JP2013048146A - Solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar cell module which has less warpage in the array direction of a solar cell element with a simple structure.SOLUTION: A solar cell module includes a plurality of solar cell elements and a wiring member. The solar cell element includes first and second electrodes which are arrayed on the first surface of a semiconductor substrate. The wiring member includes a first wiring member 15a connected to the first electrode of a first solar cell element, and a second wiring member 15b connected to the second electrode of a second solar cell element. At least any one of the first and second wiring members has a first region in a longitudinal direction of the first electrode, and a plurality of protruding second regions which project from the first side portion extending in the longitudinal direction of the first region and are arrayed so as to be separated from each other in the longitudinal direction thereof. The first region is insulated from the solar cell element. The second region has a conductive portion which can be connected to the first or second electrode, and the first side portion in the first region which is positioned between the adjacent second regions out of the plurality of the second regions has a curved portion in at least a part thereof.

Description

  The present invention relates to a solar cell module including a solar cell element.

  One type of solar cell element is a back contact type solar cell element (see, for example, Patent Document 1).

  Such a solar cell element includes a semiconductor substrate exhibiting one conductivity type, a reverse conductivity type layer exhibiting a conductivity type opposite to that of the semiconductor substrate, a first electrode, and a second electrode having a polarity different from that of the first electrode. Electrode. The semiconductor substrate includes a plurality of through holes formed over the light receiving surface and the back surface. The reverse conductivity type layer is provided inside the first reverse conductivity type layer provided on the light receiving surface of the semiconductor substrate, the second reverse conductivity type layer provided on the back surface of the semiconductor substrate, and the through hole of the semiconductor substrate. A third reverse conductivity type layer. The first electrode includes a light-receiving surface electrode portion formed on the light-receiving surface of the semiconductor substrate, a through-hole electrode portion formed inside the through-hole, and a back-surface electrode portion formed on the back surface of the semiconductor substrate. . The light-receiving surface electrode portion, the through-hole electrode portion, and the back electrode portion are electrically connected. The second electrode is formed on a portion of the back surface of the semiconductor substrate where the second reverse conductivity type layer is not formed.

  In the solar cell module, a plurality of such solar cell elements are arranged, and adjacent solar cell elements are electrically connected to each other by a wiring member. Patent Document 1 discloses an inter-element wiring member having a comb structure as a wiring member for connecting adjacent solar cell elements.

Special table 2002-500825

  When the wiring member described above is connected to an adjacent solar cell element, the warpage in the arrangement direction of the solar cell element may increase. Thereby, alignment is difficult in the manufacturing process of a solar cell module, and a crack, a crack, etc. may generate | occur | produce in a solar cell element during a manufacturing process.

  The present invention has been made based on the above problems, and an object of the present invention is to provide a solar cell module with a simple configuration and less warpage in the arrangement direction of the solar cell elements.

In order to solve the above problems, a solar cell module according to an aspect of the present invention includes a semiconductor substrate having a first surface and a second surface on the back side of the first surface, and an array on the first surface. A plurality of solar cell elements each having an elongated first electrode and a second electrode and arranged adjacent to each other, and a first solar cell element adjacent to each other among the plurality of solar cell elements Of the second solar cell elements, the first wiring member electrically connected to the first electrode of the first solar cell element and the second electrode of the second solar cell element are electrically connected to the first electrode. And a wiring member provided with a second wiring member connected to. At least one of the first wiring member and the second wiring member includes a first region that is elongated along the longitudinal direction of the first electrode, and the first region when viewed in plan. A plurality of convex second regions protruding outward from a first side extending in the longitudinal direction of the first electrode and arranged spaced apart from each other along the longitudinal direction of the first electrode And have. The first region is electrically insulated from the solar cell element. Each of the plurality of second regions has a conductive portion that can be electrically connected to the first electrode or the second electrode, and between adjacent second regions of the plurality of second regions. The first side portion of the first region located at has a curved portion at least partially when seen in a plan view.

  According to the solar cell module described above, the conductive portions that can be connected to the electrodes in the wiring member are respectively disposed in the plurality of second regions that are arranged apart from each other in the longitudinal direction of the first electrode. The stress generated by the thermal contraction in the longitudinal direction of the first electrode in the first region of the wiring member is relieved, and the warpage in the longitudinal direction of the first electrode of the solar cell element can be reduced.

It is the plane schematic diagram which looked at an example of the solar cell element from the 2nd surface side. It is the plane schematic diagram which looked at an example of the solar cell element from the 1st surface side. (A) is the cross-sectional schematic diagram seen from the cross section AA of FIG. 1, (b) is the cross-sectional schematic diagram seen from the cross section BB of FIG. FIG. 3 is an enlarged plan view of a portion C in FIG. 2. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram explaining an example of the solar cell module which concerns on one Embodiment of this invention, (a) is a partial cross section enlarged view of a solar cell module, (b) is a 1st surface side of a solar cell module. It is the top view seen. It is a plane schematic diagram explaining an example of the wiring member used for the solar cell module which concerns on one Embodiment of this invention. FIG. 7 is an enlarged plan view of a part D in FIG. 6. It is a plane schematic diagram explaining an example which connected the wiring member to the solar cell element. (A) is the cross-sectional schematic diagram seen from the cross section EE of FIG. 8, (b) is the cross-sectional schematic diagram seen from the cross section FF of FIG. It is a plane schematic diagram explaining an example of the wiring member used for the solar cell module which concerns on one Embodiment of this invention. It is an enlarged plan view of the part G of FIG. It is a cross-sectional schematic diagram explaining an example which connected the wiring member to the solar cell element. It is a cross-sectional schematic diagram explaining an example which connected the wiring member to the solar cell element. It is a plane schematic diagram explaining the formation method of the wiring member used for the solar cell module which concerns on one Embodiment of this invention.

  Hereinafter, a solar cell module and a manufacturing method thereof according to an embodiment of the present invention will be described in detail with reference to the drawings.

≪Solar cell module≫
<First Embodiment>
The solar cell module 30 according to the first embodiment of the present invention will be described with reference to FIG.

  The solar cell module 30 includes a plurality of solar cell elements 10 arranged adjacent to each other, and a wiring member 15 that electrically connects the adjacent solar cell elements 10 to each other.

  As shown in FIG. 5A, the solar cell module 30 further includes a translucent member 11, a front side filler 12, a back side filler 13, and a back surface protective material 14.

<Translucent member>
The translucent member 11 is disposed on the second surface 1F side of the solar cell element 10 and has a function of protecting the second surface 1F, and is made of, for example, glass.

<Front side filler>
The front-side filler 12 has a function of being disposed between the second surface 1F of the solar cell element 10 and the translucent member 11 and sealing the solar cell element 10, for example, a transparent olefin-based material. Made of resin or the like. An ethylene vinyl acetate copolymer (EVA) or the like can be used as the olefin resin.

<Backside filler>
The back side filler 13 is disposed on the first surface 1R side of the solar cell element 10 and has a function of sealing the solar cell element 10, and is made of, for example, a transparent or white olefin resin.

<Back protection material>
The back surface protective material 14 has a function of protecting the first surface 1R side of the solar cell element 10, and is made of, for example, a single layer or a laminated structure such as polyethylene terephthalate (PET) or polyvinyl fluoride resin (PVF). Become.

<Solar cell element>
Next, the solar cell element 10 according to the embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4.

  A solar cell element 10 according to this embodiment includes a semiconductor substrate 1 exhibiting one conductivity type, a reverse conductivity type layer 2 having a conductivity type different from that of the semiconductor substrate 1, a through hole 3, a first electrode 4, A second electrode 5 having a polarity different from that of the first electrode 4, a semiconductor layer 6, and an antireflection layer 7.

  The semiconductor substrate 1 has a first surface 1R (lower surface side in FIG. 3) and a second surface 1F (upper surface side in FIG. 3) on the back side of the first surface 1R. In the solar cell element 10, the second surface 1F is a light receiving surface. Hereinafter, for convenience of explanation, the first surface 1R may be referred to as a back surface of the semiconductor substrate 1, and the second surface 1F may be referred to as a light receiving surface of the semiconductor substrate 1.

  As the semiconductor substrate 1, a crystalline silicon substrate such as a single crystal silicon substrate or a polycrystalline silicon substrate having a predetermined dopant element (impurity for conductivity control) and exhibiting one conductivity type (for example, p-type) is used. . The thickness of the semiconductor substrate 1 can be, for example, 250 μm or less, and further 150 μm or less. Further, the shape of the semiconductor substrate 1 is not particularly limited, but may be a square shape from the viewpoint of the manufacturing method.

  In the present embodiment, a crystalline silicon substrate exhibiting p-type conductivity is used as the semiconductor substrate 1. When the semiconductor substrate 1 made of a crystalline silicon substrate is p-type, for example, boron or gallium can be used as the dopant element.

