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) / 62K

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...