What are the layout requirements for special components in PCB

Do you know the layout of special components in PCB? The rules and regulations in PCB design are very particular and not something that can be done arbitrarily. It is necessary to follow the principles of PCB design. This article elaborates on how to layout special devices in PCBs.

Layout requirements for crimping devices

1) There shall be no components higher than 3mm around the surface of the bending/male/female crimping device, and there shall be no welding devices around 1.5mm; There shall be no components within a range of 2.5mm from the center of the pin hole on the reverse side of the crimping device.

2) There should be no components within 1mm around the direct/male and direct/female crimping devices; When a protective sheath is required to be installed on the back of straight/male and straight/female crimping devices, no components shall be placed within 1mm from the edge of the sheath. When no sheath is installed, no components shall be placed within 2.5mm from the crimping hole.

3) The live plug socket of the grounding connector used in conjunction with the European connector has a 6.5mm long pin front end and a 2.0mm short pin front end.

4) The long pin of the 2mm FB power supply single PIN pin corresponds to the 8mm prohibited cloth at the front end of the single board socket.

Layout requirements for thermistor devices

1) When arranging devices, thermal sensitive devices (such as electrolytic capacitors, crystal oscillators, etc.) should be kept as far away as possible from high-temperature devices.

2) Thermistors should be tightly attached to the tested component and kept away from high-temperature areas to avoid being affected by other heat generating equivalent components and causing misoperation.

3) Place devices that generate heat and are heat-resistant near the air outlet or at the top, but if they cannot withstand high temperatures, they should also be placed near the air inlet, and be careful to avoid other heating devices and thermal sensitive devices in the direction of air rise as much as possible.

Layout requirements for polar devices

1) THD devices with polarity or directionality have consistent orientation and neat arrangement in layout.

2) Polarized SMC should be oriented as uniformly as possible on the board; Devices of the same type are arranged neatly and beautifully.

(Polarized devices include electrolytic capacitors, tantalum capacitors, diodes, etc.)

Layout requirements for through-hole reflow soldering devices

1) For PCBs with non transfer edge sizes greater than 300mm, heavier components should be avoided from being placed in the middle of the PCB as much as possible to reduce the impact of the weight of the plug-in components on PCB deformation during the soldering process, as well as the impact of the plug-in process on the components already placed on the board.

2) For ease of insertion and installation, it is recommended to place the device near the insertion operation side.

3) It is recommended that the length direction of devices with longer dimensions, such as memory module sockets, be consistent with the transmission direction.

4) The distance between the edge of the through-hole reflow soldering device's solder pad and QFP, SOP, connector, and all BGA with pitch ≤ 0.65mm is greater than 20mm. The distance between it and other SMT devices is greater than 2mm.

5) The distance between the main bodies of through-hole reflow soldering devices is greater than 10mm.

6) The distance between the edge of the through-hole reflow soldering device pad and the transfer edge is ≥ 10mm; the distance from the non transfer edge is ≥ 5mm. The above is the layout of special devices in PCB, hoping to help everyone.