WO2019150585A1

WO2019150585A1 - Solar cell module manufacturing method, solar cell module manufacturing device, and solar cell module

Info

Publication number: WO2019150585A1
Application number: PCT/JP2018/003874
Authority: WO
Inventors: 浩昭森川; 葉影　秀徳; 智英沈
Original assignee: 三菱電機株式会社
Priority date: 2018-02-05
Filing date: 2018-02-05
Publication date: 2019-08-08
Also published as: JPWO2019150585A1

Abstract

This solar cell module manufacturing method includes a first step for directing X-rays toward a region where a first metal component and a second metal component constituting a solar panel are soldered together, and acquiring an X-ray transmission image in a region where soldering is to be carried out, which is the region where the first metal component and the second metal component overlap in a direction parallel to the in-plane direction of the solar panel. This solar cell module manufacturing method also includes a second step for calculating, from the X-ray transmission image, the area ratio of a soldering portion where the first metal component and the second metal component are actually joined by soldering to the region where soldering is to be carried out in the direction parallel to the in-plane direction of the solar panel. This solar cell module manufacturing method also includes a third step for comparing the area ratio with a predefined determination standard to determine whether the solder joint state between the first metal component and the second metal component is good or not.

Description

Solar cell module manufacturing method, solar cell module manufacturing apparatus, and solar cell module

The present invention relates to a method for manufacturing a solar cell module having a terminal box, a solar cell module manufacturing apparatus, and a solar cell module.

A solar power generation system uses direct current power from a solar cell module installed at an installation site such as a roof of a building represented by a house or a site prepared on the premise of installing a solar cell system via an inverter. Is supplied to the grid. The solar power generation system is configured by electrically connecting a plurality of solar cell modules to each other. The electrical connection between the solar cell modules is via a terminal box arranged on the back surface facing the opposite side to the light receiving surface in the solar cell module.

From the solar cell array in which all the solar cells are connected in series inside the solar cell module, the plus lead wire connected to the plus electrode and the minus lead wire connected to the minus electrode are drawn to the back side of the solar cell module. ing. The terminal box has a node point where the plus lead wire and the plus module connecting cable are connected by solder joint, and a node point where the minus lead wire and the minus module connecting cable are connected by solder joint.

The soldering part, which is an electrical connection part in the terminal box, is one of the important parts that determines the product life of the solar cell module. However, since soldering in the terminal box is often performed by a person, the degree of soldering may vary depending on the skill level of the operator. For this reason, the device for ensuring the durability of an electrical connection part is made.

Patent Document 1 discloses that a protective connecting cover protects a solder connection portion in which an end portion of an output lead wire and an end portion of a terminal electrode member are solder-connected.

JP 2001-284624 A JP 2014-190701 A

However, since the soldering state of the soldering part is generally confirmed visually, the judgment may differ depending on the skill level of the operator.

On the other hand, in recent years, in surface mounting of a printed circuit board of an electronic device, as disclosed in Patent Document 2, an X-ray inspection has been performed in order to more accurately inspect a soldered portion on the surface side of the substrate. It is coming.

However, Patent Document 2 does not mention a method for determining whether the soldering state of the soldering portion is good or bad.

The present invention has been made in view of the above, and an object of the present invention is to obtain a method for manufacturing a solar cell module capable of easily determining the soldering state of a soldered portion in the solar cell module.

In order to solve the above-described problems and achieve the object, the method for manufacturing a solar cell module according to the present invention involves soldering the first metal component and the second metal component that constitute the solar cell panel. X-ray transmission in the soldering target region, which is a region where the first metal component and the second metal component overlap in a direction parallel to the in-plane direction of the solar cell panel. A first step of acquiring an image. Further, in the method for manufacturing a solar cell module, the first metal component and the second metal component are actually solder-bonded to the area of the soldering target region in a direction parallel to the in-plane direction of the solar cell panel. A second step of calculating the area ratio of the soldered portions from the X-ray transmission image. Moreover, the manufacturing method of a solar cell module includes the 3rd process which determines the quality of the solder joint state of a 1st metal component and a 2nd metal component by comparing an area ratio with a predetermined criterion.

The method for manufacturing a solar cell module according to the present invention has an effect that the soldered state of the soldered portion in the solar cell module can be easily determined.

The perspective view which looked at the solar cell module concerning Embodiment 1 of this invention from the light-receiving surface side. The perspective view which looked at the solar cell module concerning Embodiment 1 of this invention from the back surface side which faced the opposite side to a light-receiving surface. The flowchart which shows the procedure of the manufacturing method of the solar cell module concerning Embodiment 1 of this invention. The perspective view which looked at the solar cell string concerning Embodiment 1 of this invention from the light-receiving surface side The perspective view which looked at the solar cell panel concerning Embodiment 1 of this invention from the light-receiving surface side. The perspective view which looked at the solar cell panel concerning Embodiment 1 of this invention from the back surface side. The top view which shows the state by which the terminal box main body was temporarily placed in the position near the output lead of the back surface of the solar cell panel concerning Embodiment 1 of this invention. The top view which shows the state by which the output lead and the terminal board were soldered within the terminal box main body of the back surface of the solar cell panel concerning Embodiment 1 of this invention. The perspective view which looked at the solar cell module concerning Embodiment 1 of this invention from the back surface side 1 is a schematic perspective view showing an X-ray inspection apparatus according to a first embodiment of the present invention. 1 is a configuration diagram showing a functional configuration of an X-ray inspection apparatus according to a first embodiment of the present invention. The figure which shows an example of the hardware constitutions of the processing circuit concerning Embodiment 1 of this invention. Flowchart showing the procedure of transmission X-ray inspection according to the first embodiment of the present invention. Schematic perspective view showing another configuration example of the X-ray inspection apparatus according to the first embodiment of the present invention. Schematic perspective view showing another configuration example of the X-ray inspection apparatus according to the first embodiment of the present invention. The top view of the terminal box main body which shows the imaging location of the X-ray transmission image in the transmission X-ray inspection in Embodiment 1 of this invention The figure which shows the image which image | photographed the X-ray observation area | region concerning Embodiment 1 of this invention with the stereomicroscope. The figure which shows the X-ray transmissive image of the X-ray observation area | region concerning Embodiment 1 of this invention. 18 is an X-ray transmission image obtained by enlarging the X-ray observation region according to the first embodiment of the present invention, and showing an X-ray transmission image obtained by enlarging a part of FIG. The figure which shows the image simplified by performing image processing, distinguishing a soldering part and a solder non-supply part with respect to the soldering object area | region in the X-ray transmission image of FIG. The figure which shows the X-ray transmission image which expanded the other X-ray transmission image of the X-ray observation area | region concerning Embodiment 1 of this invention. FIG. 21 is a diagram showing a simplified image obtained by performing image processing on the soldering target region of the X-ray transmission image of FIG. The top view which shows the other terminal board concerning Embodiment 1 of this invention. The side view which shows the other terminal board concerning Embodiment 1 of this invention. The figure which showed the condition of the solder unsupply part and soldering part when an output lead is connected to the other terminal board concerning Embodiment 1 of this invention FIG. 26 is a diagram showing a situation of a solder unsupplied part and a soldered part when the output lead is connected to another terminal board according to the first exemplary embodiment of the present invention, and a sectional view taken along line XXVI-XXVI in FIG. The figure which showed the condition of the solder unsupply part and soldering part when an output lead is connected to the terminal board concerning Embodiment 1 of this invention FIG. 28 is a diagram showing a situation of a solder unsupplied portion and a soldered portion when an output lead is connected to the terminal board according to the first exemplary embodiment of the present invention, and a cross-sectional view taken along line XXVIII-XXVIII in FIG. Sectional drawing which shows typically the cross section of the solder layer between a terminal board and an output lead when an output lead is connected to the terminal board concerning Embodiment 1 of this invention The figure which shows the upper surface X-ray observation image of the solder layer between a terminal board and an output lead when an output lead is connected to the terminal board concerning Embodiment 1 of this invention. Sectional drawing which shows typically the cross section of the solder layer between another terminal board and an output lead when an output lead is connected to the other terminal board concerning Embodiment 1 of this invention The figure which shows the upper surface X-ray observation image of the solder layer between another terminal board and an output lead when an output lead is connected to the other terminal board concerning Embodiment 1 of this invention. The top view which shows the positional relationship of the soldering part of the output lead and terminal board concerning Embodiment 1 of this invention, and the connection tab between cells. The perspective view which looked at the solar cell array which soldered the solar cell strings concerning Embodiment 2 of this invention with the connection tab between strings, and was connected in series from the light-receiving surface side. The flowchart which shows the procedure of the manufacturing method of the solar cell module concerning Embodiment 2 of this invention.

