How to copy FPC board and precautions

Stacking of solder pads:

1. The stacking of solder pads means the stacking of holes. During the drilling process, repeated drilling in one location can cause the drill bit to break, leading to damage to the holes.

2. InFPCIn multi-layer boards, when two holes are stacked, one hole should be used as an isolation disk and the other hole should be used as a connecting disk. Otherwise, after drawing the film, it will appear as an isolation disk and become scrapped.

                                             
Unreasonable character placement:

1. The SMD solder pads for character covers bring great inconvenience to the soldering of components and the on/off testing of printed boards.

2. Character designs that are too small make screen printing difficult, while designs that are too large can cause characters to stack on top of each other and become difficult to distinguish.

The spacing between the area grids is too small:

The edges between the grid lines that form a large area are too small (less than 0.3mm), which can easily cause many broken films to adhere to the board after the image transfer process in FPC printed board manufacturing, resulting in broken lines.

Draw solder pads with filler blocks:

When designing FPC circuits, drawing solder pads with filler blocks can undergo DRC reflection, but processing is not possible because such solder pads cannot directly generate solder mask data. When applying solder mask, the area of the filler block will be covered by the solder mask, making device soldering difficult.

Setting of single-sided pad aperture:

1. Single sided solder pads do not require drilling. If drilling is needed, it should be marked and the aperture should be designed to be zero. If numerical values are designed, perhaps when drilling data occurs, the coordinates of the hole will be presented at this location, and the problem will arise.

2. If drilling is required for single-sided solder pads, it should be specifically marked.

Abuse of graphic layer:

1. Making useless connections on some graphic layers, such as designing circuits with five or more layers on a four layer board, can lead to misinterpretation.

2. When designing, it is convenient to use the Protel software as an example to draw the lines on each layer using the Board layer, and then use the Board layer to mark the lines. This way, when performing light drawing data, if the Board layer is not selected, the missing lines may be broken, and there may be a short circuit due to the selection of the Board layer's marked lines. Therefore, the design insists on the integrity and clarity of the graphic layer.

3. Violating conventional design, such as designing the component surface at the bottom layer and the welding surface at the top, creates unnecessary trouble.

The electric layer is a combination of wiring and flower solder pads:

Due to the power supply designed as a flower pad method, the image on the printed circuit board is opposite to that on the ground layer, and all connections are isolation lines, which the designer should be very clear about. When drawing isolation lines for several sets of power supplies or several fields, attention should be paid not to leave gaps that cause short circuits between the two sets of power supplies, nor to block the area where the connection is made