JP5441576B2 - Photoelectric conversion device and photoelectric conversion module - Google Patents

Description

  The present invention relates to a photoelectric conversion device and a photoelectric conversion module using the photoelectric conversion device.

  In recent years, development of a photoelectric conversion device having a photoelectric conversion element has been advanced. As an exemplary photoelectric conversion device, there is a solar cell device that converts solar energy into electric power. In particular, for the purpose of improving the power generation efficiency, a concentrating solar cell device is being developed. The photoelectric conversion device includes a photoelectric conversion element that converts light energy into electric power energy. When the photoelectric conversion device is, for example, a solar cell device, the photoelectric conversion element is a solar cell element that converts solar energy into electric power energy (see, for example, Patent Documents 1 and 2).

JP 2001-274301 A JP 2008-91440 A

  In the development of a photoelectric conversion device, a photoelectric conversion device with excellent heat dissipation is required. This invention is made | formed in view of the above, Comprising: It aims at providing the photoelectric conversion apparatus excellent in heat dissipation, and a photoelectric conversion module.

In order to solve the above problems, a photoelectric conversion device according to a first aspect of the present invention includes a first main surface region on one main surface side and a second main surface region provided on the outer periphery of the first main surface region. Formed on the second main surface region of the conductive substrate and surrounding the first main surface region, and formed on the first main surface region in the frame. A photoelectric conversion element having a lower surface electrically connected to the conductive substrate, a conductive layer electrically connected to the upper surface of the photoelectric conversion element, and the frame body. And a condensing member that covers a space surrounded by the frame body, and that the end of the conductive substrate is located in a region surrounded by the frame body in plan view. Features.

  Further, the photoelectric conversion module according to the second aspect of the present invention includes a plurality of photoelectric conversion devices, and between adjacent photoelectric conversion devices, the conductive substrate of one photoelectric conversion device and the other photoelectric conversion device. A conductive substrate of the conversion device is connected.

  Further, the photoelectric conversion module according to the third aspect of the present invention includes a plurality of photoelectric conversion devices, and between adjacent photoelectric conversion devices, the conductive substrate of one photoelectric conversion device and the other photoelectric conversion device. The conductive layer of the conversion device is connected.

  ADVANTAGE OF THE INVENTION According to this invention, the photoelectric conversion apparatus excellent in heat dissipation and a photoelectric conversion module can be provided.

It is a disassembled perspective view which shows the external appearance of the photoelectric conversion module which concerns on a reference example . It is a general-view perspective view of the photoelectric conversion apparatus which concerns on a reference example . It is a general-view perspective view except the condensing member of the photoelectric conversion apparatus which concerns on a reference example . It is a top view of the photoelectric conversion apparatus shown in FIG. It is sectional drawing of the photoelectric conversion apparatus which concerns on a reference example . It is sectional drawing of a photoelectric conversion apparatus which shows the state which connected the photoelectric conversion apparatus which concerns on a reference example electrically in series. It is a general | schematic perspective view of the photoelectric conversion apparatus which shows the state which electrically connected the several photoelectric conversion apparatus which removed the condensing member in series. It is sectional drawing of a photoelectric conversion apparatus which shows the state which connected the photoelectric conversion apparatus which concerns on a reference example electrically in parallel. It is a general | schematic perspective view of the photoelectric conversion apparatus which shows the state which connected the several photoelectric conversion apparatus which removed the condensing member electrically in parallel. It is sectional drawing of the photoelectric conversion apparatus which concerns on this embodiment . It is sectional drawing of the photoelectric conversion apparatus which concerns on one modification. It is sectional drawing of the photoelectric conversion apparatus which concerns on one modification.

  Embodiments of a photoelectric conversion module and a photoelectric conversion device according to the present invention will be described below with reference to the accompanying drawings. In addition, this invention shall not be limited to the following embodiment.

