I hope I am in the right place to ask this...
Anyway, I have an amp design, and made a pc board layout for it using ExpressPCB. I then did manage to print it out successfully without the stupid grid dots, so I have it just on a piece of paper for now. What type of board is recommended? Copper etched or photo-sensitive? Which is easier? Cheaper? How do I do both? Thanks
If size of board matters, the amp itself is about 3.3"x5.85" and the crossfeed I added (if I use it) is a separate board of about 3"x4" roughly.
Anyway, I have an amp design, and made a pc board layout for it using ExpressPCB. I then did manage to print it out successfully without the stupid grid dots, so I have it just on a piece of paper for now. What type of board is recommended? Copper etched or photo-sensitive? Which is easier? Cheaper? How do I do both? Thanks
If size of board matters, the amp itself is about 3.3"x5.85" and the crossfeed I added (if I use it) is a separate board of about 3"x4" roughly.
I seldome use PCBs.trespasser_guy said:
When I have done that, I have not used the photo method.
I have just taped the drawn circuit onto the board.
Then I have used a sharp pointed punch to mark out the holes
through the paper.
Then have I have used a pen with water resistent ink
to draw the circuit by hand, on the PCB.
Then I have etched.
It is called the direct etching method.
It is good and easy, if you do not need 10 identical PCBs.
In that case photo method is better.
/halo - simple as possible
sam9
I, on the otherhand have made a mess out of PCBs attemted with "Press-N-Peel" and hand drawn. For something as complex as an amp board, I have much better luck with photo etch. I use Datak posative process boards. These are a little more expensive than negative process, but a bit less messy. Also the latest version work with normal 100W bulbs (or even sunlight) - no florescent or UV required.
For very simple cicuits such as a power suplly or a master-slave relay cicuit, I have used pens successfully. You can go one step further and use a demel tool to grind off the copper where it should not be - crude, but fast, inexpensive, and effective.
It is worth trying all of them, because it seems different people have different degrees of success with different methods. Still, I've only heard of one person who was really happy with the iron on method (unless the invested a few hundred buck for special equipment!).
I, on the otherhand have made a mess out of PCBs attemted with "Press-N-Peel" and hand drawn. For something as complex as an amp board, I have much better luck with photo etch. I use Datak posative process boards. These are a little more expensive than negative process, but a bit less messy. Also the latest version work with normal 100W bulbs (or even sunlight) - no florescent or UV required.
For very simple cicuits such as a power suplly or a master-slave relay cicuit, I have used pens successfully. You can go one step further and use a demel tool to grind off the copper where it should not be - crude, but fast, inexpensive, and effective.
It is worth trying all of them, because it seems different people have different degrees of success with different methods. Still, I've only heard of one person who was really happy with the iron on method (unless the invested a few hundred buck for special equipment!).
Re: sam9
This is very interesting indeed. I have been looking for photo-
resist that can be exposed without using UV light, but failed
to find any. All photoresist and boards with photoresist sold
here are intended for UV and it is strongly recommended not
to use any other light sources.
It seems from what you say that these boards are rather new,
so perhaps that is an indication that they will appear also here
eventually. BTW, has anyone tried exposing photoresist in
non-UV light? For instance, I do have daylight fluoroscent tubes
which are much closer to UV than ordinarey fluoroscent tubes
and light bulbs are. I will probably make some experiments with
using these in the future, but I would welcome hearing about
other peoples experiences.
sam9 said:
This is very interesting indeed. I have been looking for photo-
resist that can be exposed without using UV light, but failed
to find any. All photoresist and boards with photoresist sold
here are intended for UV and it is strongly recommended not
to use any other light sources.
It seems from what you say that these boards are rather new,
so perhaps that is an indication that they will appear also here
eventually. BTW, has anyone tried exposing photoresist in
non-UV light? For instance, I do have daylight fluoroscent tubes
which are much closer to UV than ordinarey fluoroscent tubes
and light bulbs are. I will probably make some experiments with
using these in the future, but I would welcome hearing about
other peoples experiences.
I agree with sam9
It is only when you have some simpler, smaller circuit
when the direct etching method can be used.
