Browse Prior Art Database

VIALESS MULTILAYER BALL GRID ARRAY IC PACKAGE

IP.com Disclosure Number: IPCOM000007890D
Original Publication Date: 1996-Nov-01
Included in the Prior Art Database: 2002-May-02
Document File: 1 page(s) / 53K

Publishing Venue

Motorola

Related People

Yutaka Doi: AUTHOR

Abstract

A vialess package is disclosed to be used for a single IC (integrated circuit) whose electrical interconnection is distributed on multiple layers on the package. Offsetting of the layers allows attach- ment of solder balls for both BGA (ball grid array) package and DCA (direct chip attach) without using any vias.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 76% of the total text.

Page 1 of 1

Technical Developments

VIALESS MULTILAYER BALL GRID ARRAY IC PACKAGE

by Yutaka Doi

ABSTRACT

PROPOSED SOLUTION TO THE PROBLEM

  A vialess package is disclosed to be used for a single IC (integrated circuit) whose electrical interconnection is distributed on multiple layers on the package. Offsetting of the layers allows attach- ment of solder balls for both BGA (ball grid array) package and DCA (direct chip attach) without using any vias.

  It has been discovered that a multilayer single chip BGA can be fabricated without using vias. By slightly offsetting layers, pads can be accessible for deposition of solder balls which can eliminate vias for interlayer connection. As shown in Figs. 1 and 2, a die 1 is attached to a conductive layers, 6,7, and 8, with solder balls 2 in the case of three layer imple- mentation. The conductive layers are insulated by dielectric layers, 4 and 5. The layer 6 is placed on the substrate 3. Large solder balls 9 are deposited on the edges of layers, 6,7, and 8. By offsetting both dielectric and conductive layers, each layer can expose pads for deposition of solder balls thus eliminating any interlayer routing. The molding 1 for the die is performed following DCA.

  The sum of the heights of the die including the molding and the solder ball shall not exceed the height of the BGA solder balls. The offsets of the layers are wider than the diameters of the BGA sol- der balls.

The vialess multilayer BGA offers an economi- cal, high-performance IC...