Ball grid array and land grid array assemblies fabricated using temporary resist

摘要

Ball grid assembly (BGA) bumping solder is formed on the back side of a laminate panel within a patterned temporary resist. Processes such as singulation and flip chip module assembly are conducted following BGA bumping with the temporary resist in place. The resist is removed from the back side of the singulated laminate panel prior to card assembly. Stand-off elements having relatively high melting points can be incorporated on the BGA side of the laminate panel to ensure a minimum assembly solder collapse height. Alignment assemblies are formed on the socket-facing side of an LGA module using elements having relatively high melting points and injected solder.

主权项

1. A method comprising:
obtaining a structure including:
a panel including a front side, a back side, and a plurality of electrically conductive contact pads,a patterned resist layer directly contacting the back side of the panel, the patterned resist layer including a plurality of channels, anda plurality of solder bumps, each of the solder bumps being within one of the channels and electrically contacting one of the contact pads; singulating the panel to obtain a plurality of panel portions, each panel portion having front and back sides, portions of the resist layer, and an array of the solder bumps; connecting a chip electrically and mechanically to the front side of the panel of the structure or to the front side of one of the panel portions, connection of the chip being effected while the resist layer is on the back side of the panel or while a portion of the resist layer is on the back side of the one of the panel portions, the chip comprising one or more electronic devices; stripping the patterned resist layer from the back side of the one of the panel portions subsequent to the step of connecting the chip electrically and mechanically to the front side of the panel of the structure or to the front side of the one of the panel portions, and connecting the one of the panel portions electrically and mechanically to a circuit card, the step of connecting the one of the panel portions including the step of reflowing the solder bumps.