Plate thickness: 0.8, 1.0, 1.2, 1.6, 2.0 are commonly used specifications. If there is no special requirement, choose 1.6 mm plate thickness.

Copper foil thickness: 0.5, 1.0, 2.0 is a common specification, if the power is not particularly large plate can not be selected, manufacturers will generally use 0.5 oz board to do, if the power of about 100 W power board will be used to more than 1.0.
Weld resistance color: green, black, red, white are commonly used, there is no requirement to use green, if it is used in their own experiments, it should use green, because the color of the board circuit can be seen most clearly.
Solder pad treatment: rosin, anti-oxidation, tin spraying (divided into lead and lead-free two), generally using the latter two can be, tin spraying will last longer.
Silk screen printing color: white, black is the commonly used color, if it is green, then generally choose white words, this is mainly to see clearly, the color contrast of the choosing heel plate is large, if it is white solder resistance, it is necessary to choose black words.
Plate selection: HB, 94V-0, FR-4 are commonly used, HB is rarely used, it is not fire-resistant board, generally single panel is 94V-0, double panel is FR-4.
PCB proofing
I. Short Circuit Caused by Tin Running
1. The improper operation in the defilm dispenser can cause tin running.
2. The demembered plates are superimposed to cause tin runs.
Improvement methods:
(1) The concentration of the film-removing agent is high, the film-removing time is long, the anti-plating film has fallen off, but the board is still immersed in strong alkali solution, some tin powder is attached to the surface of copper foil, and a thin layer of metal tin protects the copper surface during etching, which plays an anti-corrosion role, causing the copper to be removed not clean, resulting in short circuit of the line. Therefore, we need to strictly control the concentration, temperature and time of the film-removing medicine. At the same time, when the film-removing is done, the inserting frame is used to insert the film-removing medicine, so that the plate and the plate can not be overlapped and collided.
(2) The stripped sheets are superimposed without drying, which makes the tin between the sheets immersed in the undried stripping solution, and part of the tin layer will dissolve and attach to the copper foil surface. During etching, a very thin layer of metal tin protects the copper surface and plays an anti-corrosion role, resulting in the copper to be removed is not clean, resulting in short circuit.