JP2020162337A - Inspection device and inspection method - Google Patents

Abstract

To inspect a mechanical characteristic of a solder bonding part decisively influencing the presence of a long-term reliability.SOLUTION: An inspection device (10) inspects a quality of a solder bonding part (80) as a crossing part in which two flat surface-like wiring parts (81 and 82) are crossed and are bonded by a solder part (83). A transmission part (31) emits an inspection ultrasonic sound into air toward the solder bonding part (80). A reception part (32) receives a delivered ultrasonic sound delivered from the inspection ultrasonic sound. A mask (40) is composed of: a transmission permission part (40a) which can be arranged so as to be housed in the region inside the solder bonding part (80); and a transmission inhibition part (40b) that surrounds the transmission permission part (40a). A control part (60) determines the quality of a bonding state of the solder bonding part (80) on the basis of the delivered ultrasonic sound.SELECTED DRAWING: Figure 1

Description

The present invention relates to an inspection technique for inspecting the quality of the joint state of the solder joint portion. In particular, the present invention relates to an inspection technique for inspecting the quality of the joint state of a solder joint portion in which the intersection of two planar wiring portions is joined via solder. For example, for a solar cell module including a wiring unit including an external power supply wiring unit that supplies power to the outside and one or a plurality of solar cells, it provides efficient power supply to the outside for a long period of time. The present invention relates to an inspection technique suitable for making it possible to determine whether or not a solar cell module includes only a good connection state that can withstand climate change and can be guaranteed.

Patent Document 1 discloses a solder joint evaluation device for a solar cell module. This solder joint evaluation device evaluates a solder joint portion of a solar cell module including a solder joint portion composed of a first conductor and a second conductor bonded via solder. Specifically, this solder joint evaluation device includes a measurement control unit, a high frequency generator that is controlled by the measurement control unit to generate a high frequency signal, and a high frequency that is connected to one end of the high frequency generator to generate a high frequency signal. Measure the coaxial cable that propagates the signal, the stylus that is connected to the other end of the coaxial cable and supplies high-frequency signals to the solder joint, and the reflected wave that is reflected from the solder joint to the stylus. It is equipped with a waveform analysis unit that calculates the impedance of the solder joint based on high-frequency signals and reflected waves.

Japanese Unexamined Patent Publication No. 2017-3408

However, in the device of Patent Document 1, the probe of the stylus portion may be pressed against the solder joint portion, so that the solder joint portion may be damaged. Further, in the apparatus of Patent Document 1, it is possible to obtain an evaluation of the quality of the electrical continuity of the solder joint, but the mechanical characteristics of the solder joint that decisively affect the presence or absence of long-term reliability can be evaluated. The results will be limited.

In view of the problems of the prior art, the present invention has a decisive influence on the long-term reliability, which is particularly important for the solder joint in which the intersection of the two planar wiring parts is joined via solder. An object of the present invention is to provide an inspection device and an inspection method capable of easily and effectively inspecting the mechanical properties of a solder joint. For example, to provide an inspection technique capable of determining the quality of a solder joint portion of a solar cell module including a wiring portion including an external power supply wiring portion that supplies power to the outside and one or a plurality of solar cells. The purpose. This problem can be solved by the apparatus and method of the present invention described below.

The present invention relates to an inspection device for inspecting the quality of the joint state of the solder joint portion, which is an intersection where two planar wiring portions of the solar cell module intersect and are joined by the solder portion. The transmitter and receiver, which can be arranged in opposite directions of the two wiring portions of the solder joint, include a mask and a control unit, and the transmitter is an ultrasonic wave for inspection toward the solder joint. The inspection ultrasonic waves can be irradiated into the air, the receiving unit can receive the derived ultrasonic waves derived from the inspection ultrasonic waves, and the mask is a transmission unit or the receiving unit and the solder joint portion. A permeation permitting portion that can be arranged between them, can be arranged so as to fit within the inner region of the solder joint when viewed from the opposite direction, and allows the transmission of ultrasonic waves, and a permeation permitting portion that allows the transmission of ultrasonic waves and the permeation allowance as viewed from the opposite direction. Sometimes, it has a permeation-inhibiting portion that surrounds the permeation-allowing portion and inhibits the transmission of ultrasonic waves, and the control unit is an ultrasonic wave that determines the quality of the bonded state of the solder-bonded portion based on the derived ultrasonic waves. It is possible to perform the determination process.

In other words, the present invention relates to, for example, an inspection device for inspecting the quality of the joint state of the solder joint portion which is the intersection of the two wiring portions joined by the solder portion of the solar cell module. A transmission unit that is arranged so as to face the joint portion and irradiates ultrasonic waves into the air toward the solder joint portion and a solder joint portion that is arranged so as to face the transmission portion between the transmission portions. The receiving portion that receives the ultrasonic waves that have been irradiated and transmitted through the solder joint portion is arranged so as to be in contact with the solder joint portion in some cases, and the transmission tolerance that allows the transmission of the ultrasonic waves in the solder joint portion is allowed. A mask having a unit, a transmission blocking unit that inhibits the transmission of ultrasonic waves in a peripheral region surrounding the solder joint portion when viewed from the opposite direction of the transmitting unit and the receiving unit, and the receiving unit. It includes a control unit that performs an ultrasonic determination process for determining the quality of the joint state of the solder joint portion based on the ultrasonic waves received by.

According to the inspection apparatus of the present invention, the quality of the joint state of the solder joint is inspected without damaging the solder joint. Further, according to the inspection device of the present invention, for an electronic / electrical device such as a solar cell module that needs to effectively inspect the mechanical properties of a solder joint, the characteristics of the electronic / electrical device can be accurately and simply obtained. Can be inspected. The solar cell module includes, for example, a wiring unit including an external power supply wiring unit that supplies electric power to the outside. The wiring portion includes a solder joint portion in which the intersections of the two planar wiring portions are joined via solder. Solar cell modules need to include, for example, only good connectivity that can withstand and guarantee efficient external power supply over the long term.

Further, it is preferable that the mask is formed in a plate shape, the permeation permitting portion is configured as a through opening of the plate-shaped member, and the permeation inhibiting portion is formed of a portion excluding the through opening. ..

Since the transmission / reception portion can be measured in a non-contact state with the solder joint portion, adverse effects due to contact can be prevented and the process load related to contact can be reduced. Further, since the measurement can be performed in a non-contact state with the solder joint including the mask, the effect of preventing adverse effects or the effect of reducing the process load becomes more remarkable.

Further, the transmitting unit and the receiving unit are arranged with the solder joint portion between them, and the mask is a transmission mask arranged on the side of the solder joint portion facing the transmitting unit and the solder joint portion. It is preferable to include a reception mask arranged on the side facing the receiving unit.

By increasing the ratio of the transmittance of ultrasonic waves in the permeation-inhibiting portion / permeation-allowing portion according to the present invention, it is possible to more accurately inspect the quality of the joint state of the solder joint portion. Further, even when the solder joint according to the present invention is separated from the main body of the electronic / electrical device (specifically, the solar cell module) according to the present invention, the solder joint can be stably attached to these two masks. Accurate inspection is possible by sandwiching it.

Further, it is preferable that the size of the permeation allowance portion is variable.

An electronic / electrical device (specifically, a solar cell module) having a plurality of types of solder joints according to the present invention can be inspected in a short time in common with the plurality of devices.

Further, in the ultrasonic determination process, the control unit generates a derived ultrasonic fluctuation amount image having a plurality of pixels, each of which indicates the fluctuation amount of the derived ultrasonic wave, based on the derived ultrasonic wave, and the derived ultrasonic wave amount image is generated. When the number of pixels in which the fluctuation amount of the derived ultrasonic waves exceeds the predetermined origin fluctuation amount threshold value exceeds the predetermined pixel number threshold value among the plurality of pixels included in the ultrasonic fluctuation amount image, the solder bonding is performed. It is preferable to determine that the joint state of the portions is good, and when the number of pixels exceeding the origin fluctuation amount threshold does not exceed the pixel number threshold, it is determined that the joint state of the solder joint portion is poor. ..

