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US 8,008,786 B2Granted
Dynamic pad size to reduce solder fatigue
AssigneeFreescale Semiconductor, Inc.
InventorsTim V. Pham, Trent S. Uehling
Life of this patent
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Abstract
A semiconductor device is provided which comprises a substrate (501) having a plurality of bond pads (503) disposed thereon. Each bond pad has a major axis and a minor axis in a direction parallel to the substrate, and the ratio of the major axis to the minor axis increases with the distance of a bond pad from the center of the substrate.
Claims20
A semiconductor device, comprising:
- a substrate having a plurality of bond pads disposed thereon;
- wherein each bond pad has a major axis and a minor axis in a direction parallel to the substrate, and wherein the ratio of the major axis to the minor axis increases with the distance of a bond pad from the center of the substrate;
- wherein each bond pad has a solder joint attached thereto, and wherein the dimension of the bond pad in any direction in the plane is proportional to the relative strain experienced by the solder joint in that direction.
A semiconductor device, comprising:
- a substrate having a plurality of bond pads disposed thereon, wherein each bond pad has a major axis and a minor axis in a direction parallel to the substrate, and wherein the ratio of the major axis to the minor axis increases with the distance of a bond pad from the center of the substrate;
- and
- a die disposed on said substrate;
- wherein the ratio ds of the major axis to the minor axis of any of said plurality of bond pads is essentially given by the equation
- ds=ΔCTE*L
- wherein L is the distance from the center of the substrate, wherein ΔCTE is the CTE stress differential between the die and the substrate, and wherein the ratio of the major axis to the minor axis of each of said plurality of bond pads is essentially proportional to the distance of the bond pad from the center of the substrate.
3 more elements
Dependencies are inferred from the claim text.