The High-Frequency Multi-Layer Hybrid Board

January 11. 2022

With the rapid development of electronic communication technology, in order to achieve high-speed and high-frequency signal transmission, more and more high-frequency printed circuit boards are used in communication equipment. The dielectric materials used in high-frequency boards have excellent electrical properties and good Chemical stability, then which of the following is its main manifestation?

1. High-precision control with characteristic impedance (Zo).

2. It has excellent heat resistance (Tg), processability and adaptability.

3. It has the characteristics of small signal transmission loss, short transmission delay time and small signal transmission distortion.

4. Has excellent dielectric properties (mainly refers to: low relative permittivity Dk, low dielectric loss factor Df). Moreover, this dielectric characteristic (Dk, Df) can still maintain its stability under environmental changes of frequency, humidity, and temperature.

Based on the above characteristics, high-frequency boards are widely used in aerospace, wireless antennas, base station receiving antennas, power amplifiers, components (splitters, confluencers, filters), radar systems, navigation systems and other communication equipment.

The design of high-frequency PCB board multi-layer hybrid board is based on cost saving, improved bending strength, electromagnetic interference control and other factors, and often appears in the form of multi-layer hybrid board, called high-frequency multi-layer hybrid board. There are many kinds of design of high-frequency board multi-layer hybrid board material selection and stacking combination, and there are too many to list. You can use Rogers RO4350+FR4, Wangling sheet F4BME+FR4, Rogers RO5880+RO4003, Teconic RF-35+FR4, Teconic TLX-8+FR4, etc., as long as you need, we can do it.

Generally, the multi-layer hybrid laminate design of high-frequency board is much more favorable than pure high-frequency board. The high-frequency hybrid board is based on one or more factors of cost saving, increased bending strength, and electromagnetic interference control, and the pressing process must be adopted. High-frequency prepregs with low resin fluidity and FR-4 substrates with smoother media surfaces. In this case, there is a greater risk for the control of the adhesion of the product during the pressing process.

Experiments show that through the selection of FR-4 material, the design of the spherical flow glue baffle block on the side of the PCB, the use of pressure-releasing materials, and the application of key technologies such as the control of the pressure parameters, the adhesion between the high-frequency board mixed materials is achieved. The structure is good, and the reliability of the high-frequency board circuit board is not abnormal after the test.