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DIY pc boards-tips I learned

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MrDEB

Well-Known Member
well I finally got around to using the laminator I purchased from Pulsar,
got to worring that I was doing something wrong. The tech support is GREAT, lots of info from the company.
I printed boards onto the transfer paper using print density 5 - a must for quality
turned on laminator, light comes on after 5 minutes. ran board through the laminator-MISTAKE!!
Run through the laminator AFTER 20 miniutes of warm up
Have a pan of water to cool board immedietly after passing board through twice-once from each end, the narrow width.

MISTAKES-not enough laminator warm up
did not cool immediately
when using the green ttf paper use the high setting.
The boards came out GREAT compared to using an iron
for etching - 1 part muratic acid and 2 parts hydrogen peroxide. cheaper, easier and seems to work just as fast.as the brown etching gunk.In the scan I havn't cleaned or cut square the boards yet.
experimented with an adapter I made for the Dremel tool to use in a drill press. Worked really well.
going with SMT as Pulsar told me they are working on a hot plate or ? that you don't use a soldering iron to use smd
 

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3v0

Coop Build Coordinator
Forum Supporter
In time your boards will look as good as commerical ones. I have been cooling my boards prior to soaking the paper off. Need to try em hot.

I do similar for SMD but use a teflon fry pan on a gass burner in the kitchen. You place the PCB in the pan then turn on the heat. When all the past becomes liquid solder it is done. Takes maybe 2 to 4 minutes. I use medium heat.

3v0
 

picbits

Well-Known Member
I'm still using photoresist. I get consistent results everytime (after years of practice).

I've got it down to a fine art now. I can etch around 40 100x160mm boards a day when on a good run.

Drilling them is another matter though - I must get round to finishing off the flaming CNC milling/drilling machine that I've been working on for the last couple of years lmao.
 

MrDEB

Well-Known Member
I tried pulling the paper hot

I find after talking to PULSAR that the process works best when the board is cool. recommend cooling in water immediately.
have to try the fry pan smd.
question ? when do you apply the solder or ??
need explanation on technique if possiable.
 

richard.c

New Member
Interesting results - I thought long and hard about trying the Pulsar system, but the shipping / delivery times were difficult - so decided to try a diy LED UV box.

Although the presensitised boards are expensive - haven't looked back - the results are good and consistent as the pics show - the pcb has T8 and T12 tracks.
 

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mvs sarma

Well-Known Member
I'm still using photoresist. I get consistent results everytime (after years of practice).
I've got it down to a fine art now. I can etch around 40 100x160mm boards a day when on a good run.
Drilling them is another matter though - I must get round to finishing off the flaming CNC milling/drilling machine that I've been working on for the last couple of years lmao.
we were searching for positive photo resist from Farnell ELECTROLUBE|PRP200|PHOTO RESIST | Farnell United Kingdom
But the Farnell (India) said that they are not permitted to air lift them
So we had to manage with only toner transfer on a glazed inkjet printer paper.
 

picbits

Well-Known Member
Interesting results - I thought long and hard about trying the Pulsar system, but the shipping / delivery times were difficult - so decided to try a diy LED UV box.

Although the presensitised boards are expensive - haven't looked back - the results are good and consistent as the pics show - the pcb has T8 and T12 tracks.
Very nice results Richard.

What UV LEDs are those ? I've got a nice double sided scanner I'm planning on using for exposing my PCBs when I get round to adapting it with LEDs :)
 

richard.c

New Member
we were searching for positive photo resist from Farnell ELECTROLUBE|PRP200|PHOTO RESIST | Farnell United Kingdom
But the Farnell (India) said that they are not permitted to air lift them
Think the did you a favour - I initially tried the spray stuff, with lots of trials and expense I'm sure you can get it to work - but what a pain !
Although expensive the CIF precoated boards like the ones from Farnells do give top class results, and you can readily cut off small pieces of the board without damaging /exposing the coating.

Don't bother with the CIF sachets of developer, its caustic soda -very agressive - try and get Sodium MetaSilicate - soldby RS as -
| PCB Prototyping & ESD Handling | PCBs or Prototyping Systems | PCB Processing | Processing Chemicals



What UV LEDs are those ? I've got a nice double sided scanner I'm planning on using for exposing my PCBs when I get round to adapting it with LEDs
Fairly standard 5mm ones - have used them from both these suppliers who gave good service.

