Hey guys!

How about sharing your pcb etching techniques, eh?

I use a marker pen with permanent ink (with different sizes of the pen's tips), and just draw it right into the pcb.

I'm thinking of buying that press n peel film transfer thingy but it's too damn expensive :mad:

so what's yours?:cool:
Posted on 2003-03-31 20:47:18 by flotsam
www.ExpressPCB.com

62 bucks for 3 boards. Free design software. Get em back in 4 days.

Great deal!
Posted on 2003-03-31 23:15:35 by Ernie
i'm agree with Ernie, especially when you design something not for hobbies, but a real-life project and something big enough that you would take more than one day to drawing it. but if for something like 10cm*10cm board, of course you can do it yourself. i dont know what it said in english, but i'm using "rugos", such thing alike what you said, just press it with something and it cover the board. the result is finer than using pen marker.

and btw, somehow i remember that theres some rule and technique in pcb design, that would influence the final result, ie more stable, having good isolation, etc.
Posted on 2003-04-01 05:08:08 by dion
I was working on an x-y router table a while ago. But it has since been put on hold. It basically has a drumel tool with a fine routing tip on two x-y arms that move by CPU control. The z direction is route and not route.

It was designed to interperet autocad drawings.. but i grew tired fussing with WDMs... (still learning how to make one properly).

:NaN:
Posted on 2003-04-01 18:08:59 by NaN
I use Proteus VSM for drawing /simulating schematics and pcb layout.
Then I print the layout on normal paper and expose it a presensitized pcb in a homemade UV exposure box and etch with ferric chloride(not the safetest!).

if i print on tracing paper the exposure time is about 1 1/2 minutes if I use normal paper it's about five minutes but if I make the normal paper transparent by brushing it with cooking oil then exposure time is about 3 minutes.
I've gotten good results with both laser and inkjet printers down to about 8 thou.

the follwing picture show's the track side of a simple pcb i made.
Posted on 2003-04-21 05:35:53 by MArtial_Code
hi martial_code!

can you share with us your homemade UV exposure box specs?? I'm sick and tired of this permanent ink thingy;)
Posted on 2003-04-21 12:59:01 by flotsam
In section A of the attached figure...we have the four F8 T5 BLB tubes in parallel. Each tube has it's own starter and ballast.
Aluminium foil lines the bottom and sides of the box to reflect/redirect light.

Section B shows the front panel (if you can call it that)
the four neon indicators are connected to the four tubes. They indicate if the attached tube has fired( may shorten the life of the tubes).

Section C show some sponge on the inside of the cover. These keep the PCB and artwork pressed tightly together against the the glass.

SectionD shows the safety micro switch. if the lid is opened then the power is cut off.

dimensions:
I built the box to have an A4 exposure area.
It's made from 1/4 inch MDF.
it's outside dimensions are 17"x13"x6"
The UV tubes are 2" apart
The exposure surface is 4" from the top of the tubes and is made from glass which i salvaged from a ?1 picture frame.

I had a relay circuit built into the box which was controlled via the parallel port but I connected the dc power incorrectly and it burned out the relay driver-haven't gotten around to fixing it yet!

It's not pretty but it gets the job done...
Posted on 2003-04-22 04:00:20 by MArtial_Code
What are the size of the tubes, the wavelength, and their power.

When I was taking HS electronics, it was pretty is to fab my own board.

Since then (4 years later) I tried fabing boards with no results. I first tried sensitizing my own boards with KPR-N (may of been too old or I was using the wrong developer). Then I tried presensitized.

This was all done using a high power UV tube (36" long short wave)
Posted on 2003-04-22 04:09:26 by eet_1024
The tubes are standard 8 watt,12inch tubes. The wavelength peaks at about 350nm. These are the same tubes used in discos etc. they're refered to as Blacklight blue (BLB tubes).

I have used two different posistive photoresist materials on presensitized boards and have had no problems.
Posted on 2003-04-22 05:21:16 by MArtial_Code