JP2021065060A - Durability test method for electrical connections of solar cell modules - Google Patents

Abstract

To provide a durability test method for electrical connection of solar cell modules that reduce test time.SOLUTION: In a durability test method for electrical connection of solar cell modules, which tests the durability of an electrical connection portion 12 of a plurality of solar cells 1 in a solar cell module, a constituent unit 10 which is one of the constituent units in the solar cell module and in which the solar cell 1 and a wiring member 2 are connected via the electrical connection portion 12 is prepared, and after tensile stress of a predetermined magnitude has been applied to the constituent unit 10 a predetermined number of repetitions, the durability of the electrical connection portion 12 is inspected on the basis of an increase in the electrical resistance of the electrical connection portion 12 in the constituent unit 10 or the presence or absence of peeling of the electrical connection portion 12 in the constituent unit 10.SELECTED DRAWING: Figure 2A

Description

The present invention relates to a durability test method for an electrical connection portion of a solar cell module.

The solar cell module includes a plurality of solar cells indirectly connected by using a wiring member or directly by a single ring method, and a glass substrate that protects the light receiving surface and the back surface of the plurality of solar cells. A protective member and a sealing material for sealing a plurality of solar cells between the protective members are provided.

In such a solar cell module, an electrical connection portion of a plurality of solar cell cells (for example, an adhesion portion between a solar cell cell indirectly connected by using a wiring member and a tag or an interconnect, or a single ring method is used. The adhesive portion between the solar cells directly connected using the above) is stressed over time due to temperature fluctuations during the day and night.

In such a solar cell module, it is known that an accelerated temperature cycle test in which the temperature is repeatedly changed in a short time is performed as a durability test against such aged stress (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2012-114227

However, in such an accelerated temperature cycle test for each solar cell module, the test time for the durability test of the electrical connection portion of the solar cell module is long. For example, in order to test the durability for 30 years, such an accelerated temperature cycle test for each solar cell module requires about half a year.

An object of the present invention is to provide a durability test method for an electrical connection portion of a solar cell module that shortens the test time.

The method for testing the durability of the electrical connection portion of the solar cell module according to the present invention is a method for testing the durability of the electrical connection portion of a plurality of solar cells in the solar cell module, and is a part of the solar cell module. The constituent unit, which is the constituent unit in which the solar cell and the wiring member are connected via the electrical connection portion, or the constituent unit in which the two solar cells are connected via the electrical connection portion. After preparing and applying a tensile stress of a predetermined magnitude to the constituent unit a predetermined number of repetitions, an increase in the electrical resistance of the electrical connection in the constituent unit and / or the said in the constituent unit. The durability of the electrical connection is inspected based on the presence or absence of peeling of the electrical connection.

The method for testing the durability of the electrical connection portion of another solar cell module according to the present invention is a method for testing the durability of the electrical connection portion of a plurality of solar cell cells in the solar cell module, and is one of the methods in the solar cell module. The constituent unit of the unit, the constituent unit in which the solar cell and the wiring member are connected via the electrical connection portion, or the configuration in which the two solar cells are connected via the electrical connection portion. A unit is prepared, a tensile stress is applied to the constituent unit at a predetermined temperature so as to gradually increase, and the electrical connection portion is based on the magnitude of the tensile stress when the electrical connection portion is peeled off. Inspect for durability.

According to the present invention, the durability test time of the electrical connection portion of the solar cell module can be shortened.

It is a side view which shows an example of the solar cell module which concerns on this embodiment. It is a side view which shows another example of the solar cell module which concerns on this embodiment. It is a side view which shows still another example of the solar cell module which concerns on this embodiment. It is a figure which shows the constituent unit for the durability test of the electrical connection part of the solar cell module shown in FIG. 1A. It is a figure which shows the constituent unit for the durability test of the electrical connection part of the solar cell module shown in FIG. 1B. It is a figure which shows the constituent unit for the durability test of the electrical connection part of the solar cell module shown in FIG. 1C. It is a figure which shows the tensile stress for the durability test of the electrical connection part of the solar cell module of 1st Embodiment. It is a figure for demonstrating the temperature in the durability test of the electric connection part of the solar cell module of 2nd Embodiment.

