Device and method for testing bonding strength of solar cell

Abstract

The invention provides a device and a method for testing the bonding strength of a solar cell piece. The testing device comprises an adjustable support frame, a switching tool, a parallel surface pulley, a vertical line pulley, a parallel surface binding line, a vertical line binding line, a parallel surface weight and a vertical line weight, the adjustable supporting frame supports a substrate with a solar cell piece. The switching tool is adhered to the surface of the solar cell; the leading-out direction of the parallel surface binding wire from the switching tool is the direction of the decomposition force of the cementing test force parallel to the cementing surface, and the leading-out direction of the vertical line binding wire from the switching tool is the direction of the decomposition force of the cementing test force vertical to the cementing surface; the gravity of the parallel surface heavy object is equal to the decomposition force of the glue joint test force parallel to the glue joint surface direction, the gravity of the vertical line heavy object is equal to the decomposition force of the glue joint test force vertical to the glue joint surface direction, and the glue joint strength test under different glue joint test forces is implemented by changing the weight of the heavy object and the leading-out direction of the binding line.

Description

Technical Field

[0001] The invention belongs to the technical field of solar cell sheet adhesive strength testing, and in particular relates to a solar cell sheet adhesive strength testing device and method. Background Art

[0002] Failure of the bonding interface of solar cells is unacceptable during the life cycle of solar cell array products. However, solar cell arrays have the characteristics of long development cycles and certain life limits, making it difficult for products to avoid long-term environmental factors, aggravating creep, fatigue and material aging of the bonding structure, leading to a decrease in bonding strength or interface failure.

[0003] The existing bonding strength test method uses specific specimens and devices to conduct bonding strength tests at the initial stage of adhesive configuration. The bonding strength of the two bonding surfaces after the adhesive is applied to the solar cell and the substrate is tested. The specific specimen is different from the surface state of the cell and the substrate, and cannot characterize the bonding strength state of the bonding surface to be tested. Moreover, the bonding strength test device performs bonding strength tests by clamping the product to be tested. However, since the substrate formed by the honeycomb interlayer and carbon fiber coating and the solar cell body are prone to brittle cracking, the existing clamping device is easy to damage the test piece and cannot effectively transfer the test force to the bonding surface. In addition, the decrease in bonding strength is the breakage of bonds at the molecular level, which has uncertainty in direction and randomness in position, and puts forward difficult-to-achieve multi-directional testing requirements for testing; and the existing bonding strength assessment methods such as non-destructive testing such as X-ray and infrared detection can only assess defects such as lack of glue, bubbles, and shedding, and it is difficult to assess the decrease in bonding strength caused by the breakage of molecular bonds after long-term storage. Summary of the invention

[0004] In order to overcome the deficiencies in the prior art, the inventors have conducted intensive research and provided a testing device and method for the bonding strength of solar cells to solve the problem that the bonding strength cannot be tested directly using a substrate with solar cells, and the need for bonding strength testing under multi-directional bonding test forces.

[0005] The technical solution provided by the present invention is as follows:

[0006] In a first aspect, a test device for the adhesive strength of a solar cell sheet includes an adjustable support frame, a transfer tool, a parallel surface pulley, a vertical line pulley, a parallel surface binding line, a vertical line binding line, a parallel surface weight, and a vertical line weight;

[0007] The adjustable support frame supports the substrate with the solar cell sheet so that the bonding surface of the solar cell sheet and the substrate coincides with the direction of gravity; the transfer tool is pasted on the surface of the solar cell sheet;

[0008] One end of the parallel plane lashing line is fixed on the transfer tooling, and the other end passes through the parallel plane pulley to hang the parallel plane weight; one end of the vertical line lashing line is fixed on the transfer tooling, and the other end passes through the vertical line pulley to hang the vertical line weight;

[0009] The lead-out direction of the parallel plane binding wire from the rotating fixture is the decomposition direction of the bonding test force parallel to the bonding surface, and the lead-out direction of the vertical line binding wire from the rotating fixture is the decomposition direction of the bonding test force perpendicular to the bonding surface; the gravity of the parallel plane weight is equal to the decomposition direction of the bonding test force parallel to the bonding surface, and the gravity of the vertical line weight is equal to the decomposition direction of the bonding test force perpendicular to the bonding surface. By changing the weight of the weight and the lead-out direction of the binding wire, the bonding strength test under different bonding test forces is implemented.

