After the PCB design work is completed, it needs to be put into production. Before putting the boards into production, the PCB designer must conduct self-inspection and correctly handle the problems found in the self-inspection. If there are problems that cannot be determined independently during the processing, they should contact Relevant personnel communicate and resolve.
Self-inspection: PCB design post-processing
After the PCB layout and routing is completed, the post-processing work that the designer needs to do includes the following aspects:
(1) DRC inspection: that is, design rule inspection. Through inspection methods such as Checklist and Report, the focus is on avoiding major design defects such as circuits and short circuits. During the inspection, the PCB design quality control process and methods are followed;
(2) DFM inspection: After the PCB design is completed, whether it is the processing of the bare PCB board or the patch assembly processing of the PCBA support board, it is necessary to use relevant inspection tool software or Checklist to check the processing-related design;
(3) ICT design: Some PCB boards will undergo ICT testing during mass processing and production, so such PCB boards need to add ICT test points during the design stage;
(4) Silk screen adjustment: Clear and accurate silk screen design can improve the convenience and accuracy of subsequent testing and assembly processing of circuit boards;
(5) Drill layer labeling: The information marked on the Drill layer is the processing requirement drawing provided to the PCB processing factory PE. It needs to follow industry standards and ensure the accuracy and completeness of the Drill processing information;
(6) PCB design file output: The final file of PCB design needs to be output into different types of packaged files according to specifications for subsequent testing, processing, and assembly;
(7) CAM350 inspection: The CAM files (also called Gerber files) that the PCB design outputs to the PCB processing factory need to use CAM350 software for design review before board delivery.
Other matters to be dealt with before listing
1. In-group QA review
After receiving the board submission process, the QA within the group first confirms that the designer has conducted sufficient self-inspection. If the process is not completed, it will return to the process and require the designer to submit the process again after completion.
Review and record review results, handling opinions, etc. If the review fails, the process will be returned to the designer.
The QA review opinions within the group must also be filled in the single board design review record database.
2. Inspection of short circuit and open circuit problems
1. There is a single point grounding; the plane layer is hollowed out; when modifying the processing of the pad flower pad and the hot pad, be careful and write the processing results into the ground source and ground division of the design file, which is conducive to self-inspection and QA review And the next board change.
2. When performing negative division on the electrical ground layer of P software, it must be carefully checked. The method for checking electrical ground layer negatives using P software is as follows: Set PLANE NETs assigned to the same layer to different colors.
Shows only all features of the layer to be inspected.
Check whether there is a network across partitions (different colors are in the same partition). If there is no network, it means the partition is successful.
If there is a cross-segmentation situation, you need to edit the PLANE THERMAL properties of the spanned pads and vias so that they do not produce flowerpots in this area, and then ensure their connectivity through wiring.
3. Where there are windows or slots, a forbidden area for wiring must be added to prevent the wiring from being dug out and causing an open circuit. structural elements
The prohibited areas defined in the figure must also meet the requirements.
4. The correct DRC must be set and all DRC checks must be turned on.
3. Complete the filling in process data and file submission as required, including board name, version number, quantity, number of layers, minimum line width/line spacing, etc.