“PCB device layout is not an arbitrary thing, it has certain rules that everyone needs to abide by. In addition to the general requirements, some special devices will have different layout requirements.

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PCB device layout is not an arbitrary thing, it has certain rules that everyone needs to abide by. In addition to the general requirements, some special devices will have different layout requirements.

Layout Requirements for Crimp Devices

1) There shall be no components higher than 3mm in 3mm around the surface of the crimping device, and no soldering device shall be placed in the surrounding 1.5mm; on the reverse side of the crimping device, the distance from the center of the pin hole of the crimping device is 2.5 There must be no components within the mm range.

2) There should not be any components within 1mm around the straight/male, straight/female crimping device; when the back of the straight/male, straight/female crimping device needs to be installed with a sheath, no element should be arranged within 1mm from the edge of the sheath. When the sheath is not installed, no components shall be arranged within 2.5mm of the crimping hole.

3) For the live plug socket of the grounding connector used with the European-style connector, the front end of the long needle is 6.5mm, and the short needle is 2.0mm.

4) The long pin of the 2mmFB power supply single PIN pin corresponds to the 8mm front end of the single-board socket.

Layout Requirements for Thermal Devices

1) When the device is laid out, heat-sensitive devices (such as electrolytic capacitors, crystal oscillators, etc.) should be kept away from high-heat devices as much as possible.

2) The thermal device should be close to the component under test and away from the high temperature area, so as not to be affected by other heating power equivalent components and cause malfunction.

3) Place the device that generates heat and heat resistance near the air outlet or at the top, but if it cannot withstand higher temperatures, it should also be placed near the air inlet, and pay attention to try to rise in the air with other heating devices and heat-sensitive devices. Staggered position in direction.

Layout Requirements for Devices with Polarity

1) THD devices with polarity or directionality have the same direction in layout and are neatly arranged.
2) The SMC with polarity should be as consistent as possible on the board; the devices of the same type are arranged neatly and beautifully.
(Devices with polarity include: electrolytic capacitors, tantalum capacitors, diodes, etc.)

Layout Requirements for Through-Hole Reflow Devices

1) For PCBs whose non-transmission side size is greater than 300mm, try not to arrange the heavier components in the middle of the PCB, in order to reduce the influence of the weight of the inserted components on the PCB deformation during the soldering process, and the impact of the insertion process on the board. impact of placement devices.

2) For the convenience of insertion, the device is recommended to be arranged close to the operation side of the insertion.

3) For devices with longer dimensions (such as memory sockets, etc.), the length direction is recommended to be consistent with the transmission direction.

4) The distance between the edge of the pad of the through-hole reflow soldering device and the QFP, SOP, connectors and all BGAs with pitch ≤ 0.65mm is greater than 20mm. The distance from other SMT devices is > 2mm.

5) The distance between the body of the through-hole reflow soldering device is more than 10mm.

6) The distance between the pad edge of the through-hole reflow soldering device and the transmission side is ≥10mm; the distance from the non-transmission side is ≥5mm.