Solderless Method for Polyimide Film Chip Carrier Attachment
Original Publication Date: 1988-Apr-01
Included in the Prior Art Database: 2005-Feb-15
Typical second-level assembly processes for attaching multiple polyimide film chip carriers (PFCCs) to printed circuit cards uses eutectic solder which is reflowed in a vapor phase soldering machine. An alternate method of attachment uses electrically and thermally conductive epoxy rather than solder. This solderless method of attachment and the advantages it offers over solder attachment are described below with reference to the figure. The solderless method of attachment involves first screening or stenciling silver-filled, electrically conductive epoxy onto outer lead bond pads 1 of the assembly sites of a chip carrier. The conductive epoxy may be a one- or two-component, moisture-resistant epoxy resin with the desired volume resistivity.