Part 3: What is the Size of Solder Mask Opening
During PCB manufacturing, the solder mask opening size should be larger than the pads or copper areas desired to be exposed. Because of the skin effect, the PCB oil around the solder mask opening will gather, and the exposed area will be smaller. Usually, the width/length of the solder mask opening is 4mil larger than the pads.
Do you need to set up the solder mask opening size during PCB design? No, you don't have to. You just need to keep the same size as the required exposed pad/via size because the EDA tool will automatically enlarge the solder mask opening size.
What's more, when you deliver your Gerber/IPC-2581 to the manufacturer PCBHERO, we will check the solder mask opening size in design for manufacturing (DFM) before production. If there's any issue, we will assist you to modify it until everything is correct.
PCBHERO is an advanced PCB manufacturer that has rich design and fabrication experiences in solder mask opening. Founded in 1999, we have two large PCB manufacturing bases and one PCB assembly factory.
Here are reasons for you to consider PCBHERO as your PCB supplier:
We provide free DFM, DFT, DFX to make sure the solder mask opening size is appropriate.
Our professional engineers will assist you in solder mask opening throughout your project.
ISO, IPC, IATF 16949, UL, REACH, ROHS-certified PCB/PCBA quality management.
From prototypes to batch production, PCB design, manufacturing, assembly, tests, can be done one-stop from PCBHERO.
Our PCB manufacturing factory in Guangdong can process PCB gold finger hard gold plating.
Conclusion
Solder mask openings are the shapes designed on the solder mask layer. On the PCB, solder mask opening allows PCB pads to solder, gold fingers to connect, exposed vias or copper areas for thermal expansion, grounding, etc. If you want assistance in solder mask opening for your project or if you want PCB/PCBA manufacturing, don't miss the 23-year-old source factory PCBHERO.