Cavity PCB manufacturing - control impedanceThere was a time when many small and medium-sized stores did not support impedance testing, but the day passed. Nowadays, impedance controlled PCB design is very common, so the ability to check impedance results has become a basic requirement to maintain business. Now, no matter where the order is built, it can be tested. If you provide the necessary information at the beginning of the project, the board should attach a report containing the results. It is expected to pay a small amount of charging power for each PCB. The additional cost includes the cost of installing and performing tests that are not performed on the same machine as the machine used to check basic continuity. Although there are no other manufacturing errors, it also covers the potential small growth of circuit boards that fail impedance tests. Cavity PCB manufacturingCavity PCB manufacturing - electroplating around the edgeSometimes it is desirable to form a connection by wrapping the coating around the edge of the PCB rather than through a standard through hole so that the edge can be used as a conductor. Immediately after drilling, the machinist performs other major milling operations to complete the filler plate. The purpose of this wiring step is to expose the PCB side walls so that they can be coated with electroless copper (or equivalent) in the same way and at the same time when applied to drilling holes.After the photographic circuit image is applied and developed, the electroless coating provides a conductive surface on which thicker and more durable electrolytic copper can be attached. If the artwork contains mats or other shapes that define the routing areas as plating features, electrolytic copper plating will cover the routing channels to form the required connections. Although this process adds steps and increases the complexity of array setup and process planning, it is not difficult to achieve good results.Cavity PCB manufacturing - edge platingRelated to the peripheral coating, the edge plating involves coating a series of holes so that the center point falls along the outline of the PCB. The holes are then passed through to leave a gap between the plated half holes. Castles are usually used to facilitate the installation of pre installed modules on smaller or larger boards. The half holes in the cast plate are usually aligned with the surface mounting pads on the large plate. When the two plates are joined together, the plating in the barrel of each half hole provides an additional mating surface for welding. The assembled solder core absorbs a half hole barrel, making the joint stronger than the basic butt joint.
