Browse Prior Art Database

Inverse Taper Head Pin

IP.com Disclosure Number: IPCOM000108057D
Original Publication Date: 1992-Apr-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 34K

Publishing Venue

IBM

Related People

Goldman, LS: AUTHOR

Abstract

Disclosed is a novel pinhead design for interconnection to an electronic substrate. The design minimizes the stress in the underlying substrate.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Inverse Taper Head Pin

       Disclosed is a novel pinhead design for interconnection
to an electronic substrate.  The design minimizes the stress in the
underlying substrate.

      Typically, pinheads 4 are cylindrical, or tapered as shown in
Fig.  1 and U.S. Patent 4,970,570.  The solder or braze forms a
fillet 1 which flows out onto the interconnecting pad 2 on the
substrate 3. The thin film stress associated with the metallurgical
pad 2 produces a stress under the periphery of the pad, while the
solder or braze produces a stress peak under the periphery of the
fillet 1.

      The proposed design, which is an inverse taper head pin 5, as
shown in Fig. 2, collects more braze or solder under the taperhead,
and thus restricts the extent of the fillet 1.  This makes the
process more tolerant of manufacturing variability and reduces stress
that is imparted on the substrate due to pin head.