ASTM_F_97_-_72_2002e1.pdf

Designation:F 97 72(Reapproved 2002)e1Standard Practices forDetermining Hermeticity of Electron Devices by DyePenetration1This standard is issued under the fixed designation F 97;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(e)indicates an editorial change since the last revision or reapproval.e1NOTEWarning notes were editorially moved into the standard text in May 2003.1.Scope1.1 These practices cover procedures that will normallydetect and locate the sites of gross leaks in electron devices.1.2 These procedures are suitable for use on selected partsduring receiving inspection or to verify and locate leakage sitesfor production control.They are not quantitative;no indicationof leak size can be inferred from the test.1.3 These procedures are most suitable for use on transpar-ent glass-encased devices;all methods are applicable to trans-parent parts with an internal cavity.Method A,Penetrant-Capillary,is also applicable to parts,such as terminals,endseals or base assemblies,without an internal cavity,andMethod C,Penetrant-Pressure Followed by Vacuum,can beused on opaque parts with an internal cavity.Method B,Penetrant-Pressure,can also be used on opaque parts with aninternal cavity if the part is opened after dye penetration andbefore inspection.Parts that have an internal cavity may eithercontain gas(such as air,nitrogen,nitrogen-helium mixture,etc.)or be evacuated.These procedures are not suitable for useon grease-filled components.1.4 Because of the possibility of dye entrapment betweenthe component and an attached part,components with me-chanically attached parts,such as a radiator on a powertransistor,should be tested before the attachment is made orafter it has been removed.NOTE1Alternative methods for determining hermeticity of electrondevices may be found in Practices F 98(see 2.1)and Test Methods F 134(see 2.1).1.5 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.For specific hazardstatement,see Section 8.2.Referenced Documents2.1 ASTM Standards:E 165 Practice for Liquid Penetrant Examination2F 98 Practices for Determining Hermeticity of ElectronDevices by a Bubble Test3F 134 Test Methods for Determining Hermeticity of Elec-tron Devices with a Helium Mass Spectrometer LeakDetector42.2Other Standards:MIL-STD-105 Sampling Procedures and Tables for Inspec-tion by Attributes5MIL-STD-883 Test Methods and Procedures for Microelec-tronics63.Summary of Practice3.1 In these methods,a penetrant dye solution is appliedlocally to an area of the component to be tested for leaks,or theentire component is immersed in a bath of the penetrant.Aftercontact with the penetrant dye for a specified time,the deviceis cleaned and visually inspected for dye penetration.3.2 Method A,Penetrant-CapillaryThe penetrant dye isapplied locally,or the device is immersed in a bath of the dye.This method,in which no external pressure is exerted to forcethe penetrant dye through the leak,is particularly suited tocomponents and subassemblies without an internal cavity or tosubassemblies that cannot be totally immersed.1These practices are under the jurisdiction of ASTM Committee F01 onElectronics and are the direct responsibility of Subcommittee F01.03 on MetallicMaterials.Current edition approved Dec.10,2002.Published May 2003.Originallyapproved in 1968.Last previous edition approved in 1997 as F 97 72(1997)e1.2Annual Book of ASTM Standards,Vol 03.03.3Discontinued.See 1991 Annual Book of Standards,Vol 10.04.4Discontinued.See 1995 Annual Book of ASTM Standards,Vol 10.04.5Available from the Superintendent of Documents,Government Printing Office,Washington,DC 20402.6Available from Standardization Documents,Order Desk,Bldg.4,Section D,700 Robbins Ave.,Philadelphia,PA 19111-5094,ATTN:NPODS.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.3.3 Method B,Penetrant-PressureThe component,withan internal cavity,is immersed in a bath of the penetrant dye.The bath is pressurized to force the dye solution through anyleaks that may exist.3.4 Method C,Penetrant-Pressure Followed by VacuumThe component,with an internal cavity,is immersed in a bathof the penetrant dye,which may or may not be pressurized.After being carefully cleaned,the component is placed in avacuum chamber.Any dye solution that may have entered aleak during immersion is forced out by the internal pressure ofthe cavity.3.5 Selection of MethodThe selection of the method toperform a dye penetration test depend