Hereinafter, a solar cell module manufacturing method, a solar cell module manufacturing apparatus, and a solar cell module according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a perspective view of a solar cell module 1 according to Embodiment 1 of the present invention as viewed from the light receiving surface side. FIG. 2 is a perspective view of the solar cell module 1 according to the first embodiment of the present invention as viewed from the back side facing the opposite side to the light receiving surface.

As shown in FIGS. 1 and 2, the solar cell module 1 according to the first embodiment is opposite to the light receiving surface protection component 11 disposed on the light receiving surface side in the solar cell array 3 and the light receiving surface in the solar cell array 3. It is sealed between the back surface protection component 12 arranged on the back surface side facing the side. The solar cell module 1 is surrounded by a reinforcing frame 13 at the outer peripheral edge. A terminal box 14 that is electrically connected to the solar cell array 3 is disposed on the back surface protection component 12 on the back surface side of the solar cell module 1.

The terminal box 14 is configured by attaching a terminal box lid 16 to an upper portion of a terminal box main body 15 bonded on the back surface protection component 12. Inside the terminal box 14, an output lead (not shown) drawn from the solar cell array 3 and a module connection cable 17 drawn into the terminal box 14 are connected by a cable connecting portion 18 as shown in FIG. 7 described later. Yes. The solar cell module 1 is electrically connected to another solar cell module via the module connection cable 17.

The solar cell array 3 is constituted by a plurality of later-described solar cell strings 4 that are electrically and mechanically joined in series or in parallel by inter-cell connection tabs 21 and later-described inter-string connection tabs. The solar cell string 4 is configured by electrically and mechanically connecting a plurality of solar cells 5 having a quadrangular shape arranged adjacent to each other in series between cell connection tabs 21.

FIG. 3 is a flowchart showing the procedure of the method for manufacturing the solar cell module 1 according to the first embodiment of the present invention. First, the outline | summary of the manufacturing method of the solar cell module 1 concerning this Embodiment 1 is demonstrated. FIG. 4 is a perspective view of the solar cell string 4 according to the first embodiment of the present invention as viewed from the light receiving surface side. FIG. 5 is a perspective view of the solar cell panel 2 according to the first embodiment of the present invention as viewed from the light receiving surface side. FIG. 6: is the perspective view which looked at the solar cell panel 2 concerning Embodiment 1 of this invention from the back surface side. FIG. 7 is a plan view showing a state in which the terminal box main body 15 is temporarily placed at a position near the output lead 22 on the back surface of the solar cell panel 2 according to the first embodiment of the present invention. FIG. 8 is a plan view showing a state in which the output lead 22 and the terminal plate 24 are soldered in the terminal box body 15 on the back surface of the solar cell panel 2 according to the first embodiment of the present invention. FIG. 9 is a perspective view of the solar cell module 1 according to the first embodiment of the present invention as viewed from the back side.

First, in step S10, a solar battery cell 5 that is a crystalline solar battery is manufactured by a known technique. The solar battery cell 5 is formed using a square silicon substrate having an outer dimension of 156 mm × 156 mm, that is, 156 mm square. As the silicon substrate, a single crystal silicon substrate or a polycrystalline silicon substrate is used. At present, the outer dimensions of the silicon substrate are in the direction of further expansion, and 161.75 mm × 161.75 mm, that is, a 161.75 mm square silicon substrate has been studied, and the outer dimension of the silicon substrate is 156 mm square. Not limited.

The solar cell 5 has electrodes arranged on the light receiving surface and the back surface. In the case of a solar cell fabricated using a commonly used p-type silicon substrate, an n-type electrode is disposed on the light receiving surface side and a p-type electrode is disposed on the back surface side.

In step S20, the solar cell string 4 is manufactured by connecting the plurality of solar cells 5 with the inter-cell connection tabs 21 by fixing the inter-cell connection tabs 21 to the solar cells 5 as shown in FIG. . The solar cell strings 4 are electrically connected in series by inter-cell connection tabs 21 in which, for example, a copper foil having a thickness of 160 μm and a width of 2 mm is coated with a 20 μm-thick solder, and the inter-cell connection tabs 21 are adjacent solar cells. A region on one end side is soldered to an electrode on the back surface side of one of the solar cells 5 among the cells 5. In addition, the inter-cell connection tab 21 is soldered at the other end side to the electrode on the light receiving surface side of the other solar cell 5 among the adjacent solar cells 5. In the first embodiment, the solar cell string 4 has nine solar cells 5 electrically connected in series.

Subsequently, in step S30, the four solar cell strings 4 are arranged in parallel, and the adjacent solar cell strings 4 are electrically connected in series with the lateral connection tabs. Thereby, the solar cell array 3 in which 36 solar cells 5 are electrically connected in series is manufactured. In the solar cell array 3, the solar cells 5 are arranged in an arrangement of 9 cells × 4 cells.

Subsequently, in step S40, a laminated body of components of the solar cell panel 2 is formed and laminated. Formation of a laminated body consists of a light-receiving surface sealing layer sheet | seat and the solar cell array 3, a back surface sealing layer sheet, and an insulating back surface side protective sheet on the light-receiving surface protection component 11 which consists of translucent substrates, such as a glass substrate. The back surface protection component 12 is sequentially laminated to form a laminate. For the light-receiving surface sealing layer sheet and the back surface sealing layer sheet, a transparent resin, ethylene-vinyl acetate (EVA) copolymer, is used.

Then, a solar cell panel 2 in which the solar cell array 3 is sealed is manufactured by performing a heat treatment step to heat and pressurize the laminate, and then cooling the laminate to laminate the laminate. That is, the light receiving surface protection component 11 and the solar cell array 3 are bonded by EVA of the light receiving surface sealing layer sheet, and the solar cell array 3 and the back surface protection component 12 are bonded by EVA of the back surface sealing layer sheet. The laminated body is integrated. That is, the cross-sectional structure of the solar cell panel 2 is, from the light receiving surface side, the light receiving surface protection component 11, EVA, the solar cell array 3, EVA, and the back surface protection component 12. Thereafter, as shown in FIG. 5, an aluminum frame 13 is mounted around the solar cell panel 2.

As shown in FIG. 6, on the back surface of the solar cell panel 2, a region where the terminal box main body 15 is installed is a terminal box forming portion 19. The back surface protection component 12 includes an output lead 22 a electrically connected to the solar battery cell 5 at one end of the solar battery array 3 as an output lead 22 drawn from the solar battery array 3, and a solar battery array 3. The output lead 22b electrically connected to the solar battery cell 5 at the other end is drawn out. As shown in FIG. 7, the output lead 22 a and the output lead 22 b are pulled out to the back surface of the solar cell panel 2 from a drawer cut 23 provided in the back surface protection component 12 in order to pull out the output lead 22 to the back surface of the solar cell panel 2. It is.

