- Apr 19, 2018 -
1.PCB design should be carried out in a sequential direction, for example, from left to right and from top to bottom
2.The line width and line spacing of the PCB layout shall be moderate , and the spacing between the two pads of the capacitor shall be consistent with the spacing of the lead feet of the capacitor as far as possible ;
3.PCB design wiring diagram as few corners as possible, strive for simple and clear lines.
4.PCB design wiring diagram should pay attention to pin arrangement order, element foot spacing should be reasonable.
5.PCB routing direction:
From the point of view of welding surface, the alignment orientation of the components is as consistent as possible with the schematic diagram, and the wiring direction is best consistent with the wiring direction of the circuit diagram, because it is usually necessary to check various parameters in the welding surface during the production process.Therefore, it is convenient to inspect, debug and overhaul in production (Note: meet the requirements of circuit performance and the installation and panel layout of the whole machine.
6.On the premise of ensuring the circuit performance requirements, the design should strive for reasonable wiring, less use of external cross-lines, and according to certain requirements of line routing, as intuitive as possible, easy to install, height and overhaul.
7.Each element arrangement, the distribution should be reasonable and even, strives for neat, beautiful, the structure rigorous craft request.
8.Incoming and outgoing terminal layout direction
(1)The associated two ends should not be too far apart, usually about 2-3 / 10 inches.
(2) focus on 1 to 2 sides as far as possible, not too discrete.
9.The Placement principle of potentiometer: IC seat
(1) potentiometer: it is used to adjust the output voltage in the voltage regulator, so the output voltage of the design potentiometer should be adjusted clockwise, and the output voltage of the counterclockwise regulator will decrease;In the adjustable constant current charger, the potentiometer is used to adjust the charge current fold, and the current increases when the potentiometer should be adjusted clockwise when the potentiometer is designed.The position of the potentiometer shall be filled with the requirements of the structure installation and panel layout of the whole machine, so it should be placed as far as possible on the edge of the board, with the rotating handle facing out.
(2)IC seat: when designing the printing board, when using IC seat, we must pay special attention to the location of the positioning slot on the IC seat and whether the position of each IC foot is correct.For example, the first foot can only be located in the lower right corner or upper left corner of the IC seat, and close to the slot (see from the welding face).
10.pcb layout resistor, diode placement direction:
Pcb design is divided into two types: horizontal and vertical:
(1)Flat: when the number of circuit elements is small and the size of the circuit board is relatively large, it is generally better to use a flat position; for a resistor below 1 / 4 W, the distance between the two pads is generally 4 / 10 inches or 1 / 2 W.The distance between the two pads is generally 5 / 10 inches; when the diode is horizontal, the 1N400X series rectifier is usually taken 3 / 10 inch / 1N 540X series rectifier, usually 4-5 / 10 inch.
(2)Vertical placement: when the number of circuit components and the size of the circuit board is not large, generally in the pcb design is vertical, vertical placement between the two pads generally take 1-2 / 10 inches.