Further, the fluctuation amount of the derived ultrasonic wave is one or more selected from the group consisting of the ultrasonic wave amount and the time from the transmission timing of the inspection ultrasonic wave to the reception timing of the derived ultrasonic wave corresponding to the inspection ultrasonic wave. It is preferable to have, and more preferably both of them.

The apparatus of the present invention preferably includes an imaging unit that acquires an image of an electronic / electrical device (specifically, a solar cell module) to be inspected. Not only the ultrasonic wave determination process according to the present invention, but also the image determination process according to the present invention can be performed before, after, or at the same time, and these determination results can be analyzed in a complex manner, and the removal rate of defective products and the manufacturing yield can be determined. Can contribute to improvement. Further, the apparatus of the present invention preferably includes a transport mechanism for transporting the transmitting unit, the receiving unit, and the mask. A large amount of inspection can be performed in a short time. Further, it is more preferable to include both the imaging unit and the transport mechanism. By doing so, the control unit derives the position information of the solder joint based on the image, and based on the position information, the transmitting unit, the receiving unit, and the mask are placed at predetermined positions, respectively. It becomes possible to control the transport mechanism so as to transport.

Further, the present invention relates to an inspection method for inspecting the quality of the joint state of the solder joint portion, which is the intersection of the two planar wiring portions joined by the solder portion of the solar cell module. A transmission unit is arranged so as to face the joint portion, a reception unit is arranged so as to face the transmission unit between the solder joint portions, and a transmission allowance portion that allows transmission of ultrasonic waves in the solder joint portion is provided. The first step of arranging a mask having a transmission obstructing portion that inhibits the transmission of ultrasonic waves in a peripheral region surrounding the solder joint portion when viewed from the opposite direction so as to be in contact with the solder joint portion, and the above. A second step in which the transmitting unit irradiates ultrasonic waves toward the solder joint portion in the air, and the receiving unit receives the ultrasonic waves transmitted from the transmitting unit and transmitted through the solder joint portion, and the receiving unit. It includes a third step of determining the quality of the joint state of the solder joint portion based on the ultrasonic waves received by.

According to the present invention, the quality of the joint state of the solder joint is inspected without damaging the solder joint.

It is the schematic which illustrates the structure of the inspection apparatus by embodiment. It is a top view which illustrates the structure of the solar cell module. It is sectional drawing which illustrates the structure of the solar cell module. It is a top view which illustrates the structure of the solder joint part of a solar cell module. It is sectional drawing which illustrates the structure of the solder joint part of the solar cell module. It is the schematic for demonstrating the image pickup part. It is the schematic for demonstrating the transmitting part and the receiving part. It is a top view which illustrates the structure of the mask arranged in the solder joint part. It is sectional drawing which illustrates the structure of the mask arranged in the solder joint part. It is a flowchart for demonstrating the operation of an inspection apparatus. It is a flowchart for demonstrating the extraction process. It is a flowchart for demonstrating the image determination process. It is a flowchart for demonstrating the ultrasonic wave determination process. It is a figure which illustrates the ultrasonic transmission amount image. It is a figure for demonstrating how the ultrasonic wave advances in the defective part of a solder joint part. It is a figure for demonstrating the difference between the reception timing of the ultrasonic wave passing through a good part of a solder joint part and the reception timing of an ultrasonic wave passing through (or bypassing) a bad part of a solder joint part. It is a flowchart for demonstrating the operation of the inspection apparatus by the modification of embodiment.

Hereinafter, embodiments will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals, and the description thereof will not be repeated.

(Inspection device)
FIG. 1 illustrates the configuration of the inspection device 10 according to the embodiment. The inspection device 10 inspects the quality of the joint state of the solder joint portion. In particular, this inspection device 10 inspects the quality of the joint state of the solder joint portion in which the intersection portion of the two planar wiring portions is joined via solder. This inspection device 10 is particularly suitable for inspecting the quality of the solder joint 80 of the solar cell module 70, which is required to withstand and guarantee the efficient power supply to the outside for a long period of time. ..

[Solar cell module]
Here, the solar cell module 70 suitable as an inspection target of the inspection device 10 will be described with reference to FIGS. 2 and 3. FIG. 3 is a cross-sectional view taken along the line III-III of FIG.

In this example, the solar cell module 70 includes a plurality of solar cell cells 71, a plurality of tab electrodes (tab wires 72), a first protective member 74, a second protective member 75, and a sealing member 76. .. Generally, the solar cell module 70 includes one or a plurality of solar cell cells 71 (solar cells) and a wiring portion for supplying electric power from the solar cells to the outside. Examples of such a wiring portion include a finger electrode wire formed on a solar cell, a plurality of tab wires 72 fixed by conductive adhesion, and a plurality of lead wires 73. Further, in addition to these configurations, for example, a module including a first protective member 74, a second protective member 75, and a sealing member 76 is also called a solar cell module. In such a solar cell module, two flat wiring portions intersect and solder from the viewpoint of manufacturing the solar cell module inexpensively and easily while guaranteeing an efficient external power supply withstanding climate variability for a long period of time. It is common to include solder joints that are intersections joined by portions, and to include multiple types of solder joints. Electronic / electrical equipment members represented by such solar cell modules (electronic / electrical equipment members including a plurality of types of solder joints) are preferable inspection targets of the present invention.

<Solar cell>
The solar cell 71 has a photoelectric conversion unit 700, a first electrode 701, and a second electrode 702. The photoelectric conversion unit 700 converts light into electric power. The first electrode 701 is provided on one surface of the photoelectric conversion unit 700. In this example, the first electrode 701 is composed of a plurality of finger electrodes 710 formed in a linear shape. The finger electrode 710 is made of a conductive metal. The second electrode 702 is provided on the other surface of the photoelectric conversion unit 700. In this example, the second electrode 702 is made of a conductive metal foil.

<Tab line>
The tab wire 72 is a wiring portion for electrically connecting two adjacent solar cell cells 71. The tab wire 72 is made of a conductive metal. In this example, one end of the tab wire 72 is connected to the first electrode 701 of one of the two adjacent solar cells 71, the solar cell 71. The other end of the tab wire 72 is connected to the second electrode 702 of the other solar cell 71 of the two adjacent solar cells 71.

<Lead>
The lead wire 73 is a wiring portion for drawing out a current. The lead wire 73 is made of a conductive metal. In this example, a plurality of lead wires 73 are provided. Specifically, there is a lead wire 73 to which the end of the tab wire 72 is connected, and a lead wire 73 to which the end of another lead wire 73 is connected.

<Protective member and sealing member>
The first protective member 74 is provided at a predetermined distance from one surface of the plurality of solar cells 71. The second protective member 75 is provided at a predetermined distance from the other surface of the plurality of solar cell 71s. The sealing member 76 is filled between the first protective member 74 and the second protective member 75. With such a configuration, a plurality of solar cell 71s are sealed.

[Solder joint]
4 and 5 illustrate the configuration of the solder joint 80 of the solar cell module 70. FIG. 4 is an enlarged plan view of the portion of the solar cell module 70 shown in FIG. 2 surrounded by the alternate long and short dash line, and FIG. 5 is a cross-sectional view taken along the line VV of FIG.

