PCB mfg/Removing silkscreen

[Oznog]

Well, I got my first prototype boards I've sent out for mfg. Three things came up so far:
1. CadSoftUSA's Eagle PCB layout library doesn't have a correct hole size for the TO-252A pkg. Bummer, I'm dremel-ing down the leads.
2. Left off 3 resistors I needed, and the diode I grabbed out of the library for a Schottkey has holes too small too.
3. The silkscreen goes RIGHT over the pads for a fine pitch SMD pkg. I hadn't thought about that. This is a problem, if I use chemical removers I might strip the solder mask or chemically alter the pad's tinned surface which may complicate the mounting process with surface mount paste.

Is there a good way to do this? I tried laquer thinner on a q-tip on another spot where the silkscreening for the TO-252's pkg goes right over the TO-252's solder pad, and it doesn't do anything. Maybe I should try aceone? I tried a Dremel wire brush, but it seemed to want to remove the tin more than the silkscreen.

 

[Sebi]

I'm sure, the acetone will remove the silkscreen, just make a test on a small surface.(Be sure,the acetone don't remove the solderstop-lack.)

 

[Oznog]

Shocking, but acetone doesn't do anything to either the silkscreen or the soldermask. Zero. Zilch.

Looks like an X-acto knife tip or the like may be the only way to do this. A wire brush is guaranteed to remove the soldermask.

 

[jbeng]

The silkscreen is basically an epoxy-based ink. I haven't found much that will touch it short of removing it mechanically (ie. grinding, scraping etc.) ... JB

 

[evandude]

as for your package size issues... why don't you make new packages for the parts? eagle is really great, and it's not very hard to make a new package and apply it to a component in any given library...

 

[laroche73]

scrape, don't grind

It's difficult to get precise results with a dremel wire brush, though it does the job. A light touch with a fine tipped X-acto knife works pretty well on small areas, as you've probably concluded.