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Browse Prior Art Database

Shared EC Pad Design

IP.com Disclosure Number: IPCOM000048967D
Original Publication Date: 1982-Apr-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 2 page(s) / 78K

Publishing Venue

IBM

Related People

Hubacher, E: AUTHOR

Abstract

The disclosed structure is preferably utilized in a multilayer ceramic (MLC) packaging structure for mounting, interconnecting and cooling a large number of integrated circuit semiconductor devices (chips). The MLC packaging structure includes an internal metallurgy network (wiring) to which the chips are flip-chip connected by solder connections (C4s). The packaging structure, which may be generally of the type disclosed in U.S. Patent 4,245,273, also includes engineering change (EC) pads. Fig. 1 shows MLC wiring between C4s and EC pads. Fig. 2 shows the connections between C4s and EC pads plus the connection paths between two chips through the personality wiring (refer to line A, for example). If, for example, the buried line A in Fig.

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Shared EC Pad Design

The disclosed structure is preferably utilized in a multilayer ceramic (MLC) packaging structure for mounting, interconnecting and cooling a large number of integrated circuit semiconductor devices (chips). The MLC packaging structure includes an internal metallurgy network (wiring) to which the chips are flip-chip connected by solder connections (C4s). The packaging structure, which may be generally of the type disclosed in U.S. Patent 4,245,273, also includes engineering change (EC) pads. Fig. 1 shows MLC wiring between C4s and EC pads. Fig. 2 shows the connections between C4s and EC pads plus the connection paths between two chips through the personality wiring (refer to line A, for example). If, for example, the buried line A in Fig. 2 is shorted to another line, the path must be corrected by deleting the connection to both chip pads B. To do this, laser cuts are made on the EC pads C at points D. This frees the buried line A. To repair the connection, a jumper wire (not shown) is bonded to the EC pads C on the larger portion of each pad. The jumper or repair wire is routed along the surface of the substrate.

Fig. 3 shows a proposed EC pad design wherein an island is shared with two adjacent EC C4 laser delete pads. To repair a shorted or open connection, laser cuts would be made at the EC pad point D on both sides of the faulty connection.

Referring to Fig. 3, the repair could be made two ways. Method 1 uses the subway wire connected to...