Browse Prior Art Database

Solderless Assembly Method for Semiconductor Carriers

IP.com Disclosure Number: IPCOM000109227D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2005-Mar-23
Document File: 2 page(s) / 79K

Publishing Venue

IBM

Related People

Booth, RB: AUTHOR [+3]

Abstract

A method is described which enables one to attach or remove semiconductor carriers from printed circuit cards without the use of solder, solder fluxes, or excessively high joining temperatures.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 88% of the total text.

Solderless Assembly Method for Semiconductor Carriers

       A method is described which enables one to attach or
remove semiconductor carriers from printed circuit cards without the
use of solder, solder fluxes, or excessively high joining
temperatures.

      One method, shown in Fig. 1, is to construct an interposer of
thermoplastic adhesive.  Electrical paths in the thermoplastic
adhesive are formed by drilling or punching holes into the adhesive,
then filling the  holes with a conductive paste which is subsequently
dried.  Assembly is achieved by aligning the semiconductor carrier,
the interposer, and the printed circuit card, then thermoplastically
joining the components together by using heat and pressure.  The
electrical connections made by the thermoplastic conductors are
already encapsulated by the thermoplastic adhesive, thereby
preventing stress on the conductors and sealing them from the
external environment.

      A second assembly method, shown in Fig. 2, places a conductive
polymer paste onto the card surface mount lands, drying the paste,
and then, after aligning the semiconductor carrier to the printed
circuit card, joining of the components is accomplished by using
elevated temperatures and pressures to form the conductive
thermoplastic joints.  The conductive joints are then encapsulated
with a liquid non-conducting thermoplastic adhesive polymer.

      The conductive plastic described is formed either of a siloxane
modified polyi...