  On the second surface 1F of the semiconductor substrate 1, as shown in FIGS. 3A and 3B, a texture structure (uneven structure) 1a having a large number of fine protrusions 1b is formed. Thereby, reflection of incident light on the second surface 1F can be reduced, and more sunlight can be absorbed into the semiconductor substrate 1. Note that the texture structure 1a is not an essential component in the present embodiment, and may be formed as necessary.

Further, as shown in FIGS. 3A and 3B, the semiconductor substrate 1 has a plurality of through holes 3 penetrating from the second surface 1F to the first surface 1R. As will be described later, the through hole 3 has a third layer 2c of the reverse conductivity type layer 3 formed on the inner surface thereof. In addition, a conduction portion 4 b of the first electrode 4 described later is formed inside the through hole 3. A plurality of through holes 3 can be formed by arranging them at a constant pitch within a range of 50 μm to 300 μm in diameter. In addition, the through-hole 3 may have different diameters of openings in the second surface 1F and the first surface 1R. For example, as shown in FIGS. 3A and 3B, the diameter of the opening in the second surface 1F of the through hole 3 is larger than the diameter of the opening in the first surface 1R of the through hole 3. May be. That is, the through hole 3 may have a shape such that the diameter decreases from the second surface 1F side toward the first surface 1R side.

  The reverse conductivity type layer 2 is a layer having a conductivity type opposite to that of the semiconductor substrate 1. The reverse conductivity type layer 2 includes a first layer 2 a formed on the second surface 1 F of the semiconductor substrate 1, a second layer 2 b formed on the first surface 1 R of the semiconductor substrate 1, And a third layer 2c formed on the surface. If a silicon substrate exhibiting a p-type conductivity is used as the semiconductor substrate 1, the reverse conductivity type layer 2 is formed to exhibit an n-type conductivity.

The first layer 2a is formed as an n ⁺ type semiconductor layer having a sheet resistance of about 40 to 100Ω / □, for example. By setting the value of the sheet resistance within this range, it is possible to reduce the increase in surface recombination and the increase in surface resistance on the second surface 1F. The first layer 2a is formed on the second surface 1F of the semiconductor substrate 1 with a thickness of about 0.2 μm to 2.0 μm, for example.

  The second layer 2b is formed on the first surface 1R of the semiconductor substrate 1 in the formation region of the first electrode 4 and its peripheral portion. The second layer 2b only needs to have a sheet resistance equivalent to that of the first layer 2a. Note that the second layer 2b may have a sheet resistance lower than that of the first layer 2a. In that case, an increase in the surface resistance on the first surface 1R can be further reduced.

  The third layer 2 c is formed on the inner surface of the through hole 3. The third layer 2c only needs to have a sheet resistance equivalent to that of the first layer 2a. Note that the third layer 2c may have a sheet resistance lower than that of the first layer 2a. In that case, an increase in surface resistance on the inner surface of the through hole 3 can be further reduced.

  By having the reverse conductivity type layer 2, a pn junction is formed between the one conductivity type region in the semiconductor substrate 1 and the reverse conductivity type layer 2 in the solar cell element 10.

  The semiconductor layer 6 is a layer provided for the purpose of forming an internal electric field inside the solar cell element 10, that is, for the purpose of obtaining a so-called BSF effect (Back Surface Field Effect). Thereby, a reduction in power generation efficiency due to recombination of carriers in the vicinity of the first surface 1R of the semiconductor substrate 1 can be reduced.

  The semiconductor layer 6 is formed on substantially the entire surface of the first surface 1R of the semiconductor substrate 1 other than the region where the second layer 2b is formed. More specifically, as shown in FIGS. 3A and 3B, the semiconductor layer 6 is formed so as not to contact the second layer 2b on the first surface 1R. The specific formation pattern of the semiconductor layer 6 varies depending on the formation pattern of the first electrode 4.

The semiconductor layer 6 has the same conductivity type as the semiconductor substrate 1. The concentration of the dopant contained in the semiconductor layer 6 is higher than the concentration of the dopant contained in the semiconductor substrate 1. That is, the dopant element is present in the semiconductor layer 6 at a concentration higher than the concentration of the dopant element doped to exhibit one conductivity type in the semiconductor substrate 1. When the semiconductor substrate 1 is p-type, the semiconductor layer 6 can be formed, for example, by diffusing a dopant element such as boron or aluminum into the first surface 1R. At this time, the concentration of the dopant element contained in the semiconductor layer 6 can be about 1 × 10 ^{18 to} 5 × 10 ²¹ atoms / cm ³ . As a result, the semiconductor layer 6 has a p ⁺ type conductivity type containing a dopant at a higher concentration than the p type conductivity type exhibited by the semiconductor substrate 1, and has a good ohmic contact with the current collector 5b described later. Is formed.

  For example, the semiconductor layer 6 may be formed in 70% or more of the entire region of the first surface 1R when the first surface 1R of the semiconductor substrate 1 is viewed in plan. In this case, the BSF effect which improves the output characteristic of the solar cell element 10 is suitably obtained.

  The semiconductor layer 6 is not an essential component in the present embodiment, and may be formed as necessary.

  The antireflection layer 7 has a role of reducing the reflection of incident light on the surface (second surface 1F) of the semiconductor substrate 1. The antireflection layer 7 is formed on the second surface 1F side of the semiconductor substrate 1, more specifically, on the first layer 2a. The antireflection layer 7 can be formed of a silicon nitride film or an oxide material film. The thickness of the antireflection layer 7 has a suitable value depending on the constituent material, but is set to a value that realizes a non-reflection condition for incident light. For example, when a silicon substrate is used as the semiconductor substrate 1, the antireflection layer 7 may be formed to a thickness of about 500 to 1200 mm by a material having a refractive index of about 1.8 to 2.3.

  The provision of the antireflection layer 7 is not an essential configuration in the present embodiment, and may be provided as necessary.

  The first electrode 4 has a plurality of main electrode portions 4a, a plurality of conduction portions 4b, and a plurality of first output extraction portions 4c. As shown in FIGS. 1, 3 (a) and 3 (b), the main electrode portion 4 a is formed on the second surface 1 F side of the semiconductor substrate 1, more specifically, on the first layer 2 a. ing. The conduction part 4 b is electrically connected to the main electrode part 4 a and is provided in the through hole 3. As shown in FIGS. 2 to 4, the first output extraction portion 4c is formed on the first surface 1R side, more specifically, on the third layer 2c, and is electrically connected to the conduction portion 4b. . In addition, as shown in this embodiment, the main electrode part 4a and the conduction | electrical_connection part 4b, or the conduction | electrical_connection part 4b and the 1st output extraction part 4c may be physically connected.

  The main electrode portion 4a has a function of collecting carriers generated on the second surface 1F side. The conduction part 4b has a function of guiding the carrier collected by the main electrode part 4a to the first output extraction part 4c provided on the first surface 1R side. The 1st output extraction part 4c has a function as a wiring connection part connected with the wiring member which connects the adjacent solar cell elements 10 electrically.

  As shown in FIG. 1, a plurality of conductive portions 4 b are provided corresponding to the through holes 3 formed in the semiconductor substrate 1. As shown in FIGS. 3A and 3B, the conduction portion 4 b is provided so as to be led out from the second surface 1 F side of the semiconductor substrate 1 to the first surface 1 R side. In FIG. 1, the formation position of the conduction part 4 b illustrated in a black circle shape corresponds to the formation position of the through hole 3.

  In the present embodiment, the plurality of conductive portions 4 b are arranged in a predetermined direction, similarly to the arrangement of the through holes 3. More specifically, in this solar cell element 10, as shown in FIG. 1, the plurality of conductive portions 4 b are arranged in a plurality of rows in a direction parallel to the reference side BS of the second surface 1 F of the semiconductor substrate 1. (4 rows in FIG. 1) are arranged. Here, the reference side BS is a side parallel to the arrangement direction of the solar cell elements 10 when the solar cell module 30 is formed by arranging a plurality of solar cell elements 10. In this specification, it is needless to say that “parallel” should not be strictly understood as in mathematical definition.

  In the solar cell element 10, the conduction | electrical_connection part 4b is provided so that it may arrange in a plurality of (four in FIG. 1) linear form. And the some conduction | electrical_connection part 4b in each row | line | column is arrange | positioned at the substantially equal space | interval.

  The main electrode portion 4a electrically connects the conducting portions 4b belonging to different columns on the second surface 1F of the semiconductor substrate 1. The main electrode portion 4a is linear. In the present embodiment, for example, as shown in FIG. 1, the linear main electrode portion 4a extends along a direction orthogonal to the arrangement direction of the conductive portions 4b, that is, a direction orthogonal to the reference side BS. In the following, the main electrode portion 4a may be referred to as a finger electrode. The main electrode portion 4a arranged in this way electrically connects the three conducting portions 4b located on a straight line orthogonal to the reference side BS. Thereby, when light is evenly applied to the second surface 1F, it is possible to reduce an increase in resistance loss caused by a current flowing concentrated on one conductive portion 4b. Therefore, it can reduce that the output characteristic of the solar cell element 10 falls.

  The width of the main electrode portion 4a can be set to, for example, 50 to 200 μm, and the interval between the main electrode portions 4a can be set to, for example, about 1 to 3 mm.

