Method for selectively preparing gold-tin eutectic solder on surface of ceramic thin film circuit of 5G optical module

Abstract

The invention relates to a method for selectively preparing a gold-tin eutectic solder on the surface of a ceramic thin film circuit of a 5G optical module. Through the method, a gold-tin alloy not only has good wettability, weldability and corrosion resistance, but also has high stability. By using the gold-tin solder prepared by the method, a gold-tin plating layer with a bright and compact surface can be obtained at a specified position, the thickness of a gold layer and the thickness of a tin layer are controllable, the wettability is good after gold-tin eutectic formation, and different packaging requirements can be met. The melting point of the formed eutectic alloy is 280+ / -0.2 DEG C, and the gold-tin alloy solder can be preset on a thin film circuit. The packaging accuracy and yield are improved, and the welding requirements of small chips are met.

Description

technical field [0001] The invention relates to the field of micro ceramic products, in particular to a method for selectively preparing gold-tin eutectic solder on the surface of a ceramic thin film circuit for a 5G optical module. Background technique [0002] At present, most of the gold-tin solders on the surface of ceramics in China are deposited through gold-tin solder preforms or electroplating deposition methods, that is, electroplating. Gold-tin alloy solder has a low melting point and has no corrosion effect on the gold-plated layer of microelectronic devices. It has high joint strength, excellent corrosion resistance, high thermal conductivity and thermal shock resistance. It is a common solder for various high-reliability electronic devices. connect material. At present, the products tend to be miniaturized. Au80Sn20 in the alloy state of gold-tin solder preforms is composed of hexagonal lattice phase and intermetallic compounds, which is brittle and difficult t...

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Problems solved by technology

At present, the products tend to be miniaturized. Au80Sn20 in the alloy state of gold-tin solder preforms is composed of hexagonal lattice phase and intermetallic compounds, which is brittle and difficult to stamp and process into thinner foils. It is easy to deviate from the alignment of the chip, and dislocation movement occurs; the formula of the electroplating deposition method is mostly a cyanide system such as gold cyanide, which seriously pollutes the environment and the stability of the plating solution is poor and easy to decompose

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