JP2012138433A - Photoelectric conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoelectric conversion device which reduces stress occurred between an element mounting substrate and photoelectric conversion elements.SOLUTION: A photoelectric conversion device includes: a substrate 1 having a recessed part 1a on an upper main surface and provided with conductive layers 1b on an upper surface of each side part around the recessed part 1a; an element mounting substrate 2 provided so as to cover the recessed part 1a of the substrate 1 and having openings 2a where light is transmitted to the interior of the recessed part 1a; lead electrodes 3 provided at a lower main surface of the element mounting substrate 2; and photoelectric conversion elements 4, each of which is mounted on the lower main surface of the element mounting substrate 2 so as to cover the opening 2a, electrically connects with the conductive layer 1a through the lead electrode 3, is housed in the recessed part 1a. A light receiving surface 4a of each photoelectric conversion element 4 is placed at the upper side and overlaps with the opening 2a in a plain view. The photoelectric conversion device further includes a light-transmissive window member 5 provided at an upper main surface of the element mounting substrate 2 so as to cover the openings 2a.

Description

  The present invention relates to a photoelectric conversion device that can reduce stress generated between a substrate on which a photoelectric conversion element is mounted and the photoelectric conversion element.

  In some photoelectric conversion devices, photoelectric conversion elements are mounted and bonded on a substrate. Such a photoelectric conversion device is disclosed in Patent Document 1, for example.

JP-A-8-316516

  However, in the above-described photoelectric conversion device, cracks are easily generated in the photoelectric conversion element due to the stress generated due to the difference in thermal expansion coefficient between the substrate on which the photoelectric conversion element is mounted and the photoelectric conversion element. There was a problem that the conversion element was easily damaged.

  This invention is made | formed in view of the said subject, The objective is the photoelectric conversion which can reduce the stress which arises between the board | substrate with which the photoelectric conversion element of the photoelectric conversion apparatus is mounted, and a photoelectric conversion element. To provide an apparatus.

  In order to achieve the above object, a photoelectric conversion device according to the present invention includes a base having a concave portion on the upper main surface, a conductive layer provided on the upper surface of the side portion around the concave portion, and the concave portion of the base. An element mounting substrate having an opening through which light passes through the recess, a lead electrode provided on a lower main surface of the element mounting substrate, and a lower main surface of the element mounting substrate. The opening is mounted on the surface so as to cover the opening, and is electrically connected to the conductive layer through the lead electrode. A photoelectric conversion element overlapping with a light receiving surface, and a translucent window member provided on the upper main surface of the element mounting substrate so as to cover the opening. .

  The photoelectric conversion device of the present invention has an effect that stress generated between the photoelectric conversion element and the substrate on which the photoelectric conversion element is mounted can be reduced.

It is a photoelectric conversion apparatus which concerns on this embodiment, Comprising: (a) is a perspective view of a photoelectric conversion apparatus, (b) is a disassembled perspective view of the photoelectric conversion apparatus shown to (a). 1A is a plan view of the photoelectric conversion device, FIG. 1B is a cross-sectional view of the photoelectric conversion device when the photoelectric conversion device of FIG. 1 is cut along AA, and FIG. ) Is a cross-sectional view showing the relationship between the element mounting substrate of another example and the window member. It is sectional drawing of the photoelectric conversion apparatus which concerns on the modification 1 of this embodiment. It is a top view of the photoelectric conversion apparatus which concerns on the modification 2 of this embodiment. It is a photoelectric conversion apparatus which concerns on the modification 3 of this embodiment, Comprising: (a) is sectional drawing of a photoelectric conversion apparatus, (b) shows the relationship between the photoelectric conversion element and lead electrode of the photoelectric conversion apparatus of (a). FIG. 4C is a plan view showing the relationship between the photoelectric conversion element of another example and the lead electrode.

  Hereinafter, a photoelectric conversion device according to an embodiment of the present invention will be described with reference to the drawings.

<Embodiment>
<Configuration of photoelectric conversion device>
The photoelectric conversion device according to this embodiment has a configuration as shown in FIGS. That is, the photoelectric conversion device is provided so as to cover the base 1 having the concave portion 1a on the upper main surface and the conductive layer 1b provided on the upper surface of the side portion around the concave portion 1a, and the concave portion 1a of the base 1. The element mounting substrate 2 having an opening 2a through which light passes through the recess 1a, the lead electrode 3 provided on the lower main surface of the element mounting substrate 2, and the lower main surface of the element mounting substrate 2 Mounted so as to cover the opening 2a, electrically connected to the conductive layer 1b via the lead electrode 3, and accommodated in the recess 1a, the opening 2a and the light receiving surface in plan view with the light receiving surface 4a facing upward The photoelectric conversion element 4 with which 4a overlaps, and the translucent window member 5 provided in the upper main surface of the element mounting substrate 2 so that the opening part 2a may be covered are provided.

