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Wafer Handling for Bumped Wafer Thinning and Subsequent Processing

IP.com Disclosure Number: IPCOM000022008D
Publication Date: 2004-Feb-18
Document File: 3 page(s) / 29K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for unique tooling that handles and thins bumped wafers during wafer thinning and subsequent wafer-level steps. Benefits include reducing yield loss and process complexity.

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Wafer Handling for Bumped Wafer Thinning and Subsequent Processing

Disclosed is a method for unique tooling that handles and thins bumped wafers during wafer thinning and subsequent wafer-level steps. Benefits include reducing yield loss and process complexity.

Background

The current process uses a wafer support system (WSS) that consists of a glass wafer attached (via an adhesive) to the bumped side of the wafer. The glass support is pre-treated with carbon black before the adhesive is attached. The adhesive is spin coated or sprayed onto the wafer, then attached to the wafer. The carbon black acts as a release between the adhesive and the glass support. The carbon black is charred with a laser treatment, releasing the glass slide from the thinned and mounted wafer. This results in a thinned and mounted wafer with a layer of adhesive that must be removed prior to sawing. The act of peeling the adhesive puts significant stress on the thin wafer, often resulting in yield loss due to destroyed wafers.

General Description

The disclosed method uses a phase change material to mount a bumped wafer to the front side of a wafer, while being compatible with additional post front-side mount processing at elevated temperatures. The die bumps act as mechanical anchors to hold the wafer in place once the release material goes from a liquid to a solid phase. The release material uniformly distributes stresses applied to the backside of the wafer. Some slight compliance may be needed during the anchoring phase.

The container for the release material enables the material to be anchored during processing. This prevents it and the front-side mounted wafer from shifting during th...