On Friday 06 December 2013 14:00:58 Bertho Stultiens did opine: > On 12/06/2013 07:07 PM, Florian Rist wrote: > >> So my question is, to someone who may have tried/done this, is can a > >> 1 ounce layer of copper be burned away rapidly enough so as not to > >> leave a burned, conductive path where the copper was? > > > > I tried this with two different Lasers sources: > > 120 W CW CO2 Laser at 10600 µm wavelength: > > Result: no way to 'burn' the copper. It was hardly possible to burn > > away a the play of photosensitive coating used in the normal 'wet' > > process. 200W q-switched Yb:Yag Laser at 1064 µm: > > Result: even the 25 kW max. pulse energy were not sufficient to burn > > away the copper properly. It is possible to cut through the coper > > layer by the precess is not controlled enough. The pulse energy would > > probably have to be at least 10 times higher to establish a decent > > process. But this laser removes the light sensitive coating quite > > well at low power settings. > > Copper boils at ~2560 deg C and has a thermal conductivity of > ~400W/(mK). > > Compare this to aluminium: 2520deg and 237W/(mK) and iron: 2860deg and > 80W/(mK). > > Getting any copper vaporized, you need a *huge* amount of energy. We are > talking about 100..250kW pulses to make any proper cut and more if it > needs to be "nice". > > Aluminium also has a great problem because it is very close to copper. > Iron has 5 times less heat transport and even though it has a higher > boiling temperature, it will vaporize more easily than copper and > aluminium due to the reduced heat transport.
I figure there was that effect in there someplace, but had no idea as to the scale. Interesting & thanks. Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> Laugh and the world thinks you're an idiot. A pen in the hand of this president is far more dangerous than 200 million guns in the hands of law-abiding citizens. ------------------------------------------------------------------------------ Sponsored by Intel(R) XDK Develop, test and display web and hybrid apps with a single code base. Download it for free now! http://pubads.g.doubleclick.net/gampad/clk?id=111408631&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
