Solder mask is not metal. It is a 'solder resist'. I prevents short circuits due to solder bridging from one pad to another.
Keith
I probably didn't make it clear that the solder mask is a negative layer - where something is drawn there is no solder mask.
I haven't commented on your pictures as they don't show up too well on my phone. That is also why I haven't replied to your private message - I haven't been able to look at the attachments yet.
Keith
The solder mask illustrated above will cause problems when soldering. There isn't enough space between the pads solder mask to allow for a dam of solder resist between the component pins, this could cause soldering problems during manufacturing.
It is standard practice these days to supply solder resist data as a 1:1 with the corresponding pad size, then let the manufacturer open up the iopening to work with his processes with the caveat below, from my PCB manufacturing notes:
Solder resist (solder mask) is required on both external faces of the printed board, it shall meet the qualification/conformance IPC-SM-840 class H. Coverage, cure and adhesion shall be as defined in paragraphs 3.8.1 to 3.8.3 of IPC-6012, except that no encroachment of solder resist is allowed on any surface mount or ball grid lands, and that ALL pad patterns have solder resist slivers between individual pads. The height of the solder resist should not cause any mounting problems for surface mount components.
Solder resist data is provided as per IPC-7351 standard, 1:1 with the land size, the manufacturer is to oversize these solder resist openings commensurate with their manufacturing procedures ensuring that ALL the above requirements are met, the amount of oversize to take into account the minimum track and gap dimensions as shown on the Printed Boards Master Drawing. Solder resist not related to a component pad is not to be enlarged.
Provide the soldermask openeing as a 1:1, same size as the component pad and use the blue text as a manufacturing instruction.
Also look at page 13.1 below
**broken link removed**
I believe you use Eagle? If so go to the DRC and find the MASKS tab. Change the STOP min & max to zero. They are probably set to something 0.1mm oversize at the moment. That is OK for large components but not for things like fine pitch TQFP devices.
Keith.
Are you sure they are all tStop layer? Turn off all layers except tStop.
Keith.
The solder mask illustrated above will cause problems when soldering. There isn't enough space between the pads solder mask to allow for a dam of solder resist between the component pins, this could cause soldering problems during manufacturing.
It is standard practice these days to supply solder resist data as a 1:1 with the corresponding pad size, then let the manufacturer open up the iopening to work with his processes with the caveat below, from my PCB manufacturing notes:
Solder resist (solder mask) is required on both external faces of the printed board, it shall meet the qualification/conformance IPC-SM-840 class H. Coverage, cure and adhesion shall be as defined in paragraphs 3.8.1 to 3.8.3 of IPC-6012, except that no encroachment of solder resist is allowed on any surface mount or ball grid lands, and that ALL pad patterns have solder resist slivers between individual pads. The height of the solder resist should not cause any mounting problems for surface mount components.
Solder resist data is provided as per IPC-7351 standard, 1:1 with the land size, the manufacturer is to oversize these solder resist openings commensurate with their manufacturing procedures ensuring that ALL the above requirements are met, the amount of oversize to take into account the minimum track and gap dimensions as shown on the Printed Boards Master Drawing. Solder resist not related to a component pad is not to be enlarged.
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