Next, as shown in FIG. 7, the terminal box main body 15 is temporarily placed on the terminal box forming portion 19 near the output lead 22 a and the output lead 22 b on the back surface protection component 12. The module connection cable 17 is drawn into the terminal box body 15 in advance and is electrically connected to the terminal plate 24 disposed inside the terminal box body 15. Then, as shown in FIG. 7, the output lead 22 a and the output lead 22 b are drawn out into the terminal box body 15 from the bottom surface output lead insertion hole 15 b provided on the bottom surface 15 a of the terminal box body 15. The bottom surface output lead insertion hole 15 b is an insertion hole provided in the bottom surface of the terminal box body 15 in order to draw the output lead 22 from the bottom surface 15 a of the terminal box body 15 into the terminal box body 15.

In step S50, the terminal box body 15 is bonded onto the temporarily placed back surface protection component 12.

Subsequently, soldering is performed inside the terminal box body 15 in step S60. As shown in FIG. 8, the output lead 22 a and the output lead 22 b drawn out inside the terminal box main body 15 are soldered inside the terminal box main body 15 and the terminal plate 24 connected to the module connecting cable 17. When the output lead 22 a and the output lead 22 b are soldered to the terminal plate 24, the output lead 22 a and the output lead 22 b are wound around the output lead insertion hole 25 opened in the terminal plate 24 with pliers or the like. In this manner, the output lead 22a and the output lead 22b and the terminal plate 24 are brought into close contact with each other, so that the output lead 22a and the output lead 22b and the terminal plate 24 are kept in contact with each other.

In this state, soldering is performed using a soldering iron while supplying solder between the output lead 22a and the terminal plate 24. Similarly, soldering is performed using a soldering iron while supplying solder between the output lead 22 b and the terminal plate 24. The output lead 22a and the output lead 22b are coated with solder at a thickness of, for example, 30 μm in the area to be soldered to the terminal board 24.

Subsequently, in step S70, a transmission X-ray inspection is performed on the solar cell panel 2, and it is determined whether the soldering state between the output lead 22 and the terminal plate 24 satisfies a predetermined determination criterion. That is, the transmission X-ray inspection is performed in a state where the terminal box body 15 is bonded to the back surface protection component 12 on the back side of the solar cell panel 2 and the output lead 22 and the terminal plate 24 are soldered.

In the transmission X-ray inspection, the area to be soldered between the output lead 22 and the terminal board 24 is imaged with X-rays, and the soldering between the output lead 22 and the terminal board 24 is in an appropriate soldering state. Or whether the soldering state is inappropriate. That is, the X-ray image transmitted through the soldering target region between the output lead 22 and the terminal plate 24 is analyzed by irradiating the soldering target region between the output lead 22 and the terminal plate 24 with X-rays, The soldering state between the output lead 22 and the terminal board 24 is automatically determined according to a predetermined criterion. The soldering target region between the output lead 22 and the terminal plate 24 is a region where the output lead 22 and the terminal plate 24 overlap in a direction parallel to the in-plane direction of the solar cell panel 2. The predetermined criterion is a criterion for determining whether the soldering between the output lead 22 and the terminal board 24 is an appropriate soldering state or an inappropriate soldering state. Details of the transmission X-ray inspection will be described later.

If the soldering target area between the output lead 22 and the terminal board 24 does not satisfy the predetermined criterion, the result is No in step S70 and the process returns to step S60 to solder the output lead 22 and the terminal board 24. Is done again. As a result, it is possible to eliminate a soldering failure between the output lead 22 and the terminal plate 24.

If the soldering target area between the output lead 22 and the terminal board 24 satisfies a predetermined determination criterion, the result is Yes in step S70 and the process proceeds to step S80.

In step S80, a potting agent (not shown) is filled in the terminal box body 15. The potting agent is, for example, a resin. Further, as shown in FIG. 9, the terminal box lid 16 is attached to the upper part of the terminal box body 15 to form the terminal box 14. Thereby, the solar cell module 1 is manufactured.

Subsequently, in step S90, the output inspection of the solar cell module 1 is performed, and a series of processes for manufacturing the solar cell module 1 is completed.

Next, the details of the transmission X-ray inspection for the solar cell panel 2 will be described. FIG. 10 is a schematic perspective view showing the X-ray inspection apparatus 200 according to the first embodiment of the present invention. FIG. 11 is a configuration diagram showing a functional configuration of the X-ray inspection apparatus 200 according to the first embodiment of the present invention. The X-ray inspection apparatus 200 is used for manufacturing a solar cell module, and is a solar cell module manufacturing apparatus that inspects the solder joint state between the first metal component and the second metal component that constitute the solar cell panel 2. . The X-ray inspection apparatus 200 includes a transfer device 201, an X-ray generation device 202, an X-ray nondestructive inspection camera 203, a control device 204, and a display unit 205.

The transport device 201 is configured to horizontally support and transport the solar cell panel 2 to be inspected with the back side facing upward. The transport device 201 is a conveyor configured to include, for example, a belt on which the solar battery panel 2 is placed, a transport roller (not illustrated) that moves the belt, a drive mechanism (not illustrated) that drives the transport roller, and the like. .

The X-ray generator 202 irradiates the X-ray 206 toward the terminal box body 15 of the solar cell panel 2 transported by the transport device 201. The X-ray generation apparatus 202 limits an emission angle of an X-ray source (not shown) that generates a conical X-ray 206 and an X-ray 206 generated from the X-ray source to form an X-ray belt-like beam. And the restriction part.

The X-ray nondestructive inspection camera 203 is a detector that detects the X-ray 206 that has passed through the soldering target region between the output lead 22 and the terminal plate 24 in the solar battery panel 2 and generates an X-ray transmission signal. is there. The X-ray generator 202 is an X-ray non-destructive inspection camera 203, which is disposed above the transfer device 201 in a direction parallel to the in-plane direction of the solar cell panel 2, that is, extending in the horizontal direction. It has a non-destructive inspection camera 203a. The X-ray nondestructive inspection camera 203 is configured by arranging pixels of a large number of light receiving elements that receive the X-ray 206. In the first embodiment, a charge-coupled device (CCD) camera is used as the X-ray nondestructive inspection camera 203. Note that a line sensor may be used as the X-ray nondestructive inspection camera 203.

The control device 204 includes an X-ray control unit 204a, a conveyance control unit 204b, an image information generation unit 204c, a calculation unit 204d, and a determination unit 204e.

The X-ray control unit 204a controls the X-ray generator 202 to irradiate the X-ray 206 from the X-ray generator 202.

The conveyance control unit 204b controls the conveyance device 201 to convey the solar cell panel 2.

The image information generation unit 204c takes in the X-ray transmission signal generated by the X-ray nondestructive inspection camera 203 and generates image information of the X-ray transmission image. In the generation of the image information in the image information generation unit 204c, various conventionally known image processes are used. When the X-ray 206 irradiated from the X-ray generator 202 and transmitted through the solar battery panel 2 is detected by the X-ray nondestructive inspection camera 203, an X-ray transmission signal having a luminance corresponding to the intensity distribution of the X-ray 206 is X. It is generated by the non-destructive inspection camera 203.

The calculation unit 204d calculates the area ratio of the soldering portion where the terminal plate 24 and the output lead 22 are actually soldered to the area of the soldering target region in the direction parallel to the in-plane direction of the solar battery panel 2. And calculation from an X-ray transmission image.

The determination unit 204e determines whether the solder joint state between the terminal board 24 and the output lead 22 is good or not. The determination unit 204e compares the area ratio of the soldered portion where the terminal plate 24 and the output lead 22 are actually soldered to the area of the soldering target region with a predetermined determination criterion stored in advance. The quality of the solder joint state is determined.

Further, the control device 204 is realized, for example, as a processing circuit having a hardware configuration shown in FIG. FIG. 12 is a diagram illustrating an example of a hardware configuration of the processing circuit according to the first embodiment of the present invention. When the control device 204 is realized by the processing circuit shown in FIG. 12, the control device 204 is realized by, for example, the processor 111 executing a program stored in the memory 112 shown in FIG. A plurality of processors and a plurality of memories may cooperate to realize the above function. Further, a part of the function of the control device 204 may be mounted as an electronic circuit, and the other part may be realized using the processor 111 and the memory 112.