The solder joint portion 80 is an intersection of two flat wiring portions (first wiring portion 81 and second wiring portion 82) joined by the solder portion 83. In the solder joint portion 80, a solder portion 83 is provided between the first wiring portion 81 and the second wiring portion 82. In this example, the solar cell module 70 is provided with a plurality of types of solder joints 80. Specifically, the solder joint portion 80 (see the upper part of FIG. 4), which is the intersection of the lead wire 73 joined by the solder portion 83 and the lead wire 73, and the tab wire 72 joined by the solder portion 83. Solder which is the intersection of the solder joint 80 (see the lower part of FIG. 4) which is the intersection with the lead wire 73, the tab wire 72 which is joined by the solder portion 83, and the first electrode 701 of the solar cell 71. A joint portion 80 (not shown) and a solder joint portion 80 (not shown) which is an intersection of the tab wire 72 joined by the solder portion 83 and the second electrode 702 of the solar cell 71 are provided. There is.

As shown in FIGS. 4 and 5, the solder portion 83 has two fillets 83a. The two fillets 83a are arranged on both sides of the first wiring portion 81 in the width direction in a plan view. The fillet 83a is formed so that the cross-sectional shape of the first wiring portion 81 in the width direction gradually expands outward in the width direction of the first wiring portion 81 from the first wiring portion 81 side toward the second wiring portion 82 side. Has been done. Further, the fillet 83a is formed in a rectangular shape in a plan view.

[Configuration of inspection equipment]
The inspection device 10 of the present invention includes at least an ultrasonic inspection mechanism including a transmission unit 31 and a reception unit 32, a mask 40, and a control unit 60. Preferably, one or more selected from the group consisting of the inspection device 10 imaging unit 20 and the transport mechanism 50 of the present invention is further included.

As shown in FIG. 1, in this example, the inspection device 10 includes an imaging unit 20, a transmitting unit 31 and a receiving unit 32 included in the ultrasonic inspection mechanism, a mask 40, a transport mechanism 50, and a control unit 60. Is equipped with. In the inspection of the quality of the solder joint portion 80 of the solar cell module 70 by the inspection device 10 described below, the solar cell module 70 in which the first protective member 74, the second protective member 75, and the sealing member 76 are not provided. Is done against. That is, before the first protective member 74, the second protective member 75, and the sealing member 76 are provided in the solar cell module 70 (that is, before the plurality of solar cell cells 71 are sealed), the solar cell by the inspection device 10 is used. The quality of the solder joint 80 of the module 70 is inspected.

[Image pickup unit]
The imaging unit 20 images the entire electronic / electrical equipment (specifically, the solar cell module 70) to be inspected according to the present invention and a local area including the solder joint portion 80. Preferably, the imaging unit 20 has a function of transmitting the position information of a minute region in the inspection target including the relative position information with respect to the inspection device 10 and the image data composed of light and dark hues and the like. For example, the imaging unit 20 acquires an image of the solar cell module 70 by imaging the solar cell module 70. As shown in FIG. 6, the imaging unit 20 acquires an image of the solar cell module 70 by, for example, imaging the solar cell module 70 transported by the transport mechanism 50 described later. In this example, the imaging unit 20 is composed of a line sensor camera that images a linear region. The imaging unit 20 may be configured by an area camera that captures a rectangular region.

(Ultrasonography mechanism)
The ultrasonic inspection mechanism includes a transmitting unit 31 and a receiving unit 32 that can be arranged in the opposite direction (hereinafter, simply referred to as “opposing direction”) of the two wiring portions 81 and 82 of the solder joint portion 80. The facing direction is generally parallel to the normal direction of the plane of the solder joint portion 80, but the inspection accuracy may be improved by setting the direction at an angle from the parallel direction.

[Transmitter]
The transmission unit 31 can irradiate inspection ultrasonic waves, which are inspection ultrasonic waves, in the opposite direction and in the air. Specifically, the transmission unit 31 is arranged so as to face the solder joint portion 80, and irradiates the inspection ultrasonic waves into the air toward the solder joint portion 80. As shown in FIG. 7, the transmission unit 31 is arranged so as to face the solder joint unit 80 at a predetermined distance.

[Receiver]
The receiving unit 32 can receive the derived ultrasonic waves derived from the inspection ultrasonic waves. In this example, the derived ultrasonic waves are ultrasonic waves that have passed through the solder joint. Then, in this example, the receiving unit 32 is arranged so as to face the transmitting unit 31 with the solder joint portion 80 between them. Then, the receiving unit 32 receives the ultrasonic waves irradiated from the transmitting unit 31 and transmitted through the solder joint portion 80. As shown in FIG. 7, the receiving unit 32 is arranged so as to face the solder joint unit 80 at a predetermined distance.

〔mask〕
The mask 40 can be arranged between the transmission unit 31 (or the reception unit 32) and the solder joint portion 80. Preferably, the mask 40 is formed in a plate shape, can be arranged so as to fit within the inner region of the solder joint 80 when viewed from the opposite direction, and allows the transmission of ultrasonic waves. It has a permeation blocking portion 40b that surrounds the permeation permitting portion 40a and inhibits the transmission of ultrasonic waves when viewed from the opposite direction. Further, when the transmission unit 31 and the reception unit 32 are arranged between the solder joint portions 80, a set of submasks of a transmission mask 41 and a reception mask 42, each of which is formed in a plate shape, may be combined. it can. That is, one transmission mask 41 and one reception mask 42 form one set.

8 and 9 illustrate the configuration of the mask 40. 8 and 9 correspond to FIGS. 4 and 5, respectively. FIG. 9 is a cross-sectional view taken along the line IX-IX of FIG.

In this example, the mask 40 is arranged so as to be in contact with the solder joint 80. The mask 40 may be in non-contact with the solder joint portion 80. Further, as described above, the mask 40 has a permeation permitting portion 40a and a permeation inhibiting portion 40b.

The permeation permitting portion 40a allows the transmission of ultrasonic waves in the solder joint portion 80. Preferably, the transmittance of the permeation allowable portion 40a is 0.0001% or more and 100% or less. More preferably, the transmittance of the permeation allowable portion 40a is 0.01% or more and 1% or less.

The permeation blocking portion 40b, for example, inhibits the transmission of ultrasonic waves in the peripheral region surrounding the solder joint portion 80 when viewed from the opposite direction. The transmittance of the permeation-inhibiting portion 40b is lower than that of the permeation-allowing portion 40a. Preferably, the transmittance of the permeation inhibitor 40b is less than 0.001%. More preferably, the transmittance of the permeation-inhibiting portion 40b is less than 0.00001%.

Further, the size of the permeation allowable portion 40a of the mask 40 is preferably variable. More preferably, the size of the permeation allowable portion 40a is variable depending on the size of the solder joint portion 80. More preferably, the size of the permeation allowance portion 40a is variable depending on the size of the solder joint portion 80 obtained from the image of the solar cell module 70 described above. It is one of the features of the present invention that the size of the permeation permitting portion 40a can be changed in this way. For example, when the permeation permitting portion 40a is rectangular, the mask 40 changes the vertical and horizontal lengths of the permeation permitting portion 40a by moving a shielding plate (not shown) that is a part of the permeation inhibiting portion 40b in parallel. It may be configured to allow. With such a configuration, the size of the permeation allowance portion 40a can be changed. Further, a mask selected from a plurality of masks corresponding to the types of the plurality of solder joints provided in the solar cell module 70 (for example, a plurality of masks each having a transmission allowable portion 40a having a different shape) is used. Thereby, it is possible to make the size of the permeation allowable portion 40a of the mask 40 variable.

