Browse Prior Art Database

Customable Multi-Contact-Point Interposer

IP.com Disclosure Number: IPCOM000112128D
Original Publication Date: 1994-Apr-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 2 page(s) / 64K

Publishing Venue

IBM

Related People

Mace, EW: AUTHOR [+2]

Abstract

Multi-Chip-Modules are finding increasing use to solve today's packaging issues. The integration of many chips on one substrate helps improve performance but also increases the number of off-module I/O's. If the number of I/O's are 500 - 600, both Pin-Grid-Array (PGA) and Ball-Grid-Array (BGA) provide an effective solution for the carrier attachment process. As the carrier size increases, both the assembly process and repair/rework process becomes a problem. Further, the inspection of array joints for manufacturing defects and quality control is not very practical. For large size carriers, solder joint reliability is also of concern due to differential expansion of materials.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Customable Multi-Contact-Point Interposer

      Multi-Chip-Modules are finding increasing use to solve today's
packaging issues.  The integration of many chips on one substrate
helps improve performance but also increases the number of off-module
I/O's.  If the number of I/O's are 500 - 600, both Pin-Grid-Array
(PGA) and Ball-Grid-Array (BGA) provide an effective solution  for
the carrier attachment process.  As the carrier size increases, both
the assembly process and repair/rework process becomes a problem.
Further, the inspection of array joints for manufacturing defects and
quality control is not very practical.  For large size carriers,
solder joint reliability is also of concern due to differential
expansion of materials.

      The use of a interposer to provide a demountable Z-axis
electrical path for large I/O packages addresses the manufacturing
and reliability issues mentioned above.  The Figure shows the basic
concept of such aninterposer.  The electrical paths are suitable for
signal as well as power connections.  The design can be a simple
interposer for Z connection or an intelligent design with caps,
resistors and circuitry to common ground or signal connections.

      The interposer carrier is made of a polymer with holes that are
drilled or molded.  Small slugs of Multi-Strand-Wire are inserted
into holes where open ends of many wires pressing against the I/O
pads of MCM or PCB board provide a multi-point contact system.

      Th...