Most electronics engineers encounter more or less problems when PCB circuit board prototyping design. Here I have sorted out the 10th difficult points of PCB circuit board prototyping design for everyone.
1.PCB prototyping processing level definition is unclear.
The single circuit board design at the top layer. If you do not specify the top and bottom, maybe you made the circuit board , and it is not easy to solder after mounting the electronic components.
2.The Large area copper foil frame distance is too close in PCB Prototyping
The large-area copper foil frame should be guaranteed at least 0.2mm pitch. When milling the copper foil, it is easy to cause the copper foil to rise and cause the solder resist to fall off.
3.Draw pads with filled block in PCB prototyping
Drawing pads with filled block can pass DRC inspection when designing the circuit, but it is not possible for processing. Because this type of pad cannot directly generate solder mask data. When the solder resist is applied, the pad area will be covered by the solder mask causing the electronic components soldering difficulties.
4.PCB prototyping ground layer is flower pads and wiring
Because it is designed as a flower pad power supply, the ground layer is the opposite of the image on the actual printed circuit board. All connections are isolated lines. when drawing several sets of power supplies or several types of ground isolation lines should be careful. No gap must be left to short-circuit the two sets of power supplies, nor should the connection area be blocked.
5.PCB prototyping characters are scattered
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 and difficult to distinguish.
6.PCB prototyping surface mount electronic components pad is too short
For the continuity test, the dense surface mount component has a relatively small distance between the two feet and the pads are quite thin. The test pins must be staggered up and down.If the pad design is too short, although it does not affect the device installation, it will cause the test pin to stagger.
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 drilling is designed, when the drilling data is generated, the hole coordinates appear at this position.When problems occur, single-sided pads such as drill holes should be specially marked.
8.PCB prototyping pads overlap
When PCB prototyping and drilling process, the drill will be broken 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.Too many pads in the PCB prototyping design
The light drawing data is lost, and the light drawing data is incomplete. Because the filling blocks are drawn with lines one by one when processing light drawing data, So the amount of light drawing data generated is quite large, which increases the difficulty of data processing.
10.Graphics layer abused
Made some useless wiring on some graphics layers, but originally it was a four-layer board but designed more than five layers of circuits, which caused misunderstanding. The graphics layer should be kept complete and clear when designing.