Today I will tell you what are the difficulties of multilayer PCB proofing production. The four major difficulties in the production and processing of multilayer circuit boards. As communications, medical, industrial control, security, automotive, electric power, aviation, military, computer peripherals and other areas of the "backbone", multilayer pcb fabrication more and more functions, the line is more and more dense, the production difficulty is relatively more and more.

At present, the domestic mass production of multi-layer printed circuit board manufacturers mostly from foreign-funded enterprises, only a small number of domestic enterprises have the strength of mass production. The production of multilayer circuit boards not only requires high investment in technology and equipment, but also requires experienced production technicians. At the same time, to obtain the multilayer printed circuit board user certification, the procedures are cumbersome and strict, so the entry threshold for multilayer printed circuit boards is high, and the industrialized production cycle is long. Specifically, the difficulties encountered in the production and processing of multilayer circuit boards are mainly the following four aspects.

Four major difficulties in the production and processing of multilayer circuit boards

1, the inner layer of the line design and production of a difficult point

Multilayer board circuit with high-speed, thick copper, high-frequency, high TG value and other special requirements, the internal wiring and graphic size control requirements are increasingly high. For example, ARM development boards, the inner layer has a lot of impedance signal lines, PCB factory in order to ensure the integrity of the impedance increases the difficulty of the inner line production.

The inner layer has more signal lines, and the width and spacing of the lines are basically around or below 4 mil; laminated multi-core boards are prone to wrinkling during thin production, which will increase the production cost of the inner layer.

2. Difficulty of inner layer alignment

The number of layers of multilayer boards is increasing, and the alignment requirements of the inner layer are also increasing. The film will expand and contract under the influence of temperature and humidity in the workshop environment, and the core board will also undergo the same expansion and contraction, making it more difficult to control the accuracy of the alignment between the inner layers.

3. Difficulties in the pressing process

Multi-core boards laminated with PP (semi-cured boards) are prone to delamination, slippage and roller residue problems. Due to the large number of layers, variation control and size factor compensation cannot be maintained consistently.

4. Difficulty in drilling

Multilayer plates are made of high Tg or other special plates, and the hole roughness of different materials is different, which increases the difficulty of removing the residual glue in the hole. The high density of holes in high-density multilayer boards results in low productivity and tends to break the tool. Too close hole edges between different network perforations will lead to CAF effect problems.

Therefore, in order to be able to ensure the high reliability of the final product of the enterprise, it is necessary to multi-layer board manufacturers in the production development process can be analyzed corresponding control.