Semiconductor device and method of bump formation

Abstract

The present invention discloses a semiconductor device including a semiconductor substrate, a contact pad, a passivation layer, a bump, and a seeding layer is provided. The semiconductor substrate has an active surface. The contact pad is disposed on the active surface. The passivation layer is disposed on the active surface and exposes a central part of the contact pad. The seeding layer is disposed on the exposed central part of the contact pad. The bump has a top surface, a bottom surface opposite to the top surface, and a side surface connecting the top surface and the bottom surface. The bump is disposed on the seeding layer. The bump is placed in contact with the seeding layer by the bottom surface and by part of the side surface. The present invention also discloses a bump preparing method.

Description

technical field [0001] The invention relates to an electronic device and its technology, and in particular to a semiconductor element and a method for making bumps. Background technique [0002] Flip-chip technology is a packaging technology often used in chip scale packaging (Chip Scale Packaging, CSP). Since the flip-chip technology adopts a planar array (Area Array) for the configuration of the pads on the chip, the packaging area can be reduced. In addition, since the flip-chip technology uses bumps to electrically connect the chip and the carrier, the signal transmission path can be shortened. [0003] Generally, the chip surface is covered with a protective layer, which is present covering the chip surface and exposing the chip's aluminum pads. When the flip-chip technology is in progress, an under bump metal (UBM) layer will be formed on the protection layer and the pads first. Then, a photoresist layer is formed on the UBM layer, but the photoresist layer will exp...

AI Technical Summary

Problems solved by technology

When the gold bump is bonded to the carrier through the anisotropic conductive film (Anisotropic Conductive Film, ACF), the increase in the roughness of the upper surface will make some parts of the gold bump unable to be pressed into the conductive film in the anisotropic conductive film. Particles, which reduce the conductivity between the chip and the carrier

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