Contents
How tall do pins have to be for SMD?
SOP packages with pitch ≥ 1.27mm and Standoff value ≤15mm. SOT packages with pitch ≥ 27mm and visible pins. Note: The pins of SMD components undergoing wave soldering must be less or equal to 2mm. Other components must be less than 4mm in height.
Can a SMD pad overlap a through hole device?
Through-hole devices and SMD components are allowed to overlap when it can be confirmed that the SMD pad and the solder paste printed thereon has no effect on the soldering of the through-hole device. See Figure 20. Figure 20: Acceptable through-hole and SMD component layout design.
How tall are the pins on a sot package?
SOT packages with pitch ≥ 27mm and visible pins. Note: The pins of SMD components undergoing wave soldering must be less or equal to 2mm. Other components must be less than 4mm in height. The long axis of SOP package components should be perpendicular to the direction of travel of the solder wave in the wave soldering process.
What kind of wave soldering is used for SMD?
Wave soldering is suitable for the following SMD components: Chip resistors, capacitors, and inductors that have a package size greater or equal to 0603 and standoff value less than 0.15mm. SOP packages with pitch ≥ 1.27mm and Standoff value ≤15mm. SOT packages with pitch ≥ 27mm and visible pins.
What should be the clearance area for CSP?
Avoid positioning taller components next to shorter ones, which may hinder inspection. A viewing angle of no less than 45 degrees must be maintained throughout the layout to aid manual solder joint inspection. Surface array devices such as CSP, BGA, must have a clearance area of 2mm, but 5mm is ideal.
What is the minimum clearance for a PCB wave solder?
Vias not connecting to component pads will have a minimum clearance of 0.025″. When the PCB is to be wave soldered, via clearance to component pads on the solder side of the PCB will be 0.040″ if the via is placed before or after the pad in the direction of solder wave (see Figure 6-7).
How is Smt spacing determined on a PCB?
For PCBs requiring solder reflow, SMT device spacing varies according to the table 1. Description: The quoted value is the largest of the two: either the pad or the body of the device, whichever is most applicable. The values in brackets represent the lowest acceptable value.