What is Epoxy Glass Fiber Laminate Sheet?
Epoxy Glass Fiber Laminate Sheet (also named 3240 Epoxy Sheet)is a thermosetting laminated insulation board made of glass fiber as the reinforcing skeleton and epoxy resin as the matrix resin. It is formed by impregnation, drying, and high-temperature and high-pressure hot pressing and curing. It is one of the most mainstream engineering insulation structural materials in the industrial and electronic fields.
Material Composition
Reinforcing Material: The core is electronic-grade/industrial-grade fiberglass cloth (mainly alkali-free fiberglass cloth), with some specifications incorporating fiberglass mat and chopped fiberglass strands to provide mechanical strength and dimensional stability to the sheet.
Matrix Resin: Primarily bisphenol A type epoxy resin; flame-retardant versions may include brominated epoxy and other flame-retardant modifiers to achieve bonding, curing, and insulation functions.
Auxiliary Materials: Curing agents (amines, anhydrides), flame retardants, fillers, colorants, etc., to adjust curing rate, flame retardancy, heat resistance, and appearance.
Core Characteristics and Advantages of Fiber Glass Epoxy Sheet
Characteristics
Electrical Insulation: High volume resistivity, stable dielectric properties, high voltage resistance, and arc resistance.
Mechanical Properties: High bending/tensile strength, impact resistance, creep resistance, and dimensional stability.
Heat and Temperature Resistance: High heat distortion temperature, wide long-term operating temperature range.
Chemical Stability: Resistant to acids, alkalis, organic solvents, and oils; corrosion resistant.
Good Machinability: Can be cut, drilled, milled, and stamped; suitable for precision machining.
Controllable Flame Retardancy: Standard/flame retardant grades are available, meeting industry fire protection standards.
Advantages
Balanced overall performance, balancing insulation, structural strength, and heat resistance.
High cost-effectiveness, mature mass production, suitable for large-scale industrial applications.
Excellent weather resistance, long service life under indoor and outdoor/harsh conditions.
Thermosetting material, does not melt or flow at high temperatures, and maintains stable form.
Common Application Areas of Epoxy Glass Fiber Sheet
Electronics & Electrical: PCB printed circuit board substrates, electrical insulation partitions, terminal blocks, switch panels.
Mold Manufacturing: Prototype molds, jigs and fixtures, injection mold pads.
New Energy: Insulation components for photovoltaic/wind power equipment, battery pack insulation sheets.
Machinery Industry: Precision machinery gaskets, gears, sliders, wear-resistant structural parts.
Rail Transportation/Marine: Vehicle insulation boards, ship cabin insulation structural parts.
Electrical Equipment: High-voltage switchgear insulation baffles, motor slot wedges, end plates.
Comparison with FR4 Fiberglass Sheet
| Epoxy Glass Fiber Laminate Sheet | FR4 Glassfiber Sheet | |
| Category Relationship | A broad category encompassing various flame-retardant and non-flame-retardant epoxy fiberglass boards. | Specific flame-retardant grades and models within this category, belonging to its subset. |
| Flame Retardant Standards | Divided into flame retardant and regular types, with no fixed flame retardant rating. | Complies with UL94 V-0 flame retardant standard, and is a designated flame retardant grade epoxy board. |
| Scope of Application | Broad, covering various specifications such as FR-1/FR-3/FR4/G10 Epoxy Sheet | Specifically refers to flame-retardant epoxy fiberglass cloth laminate, the industry default for high-end general-purpose models. |
| Application Focus | General insulation and structural components, covering low, medium, and high-end applications | High-end electronics, precision electrical components, and core applications with stringent flame-retardant requirements |
| Performance Differences | Standard models have lower heat resistance and flame retardancy than FR4; high-specification models approach FR4 Sheet. | They offer superior heat resistance, flame retardancy, and dielectric properties, representing the mainstream standard in the electronics industry. |
FR4 Glassfiber Sheet (Glass Epoxy Laminate Sheet) is the most commonly used and widely applied flame-retardant sub-product of Epoxy Glass Fiber Laminate Sheet. In daily industrial communication, unless otherwise specified, the two are often used interchangeably to refer to the same high-end epoxy fiberglass board. For formal selection, specific parameters such as flame retardancy and heat resistance should be used to distinguish them.