  In the present embodiment, the number of conductive portions 4b arranged in the direction along the reference side BS and the number of main electrode portions 4a are the same. Thereby, it is possible to reduce an increase in resistance loss of the electrode portion on the light receiving surface while securing a light receiving area on the second surface 1F.

  Further, as shown in FIG. 1, the first electrode 4 may be disposed so as to cover the through hole 3 and may have a circular pad electrode portion 4 e having a diameter larger than the diameter of the through hole 3. . With such a configuration, it is possible to connect the main electrode portion 4a and the conductive portion 4b even if the formation position of the main electrode portion 4a slightly deviates from a desired position in the manufacturing process. Thereby, the reliability of the solar cell element 10 is improved.

  Moreover, the 1st electrode 4 may have the auxiliary electrode part 4f which connects each edge part of each main electrode part 4a, as shown in FIG. The auxiliary electrode portion 4f has a function of electrically connecting adjacent linear main electrode portions 4a. Specifically, the first electrode 4 includes an auxiliary electrode portion 4f that connects one end of each main electrode portion 4a and an auxiliary electrode portion 4f that connects the other ends of each main electrode portion 4a. Yes. According to such a configuration, even if a disconnection occurs in some main electrode portions 4a, carriers can be guided to the other main electrode portions 4a through the auxiliary electrode portions 4f. Can be reduced.

  In the solar cell element 10 as described above, when the portion of the first electrode 4 formed on the second surface 1F side that is the light receiving surface is the light receiving surface electrode portion, the entire surface of the second surface 1F is formed. In comparison, the proportion of the light receiving surface electrode portion is very small. For this reason, high light receiving efficiency is realized. In addition, since the light receiving surface electrode portion is uniformly formed on the second surface 1F, carriers generated on the second surface 1F can be collected efficiently.

  Furthermore, the first electrode 4 corresponds to a plurality of conductive portions 4b (through holes 3) on the first surface 1R of the semiconductor substrate 1, as shown in FIGS. 3 (a) and 3 (b). It has the some 1st output extraction part 4c provided in the position.

The first output extraction portion 4c is formed in a long shape having a longitudinal direction in a direction different from the longitudinal direction of the main electrode portion 4a. In the present embodiment, one first output extraction portion 4c and a plurality of conduction portions 4b are connected. Here, in the present embodiment, as described above, the longitudinal direction of the main electrode portion 4a is a direction orthogonal to the arrangement direction of the conducting portions 4b, that is, a direction orthogonal to the reference side BS.

  Moreover, the 1st output extraction part 4c is formed in several rows (4 rows in FIG. 2) corresponding to the arrangement | sequence of the conduction | electrical_connection part 4b. Hereinafter, the longitudinal direction of the first output extraction portion 4c, that is, the direction along the reference side BS (direction parallel to the reference side BS) is referred to as an arrangement direction. This arrangement direction is the same as the direction in which the conductive portions 4b are arranged.

  On the other hand, the second electrode 5 has a polarity different from that of the first electrode 4 and is electrically insulated from the first electrode 4. As shown in FIGS. 2 to 4, the second electrode 5 has a second output extraction portion 5a and a current collecting portion 5b.

  As shown in FIGS. 3A, 3B, and 4, the current collector 5b is formed on the semiconductor layer 6 provided on the first surface 1R of the semiconductor substrate 1, and the first The carriers generated on the surface 1R side are collected. The current collector 5b is provided on substantially the entire first surface 1R excluding, for example, the first output extraction portion 4c and its peripheral portion and a part of the region where the second output extraction portion 5a is formed. . In other words, the current collector 5b is paired so as to sandwich the first output extraction portion 4c when the first surface 1R is viewed in plan.

  Here, “substantially the entire surface” refers to a surface of 70% or more of the entire region of the first surface 1R when the first surface 1R of the semiconductor substrate 1 is viewed in plan. By providing the current collector 5b on substantially the entire surface of the first surface 1R other than the region where the first electrode 4 is formed, the moving distance of carriers collected by the current collector 5b can be shortened. . Therefore, since the amount of carriers taken out from the second output take-out part 5a can be increased, the output characteristics of the solar cell element 10 can be improved.

  The 2nd output extraction part 5a has a role as a wiring connection part connected with the wiring member which connects the adjacent solar cell elements 10 electrically. The second output extraction unit 5a may be formed so that at least a part of the second output extraction unit 5a overlaps with the current collecting unit 5b, so that the carriers collected by the current collecting unit 5b can be output to the outside. Therefore, as shown in FIG. 3B, the second output extraction portion 5a may be arranged in a region of the first surface 1R where the current collecting portion 5b is not formed.

  Moreover, the 2nd output extraction part 5a is arranged in parallel with the 1st output extraction part 4c, and is formed in multiple rows (five rows in FIG. 2).

  In the present embodiment, a plurality of second output extraction portions 5a are formed along the arrangement direction of the second output extraction portions 5a. However, the second output extraction portions 5a are formed in a single strip having a longitudinal direction parallel to the arrangement direction. It may be formed. At this time, the lengths of the first output extraction portion 4c and the second output extraction portion 5a in the direction along the reference side BS may be different or the same.

  The current collector 5b can be formed of aluminum, for example. The 2nd output extraction part 5a can be formed with silver, for example.

  In the present embodiment, as shown in FIGS. 3A and 4, the first output extraction portion 4c is connected to the conduction region 4c1 (overlapping portion) connected to the conduction portion 4b and the conduction region 4c1. An extraction area 4c2.

The conduction region 4c1 is provided so as to cover a part of the plurality of conduction portions 4b. The conduction region 4c1 is located immediately below the plurality of conduction portions 4b (through holes 3) on the first surface 1R of the semiconductor substrate 1. The conduction region 4c1 has a long shape having a longitudinal direction in the arrangement direction of the conduction portions 4b (direction along the reference side BS). That is, the conduction region 4c1 is provided along the arrangement direction of the conduction parts 4b. In addition, the dimension in the short direction (direction perpendicular to the reference side BS) of the conduction region 4c1 may be substantially equal to the diameter of the conduction part 4b, but is slightly smaller than the diameter of the conduction part 4b in consideration of misalignment or the like. It is preferable to provide a large size. In the present embodiment, the conduction region 4c1 is connected to the plurality of conduction parts 4b.

  In addition, since the conduction | electrical_connection area | region 4c1 should just be electrically connected with the conduction | electrical_connection part 4b, it should just have a shape which covers at least one part of the conduction | electrical_connection part 4b.

  The extraction region 4c2 is adjacent to the conduction region 4c1 and connected to the conduction region portion 4c1 on the first surface 1R. In the present embodiment, the plurality of extraction regions 4c2 are provided so as to protrude from the conduction region 4c1, and are arranged away from each other along the reference side BS. And each extraction area | region 4c2 is arrange | positioned between the conduction | electrical_connection area | region 4c1 and the current collection part 5b.

  The conduction region 4c1 and the extraction region 4c2 are formed in a plurality of rows (four rows in FIG. 2) corresponding to the number of rows of the conduction portions 4b arranged.

  In the present embodiment, as described above, a part of the current collector 5b protrudes so as to be positioned between adjacent extraction regions 4c2 among the plurality of extraction regions 4c2 arranged along the reference side BS. Is provided.

  As described above, in the present embodiment, the first output extraction portion 4c has a portion protruding from the conduction region 4c1 (extraction region 4c2), but the extension portion may be provided in both directions of the conduction region 4c1. .

<Wiring member>
Next, the wiring member 15 in the solar cell module 30 according to the present embodiment will be described in detail with reference to FIGS.

  As described above, as shown in FIG. 5B and FIG. 8, the plurality of solar cell elements 10 is the wiring member 15 in which the adjacent solar cell elements 10 function as connecting members in the solar cell module 30. Are connected in series with each other. Hereinafter, as shown in FIG. 8, one of the two adjacent solar cell elements 10 electrically connected to each other by one wiring member 15 is referred to as a first solar cell element 10 </ b> A, and the other This solar cell element 10 is defined as a second solar cell element 10B.

  As shown in FIGS. 6 to 9, the wiring member 15 includes a first wiring member 15a and a second wiring member 15b. The first wiring member 15a is electrically connected to the first output extraction portion 4c (first electrode 4) of the first solar cell element 10A, and the second wiring member 15b is connected to the second solar cell element 10B. It is electrically connected to the second output extraction portion 5a (second electrode 5). In the present embodiment, the wiring member 15 includes a plurality of first wiring members 15a and second wiring members 15b.

  As shown in FIG. 6, the wiring member 15 includes four first wiring members 15a and five second wiring members 15b. The first wiring member 15a and the second wiring member 15b have a first region 16 and a plurality of second regions 17, respectively.

  Hereinafter, the first region 16 and the second region 17 will be described in detail with reference to FIG.

The first region 16 has a long shape along the longitudinal direction of the first output extraction portion 4c. The first region 16 has a first side portion 16a extending in the longitudinal direction of the first output extraction portion 4c when viewed in plan.
And a second side portion 16b facing the first side portion 16a. The first region 16 is electrically insulated from the solar cell element 10.

