A test method and device for the influence of silver-aluminum paste lap joint area on the opening voltage of a perc cell

Abstract

The present application relates to the technical field of photovoltaic detection, more particularly, the present application relates to a kind of silver aluminum paste lap joint area influence on the test method and device of PERC cell open voltage.Silver aluminum paste lap joint area influence on the test method of PERC cell open voltage, comprising: silver paste is printed in the PERC test silicon piece without laser grooving, after drying, silver paste is printed using the same pattern screen printing, then print aluminum paste, after drying again, the printed silicon piece is sintered, then the electrode after sintering is tested using resistance tester, and the resistance tester reading is recorded.The present application test method is simple, pattern is simple, the influence of silver paste aluminum paste lap joint area on cell open voltage can be accurately measured, the accuracy of evaluating back silver silver paste performance data can be guaranteed, and the test efficiency can be improved, the influence of printing factors and test factors is small, data accuracy is high, and the data obtained by testing is convenient to handle, intuitive.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic detection, more particularly, the present application relates to a test method and device for the influence of silver-aluminum paste overlap area on PERC cell open voltage. BACKGROUND

[0002] In the photovoltaic industry, silver paste manufacturers will encounter the problem of silver paste and aluminum paste matching, which is also a problem that each cell manufacturer pays attention to. The matching problem of silver paste and aluminum paste is a problem that silver paste manufacturers pay great attention to, and is the focus of their research and development. How to accurately evaluate the practicality, accuracy, stability and reliability of silver paste cannot be separated from necessary scientific test methods and tools. In addition to focusing on the properties of the back silver paste, the influence of the silver paste and aluminum paste overlap area after mixing should also be focused on. The overlap area will corrode the silicon nitride passivation layer and aluminum oxide passivation layer on the back of the PREC cell due to the increased corrosion of the mixed paste after mixing, thereby affecting the open voltage of the cell. At present, the influence of the open voltage caused by the matching problem of the back silver and aluminum paste is becoming more and more obvious, mainly in the silver-aluminum overlap area. Although the cell factory can accurately compare the open voltage influence of different types of silver paste on about 1000 silicon wafers, silver paste manufacturers need a simpler test method to test the influence of silver paste on the open voltage of the cell in the aluminum paste overlap area. SUMMARY

[0003] In view of the problems in the prior art, the first aspect of the present application provides a test method for the influence of silver-aluminum paste overlap area on the open voltage of a PERC cell, comprising: printing silver paste on a PERC test silicon wafer without laser grooving, drying, printing aluminum paste with the same pattern of screen printing, drying again, sintering the printed silicon wafer, and then testing the sintered electrode with a resistance tester, and recording the resistance meter reading.

[0004] In the test method for the influence of silver-aluminum paste overlap area on the open voltage of a PERC cell, the larger the reading on the resistance tester, the smaller the influence of the silver-aluminum paste overlap area on the open voltage of the PERC cell.

[0005] In one embodiment, the pattern printed by the silver paste and the aluminum paste is an axisymmetric structure, including a first structure and a second structure which are mirror images.

[0006] Preferably, the first structure and the second structure are horizontal T-shaped structures, and the specific structure is shown in Figure 1 .

[0007] Preferably, the length of the first structure and the second structure is 28-32mm, more preferably 30mm; the width is 6-8mm, preferably 7mm; the length of the horizontal T-shaped structure angle tail is 18-22mm, more preferably 20mm, and the width is 6-8mm, more preferably 7mm.

[0008] Preferably, the distance between the first structure and the second structure is 3-5mm, more preferably 4mm.

[0009] The specific arrangement of the first structure and the second structure in the application makes the printing simple, the pattern occupies a small position, and multiple printing can be performed on the same test silicon wafer, and the patterns used by the silver paste and the aluminum paste are consistent.

[0010] In an embodiment, the silver paste and the aluminum paste are printed on the PERC test silicon wafer by a screen.

[0011] In an embodiment, the sintering condition is 750-790℃.

[0012] The second aspect of the application provides a test device for the influence of a silver-aluminum paste lap joint area on a PERC cell, comprising: a PERC test silicon wafer 1 without laser grooving, and a silver-aluminum paste module 2 printed on the surface of the PERC test silicon wafer.

[0013] In an embodiment, the silver-aluminum paste module is a silver paste module and an aluminum paste module that overlap each other, wherein the silver paste module is in contact with the PERC test silicon wafer.

[0014] In an embodiment, the silver paste module and the aluminum paste module are axisymmetric structures, comprising mirror image first structures and second structures.

[0015] Preferably, the first structure and the second structure are horizontal T-shaped structures, and the specific structure is shown in Figure 1 .

[0016] Preferably, the length of the first structure and the second structure is 28-32mm, more preferably 30mm; the width is 6-8mm, preferably 7mm; the length of the horizontal T-shaped structure angle tail 201 is 18-22mm, more preferably 20mm, and the width is 6-8mm, more preferably 7mm.

[0017] Preferably, the distance between the first structure and the second structure is 3-5mm, more preferably 4mm.