  The photoelectric conversion device according to the present embodiment converts solar energy into electric power. And the photoelectric conversion apparatus contains the photoelectric conversion element 4 which converts light energy into electric power. For example, the photoelectric conversion element 4 is a solar cell element having a function of converting solar energy into electric power. In the photoelectric conversion device, light passes through the window member 5 and enters the light receiving surface of the photoelectric conversion element 4 through the opening 2a. And the photoelectric conversion element 4 converts light energy into electric power.

  As shown in FIG. 1, the substrate 1 has a recess 1a on the upper main surface, and a conductive layer 1b is provided on the upper surface of the side portion around the recess 1a. That is, the base 1 has a concave portion 1ca on the upper main surface, and as shown in FIG. 2, conductive layers 1b are provided on the upper surfaces of the side portions facing each other in plan view. In addition, the conductive layer 1b is provided on the upper surface of the opposing side portion so as to be exposed from the outer periphery of the element mounting substrate 2 provided so as to cover the concave portion 1a. The conductive layer 1b is preferably provided on the upper surface of the side portion so as to face each other in order to facilitate the joining of the lead electrodes 3 and 30 and the photoelectric conversion element 4.

  The conductive layer 1 a provided on the upper surface of the side portion around the recess 1 a of the substrate 1 is electrically connected to the photoelectric conversion element via the lead electrodes 3 and 30. In addition, the conductive layer 1b can be provided with an external lead terminal through a bonding material in order to extract electricity to the outside. In addition, the base | substrate 1 is not restricted square shape in planar view, Circular shape may be sufficient and a shape is not limited. The base 1 has, for example, one side width of 2 (mm) to 250 (mm), the other side width of 2 (mm) to 250 (mm), and a thickness of 0.25 (mm) to It is set to 5 (mm). Moreover, the depth of the recessed part is set to 0.24 (mm) -4.9 (mm), for example.

  The substrate 1 is made of a ceramic material such as alumina ceramic, aluminum nitride ceramic, or mullite ceramic. The substrate 1 is preferably made of a material that quickly dissipates heat generated by the photoelectric conversion element 4 and has high insulating properties. The thermal conductivity of the substrate 1 is set to, for example, 10 (W / m · K) or more and 300 (W / m · K) or less. In addition, the thermal expansion coefficient of the substrate 1 is set to, for example, 3 (ppm / ° C.) or more and 10 (ppm / ° C.) or less.

  The conductive layer 1b provided on the upper surface of the side portion around the recess 1a of the substrate 1 is made of tungsten, molybdenum, manganese, or the like.

The substrate 1 is manufactured according to each shape by punching a flat green sheet using a mold. The conductive layer 1b on the upper surface of the side portion around the recess 1a of the substrate 1 is preliminarily made of a metal paste formed by adding an organic solvent and a solvent to a ceramic green sheet, for example, a powder of tungsten, molybdenum, manganese or the like. It is formed by printing and applying a predetermined pattern by a known screen printing method. The substrate 1 is formed by laminating a plurality of these ceramic green sheets.

  The element mounting substrate 2 is a member formed in a rectangular shape when viewed in plan. The element mounting substrate 2 is provided so as to cover the concave portion 1 a on the upper main surface of the base 1. The element mounting substrate 2 has an opening 2a through which light passes through the recess 1a. The element mounting substrate 2 has, for example, one side width of 4 (mm) to 200 (mm), the other side width of 4 (mm) to 200 (mm), and a thickness of 0.1 (mm). ) To 5 (mm). Moreover, as shown to Fig.2 (a), as for the opening part 2a, X is set to 3 (mm) -30 (mm), Y is set to 3 (mm) -30 (mm).

