bodies. The main body unit 32 is connected to the main body unit 30. Although not shown in the figure, after connecting the inter-element connection portion 31 to the current extraction electrode 15, except for the part on the inter-element connection portion 31 and a part of the end of the current extraction electrode 15, FIG. As shown in FIG. 13, the adhesive layer 26 is formed. When forming the adhesive layer 26, the adhesive layer 26 may partially overlap the linear electrode 12. Further, when the main body portion 32 has the slit S, the inter-element connection portion 31 may not be covered with the adhesive layer 26.

When forming the adhesive layer 26, the adhesive layer 26 is once formed thicker than a predetermined gap between the main body portion 32 and the semiconductor substrate 11, and after the formation, the main body portion 32 is pressed against the semiconductor substrate 11. A method of spreading 26 in the lateral direction can be used. In the case of the above method, the width of the adhesive layer 26 formed before the main body portion 32 is crimped is formed to be narrower than the distance between the linear electrodes 12. The adhesive layer 26 has a function of insulating not only between the element electrodes on the same substrate but also between the inter-element connection body 30 and the element electrode. In the third embodiment, the inter-element connection body is the same as in the first embodiment. 30 also has a function of insulating between the main body portion 32 of the device, the inter-element connection portion 31 of the inter-element connection body 30, and the element end portion of the current extraction electrode 15. Further, it has a function of improving the insulation between the current collecting electrode 14 of the light receiving element 10 and the main body 32 of the inter-element connector 30.

As described above, in the third embodiment, as in the first embodiment, the adhesive layer 26 is sandwiched between the main body portion 32 of the inter-element connector 30 and the semiconductor substrate 11 that is the light receiving element substrate. Therefore, by setting the thermal expansion coefficient of the adhesive layer 26 to an intermediate value between the semiconductor substrate 11 and the inter-element connection body 30, the expansion coefficient difference between the semiconductor substrate 11 and the main body portion 32 of the inter-element connection body 30 is caused. The resulting warp or stress can be relaxed in the adhesive layer 26. Further, the main body portion 32 of the inter-element connector 30 is not flat but has a concavo-convex structure, and even if the concavo-convex portion is deformed, warping or stress generated in the device due to a difference in expansion coefficient can be reduced in the adhesive layer 26. It has the advantage of being able to. As the pattern of the concavo-convex structure of the main body portion 32 of the inter-element connector 30, the pattern shown in FIG. 17, the shape where the concavo-convex portions on the stripe intersect, or the like can be used. Therefore, the light receiving element 10 according to the third embodiment can use a member having a thickness larger than that in which the electrode layer is formed directly on the back of the element as the main body portion 32 of the inter-element connector 30. It has the advantage that it can be set as a light receiving element with low resistance. The effect is particularly great in an element having a large element area. Further, in order to alleviate the difference in expansion coefficient between the element substrate and the inter-element connector 30, the inter-element connector 30 is made of a plate-like conductor such as a metal having an expansion coefficient close to that of the semiconductor substrate, such as Invar or Kovar bonded with copper. Alternatively, a soft material such as one having metal particles in the resin can be used.

As described above, between the current collecting electrode 14 and the main body portion 32 of the inter-element connector 30, between the current extraction electrode 15 and the main body portion 32 of the inter-element connector 30, the current collecting electrode 14 and the linear electrode 12. In order to insulate between the two, a portion other than the soldered portion between the main body portion 32 of the inter-element connector 30 and the electrode on the light receiving element 10 is insulated by the adhesive layer 26. Specifically, the adhesive layer 26 is made of resin such as ethylene vinyl acetate, polyimide or epoxy containing filler, glass frit, SiO ₂ film formed by CVD, silicon nitride film or other inorganic film or resin and inorganic particles. A complex of the above can be used. However, in order to reflect the light transmitted through the light receiving element 10 by the inter-element connector 30 and to enter the light receiving element 10 again, it is preferable to use light that does not absorb light as much as possible. The filler is also used as a regulator for bringing the thermal expansion coefficient closer to the light receiving element.

The main body portion 32 of the inter-element connection body 30 is made of, for example, a conductive foil. For example, a tin-silver solder is formed on one surface and press processing, Thomson processing that is processing using a simple die, or the like is performed. The main body portion 32 and the inter-element connection portion 31 of the inter-connection body 30 can be formed separately or integrally. Moreover, you may have an uneven | corrugated shape like Fig.19 (a) beforehand, for example, what is necessary is just to give an unevenness | corrugation to copper foil previously by processes, such as press work. Moreover, it is preferable that the main-body part 32 of the inter-element connection body 30 has flexibility.

The thickness of the main body 32 of the inter-element connector 30 is, for example, 0.001 to 1.0 mm. The height difference of the formed irregularities can be set to about 0.01 to 0.5 mm, for example. Further, two adjacent light receiving elements 10 connected by the inter-element connector 30 are arranged with a slight gap therebetween, and in the gap portion, the inter-element connection portion 31, the light receiving surface of the light receiving element 10, and the back side main surface material 25. And how it looks from the light receiving surface side is different. Therefore, if necessary, the outer appearance of the gap portion is substantially the same as that of the other back side main surface material 25 portion by applying a paint to the light receiving surface side of the inter-element connection portion 31 or attaching a light shielding tape. Can be the same.

One end of the inter-element connection portion 31 of the inter-element connection body 30 is connected to the current extraction electrode 15 formed on the back surface of the light receiving element 10, and the other end is connected to the main body portion 32 of the adjacent inter-element connection body 30. Connected. The main body 32 is connected to the linear electrode 12 on the element formed on the back surface side of the light receiving element 10 different from the light receiving element 10 and achieves electrical connection between two adjacent light receiving elements 10. The inter-element connection body 30, the current extraction electrode 15 of the light receiving element 10 and the linear electrode 12 of another light receiving element are connected by a conductive thin film such as the electrical connection body 21 and the electrical connection body 33. When the inter-element connection portion 31 of the inter-element connection body 30 and the main body portion 32 of the inter-element connection body 30 are configured from different parts, and the main body portion 32 and the inter-element connection portion 31 are connected, The inter-element connection portion 31 may also be connected by the electrical connection body 21 or the electrical connection body 33. The melting temperatures of the

electrical connection bodies

21 and 33 may be different so that the element electrodes and the inter-element connection bodies 30 do not come off during heating to connect the elements to form a string. In the case of the above-described structure, it is preferable that the melting temperature or the connection temperature at the portion where the connection process is performed later is lowered according to the manufacturing process. As the

electrical connectors

21 and 33, tin silver solder, tin bismuth solder, or the like can be used. As the material of the electrical connection body 21, the lower the temperature required for forming the electrical connection body 21 portion, the light receiving element when the temperature is lowered to room temperature after joining the connection body and the body portion 32 of the inter-element connection body 30. Therefore, it is preferable to use a material that can be formed at the lowest possible temperature including the electrical connection body 33 because it is preferable to obtain a light receiving element module that has less warpage of the light receiving element and is excellent in strength and long-term reliability. preferable. As a material for the

electrical connectors

21 and 33, a conductive resin containing metal particles or a resin material can be used in addition to a conductive thin film such as solder.

The electrical connection body 21 that electrically connects the linear electrode 12 and the inter-element connection body 30 is provided on the entire surface of the inter-element connection portion 31 of the inter-element connection body 30 and the element side of the main body portion 32 of the inter-element connection body 30. Although the surface may be covered widely, for example, as shown in FIG. 20 which will be described later by immersing an element with an element electrode in a molten solder bath, the current collecting electrode 14, the current extraction electrode 15 and the linear electrode are self-aligned. You may form a solder layer only in the connection part with the connection body 30 between elements on 12 element electrodes. In the case where the solder layer is selectively formed only on the connection portion, the electrical connection body 21 exists on the electrode and the electrical connection body 21 formed on the main body portion 32 may be omitted. In addition, since the main body 32 only needs to be thin, there is an advantage that warpage and stress due to a difference in thermal expansion coefficient between the element and the inter-element connector 30 can be reduced. Further, as shown in FIG. 21, the electrical connection body 21 made of a solder plating layer covers the entire surface on the element side of the main body 32, and the electrical connection body 21 in the wavelength region where the light absorption coefficient of the light receiving element 10 is small. When the light reflectance is not high, it is preferable to reflect light by including a light reflector or scatterer such as titanium dioxide particles in the adhesive layer 26. As the light reflector, not only particles but also a dielectric laminated film, for example, a reflective film such as a dielectric multilayer film in which SiO ₂ and TiO ₂ are laminated can be used on the back of the element. The region where the light absorption coefficient of the light receiving element 10 is small is a wavelength region of approximately 900 nm to 1300 nm when the light receiving element is made of silicon and a substrate having a thickness of about 200 micrometers is used, for example. When the thickness of the substrate is as thin as several tens of micrometers, it is preferable that the reflectance of the material on the back surface side of the element is high even in the shorter wavelength region.

