Browse Prior Art Database

Head/Cable Testing

IP.com Disclosure Number: IPCOM000106496D
Original Publication Date: 1993-Nov-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 2 page(s) / 69K

Publishing Venue

IBM

Related People

Walston, K: AUTHOR

Abstract

Today, Tape Heads and Head Cables cannot be electrically tested until they are bonded together. Bonding is done by Thermal Compression of Gold to Gold. After testing if one component is bad the whole assembly is lost as the bonding processes is not reversible. The concept presented here will allow testing of the head and cable as individual units prior to bonding.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Head/Cable Testing

      Today, Tape Heads and Head Cables cannot be electrically tested
until they are bonded together.  Bonding is done by Thermal
Compression of Gold to Gold.  After testing if one component is bad
the whole assembly is lost as the bonding processes is not
reversible.  The concept presented here will allow testing of the
head and cable as individual units prior to bonding.

      The main difficulty is testing heads and cables is trying to
probe the tiny gold plated pads to make electrical contact.  It is
very difficult to align a set of test probes and usually results in
damage to the pads.  Test probes need to be pressed hard against the
pads to break the skin effect to get good electrical contact.  The
test probes are large and bend or deform the pads when contact is
made.

      A product is available on the market under several brand names.
One product consists of a thin rubber sheet that has imbedded in it
very small wires running vertical thru the thin part of the sheet.
These wires extend a small amount on both sides of the sheet.  The
density of the wires is very high so that if a small sheet of this
material were laid on the set of head pads, each pad would have 5 to
10 wired touching the pad.  By having a large number of contact
points, no damage occurs to the pads.  Due to the small size of each
wire, the wire point is able to penetrate thru the skin of the gold
pad and make good electrical contact.

The solution is made up of the following components:

o   the unit under test (head or head cable)

o   a thin rubber sheet with wires

o   a test connector and cable

o   a desktop PC

o   and special software

      The thin rubber sheet is described above.  It is cut to the
size of the unit to be tested and will be replaced after a defined
number of tests as the wires will bend under use.

      A test connector is made of a...