Theoretical estimation of dicing blade efficiency.(ABRASIVES)

A team of researchers from Nagaoka University of Technology, Japan, has developed a constant feeding-force system that enables the efficiency of a grinding wheel to be analysed. In the system, the feeding speed alters during processing, depending on the surface conditions of a grinding wheel, and this indicates its effectiveness.

The system could potentially be applied to the development of better dicing blades and a more reproducible dicing process for the machining of advanced ceramics such as alumina and silicon carbide (SiC). These ceramics are increasingly being used to make small, complex components for such applications as read/write head sliders for computer hard drives, where dimensional accuracy is extremely important and yet difficult to achieve with these hard-to-machine materials.

In this study, the theoretical grinding efficiency of dicing blades was estimated by establishing a new model for feeding speeds under constant feeding-force dicing. The model was evaluated by comparing empirical and theoretical dicing speeds for different abrasive grain sizes. The researchers were able to conclude that the grinding efficiency of dicing blades depends on the abrasive grains size, number and distribution on the surface of the dicing blade.

In experiments, three kinds of dicing blades were fabricated with different diamond grain sizes: 5-12 [micro]m, 10-20 [micro]m and 30-40 [micro]m. Tungsten carbide-cobalt (WC-Co) was used as a matrix material. The dicing blades consisted of 31 vol% of pores, 38 vol% of diamond grains and 31 vol% of WC-Co matrix material. Their thickness was between 85 and 90 [micro]m. The fabricated dicing blades were dressed under wet condition by using a plate containing alumina abrasive grains of mesh number 600. The dressing conditions were 2.0 mm dicing depth, 1 [mmxs.sup.-1] feeding table speed and 240 mm dressing length.

The number of grains and the distribution of grains on the surface of all fabricated dicing blades were observed by using a confocal laser microscope.

The work was carried out by Dr Takuya Adachi, Dr Koji Matsumaru and Dr Kozo Ishizaki.

For further information, contact: Dr Takuya Adachi, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan; tel: +81-258-46-6000; Internet: www.nagaokaut.ac.jp/e