  The element mounting substrate 2 is made of an insulating material, for example, a ceramic material such as alumina ceramic, aluminum nitride ceramic, or mullite ceramic. Alternatively, it is composed of a composite system in which a plurality of these materials are mixed. In addition, the element mounting substrate 2 is provided with a metallized layer at a joint portion between the lead electrodes 3 and 30 and the window member 5. In addition, the element mounting substrate 2 is provided with a dummy pattern 2b in order to ensure flatness when bonded to the photoelectric conversion element 4, that is, to adjust the height from the photoelectric conversion element 4 to the element mounting substrate 2. Can do. The dummy pattern 2b can also be provided on the photoelectric conversion element 4. The element mounting substrate 2 is manufactured in the same manner as the base 1 described above.

  Further, the thermal conductivity of the element mounting substrate 2 is set to, for example, 20 (W / m · K) or more and 600 (W / m · K) or less. The coefficient of thermal expansion of the element mounting substrate 2 is set to 3 (ppm / ° C.) or more and 23 (ppm / ° C.) or less, for example. Note that the shape of the element mounting substrate 2 in plan view is not limited to a rectangular shape, and may be a circular shape or the like in accordance with the shape of the recess 1a. The element mounting substrate 2 is bonded to the base 1 on the upper surface of the side portion around the recess 1a of the base 1 via a bonding material made of, for example, glass or resin.

  The lead electrode 3 is provided on the lower main surface of the element mounting substrate 2 as shown in FIG. The lead electrode 3 has one end electrically connected to the conductive layer 1 b on the upper surface of the side portion around the recess 1 a and the other end connected to the first electrode 4 b provided on the lower surface of the photoelectric conversion element 4. Electrically connected. The lead electrode 3 has a staircase shape as shown in FIG. A flat lead electrode 30 is electrically connected to the conductive layer 1b provided on the side opposite to the side provided with the conductive layer 1b to which the lead electrode 3 is connected. .

  One end of the lead electrode 30 is electrically connected to the second electrode 4c provided on the upper surface of the photoelectric conversion element 4, and the other end is electrically connected to the conductive layer 1b on the upper surface of the side portion around the recess 1a. Connected. The lead electrodes 3 and 30 are electrically connected to the conductive layer 1b, the first electrode 4b, and the second electrode 4c, respectively, through a bonding material. The bonding material is made of, for example, a brazing material such as silver (Ag) brazing or silver (Ag) -copper (Cu) brazing, low melting point solder or conductive epoxy resin. The lead electrodes 3 and 30 are provided on the metallized layer formed on the lower main surface of the element mounting substrate 2 via a bonding material.

  Moreover, since the photoelectric conversion element 4 is electrically connected by the lead electrodes 3 and 30, the electrical resistance can be reduced. The lead electrodes 3 and 30 can radiate the heat generated in the photoelectric conversion element 4 to the outside.

  The lead electrodes 3 and 30 are made of, for example, a metal material such as an iron (Fe) -nickel (Ni) -cobalt (Co) alloy or an iron (Fe) -nickel (Ni) alloy. These metal ingots are manufactured to have a predetermined shape by adopting a known metal working method such as a rolling method, a punching method, and an etching method. The thermal conductivity of the lead electrodes 3 and 30 is set to, for example, 10 (W / m · K) or more and 450 (W / m · K) or less. Moreover, the thermal expansion coefficient of the lead electrodes 3 and 30 is set to 3 (ppm / ° C.) or more and 23 (ppm / ° C.) or less, for example. The lead electrodes 3 and 30 have, for example, a length of 0.5 (mm) to 70 (mm), a width of 0.25 (mm) to 25 (mm), and a thickness of 0.1. (Mm) to 2.0 (mm).

  The photoelectric conversion element 4 has a light receiving surface 4a that receives light that is incident through the opening 2a. The photoelectric conversion element 4 is mounted on the lower main surface of the element mounting substrate 2 so as to cover the opening 2 a and is electrically connected to the conductive layer 1 b via the lead electrodes 3 and 30. And the photoelectric conversion element 4 is accommodated in the recessed part 1a, and is mounted so that the opening part 2a and the light-receiving surface 4a may overlap in plan view with the light-receiving surface 4a facing upward. Although a plurality of photoelectric conversion elements 4 are mounted on the element mounting substrate 2, the number of photoelectric conversion elements 4 is not limited to a plurality, and one photoelectric conversion element 4 may be mounted on the element mounting substrate 2. In addition, when the light-receiving surface 4a is square shape, as for the light-receiving surface 4a, one side width is 1 (mm)-40 (mm), and the other side width is 1 (mm)-40 (mm), for example. Is set to

  Moreover, although the photoelectric conversion element 4 is accommodated in the recessed part 1a away from the bottom face as shown in FIG. 1, it is not restricted to this. By providing a recess where the lead electrode 3 can be accommodated in a portion corresponding to the lead electrode 3 on the bottom surface of the recess 1a, that is, by providing a relief portion of the lead electrode 3, the photoelectric conversion element 4 contacts the bottom surface of the recess 1a. Can be accommodated. Accordingly, the photoelectric conversion device can efficiently dissipate heat generated from the photoelectric conversion element 4 from the lower surface of the photoelectric conversion element 4 to the outside of the photoelectric conversion device via the base 1.