In this example, the mask 40 is formed in a plate shape. An opening is provided in the central portion of the mask 40. That is, in this example, the permeation permitting portion 40a is configured as a through opening of the plate-shaped member (specifically, a through opening provided in the central portion of the plate-shaped member), and the permeation inhibiting portion 40b is a through opening. It is composed of parts excluding. In this example, the mask 40 can expose the solder joint 80 from the opening of the mask 40 when viewed from a direction parallel to the direction from the transmission unit 31 side to the reception unit 32 side (that is, the opposite direction). It is arranged so as to expose the solder joint portion 80 from the opening of the mask 40. That is, the permeation permitting portion 40a is configured so that it can be arranged so as to fit within the inner region of the solder joint portion 80 when viewed from the opposite direction. In other words, the permeation permitting portion 40a is configured such that its outer peripheral edge is located inside the outer peripheral edge of the solder joint portion 80 in a plan view.

As described above, in this example, the permeation permitting portion 40a is composed of the opening of the mask 40. The permeation-inhibiting portion 40b is composed of a portion excluding the opening of the mask 40. The permeation inhibitory portion 40b is configured to surround the permeation permitting portion 40a when viewed from the opposite direction. Further, the mask 40 is made of, for example, a resin material or a rubber material, and is formed in a rectangular shape larger than the solder joint portion 80 when viewed from the opposite direction (hereinafter referred to as “planar view”). The opening provided in the central portion of the mask 40 is formed in a rectangular shape in a plan view. That is, in this example, the permeation permitting portion 40a is formed in a rectangular shape in a plan view, and the permeation inhibiting portion 40b is formed in a rectangular frame shape surrounding the permeation permitting portion 40a in a plan view. In other words, the permeation inhibitor 40b is made of a material that constitutes the mask 40 that surrounds the through opening.

Further, as shown in FIG. 8, in this example, the permeation permitting portion 40a is formed so that the outer peripheral edge of the permeation permitting portion 40a is located inside the outer peripheral edge of the solder joint portion 80 when viewed from the opposite direction. Has been done. For example, when viewed from the opposite direction, the outer peripheral edge of the permeation permitting portion 40a is located about 1 mm inward of the outer peripheral edge of the solder joint portion 80. In this example, the length X of the permeation allowable portion 40a in the width direction of the first wiring portion 81 is the length A of the solder joint portion 80 in the width direction of the first wiring portion 81 (that is, the width direction of the first wiring portion 81). The length Y of the transmission allowable portion 40a in the width direction of the second wiring portion 82 is shorter than the length B (that is, the second length B) of the solder joint portion 80 in the width direction of the second wiring portion 82. It is shorter than the width direction length of the wiring portion 82). For example, the length X of the permeation allowance portion 40a is shorter than the length A of the solder joint portion 80 by about 2 mm, and the length Y of the permeation allowance portion 40a is shorter than the length B of the solder joint portion 80. It is shortened by about 2 mm.

Further, as shown in FIG. 9, in this example, the mask 40 includes a transmission mask 41 and a reception mask 42. The transmission mask 41 is arranged on the side of the solder joint portion 80 facing the transmission portion 31. The reception mask 42 is arranged on the side of the solder joint 80 facing the reception unit 32. Specifically, the transmission mask 41 is arranged so as to be in contact with the first wiring unit 81, and the reception mask 42 is arranged so as to be in contact with the second wiring unit 82. The configuration of the reception mask 42 is the same as the configuration of the transmission mask 41.

As shown in FIG. 8, in this example, the inspection device 10 includes a plurality of masks 40 corresponding to the types of the plurality of solder joints 80. Specifically, it is joined by the solder portion 83 with the mask 40 (see the upper part of FIG. 8) corresponding to the solder joint portion 80 which is the intersection of the lead wire 73 and the lead wire 73 joined by the solder portion 83. The mask 40 (see the lower part of FIG. 8) corresponding to the solder joint 80 which is the intersection of the tab wire 72 and the lead wire 73, and the tab wire 72 and the solar cell 71 joined by the solder portion 83. At the intersection of the mask 40 (not shown) corresponding to the solder joint 80 which is the intersection with the one electrode 701, the tab wire 72 joined by the solder portion 83, and the second electrode 702 of the solar cell 71. A mask 40 (not shown) corresponding to a certain solder joint portion 80 is provided. The mask 40 arranged so as to come into contact with the solder joint portion 80 is a mask 40 selected from a plurality of masks 40 corresponding to each of the types of the plurality of solder joint portions 80.

Specifically, in this example, the inspection device 10 has a plurality of transmission masks 41 corresponding to the types of the plurality of solder joints 80 and a plurality of reception masks 42 corresponding to the types of the plurality of solder joints 80. And have. Then, the transmission mask 41 and the reception mask 42 corresponding to the solder joint portion 80 to be inspected are selected from the plurality of transmission masks 41 and the plurality of reception masks 42, respectively, and the selected transmission mask 41 and reception mask 42 are selected. The 42 is arranged so as to come into contact with the transmission unit 31 side and the reception unit 32 side of the solder joint portion 80, respectively.

[Limitation of ultrasonic transmission by mask]
Here, the transmission limitation of ultrasonic waves by the mask 40 will be described with reference to FIGS. 8 and 9. As the difference in acoustic impedance between two adjacent regions increases, the amount of ultrasonic waves reflected at the interface between the two regions tends to increase.

In the examples of FIGS. 8 and 9, the transmission permissible portion 40a of the transmission mask 41 is composed of an opening (specifically, an air layer) of the transmission mask 41, and the transmission obstruction portion 40b of the transmission mask 41 is the transmission mask 41. It is composed of a part excluding the opening (specifically, a part made of resin). Therefore, the amount of ultrasonic waves reflected at the interface between the air layer and the transmission mask 41's transmission blocking portion 40b is larger than the amount of ultrasonic waves reflected by the transmission mask 41's transmission allowable portion 40a. Similarly, the amount of ultrasonic waves reflected at the interface between the air and the permeation blocking portion 40b of the reception mask 42 is larger than the amount of ultrasonic waves reflected by the permeation allowance portion 40a of the reception mask 42.

Therefore, the ultrasonic waves traveling from the transmission unit 31 toward the solder joint portion 80 are not substantially reflected by the transmission tolerance unit 40a of the transmission mask 41 and the transmission tolerance unit 40a of the reception mask 42, and are transmitted through the transmission mask 41. The permissible portion 40a, the solder joint portion 80, and the permeation permissible portion 40a of the reception mask 42 pass in order to reach the reception unit 32. On the other hand, a part of the ultrasonic waves traveling from the transmission unit 31 toward the peripheral region of the solder joint portion 80 is reflected at the boundary surface between the air layer and the transmission blocking unit 40b of the transmission mask 41. Further, the ultrasonic waves that are not reflected at the interface between the air layer and the transmission mask 41 permeation-inhibiting portion 40b and pass through the transmission mask 41 permeation-inhibiting portion 40b are partially impaired in the air layer and the reception mask 42. It is reflected at the interface with the portion 40b.

In this way, the transmission permissible portion 40a of the transmission mask 41 allows the transmission of ultrasonic waves from the transmission unit 31 to the solder joint portion 80. The transmission blocking portion 40b of the transmission mask 41 inhibits the transmission of ultrasonic waves from the transmitting portion 31 toward the peripheral region (specifically, the air layer) of the solder joint portion 80. The transmission allowable portion 40a of the reception mask 42 allows transmission of ultrasonic waves from the solder joint portion 80 to the reception portion 32. The transmission blocking portion 40b of the receiving mask 42 inhibits the transmission of ultrasonic waves from the peripheral region (specifically, the air layer) of the solder joint portion 80 toward the receiving portion 32.

