Production requirements

I. Introduction

Second, as science and technology, especially information technology continues to evolve, PCB production process technology appropriate to mention

High in order to meet the needs of different users. In recent years, communications, automotive and other areas are developing very rapidly, to India

System board needs some changes, high power PCB, high frequency microwave board increased demand. PCB

Many CEOs manufacturers are optimistic about the growth, but how to do high-frequency microwave boards, companies must practice

Good strength. I already own the problems encountered in the production of shallow high-frequency microwave board production above precautions.

Second, the basic requirements for high frequency microwave board

1, the substrate

Telecommunications engineers in the design has been based on the actual impedance needs, choose a designated referral

Dielectric constant, dielectric thickness, foil thickness, therefore, accept orders, you should carefully check, be sure to meet

Design requirements.

2, the transmission line making precision high-frequency signal transmission, the characteristic impedance of the printed conductors requires ten

Of strict, that the production of precision transmission line is generally ± 0.02mm (± 0.01mm

Accuracy of the input transmission line is also very common), the edge of the transmission line to be very neat, tiny burrs, nicks are not allowed to produce.

3, the coating requirements

High-frequency microwave plate transmission line characteristic impedance directly affect the microwave signal transmission quality. The characteristic impedance of the size of the thickness of copper foil

Have a certain relationship, especially for microwave hole metal plate, coating thickness affects not only the total thickness of copper foil, but also affect the erosion carved room

After the accuracy of the wire, therefore, the coating thickness and uniformity of size, to be strictly controlled.

4, machining requirements

First, high-frequency microwave PCB board material and epoxy glass cloth material machining have very different; then the high frequency microwave

PCB board processing accuracy requirements much higher than the general shape tolerance of ± 0.1mm (high accuracy is typically ± 0.05mm or

0 ~-0.1mm).

5, the characteristic impedance requirement

As already talked about the characteristic impedance of the content, it is the basic requirement of high-frequency microwave plate, can not meet the requirements of the characteristic impedance, all in vain.


An engineering data processing: the customer files for CAM treatment, we must grasp the two aspects, one should seriously thorough understanding of the transmission line production accuracy requirements; second is based on the accuracy requirements and process capability combined with factory and make appropriate craft compensation.

2, cutting: Usually PCB cutting shears are used or automatic cutting machine, but for the microwave dielectric materials can not be generalized, according to the characteristics of different media, and the choice of different cutting methods, mostly milling, cut mainly to affect the flatness of the material and the quality of the board.

3, Drilling: For different dielectric materials, not only different drilling parameters, but also on the angle drill, hole processing methods are different, in order to avoid the burrs.

4, vias Ground: Under normal circumstances, the via hole using the electroless copper by grounding, electroless copper typically used chemical method or a plasma method for processing, from safety considerations, we used plasma method, the effect is very good; For the aluminum microwave dielectric materials, the use of the usual copper plating school, there is considerable difficulty, metallic conductive material generally recommended grounding through hole method is more suitable, but the hole resistance is generally less than 20m?. 5, the pattern transfer: This step is to ensure the accuracy of an important process graphics. In the choice of the photoresist, wet film, dry film and other photographic materials must meet the requirements of precision graphics; while lithography light source or exposure machine must also meet the needs of the process.

6, the etching: This step is necessary to strictly control the etching process parameters, such as: the content of each component of the etching solution, the temperature of the etching solution, the etching speed. Sure that the wires neat edges, no burrs, nicks, accuracy tolerances required range. To surly do this, we need fine effort, it is very necessary.

7, Tudu: high-frequency microwave plate conductors generally have the final coating of tin-lead alloy, tin-indium alloy, tin, strontium alloys, silver and gold. But gold plating is more common.

8, forming: forming and high-frequency microwave PCB board as to CNC milling based. But milling methods for different materials, there is a big difference. Milling the metal base of the microwave board requires a neutral liquid cooled, and the milling parameters is also considerable differences. In short, high-frequency microwave board production, in addition to pay attention to some of the above questions, you must also be careful HASL usually tin cylinder temperature, air pressure and the size of turnover, clip during indentation and scratches. Only a careful and detailed attention to every aspect in order to really make qualified products to.