Browse Prior Art Database

Flip Chip Joining Physical Land Restriction

IP.com Disclosure Number: IPCOM000090614D
Original Publication Date: 1969-Jun-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 20K

Publishing Venue

IBM

Related People

Massey, RH: AUTHOR

Abstract

Solder attaching or joining a component to a substrate or printed circuit is improved by constructing the substrate lands at the point of component attachment. Metal lands 10 on substrate 12 are narrowed at the point where a component, typically an active or passive device, is to be attached by solder-reflow techniques. For example, a semiconductor device of the order of .003 to .010 square mils with a land width of 4 to 8 mils requires a notch in the land which results in a reduced land width of approximately 50% in the vicinity where the component is to be attached. The narrowed land width prevents the build-up of solder heights which collapse when engaged by the component.

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Flip Chip Joining Physical Land Restriction

Solder attaching or joining a component to a substrate or printed circuit is improved by constructing the substrate lands at the point of component attachment. Metal lands 10 on substrate 12 are narrowed at the point where a component, typically an active or passive device, is to be attached by solder- reflow techniques. For example, a semiconductor device of the order of .003 to
.010 square mils with a land width of 4 to 8 mils requires a notch in the land which results in a reduced land width of approximately 50% in the vicinity where the component is to be attached. The narrowed land width prevents the build-up of solder heights which collapse when engaged by the component. The solder reflow temperature is of the order of 330 degrees C to 350 degrees C and a firing time of less than one is employed to obtain a reliable connection that does not collapse.

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