Re: [Homebrew_PCBs] Sodium PerCarbonate
2013-07-17 by Norm
... H2O2 is available at 3% concentration in drugstores (pharmacies) as a topical antiseptic should be cheap - here in the US it s about $0.95 per pint. It is
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Sodium PerCarbonate
2013-07-17 by Kerry Koppert
I live in a small largely agricultural country any chemical is difficult to obtain (unless it has a household or agricultural use). I d like to try
Re: How to tackle thermal pads on SMT packages?
2013-07-15 by RDHeiliger
Have never had a heat problem with ceramic caps, would think even with ground connection on bottom of board heat will travel to them anyway. Likely get by with
Re: [Homebrew_PCBs] Re: For a DIY exposure box ... is collimated light an issue?
2013-07-15 by Mitch Davis
... LOL, paid.
Re: [Homebrew_PCBs] Re: For a DIY exposure box ... is collimated light an issue?
2013-07-15 by Phil@Yahoo
Darn. I was planning on getting an appliance box and closing it up with myself inside with a mercury vapor lamp with the glass envelope broken off and making
Re: [Homebrew_PCBs] Cheap chinese toner transfer sheet
2013-07-14 by James Sleeman
Kerry, gail_and_nick on Trade Me has these instructions in their listings for what looks to be the same stuff
Re: [Homebrew_PCBs] Re: For a DIY exposure box ... is collimated light an issue?
2013-07-14 by Donald H Locker
That would be Carbon Monoxide (which binds to hemoglobin better than normal Oxygen, causing suffocation). Ozone is a pulmonary irritant, causing lung damage in
Cheap chinese toner transfer sheet
2013-07-14 by Kerry Koppert
I have purchased some cheap toner transfer sheet off ebay
Re: [Homebrew_PCBs] Re: Another Approach to DIY PCBs - PCB Press
2013-07-14 by Andrew Hakman
Back in highschool, which was quite a while ago now, we used to use a similar method, but using a tee shirt press, and something that looked like overhead
Re: Another Approach to DIY PCBs - PCB Press
2013-07-14 by fred27murphy
Looks like you made it onto Hackaday. Always a good sign.
Re: How to tackle thermal pads on SMT packages?
2013-07-14 by ohmware
Yeah, I ve gotten to this point for many of the same reasons. I m trying my first experiment with the TPS54386. I picked it partly because TI offers a nice
Re: How to tackle thermal pads on SMT packages?
2013-07-14 by ohmware
The data sheet shows something like this, but they isolate an area of the bottom ground plane directly under the chip from all of the other large PS components
Re: How to tackle thermal pads on SMT packages?
2013-07-14 by ohmware
I have lain out the board with this approach in mind. It s pretty close to the data sheet layout, and if I later want to have boards made professionally I can
Re: [Homebrew_PCBs] Another Approach to DIY PCBs - PCB Press
2013-07-14 by Todd F. Carney / K7TFC
Hey, Mark! Did you try using Aunt Jemima as a resist? Yuk, yuk, yuk! 73, Todd ... K7TFC / Medford, Oregon, USA / CN82ni / UTC-8 ... [Non-text portions of this
Re: [Homebrew_PCBs] Another Approach to DIY PCBs - PCB Press
2013-07-14 by James
You might try a wet cloth on top of the paper when you press it, like Fran Blanche does - she s using the Press-n-Peel paper stuff, but it might help with your
Another Approach to DIY PCBs - PCB Press
2013-07-14 by Mark Schoonover
Still digging the toner-transfer method over any other process, came up with the PCB Press. http://www.ka6wke.net/finished-projects/pcb-press Comments most
Re: [Homebrew_PCBs] Re: Developing dry film photoresist
2013-07-12 by DJ Delorie
... Anyone doing photo exposures should get a step transmission gauge and *test* their exposure, so that they *know* it s correctly exposed. They re cheap and
Re: How to tackle thermal pads on SMT packages?