Further, the element electrodes such as the linear electrode 12 and the current collecting electrode 14 do not need to be a single metal layer, and nickel and tin are plated by plating as a surface layer for connection with the main body portion 32 of the inter-element connector 30. It may be formed on the surface of the underlying layer such as copper. Not only the element electrode part but also the main body 32 of the inter-element connector 30 may be plated to improve the connectivity with the electrical connector 21. As an example, for example, an aluminum foil is used as the main body portion 32 of the inter-element connection body 30, nickel and tin are formed by plating as a surface layer on the surface of the main body portion 32 on the element electrode side, and a tin-silver solder layer is formed as the electric connection body 21. May be formed mainly in a portion between the inter-element connector 30 and the element electrode. In addition to the above, the pattern of the convex portions of the main body portion 32 of the inter-element connector 30 may be a shape in which stripe-shaped uneven portions intersect.

As a further modification of the element electrode in the light receiving element with the inter-element connection body according to the third embodiment, the electrical connection body 21 is mainly formed only on the element electrode, and the inter-element connection is performed only at a part of one of the element electrodes. When connected to the convex portion of the body 30, the electrode is composed of a plurality of layers, and when the first layer functions as a reflective layer and the layer outside the reflective layer mainly bears electric conduction, the linear electrode 12 constituting the element electrode 20 to 23 are shown as modified examples 5, 6 and 7, respectively, in which the heights of the collector electrode 14 and the collector electrode 14 are the same.

Modification 5
In the element structure shown in FIG. 20, for example, by immersing the light receiving element in a molten solder bath, the solder layer as the electrical connection body 21 is self-aligned on the linear electrode 12 and the current collecting electrode 14 that are element electrodes. It is formed. When forming the solder layer in a self-aligning manner, the electrode of one electrode and the electrode of the other electrode are made of different materials, or only the surface of the current collecting electrode 14 is covered with an inorganic material, so that only one electrode is covered. You may make it solder. Moreover, as the electrical connection body 21, what apply | coated the mixture of a metal particle and resin other than solder may be used. The other parts are the same as those in the first embodiment shown in FIGS. 4B to 4D, and thus the description thereof is omitted, but the same parts are denoted by the same reference numerals.

However, the main body portion 32 and the inter-element connection portion 31 may be composed of different parts and may have different thicknesses. By forming the electrical connection body 21 by selective plating using solder, the electrical connection body 21 is formed mainly only in the portion where the element electrode is present. Therefore, even if the electrical connection body 21 having a low reflectance is used, the electrical connection body 21 is electrically connected. Light absorption by the body 21 is small, and there is an advantage that light can be reflected by the main body portion 32 of the inter-element connection body 30.

Further, when the electrical connection body is formed on the current extraction electrode 15 and the linear electrode 12 as in this modification, the main body portion 32 does not have to have the electrical connection body 21 and the main body portion 32 having a large area. It is not necessary to form the electrical connection body 21 in the whole. In general, for example, a silver electrode having a high rarity as a metal having high conductivity is often used as a device electrode in a solar cell. However, according to the present embodiment, since the inter-element connection body 30 is responsible for conductivity, the device electrode Can reduce the amount of metal used. Therefore, there is an advantage that the amount of silver can be reduced for use in manufacturing a solar cell, and resource saving and cost reduction can be achieved.

Further, the electrical connection body 21 may not be used. For example, the electrical connection body 21 and the second connection body 30 are melted by using a low melting point metal or the like as the main body portion 32 of the inter-element connection body 30. The electrical connection body 33 may be used instead.

As a further modification, when using the electrical connector 21 having a high reflectivity, the electrical connector 21 made of a solder layer may be formed on the entire surface of the main body 32 as shown in FIG. Further, as shown in FIG. 21, the size of the uneven structure on the inter-element connector 30 may be larger than that of the element electrode. Further, the pitch of the concavo-convex structure may be wider than the pitch of the element electrodes. Further, in FIG. 21, the width of the concave portion of the main body of the concavo-convex structure toward the light receiving surface is narrower than the width of the linear electrode 12 that is the first element electrode, so that the connection can be easily made without alignment. be able to. The width of the widest portion that is concave toward the light receiving surface is made narrower than the width of the linear electrode 12 that is the first element electrode, thereby preventing the linear electrode 12 from entering the concave portion. be able to. By making the width of the cross section of the convex portion of the concavo-convex structure of the main body portion to the light receiving surface side wider than the gap between the first element electrodes, it is possible to reliably connect without alignment.

Modification 6
In the element structure shown in FIG. 22, a reflective layer 52 made of an aluminum layer having a high reflectivity is directly formed on the entire surface by, for example, vacuum deposition, and titanium tungsten is laminated on the reflective layer 52 by sputtering deposition or the like, and soldered. Copper which is easy to perform is formed on titanium tungsten, and the reflective layer 52 which is a reflector, the linear electrode 12 which is an electric conductor, and the current collecting electrode 14 are separately formed. The other parts are the same as those in the first embodiment shown in FIGS. 4B to 4D, and thus the description thereof is omitted, but the same parts are denoted by the same reference numerals. This has the advantage that an electrode structure that is highly reflective but easy to solder can be formed. Moreover, the usage-amount of noble metals, such as silver, can be reduced. The reflective layer 52 is preferably formed over the entire surface of the semiconductor substrate 11, but it may be formed over the entire surface.

Modification 7
In the element structure shown in FIG. 23, the heights of the element electrodes of one pole and the other pole are the same, but the protrusion 32P of the main body part 32 of the inter-element connector 30 is aligned at the part where one electrode is present. Therefore, the inter-element connector 30 is connected to only one electrode on the element. The other parts are the same as those in the first embodiment shown in FIGS. 4B to 4D, and thus the description thereof is omitted, but the same parts are denoted by the same reference numerals. According to such a configuration, since the height of the element electrode is constant, the process of manufacturing the element can be simplified. However, alignment between the element and the inter-element connector 30 is required.

As described above, in the light receiving element module 1 according to the first to third embodiments of the present invention, the pattern of the element electrodes on the substrate is different from the conventional one, and the current flowing out of the element substrate reaches the inter-element connection portion 31. The average distance that the current needs to flow through the current collecting electrode 14 in the in-plane direction of the current is, for example, in accordance with the number n of the bus electrodes, that is, the current extraction electrodes 15 or the inter-element connection portions 31 of the inter-element connection body. In (a), the length of the semiconductor substrate 11 in the Y direction is about ½n of the length in the Y direction, and the current collecting resistance on the element electrode can be greatly reduced. Since it is smaller than the resistance due to the element electrode, the resistance of the entire module can be reduced.

Specifically, for example, on a substrate of 156 mm, which is a common solar cell element size, the current collecting resistance of one silver grid electrode having a width of 100 μm, a height of 10 μm, and a length of 150 mm is 1. Whereas it is about 6Ω, it can be reduced to about 0.2Ω by using two bus electrodes.

For the other polarity electrode, the average distance that the current needs to flow through the linear electrode 12 in the in-plane direction of the substrate in order to reach the main body 32 of the inter-element connector 30 is the convex portion of the inter-element connector 30. The interval of the cross section in the Y direction of 32P or the interval of the cross section in the Y direction of the convex portion 32P of the inter-element connector 30 when the convex portion and the electrode do not correspond one-to-one as shown in FIGS. This is about the least common multiple of the distance between the linear electrodes 12, and the current collecting resistance on the element electrode can be greatly reduced. In general, only the portion corresponding to the distance in the height direction of the electrode or the thickness of the electrode becomes the current collecting resistance, thereby reducing the current collecting loss due to the electric resistance even if a device having a larger element size is used in the module. The photoelectric conversion element module including the light receiving element module excellent in photoelectric conversion efficiency can be obtained.

