T-Wing Heat Spreader Applied
to a Plastic Quad Flat Pack

T-Wing heat spreaders from Chomerics are thin, flexible cooling devices designed for easy attachment to component packages using pressure-sensitive adhesive. The T-Wing consists of a thin (0.178mm) copper strip with an even thinner (0.038mm) layer of electrically insulating black film laminated on both sides.

Figure 1 - Chomerics T-Wing applied to a Plastic Quad Flat Pack (PQFP).

In order to evaluate the thermal performance of the T-Wing, a detailed 3-dimensional thermal model of a 208 lead plastic quad flat pack mounted on a thermal test board was created using FLOTHERM. The thermal model exactly mimics the experimental setup specified by the JEDEC JC15.1 committee and has been fully validated by comparisons with both thermocouple and IR thermography measurements(see reference below).

The package dimensions are 28mm x 28mm x 3mm. It is mounted on a horizontal test board in a natural convection environment in a cubic enclosure of side 305mm. In the original JEDEC test case, the component power was 1W. In the case illustrated here, the component power was 3W.

Figure 2 - Results WITHOUT the T-Wing

The FLOTHERM simulation was run with and without a T-Wing (20267) heat spreader attached to the top surface of the PQFP.

Figure 3 - Results WITH the T-Wing

Adding the T-Wing dramatically reduces the peak temperature within the package (i.e. at the silicon die itself) and the temperature gradients within the plastic encapsulant.

Figure 4 - Comparison of Results With and Without the T-Wing

Reference:

"Development, Validation and Application of a Thermal Model of a Plastic Quad Flat Pack" by H I Rosten, J D Parry and J S Addison (Flomerics); R Viswanath (Intel); M Davies and E Fitzgerald (NMRC, Eire).
Presented at the Electronic Components and Technology Conference (ECTC), Las Vegas, 22-24 May, 1995.

For copies of this paper, please contact Flomerics.