Classification and selection of common PCB plate FR4
2021-12-07
FR-4
FR-4 sheet, one of the commonly used substrates, is a code number of a flame-resistant material, which means a material specification that the resin material must be able to extinguish themselves. FR-4 is not a material name, but a material level.
FR-4 is generally divided into:
FR-4 rigid plate, common plate thickness 0.8-3.2mm;
FR-4 thin plate, common plate thickness is less than 0.78 mm.
The general technical indicators of FR-4 sheets are: bending strength, peel strength, thermal impact performance, flame retardant performance, volume resistance coefficient, surface resistance, dielectric constant, dielectric loss angle, glass transition temperature Tg, dimensional stability Using temperature, warpage, etc.
Knowledge extension: PCB material classification
1, glass cloth substrate: FR-4, FR-5
The plate-shaped compressed article formed by the dedicated electronclock in the epoxy phenolic epoxy resin is passed through high temperature, high pressure, and hot press.
Epoxy glass fiber cloth (commonly known as: epoxide plate, glass fiberboard, fiberboard, FR4). The epoxy glass fiber non-substrate is a class of substrates for reinforcing materials with an epoxy resin.
Epoxy glass fiber coated copper plate strength, good heat resistance, good dielectric, substrate through holes can be metallized, realize circuit conduction between double-sided multilayer printed layer and interlayer, epoxy glass coated copper plate It is a class of the most useful use in all quality of copper.
2, paper substrate: FR-1, FR-2, FR-3, etc.
The phenolic paper substrate is a phenolic resin as an adhesive to reinforce material as a surface layer.
3, composite substrate: CEM-1 and CEM-3
Such substrates are mainly CEM series coated copper plates, of which CEM-1 (epoxy paper-based cores) and CEM-3 (epoxy glass nonwoven core) are two important varieties in CEM. The CEM series plate has good workability, flatness, dimensional stability, thickness accuracy, its mechanical strength, dielectric performance, metal mobility, etc., is higher than paper substrate, while mechanical strength (CEM-3) A 80% of FR-4, the price is lower than the FR-4 board.
