The circuit board industry has windows in many manufacturing processes. It is a professional term for this industry, mainly referring to solder mask opening: using film to open the window, the PAD that needs to be soldered or dissipated is exposed to the green Outside the oil layer, in order to meet the needs of customers, the following editor will explain in detail what is the reason for opening and opening the circuit board.
Introduction to windowing of solder mask on circuit board
The solder mask of the circuit board is the soldermask, which refers to the part to be painted on the printed circuit board. In fact, this solder mask layer uses negative output, so after the shape of the solder mask layer is mapped to the board, it is not the green solder mask, but the copper skin is exposed. The gold finger position in the above picture is obvious. window.
The solder mask window refers to the size of the part where the copper is exposed at the position that needs to be soldered, that is, the size of the part that is not covered with ink, and the cover line refers to the size and how much of the circuit part covered by the solder mask. If the distance of the cover line is too small, the line will be exposed during the production process.
The reason why the solder mask of the circuit board opens
1. Opening window with aperture: Because many customers do not need ink plug hole, if window is not opened, ink will enter the hole. (This is for small holes) If the large hole is filled with ink, the customer cannot press the key. In addition, if it is a gold plate, the window must also be opened.
2. PAD (that is copper) window opening: customers need welding, surface treatment (gold/tin spray, etc.).