MANUFACTURE PCB

[Davor]

I prefer jumpers over 2 sided PCBs and no tracks between IC pads.
I'm OK with 2 sided boards, provided one side is exclusively used for ground plane and preferably with heat relief pads for ground connection. And certainly no vias.

[Pete the Builder]

I prefer jumpers over 2 sided PCBs and no tracks between IC pads.
I'm OK with 2 sided boards, provided one side is exclusively used for ground plane and preferably with heat relief pads for ground connection. And certainly no vias.

...and would you like fries with that?

Don't forget, I can arrange for manufactured double-sided boards, with solder mask and so on, which makes the final design a lot more robust - not to mention easier to solder! I get them done through ETT in Thailand, and so far they've been exceptionally well-made. They'll even go outside spec if you ask nicely, and they're always happy to cut the boards as well. And even with a $25 solder mask and $25 silkscreen setup cost, single board quantities are really reasonably priced. And if a design is popular, that works out to be an extra couple of bucks a board. And the solder masking sure makes it easier to do a great job, and it beats the heck out of trying to align vias by hand!

If you have specific requirements above and beyond typical relief specs, I'm more than happy to add prunes to All Bran. I'd rather over-design something and have it last a lot longer and keep you a happy camper, than take shortcuts and risk reliability. It's just the way I roll...

Thanks for the feedback!

[Pete the Builder]

Hello Pete,

For my boards I use most 0,8 mm for tracks and 2,0mm for pads as best, (dips 1,6mm) no go between dip's ...beter an extra link on the board.. and lots off space for tracks and pads..

Most DIY people here have 'normal' tools .. so design boards that can be made and used by all ... just may way..

Best regards.

Ap

That's right up my alley. I veer away from huge square pads with enormous blank voids, as that makes it so much harder to drill accurately, and pointy things always mess things up in a complicated layout.

I use very conservative tracks and pads everywhere (typically 25mil for signals, 70mil for low-current power, 200mil for high-current) (Sorry, I learned all my drafting in the late 70s, and it's the one area I still can't metric-ise... I'm starting to have to for MCUs, they're nearly always in mm these days).

I drill all my single-sided stuff by hand too, so I know how important that is. You'll find that I use big round thick pads for passives, generally 60mil with 32mil holes, so after plating there's still a generous solder area and the leads don't get stuck or damage the plating. I'm really fussy about IC pads, power tracks, signal traces, and capacitive and inductive coupling, but that's from a TTL or CMOS digital perspective. It will be interesting to work with microvolts and picofarads making a difference!

And I always go overboard on mounting holes wherever I can get away with it. There's nothing worse than having to dig around for an insulating washer because some ******** has put components too close to the mounting hole. Or worse, the holes are too small and there's not enough annulus! I always create mounting holes to take M3 or M4 screws.

As far as grounding goes, I'm quite happy to do a VCC/GND plane fill for those who like that, or a GND/GND for the traditionalists, or a single GND plane, or none at all. Altium makes that stuff so simple it's ridiculous. As long as I remember which is which, of course!

I might put up a recent PCB design to show what I mean. I think I still have an old Rover design floating around on the big system. I'll dig it out and post it here so folks can see what I mean. That's probably better than just flapping my gums about how wonderful, intelligent, and handsome I am.

-Pete

[golfnut]

Is there a link to the Print and Peel method. ??

S

[Pete the Builder]

Is there a link to the Print and Peel method. ??

S

Have a look at http://techniks.com. They have a great explanation of how the process works (it also comes printed with their packs, or at least it used to).

It's basically like a t-shirt transfer, except instead of a t-shirt, you use a blank PCB!

It's not a difficult process at all, but you do need access to a laser printer. Any photocopy place should be happy to print off a design for you if that's a better solution. I bought a new HP laser printer at **** Smith's for AUD$78.00, so I'm sure other countries can find even cheaper bargains. It actually costs more for toner than it cost for the printer, but it then became a throw-away printer!

Basically, you print the 1:1 PCB design on the special paper. You then take that paper and use heat and pressure (from a clothes iron is fine) to make the toner on the sheet stick to the bare copper PCB surface. Then you etch the board. Then (I assume) you win the Nobel Prize! (I mean, it all sounds so easy, but real life physics gets in the way!)