[Transport mechanism]
The transport mechanism 50 transports the transmission unit 31, the reception unit 32, and the mask 40 to predetermined positions (positions corresponding to the positions of the solder joint 80) based on the position information of the solder joint 80 described later. In this example, the transport mechanism 50 transports the transmission unit 31, the reception unit 32, the transmission mask 41, the reception mask 42, and the solar cell module 70. Specifically, in this example, the transfer mechanism 50 includes a transmission transfer unit 51 (see FIG. 7) that conveys the transmission unit 31 in an arbitrary direction, and a reception transfer unit 52 (see FIG. 7) that conveys the reception unit 32 in an arbitrary direction. (See FIG. 7), a mask transport unit that transports the transmission mask 41 and the reception mask 42 in an arbitrary direction (not shown), and a module transport unit that transports the solar cell module 70 in a predetermined transport direction (not shown). Omitted) and.

[Control unit]
The control unit 60 is electrically connected to each part of the inspection device 10 (in this example, the image pickup unit 20, the transmission unit 31, the reception unit 32, the transport mechanism 50, etc.), and signals and information are transmitted between each part of the inspection device 10. To transmit. Then, the control unit 60 controls each part of the inspection device 10 and controls the operation of the inspection device 10 based on signals and information from the outside of the inspection device 10 and the inspection device 10. For example, the control unit 60 is composed of a processor and a memory for storing programs and information for operating the processor. In this example, the control unit 60 performs ultrasonic wave determination processing, derivation of position information of the solder joint portion, control of the transport mechanism, image determination processing, control of the size of the transmission allowable portion, and the like.

The control unit 60 performs ultrasonic wave determination processing. In the ultrasonic wave determination process, the control unit 60 determines whether the solder joint 80 is in a good or bad state based on the ultrasonic waves received by the receiving unit 32. In this example, the control unit 60 performs the extraction process. In the extraction process, the control unit 60 derives the position information of the solder joint portion 80 based on the image of the solar cell module 70 acquired by the imaging unit 20. Then, the control unit 60 controls the transfer mechanism 50 so that the transmission unit 31, the reception unit 32, and the mask 40 are conveyed based on the position information of the solder joint portion 80 in the ultrasonic wave determination process. The extraction process and the ultrasonic wave determination process will be described in detail later.

Further, in this example, the control unit 60 performs an image determination process on the solder joint portion 80. In the image determination process, the control unit 60 determines whether or not the joint state of the solder joint 80 is good or bad based on the image of the solar cell module 70 acquired by the image pickup unit 20. Then, when the image determination process performed on the solder joint 80 determines that the bonding state is poor, the control unit 60 performs an ultrasonic determination process on the solder joint 80. The image determination process will be described in detail later.

[Operation of inspection device]
Next, the operation of the inspection device 10 (inspection of the solar cell module 70 by the inspection device 10) will be described with reference to FIG. The inspection by the inspection device 10 is performed on the solar cell module 70 which is not provided with the first protective member 74, the second protective member 75, and the sealing member 76.

<Step S10>
First, the inspection device 10 performs an extraction process. In the extraction process, the solar cell module 70 is imaged by the imaging unit 20 to acquire an image of the solar cell module 70, and the solder joint portion image which is an image including the solder joint portion 80 is obtained from the image of the solar cell module 70. Be extracted. In the extraction process, an image including a portion that is predetermined to be the solder joint portion 80 is extracted based on the design drawing of the solar cell module 70 (that is, the inspection target), and an appropriate image is extracted from the extracted image. It is preferable to extract the portion (the portion including the solder joint portion 80) as a solder joint portion image. Further, in the extraction process, when the image of the solder joint portion including the solder joint portion 80 cannot be properly extracted, the control unit 60 can send an alert signal to the inspection execution subject side (not shown). preferable.

<Step S20>
Next, the inspection device 10 performs image determination processing. In the image determination process, the quality of the bonding state of the solder bonding portion 80 is determined based on the image of the solar cell module 70 (specifically, the solder bonding portion image extracted from the image of the solar cell module 70).

<Step S30>
Next, the inspection device 10 performs an ultrasonic determination process. In this example, in the ultrasonic determination process, the transmission unit 31 is arranged so as to face the solder joint portion 80, and the receiving unit 32 is arranged so as to face the transmission unit 31 between the solder joint portions 80 and solder joints. The mask 40 is arranged so as to come into contact with the portion 80. Next, the transmitting unit 31 irradiates the solder joint portion 80 with ultrasonic waves in the air, and the receiving unit 32 receives the ultrasonic waves irradiated from the transmitting unit 31 and transmitted through the solder joint portion 80. Then, based on the ultrasonic waves received by the receiving unit 32, the quality of the bonding state of the solder bonding unit 80 is determined.

<Step S40>
Next, the inspection device 10 outputs the inspection result. Specifically, the control unit 60 outputs the result of the image determination process and the result of the ultrasonic wave determination process. The result of the image determination process and the result of the ultrasonic wave determination process output from the control unit 60 are displayed, for example, on a display unit (not shown) provided in the inspection device 10. In this way, the inspection result is notified to the inspection executing subject side (not shown).

[Extraction process]
Next, the extraction process (step S10) will be described with reference to FIG.

<Step S11>
First, the imaging unit 20 images the solar cell module 70 in response to the control by the control unit 60. In this example, as shown in FIG. 6, the control unit 60 controls the transport mechanism 50 so that the solar cell module 70 is transported in a predetermined transport direction, and also controls the imaging unit 20 to transport the transport mechanism. The solar cell module 70 transported in the transport direction by the 50 is imaged by the imaging unit 20. As a result, the image of the solar cell module 70 is acquired. For such transport according to the present invention, the transmission allowance portion can be arranged so as to fit within the region inside the plan view intersection, and preferably, if the image group of the solar cell module can be imaged, the sun It goes without saying that the battery, the transmitting unit, the receiving unit, and the mask need only be able to be transported relative to each other.

<Step S12>
Next, the control unit 60 searches for a solder joint image including the solder joint 80 to be inspected from the image of the solar cell module 70 acquired in step S11, and the solder joint detected by the search. Extract the part image. The search and extraction of the solder joint image can be realized by a known image search technique and image extraction technique.

<Step S13>
Next, the control unit 60 derives the position information of the solder joint portion 80 included in the solder joint portion image by comparing the solder joint portion image extracted in step S12 with a predetermined reference image. The reference image is an image including the solder joint portion 80 as a reference for comparison. In the reference image, the solder joint portion 80 having a predetermined reference shape is arranged at a predetermined reference position.

Specifically, the control unit 60 acquires the position coordinates of the solder joint image. Further, the control unit 60 compares the solder joint portion image with the reference image, and compares the position shift amount with respect to the position shift of the solder joint portion 80 in the solder joint portion image with respect to the position shift amount of the solder joint portion 80 in the solder joint portion image. , The amount of angular deviation, which is the amount of deviation of the angle of the solder joint 80 in the image of the solder joint with respect to the angle of the solder joint 80 in the reference image, is derived. Next, the control unit 60 derives the position correction amount and the angle correction amount of the solder joint portion 80 in the solder joint portion image so that the derived positional deviation amount and the angle deviation amount become zero. Then, the control unit 60 stores the image of the solder joint portion and the position information including the position coordinates of the solder joint portion image, the position correction amount, and the angle correction amount in association with each other.

In this example, the control unit 60 detects the type of the solder joint portion 80 included in the solder joint portion image, and shows the solder joint portion image and the type of the solder joint portion 80 included in the solder joint portion image. Stores in association with type information. Specifically, the control unit 60 compares the solder joint image extracted in step S12 with the reference image prepared for each type of the solder joint 80, and the solder included in the solder joint image. The position information and the type information of the joint portion 80 are derived.

<Step S14>
Next, the control unit 60 determines whether or not the search for the solder joint image in the image of the solar cell module 70 is completed. That is, the control unit 60 determines whether or not the extraction of the solder joint portion image including the solder joint portion 80 to be inspected is completed. If the extraction of the image of the solder joint portion including the solder joint portion 80 to be inspected is not completed, the process proceeds to step S11. On the other hand, when the extraction of the image of the solder joint portion including the solder joint portion 80 to be inspected is completed, the extraction process is terminated.

