Browse Prior Art Database

Electrostatic Discharge Control Card Cassette

IP.com Disclosure Number: IPCOM000100420D
Original Publication Date: 1990-Apr-01
Included in the Prior Art Database: 2005-Mar-15
Document File: 4 page(s) / 125K

Publishing Venue

IBM

Related People

Launikitis, JA: AUTHOR

Abstract

Disclosed is a device to safely control the discharge rate of electrostatic charge which may accumulate on the surface or internal ground plane of a multilayer printed circuit card.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 56% of the total text.

Electrostatic Discharge Control Card Cassette

       Disclosed is a device to safely control the discharge
rate of electrostatic charge which may accumulate on the surface or
internal ground plane of a multilayer printed circuit card.

      The device is called a cassette and consists of three elements:
a card populated with components, a front and a back cover.  A rigid
single element cassette assembly is created around the card by simply
snapping together integrally molded latches located on each cover
half (Fig. 1).  One edge of the card has contact tabs exposed to mate
with a connector located on a printed circuit board.  The PCB
attaches to a cage assembly which is a metal structure grounded to
the machine frame.  There are rails molded on two outer edges of the
card covers which help guide the card into the cage and into the
mating connector.  The general package concept is shown in Fig. 2.

      The cassette protects the card components from damage caused by
electrostatic discharge (ESD) by controlling the amount of static
charge surrounding the card in the following manner:

      1)  ESD Damage Resulting from Operator Handling The covers are
made from a static dissipative polycarbonate designed to dissipate
the amount of electrical energy created from an electrostatic charge
across the entire surface of the cover.  The surface resistance of
the cover material is determined by acceptable electrical limits of
the card components.

     ...