PCB device layout is not a matter of arbitrariness. It has certain rules that everyone needs to follow. In addition to general requirements, some special devices will also have different layout requirements.
Layout requirements for crimping devices
1) There shall be no components higher than 3mm around the surface of the bent/male and bent/female crimping devices within 3mm, and no welding devices shall be allowed within 1.5mm around; there shall be no components within 2.5mm from the center of the pin hole of the crimping device on the reverse side of the crimping device.
2) There shall be no components within 1mm around the straight/male and straight/female crimping devices; when the back of the straight/male and straight/female crimping devices needs to be installed with a sheath, no components shall be arranged within 1mm from the edge of the sheath, and no components shall be arranged within 2.5mm from the crimping hole when the sheath is not installed.
3) For the live plug-in socket of the grounding connector used with the European connector, the front end of the long pin is prohibited from 6.5mm, and the short pin is prohibited from 2.0mm.
4) The long pin of the 2mmFB power single PIN pin corresponds to the 8mm bar at the front end of the single board socket.
Layout requirements for thermal devices
1) When laying out the device, thermal devices (such as electrolytic capacitors, crystal oscillators, etc.) should be kept as far away from high-temperature devices as possible.
2) The thermal device should be close to the component under test and away from the high-temperature area to avoid being affected by other heat-generating work equivalent components and causing malfunctions.
3) Place the device that generates heat and is heat-resistant near the air outlet or on the top, but if it cannot withstand higher temperatures, it should also be placed near the air inlet, and pay attention to stagger the position with other heating devices and thermal devices in the direction of air rise as much as possible.
Layout requirements for polar devices
1) THD devices with polarity or directionality are arranged in the same direction and neatly.
2) The direction of polar SMCs on the board should be as consistent as possible; devices of the same type are arranged neatly and beautifully.
(Polar devices include: electrolytic capacitors, tantalum capacitors, diodes, etc.)
Layout requirements for through-hole reflow devices
1) For PCBs with non-transmission side dimensions greater than 300mm, heavier devices should not be placed in the middle of the PCB as much as possible to reduce the impact of the weight of the plug-in device on the deformation of the PCB during the soldering process, as well as the impact of the plug-in process on the devices already placed on the board.
2) For easy insertion, the device is recommended to be placed close to the insertion operation side.
3) For longer devices (such as memory stick sockets, etc.), the length direction is recommended to be consistent with the transmission direction.
4) The distance between the edge of the through-hole reflow device pad and QFP, SOP, connectors and all BGAs with pitch ≤ 0.65mm is greater than 20mm. The distance with other SMT devices is greater than 2mm.
5) The distance between the through-hole reflow device body is greater than 10mm.
6) The distance between the edge of the through-hole reflow device pad and the transmission side is ≥10mm; the distance with the non-transmission side is ≥5mm.