2013-07-12 by cunningfellow
... For prototypes that need vias and you want to do at least one spin at home before sending off to a factory made board TRY the copperset through hole
Re: How to tackle thermal pads on SMT packages?
2013-07-11 by epa_iii
I know this is a Homebrew PCB group, but sometimes you have to get out of the box. I also am presently working on a power regulator design, using modern
Re: How to tackle thermal pads on SMT packages?
2013-07-11 by RDHeiliger
Have done a number of boost and buck converters, down to .5mm. Done them all single sided. If you fiddle with the layout you can get the traces pretty short.
Re: Developing dry film photoresist
2013-07-11 by David Punsalan
I think the reccomendation of checking the mask is a good one. You might try reducing your exposure time as well
Re: [Homebrew_PCBs] How to tackle thermal pads on SMT packages?
2013-07-10 by DJ Delorie
What I ve done is just make a big hole where the heatsink goes, big enough to solder the heatsink from the other side after the part s other pins are soldered.
Re: [Homebrew_PCBs] How to tackle thermal pads on SMT packages?
2013-07-10 by Phil@Yahoo
I have no direct experience but I know what I would do. I would put the rivets in the thermal pad area first, cover the rest of the board with adhesive plastic
How to tackle thermal pads on SMT packages?
2013-07-10 by Kaelin Colclasure
I m looking to stretch my luck by trying a design that uses all SMT packages. At the moment I am pondering how to tackle the thermal pads commonly found on SMT
~7:1 contrast laser printed phototools
2013-07-10 by Robin Whittle
In Re: [Homebrew_PCBs] Re: Developing dry film photoresist , Kerry Koppert wrote about trouble with the track resist not being solid enough ... I have had
Re: [Homebrew_PCBs] Re: Developing dry film photoresist
2013-07-10 by Kerry Koppert
... Interesting, but I can t find it in New Zealand and importing 50 sheets would cost $100. ... [Non-text portions of this message have been removed]
Re: [Homebrew_PCBs] Re: Developing dry film photoresist
2013-07-09 by James Sleeman
... You print two copies of the artwork on tracing paper and put them togethor.
Re: [Homebrew_PCBs] Re: Developing dry film photoresist
2013-07-09 by Leon Heller
... Should be JetStar Premium. Leon -- Leon Heller G1HSM
Re: Developing dry film photoresist
2013-07-09 by Steve Keller
Hi, What is a gelatine coated trannys ? Thanks. Steve K. [Non-text portions of this message have been removed]
Re: Developing dry film photoresist
2013-07-09 by Leon
... You don t use a laser printer! I get excellent results with an HP 5940 inkjet and Mega Electronics JetStar film. Leon
Re: Developing dry film photoresist
2013-07-09 by cunningfellow
... You buy a $30K laser printer. When I lost access to the excellent fuji/textronix printer that I used to make artwork on I used a HP4xxx for a little while
Re: [Homebrew_PCBs] Re: For a DIY exposure box ... is collimated light an issue?
2013-07-09 by Todd F. Carney / K7TFC
On Mon, Jul 8, 2013 at 10:34 PM, Todd F. Carney / K7TFC ... Damn me if I didn t finally figure out where to look! Google: daylight
Re: [Homebrew_PCBs] Re: For a DIY exposure box ... is collimated light an issue?
2013-07-09 by Todd F. Carney / K7TFC
... Steve, The bulbs I used were sold through graphic-arts suppliers. I haven t been able to find them by Googling yet. Maybe they re not made anymore. I m
Re: [Homebrew_PCBs] Developing dry film photoresist
2013-07-09 by Kerry Koppert
... The stuff sold as developer by the chinese supplier is anhydrous sodium carbonate (washing soda). The solution I m using is 20g/L which is the strength
Re: [Homebrew_PCBs] Re: Developing dry film photoresist
2013-07-09 by Kerry Koppert
... Ah right on. Careful examination of the negative show mottling in the black (I m using artist s tracing paper in a Kyocera FX720 laser but I ve also tried
Re: For a DIY exposure box ... is collimated light an issue?
