What is solder mask expansion?
Positive solder mask expansion means there exists a distance between the pad outer perimeter and the end of the solder mask around it that is uncovered. Zero solder mask expansion involves no space or “gap” between where the pad ends and the solder mask starts.
When would you use a solder mask?
Solder mask, solder stop mask or solder resist is a thin lacquer-like layer of polymer that is usually applied to the copper traces of a printed circuit board (PCB) for protection against oxidation and to prevent solder bridges from forming between closely spaced solder pads.
What can I use instead of solder mask?
Epoxy is the cheapest alternative among solder masks. Epoxy is a polymer that is silkscreened on the PCB. Silkscreening is a printing methodology which employs woven mesh to support the ink-blocking patterns. The mesh allows for the open areas to be identified for ink transfer.
What material is solder mask?
Solder Mask material is a fine layer of polymer. In terms of application, engineers will often use this material for copper traces in a circuit board, PCB. It is an essential material in circuit building projects, protecting the PCB from oxidization.
How thick is solder resist?
The typical solder mask thickness (perpendicular to the board) is at least 0.8 mils. Solder mask will be thinner near the edges of traces and can reach as thin as 0.3 mils or less. In general, you’ll want about 0.5 mils of solder mask over your traces.
What is the purpose of solder mask expansion?
Epoxy Liquid. The epoxy liquid solder mask is the most affordable of all.
What are the types of solder mask?
– IPC-SM-840 Qualification and Performance Specification of Permanent Solder Mask – IPC-7525 – Guidelines for Stencil Design – IPC-7527 – Requirements for Solder Paste Printing – IPC-7350 – Guidelines for Temperature profiling for Mass Soldering Process (Wave and Reflow) – IPC-HDBK-840 supplements the solder mask requirements established in IPC specifications
What is solder mask color?
Green Solder Mask. The green standard is still a common PCB solder mask option because it allows everything to be seen clearly.