<Schematic configuration of photoelectric conversion module>
FIG. 1 is an overview perspective view of a photoelectric conversion module according to a reference example , and an exploded perspective view in which a part thereof is enlarged. FIG. 2 is a schematic perspective view of the photoelectric conversion device shown in FIG. FIG. 3 is a schematic perspective view of the photoelectric conversion device from which the light collecting member is removed. FIG. 4 is a plan view of the photoelectric conversion device from which the light collecting member is removed. FIG. 5 is a cross-sectional view of the photoelectric conversion device.

The photoelectric conversion module 1 according to the reference example is a photovoltaic power generation module that converts sunlight into electric power. The photoelectric conversion device 2 according to the reference example includes a photoelectric conversion element 3 that collects light. For example, the photoelectric conversion element 3 has a function of collecting power by collecting sunlight.

  The photoelectric conversion module 1 includes a plurality of photoelectric conversion devices 2 and a light receiving member 4 that receives light. The light receiving member 4 is, for example, a dome-shaped Fresnel lens. The light receiving member 4 has a function of receiving light from the outside and collecting the received light in the photoelectric conversion device 2. The light receiving member 4 is made of, for example, glass, plastic, or translucent resin. The light receiving member 4 includes a frame member 4a and a lens member 4b, and is fixed by the frame member 4a so as to surround the lens member 4b.

  The photoelectric conversion device 2 includes: a conductive substrate 5 having a first main surface region S1 on one main surface side and a second main surface region S2 provided on the outer periphery of the first main surface region S1; A frame 6 formed on the second main surface region S2 and surrounding the first main surface region S1. Furthermore, the photoelectric conversion device 2 is formed on the first main surface region S1 in the frame body 6, the photoelectric conversion element 3 formed on the frame body 6 and provided on the inside and outside of the frame body 6, and photoelectric conversion. A conductive layer 7 that is electrically connected to the upper surface of the element 3 and a light collecting member 8 that is joined to the frame body 6 and covers the space SP surrounded by the frame body 6 are included.

  The conductive substrate 5 has a step. A first main surface region S1 is formed on the surface having the higher step height. In addition, the second main surface region S2 is formed on the surface having the lower step height position. The conductive substrate 5 is a conductive substrate and is made of, for example, a metal material such as copper, silver, gold, iron, aluminum, nickel, cobalt, or chromium, or an alloy thereof. The conductive substrate 5 is made of a material having excellent thermal conductivity, and the thermal conductivity of the conductive substrate 5 is set to, for example, 30 W / m · K or more and 500 W / m · K or less. The thermal expansion coefficient of the conductive substrate 5 is set to, for example, 5 × 10 −6 / ° C. or more and 25 × 10 −6 / ° C. or less.

  In addition, the photoelectric conversion element 3 is provided on the first main surface region S <b> 1 and is connected to the conductive substrate 5.

  The photoelectric conversion element 3 is, for example, a solar cell element that includes a III-V group compound semiconductor. The photoelectric conversion element 3 can immediately convert the received light into electric power and output it by the photovoltaic effect. An exemplary solar cell element has an InGaP / GaAs / Ge3 junction cell structure. The indium gallium phosphide (InGaP) top cell converts energy contained in a wavelength region of, for example, 660 nm or less. A gallium arsenide (GaAs) middle cell converts energy contained in a wavelength region of, for example, 660 nm to 890 nm. The germanium (Ge) bottom cell converts energy contained in a wavelength region from 890 nm to 2000 nm, for example. 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. Note that one side of the photoelectric conversion element 3 has a length of, for example, 3 mm or more and 15 mm or less. Moreover, the photoelectric conversion element 3 has a thickness of 0.3 mm or more and 5 mm or less, for example.

  A lower surface electrode pattern is formed on the lower surface of the photoelectric conversion element 3. The lower electrode pattern is electrically connected to the conductive substrate 5 through, for example, solder.

  An upper surface electrode pattern is formed on the upper surface of the photoelectric conversion element 3. The upper surface electrode pattern is electrically connected to the conductive layer 7 formed on the frame body 6 through, for example, a wire.

  Here, the conductive substrate 5 functions as a positive electrode. The conductive layer 7 functions as a negative electrode. The photoelectric conversion element 3 is electrically connected to the conductive substrate 5 and the conductive layer 7, and electricity can be taken out through the conductive substrate 5 or the conductive layer 7.

