Browse Prior Art Database

Edge-Connected TAB Memory Package

IP.com Disclosure Number: IPCOM000035391D
Original Publication Date: 1989-Jul-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 4 page(s) / 221K

Publishing Venue

IBM

Related People

Powell, DO: AUTHOR [+2]

Abstract

In conventional tape automated bonding (TAB) integrated circuit mounting, chips are mounted co-planar with the carrier or card. TAB to carrier bonding pads or outer lead bonds (OLBs) run along all four edges of the TAB.

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 58% of the total text.

Page 1 of 4

Edge-Connected TAB Memory Package

In conventional tape automated bonding (TAB) integrated circuit mounting, chips are mounted co-planar with the carrier or card. TAB to carrier bonding pads or outer lead bonds (OLBs) run along all four edges of the TAB.

Unfortunately, the TAB footprint is up to 6 times the area of the chip and standard TABs are not compatible with vapor phase reflow soldering techniques or assembly apparatus due to their flexibility. Testing and burn-in for standard TABs in continuous tape form is difficult because many OLBs and test pads are displaced from the edge of the tape.

(Image Omitted)

Fig. 1 is a diagram of one embodiment of the invention. Outer leads are along one edge of the TAB, forming the edge to be soldered to the card. Chips can be mounted on either or both sides of the TAB in accordance with process convenience or density requirements. Additional memory density can be achieved by mounting chips on both sides of the TAB.

Fig. 2 depicts TAB layout on tape for processing. All leads come to the edges of the tape where they are easily accessible for testing and burn-in connections.

Multiple TABs can be mounted on a carrier strip (Fig. 3) to provide multi-chip single in-line packages. The carrier strip can optionally be made of a thermally conductive material to act as a heat spreader/sink.

Clips (Fig. 4) position and hold the TABs to allow vapor phase reflow soldering to the card. TABs can be positioned at an angle, as shown, or they...