Quick-turn PCB assembly: what to confirm before you send a BOM

Quick-turn assembly is usually limited by parts and preparation, not by placement speed. Confirm these items before you commit to a date.

1. Are the parts actually available?

A BOM can look complete and still contain four lines on 12-week lead time. Ask for an availability check before the build date is agreed. If a critical part is short, decide early whether to accept an alternate, buy from a different package or delay the build.

2. Are the footprints correct for the parts you will use?

Alternates often come in a different package or pinout. A part that is electrically equivalent but mechanically different will not drop into the same footprint. Confirm the manufacturer part number and package before approving a substitute.

3. What is the moisture sensitivity level?

MSL 3 and above parts have a limited floor life after the bag is opened. If the build is delayed, they need baking before reflow. Tell us if you are supplying consigned parts that have been stored outside a dry cabinet.

4. Is the centroid complete?

Every placed part needs a centroid line with the correct side and rotation. Connectors, test points and fiducials are common omissions. A missing line becomes a manual placement or a missing part — both cost time.

5. What test coverage do you need?

AOI is standard. Add X-ray for BGA and hidden joints, ICT for production volumes and functional test for anything that must power up. Decide before the fixture or test procedure is built, not after the boards are assembled.

6. Do you need programming or serialisation?

If firmware must be loaded, send the image and version with the order. For serialised products, define the format and starting number before programming begins. Retrofitting serial numbers after assembly is possible but always slower.