Name: FR4 PCB
Brand: PCB Printed Circuit Board and PCBA manufacturing
Availability: InStock
Rating: 5 (1 reviews)

Description
Data Sheet

FR4 is a standardized flame-retardant material grade, rather than an independent material name. It specifies a resin system with mandatory self-extinguishing performance, meaning the resin stops burning automatically once the external flame is removed.

Commercially mainstream FR4-grade PCB substrates are composite materials formulated with tetrafunctional epoxy resin, functional fillers and woven glass fiber. In the PCB industry, glass fiber-reinforced epoxy copper-clad laminates are collectively named FR4 PCB by convention. FR4 is a full glass-fiber substrate, widely adopted for mass production of double-sided and multilayer printed circuit boards.

FR4 Material Grade Classification

FR‑4 Class A1

The highest-performance grade, applied in military equipment, communication devices, computers, digital circuits, industrial instruments and automotive electronics. It meets global high-standard specifications with outstanding stability and comprehensive electrical performance.

FR‑4 Class A2

Suitable for common computers, precision instruments, high-end home appliances and general industrial electronic products. It balances stable performance and cost, delivering excellent cost competitiveness for mainstream commercial applications.

FR‑4 Class A3

Custom-developed for household appliances, computer peripherals, toys, calculators and consumer electronic devices. It meets basic application requirements with ultra-cost-effective pricing.

FR‑4 Class A4

Entry-level FR4 material for low-end home appliances and daily electronic products. It satisfies conventional electrical demands with the most competitive market price.

FR‑4 Class B

Economy low-grade FR4 material with relatively weak stability. It is not recommended for large-size PCB designs and is limited to small-size boards (100mm×200mm or below). It is the lowest-cost option and requires careful application screening.

FR4 PCB Functional Classification

Based on structural and functional differences, FR4 printed circuit boards are divided into single-sided, double-sided, multilayer, and impedance-controlled PCB. As a common insulating substrate, glass fiber forms the core structure of mainstream civilian and industrial circuit boards.

Glass fiber features high structural strength and stable insulation, and can be tightly compounded with epoxy resin. The typical layered white fracture and delamination of broken FR4 boards is a distinct feature of resin and glass fiber composite materials.

Core Characteristics of FR4 PCB

Structure: Consists of insulating FR4 substrate and etched copper circuit layers.
Core Function: Serves as a rigid structural skeleton and conductive interconnection carrier to realize complete circuit connection for electronic components.
Layer Composition: Available in single-layer, double-layer, 4-layer, 8-layer, 12-layer, 16-layer up to 24-layer stacked structures.
Surface Structure: Conductive copper foil forms circuit traces on the insulated FR4 core; solder mask ink covers the surface for anti-oxidation and insulation, with reserved pads for pin or SMT welding and surface finishing such as tin plating.

FR4 PCB Material

Substrate Material Comparison

In addition to rigid FR4 boards, flexible PCBs adopt high-temperature-resistant polyimide substrates. Low-cost low-end circuit boards use ordinary epoxy or phenolic resin materials, with poor durability, low thermal decomposition temperature, and unpleasant odor during welding, only applicable to low-grade consumer goods.

Conventional FR4 laminates exhibit significant attenuation of high-frequency harmonics and high-frequency sinusoidal signals. Digital signals are synthesized by multi-frequency sine waves; excessive signal attenuation causes waveform edge degradation and amplitude loss, limiting transmission bandwidth. High-speed specialized PCB materials effectively reduce high-frequency loss to ensure larger signal margin and longer routing design allowance under the same loss requirements.

FR4 Multilayer PCB

High-end electronic products widely adopt FR4 multilayer PCB to adapt to compact space design. Multiple single-sided and double-sided circuit layers are superimposed, positioned and pressed as a whole through precision optical lamination processes.

Multilayer PCB realizes reliable inter-layer electrical conduction via pre-drilled plated through holes. The inner two layers adopt traditional double-sided board technology, while outer layers use independent single-sided substrates. After lamination, the integrated multi-layer structure supports high-density wiring and complex circuit design, including rigid multilayer, flexible multilayer and rigid-flex combined boards.

Maxipcb FR4 Manufacturing Strength

FR4 is the most widely used conventional substrate in the electronics industry. Maxipcb has rich experience and mature process technology in FR4 PCB mass production, covering diversified specifications of single-sided, double-sided and multilayer boards, with stable quality, controllable cost and reliable delivery.

Model: FR4 PCB Circuit Board

Material: FR-4

Layer: 2 Layer FR4 PCB

Color: Green/Black/Blue/White

Finished Thickness: 1.20mm

Copper Thickness: 1/1 OZ

Surface Treatment: Immersion Gold/HASL

Min Trace: 4mil, 0.1mm

Min Space: 4mil, 0.1mm

Application: Wifi module, Electrical apparatus

FR4 PCB

Description

Data Sheet