When things get very complex, and the place is narrow
with thin rails,
some method for copy an original is better.
But for simpler cicuits, or parts of cicuits,
or non-critical stuff,
when you only need 1 PCB,
the direct method is quicker and good enough method.
/halo - the p2p hardwire man
It is only when you have some simpler, smaller circuit
when the direct etching method can be used.
When things get very complex, and the place is narrow
with thin rails,
some method for copy an original is better.
But for simpler cicuits, or parts of cicuits,
or non-critical stuff,
when you only need 1 PCB,
the direct method is quicker and good enough method.
/halo - the p2p hardwire man
Attachments
I burn my own boards (positive boards) when I need to turn something around the same day -- I use a lightbox that is normally used for viewing negatives -- 6 to 8 minutes exposure is satisfactory. develop the board in a 3% solution of Sodium Hydroxide. Drill the holes before you etch! (Using surface mount means you drilll far fewer holes !) You can touch up the traces with an indelible marker.
The prototyping boards sold by (aaaarrrrghhhh!) Radio Shack actually work very well and are extremely easy to use. I just built a power supply controller with one today.
But remember, TIME=MONEY. You can get prototype boards made pretty inexpensively in the US ./
The prototyping boards sold by (aaaarrrrghhhh!) Radio Shack actually work very well and are extremely easy to use. I just built a power supply controller with one today.
But remember, TIME=MONEY. You can get prototype boards made pretty inexpensively in the US ./
For info. Non-UV boards I mentioned are sold by DATAK and called "Premier". Wierd thing is that tey come in the same foil packet as the older types and the insert talks only about UV. There is a plastic packet around the foil packet that includes an inset regarding the standard light version. Recomends a 100W bulb in a reflector at a distance of 12" up to a 5"x5" for 10 minutes. Appearently UV still works if you are already set up that way.
Anyway, the 100W method definately works - I exposed two boards last night. I'm going down to the garage right now to drop them in the ferrous chloride.
Anyway, the 100W method definately works - I exposed two boards last night. I'm going down to the garage right now to drop them in the ferrous chloride.
Etching PC Boards!
You guys reminded me of an experience I had as a wee lad, about 11 years old.
I was etching a circuit board in the bathroom laboratory, since it had adequate ventilation and running water- plus the approval of my parents. This was an ambitious project, a 10 watt transistor amplifier based upon the topology of my first amplifier, a 3.85W monaural amplifier: a Heathkit.
I carefully traced the circuit on a 6-inch square piece of fresh clad board, and realized that the plastic solution tray I planned to use was too small!
Off to the kitchen for a suitable substitute. I knew my mother would not appreciate the laboratory use of her pretty Corningware dishes...so I rummaged through the cabinet. Ah! Pie tins! So clean...utilitarian, and flat they are! Surely, Mum would appreciate her son using the old pie tin instead of wares for cooking!
It was at this point that I filled the tray with etching solution, started the timer, turned the vent fan on, and added the copper board to the soup. Then I learned an important lesson in another discipline other than electronics: chemistry!
It's called heat of reaction, I believe. As a chemical reaction takes place, it accelerates rapidly as the ongoing reaction liberates heat...more reaction can then take place at the elevated temperature.
I know many of you are quite amused at this point. Well, I was in a state of amazement and adrenaline-induced activity! The demise of the pie tin was a glorious spectacle indeed!
The etching solution destroyed the aluminum pie tin in record time! At least I knew from my father that one never adds water to a happy reagent...I scooted the disaster into the sink, and carefully washed it up once the fizzing subsided.
My experience in photography led me to a different method of laying the circuit pattern on the board. I like to draw the pattern on acetate, sandwich this layer over the board, and expose the image.
What methods of board production work for all of you? This might be an interesting topic....
You guys reminded me of an experience I had as a wee lad, about 11 years old.
I was etching a circuit board in the bathroom laboratory, since it had adequate ventilation and running water- plus the approval of my parents. This was an ambitious project, a 10 watt transistor amplifier based upon the topology of my first amplifier, a 3.85W monaural amplifier: a Heathkit.
I carefully traced the circuit on a 6-inch square piece of fresh clad board, and realized that the plastic solution tray I planned to use was too small!