Specifically, for example, when connecting to a body part of an inter-element connection body composed of a silver grid electrode having a height of 10 micrometers and copper having a thickness of about 30 micrometers at 15 mm intervals, the main body part with the inter-element connection body Since the resistance of 32 is sufficiently smaller than the device electrode, the current collecting resistance per one can be reduced to about 0.2Ω. The advantage is the same for the thermal resistance for heat dissipation from the element, and it is possible to obtain a light receiving element module having high heat dissipation and keeping the element temperature low, resulting in excellent photoelectric conversion efficiency. Have As described above, according to the present embodiment, the current collecting electrode and the extraction electrode constitute a cross-connecting portion so that the current collecting distance in the planar arrangement is as small as possible, and the inter-element connector 30 is provided. By taking charge, the current collecting resistance on the element electrode can be reduced, and the amount of metal used for the element electrode can be reduced. Therefore, there is an advantage that resource saving and cost reduction can be achieved.

Further, in the light receiving element module 1 according to the first to third embodiments, the adhesive layer 26 is formed on the current collecting electrode 14 on one substrate in advance, thereby performing high-accuracy alignment during modularization. Without having this, there is an advantage that the inter-element connector 30 can be connected only to the linear electrode 12 having the other polarity. Therefore, the fine alignment between the inter-element connector 30 and the element, which is necessary in the conventional light receiving element module, is unnecessary, and the electrode pitch of the element electrodes can be reduced without depending on the alignment accuracy. it can. In addition, since an alignment mark for improving the alignment accuracy is not required on the element, a photoelectric conversion efficiency reduction region caused by the alignment mark does not occur in the light receiving element. Therefore, it is possible to manufacture a light receiving element module having a narrower electrode pitch while having the advantages of a light receiving element module having a low internal resistance, high carrier collection efficiency, and excellent photoelectric conversion efficiency.

Further, in the light receiving element module 1 according to the first to third embodiments, the inter-element connection body 30 made of a copper foil having a high reflectance with respect to light having a certain wavelength that transmits a small light absorption coefficient of the silicon substrate. Since the main body portion 32 is provided on the back of the element and only the adhesive layer 26 having a high light-transmitting property is mainly provided between the element and the main body portion 32 of the inter-element connector 30, light having a wavelength of about 900 nm to 1300 nm is used. Even if the light is transmitted to the back surface of the element, light can be incident on the element again by the main body 32 of the inter-element connector 30, so that the light loss is reduced and a light receiving element module having excellent photoelectric conversion efficiency is obtained. Has the advantage of being able to.

In the light receiving element modules according to Embodiments 1 to 3, since the element electrode portion can be covered with metal and resin, moisture reaching the element electrode portion from the ambient environment of the light receiving element can be reduced. Therefore, a short circuit due to migration of element electrodes or an increase in resistance due to an electrochemical reaction can be prevented, and the light receiving element module is excellent in photoelectric conversion efficiency and long-term reliability. This is particularly important in the case of a light-receiving element having a small distance between the positive electrode and the negative electrode and high photoelectric conversion efficiency.

In the first to third embodiments, in order to connect the inter-element connector 30 to the element when modularization is performed, the inter-element connector 30 may be connected so as to match the back surface of the element. For example, high-accuracy alignment that is the same as or similar to the distance between the p region and n region in the element as in Patent Document 4 is unnecessary when modularized, and the number of alignments is reduced compared to the conventional module. Can do. Therefore, the alignment accuracy can be increased as a result of reducing the number of alignments. Note that the adhesive layer 26 may be formed prior to the connection of the inter-element connector 30. When the formation of the adhesive layer 26 is performed prior to the connection of the inter-element connector 30, the alignment is performed, but also the alignment of the adhesive layer 26 is completely covered with one electrode and a part of the other electrode. Therefore, it is not necessary that the alignment be highly accurate.

In the first to third embodiments, the back side electrode that contributes to the current collection in the element is formed, the back surface reflecting film that reflects the light transmitted through the element, and the inter-element connection body 30 that connects the elements are reduced. Since it can be formed by the number of steps, a light receiving element and a light receiving element module excellent in photoelectric conversion efficiency can be manufactured by fewer steps.

In the first to third embodiments, since the photoelectric flow rate is evaluated after the main body portion 32 of the inter-element connection body 30 is connected to the element, and a module can be created by combining those having the same photoelectric flow rate, each light receiving element Ten generated current values can be matched. As a result, since the string does not have the light receiving element 10 having a significantly lower power generation current value than the other light receiving elements 10, the power generation efficiency of the light receiving element module 1 can be increased as compared with the conventional one. Therefore, the module structure of the present invention is a structure that can prevent the situation where the currents between the light receiving elements do not coincide with each other as in the prior art.

As described above, according to the first to third embodiments, the distance between the inter-element electrodes is small, the connection resistance between the elements is small, and the light transmitted through the element is reflected without performing highly accurate alignment. Thus, it is possible to obtain a light receiving element and a module that can be effectively used and have excellent photoelectric conversion efficiency.

In addition, since not only the linear electrode 12 and the collector electrode 14 on the substrate but also the inter-element connection portion 31 and the main body portion 32 of the inter-element connection body 30 contribute to the current collection on the element, the conductive resistance in the element is reduced. Since it can reduce, it has the effect that the light receiving element module excellent in the electric power generation output can be manufactured. According to the above embodiment, the light lost through transmission between the linear electrode 12 as the element electrode and the current collecting electrode 14 is reflected by the main body 32 of the inter-element connector 30 and enters the element. Accordingly, light transmission loss can be reduced, and the light receiving element module 1 having excellent photoelectric conversion efficiency can be manufactured.

When the reflector as described above is on the back surface of the element, the light transmitted between the linear electrode 12 and the collector electrode 14 on the substrate is reflected by the main body 32 of the inter-element connection body 30 due to the gain obtained. The photoelectric flow rate changes. However, according to the above embodiment, the photoelectric flow rate is evaluated after the main body portion 32 of the inter-element connector 30 is connected to the element, and a module can be created by combining those with the same photoelectric flow rate. The generated current value of the light receiving element 10 can be matched. As a result, since the string does not have the light receiving element 10 having a significantly lower power generation current value than the other light receiving elements 10, the power generation efficiency of the light receiving element module 1 can be increased. Therefore, the light receiving element module of the above embodiment has an advantage that the situation where the currents between the light receiving elements do not coincide with each other can be prevented.

In the second embodiment, unlike the first embodiment, it is not necessary to change the shape of the inter-element connection body between the string end and the inside of the string. Since it is only necessary to rotate the inter-element connection body by 90 degrees and connect it, there is an advantage that the process of forming the module can be simplified. Further, since it is not necessary to newly provide an interstring connection body at the end of the string, the area occupied by modules other than the elements can be reduced. In the present embodiment, elements other than elements are inter-string connectors. Therefore, there is an advantage that a module having an excellent power generation amount per area can be obtained.

Embodiment 4 FIG.
FIG. 24 is a plan view of a light receiving element with an inter-element connector constituting the light receiving element module according to the fourth embodiment as viewed from the back side. FIG. 24 shows a module in which a light receiving element with an inter-element connection body is taken out by one repeating unit, and a linear electrode as an element electrode when the inter-element connection body 30 and the light receiving element 10 are connected. 12, the adhesive layer 26 or the sealing material 22, the light receiving surface side main surface material 23, and the back surface side main surface material 25 are omitted so that the positional relationship between the electrode 12 and the current collecting electrode 14 can be understood. In the light receiving element module according to the present embodiment, the main body portion 32 is divided into five parts, and four current extraction electrode connection portions 31 b of inter-element connection portions are provided between the main body portions 32. The strip-shaped main body portion 32 and the current extraction electrode connection portion 31b are juxtaposed. One end of the main body 32 is connected to the current extraction electrode connection 31b connected to the adjacent cell via the inter-element portion 31a. On the other hand, the four current extraction electrode connection portions 31b are connected to an inter-element portion 31a connected to the main body portion 32 connected to an adjacent cell on the lower side of the drawing, not shown. That is, in this embodiment, both the element electrode and the inter-element connector 30 have a structure in which members having different polarities do not overlap on the element.

In order to show the positional relationship between the inter-element connection body 30 and the electrodes on the light-receiving element 10, a plan view of the light-receiving element with inter-element connection body in FIG. FIG. 25B shows a plan view excluding only the main body 32 and the insulating layer 26 of the inter-element connector. FIGS. 26A to 26C are views of 6A-6B in a state where the main body portion 32 and the inter-element connection portion 31 of the inter-element connection body 30 are connected to the light receiving element 10 of FIGS. 24 and 25B. FIG. 6 is a cross-sectional view when a light receiving element with an inter-element connection body is cut off along each line segment of 6C-6D and 6E-6F.

