[bobJandal]

Okay, so,

The milling procedure works great, the drilling procedure works great, the board is thankfully held flat and sturdy by some double sided sticky tape, everything goes well and wow-wee - a finished pcb looking sparkly and new.

So, lift it off, and go to peel off the sticky tape - uh-oh - darn stuff won't come off !

What on earth do I do ?

I just spent a half hour rubbing with solvent, dissolving whats left of my brain, and filling all the finely drilled holes with gummy gunk !

Help ?! there has got to be a better way.....

[Switcher]

Contact Cleaner !

The trick is, leave one edge so you are able to get a hold of the tape, then gently pull the tape up while spraying the contact cleaner between the tape and the board.


.

[smallshop]

The solvents release quick but make quite a mess. Denatured alchohol will relax the tape's hold a bit and allow you to easily peel it off but it will take 5-10 minutes. If you're running stuff with tape try not to leave stuff taped down overnight or for long periods. It does get harder to remove the longer it is left on.

[NC Cams]

Go the the auto parts dept of any mass merchandiser or to an auto parts store.

Buy some "BrakeClean" from CRC. You want the 'good' stuff in the red can. You can also use "Electromotive Parts Cleaner" of the same brand - essentially the same stuff but not as strong.

Spray/dribble a bit on the tape with the concentrator nozzle and then spray some on a paper towel.

Let the towel saturated with solvent soak onto the tape for a minute or two. The tape should peel off quite easily after the soak.

The stuff should also clean off the sticky residue.

[smallshop]

Btw, the alchohol leaves no residue.....

[pminmo]

Btw, the alchohol leaves no residue.....

Only 100% denatured, isopropyl will.

[Torchhead]

You want a solvent that attacks "sticky" stuff. We use various kinds of adhesive and tape in our production. I find that VMP Naptha that you can get in any paint dept will loosen most sticky adhesive and even totaly remove it if its allowed to soak an little while.

Of course you could add a floating head and depth control device (adjustable nosepiece around the cutter bit) and eliminate having to use tape at all. I mill PCB's and just use quick corner holddowns. The depth of the cut is critical for tight runs and the floating head keeps to constant.

[NC Cams]

Neither "BrakeClean" nor "Electromotive Parts Cleaner" leave a residue either.

The "residue" I was referring to in my prior post was the glop left over from the stickem on the tape....

[fyffe555]

Or just use the right double sided tape - don't use the carpet or other industrial strength tape, just get the scotchbrand clear doublesided. If the board is clean when you stick it on it peels right off...

[smallshop]

I understand what residue we're talking about. I use a 3m double sided tape. The way the alchohol works is it just loosens the bond a bit so you can pull the part off. It does not attack the adhesive. I have actually run plastic parts where I had a piece of tape down in a cut plastic "fixture" and have been able to run up to 20 parts on one piece of tape.A little compressed air to dry and the tape was good for the next part. You do have to wet the area pretty good with the denatured alchohol to get the part to release. I learned this from a modelmaker friend (I do modelmaking/prototype machining) and tried it. Almost everyone I have suggested this to argues it, with out trying it....go figure. It requires a bit of technique but once you get it dialed in it is faster than yanking the part immedietely with solvents and then having to cleanup the goo.I hate the feeling of that crap on my fingers. On something as light as a circuit board where you have good surface area for the amount of cutting forces I just don't tape it down as hard and usually don't need anything to free it. All these tapes are pressure sensitive so when you get a feel for the tape you like to use you know how much pressure is enough. Yes....I have flung a few....

[One of Many]

WD40 or other solvent based oils can help too. The oil keeps the goo from re-attaching itself as it is removed. Then just spray off the board with some good brake cleaner or contact cleaner to remove the oil.

As with any solvent. Test it on a scrap piece just in case it is not compatible with the material the adhesive is being removed from. Circuit board material is fairly impervious to most fluids, but some plastics may desolve. Not all brake and contact cleaners are created equal.

DC

[Switcher]

http://www.lpslabs.com/Products/Elec...eaners/ecc.asp

I use this everyday at work.



.

[bobJandal]

Thanks for the replies.

Much appreciated.