Hereinafter, an example of the embodiment of the present invention will be described with reference to the accompanying drawings. In addition, the same reference numerals are given to the same or corresponding parts in each drawing. In addition, for convenience, hatching, member codes, and the like may be omitted, but in such cases, other drawings shall be referred to.

(Example of solar cell module)
FIG. 1A is a side view showing an example of the solar cell module according to the present embodiment. The solar cell module 100 shown in FIG. 1A includes a plurality of solar cell cells 1, a wiring member 2, a light receiving surface protection member 3, a back surface protection member 4, and a sealing material 5.

The solar cell module 100 is a wiring connection type solar cell module in which a plurality of solar cell 1s are indirectly connected by using a wiring member 2. Specifically, the solar cell 1 is a so-called comb-shaped electrode, and has a plurality of finger electrodes corresponding to comb teeth and a bus bar electrode corresponding to a support portion of the comb teeth. The wiring member 2 is a known interconnector such as a tab. The wiring member 2 is connected to the bus bar electrode of the solar cell 1 via the adhesive member 6. In this wiring connection type solar cell module 100, an electrical connection portion 12 (including an adhesive member 6) is between the solar cell 1 and the wiring member 2.

The solar cell 1 and the wiring member 2 are sandwiched between the light receiving surface protection member 3 and the back surface protection member 4. The light receiving surface protection member 3 is, for example, a glass substrate and protects the light receiving surface of the solar cell 1. The back surface protection member 4 is, for example, a glass substrate or a metal plate, and protects the back surface of the solar cell 1.

A sealing material 5 is filled between the light receiving surface protection member 3 and the back surface protection member 4. The sealing material 5 is, for example, a liquid or solid transparent resin, and seals the solar cell 1 and the wiring member 2.

(Another example of a solar cell module)
FIG. 1B is a side view showing another example of the solar cell module according to the present embodiment. The solar cell module 100 shown in FIG. 1B includes a plurality of solar cell cells 1, a wiring member 2, a light receiving surface protection member 3, a back surface protection member 4, and a sealing material 5.

The solar cell module 100 is also a wiring connection type solar cell module in which a plurality of solar cell cells 1 are indirectly connected by using a wiring member 2. Specifically, the solar cell 1 is a so-called striped electrode, and has a plurality of finger electrodes. The wiring member 2 is a known interconnector such as a tab. The wiring member 2 is connected to the finger electrode of the solar cell 1 via the adhesive member 6. Even in this wiring connection type solar cell module 100, the space between the solar cell 1 and the wiring member 2 is an electrical connection portion 12 (including the adhesive member 6).

The solar cell 1 and the wiring member 2 are sandwiched between the light receiving surface protection member 3 and the back surface protection member 4. The light receiving surface protection member 3 is, for example, a glass substrate and protects the light receiving surface of the solar cell 1. The back surface protection member 4 is, for example, a glass substrate or a metal plate, and protects the back surface of the solar cell 1.

A sealing material 5 is filled between the light receiving surface protection member 3 and the back surface protection member 4. The sealing material 5 is, for example, a liquid or solid transparent resin, and seals the solar cell 1 and the wiring member 2.

(Another example of a solar cell module)
FIG. 1C is a side view showing still another example of the solar cell module according to the present embodiment. The solar cell module 100 shown in FIG. 1C includes a plurality of solar cell cells 1, a light receiving surface protection member 3, a back surface protection member 4, and a sealing material 5.

The solar cell module 100 is a single ring connection type solar cell module in which a plurality of solar cell 1s are directly connected by using a single ring method. Specifically, by overlapping a part of the end portions of the adjacent solar cell 1s, the adjacent solar cells 1 are connected via the adhesive member 6. In this single ring connection type solar cell module 100, an electrical connection portion 12 (including an adhesive member 6) is between adjacent solar cell cells 1.

In this way, since the plurality of solar cells 1 have a sedimentary structure that is uniformly tilted in a certain direction as if the roof tiles were covered with roof tiles, the solar cells 1 are electrically connected in this way. The method is referred to as a single ring method. Further, a plurality of solar cell 1s connected in a string shape are referred to as a solar cell string.

