Hi,
I purchased an etching kit from RadioShack for a small amp project. I cleaned the copper on both sides and followed the directions to a "T", but it did not work. The directions say to leave it in the solution for about 20min. In 20min almost no copper left the board. I left it in over an hour and still not all the copper dissolved, however some of the areas that were not supposed to dissolve did.
Does anyone have any advice, tricks or knowledge that they can pass on to me? The directions are lame and I'm sure there is more to it than they explain.
Thanks
Jeff
I purchased an etching kit from RadioShack for a small amp project. I cleaned the copper on both sides and followed the directions to a "T", but it did not work. The directions say to leave it in the solution for about 20min. In 20min almost no copper left the board. I left it in over an hour and still not all the copper dissolved, however some of the areas that were not supposed to dissolve did.
Does anyone have any advice, tricks or knowledge that they can pass on to me? The directions are lame and I'm sure there is more to it than they explain.
Thanks
Jeff
it helps if the etchant is warm -- but don't warm it on a gas stove since the reaction releases hydrogen.
i now prefer to use hydrogen peroxide and muriatic acid. the hydrogn peroxide can be bought at the drugstore for under a buck for a quart, the muriatic acid is at the hardware store -- used to clean stone, it's pretty nasty stuff (Dilute hydrochloric acid). The HCl acts to accelerate the oxidizing effect of the H2O2 -- it takes less time than ferric chloride.
i now prefer to use hydrogen peroxide and muriatic acid. the hydrogn peroxide can be bought at the drugstore for under a buck for a quart, the muriatic acid is at the hardware store -- used to clean stone, it's pretty nasty stuff (Dilute hydrochloric acid). The HCl acts to accelerate the oxidizing effect of the H2O2 -- it takes less time than ferric chloride.
I have just started to do this myself also. My first couple tries were hideous, but my third was a clean success!
As you have probably heard, there are several ways to mask the copper. The some ways I know of are permenent marker, laser print transfers, and the Radio Shack stickers.
I had no success getting those Radio Shack stickers to stay on, and I don't recommend them.
The only way I've tryed to etch with is using a permenent marker. It may sound like it wouldn't give good results, but with good planning, patients, and a steady hand, a nice turn-out can be had.
To ensure good results with this method be sure to clean the board before hand and after etching. In both cases I used fine-grit sandpaper, soap and water, and alcohol.
I used a Sharpie to mask. When I drew the traces, I copied and pcb layout I had found online and used the IC I needed to make sure it would line up correctly. When applying the marker, make sure that there is a thick layer of ink covering the traces, or the solution will eat right through the copper underneath.
There are a couple tricks I have heard and learned with this method. One I learned is to pull the board out mid-etch, wipe the board, and go back over the traces with the marker. This will leave thicker copper tracks and more unwanted copper disolved.
Another trick is to completely mask a whole row of a DIN IC and separate the pads with a knife after etching. This will allow for wider pads for the IC and better alignment.
Follow these steps and you should quickly learn how to cheaply and easily etch with just a marker and some solution.
I plan to try the laser printer iron-on masking next. I read a review somewhere that the best paper for this is Staples photo paper. We'll see how that turns out.
Oh yeah, by the way, make sure you don't get any solution on your hands. If you do, don't eat any crackers or anything. I did, and get not get to sleep that night because I could not get the taste and smell out of my mouth.
I hope all this helped.
As you have probably heard, there are several ways to mask the copper. The some ways I know of are permenent marker, laser print transfers, and the Radio Shack stickers.
I had no success getting those Radio Shack stickers to stay on, and I don't recommend them.
The only way I've tryed to etch with is using a permenent marker. It may sound like it wouldn't give good results, but with good planning, patients, and a steady hand, a nice turn-out can be had.
To ensure good results with this method be sure to clean the board before hand and after etching. In both cases I used fine-grit sandpaper, soap and water, and alcohol.
I used a Sharpie to mask. When I drew the traces, I copied and pcb layout I had found online and used the IC I needed to make sure it would line up correctly. When applying the marker, make sure that there is a thick layer of ink covering the traces, or the solution will eat right through the copper underneath.
There are a couple tricks I have heard and learned with this method. One I learned is to pull the board out mid-etch, wipe the board, and go back over the traces with the marker. This will leave thicker copper tracks and more unwanted copper disolved.
Another trick is to completely mask a whole row of a DIN IC and separate the pads with a knife after etching. This will allow for wider pads for the IC and better alignment.
Follow these steps and you should quickly learn how to cheaply and easily etch with just a marker and some solution.
I plan to try the laser printer iron-on masking next. I read a review somewhere that the best paper for this is Staples photo paper. We'll see how that turns out.
Oh yeah, by the way, make sure you don't get any solution on your hands. If you do, don't eat any crackers or anything. I did, and get not get to sleep that night because I could not get the taste and smell out of my mouth.
I hope all this helped.
PCB home fabrication
You may want to check Think & Tinker for a dry resist process I use and recommend.
Select only the chapters relevant for you, there are procedures and products for through hole, multilayer and solder mask processes also.
You may substitute an ironing appliance for laminator - be ready to spoil some trials - but cut no other corners. I can routinely make .01" tracks this way after tunning carefuly the process.
Rodolfo
You may want to check Think & Tinker for a dry resist process I use and recommend.
Select only the chapters relevant for you, there are procedures and products for through hole, multilayer and solder mask processes also.
You may substitute an ironing appliance for laminator - be ready to spoil some trials - but cut no other corners. I can routinely make .01" tracks this way after tunning carefuly the process.