UV 5mm LED - phenoptix

GOODWILLSALES LTD 3mm leds, 5mm leds, 10mm leds, ledstrip lights, superflux leds. led holders, T5 led auto lights, T10 led auto lights, waterproof led strips-B CLEAR 5mm-G4 QTY 100 WATERCLEAR ULTRA VIOLET 130mcd 5mm LEDS
 

Mr RB

Well-Known Member
Interesting results - I thought long and hard about trying the Pulsar system, but the shipping / delivery times were difficult - so decided to try a diy LED UV box.

Although the presensitised boards are expensive - haven't looked back - the results are good and consistent as the pics show - the pcb has T8 and T12 tracks.
Richard, what system do you use for artwork? Is that a special paper, and what printer do you use. Thanks.
 

richard.c

New Member
Mr RB
Quote:

Richard, what system do you use for artwork? Is that a special paper, and what printer do you use. Thanks.
I use an early, purchased version of Proteus Ares and the printer is a cheap Brother 2030 laser.
The paper - you need to try a couple to see what gives the best results on your printer - I have tried a thickish tracing paper and Laser Star film which both give good results although there are many others.
You need to look at two things - one, the obvious quality of the printed tracks, the other - hold the paper up to a light and look at a solid area through a magnifying glass - as you will see its probably not a solid black, so use whatever paper gives the most solid results.







mvs sarma Thanks richard.c for the comments regarding PRP200.
You are welcome - just wish we had your sunshine - would have saved me the cost of the UV box !
 

richard.c

New Member
picbits Out of curiousity, what is your exposure time on the LED box Richard ?
4.5 mins for pre coated boards from Farnells or Mega - although that will very much depend on your leds parameters, their spacing and distance from the copy.

The only helpful facts I found was from this Elektor article - but use it as a general guide only, those paricular leds are not readily available any more .

http://www.electro-tech-online.com/custompdfs/2009/05/uv_light_box.pdf

Both me and a friend found that the leds, 5mm at 20deg ,130mcd, 20mm spacing needed to be positioned much further away from the copy to give an even light spread - typically 6" or more.

If you cover your copy board with plain paper, it shows how good the led beams are - the first pic is at the Elektor suggested distance the latter at 6 inch depth which does give, in practice, a good even coverage across the entire A5 area and produced the t8 tracks shown earlier.
.
 

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3v0

Coop Build Coordinator
Forum Supporter
question ? when do you apply the solder or ??
need explanation on technique if possiable.
There are several ways to build a SMD board.

You can solder the parts in place using a soldering iron.

The remaining methods use solder paste.

Solder Paste 200X

It is a flux paste with tiny balls of solder in it. The paste is applied to the PCB solder pads using a syringe or a stencil and squeege. You can have clear plastic stencils cut by Pololu or etch them from brass sheets. I cut my plastic stencils using a method I worked out for the cricut.

Once the paste is on heat the PCB to melt or reflow the solder.

The use of electric fry pans was first suggested by SparkFun Electronics. They used this method for production until recently. Sparkfun has several good tutorials on SMD soldering. Sparkfun tutorials

More "professional" soldering is done in an oven. A contoller is used to ramp the temperature up and down according to a specified profile. Some people have modified toaster ovens to follow the profile.

3v0
 

richard.c

New Member
3v0 Richard,
Pulsar uses a "foil" that bonds to the toner. It comes in several colors. You may be able to use this or a similar foil to darken you artwork.
Yes that may well help, the problem is the Pulsar system is not readily available in the UK.

- and apologies to MrDeb if I've high-jacked his thread


Other suggested methods for increasing the copy density - using a wipe off marker, which didn't wipe off my copy ! - and also using two printouts together, but that is very difficult to hold in register when using fine tracks

Once I got the leds positioned correctly and step test done, I found I could get a good image with the original raw printout.
 

richard.c

New Member
3v0
Quote:

Plusar Transfer Paper and foil is carried by Flightline Graphics in the UK
Thanks - that's good to hear - didn't find them in the dealer list when I was looking at the Pulsar system earlier in the year - looks like its proving very popular with all those big name dealers onboard.
 
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