The solar cell 1 is sandwiched between the light receiving surface protection member 3 and the back surface protection member 4. The light receiving surface protection member 3 is, for example, a glass substrate and protects the light receiving surface of the solar cell 1. The back surface protection member 4 is, for example, a glass substrate or a metal plate, and protects the back surface of the solar cell 1.

A sealing material 5 is filled between the light receiving surface protection member 3 and the back surface protection member 4. The sealing material 5 is, for example, a liquid or solid transparent resin, and seals the solar cell 1.

In such a solar cell module 100, stress is applied to the electrical connection portions 12 (including the adhesive member 6) of the plurality of solar cell 1 over time due to fluctuations in the actual usage environment (for example, temperature fluctuations during the day and night). It takes. Due to such aging stress, the electrical connection portion 12 may be cracked or partially peeled off, and as a result, the electrical resistance of the electrical connection portion 12 may increase. When the electrical resistance of the electrical connection portion 12 increases, the electrical connection portion 12 generates heat, which may cause a fire, for example.

In such a solar cell module, it is known to perform an Accelerated Temperature Cycle (ATC) test in which the temperature is repeatedly changed in a short time as a durability test against stress over time. However, in such an accelerated temperature cycle test for each solar cell module, the test time for the durability test of the electrical connection portion of the solar cell module is long. For example, in order to test the durability for 30 years, such an accelerated temperature cycle test for each solar cell module requires about half a year.

Therefore, the inventor of the present application devises a durability test method for the electrical connection portion of the solar cell module, which shortens the test time. Hereinafter, the durability test method of the electrical connection portion of the solar cell module according to the present embodiment will be described.

(First Embodiment)
(Durability test method for electrical connections of solar cell modules)
Next, the durability test method of the electrical connection portion of the solar cell module according to the first embodiment will be described with reference to FIGS. 2A to 3. FIG. 2A is a diagram showing a component unit for a durability test of an electrical connection portion of the solar cell module shown in FIG. 1A. FIG. 2B is a diagram showing a component unit for a durability test of an electrical connection portion of the solar cell module shown in FIG. 1B. FIG. 2C is a diagram showing a component unit for a durability test of an electrical connection portion of the solar cell module shown in FIG. 1C. FIG. 3 is a diagram showing tensile stress for a durability test of an electrical connection portion of the solar cell module of the first embodiment.

First, as shown in FIG. 2A, it is a part of the constituent units 10 in the solar cell module 100 shown in FIG. 1A, and the solar cell 1 and the wiring member 2 are connected to the electrical connection portion 12 (including the adhesive member 6). The configuration unit 10 connected via the device is prepared. Alternatively, as shown in FIG. 2B, a part of the constituent units 10 in the solar cell module 100 shown in FIG. 1B, the solar cell 1 and the wiring member 2 are connected to the electrical connection portion 12 (including the adhesive member 6). The configuration unit 10 connected via the device is prepared. Alternatively, as shown in FIG. 2C, it is a part of the constituent units 10 in the solar cell module 100 shown in FIG. 1C, and two solar cell 1s are connected via an electric connection portion 12 (including an adhesive member 6). Prepare the configured configuration unit 10.

Next, the prepared constituent unit 10 is set in the tensile tester. As the tensile tester, a known tensile tester is used. At this time, the portion of the constituent unit 10 to be gripped by the tensile tester may be fixed to the carrier using an adhesive, and the carrier may be gripped by the tensile tester. As the carrier, plastic, glass, or the like is used. According to this, it is possible to reduce the damage of the constituent unit itself due to being gripped by the tensile tester.

Next, a tensile stress is applied to the constituent unit 10 (tensile test). The tensile stress is a pulse-shaped tensile stress as shown in FIG. 3, and is set to a predetermined magnitude and a predetermined number of repetitions.

The predetermined magnitude of the tensile stress is set to be equal to or higher than the stress applied to the electrical connection portion 12 in the actual use environment and in the state of the solar cell module 100 (non-destructive test). The predetermined magnitude of the tensile stress may be set, for example, based on the maximum value of the stress applied to the electrical connection portion 12, or may be set based on the average value of the stress applied to the electrical connection portion 12.

