Browse Prior Art Database

Stacked Packages Using Anisotropic Conductive Films

IP.com Disclosure Number: IPCOM000010731D
Publication Date: 2003-Jan-15
Document File: 2 page(s) / 83K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method that uses anisotropic conductive film (ACF) to bond and stack ultra thin flex tape packages. Benefits include minimizing interconnects and package height.

This text was extracted from a Microsoft Word document.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 95% of the total text.

Stacked Packages Using Anisotropic Conductive Films

Disclosed is a method that uses anisotropic conductive film (ACF) to bond and stack ultra thin flex tape packages. Benefits include minimizing interconnects and package height.

Background

The disclosed method addresses the following problems with the current state of the art:

 

  • Stacking packages together to meet reduced total height, and to meet reliability stresses
  • Simplifying the stacked die components manufacturing process
  • Improving stacked package reliability

Currently, stacking is done prior to molding the wire bonded die (i.e. bare die package stacking).

General Description

The following are the key elements of the disclosed method:

 

  • Package-to-package stacking uses ACF for electrical continuity instead of solder balls.
  • Ultra thin die on flex tape packages can be stacked and bonded using ACF to form an electrical joint between the stacked packages.  
  • The ACF can be applied to the package interconnect area, stacked, then bonded. The disclosed method uses temperature and pressure to form the electrical joint and stress absorbing region all in one process.

Figure 1 illustrates the disclosed method.

Advantages

The following are advantages of the disclosed method:

 

  • A thinner interconnect joint than the conventional solder ball joint, therefore reducing the overall package height for multi-die packages.
  • Ease of manufacturing by integrating multiple packages into one component in one bond & cure process. 
  • The design of the comp...