The inter-element connection body 30 of the present embodiment, like the inter-element connection body 30 of the light-receiving element module described in the first embodiment, has a back connection type light reception having first and second element electrodes on the back surface side. The elements 10a to 10f are connected. The inter-element connection portion 31 of the inter-element connection body 30 and the main body portion 32 of the inter-element connection body 30 are both made of a conductive foil having flexibility. Then, as shown in FIG. 24, a main body portion 32 that covers almost the entire surface excluding the current extraction electrode 15 on the back surface of the light receiving element 10, and a current extraction electrode connection portion 31b of an inter-element connection portion connected to the current extraction electrode 15 The inter-element portion 31a of the inter-element connection body 30 connected between the back surface of the main body portion 32 and the current extraction electrode connection portion 31b of the inter-element connection portion 31.

The main body part 32 of the inter-element connector 30, the inter-element part 31 a of the inter-element connector 30, and the current extraction electrode connection part 31 b of the inter-element connector 30 are connected by the

electrical connector

21 or 33. When connecting the main body part 32 of the inter-element connection body 30 and the inter-element part 31a, they may be directly connected by spot welding, thermocompression bonding or the like without using an electrical connection body.

Further, the main body portion 32 does not have a slit S, that is, a notch, is divided into five strips, and covers the entire semiconductor substrate 11 constituting the light receiving element except for the current extraction electrode 15. Different from 1. Furthermore, the main part 32 of the interelement connection body 30, the interelement part 31a, and the electric current extraction electrode connection part 31b differ in the point comprised from the components of three separate units. Other portions are the same as those in the first and second embodiments, and the description thereof is omitted here.

Here, FIG. 24, FIG. 25 (a), FIG. 25 (b) is the figure which looked at the connection body 30 between elements from the back side of the module. The inter-element portion 31a of the inter-element connector 30 connected to the main body 32 selectively connected to the linear electrode 12 which is one of the element electrodes is the second element of the adjacent light receiving element 10. It contacts the current extraction electrode connection portion 31b of the inter-element connector 30 connected to the current extraction electrode 15 that is an electrode. In the light receiving element 10, current collecting electrodes 14 as second element electrodes are also formed in a stripe shape (linear shape) at regular intervals, and four current extraction electrodes 15 intersecting the current collecting electrodes 14. Is formed. Since the current extraction electrode connection portion 31b of the inter-element connector 30 is in contact with the current extraction electrode 15, the current collection distance of the second element electrode can be reduced, so that the current collection resistance is reduced. be able to.

Also in the present embodiment, similar to the light receiving element module of the first or second embodiment, resin sealing is performed to obtain a light receiving element module. In the fourth embodiment, as shown in FIGS. 24, 25 (a) and 25 (b), the body portion 32 of the inter-element connector 30 located on the light receiving element 10 is formed on the current extraction electrode 15. Therefore, the current extraction electrode connection portion 31b of the inter-element connection body 30 can be connected to the entire current extraction electrode 15 on the element, and the current collector on the current extraction electrode 15 can be connected. The resistance can be reduced, and a short circuit between the main body 32 and the current extraction electrode connection part 31b of the inter-element connector 30 can be prevented. That is, as compared with the first embodiment, a portion where the current extraction electrode connection portion 31 is not connected to the current extraction electrode 15 is generated, and a portion where the current collecting resistance is increased on the current extraction electrode 15 is more reliably prevented. be able to. Further, the possibility that the insulating property is lowered in the laminated portion portion of the current extraction electrode 15 and the main body portion 32 can be more reliably suppressed in the present embodiment than in the case of the first embodiment.

Also in the second embodiment, as shown in FIGS. 12B and 13, the inter-element connection portion 31 of the inter-element connection body 30 formed on the current extraction electrode 15 and the main body on the inter-element connection portion 31. Although it was necessary to insulate between the part 32 with the adhesive layer 26 made of an insulating layer, in the fourth embodiment, since the main body part 32 of the inter-element connector 30 does not exist on the current extraction electrode 15, In the second embodiment, the portion corresponding to the laminated structure portion formed by the inter-element connection portion 31 of the inter-element connection body 30, the main body portion 32 of the inter-element connection body 30, and the inter-element connection portion 31 of the inter-element connection body 30 is provided. Can be eliminated. Therefore, the current extraction electrode 15 and the current extraction electrode connection portion 31b of the inter-element connection body 30 and the main body portion 32 are arranged in parallel and separated from each other, so that they are insulated in advance, have high reliability, and have a new insulating layer. There is an advantage that a module can be easily created without the need to provide a module.

In the fourth embodiment, in the current extraction electrode 15, the inter-element connection portion 31 of the inter-element connection body 30 has a structure that does not overlap with the main body portion 32 of the inter-element connection body 30 on the same element. In the second embodiment, the inter-element connection portion 31 overlaps the main body portion 32. On the other hand, the main body 32 in the fourth embodiment is connected between the elements by the amount of the laminated portion of the current extraction electrode connecting portion 31b and the main body 32 of the inter-element connector 30 on the current extraction electrode 15. The thickness of the light receiving element with the body is reduced.

The inter-element connection section 31, the main body section 32, the linear electrode 12, and the current extraction electrode 15 of the inter-element connection body 30 are connected by an electric connection body. In the fourth embodiment, between the body part 32 and the inter-element part 31a of the inter-element connection body 30, and between the current extraction electrode connection part 31b of the inter-element connection body and the inter-element part 31a of the inter-element connection body 30. Are connected by a second electrical connection body 33 (not shown), between the main body portion 32 of the inter-element connection body 30 and the linear electrode 12, and between the current extraction electrode 15 and the current extraction electrode of the inter-element connection body. The connection part 31b is connected by an electrical connection body 21.

As the

electrical connection bodies

21 and 33, the same material or different ones may be used. Furthermore, the inter-element connection section 31, the main body section 32, and the linear electrode 12 of the inter-element connection body 30 may be used. A different electrical connection body may be formed in each part of the current extraction electrode 15. For example, as a combination of parts using different

electrical connection bodies

21 and 33, in the fourth embodiment, “between the main body portion 32 of the electrical connection body and the linear electrode 12” and “connection between the current extraction electrode 15 and the element” The electrical connection body 21 is connected to the connection portion between the current extraction electrode connection portions 31b of the body 30, the inter-element connection portion 30a of the inter-element connection body 30 and the main body portion 32 of the electrical connection body, and the inter-element connection. The electrical connection body 33 can be used for the connection portion between the inter-element portion 31 a of the body 30 and the current extraction electrode connection portion 31 b of the inter-element connection body 30. In the case of the above configuration, as the formation region of the electrical connection body 21, for example, the electrical connection body 21 is formed so as to cover the entire surface of the inter-element connection section 31 on the inter-element connection section 31. With respect to the main body 32, the electrical connection body 21 can be formed only in the portion connected to the element electrode.

The type of the electrical connection body and the formation site of each electrical connection body may be arbitrarily combined, but the connection portion between the element electrode and the inter-element connection body so that the heating time of the element substrate is short and the heating temperature is low. It is good to use separately in the connection part between the connection body between elements, and the connection body between elements. For example, the melting temperatures of the

electrical connectors

21 and 33 are different so that the element electrode and the body portion 31 of the inter-element connector 30 are not detached from the element electrode when heating is performed to connect the elements to form a string. It may be. In the case of the combination of the use parts of the

electrical connection bodies

21 and 33 in the fourth embodiment, when the connection temperature of the electrical connection body 33 is higher than the connection temperature of the electrical connection body 21, the Connection between the inter-element part 31a of the connection body 30 and the main body part 32 of the electric connection body and "between the inter-element part 31a of the inter-element connection body 30 and the current extraction electrode connection part 31b of the inter-element connection body 30" Are connected by the electric connection body 33, and then “between the main body portion 32 of the electric connection body and the linear electrode 12” and “the current extraction electrode 15 and the current extraction electrode connection section 31b of the inter-element connection body 30”. By performing the “inter-connection” with the electrical connection body 21, the electrical connection body 33 having a higher connection temperature is less affected by heat even in the subsequent connection of the electrical connection body 21, so that the string can be easily formed. The advantage of being able to A. When the connection temperature of the electrical connection body 33 is lower than the connection temperature of the electrical connection body 21, it is preferable to reverse the order of connection by each electrical connection body.