The predetermined number of repetitions of tensile stress is set to the desired endurance days or more (accelerated test). For example, when the desired durability is 30 years, the predetermined number of repetitions of tensile stress is set to 365 days × 30 years = about 11,000 times or more.

The direction of the tensile stress is set to be 0 degree direction (in other words, 180 degree direction) with respect to the main surface (light receiving surface and back surface) of the solar cell 1 in the constituent unit 10.

After that, the electrical resistance of the electrical connection portion 12 in the constituent unit 10 is measured, and the durability of the electrical connection portion 12 is inspected (evaluated) based on the increase in the electrical resistance. For example, when the electric resistance is equal to or more than a predetermined value, it is determined that the desired durability is not satisfied.

Further, the presence or absence of peeling of the electrical connection portion 12 in the constituent unit 10 is visually inspected using a microscope or the like, and the durability of the electrical connection portion 12 is inspected (evaluated) based on the presence or absence of peeling. For example, if there is peeling, it is determined that the desired durability is not satisfied.

For example, if the adhesiveness of the adhesive member 6 of the electrical connection portion 12 is low, peeling occurs in a part between the wiring member 2 and the adhesive member 6, and as a result, the electrical resistance of the electrical connection portion 12 increases. Is expected. On the other hand, if the adhesive member 6 of the electrical connection portion 12 has high adhesiveness, partial peeling does not occur between the wiring member 2 and the adhesive member 6, and as a result, the electrical resistance of the electrical connection portion 12 does not increase. Is expected.

As described above, in the durability test method of the electrical connection portion 12 of the solar cell module 100 of the present embodiment, a part of the constituent units 10 of the solar cell module 100 is prepared, and the constituent units 10 are predetermined. A tensile stress of magnitude is applied a predetermined number of repetitions (accelerated test). According to this, as compared with the above-mentioned conventional accelerated temperature cycle test for each solar cell module, the time required for the temperature change is unnecessary, so that the test time can be shortened.

By the way, in the tensile test on the constituent unit 10, the inventor of the present application applies a tensile stress in the direction of 90 degrees to the main surfaces (light receiving surface and back surface) of the solar cell 1 in the constituent unit 10 to continuously apply the tensile stress. It was devised to inspect (evaluate) the durability of the electrical connection portion 12 based on the magnitude of the tensile stress when the electrical connection portion 12 is peeled off (destructive test). However, in such a durability test method, the test accuracy is low with respect to the durability against stress in the actual use environment.

In particular, in the solar cell module 100 sealed with a protective member such as a glass substrate on the light receiving surface and the back surface, the direction is 0 degrees with respect to the main surface of the solar cell 1 due to the difference in the coefficient of linear expansion of the components. Stress is generated in the 180 degree direction). However, in such a solar cell module 100, stress is hardly generated in the direction of 90 degrees with respect to the main surface of the solar cell 1 due to a protective member such as a glass substrate.

Regarding this point, in the durability test method of the electrical connection portion 12 of the solar cell module 100 of the present embodiment, the direction of the tensile stress is relative to the main surface (light receiving surface and back surface) of the solar cell 1 in the constituent unit 10. It is in the 0 degree direction (180 degree direction). As a result, the tensile stress in the 0 degree direction (180 degree direction), which is close to the actual use environment, is used, so that the accuracy of the durability test can be improved.

Further, in the durability test method of the electrical connection portion 12 of the solar cell module 100 of the present embodiment, the predetermined magnitude of the tensile stress is applied to the electrical connection portion 12 in the actual use environment and in the state of the solar cell module 100. Such stress or more is set, and the predetermined number of repetitions of tensile stress is set to the desired endurance days or more (non-destructive test). As a result, the accuracy of the durability test can be improved because the tensile stress of a magnitude and change close to that of the actual use environment is used.

Generally, the life of a solar cell has been considered to be about 20 years, but even after 20 years, the electrical performance of the solar cell does not deteriorate sharply, and it is possible to continue using the solar cell thereafter. .. Therefore, the manufacturer needs to guarantee the durability and safety of the solar cell module for about 30 years, for example. Along with this, it is particularly necessary to guarantee the durability and safety of electrical connections that are stressed over time due to the actual usage environment (for example, temperature fluctuations during the day and night).