[0010] In combination with the first aspect, the transfer tool is adhered to the surface of the solar cell sheet by adhesive, and the bonding strength between the transfer tool and the bonding surface of the solar cell sheet to be tested is greater than the bonding strength between the bonding surface of the solar cell sheet and the substrate.

[0011] In combination with the first aspect, the size of the transfer tool is similar to the size of a single solar cell panel.

[0012] In combination with the first aspect, an annular groove is processed on the thickness surface of the transfer tooling, one end of the parallel surface binding line is tied around the annular groove, and the other end is passed around the parallel surface pulley to hang the parallel surface weight. Preferably, the groove is located in the middle of the thickness surface of the transfer tooling.

[0013] In combination with the first aspect, a protrusion is provided at the center of the outer panel surface of the transfer tooling, one end of the vertical line binding wire is tied to the protrusion, and the other end passes through the vertical line pulley to hang the vertical line weight.

[0014] In combination with the first aspect, a through hole is opened on the side of the protrusion, and the vertical line binding wire passes through the through hole and is tied to the protrusion, so that the force application point of the vertical line binding wire is located in the middle of the protrusion, perpendicular to the bonding surface of the solar cell panel and the substrate.

[0015] In combination with the first aspect, the outer plate surface of the transfer tool is processed with 360° angle scale lines, and preferably the angle scale lines extend to the edge of the outer plate surface. Preferably, the angle scale lines extend to the edge of the outer plate surface.

[0016] In combination with the first aspect, the parallel plane binding lines and the vertical line binding lines are installed with tension gauges for measuring the gravity of the parallel plane weights and the vertical line weights.

[0017] In a second aspect, a method for testing the bonding strength of a solar cell sheet is implemented using the testing device for the bonding strength of a solar cell sheet described in the first aspect, comprising:

[0018] The cylindrical coordinate system of the bonding surface is established with the center of the solar cell as the origin, and the bonding test force to be applied in the hemispherical surface is decomposed into two decomposed forces F1 parallel to the bonding surface and perpendicular to the bonding surface: (F x ,θ,0) and F2(0,0,F Z ); the X-axis is perpendicular to the long side of the solar cell, the Z-axis is perpendicular to the outward direction of the solar cell, and the F x / cosθ is the decomposition force parallel to the bonding surface, F x is the force pointing to the long side of the solar cell, θ is the angle between the decomposed force parallel to the bonding surface and the X-axis, F Z is the magnitude of the decomposition force perpendicular to the bonding surface;

[0019] The transfer tool is pasted on the solar cell to be tested by adhesive, and the substrate with the solar cell is placed on the support frame, and the adhesive surface of the solar cell to be tested coincides with the gravity direction;

[0020] The parallel plane weight is hung on the transfer fixture through the parallel plane binding wire, and the vertical line weight is hung on the transfer fixture through the vertical line binding wire. The angle between the parallel plane binding wire and the X-axis is θ, and the direction of the vertical line binding wire from the transfer fixture is perpendicular to the bonding surface of the solar panel.

[0021] Gradually increase the weight of the parallel plane weight until the force F1 reaches F x / cosθ, increase the weight of the vertical line weight to force F2 to F Z ;

[0022] After the target bonding strength test is completed, adjust the direction of the two binding lines or the size of the weight and carry out another bonding strength test under the bonding test force.

[0023] A solar cell sheet bonding strength testing device and method according to the present invention has the following features:

[0024] Beneficial effects:

[0025] (1) The present invention provides a testing device and method for the bonding strength of a solar cell sheet, which adopts a transfer fixture to be pasted on the surface of the solar cell sheet; one end of the parallel plane binding line is fixed on the transfer fixture, and the other end is passed around the parallel plane pulley to hang the parallel plane weight; one end of the vertical line binding line is fixed on the transfer fixture, and the other end is passed around the vertical line pulley to hang the vertical line weight; the lead-out direction of the parallel plane binding line from the transfer fixture is the direction of the decomposition force of the bonding test force parallel to the bonding surface direction, and the lead-out direction of the vertical line binding line from the transfer fixture is perpendicular to the bonding surface; the gravity of the parallel plane weight is equal to the decomposition force of the bonding test force parallel to the bonding surface direction, and the gravity of the vertical line weight is equal to the decomposition force of the bonding test force perpendicular to the bonding surface direction. The bonding strength test under different bonding test forces is implemented by changing the weight of the weight and the lead-out direction of the binding line. The present invention can provide reliable mechanical test results in any direction within the hemispherical surface, accurately reflect the bonding interface state of the tested piece, and provide powerful evaluation and support for the relatively weak bonding strength of the solar wing after long-term storage.

