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Elimination of the Adhesion Medium During the Die Attach Step in Wire-Bound Applications

IP.com Disclosure Number: IPCOM000010572D
Publication Date: 2002-Dec-18
Document File: 2 page(s) / 35K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method that uses a process vacuum to temporarily hold the die in place during wire bonding. Benefits include simplifying the assembly process and reducing material costs.

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Elimination of the Adhesion Medium During the Die Attach Step in Wire-Bound Applications

Disclosed is a method that uses a process vacuum to temporarily hold the die in place during wire bonding. Benefits include simplifying the assembly process and reducing material costs.

Background

Currently an adhesive tape or paste is used to attach the die to the substrate prior to wire bonding (see Figure 1). However, this solution is not entirely reliable, and adds cost to the wire
bond process.

General Description

In the disclosed method, the die is held in place by a vacuum supplied through the substrate ports (Figure 2). The wire bonding process proceeds while the die is held in place via the vacuum.� The over mold is done while the substrate/die interface is still under vacuum. This allows for the� mold compound to be pulled under the die to fill the substrate port(s); this creates a self-sealed environment (Figure 3). The following is the proposed process flow:

 

  1. The pick and place puts the die on the substrate.
  2. The vacuum (via the ports in the substrate) holds the die in place.
  3. The die is wire bonded to the substrate.
  4. The over mold is completed while the substrate/die interface is under vacuum.

Advantages

The following are advantages of the disclosed method:

 

  • Reduces costs by reducing materials
  • Simplifies the assembly process
  • Improves reliability by removing the die/adhesion/substrate interface

Fig. 1

Fig. 2

Fig. 3

Disclosed anonymously