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Method for SCSP upper-die cracking prevention

IP.com Disclosure Number: IPCOM000022677D
Publication Date: 2004-Mar-25
Document File: 2 page(s) / 15K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for stacked chip-scale package (SCSP) upper-die cracking prevention. Benefits include improved functionality and improved reliability.

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Method for SCSP upper-die cracking prevention

Disclosed is a method for stacked chip-scale package (SCSP) upper-die cracking prevention. Benefits include improved functionality and improved reliability.

Background

In stacked die packaging, if the upper die is larger than the lower die, die overhang occurs. If the overhang is too long, damage can occur to the upper die without proper mechanical support during wire bond operation because the overhang acts as a cantilever.

Conventionally, overhang distance is closely monitored, impacting production.

General description

The disclosed method includes the dispensing of a guard ring of epoxy around the lower die to act as mechanical support for upper die during the wire bond process.

         The key elements of the method include:

•         Guard-ring epoxy around the lower die

•         Back-grinding the guard-ring epoxy to create a smooth surface for upper die attach

Advantages

         The disclosed method provides advantages, including:

•         Improved functionality due to providing a mechanical support under the upper die overhang

•         Improved reliability due to preventing die cracking

Detailed description

The disclosed method uses epoxy to create a mechanical support under the upper die for wire bonding. The overhang portion of the upper die acts as a cantilever. The guard-ring epoxy acts as a support for the upper die overhang to prevent die cracking.

         The guard-ring zone is the overhang width plus tolerances.

         The viscosity of the guard-ring material is pre...