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Method for channel-cut die stacking for high-density CSP applications

IP.com Disclosure Number: IPCOM000020315D
Publication Date: 2003-Nov-12
Document File: 2 page(s) / 77K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for channel-cut die stacking for high-density chip scale package (CSP) applications. Benefits include improved functionality and improved performance.

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Method for channel-cut die stacking for high-density CSP applications

         Disclosed is a method for channel-cut die stacking for high-density chip scale package (CSP) applications. Benefits include improved functionality and improved performance.

Background

         Thin, same size, stacked dice with overhang designs conventionally lack the capability to be wire bonded. Their limitation is that the bonding force required during wire bonding can exceed the break-load strength of the dice on the overhang end. This limitation is typically resolved by using a channel-cut die design. Same-sized die can be stacked with the second die rotated 90 degrees with respect to the bottom die. The second die is channel cut, leaving space for wire bonding on the bottom die (first die, see Figure 1).

Description

         The disclosed method is die stacking for CSP packaging using a channel cut design under the die to provide support to the die during wire bonding, enabling the stacking of thinner dies for CSP packaging (see Figure 2). This packaging concept enables the stacking of a wide variety of sizes and thinner die over another while extending the capability to be wire bonded over thinner die due to support from the underneath channel cut.

         The channel-cut design provides mechanical support to the critical end-portion of the die (that would have been an overhang) during wire bonding. The critical thickness limit of the die is extended without exceeding the break-load strength during wire bonding. As a result,...