Pcb design you need to master the layout component direction
The design of printed circuit board is based on the circuit schematic diagram to realize the functions required by the circuit designer. The design of printed circuit board mainly refers to layout design, which needs to consider the layout of external connections. The optimal layout of internal electronic components, the optimal layout of metal wiring and through-hole, electromagnetic protection, heat dissipation and other factors. Excellent layout design can save production costs and achieve good circuit performance and heat dissipation. Simple layout design can be realized by hand, while complex layout design needs to be realized by computer aided design (CAD)
1. The design shall be carried out in a certain order, such as from left to right and from top to bottom
2. The width and spacing of the wiring strip shall be moderate, and the spacing between the two pads of the capacitor shall be consistent with the spacing between the capacitor lead pins as far as possible;
3. When designing the wiring diagram, the routing shall be as simple and clear as possible.
4. When designing the wiring diagram, pay attention to the order of pin arrangement, and the spacing between component pins should be reasonable.
5. Wiring direction:
From the welding surface, the arrangement orientation of the components should be consistent with the schematic diagram as much as possible, and the wiring direction should be consistent with the wiring direction of the circuit diagram. Since it is usually necessary to detect various parameters on the welding surface in the production process, this is convenient for inspection, debugging and repair in production (Note: it refers to the premise of meeting the requirements of circuit performance, complete machine installation and panel layout).
6. On the premise of ensuring the circuit performance requirements, the design shall strive for reasonable wiring, less use of external jumper, and wiring shall be carried out according to certain charging requirements, so as to be intuitive, convenient for installation, height and maintenance.
7. The arrangement and distribution of all elements shall be reasonable and even, and the process requirements of tidiness, beauty and rigorous structure shall be strived for.
8. Layout direction of incoming and outgoing terminals
(1) The distance between the two associated lead ends should not be too large, generally about 2-3/10 inches is appropriate.
(2) The incoming and outgoing line ends shall be concentrated on 1 to 2 sides as far as possible, and shall not be too discrete.
9. Potentiometer: placement principle of IC base
(1) Potentiometer: it is used to adjust the output voltage in the voltage regulator. Therefore, the design of the potentiometer should increase the output voltage when it is fully adjusted clockwise, and decrease the output voltage when it is adjusted counterclockwise; In the adjustable constant current charger, the potentiometer is used to adjust the charging current fold. When the potentiometer is designed to be full and adjusted clockwise, the current will increase. The position of the potentiometer should meet the requirements of the whole machine structure installation and panel layout, so it should be placed at the edge of the board as far as possible, with the rotary handle facing outward.
(2) IC base: When designing the printed board drawing, when using the IC base, pay special attention to whether the positioning slot on the IC base is placed in the correct direction, and whether each IC pin position is correct. For example, the first pin can only be located at the lower right corner or upper left corner of the IC base, and close to the positioning slot (from the welding surface).
10. Placement direction of resistance and diode in pcb layout:
The pcb design is divided into horizontal and vertical:
(1) Horizontal placement: When the number of circuit components is small and the size of the circuit board is large, it is generally better to use horizontal placement; When the resistance below 1/4W is placed horizontally, the distance between two pads is generally 4/10 inches, and when the resistance below 1/2W is placed horizontally, the distance between two pads is generally 5/10 inches; When the diode is laid horizontally, 1N400X series rectifier tube is generally 3/10 inch; 1N540X series rectifier tube, generally 4-5/10 inches.
(2) Vertical placement: When the number of circuit components is large and the size of the circuit board is small, vertical placement is generally used in the pcb design. The spacing between two pads is generally 1-2/10 inches. Circuit board assembly, circuit board design, and circuit board processing manufacturers explain the direction of layout components you need to master in pcb design.