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CN-122002915-A - Composite welding strip and photovoltaic module

CN122002915ACN 122002915 ACN122002915 ACN 122002915ACN-122002915-A

Abstract

The invention discloses a composite welding strip and a photovoltaic module. The composite welding strip comprises a conductive core body made of an aluminum material and a copper conductive coating material coated on the outer layer of the conductive core body. The total cross-sectional area of the composite welding strip is S, the unit is mm <2 >, the mass of the conductive coating material in the unit length direction is A, the unit is g/m, wherein A and S are in negative correlation, and the relation is 0.32-23.38. According to the invention, through the design, a differential structure with a relatively thin copper layer of the coarse welding strip and a relatively thick copper layer of the fine welding strip is realized, so that the composite welding strips with different specifications are balanced among conductivity, light weight and economy, and the comprehensive benefit of the welding strips is obviously improved.

Inventors

  • HE YAN
  • WANG XIAOLIANG
  • LIU XIAOYUN

Assignees

  • 隆基绿能科技股份有限公司

Dates

Publication Date
20260508
Application Date
20251219

Claims (13)

  1. 1. The composite welding strip is characterized by comprising a welding strip body (10) and a welding layer (11) coated on the outer layer of the welding strip body (10); The solder strip body (10) includes: a conductive core (101), the conductive core (101) being an aluminum core; A conductive coating (102), wherein the conductive coating (102) is a copper layer, and the conductive coating (102) is coated outside the conductive core (101); The total cross section area of the composite welding strip is S, the unit is mm < 2 >, the unit length mass of the conductive coating material (102) is A, the unit is g/m along the length direction of the conductive coating material, wherein A and S are in negative correlation, and the A and S satisfy the relational expression that A/S is more than or equal to 0.32 and less than or equal to 23.38.
  2. 2. The composite solder strip of claim 1, wherein A and S satisfy the condition 0.91A/S7.97.
  3. 3. The composite solder strip of claim 1, wherein A and S satisfy the condition 1.08. Ltoreq.A/S. Ltoreq.2.25.
  4. 4. The composite solder strip of claim 1, in which a and S satisfy a functional relationship of a=k 1 *ln(S)+k 2 , where k 1 ＜0,k 2 is a constant.
  5. 5. The composite solder strip of claim 4, in which a and S satisfy a functional relationship of a= -0.152ln (S) -0.0047.
  6. 6. The composite solder strip of any of claims 1 to 5, wherein the total mass per unit length of the composite solder strip is M in g/M, the mass ratio of the conductive coating is p=a/M, and one of the following conditions is satisfied: when S is less than or equal to 0.15 mm < 2 >, P is more than 50%, or, When 0.15 mm2< S≤0.25 mm2, 25% P≤50%, or, P <25% when 0.25 mm2< S.
  7. 7. The composite solder strip of claim 1, wherein the thickness of the conductive coating (102) is d,2 μm less than or equal to d less than or equal to 30 μm.
  8. 8. The composite solder strip of claim 7, wherein d is 5 μm or less and 20 μm or less.
  9. 9. The composite solder strip of claim 1, wherein the solder strip body (10) has a width of 0.15 mm to 1.5 mm and a thickness of 0.15 mm to 0.25 mm.
  10. 10. The composite solder strip according to claim 1, wherein the copper layer of the conductive coating (102) is made of pure copper or copper alloy, and/or the aluminum core of the conductive core (101) is made of pure aluminum or aluminum alloy.
  11. 11. The composite solder strip of claim 1, wherein the solder layer is a tin-lead alloy or a tin-lead-bismuth alloy, and the thickness of the solder layer is 0.010 mm to 0.030 mm.
  12. 12. The composite solder strip of claim 1, wherein the conductive coating (102) is formed outside the conductive core by an electroplating, electroless plating, cladding welding, or lamination process.
  13. 13. A photovoltaic module, comprising: the composite solder strip of any of claims 1 to 12; And the composite welding strips are used for welding and connecting the adjacent battery pieces.