  As shown in FIG. 2, the light receiving surface 4 a of the photoelectric conversion element 4 can be positioned inside the opening 2 a of the element mounting substrate 2 in a plan view. Since the light receiving surface 4a is located inside the opening 2a in plan view, the photoelectric conversion element 4 effectively transmits light that is transmitted through the opening 2a and incident on the photoelectric conversion element 4 through the light receiving surface 4a. It can receive light. In addition, it is preferable that the outer periphery of the light receiving surface 4a is positioned inside the opening 4a and closer to the outer periphery of the opening 4a in plan view. Accordingly, the photoelectric conversion device can effectively receive light that passes through the opening 2a and enters the photoelectric conversion element 4.

  Further, the light receiving surface 4a of the photoelectric conversion element 4 can be positioned on the inner side of the opening 4a when the opening 2a of the element mounting substrate 2 is viewed in cross section. Thus, the photoelectric conversion device can improve the photoelectric conversion efficiency because the light receiving surface 4a of the photoelectric conversion element 4 approaches the window member 5.

  Since the distance between the light receiving surface 4a of the photoelectric conversion element 4 and the window member 5 can be shortened by reducing the thickness of the element mounting substrate 2, the photoelectric conversion element 4 transmits the opening 2a through the light receiving surface 4a. Thus, the light incident on the photoelectric conversion element 4 can be received efficiently.

  Further, as shown in FIG. 2C, the element mounting substrate 2 has a shape of the opening 2 a when viewed in cross section, and the opening 2 a is from the side on which the photoelectric conversion element 4 is mounted toward the window member 5. A reverse taper shape that expands can be obtained. Thereby, the photoelectric conversion element 4 can take in efficiently the light which permeate | transmits the opening part 2a and injects into the light-receiving surface 4a.

Further, the light receiving surface 4a of the photoelectric conversion element 4 may be positioned below the opening 2a in a cross-sectional view as long as it is positioned inside the opening 2a in a plan view.

  The photoelectric conversion element 4 is provided with a first electrode 4b serving as a lower electrode on the lower surface. The first electrode 4b is made of, for example, silver or aluminum. The first electrode 4b of the photoelectric conversion element 4 is electrically connected to one end of the lead electrode 3 through a bonding material such as low melting point solder or conductive epoxy resin, for example.

  Moreover, the photoelectric conversion element 4 is provided with a second electrode 4c serving as an upper surface electrode on the upper surface. The second electrode 4c is made of, for example, silver or aluminum. The second electrode 4c of the photoelectric conversion element 4 is electrically connected to the other end of the lead electrode 3 through a bonding material such as low melting point solder or conductive epoxy resin, for example.

The photoelectric conversion element 4 is a solar cell element including a III-V group compound semiconductor, for example. The photoelectric conversion element 4 can immediately convert the received light energy into electric power and output it by the photovoltaic effect. For example, the solar cell element has an InGaP / GaAs / Ge3 junction type cell structure. The indium gallium phosphide (InGaP) top cell converts energy contained in a wavelength region of 660 nm or less. The gallium arsenide (GaAs) middle cell converts energy contained in a wavelength region from 660 nm to 890 nm. The germanium (Ge) bottom cell converts light contained in a wavelength region from 890 nm to 2000 nm. The three cells are connected in series via a tunnel junction. The open circuit voltage is the sum of the electromotive voltages of the three cells.

  Here, the 1st electrode 4b provided in the lower surface of the photoelectric conversion element 4 is functioning as a positive electrode, for example. Moreover, the 2nd electrode 4c provided in the upper surface of the photoelectric conversion element 4 is functioning as a negative electrode, for example. In the photoelectric conversion element 4, the first electrode 4b and the second electrode 4c are electrically connected by the lead electrodes 3 and 30, and the photoelectric conversion device is connected via the conductive layer 1b facing each other. Electricity can be taken out to the outside.

