CASE STUDY

Copper Heat Exchanger uses Electron Beam Welding to Seal Heat Sinks

A manufacturer of copper heat exchangers used with commercial lasers needed to weld very small copper parts in their precision-machined heat sinks. These heat sinks included a copper housing and lid with cooling geometry sealed inside each unit. The customer needed the lid and housing unit to be joined without any damage to the cooling geometry. 

Solution: Tiny parts needing precision, delicate welds are perfect for EB Welding. The challenge in welding small parts is getting a good weldment without damaging adjacent parts. This was certainly true in this case. Copper melts at a high heat. EB Welding digitally controls the heat and depth of the welds. This allows the proper heat needed to fuse the copper housing to the lid to be focused on a small area without damaging the cooling components. This is all done in one pass and the weld is barely visible to the eye.

Another difficulty with this particular job was the diffusion of heat. Copper is used with heat sinks because it draws heat away from the source. This is one of the reasons why laser welding is ineffective when fusing copper. In this case, the engineers at Roark Welding tested the parts to determine the speed and penetration depth of the electron beam, yet created enough heat to melt the copper. Heat, speed and the depth of the weld are all computer-controlled with EB Welding to provide a very precise weldment according to specifications. 

In the end, the customer was very pleased with the welds on the heat exchangers. For more information on EB Welding and fusing delicate parts, contact Roark Welding at 317-852-3163, ext. 901 or info@roarkfab.com.