Description

Composite welding strip and photovoltaic module Technical Field The invention relates to the technical field of photovoltaics, in particular to a composite welding strip and a photovoltaic module using the same. Background In photovoltaic modules, solder strips are the key components that connect the cells and conduct current. The traditional welding strip is made of pure copper, and has good conductivity, but has larger weight and higher cost. With the development of photovoltaic technology to high efficiency, light weight and low cost, higher requirements are put on the performance of welding belts. Aluminum materials are of interest because of their light weight and low cost, but their electrical conductivity and solderability are relatively poor. For this reason, copper-aluminum composite solder strips are proposed in the industry to achieve the goals of conductivity, weight reduction, and cost effectiveness. At present, a common composite welding strip mostly adopts a copper-clad aluminum structure, however, the proportion of a copper layer to an aluminum core is usually fixed, and the copper layer and the aluminum core are not optimized in a targeted manner according to the thickness of the welding strip. Because copper and aluminum have differences in mechanical and conductive properties, the problem that the performance is unbalanced easily occurs when the copper-aluminum composite solder strip is applied to solder strips with different specifications is that when the overall sectional area of the composite solder strip is smaller, the resistance is high easily due to insufficient conductive section, and when the sectional area is larger, the weight and cost reduction effect is not obvious due to excessive thickness of a copper layer. If the same copper-aluminum ratio is maintained in the welding strips with different thicknesses, the thin welding strip can increase the resistance due to the too small sectional area of the aluminum core, and the thick welding strip can reduce the cost and weight advantages due to the larger absolute thickness of the copper layer, and the stress release of the battery piece can be influenced due to the rigidity enhancement. Therefore, the composite welding strip with fixed proportion is difficult to realize the cooperative optimization of performances such as conductivity, mechanics, light weight, cost and the like in specifications with different thicknesses. It is necessary to develop a composite solder strip structure capable of dynamically adjusting the copper-aluminum ratio according to the thickness of the solder strip so as to comprehensively improve the comprehensive performance of the solder strip. Disclosure of Invention The invention aims to provide a composite welding strip and a photovoltaic module, and aims to solve the problems of unbalanced performance advantages and low comprehensive benefit of the composite welding strip of copper-aluminum composite welding strips with different thickness degrees and realize balance of light weight, low cost and high conductivity by optimizing the ratio of copper materials of conductive coating materials in the composite welding strip. In a first aspect, the application provides a composite welding strip, which comprises a welding strip body and a welding layer coated on the outer layer of the welding strip body; the solder strip body includes: the conductive core body is an aluminum core; The conductive coating material is a copper layer and is coated outside the conductive core body; The total cross section area of the composite welding strip is S, the unit is mm < 2 >, the unit length mass of the conductive coating material is A, the unit is g/m along the length direction of the conductive coating material, wherein A and S are in negative correlation, and the A and S satisfy the relational expression that A/S is more than or equal to 0.32 and less than or equal to 23.38. Alternatively, A and S satisfy the condition that 0.91≤A/S≤7.97. Alternatively, A and S satisfy the condition that 1.08≤A/S≤2.25. Optionally, a and S satisfy a functional relationship of a=k 1*ln(S)+k2, where k 1＜0,k2 is a constant. Alternatively, A and S satisfy a functional relationship of A= -0.152ln (S) -0.0047. Optionally, the total mass of the composite welding strip per unit length is M, and the unit is g/M, and the mass ratio p=a/M of the conductive coating material satisfies one of the following conditions: When S is less than or equal to 0.15 mm < 2 >, P is more than 50%, or, When 0.15 mm2< S≤0.25 mm2, 25% P≤50%, or, P <25% when 0.25 mm2< S. Optionally, the thickness of the conductive coating is d, and d is more than or equal to 2 microns and less than or equal to 30 microns. Alternatively, d is 5 μm≤d is≤20 μm. Optionally, the solder strip body has a width of 0.15 mm to 1.5 mm and a thickness of 0.15 mm to 0.25 mm. Optionally, the copper layer of the conductive coating is made of pure copper or copper alloy, and/or the aluminum core of