  The window member 5 is provided on the upper main surface of the element mounting substrate 2 so as to cover the opening 2a. It is a translucent member formed in a square shape when viewed from above. The shape of the window member 5 is not limited. The window member 5 has a function of transmitting light and guiding it to the photoelectric conversion element 4. The window member 5 may have a function of condensing light on the photoelectric conversion element 4. The translucency of the window member 5 means that when the photoelectric conversion element 4 is a solar cell element, light included in at least a part of the wavelength region of sunlight can be transmitted. The window member 5 is made of a material such as sapphire, borosilicate glass, plastic, or translucent resin, and may be any material that can transmit sunlight. In addition, an optical member formed in a hemispherical shape, for example, a condensing lens may be provided as the window member 5 to collect light on the photoelectric conversion element 4. Further, the window member 5 can be provided with a non-reflective coating material suitable for the wavelength on both surfaces.

  The thermal conductivity of the window member 5 is set to, for example, 10 (W / m · K) or more and 20 (W / m · K) or less. The thermal expansion coefficient of the window member 5 is set to 3 (ppm / ° C.) or more and 23 (ppm / ° C.) or less, for example. The window member 5 has, for example, one side width of 4 (mm) to 200 (mm), the other side width of 4 (mm) to 200 (mm), and a thickness of 0.15 ( mm) to 5 (mm).

  In addition, since the photoelectric conversion device is hermetically sealed by the window member 5, the atmosphere is blocked and adhesion of moisture to the window member 5, the photoelectric conversion element 3, and the like is suppressed.

Further, a metal layer is formed on the lower surface main surface of the window member 5 at a position where it is joined to the element mounting substrate 2 at least in a region excluding the opening 2a. The metal layer is formed by a thin film forming technique such as a vapor deposition method or a sputtering method. The metal layer is made of a metal material such as titanium, platinum, gold, chromium, nickel, gold, silver, copper, or an alloy thereof. In the window member 5, the metal layer on the lower surface main surface is bonded to the upper main surface of the element mounting substrate 2 via a bonding material made of, for example, brazing material, solder, low-melting glass, epoxy resin, or the like. The joining method is, for example, a method such as brazing, solder joining, or resin joining. The brazing material is made of, for example, silver-copper brazing. The solder is made of, for example, a gold-tin system, a gold-germanium system, or a tin-lead system. The low melting point glass means a glass having a glass transition point of 600 ° C. or lower.

  The photoelectric conversion device of this embodiment is mounted on the element mounting substrate 2 only at the outer peripheral portion of the upper surface of the photoelectric conversion element 4 so that the photoelectric conversion element 4 covers the opening 2 a of the element mounting substrate 2. That is, the photoelectric conversion element 4 is not directly joined to the element mounting substrate 2 because the central region where the temperature rise is high due to incident light incident on the photoelectric conversion element 4 is located in the opening 2a. As a result, the photoelectric conversion device is not in contact with the element mounting substrate 3 in the central region where the temperature rise is high, so that the thermal stress generated by the difference in thermal expansion coefficient between the element mounting substrate 2 and the photoelectric conversion element 4 is generated. Reduced. Therefore, the photoelectric conversion device can suppress the occurrence of cracks and cracks at the joint between the photoelectric conversion element 4 and the element mounting substrate 2. In addition, the photoelectric conversion device can suppress the occurrence of cracks and cracks in the photoelectric conversion element 4.

  The present invention is not limited to the above-described embodiments, and various changes and improvements can be made without departing from the scope of the present invention. Hereinafter, modifications of the first embodiment will be described. Note that, in the photoelectric conversion device according to the modified example of the present embodiment, the same parts as those of the photoelectric conversion device according to the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

<Modification 1>
As illustrated in FIG. 3, the photoelectric conversion device according to the modification according to the present embodiment may have a configuration in which the third electrode 4 d and the second electrode 4 c are provided on the upper surface of the photoelectric conversion element 40. Note that the third electrode 4d has the same function as the first electrode 4b described above. That is, the photoelectric conversion element 40 is provided with two electrodes, the third electrode 4d functioning as a positive electrode and the second electrode 4c functioning as a negative electrode, on the same surface of the upper surface.

