Selective Wave Soldering Process Design Guide[electronic equipment China Knowledge]

11 Jul 2019

Selective wave soldering process design guidelines to achieve optimal soldering electronic equipment China results, meeting special process conditions.

High standard process reliability depends on the following points:

  • Pad design (pad type, distance between pads)
  • Pad and peripheral component pad distance (eg, should not touch SMD device)
  • The length of the PIN pin should not exceed the length of the PIN pin under the board
  • PIN foot spacing (eg, connector spacing)

These influence factors directly affect the peeling of the flowing solder. In order to avoid the occurrence of tin bridges, repeated stripping is required. Tin bridge is the main cause of welding failure (more than 80%). In general, there are significant differences between the small drag welding process and the dip soldering process. Each process requires a special printed circuit board design. The following design guidelines ensure optimum process conditions. If you do not follow the electronic equipment China recommendations below, the process window will be limited and additional steps will be required to stabilize the process. These extra steps require more maintenance and increase wear on the mold parts.

Optimal layout of the dip soldering process

Clearance between pads

  • Priority use of round pad
  • Distance between round pads: >0.60mm
  • PIN foot distance: >2.54mm

The length of the PIN pin should not exceed the length of the PIN pin under the board

  • Solder nozzle gap - distance to adjacent pad (not soldered)
  • On the 3rd side: > 3.0mm
  • On the fourth side: > 5.0mm
  • Microwave / drag welding process optimal layout

Clearance between pads

  • Priority use of round pad
  • Distance between round pads: >0.60mm
  • PIN foot distance: > 1.9mm

PIN pin length should not exceed the board

Microwave gap - distance to adjacent pad (not soldered)

  • On 3 sides: > 2.0mm
  • On the fourth side: > 5.0mm

Minimum size of solder nozzle

  • Rectangular solder nozzle
  • Welding area 40mm2
  • Round solder nozzle
  • Welding zone 7mm2

Maximum height of adjacent components

The maximum component height that the bottom (welding surface) can accommodate is limited by the height of the electronic equipment China solder nozzle. The standard solder nozzle height is 32mm. Therefore, the maximum component height should not exceed 25mm. Higher components require a higher solder nozzle design and we can design according to your requirements.

In addition, the distance between each component and the solder joints needs to be noted to prevent the components from contacting the nitrogen hood during the drag welding process. For example, if the component height exceeds 10 mm, a solder fillet will appear in this process. Rule of thumb: The angle of the weld appears and the component exceeds 10 mm. Component height (mm) ≤ distance to solder joint (mm)


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