Electrode soldering method for a back contact solar module

Abstract

An electrode soldering method for a back contact solar module is to place a curved solder part on two electrode solder pads of two solar cells on a substrate respectively, and to solder the curved solder part on the electrode solder pads. The curved solder part includes a curved portion between the two electrode solder pads. The curved portion curves parallel to the substrate. Therefore, the elasticity in structure or the allowable deformation of the curved portion can release the internal stress induced by the soldering of the curved solder part on the electrode solder pads or by a following lamination packaging, which solves a problem in the prior art that internal residual stress in an electrode solder part harmfully affects the electrical connection between solar cells.

What is claimed is: 
     
         1 . An electrode soldering method for a back contact solar module, comprising the following steps:
 (a) preparing a substrate, a first solar cell, and a second solar cell, the first solar cell and the second solar cell being formed on the substrate, the first solar cell comprising a first electrode solder pad, the second solar cell comprising a second electrode solder pad;   (b) placing a curved solder part on the first electrode solder pad and the second electrode solder pad, the curved solder part comprising a curved portion between the first electrode solder pad and the second electrode solder pad, the curved portion curving parallel to the substrate; and   (c) soldering the curved solder part on the first electrode solder pad and the second electrode solder pad.   
     
     
         2 . The electrode soldering method of  claim 1 , wherein the curved solder part comprises a first indentation and a second indentation, and the step (b) is performed by the following steps:
 (b1) forming a first solder ball on the first electrode solder pad and a second solder ball on the second electrode solder pad; and   (b2) placing the curved solder part on the first electrode solder pad and the second electrode solder pad simultaneously by accommodating the first solder ball and the second solder ball in the first indentation and the second indentation respectively.   
     
     
         3 . The electrode soldering method of  claim 2 , wherein in the step (c), the first solder ball and the second solder ball are melted in the first indentation and the second indentation respectively. 
     
     
         4 . The electrode soldering method of  claim 1 , wherein the step (c) is performed by the following steps:
 (c1) covering the first solar cell, the second solar cell, and the curved solder part with a packing film of thermal adhesive;   (c2) placing a back plate on the packing film of thermal adhesive; and   (c3) heating the packing film of thermal adhesive such that the packing film of thermal adhesive bonds the back plate to the first solar cell and the second solar cell and the curved solder part is soldered onto the first electrode solder pad and the second electrode solder pad simultaneously.   
     
     
         5 . The electrode soldering method of  claim 4 , wherein the packing film of thermal adhesive is made of Ethylene Vinyl Acetate, the step (c1) and the step (c2) are performed under a vacuum, and the step (c3) is performed under an atmospheric pressure. 
     
     
         6 . The electrode soldering method of  claim 1 , wherein the curved solder part comprises a first through hole and a second through hole, and the step (b) is performed by the following steps:
 (b3) forming a first solder ball on the first electrode solder pad and a second solder ball on the second electrode solder pad; and   (b4) placing the curved solder part on the first electrode solder pad and the second electrode solder pad simultaneously by accommodating the first solder ball and the second solder ball in the first through hole and the second through hole respectively.   
     
     
         7 . The electrode soldering method of  claim 6 , wherein in the step (c), the first solder ball and the second solder ball are melted in the first through hole and the second through hole.