摘要 |
Making the relative size of the surface area of a bump electrode at a portion in contact with an under electrode larger than the surface area of a base of a hole increases the contact surface area between the lower surface of the bump electrode and a polyimide layer. As a result, effect by the polyimide layer to mitigate the impact loads applied during bonding greatly increases. The impact loads applied during bonding can also be mitigated by using a material for the conductive layer that is as flexible as, or even more flexible than, the material of the bump electrode. It is therefore possible to reduce cracks in semiconductor chips or the like directly under the bump electrode more efficiently.
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