Pace Technologies PICO 155S, Инструкция по эксплуатации

Страница: 51 / 54

Please read this instruction manual carefully and follow all installation, operating and safety guidelines.
47
PICO-155S Precision Saw
I
NSTRUCTION
M
ANUAL
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ▲
3601 E. 34th St. Tucson, AZ 85713 USA Tel. +1 520-882-6598 Fax +1 520-882-6599 email: pace@metallographic.com Web: http://www.metallographic.com
TABLE IV. Guidelines for Wafering Cutting Various Materials
Characteristic Speed (rpm) Load (grams) Blade (grit/conc.)
Silicon substrate Soft / brittle <300 <100 Fine / low
Gallium arsenide Soft / brittle <200 <100 Fine / low
Boron composites Very brittle 500 250 Fine / low
Ceramic fiber com-
posites Very brittle 1000 500 Fine / low
Glasses Brittle 1000 500 Fine / low
Minerals Friable / brittle 1500 >500 Medium / low
Alumina ceramic Hard / tough 1500 >500 Medium / low
Zirconia (PSZ) Hard / tough 1500 >800 Medium / low
Silicon nitride Hard / tough 1500 >800 Medium / low
Metal matrix
composites 1500 >500 Medium / high
General purpose Variable Variable Medium / high
9.2 CUTTING PARAMETERS
Most wafer cutting is done at speed between 50 rpm and 5000 rpm with loads varying from 10-1000
grams. Generally, harder specimens are cut at higher loads and speeds (e.g. ceramics and minerals)
and more brittle specimens are cut at lower loads and speeds (e.g. electronic silicon substrates) (see
Table IV). It is interesting to note that the cutting efficiency for sectioning hard/tough ceramics
improves at higher speeds and higher loads. Figure 9.8 compares the resulting surface finish for
sectioning partially stabilized zirconia at a low speed/low load (Figure 9-8a) vs cutting at a higher
load/higher speed (Figure 9-8b). As can be seen, partially stabilized zirconia has less fracturing and
grain pull out after sectioning at higher speeds and loads. This observation may seem counter
intuitive, however for sectioning hard/tough ceramics, high cutting speeds and loads result in
producing a crack that propagates in the direction of the cut instead of laterally into the specimen.