PCB Tech - pcb technology strategy part 2

Block Diagram, frame the assembly board and the various components required on the design drawing with square or rectangular empty boxes, and use various electrical symbols to communicate the relationship between the boxes one by one, so that the composition has System architecture diagram.

Bomb Sight, PCB, for the purpose of alignment, also set up the target for the upper and lower two-layer alignment in each corner for the purpose of alignment. Its more accurate official name should be called Photographers' Target.

Break-away panel ,refers to many small circuit boards. For the convenience of plug-in, component placement, soldering and other operations on the downstream assembly line, in the PCB manufacturing process, they are specially merged on a large board to perform Various processing. When the work is completed, the method of jumping blades is used to perform a local cutting shape (Routing) disconnection between the independent small plates, but several "Tie Bar or Break-away Tabs" with sufficient strength are retained, and they are connected. Drill a few more small holes between the sheet and the edge of the board; or cut V-shaped notches up and down to facilitate the separation of the boards after the assembly process is completed. This kind of small board joint assembly method will be more and more in the future, IC card is an example.

Buried Via Hole, refers to the local via hole of the multilayer board. When it is buried in the inner layer of the multilayer board, it becomes an "internal via hole" and is not "connected" with the outer board, which is called a buried via hole or buried for short. hole.

Bus Bar, refers to the cathode or anode rod itself on the electroplating tank, or the cable to which it is connected. In the circuit board "in process", the outer edge of the gold finger is close to the edge of the board, the original connecting wire (which must be covered during the gold plating operation), and a small narrow piece (all for saving gold (It is necessary to reduce the area as much as possible) to connect with each finger. This kind of conductive connection is also called Bus Bar. The small piece where each individual finger is connected to the Bus Bar is called Shooting Bar. When the board is finished cutting the shape, both will be cut off together.