[Image judgment processing]
Next, the image determination process (step S20) will be described with reference to FIG.

<Step S21>
The control unit 60 selects the solder joint 80 to be image-determined from the solder joints 80 extracted in the extraction process (step S10). Specifically, the control unit 60 selects any one solder joint image (a solder joint image that has not yet been selected) from the solder joint images extracted in the extraction process.

<Step S22>
Next, the control unit 60 corrects the solder joint image including the solder joint 80 selected as the target of the image determination in step S21. Specifically, the control unit 60 uses the solder joint selected in step S21 based on the position correction amount and the angle correction amount included in the position information associated with the solder joint image selected in step S21. Correct the position and angle of the part image.

<Step S23>
Next, the control unit 60 makes an image determination based on the solder joint image corrected in step S22. In this image determination, the control unit 60 determines whether or not the joint state of the solder joint 80 is good or bad based on the appearance of the solder joint 80 included in the image of the solder joint 80. Then, the control unit 60 stores the image of the solder joint portion including the solder joint portion 80 and the result of image determination for the solder joint portion 80 in association with each other. Specifically, in the image determination, the control unit 60 performs a fillet abnormality determination and a wiring abnormality determination.

In the fillet abnormality determination, it is determined whether or not the shape of the fillet 83a of the solder joint portion 80 included in the solder joint portion image is abnormal. For example, in the fillet abnormality determination, the shape of the fillet 83a of the solder joint portion 80 when the length (or the length in the lateral direction) of the fillet 83a in the plan view does not fall within a predetermined allowable range. Is determined to be abnormal, and the bonding state of the solder bonding portion 80 is determined to be defective. On the other hand, in the fillet abnormality determination, when the length in the longitudinal direction (or the length in the lateral direction) of the fillet 83a in the plan view is within a predetermined allowable range, the shape of the fillet 83a of the solder joint portion 80 is changed. It is determined that it is normal, and it is determined that the bonding state of the solder bonding portion 80 is good.

In the wiring abnormality determination, it is determined whether or not the positions and angles of the first wiring portion 81 and the second wiring portion 82 constituting the solder joint portion 80 included in the solder joint portion image are abnormal. For example, in the wiring abnormality determination, when the length (or angle) between the edge of the first wiring portion 81 and the edge of the second wiring portion 82 in the plan view does not fall within a predetermined allowable range, the first It is determined that the positions (or angles) of the 1 wiring portion 81 and the 2nd wiring portion 82 are abnormal, and it is determined that the bonding state of the solder bonding portion 80 is poor. On the other hand, in the wiring abnormality determination, when the length (or angle) between the edge of the first wiring portion 81 and the edge of the second wiring portion 82 in the plan view is within a predetermined allowable range, the first It is determined that the positions (or angles) of the wiring portion 81 and the second wiring portion 82 are normal, and it is determined that the joint state of the solder joint portion 80 is good.

<Step S24>
Next, the control unit 60 determines whether or not the image determination is completed for all of the solder joints 80 to be the target of the image determination in the image determination process. In this example, the control unit 60 determines whether or not the image determination is completed for all of the solder joints 80 extracted in the extraction process. If the image determination is not completed for all the solder joints 80 to be the target of the image determination in the image determination process, the process proceeds to step S21. On the other hand, when the image determination is completed for all the solder joints 80 to be the target of the image determination in the image determination process, the image determination process is terminated.

[Ultrasonic judgment processing]
Next, the ultrasonic wave determination process (step S30) will be described with reference to FIG.

<Step S31>
The control unit 60 selects the solder joint 80 to be ultrasonically determined from the solder joint 80 determined to have a poor joint state in the image determination process (step S20). Specifically, the control unit 60 uses any one of the solder joint image (solder that has not yet been selected) from the solder joint images associated with the result of the image determination indicating that the joint state is poor. Join image) is selected.

<Step S32>
Next, the control unit 60 selects the mask 40 corresponding to the solder joint 80 selected in step S31 from the plurality of masks 40 corresponding to the types of the plurality of solder joints 80. Specifically, the control unit 60 is one of a plurality of masks 40 based on the type of the solder joint 80 shown in the type information associated with the solder joint image selected in step S31. One mask 40 (one transmission mask 41 and one reception mask 42 in this example) is selected.

Next, the control unit 60 controls the transfer mechanism 50 so that the transmission unit 31, the reception unit 32, and the mask 40 are conveyed based on the position information of the solder joint portion 80 selected in step S31. Specifically, the control unit 60 determines the sun based on the position coordinates, the position correction amount, and the angle correction amount of the solder joint image included in the position information associated with the solder joint image selected in step S31. The position coordinates and the orientation of the solder joint 80 in the battery module 70 are specified. Then, the control unit 60 controls the transport mechanism 50 to adjust the positions of the transmission unit 31 and the reception unit 32 so that the transmission unit 31 and the reception unit 32 face each other with the solder joint portion 80 between them. Further, the control unit 60 controls the transport mechanism 50 so that the transmission allowable portion 40a of the mask 40 (in this example, each of the transmission mask 41 and the reception mask 42) overlaps the solder joint portion 80 in a plan view, and the mask 40 is controlled. Adjust the position and angle of.

<Step S33>
Next, in response to the control by the control unit 60, the transmission unit 31 irradiates the solder joint portion 80 with ultrasonic waves in the air. The receiving unit 32 receives the ultrasonic waves irradiated from the transmitting unit 31 and transmitted through the solder joint portion 80.

<Step S34>
Next, the control unit 60 makes an ultrasonic determination based on the ultrasonic waves received by the receiving unit 32 in step S33. In this example, in the ultrasonic determination, the control unit 60 transmits the ultrasonic wave, which is the amount (specifically, the intensity) of the ultrasonic wave that has passed through the solder joint portion 80 from the transmitting unit 31 and reached the receiving unit 32. Based on the above, the quality of the joint state of the solder joint portion 80 is determined. Then, the control unit 60 stores the image of the solder joint portion including the solder joint portion 80 and the result of the ultrasonic wave determination for the solder joint portion 80 in association with each other.

Specifically, in the ultrasonic determination, the control unit 60 is an example of the amount of ultrasonic waves transmitted through the solder joint 80 (an example of the amount of fluctuation of the derived ultrasonic waves) based on the derived ultrasonic waves received by the receiving unit 32. ) Is generated (an example of the derived ultrasonic amount image) having a plurality of pixels. As shown in FIG. 14, the ultrasonic transmission amount image includes m × n pixel blocks arranged in a matrix of m rows and n columns. m and n are integers of 2 or more. The m × n pixel blocks of the ultrasonic transmission amount image correspond to the m × n block regions obtained by dividing the solder joint portion 80 into a matrix of m rows and n columns in a plan view. The m × n pixel blocks of the ultrasonic transmission amount image each indicate the transmission amount of ultrasonic waves in the block region of the solder joint portion 80. In the example of FIG. 14, the first pixel region R1 indicates a pixel region in which the ultrasonic transmission amount belongs to the first range, and the second pixel region R2 has a higher ultrasonic transmission amount than the first range. The area of the pixel belonging to the second range is shown, the third pixel area R3 shows the area of the pixel belonging to the third range where the amount of ultrasonic transmission is larger than the second range, and the fourth pixel area R4 is the area of the ultrasonic wave. It shows a region of pixels belonging to the fourth range in which the amount of transmission is larger than that of the third range.