Display unit 205 displays an X-ray transmission image and other information.

In addition, the X-ray control unit 204a, the X-ray nondestructive inspection camera 203a, and a part of the transfer apparatus 201 are covered with a housing 207, and leakage of X-rays unnecessary for transmission X-ray inspection is prevented. Is prevented. The control device 204 may be provided inside the housing 207 or may be provided outside the housing 207.

Next, the procedure of the transmission X-ray inspection for the solar cell panel 2 will be described. FIG. 13 is a flowchart showing the procedure of the transmission X-ray inspection according to the first embodiment of the present invention. In the transmission X-ray inspection, an X-ray transmission image acquisition process, a calculation process, and a determination process are sequentially performed.

In step S210, an X-ray transmission image acquisition process is performed. In the X-ray transmission image acquisition step, X-rays are irradiated toward the area where the terminal plate 24 and the output lead 22 constituting the solar cell panel 2 are soldered, and in the in-plane direction of the solar cell panel 2. An X-ray transmission image is acquired in a soldering target region, which is a region where the terminal board 24 and the output lead 22 overlap in a parallel direction.

In the X-ray transmission image acquisition process, the solar cell panel 2 is placed on the transfer device 201. Then, the X-ray generator 202 irradiates the X-ray 206 toward the terminal box body 15 of the solar cell panel 2 placed on the transport device 201. Further, the solar cell panel 2 is transported by the transport device 201. The X-ray nondestructive inspection camera 203 detects the X-ray 206 that has passed through the periphery of the terminal box body 15, images the periphery of the terminal box body 15, and generates an X-ray transmission signal. Then, the image information generation unit 204c takes in the X-ray transmission signal generated by the X-ray nondestructive inspection camera 203 and generates image information of the X-ray transmission image around the terminal box body 15 including the soldering target region. To do.

Next, in step S220, a calculation process is performed. In the calculation process, the calculation unit 204d is actually a soldered part in which the terminal plate 24 and the output lead 22 are soldered to the area of the soldering target region in a direction parallel to the in-plane direction of the solar battery panel 2. Is calculated from the X-ray transmission image.

Next, in step S230, a determination process is performed. In the determination step, the determination unit 204e compares the area ratio of the soldered portion where the terminal plate 24 and the output lead 22 are actually soldered with respect to the area of the soldering target region to a predetermined determination standard. The quality of the solder joint state between the output lead 22 and the output lead 22 is determined.

Here, the terminal plate 24 corresponds to the first metal component constituting the solar cell panel 2. The output lead 22 corresponds to a second metal part that constitutes the solar cell panel 2.

In the X-ray inspection apparatus 200 shown in FIG. 10, an X-ray belt-like beam is radiated from the X-ray generation apparatus 202 in the horizontal direction and upward direction, and the X-ray nondestructive inspection camera 203a It is possible to detect the X-ray 206 transmitted through the soldering target area. Thereby, a two-dimensional X-ray transmission image parallel to the in-plane direction of the solar cell panel 2 is obtained.

Basically, the two-dimensional X-ray transmission image is obtained by the X-ray non-destructive inspection by moving the solar cell panel 2 placed on the transfer device 201 in the traveling direction 208 of the transfer device 201 with respect to the X-ray belt-like beam. The X-ray transmission signal generated by the camera 203a is captured by the image information generation unit 204c and rendered as two-dimensional image information.

FIG. 14 is a schematic perspective view showing another configuration example of the X-ray inspection apparatus 200 according to the first embodiment of the present invention. In the X-ray inspection apparatus shown in FIG. 14, a line sensor is used for the X-ray nondestructive inspection camera 203. In the X-ray inspection apparatus shown in FIG. 14, an X-ray belt-like beam is radiated in the horizontal direction and the upward direction from the X-ray generator 202 while the solar cell panel 2 is transported by the transport device 201. In the present apparatus, the X-ray 206 that has passed through the soldering target region between the output lead 22 and the terminal plate 24 is parallel to the in-plane direction of the solar cell panel 2 above the transfer device 201, that is, in the horizontal direction. Detection is performed by an X-ray line sensor 203al arranged so as to extend. Further, in this apparatus, the X-ray 206 that has passed through the soldering target region between the output lead 22 and the terminal plate 24 is orthogonal to the in-plane direction of the solar cell panel 2 and is along the transport direction of the solar cell panel 2. It is also detected by the X-ray line sensor 203bl that extends in the direction and is disposed on the side of the transport device 201 in a direction orthogonal to the transport direction of the solar cell panel 2. The conveyance direction of the solar cell panel 2 is the same direction as the traveling direction 208 of the conveyance device 201.

FIG. 15 is a schematic perspective view showing another configuration example of the X-ray inspection apparatus 200 according to the first embodiment of the present invention. In the X-ray inspection apparatus shown in FIG. 15, a line sensor is used for the X-ray nondestructive inspection camera 203. In the X-ray inspection apparatus shown in FIG. 15, an X-ray belt-like beam is emitted upward from an X-ray generator 202 a disposed under the transfer apparatus 201 while the transfer panel 201 transfers the solar battery panel 2, and an output lead X-ray 206 transmitted through the soldering target area between the terminal board 24 and the terminal board 24 can be detected by the X-ray line sensor 203al. In the X-ray inspection apparatus shown in FIG. 15, an X-ray belt-like beam is radiated in the horizontal direction from the X-ray generator 202 b disposed on the side surface of the transfer apparatus 201, and between the output lead 22 and the terminal plate 24. The X-ray 206 transmitted through the soldering target area can be detected by the X-ray line sensor 203bl.

14 and 15, by using the information of the X-ray 206 detected by the X-ray line sensor 203al and the information of the X-ray 206 detected by the X-ray line sensor 203bl, the direction perpendicular to the traveling direction 208 of the transport device 201 is used. A two-dimensional X-ray transmission image of a longitudinal section can be obtained. Further, while conveying the solar cell panel 2 by the conveying device 201, the X-ray band beam is emitted from the X-ray generating device 202a and the X-ray generating device 202b, and the information of the X-ray 206 detected by the X-ray line sensor 203al By using the information of the X-ray 206 detected by the line line sensor 203bl, a three-dimensional X-ray transmission image including the traveling direction 208 of the transport device 201 is obtained.

Further, in FIG. 15, the X-ray transmission signal generated by the X-ray line sensor 203bl is captured by the image information generation unit 204c and drawn as two-dimensional image information, so that the information in the height direction of the solar cell panel 2 and the output are output. Information on the solder thickness in the soldering target region between the lead 22 and the terminal board 24 is obtained.

FIG. 16 is a plan view of the terminal box main body 15 showing an X-ray transmission image capturing location in the transmission X-ray inspection in the first embodiment of the present invention. In the transmission X-ray inspection in the first embodiment, the inspection is performed by observing the X-ray observation region 120 in FIG. Hereinafter, observation results of the X-ray observation region 120 will be described. The X-ray output conditions in the observation of the X-ray observation region 120 were a tube voltage in the range of 50 kV to 160 kV and a tube current in the range of 40 μA to 120 μA. By using such X-ray output conditions, an X-ray transmission image of the X-ray observation region 120 can be obtained with certainty. By setting the lower limit of the tube voltage to 50 kV, a clear X-ray transmission image of the X-ray observation region 120 can be obtained. The upper limit value of the tube voltage, 160 kV, is a restriction on the device performance. The tube current range is an appropriate range in which a clear X-ray transmission image of the X-ray observation region 120 can be obtained in the tube voltage range. *

FIG. 17 is a view showing an image obtained by photographing the X-ray observation region 120 according to the first embodiment of the present invention with a stereomicroscope. Solder 26 is stacked on the output lead 22 and the other terminal plate 24a. 17 to 22 show a case where another terminal plate 24a, which is a more preferable form of the terminal plate 24, and the output lead 22 are soldered as will be described later. Details of the other terminal board 24a will be described later. FIG. 18 is a diagram showing an X-ray transmission image of the X-ray observation region 120 according to the first embodiment of the present invention. In the X-ray transmission image of FIG. 18, it can be seen that the solder 26 is supplied between the output lead 22 and the other terminal plate 24a, and the solder 26 is interposed between the output lead 22 and the other terminal plate 24a. Solder 26 is filled between the solder unsupplied portion 212 where there is a gap because it is not filled and the output lead 22 and the other terminal plate 24a, and the output lead 22 and the other terminal plate 24a are soldered. It is possible to distinguish and observe the soldering portions 211 that are present. The solder unsupplied portion 212 is in the case where the solder is not supplied to all regions in the thickness direction between the output lead 22 and the other terminal plate 24a, and in the thickness direction between the output lead 22 and the other terminal plate 24a. Including a case where solder is not supplied to some areas.

