ASTM_F_7_-_95_2016.pdf

Designation:F795(Reapproved 2016)Standard Specification forAluminum Oxide Powder1This standard is issued under the fixed designation F7;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 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 asan ingredient of ceramic mixtures for components of electronicdevices as follows:1.1.1 Particle Sizes:1.1.1.1 Class AParticle size No.500 nominal mesh(nominal average particle size=24.3 m).1.1.1.2 Class BParticle size No.900 nominal mesh(nominal average particle size=1.7 m).1.1.2 Chemical GradesGrades 1 and 2 as specified underchemical 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 asstandard.No other units of measurement are included in thisstandard.1.3 The following safety hazards caveat pertains only to thetest methods in this specification.This standard does notpurport to address all of the safety concerns,if any,associatedwith its use.It is the responsibility of the user of this standardto establish appropriate safety and health practices anddetermine the applicability of regulatory limitations prior touse.2.Referenced Documents2.1 ASTM Standards:2C183 Practice for Sampling and the Amount of Testing ofHydraulic CementE70 Test Method for pH of Aqueous Solutions With theGlass Electrode3.Chemical Composition3.1 For a specified particle size and level of acidity,thealuminum oxide shall conform to the requirements of Table 1as to chemical composition.4.Physical Properties4.1 The alumina shall be“chalk white,”dry,free fromlumps,and of particle size distribution as agreed upon betweenpurchaser and seller.5.Sampling5.1 Each lot of alumina shall be properly sampled inaccordance with standard techniques,such as Practice C183.6.Test Methods6.1 Water-Soluble Content:6.1.1 ProcedureDetermine the total water-soluble contentby measuring the electrical conductivity of a 100-mL distilledor deionized water extract from a 5-g sample of alumina.Elutriate by vigorously shaking the alumina suspension in aflask for 1 to 2 min,allowing the solids to settle and decantingthe clear supernatant liquid after 60 min.Measure the conduc-tivity of the liquid with a standard cell and bridge.Correct thismeasurement for the“blank”reading on a similarly treatedequal volume of the same pure water.Convert the net increasein conductivity of the water extract first to parts of water-soluble content as sodium chloride(NaCl)per million parts ofwater(factor is 1 micromho=0.5 ppm NaCl),then relate to theactual weight of elutriated alumina.For example,on a typical100-mL extract 10 micromhos(net)or 5 parts of NaCl permillion of water in this volume of liquid is equivalent to 100parts of NaCl per million of alumina on the basis of a 5-gsample.6.1.2 Calculation Determine the parts per million ofwater-soluble content as follows:ppm5 107KcRb2 Rx!/RbRx#(1)where:Kc=cell constant,cm1,Rb=specific resistance of test water,cm,andRx=specific resistance of alumina extract in test water,cm.6.2 Particle Size:1This specification is under the jurisdiction of ASTM Committee F01 onElectronics and is the direct responsibility of Subcommittee F01.03 on MetallicMaterials,Wire Bonding,and Flip Chip.Current edition approved May 1,2016.Published May 2016.Originallyapproved in 1958.Last previous edition approved in 2011 as F7 95(2011).DOI:10.1520/F0007-95R16.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.2.1 Determine particle size distribution by any of thefollowing methods:(a)Coulter counter,(b)M.S.A.centrifugemethod,(c)Cahn Sedimentometer,or(d)Sharples Micromero-graph.NOTE1Procedures for determining particle size by the methodsshown in Table 2 are described in the operating manuals of the equipmentlisted.6.2.2 Number average particle size may be taken as the50%point on the particle size distribution curve or may bemeasured by the Fisher sub-sieve sizer.6.2.3 A density of 3.97 g/cm3for aluminum oxide will beused in all calculations.6.2.4 Particle size distribution of acceptable material in bothClass A and Class B will be by agreement between purchaserand seller.Sample size and method of dispersion will beidentical in all test correlations,as specified in Table 2.Typicalresults are shown in Table 3.6.2.5 Number average particle size of acceptable material inboth Class A and Class B wi