The production and processing of FR4 PCBs must adhere to a series of stringent standards and specifications. These standards cover multiple aspects, including board thickness, copper foil thickness, electrical performance, and mechanical performance, to ensure that the produced PCBs meet quality requirements and can satisfy the needs of various electronic devices. Simultaneously, with the continuous development of electronic technology, the performance requirements for FR4 PCBs are constantly increasing, driving the continuous updating and improvement of industry standards.
Basic Substrate Standards: IPC-4101 is the core international standard for FR4 copper clad laminates. It classifies FR4 according to performance into Type 1 general-purpose and Type 2 and above reinforced types, clearly specifying hard indicators such as board thickness tolerance, copper foil specifications, and thermal stability, replacing earlier, fragmented industry requirements.
Grading Standards: The domestic industry classifies FR4 copper clad laminates into grades A1 to A4 and grade B, from high to low performance. Grade A1 is geared towards high-reliability applications such as military and automotive electronics, while grade B is only suitable for small-sized ordinary household appliances. Different grades correspond to specific thresholds for mechanical strength, temperature resistance, and insulation performance.
General Performance Specifications
Complies with UL94 V-0 flame retardant requirements; standard FR4 has a glass transition temperature (Tg) ≥ 130℃, a dielectric constant of 4.2~4.8 at 1GHz, and a water absorption rate ≤ 0.10%. It must also meet EU RoHS 2.0 halogen-free environmental requirements.
Processing Acceptance Standards
IPC-A-600 is the general acceptance standard for FR4 PCB finished products. It provides clear acceptance criteria for dimensions such as dielectric layer thickness, copper foil thickness, metallized hole quality, and appearance defects, serving as a common acceptance basis for both PCB manufacturers and customers.