Package substrate

Abstract

The invention relates to a package substrate which comprises a bare copper flat heat pipe and a coating arranged on the outer surface of the flat heat pipe, wherein the coating consists of a bright copper layer, a nickel-plated layer, a silver-plated layer and an anti-oxidization layer which are sequentially arranged from inside to outside. The package substrate has high reflection rate, a semiconductor can be directly welded on the package substrate, the problems that the chip (semiconductor) has overhigh heat density and can not fast radiate heat can be fundamentally solved, the service life and properties of the chip can be ensured, thus overcoming the bias that the flat heat pipe can not be applied to the field of packaging the semiconductor for a long term.

Description

technical field [0001] The invention relates to a packaging substrate, in particular to a packaging substrate suitable for the semiconductor industry. Background technique [0002] The development trend of semiconductor packaging is ultra-miniaturization and multi-chip. For chips, temperature is the main factor restricting their life and performance. At present, the existing packaging substrates on the market cannot completely export the light generated by the light source to a certain extent. Heat, especially for integrated high-power light sources, on the one hand, the size of the chip is small but the power is large, the heat flux is large, and the heat distribution is uneven; on the other hand, the distance between the chips is small, and the heat on the substrate is concentrated, which cannot be effectively export. Therefore, excessive heat flux is a key problem restricting the development of semiconductor packaging. Excessive heat flux will cause excessive chip juncti...

AI Technical Summary

Problems solved by technology

[0004] However, although flat heat pipes have the advantages of fast heat transfer speed and high thermal conductivity, the existing flat heat pipes in the market are generally used in notebook computers, computer workstations or network servers for passive heat dissipation, but are rarely used in semiconductor packaging. The reasons are as follows: Since the outer surface of the flat heat pipe is bare copper, it is not easy to weld, and it is extremely easy to oxidize, especially under high temperature conditions (such as welding), the oxidation rate increases sharply. When the chip is welded to the flat heat pipe, the oxidized A layer of thermal resistance will be added between the flat heat pipe and the chip, which will hinder the heat transfer of the chip and affect the heat conduction effect of the flat heat pipe. At the same time, the oxidized area will also affect the reflectivity of the substrate and reduce the luminous flux output of the chip.

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