Browse Prior Art Database

Design of "Fuse-Joint" for Glass-Ceramic Pin Attachment

IP.com Disclosure Number: IPCOM000038526D
Original Publication Date: 1987-Jan-01
Included in the Prior Art Database: 2005-Jan-31
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Kapur, S: AUTHOR [+3]

Abstract

This article concerns the design of a frangible solder joint for bonding an I/O pin to a substrate made of low fracture material, such as glass-ceramic. Non-repairable ceramic failures resulting from the high stresses incurred during pin brazing operations are reduced or eliminated by employing the disclosed "fuse" joint. Ceramic tear-out under low externally applied stress is of primary concern following a glass-ceramic I/O pin brazing process in which pins are brazed onto metallized I/O substrate pads. Ceramic substrates can be saved from such non-repairable ceramic fractures by use of the low stressed, fail-safe, pin attachment structure here disclosed.

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Design of "Fuse-Joint" for Glass-Ceramic Pin Attachment

This article concerns the design of a frangible solder joint for bonding an I/O pin to a substrate made of low fracture material, such as glass-ceramic. Non-repairable ceramic failures resulting from the high stresses incurred during pin brazing operations are reduced or eliminated by employing the disclosed "fuse" joint. Ceramic tear-out under low externally applied stress is of primary concern following a glass-ceramic I/O pin brazing process in which pins are brazed onto metallized I/O substrate pads. Ceramic substrates can be saved from such non-repairable ceramic fractures by use of the low stressed, fail-safe, pin attachment structure here disclosed. When excessive stresses due to mishandling of the pins or other such causes occur, the "fuse-joint" will fail before that force can be transmitted to the substrate itself, hence the label of "fuse-joint".

Two versions of the disclosed "fuse-joint" are shown in Figs. 1 and
2. In Fig. 1, a multilayered adhesive joint structure is shown.

Layer 1 shows the thin film bottom surface metallurgy (BSM) pad.

Layer 2 identifies a thin layer of solder or braze joint which can be fabricated by roll-cladding, E-beam co-evaporation, preforms or screen pasting on either of the layers 1 and 3. Layer 3 represents an INVAR* or KOVAR** disk. Layer 4 is a braze or solder joint for joining the I/O pins to the INVAR/KOVAR disk. The"fuse-joint" in the Fig. 1 structure, i.e., eith...