FIG. 19 is an X-ray transmission image obtained by enlarging the X-ray observation region 120 according to the first embodiment of the present invention, and shows an X-ray transmission image obtained by enlarging a part of FIG. FIG. 20 is a diagram showing a simplified image obtained by subjecting the soldering target region 221 in the X-ray transmission image of FIG. 19 to image processing by distinguishing between the soldering portion 211 and the solder non-supplying portion 212. From FIG. 20, it is observed that there are a plurality of solder non-supply parts 212 in addition to the solder non-supply part 212 present at the center of the soldering part 211.

FIG. 21 is a diagram showing an X-ray transmission image obtained by enlarging another X-ray transmission image of the X-ray observation region 120 according to the first embodiment of the present invention. FIG. 22 is a diagram illustrating a simplified image obtained by performing image processing on the soldering target area 221 of the X-ray transmission image of FIG. From FIG. 22, it is observed that the solder unsupplied portion 212 occupies a large area in the soldering target region 221 between the output lead 22 and the other terminal plate 24a, and the soldered portion 211 exists partially. Is done.

As described above, depending on the soldering state in the soldering target region 221 between the output lead 22 and the other terminal plate 24a, the solder unsupplied portion 212 is connected to the output lead 22 and the other terminal plate. In the soldering target region 221 between 24a and 24a, the area of the soldering part 211 may be different. Based on the above knowledge, the inventor uses the X-ray transmission image of the soldering target region 221 in the direction parallel to the in-plane direction of the solar cell panel 2 and the soldering portion 211 in the area of the soldering target region 221. It has been found that by deriving the area ratio, it is possible to determine the state of solder bonding in the soldering target region 221, that is, the degree of solder bonding.

Currently, regarding the reliability of the solar cell module, the degree of soldering is grasped by a temperature cycle test. Generally, a temperature cycle test A-1 of JIS8917 is performed as the temperature cycle test. The specified number of cycles in the temperature cycle test of JIS8917 is 200 cycles. In the pass range of this test, the degree of deterioration with respect to the initial value after the test is less than 5%. Manufacturers of solar cell modules have estimated lifetimes of, for example, several tens of years by uniquely defining temperature ranges and cycle numbers based on these conditions. In the first embodiment, an example in which the degree of deterioration in 1000 cycles is evaluated will be described.

The degree of deterioration with respect to the initial value has a correlation with the number of temperature cycles and the area of the soldering part 211. As a result of the inventor's investigation, in the case of 1000 cycles, when the area ratio of the soldering portion 211 to the area in the surface of the soldering target region exceeds 7% in the direction parallel to the in-plane direction of the solar cell panel 2. It was confirmed that the degree of deterioration was suppressed to less than 5%. In the case of FIG. 20 described above, the area ratio of the soldering part 211 to the in-plane area of the soldering target region is about 90% and exceeds 7%, so that the degree of deterioration satisfies the requirement of less than 5%. . On the other hand, in the case of FIG. 22 described above, the area ratio of the soldering portion 211 to the in-plane area of the soldering target region is about 4% and does not exceed 7%, so the degree of deterioration is less than 5%. Does not meet regulations.

As in the above example, in the direction parallel to the in-plane direction of the solar cell panel 2, the area ratio of the soldering part 211 to the in-plane area of the soldering target region is set, and the degree of deterioration is less than 5%. For the solar battery panel 2 that does not satisfy the regulations, the soldering failure between the output lead 22 and the other terminal plate 24a is eliminated by performing the soldering between the output lead 22 and the other terminal plate 24a again. It becomes possible. In FIGS. 17 to 22, as an example of an X-ray transmission image in the transmission X-ray inspection, a case where the other terminal board 24 a and the output lead 22 are soldered is shown. Even in the case where the terminal board 24 and the output lead 22 that are not formed are soldered, it is possible to eliminate the soldering failure between the terminal board 24 and the output lead 22 in the same manner. That is, in a direction parallel to the in-plane direction of the solar cell panel 2, the area ratio of the soldering portion 211 to the in-plane area of the soldering target region is set, and the degree of deterioration is less than 5%. For the battery panel 2, soldering between the output lead 22 and the terminal plate 24 may be performed again.

FIG. 23 is a plan view showing another terminal board 24a according to the first embodiment of the present invention. FIG. 24 is a side view showing another terminal board 24a according to the first embodiment of the present invention. 23 and 24 have a groove 27 in the region including the soldering target region in the configuration of the terminal plate 24 in order to make the solder unsupplied portion 212 in the X-ray transmission image clearer. It is the formed terminal board.

The dimensions of the groove 27 are, for example, a width x of 1 mm and a depth y of 0.2 mm. The width x is a length in a direction parallel to the width direction of the output lead 22 soldered to the other terminal plate 24a. When the thickness of the solder unsupplied portion 212 is greater than 0.1 mm, the contrast between the solder unsupplied portion 212 and the soldered portion 211 in the X-ray transmitted image becomes strong. The sharpness of 212 becomes higher. For this reason, the depth y is set to 0.2 mm with a margin. For example, in FIG. 19, the image of the solder unsupplied portion 212 existing in the region where the groove 27 is formed is clearer than the image of the other solder unsupplied portion 212 existing in the region where the groove 27 is not formed. . It is preferable that a part of the interval between the output lead 22 and the other terminal plate 24a is soldered at a thickness greater than at least 0.1 mm. That is, when soldering the output lead 22 and the other terminal plate 24a, the solder is supplied so that a part of the interval between the output lead 22 and the other terminal plate 24a is at least thicker than 0.1 mm. It is preferable to perform soldering. It is more preferable that all the intervals between the output lead 22 and the other terminal plate 24a are soldered at a thickness greater than at least 0.1 mm.

Further, it is preferable that the width of the groove 27 is 10% or more of the length in the length direction of the output lead 22 in the soldering target region, and the depth is larger than 0.1 mm. Thereby, the sharpness of the solder non-supplying portion 212 in the X-ray transmission image becomes higher. When the width of the groove 27 is less than 10% of the width in the length direction of the output lead 22 in the soldering target region, the reliability of the solder joint between the output lead 22 and the other terminal plate 24a with respect to the temperature cycle is ensured. Therefore, a clear X-ray transmission image can be obtained for securing the area ratio of the soldering portion where the other terminal plate 24a and the output lead 22 are actually soldered to the area of the soldering target region necessary for the purpose. The area area is narrowed. As a result, in the X-ray inspection apparatus 200, it is difficult to automatically determine whether or not the solder joint state between the other terminal plate 24a and the output lead 22 is good. The upper limit of the width of the groove 27 is a length in a range in which contact with the bottom surface of the groove 27 due to the deflection of the output lead 22 does not occur in consideration of the mechanical strength of the output lead 22.

