pcb设计规则（PCB design rules）.docVIP

pcb设计规则（PCB design rules） Basic principles of PCB layout and routing First, the basic rules of component layout 1., according to the circuit module layout, the realization of the same function of the relevant circuit is called a module, the circuit module should be used in the vicinity of the principle of concentration, while digital circuits and analog circuits separate; 2., the positioning hole, standard hole and other non installation holes, 1.27mm shall not be installed around the yuan, devices, screws and other installation holes, 3.5mm (for M2.5), 4mm (for M3) shall not be affixed to components; 3. lie resistance, inductance (plug-in), electrolytic capacitor and other components, to avoid the cloth hole, so as to avoid the wave soldering after the hole and the element shell short circuit; 4. the distance from the outer edge of the component to the edge of the plate is 5mm; The outer side of the pad of the 5. mounting element and the outer part of the adjacent plug-in element is greater than 2mm; 6. metal shell components and metal parts (shielding boxes) can not collide with other components, not close to the printed line, the distance between the pads, should be more than 2mm. The locating hole, the fastener mounting hole, the elliptical hole and the other side holes in the plate are larger than the size of the edge of the plate from the outside of the plate. The outer edge of the plate is larger than 3mm; 7. the heating element can not be adjacent to the wire and the heat sensitive element; 8., the power outlet should be arranged as far as possible around the printed board, the power outlet and its connected bus terminals should be arranged on the same side. Special attention should be paid not to between the power outlet and other welding connectors arranged between the connector, in order to facilitate the welding of these sockets, connectors and power cable design and tie line. The arrangement distance between the power supply socket and the welding conne