Method for forming via holes and embedded holes in multilayer circuit board

Abstract

The invention relates to a copper cylinder used in the manufacturing process of a circuit board. The copper cylinder is a hollow copper cylinder. Through holes are vertically formed in the side wall of the hollow copper cylinder. Based on the hollow copper cylinder, environment-friendly forming of via holes and embedded holes in a multilayer circuit board can be achieved. According to the forming method of the embedded holes, the hollow copper cylinder is arranged in the circuit board, one end or two ends of the hollow copper cylinder are welded to the circuit board, and accordingly circuits on the two sides of the circuit board can be communicated. Single-layer circuit boards and double-layer circuit boards are laminated to form the multilayer circuit board, and the through holes in the inner-layer circuit board form the embedded holes. When the embedded holes need to be connected with one certain layer of circuit board, the hollow copper cylinder is used, the hollow copper cylinder is inserted into the corresponding positions of the embedded holes from the circuit board at the uppermost layer, tin soldering is performed, and soldering tin is led in through the through holes of the hollow copper cylinder so that soldering tin and the embedded holes of the inner-layer circuit board can be welded. A brand new method for forming via holes and embedded holes in the circuit board is provided, it is hopeful that the etching technology of the circuit board can be overall improved, an electroless plating copper electroplating technology is eliminated, and energy saving and environmental protection are achieved.

Description

technical field [0001] The invention relates to the technical field of circuit boards, in particular to a method for manufacturing via holes and buried holes of a multilayer circuit board. Background technique [0002] The pollution existing in the manufacturing process of the existing multilayer circuit board is well known, and the pollution problem is a common problem in the whole industry. Each circuit board manufacturer has to spend a lot of manpower and financial resources on the prevention and control of pollution, and optimize the process as much as possible to reduce pollution. However, these process optimizations are solutions that treat the symptoms rather than the root cause. Therefore, its processing technology must be fundamentally changed. At present, laser engraving circuit technology has appeared. Although the cost is high, the circuit production precision is high, the finished board is of good quality, and there is no pollution. However, for double-sided ...

AI Technical Summary

Problems solved by technology

At present, laser engraving circuit technology has appeared. Although the cost is high, the circuit production precision is high, the finished board is of good quality, and there is no pollution.

However, for double-sided or multi-layer circuit boards, the production of via holes or buried holes is still impossible, which limits the application of laser engraving circuit technology in the circuit board industry

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