What is PCB Assembly?

PCB assembly is an important element when it comes to making an electronic device work. For example, for your computer or telephone to work, integrating electronic chips onto a PCB (printed circuit board) is essential.

The definition of a printed circuit board (PCB) is a material that mechanically supports and electrically connects electronic components or electrical components using conductive tracks, pads and other features etched from one or more sheet layers of copper laminated onto and/or between sheet layers of a non-conductive substrate. Components are generally soldered onto the PCB to both electrically connect and mechanically fasten them to it.

PCBs can be single-sided (one copper layer), double-sided (two copper layers on both sides of one substrate layer), or multi-layer (outer and inner layers of copper, alternating with layers of substrate). Multi-layer PCBs allow for much higher component density, because circuit traces on the inner layers would otherwise take up surface space between components. The rise in popularity of multilayer PCBs with more than two, and especially with more than four, copper planes was concurrent with the adoption of surface mount technology.

So the process of PCB assembly can range from straight forward to very complex depending on how the PCB is designed and the type of application it is used in. So lets talk about the actual process of assembling a PCB below.

The PCB Assembly Process

1. Solder Paste Printing

Using a stencil, solder paste is printed onto the PCB. It binds the devices materials to the PCB.

2. SMT Pick & Place Assembly

All individual chips are accurately placed on their designated location on the PCB.

3. Reflow/Through-hole curing

After placing the chips onto the solder paste, the boards go through a conveyor oven to melt the solder and bind the chips to the PCB.

4. Conformal Coating

Some boards require a protective lacquer coating. Conformal “Selective Coating” machines quickly and accurately provide a layer of protective coating on the PCBs.

5. AOI and AXI

AOI (Automatic Optical Inspection) and AXI (Automated X-ray Inspection). These processes are key to confirming that no mistakes have been made during the assembly process

6. Reworking if needed

If any mistakes or defects are found, some devices can be reworked. Reworking consists of heating the board or device, and removing it from the PCB so that a replacement can be placed in its stead.

Where To Buy?

For a full value and high performance PCB mount transformer, look no further than Express Transformers and Controls Ltd. We are a trustworthy transformer manufacturer that offers you quality products with support at the price you can afford. Reap the benefits of quality transformers from us today!


Furthermore, you can check out examples of our work by visiting our gallery.

Please feel free to contact us to discuss your design requirements. Our lead engineer details are listed below and they are very happy to discuss your particular project needs with you.