7 items of self-inspection before the PCB design engineer puts the board in!

2024-02-21

After the PCB design work is completed, it is necessary to put the board into production, and before the board, the PCB designer must carry out self-inspection, and the problems detected by the self-detection should be correctly handled, and the problems that cannot be determined separately should be communicated with the relevant personnel to solve them in the processing process.

Self-test: post-processing of PCB design

After the PCB layout is completed, the post-processing work that designers need to do includes the following aspects:

(1) DRC inspection:

that is, design rule inspection, through checklist and report and other inspection methods, focus on avoiding major design defects such as open circuit and short circuit, and follow the PCB design quality control process and method while inspecting;

(2) DFM inspection:

After the PCB design is completed, whether it is the processing of the PCB bare board or the patch assembly processing of the PCBA support board, it is necessary to check the processing-related design with the help of relevant inspection tool software or Checklist;

(3) ICT design:

Some PCB boards will be tested for ICT in mass production, so ICT test points need to be added in the design stage of such PCB boards;

(4) Silk screen adjustment:

clear and accurate screen printing design can improve the convenience and accuracy of subsequent testing and assembly of circuit boards;

(5) Drill layer annotation:

The information of Drill layer annotation is the processing requirement drawings provided to the PE of the PCB processing factory, which needs to follow the industry norms 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 as different types of packaging files according to the specifications for subsequent testing, processing and assembly;

(7) CAM350 inspection:

The CAM file (also called Gerber file) output of the PCB design to the PCB processing factory needs to use CAM350 software for the design review before the board is submitted.

Other matters that need to be dealt with before pitching

One, QA review within the group

After receiving the board submission process, the QA in the group first confirms that the designer has carried out sufficient self-check, and returns to the process if the processing is not completed, and requires the designer to submit the process again after completion.

Review and record the results of the examination, handling opinions, etc. When the review fails, the process is returned to the designer.

The QA review comments in the group should also be filled in the board design review record database.

Two, Check for short circuit and open circuit

1. There is a single point grounding, the plane layer is hollowed out, and when modifying the treatment of the hot pad of the pad flower pad, it is necessary to be cautious, and write the processing results into the source division of the design file, which is conducive to self-inspection and QA review and the next board modification.

2. When the electric stratum of P software is negatively divided, it must be carefully checked. The method of checking the negative of the electric formation with P software is as follows: set the PLANE NET assigned to the same layer to a different color.

Displays only all the features of the layer you want to inspect.

Check whether there is a network across partitions (different colors are in the same partition), if not, the segmentation is successful.

If a span splits occur, you need to edit the PLANE THERMAL properties of the pads and vias in the span so that they do not create faceplates in the area, and then ensure their connectivity through routing.

3. Where there is a window or slot, the wire must be added to the forbidden area to prevent the line from being cut off and causing a broken circuit. Structural features

The no-go zone defined in the diagram also needs to meet the requirements.

4. The correct DRC must be set and all DRC checks must be turned on.