Browse Prior Art Database

Thin Film Metallurgical Structure and Wire for Engineering Change

IP.com Disclosure Number: IPCOM000103575D
Original Publication Date: 1993-Jan-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 2 page(s) / 67K

Publishing Venue

IBM

Related People

Chance, D: AUTHOR [+4]

Abstract

This article describes a structure and technique for wire bonding to thin films using high strength Cd-Cu wires for engineering change.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 76% of the total text.

Thin Film Metallurgical Structure and Wire for Engineering Change

       This article describes a structure and technique for wire
bonding to thin films using high strength Cd-Cu wires for engineering
change.

      Insulated Au-coated Cd-Cu wires have been used as engineering
change wires on MLC modules.  These wires exhibit high strength and
are more suitable for engineering change wires.  Other wires, such as
Au or Al, are typically used for short jumper connections from chip
to a chip carrier.  Whereas soft Au or Al pad, Au-coated Cd-Cu wires
have not been previously bonded to thin film pads.  In the
thermo-conduction multilayer ceramic (m-c) module a thick (12-15 mm)
electroplated Au pad is deposited on electrolessly deposited Ni which
is diffused into the underlying Mo/Al2O3 pad, as shown in Fig. 1.

      A thin film structure on which Au coated Cd-Cu wires can be
ultrasonically bonded is disclosed herein.  Referring to Fig. 2,
which shows the structure of metallurgy and wire, the thin film
consists of the following metals:
1.  A thin adhesion layer, 500 - 5000 o of Cr, Ti, etc.
2.  A conductive layer of desired thickness 2 mm to 10 mm of highly
conductive metal, such as Cu, Al, etc.
3.  A barrier layer which provides a diffusion and an equally
important mechanical barrier, 2000 Ao to 1 mm thick of Ni, Co, etc.
4.  A soft bondable and oxidation resistant layer 1000 Ao to 1 mm
thick of Au, Pt, etc.

      It has been shown that a 1.5-mil Au-c...