Patent ID: 9711472
Date: 2017-07-18
CPC Classifications: H01L

Claim:
1. A solder bump structure, comprising: a connector feature on a substrate; a passivation layer on the connector feature and the substrate; a first under bump metal (UBM) layer on the passivation layer and the connector feature, a bottommost surface of the first UBM being lower than a topmost surface of the passivation layer; a second UBM layer on the first UBM layer, a bottommost surface of the second UBM layer being lower than a topmost surface of the first UBM layer; a copper layer on the second UBM layer, a bottommost surface of the copper layer being lower than a topmost surface of the second UBM layer; a solder bump formed on the copper layer, the solder bump having a width in a first direction parallel to a major surface of the substrate, the solder bump having a height in a direction perpendicular to the major surface of the substrate, a ratio of the height to the width being less than 1, wherein the ratio of the height to the width is greater than or equal to 0.05; and at least one non-metallic core inside the solder bump, the solder bump contacting the at least one non-metallic core.