Ten defects in PCB board design process

- Mar 06, 2017-

First, the definition of processing level is not clear

Single panel design in the TOP layer, such as not to make a positive and negative to do, perhaps out of the board installed on the device and not good welding.

Two, a large area of copper from the frame too close

A large area of copper from the frame should at least ensure that more than 0.2mm spacing, because in the milling form such as milling to copper foil copper foil is easy to cause the warped and solder resist caused by the falling off problem.

Three, with the filler block painting pad

Filling blocks for painting pad in the design of the line can be checked by DRC, but for processing is not so kind of pad solder can not directly generate data, the solder resist, the block will be a solder resist coverage, resulting in difficult welding device.

Four, the electric layer is the flower pad is connected

Because the design of flower pad mode power supply, and the actual formation on the printed circuit board image is on the contrary, all attachment is the line of separation, should be careful to draw a few sets of power or several kinds of isolation line, can not leave the gap, so that the two groups of power circuit, also can cause the connection of regional blockade.

Five, your character

The character of the cover pad SMD welding piece, to the printed circuit board break test and component welding inconvenience. Character design is too small, resulting in screen printing difficult, too much overlap between the general characters, it is difficult to distinguish.

Six, surface mount device pad is too short

This is the on-off test, for the too dense surface mount devices, the spacing between the feet is quite small, the pad is quite fine, install the test pins, must be staggered up and down position, such as the pad design is too short, although does not affect the device installation, but will make the test without a wrong needle.

Seven, the single side of the aperture plate settings

One side welding pads are not generally drilled, if the hole to be marked, the aperture should be designed to zero. If a numerical value is designed, the position of the hole appears as a result of the drill hole data. Single side pads such as holes should be marked.

Eight, pad overlap

In the drilling process, the drill hole will be broken because of a plurality of drilling holes. The two holes in the multilayer plate overlap, and the negative plate is shown as an isolating plate after being drawn off.

Nine, the design of the filling block is too large or filled with very thin filling

There is a phenomenon of loss of light drawing data. As a result of filling blocks in the light of the data processing is to use a line to draw a picture, so the amount of data generated by a large amount of light painting, increasing the difficulty of data processing.

Ten, graphic layer abuse

In a number of graphics layer on the line to do some useless, it was originally designed four layers of more than five lines, so that misunderstanding. Violation of conventional design. Design should keep the graphics layer complete and clear.

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