A variety of methods are used to mount integrated circuit devices to substrates such as PWBs and flex circuitry. Solder paste is selectively applied to the integrated circuit device or substrate to which the IC is to be attached. The device and substrate are exposed to reflow temperatures of approximately 220° C. The device is, consequently, soldered to the substrate.
Typically, however, the formed solder joints will re-melt during subsequent processing. Common tin-lead solders start to melt at 183° C. and, when exposed to such temperatures and higher, the exposed joint may re-melt and become unreliable.
What is needed, therefore, is a technique and system for mounting integrated circuit devices on substrates that provides an efficient and readily implemented technique to create structures that reliably withstand subsequent exposure to typical tin-lead solder melting point temperatures.
USPTO Backgrounds
USPTO Backgrounds