Patent ID: 8616433

Claim:
A method comprising: placing a second work piece over a first work piece; placing a heating tool over and contacting the second work piece; heating the second work piece using the heating tool to melt a solder region between the first work piece and the second work piece; when the solder region is melted, pulling up the second work piece to increase a height of the solder region from a first height to a second height greater than the first height, wherein the second work piece is pulled up until an angle formed between a tangent line of the solder region and a top surface of a surface dielectric layer in the first work piece is greater than about 50 degrees, and wherein the tangent line is drawn starting from a joint of the solder region and the surface dielectric layer; and cooling the solder region, wherein after the step of cooling, the first work piece and the second work piece are bonded to each other through the solder region.