Browse Prior Art Database

Chip Carrier Interface With Signal Path Change Capability

IP.com Disclosure Number: IPCOM000048539D
Original Publication Date: 1982-Feb-01
Included in the Prior Art Database: 2005-Feb-08
Document File: 2 page(s) / 54K

Publishing Venue

IBM

Related People

Ecker, ME: AUTHOR [+2]

Abstract

In the packaging of semiconductor chips, one technique, as shown in Fig 1, employs a ceramic chip carrier 10, on which a semiconductor chip 12 is mounted by means of solder connections 14. The carrier 10 has vias (not shown) extending therethrough, with the vias terminating in solder balls 16 on the underside of the carrier 10. These solder balls 16 provide the means to form a solder connection of the carrier 10 to a substrate 18.

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Chip Carrier Interface With Signal Path Change Capability

In the packaging of semiconductor chips, one technique, as shown in Fig 1, employs a ceramic chip carrier 10, on which a semiconductor chip 12 is mounted by means of solder connections 14. The carrier 10 has vias (not shown) extending therethrough, with the vias terminating in solder balls 16 on the underside of the carrier 10. These solder balls 16 provide the means to form a solder connection of the carrier 10 to a substrate 18.

The substrate 18 has formed on the surface thereof copper hemispheres 20 which are positioned to be solder bonded to the solder balls 16 on the chip carrier. The hemispheres 20 are connected by surface wiring to through vias (not shown) which connect to pins 22 on the reverse side thereof.

The surface wiring, a portion of which is shown in Fig. 2, includes a plurality of surface wires 24 which are connected to the copper hemispheres on the substrate surface. Each of the wires connect to a weld pad 26, which, in turn, connects through a delete land 28 to the end of a via 30, each via 30 being connected with a pin 22 on the opposite side of the substrate.

The weld pad and delete land configuration allows for easy change of surface wiring to rearrange the connection of pins and/or surface wiring. To change a connection, the desired delete land 28 is removed, e.g., with a laser beam, and the associated weld pad can then be connected by adding surface wiring to connect that pad with a...