another PCB recipe.

[carsten_the_dane]

Hey

Found this link. its a very clear recipe for the wellknown "way of the inkjet" pcb.

http://www.5bears.com/pcb.htm

/Carsten

[carsten_the_dane]

Btw. is there a way to avoid using Ferric clorid, which gives me the creeps.

/Carsten

[moebius]

Btw. is there a way to avoid using Ferric clorid, which gives me the creeps.

/Carsten

Yes,

By using something, which should give You even more creeps:

http://www.midibox.org/forum/index.php?topic=1964.0

Moebius

[carsten_the_dane]

:o I´ll stick to vero- and stripboards. Might not be as efficiant and small, i dont care.

[pay_c]

Reaaaheaaaaheaaaaally think over that again... I thought so, too and this here: http://www.midibox.org/forum/index.php?topic=6043.0 (especially the first picture) was the last result of some dozens stripboard/vectorboard projects.

You know what? Soldering took me about 5 days work, DEBUGGING A FRIGGIN MONTH! As I´m using self-made PCB´s now, soldering takes me nothin´anymore (about a quarter of the stripboard time) and there´s nearly no debugging anymore (REALLY NOT!). The only big price is that PCB designing takes it´s time (training and designing to be exact) and you gotta have some funds to build it up (chemicals, light, etcher and so on). Also you gotta take into account that you have to produce the PCB including drilling (normally also BIG PCBs are done within 2 hours max). But hell I think it´s worth it compared to vec/stripboards!!!

:) Greetz! :)

[RTurner]

I posted a method for etching with HCl and H2O2 several weeks ago.  I know that there has been a little talk on here about it before as well.  I also know that a lot of people frown upon this method, and the only reasons I can find for it is that

A> It uses dangerous chemicals (as if ferric chloride is particularly safe)

B> It's easy to over-etch if your solution is too strong, or if you use the "sponge" method common with ferric chloride.

So, use common sense with this method, you absolutely have to do this outside, under a hood, or in a large room with amazing ventilation.

You absolutely have to wear eye protection- if you get HCl in your eyes, you *will* have to visit the hospital.

You also have to be careful not to splash yourself with the etching solution- it won't be strong enough to instantly burn you, and having given myself chemical burns before, you'll know it's happening when you get this weird painful itch.  But plenty of water, and replacement gloves will fix that.

The two main dangers are:

A> inhalation of HCl fumes (it can break down into chlorine gas), the stuff is really noxious, but if you perform the etch outdoors- you should be fine presuming that you aren't standing over the etch pan.

B> too strong of a reaction, again, I recommend against using 40% H2O2 for this reason, and to either use regular store-bought (3%) or to dilute the 40% down to under about 7-8%- though the 3% H2O2 is easy to get, has never led to a run-away reaction, and makes the etch time a bit more manageable (in fall weather, the etching seems to take between 15 and 30 minutes)

Anyways, in a runaway reaction, since this is an exothermic reaction, the etch solution can get hot enough to boil- in which case the best way to bring it back under control is to add water to the etchant. 

If you feel comfortable with the risks, I'd suggest trying the HCl + H202 method.  Despite all of the caveats I've listed, I find it to be a bit more reliable, less finicky, less expensive, less time-consuming, and (if handled correctly) less dangerous than the ferric chloride method.  I've never tried the ammonium persulfate etch before though.  I'm curious, but, the HCl method hasn't done me wrong yet.

About PCBs versus the various proto-boards:

Having a well thought out PCB will always be worth the effort.  Design takes a bit of time and expertise, but should be within the grasp of anyone who would seriously sit down with a schematic and a protoboard.  For simple designs I draft them up in Autocad Mechanical, or course you'll have to know your component spacings before hand.  More complex designs have to be done in something like Eagle (which invariably I have to send back through autocad, since I find eagle kinda retarded for drafting).  But I've known people that have successfully generated PCB artwork in Adobe Illustrator even. 

Advantages of PCBs: 

-very few jumpers, which makes trouble shooting a LOT easier.

-correct spacing and pin layouts for components, which means that you have fewer jumpers (which can short, wiggle out of position, and are just plain visually confusing), or that you don't have to 'make it fit'.

-logical layout

-more reliable

-and the aesthetics are just plain better- even the best looking protoboard project pales next to an average PCB

Disadvantages:

-Manufacturing (expensive to send-off, or requires setup for masking, etching, and drilling)

I have a small boutique audio company, and we can have a board exposed (about 30 minutes, including exposure time, developer time, and proofing), etched (again, about 30 minutes, though it's good to take the board out part-way through, rinse it, and with magnification double-proof the circuit before completing the etch), and drilled (this can take between 10 and 45 minutes, depending on the size of the board, and how fast you are) in well under 2 hours.  more like an hour and a half.  A lot of time is spent on proofing, and this is one of those things- it's a pain, and it's time consuming, and the surgeon glasses I have hurt my eyes, but every minute spent proofing will save you the that amount times 10 down the line.  Again, this is well within the capabilities of anyone with some experience in electronics, a basic understanding of chemistry, time to make a mistake or two while learning, and a hundred dollars for supplies: drill accessories (either use a tabletop drill, or a small hand-operated jewelers drill, with *steel* bits), exposure lamp, boards, chemicals, gloves, eye-wear, dishes, x-acto knife, the trusty sharpie marker, and a can of clear acrylic spray.

anyways..  good luck

[moebius]

(as if ferric chloride is particularly safe)

In this matter it IS particularly safe.

