FR-4 (Glass Epoxy Laminate) vs PET (Polyester): 0% composition overlap. Significantly different materials serving different application areas.
FR-4 (Glass Epoxy Laminate) vs PET (Polyester)
Side-by-side chemical composition and mechanical property comparison.
Overview
FR-4 (Glass Epoxy Laminate)
Flame retardant woven fiberglass cloth with epoxy resin binder — the worldwide standard substrate material for printed circuit boards (PCBs). Designated NEMA grade FR-4 and IPC-4101. Good mechanical strength, dimensional stability and electrical insulation up to 130°C (Tg). Dielectric constant 4.2–4.7 at 1 MHz. Self-extinguishing (UL94 V-0). Used for single/multilayer PCBs, electrical insulation boards, structural composites in electronics, test fixtures and jigs. Available in thicknesses 0.1–50 mm.
PET (Polyester)
Polyethylene Terephthalate (semi-crystalline stock shape) — combines the stiffness of POM with the wear resistance of PA, without centerline porosity or moisture sensitivity. Excellent dimensional stability, low friction, very low water absorption (~0.1%). Better creep resistance than POM or PA. Widely known from bottles/packaging, but engineering PET-P is semi-crystalline and much stiffer. Trade names include Ertalyte (MCAM), Arnite (DSM), Rynite (DuPont, GF grades). Used for precision bearings in water, gears, slide elements, pump parts, and electrical insulators.
| FR-4 (Glass Epoxy Laminate) | PET (Polyester) | |
|---|---|---|
| Material Number | — | — |
| Category | Polymers | Polymers |
| Standard | IPC-4101 | ISO 10350 |
Mechanical properties
| Property | FR-4 (Glass Epoxy Laminate) | PET (Polyester) | Unit |
|---|---|---|---|
| Flexural Strength | 380–480 | — | MPa |
| Tensile Strength | 280–340 | — | MPa |
| Compressive Strength | 350–420 | — | MPa |
Compatibility Assessment
FR-4 (Glass Epoxy Laminate) and PET (Polyester) have significantly different compositions (0% overlap). These materials are not interchangeable and serve different application areas.
Automated assessment based on composition analysis
Frequently Asked Questions
Is FR-4 (Glass Epoxy Laminate) the same as PET (Polyester)?
FR-4 (Glass Epoxy Laminate) and PET (Polyester) have a 0% composition overlap. They are generally not directly interchangeable.
Can I replace FR-4 (Glass Epoxy Laminate) with PET (Polyester)?
Generally not recommended. The compositions differ significantly (0% overlap). These materials have different alloying concepts and are intended for different applications.
What is the difference between FR-4 (Glass Epoxy Laminate) and PET (Polyester)?
The main differences are in the following elements: overall alloying content. FR-4 (Glass Epoxy Laminate) is a Polymers grade, while PET (Polyester) is a Polymers grade.
Related Comparisons
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Data provided for reference only. Always verify against the applicable specification for critical applications.
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