Browse Prior Art Database

Energy Beam Attachment of Leads to Ceramic Chip Carriers

IP.com Disclosure Number: IPCOM000061941D
Original Publication Date: 1986-Aug-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Berding, JT: AUTHOR [+2]

Abstract

The article describes a method for welding lead frames to chip carriers. The invention finds use in surface solder packages and solves the problems of distortion in lead frames and thermal hierarchy normally associated with lead attachment. The figure shows a chip carrier 10 having a number of attachment pads 12 arranged along the periphery of the top surface. Also shown is a lead frame 14 attached to a tie bar 16.

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Energy Beam Attachment of Leads to Ceramic Chip Carriers

The article describes a method for welding lead frames to chip carriers. The invention finds use in surface solder packages and solves the problems of distortion in lead frames and thermal hierarchy normally associated with lead attachment. The figure shows a chip carrier 10 having a number of attachment pads 12 arranged along the periphery of the top surface. Also shown is a lead frame 14 attached to a tie bar 16.

Small pads 18 of high temperature solder are formed onto the ends of the lead frame 14 where attachment to the pads 12 is to occur. Contact between pads 18 and pads 12 is made and they are fused with focussed laser energy or electron beam energy.

This process permits the attachment of leads after chip attachment, sealing and test, with high localization of heat, thus easing thermal problems. The process also is suitable for automated assembly.

Disclosed anonymously.

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