For example, in the case of the second embodiment, the electrical connection body 33 can have a lower melting temperature than the electrical connection body 21. When the melting temperature of the electrical connection body 33 is lower than that of the electrical connection body 21, when connecting each part by the electrical connection body, the electrical connection body 21 is first melted at a high temperature, and the current extraction electrode 15 and the element are connected. The inter-connection portion 31 and the inter-element connection portion 31 and the main body portion 32 are connected, and then the main body portion 32 and the linear electrode are heated at a temperature at which the electric connection body 33 does not melt and the electric connection body 33 melts. 12 is advantageous in that it is easy to create a string because the former electrical connector connecting portion can be held without melting during the latter heating. The combination of the location where the electrical connection body is used and the melting temperature may be reversed in the second embodiment according to the order of manufacture. As the electrical connector, tin silver solder, tin bismuth solder, metallic tin, or the like can be used. For connection between an element such as a light receiving element and an inter-element connector, heating means such as a laser as described in prior art documents such as Patent Documents 5 to 6 in addition to solder or conductive adhesive The metal material may be melted and connected.

Modification 8
Next, a modification of the fourth embodiment will be described. In the light receiving element module of the modification shown in FIG. 27, the main body 32 of the inter-element connector 30 has a recess 32R and a protrusion indicated by a dotted line in the figure. A portion 32P is provided. When the convex portion 32P protruding to the light receiving surface side is larger than the gap between the protruding element electrodes 12, or the interval between the concave portions 32R that are concave to the light receiving surface side, that is, the width is the width of the linear electrode 12 that is the element electrode. If smaller, the main body portion 32 of the inter-element connector 30 contacts the linear electrode 12 that is an element electrode. Accordingly, the main electrode 32 and the linear electrode 12 are not contacted with the collector electrode 14 which is an element electrode having a polarity opposite to that of the main body 32 of the inter-element connector 30 without alignment. Can only be connected with. Further, the width of the cross section of the convex portion 32P, which is a portion that protrudes toward the light receiving surface, is wider than the gap between the second element electrodes, that is, the linear electrodes 12, so that the main body portion 32 is a linear shape that is an element electrode. The electrode 12 is securely connected to the electrode 12.

In the light receiving element 10 having parallel thin wire electrodes as shown in FIG. 25B, the widths of the convex portions 32P in the X and Y directions are larger than the gaps in the X and Y directions between the linear electrodes 12 which are element electrodes. It is preferable that the distances in the X and Y directions of the recess 32R are smaller than the widths in the X and Y directions of the linear electrode 12 itself that is an element electrode. As a result of the above configuration, the light-receiving element module having the repeating unit shown in FIG. 27 uses the main body portion 32 of the inter-element connection body 30 having the concave portions 32R and the convex portions 32P. The deformation of the part 32 is facilitated, the warp of the light receiving element with the inter-element connection body can be reduced and the strength can be increased, and the body part 32 and the element electrode of the inter-element connection body 30 can be obtained without alignment. 12 has the advantage that only 12 can be connected.

According to the light receiving element module 1 of the present embodiment, since the main body portion 32 of the inter-element connector 30 does not cover the current extraction electrode 15 on the entire surface of the light receiving element, the adhesive layer 26 made of an insulating layer is formed on the current extraction electrode 15. Even if it does not form, it has the advantage that the short circuit between the main-body part 32 and the electric current extraction electrode 15 on the same element can be prevented. Accordingly, the number of steps for forming the insulating layer can be reduced.

Modification 9
FIG. 28 is a diagram showing a modification of the light receiving element module constituting the solar cell module according to Embodiment 4. In the light receiving element module of the modified example shown in FIG. 28, the strip-shaped main body portion 32 protrudes from the semiconductor substrate 11 constituting the element substrate of the light receiving device, and the inter-element portion 31a is made of a metal foil orthogonal to the main body portion 32. . And the current extraction electrode connection part 31b of the inter-element connector 30 connected to the adjacent cell is connected to the inter-element part 31a. Other parts are the same as those in the fourth embodiment.

According to the above configuration, the configuration of the inter-element portion is simpler than that of the fourth embodiment, and can be slightly downsized. The inter-element portion 31a of the inter-element connection body 30 used in the fourth embodiment and the modified examples 8 and 9 and the main body portion 32 can be integrally formed. Although it is easy to handle by forming it integrally, the alignment accuracy may be severe.

Modification 10
29, 30, and 31 are diagrams showing a light receiving element module according to a modification of the fourth embodiment, in which a light receiving element having element electrodes on the semiconductor substrate having a polarity opposite to that in the semiconductor substrate is used. It is the top view which shows the pattern of the conductive area | region of a board | substrate, and the position of an electrode, a top view, and sectional drawing. In the modified example 10, while the contact area between the semiconductor layer that becomes the recombination center of the carrier and the metal electrode is reduced, the distance to the inter-element connector 30 is minimized, and the current has a large plate thickness and low resistance. The configuration is such that it flows through the inter-element connection body. FIG. 29 is a diagram showing the in-plane distribution of the semiconductor region on the substrate surface on the back surface side of the semiconductor substrate, which is described not only for the inter-element connector 30 and the module member such as the sealing material but also for the passivation film or electrode. Yes. FIG. 29 shows that the surface of the semiconductor substrate 11 is a semiconductor layer different from the semiconductor substrate 11 but is not formed. About the p-type doped region 16, the lightly doped n-type doped region 17a, and the heavily doped n-type doped region 17b. Indicates that a conductive region different from the semiconductor substrate 11 itself is formed on the surface. FIG. 30 is a view of only the element including the element electrode as viewed from the back side, and is a plan view showing the pattern of the element electrode of the light receiving element 10 using the point-like electrode 12D as the element electrode of one polarity. In FIG. 30, the passivation film 18 a covers the semiconductor substrate 11 constituting the element substrate, and the point electrode 12 </ b> D, the current collecting electrode 14, and the current extraction electrode 15, which are element electrodes, are formed in portions other than the region covered with the passivation film 18 a. It is formed so as to be juxtaposed on the back surface side of the semiconductor substrate 11. 31 is a cross-sectional view taken along 6G-6H in FIG. FIG. 31 shows a string cross section in a state where elements are connected by an inter-element connector 30, and a passivation film on the light receiving surface side, a module sealing material, a light receiving surface material, and a back surface protective material are omitted. .

Generally, a photoelectric conversion element uses an internal photoelectric effect of a semiconductor substrate. Since the semiconductor substrate 11 used for the photoelectric conversion element has a relatively low conductivity, the resistance loss increases when the distance through which the current flows in the semiconductor substrate 11 is long. In addition, if the distance that the minority carriers move in the semiconductor substrate 11 is long, the extraction current to the outside of the semiconductor decreases due to the deactivation of the photogenerated carriers. Therefore, a general photoelectric conversion element has a structure in which conductivity in the in-plane direction is ensured by forming a metal electrode or a translucent electrode on the semiconductor substrate 11. In the case where the metal electrode is used for in-plane conduction, the structure is widely distributed throughout the semiconductor substrate surface while being spaced apart at a certain distance so that the electrode does not cover the entire semiconductor substrate in consideration of light loss due to the electrode shadow. . Here, the structure in which the electrodes are widely distributed refers to a structure in which the electrodes in contact with the semiconductor substrate are distributed over the entire surface of the semiconductor substrate at intervals equal to or less than the diffusion length of minority carriers in the substrate. In the above structure, the semiconductor substrate is much lower in conductivity than the metal, so that in the part where there is no electrode, the semiconductor substrate up to the element electrode in addition to the thickness of the element until the current flows through the element and reaches the electrode part It is preferable to reduce the distance between the device electrodes because the resistance itself increases and the resistance loss in the substrate increases. On the other hand, since the recombination speed of the carrier is increased at the portion where the semiconductor and the metal are in contact with each other, it is preferable that the contact area between the element electrode and the semiconductor is small. Therefore, the distance between the element electrodes has an optimum value.

