| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide silica particles which scarcely dischargeα-rays, which is excellent in dispersibility to a resin, and which can be contained in a paste for semiconductor packaging. <P>SOLUTION: The silica particles have an average particle size of 10 nm to 10μm measured by dynamic light scattering, wherein the ratio (U/SiO<SB POS="POST">2</SB>) of mass of uranium to mass of silicon oxide (in terms of SiO<SB POS="POST">2</SB>) is 2 ppb or less, the ratio (Th/SiO<SB POS="POST">2</SB>) of mass of thorium to mass of silicon oxide (in terms of SiO<SB POS="POST">2</SB>) is 2 ppb or less, and the ratio (alkali metal element/SiO<SB POS="POST">2</SB>) of mass of alkali metal elements to mass of silicon oxide (in terms of SiO<SB POS="POST">2</SB>) is 10 to 1,000 ppm. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
