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. -- Greetings Bertho (disclaimers are disclaimed) ------------------------------------------------------------------------------ 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