  With such a configuration, the photoelectric conversion device can improve the flatness of the joint portion between the element mounting substrate 2 and the photoelectric conversion element 4 without providing the dummy pattern 2b or the like. Accordingly, the photoelectric conversion device can suppress the inclination of the photoelectric conversion element 4, and the photoelectric conversion element 4 can efficiently make incident light from the opening 2 a incident on the light receiving surface.

  In addition, with such a configuration, the photoelectric conversion device can electrically connect the conductive layer 1b and the photoelectric conversion element 4 only through the flat lead electrode 30. Thereby, since the photoelectric conversion apparatus manufactures only the lead electrode 30, it can improve productivity.

  Further, the photoelectric conversion device may function as the lead electrode 30 by providing a conductive layer on the element mounting substrate 2 instead of the lead electrode 30. Thereby, the photoelectric conversion device can facilitate the bonding between the element mounting substrate 2 and the photoelectric conversion element 4.

  In addition, since the wiring distance can be shortened and the electrical resistance can be reduced, the photoelectric conversion device can improve the photoelectric conversion efficiency.

Moreover, although the photoelectric conversion element 4 is accommodated in the recessed part 1a away from the bottom face as shown in FIG. 3, it is not restricted to this. The photoelectric conversion element 4 can be accommodated by bringing the lower surface of the photoelectric conversion element 4 into contact with the bottom surface of the recess 1a. Accordingly, the photoelectric conversion device can efficiently dissipate heat generated from the photoelectric conversion element 4 from the lower surface of the photoelectric conversion element 4 to the outside of the photoelectric conversion device via the base 1.

<Modification 2>
As shown in FIG. 2 or FIG. 4, in the photoelectric conversion device of the modification according to this embodiment, the light receiving surface 4 a of the photoelectric conversion element 4 is provided in a shape similar to the shape of the opening 2 a in plan view. Yes.
As shown in FIG. 2A, the light receiving surface 4a of the photoelectric conversion element 4 is provided with an opening 2a in a quadrangular shape, and is provided in a quadrangular shape accordingly. Moreover, as shown in FIG. 4, the light-receiving surface 4a of the photoelectric conversion element 4 is provided with a circular opening portion 2a. Moreover, if the opening part 2a is polygonal shape, the light-receiving surface 4a will be provided in polygonal shape. Thus, the light receiving surface of the photoelectric conversion element 4 is preferably provided in a shape similar to the shape of the opening 2a in plan view.

  With such a configuration, since the shapes of the opening 2a and the light receiving surface 4a are similar, the photoelectric conversion element can efficiently make incident light from the opening 2a incident on the light receiving surface 4a.

<Modification 3>
As shown in FIG. 5A or 5B, the photoelectric conversion device according to the modification according to the present embodiment is configured such that one end of the lead electrode 3 is electrically connected to the lower surface of the photoelectric conversion element 4 and is planar. In fluoroscopy, at least a portion overlaps the light receiving surface 4a. That is, it is only necessary that a part of the lead electrode 3 is provided so as to overlap the light receiving surface 4a in a plan view.

  As shown in FIG. 5B, one end of the lead electrode 3 is provided so as to extend outside the light receiving surface 4a through the inside of the light receiving surface 4a of the photoelectric conversion element 4 in plan view. One end of the lead electrode 3 is provided outside the light receiving surface 4a so as to extend in a range of 1 (mm) to 25 (mm), for example. As a result, the lower surface of the photoelectric conversion element 4 in the region corresponding to the light receiving surface 4a has a high temperature rise and generates more heat, but one end of the lead electrode 3 is provided at a position corresponding to the light receiving surface 4a. Therefore, heat can be made uniform over the entire photoelectric conversion element 4. Therefore, the photoelectric conversion device can suppress heat from being locally distributed in the photoelectric conversion element 4, and the photoelectric conversion element 4 can improve the photoelectric conversion efficiency. Further, the photoelectric conversion device transmits heat generated as the temperature of the photoelectric conversion element 4 rises to the element mounting substrate 2 via the lead electrode 3 from directly below the light receiving surface 4 a and performs photoelectric conversion via the base 1. Heat can be radiated to the outside of the device.

