Double sided connection without covering layer
This type of connection disk interface can be connected on both the front and back of the wire. To achieve this, a passage hole is opened on the insulating substrate at the solder pad, which can be made by punching, etching, or other mechanical methods at the desired position of the insulating substrate. It is used for double-sided installation of components, devices, and occasions that require soldering. There is no insulating substrate in the solder pad area at the path, and this type of solder pad area is commonly removed by chemical methods.
Double sided connection with covering layer
This type differs from the previous type in that it has a surface covering layer. However, the covering layer has access holes that allow both sides to be terminated while still maintaining the covering layer. This type of soft PCB is made of two layers of insulation material and one layer of metal conductor. Used in situations where the covering layer needs to be insulated from surrounding devices, and also needs to be insulated from each other, with both sides connected at the end.
