Ten Difficulties of PCB Circuit Board Proof Design
1. PCB proofing process level is not clear
The single-panel design is in the TOP layer. If you do not specify the pros and cons, you may make a board and install the device instead of soldering.
2.PCB proofing large area copper foil is too close to the outer frame
The large-area copper foil should be at least 0.2mm away from the outer frame. When milling the copper foil, it is easy to cause the copper foil to rise and cause the solder resist to fall off.
3.Pad pads for PCB proofing
Drawing pads with pads can pass DRC inspection when designing the circuit, but it is not possible for processing. Therefore, solder pads cannot directly generate solder mask data. When the solder mask is applied, the pad block area will be covered by the solder resist, causing the device Difficult to weld.
4.PCB proofing electrical ground is flower pad and connection
Because it is designed as a flower pad power supply, the ground layer is the opposite of the image on the actual printed board. All connections are isolated lines. Care should be taken when drawing several sets of power supplies or several ground isolation lines. A short circuit in the power supply should not cause the connection area to be blocked.
5.PCB proofing characters are randomly placed
The SMD solder pads of the character cover pads bring inconvenience to the on-off test and component welding of printed boards. Character design is too small, making screen printing difficult, and too large will make characters overlap each other, making it difficult to distinguish.
6. PCB proofing surface mount device pad is too short
This is for the continuity test. For too dense surface-mount devices, the distance between the two feet is quite small, and the pads are quite thin. The test pins must be staggered up and down. Affects the device installation, but will make the test pin staggered.
7. Single-sided pad aperture setting
Single-sided pads are generally not drilled. If drilling is required, the hole diameter should be designed to be zero. If the value is designed, when the drilling data is generated, the hole coordinates appear at this position, and a problem occurs. Single-sided pads, such as drilled holes, should be specially marked.
8.PCB proofing pads overlap
Drilling in the PCB proofing process will cause the drill to break due to multiple drilling in one place, resulting in hole damage. The two holes in the multilayer board overlapped, and after drawing the negative, it appeared as an isolation disk, which caused scrap.
9. There are too many pads in the PCB proofing design or the pads are filled with very thin lines
The light drawing data is lost, and the light drawing data is incomplete. Because the filled blocks are drawn with lines one by one when processing light drawing data, the amount of light drawing data generated is quite large, which increases the difficulty of data processing.
10. Graphics layer abuse
I made some useless wiring on some graphics layers, but it was originally a four-layer board but designed more than five layers of circuits, which caused misunderstanding. Violates conventional design. Design should keep the graphics layer complete and clear.