2013-07-09 by AlienRelics
In the 80s, I used bulbs that fit that description to expose negative resist coated boards. They were called Gro lights. There are several brands, that was
Re: For a DIY exposure box ... is collimated light an issue?
2013-07-09 by AlienRelics
If you choose not to take someone s advice regarding safety, that is your choice. But being snotty is not necessary. Steve Greenfield AE7HD your friendly
Re: [Homebrew_PCBs] Re: For a DIY exposure box ... is collimated light an issue?
2013-07-08 by Phil@Yahoo
Hmmm.... A tad bitter and hypersensitive, but boring. And off topic. Try CL R&R -- Phil M. ... From: Todd F. Carney / K7TFC To:
Developer box
2013-07-08 by gail21
I have had great success with my home made light developer box, I used facial tanning tubes complete units can be bought off ebay complete with the timer
Re: For a DIY exposure box ... is collimated light an issue?
2013-07-08 by designer_craig
Here is another idea for consideration. On Ebay one can buy HID Xenon auto head light kits for around $30. The kits have 2 bulbs with 2 ballast but no
Re: For a DIY exposure box ... is collimated light an issue?
2013-07-08 by designer_craig
Years back I had a nice exposure box, three 18 desk lamp size T8 15W UV tubes on the bottom half and 3 on the top half. Boxes (upper and lower)were of white
Re: [Homebrew_PCBs] Re: For a DIY exposure box ... is collimated light an issue?
2013-07-08 by "Zoran A. Šćepanović"
... HG vapour lights have the same UVC wavelength as the germicidal lamps, i.e. 273 nm. Not to poke your eye with a couple of fingers :-) Hg vapour lamps with
Re: Developing dry film photoresist
2013-07-08 by tda7000
Washing Soda does work, I have been using it since Day 1 with the photo-resist process as it was the cheapest and easiest for me to get. (And with the blue
RE: [Homebrew_PCBs] Re: For a DIY exposure box ... is collimated light an issue?
2013-07-07 by Boman33
Phil, You sound like me. Decades ago I also tested mercury lamps with the outer glass envelope broken off. Surprisingly it worked worse than with the envelope
Re: [Homebrew_PCBs] Re: For a DIY exposure box ... is collimated light an issue?
2013-07-07 by Todd F. Carney / K7TFC
... Wow. Interesting comment, though it doesn t seem very relevant. I guess it s the sort of thing we can expect when someone tries to bolster his own self
Re: [Homebrew_PCBs] Re: For a DIY exposure box ... is collimated light an issue?
2013-07-07 by Phil@Yahoo
Wow. Interesting story, though it doesn t seem very relevant. I guess that s the sort of thing we can look forward to as a result of emphasizing self-esteem
Re: [Homebrew_PCBs] Re: For a DIY exposure box ... is collimated light an issue?
2013-07-07 by Todd F. Carney / K7TFC
... A drive-in printer!! Very cool! Back in the 70s, I used to expose offset printing plates using a 300w blue frosted bulb with a high-UV output. It was just
Re: For a DIY exposure box ... is collimated light an issue?
2013-07-07 by fred27murphy
I totally agree. Whilst you don t want to completely waste time and effort repeating others mistakes, there s a lot to be learned from giving version 1.0 a go
Re: [Homebrew_PCBs] Re: For a DIY exposure box ... is collimated light an issue?
2013-07-07 by Todd F. Carney / K7TFC
... This is the single-most important piece of advice related to contact printing anything photographic. We used to specify that pcb negatives be
Re: [Homebrew_PCBs] Re: For a DIY exposure box ... is collimated light an issue?
2013-07-07 by brane2
... I didn t mean to be rude here, just to say that satisfying legal constraints usually needs knowing _exact_ requirements and just plopping _somewhere_