G11 Epoxy Glass Laminate in Test Fixtures | High Strength & Heat Resistance

What Is G11 Epoxy Glass Laminate? G11 epoxy glass laminate is a high-grade composite material made of alkali-free fi...

What Is G11 Epoxy Glass Laminate?

G11 epoxy glass laminate is a high-grade composite material made of alkali-free fiberglass cloth impregnated with epoxy resin and laminated under high temperature and pressure.
It meets NEMA G11, IEC 61212, and MIL-I-24768/3 standards.

Compared with FR4 or G10, G11 offers higher heat resistance (155–180°C), excellent mechanical strength, and outstanding electrical insulation — making it ideal for test fixtures and industrial testing equipment that operate under thermal and electrical stress.

Why Use G11 sheet in Test Fixtures?

Test fixtures (also called testing jigs or testing holders) are used to secure and connect components such as PCB boards, connectors, relays, or battery modules during electrical performance testing.
G11 is widely used as the insulating and supporting base due to its stability, strength, and electrical reliability.

Application Area	Function	Reason for Using G11
Insulating Support Plate	Separates high-voltage or signal circuits	Dielectric strength ≥ 19 kV/mm
Base Plate	Structural base for components and probes	High mechanical strength and dimensional stability
Probe Guide Plate	Aligns test probes precisely	Excellent wear resistance
Thermal Isolation Layer	Prevents heat conduction from DUT	Heat deflection >180°C
Mounting Brackets	Connects metal frames and circuits	High insulation and mechanical reliability

G11 vs G10 vs FR4: Key Performance Comparison

 Conclusion: G11 is the upgraded version of FR4 and G10, designed for continuous high-temperature, high-voltage testing in advanced industries.

Applications of G11 in Test Fixtures

1. PCB and ATE (Automatic Test Equipment) Fixtures

Used as the top and bottom support boards, probe guide plates, and fixture bases.
Provides high rigidity, insulation, and stability during repeated mechanical cycles.

2. Battery Pack Testing Equipment

Acts as an insulating support plate and thermal barrier for lithium battery cells during charge/discharge testing.
Prevents current leakage and deformation at high temperatures.

3. Automotive ECU and Relay Testing Fixtures

Used for structural frames and insulation layers in engine control module tests.
Resists heat, electrical arcing, and vibration during long testing cycles.

4. Power Module and High-Voltage Component Testing

Used as a high-voltage isolation plate or support block in IGBT and relay testing.
Withstands high dielectric stress and prevents breakdown.

5. Semiconductor Device Test Fixtures

Serves as the fixture skeleton or protective insert, ensuring accuracy and stability under high temperature and pressure.

Processing and Design Tips

CNC Machining:

G11 can be precisely cut, drilled, and milled.
Use carbide or diamond tools for the best surface quality.

Thread Inserts:

Use stainless-steel inserts or bushings to prevent stress cracking.

Hole Spacing:

Maintain >5 mm edge distance to avoid delamination.

Storage Conditions:

Keep in a dry environment (<60% humidity) and avoid prolonged UV exposure.

Why Choose XUJUE ELECTRICAL G11 for Test Fixtures

Xujue Electrical  G11 epoxy fiberglass sheet are engineered for industrial-grade test environments.
Key advantages include:

Uniform epoxy resin impregnation and high laminate density

Superior delamination resistance and surface smoothness

Thickness range: 0.3 mm – 50 mm

Excellent machinability for CNC precision parts

Certified to UL 94 V-0 / RoHS / REACH standards

Widely used in ATE fixtures, battery pack testing, power module insulation parts