(1) Line
In general, the signal line width is 0.3mm (12mil), the power line width is 0.77mm (30mil) or 1.27mm (50mil); the distance between the line and the line and the pad is greater than or equal to 0.33mm (13mil) ). In practical applications, increase the distance when conditions permit;
When the wiring density is high, two lines can be considered (but not recommended) to use IC pins. The line width is 0.254mm (10mil), and the line spacing is not less than 0.254mm (10mil). Under special circumstances, when the device pins are dense and the width is narrow, the line width and line spacing can be appropriately reduced.
(2) Pad (PAD)
The basic requirements for pads (PAD) and transition holes (VIA) are: the diameter of the disk is greater than the diameter of the hole by 0.6mm; for example, general-purpose pin resistors, capacitors, and integrated circuits, etc., use a disk/hole size of 1.6mm/0.8 mm (63mil/32mil), sockets, pins and diodes 1N4007, etc., adopt 1.8mm/1.0mm (71mil/39mil). In actual applications, it should be determined according to the size of the actual component. If conditions permit, the pad size can be appropriately increased;
The component mounting aperture designed on the PCB should be about 0.2～0.4mm (8-16mil) larger than the actual size of the component pin.
(3) Via (VIA)
Generally 1.27mm/0.7mm (50mil/28mil);
When the wiring density is high, the via size can be appropriately reduced, but it should not be too small. Consider using 1.0mm/0.6mm (40mil/24mil).

(4) Pitch requirements for pads, lines, and vias
PAD and VIA: ≥ 0.3mm (12mil)
PAD and PAD: ≥ 0.3mm (12mil)
PAD and TRACK: ≥ 0.3mm (12mil)
TRACK and TRACK: ≥ 0.3mm (12mil)
At higher density:
PAD and VIA: ≥ 0.254mm (10mil)
PAD and PAD: ≥ 0.254mm (10mil)
PAD and TRACK: ≥ 0.254mm (10mil)
TRACK and TRACK: ≥ 0.254mm (10mil)