Browse Prior Art Database

Thermal Enhancement for Marginal Electronic Devices

IP.com Disclosure Number: IPCOM000037391D
Original Publication Date: 1989-Jan-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Davis, TL: AUTHOR

Abstract

A novel heat exchange which can use the existing manufacturing tools for attachment is described.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 88% of the total text.

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Thermal Enhancement for Marginal Electronic Devices

A novel heat exchange which can use the existing manufacturing tools for attachment is described.

An aluminum or copper heat sink which has leads identical to those of a 68 Plastic Leaded Circuit Component (PLCC) is described.

The heat sink would be surface mountable with pad locations identical to the 68-lead PLCC. The existing pick and place machines could be used to place the component. If reflow problems occur because of the thermal mass of the heat sink, a plastic cover could be placed over it to reduce its heat dissipation and replicate the 68-lead PLCC during attachment.

The heat sink could be attached to the backside of the card (opposite side from a Tape Automated Bonded (TAB) component just, as shown in Fig. 1).

TAB is a candidate for this heat exchanger configuration for several reasons. First, the TABs are thermally marginal. Secondly, present heat exchangers require special processes for attachment. Also, active and pin-through components will not be allowed behind the TAB. Furthermore, TABs conduct most of their heat into the card.

The effect of placing unpowered surface mounted (plastic) components behind a powered component was observed during thermal evaluations. The change in the external thermal resistance of the powered component was lowered approximately 5-10% depending on the particular module. Using a component which is not coated with plastic would result in a larger reduction in the ther...