According to the durability test method of the electrical connection portion 12 of the solar cell module 100 of the present embodiment, the durability of the electrical connection portion 12 is inspected (evaluated) in a short time to provide feedback to the manufacturing line of the solar cell module. It is possible to manufacture a product that guarantees the durability and safety of the electrical connection part.

(Modified example of the first embodiment)
(Durability test method for electrical connections of solar cell modules)
In the first embodiment, the room temperature was set when the tensile stress was applied to the constituent unit 10. However, when applying tensile stress to the constituent unit 10, it may be set to a predetermined temperature. The predetermined temperature of the tensile test is set to the outdoor temperature in the actual use environment, or higher than the maximum outdoor temperature or lower than the minimum outdoor temperature. The predetermined temperature of the tensile test may be set based on, for example, the maximum or minimum value of the outdoor temperature in the actual use environment, or may be set based on the average value of the outdoor temperature in the actual use environment.

The characteristics of the adhesive member 6 in the electrical connection portion 12 may change depending on the temperature. In this regard, in the durability test method of the electrical connection portion 12 of the solar cell module 100 of this modified example, when a tensile stress is applied to the constituent unit 10, a predetermined temperature is set to the outdoor temperature in the actual use environment. Alternatively, it is set above the maximum outdoor temperature or below the minimum outdoor temperature (non-destructive test). As a result, since the tensile test is performed at an outdoor temperature close to the actual use environment, the accuracy of the durability test can be improved in consideration of the change in the characteristics of the adhesive member 6 due to the temperature change.

(Second Embodiment)
(Durability test method for electrical connections of solar cell modules)
In the first embodiment and the modified example described above, in the tensile test, a tensile stress of a predetermined magnitude was applied to the constituent unit 10 a predetermined number of times (non-destructive test).

In the second embodiment, in the tensile test, a tensile stress is applied to the constituent unit 10 at a predetermined temperature so as to gradually increase (destruction test). The direction of the tensile stress is 0 degree direction (in other words, 180 degree direction) with respect to the main surface (light receiving surface and back surface) of the solar cell 1 in the constituent unit 10 as in the first embodiment and the modified example described above. Is set to.

The predetermined temperature of the tensile test is set to the outdoor temperature in the actual use environment, or higher than the maximum outdoor temperature or lower than the minimum outdoor temperature. The predetermined temperature of the tensile test may be set based on, for example, the maximum or minimum value of the outdoor temperature in the actual use environment, or may be set based on the average value of the outdoor temperature in the actual use environment.

Then, the durability of the electrical connection portion 12 is inspected (evaluated) based on the magnitude of the tensile stress when the electrical connection portion 12 of the constituent unit 10 is peeled off.

Further, the method of peeling the electrical connection portion 12 in the constituent unit 10 may be visually inspected using a microscope or the like, and the durability of the electrical connection portion 12 may be inspected (evaluated) based on the method of peeling. For example, if the adhesive member 6 of the electrical connection portion 12 has high adhesiveness, the adhesive member 6 is peeled off while being adhered to the wiring member 2 side. That is, the adhesive member 6 does not remain on the peeled surface of the solar cell 1, and the silicon material appears to be exposed. On the other hand, if the adhesiveness of the adhesive member 6 of the electrical connection portion 12 is low, the adhesive member 6 is peeled off while being adhered to the solar cell 1 side. That is, the adhesive member 6 remains on the peeled surface of the solar cell 1, and the silicon material cannot be seen.

In the durability test method of the electrical connection portion 12 of the solar cell module 100 of the second embodiment, a part of the constituent units 10 of the solar cell module 100 is prepared, and the constituent units 10 are gradually subjected to a predetermined temperature. Tensile stress is applied so as to increase (accelerated test). According to this, as compared with the above-mentioned conventional accelerated temperature cycle test for each solar cell module, the time required for repeated temperature changes is unnecessary, so that the test time can be shortened.

