With the rapid development of electronic communication technology, in order to realize high speed and high fidelity transmission of signal, more and more high-frequency circuit boards are used in communication equipment.The dielectric materials used in the high frequency board have excellent electrical properties and good chemical stability, which are mainly shown in the following four aspects:
- It has the characteristics of small signal transmission loss, short transmission delay time and small signal transmission distortion.
- It has excellent dielectric properties (mainly: low relative dielectric constant -Dk, low dielectric loss factor- Df). In addition, the dielectric properties (Dk, Df) remain stable under the environment of frequency, humidity and temperature.
- High precision control of impedance (Zo)
- It has excellent heat resistance (Tg), processing formability and adaptability.
Based on the above characteristics, the high frequency PCB board is widely used in wireless antenna, base station receiving antenna, power amplifier, components (shunt, confluence, filter), radar system, navigation system and other communication devices.
The design of multilayer high frequency PCB based on cost saving, bending strength and electromagnetic interference control. It is often appearance by high frequency hybrid PCB.The selection of high frequency mixed pressure material and the design of the composite structure are varied and enumerate。King Sun through research and development, a 6 laminate was produced by experiment, and the mixed pressure of high frequency material RO4350B/RO4450B and FR4 was combined.
The test results show that the design of the high frequency mixed pressure plate is based on one or more factors in the control of the cost saving, the improvement of the bending strength and the control of the electromagnetic interference.It is necessary to use high frequency prepreg with low resin fluidity and smooth FR-4 substrate on the medium surface during the press process. In such a case, there is a great risk for the product’s caking control during the press process.
The experimental results show that the key technologies such as FR-4 A material, plate edge flow block, flow retarding block design, compression retarding material usage and press parameter control are selected. The bonding property between the mixed pressure material is good, and the reliability of the circuit board is not abnormal.