  Here, as described above, the longitudinal direction of the first output extraction portion 4c is a direction parallel to the reference side BS, and the short direction of the first output extraction portion 4c described later is the reference side BS. It is a direction orthogonal to.

  The second region 17 protrudes from the first side portion 16a toward the short direction of the first output extraction portion 4c, and is formed in a convex shape. The plurality of second regions 17 are arranged so as to be separated from each other along the longitudinal direction of the first output extraction portion 4c. Each of the plurality of second regions 17 has a conductive portion 18 that can be electrically connected to the first output extraction portion 4c or the second output extraction portion 5a. When viewed in plan, the first side portion 16a of the first region 16 located between adjacent second regions among the plurality of second regions 17 has a curved portion 19 at least in part.

  According to said structure, the electroconductive part 18 which can be connected with the electrode in the wiring member 15 is each arrange | positioned in the several 2nd area | region 17 provided mutually spaced apart in the longitudinal direction of the 1st output extraction part 4c. Yes. Further, the first side portion 16a of the first region 16 located between the adjacent second regions 17 has a curved portion 19 at least partially. Thereby, it occurs by thermal contraction in the longitudinal direction of the first output extraction portion 4 c in the first region 16 a of the wiring member 15, which is applied to the first side portion 16 a of the first region 16 located between the adjacent second regions 17. Stress can be relaxed. Therefore, the stress generated by the thermal contraction of the first region 16a of the wiring member 15 applied to the solar cell element is relaxed, and as a result, the warpage of the solar cell element 10 in the longitudinal direction of the first output extraction portion 4c is reduced. Can do. Furthermore, since the first side portion 16a of the first region 16 located between the adjacent second regions 17 has the curved portion 19 at least in part, cracks or the like may occur in the first side portion 16a due to daily temperature cycles. The possibility of occurring can be reduced.

  In the present embodiment, the first wiring member 15a and the second wiring member 15b both have the first region 16 and the second region 17 as described above, but the first wiring member 15a and the second wiring member 15b are exemplified. The configuration of the second wiring member 15b is not limited to this. If at least any one of the 1st wiring member 15a and the 2nd wiring member 15b has the 1st field 16 and the 2nd field 17 which were mentioned above, there will be the above-mentioned effect.

  As a material of the wiring member 15, what is necessary is just to have electroconductivity, For example, metal members, such as copper, aluminum, and silver, can be used. In addition, a plating layer having corrosion resistance such as tin or zinc chrome may be formed on at least the surface of the metal member. Moreover, the thickness of the wiring member 15 can be about 10-50 micrometers, for example. Thereby, the thermal contraction in the wiring member 15 can be reduced and the curvature of the solar cell element 10 can be reduced.

  As shown in FIGS. 9A and 9B, the first region 16 is electrically connected to the solar cell element 10 by forming the insulating layer 20 between the wiring member 15 and the solar cell element 10. Can be insulated. In particular, by providing the insulating layer 20 in the first region 16 of the first wiring member 15a, the first wiring member 15a and the second electrode 5 of the first solar cell element 10A are electrically insulated from each other. The width of the wiring member 15a can be increased.

As the insulating layer 20, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or polyvinyl fluoride resin (PVF) can be used. For example, the insulating layer 20 is made of PET having carbodilite or the like. The reliability of the solar cell module can be improved by using a hydrolyzable resin. The thickness of the insulating layer 20 may be a thickness that can maintain insulation, and may be, for example, about 30 to 150 μm. Further, such an insulating layer 20 may be bonded to the wiring member 15 in advance using a thermosetting adhesive or the like. At this time, an epoxy-based or urethane-based adhesive can be used as the thermosetting adhesive.

  Such an insulating layer 20 may be bonded to the wiring member 15 or may be bonded to the solar cell element 10 as described later.

  As shown in FIGS. 9A and 9B, the conductive portion 18 is formed by not providing the wiring member 15 with the insulating layer 20. That is, a portion of the second region 17 where the insulating layer 20 is not provided becomes the conductive portion 18, and this portion can be electrically connected to the first electrode 4 or the second electrode 5. As a method for connecting the conductive portion 18 and the corresponding electrode, for example, a solder paste or a conductive adhesive is used to connect the conductive portion to the first output extraction portion 4c or the second output extraction portion 5a of the solar cell element 10. The method of physically connecting 18 is mentioned.

  Further, in the present embodiment, as shown in FIG. 7, the first side portion 16 a of the first region 16 located between the adjacent second regions 17 among the plurality of second regions 17 when viewed in plan is: Two connection portions 16 c are respectively connected to the second region 17. And the curve part 19 may each arrange | position the curve part 19 to these two connection parts 16c. As a result, the thermal stress is relaxed in the connection portion 16c that is easily subjected to thermal stress, and the possibility that a crack or the like is generated in the connection portion 16c due to the daily temperature cycle can be suitably reduced.

  Further, the two curved portions 19 may be connected by the straight portion 21. By providing such a straight portion 21, it is possible to easily perform alignment when connecting the wiring member 15 to the solar cell element 10. Moreover, this linear part 21 may be substantially parallel to the longitudinal direction of the 1st output extraction part 4a. In this case, the possibility of contact with the second region 17 of the other wiring member 15 adjacent in the first side portion 16a can be reduced, and the occurrence of leakage can be reduced.

  Further, as shown in FIGS. 7 and 9, the conductive portion 18 where the insulating layer 20 is not provided may be provided over the entire corresponding second region 17. In the present embodiment, as shown in FIG. 7, the conductive portion 18 has a quadrangular shape when seen in a plan view, and three sides of the quadrilateral reach the outer edge of the second region 17, and the remaining 1 One side is in contact with the first region 16. With such a configuration, since there is no insulating layer 20 in the second region 17, the second region 17 can be easily bent toward the solar cell element 10 side, and the connection region with the first output extraction portion 4 c or the second output extraction portion 5 a. Becomes larger. As a result, the wiring work in the manufacturing process is facilitated, and the possibility that the wiring member 15 is detached from the electrode due to the daily temperature cycle can be reduced.

  Moreover, as shown in FIG. 6, the wiring member 15 has a plurality of first wiring members 15a respectively corresponding to the first output extraction portions 4c formed in a plurality of rows. Specifically, as described above, in the present embodiment, the wiring member 15 has four first wiring members 15a. The wiring member 15 further includes a first current collecting member 15c that electrically connects one ends of the plurality of first wiring members 15a and extends in the short direction of the first output extraction portion 4c. The plurality of first wiring members 15 a each have a first region 16 and a second region 17. In such a case, as shown in FIG. 6, the dimension W1 in the short direction of the first wiring member 15a may be larger as the first current collecting member 15c is approached. Since the amount of current flowing through the first wiring member 15a increases as it approaches the first current collecting member 15c, the resistance in the wiring member 15 is increased by increasing the size of the first wiring member 15a in the short direction as described above. Loss can be reduced.

Further, as shown in FIG. 6, the wiring member 15 has a plurality of second wiring members 15b respectively corresponding to the second output extraction portions 5a formed in a plurality of rows, like the plurality of first wiring members 15a. ing. Specifically, as described above, in the present embodiment, the wiring member 15 has five second wiring members 15b. The wiring member 15 further includes a second current collecting member 15d that electrically connects one ends of the plurality of second wiring members 15b and extends in the short direction of the first output extraction portion 4c. The plurality of second wiring members 15 b each have a first region 16 and a second region 17. In such a case, the dimension W2 in the short direction of the second wiring member 15b may be increased as the second current collecting member 15d is approached. With such a configuration, the same effect as that obtained by the first current collecting member 15c can be obtained.

  As shown in FIG. 6, in the present embodiment, the second current collecting member 15d is integrated with the first current collecting member 15c. In other words, the second current collecting member 15d is the first current collecting member 15c itself.

  In the first wiring member 15a and the second wiring member 15b, for example, the dimensions W12 and W22 at the connection portion with the first current collecting member 15c (second current collecting member 15d) are the first wiring member 15a and the second wiring member 15b. It can be made about 2 to 5 times larger than the dimensions W11 and W21 at the outer end of the wiring member 15b.

  Moreover, in this embodiment, in either the 1st wiring member 15a and the 2nd wiring member 15b, the dimension W of the transversal direction is made to go to the 1st current collection member 15c (2nd current collection member 15d). It is a continuously enlarged form. More specifically, when described using the first wiring member 15a, as shown in FIG. 6, the dimension W11 at the outer end of the first wiring member 15a is the first current collecting member of the first wiring member 15a. It is smaller than the dimension W12 in the connection part with 15c. A similar magnitude relationship holds for the dimension W2 of the second wiring member 15b. As described above, according to the embodiment in which the lateral dimension W of the first wiring member 15a and the second wiring member 15b is continuously increased, corners are not formed on both side portions, and therefore, depending on the daily temperature cycle. The possibility that cracks or the like occur in the first wiring member 15a or the second wiring member 15b can be reduced.

