Last updated: August 2020
Reason of failed review:
A: The Space between IC pads should be at least 0.2mm if solder mask bridge for green soldermask needed of 1oz/2oz/3oz copper board.
B: Space between IC is smaller than 0.22mm, we can not do solder mask bridge for blue/red/white/yellow/black/matte black solder mask of 1oz/2oz/3oz copper.
C: For 3oz ~10oz copper, if solder mask bridge is needed, IC pad width and IC pad spacing should be ≥ trace width and trace spacing corresponding to copper thickness. For example, for 3oz copper thickness board, trace width/spacing should be ≥ 0.25mm/0.23MM. Then IC pad spacing should be at least 0.23mm, so that solder mask bridge is available.
Suggestion:
A: Modify the space between IC pads to reach our standard.
B: Just do as your file and accept no soldermask bridge between IC pads.
To ensure quality, the following content is no longer available and outdated.
We can only give a limited recommendation for coating vias (plated-through holes) with solder-stop. Please refer to our Design Aid Via Covering.
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) and 150μm (coloured solder-stop) respectively.
Solder-stop parameters (colour: green)
Solder-stop parameters (colour: red, blue, white, black)
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)
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)
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 immersion tin or immersion gold.
