Browse Prior Art Database

Placing Bond Pads on the Die Edge

IP.com Disclosure Number: IPCOM000074596D
Publication Date: 2005-Feb-23
Document File: 3 page(s) / 261K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for placing wire bond pads on the die edge. Benefits include freeing up the die surface area and eliminating the need for a spacer to facilitate wire bonding when stacking overhanging die.

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Placing Bond Pads on the Die Edge

Disclosed is a method for placing wire bond pads on the die edge. Benefits include freeing up the die surface area and eliminating the need for a spacer to facilitate wire bonding when stacking overhanging die.

Background

Circuit connections are usually made with wires bonded to pads on the die top surface
(see Figure 1). When various die are stacked on top of each other, clearance for wire bond connections is usually obtained by adding a small spacer or making a shallow step or bevel cut. Die of dissimilar sizes cannot be stacked unless the smaller die is placed on the top.

General Description

In the disclosed method, bond pads are moved to the edge or sidewall of the die, permitting wire bonds to contact the edge directly (see Figure 2). Elimination of the spacer reduces the die stack height, permitting a reduction in the overall package height or allowing for additional die to be stacked. The disclosed method integrates several already existing technologies in a novel way. The following are the ways in which the disclosed method can be produced:

§         Deep vias are, etched ~60 microns into the silicon wafer around the perimeter of the die, in the area commonly known as the street or scribe region. The vias may be created with a variety of etching chemistries, including for instance, Xenon chloride reactive ion.

§         The deep vias are filled with metallization, typically by means of a copper plating process.

§         The deep vias are connected to the device circuitry using the typical metal...