Further, also in the durability test method of the electrical connection portion 12 of the solar cell module 100 of the second embodiment, the direction of the tensile stress is 0 with respect to the main surface (light receiving surface and back surface) of the solar cell 1 in the constituent unit 10. The degree direction (180 degree direction). As a result, the tensile stress in the 0 degree direction (180 degree direction), which is close to the actual use environment, is used, so that the accuracy of the durability test can be improved.

Here, as shown in FIG. 4, in the sample A of the constituent unit 10, the electrical connection portion 12 of the constituent unit 10 is peeled off in both the tensile test (breaking test) at room temperature and the tensile test (breaking test) at high temperature. The magnitude of the tensile stress (that is, the adhesive strength) at that time exceeds the adhesive strength that can withstand the stress generated at the time of glass sealing in the state of the solar cell module. On the other hand, in sample A of the constituent unit 10, in the tensile test (destruction test) at room temperature, the magnitude of the tensile stress (that is, the adhesive strength) when the electrical connection portion 12 of the constituent unit 10 is peeled off is determined by the solar cell module. In the tensile test (destruction test) at a high temperature, the tensile stress when the electrical connection portion 12 of the constituent unit 10 is peeled off (that is, that is,) exceeds the adhesive strength that can withstand the stress equivalent to the stress generated during glass sealing in the above state. The magnitude of (adhesive strength) is less than the adhesive strength that can withstand the stress equivalent to the stress generated during glass sealing in the state of the solar cell module. It is presumed that this is because the characteristics of the adhesive member 6 in the electrical connection portion 12 change with temperature.

In this regard, in the durability test method of the electrical connection portion 12 of the solar cell module 100 of the second embodiment, when a tensile stress is applied to the constituent unit 10, a predetermined temperature is set to an outdoor temperature in an actual use environment. , Or above the maximum outdoor temperature or below the minimum outdoor temperature. As a result, the tensile stress is applied at an outdoor temperature close to the actual use environment, so that the accuracy of the durability test can be improved in consideration of the change in the characteristics of the adhesive member 6 due to the temperature change.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and modifications can be made. For example, in the above-described embodiment, the durability test method of the electrical connection portion 12 of the solar cell module 100 including the double-sided electrode type (double-sided junction type) solar cell 1 has been exemplified, but the durability test method of the present invention is described. It can also be applied to a durability test method for an electrical connection portion of a solar cell module including a back electrode type (back surface bonding type, back contact type) solar cell.

Hereinafter, the present invention will be specifically described based on Examples, but the present invention is not limited to the following Examples.

(Example 1)
The constituent unit 10 shown in FIG. 2A was produced. The constituent unit 10 of Example 1 was manufactured under the same conditions as the conditions for manufacturing the solar cell module 100. Specifically, a heterojunction type double-sided light-receiving solar cell is cut into a rectangular shape with a width of 4.2 mm using a laser processing device, and then conductively adhered to the printed electrode at the end of the cut rectangular cell (1). Agent (6) (product name: conductive film CF for solar cells, manufactured by Hitachi Kasei Co., Ltd.) was applied. After that, solder-plated copper wiring (2) (product name: flat copper wire for solar cells, manufactured by Marusho Co., Ltd.) is placed on the conductive adhesive (6) coated portion, and pressure-bonded heating (temperature) under predetermined conditions. 180 ° C. to 210 ° C., pressure 8 N / mm ^{2 to} 8.9 N / mm ² ). As the wiring (2), a wiring containing no lead was used. As a result, the constituent unit 10 of Example 1 in which the cell (1) and the wiring (2) are connected via the conductive adhesive (6, 12) is produced.

In conducting a tensile test (durability test) of the constituent unit 10, the constituent unit 10 was adhered to a plastic rod in order to fix the constituent unit 10 to the test apparatus. A 5 mm square rod was used as the plastic rod, and a commercially available adhesive (product name: Aron Alpha (registered trademark), manufactured by Konishi Co., Ltd.) was used as the adhesive. The constituent unit 10 supported on the plastic rod is set in an electric fatigue test device (product name: E1000 type, manufactured by Instron), and the constituent unit 10 is set in the 0 degree direction shown in FIG. 2A at room temperature (25 ° C.). The stress of peeling the cell (1) and the wiring (2) in the above was applied until the electrical connection portion 12 (6) was peeled off.

