nice description.
i have never seen this pcb material here but also have no need for it (have plenty of fr4 for.. well
lets say many years.)
the problem with drilling of fr4 i solve by buying good drill bits at ebay. a guy there (actually a
woman i think) sells lots of them which have been exchanged in precautionary tool exchange.
they are in very good shape, no resharpening required. (they normally break before they get dull - i
hope this improoves with the new drill press).
the cutting i do with a padsaw and a blade which is sold for cutting flagstones.
how do you cut the pcb material?
i know it is possible by this paper-cutter like machine which has a blade that chops it of.
this cutters are also used for sheet metal in a similar construction.
but they are expensive and i also don't like the edges (i have seen a original bungard one and the edges
are broken not cut)
i thought of using a angle grinder with 1mm thick cutting wheel or diamond wheel and fix it somehow
under a small desk but never tried.
any new and nice ideas are very welcome.
have all of you professional pcb drill presses or how do you drill your boards?
(maybe homebuilt ones and a picture of them???)
regrinding drill bits (for pcb) should be possible with a small diamond wheel?
is this true / is this possible & good for one who can regrind a normal drill bit so that it works
again? i have no idea where to get a diamond grinding wheel, has anyone ideas?
regards
stefan
(@ Leon especially:
why have you so small rings around the drill holes?
has this a certain reason or simply do you like it this way?
i make them much bigger because they provide much more mechanical stability then.
i actually like oblong pads at in-line parts (like dil).
they are good to solder and also withstand the one or other soldering out and in again.
)
18.05.2003 13:42:22, "Leon Heller" <
leon_heller@...> wrote:
>I've been making my own PCBs at home for about 40 years, starting by
>painting the pattern onto single-sided PCB material using a fine
>paintbrush and cellulose paint, with ferric chloride or ammonium
>persulphate etchant. I used 0.1" graph paper for designing the layout
>then marked the holes with a centre punch through the paper onto the
>copper surface. I even made a couple of double-sided PCBs using this
>technique, by masking off one side, etching the other side, drilling it,
>and using the drill holes as a guide when painting on the resist on the
>second side. I then masked off the first side with tape to etch the
>second side.
>
>When low-cost CAD software became available (I used Easy-PC from Number
>One Systems for years) I progressed to printing 2:1 artwork on a dot
>matrix printer. I then got a local litho platemaking company to produce
>a 1:1 positive transparency that I used with a home-made UV exposure
>unit and resist-coated PCB material. When I got an ink jet printer I
>found that I could get reasonable results by printing 1:1 artwork onto
>tracing paper.
>
>I now use an old LaserJet IIIp I picked up very cheaply to print 1:1
>onto LaserStar film and expose the PCBs in a home-made UV exposure unit.
>I sometimes use tracing paper (nice and cheap), but find that I get
>better results from the LaserStar film. The CAD software I use is
>Pulsonix, a professional package out of the same stable as Easy-PC. I
>regularly use 12/12 design rules, occasionally going down to 10 mils if
>I need to route tracks between IC pads. Rather than conventional
>positive-resist FR4 PCB material, I usually use something called FPC-16
>which consists of a sandwich of compressed paper between thin layers of
>fibreglass. It's cheaper than FR4 and much easier to cut and drill. It's
>available from Mega Electronics, as is the LaserStar film.
>
>Etching is in ferric chloride. I place the etchant in a small plastic
>food container inside a larger container half-filled with hot water and
>continuously agitate the etchant manually by rocking the container.
>Etching typically takes 5-10 minutes.
>
>I'm quite pleased with the results. I intend to experiment with
>double-sided boards by making a UV exposure unit that can expose both
>sides of the PCB simultaneously. With a better printer and vacuum on the
>UV exposure unit I think I could get 8 mil tracks quite reliably. I've
>heard of other people managing it at home.
>
>Here is an example of one of my PCBs:
>
> http://www.geocities.com/leon_heller/pcb.html
>
>I often use the Pulsonix copper pour facility for this type of board, as
>it makes the routing easier. Cross-hatching is better with a laser
>printer, as they don't tend to print large black areas very well.
>
>Links:
>
>Mega Electronics: http://www.megaelect.demon.co.uk/
>Number One Systems: http://www.numberone.com/
>Pulsonix: http://www.pulsonix.com/
>
>Leon
>--
>Leon Heller, G1HSM
>leon_heller@...
>http://www.geocities.com/leon_heller
>
>
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