High-purity low-radioactivity spherical silicon micropowder and preparation method thereof

Abstract

The invention discloses high-purity low-radioactivity spherical silicon micropowder. In the silicon micropowder, the content of SiO2 is not lower than 99.90 percent, the content of radioelement U is less than or equal to 1*10g/g, sphericization ratio is between 90 and 100 percent, and non-crystalline ratio is between 99 and 100 percent. The method for preparing the silicon micropowder comprises the following steps: preparing stable silica sol which has purity not lower than 99.90 percent and the ion content of an arbitrary impurity less than or equal to 5*10g/g by a silicon source with the content of radioelement U being less than or equal to 1*10g/g; concentrating the silica sol to lead the solid content of the silica sol to be between 41 and 70 percent; granulating the concentrated silica sol to lead grain diameter of the silica sol to be between 0.5 and 60 mu meters; roasting the granulated silicon oxide micropowder at a temperature of between 500 and 1,100 DEG C; and carrying out sphericization treatment on the micropowder in a flame burner and a sphericizing furnace, and classifying and collecting the micropowder after cooling to obtain the high-purity low-radioactivity spherical silicon micropowder. The spherical silicon micropowder of the invention can meet the requirement of a large-scale integrated circuit on capsulation packing, and the invention has simple process, low cost, simple required equipment, and is applicable to industrial production.

Description

technical field [0001] The invention relates to a high-purity, low-radioactive spherical silicon micropowder used in large-scale integrated circuit packaging and a preparation method thereof. Background technique [0002] Spherical silica powder is widely used in the packaging of semiconductor integrated circuits. With the development of large-scale and ultra-large-scale integrated circuits, the requirements for packaging fillers are getting higher and higher. Not only high purity, ultra-fine, spherical, but also radioactive elements are required. Low content. The α-rays emitted by the radioactive elements in the packaging material make the integrated circuit not work properly, produce soft errors, and destroy the information stored in the integrated circuit. When packaging more than 16M memories, the problem of soft errors caused by α-rays will become very prominent. Therefore, VLSI puts forward stricter requirements on the content of radioactive elements in spherical sil...

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Problems solved by technology

Moreover, in the process of preparing spherical silicon micropowder by physical method, most of them use natural quartz as raw material (US Application 20030070452, JPA58145613, JPA11199219), because it is difficult to remove radioactive elements in natural quartz, it is impossible to produce low-radioactive spherical silicon micropowder

[0005] In short, although there are many methods for preparing spherical silica powder, most of them have certain deficiencies, such as the high cost of the method, or easy pollution to the environment, or the inability to prepare low-radioactive spherical silica powder, or the prepared spherical silica powder cannot meet the requirements of large-scale production. Integrated Circuit Requirements

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