Further, it is preferable that the groove 27 has a width of 1 mm or more and a depth of more than 0.1 mm. Thereby, the sharpness of the solder non-supplying portion 212 in the X-ray transmission image becomes higher. When the width of the groove 27 is less than 1 mm, the area of the soldering target area necessary for ensuring the reliability of the solder joint between the output lead 22 and the other terminal plate 24a with respect to the temperature cycle as described above. The area of the area where a clear X-ray transmission image for securing the area ratio of the soldered portion where the other terminal plate 24a and the output lead 22 are actually soldered is reduced. As a result, in the X-ray inspection apparatus 200, it is difficult to automatically determine whether or not the solder joint state between the other terminal plate 24a and the output lead 22 is good. The upper limit of the width of the groove 27 is when the thickness of the output lead 22 is 100 μm thick without including the solder arranged above and below, that is, when the actual thickness of the output lead 22 is 100 μm. Considering the mechanical strength, the length of the output lead 22 is 2 mm in a range where the output lead 22 is bent and does not contact the bottom surface of the groove 27.

FIG. 25 is a diagram showing the situation of the solder unsupply part 212a and the soldering part 211 when the output lead 22 is connected to the other terminal plate 24a according to the first embodiment of the present invention. Note that FIG. 25 shows a state seen through the output lead 22. FIG. 26 is a diagram illustrating a situation of the solder unsupplied portion 212a and the soldered portion 211 when the output lead 22 is connected to the other terminal plate 24a according to the first embodiment of the present invention. It is sectional drawing in the XXVI-XXVI line. In FIG. 26, the output lead 22 is shown. FIG. 27 is a diagram showing the state of the solder

unsupplied portions

212b and 212c and the soldering portion 211 when the output lead 22 is connected to the terminal plate 24 according to the first embodiment of the present invention. FIG. 27 shows a state seen through the output lead 22. A groove 27 is not formed in the terminal plate 24. FIG. 28 is a diagram showing a situation of the solder

unsupplied parts

212b and 212c and the soldering part 211 when the output lead 22 is connected to the terminal plate 24 according to the first embodiment of the present invention. It is sectional drawing in the XXVIII-XXVIII line. In FIG. 28, the output lead 22 is shown.

When soldering the output lead 22 to the terminal plate 24 or another terminal plate 24a, the output lead 22 is temporarily fixed by being tangled to the terminal plate 24 or another terminal plate 24a as described above. To do. For this reason, it is difficult to hold the opposing surfaces of the output lead 22 and the terminal plate 24 or other terminal plate 24a in parallel during the soldering operation. Further, although the amount of solder used for soldering is controlled to be constant, it is difficult to make the amount of solder 26 supplied between the output lead 22 and the terminal plate 24 or another terminal plate 24a constant. .

In the example shown in FIG. 26, the output lead 22 and the other terminal plate 24a are not parallel, and the interval between the output lead 22 and the other terminal plate 24a is h1 at one end and h2 at the other end. H1> h2. In the example shown in FIG. 26, the solder non-supply portion 212a exists in the region where the groove 27 is formed. And the thickness of the solder unsupply part 212a is larger than at least 0.2 mm which is the depth of the groove 27. Accordingly, when the X-ray transmission image of the example shown in FIG. 26 is observed, the contrast between the non-solder supply part 212a and the soldering part 211 becomes strong, so that the clear solder non-supply part 212a in the X-ray transmission image is clear. The degree becomes higher.

On the other hand, in the example shown in FIG. 28, the output lead 22 and the terminal plate 24 are not parallel, and the distance between the output lead 22 and the terminal plate 24 is h3 at one end and h4 at the other end. , H3> h4. In the example shown in FIG. 28, the terminal plate 24 does not have the groove 27. When the thickness of the solder unsupplied portion 212b is close to the lower limit at which a clear image is obtained in the X-ray transmission image, the solder non-supply portion 212c existing around h4 is difficult to discriminate in the X-ray transmission image. There is a case.

Therefore, it is preferable to form the groove 27 in the terminal plate 24 so that the thickness of the solder non-supply part 212 is increased when the solder non-supply part 212 is formed.

Further, the output lead 22 may be entangled with the terminal plate 24 in advance so that the distance between the output lead 22 and the terminal plate 24 is larger than the thickness near the lower limit at which a clear image can be obtained in the X-ray transmission image. In this case, for example, soldering is performed while supplying the solder while temporarily holding the terminal board 24 with a dedicated jig or the like coated with polytetrafluoroethylene to which no solder adheres.

The definition of the X-ray transmission image will be described with reference to FIG. The target portions are the output lead 22, the solder 26 of the other terminal plate 24 a, and the solder unsupplied portion 212 a. When the X-rays passing through the solder 26 pass through the solder 26, a part of the X-rays is absorbed by the solder 26 and attenuates. The attenuation is expressed by Lambert-Beer's law. For example, even when the solder unsupply portion 212a, that is, the atmospheric transmittance is 1, and the transmittance of the solder 26 is 0.99, which is slightly smaller than the transmittance 1, for example. The ratio of the intensity of X-rays transmitted through the solder 26 and the intensity of X-rays transmitted through the solder unsupplied portion 212a is about 3 times when the thickness of the solder 26 is 0.1 mm, and about 5 times when the thickness of the solder 26 is 0.2 mm. Become. On the other hand, when the resolution of the X-ray nondestructive inspection camera 203 is a megapixel specification, if the field of view is 20 mm square or more, the resolution is about 50 μm, and therefore, it is possible to detect the submillimeter solder unsupplied portion 212a. Become. From the above relationship, the depth of the groove 27 of the terminal board 24 is 0.2 mm, and the specification is carried out with an increased clarity.

Lambert-Beer's law is that the intensity of radiation before entering an object is I ₀ , the intensity of radiation after passing through the object is I, the thickness of the object is x, and the absorption coefficient of the object is μ. The following formula (1) is established.

I = I ₀ e ^−μx (1)

In FIG. 28, consider a case where the X-ray transmission image is unclear at the other end where the distance between the output lead 22 and the terminal plate 24 is h4. In this case, the detected intensity of the X-ray at the portion where the solder exists near the other end is set to 1 / a. The X-ray detection intensity is set to 1 because the X-rays are completely transmitted through the solder non-supply part 212b and the solder non-supply part 212c. Therefore, the difference in detected X-ray intensity between the solder unsupplied portion 212b and the solder unsupplied portion 212c and the vicinity of the other end is 1-1 / a.

In FIG. 26, the detected intensity of the X-ray near the other end where the distance between the output lead 22 and the other terminal plate 24a is h2 is 1 / a. In addition, the interval between the output lead 22 and the other terminal plate 24a in a part of the formation part of the groove 27 is h5. From the Lambert-Beer law, the detected intensity of X-rays at the formation portion of the groove 27 is expressed as (1 / a) ^{h5 / h2} . Here, h2 = h4. The X-ray detection intensity is 1 because the X-rays are completely transmitted through the solder unsupplied portion 212a. Therefore, the difference in detected X-ray intensity between the other end and the portion where the groove 27 is formed is 1− (1 / a) ^{h5 / h2} .

Here, when the X-ray transmission image near the other end is unclear, for example, when h2 = 0.05 mm, the depth of the groove 27 = 0.2 mm, and 1 / a = 0.99, the other end The detected intensity of the X-ray near the portion is 1-1 / a = 0.01. On the other hand, the detected intensity of X-rays at the formation portion of the groove 27 is 1− (1 / a) ^{h5 / h2} = 0.05. Therefore, the ratio of the X-ray detection intensity is 5 times between the other end and the formation part of the groove 27. If the distance between the output lead 22 and the other terminal plate 24a in the groove 27 forming portion when the depth of the groove 27 is 0.1 mm is h6, the detected intensity of X-rays in the groove 27 forming portion. Is 1− (1 / a) ^{h6 / h2} = 0.03, and the ratio of the detected intensity of X-rays is tripled between the other end and the portion where the groove 27 is formed. In the first embodiment, the lower limit of the X-ray detection intensity ratio between the other end and the groove 27 forming portion is set to 3 times.

In addition, since the amount of X-ray transmitted through the solder decreases as the thickness of the solder increases, if the thickness of the solder unsupplied portion 212 to which no solder is supplied is constant, the presence or absence of solder increases as the thickness of the solder increases. The difference in contrast of the X-ray transmission image due to is increased. Therefore, by forming the groove 27 described above, it also has a function of strengthening the difference in contrast of the X-ray transmission image when the solder non-supplying portion 212 occurs.

