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Enhanced Encapsulation Technique

IP.com Disclosure Number: IPCOM000041124D
Original Publication Date: 1987-Sep-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Carden, TF: AUTHOR [+4]

Abstract

An alternative to the current metallized ceramic/metallized ceramic polyimide internal thermal enhancement (ITE) encapsulation technique is to use a stamped cap with an external heatsink attached. A variation of this design is to use a cap with a hole or window over the chip site. The ITE would then provide a direct thermal path from the chip to the heatsink. The assembly options of this concept are to backseal the assembly prior to or after heatsink attach. If the module is backsealed prior to heatsink attach there is a concern that the backseal will enter the open window. This problem is addressed by a backseal process which seals open window caps prior to attaching a heatsink. The process is described in the following.

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Enhanced Encapsulation Technique

An alternative to the current metallized ceramic/metallized ceramic polyimide internal thermal enhancement (ITE) encapsulation technique is to use a stamped cap with an external heatsink attached. A variation of this design is to use a cap with a hole or window over the chip site. The ITE would then provide a direct thermal path from the chip to the heatsink. The assembly options of this concept are to backseal the assembly prior to or after heatsink attach. If the module is backsealed prior to heatsink attach there is a concern that the backseal will enter the open window. This problem is addressed by a backseal process which seals open window caps prior to attaching a heatsink. The process is described in the following.

The cap/substrate assembly is preheated at the first station of the dispense operation. The initial dispense consists of a dispense head with four needles aligned with the corners of the module.

A minimal volume of backseal is initially dispensed and allowed to flow between the substrate and cap sidewalls. The assembly is then sent to the flow- gel station where the controlled backseal run-in is gelled to seal the cap to the substrate. The module then receives the normal backseal process including preheat, shot size and gel/cure cycles.

Disclosed anonymously.

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