Lower PCB assembly cost

There are many factors that impact the price of your PCB assemblies. Being aware of and implementing some of the tips below can help you lower your circuit board assembly cost.

Design for PCB assembly to lower cost

So, let’s get started.

1. For double-sided printed circuit assembly designs, keep the SMT, heavy and sensitive components on one side – (it is best to try and keep all components on the primary side)

2. Avoid components placements that are not 0 or 90 degrees – some SMT pick & place machines cannot handle arbitrary angles.

3. Allow at least 100mil spacing between components and the edge of the printed circuit board. There needs to be enough spacing to allow for the individuation of the circuit assemblies.

4. To the extent possible, space component evenly on the board to allow better thermal distribution in the reflow soldering oven.

5. Include parts with visible leads in your design and avoid using BGAs and QFNs if possible because these devices are x-rayed to ensure proper assembly, resulting in a higher PCB assembly cost.

PCB assembly BGA X-ray
6. Avoid placing smaller SMT parts next to large or tall parts to make soldering of the oversized components easier and less time consuming.

Design for PCB assembly

7. Keep the orientation of similar components in the same direction. This makes it easier for your PCB assembly house to install and inspect the parts.

8. If you are supplying parts to your PCB assembly manufacturer, try to provide components on reels or continuous strips. This reduces machine set-up time.

9. Minimize the use of through-hole parts because they require PCBs with drilled holes and the components are usually hand soldered. So, you pay more for PCB fabrication and assembly. Surface mount devices are assembled using machines and do not require drilled holes in the PCB.

10. Panelize your boards – it is easier and less time consuming for the PCB assembly company to work with large board/panels.

11. Use fiducial markers for orientation to make it easier to locate and place parts on the PCB accurately

PCB fiducials for PCB assembly
For very fine pitch components consider using local fiducials

12. Ensure your PCBs have proper reference designator markings

PCB reference designator marking

13. Use industry-standard sizes for PCBs and electronic components

14. Include alternative/substitute parts on your BOM so you can take advantage of potential lower component pricing

15. Make it easier to test your circuit assemblies by taking note of the following:

  • Test pads that can be probed should all be on one side of the board
  • Place test points around the perimeter of BGAs
  • Keep test point size to 30mils or larger
  • Test-point centers must be .125” from the edge of the PCB
  • Include a sufficient number of ground test points – generally 10% of connected nodes. The ground test points should be distributed evenly across the board.
  • There should be at least two power net test points when the current on a net is less than 1Amp. Add two test pads for every additional 1Amp current requirement for the board.