Browse Prior Art Database

Method for stacking dice with center bond pads

IP.com Disclosure Number: IPCOM000020166D
Publication Date: 2003-Oct-29
Document File: 3 page(s) / 51K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for stacking dice with center bond pads. Benefits include improved reliability and improved performance.

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Method for stacking dice with center bond pads

Disclosed is a method for stacking dice with center bond pads. Benefits include improved reliability and improved performance.

Background

A method is required for stacking integrated circuits (ICs) with center bond pads. Longer wires on silicon dice with center bond pads violate design rules and cause wire-sweep issues during the conventional transfer mold process. The problem is conventionally solved by using a stencil or screen print process to attach the dice, encapsulate the dice, and encapsulate the wires prior to stacking (see Figure 1).

General description

The disclosed method is dispensing/encapsulating to stack dice with center bond pads.

         The key elements of the method include:

•         Die attach/encapsulant material

•         Dispense process for stacking dice with center bond pads

Advantages

         The disclosed method provides advantages, including:

•         Improved reliability due to eliminating the wire sweep issue because of the dispense/encapsulation process

•         Improved reliability due to absorbing the stress during mechanical stacking prevents damage to the long wires because the die attach/spacer material effectively holds a bond line and is compliant

•         Improved performance due to enhancing die fit flexibility in cases where the die with the center bond pads is larger than the other dice and must be placed at the bottom of the stack

Detailed description

The disclosed method enables the use of existing die attach and encapsulation dispense equipment infrastructure for stacking dice with center bond pads.

The method requires the purchase and qualification of stencil/screen print equipment. However the reuse of existing assembly equipment infrastructure lowers manufacturing costs.

Material that a...