  In addition, the dimension W of the short direction of the 1st wiring member 15a and the 2nd wiring member 15b is not limited to the above-mentioned form. For example, the dimension W in the short direction may be increased stepwise toward the first current collecting member 15c (second current collecting member 15d).

  Further, as shown in FIGS. 1 and 2, in the present embodiment, the area ratio of the first electrode 4 on the first surface 1R is larger than the area ratio of the second electrode 5 on the first surface 1R. small. In such a case, as shown in FIG. 6, in the short direction of the first output extraction portion 4c, the dimension W1 (W11) of the first wiring member 15a is larger than the dimension W2 (W21) of the second wiring member 15b. May be larger. With such a configuration, even if the area occupied by the first output extraction portion 4c (first electrode 4) on the first surface 1R is small, the dimension W1 of the first wiring member 15a connected to the first electrode 4 is small. Therefore, the resistance loss in the solar cell module 30 can be reduced.

  Here, the comparison of the dimension W1 of the first wiring member 15a and the dimension W2 of the second wiring member 15b is performed, for example, as shown in FIG. 6, for example, the dimension W11 and the dimension W21 at the outer end, respectively. Can be used.

  The dimension W1 of the first wiring member 15a can be increased by about 1.1 to 2.5 times the dimension W2 of the second wiring member 15b, for example.

  In addition, when the dimension W in the short direction of the first wiring member 15a and the second wiring member 15b is increased as it approaches the first current collecting member 15c (second current collecting member 15d), the second wiring member 15b second The ratio R1 of the dimension W12 at the connection portion of the first wiring member 15a to the first current collection member 15c with respect to the dimension W22 at the connection portion with the current collecting member 15d is relative to the dimension W21 at the outer end portion of the second wiring member 15b. It may be smaller than the ratio R2 of the dimension W11 at the outer end of the first wiring member 15a.

  In the region close to the first current collecting member 15c and the second current collecting member 15d (in the vicinity of the connecting portion), the amount of current flowing through the first wiring member 15a and the second wiring member 15b increases, so that the ratio is as described above. By making R1 smaller than the ratio R2, resistance loss in the wiring member 15 can be reduced.

  As shown in FIGS. 6 and 7, each of the plurality of first wiring members 15a has a first side portion 16a and a second side portion 16b facing the first side portion 16a. The first side portion 16a is parallel to the longitudinal direction of the first output extraction portion 4c when viewed in plan, and the second side portion 16b is inclined with respect to the first side portion 16a when viewed in plan. That is, you may incline with respect to the longitudinal direction of the 1st output extraction part 4c.

  In such a configuration, since the first side portion 16a is parallel to the longitudinal direction of the first output extraction portion 4c, it is easy to perform alignment when connecting the wiring member 15 to the solar cell element 10, and Since the second side portion 16b is inclined with respect to the first side portion 16a, the dimension W1 in the short direction of the first wiring member 15a can be continuously increased.

  Similarly, the plurality of second wiring members 15b may each include a first side portion 16a and a second side portion 16b. With such a configuration, it is possible to achieve the same effect as that of the first wiring member 15a.

  As shown in FIG. 6, the inclination angles θ1 of the second side portions 16b of the first regions 16 of the plurality of first wiring members 15a are substantially the same. Further, the inclination angle θ2 of the second side portion 16b of the first region 16 of the plurality of second wiring members 15b is also the inclination of the second side portion 16b of the first region 16 of the third outer wiring member 15g as will be described later. Except for the angle, they are substantially identical. In the present embodiment, the inclination angle θ1 of the first wiring member 15a and the inclination angle θ2 of the second wiring member 15b are substantially the same. With such a configuration, the possibility that the second side portion 16b of one wiring member 15 contacts the second side portion 16b of the other adjacent wiring member 15 can be reduced, and the occurrence of leakage can be reduced. Can do.

  Further, as shown in FIGS. 6 and 8, the plurality of first wiring members 15a have first outer wiring members 15e located on the outermost side. And this 1st outer wiring member 15e may have the level | step-difference part 22 in the 2nd side part 16b.

  With such a configuration, while providing an area where the second wiring member 15b of the other adjacent wiring member 15 can be disposed on the second side portion 16b side of the first outer wiring member 15e in the one wiring member 15, The dimension W1 in the short side direction in the region near the first current collecting member 15c of the one outer wiring member 15e can be increased. Thereby, the resistance loss in the wiring member 15 can be reduced.

  At this time, as shown in FIG. 6, for example, the dimension W3 in the short direction of the wide region of the stepped portion 22 is about 1.2 to 1.8 times larger than the dimension W4 in the short direction of the narrow region. Can be formed.

  Further, as shown in FIG. 6, the plurality of second wiring members 15 b include a second outer wiring member 15 f and a third outer wiring member 15 g located at both ends on the outer peripheral side of the solar cell element 1. Yes. The dimension L15f in the longitudinal direction of one second outer wiring member 15f of the two outer wiring members 15f and 15g may be smaller than the dimension L15b in the longitudinal direction of the other second wiring member 15b. . With such a configuration, it is possible to further increase the lateral dimension of the first outer wiring member 15e in the region near the first current collecting member 15c, and to reduce resistance loss in the wiring member 15.

  The dimension L15f in the longitudinal direction of the second outer wiring member 15f can be made about 0.5 to 0.8 times smaller than the dimension L15b in the longitudinal direction of the other second wiring members 15b.

  Furthermore, as shown in FIG. 6, the lateral dimension W15g1 at the outer end of the other third outer wiring member 15g located at both ends on the outer peripheral side of the solar cell element 1 is the other second wiring. It may be larger than the dimension W21 in the lateral direction at the outer end of the member 15b. On the other hand, the dimension W15g2 in the short direction at the connection part of the other third outer wiring member 15g may be smaller than the dimension W22 in the short direction at the connection part of the other second wiring member 15b. By having such a third outer wiring member 15g, resistance loss in the wiring member 15 can be reduced.

  Moreover, as shown in FIG. 6, the 1st current collection member 15c is along the arrangement direction of the some 2nd area | region 17 arranged in the at least 1 1st wiring member 15a among the some 1st wiring members 15a. You may have the auxiliary | assistant conductive part 18a arrange | positioned. The auxiliary conductive portion 18a has conductivity, and can be configured similarly to the conductive portion 18, for example. By having such an auxiliary conductive portion 18a, the auxiliary conductive portion 18a is connected to the first output extraction portion 4c while increasing the longitudinal dimension of the first output extraction portion 4c of the first current collecting member 15c. Can do. As a result, the resistance loss in the wiring member 15 can be further reduced.

  At this time, the auxiliary conductive portion 18a may be located outside the first current collecting member 15c. That is, as shown in FIG. 6, you may be located so that a part of outer edge of the 1st current collection member 15c may be included.

  Similarly, the second current collecting member 15d is arranged along the arrangement direction of the plurality of second regions 17 arranged in at least one second wiring member 15b among the plurality of second wiring members 15b. You may have the electroconductive part 18a. With such a configuration, it is possible to achieve the same effect as that of the first current collecting member 15c described above.

  As shown in FIGS. 1 and 9, the solar cell element 10 includes a plurality of solar cells 10 extending on the second surface 1F along the short direction (direction perpendicular to the reference side BS) of the first output extraction 4c. It further has a finger electrode 4a. And when planarly seen from the 1st surface 1R side, the electroconductive part 18 may be located on the several finger electrode 4a. With such a configuration, when the conductive portion 18 is pressed and connected to the first output extraction portion 4c or the second output extraction portion 5a, the local stress applied to the solar cell element 10 can be reduced. As a result, the occurrence of cracks and cracks in the solar cell element 1 can be reduced.

  Further, as shown in FIG. 7, the dimension D2 of the second region 17 in the short direction of the first output extraction portion 4c is larger than the dimension D1 of the first region 16 in the short direction of the first output extraction portion 4c. May be small.

With such a configuration, it is possible to reduce the warp of the solar cell element 10 in the short direction of the first output extraction portion 4 c while reducing the resistance loss in the wiring member 15.

  Further, the dimension D2 of the second region 17 in the short direction of the first output extraction portion 4c is short of the first output extraction portion 4c of the first region 16 at the outer end of the first wiring member 15a. It may be smaller than the dimension in the direction.

  In addition, in this embodiment, although the 1st current collection member 15c and the 2nd current collection member 15d illustrated the form integrally formed, the form of both current collection members is not restricted to this. For example, each of the first current collecting member 15c and the second current collecting member 15d extending in the short direction of the first output extraction portion 4c may be connected by a connection portion extending in the longitudinal direction of the first output extraction portion 4c. Good.

  Moreover, as shown in FIG. 6, the hole part 25 may be provided in the 1st current collection member 15c or the 2nd current collection member 15d. Such a hole 25 can be used as an alignment mark for alignment. In the present embodiment, two holes 25 are provided at both ends of the first current collecting member 15c (second current collecting member 15d) in the short direction of the first output extraction portion 4c.

