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Method for an IHS attachment to an IC package using stake pinning techniques

IP.com Disclosure Number: IPCOM000012444D
Publication Date: 2003-May-07
Document File: 3 page(s) / 107K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for an integrated heat spreader (IHS) attachment to an integrated circuit (IC) package using stake pinning techniques. Benefits include improved reliability.

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Method for an IHS attachment to an IC package using stake pinning techniques

Disclosed is a method for an integrated heat spreader (IHS) attachment to an integrated circuit (IC) package using stake pinning techniques. Benefits include improved reliability.

Background

              As processor frequency and power increase, cooling requirements and costs increase. A requirement exists to reduce the cost of an IHS and its attachment process. Cost improvements can be achieved with an improved design and reduced assembly steps.

              Conventional IHSs have selective gold plating with plating over the die. The IHS is flat (0‑35 µm) and clips on top of the die to maintain its position.

              Integrated heat spreaders are conventionally attached to the package using a sealant-dispense process that requires curing (see Figure 1). The general processing steps are:

1.           Dispense sealant onto the substrate.

2.           Dispense flux onto the die.

3.           Pick-and-place a solder preform onto the die.

4.           Dispense flux onto the solder perform.

5.           Place the integrated heat spreader.

6.           Reflow the thermal interface solder.

7.           Cure the sealant adhesive.

8.           Remove the spring clip.

General description

              The disclosed method attaches an IHS to an IC package, using stake pinning techniques. A set of stake pin features is integrated into the substrate. The heat spreader is lowered over the pins and staked into position, mechanically attaching the IHS to the package

              The key elements of the method include:

•             Pin features incorporated into the substrate

•             Holes in the IHS matching the stake pins

•             Precision-forming die used to stake the IHS to the pins

Advantages

              The disclosed method provides advantages, including:

•             Improved reliability due to preventing sealant delamination, which results in the failure of the seal

•             Improved process simplicity due to eliminating the conventional sealant-dispense, sealant-cure, spring clip placement and sprint clip removal process steps

•             Improved cost effectiveness due to eliminating pro...