1. Wiring direction: From the perspective of the welding surface, the arrangement direction 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. As various parameters are usually required to be tested on the welding surface during production, this is convenient for inspection, debugging, and maintenance during production (note: it refers to meeting the requirements of circuit performance, overall installation, and panel layout)

2. The arrangement and distribution of each component should be reasonable and uniform, striving for neatness, aesthetics, and rigorous structural process requirements

3. The placement of resistors and diodes can be divided into two types: flat placement and vertical placement:

(1) Flat placement: When the number of circuit components is not large and the circuit board size is large, it is generally better to use flat placement; For resistors below 1/4W, the distance between two pads is generally taken as 4/10 inches. For resistors below 1/2W, the distance between the two pads is generally taken as 5/10 inches; When the diode is laid flat, the 1N400X series rectifier tube is generally taken as 3/10 inch; The 1N540X series rectifier tube is generally 4-5/10 inches

(2) Vertical placement: When there are a large number of circuit components and the size of the circuit board is not large, vertical placement is generally used. When vertical placement is used, the spacing between two solder pads is generally 1-2/10 inches