  In the conductive substrate 5, the height position of the first main surface region S1 is set higher than the height position of the second main surface region S2. Therefore, the current that flows between the conductive substrate 5 and the conductive layer 7 flows through the first main surface region S1 that is higher in height than the second main surface region S2. Since a current flows between the lower surface of the photoelectric conversion element 3 and the first main surface region S <b> 1, the current path is set short between the conductive substrate 5 and the conductive layer 7. As a result, it is possible to take out the power to the outside after reducing the loss of the power generated by the photoelectric conversion element 3.

  The frame 6 is formed on the second main surface region S2 of the conductive substrate 5 so as to surround the first main surface region S1. The conductive layer 7 extends to the inside and outside of the frame body 6. The conductive layer 7 is made of, for example, a metal material such as copper, silver, gold, iron, aluminum, nickel, cobalt, or chromium, or an alloy thereof.

  The frame 6 is made of an insulating material, for example, a ceramic material such as alumina or mullite, or a glass ceramic material. Or it consists of a composite material which mixed several materials among these materials. In addition, the thermal expansion coefficient of the frame 6 is set to, for example, 4 × 10 −6 / ° C. or more and 10 × 10 −6 / ° C. or less. Note that the frame body 6 is formed on the conductive substrate 5, the first frame body 6 a surrounding the photoelectric conversion element 3, and the second frame formed on the first frame body 6 a and connected to the light collecting member 8. It is comprised from the body 6b.

  A gap A <b> 1 is provided between the side surface of the conductive substrate 5 located between the first main surface region S <b> 1 and the second main surface region S <b> 2 and the first frame body 6 a of the frame body 6. A part of the lower surface of the frame 6 and the second main surface region S2 of the conductive substrate 5 are connected. Note that the length of the gap A1 is set to, for example, 0.1 mm or more and 3 mm or less.

  The conductive substrate 5 and the frame body 6 are different in thermal expansion coefficient, and the thermal expansion coefficient of the conductive substrate 5 is larger than the thermal expansion coefficient of the frame body 6. The substrate 5 may be thermally expanded. If the side surface of the conductive substrate 5 located between the first main surface region S1 and the second main surface region S2 and the inner wall surface of the frame 6 are in contact with each other, thermal expansion of the conductive substrate 5 occurs. As a result, the conductive substrate 5 may apply stress to the inner wall surface of the frame 6, and cracks may occur in the frame 6. According to the present embodiment, by providing the gap A1 between the side surface of the conductive substrate 5 located between the first main surface region S1 and the second main surface region S2 and the frame 6, the conductive substrate Even if thermal expansion of 5 occurs, it is difficult to come into contact with the frame 6, so that it is possible to suppress the occurrence of cracks in the frame 6.

  A support portion 6 c that supports the light collecting member 8 is formed on the upper portion of the frame body 6. The support portion 6 c is inclined from the upper surface of the frame body 6 to the inner wall surface of the frame body 6.

  The condensing member 8 is connected to the support portion 6c of the frame 6 so as to cover the space SP. The photoelectric conversion element 3 located in the space SP is hermetically sealed by being surrounded by the conductive substrate 5, the frame body 6, and the light collecting member 8. Moreover, the condensing member 8 is fixed to the support portion 6c of the frame 6 via, for example, solder, resin, or glass.

  The condensing member 8 has a function of condensing the light transmitted through the light receiving member 4 and concentrating the condensed light on the photoelectric conversion element 3. The light collecting member 8 is made of, for example, glass, plastic, or translucent resin.

  Further, as shown in FIG. 5, a terminal 9 electrically connected to the outside is formed on the conductive layer 7 located outside the frame body 6. The terminal 9 is for taking out the electric power generated by the photoelectric conversion element 3 to the outside. The terminal 9 is made of, for example, a metal material such as copper, silver, gold, iron, aluminum, nickel, cobalt, or chromium, or an alloy thereof.

