2. PCB Basic Specification Table

Specification Item	Detailed Parameters
PCB Layer Count	6 Layers
Core Board Material & Thickness	3pcs of 0.127mm Astra MT77 Core Board
Prepreg Material	Astra MT77 PP
Finished Board Thickness	0.994mm
Inner Layer Copper Weight	0.5oz
Outer Layer Copper Weight	1oz
Surface Treatment	Immersion Silver
Solder Mask & Printing	Green Solder Mask, White Silk Screen
Board Dimension	131mm × 107mm (1pcs)
Special Process	G12 Resin Plug Hole (Electroplating Filling), L1-L2 & L5-L6 Blind Holes

3. PCB Stackup Structure

This 6-layer high-frequency PCB built with Astra MT77 dielectric materials adopts a scientific and symmetrical stackup design, which guarantees uniform structural stress, stable electrical performance and minimal high-frequency signal loss. The detailed layer stackup configuration is listed as follows:

4. CCL Material Knowledge of Astra MT77

Astra MT77 is a high-performance ultra-low loss copper clad laminate (CCL) material developed for millimeter wave and high-frequency microwave applications, delivering outstanding and stable electrical performance across wide frequency and temperature ranges. As a cost-effective alternative to traditional PTFE microwave materials, MT77 has been widely adopted in commercial high-frequency circuit design scenarios.

4.1 Industry Certification & Compliance

Astra MT77 PCB materials have obtained authoritative industry recognition and meet global environmental and safety standards. It holds UL certification with the file number E41625, providing reliable quality certification for commercial and industrial applications. Meanwhile, the material is fully RoHS compliant and compatible with lead-free assembly processes, which conforms to the environmental protection requirements of global electronic manufacturing industries.

4.2 Core Performance Advantages

MT77 laminate features extremely stable dielectric constant (Dk) and ultra-low dissipation factor (Df). Its Dk value remains stable in the temperature range from -40°C to +140°C and adapts to W-band high-frequency signals. The ultra-low Df value of 0.0017 effectively reduces high-frequency signal transmission attenuation, ensuring high signal integrity for RFand microwave circuits. Compared with conventional high-frequency materials, Astra MT77 achieves balanced high performance and cost control, with more competitive application value.

4.3 Processing Characteristics

Astra MT77 material has excellent process compatibility and manufacturability, perfectly matching standard FR-4 production processes. It supports short lamination cycles, which effectively improves production efficiency and reduces manufacturing costs. The material can reduce drill wear during processing and does not require plasma desmear treatment, simplifying the production process. It also presents good flow and filling performance, excellent dimensional stability, and supports multiple lamination cycles. In addition, it is compatible with any layer technology, HDI technology and VIPPO design, meeting the manufacturing requirements of high-density, multi-layer and high-precision PCBs.

4.4 Product Supply Specifications

Astra MT77 provides standardized laminate and prepreg product series with complete size specifications. The laminate thickness options cover 2.5mil to 60mil (0.0635mm to 1.50mm), including the 0.127mm core board adopted by this PCB. For copper foil matching, it supports HVLP (VLP2) copper foil with Rz ≤2.5 micron JIS, embedded resistor foil, and multiple copper weight specifications of 0.5oz, 1oz and 2oz. Customized thinner copper foil is also available to meet diverse design demands. All prepreg panels are packaged with moisture barrier protection to ensure stable material performance.

4.5 Main Application Fields

Benefiting from its superior high-frequency and high-temperature resistant performance, Astra MT77 materials are mainly applied in commercial RFand microwave circuit designs, especially widely used in automotive intelligent antenna and radar systems. Typical application scenarios include automotive adaptive cruise control system, pre-collision safety system, blind spot detection system, lane departure warning system and stop-and-go driving assist systems, providing stable and reliable material support for automotive intelligent driving electronic equipment.

5. Astra Mt77 Datasheet

Property	Typical Value	Units	Test Method
Glass Transition Temperature (Tg) by DSC	200	°C	IPC-TM-650 2.4.25C
Decomposition Temperature (Td) by TGA @ 5% weight loss	360	°C	IPC-TM-650 2.4.24.6
Time to Delaminate by TMA (Copper removed)A. T260B. T288	>60	Minutes	IPC-TM-650 2.4.24.1
Z-Axis CTEA. Pre-TgB. Post-Tg	50 – 70250 – 350	ppm/°C	IPC-TM-650 2.4.24C
X/Y-Axis CTE (Pre-Tg)	12	ppm/°C	IPC-TM-650 2.4.24C
Thermal Conductivity	0.45	W/m·K	ASTM E1952
Thermal Stress 10 sec @ 288ºC (550.4ºF)A. UnetchedB. Etched	PassPass	Visual	IPC-TM-650 2.4.13.1
Dk, PermittivityA. @ 2 GHzB. @ 10 GHz	3.00	—	IPC-TM-650 2.5.5.5
Df, Loss TangentA. @ 2 GHzB. @ 10 GHz	0.0017	—	Bereskin Stripline
Volume Resistivity (C-96/35/90)	1.33 × 10⁷	MΩ-cm	IPC-TM-650 2.5.17.1
Surface Resistivity (C-96/35/90)	1.33 × 10⁵	MΩ	IPC-TM-650 2.5.17.1
Dielectric Breakdown	45.4	kV	IPC-TM-650 2.5.6B
Arc Resistance	139	Seconds	IPC-TM-650 2.5.1B
Electric Strength (Laminate & laminated prepreg)	45 (1133)	kV/mm (V/mil)	IPC-TM-650 2.5.6.2A
Comparative Tracking Index (CTI)	3 (175–249)	Class (Volts)	UL 746A / ASTM D3638
Peel Strength (1 oz. EDC foil)	1.0 (5.7)	N/mm (lb/inch)	IPC-TM-650 2.4.8.3
Flexural StrengthA. Length directionB. Cross direction	338 (49.0)269 (39.0)	MPa (kpsi)	IPC-TM-650 2.4.4B
Tensile StrengthA. Length directionB. Cross direction	214 (31.0)165 (24.0)	MPa (kpsi)	ASTM D3039
Poisson's RatioA. Length directionB. Cross direction	0.1830.182	—	ASTM D3039
Moisture Absorption	0.1	%	IPC-TM-650 2.6.2.1A
Flammability (Laminate & laminated prepreg)	V-0	Rating	UL 94
Relative Thermal Index (RTI)	130	°C	UL 796

6. Summary

This 6-layer 0.994mm Astra MT77 high-frequency PCB integrates premium low-loss CCL materials and advanced PCB manufacturing technologies. With a reasonable symmetrical stackup structure, differentiated internal and external copper thickness design, immersion silver surface finishing and professional blind hole & resin plug hole processes, the product achieves excellent signal integrity and structural stability. Supported by Astra MT77’s ultra-low loss electrical performance, wide temperature adaptability and mature processing compatibility, this PCB is highly suitable for automotive radar, RFantenna and other high-frequency microwave electronic devices. It balances high performance, cost-effectiveness and industrial reliability, meeting the strict manufacturing and application standards of the European and American electronic markets.

Tags: Astra Mt77 PCB, 6-Layer Low Loss PCB,  Mt77 High Frequency PCB, Immersion Silver PCB, RF Microwave PCB, Automotive Radar PCB, Hdi Blind Hole PCB，0.127mm MT77 material