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Modified Heat Sink Attachment Technique for Tape Automated Bonding Packages

IP.com Disclosure Number: IPCOM000102172D
Original Publication Date: 1990-Nov-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Buller, L: AUTHOR [+2]

Abstract

The attachment technique described in this article allows the use of a snap-fit rivet to hold a heatsink in place without the requirement that holes be drilled in the second level carrier.

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This is the abbreviated version, containing approximately 96% of the total text.

Modified Heat Sink Attachment Technique for Tape Automated Bonding Packages

       The attachment technique described in this article allows
the use of a snap-fit rivet to hold a heatsink in place without the
requirement that holes be drilled in the second level carrier.

      The concept disclosed in this article is to adhesively fasten
rivet heads 4 to a card 2, as shown in Fig. 1.  This technique has
several distinct advantages:
1.   No holes are drilled in the card, so wireability is not
impacted.
2.   The rivets can be fastened on top of wiring or vias 5 on
external planes.
3.   Alignment of the heatsink is not critical.
4.   The reworkability of the original design is retained.
5.   A variety of different heat sinks for different applications can
be accommodated, since a fixed hole size and pattern are not
required.  Additionally, since no predrilled holes are required, a
heatsink can be added after card design is complete, provided
sufficient clearance 3 is available around the TAB (tape automated
bonding) device.
6.   By using an inboard rivet placement, as shown in Fig. 2, the
overall footprint of the TAB  heatsink can be reduced.

      Assembly could be done by incorporating the rivets 4 into the
heatsink 1 initially.  Adhesive would then be dispensed onto the
rivet heads prior to assembly on the card.  In this way, the
heatsink-to- rivet placement is self-aligning, and the assembly
orientation is not critical. Rework would use the...