Manufacturing method of thick-copper high-density interconnected printed board

Abstract

The invention discloses a manufacturing method of a thick-copper high-density interconnected printed board. The method comprises the following steps of: manufacturing a blind hole windowing pattern ona production board, removing a copper layer at the windowing position by etching, and drilling a blind hole at the windowing position by using laser; drilling a plug hole in the production board after a film is removed, and then metallizing the blind hole and a plug hole; manufacturing a hole plating pattern on the production board, and thickening hole wall copper layers of the plug hole and theblind hole through electroplating; filling the plug hole and the blind hole with resin ink and performing curing after the film is removed, and flattening the board surface through a grinding plate; manufacturing a mask hole pattern on the production board, and thinning the thickness of the surface copper layer through micro-etching; flattening the board surface through the grinding plate after the film is removed; drilling a through hole and a through groove in the production board, and then metallizing the through hole and the through groove; and sequentially subjecting the production boardto subsequent processes, thus obtaining the thick-copper high-density interconnected printed board. According to the method, manufacturing of large-aperture blind holes and thick-copper high-density interconnected printed boards is achieved, and resin is prevented from entering through holes and grooves which do not need hole plugging.

Description

technical field [0001] The invention relates to the technical field of manufacturing printed circuit boards, in particular to a method for manufacturing thick copper high-density interconnected printed boards. Background technique [0002] Thick copper circuit board refers to a type of product in which the copper thickness of the inner layer and / or outer layer is thicker than that of conventional circuit boards. It is used to carry large currents, dissipate heat and reduce thermal strain. It is mostly used in communication equipment, aerospace, and networks. Energy, new energy vehicle power supply, etc. [0003] In recent years, new energy equipment and facilities with electric vehicles as the main focus have risen rapidly, and related supporting facilities such as charging piles, charging boxes and other equipment have also been developed in full swing. An essential part of industrial development. [0004] Circuit boards used in new energy equipment require high current t...

AI Technical Summary

Problems solved by technology

[0005] A thick copper high-density interconnected printed board, the total number of layers is 14L, the inner core board is made of 0.11mm4 / 4OZ thick copper copper clad laminate (1OZ≈35μm), the laser blind hole diameter is 0.25mm, and the mechanical drilling diameter is 0.4mm (The aspect ratio reaches 8:1), the outer layer copper foil is 0.33OZ, and is designed with resin plug holes and metallization grooves. The final requirement is that the outer layer copper thickness reaches 90μm, the hole copper is 50μm, and the metal side wall copper is 50μm; It is too difficult to make the board using conventional technology, and the production cannot be realized. There will be the following problems in the specific production process:

[0006] 1. Before laser drilling, it is necessary to use the browning process to process the outer layer of copper foil to increase the roughness and improve the copper foil's ability to absorb laser light. The browning process will cause the entire copper foil to lose 3-4 μm of copper thickness, and the surface copper thickness cannot be guaranteed. , bringing quality risks to subsequent copper sinking and full-board electroplating;

[0007] 2. The diameter of the laser blind hole is 0.25mm, which is a blind hole with a super large aperture, which cannot be filled by electroplating (conventional blind holes≤0.15mm);

[0009] 4. The thickness-to-diameter ratio is 8:1, and through-blind holes cannot achieve one-time co-plating;

[0010] 5. The hole copper is required to be 50 μm. Using conventional electroplating methods will make the surface copper too thick, resulting in serious problems such as unclean line etching, drilling, and forming.