Then, in the ultrasonic determination, the control unit 60 transmits ultrasonic waves among the m × n pixels included in the ultrasonic transmission amount image (an example of the origin ultrasonic amount image) generated based on the origin ultrasonic waves. When the number of pixels whose amount exceeds the predetermined transmission amount threshold (an example of the fluctuation amount threshold) exceeds the predetermined number of pixels threshold, it is determined that the bonding state of the solder bonding portion 80 is good. On the other hand, the control unit 60 is a solder joint portion when the number of pixels whose ultrasonic transmission amount exceeds the transmission amount threshold value does not exceed the pixel number threshold value among the m × n pixels included in the ultrasonic transmission amount image. It is determined that the joint state of 80 is defective.

If a cavity or crack is formed in the solder portion 83 provided between the first wiring portion 81 and the second wiring portion 82 in the solder joint portion 80, a part of the ultrasonic wave is reflected in the cavity or crack. Therefore, the amount of ultrasonic waves transmitted from the transmitting unit 31 to the receiving unit 32 through the solder joint portion 80 is smaller than that in the case where the solder portion 83 has no cavities or cracks. That is, when the joint state of the solder joint portion 80 is poor, the amount of ultrasonic waves transmitted through the solder joint portion 80 is smaller than when the joint state of the solder joint portion 80 is good. Therefore, it is possible to determine whether the solder joint 80 is in a good joint state based on the amount of ultrasonic waves transmitted through the solder joint 80.

<Step S35>
Next, the control unit 60 determines whether or not the ultrasonic wave determination is completed for all the solder joints 80 to be the target of the ultrasonic wave determination in the ultrasonic wave determination process. In this example, the control unit 60 determines whether or not the ultrasonic determination is completed for all of the solder joints 80 that are determined to have a poor joint state in the image determination process. If the ultrasonic wave determination is not completed for all of the solder joints 80 to be the target of the ultrasonic wave determination in the ultrasonic wave determination process, the process proceeds to step S31. On the other hand, when the image determination is completed for all of the solder joints 80 to be the target of the ultrasonic determination in the ultrasonic determination process, the ultrasonic determination process is terminated.

[Effect of Embodiment]
As described above, by inspecting the quality of the joint state of the solder joint portion 80 by the aerial ultrasonic method, the quality of the joint state of the solder joint portion 80 is inspected without damaging the solder joint portion 80. Further, by arranging the mask 40 on the solder joint portion 80, the wraparound of ultrasonic waves from the transmission unit 31 through the peripheral region of the solder joint portion 80 to the receiving unit 32 is suppressed. As a result, the detection accuracy of the ultrasonic waves transmitted from the transmitting unit 31 through the soldering unit 80 to the receiving unit 32 is improved, so that the inspection accuracy of the quality of the bonded state of the soldering unit 80 is improved.

Further, by forming the permeation permitting portion 40a so that the outer peripheral edge of the permeation permitting portion 40a is located inside the outer peripheral edge of the solder joint portion 80 when viewed from the opposite direction, when viewed from the opposite direction. Compared to the case where the permeation permitting portion 40a is formed so that the outer peripheral edge of the permeation permitting portion 40a overlaps with the outer peripheral edge of the solder joint portion 80, the transmission unit 31 transmits the peripheral region of the solder joint portion 80 to the receiving unit. The wraparound of ultrasonic waves up to 32 is suppressed. As a result, the inspection accuracy of the quality of the joint state of the solder joint portion 80 is improved.

Further, by arranging the masks 40 on both the transmitting unit 31 side and the receiving unit 32 side of the solder joint portion 80, the masks 40 are arranged only on one of the transmitting unit 31 side and the receiving unit 32 side of the solder joint portion 80. More than in the case, the wraparound of the ultrasonic wave from the transmitting unit 31 to the receiving unit 32 through the peripheral region of the solder joint portion 80 is suppressed. As a result, the inspection accuracy of the quality of the joint state of the solder joint portion 80 is improved.

Further, by selecting the mask 40 arranged in the solder joint 80 from the plurality of masks 40 corresponding to the types of the plurality of solder joints 80, the mask 40 suitable for the solder joint 80 can be obtained by the solder joint 80. It is arranged at 80. As a result, the inspection accuracy of the quality of the joint state of the solder joint portion 80 is improved.

Further, by arranging the transmission unit 31, the reception unit 32, and the mask 40 based on the position information of the solder joint portion 80, the transmission unit 31, the reception unit 32, and the mask 40 are arranged at positions suitable for the solder joint portion 80. To. As a result, the inspection accuracy of the quality of the joint state of the solder joint portion 80 is improved.

Further, when it is determined in the image determination process performed on the solder joint portion 80 that the joint state of the solder joint portion 80 is poor, the solder joint portion 80 is subjected to the ultrasonic wave determination process. The time required for the inspection is shortened as compared with the case where both the image determination process and the ultrasonic wave determination process are always performed on the solder joint portion 80.

When the control unit 60 performs an image determination process for determining the quality of the bonding state of the solder bonding unit 80 based on the image of the solar cell module 70, and the image determination process determines that the bonding state is good. In addition, the solder joint portion 80 may be configured to perform an ultrasonic determination process.

(Variation example of ultrasonic fluctuation amount)
In the above description, the case where the "variation amount of the derived ultrasonic wave" is the "transmission amount of the ultrasonic wave at the solder joint 80" is taken as an example, but the "variation amount of the derived ultrasonic wave" is "inspection super The time from the transmission timing of the sound wave to the reception timing of the derived ultrasonic wave derived from the inspection ultrasonic wave ”may be used.

For example, as shown in FIG. 15, in the solder joint portion 80 where voids (internal bubbles) exist (that is, defective portions), ultrasonic waves are reflected or bypassed. Therefore, as shown in FIG. 16, the ultrasonic waves passing through the defective portion of the solder joint portion 80 are more transmitted than the ultrasonic waves passing through the portion of the solder joint portion 80 where no voids exist (that is, the good portion). The time required from the transmission from the above to the reception by the receiving unit 32 becomes longer. Therefore, for example, the quality of the joint state of the solder joint portion 80 is determined by utilizing the delay (time difference) from the start of reception of the ultrasonic wave passing through the good portion to the start of reception of the ultrasonic wave passing through the bad portion. Is possible.

For example, in the ultrasonic determination, the control unit 60, based on the derived ultrasonic waves received by the receiving unit 32, respectively, from the transmission timing of the inspection ultrasonic waves in the transmitting unit 31, the derived ultrasonic waves in the receiving unit 32 (inspection ultrasonic waves). A time image (an example of the derived ultrasonic amount image) having a plurality of pixels showing the time until the reception timing of the derived ultrasonic wave) (an example of the fluctuation amount of the derived ultrasonic wave) is generated. The plurality of (for example, m × n) pixel blocks of this time image correspond to a plurality of block regions obtained by dividing the solder joint portion 80 into a matrix in a plan view. Then, the control unit 60 has a time threshold (an example of the fluctuation amount threshold) in which the time is predetermined among a plurality of pixels included in the time image (an example of the derived ultrasonic amount image) generated based on the derived ultrasonic wave. When the number of pixels exceeding the above exceeds a predetermined pixel number threshold value, it is determined that the bonding state of the solder bonding portion 80 is good. On the other hand, the control unit 60 determines that the bonding state of the solder bonding unit 80 is poor when the number of pixels whose time exceeds the time threshold value does not exceed the pixel number threshold value among the plurality of pixels included in the time image. ..

The "variation amount of the derived ultrasonic wave" is "the amount of ultrasonic wave transmitted through the solder joint 80" and "the time from the transmission timing of the inspection ultrasonic wave to the reception timing of the derived ultrasonic wave derived from the inspection ultrasonic wave". It may be a combination of. For example, the control unit 60 may be configured to determine the quality of the bonding state of the solder bonding unit 80 based on both the ultrasonic transmission amount image and the time image.

