I have a robotic vehicle control box that I farmed out to the EE boys. They designed it with some factory 'H' gate integrated circuits, the hole spacing is a weird as it can be. (IIRC its .150" C to C, two rows) So now it is getting kicked back to me to deal with a PC board. I'm wondering about just milling the foil on one side of a PC, drill the holes? the circuit is no big deal, big need is to mount the IC on a standard PC board for reliability. Board size is around 3"x4" I have 2 Haas mills (VF-0 and TM-1), Solidworks, and Gibscam.
PC board drilling
Sep 20, 2007
17 Replies
Make that .067"/.134"
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Of course what I REALLY want is one of the Protoboard places that will do this cheaply for quantity 6!!! Trying for under a couple hundred for
6 boards.
RoyJ wrote:
If you have the right toys, and it sounds like you do, that plan could work. Be certain that the board design is such that it allows for cutting (size of spaces and traces compatible with cutters you have). However, if it's for work and involves charging for your time (to the project, company, whatever) you might be better off sending it out - you can get a better board (with soldermask and silkscreen) pretty cheap from any of several board houses in small quantities. Does not take much of your time to make that a paying proposition if you or your machines cost much to run (.vs. cost of sitting around twiddling thumbs, or .vs. doing "real work" better suited...)
That is a deep time and money hole that only looks like a puddle.
The best answer is to hand over the schematic and the parts to a real PCB designer and have the board made. Much better quality and when they toast the first board, you can hand them one of the spares muy pronto.
Second best answer is to lay out the board using a combo house like:
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Using your valuable machining skills to make a $30.00 PCB is a *very distant* third in efficiency terms.
--Winston
I have in the past used ExpressPCB and was satisfied with their work. They'll give you three 2.5" x 3.8" double sided boards, two day turnaround for $51 plus shipping.
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Disclaimer: No connection, just a satisfied customer.
Jerry
12 square inches. 6 boards. With barely any looking at all:
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2 layer, no soldermask, no silkscreen 6 boards $123 +shipping
2 layer, soldermask, silkscreen 6 boards $258 +shipping
Get the size down to 9 square inches and save some money, or go as big as 19 for the same money.
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does slightly smaller boards at $59.60 for 3 delivered- size 2.5"x3.8" (exactly) no soldermask or silkscreen.
For soldermask and silkscreen, the protopro service will do batches of 4 at $179 +ship - you might make each delivered board be two boards you cut apart and get 8, if you can get the size down to 10.5 sq inches (max of 21 in this price/production class).
There are others, depending on where you want to go and how fast you want to ship.
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is in Bulgaria, for instance - and will give you as many of your little boards as fit in a 12.6x7.8 inch rectangle (cut apart by them), with soldermask and silkscreen, for $132 (plus shipping). I think you can get at least 6 3x4 boards out of that panel - 8 if you shrink the 4 inch dimension just a touch.
According to Ecnerwal :
Be warned that you *will* need (tiny) solid carbide end mills, and that the swarf will be *very* abrasive to your machine's ways, so better fix a shop vac to control the waste.
HSS *will* go dull so quickly you won't believe it with any form of fiberglass epoxy printed circuit board material.
Good luck, DoN.
What about Eagle? It has a free version that should do the trick, and will generate standard Gerbers that you can shop around. I don't use it, but a lot of people do:
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Best regards, Spehro Pefhany
Don is correct about the drill bits. Sometimes resharpened, but rejected bits are available on EBAY. Also, be aware, your equipment will never be able to turn the drill bits fast enough and they will probably break on you. They need to turn 20,000 rpm of faster.
Also, good luck!
Paul
I had a special machine to do that with - a CNC. The tough part is the 10 and 7 and 5 mil 2 edge endmills and stuff like that. Tiny stuff for between IC pads and making transmission lines right. If you have a simple one and think you can keep the board down FLAT then try. Side load is a killer.
Mart> I have a robotic vehicle control box that I farmed out to the EE boys.
Try E-teknet, in Arizona. They have a proto deal right now that is $24 each for 4 boards. You could maybe put two patterns on the board and get 8 units. You'd just have to cut them apart.
See
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Jon
And the green "stuff" gets into your skin like a hair shirt. (The mill I bought was used for PCB work, and I didn't tumble until too late, to the fact that the green stuff was G10 itching powder..., and not some type of cooland-borne algae..) /mark
50 mil spacing isn't odd at all unless the design grid is set to 100.
If you can change the grid, place your parts at 100, then change to 50 (or 25) for routing.
If not and you can top-solder the H Bridge pins, you could make the pads oversize or use Copper to place fake pads where you want the off- grid holes, then drill them manually.
jw
What is the manufacturer and part number? Sometimes they have dimensions for the decal in the data sheet.
jw
Full spec on the package here
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