  Further, as shown in FIG. 6, in the third outer wiring member 15g of the second wiring members 15b among the plurality of second wiring members 15b, the second side portion 16g in the first region 16 extends in the longitudinal direction of the first output extraction portion 4c. Parallel. With such a configuration, alignment when connecting the wiring member 15 to the solar cell element 10 can be easily performed.

  Furthermore, in this embodiment, the insulating layer 20 has a shape corresponding to the shaded area in FIG. That is, the insulating layer 20 has a shape obtained by removing the conductive portion 18 from the shape of the wiring member 15. With such a configuration, the insulating layer 20 can be easily integrated with the wiring member 15, and by using the integrated structure, the connection process for electrically connecting the wiring member 15 and the electrode can be facilitated.

  In addition, in this embodiment, although the insulating layer 20 illustrated the form which has the shape remove | excluding the part of the electroconductive part 18 from the shape of the wiring member 15 in this way, the shape of the insulating layer 20 is not restricted to this. Absent. The insulating layer 20 may have any shape as long as the first region 16 of the wiring member 15 is electrically insulated from the solar cell element 10. For example, the insulating layer 20 may be formed outside the outer edge of the wiring member 15 except the conductive portion 18. The shape may extend.

  Further, as described above, the configuration in which the first region 16 is electrically insulated from the solar cell element 10 is exemplified by the configuration in which the insulating layer 20 is interposed as shown in FIG. 9, but is not limited to this configuration. . As a configuration in which the first region 16 is electrically insulated from the solar cell element 10, the first region 16 and the solar cell element 10 are not interposed between the first region 16 and the solar cell element 10. It may be a configuration arranged without touching. Further, the back side filler 13 may be provided between the first region 16 of the wiring member 15 and the solar cell element 10.

<Second Embodiment>
Next, the solar cell module 40 which concerns on the 2nd Embodiment of this invention is demonstrated in detail using FIG. 10 and FIG.

  The solar cell module 40 according to the present embodiment is different from the solar cell module 30 according to the first embodiment in the shape of the wiring member 15. Here, about the structure similar to the solar cell module 30 which concerns on 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

More specifically, as shown in FIGS. 10 and 11, when viewed in plan, the curved portion 19 is
It extends over the entire length of the first side portion 16 a of the first region 16 located between the adjacent second regions 17 among the plurality of second regions 17. That is, as shown in FIG. 11, the top surfaces of the convex second regions 17 are connected by a single curved portion 19.

  With such a configuration, the thermal stress applied to the first side portion 16a can be further relaxed, and the possibility that cracks and the like are generated in the first side portion 16a due to the daily temperature cycle can be reduced.

  In the first embodiment, the conductive portion 18 has a quadrangular shape when viewed in plan, whereas in the present embodiment, the conductive portion 18 has a flat surface as shown in FIG. When viewed, it is circular. In the first embodiment, only one rectangular side is in contact with the insulating region. In the present embodiment, the entire circumference of the circular conductive portion 18 is surrounded by the insulating region. It is.

  Furthermore, in the present embodiment, unlike the first embodiment, among the plurality of second wiring members 15b, in the third outer wiring member 15g, the second side portion 16b of the first region 16 is the first It inclines with respect to the longitudinal direction of the output extraction part 4c.

<Third Embodiment>
Next, the solar cell module 50 which concerns on the 3rd Embodiment of this invention is demonstrated in detail using FIG.

  The solar cell module 50 according to the present embodiment is different from the solar cell module 30 according to the first embodiment in that it further includes a base sheet 23. Here, about the structure similar to the solar cell module 30 which concerns on 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  More specifically, as shown in FIG. 12, in this embodiment, the wiring member 15 is disposed in a state of being bonded to the base sheet 23.

  As the material of the base sheet 23, for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or polyvinyl fluoride resin (PVF) can be used. Also, use a resin with excellent heat resistance such as polyimide (PI), polyamideimide (PAI), polyether ether ketone (PEEK), tetrafluoroethylene (PTFE), polyethersulfone (PES), etc. Also good.

  The thickness of the base sheet 23 can be, for example, about 50 to 200 μm.

  The base sheet 23 may have a single layer structure or a multilayer structure.

<Fourth Embodiment>
Next, a solar cell module 60 according to a fourth embodiment of the present invention will be described in detail with reference to FIG.

  The solar cell module 60 according to the present embodiment is different from the solar cell module 30 according to the first embodiment in that it further includes a filling sheet 24. Here, about the structure similar to the solar cell module 30 which concerns on 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

More specifically, as shown in FIG. 13, in the present embodiment, a filling sheet 24 is interposed between the wiring member 15 and the solar cell element 10. By providing such a filling sheet 24, the gap between the wiring member 15 and the solar cell element 10 can be filled with the filling sheet 24 and the wiring member 15 and the solar cell element 10 can be bonded.

  As a material for such a filling sheet 24, polyethylene or olefin resin may be used. Moreover, the same material as the front side filler 12 or the back side filler 13 may be used.

  As thickness of the filling sheet 24, it can be set as the thickness of about 50-500 micrometers, for example.

≪Solar cell module manufacturing method≫
Next, the manufacturing method of the solar cell module which concerns on one Embodiment of this invention is demonstrated. Specifically, the manufacturing method of the solar cell module 30 according to the first embodiment described above will be described.

  First, as described above, the solar cell element 10 in the first solar cell module 30 is prepared.

<Method for producing solar cell element>
Hereinafter, the manufacturing method of the solar cell element 10 will be described in detail.

<Preparation process of semiconductor substrate>
First, a semiconductor substrate 1 exhibiting a p-type conductivity is prepared.

  If a single crystal silicon substrate is used as the semiconductor substrate 1, the semiconductor substrate 1 can be obtained by cutting a single crystal silicon ingot to a predetermined thickness. As the single crystal silicon ingot, one produced by a known manufacturing method such as FZ or CZ method can be used.

  If a polycrystalline silicon substrate is used as the semiconductor substrate 1, the semiconductor substrate 1 can be obtained by cutting a polycrystalline silicon ingot to a predetermined thickness. As the polycrystalline silicon ingot, those produced by a known production method such as a casting method or an in-mold solidification method can be used.

In the following, a crystalline silicon substrate having a p-type conductivity type doped with about 1 × 10 ¹⁵ to 1 × 10 ¹⁷ atoms / cm ³ of B (boron) or Ga (gallium) as a dopant element is used as the semiconductor substrate 1. A case will be described as an example.

  In addition, it is good to remove the mechanical damage layer and contamination layer of the surface layer part of the semiconductor substrate 1 accompanying cutting (slicing). For example, the surface layer portions on the front surface side and the back surface side of the cut-out semiconductor substrate 1 may be etched by about 10 to 20 μm with NaOH, KOH, or a mixed solution of hydrofluoric acid and nitric acid, and then washed with pure water or the like. Thereby, an organic component and a metal component are removed.

<Through-hole formation process>
Next, the through hole 3 is formed between the second surface 1F and the first surface 1R of the semiconductor substrate 1.

  The through hole 3 can be formed using a drill, a water jet, a laser processing apparatus, or the like. The through hole 3 is formed by processing from the first surface 1R side of the semiconductor substrate 1 toward the second surface 1F side so that the second surface 1F serving as the light receiving surface is not damaged. Like that. However, if there is little damage to the semiconductor substrate 1 due to the processing, the processing may be performed from the second surface 1F side toward the first surface 1R side.

<Texture structure forming process>
Next, a texture structure 1 a having fine protrusions (convex portions) 1 b is formed on the light receiving surface side of the semiconductor substrate 1 in which the through holes 3 are formed. The texture structure 1a is for effectively reducing the light reflectance as described above.

  As a method for forming the texture structure 1a, a wet etching method using an alkaline aqueous solution or a hydrofluoric nitric acid solution such as NaOH or KOH, or a dry etching method using an etching gas having a property of etching silicon that is a material of the semiconductor substrate 1 is used. Can do.

<Reverse conductivity type layer formation process>
Next, the reverse conductivity type layer 2 is formed. That is, the first layer 2 a is formed on the second surface 1 F of the semiconductor substrate 1, the second layer 2 b is formed on the first surface 1 R, and the third layer 2 c is formed on the inner surface of the through hole 3.

  When a crystalline silicon substrate exhibiting p-type conductivity is used as the semiconductor substrate 1, the reverse conductivity type layer 2 exhibits n-type. P (phosphorus) can be used as an n-type doping element for forming the reverse conductivity type layer 2.

  The reverse conductivity type layer 2 can be formed using, for example, the following method.

As a first method, coating thermal diffusion is performed in which P ₂ O ₅ in a paste state is applied to the first surface 1R, the second surface 1F and the through hole 3 in the semiconductor substrate 1 and thermally diffused. There is a law.

As a second method, there is a gas phase thermal diffusion method in which POCl ₃ (phosphorus oxychloride) in a gas state is diffused as a diffusion source to a formation target site. If this vapor phase diffusion method is used, the reverse conductivity type layer 2 can be formed in the same process on the formation target portion on both main surfaces of the semiconductor substrate 1 and the inner surface of the through hole 3.

