Hi,
I’m using Eagle and have some mounting holes in my PCB. As it is, they will come back with plating on the inside. Is there anyway to specify that you just want the hole drilled, with no plating?
Thanks,
Matt
The board houses I’ve used have asked for separate drill files for plated (vias/pads) and non-plated holes. Most inexpensive services don’t allow unplated holes because it’s an extra manufacturing step which costs money for setup and tooling. Because of that you typically only get the non-plated option if you’re ordering production quantities of boards or if you spend a lot of money for your prototypes.
-Bill
What’s the issue with the plating?
What about putting the hole in the board outline? Would that work?
Identify them in your manufacturing notes drawing. (drill drawing).
At the manufacturing level, having holes without plating means an extra drilling step. The usual process goes: drill, plate, resist, etch, strip, route. Unplated holes would be done on the drill machine AFTER etching (could be combined with routing, maybe.) More info here: http://www.thinktink.com/faqs/pcbshop/pcbproguid.htm (or there may be a similar breakdown from your own board house.)
Non plated mounting holes may well be done in a different process to plated holes however I have never come across a board supplier that charges lots more because of non plated mounting holes.
Drilling is all done with CNC machines that need little manual intervention these days - its not a case of
someone sits there and hand drills them.
If they are above 2mm then they can easily be routed out at the same time as the board is routed in its manufacturing panel, or he panel is routed.
Just mark them up on your drill drawing, or provide a seperate drill file for non plated holes
and they will be non plated. PCB manufacturers are used to many methods of identifying them.
Not for production. But the requirement might bounce you out of the "super low cost, low-volume, here are the features you get, prototyping deal" that hobbyists survive on. For instance, I doubt that the batchpcb or dorkbot services allow for unplated holes.I have never come across a board supplier that charges lots more because of non plated mounting holes.
What’s the difference between an un-plated hole and internal routing?
george graves:
What’s the difference between an un-plated hole and internal routing?
One is drilled in one step using a drill bit the same size as the hole. The other uses complex motion and a more expensive end mill/fiberglass burr to create the profile a drill bit did in a single step.
-Bill
Let me re-phrase that. What’s the difference between specifying an unplated hole in drill file…or…why not just include it on the board outline as an internal route? Isn’t that a better way to go about it? No?
Cost is the big difference which I was hinting at in my previous post. In production quantities, the speed improvement with a drill saves machine time in the long run. Fiberglass end cutting burrs cost more than non-end cutting ones and would be necessary for making the plunge cuts for an internal route. Couple that with increased machine time on a more expensive machine (expensive CNC mill vs. CNC drill), it’s a more expensive process.
In prototype quantities, plated holes obviously cost less due to the elimination of a machining step. Drills are still cheaper than routing for the above mentioned reasons.
-Bill