  FIG. 6 is a cross-sectional view of the photoelectric conversion module 1 showing a state where two photoelectric conversion devices 2 are electrically connected. FIG. 7 is a schematic perspective view of the photoelectric conversion module 1 showing a state in which the plurality of photoelectric conversion devices 2 from which the light collecting member is removed are electrically connected in series.

  As shown in FIG. 6, the photoelectric conversion device 2 is fixed on the base substrate 10 via an insulating layer 11. The insulating layer 11 is made of, for example, a resin having excellent thermal conductivity such as an epoxy resin, a glass epoxy resin, or a silicone resin, or a ceramic material such as alumina or aluminum nitride. The insulating layer 11 has a function of dissipating heat transmitted from the photoelectric conversion element 3 to the conductive substrate 5.

  The base substrate 10 has a function of radiating heat transmitted to the photoelectric conversion device 2 to the outside. In the photoelectric conversion device 2, a part of the energy of the light transmitted through the light receiving member 4 is converted into heat to generate heat. Therefore, the base substrate 10 is connected to the photoelectric conversion device 2 via the insulating layer 11 and absorbs heat transmitted from the photoelectric conversion device 2 and dissipates it to the outside. The base substrate 10 is made of a metal material having a heat radiation function such as aluminum, copper, or molybdenum.

  The conductive substrate 5, the insulating layer 11, and the base substrate 10 have screw grooves H formed in regions that are not surrounded by the frame body 6 in plan view. Then, the screw 12 is inserted into the screw groove H, and the conductive substrate 5, the insulating layer 11, and the base substrate 10 are fixed. The screw 12 is an insulating member and is made of, for example, plastic or resin. Therefore, the conductive substrate 5 and the base substrate 10 are not electrically connected via the screw 12, and the electricity generated by the photoelectric conversion device 2 is designed not to flow to the base substrate 10.

  FIG. 7 is a schematic perspective view of a plurality of photoelectric conversion devices 2 showing a state where the photoelectric conversion devices 2 from which the light collecting member 8 is removed are electrically connected in series.

  As shown in FIG. 7, between the adjacent photoelectric conversion devices 2, the conductive substrate 5 of one photoelectric conversion device 2 is electrically connected via the conductive layer 7 and the terminal 9 of the other photoelectric conversion device 2. Has been. As shown in FIG. 7, electricity generated by the photoelectric conversion device 2 can be flowed to the adjacent photoelectric conversion device 2 to extract electricity to the outside.

  FIG. 8 is a schematic perspective view of a plurality of photoelectric conversion devices 2 showing a state in which the photoelectric conversion devices 2 from which the light collecting member 8 is removed are electrically connected in parallel.

  As shown in FIG. 8, a plurality of photoelectric conversion devices 2 are provided side by side, and between the adjacent photoelectric conversion devices 2, the conductive substrate 5 of one photoelectric conversion device 2 and the conductivity of the other photoelectric conversion device 2. The conductive substrate 5 is connected. As shown in FIG. 8, electricity generated by the plurality of photoelectric conversion devices 2 can be directly taken out from the respective photoelectric conversion devices 2.

According to the reference example , since the photoelectric conversion element 3 is directly connected to the conductive substrate 5, heat generated in the photoelectric conversion element 3 can be efficiently transmitted to the conductive substrate 5. High temperature can be effectively suppressed. Moreover, the photoelectric conversion element 3 can be made hard to become high temperature, and it can suppress effectively that the electrical property of the photoelectric conversion element 3 changes.

  In addition, this invention is not limited to the above-mentioned form, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention.

<Method for producing photoelectric conversion module>
Here, a method for manufacturing the photoelectric conversion module 1 shown in FIG. 1 and the photoelectric conversion device shown in FIG. 2 will be described.

  First, the conductive substrate 5 is prepared. The conductive substrate 5 can be produced by injecting a conductive metal dissolved in a mold of the conductive substrate, cooling it and taking it out of the mold.

  Moreover, the frame 6 is prepared. When the frame 6 is made of, for example, an aluminum oxide sintered body, an organic binder, a plasticizer, a solvent, or the like is added to and mixed with raw material powders such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide to obtain a mixture.