Off to the kitchen for a suitable substitute. I knew my mother would not appreciate the laboratory use of her pretty Corningware dishes...so I rummaged through the cabinet. Ah! Pie tins! So clean...utilitarian, and flat they are! Surely, Mum would appreciate her son using the old pie tin instead of wares for cooking!
It was at this point that I filled the tray with etching solution, started the timer, turned the vent fan on, and added the copper board to the soup. Then I learned an important lesson in another discipline other than electronics: chemistry!
It's called heat of reaction, I believe. As a chemical reaction takes place, it accelerates rapidly as the ongoing reaction liberates heat...more reaction can then take place at the elevated temperature.
I know many of you are quite amused at this point. Well, I was in a state of amazement and adrenaline-induced activity! The demise of the pie tin was a glorious spectacle indeed!
The etching solution destroyed the aluminum pie tin in record time! At least I knew from my father that one never adds water to a happy reagent...I scooted the disaster into the sink, and carefully washed it up once the fizzing subsided.
My experience in photography led me to a different method of laying the circuit pattern on the board. I like to draw the pattern on acetate, sandwich this layer over the board, and expose the image.
What methods of board production work for all of you? This might be an interesting topic....
I use Avery Labels
Clear Labels, Avery #8665 , and a laser printer. You use the "reflected" setting in postprocessing and just stick the label to the unexposed board. I have used mylar sheets (overhead transparency medium) with both a laser printer and ink jet.
Sometimes you won't get the deep density in the areas like ground planes and the temptation is to run them through the printer again, but if you are working with 10 mil traces and TSSOP devices it's not a good idea at all.
For holes -- I start them out with a 0.011 drill --
Need light -- a red darkroom safelight won't affect the PCBoard.
Someone has said that if you can get a refillable pen and use acrylic floorwax tinted with green food coloring it should work. Has anyone tried this ?
My last word of advice -- a lot of the pens which say they're waterproof aren't.
Clear Labels, Avery #8665 , and a laser printer. You use the "reflected" setting in postprocessing and just stick the label to the unexposed board. I have used mylar sheets (overhead transparency medium) with both a laser printer and ink jet.
Sometimes you won't get the deep density in the areas like ground planes and the temptation is to run them through the printer again, but if you are working with 10 mil traces and TSSOP devices it's not a good idea at all.
For holes -- I start them out with a 0.011 drill --
Need light -- a red darkroom safelight won't affect the PCBoard.
Someone has said that if you can get a refillable pen and use acrylic floorwax tinted with green food coloring it should work. Has anyone tried this ?
My last word of advice -- a lot of the pens which say they're waterproof aren't.
Ok, I used some kind of really waxy paper, printed it, ironed it, and soaked it in water until the paper fell off. I now have most of the transfer on the board... unfortunately, some things fell off.
Should I get a pack of dry transfers and fill in the missing places or should I use something like the RadioShack resist-ink pen to draw in the missing spots?
Should I get a pack of dry transfers and fill in the missing places or should I use something like the RadioShack resist-ink pen to draw in the missing spots?
use a method from a dutch guy
I use a, in my eyes, simple method.
you take HQ photo paper (Kodak or similar)
then print the layout on to the paper by means of a real LAZERPRINTER (like the HP L5 lazerprinter) not a lazerjet.
te print quality should be highest to be sure that the ink is built up on the paper!
clean the pcb , by first lightly scrubbing it with a scotschbrite, after clean it with some acetone (nailpoishremover). Rinse and dry!
stick the printed paper on the pcb (printside against the copperside.
Iron for some 5 minutes not releasing the iron, constantly putting some pressure on it. NO STEAM please!!!
after that you peel the paper of, if it does not come off right away, happens a lot, just soak it off with some hot water .
I have made a few already and it seems to work just fine.
tha tricky part for me is the etching itself, i use the rocktype, after the powder burnt a hole in my cooler!
J-P
I use a, in my eyes, simple method.
you take HQ photo paper (Kodak or similar)
then print the layout on to the paper by means of a real LAZERPRINTER (like the HP L5 lazerprinter) not a lazerjet.
te print quality should be highest to be sure that the ink is built up on the paper!
clean the pcb , by first lightly scrubbing it with a scotschbrite, after clean it with some acetone (nailpoishremover). Rinse and dry!
stick the printed paper on the pcb (printside against the copperside.
