A kind of copper surface treatment method

Abstract

The invention provides a surface treatment method for copper sheets. The copper sheets are treated by a sandblasting process, and the emery suspension is sprayed onto the copper surfaces at a high speed, so as to change the surface morphology of the copper surfaces and eliminate the stripes of the copper sheets during the processing. Defects; while removing copper surface defects (impurities, oil stains, stains, oxidation), it can also form a certain roughness on the surface of the copper sheet, increase a certain surface area for the subsequent process (copper sheet oxidation), and improve the wettability of DCB sintering; Then, the nano-copper coated with titanium dioxide and the sandblasted copper sheet are connected by physical melting using a laser, and the primary rough structure after sandblasting of the copper sheet is modified and optimized to form a tertiary micro-nano structure. The surface roughness of the sheet can be adjusted to make the surface roughness of the copper sheet uniform; and the nano-copper coated with titanium dioxide and the microporous structure on the copper sheet can synergistically improve the anti-rust and hydrophobicity of the copper sheet and prolong the service life of the copper sheet. .

Description

technical field [0001] The invention relates to the technical field of DCB substrate preparation, in particular to a method for surface treatment of copper sheets. Background technique [0002] In the process of multi-layer printed circuit board manufacturing, the requirements for precision and multi-functionalization are significantly improved, and the improvement of the adhesion between the inner layer copper sheet and the resin material is a hot issue of research; therefore, the surface roughness of the copper sheet has an impact on the resin pressure. Processes such as bonding, bonding of copper layer and dry film, and ink solder mask have an important impact; the commonly used methods for roughening the surface of copper sheets include two chemical oxidation processes: blackening and browning; after blackening, The copper oxide layer grown on the base copper will form a dendritic structure, which is conducive to promoting the combination of the copper layer and the prep...

AI Technical Summary

Problems solved by technology

[0002] In the manufacturing process of multi-layer printed circuit boards, the requirements for precision and multi-functionality have been significantly improved, and the improvement of the adhesion between the inner layer copper sheet and the resin material is a hot topic of research; Bonding, copper layer and dry film bonding, ink solder resist and other processes have important influences; commonly used methods for roughening the surface of copper sheets include two chemical oxidation processes: blackening and browning; after blackening, The copper oxide layer grown on the base copper will form a dendritic structure, which is beneficial to promote the combination of the copper layer and the prepreg; after the browning treatment, the copper sheet will form a moderately deep micro-rough structure, which is in close contact with the resin and has a good Thermal stability and corrosion resistance; because the black oxidation method based on the alkaline system is inconvenient to operate, the relatively safe and easy-to-handle brown oxidation method is gradually replaced by the black oxidation method, but the brown oxidation method also has a roughening effect on the surface of the copper sheet Low quality and insufficient reliability of finished products, and the degree of roughness of the surface of the copper sheet and the uniformity of the roughness of the surface of the copper sheet are not easy to control

[0003] In order to remove defects (impurities, oil stains, stains, oxidation) on the surface of the copper sheet (raw material) and to form a certain roughness on the surface of the copper sheet, it is necessary to clean the copper sheet. The process in the industry generally uses a microetching solution ( Sulfuric acid + sodium persulfate system) to clean the copper sheet, but because the existing copper sheet cannot guarantee the flatness of the copper sheet surface during the manufacturing process (calendering process), grooves will be formed on the copper sheet, using sulfuric acid + persulfate system) The liquid medicine system of sodium sulfate cannot eliminate this defect, which will affect the stability of the subsequent process (oxidation, sintering)

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