Here, the concept of pixel resolution in the X-ray nondestructive inspection camera 203 will be described. The pixel resolution is determined by the number of pixels of the CCD of the X-ray nondestructive inspection camera 203 and the size of the visual field projected by the X-ray nondestructive inspection camera 203. The CCD is an image sensor and is composed of a collection of small elements called pixels, which convert the intensity of brightness into electrical signals. At present, 310,000 pixels are standard for industrial X-ray nondestructive inspection cameras 203. The high-performance X-ray non-destructive inspection camera 203 is mainly a 5 megapixel camera called a megapixel type.

In addition, the visual field here is a range that appears as an image when the image is captured by the X-ray nondestructive inspection camera 203. The field of view can be freely changed from a wide field of view to a narrow field of view by adjusting the lens used in the X-ray nondestructive inspection camera 203. In the diagrams shown in FIGS. 19 to 22, the range of the visual field is 5 mm in length and 4 mm in width. Therefore, the 20 mm square field of view is based on the range of the field of view in the drawings shown in FIGS. 19 to 22 which is 5 mm long × 4 mm wide = 20 mm square. The actual size of the X-ray observation region 120 shown in FIGS. 17 and 18 is 15 mm square.

The clarity of the X-ray transmission image will be described with reference to FIGS. 29 is a cross-sectional view schematically showing a cross section of the solder layer 231 between the terminal plate 24 and the output lead 22 when the output lead 22 is connected to the terminal plate 24 according to the first embodiment of the present invention. It is. FIG. 30 is a view showing an upper surface X-ray observation image of the solder layer 231 between the terminal plate 24 and the output lead 22 when the output lead 22 is connected to the terminal plate 24 according to the first embodiment of the present invention. It is. 30 is an X-ray observation image when X-rays 206 are detected above the output lead 22 by irradiating the solder-bonded terminal plate 24 and the output lead 22 with X-rays from below the terminal plate 24. It is a line transmission image.

FIG. 31 is a schematic cross-sectional view of the solder layer 231 between the other terminal plate 24a and the output lead 22 when the output lead 22 is connected to the other terminal plate 24a according to the first embodiment of the present invention. FIG. FIG. 32 shows an upper surface X-ray observation of the solder layer 231 between the other terminal plate 24a and the output lead 22 when the output lead 22 is connected to the other terminal plate 24a according to the first embodiment of the present invention. It is a figure which shows an image. 32, the X-ray 206 is detected above the output lead 22 by irradiating X-rays from below the other terminal plate 24a on the other terminal plate 24a and the output lead 22 that are soldered together. It is an X-ray transmission image in the case of. The depth of the groove 27 in the other terminal plate 24a is 0.2 mm.

29 and FIG. 30, the solder layer 231 includes a void 232a and a void 232b, which are solder unsupplied portions 212a, in the soldering portion 211. As shown in FIG. In the example shown in FIG. 29, the output lead 22 and the terminal plate 24 are not parallel, and the interval between the output lead 22 and the terminal plate 24 is h3 at one end, and h4 at the other end. > H4. In the example shown in FIG. 29, the terminal plate 24 has no groove 27. When the thickness of the void 232a is close to the lower limit at which a clear image is obtained in the X-ray transmission image, the void 232a is determined in the upper surface X-ray observation image of FIG. On the other hand, in the void 232b existing around the other end, the thickness of the solder layer 231 is thinner than the lower limit at which a clear image is obtained in the X-ray transmission image, and it may be difficult to distinguish in the X-ray transmission image.

As shown in FIGS. 31 and 32, the solder layer 231 includes a void 232c and a void 232d that are not supplied with the solder 212a in the soldering portion 211. In the example shown in FIG. 31, the output lead 22 and the other terminal plate 24a are not parallel, and the distance between the output lead 22 and the other terminal plate 24a is h1 at one end and h2 at the other end. H1> h2. In the example shown in FIG. 31, the void 232c and the void 232d exist in the region where the groove 27 is formed. The thickness of the void 232d is greater than at least 0.2 mm, which is the depth of the groove 27. Thereby, when the X-ray transmission image of the example shown in FIG. 31 is observed, the contrast between the void 232d and the soldering portion 211 becomes strong, so the sharpness of the void 232d in the upper surface X-ray observation image of FIG. Get higher.

In addition, the solder layer 231 becomes thicker in the groove 27 portion, and even if there is a difference in the thickness of the solder layer 231 due to the inclination, the influence on the contrast between the soldered portion 211 and the solder unsupplied portion 212a in the X-ray transmission image. Less is. Therefore, when the X-ray transmission image of the example shown in FIG. 32 is observed, the contrast between the void 232d and the soldering portion 211 becomes stronger, so that the upper surface X-ray observation image of FIG. A void 232c that is thin and buried in the groove 27 can be identified.

Further, in order to obtain a clear X-ray transmission image, it is preferable to arrange the terminal box 14 so that only the soldered portions 211 of the output lead 22 and the terminal plate 24 exist in the cross-sectional structure of the solar cell module 1. . The cross-sectional structure of the lower portion of the terminal box 14 in the terminal box forming portion 19 is such that components are arranged in the order of adhesive, back surface protection component 12, EVA, solar battery cell 5, EVA, and light receiving surface protection component 11 from the back side. .

Currently, in the case of a generally manufactured solar cell 5, four or five inter-cell connection tabs 21 are arranged at equal intervals in one solar cell 5, and output leads 22 and terminals There is a possibility that the inter-cell connection tab 21 is disposed below the soldering portion of the plate 24.

FIG. 33 is a plan view showing a positional relationship between the soldered portions of the output lead 22 and the terminal plate 24 and the inter-cell connection tab 21 according to the first embodiment of the present invention. Among the materials constituting the solar cell module 1 described above, the one having a relatively high X-ray absorption rate is the inter-cell connection tab 21 covered with solder. Therefore, as shown in FIG. It is preferable to arrange so that the soldered portion of the terminal plate 24 and the inter-cell connection tab 21 do not overlap. That is, when arranging the terminal box 14 on the solar cell panel 2, it is preferable to arrange the terminal box 14 at a position that does not overlap the inter-cell connection tab 21 in the in-plane direction of the solar cell panel 2. On the other hand, other materials have a relatively low X-ray absorptance and have little effect on the sharpness of the X-ray transmission image, and thus do not cause a problem.

As described above, in the method for manufacturing the solar cell module according to the first embodiment, the soldered state between the output lead 22 and the terminal plate 24 in the terminal box 14 of the solar cell panel 2 can be grasped from the X-ray transmission image. As a result, it is possible to easily determine whether the soldering state between the output lead 22 and the terminal plate 24 is an appropriate soldering state or an inappropriate soldering state. Then, the soldering failure between the output lead 22 and the terminal plate 24 can be eliminated by re-soldering the soldering failure between the output lead 22 and the terminal plate 24.

Therefore, according to the manufacturing method of the solar cell module according to the first embodiment, it is possible to easily determine the soldering state of the soldering portion in the solar cell module 1, and to ensure the desired long-term reliability. Can be realized stably, and an effect that a highly reliable solar cell module can be provided is obtained.

Embodiment 2. FIG.
FIG. 34 is a perspective view of the solar cell array 3 in which the solar cell strings 4 according to the second embodiment of the present invention are soldered together by the inter-string connection tabs 28 and connected in series, as viewed from the light receiving surface side. FIG. 35 is a flowchart showing the procedure of the method for manufacturing the solar cell module 1 according to the second embodiment of the present invention.

