High frequency PCB board concept and its unique characteristics

High-frequency PCB board refers to a special circuit board with a high electromagnetic frequency, which is used for PCB in the field of high frequency (frequency greater than 300MHZ or wavelength less than 1 meter) and microwave (frequency greater than 3GHZ or wavelength less than 0.1 meter). It is a circuit board produced on a microwave substrate copper clad plate by using part of the ordinary rigid circuit board manufacturing process or by using a special treatment method.

First, what are the materials used to make high-frequency PCB board?

The performance of the high-frequency board in wireless or other high-frequency applications depends on the building material. For many applications, the use of laminated FR4 materials can improve dielectric properties. When manufacturing high-frequency PCB boards, the commonly used plates are Rogers /Rogers, Taikonick /Taconic, Isola (Isona), F4B (Teflon), TP-2, FR4, Panasonic, Taiyao and other materials.

Second, the DF level of general materials directly determines the performance of PCB:

1, DK (DK material dielectric constant, indicating the ability to store charge.) It should be small and stable enough, usually smaller is better, high DK may cause signal transmission delay.

2, DF (DF is the loss Angle of the material, the signal in the material is not completely transmitted along the signal path forward, there will be a part of the material into the nearby conductor.) It should be small, which mainly affects the quality of signal transmission, and smaller DF can correspondingly reduce signal loss.

3, the coefficient of thermal expansion should be the same as the copper foil as much as possible, because the difference will cause the copper foil to separate when the heat and cold change.

4, in a humid environment, water absorption must be low, high water absorption, will affect DK and DF.

5, heat resistance, chemical resistance, impact resistance, stripping resistance must be good.

The thermal expansion coefficient of the high-frequency PCB board needs to be the same as the copper foil as much as possible, because the high-frequency circuit board may cause the separation of the copper foil in the case of hot and cold alternations, and the same as the copper foil as much as possible in order to ensure the performance of the high-frequency circuit board can be perfect. High frequency PCB has the characteristics of heat resistance, chemical corrosion resistance, impact resistance, good stripping resistance and so on.

Third, what are the advantages of high frequency PCB board so popular?

1) High efficiency

In general, the consumption of high-frequency circuit boards benefits from its smaller dielectric constant, that is, from the performance of the material it uses, so its consumption is naturally less than other circuit boards. Under such excellent innate conditions, induction heating technology, which is at the forefront of technological development, can also meet the needs of target heating, making the efficiency of high-frequency circuit boards very high. Of course, in the pursuit of efficiency, we should not give up environmental protection.

2) Fast working speed

It is well known that the transmission speed is proportional to the dielectric constant. In terms of electrical principle, the transmission speed is inversely proportional to the square root of the dielectric constant, that is, the greater the dielectric constant, the slower the transmission speed; The smaller the dielectric constant, the faster the transmission speed. This is also one of the reasons why PCB high frequency board is welcomed by everyone. It uses special materials that can well ensure the characteristics of small dielectric constants, but also ensure the transmission speed, while making the operation of the board relatively stable.

3) Adaptability

It is widely used in high-frequency circuit boards in various industries that require the heating treatment of precision metal materials. In its technical field, it can not only realize the heating of components at different depths, but also centralized heating for local characteristics, whether surface or depth, centralized or decentralized heating methods can be easily accomplished.

4) Strong tolerance, strong anti-interference ability

The environment affects the composition of the medium, so the high-frequency circuit board still has some environmental requirements, especially in the south, where the weather is more humid. High-frequency circuit boards can be well adapted to such an environment. High-frequency circuit boards made of materials with extremely low water absorption can challenge such environments. At the same time, it is best to make the PCB circuit board has the advantage of chemical corrosion resistance, so that it can resist moisture and high temperature in a humid environment, and has a great peeling strength.