This specification covers aluminum oxide (alumina) powder in two classes of particle size, two chemical grades, and two levels of acidity. Aluminum oxide powder shall conform to the chemical composition requirements indicated in this specification. The alumina powder shall be tested for water-soluble content, particle size, and hydrogen-ion concentration according to the procedures in this specification.

1.1 This specification covers aluminum oxide (alumina) powder in two classes of particle size, two chemical grades, and two levels of acidity, for use as an insulating coating or as an ingredient of ceramic mixtures for components of electronic devices as follows:

1.1.1 Particle Sizes:

1.1.1.1 Class A—Particle size No. 500 nominal mesh (nominal average particle size = 24.3 μm).

1.1.1.2 Class B—Particle size No. 900 nominal mesh (nominal average particle size = 1.7 μm).

1.1.2 Chemical Grades—Grades 1 and 2 as specified under chemical requirements in Section 3.

1.1.3 Acidity Levels: pH (acid) 4.5 to 6.5 and pH (neutral) 6.5 to 7.5.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.3 The following safety hazards caveat pertains only to the test methods in this specification. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.