[0026] (2) The present invention provides a test device and method for the bonding strength of solar cell sheets. An annular groove is processed in the middle of the thickness surface of the transfer tool. One end of the parallel surface binding wire is tied around the annular groove, and the other end is tied around the parallel surface pulley to hang the parallel surface weight. The design of the groove can meet the application of force in any direction on the parallel solar cell sheet bonding surface.

[0027] (3) The present invention provides a testing device and method for the bonding strength of solar cell sheets. The outer panel center of the transfer tooling has a protrusion installed on its side. A through hole is provided. The vertical binding wire passes through the through hole and is then tied to the protrusion. The design of the protrusion can satisfy the application of force in the direction perpendicular to the bonding surface of the solar cell sheet.

[0028] (4) The present invention provides a solar cell panel bonding strength testing device and method, which is designed with angle scale lines on the outer panel of the adapter. When heavy objects are hung in the groove, the angle between the parallel binding line and the X-axis can be read, making it easy to control the direction of the bonding test force. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the decomposition of the bonding test force of the present invention in the vertical and parallel directions to the bonding surface;

[0030] Figure 2 It is a structural schematic diagram of a solar cell sheet bonding strength testing device of the present invention;

[0031] Figure 3 It is a structural schematic diagram of the transfer tooling of the present invention. DETAILED DESCRIPTION

[0032] The following detailed description of the present invention will make the features and advantages of the present invention more clear and explicit.

[0033] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0034] The present invention provides a device for testing the bonding strength of solar cells. Figure 2 As shown, it includes an adjustable support frame 1, a transfer tooling 2, a parallel plane pulley 3, a vertical line pulley 4, a parallel plane binding line 5, a vertical line binding line 6, a parallel plane weight 7 and a vertical line weight 8.

[0035] The support frame 1 can be adjusted to support the substrate with the solar cell so that the bonding surface between the solar cell and the substrate coincides with the direction of gravity. The adapter 2 is adhered to the surface of the solar cell by an adhesive (such as HY-914 room temperature fast curing epoxy resin adhesive). The bonding strength between the adapter 2 and the solar cell to be tested is greater than the bonding strength between the solar cell and the substrate. In order to improve the overall test accuracy of the bonding surface between the solar cell and the substrate, the size of the adapter 2 is close to the size of a single solar cell. Figure 3 As shown, an annular groove 9 is processed on the thickness surface of the transfer tooling 2, and a protrusion 10 is set in the center of the outer plate surface. One end of the parallel surface binding line 5 is tied after being wrapped around the annular groove 9, and the other end passes around the parallel surface pulley 3 to hang the parallel surface weight 7; one end of the vertical line binding line 6 is tied to the protrusion 10, and the other end passes around the vertical line pulley 4 to hang the vertical line weight 8.

[0036] The design of the groove 9 can satisfy the application of force in any direction parallel to the bonding surface of the solar cell sheet. In order to ensure that the bonding test force is evenly applied on the bonding surface, the groove is designed in the middle of the thickness surface of the transfer tool 2. The design of the protrusion 10 can satisfy the application of force in the direction perpendicular to the bonding surface of the solar cell sheet. In order to ensure that the force is evenly applied on the bonding surface, the protrusion is designed in the middle of the transfer tool surface. A through hole is opened on the side of the protrusion 10, and the vertical line binding line 6 is tied to the protrusion 10 after passing through the through hole. The design of the side through hole can facilitate the force application point of the vertical line binding line 6 to be located in the middle of the protrusion 10, perpendicular to the bonding surface of the solar cell sheet and the substrate. The outer panel of the transfer tool 2 is processed with a 360° angle scale line 11, and the angle scale line 11 is preferably extended to the edge of the outer panel surface; the angle scale line design of the outer panel of the transfer tool can read the angle between the parallel surface binding line 5 and the X-axis when hanging heavy objects in the groove 9, which is easy to control the direction of the application of the bonding test force.

[0037] The lead-out direction of the parallel plane binding line 5 from the rotating fixture 2 is the decomposition direction of the bonding test force parallel to the bonding surface, and the lead-out direction of the vertical line binding line 6 from the rotating fixture 2 is perpendicular to the bonding surface; the gravity of the parallel plane weight 7 is equal to the decomposition direction of the bonding test force parallel to the bonding surface, and the gravity of the vertical line weight 8 is equal to the decomposition direction of the bonding test force perpendicular to the bonding surface. By changing the weight of the weight and the lead-out direction of the binding line, the bonding strength test under different bonding test forces is implemented.

