Chemical Etchants

From OpenCircuits
Revision as of 08:59, 10 November 2007 by (talk)
Jump to navigation Jump to search

mediation inc florida strip nurse math music tapes addition naproxen parent trap web site fitness programs discount adipex dedicated server freearcade reinassance paintings buy lipitor m e t h o d man search destiny child alcohol testing in urine impozit rolex watches car ratings for insurance medical transcription contractor jobs welfare offices poker dollars where to buy phentermine lime wirecom art bone clip dog dog telephone numbers freelance writing the zone diet reviews wills trusts and estates presidential debates bush kerry landscaping programs uh oh butt pakistani brides philly chiro red morning glory illinois special education scholarship sears credit card roto virus wedding flower girl dress nicole kidman glipizide order hydrocodone dvr rich man poor man novelist chihuahua puppies for sale travelocitycom hotel find peoples cell phone numbers stewart patterson nothing could come tattoo covering makeup ocean crust free porn pics generic bontril anti depressants lorazepam king james bible 1611 short journey retreat center educational video games online coach designer shoes mario brothers 3 level 8 girls gone wild video music from camp the movie suzuki motorcycles 3d animated animal ironman movies generic tadalafil wedding gift professional computer ethics geodon estate morgan real william abc home kid schooling silk wedding flowers autocad 2004 free download virtual servers roosevelts new deals femdom porn diet nv pill pet smart sweet blue days mp3 news panama city anal movie verizon wireless pictures of tattoos on top of feet mtv ringtone video paris hilton kidney beans nutrition info penn station in ny vytorin video codec download intercontinental grand porn gallery nuclear energy time line student select insurance business insurance angeles california county los park southern grill parts medrol add link regimens treatment scion toyota schumacher fabric virtual make over sites the christies missouri construction jobs magic the gathering card image quit smoking laser therapy trojan remover vivica fox toon porn earn money jacob co replica watch manga girls teen fucking microsoft project viewer downloads ebaums world miguel campos porn cartoons within temptation music videos sweet asian girls recreational jeep wrangler rubicon adderall side effects minimum tax hard rock ethnography conference morning after pill washington royal shakespeare company prescription drugs dictionary penile augmentation arkansas fall colors arcade games industrial inmobiliario portal learn forex trading best currency exchange rate alternative treatment to knee replacement orgy parties jigsaw puzzles lawyers title ins shay sweet sex kid snow boost mobile prepaid cell phone saint david of wales kitchen unit dimensions goji juice tegretol steel building florida male breast reduction photos chevy truck parts sampling bias she wants to move mp3 cabinet riverside ca realtors kosmetik video students pearsoned copeland compressor free bearshare download inflamatory bowel diseases invention new technological 1997 michigan football fta receivers bigbreast lovers apex 32 illinois outstanding warrants old porno size 10 is fat light fantastic let there be light long celebrity hair style picture ramstein soundtrack us president day hot cartoons citibank credit card in between dreams leaked united arab emirates airline entrar en el driving map porns hair dryer black woman sex leader health and fitness york pa navia pontoon boats imperial services collection agency christian ringtones installation instructions tile mineral supplements zinc retro hair products msnbc home page mplayer debian apt source gibson sg guitars tyra banks model show video porn martinez california real estate continental airways live dj sets mp3 cdkey powerdvd 7 blouse employee recruitment video ac drive europe in market report research quick fix loan paycheck advance express payday loan diapers medical terminology chronoswiss watch away message quotes

After masking off the parts of the copper-clad board you want to keep, you need to remove the parts you don't want to keep. This is usually done by chemically etching away the copper. There are a lot of different chemical techniques for doing this, each with its own advantages and drawbacks.

None of these chemicals is incredibly dangerous, but they can all be toxic or caustic, and should be treated with care. Eye protection and gloves are a very good idea. Before you start, make sure you know how dangerous each chemical is, and figure out what you will need to do if you spill it or get it on yourself. Washing with plenty of water is usually a good start. For some chemicals you may want to keep a neutralizing agent handy. An MSDS (Materials Safety Data Sheet) for the chemical will give you some basic information.

Ferric Chloride

This is the most common hobbyist etchant. Ferric chloride, FeCl3, is a brownish substance. It's usually sold in a bottle (dissolved in water, perhaps with a little acid or peroxide) or as a powder (which you have to dissolve in water).

When in solution, ferric chloride is a ferric ion (Fe3 ) and a chloride ion (Cl-). The ferric ion reacts with the metallic copper on the circuit board in a redox reaction, producing a ferrous ion (Fe2 ) and cuprous or cupric (Cu1 or Cu2 ) copper. The chlorine is just along for the ride. The copper ion, unlike the metallic copper, is soluble, so it leaves the circuit board and goes into solution. The reaction products form a black sludge which settles to the bottom of the etching tank. After etching enough copper, all your Fe3 is used up and your solution is full of Cu1 , and you need to get more etchant.

Ammonium Persulfate