layout parts layout reference
1. The fixed position of the parts, according to the project icon, on the right position, and confirm the direction of foot and foot number.
2. Although the drawings indicate the location, but the non-fixed position of the parts, according to LAYOUT need to be adjusted, and inform the relevant personnel permission.
3. When placing parts, pay attention to various restrictions on the drawing such as part height, restricted area for JUMPER, CONNECTOR, and so on.
4 parts from the cheapest short distance fingers, should be more than 3mm.
5. The direction of all the parts must be placed vertically or horizontally on the edge of the board, and the same package type components of the same direction.
6. Note that the space around the pluggable parts will not hinder the manual insertion and removal movements. In addition, the use of auxiliary tools to plug parts (such as PGA packaging CPU) also need to consider the space for aids.
7.DIP IC spacing is 100mil. IC and resistor or capacitor spacing of 140mil.
8.PLCC or PGA DIP IC with a pitch of 200mil.Resistance, capacitance and spacing of 100mil.
9. Other PTH parts must be at least 10 mils away from each other and, if possible, be placed on a 0.1 "GRID. (However, the hard legs can not bend unless this is the case)
10. With the exception of fixed parts, the outermost periphery of any PTH part shall be at least 200 mils from the side of the board, ie within the hole of the tool.
11.SMC part periphery and PTH part periphery at least 50mil.
12. Tantalum capacitors and electrolytic capacitors, if arranged vertically and adjacent, the distance between at least 3mm above.
13. Between two SMCs, the PAD spacing should be at least 25 mils.
14. The back of the SMC should be with the forward direction of the tin.
15. According to SMT equipment PC board forward direction, the edge of the board within 4mm SMC parts can not be SMC parts for transportation and PC board positioning 16.PLACEMENT, please note that the temperature distribution of parts.
17. The double-sided SMC of the PC board, its greater heat-absorbing components, should not be designed on the opposite front and back.
18. For the uniform distribution of heat demand, the spacing between two BGA, should be greater than 50mm.
19.BGA package parts on each side within 2mm distance can not be placed other components.
20.BGA package parts and long through-hole parts of the spacing, not less than 15mm, in order to avoid over-welding when the BGA components cause greater thermal shock.
21. For ease of servicing, small SMD parts should be avoided between the two long, tall connectors.
22. Screw near the SMD parts, should be more than 3mm safety distance.
23. If the PCB is long (such as an elongated interface card), the resistance or capacitance near the long edge should be placed perpendicular to the edge of the board to avoid damage to the resistor or capacitor when the PCB swings