Chemical Etchants

From OpenCircuits
Revision as of 11:02, 27 September 2007 by 212.72.30.140 (talk)
Jump to navigation Jump to search

moto zundapp labtec webcam pro usb abit aa8xe telegiornali acapulco prima spiaggia a sinistra rifiuti 16 arresti konicaminolta a2 casnova laserjet color 3550n www virtuagirl com orari autobus in calabria numeri di telefoo villa dei cedri lazzise www cellulare panasonic x60 kirkuk impianti home theatre come e triste venezia coppia catania vaschetta ok baby fuga a mezzanotte hunny bunny regole gazebo kamrup whit temptation hard disk sata maxtor 250 gb maxline giulietta sacco dvd my life puma ferrari epson 4000 cartucce sigle gratis 2002 2003 url page stagioni di francesco guccini video pissing bella notre dame sintoamplificatore yamaha 6 1 mifune dogma 3 new beauty magazines www inter com scooter desenzano km0 bmw 325 auto km 0 camicie napoli aloe barbadensis un assassino per un testimone malattia fegato home netgear mimo garden state lancia ypsilon toscana forno da incasso smeg video 3gp porno doghe materassi risultati esami avvocato 2003 caserta alberghi rut sin die ruse donne che scopano con i figli key page www motorquality it puntatori url il punto biella acer al1711 s gloria a dio page capo verde alberghi e hotel prenotazioni albergo montecarlo bring to life mano negra illegal quien invento radio shakur tupac thug angel joypad dualshock www sfondi it fuoco di s antonio yu gi ho per visual boy advanc programmi media player gioco di carte bridge copertine di playboy memorie pc100 decapitazione ultima xdpicture card fujifilm site netzero net que es wordpad overjoyed azzioni canon ef 85mm f 1 2l usm lancia musa km o jaguar xk8 memoria sd mmc condizionatori fissi inverter exsorcista corse dei cavalli www kin arthur it manutenzione caldaia e piu bello insieme strozzino edoardo e carolina gassion giovanna firenze alberghi seneca versioni immagini bar lbe 68 sx funcard il cielo su torino subsonica thesis teac amplificatori the summer sunshine uomini senza paura oakley occhiali off line 2 0 stampante hp a4 www rote it ela ele placche elettriche la falena dargento lx 500 testi di sandro giacobbe televisori samsumg lcd hd kit refill cartucce planeta eskoria eighteen and life progettazione giardino corsi di cucina a piacenza lettori radio cd mp3 ave maria di zero en er mundo pioneer autoradio cd dehp70bt bellsouth enternet mercedes benz vito rifiuti sanitari babble babble la gallina twist archos gmini xs blue lyrics silvia saint foto porno amd athlon 2 0 contrattocollettivo commercio prestito riccione frate cuffie dj pioneer mivar tv 21 tendenze tagli di capelli amd 64 dissipatore geen day scene del film irreversible gay hard foto citta di mantova cartina politica radio am fm lw usb mac wireless kit home theatre shin getter robot contro neo getter robot vol 01 pensioni cervia champions legue motori scoppio 3 5 lan wireless dlink dwl2000ap joensuu prive a novara karina bacchi il calendario di paola perego testi canzoni di tony braxton www ferrari it gigaset c200 cordless philips hc8440 griffin technology custodie in havana loco nuova mercedes clk diesel auto nuove pic porsche 901 corde acustica z520i cellulari sony ericsson telefonia ahead nero reloaded sistema elettorale americano pitas sve narodne seweryn krajewski ujiji e femmene di v salemme decoder digitale telesystem rasmus guilty acer al1722 pacchetto viaggio eurodisney parigi www cantanapoli it decreto 266 91 katie jordan price nuda foto rubinetti per giardino rs mmc card sandisk whatever want milian 5 per mille trash chileno aciclovir san 25 cpr 400 mg parodie robusta idroguida bubblin e ludmilla nuda testi oto hom cover pooh ascolta clifton webb router firewall 11g wireless adsl 3com video della prima puntata di sailor moon

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