What are the matters needing attention in PCB circuit board proofing?
PCB proofing is a complicated process, the same board, the same components, different engineers produce different effects. So, what are the matters needing attention in PCB circuit board proofing? First, it is necessary to clarify the design goal to accept a design task, first of all, it must be clear whether the design goal is an ordinary board, a high-frequency board, a small signal processing board, or a high-frequency There is a small signal processing board. If it is an ordinary board, as long as the layout and wiring are reasonable and tidy, and the mechanical size is accurate. 2. Understand the functions of the components used and the requirements for layout and routing. Some special components have special requirements for layout and routing. For example, the analog signal amplifier must have a stable power supply and small ripple; the analog small signal part should be as far away from the power device as possible; For components with high power consumption and high heat generation, the heat dissipation problem must be specially considered during the layout. 3. The first consideration of component layout is electrical performance. The components with close connections should be put together as much as possible. Especially for some high-speed lines, the layout should be as short as possible. The power signal and the power signal should be as short as possible. Small signal devices should be separated. Secondly, we must consider the transmission delay time on the ground and interconnection lines in the high-speed system. Fourth, the consideration of wiring 1. Any 'long' signal path on the printed circuit board of the transmission line can be regarded as a transmission line. If the transmission delay time of the line is much shorter than the signal rise time, the main reflections produced during the signal rise period will be submerged, and no overshoot, recoil, and ringing will appear. 2. Several types of transmission lines (1) Coaxial cable and twisted pair: They are often used in the connection between systems. (2) The microstrip line on the printed board: The microstrip line is a strip conductor (signal line), separated from the ground plane by a dielectric. (3) Strip line in the printed board: The strip line is a copper strip line placed in the middle of the dielectric between two conductive planes. 3. Terminating the transmission line At the receiving end of a line is terminated with a resistance equal to the characteristic impedance of the line, then the transmission line is called a parallel connection. It is mainly used to obtain the best electrical performance, including driving distributed loads. The above are the matters needing attention in PCB circuit board proofing, I hope it will be helpful to you.