4-layer MT77 PCB 0.5oz/1oz Copper Immersion Silver Finish

This 4-layer PCB employs Astra MT77 laminates and 1078 MT77 prepreg, with Immersion Silver (Ag) as its surface finish. It features 0.5oz inner copper layers, 1oz outer copper layers, and a finished board thickness of 0.574mm. The product adopts green solder mask with white silkscreen and incorporates 0.25mm resin-filled capped vias. Tailored for RF/microwave applications, Astra MT77 laminates deliver exceptional electrical stability and ultra-low loss performance, serving as a cost-effective alternative to PTFE materials.

PCB Specifications

Stack-up Configuration

Astra MT77 Laminate Material Properties

Astra MT77 laminate materials exhibit exceptional electrical properties with high stability across a broad frequency and temperature range, making them ideal for modern commercial RF/microwave printed circuit designs. Core advantages include:

-Stable Dielectric Constant (Dk): The dielectric constant maintains stability between -40°C and +140°C, even at frequencies up to W-band (75GHz~110GHz), ensuring consistent signal transmission performance in extreme operating environments.

-Ultra-Low Dissipation Factor (Df): With a Df value of 0.0017, Astra MT77 minimizes signal attenuation and energy loss, outperforming conventional materials and supporting high-fidelity RF/microwave signal transmission.

-Cost-Effectiveness: Serving as a high-performance alternative to PTFE and other commercial microwave laminates, MT77 balances superior electrical properties with competitive costs, suitable for mass-produced RF applications.

-Application Versatility: Particularly suited for automotive long antennas and radar systems, including adaptive cruise control, pre-crash detection, blind spot monitoring, lane departure warning, and stop-and-go systems.

What is Resin Filled and Capped Via?

Resin filled and capped via is a precision PCB manufacturing process tailored for high-density, high-frequency applications, which involves filling the via hole with insulating resin and capping both sides to ensure flatness and performance. Key details are as follows:

Process Principle: First, 0.25mm vias are drilled through the PCB layers; then, high-temperature resistant insulating resin is injected into the vias to fully fill the holes, eliminating air gaps. After curing, the resin surface is ground flat and capped with a thin copper layer or solder mask to achieve a smooth surface consistent with the PCB.

Core Functions:

-Prevents solder bridging during surface mount technology (SMT) by eliminating via holes that may trap solder paste.

-Reduces signal reflection and crosstalk in RF/microwave circuits, ensuring stable signal integrity at high frequencies.

-Enhances mechanical strength of the via structure, preventing cracking or delamination under thermal cycling and vibration.

-Enables uniform solder mask application and flat surface, facilitating precise component placement for high-density designs.

Applicability for MT77 PCB: For RF/microwave circuits using MT77 material, resin filled and capped vias complement the material’s low-loss properties, avoiding signal degradation caused by via discontinuities and ensuring the PCB meets the strict performance requirements of automotive radar and antenna systems.

Quality & Application Scope

Typical applications focus on automotive RF/microwave systems, including adaptive cruise control (ACC), pre-crash detection modules, blind spot detection (BSD) sensors, lane departure warning (LDW) systems, and stop-and-go control units. It is also suitable for other commercial RF devices requiring stable electrical performance across broad frequency and temperature ranges. This PCB is available worldwide, supporting global automotive electronics project demands and ensuring timely delivery.