Moebius

[RTurner]

HCl isn't safe, but- the same precautions should be made with either chemical.  You obviously don't want to ingest them in any way.  You don't want to come in direct contact with either of them.  Both put out some nasty fumes and should be used only under the best ventilation you can provide. 

My main complaints about the safety of FeCl is that...

A> Without a bubble tank you're probably in more-or-less direct contact with the stuff (fumes and all) either sloshing a board back and forth in a bin of the stuff, or rubbing the board with a sponge soaked with it- both ways tend to get the stuff everywhere, on yourself, and on your workspace.  Again, the only way to mitigate that is to have a bubble tank.

B> It requires heating- which is dangerous for several reasons (electricity + electrically conductive liquids, burns, and the heating only makes it more noxious).

Where-as HCl + H2O2 requires little to no agitation, and can be used at room-temperature.  All this means is that you can start the etch process and step away from the dangerous chemicals.  3% H2O2 isn't particularly dangerous without being inventive- at that dilution you could probably even drink it if you don't mind sitting on the toilet for a couple hours.  Not to mention that there simply isn't a good or at least practical way to dispose of FeCl (how many of you actually have a hazardous waste disposal company come pick it up???  Now, how many of you have dumped it down your sink, or on the lawn??)...  HCl, while being a strong acid, isn't particularly toxic and can be poured down the drain or dumped in the yard in reasonable quantities.

But obviously, people should use whichever method they like most, and you should be able to comfortably handle chemicals to use either process- especially when dealing with strong acids (though I'm willing to bet that if you're using a photo-mask, you're also using NaOH as a developer- which is very caustic, and could blind you as easily as it would clean your oven).  Personally, I don't like dealing with FeCl for the above reasons, and I seem to have better and faster etches with HCl.  The Gyraf Audio (gyraf.dk) website has a primer on using it (though I like to use a more dilute solution to prevent over-etching as well as for safety reasons) that piqued my interest a while back- now we use nothing but HCl + H202..

[carsten_the_dane]

Im completely paranoid when it comes to chemicals. You cant see the harm its doing, before you got your lungs filled with water, and drown :-X ... Yep, paranoid.

I realize that using stripboards will become a hassle. But thats why im trying to create the stripboard archive, which eventually will make MidiBox stripboards easier to create.

Unfortunately the university is demanding increasingly more time from now untill the  end of January, so i dont have much time for stripboards or my MidiBox SID. Sigh

/Carsten

[Jaicen]

Have you considered the additional levels of solder you're ingesting by sticking to stripboard? A pcb would reduce your solder exposure considerably.

[stryd_one]

Hah, I've just soldered a core and was thinking exactly that. That smoke is funky  :-X

[RTurner]

You know, I've been worrying about solder.  My partner and I recently switched back from ROHS compliant stuff (it can be a real pain to use, is real finnicky, has a higher melt point, doesn't produce as many shiny joints  as lead solder, and it's an absolute b*tch for soldering big connections).  We can pretty easily go through a half pound of the stuff in a weekend making tube-gear.  I swear one night after leaving the workshop my lips were tingling.  Did I mention that we chain-smoke while we solder?  I dunno.  Hopefully I won't end up stunted, and my future children will be alright.

As far as etching methods:

Carsten:  I understand if you have reservations concerning the various etching methods.  The methods take a bit of trial-and-error to get half-way decent results from, and almost all of the chemicals involved are toxic and or corrosive/caustic.  None of this is stuff you should be doing in a dorm room anyways (sorry for being presumptuous about your living situation/ for that matter you could be a professor for all I know). 

If you're only doing MBHP stuff, why not send-off for the pre-made PCBs???  The stuff from Smash_TV is waaaay cheaper than anything you could do on your own (without already having the required chemicals/equipment)- and yes it might take forever and a day to arrive, but the PCBs he has made are of much higher quality than anything you're likely to make on your own, plus the kits come with the components.  Really, I think this is the best solution for someone who clearly doesn't want to make their own (and realistically, probably the best solution for 90% of the people that DO want to make their own).

[DavidBanner]

  I swear one night after leaving the workshop my lips were tingling.  Did I mention that we chain-smoke while we solder? 

What ya been smokin to make your lips tingle??? lol

[Therezin]

@ RTurner: My advice to you would be... zinc tablets. My mom works in the office at a lead mill, and to counter the effects of the huge amounts of lead in the air there they all have to take zinc tablets and have a monthly lead count test. You can pick them up from just about anywhere that sells vitamins.

[RTurner]

Yeah, I guess I should switch brands of cigarettes :)

Therezin:  Hey thanks.  I'll look up the info on the web, but I think I have a bottle of zinc tablets somewhere.  I've caught my partner holding stips of solder in his mouth before (it's the whole not having 3 hands thing.  The panavises and hemostats make it a little easier, but sometimes you just need an extra limb...Personally I'll go for a shady solder joint before I do something which is clearly damaging)- I should require him to take these zinc if what you say is true...

robin