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PCB design problems

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Azraels:
I think I've got the laser printer/ iron on pcb board down although it took more than a few tries. So tonight I finally have a board I was satisfied with and I go to start drilling my holes and the vias  start ripping up as soon as the drill bit touches them. Seriously frustrating! I have used Eagle, the lite version, to design the board which is a driver for two steppers and an H-bridge. I have been using the pinhead library for my headers which is just the standard headers you use with arduino boards. I do know how to edit the libraries after reading another post on here, thank you Soeren.

I thought maybe  to re-size to a larger hole might help but I'm not for sure.  After googling I have read to make the drill hole smaller. I would really rather not make another new board for experimenting. So I just wanted some more opinions.
My drill bit for the headers is 1/32" or .0370" on the caliper. The only smaller size I have than that is 1/64" which is to small for the headers.  But it still ripped up the vias for the resistors and chips!
When the bits dont rip up the vias they still deform the copper on the other side of the board when the bit pushes through. I have tried using a backer plate.
The drill press is set at its maximum speed which is 3100 rpm.
Hope you guys can help me out!

Jon_Thompson:
If the pads on the back side of the board are pulling up, it sounds like a registration problem. The hardest part of making PCBs at home (I've always found) is getting the vias to line up. I use a hand-held battery drill and angle it as I go to compensate for this problem. It's a good idea to add an extra pinhead to the board so that you can drill it first to work out how to compensate.

jwatte:
In typical machining, you want to drill first, then cut. This is so that the drills go through as rigid a piece as possible. I recommend doing that for home-made PCBs, too.

Also, you may be able to "spot" the holes from both sides, and drill through half the board, without coming out the back, from each side, for less punch-through problems.

Finally, the quality of your drill bit does make a difference. Try different brands and cuts. I'd probably stay away from big-box brands like DeWalt or Bosch or whatever for drill bits -- they are overpriced and underperforming. Go to a hardware supply store and see what they have. Maybe even use a high-quality center cutting (or ball) end mill instead of a drill, for more precision in the cutting surface, assuming you have a rigid holder ("hand drill" doesn't sound like it, though :-)

Regarding the "I'd rather not make another board" comment -- when you're learning something you haven't done before, you *have* to plan to try several times until you perfect the skill. That's how learning works :-) And, because of all the annoying parts of making a home board (be it etched or milled,) I've switched to using OSHpark.com (formerly dorkbot-pdx) and iteadstudio.com for making my boards. The boards are 100x nicer than I can make at home, and actually work :-) A two-week wait is well worth it.

Azraels:
Thank you Jwatte, I had been considering drilling all the holes first, but didnt know if this might actually weaken copper around the holes when the acid is doing its job.
I have also gone in and edited all of my common components making the drill size slightly larger and the pads/vias larger.

And yes I know I have to experiment, this will be about the 4th remake of this board, I just hate  "reinventing the wheel."

Will see how this one goes.

Azraels:

--- Quote from: Jon_Thompson on March 07, 2013, 07:41:33 AM ---If the pads on the back side of the board are pulling up, it sounds like a registration problem. The hardest part of making PCBs at home (I've always found) is getting the vias to line up. I use a hand-held battery drill and angle it as I go to compensate for this problem. It's a good idea to add an extra pinhead to the board so that you can drill it first to work out how to compensate.

--- End quote ---
Thanks, I will have to try to angle the table on the drill press and see if that helps

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