According to the tensile test (durability test) of the constituent unit 10 of Example 1, the adhesive strength of the electrical connection portion 12 (6) at the test temperature of room temperature was 95 N on average (number of tests n = 4). When the test temperature was changed to 85 ° C., the adhesive strength of the electrical connection portion 12 (6) was 86 N on average (number of tests n = 9).

(Comparative Example 1)
The constituent unit of Comparative Example 1 was produced by the same production method as in Example 1. In the constituent unit of Comparative Example 1, a lead-containing solder-plated copper wiring was used as the wiring (2) in the constituent unit 10 of the first embodiment.

In the tensile test (durability test) of the constituent unit of Comparative Example 1, the constituent unit supported on the plastic rod was set in the electric fatigue test apparatus in the same manner as in Example 1, and at room temperature (25 ° C.). The stress of peeling the cell and the wiring in the constituent unit was applied in the 0 degree direction shown in FIG. 2A until the electrical connection portion was peeled off.

According to the tensile test (durability test) of the constituent unit of Comparative Example 1, the adhesive strength of the electrical connection portion at the test temperature of room temperature was 91 N on average (number of tests n = 5). The adhesive strength of the electrical connection portion when the test temperature was changed to 85 ° C. was 54 N on average (number of tests n = 9), which was lower than that of Example 1.

(Example 2)
The constituent unit 10 of Example 2 was manufactured by the same manufacturing method as that of Example 1.

In the tensile test (durability test) of the constituent unit 10 of the second embodiment, the constituent unit 10 supported on the plastic rod is set in the electric fatigue test apparatus, and at room temperature (25 ° C.), 0 shown in FIG. 2A. A tensile stress of 70 N was repeatedly applied in the degree direction for 10,000 cycles as shown in FIG.

According to the tensile test (durability test) of the constituent unit 10 of Example 2, no peeling or the like was observed in the electrical connection portion 12 (6) after the test, and the resistance of the electrical connection portion 12 (6) before and after the test was observed. The value did not increase either.

(Example 3)
The constituent unit 10 of Example 3 was manufactured by the same manufacturing method as that of Example 1.

In the tensile test (durability test) of the constituent unit 10 of the third embodiment, the constituent unit 10 supported on the plastic rod is set in the electric fatigue test apparatus, and at room temperature (25 ° C.), 0 shown in FIG. 2A. Tensile stresses of 60N, 70N or 80N were repeatedly applied in the degree direction as shown in FIG. 3 until the electrical connection portion 12 (6) was peeled off.

According to the tensile test (durability test) of the constituent unit 10 of Example 2, in the tensile test of 60 N, the electrical connection portion 12 (6) was peeled off at the 20th and 146th cycles. In the 70N tensile test, the electrical connection portion 12 (6) was peeled off at the 13,551th cycle. In the 80N tensile test, the electrical connection portion 12 (6) was peeled off at the 561st cycle. The useful life of the electrical connection 12 (6) can be estimated from the relationship between the load stress of the test and the number of test cycles until peeling.

(Example 4)
The constituent unit 10 shown in FIG. 2C was manufactured. The constituent unit 10 of Example 4 was manufactured under the same conditions as the conditions for manufacturing the solar cell module 100. Specifically, a heterojunction type double-sided light-receiving solar cell is cut into a rectangular shape with a width of 26 mm using a laser processing device, and then the printed electrodes at the cut rectangular cell ends (1, 1) are conductive with each other. Connected via an adhesive (6) (product name: conductive film for solar cells "CF series", manufactured by Hitachi Kasei Co., Ltd.), and pressure-bonded and heated (temperature 180 ° C to 210 ° C, pressure 8N / mm ^{2) under predetermined conditions.} ~ 8.9 N / mm ² ). As a result, the constituent unit 10 of Example 4 in which the cells (1,1) were connected to each other via the conductive adhesive (6,12) was produced.