As the element structure of the back connection type photoelectric conversion element, there are generally an MWT (Metal Wrap Through) cell, an EWT (Emitter Wrap Through) cell, and an IBC (Inter-digit Back-contact) cell. Among the above cells, in the IBC cell and the EWT cell, since there is no electrode on the light receiving surface, both the positive and negative electrodes need to be widely distributed on the back surface while being separated. On the other hand, since the MWT cell has a grid electrode on the light receiving surface side, an electrode shadow is generated, but only the positive electrode or the negative electrode needs to be widely distributed on the back surface side. The structure is relatively simple. Therefore, although the light receiving element module of the present embodiment is mainly intended for an element structure having no element electrode on the light receiving surface, it can also be applied to an element having an element electrode on the light receiving surface. When element electrodes having two different polarities, such as IBC cells and EWT cells, need to be widely distributed while being separated only on one surface, wiring becomes complicated. Conventionally, a structure in which element electrodes are connected to a wiring board facing comb-like wiring electrodes as in Patent Document 8 to collect current, or a method in which element electrodes are multilayered as in Patent Document 9 has been proposed. I came. However, in order to form the element electrode so as to reduce the resistance with respect to the semiconductor substrate, for example, after metal deposition, heat treatment is performed at about 200 to 400 ° C. for 5 to 30 minutes, or glass frit is contained. High-temperature heat treatment such as heat treatment at about 400 to 900 ° C. is required after printing the paste. When performing heat treatment, for example, in a light receiving element having a passivation film as shown in FIGS. 19A and 19B, a metal material is formed from portions other than the first opening 12h and the second opening 14h which are contact holes. The semiconductor film reaches the semiconductor substrate by diffusing through the passivation film 18a or through a pinhole formed accidentally in the passivation film. In such a case, there is a problem that the metal acts as a recombination center in the semiconductor and the photoelectric conversion efficiency of the light receiving element is lowered. In particular, when a metal exists in a region having a low conductivity in a semiconductor in which a diffusion layer region such as 16, 17a, and 17b in FIG. 31 is not formed, the metal acts strongly as a recombination center.

Furthermore, in the case of a structure in which one polar electrode is formed on a semiconductor region having the other polarity through a thin inorganic insulating layer formed on the semiconductor substrate, metal diffusion or pinholes existing in the insulating film Non-Patent Document 1 describes that the leakage current between the two electrodes increases because the semiconductor layer and the metal having different potentials are short-circuited through each other. In this case, there is a problem that the photoelectric conversion efficiency is significantly lowered due to an increase in the leakage current, and the reliability of the element module is lost, for example, the element generates heat during the reverse bias and the sealing material melts. . In particular, pinholes serving as metal diffusion paths are conspicuously generated in a passivation film on a semiconductor substrate having an uneven surface such as a solar cell, and thus the above-described problems are likely to occur. In this embodiment, since a plate or foil that can stand on the metal electrode is used, even if there is a pinhole in the insulating film, it is not possible for the metal to follow the fine pinhole formed in the insulating film. In addition, it is possible to carry current by the low-resistance inter-element connection body 30 without causing direct contact with the semiconductor substrate or the element electrode, without causing a short circuit between the two electrodes, or causing metal diffusion to the semiconductor substrate. There is an advantage that you can. Further, since the thicker insulating layer 26 is formed on the passivation film 18a, the metal material is prevented from penetrating the passivation film 18a from portions other than the first opening 12h and the second opening 14h which are contact holes. It becomes possible.

Further, for example, Non-Patent Document 1 proposes a structure in which an electrode having the other polarity is directly in contact with a semiconductor layer having one polarity via a thin inorganic insulating layer formed on the semiconductor substrate. In the case of the above structure, a portion where metal is directly formed on the semiconductor substrate through a pinhole existing in the insulating film is generated, so that the metal diffused from the electrode onto the semiconductor layer having one polarity has a different potential from the semiconductor layer Since the metal is short-circuited, the decrease in photoelectric conversion efficiency becomes remarkable. The above problem occurs because the semiconductor substrate and the electrode metal are in close contact with each other over only a thin insulating film, and the metal is heated to a high temperature on the semiconductor substrate having a large area. Further, the above problem is more prominent as the element area is larger. On the other hand, in the modified example and the present embodiment, since the thick insulating layer 26 made of the resin layer is formed, the problem as in Non-Patent Document 1 can be avoided, and the photoelectric conversion efficiency can be improved. Can be planned.

Further, as in Patent Document 2, the element electrode is directly contacted on the semiconductor substrate via an insulating film or a passivation film formed directly on the semiconductor substrate, and the element electrode is connected to the extraction wiring of the wiring portion. In the element structure, there is a possibility that the metal constituting the element electrode diffuses in the insulating layer by high temperature treatment for reducing contact resistance, diffuses into the semiconductor substrate, and functions as a recombination center. For the above reasons, Patent Document 2 has a problem in that a barrier layer is formed to prevent metal diffusion and the number of steps increases due to multilayering.

On the other hand, in the fourth embodiment, as shown in FIG. 31, a metal foil having a large area and low resistance is provided on the main body portion 32 of the inter-element connection body 30 which is a conductor that does not directly contact the semiconductor substrate 11. The current extraction electrode 15 and the point-like electrode 12D, which are element electrodes, and the current extraction part 31b and the main body part 32 of the inter-element connector 30 are taken at a relatively low temperature by using a joining member such as solder. As described above, in Patent Documents 2 and 7, when the element electrodes are stacked on the element substrate, a short circuit may occur between the element electrodes through pinholes or thermal diffusion. Is a structure in which metal foil, which is a conductive plate-like body, is connected at a low temperature, instead of a structure in which metal is directly formed on an insulating film or element substrate. The body does not follow and the metal does not come into contact with the semiconductor substrate. Therefore, a short circuit from the inter-element connection body to the element substrate or the electrode having the opposite polarity hardly occurs. Further, the region in which the metal constituting the device electrode is in direct contact with the semiconductor substrate of the light receiving device that is the power generation device is limited to the low resistance semiconductor region to which the dopant is added at a relatively high concentration. be able to. Further, the insulating property can be improved by forming a sufficiently thick insulating layer 26 using a resin such as a polyimide resin which is less likely to cause pinholes.

As described above, in the light receiving element module according to the present embodiment, even if there is a pinhole in an insulating film such as a passivation film on the element substrate, recombination in the semiconductor due to metal diffusion or the element electrode and vice versa. There is an advantage that short circuit between the semiconductor layers having the polarities is difficult to occur. By suppressing the short circuit as described above, heat generation due to leakage current is suppressed and photoelectric conversion efficiency is improved.

Specifically, when the semiconductor region in FIG. 29 is an n-type conductive layer and is a low-concentration n-type doped region 17a and a high-concentration n-type doped region 17b, the current extraction electrode 15 that is an element electrode and the same element The inter-element connection portion 31b of the upper inter-element connection body 30 becomes a negative electrode in a light irradiation state, and the point-like electrode 12D that is an element electrode on the same element and the main body portion 32 of the inter-element connection body 30 become a positive electrode. In the case where the main body 32 is a positive electrode, as shown in FIG. 31, the element substrate having a relatively positive potential is directly above the semiconductor substrate 11 and the heavily doped n-type doped region 17b, which are element substrates having a negative potential. Although the main body 32 of the connection body 30 is in an adjacent state via the insulating layer 26, the metal is not in direct contact with the semiconductor substrate and the connection temperature is low, so that high insulation can be obtained. Have

In particular, when copper is used as an electrode, since copper easily diffuses into silicon, there is a problem that a short circuit or carrier recombination is very likely to occur at the copper diffusion portion. On the other hand, in the present embodiment, the electrical connection body 21 can exist only in the electrical conduction portion of the element electrode, and the main body portion 32 of the inter-element connection body 30 does not directly contact the semiconductor substrate 11. High insulation can be obtained. Therefore, copper, which is a good conductor with good solderability, is used as an electrode material for easily reducing the resistance in the device. Generally, it is used for device electrodes and is a rare resource, such as silver. Can be reduced.

Note that the metal is in contact with the semiconductor substrate 11 in a low-concentration p-type doped region, that is, the p-type diffusion layer which is the p-type doped region 16, but a relatively high-concentration dopant is in contact with the metal as in the present embodiment. Since the influence of recombination by the metal is small when it exists in the semiconductor substrate in contact with the semiconductor substrate 11, the metal constituting the point electrode 12 </ b> D is in contact with the semiconductor substrate 11 through the p-type doped region 16 in the present embodiment. As compared with the case where a metal is present in a portion other than the p-type doped region 16, this is not a big problem.