(Modified example of embodiment)
The operation of the control unit 60 of the inspection device 10 according to the modified example of the embodiment is different from that of the inspection device 10 according to the embodiment. In the modified example of the embodiment, the control unit 60 performs both an image determination process and an ultrasonic wave determination process on the solder joint portion 80. In the image determination process, the control unit 60 determines whether or not the joint state of the solder joint 80 is good or bad based on the image of the solar cell module 70 acquired by the image pickup unit 20. In the ultrasonic wave determination process, the control unit 60 determines whether the solder joint 80 is in a good or bad state based on the ultrasonic waves received by the receiving unit 32.

Specifically, in the modified example of the embodiment, the control unit 60 may be configured to perform the ultrasonic wave determination process shown in FIG. 17 instead of the ultrasonic wave determination process shown in FIG. In the ultrasonic wave determination process shown in FIG. 17, the following step S36 is performed instead of step S31 shown in FIG. The other steps of the ultrasonic wave determination process shown in FIG. 17 are the same as the steps of the ultrasonic wave determination process shown in FIG.

<Step S36>
The control unit 60 selects the solder joint 80 to be image-determined from the solder joints 80 extracted in the extraction process (step S10). Specifically, the control unit 60 selects any one solder joint image (a solder joint image that has not yet been selected) from the solder joint images extracted in the extraction process. Next, the process proceeds to step S32.

[Effect of Modified Example of Embodiment]
As described above, by performing both the image determination process and the ultrasonic wave determination process on the solder joint portion 80, the solder joint portion 80 is more than the case where only the image determination process is performed on the solder joint portion 80. The inspection accuracy of the quality of the joint condition is improved.

In the operation of the inspection device 10 according to the modified example of the third embodiment, the image determination process (step S20) may be performed after the ultrasonic wave determination process (step S30).

(Other embodiments)
In the above description, the case where the transmission unit 31 and the reception unit 32 are arranged between the solder joint portions 80 has been described as an example, but the transmission unit 31 and the reception unit 32 are grouped on one side of the solder joint portion 80. It may be arranged. That is, the transmission unit 31 and the reception unit 32 may constitute an integrated transmission / reception unit. In this case, the origin ultrasonic wave is an echo wave in which the inspection ultrasonic wave is reflected by the inspection target. By integrating the transmitting unit 31 and the receiving unit 32 into a transmitting / receiving unit in this way, there is an advantage that the device can be miniaturized and the transport mechanism 50 becomes simple. Further, since a relatively thick electronic / electrical device (for example, a solar cell module) can be inspected, there is an advantage that the inspection target can be expanded.

In addition, the above embodiments and modifications may be combined as appropriate. The above embodiments and modifications are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or its uses.

10 Inspection device 20 Imaging unit 31 Transmission unit 32 Reception unit 40 Mask 40a Permeation allowance unit 40b Transmission obstruction unit 41 Transmission mask 42 Reception mask 50 Conveyance mechanism 60 Control unit 70 Solar cell module 71 Solar cell 72 Tab wire 73 Lead wire 80 Solder Joint 81 1st wiring 82 2nd wiring 83 Solder 83a Fillet

Claims (11)

It is an inspection device that inspects the quality of the joint state of the solder joint, which is the intersection where the two planar wiring parts of the solar cell module intersect and are joined by the solder part.
It includes a transmitting unit and a receiving unit that can be arranged in opposite directions of the two wiring units of the solder joint portion, a mask, and a control unit.
The transmitting unit can irradiate the solder joint portion with inspection ultrasonic waves, which are ultrasonic waves for inspection, in the air.
The receiving unit can receive the derived ultrasonic wave derived from the inspection ultrasonic wave.
The mask can be arranged between the transmitting unit or the receiving unit and the solder joint portion, and can be arranged so as to fit within the inner region of the solder joint portion when viewed from the opposite direction. It has a permeation permitting portion that allows the transmission of ultrasonic waves and a permeation inhibiting portion that surrounds the permeation permitting portion and inhibits the transmission of ultrasonic waves when viewed from the opposite direction.
The control unit is an inspection device capable of performing ultrasonic wave determination processing for determining the quality of the joint state of the solder joint portion based on the derived ultrasonic waves. In the inspection device according to claim 1,
The mask is formed in a plate shape and
The permeation permitting portion is configured as a through opening of the plate-shaped member.
The permeation-inhibiting portion is an inspection device composed of a portion excluding the through-opening. In the inspection device according to claim 1 or 2.
The transmitting unit and the receiving unit are arranged with the solder joint portion between them.
The mask is an inspection device including a transmission mask arranged on the side of the solder joint portion facing the transmitting portion and a receiving mask arranged on the side of the solder joint portion facing the receiving portion. In the inspection device according to any one of claims 1 to 3.
An inspection device in which the size of the permeation allowance portion is variable. In the inspection device according to any one of claims 1 to 4.
In the ultrasonic determination process, the control unit generates a derived ultrasonic fluctuation amount image having a plurality of pixels, each of which indicates the fluctuation amount of the derived ultrasonic wave, based on the derived ultrasonic wave, and the derived ultrasonic wave. Fluctuation amount When the number of pixels in which the fluctuation amount of the derived ultrasonic waves exceeds the predetermined origin fluctuation amount threshold value exceeds the predetermined pixel number threshold value among the plurality of pixels included in the image, the solder joint portion An inspection device for determining that the bonding state is good, and when the number of pixels exceeding the origin fluctuation amount threshold does not exceed the pixel number threshold, the bonding state of the solder joint portion is determined to be poor. In the inspection apparatus according to claim 5,
The inspection device including the time from the transmission timing of the inspection ultrasonic wave to the reception timing of the origin ultrasonic wave corresponding to the inspection ultrasonic wave. In the inspection device according to any one of claims 1 to 6.
An imaging unit that acquires an image of the solar cell module by imaging the solar cell module, and
Further including the transmitting unit, the receiving unit, and a transport mechanism for transporting the mask.
The control unit derives the position information of the solder joint portion based on the image of the solar cell module, and in the ultrasonic determination process, the transmitter unit, the receiver unit, and the receiver unit are based on the position information of the solder joint portion. An inspection device that controls the transport mechanism so that each mask is transported to a predetermined position. In the inspection device according to claim 7.
The control unit performs image determination processing for determining the quality of the bonding state of the solder bonding portion based on the image of the solar cell module, and when it is determined in the image determination processing that the bonding state is poor, An inspection device that performs the ultrasonic determination process on the solder joint. In the inspection device according to claim 7.
The control unit performs an image determination process for determining the quality of the joint state of the solder joint portion based on the image of the solar cell module, and when the image determination process determines that the joint state is good, the control unit performs an image determination process. An inspection device that performs the ultrasonic determination process on the solder joint. In the inspection device according to claim 7.
The control unit is an inspection device that performs both an image determination process for determining the quality of the joint state of the solder joint portion and an ultrasonic wave determination process based on the image of the solar cell module. This is an inspection method for inspecting the quality of the joint state of the solder joint, which is the intersection where the two planar wiring parts of the solar cell module intersect and are joined by the solder part.
The transmission unit is arranged so as to face the solder joint portion, the receiving unit is arranged so as to face the transmission unit between the solder joint portions, and the transmission allowance allows the transmission of ultrasonic waves in the solder joint portion. The first step of arranging a mask having a transmission obstructing portion that inhibits the transmission of ultrasonic waves in a peripheral region surrounding the solder joint portion when viewed from a direction facing the portion so as to be in contact with the solder joint portion. ,
A second step in which the transmitting unit irradiates ultrasonic waves toward the solder joint portion in the air, and the receiving unit receives ultrasonic waves irradiated from the transmitting unit and transmitted through the solder joint portion.
An inspection method including a third step of determining the quality of the joint state of the solder joint based on the ultrasonic waves received by the receiver.

Images