Active solid-state devices (e.g. – transistors – solid-state diode – Combined with electrical contact or lead – Bump leads
Patent
1997-04-23
1999-01-12
Thomas, Tom
Active solid-state devices (e.g., transistors, solid-state diode
Combined with electrical contact or lead
Bump leads
257738, 257778, 257779, H01L 2348
Patent
active
058594744
ABSTRACT:
A first array of elongate pads is formed on a first surface, such as that of an integrated circuit substrate, and a second array of elongate pads is formed on a second surface, such as that of a printed circuit board. An array of solder balls are reflow attached to the pads of the first array and then to the pads of the second array, to thereby electrically connect the substrate to the printed circuit board. The reflow solder balls thereby conform to the elongate shapes of the pads to be configured like truncated ellipsoids. Due to the surface tension forces between the pads and the balls therebetween, the "ellipsoids" advantageously have a high standoff. Also, the pads on each of the sides of the perimeter of the array are aligned longitudinally perpendicular to the respective sides. Thereby, wide channels between adjacent elongate pads are defined, through which one or more additional traces can advantageously be routed on the surface between the pads.
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LSI Logic Corporation
Potter Roy
Thomas Tom
LandOfFree
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