PCBA
Printed Circuit Board Assembly
PCBA (Printed Circuit Board Assembly) is the process of populating a bare PCB with electronic components — resistors, capacitors, ICs, connectors, and other parts — to produce a functional electronic assembly ready for testing or integration into a finished product.
What it is
PCBA covers everything that happens after the bare PCB is fabricated: component procurement, kitting, paste printing, component placement, soldering, inspection, and any optional steps such as conformal coating, testing, or programming. The output is a populated board ready for use.
Two main technologies dominate. Surface mount technology (SMT) places components on the board surface using solder paste and reflow soldering — the dominant method for most modern components including 0402 resistors, BGAs, QFNs, and ICs. Through-hole technology (THT) inserts component leads through plated holes and solders them from the opposite side, typically using wave or selective soldering — used for connectors, large capacitors, and mechanically stressed parts.
Most boards today are mixed-technology assemblies with SMT on both sides and selected THT parts added in a separate pass. PCBA quality is judged against IPC-A-610, which defines acceptance criteria for solder joints, component placement, cleanliness, and damage.
When it matters
PCBA decisions affect cost, lead time, and product quality more than bare board fabrication does. Component sourcing alone often accounts for the largest share of cost and lead time risk — a single end-of-life or long-lead-time part can delay an entire build by weeks. Choosing turnkey assembly (where the EMS sources and assembles everything) versus consigned assembly (where the customer supplies components) trades convenience against control and unit cost. For prototypes and low-volume builds, turnkey is usually faster and lower-risk; for high-volume production with strategic component agreements, consigned can be cheaper.
At Nordic PCB
We offer PCBA as a turnkey service: bare board fabrication, component sourcing from authorised European distributors, assembly, inspection to IPC-A-610 (Class 2 by default, Class 3 on request), and shipment as a single order with one commercial counterparty. DFM review is included for both bare board and assembly, flagging issues such as incompatible footprints, missing fiducials, or panelisation problems before production starts.
Related terms
- SMT
SMT (Surface Mount Technology) is the dominant PCB assembly method where components are placed directly onto the surface of the board and soldered using reflow ovens. It enables smaller, denser, double-sided boards and supports nearly all modern component packages including BGAs, QFNs, and 0402 passives.
- THT
THT (Through-Hole Technology) is an assembly method where component leads are inserted through plated holes in the PCB and soldered from the opposite side, typically using wave or selective soldering. Used for connectors, large capacitors, transformers, and parts requiring mechanical strength or high current capacity.
- Turnkey assembly
Turnkey assembly is a full-service PCBA model where the supplier handles everything: bare board fabrication, component sourcing, assembly, inspection, and delivery. The customer supplies design files and receives finished, tested boards — a single commercial counterparty for the whole build.
- IPC-A-610
IPC-A-610 is the most widely used acceptance standard for assembled PCBs, defining visual criteria for solder joints, component placement, cleanliness, and damage across three class levels. The current revision is IPC-A-610J (March 2024). It is the companion standard to IPC-A-600 for bare boards.
- BOM
A BOM (Bill of Materials) is the structured list of every component needed to build a PCB, mapping reference designators on the board to specific manufacturer parts. It is one of the three core files — alongside Gerber and pick and place — required to quote and assemble a PCBA.