  And after filling the formwork of the frame 6 with a mixture and making it dry, the frame 6 before sintering is taken out.

  Moreover, a high melting point metal powder such as tungsten or molybdenum is prepared, and an organic binder, a plasticizer, a solvent, or the like is added to and mixed with the powder to obtain a metal paste.

  Then, a conductive layer 7 for joining the terminals 9 is formed on the upper surface of the first frame body 6a before sintering by applying a metal paste using, for example, a screen printing method. And the frame 6 can be produced by simultaneous baking in the state which joined the 1st frame 6a and the 2nd frame 6b.

  Next, the frame body 6 is joined to the second main surface region S2 of the conductive substrate 5 with a brazing material or the like. Then, the photoelectric conversion element 3 is mounted on the conductive substrate 5 surrounded by the frame body 6. Then, the lower surface of the photoelectric conversion element 3 and the upper surface of the conductive substrate 5 are electrically connected. Further, for example, a bonding wire is connected from the conductive layer 7 surrounded by the frame body 6 to the upper surface of the photoelectric conversion element 3.

  Next, the condensing member 8 is fixed to the support portion 6c of the frame body 6 via solder. In this way, the photoelectric conversion device 2 can be manufactured.

  Next, a method for manufacturing the photoelectric conversion module 1 will be described. First, a plurality of photoelectric conversion devices 2, a base substrate 10, and an insulating layer 11 are prepared. Note that a screw groove H is provided in advance in the photoelectric conversion device 2, the base substrate 10, and the insulating layer 11.

  Here, a method of electrically connecting two photoelectric conversion devices 2 in series will be described. Two photoelectric conversion devices 2 are arranged so that the terminal 9 of one photoelectric conversion device 2 and the conductive substrate 5 of the other photoelectric conversion device 2 are adjacent to each other. In addition, the insulating layer 11 is provided over the base substrate 10. Then, two adjacent photoelectric conversion devices 2 are arranged on the insulating layer 11.

  Next, the screw 12 is inserted into the screw hole H of the two photoelectric conversion devices 2 arranged on the insulating layer 11, and the photoelectric conversion device 2 is screwed to the base substrate 10 and the insulating layer 11. it can.

  In this way, the photoelectric conversion device 2 can be fixed to the base substrate 10. Similarly, a plurality of photoelectric conversion devices 2 are arranged and fixed on the base substrate 10 via the insulating layer 11. And the photoelectric conversion module 1 is producible by providing the light-receiving member 4 on the photoelectric conversion apparatus 2. FIG.

< This embodiment >
In the reference example described above, the end of the conductive substrate 5 extends to a region that is not surrounded by the frame body 6 in plan view. For example, as shown in FIG. 10, the end of the conductive substrate 5 may be located in a region surrounded by the frame body 6 in plan view.

  By providing the end portion of the conductive substrate 5 in a region surrounded by the frame body 6 in plan view, heat transmitted from the photoelectric conversion element 3 to the conductive substrate 5 can be hardly transmitted to the frame body 6. . By making it difficult to transmit the heat generated in the photoelectric conversion element 3 to the frame body 6, the heat transmitted from the frame body 6 to the light collecting member 8 can be reduced. If a large amount of heat is transmitted from the frame body 6 to the light collecting member 8, the connecting member connecting the frame body 6 and the light collecting member 8 is melted, and there is a possibility that the light collecting member 8 is displaced. When the position shift of the condensing member 8 occurs, it is difficult for light traveling through the condensing member 8 to gather in the photoelectric conversion element 3 through the space SP. As a result, the power generation characteristics of the photoelectric conversion element 3 are deteriorated. On the other hand, according to the present embodiment, the heat transmitted from the conductive substrate 5 to the frame body 6 can be reduced by providing the end portion of the conductive substrate 5 in a region surrounded by the frame body 6 in plan view. As a result, the electrical characteristics of the photoelectric conversion element 3 can be maintained well.

<Modification 1 >
In the above embodiment , the end portion of the conductive substrate 5 is positioned in the region surrounded by the frame body 6 in plan view. However, as shown in FIG. The portion may extend outward along the lower surface of the first frame 6a.

