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Mechanical Supports for Surface-Mounted Leaded and Leadless Components

IP.com Disclosure Number: IPCOM000062303D
Original Publication Date: 1986-Nov-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 2 page(s) / 29K

Publishing Venue

IBM

Related People

Baweja, AS: AUTHOR [+2]

Abstract

Surface-mounted technology uses solder joints to both complete I/O connections and provide the mechanical support necessary to hold a component on a card. Testing has shown that solder joint surface- mounted connections cannot take the loads that pin-in-hole connections can. When a surface-mounted connection is subjected to excessive loads, the solder joint will crack. The crack can disrupt I/O transmissions and cause a card to fail. Testing also shows that the eight corner leads of a surface-mounted component support the most load, and will be the first to crack, causing a card to fail. If a corner solder joint cracks, a card will fail when the corner leads of a component are functional I/O leads. In the improved arrangement, the corner leads are used for mechanical support only.

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Mechanical Supports for Surface-Mounted Leaded and Leadless Components

Surface-mounted technology uses solder joints to both complete I/O connections and provide the mechanical support necessary to hold a component on a card. Testing has shown that solder joint surface- mounted connections cannot take the loads that pin-in-hole connections can. When a surface-mounted connection is subjected to excessive loads, the solder joint will crack. The crack can disrupt I/O transmissions and cause a card to fail. Testing also shows that the eight corner leads of a surface-mounted component support the most load, and will be the first to crack, causing a card to fail. If a corner solder joint cracks, a card will fail when the corner leads of a component are functional I/O leads. In the improved arrangement, the corner leads are used for mechanical support only. This eliminates the use of the corner leads as I/O's. A crack in a corner solder joint will, therefore, not cause a functional card failure.

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