Furthermore, in addition to the above problem, in the structure in which the element electrode of

Patent Documents

1 and 2 bears current collection, the element electrode itself needs a thickness to reduce the current collection resistance in the element plane. Although a process for increasing the thickness of the element electrode by vacuum deposition, plating, or the like is necessary, if the light receiving element module of the present embodiment described in the first to fourth embodiments is used, the element of one pole The electrodes are not thick and have the advantage that the number of steps can be reduced because the resistance in the element substrate surface can be reduced at the same time as the elements are connected. Further, in the combination of the polyimide insulating layer and the metal vapor deposition film as in Patent Document 2, the metal vapor deposition film is not formed in an island shape due to a crack or a shape change caused by a volume change due to swelling of the resin insulation layer depending on the use environment of the module. There is a possibility that the conductivity of the metal film in the in-plane direction of the element is lowered due to continuous or peeling from the insulating layer. In addition, when the deposited metal film is thin, there is a problem that the metal thin film is oxidized by moisture or the like and the conductivity is lowered. On the other hand, since the inter-element connection body used in each embodiment is a continuous metal film that can be self-supported, it is difficult to break, and the inter-element connection body on the back surface of the element is kept highly conductive. Has the advantage of being able to.

In addition to the above problems, in the conventional back connection type light receiving element module in which the inter-element connection body is connected to the element electrode as in Patent Documents 8 and 9 over almost the entire surface of the element substrate, There is a problem that alignment is necessary when connecting the electrodes, and that the interval between the positive electrode and the negative electrode of the electrode element cannot be narrower than the alignment accuracy when connecting the devices.

In Patent Documents 8 and 9, since there are two polar electrodes on the same surface, alignment between the positive and negative element electrodes and the positive and negative inter-element connectors cannot be performed with high accuracy. Short circuit occurs between the positive and negative electrodes, and the photoelectric conversion efficiency of the module is greatly reduced. Therefore, it is necessary that the positive and negative element electrodes and the inter-element connector have a one-to-one correspondence, and it is necessary to align the electrode interval between the positive and negative inter-element connectors and the element electrodes. Therefore, the distance necessary to prevent a short circuit between the positive electrode and the negative electrode between the element electrode and the inter-element connector is not only the positional accuracy of the element electrode but also the alignment between the element and the insulating layer made of a resin film or the like. Depending on the accuracy, the distance between the positive electrode and the negative electrode is limited by the alignment accuracy between the element and the inter-element connector. In order to prevent a short circuit between the positive and negative electrodes, when the distance between the positive electrode and the negative electrode of the element electrode is long, the distance until the carriers generated in the element substrate reach the electrode between the positive electrode and the negative electrode is long. Therefore, the photoelectric conversion efficiency decreases due to resistance loss and carrier deactivation.

Conversely, in order to improve the photoelectric conversion efficiency, it is necessary to improve the alignment accuracy, which increases the number of processes. The specific separation distance, that is, the pitch of the contact portion between the element electrode and the semiconductor substrate is preferably smaller than the minority carrier diffusion length in the semiconductor element substrate, and the resistance of the substrate, the minority carrier diffusion length of the substrate, and the semiconductor For example, in the case of a silicon substrate with a passivation film, the thickness is approximately 0.05 mm to 2 mm, although it depends on the method of forming the bond. In the case where a substrate having a size of about 150 mm square is used with the above electrode spacing, in Patent Document 4, about 100 inter-element connection bodies including the positive electrode and the negative electrode are arranged accurately so that adjacent inter-element connection bodies do not contact each other. There is a problem that it is necessary to connect to the device electrode, and it is necessary to insulate between the electrodes having different polarities, which requires the number of processes and time. Also in Patent Document 3, there is a problem that the alignment accuracy is lowered due to thermal contraction of the resin sheet, or a marking process for alignment is required.

When the surface of the element is covered with a passivation film having a low surface recombination speed and the recombination speed is low even in the element electrode part, in particular, a heterojunction type in which a metal electrode is formed on a semiconductor substrate via a translucent electrode In the case of the solar cell, a narrower pitch of the connecting portion between the metal electrode and the semiconductor (or translucent electrode) can reduce the current collecting resistance, which is preferable for improving the photoelectric conversion efficiency. Therefore, in the present invention, the fine alignment between the inter-element connection body and the element, which is necessary at the time of creating the module in the conventional light receiving element module, is unnecessary, and the electrode of the element electrode does not depend on the alignment accuracy. The pitch can be narrowed, the distance between the positive and negative electrodes can be narrowed, and the light receiving element module having excellent photoelectric conversion efficiency can be produced by a simple structure and method.

In addition, when the element substrate and the inter-element connection body are directly joined by laser as in Patent Document 6, the inter-element connection body is limited to a metal acting as a dopant in the semiconductor substrate. According to the embodiment, by using a conductive bonding member such as solder or conductive adhesive, various metal or other conductive materials can be combined and used as an inter-element connection body and an element electrode. In addition, it has an advantage that a module excellent in productivity and resource saving can be manufactured.

Further, in Patent Document 1, the inter-element connection body and the element electrode can be used as an electrode only in an area up to about the same as the element area. By adopting an electrode extraction structure having a connection body, the inter-element connection body and the element electrode can be combined to use an area approximately twice the element area as the electrode. Furthermore, since the inter-element connection body is composed of a metal foil or a metal plate, it has extremely low resistance compared to the element electrode formed on the element, so that the overall module resistance can be reduced and the inter-element connection body thickness is generally reduced. Since it can be made thinner than a typical inter-element connection body, there is an advantage that the stress generated in the element due to a connecting process such as soldering can be reduced.

Further, when compared with Patent Document 4 or Patent Document 11, each width of the body portion of the inter-element connection body is wider than the width of the inter-element portion of the inter-element connection body, and is widely distributed on the semiconductor substrate. Since it is possible to cover almost the entire area of the linear electrode 12 or the dotted electrode 12 which is the element electrode, there is an advantage that the current collecting resistance in the element substrate surface can be lowered.

Further, when the method of the present invention is used, the inter-element connection body is connected for each light receiving element, and when the light receiving element is replaced, the light receiving element is removed from the inter-element connection body and a new element is attached again. Therefore, the waste of the light receiving element can be reduced.

In the above embodiment, the light receiving element formed by impurity diffusion into the silicon substrate is described as an example. However, the heterojunction solar cell of amorphous silicon and single crystal silicon, and the heterojunction using a compound semiconductor substrate such as GaAs as the semiconductor substrate. The present invention can be applied to all types of photoelectric conversion elements such as a junction light receiving element and a light emitting element. Moreover, although the solar cell of the use which does not condense was described in the said embodiment, you may use for the solar cell which has a condensing system. In the case of a solar cell having a condensing system, the size of the element is made smaller, the space between the elements is expanded, and the light receiving surface material is not a flat plate glass, but a translucent member having a lens corresponding to each element may be used. The basic structure is the same as that described in the embodiment. In addition, since the light receiving element module according to the present embodiment does not include electrodes on the light receiving surface side and can have a uniform appearance, it has high designability and is used for an external mounting element such as a power source for a watch or a light receiving sensor. You can also.

In the embodiment, for example, as shown in FIG. 4D, the second element electrode having one polarity is divided into two parts, ie, a current extraction electrode 15 and a current collecting electrode 14. is doing. The current extraction electrode 15 is an element electrode formed on the element, and indicates a part of the element electrode whose main purpose is to be connected to the inter-element connector. The current collecting electrode 14 is not connected to the inter-element connection body, but is connected to the current extraction electrode, and is an element electrode for collecting current up to the current extraction electrode on the semiconductor substrate surface. For example, as shown in Patent Document 12, there is a structure in which a bus electrode is not formed as an electrode on an element, and a tab electrode, that is, an inter-element connector is directly connected to the finger electrode. In the above structure, a portion of the finger electrode that is in direct contact with the inter-element connection body is used as a current extraction electrode, and a portion of the finger electrode that is not in contact with the inter-element connection body is a current collection electrode. It is also possible to apply a light receiving element module having an inter-element connection body according to each embodiment to a light receiving element substrate having no so-called bus electrode.

Furthermore, the element electrode structure is not limited to the above-described embodiment, and can be applied to, for example, a device having another type of element electrode structure that is in direct contact with a semiconductor and connected to the current collecting electrode. It is. Moreover, in the said embodiment, although the case where the 1st element electrode mainly has only a current collection electrode is handled, since it connects with the main-body part of an inter-element connection body, it functions as a current extraction electrode. Also have. The first element electrode may also have a current extraction electrode in addition to the current collecting electrode.

