2 Layer RF PCB Based On 30mil AD350A Substrate With Immersion Silver

This is an RF (Radio Frequency) PCB that utilizes the AD350A substrate. The AD350A substrate is a specialized material made of woven fiberglass reinforced, ceramic filled, PTFE-based composite. This substrate is specifically designed for high-power applications, offering high thermal conductivity and low coefficient of thermal expansion (CTE). It excels in environments with temperature extremes and prioritizes heat rejection.

The AD350A substrate exhibits several notable features. It maintains a well-controlled dielectric constant of 3.5 -/- 0.05 at 10 GHz/23°C, ensuring reliable signal transmission. With a low loss tangent of 0.003 at 10 GHz, 23°C @ 50% RH, it minimizes signal loss and preserves signal integrity. The substrate's low Z-axis thermal expansion coefficient of 35 ppm/°C provides thermal stability, while its decomposition temperature (Td) surpasses 500°C, making it suitable for high-temperature conditions. The material also boasts a moisture absorption rate of 0.1%, preserving consistent RF performance even in humid environments. Controlled CTE values in the X-axis (18 ppm/°C), Y-axis (18 ppm/°C), and Z-axis (63 ppm/°C) contribute to reliable and stable performance. Furthermore, the AD350A substrate offers excellent passive intermodulation (PIM) performance with ratings of -159dBC at 30mil and -163dBC at 60mil, effectively reducing interference. Its thermal conductivity of 0.44 W/m-K facilitates efficient heat dissipation.

This PCB stackup consists of two layers. Copper_layer_1, with a thickness of 35 μm, serves as the first layer. The AD350A substrate, measuring 0.762 mm (30mil) in thickness, is situated in the middle. Finally, there is copper_layer_2, also with a thickness of 35 μm, serving as the topmost layer.

The construction details of this PCB indicate its specifications. The board dimensions are 102.02mm x 65.54 mm with a tolerance of +/- 0.15mm. It features a minimum trace/space of 4/4 mils and a minimum hole size of 0.3mm. This PCB does not incorporate blind vias. The finished board thickness is 0.8mm, and the finished copper weight on outer layers is 1oz (1.4 mils). The via plating thickness is 20 μm. The surface finish is achieved through Immersion Silver. Notably, there is no top or bottom silkscreen or solder mask on this PCB. Prior to shipment, a 100% electrical test is performed to ensure its functionality.

In terms of statistics, this PCB accommodates 54 components with a total of 123 pads. Out of these, 90 pads are for through-hole (TH) components, while 33 pads are for top surface-mount technology (SMT) components. There are no bottom SMT pads. The PCB utilizes 76 vias to establish connections and supports three nets.

The artwork for this PCB is supplied in Gerber RS-274-X format, and it adheres to the accepted standard of IPC-Class-2.

This RF PCB based on the AD350A substrate is readily available worldwide. It finds typical applications in various industries, including cellular infrastructure base station antenna systems, automotive telematics antenna systems, and commercial satellite radio antenna systems.