Chemical Etchants

From OpenCircuits
Revision as of 18:05, 23 September 2007 by 129.106.247.249 (talk)
Jump to navigation Jump to search

magicanotte iomega 1gb micro mini occhi di laura mars nonda distributore sapone liquido termotec cap 1 rivista mensile chiamami jesolo case affitto top cantanti midi files gratis supercar the best of ben harper pleasure and pain bmw serie 5 platinum atherurus happy cristhmas www keycomm it perverted frankenstein kids cartoons porta batterie testi con accordi lou rawls oakley gascan skank garota nacional matshita dvd ram uj 811 eva adam videocamera dvd92 sony angelx here whit me dido mcintyre alasdair adobe premiere pro 1 5 cha fantastica storia la vita faber mobili srl pc con monitor lcd nina mercedez panasonic car audio canzone testo qualcosa che scotta web cam hot nissan patrol gr usato dx 50 codec cole della trinita seka key www shopping it piaf hyundai coupe 2000 km0 bmw 120d auto km 0 nicola siri tastiera microsoft mouse e tastiere hotel villa eden tek srl www fica darkness fall telefilm americani let s get autografo arriva wonder woman pepero porto cervo vettura formula 1 2006 stampante rete a2 riicerca vendita cd dvd vergini neve falco live digicom firegate prefabbricato legno programmi download gratis case vacanza jesolo fiat panda usate egeforce 7800gtx g robert srl nick32 riassunto la locandiera immagini tatuaggi video dell americano morto kingston ddr 333 tina tuner registratori dvd vcr nokia 9500 i ngoc nuove stagioni coldplay video configurazione wap meteora realizzazioni siti internet palermo jeremy chatelain merengue azul auricolare bluetooth nokia 6230 tuscany lodging grande baboomba zucchero luca barbarossa lynk sport ps2 videogiochi dolce gabbana spot nike skylon 3 hp officejet k60 stend by me la morte corre incontro a jessica ke p42m1s tdk stampante cd schemi di posa san fedele claudio grimm trieste normas del imss para proyecto arq testo pgr panda 4x4 nuova bias definizione roberto grotti www iou it aldo busi libri escrementi elettrostimolatori gymmy olympia sydney 2000 song no me puedo explicar miglia meliconi flat 1 notti del terrore controller playstation 2 kalimba de luna tony esposito www geocities bmw 535d villaggio calabria villaggio turistico vacanza mercedes ml new model raise thy sword mp3 cd changer cesaretin var mercedes a nuove aspit safroncik ragazza belluno supereva donne donna minigonna nokia pd2 camera flash pny geforce 7800gt 256 mb pci express kit pulizia strumenti musicali giochi puzzle on line usb blutooth la casa found last palomo canzoni napoletane classiche screensaver paesaggio giornale bella it offline pellegrino di puglia bmw 530 touring new beetle tdi cabrio www costantino vitigliano heco libero belgio hotel astraeus ascendente astrale motherless child monitor lcd scart india sesso arbois de jubainville henri d aquaf d30 canon scarface lo sfregiato volo low cost catania hit mania dance champions highway tell me why did fly away autore boccherini minuetto handel ginecologia neoplasie da virus julieta venegas andar conmigo fiat panda milano giochi semplici kdcpsw9531 kenwood autoradio concessionari fiat punto 2 serie hotel pizzo degli uccelli video stay la ragazza sull altalena dolce carnevale romagna ricetta su puo dare di piu mitac mio tom hotel diva futura che guevara lorena frate resident evil outbreak in una home page europea karate kid collection hd portatile 2 5 mp3 spears prerogative marea fiat sicilia try nelly dvd sharp macchina fotografica sony porgi laltra guancia occasioni computer foto renato zero tv lcd 15 sharp aquos gps ipaq clip art di matrimonio albergo 4 stella roma wather tossicodipendenza nach scratch kiss and say goodbye foto beckham david typhoon mp3 player 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

Expensive