Rodolfo
I use dry transfers, toner iron-ons, and sharpies to get the patterns I want. Make sure the board is very clean and oil free(no fingerprints) and the dry transfers stick fine and work well. The best method is to get some laser printer transpearancy sheets and print your pattern on them and iron the pattern onto the board, it takes practice to get the right tempuratures on the iron but its worth it! You can go over the iron-on with a sharpie if you wish. If you have very wide traces you can go over them with nail polish. When done acetone takes the polish and toner transfer off the traces.
Pulsar for the toner transfer method. Read through and you'll see that toner alone is porous, leading to pinholing. Toner reactive film is supposed to fix this. They also have a sponging technique for etching, that I've not tried.
I've had good results using toner transfer, and ammonium persulfate etchant.
Keeping your etch bath at 50C is essential, also constant agitation for even etching.
I've had good results using toner transfer, and ammonium persulfate etchant.
Keeping your etch bath at 50C is essential, also constant agitation for even etching.
I use those stickers. You put them on the board, then rub them on top and they stay on the PCB. Works al right with me. They dont come of or anything.
One major disadvantage, the minimum track width with the ones I use is about 1 mm (1/25 inch), which means you cant make a track between two pins of a DIL IC.
I'm looking for a nice UV light and then I want to try it tha way.
Greetz Mark
One major disadvantage, the minimum track width with the ones I use is about 1 mm (1/25 inch), which means you cant make a track between two pins of a DIL IC.
I'm looking for a nice UV light and then I want to try it tha way.
Greetz Mark
Markje said:
Get one of those inexpensive 125W mercury vapor lamp and ballast.
VERY CAREFULY break the outer envelope (draped with a piece of cloth or something) to expose the inner quartz bulb, remove with pliers the broken glass sticking from the base and you are done.
Take care to construct a box shield or something (you may even make an inexpensive aluminium parabolic reflector). Avoid staring at the bulb directly when turned on.
This is the setup I use and it works fine for boards up to 5x8" or so. With dry resist from Think & Tinker, exposures are excellent with less than 3 minutes including lamp warmup.
Rodolfo
markp said:Not a great idea!
Nothing like mercury vapor to make your day!
You are not supposed to break the inner quartz bulb (which is quite tough anyway) where the mercury vapor is enclosed. As long as it is contained there is absolutely no risk.
As said, I've made several of this setups for years with no mishaps and excellent results.
Rodolfo
Check my thread. This is how I did it with good results. Bye...
http://www.diyaudio.com/forums/showthread.php?s=&threadid=19585&perpage=15&pagenumber=1
http://www.diyaudio.com/forums/showthread.php?s=&threadid=19585&perpage=15&pagenumber=1
If you want high levels of UV just buy a blacklight for a couple bucks. Easy to run, cool temp and no safety issues.
The thought of breaking open a mercury vapor lamp is way NOT COOL. The reason that outer glass case is there is that if the HID tube breaks(and they do) the mercury and other chemicals will be contained.
That HID tube has a surface temp of over 3000 degrees Kelvin! Just touching the tube and getting oil from your fingers on the quartz is enough to create a hot spot on the tube which can lead to failure.
The same holds true for any of the HID lamps. I've been involved with them for years in lighting of aquariums, as a Facilities manager I used them for building and car park lighting, and other applications.
The thought of doing this with children or pets in the house... If they break the lamp by mistake. Lord help 'em
Mike
The thought of breaking open a mercury vapor lamp is way NOT COOL. The reason that outer glass case is there is that if the HID tube breaks(and they do) the mercury and other chemicals will be contained.
That HID tube has a surface temp of over 3000 degrees Kelvin! Just touching the tube and getting oil from your fingers on the quartz is enough to create a hot spot on the tube which can lead to failure.
The same holds true for any of the HID lamps. I've been involved with them for years in lighting of aquariums, as a Facilities manager I used them for building and car park lighting, and other applications.
The thought of doing this with children or pets in the house... If they break the lamp by mistake. Lord help 'em
Mike
Blacklights are generally not short enough wavelength.
There is stuff all mercury in these lamps, you're at more risk from amalgum tooth fillings, or eating Tuna!
The quartz tube cannot possibly be at 3000K, it would be a runny puddle at that temp
. Quartz softens around 1600 C.
One of my work mates simply uses bright sunshine - it behave like a point source, giving better shadow edges than diffuse light from a mercury lamp.
You really ought to give the toner method a crack. With a 1200dpi laser printer I can produce boards with 10 mil track / clearance, though 15 mil is easier.
There is stuff all mercury in these lamps, you're at more risk from amalgum tooth fillings, or eating Tuna!
The quartz tube cannot possibly be at 3000K, it would be a runny puddle at that temp
. Quartz softens around 1600 C.One of my work mates simply uses bright sunshine - it behave like a point source, giving better shadow edges than diffuse light from a mercury lamp.
You really ought to give the toner method a crack. With a 1200dpi laser printer I can produce boards with 10 mil track / clearance, though 15 mil is easier.
Mercury lights????
Guys,
There are special UV TL-tubes available from Philips or Osram for exposing presensitized PCBs. DO NOT BREAK OPEN Mercury lights. DO NOT even think of bringing these in your home!
Mercury poisoning is very nasty and takes a VERY long time to recover, if ever.
Part number:
Philips TL8W/05 Part#530697 on www.conrad.de
Exposure time about 1 minute and 25 seconds.
Guys,
There are special UV TL-tubes available from Philips or Osram for exposing presensitized PCBs. DO NOT BREAK OPEN Mercury lights. DO NOT even think of bringing these in your home!
Mercury poisoning is very nasty and takes a VERY long time to recover, if ever.
Part number:
Philips TL8W/05 Part#530697 on www.conrad.de
Exposure time about 1 minute and 25 seconds.
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