In addition, since the present invention relates to a device electrode and an inter-element connection body, and a connection structure between them, the device structure to be used may be a back-connection type device structure, and the junction formed in the device is arbitrary. Can be used. For example, regarding the light emitting element, not only a pn junction but also a double heterojunction junction of GaN and GaInN may be used.

Further, in the present invention, the term “direct contact” means that the contact is made with a low contact resistance, including a contact through a conductive member such as a plating layer or a conductive adhesive.

The configuration described in the above embodiment shows an example of the content of the present invention, and can be combined with another technique, and a part of the configuration can be used without departing from the gist of the present invention. It can be omitted or changed.

1 light receiving element module, 10, 10a to 10f light receiving element, 11 semiconductor substrate, 12 linear electrode, 12D dotted electrode, 12h first opening, 12a negative electrode first layer, 12b negative electrode second layer, 12c negative electrode third Layer, 12d negative electrode fourth layer, 13 current extraction electrode, 14h second opening, 14 current collecting electrode, 14a positive electrode first layer, 14b positive electrode second layer, 14c positive electrode third layer, 15 current extraction electrode, 16p Type doped region, 17 n type doped region, 17a high concentration n type doped region, 17b low concentration n type doped region, 17S surface electric field layer, 18a first passivation film, 18b second passivation film, 18c third passivation film, 21 Electrical connection body, 22 sealing material, 23 front side main surface material, 25 back side main surface material, 26 adhesive layer Insulating layer), 30 inter-element connection body, 31 inter-element connection section, 31a inter-element connection section, 31b current extraction electrode connection section, 32 main body section, 32P convex section, 32R concave section, 33 second electrical connection body, 38 current extraction Line, 52 reflective layer.

Claims

A back connection type photoelectric conversion element having first and second element electrodes having different polarities on the back side of the semiconductor substrate;
A photoelectric conversion element module comprising a main body part and an inter-element connection part connected to the main body part, and comprising an inter-element connection body made of a conductive plate for connecting the photoelectric conversion element to an adjacent photoelectric conversion element. And
The first and second element electrodes are arranged in a plane,
The second element electrode is composed of a current extraction electrode connected to the inter-element connection portion and a plurality of current collecting electrodes connected to the current extraction electrode,
The collector electrode of the second element electrode has a portion that crosses and connects to the inter-element connection portion on the back surface of the semiconductor substrate,
The first element electrode has a plurality of regions divided by the inter-element connection portion,
The body part of the inter-element connection body has a plate shape, and the width of the body part is wider than the width of the inter-element connection part, and is directly electrically connected to the first element electrode on the back surface of the photoelectric conversion element. And is insulated from the second element electrode,
The inter-element connection portion of the inter-element connection body electrically connected to the main body portion is directly connected to the current extraction electrode of the second element electrode of the photoelectric conversion element that is adjacently disposed,
A photoelectric conversion element module.
The second element electrode has a portion that intersects and connects in the same plane on the back surface of the semiconductor substrate,
The first element electrode has a plurality of regions divided by the second element electrode,
The inter-element connection portion is disposed along a current extraction electrode of the second element electrode, and is directly connected to the current extraction electrode;
The photoelectric conversion element module according to claim 1.
The main body has a notch corresponding to the shape of the inter-element connection portion, and has a complementary shape with the inter-element connection portion;
The photoelectric conversion element module according to claim 1 or 2.
The body part of the inter-element connection body located on the same photoelectric conversion element and the inter-element connection part of the inter-element connection body of the adjacent elements are juxtaposed on the same plane,
The photoelectric conversion element module according to any one of claims 1 to 3, wherein:
The second element electrode includes a collecting electrode arranged in a grid parallel to each other at a constant interval, and a current extraction electrode that intersects the collecting electrode and interconnects the collecting electrode.
The first element electrode is composed of a plurality of regions divided by the second element electrode;
The photoelectric conversion element module according to claim 1, wherein:
The main body abuts on the second element electrode through an insulating layer,
The insulating layer is a resin layer;
The photoelectric conversion element module according to any one of claims 1 to 5, wherein:
The body part of the inter-element connection body is a metal plate,
The main body is connected to the first element electrode by solder or conductive adhesive;
The photoelectric conversion element module according to claim 1, wherein:
The metal plate is a copper foil,
The body is connected to the first element electrode by solder;
The photoelectric conversion element module according to claim 7.
The base material of the main body is copper or aluminum;
The photoelectric conversion element module according to claim 1, wherein:
The photoelectric conversion element module according to any one of claims 1 to 9, wherein a surface of the second element electrode is closer to the semiconductor substrate than a surface of the first element electrode.
The semiconductor substrate is a first conductivity type silicon substrate;
The first element electrode is connected to a first conductivity type semiconductor region formed in the silicon substrate,
The second element electrode is connected to a second conductivity type semiconductor region formed in the silicon substrate,
11. The photoelectric conversion element module according to claim 1, wherein the surface of the first conductivity type semiconductor region is formed at a position higher than the second conductivity type semiconductor region.
The semiconductor substrate is an n-type silicon substrate;
The first element electrode is formed in the n-type silicon substrate and connected to an n + type semiconductor region having a higher concentration than in the n-type silicon substrate,
The second element electrode is connected to a p-type semiconductor region formed in the n-type silicon substrate,
The p-type semiconductor region surface is formed at a position higher than the n + -type semiconductor region;
The photoelectric conversion element module according to claim 1, wherein:
Having an insulating resin layer between the main body of the inter-element connector and the second conductive semiconductor region;
The photoelectric conversion element module according to claim 12.
An electrical connection is selectively formed only in a connection region with the inter-element connection on the first and second element electrodes;
The photoelectric conversion element module according to claim 1, wherein:
The main body of the inter-element connector has an uneven structure;
The photoelectric conversion element module according to claim 1, wherein:
The width of the concave portion on the light receiving surface side of the concavo-convex structure of the main body is narrower than the width of the first element electrode;
The photoelectric conversion element module according to claim 15.
The width of the cross section of the convex portion toward the light receiving surface of the concavo-convex structure of the main body is wider than the gap between the first element electrodes;
The photoelectric conversion element module according to claim 15 or 16, wherein:
A back connection type photoelectric conversion element having first and second element electrodes having different polarities on the back side of the semiconductor substrate;
A photoelectric conversion element module comprising a main body portion and an inter-element connection portion connected to the main body portion, and comprising an inter-element connection body made of a conductive plate for connecting the photoelectric conversion element to an adjacent photoelectric conversion element. Because
The first and second element electrodes are arranged in a plane,
The second element electrode includes a current extraction electrode and a plurality of current collecting electrodes connected to the current extraction electrode.
The second element electrode has a portion that intersects and connects in the same plane on the back surface of the semiconductor substrate,
The first element electrode has a plurality of regions divided by the current extraction electrode,
The inter-element connector is
A main body divided into a plurality of strips and abutting against the first element electrode;
A current extraction electrode connecting portion made of a strip-shaped metal plate disposed between the main body portions and in contact with the current extraction electrode;
One end is connected to the current extraction electrode connection portion and the main body portion, and the other end is connected to the main body portion and current extraction electrode connection portion of an adjacent cell, and is configured with an inter-element portion.
A photoelectric conversion element module.
On the back side of the semiconductor substrate, there are first and second element electrodes having different polarities arranged in a plane without overlapping portions,
The second element electrode includes a current extraction electrode and a plurality of current collecting electrodes connected to the current extraction electrode.
The second element electrode has a portion that intersects and connects in the same plane,
A step of forming a back connection type photoelectric conversion element, wherein the first element electrode has a plurality of regions separated by the current extraction electrode;
Forming an inter-element connection body including a main body portion and an inter-element portion connected to the main body portion;
The body part of the inter-element connection body is directly electrically connected to the first element electrode on the back surface of the photoelectric conversion element, and is in contact with the second element electrode through an insulating layer to be electrically connected. Insulate and
Directly connecting the inter-element connection portion of the inter-element connection body electrically connected to the main body portion with the current extraction electrode of the second element electrode of the photoelectric conversion element disposed adjacently,
Connecting the photoelectric conversion element to an adjacent photoelectric conversion element,
A method for producing a photoelectric conversion element module, comprising:
Prior to the connecting step,
Including a selective plating step of selectively depositing metal on the device electrode by electrolytic plating;
The method for producing a photoelectric conversion element module according to claim 19.