FR4 Epoxy Fiberglass Laminated Sheet

FR4 epoxy fiberglass insulation sheet is a high-performance rigid laminate made from woven fiberglass cloth and epoxy resin under heat and pressure. It is widely used in electrical insulation and industrial applications where both mechanical strength and electrical reliability are required.

FR4 is one of the most commonly used glass epoxy insulation materials because it offers a strong balance of:

• electrical insulation

• mechanical strength

• flame resistance

• dimensional stability

What Is FR4 Epoxy Fiberglass Insulation Sheet?

FR4 is a glass fiber reinforced epoxy laminate sheet. It is manufactured by impregnating woven fiberglass cloth with epoxy resin and laminating it under controlled heat and pressure.

The result is a rigid board with:

• high strength

• good dielectric performance

• low water absorption

• stable dimensions

• flame-retardant properties

In practical use, FR4 is selected when ordinary insulation boards are not strong enough, or when the application requires a flame-retardant insulation material with good machining performance.

FR4 is an abbreviation for "Flame Retardant 4". It is a specific level of G10 epoxy glass laminate with the addition of flame retardants such as brominated epoxy resin, achieving a stringent flame retardant standard (UL94 V-0). FR4 is designed to self-extinguish rapidly once removed from an open flame, a fundamental safety requirement for electronic products to prevent fires caused by circuit failures.

Key Features

1.Excellent Electrical Insulation

FR4 is widely used in electrical insulation structures because it provides reliable dielectric performance and stable insulation behavior.

2.High Mechanical Strength

The fiberglass reinforcement gives the sheet strong mechanical support and rigidity, making it suitable for structural and fabricated parts.

3.Flame Retardant

FR4 is known for its flame-retardant performance, which is one of the main reasons it is preferred over some non-FR epoxy laminate materials.

4.Good Dimensional Stability

The board remains stable under normal electrical and mechanical working conditions, which helps ensure reliable assembly and long-term use.

5.Good Machinability

FR4 can be cut, drilled, milled, punched and machined into different industrial and electrical insulation parts.

FR4 Sheet Data Sheet

Typical Applications

FR4 epoxy fiberglass insulation sheet is widely used in:

Electrical Insulation Parts, Transformers and Motors, Industrial Machined Components(CNC machined plates)

How to Choose the Right FR4 Sheet

Before ordering FR4, buyers should confirm the following points:

1. Electrical or Structural Use: Is the sheet mainly used for insulation, for support, or for both?

2. Thickness: The correct thickness depends on voltage requirement, mechanical load and finished part design.

3. Flame Requirement: If flame-retardant performance is required, FR4 is often the suitable grade.

4. Machining Requirement: If the material will be drilled, milled or CNC machined, the part drawing should be reviewed in advance.

5. Working Environment: Humidity, temperature and mechanical stress may all affect the final material choice.

FR4 vs G10 vs G11:

G10 insulation sheet: Specifically refers to a laminate made of continuous long-filament fiberglass cloth and epoxy resin binder. It is renowned for its extremely high mechanical strength, excellent electrical insulation, good moisture resistance, and processability.

G11 insulation sheet uses an epoxy resin system with higher thermal stability (usually phenolic epoxy or other modified epoxy). Building upon all the advantages of G10, it significantly improves long-term heat resistance.

These insulation epoxyglass cloth boards can be used In motor, electrical equipment for insulationstructure parts, soft plate reinforcement and various kinds of machine parts, etc.

FAQ

Q1:What is FR4 epoxy fiberglass insulation sheet made of?

A: It is made from woven fiberglass cloth reinforced with epoxy resin and laminated under heat and pressure.

Q2:Is FR4 a good electrical insulation material?

A: Yes. It is widely used for electrical insulation parts because of its reliable dielectric performance and mechanical strength.

Q3: Is FR4 flame retardant?

A: Yes. Flame-retardant performance is one of the main reasons buyers choose FR4.

Q4: Can FR4 be machined?

A: Yes. It can be cut, drilled, milled and CNC machined into customized insulation and structural parts