I had a really bad run of board designs, then I found out I'd bought a refilled toner cartridge. So I tried 3 different toner refillers (price didn't matter), and I got the same problem with each. At the time, it was a terrible waste. So I don't care how great a toner refill process is, genuine toner will make your life so much easier you could kiss me! Please don't kiss me. Just use good quality toner, and you'll figure out the precise temperature and pressure you need to use. Then stick with what works for you.

You can easily etch tracks between IC pins, and if you're really keen, you can print and solder nearly any modern IC, certainly down to 12.5 mil pitch with a 600dpi printer. Soldering those suckers is another art in itself, but it's absolutely possible to print, transfer, and etch at least as clearly as your laser printer allows. With care, you can hand-solder LQFP packages (the ones with no leads at all).

BTW, I like the idea of HCL and H2O2... But in Australia, that's not easy for the average Joe to find... at least, not good quality items! We can easily get brickies' cleaner (which is about 17% HCL, but it contains many impurities), but anything that I'd consider usable in etching would have to be ordered from a specialist chemical company. Unless someone's tried cement cleaner?

Jaycar (and I think Altronics) still stocks a great etching tank kit, consisting of an etching tank (they still call it a 'kit' though). You can buy a small air pump (1-2 cu. ft/min is fine) at any aquarium place, and since the acid doesn't come into contact with the pump, it should be fine. You do need to compress the fittings though, the plastic air inlet is usually a bit dodgy on those plastic tanks.

For a reasonable cost, you could get an etching system that should produce pretty much any board you care to design, is easy to clean and pack away, and it's a lot of fun figuring out how to defeat the bubbles sticking to your pad holes in the tank... What fun for everyone!

Sorry to go on about it. it's just such a reliable and repeatable process... You can turn around a design in under 20 minutes, screen to fully etched board (18 minutes is my record, but that was with fresh everything - PnP film, toner, etchant, and PCB).

I hope this helps and doesn't confuse anyone!
PtB

[nick_f]

Hi, It is very easy to purchase hydrochloric acid in Australia. Any Bunnings store has plenty in stock and it is really cheap (about $13 for five liters or $5 for 500ml) and it has perfect quality for PCB etching.
I was also able to buy 500ml H2O2 concentration 45% or 50% from a hydroponics shop, which now closed down, for only $10. I enquired with some other hydroponics companies, but most didn't bother to answer my emails.
But on ebay you can still buy H202 35% but it is much more expensive ($60 for 500ml, food grade).
If people decide to use this mixture, they need to dilute it with water, probably in a 1:3 to 1:4 ratio. I used the same solution for over one year, just by adding a bit of H2O2 as required and sometimes a bit of HCl.
Recently I moved from PressNPeel blue sheets to Kinsten presensitized and a UV Light board made with over 200 UV leds. Results are extremely good. In Australia, sun is so rich in UV that probably exposing the board for 5 minutes in the sun will be enough for presensitized PCB.

Regards,
Nicolae

Have a look at http://techniks.com. They have a great explanation of how the process works (it also comes printed with their packs, or at least it used to).

It's basically like a t-shirt transfer, except instead of a t-shirt, you use a blank PCB!

It's not a difficult process at all, but you do need access to a laser printer. Any photocopy place should be happy to print off a design for you if that's a better solution. I bought a new HP laser printer at **** Smith's for AUD$78.00, so I'm sure other countries can find even cheaper bargains. It actually costs more for toner than it cost for the printer, but it then became a throw-away printer!

Basically, you print the 1:1 PCB design on the special paper. You then take that paper and use heat and pressure (from a clothes iron is fine) to make the toner on the sheet stick to the bare copper PCB surface. Then you etch the board. Then (I assume) you win the Nobel Prize! (I mean, it all sounds so easy, but real life physics gets in the way!)

I had a really bad run of board designs, then I found out I'd bought a refilled toner cartridge. So I tried 3 different toner refillers (price didn't matter), and I got the same problem with each. At the time, it was a terrible waste. So I don't care how great a toner refill process is, genuine toner will make your life so much easier you could kiss me! Please don't kiss me. Just use good quality toner, and you'll figure out the precise temperature and pressure you need to use. Then stick with what works for you.

