Design tips and key points for efficient automatic routing of PCB

- Sep 01, 2018-

Overlap of welding pads

1. The overlapping of the welding pads (except the surface mounted on the welding pad) means the overlapping of the holes. In the drilling process, the drill bit will be broken due to multiple drilling in one place, resulting in the hole damage. 

2. Two holes are overlapped in the multi-layer plate. For example, one hole position is the isolation plate and the other hole position is the connection plate (flower weld plate).

2. Abuse of graphics layer

1. Some useless wires have been made on some graphics layers, but the wires with five layers or more have been designed on the original four-layer board, thus causing misunderstanding. 

2. It is convenient to use Protel software as an example to draw the lines of all layers with the Board layer and mark the lines with the Board layer. In this way, when performing the optical drawing data, the lines will be broken because the Board layer is not selected, or the line will be missed, or the line of the Board layer will be short-circuited. 

3. Break the routine design, such as component surface design in Bottom layer and welding surface design in Top, causing inconvenience. 

The scrambling of characters

1. The SMD welding plate of character cover welding pad brings inconvenience to the on-off test of the printing plate and the welding of components. 

2. The character design is too small, which makes the screen printing difficult. 

Setting the aperture of one side welding disc

1. The single-side welding pad is generally not drilled. If the hole needs to be marked, the hole diameter shall be designed to be zero.If the values are designed, the coordinates of the hole will appear at this position when the borehole data is generated, and problems will arise. 

2. Single side welding plate shall be specially marked if drilling. 

5. Draw the pad with the filling block

The filling block is designed to pass DRC inspection in circuit design, but it is not suitable for processing. Therefore, the type of welding pad cannot directly generate resistance welding data. When soldering flux is on, the filling block area will be covered by resistance soldering agent, resulting in the device welding difficulty. 

6. The electric layer is also a welding pad and a connecting line

Because of the power source designed in the form of a splay pad, the layer is the opposite of the actual image on the board, and all the wires are insulated, as the designer should be very clear.By the way, you should be careful when drawing a few power lines or several types of isolation lines, not to leave a gap, short circuit the two power lines, or block the area where the connection is made. 

The definition of processing level is not clear

1. The single panel is designed on the TOP layer. If it is not done with positive and negative instructions, the prepared board may be installed with the device and cannot be welded. 

2. For example, a four-layer board is designed with four layers: TOP mid1 and mid2 bottom, but it is not placed in such order during processing, which requires explanation. 

8. Too many filling blocks in the design or filling blocks are filled with extremely thin lines

1. The light painting data is missing, and the light painting data is incomplete. 

2. As the filling blocks are drawn one by one with lines in the light painting data processing, the amount of light painting data generated is quite large, which increases the difficulty of data processing.