ASTM_F_816_-_83_2003.pdf

Designation:F 816 83(Reapproved 2003)Standard Test Method forCombined Fine and Gross Leaks for Large HybridMicrocircuit Packages1This standard is issued under the fixed designation F 816;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method applies to hermetic package leaktesting to detect leaks of a broad spectrum in size with aminimum detection level equal to the sensitivity of the heliummass spectrometer equipment used in the test.1.2 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.2.Referenced Documents2.1 ASTM Standards:2E691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodF78 Test Method for Calibration of Helium Leak Detectorsby Use of Secondary StandardsF98 Practices for Determining Hermeticity of ElectronDevices by a Bubble Test3F134 Test Methods for Determining Hermeticity of Elec-tron Devices with a Helium Mass Spectrometer LeakDetector42.2Federal Standard:Federal Standard 209B Clean Room and Work Station Re-quirements,Controlled Environment53.Summary of Method3.1 This test method for the hermeticity of packages usedfor housing multichip and hybrid microcircuits is to be appliedgenerally to those equal to or greater than 1 in.2(645 mm2)inarea or 0.60 cm3in volume.Avent hole(See Fig.1)is designedinto the lid of the package.After sealing the lid on the package,the vent hole in the lid is presented to a port in the inlet of thehelium leak detector using an interface seal(See Fig.2).Afterthe internal volume is evacuated,a cloud of helium gas isbrought into close proximity to the entire outer surface of thepackage.Helium passing into the inner volume of the packagethrough any leak orifice in an amount greater than theminimum sensitivity of the leak detector will be detectedwithin a few seconds.The successfully sealed product is thenplaced into a controlled atmosphere dry box for vacuumpurging and back filling the internal volume of the packagethrough the vent hole with an inert gas having some detectablepartial pressure level of helium gas.While under this lattercondition,the vent hole is sealed off by a suitable manner.Thespecimen is then immediately retested by the above method todetect successful sealing of the vent hole.4.Significance and Use4.1 This test method provides an evaluation of the quality ofan in-line sealing process on a real time basis for sealedpackages.It eliminates the need to expose the specimen to longexposures of high pressure to drive the helium gas into thepackage to later be detected by the same method herein used.Previously,separate test methods were required to detect largeor small leaks.This method provides only one test to accom-plish all test levels without potential for specimens with leaksto escape detection within the range of detection being em-ployed(see Practices F 98).4.2 Both development and research,along with manufactur-ing control,may be served by using this test method.Currentgross leak test methods and fine leak test methods may becombined into one using this method.No exposure to highpressure processing hazards is involved and safety of operationin production environment is enhanced.5.Interferences5.1 The use of the helium leak detector requires a specificgas transit time for the helium to pass through a leak orifice inthe specimen and travel into the mass spectrometer sensingelement for detection.The value of this time constant should beexceeded for all test conditions to be considered valid.Forsmall leaks,the time constant will be maximum.Allowing the1This test method is under the jurisdiction of ASTM Committee F01 onElectronics and is the direct responsibility of Subcommittee F01.03 on MetallicMaterials.Current edition approved May 27,1983.Published July 1983.2For 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.3Discontinued;see 1990 Annual Book of ASTM Standards,Vol 10.04.4Discontinued;see 1996 Annual Book of ASTM Standards,Vol 10.04.5Available from Standardization Documents Order Desk,Bldg.4 Section D,700Robbins Ave.,Philadelphia,PA 19111-5094,Attn:NPODS.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.helium gas to bathe the specimen for a time in excess of thistime constant will suffice.This time constant should normallybe no longer than 5 s.5.2 Any contaminating films or seal defec