Browse Prior Art Database

Method for a die stacking architecture for mixed sizes of dice

IP.com Disclosure Number: IPCOM000010063D
Publication Date: 2002-Oct-16
Document File: 4 page(s) / 55K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for a die stacking architecture for mixed sizes of dies. Benefits include improved functionality and improved performance.

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Method for a die stacking architecture for mixed sizes of dice

Disclosed is a method for a die stacking architecture for mixed sizes of dies. Benefits include improved functionality and improved performance.

Background

� � � � � Package thickness is a factor that conventionally limits the stacking of dice in a package. Wire loop height and mold cap height add to the overall thickness of a stack package.

� � � � � The long loop length of wirebond stacking degrades the performance of stack packages.

        � � � � � Conventional stacked package solutions include the following (see Figure 1):

•        � � � � Wire-bond stack die packages

•        � � � � Wire-bond flip-chip mixed stacks

•        � � � � Folded stacks

� � � � � Package thickness is conventionally addressed by the following solutions:

•        � � � � Thinner die

•        � � � � Thinner substrate

•        � � � � Low loop wirebonding process

•        � � � � Thinner moldcap

� � � � � Dice are conventionally determined to be good by testing the package after stacking. Substandard dies result in yield loss because the entire stacked package must be scrapped.

Description

        � � � � � The disclosed method is a technique to stack multiple dice for stack packaging (see Figure 2, cross section). This method is an all flip-chip, low thickness stack architecture that utilizes a cavity substrate. The disclosed method uses conventional materials and processes.

        � � � � � A cavity is opened in the center of substrate. The dimension/width of this cavity is slightly less than the die. The die can be flip-chip mounted to the overlap area of the substrate at the rim of the cavity. The next level substrate has a cavity that matches in dimension and aligns to the lower level die. During stacking, t...