You can easily etch tracks between IC pins, and if you're really keen, you can print and solder nearly any modern IC, certainly down to 12.5 mil pitch with a 600dpi printer. Soldering those suckers is another art in itself, but it's absolutely possible to print, transfer, and etch at least as clearly as your laser printer allows. With care, you can hand-solder LQFP packages (the ones with no leads at all).

BTW, I like the idea of HCL and H2O2... But in Australia, that's not easy for the average Joe to find... at least, not good quality items! We can easily get brickies' cleaner (which is about 17% HCL, but it contains many impurities), but anything that I'd consider usable in etching would have to be ordered from a specialist chemical company. Unless someone's tried cement cleaner?

Jaycar (and I think Altronics) still stocks a great etching tank kit, consisting of an etching tank (they still call it a 'kit' though). You can buy a small air pump (1-2 cu. ft/min is fine) at any aquarium place, and since the acid doesn't come into contact with the pump, it should be fine. You do need to compress the fittings though, the plastic air inlet is usually a bit dodgy on those plastic tanks.

For a reasonable cost, you could get an etching system that should produce pretty much any board you care to design, is easy to clean and pack away, and it's a lot of fun figuring out how to defeat the bubbles sticking to your pad holes in the tank... What fun for everyone!

Sorry to go on about it. it's just such a reliable and repeatable process... You can turn around a design in under 20 minutes, screen to fully etched board (18 minutes is my record, but that was with fresh everything - PnP film, toner, etchant, and PCB).

I hope this helps and doesn't confuse anyone!
PtB

[shutter]

Hi everyone. Great info here!

I am about to make my first MD, and I've reached the part where I have to manufacture the PCB. I purchased a few sheets of transparent foils for the press and peel method, called TES 200. Anyone used them before? I will try them out today and will get back with the results.

Regards,

[sido]

Hi everyone,

Not sure if Andreas still posts here, but what he was referring to his initial post was modifying a existing printer to accept the right thickness PCB+feeder plate to print direct on to the PCB instead of paper then place in acid to etch.

I just started to modify a surplus Canon printer after seing a Youtube video which someone did the same and produced boards to accomidate up to SMT format. Dont have a link to it, but you could do a search.

The process is you first print on rear feeder plate to see where you will place the blank PCB. Then you tape the PCB on the rear plate where the outline is established, heat it up with a hot air gun to allow ink to stick better and re-feed it through the printer to produce the track layout. Reheat the board again so the ink dries up well and then place in the etching solution.

Very simple process with great results if you can modify the printer to accept the right thickness.

Not all printers will do due to mechanical restrictions and some require the scanner bed connected due to fault symptoms diagnosis restricting proper operation.

The one i have here still works without the scanner bed so even though it detects that it is not connected....it still works. Not many do, but this model Canon does

There is alot to modify, but will see if the effort is worth it. Slow project, but on the to do list.

Cheers Sid

[satdaveuk]

Hi
I started hacking a Epson C80 earlier last year but left it on hold because there is alot more involved with mine, and another reason Ive not been that eager to carry on at the moment is inks.
I belong to a forum that specializes in just that, hacking printers for PCB purposes and theres been some very good results but often its getting the inks that will do the job without clogging up the jets Anyway on another note, push forward with it and let me know how you get on because its all about new ideas trials and errors.

Regards

[Qiaozhi]

I belong to a forum that specializes in just that, hacking printers for PCB purposes ...

Is there any chance you could post a ink to the forum?

[laika]

http://alex-avr2.livejournal.com/925...age=1#comments

[Baterista]

http://alex-avr2.livejournal.com/925...age=1#comments

Excellent, very interesting.

[barwildi]

Just thought I should mention this:

For the heat/toner transfer method, I read somewhere on the 'net that parchment paper works very well. More so than any of the glossy papers because it requires less pressure to make the toner stick. I have not yet tried this. But I plan to for my next PCB build.

Cheers!

[6666]

Maybe this one ?

http://www.ebay.com.au/itm/SILICONE-...item19e06b4090

[barwildi]

Maybe this one ?

http://www.ebay.com.au/itm/SILICONE-...item19e06b4090

No, that's way too expensive! I'm talking about the 45 sq. ft. roll of paper anyone can buy from their local supermarket for around $3.50. See picture.