One of the reasons I like being a field application engineer for NCAB Group is to be able to interact with all kinds of customers. They have different ideas, but they all want to create cool products. I have noticed that customers have gradually realized that PCB is a key component of products, but they still have difficulty coping with the challenges of production requirements when communicating with PCB suppliers. When receiving a Gerber file for an order, we sometimes have a headache, because the file does not contain the necessary information to ensure zero defects in PCB production. We hope that customers consider the following key factors before sending the design file.
First of all, I hope that customers can update the document to match the Gerber data. When PCB designers complete the routing of the last trace, they will be very excited and send the board files directly, so that they ignore the last modification. We call these last changes the manufacturing instructions notes, and they are often ignored. Have you checked that the version has been updated? Has the part number been included to help distinguish it? If there is a general comment for each circuit board, does the general comment apply to this circuit board? Don’t we want to be as precise as possible when designing such a complex product? All these factors affect the overall quality of the circuit board.
Manufacturing instructions notes are also important for details, such as drill floor, circuit board stackup and dimensions. If these details do not match or are inconsistent with the Gerber file, the factory must resolve it before production can begin. This may waste hours or even days, and a simple update can completely avoid this problem. If there is a drilling table (other than the NC drilling file), be sure to update this table to match the Gerber data. The design software will update the drilling table by clicking a button. This small action will reduce confusion and additional problems. If the board stack file is embedded in the Gerber file, it should also be updated. Another advantage of this is that when exporting Gerber files to PDF files, you can easily refer to the manufacturing instructions to understand the number of layers and holes in the design.
Secondly, consider the materials required to manufacture a specific PCB. Although most of them use FR-4 material by default, they will also encounter circuit boards with specified material requirements. It is helpful to understand the customer’s application, but the disadvantage is that when these materials are not common, it will lead to a longer delivery time or the factory rejects the order. This situation is more common for companies with years of experience in designing and/or manufacturing PCBs, but it can also happen to engineers who are designing high-speed and high-frequency PCBs for the first time.
Remember, PCB manufacturing is mainly a chemical process. There are many steps that require proper chemical potion balance, and new laminate materials will create uncertainty. If possible, indicate whether equivalence is acceptable. I also recommend specifying materials in accordance with the IPC specification (ie IPC 4101-126). If the factory recommends another material and they are experienced in producing such materials, they can be asked to perform circuit board stacking or impedance calculations to ensure that both the designer and the factory are satisfied with the proposed changes.
Finally, consider updating the design rules. These design rules ensure the size of features such as component pads, vias, and traces, which helps the spacing between different features on the entire PCB. We are always asked to make features smaller and closer, but if we do not cooperate with the right factory, we may be in a difficult situation. Inquire about the factory’s design rules in order to design a PCB that is easy to manufacture. At the same time, the factory will also clarify whether it can adopt those technical specifications under normal conditions.
Producing zero-defect, high-quality PCBs on time requires teamwork. Although there are standard technical specifications, there are almost always exceptions. A sophisticated PCB is like a work of art. Each circuit board is unique and has different rules. In order to produce PCBs with the best quality on time at the lowest total cost, the above requirements should be completed in the normal design routine, and then the circuit board design files should be sent to the circuit board manufacturer to save the PCB manufacturer’s clarification information And the time wasted in answering the questions raised.