[0038] The parallel plane binding line 5 and the vertical line binding line 6 are equipped with dynamometers, which can measure the gravity of the parallel plane weights 7 and the vertical line weights 8. The required bonding test force can be conveniently measured by adjusting the weights of the parallel plane weights 7 and the vertical line weights 8.

[0039] The present invention provides a method for testing the bonding strength of a solar cell sheet, comprising the following steps:

[0040] (1) Figure 1 As shown in the figure, a cylindrical coordinate system of the bonding surface is established with the center of the solar cell as the origin, and the coordinate formula of the bonding test force to be applied within the hemispherical surface is obtained. x ,θ,F Z ), decompose the bonding test force to be applied in the hemispherical surface into two decomposed forces F1, one parallel to the bonding surface and the other perpendicular to the bonding surface: (F x ,θ,0) and F2(0,0,F Z ); the X-axis is perpendicular to the long side of the solar cell, the Z-axis is perpendicular to the outward direction of the solar cell, and the F x / cosθ is the decomposition force parallel to the bonding surface, F x is the force pointing to the long side of the solar cell, θ is the angle between the decomposed force parallel to the bonding surface and the X-axis, F Z It is the magnitude of the decomposition force perpendicular to the bonding surface.

[0041] (2) The transfer tool 2 is adhered to the solar cell to be tested by adhesive, and the substrate with the solar cell is placed on the support frame 1, so that the adhesive surface of the solar cell to be tested coincides with the direction of gravity.

[0042] The adhesive satisfies the following requirement: the bonding strength between the transfer fixture 2 and the bonding surface of the solar cell sheet to be tested is greater than the bonding strength between the bonding surface of the solar cell sheet and the substrate.

[0043] (3) The parallel surface weight 7 is hung on the transfer fixture 2 through the parallel surface binding line 5, and the vertical line weight 8 is hung on the transfer fixture 2 through the vertical line binding line 6. The lead-out direction of the parallel surface binding line 5 from the transfer fixture and the included angle with the X-axis is θ, and the angle can be read and adjusted through the angle scale line 11. The lead-out direction of the vertical line binding line 6 from the transfer fixture is perpendicular to the bonding surface.

[0044] (4) Gradually increase the weight of the parallel weight 7 until the force F1 reaches F x / cosθ, increase the weight of the vertical weight 8 to force F2 to F Z , the system is kept stable throughout the whole process; the system is kept stable throughout the whole process, and a certain size and direction of force is loaded on the bonding surface.

[0045] (5) After the target bonding strength test is completed, adjust the direction of the two binding lines or the size of the weight and carry out another bonding strength test under the bonding test force.

[0046] A solar wing contains two specifications of solar cells (4cm×3cm and 6cm×4cm). According to the mechanical impact requirements of the solar cell array, the solar cells will simultaneously withstand an impact acceleration of 18g in the direction of gravity parallel to the bonding surface and a lateral impact acceleration of 2g, as well as an impact acceleration of 9g perpendicular to the bonding surface; therefore, the test force for the bonding strength of the cell is (2Mg, 83.66°, 9Mg). In order to reserve a certain margin to improve reliability, baseline tests of 2 times, 5 times, and 10 times the impact acceleration are carried out respectively.

[0047] Correspondingly, in the bonding strength test, the parallel plane binding lines are led out along the direction, and the weights of the parallel plane weights are shown in Table 1 below; the vertical line binding lines are led out along the direction perpendicular to the bonding surface, and the weights of the vertical line weights are shown in Table 1 below.

[0048] Table 1 Test conditions for different bonding strength tests

[0049]

[0050] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

[0051] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A test device for the bonding strength of solar cells, characterized in that: It comprises an adjustable support frame (1), a transfer tool (2), a parallel surface pulley (3), a vertical line pulley (4), a parallel surface binding line (5), a vertical line binding line (6), a parallel surface weight (7) and a vertical line weight (8); The adjustable support frame (1) supports the substrate with the solar cell sheet so that the bonding surface between the solar cell sheet and the substrate coincides with the direction of gravity; the transfer tool (2) is adhered to the surface of the solar cell sheet; One end of the parallel plane binding line (5) is fixed on the transfer tooling (2), and the other end passes through the parallel plane pulley (3) to hang the parallel plane weight (7); one end of the vertical line binding line (6) is fixed on the transfer tooling (2), and the other end passes through the vertical line pulley (4) to hang the vertical line weight (8); The direction in which the parallel plane binding wire (5) is led out from the rotating fixture (2) is the direction in which the bonding test force is decomposed in a direction parallel to the bonding surface, and the direction in which the vertical line binding wire (6) is led out from the rotating fixture (2) is the direction in which the bonding test force is decomposed in a direction perpendicular to the bonding surface; the gravity of the parallel plane weight (7) is equal to the decomposed force of the bonding test force in a direction parallel to the bonding surface, and the gravity of the vertical line weight (8) is equal to the decomposed force of the bonding test force in a direction perpendicular to the bonding surface. By changing the weight of the weight and the direction in which the binding wire is led out, bonding strength tests under different bonding test forces are implemented.

