care must be taken in designing the tracks to match the impedance of the upstream and downstream components. The longer the route or the higher the frequency, the better adaptation is required. When producing HASL the printed circuit with controlled impedance, the impedance will be controlled by acting on the dimensions of the tracks and the
protects the copper from corrosion and reduces the chances of solder shorting between traces or unwanted electrical contact with possible loose wires. HASL For its function of helping to prevent solder shorts, the coating is called a solder mask. Soldermask is generally green in color but can have different colors:
to connect them electrically HASL and to fix them mechanically. Printed circuit boards are used in almost all electronic products and some electrical products. Currently, the production and assembly of printed circuits are automated. Electronic computer aided design software is available to do much of the layout work. Multilayer PCBs