Browse Prior Art Database

Method for Adding Circuits to a Plastic Leadless Chip Carrier Circuit Module

IP.com Disclosure Number: IPCOM000113274D
Original Publication Date: 1994-Aug-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 42K

Publishing Venue

IBM

Related People

Combs, JL: AUTHOR

Abstract

Disclosed is a method for adding logic circuits to a PLCC (Plastic Leadless Chip Carrier) which has been attached by soldering to a circuit board. This method may be used, for example, to provide an additional feature without reworking the circuit card.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 82% of the total text.

Method for Adding Circuits to a Plastic Leadless Chip Carrier Circuit
Module

      Disclosed is a method for adding logic circuits to a PLCC
(Plastic Leadless Chip Carrier) which has been attached by soldering
to a circuit board.  This method may be used, for example, to provide
an additional feature without reworking the circuit card.

      The Figure is a partially sectional view of a circuit
attachment 10 in an exploded relationship with an existing PLCC
module 12 soldered to a circuit board 14.  Circuit attachment 10
includes logic circuits, in an additional PLCC module 16, to be added
to the logic circuits within existing PLCC module 12.  Additional
PLCC module 16 is soldered to an upper side of a circuit card 18.  An
inverted PLCC socket 20 is soldered to the lower side of circuit card
18.

      As this circuit attachment 10 is plugged downward over existing
PLCC module 12, electrical contact is made between each contact tab
22 of module 12 and an adjacent contact spring 24 of inverted PLCC
socket 20.  Since each contact spring 24 is soldered in place within
circuit card 18, and since each contact tab 26 of additional PLC C
module 16 is soldered to a conductive pad on the upper surface of
circuit card 18, the desired electrical connections between circuits
within existing PLCC module 12 and circuits with in additional PLCC
module 16 can be accomplished by circuit traces extending along
circuit card 18 to connect various contact springs 24 with vario...