  As another example, one end of the lead electrode 3 is provided so as to be located outside the outer periphery of the light receiving surface 4a of the photoelectric conversion element 4 in a plan view, as shown in FIG. The lead electrode 3 is provided so as to be located outside the outer periphery of the light receiving surface 4a, for example, in the range of 1 (mm) to 25 (mm). Thus, in the photoelectric conversion element 4, one end of the lead electrode 3 is located outside the region corresponding to the light receiving surface 4 a of the photoelectric conversion element 4, so that heat is further locally distributed in the photoelectric conversion element 4. Can be effectively suppressed. Further, the photoelectric conversion device transmits heat generated as the temperature of the photoelectric conversion element 4 rises from the lower surface of the photoelectric conversion element 4 to the element mounting substrate 2 via the lead electrode 3, and photoelectrically passes through the base 1. Heat can be radiated to the outside of the converter.

<Method for Manufacturing Photoelectric Conversion Device>
Here, a method for manufacturing the photoelectric conversion device will be described.

For example, when the substrate 1 is made of alumina ceramics, the green sheet is prepared by mixing and adding an organic binder, a plasticizer, a solvent, a dispersant, and the like to raw powders such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide. The paste is formed and formed by a doctor blade method, a calendar roll method, or the like.

  Further, the flat green sheet has a predetermined position on the upper side of the peripheral portion of the recess 1a with a metal paste obtained by adding an organic binder, a plasticizer, a solvent, etc. to a high melting point metal powder such as tungsten, molybdenum or manganese. A metallized layer to be a conductive layer 1b is formed by printing by screen printing or the like.

  Then, a flat plate-like green sheet is manufactured according to each shape by punching using a mold.

  These flat green sheets are laminated and fired at a temperature of about 1600 ° C. at the same time. The base 1 is formed with a nickel plating layer having a thickness of 3 (μm) or less on the metallized layer by a plating method such as electrolytic plating or electroless plating.

  The element mounting substrate 2 has a shape having the opening 2a and is manufactured in the same manner as the base 1 described above.

  For example, the lead electrodes 3 and 30 are made of an ingot produced by casting an iron (Fe) -nickel (Ni) -cobalt (Co) alloy into a mold using a known metal working method such as cutting or punching. Produced in a predetermined shape.

The photoelectric conversion element 4 is mounted on the lower main surface of the element mounting substrate 2, and the first electrode 4b, the second electrode 4c, and the lead electrodes 3 and 30 of the photoelectric conversion element 4 are electrically connected via a bonding material. Connected. Further, the conductive layer 1 a of the base 1 is electrically connected to the lead electrodes 3 and 30.
The bonding material is, for example, a material such as silver (Ag) solder, silver (Ag) -copper (Cu) solder, gold (Au) -tin (Sn) solder, gold (Au) -germanium (Ge) solder, or the like. For example, a conductive epoxy resin.

  The window member 5 is, for example, Au—Sn solder, Sn—silver (Ag) —copper (Cu) solder, Sn—zinc (Zn) —bismuth so as to cover the opening 2 a on the upper main surface of the element mounting substrate 2. (Bi) Joined via a resin or the like. Thus, a photoelectric conversion device is obtained.

DESCRIPTION OF SYMBOLS 1 Base 1a Recessed part 1b Conductive layer 2 Element mounting board | substrate 2a Opening part 2b Dummy pattern 3, 30 Lead electrode 4, 40 Photoelectric conversion element 4a Light-receiving surface 4b 1st electrode 4c 2nd electrode 4d 3rd electrode 5 Window member

Claims (4)

A base body having a concave portion on the upper main surface, and a conductive layer provided on the upper surface of the side portion around the concave portion;
An element mounting substrate provided so as to cover the concave portion of the base body and having an opening through which light passes through the concave portion;
A lead electrode provided on the lower main surface of the element mounting substrate;
Mounted on the lower main surface of the element mounting substrate so as to cover the opening, electrically connected to the conductive layer via the lead electrode, and housed in the recess, with the light receiving surface facing upward A photoelectric conversion element in which the opening and the light receiving surface overlap in plan view;
A photoelectric conversion device, comprising: a translucent window member provided on the upper main surface of the element mounting substrate so as to cover the opening. The photoelectric conversion device according to claim 1,
The photoelectric conversion device according to claim 1, wherein the light receiving surface of the photoelectric conversion element is positioned inside the opening in a plan view. The photoelectric conversion device according to claim 1 or 2, wherein
The photoelectric conversion device according to claim 1, wherein the light receiving surface of the photoelectric conversion element has a shape similar to the shape of the opening in a plan view. A photoelectric conversion device according to any one of claims 1 to 3,
One end of the lead electrode is electrically connected to the lower surface of the photoelectric conversion element, and at least part of the lead electrode overlaps with the light receiving surface in a plan view.

Images