The soldered state between the solar cell string 4 and the connection tabs 28 between strings can be inspected by the transmission X-ray inspection described above. That is, the soldering state between the inter-cell connection tab 21 and the inter-string connection tab 28 can be inspected by the transmission X-ray inspection described above. Inspection is performed by the X-ray inspection apparatus 200 described above in a state where the solar cell array 3 is placed on the light receiving surface protection component 11. This transmission X-ray inspection is a step S110 between step S30 and step S40. In the case of No in step S110, the process returns to step S30, and soldering between the inter-cell connection tab 21 and the inter-string connection tab 28 is performed again. Thereby, it is possible to eliminate a soldering failure between the inter-cell connection tab 21 and the inter-string connection tab 28. In this case, the interstring connection tab 28 corresponds to the first metal part. The inter-cell connection tab 21 corresponds to the second metal part.

Similarly, the soldering state between the solar battery cell 5 and the inter-cell connection tab 21 can be inspected by the transmission X-ray inspection described above. That is, by the above-described transmission X-ray inspection, the soldering state between the inter-cell connection tab 21 and the back surface connection electrode 31 can be inspected as shown in FIG. Inspection is performed by the X-ray inspection apparatus 200 described above in a state where the solar cell array 3 is placed on the light receiving surface protection component 11. This transmission X-ray inspection is a step S110 between step S30 and step S40. In the case of No in step S110, the process returns to step S20, and soldering between the solar battery cell 5 and the inter-cell connection tab 21 is performed again. Thereby, it becomes possible to eliminate the soldering failure between the solar battery cell 5 and the inter-cell connection tab 21. In this case, the inter-cell connection tab 21 corresponds to the first metal part. Further, the back surface connection electrode 31 corresponds to the second metal part. Similarly, the soldering state between the light receiving surface side bus electrode of the solar battery cell 5 and the inter-cell connection tab 21 can be inspected.

Therefore, according to the manufacturing method of the solar cell module according to the first embodiment, the soldering state between the inter-cell connection tab 21 and the inter-string connection tab 28 and the solar cell 5 and the inter-cell connection tab 21. Highly reliable solar cell module by identifying places where soldering is not sufficiently performed by inspecting the soldering state between them, performing appropriate soldering again, and preventing the occurrence of defective soldering Can be manufactured.

The configuration described in the above embodiment shows an example of the contents of the present invention, and the technologies of the embodiment can be combined with each other or can be combined with another known technology. However, part of the configuration may be omitted or changed without departing from the gist of the present invention.

1 solar cell module, 2 solar cell panel, 3 solar cell array, 4 solar cell string, 5 solar cell, 11 light receiving surface protection component, 12 back surface protection component, 13 frame, 14 terminal box, 15 terminal box body, 15a bottom surface 15b Bottom output lead insertion hole, 16 Terminal box cover, 17 Module connection cable, 18 Cable connection part, 19 Terminal box formation location, 21 Inter-cell connection tab, 22, 22a, 22b Output lead, 23 Drawer cut, 24 Terminal board 24a Other terminal board, 25 Output lead insertion hole, 26 Solder, 27 groove, 28 Inter-string connection tab, 31 Back connection electrode, 111 Processor, 112 Memory, 120 X-ray observation area, 200 X-ray inspection device, 201 apparatus, 02, 202a, 202b X-ray generator, 203, 203a X-ray non-destructive inspection camera, 203al, 203bl X-ray line sensor, 204 controller, 204a X-ray controller, 204b transport controller, 204c image information generator, 204d operation unit, 204e determination unit, 205 display unit, 206 X-ray, 207 housing, 208 traveling direction, 211 soldering unit, 212, 212a, 212b, 212c solder unsupplied unit, 221 soldering target area.

Claims

The X-ray is irradiated toward the area where the first metal part and the second metal part constituting the solar cell panel are soldered, and the direction is parallel to the in-plane direction of the solar cell panel. A first step of obtaining an X-ray transmission image in an area to be soldered, which is an area where the first metal part and the second metal part overlap;
The area of the soldering part where the first metal part and the second metal part are actually soldered to the area of the soldering target region in the direction parallel to the in-plane direction of the solar cell panel A second step of calculating a ratio from the X-ray transmission image;
A third step of comparing the area ratio with a predetermined determination criterion to determine whether the solder joint state between the first metal part and the second metal part is good or not;
The manufacturing method of the solar cell module characterized by including.
The X-ray transmission image is a two-dimensional X-ray transmission image in a direction parallel to the in-plane direction of the solar cell panel;
The manufacturing method of the solar cell module of Claim 1 characterized by these.
The X-ray transmission image is a three-dimensional X-ray transmission image in a direction parallel to the in-plane direction of the solar cell panel and a direction perpendicular to the in-plane direction of the solar cell panel;
The manufacturing method of the solar cell module of Claim 1 characterized by these.
The first metal component is a terminal plate provided in a terminal box disposed on one surface of the solar cell panel;
The second metal part is an output lead drawn from the solar cell panel;
The method for manufacturing a solar cell module according to any one of claims 1 to 3, wherein:
The X-ray output condition is that the tube voltage is in the range of 50 kV to 160 kV and the tube current is in the range of 40 μA to 120 μA.
The manufacturing method of the solar cell module of Claim 4 characterized by these.
The detector that detects the X-ray transmitted through the soldering target region and generates an X-ray transmission signal for obtaining the X-ray transmission image has a resolution of megapixels or more and a field of view. Less than 20 mm square,
A method for manufacturing a solar cell module according to claim 4 or 5.
Soldering the output lead and the terminal plate at a thickness greater than 0.1 mm at least between the output lead and the terminal plate;
The method for manufacturing a solar cell module according to claim 6.
A groove extending in a direction parallel to the width direction of the output lead is provided in the soldering target region of the terminal board;
The method for manufacturing a solar cell module according to claim 4, wherein:
The groove has a width of 10% or more of the length in the length direction of the output lead of the soldering target region, and a depth greater than 0.1 mm.
The manufacturing method of the solar cell module of Claim 8 characterized by these.
The groove has a width of 1 mm or more and a depth of more than 0.1 mm;
The manufacturing method of the solar cell module of Claim 8 characterized by these.
When arranging the terminal box on the solar cell panel, the soldering portion in the terminal box is connected between cells connecting a plurality of solar cells constituting the solar cell panel in the in-plane direction of the solar cell panel. Arrange it so that it does not overlap the connection tab,
The method for manufacturing a solar cell module according to any one of claims 4 to 10, wherein:
The first metal component is an interstring connection tab that connects solar cell strings that constitute the solar cell panel;
The second metal part is an inter-cell connection tab connected to the solar cell string;
The method for manufacturing a solar cell module according to any one of claims 1 to 3, wherein:
The first metal part is an inter-cell connection tab connected to an electrode of a solar battery cell constituting the solar battery panel,
The second metal part is an electrode of the solar battery cell;
The method for manufacturing a solar cell module according to any one of claims 1 to 3, wherein:
An X-ray generator for irradiating X-rays toward a region where soldering of the first metal part and the second metal part constituting the solar cell panel is performed;
An X-ray nondestructive inspection camera that detects an X-ray transmitted through a region where the first metal part and the second metal part are soldered and generates an X-ray transmission signal;
An image information generation unit that takes in the X-ray transmission signal and generates an X-ray transmission image;
Actually, the first metal part with respect to the area of the soldering target area, which is an area where the first metal part and the second metal part overlap in a direction parallel to the in-plane direction of the solar cell panel And an arithmetic unit that calculates an area ratio of a soldered portion where the second metal part is solder-joined from the X-ray transmission image,
A determination unit that compares the area ratio with a predetermined determination criterion and determines whether the solder joint state between the first metal part and the second metal part is good,
An apparatus for manufacturing a solar cell module, comprising:
A solar battery panel in which a solar battery array in which a plurality of solar battery cells are electrically connected by inter-cell connection tabs is sealed between a light-receiving surface protection component and a back surface protection component;
A terminal box arranged on the surface of the back surface protection component;
With
A soldering portion in which a terminal plate provided in the terminal box and an output lead drawn from the solar battery panel are solder-bonded is disposed at a position not overlapping the inter-cell connection tab. ,
A solar cell module characterized by.