Microwave Tech - Microwave High-frequency Printed Circuit Board should be attention to the problems.

1., Microwave High-Frequency Printed Circuit Board

With the continuous development of science and technology, especially information technology, the production of printed circuit board technology corresponding growth, to meet the needs of different users. In recent years, communication, transportation and other fields of development is very rapid, the need for printed boards has changed a little, the demand for high-power printed circuit boards, high frequency microwave board increased. Many bosses of printed board production companies are optimistic about this high point, but how to do a good job of high frequency microwave board, the company must practice Qigong. I on their own encountered in the production of the problem, high frequency microwave plate production should pay attention to the project.

2, Microwave high-frequency board basic requirements

1. Base material, telecommunications engineers have selected the specified dielectric constant, media thickness and copper foil thickness according to the actual impedance requirements in the preset. Because of this, when accepting orders, we must take seriously the audit and check, and must satisfy the preset requirements.

2. the transmission line manufacturing precision requirements, high frequency signal transmission, for the special nature of printed wire impedance requirements are very strict, that is, the transmission line manufacturing precision requirements of ±0.02mm (±0.01mm precision transmission line is also very common), the transmission line edge to be very clear, Subtle burr, gap children are not allowed to germinate.

3.coating requirements, high frequency microwave plate transmission line of the special nature of the impedance directly affects the transmission quality of microwave signals. The special property of the volume of impedance and the thickness of copper foil has a certain relationship, especially for the hole metallized microwave plate, coating thickness not only affects the total thickness of copper foil, and affects the precision of the wire after etching, because of this, coating thickness volume and average, to strictly control.

4. the requirements of mechanical processing, first of all, the material of the high frequency microwave board and the printed circuit board epoxy gas glass cloth material in the machining is very different; The second is the high frequency microwave board processing precision than the printed board requirements, the general shape tolerance of ±0.1mm (high precision of the common ±0.05mm or 0~-0.1mm).

3, High Frequency Microwave plate production should pay attention to the problem

1. Disposition of engineering data: When implementing CAM disposal on customer's documents, it is necessary to grasp the internal essence of two aspects. First, it is necessary to seriously understand the manufacturing precision requirements of the transmission line. Second, according to the precision requirements and the factory's manufacturing process experience, to make the appropriate process repayment.

2, blanking: general printed circuit board blanking is the use of shearing machine or semi-automatic material opener, but for microwave media materials can not be taken together, according to the special nature of different media, and choose different blanking methods, mostly milling, cutting, so as not to affect the flatness of the material and the quality of the board.

3. Drilling: for different media materials, not only the parameters of drilling are different, but also the top Angle, blade length and spiral Angle of the drill have its special requirements. For aluminum and copper based microwave media materials, drilling processing forms are also different to prevent the initiation of burrs.

4, through hole grounding: ordinary things, through hole is considered appropriate and the use of chemical copper grounding, chemical copper sinking method is generally used to dispose of chemical method or plasma method, from the safety aspect of thinking, we think appropriate and the use of plasma method, the effect is good; For aluminum based microwave medium materials, if the use of general chemical precipitation copper, there is a considerable degree of difficulty, the general proposal is considered appropriate and the use of metal conductive material hole grounding method is more appropriate, but the hole resistance is generally less than 20m? .

5. Graph transfer: this procedure is a closing procedure to ensure the precision of the graph. In the selection of photoresist, wet film, dry film and other gelatin, be sure to meet the requirements of graphic precision; At the same time, the light source of the lithography or exposure machine must also meet the requirements of the process.

6. Carve: this process should strictly control the process parameters of carve, such as the content of each component of the carve solution, the temperature of the carve solution, the speed of the carve, etc. Ensure that the edge of the wire is clear, without burr and notch, and the precision of the wire is within the tolerance requirements. It is very indispensable to make it practical and practical.

7, coating: high frequency microwave board wire final coating common tin lead alloy, tin indium alloy, tin strontium alloy, silver, gold and so on. However, electroplated gold is widely used.

8, forming: the forming of high frequency microwave board and printed board, mainly to digital control milling. But the method of milling for different materials, there are very big differences. Milling of metal-based microwave plates requires the use of neutral coolant, and the milling parameters are quite different.

In short, in the production of microwave high-frequency board, in addition to the above problems, we must also be careful about the temperature of hot air daily tin cylinder, the volume and turnover of wind pressure, the indentation and scratches in the clamping process. Only seriously treat carefully pay attention to each link, the ability to really make products that meet the standards.