Cylindrical bump packaging structure

Abstract

The invention relates to a cylindrical bump packaging structure. The cylindrical bump packaging structure comprises a chip, an under bump metallization layer, copper columns, oxide layers and solder bumps, wherein bonding pads and a passivation layer are arranged on the upper surface of the chip, the passivation layer is covered on the upper surface outside openings of the bonding pads of the chip, the under bump metallization layer is arranged on the bonding pads, the copper columns are arranged on the under bump metallization layer, the oxide layers are wrapped on the side surfaces of the copper columns, and the solder bumps are arranged above the copper columns. According to the cylindrical bump packaging structure disclosed by the invention, the electrical performances and the reliability of the solder bumps can be improved, and the cylindrical bump packaging structure is suitable for chip level packaging with close intervals of the bonding pads and multiple output functions.

Description

technical field [0001] The invention relates to the field of semiconductor device packaging, in particular to packaging structures of flip-chip welding, solder bumps, and wafer-level chip scale packaging (Wafer Level chip Scale Package, WLCSP). Background technique [0002] In recent years, since the microcircuit manufacturing of chips is developing toward high integration, the chip packaging also needs to develop in the direction of high power, high density, thinness and miniaturization. Chip packaging means that after the chip is manufactured, the chip is wrapped in plastic or ceramic materials to protect the chip from external moisture and mechanical damage. The main functions of the chip package are power distribution, signal distribution, heat dissipation and protection support. [0003] Since today's electronic products are required to be light, thin, small and highly integrated, the fabrication of integrated circuits will be miniaturized, resulting in an increase in ...

AI Technical Summary

Problems solved by technology

[0012] In the process of forming wafer-level chip size packaging in the prior art, since the solder bump material is in direct contact with the metal wetting layer, the copper in the metal wetting layer easily diffuses into the tin of the solder bump to form a copper-tin alloy, which affects the welding quality

At the same time, before the solder is formed on the metal wetting layer, the exposed wetting layer is easily oxidized, which reduces the performance and reliability of the subsequently formed solder bumps

On the other hand, during the formation of solder bumps, the solder is easy to drip and affect the reliability of the product, especially for products with dense metal pads, the problem of short circuit between solder bumps is more likely to occur

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