  In addition, after forming the reverse conductivity type layer 2, when the semiconductor layer 6 is formed with an aluminum paste as will be described later, in the formation process of the reverse conductivity type layer 2, a sufficient concentration of aluminum as a p-type dopant element is sufficient. The semiconductor layer 6 can be formed by diffusing to a sufficient depth. Therefore, in this case, the existence of the shallow diffusion region that has already been formed can be ignored. That is, in this case, it is not necessary to remove the reverse conductivity type layer 2 present at the location where the semiconductor layer 6 is to be formed.

  Further, pn separation may be performed by a known method such as laser irradiation around the region where the first electrode 4 is formed or the peripheral portion of the first surface 1R of the semiconductor substrate 1.

<Formation process of antireflection layer>
Next, the antireflection layer 7 may be formed on the first layer 2a.

As a method for forming the antireflection layer 7, a PECVD method, a vapor deposition method, a sputtering method, or the like can be used. For example, when the antireflection layer 7 made of a SiN _x film is formed by PECVD, the reaction chamber is set to about 500 ° C. and silane (Si ₃ H ₄ ) diluted with nitrogen (N ₂ ) and ammonia (NH ₃ ). The anti-reflective layer 7 is formed by depositing the gas mixture with) into plasma by glow discharge decomposition. The antireflection layer 7 may also be formed on the third layer 2c.

<Semiconductor layer formation process>
Next, the semiconductor layer 6 is formed on the first surface 1 </ b> R of the semiconductor substrate 1.

When boron is used as a dopant element, it can be formed at a temperature of about 800 to 1100 ° C. by a thermal diffusion method using BBr ₃ (boron tribromide) as a diffusion source. In this case, prior to the formation of the semiconductor layer 6, a diffusion prevention layer made of an oxide film or the like on the region other than the formation target portion of the semiconductor layer 6, for example, on the reverse conductivity type layer 2 or the like that has already been formed. The semiconductor layer 6 may be removed after the semiconductor layer 6 is formed.

  When aluminum is used as the dopant element, an aluminum paste made of aluminum powder and an organic vehicle or the like is applied to the first surface 1R of the semiconductor substrate 1 by a printing method, followed by heat treatment (baking at a temperature of about 700 to 850 ° C. The semiconductor layer 6 can be formed by diffusing aluminum toward the semiconductor substrate 1. In this case, the semiconductor layer 6 that is a desired diffusion region can be formed only on the first surface 1R that is the printing surface of the aluminum paste. In addition, in this case, the layer made of aluminum formed on the first surface 1R after firing can be used as it is as the current collector 5b without being removed.

<Method for forming electrode>
Next, the light-receiving surface electrode part (main electrode part 4a, pad electrode part 4e, auxiliary electrode part 4f) of the first electrode 4 and the conduction part 4b are formed.

  The light-receiving surface electrode part and the conduction part 4b are formed using, for example, a coating method. Specifically, a coating film is formed on the second surface 1F of the semiconductor substrate 1 by applying a conductive paste in the formation pattern of the light receiving surface electrode portion shown in FIG. And the light-receiving surface electrode part and the conduction | electrical_connection part 4b can be formed by baking the formed coating film for about several dozen seconds-several tens of minutes at the maximum temperature of 500-850 degreeC.

  As the conductive paste used here, for example, a material obtained by adding 10 to 30 parts by mass of an organic vehicle and 0.1 to 10 parts by mass of glass frit to 100 parts by mass of metal powder made of silver or the like can be used. .

  In this case, the conductive portion 4b can be formed in the same step as the step of forming the light receiving surface electrode portion by filling the through hole 3 with the conductive paste when applying the conductive paste. However, the through-hole 3 may not be sufficiently filled with the conductive paste when the conductive paste is applied to the second surface 1F. This is because, as will be described later, also when forming the first output extraction portion 4c, the conductive paste is applied from the first surface 1R side, and at this time, the through-hole 3 is again filled with the conductive paste. This is because it is fired after a while.

  In addition, after apply | coating an electrically conductive paste, you may evaporate the solvent in a coating film at predetermined temperature and dry this coating film prior to baking. Alternatively, the light-receiving surface electrode part (including the main electrode part 4a) and the conductive part 4b may be separately applied and baked. Specifically, the conductive paste is filled and dried only in the through-holes 3 in advance, and then the conductive pattern is used in the pattern of the light-receiving surface electrode portion (including the main electrode portion 4a) shown in FIG. The paste may be applied and fired.

  As described above, when the antireflection layer 7 is formed prior to the formation of the light receiving surface electrode portion (including the main electrode portion 4a), the light receiving surface electrode portion is formed in the patterned region, or The light receiving surface electrode portion may be formed by a fire-through method.

On the other hand, the antireflection layer 7 may be formed after the light receiving surface electrode portion is formed. In this case, it is not necessary to pattern the antireflection layer 7 and it is not necessary to use the fire-through method. For this reason, the conditions for forming the light-receiving surface electrode portion are moderate. If it is such a process, a light-receiving surface electrode part can be formed, without baking at the high temperature of about 800 degreeC, for example. As a result, damage to the semiconductor substrate 1 due to heat can be reduced.

  Subsequently, the current collector 5 b is formed on the first surface 1 </ b> R of the semiconductor substrate 1.

  The current collector 5b can also be formed using a coating method. Specifically, a coating film is formed on the first surface 1R of the semiconductor substrate 1 by applying a conductive paste in the formation pattern of the current collector 5b shown in FIG. The current collector 5b can be formed by baking the formed coating film at a maximum temperature of 500 to 850 ° C. for several tens of seconds to several tens of minutes.

  As the conductive paste used here, for example, a paste obtained by adding 10 to 30 parts by mass of an organic vehicle and 0.1 to 10 parts by mass of glass frit to 100 parts by mass of metal powder made of aluminum or silver is used. be able to. In addition, when using an aluminum paste for an electrically conductive paste, the semiconductor layer 6 and the current collection part 5b can be formed in the same process.

  Further, the first output extraction portion 4 c and the second output extraction portion 5 a are formed on the first surface 1 R of the semiconductor substrate 1.

  The 1st output extraction part 4c and the 2nd output extraction part 5a can be formed in one process using a coating method, for example. Specifically, a conductive film is applied to the first surface 1R of the semiconductor substrate 1 with an electrode pattern as shown in FIGS. 2 and 4 to form a coating film. And the 1st output extraction part 4c and the 2nd output extraction part 5a can be formed by baking the formed coating film at the maximum temperature of 500-850 degreeC for about several dozen seconds-tens of minutes.

  As the conductive paste used here, for example, a material obtained by adding 10 to 30 parts by mass of an organic vehicle and 0.1 to 10 parts by mass of glass frit to 100 parts by mass of metal powder made of silver or the like is used. it can.

  In addition, each output extraction part may be formed in a separate process, and may be formed using the conductive paste of a different composition.

  Moreover, you may form the semiconductor layer 6 and the current collection part 5b in one process using an aluminum paste. In this case, a part of the second output extraction portion 5a is formed on the second layer 2b, but there is no particular problem.

  The solar cell element 10 according to the present embodiment can be manufactured by the procedure as described above.

<Manufacturing method of wiring member>
Next, a method for manufacturing the wiring member 15 that electrically connects the solar cell elements 10 formed as described above will be described.

  First, the wiring member 15 is formed by punching into a predetermined shape from one metal member made of copper or the like.

More specifically, as shown in FIG. 14, first, in forming the wiring member 15, for example, a plurality of openings 26 having curved portions 19 are arranged, and the arrangement of the openings 26 has a plurality of rows. A metal member is punched into Then, the 2nd area | region 17 of the 1st wiring member 15a or the 2nd wiring member 15b can be formed by cut | disconnecting a metal member so that the opening part 26 of each row | line | column may be straddled. The cutting at this time is to cut the second region 17 of the first wiring member 15a and the second region 17 of the second wiring member 15b in the wiring members 15 different from each other, as indicated by a dotted line in FIG. That is, the cutting at this time is performed as shown by a dotted line in FIG. 14. The second region 17 of the first wiring member 15 a in one wiring member 15 and the second region of the second wiring member 15 b in the other wiring member 15. 17 is cut off. Thereafter, the wiring member 15 is formed by cutting the metal member into a predetermined shape.

  By such a method, the waste of the metal member material can be reduced, and a plurality of wiring members 15 having a complicated shape can be easily formed from a single metal member material.

  As described above, the solar cell element 10 and the wiring member 15 that are the main members of the solar cell module 30 can be prepared. About other members, such as the translucent member 11, it can prepare suitably with a well-known manufacturing method.

  Hereinafter, the process of manufacturing the solar cell module 30 using these components will be described in detail.

  First, as shown in FIG. 8, the plurality of wiring members 15 described above are arranged so as to be shifted from each other and arranged on the first surface 1 </ b> R side of the solar cell element 10, so that the wiring members 15 do not contact each other. be able to. Then, the first region 16 is electrically insulated from the solar cell element 10 by disposing the insulating layer 20 having the shape of the hatched area in FIG. 6 between the solar cell element 10 and the wiring member 15.

