PCB design and PCB Copy Engineering general principles
PCB design and PCB Copy Engineering general principles:
For the best performance of electronic circuits, the layout of components and wiring layout is very important. In order to design good quality, low cost PCB, should follow the following general principles:
Layout, first of all, to consider the PCB size. PCB size is too large, the printed line length, impedance increases, anti-noise ability to decline, the cost also increased; too small, the heat is not good, and adjacent lines susceptible to interference. Determine the size of the PCB, and then determine the location of special components. Finally, according to the functional unit of the circuit, all the components of the circuit layout.
In the PCB design and PCB Copy Engineering to determine the location of special components to comply with the following principles:
(1) as short as possible between the high-frequency components of the connection, try to reduce their distribution parameters and mutual electromagnetic interference. Disturbed components can not be too close to each other, the input and output components should be kept away from.
(2) Some components or wires may have a higher potential difference between them should increase the distance between the discharge in order to avoid accidental short circuit. Components with high voltage should be placed in the hands of the debugging is not easy to reach the place.
(3) The weight of more than 15g of components, should be used to fix the bracket, and then welding. Those large and heavy, heat and more components, should not be installed in the printed circuit board, but should be installed in the machine chassis floor, and should consider the heat problem. The thermal element should be located away from the heating element.
(4) For the potentiometer, adjustable inductance coil, variable capacitor, micro switch and other adjustable components of the layout should be considered the structural requirements of the machine. If the adjustment inside the machine, should be placed on the printed circuit board to facilitate the adjustment of the place; if the machine outside the adjustment, the position and adjustment knob on the chassis panel to adapt to the position.
(5) should be left out of the PCB positioning holes and fixed bracket occupied by the location.
According to the functional unit of the circuit. PCB layout of all components of the circuit to meet the following principles: (1) in accordance with PCB Copy Engineering circuit in the process of arranging the location of the various functional circuit elements, so that the layout to facilitate signal flow, and the signal as far as possible to maintain a consistent direction .
(2) to the core of each functional circuit components as the center, around it to layout. Components should be uniform, neat, compact arrangement in the PCB. Minimize and shorten the lead between the components and connections.
(3) in the high-frequency operation of the circuit, to consider the distribution parameters between components. General circuit should be as much as possible so that parallel arrangement of components. In this way, not only beautiful, but also easy assembly and welding, easy to mass production.
(4) at the edge of the circuit board components, from the edge of the circuit board is generally not less than 2mm. The best shape of the circuit board is rectangular. Length and width double for 3: 2 or 4: 3. Circuit board surface size greater than 200 × 150mm, the circuit board should be considered the mechanical strength.