Microwave Tech - Study on Multilayer Fabrication of Microwave Printed Circuit Board

1., Preface

It is well known that the electromagnetic wave with a wavelength shorter than 300mm or a frequency higher than 1000MHz (1GHz) is called microwave. Microwave printed circuit board (PCB) refers to the microwave substrate produced by the common rigid PCB manufacturing method on a specific microwave substrate coated with copper.

In the manufacturing of multilayer, microwave printed board, the American counterparts have mastered and realized the multilayer manufacturing technology of multilayer microwave printed board with various types of double-sided microwave laminate substrate. These technologies include multilayer lamination manufacturing of microwave dielectric substrate, metalized hole interconnection, and buried/blind hole manufacturing, multilayer microwave printed board electro-loading, and environmental protection solder resistance film manufacturing, multilayer microwave circuit surface plating nickel gold, and three-dimensional numerical control milling processing of multilayer microwave printed circuit board substrate.

2, Microwave printed cuicuit board multilayer manufacturing process

Microwave multilayer PCB manufacturer, according to the design requirements, can have a variety of ways to achieve. Given the differences in specific design requirements, different process routes can be adopted. The manufacturing process for a typical microwave multilayer board is listed below:

(1) Production of light painting template and inner layer graphics:

3, Characteristics of Microwave copper-clad laminate material

Undoubtedly, in the design and manufacture process of microwave multilayer plate, the most chosen is the PTFE coppered laminate material with the dielectric constant of 2.94. Due to the realization of the manufacturing process, according to the different characteristics of the microwave plate, so through the following introduction, I hope to give you a preliminary understanding.

This paper mainly introduces a ceramic powder-filled, glass short fiber reinforced polytetrafluoroethylene (PTFE) microwave copper-clad laminate material, through its multilayer processing, that can realize the fabrication of microwave multilayer printed board. RT/DuroID 6002 plate produced by Rogers company in the United States is the most widely used such material, which has the following significant characteristics:

(1) Excellent high frequency and low loss characteristics;

(2) Strict control of dielectric constant and thickness;

(3) Excellent electrical and mechanical properties;

(4) Extremely low dielectric constant thermal coefficient;

(5) plane expansion coefficient matching with copper;

(6) low Z-axis expansion;

(7) Low permeability, is an ideal material for space applications.

Due to the above advantages, the microwave high-frequency dielectric material is widely used in the following aspects:

(1) Phase array antenna;

(2) Ground and airborne radar systems;

(3) Global positioning system antenna;

(4) High-power baseboard;

(5) High-reliability complex multilayer line;

(6) Commercial aviation collision avoidance systems.

4., Conclusion

Microwave printed board, one of the specially printed boards used in communication, especially the application of PTFE microwave materials, has gradually stepped forward to the direction of microwave multilayer circuit board manufacturing based on the original single and double side manufacturing requirements of the printed board. This kind of microwave multilayer printed circuit board is different from the traditional multilayer printed board, because of the particularity of the lamination manufacturing, in addition to the selection of microwaveprinted circuit board bonding materials, the lamination manufacturing of microwave multilayer.