Browse Prior Art Database

Ceramic Leaded Chip Carrier Capping Technique

IP.com Disclosure Number: IPCOM000061348D
Original Publication Date: 1986-Jul-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 2 page(s) / 42K

Publishing Venue

IBM

Related People

Bitaillou, A: AUTHOR [+4]

Abstract

IBM chips assembled in MC (Metallized Ceramic) packages usually use protective coatings, such as polyimide or SYLGARD*, and then an aluminum cap is placed around the substrate. Such a technique is not applicable when the cap is glued on top of the substrate, as in the Ceramic Leaded Chip Carrier (CLCC) technique, where connectors are soldered on the edges of the ceramic. The technique proposed here combines standard CLCC capping with the resin dispense. This is done by delimiting a wetting area around the chip(s) on the substrate by means of a frame; that frame must be 0.2 mm minimum high; its dimensions must be smaller than the cap, and it can be formed either by epoxy with a short curing time (in such a case, the process is: (1) epoxy dispensing by epoxer or by stamping, (2) drying and curing (Figs.

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Ceramic Leaded Chip Carrier Capping Technique

IBM chips assembled in MC (Metallized Ceramic) packages usually use protective coatings, such as polyimide or SYLGARD*, and then an aluminum cap is placed around the substrate. Such a technique is not applicable when the cap is glued on top of the substrate, as in the Ceramic Leaded Chip Carrier (CLCC) technique, where connectors are soldered on the edges of the ceramic. The technique proposed here combines standard CLCC capping with the resin dispense. This is done by delimiting a wetting area around the chip(s) on the substrate by means of a frame; that frame must be 0.2 mm minimum high; its dimensions must be smaller than the cap, and it can be formed either by epoxy with a short curing time (in such a case, the process is: (1) epoxy dispensing by epoxer or by stamping, (2) drying and curing (Figs. 2 and 3) or by a photoresistive preform (in which case the process would be: (1) heat sealing placement, (2) insulation, (3) curing)). Then, the protective resin (AIP11, manufactured by Amoco Inc., or SYLARD) is dispensed and cured; the previous frame impedes the resin run-out (Fig. 4). Then, the capping process, using a cap which is larger than the previous frame, can be standard and follow the steps, as described here: - dispense an epoxy sealing ring around the interior frame by stamping or with an epoxer (Fig. 5) - pre-coat the cap (by dipping) - Dry - cap placement and clamping (Fig. 6) - cure. * Trademark of Dow Co...