All PCB orders need to go through the engineering department before being scheduled for production. Now let's explore what the engineering department does to ensure the smooth production.
After customers upload the Gerber files, the engineering department will first pre-review them. The contents reviewed generally include: whether the design files are complete, whether the production information is clear, whether the circuit design is reasonable (whether there exists short-circuit or breakage problems), whether there is any requirement beyond our capability and other issues. When making sure there is no problem of the files, engineers start to prepare instructional materials and processing program needed for production.
Each PCB order is prepared with a complete MI, namely Manufacturing Instruction, which contains detailed requirements for each process, from board cutting to packaging and warehousing. After production engineers read the Gerber files in detail, they send an EQ to the customer if there is any doubtful point. For example, if the laminate structure provided by the customer is asymmetric, which may lead to board warp and affect the assembly quality, then they will suggest the client to modify it into a symmetrical one. When all the design requirements meet the factory's process capability, a detailed instruction document will be forwarded to the relevant production department.
In addition to the MI, a production drawing and process card also assist PCB production together. The production drawing is a special instruction for the important contents of the design files, including external dimensions, drilling requirements, circuits, soldermask, silkscreen, etc. Process cards are mainly used to track the warehousing, receipt, quantity and acceptance of each prouduction process to ensure that each step is in order and can be accurately traced in case of problems.
The information in the Gerber files can’t be directly input to the corresponding machines for various processing. CAM is then used to make additional modifications to the file in order to achieve the best production method, such as choosing the type of penalization, but only if it does not affect the electrical performance to be achieved in the user's design. At the same time, the film data, drilling, routing data, tooling data should also need to be prepared.
When all the needed data is prepared and sent to the corresponding process or department, PCB production will start very soon.
