It’s happened more times than we’d like to admit: you submit a Request For Quote with a handful of contract manufacturers. You’re working on a project with a tight budget and an even tighter deadline. You’ve communicated a due date for all quotes, yet the constant questions from the CM’s are putting that deadline in jeopardy. What gives?

Two words: Your Documentation. If you want the PCBA process to be executed efficiently and produce a high-quality product, your documentation package needs to be just as efficient and high-quality. Proper documentation not only allows CM’s to accurately quote pricing for your assembly, but it will also be manufactured to your exact specifications. So, what goes into a standard documentation package? At the very minimum, your package should contain the following:

Bill of Materials– an Excel spreadsheet is most common and desired, though other forms are acceptable as long as they contain complete information. A BOM should list each component that will be used in the assembly, along with the manufacturer, manufacturer part number, and the quantity of each. List acceptable alternate components and manufacturers to ensure flexibility and check for obsolescence and any EOL (end of life) components.

Assembly Drawing– an assembly drawing provides a basic dimensional view of your PCB. It shows components on the PCB while calling out any special instructions for hardware, RTV, conformal coating, build standards and specifications.

PCB Fabrication Drawing– includes essential information for the PCB fabrication, including dimensions and tolerances for the PCB and holes, material requirements such as type, thickness, and copper weight, plating and finish requirements. Be sure to include fab standards or specifications, solder mask requirements, silkscreen requirements, and any agency requirements.

Gerber and Drill files– these are also necessary for board fabrication. Drill files indicate the location, size, and plating status of all drilled holes in the board while the Gerber files provide layer-by-layer copper information.

Electrical Schematic– necessary if the assembly is to be tested, but also otherwise helpful, as it provides information about component polarities.

Other helpful information to ensure a smooth manufacturing process? Logistics. Define your packing and delivery terms ahead of time. Contact information. Provide a point of contact (or contacts) that will own this assembly and respond quickly to any vendor/CM questions. An old boss of mine used to preach the 5 P’s: proper preparation prevents poor performance. If you take the time to have your documentation reviewed (sometimes by multiple people), you’ll ensure the correct materials are purchased and the assembly is manufactured to the correct Rev. While CM’s have quality measures and processes in place already, they are relying on your help.

Misquoting an assembly isn’t okay. Missing a deadline isn’t okay. Going over budget isn’t okay. But with the right documentation, we can work together and avoid those headaches all while ensuring a great customer experience!