  More specifically, first, a solder paste or a conductive adhesive is applied to the first output extraction portion 4c and the second output extraction portion 5a, and the wiring member 15 is placed thereon. In this state, the conductive portion 18 of the wiring member 15 is locally heated, thereby electrically connecting the wiring member 15 to the first output extraction portion 4c and the second output extraction portion 5a. As a heating method, a known method such as a soldering iron, hot air, laser, or pulse heat can be used.

  In the present embodiment, as described above, the wiring member 15 and the solar cell element 10 are connected by locally heating only the conductive portions 18 respectively provided in the second regions 17 arranged apart from each other. The Thereby, since the thermal contraction of the wiring member 15 in the connection process by heating can be reduced, the warp of the solar cell element 10 can be reduced.

  When the solar cell module 60 according to the above-described fourth embodiment shown in FIG. 13 is manufactured, the filling sheet 24 is interposed between the solar cell element 10 and the wiring member 15 so that the above-described electrical operation is performed. Just connect.

  Here, as the conductive adhesive, for example, a conductive filler such as silver, nickel, or carbon containing an epoxy resin, a silicon resin, a polyimide resin, a polyurethane resin, or the like as a binder can be used.

  In the manufacturing method of the wiring member 15 described above, an insulating member having substantially the same shape as the metal member is bonded to the metal member used for the wiring member 15 by using a thermosetting adhesive. The wiring member 15 may be formed by removing a portion of the insulating member to be punched out and then punching into a predetermined shape. In the wiring member 15 obtained by such a method, an insulating layer 20 for electrically insulating the first region 16 from the solar cell element 10 is integrated at a desired location. In addition, when the wiring member 15 is formed by bonding such an insulating member and a metal member in advance and then punching into a predetermined shape, the insulating member is a portion in which the conductive portion 18 is cut out in advance. It may be used.

  As described above, by using the wiring member 15 to which the insulating layer 20 is bonded, a connection process between the wiring member 15 and the solar cell element 10 described later is facilitated.

  As described above, the adjacent solar cell elements 10 are electrically connected by the wiring member 15.

  Finally, on the translucent member 11, a front side filler 12, a plurality of solar cell elements 10 connected to each other by a wiring member 15, a back side filler 13, and a back surface protective material 14 are sequentially laminated. A module substrate is produced. The module base is integrated by degassing, heating and pressing in a laminator to produce a solar cell module 30.

  And as shown in FIG.5 (b), the frames 26, such as aluminum, are inserted in the outer periphery of the solar cell module 30 mentioned above as needed. Moreover, as shown to Fig.5 (a), among the some solar cell elements 10 connected in series, the terminal of the electrode of the 1st solar cell element 10 and the last solar cell element 10, and the terminal which takes out an output outside The box 27 is connected to the output extraction wiring 28.

  The solar cell module 30 according to this embodiment can be obtained by the procedure described above. In the solar cell module 30 obtained in this manner, the wiring member 15 is connected to the electrode of the solar cell element 10 by the conductive portions 18 provided in the second regions 17 arranged apart from each other as described above. Is done. Thereby, the thermal contraction of the wiring member 15 in the connection process to the solar cell element 10 of the wiring member 15 using a heating means can be reduced. As a result, the warpage in the arrangement direction of the solar cell elements 10 can be reduced, and the resistance loss due to the displacement of the wiring member 15 can be reduced, so that the power generation efficiency can be improved with a simple configuration.

  As mentioned above, although the specific form was illustrated and demonstrated about embodiment of this invention, it cannot be overemphasized that this invention is not limited to the above embodiment. Needless to say, the present invention includes various combinations of the above-described embodiments.

For example, the solar cell element 10 may have a passivation film on the first surface 1R side. The passivation film has a role of reducing carrier recombination on the first surface 1 </ b> R of the semiconductor substrate 1. As the passivation film, Si nitride films such as silicon nitride (Si ₃ N ₄ ), amorphous Si nitride film (a-SiNx), silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), titanium oxide (TiO ₂ ) ₂ ) etc. can be used. The thickness of the passivation film may be about 100 to 2000 mm.

1: Semiconductor substrate 2: Reverse conductivity type layer 3: Through hole 4: 1st electrode 5: 2nd electrode 6: Semiconductor layer 7: Antireflection layer 10: Solar cell element 15: Wiring member 15a: 1st wiring member 15b: second wiring member 15c: first current collecting member 15d: second current collecting member 15e: first outer wiring member 15f: second outer wiring member 15g: third outer wiring member 16: first region 16a : First side portion 16b: second side portion 17: second region 18: conductive portion 19: curved portion 20: insulating layer 21: linear portion 22: stepped portion 25: hole portion 26: openings 30, 40, 50, 60: Solar cell module

Claims (13)

A semiconductor substrate having a first surface and a second surface on the back side of the first surface, and an elongated first electrode and a second electrode respectively arranged on the first surface A plurality of solar cell elements arranged next to each other;
The first wiring member electrically connected to the first electrode of the first solar cell element among the first solar cell element and the second solar cell element adjacent to each other among the plurality of solar cell elements. And a wiring member comprising a second wiring member electrically connected to the second electrode of the second solar cell element,
At least one of the first wiring member and the second wiring member includes an elongated first region along the longitudinal direction of the first electrode, and the first region of the first region when viewed in plan. A plurality of convex second regions protruding outward from a first side extending in the longitudinal direction of one electrode and spaced apart from each other along the longitudinal direction of the first electrode; Have
The first region is electrically insulated from the solar cell element;
Each of the plurality of second regions has a conductive portion that can be electrically connected to the first electrode or the second electrode,
The solar cell module, wherein the first side portion of the first region located between adjacent second regions among the plurality of second regions has a curved portion at least partially when viewed in plan. .   The first side portion of the first region located between the adjacent second regions among the plurality of second regions is connected to each of the two connection portions respectively connected to the second region when seen in a plan view. The solar cell module of Claim 1 which has the said curve part.   The two curved portions included in the first side portion of the first region located between adjacent second regions among the plurality of second regions are connected by a straight line portion when viewed in plan. The solar cell module according to claim 2, wherein   The curved portion extends over the entire length of the first side portion of the first region located between adjacent second regions among the plurality of second regions when viewed in plan. Solar cell module. The solar cell module according to claim 1, wherein the conductive portion extends over the entire corresponding second region. The solar cell element has a plurality of the first electrodes,
The wiring member electrically connects a plurality of first wiring members respectively corresponding to the plurality of first electrodes, and ends of the plurality of first wiring members, and a longitudinal direction of the first electrodes. A first current collecting member extending in a direction orthogonal to
Each of the plurality of first wiring members has the first region and the second region, and the dimension of the first wiring member in the direction perpendicular to the longitudinal direction is the same as that of the first current collecting member. The solar cell module according to any one of claims 1 to 5, wherein the solar cell module becomes larger as it approaches. The solar cell element has a plurality of the second electrodes,
The wiring member electrically connects a plurality of the second wiring members respectively corresponding to the plurality of second electrodes, and one ends of the plurality of second wiring members, and the longitudinal direction of the first electrodes And a second current collecting member extending in a direction orthogonal to the
Each of the first wiring member and the second wiring member has the first region and the second region,
The area ratio of the first electrode on the first surface is smaller than the area ratio of the second electrode on the first surface;
The solar cell module according to claim 6, wherein a dimension of the first wiring member is larger than a dimension of the second wiring member in a direction orthogonal to the longitudinal direction of the first electrode. Each of the plurality of first wiring members is opposed to the first side and the first side parallel to the longitudinal direction of the first electrode when viewed in plan. The solar cell module according to claim 6, further comprising a second side portion inclined with respect to the second side portion. Among the plurality of first wiring members, when two first wiring members located at both ends in the direction orthogonal to the longitudinal direction are used as first outer wiring members, at least one of the first outer wirings The solar cell module according to claim 8, wherein the member has a step portion on the second side portion. Of the plurality of second wiring members, when two second wiring members located at both ends in the direction orthogonal to the longitudinal direction are used as second outer wiring members, at least one of the second outer wirings. 10. The solar cell module according to claim 7, wherein a dimension of the member in the longitudinal direction is smaller than a dimension of the other second wiring member in the longitudinal direction.   The first current collecting member has an auxiliary conductive portion arranged along the arrangement direction of the plurality of second regions in at least one of the plurality of first wiring members. The solar cell module according to any one of claims 6 to 10. The solar cell element further includes, on the second surface, a plurality of finger electrodes each extending in a direction perpendicular to the longitudinal direction of the first electrode,
The solar cell module according to any one of claims 1 to 11, wherein the conductive portion is positioned so as to overlap the plurality of finger electrodes when seen in a plan view from the first surface side.   2. The solar cell module according to claim 1, wherein a dimension of the second region in a direction orthogonal to the longitudinal direction is smaller than a dimension of the first region in a direction orthogonal to the longitudinal direction.

Images