[0018] Compared with the prior art, the application has the following beneficial effects:

[0019] The application can accurately measure the influence of the silver paste and aluminum paste overlap area on the open voltage of the battery by printing the silver paste and the aluminum paste on the PERC test silicon wafer in sequence and controlling specific printing patterns, can ensure the accuracy of the evaluation of the silver paste performance data of the back silver, and can improve the test efficiency, has small influence of printing factors and test factors, high data accuracy, and the data obtained by the test is convenient to process and intuitive. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 A structure schematic diagram of a test device for the influence of the silver and aluminum paste overlap area on the open voltage of the PERC battery.

[0021] Figure 2 A schematic diagram of a resistance test principle of the silver and aluminum paste overlap area.

[0022] In the schematic diagram, 1 is a PERC test silicon wafer without laser grooving, 2 is a silver and aluminum paste module, 201 is a horizontal T-shaped structure corner tail, 3 is a certain electrode after sintering, 4 is another electrode after sintering, 5 is a silicon nitride passivation layer, 6 is an aluminum oxide passivation layer, 7 is a contact point of the etched back medium film and the silicon, and 8 is a current flow direction. DETAILED DESCRIPTION

[0023] The application is described below through a specific embodiment, but is not limited to the specific embodiment given below.

[0024] Embodiments

[0025] A test method for the influence of the silver and aluminum paste overlap area on the open voltage of the PERC battery, specifically comprising the following steps: printing the silver paste on the PERC test silicon wafer without laser grooving through a screen, printing the aluminum paste on the same pattern screen after drying, sintering after drying the aluminum paste, combining two probes of a resistance tester with two ends of the printed electrodes, and reading the reading of the resistance tester.

[0026] Figure 2 A schematic diagram of a resistance test principle of the silver and aluminum paste overlap area, in which 1 is a PERC test silicon wafer without laser grooving, 2 is a silver and aluminum paste module, 3 is a certain electrode after sintering, 4 is another electrode after sintering, 5 is a silicon nitride passivation layer, 6 is an aluminum oxide passivation layer, 7 is a contact point of the etched back medium film and the silicon, and 8 is a current flow direction. The resistance value of the two electrodes is tested by using a resistance tester, and the reading is read. The smaller the reading of the resistance tester, the stronger the corrosion of the silver and aluminum paste overlap area, the greater the flow current under the passivation layer, and the greater the influence of the silver and aluminum paste overlap area on the open voltage of the battery.

[0027] The device for testing the influence of silver aluminum paste lap joint area on the opening voltage of PERC cell comprises a PERC test silicon wafer 1 without laser grooving and a silver aluminum paste module 2 printed on the surface of the PERC test silicon wafer.

[0028] The silver aluminum paste module is a silver paste module and an aluminum paste module overlapped up and down, wherein the silver paste module is in contact with the PERC test silicon wafer. The silver paste module and the aluminum paste module are axisymmetric structures, comprising a first structure and a second structure which are mirror images.

[0029] The first structure and the second structure are horizontal T-shaped structures, the length of the first structure and the second structure is 30mm, and the width is 7mm; the length of the horizontal T-shaped structure angle tail 201 is 20mm, and the width is 7mm; the spacing between the first structure and the second structure is 4mm.

Claims

1. A test method for the influence of the silver-aluminum paste overlap area on the on-state voltage of a PERC cell, characterized in that, include: Silver paste is printed on a PERC test silicon wafer without laser grooving. After drying, aluminum paste is printed using a screen with the same pattern. After drying again, the printed silicon wafer is sintered. Then, the sintered electrodes are tested with a resistance meter, and the resistance meter reading is recorded. The smaller the reading of the resistance tester, the stronger the corrosion of the silver-aluminum paste overlap area, and the greater the current flowing through the passivation layer, indicating that the silver-aluminum paste overlap area has a greater impact on the battery's opening voltage. The patterns printed by the silver paste and aluminum paste are axially symmetric structures, including a mirrored first structure and a second structure. The first and second structures are horizontal T-shaped structures; The distance between the first structure and the second structure is 3-5mm; The length of the first and second structures is 28-32mm and the width is 6-8mm; the length of the corner tail of the horizontal T-shaped structure is 18-22mm and the width is 6-8mm.

2. The test method for the influence of the silver-aluminum paste overlap area on the on-state voltage of PERC cells according to claim 1, characterized in that, The sintering conditions are 750-790℃.

3. A testing apparatus for the influence of the silver-aluminum paste overlap area on the on-state voltage of a PERC cell, used to implement the testing method as described in claim 1, characterized in that, include: Laser-grooved PERC test silicon wafers, and silver-aluminum paste modules printed on the surface of PERC test silicon wafers.

4. The testing apparatus for the influence of the silver-aluminum paste overlap area on the on-state voltage of PERC cells according to claim 3, characterized in that, The silver-aluminum paste module consists of an overlapping silver paste module and an aluminum paste module, wherein the silver paste module is in contact with the PERC test silicon wafer.

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