Making a home brew printed circuit board

[chucketn]

I have finally succeeded in making apcb for my Rotary Table indexer project. Next step is drilling thethrough holes for the components. The component leads range from.020” to .042” Can I use HHS drill bits or should I getcarbide?
I have a HF bench model drill press and an X2 mill. Whichwould be better? What speeds for the dill bits? Any othersuggestions/cautions?

Chuck

 

[Journeyman]

Fibreglass PCB material wears out HSS fairly quickly so carbide will last longer but either could be used if you are only doing the one board. I doubt whether either of your machines will really get a high enough speed for such a small drill. You need in excess of 3000rpm. Something like a dremel or proxxon in a stand is ideal. If you have to use the drill or mill go for the highest speed you can get. The mill might be best for doing rows of holes for IC's.

Cheers John

 

[Tin Falcon]

I will do my best to answer this here . I have never make my own PCB . On my to do list I have a couple nice size pieces of PCB material. I would probably buy a pack of quality HSS 3/64 (.0469) bits and use the Dremmel drill press.
in your case use the x-2 at top speed.
small bits are sold by the dozen IMHO 3/64 is a good choice all leads will fit through and it happens to be the tap drill size for 0-80 screws. So a good size to have on hand.
I am trained as a machinist and work as an electronics tech of sorts so that may give me some credit. .
Tin

PS: This is my WAG answer if someone out there experienced has better advice take it. maybe troutsqueezer can help. It is science but you are not building a space craft.

 

[KIMFAB]

Used to do this back in the 70's
Even had an aluminum chase w/ stainless 600 mesh screen for the printing.

A good affordable method is to get a Foredom setup like the SR series

http://www.foredom.net/Foredom-Motors-Controls.aspx

and either figure a way to mount it to the quill or get a small drillpress stand.

Make sure you get the chuck with it and use carbide drills unless you only need to make a small PCB

 

[jasonh]

My 0.02:

If you like making your own PCBs, and that's an end in itself, then more power to you- but if you just want a PCB then using one of a number of PCB fabrication services is more convenient and gives better final results than homemade. ie- double sided, plate through vias, soldermask and silk screen. I can vouch for:

http://www.expresspcb.com/
They have simple downloadable (windows) tools for schematic capture and board design.
Submit your design via the internet - get it back in about a week. 3 x 2.5" x 3.8" boards - $51

http://www.goldphoenixpcb.com/
Send these guys the gerbers and drill file for your design.
100 in^2 = $100. You get as many of your design as fits in the area.
Made in Wuhan China, shipping is free and you get it about 7-10 days after order submission.

I used to make my own PCBs, but why mess with the chemicals, fiber glass dust and worn out drills when you can get such great results from the PCB fabrication vendors?

 

[gunna]

HSS drills may wear out quicker, but carbide drills are EXTREMELY fragile if put under sideways pressure such as moving the board slightly while withdrawing the drill for example.
Just my 50 cents worth.
Ian.

 

[skyline1]

I use A Dremel for mine But I would not recommend the latest Dremel drill stand (the 220) it is mostly made of plastic components and lacks rigidity use one of the third party ones like this http://www.ebay.co.uk/itm/1097-Milescraft-Rotary-Drill-Press-Tool-Stand-add-precision-to-Dremel-Type-tool-/221046012143?pt=Model_Kit_US&hash=item33775e78ef or one of the older Dremel ones like the 212 often available on EBay 2nd Hand. I fear that like many things Dremel accesssories are not as well made as they were.

If it is sufficiently large it is also possible to actually mount the Dremel on your mill and get the best of both worlds. as the spindle nose of a Dremel is a fairly standard size (3/4 x 12 T.P.I. B.S.F. ) and the body is the same size as the handle collar on most pistol drills. So you could even use a full size drill stand if you can find one accurate enough. simply clamp the entire Dremel in it.

As for drills, It depends on the type of boards you are doing and how many. the older S.R.B.P boards (the brownish ones) are quite suitable for H.S.S.
but the more modern fibreglass ones (the green stuff) like the common FR4 will blunt H.S.S. quite quickly (like about 50 holes or so) and as such small drills are very difficult to sharpen by conventional means. this can be a problem.
Solid carbide ones have a much better life but as other posters have mentioned are very brittle you will need a good solid drill stand and great care. They are also quite expensive but they will produce accurate precise holes in the toughest of P.C.B. materials.

Little drills like this, (in the range of 0.5 to 1.2mm typically) do require high speeds I run mine at 8000 - 15000 R.P.M. depending on size. In industry with rigid specialised machines speeds of up to 100,000 are common.

Regards Mark