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Joining Semiconductor Chips to a Decal Interconnection Overlay

IP.com Disclosure Number: IPCOM000092056D
Original Publication Date: 1968-Aug-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Kurtz, FJ: AUTHOR

Abstract

This solder reflow method electrically connects the terminals of a semiconductor chip to the printed circuit pattern of an overlay decal. Electrical resistance heater 10 has recess 12 for receiving semiconductor 14 with the ball terminals 15 extending upwardly. Heater 10 is connected to a relatively large heat sink to dissipate heat between joining operations. Positioned above heater 10 is table 16 provided with locating pins 17 to engage locating holes in decal 18. Pressure pad arm 20 is provided with weight 22 and rubber pressure pad 24 which urges the portions of decal 18 into intimate contact with terminals 15. Arm 20 is pivotally mounted to swing into and out of position over semiconductor 14. Decal 18 has a conductive stripe pattern of copper having a relatively thin solder plating.

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Joining Semiconductor Chips to a Decal Interconnection Overlay

This solder reflow method electrically connects the terminals of a semiconductor chip to the printed circuit pattern of an overlay decal. Electrical resistance heater 10 has recess 12 for receiving semiconductor 14 with the ball terminals 15 extending upwardly. Heater 10 is connected to a relatively large heat sink to dissipate heat between joining operations. Positioned above heater 10 is table 16 provided with locating pins 17 to engage locating holes in decal 18. Pressure pad arm 20 is provided with weight 22 and rubber pressure pad 24 which urges the portions of decal 18 into intimate contact with terminals 15. Arm 20 is pivotally mounted to swing into and out of position over semiconductor 14. Decal 18 has a conductive stripe pattern of copper having a relatively thin solder plating.

In use, device 14 is placed in pocket 12. Decal 18 is secured in position and located by pin 17 on table 16 and arm 20 is swung over into position. Decal 18 has an interconnection metallurgy pattern having a layer of copper or other conductive metal with a top layer of solder. Heater 10 is activated, which provides an intense but relatively short heat pulse. Heat is conducted through semiconductor 14 and terminals 15 to melt the end portions of the overlying solder film on the metallurgy pattern decal 18. The completeness of solderable connection can be instantly checked by observing whether or not the solder on the...