When I generate the outputs such as PDF or Gerber, some of the pads appear as filled pads. Actually the trace is getting filled in the pad's hole hence it is seen as filled in the output. This issue is not there when I directly print in windows option. But in many cases I need to generate PDF/Gerber. How to fix this issue?
In the Plotting & Printing dialogue, select "Settings" for each copper layer, then make sure "Fill Plated Drill Holes" and "Fill Unplated Holes" are unticked.
In commercial pcb manufacture it really doesn't matter whether the pads are filled or not as the pcb is usually drilled before being etched. Hollow pads are useful for "home-brew" pcbs which are etched before drilled and the hollow in the pad helps to centralises the drill bit when manually drilling.
But, it can also be caused by error "Track too wide to backoff from drill" (depending on how you are viewing!). I always have "Fill Plated Drill Holes" and "Fill Unplated Holes" ticked for production pcbs.
I have double checked the untick of "fill" option in all the layers and found as suggested. Still the problem exists. I understand that it is due to the width of the trace but the drill hole is supposed to superimpose it right? Unfortunately my PCB fabricator is accepting the PDF format only. Another question I have is whether we can print the mask layer in negative? I mean all the white places should come as black and vice versa in the PDF.
I don't believe that the drill hole will superimpose the "fat track" issue as the drill data is in a different format (Excellon). Suggest you tick "Fill Plated Drill Holes" and "Fill Unplated Holes" and re-issue to your pcb manufacturer.
If I tick the "Fill Plated Drill Holes" and "Fill Unplated Holes" options, the pads are appearing as filled in the output. My issue itself is, some of the pads are getting filled and I need all of the pads as unfilled in the copper layer.
I always "fill" both plated and unplated pads and never had a problem in over 30 years! The pcb is drilled (from the Excellon data) before the copper is etched, so it really makes no difference.
Thanks Ed. Unfortunately my PCB manufacturer needs the PDF output in which all the Pads should appear hollow (not filled). If I have both thick and thin traces connected to the pads in my design how can I generate a PDF of the copper layer with all the pads as hollow? Please suggest the settings for the same.
Before you terminate the thick track onto a (small) pad, change the track width to a narrower width such that a "Track too big to backoff from drill" error isn't generated when you terminate the narrower track onto the pad.
Make the track width change close to pad (but not too close).