  In the photoelectric conversion device 2 shown in FIG. 11, a third main surface region S3 that surrounds the outer periphery of the second main surface region S2 is formed on one main surface side of the conductive substrate 6, and the third main surface region S3 and A gap A <b> 2 is provided between the lower surface of the frame body 6.

As shown in FIG. 11, the area of the lower surface of the conductive substrate 5 is increased and, similarly to the embodiment , the portion where the conductive substrate 5 and the frame 6 are in contact with each other is seen in a plan view in the frame 6 To do. The photoelectric conversion device 2 shown in the embodiment can improve the stability of the photoelectric conversion device 2 fixed on the base substrate by increasing the area of the lower surface of the conductive substrate 5. Further, similarly to the embodiment , heat transmitted from the conductive substrate 5 to the frame body 6 can be reduced.

<Modification 3>
In the second modification, a part of both side surfaces of the conductive substrate 5 extends outward along the lower surface of the first frame 6a. However, as shown in FIG. A part of one side surface of 5 may extend outward along the lower surface of the first frame body 6a.

  In the photoelectric conversion device 2 shown in FIG. 12, a part of one side surface of the conductive substrate 5 extends outward along the lower surface of the first frame 6a. A part of the other side surface of the conductive substrate 5 is set so as to be accommodated in the frame body 6 in plan view.

  By extending a part of one side surface of the conductive substrate 5 outward along the lower surface of the first frame 6a, the current flow in the photoelectric conversion device 2 is changed from the conductive substrate 5 to the photoelectric conversion element. 3 to flow to the terminal 9, it is possible to make it difficult for excess current to be dispersed in the conductive substrate 5 and flow. That is, by not extending and providing a part of the other side surface of the conductive substrate 5, no current flows through a part of the other side surface of the conductive substrate 5, and no current is distributed in the conductive substrate 5. Can be.

DESCRIPTION OF SYMBOLS 1 Photoelectric conversion module 2 Photoelectric conversion apparatus 3 Photoelectric conversion element 4 Light receiving member 4a Frame member 4b Lens member 5 Conductive substrate 6 Frame body 6a 1st frame body 6b 2nd frame body 6c Support part 7 Conductive layer 8 Condensing member 9 Terminal 10 base substrate 11 insulating layer 12 screw S1 first main surface region S2 second main surface region SP space A1 gap H screw groove

Claims (6)

A conductive substrate having a first main surface region on one main surface side and a second main surface region provided on an outer periphery of the first main surface region;
A frame formed on the second main surface region of the conductive substrate and surrounding the first main surface region;
A photoelectric conversion element formed on the first main surface region in the frame and having a lower surface electrically connected to the conductive substrate;
A conductive layer which is provided over the inside and outside of the frame and is electrically connected to the upper surface of the photoelectric conversion element;
A condensing member that is joined to the frame and covers a space surrounded by the frame;
And an end portion of the conductive substrate is located in a region surrounded by the frame body in plan view .

The photoelectric conversion device according to claim 1,
The photoelectric conversion device, wherein the conductive substrate is set such that a height position of the first main surface region is higher than a height position of the second main surface region. The photoelectric conversion device according to claim 2,
A photoelectric conversion device, wherein a gap is provided between a side surface of the conductive substrate located between the first main surface region and the second main surface region and the frame. The photoelectric conversion device according to claim 3,
A third main surface region surrounding the outer periphery of the second main surface region is formed on one main surface side of the conductive substrate;
An air gap is provided between the third main surface region and the lower surface of the frame body.   A plurality of photoelectric conversion devices according to claim 4 are provided side by side, and a conductive substrate of one photoelectric conversion device and a conductive substrate of the other photoelectric conversion device are connected between adjacent photoelectric conversion devices. A photoelectric conversion module characterized by comprising:   A plurality of photoelectric conversion devices according to claim 4 are provided side by side, and a conductive substrate of one photoelectric conversion device and a conductive layer of the other photoelectric conversion device are connected between adjacent photoelectric conversion devices. A photoelectric conversion module characterized by comprising:

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