Browse Prior Art Database

Burn In Test Vehicle for C-4 Chip Technologies

IP.com Disclosure Number: IPCOM000107200D
Original Publication Date: 1992-Jan-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 2 page(s) / 55K

Publishing Venue

IBM

Related People

Gjone, R: AUTHOR [+2]

Abstract

This article describes a device that can be used to test and burn-in electronic chips with C-4 (flip chip) I/O, without reflowing or rigidly attaching the chips to the tester.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 87% of the total text.

Burn In Test Vehicle for C-4 Chip Technologies

       This article describes a device that can be used to test
and burn-in electronic chips with C-4 (flip chip) I/O, without
reflowing or rigidly attaching the chips to the tester.

      The key to this invention is the use of the anisotropic
conductive elastomer which provides the compliance necessary to
conform to the surface irregularities between the chip and the
substrate while providing an electrical path through the elastomer
via imbedded conductors.

      The hat (see the figure) is positioned by locator pins off the
cofired multilayer ceramic (MLC) substrate. Cavities in the hat would
precisely position the chips such that the locations of the C-4
conductor balls would correspond with pads on the MLC substrate.

      The internal wiring in the MLC substrate will electrically
connect all the chip C-4 pads to a tester through the pins brazed to
the bottom such that voltages can be applied and test sequences
performed.

      Test vehicle materials can be selected to permit tests to be
conducted at elevated temperatures to accelerate failure.  Such
materials include an elastomer which is typically a silicon rubber.
If needed, the elastomer is expendable and can be replaced as
frequently as after each burn-in.

      Current procedures require the C-4 chips to be reflow soldered
onto special small pads and mechanically severed upon completion for
use in the ultimate product.  This must be pe...