Multilayer HASL circuit board

4-layer multilayer HASL circuit board. Lead free. Green slodermask and white silkscreen. Outer copper finished 1.5oz. board thickness 1.2 +/-0.12mm.

However, due to its processing characteristics of the hot air solder level, the surface roughness of sprayed tin treatment is not good, especially for small electronic components such as BGA and other package types, since the soldering area is small, if the flatness is not good, it may cause short circuit and other problems, so it needs to be leveled. A better process to solve the problem of HASL board. Generally choose the immersion gold process.