PCBA (Printed Circuit Board Assembly) assembly service is the complete industrial solution that turns a bare PCB into a fully functional circuit board by purchasing all the specified electronic components, mounting them onto the board (using SMT, THT or both), soldering, and then testing the finished assembly.

In practice, a PCBA service provider will:

• Review your Bill-of-Materials (BOM) and Gerber files
• Source or accept consigned components
• Fabricate solder-paste stencils and any necessary jigs
• Print solder paste, place components, reflow-solder (SMT) and/or wave-/hand-solder (THT)
• Carry out in-line inspections (SPI, AOI, X-ray) plus electrical tests (ICT, flying-probe, functional test)
• Clean, conformal-coat, program, final-assemble and pack the boards

The service is usually offered in two forms:

• Turn-key - the supplier buys all parts and handles everything
• Consigned / partial - you supply some or all components, the supplier assembles

It covers prototype, low-volume and high-volume production, with options like design-for-manufacturing (DFM) reviews, supply-chain management, fast turnaround and after-sales support.