Iron for some 5 minutes not releasing the iron, constantly putting some pressure on it. NO STEAM please!!!
after that you peel the paper of, if it does not come off right away, happens a lot, just soak it off with some hot water .
I have made a few already and it seems to work just fine.
tha tricky part for me is the etching itself, i use the rocktype, after the powder burnt a hole in my cooler!
J-P
Re: use a method from a dutch guy
This seems somewhat inconsistent. As I understand you
one should use a laserprinter, not an inkjet printer, in which
case it is not really ink at all on the paper, but carbon toner.
Is that correct?
Anyway, it sounds like an interesting method to try. Thanks
for the tip.
uvodee said:
This seems somewhat inconsistent. As I understand you
one should use a laserprinter, not an inkjet printer, in which
case it is not really ink at all on the paper, but carbon toner.
Is that correct?
Anyway, it sounds like an interesting method to try. Thanks
for the tip.
Re: Re: use a method from a dutch guy
i could not believe how easy it was untill my first pcb with this
the link (with all the info) is as follows
www.fullnet.com/u/tomg/gooteepc.htm
i did not follow his advice on the photopaper, I use whatever I have in my cabinet, usually HP or Kodak
J-P
Christer said:
i could not believe how easy it was untill my first pcb with this
the link (with all the info) is as follows
www.fullnet.com/u/tomg/gooteepc.htm
i did not follow his advice on the photopaper, I use whatever I have in my cabinet, usually HP or Kodak
J-P
uvodee-
a quote from your link
"Glossy, coated paper has been found to work very well, since the coating on the paper will separate from the paper, when soaked in water. "
=>this is the paper I use and it never fails, always able to transfer all the toner to the PCB. I iron it, let it sit and then put it in water to let paper dissolve. Then rubb gently with scotchbrite to leave a bit of paper on the toner. Finally eatch it...
Never failed, from PS PCB's to SMD PCB's
a quote from your link
"Glossy, coated paper has been found to work very well, since the coating on the paper will separate from the paper, when soaked in water. "
=>this is the paper I use and it never fails, always able to transfer all the toner to the PCB. I iron it, let it sit and then put it in water to let paper dissolve. Then rubb gently with scotchbrite to leave a bit of paper on the toner. Finally eatch it...
Never failed, from PS PCB's to SMD PCB's
i use Press-n-Peel
http://www.techniks.com/
just print your circuit on mirror image setting
put Press-n-Peel paper in a copyer or laser printer,
print it.
iron it on to your copper board
peel it off under running water
etch that bad boy... used it this last weekend
to etch my BOSOZ boards... like a charm!
not sure how well it holds up with very fine tracing...
but most AMP tracings are on the large side, at least
that i've seen.
-----------
moe29
-----------
http://www.techniks.com/
just print your circuit on mirror image setting
put Press-n-Peel paper in a copyer or laser printer,
print it.
iron it on to your copper board
peel it off under running water
etch that bad boy... used it this last weekend
to etch my BOSOZ boards... like a charm!
not sure how well it holds up with very fine tracing...
but most AMP tracings are on the large side, at least
that i've seen.
-----------
moe29
-----------
Laser film
For those of you that photocopies the drawing to the PCB, there is a product on the market , in Europe at least, called Laserstar, which does an excellent job for fine traces. Have used it quite extensively for SMD. Laserstar looks to me exactly like the slightly matte plastic drawing film we used for ink drawings back in the early 80-ies.....
Two laserprinted transparents atop of each other somehow does the job, but the film stuff gives better contrast and saturation in the blacks.......
For those of you that photocopies the drawing to the PCB, there is a product on the market , in Europe at least, called Laserstar, which does an excellent job for fine traces. Have used it quite extensively for SMD. Laserstar looks to me exactly like the slightly matte plastic drawing film we used for ink drawings back in the early 80-ies.....
Two laserprinted transparents atop of each other somehow does the job, but the film stuff gives better contrast and saturation in the blacks.......
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