2. The solar cell sheet bonding strength testing device according to claim 1, characterized in that: The transfer tool (2) is adhered to the surface of the solar cell sheet by means of an adhesive, and the bonding strength between the transfer tool (2) and the bonding surface of the solar cell sheet to be tested is greater than the bonding strength between the bonding surface of the solar cell sheet and the substrate.

3. The solar cell sheet bonding strength testing device according to claim 1, characterized in that: The size of the transfer tool (2) is similar to that of a single solar cell sheet.

4. The solar cell sheet bonding strength testing device according to claim 1, characterized in that: An annular groove (9) is machined on the thickness surface of the transfer tool (2), one end of the parallel surface binding line (5) is tied around the annular groove (9), and the other end is tied around the parallel surface pulley (3) to hang the parallel surface weight (7), and the groove (9) is preferably located in the middle of the thickness surface of the transfer tool (2).

5. The solar cell sheet bonding strength testing device according to claim 1, characterized in that: A convex block (10) is arranged at the center of the outer plate surface of the transfer tool (2); one end of the vertical line binding wire (6) is bound to the convex block (10), and the other end passes around the vertical line pulley (4) to hang the vertical line weight (8).

6. The solar cell sheet adhesive strength testing device according to claim 5, characterized in that: A through hole is provided on the side of the protrusion (10), and the vertical line binding wire (6) passes through the through hole and is then bound to the protrusion (10), so that the force application point of the vertical line binding wire (6) is located in the middle of the protrusion (10) and is perpendicular to the bonding surface between the solar cell sheet and the substrate.

7. The solar cell sheet bonding strength testing device according to claim 1, characterized in that: The outer plate surface of the transfer tool (2) is processed with 360° angle scale lines (11).

8. The solar cell sheet adhesive strength testing device according to claim 7, characterized in that: The angle scale line (11) extends to the edge of the outer plate surface.

9. The solar cell sheet bonding strength testing device according to claim 1, characterized in that: The parallel plane binding wire (5) and the vertical line binding wire (6) are equipped with a tension meter for measuring the gravity of the parallel plane weight (7) and the vertical line weight (8).

10. A method for testing the bonding strength of solar cells, characterized in that: The method is implemented by using the solar cell sheet bonding strength testing device as claimed in any one of claims 1 to 9, comprising the following steps: The cylindrical coordinate system of the bonding surface is established with the center of the solar cell as the origin, and the bonding test force to be applied in the hemispherical surface is decomposed into two decomposed forces F1 parallel to the bonding surface and perpendicular to the bonding surface: (F x ,θ,0) and F2(0,0,F Z ); the X-axis is perpendicular to the long side of the solar cell, the Z-axis is perpendicular to the outward direction of the solar cell, and the F x / cosθ is the decomposition force parallel to the bonding surface, F x is the force pointing to the long side of the solar cell, θ is the angle between the decomposed force parallel to the bonding surface and the X-axis, F Z is the magnitude of the decomposition force perpendicular to the bonding surface; The transfer tool is pasted on the solar cell to be tested by adhesive, and the substrate with the solar cell is placed on the support frame, and the adhesive surface of the solar cell to be tested coincides with the gravity direction; The parallel plane weight is hung on the transfer fixture through the parallel plane binding wire, and the vertical line weight is hung on the transfer fixture through the vertical line binding wire. The angle between the parallel plane binding wire and the X-axis is θ, and the direction of the vertical line binding wire from the transfer fixture is perpendicular to the bonding surface of the solar panel. Gradually increase the weight of the parallel plane weight until the force F1 reaches F x / cosθ, increase the weight of the vertical line weight to force F2 to F Z ; After the target bonding strength test is completed, adjust the direction of the two binding lines or the size of the weight and carry out another bonding strength test under the bonding test force.

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