In conducting a tensile test (durability test) of the constituent unit 10, the constituent unit 10 was adhered to a glass plate in order to fix the constituent unit 10 to the test apparatus. As the adhesive, a commercially available adhesive (product name: Aron Alpha, manufactured by Konishi Co., Ltd.) was used. The constituent unit 10 supported on the glass plate is set in an electric fatigue test device (product name: E1000 type, manufactured by Instron), and the constituent unit 10 is set in the 0 degree direction shown in FIG. 2C at room temperature (25 ° C.). The stress of peeling the cells (1,1) from each other was applied until the electrical connection portion 12 (6) was peeled off.

According to the tensile test (durability test) of the constituent unit 10 of Example 4, the adhesive strength of the electrical connection portion 12 (6) at the test temperature of room temperature was 87 N (number of tests n = 1).

(Comparative Example 2)
The constituent unit of Comparative Example 2 was produced by the same production method as in Example 4. In the constituent unit of Comparative Example 2, the temperature condition of the connection process for connecting the cells to each other with the conductive adhesive was set to be relatively low as compared with that of Example 4.

In the tensile test (durability test) of the constituent unit of Comparative Example 2, the constituent unit supported on the glass plate was set in the electric fatigue test apparatus in the same manner as in Example 4, and at room temperature (25 ° C.). In the 0 degree direction shown in FIG. 2C, a stress for peeling the cells from each other in the constituent unit was applied until the electrical connection portion was peeled off.

According to the tensile test (durability test) of the constituent unit of Comparative Example 2, the adhesive strength of the electrical connection portion at the test temperature of room temperature was 78 N (number of tests n = 1), which was lower than that of Example 4. It was.

1 Solar cell 2 Wiring member 3 Light receiving side protective member 4 Back side protective member 5 Encapsulant 6 Adhesive member 10 Component unit 12 Electrical connection 100 Solar cell module

Claims (8)

A method of testing the durability of electrical connections of multiple solar cells in a solar cell module.
A part of the constituent units in the solar cell module, the constituent unit in which the solar cell and the wiring member are connected via the electrical connection portion, or the two solar cell cells are connected to the electrical connection portion. Prepare the above-mentioned component unit connected via
After applying a tensile stress of a predetermined magnitude to the constituent unit a predetermined number of times,
The durability of the electrical connection is inspected based on the increase in electrical resistance of the electrical connection in the configuration unit and / or the presence or absence of peeling of the electrical connection in the configuration unit.
Durability test method for electrical connections in solar cell modules. The method for testing the durability of an electrical connection portion of a solar cell module according to claim 1, wherein the direction of the tensile stress is the direction of 0 degrees with respect to the main surface of the solar cell in the constituent unit. The solar cell module according to claim 1 or 2, wherein the predetermined magnitude of the tensile stress is set to be equal to or higher than the stress applied to the electrical connection portion in the actual use environment and in the state of the solar cell module. Durability test method for electrical connections. The method for testing the durability of an electrical connection portion of a solar cell module according to any one of claims 1 to 3, wherein the predetermined number of repetitions of the tensile stress is set to a desired durability day or more. When the tensile stress is applied to the constituent unit, the temperature is set to a predetermined temperature.
The predetermined temperature is set to a temperature in an actual use environment, or a maximum temperature or more or a minimum temperature or less.
The method for testing the durability of an electrical connection portion of a solar cell module according to any one of claims 1 to 4. A method of testing the durability of electrical connections of multiple solar cells in a solar cell module.
A part of the constituent units in the solar cell module, the constituent unit in which the solar cell and the wiring member are connected via the electrical connection portion, or the two solar cell cells are connected to the electrical connection portion. Prepare the above-mentioned component unit connected via
Tensile stress is applied to the constituent units at a predetermined temperature so as to gradually increase.
The durability of the electrical connection is inspected based on the magnitude of the tensile stress when the electrical connection is peeled off.
Durability test method for electrical connections in solar cell modules. The method for testing the durability of an electrical connection portion of a solar cell module according to claim 6, wherein the direction of the tensile stress is the direction of 0 degrees with respect to the main surface of the solar cell in the constituent unit. The durability test method for an electrical connection portion of a solar cell module according to claim 6 or 7, wherein the predetermined temperature is set to a temperature in an actual use environment, or a maximum temperature or more or a minimum temperature or less.

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