1. FR4 — The PCB Base Material
FR4 is a grade of glass-reinforced epoxy laminate, and it’s the most common material used for PCB substrates.
Key features of FR4:
"FR" = Flame Retardant (meets UL94-V0 standard)
Strong mechanical strength
Excellent electrical insulation
Good moisture resistance
Affordable and widely available
Structure:
It consists of woven fiberglass cloth (for strength) and epoxy resin (for insulation).
2. PCBA — Printed Circuit Board Assembly
PCBA refers to a fully assembled PCB, meaning all the electronic components (like resistors, capacitors, ICs, connectors, etc.) have been soldered onto the board.
There are typically two processes:
SMT (Surface Mount Technology) — for small surface-mount parts
THT (Through-Hole Technology) — for components with leads going through the board
3. Putting It Together: FR4 PCBA
So, an FR4 PCBA is:
A circuit board assembly that uses an FR4 material PCB as its base.
This is the most common type of PCBA used in:
Consumer electronics (phones, TVs, computers)
Industrial controllers
Automotive electronics
LED lighting
Communication equipment
4. Advantages of FR4 PCBA
Cost-effective for mass production
Stable mechanical and dielectric performance
Supports multilayer PCB designs
Compatible with both leaded and lead-free soldering
Suitable for a wide range of applications (0–130°C typical range)
