Solder-stop mask

You should pay special attention to solder-stop bridges (solder-stop between two pads or vias), which should not be smaller than 100µm (green solder-stop) or 150µm (coloured solder-stop) respectively.

We can only conditionally recommend vias (vias) covered with solder-stop. Please refer to our Design Aid Via Covering.

Solder-stop parameters (colour: green)

  clearance min clearance recommended bridge width min. bridge width recommended
 Viaclearance min50µmclearance recommended-bridge width min.100µmbridge width recommended125µm
 Component holeclearance min50µmclearance recommended75µmbridge width min.100µmbridge width recommended125µm
 SMD padclearance min50µmclearance recommended75µmbridge width min.100µmbridge width recommended125µm

Solder-stop parameters (colour: red, blue, white, black)

  clearance min. clearance recommended bridge width min. bridge width recommended
 Viaclearance min.75µmclearance recommended-bridge width min.150µmbridge width recommended150µm
 Component holeclearance min.75µmclearance recommended75µmbridge width min.150µmbridge width recommended150µm
 SMD Padclearance min.75µmclearance recommended75µmbridge width min.150µmbridge width recommended150µm

Solder-stop type

Depending on the production line and utilization, we are usinge various brands and processes for the solder-stop. These brands behave technically absolutely equivalent but can slightly differ optical (matt/glossy).

If a particular solder-stop accomplishment is desired, this may impact costs and production times. The feasibility of certain brand and process -combinations can not always be guaranteed.

Exemption of component holes

Exemption of component holes

For component holes, please ensure a clearance (spacing between copper to solder-stop) of at least 50µm (green solder-stop).

This clearance should be larger if possible (75µm), to avoid manufacture with extreme tolerances.

For other colours, the minimum solder-stop clearance is 75µm.

The smallest possible solder-stop bridge width is 100µm (green) or 150µm (other colours), respectively.

Exemption of SMD pads (fine pitch)

Exemption of SMD pads

The minimum solder-stop clearance for SMD pads should at least be 50µm, better: 75µm.

For other colours than green, the min. solder-stop clearance is 75µm.

The smallest possible solder-stop bridge width is 100µm (green) or 150µm (other colours), respectively.

BGA (Ball Grid Array)

PCB with BGA - Ball Grid Array

The following possibilities exist for BGAs (for explanation see Via Covering):

  • Via Tenting
  • Via Filling
  • Via-in-Pad

 

You should consult your assembly partner when selecting an appropriate surface, normally our customers select the PCB surface finish chemical gold.

Continue with: BGA - Design Recommendations