ASTM_F_18_-_12.pdf

Designation:F1812Standard Specification and Test Method forEvaluation of Glass-to-Metal Headers Used in ElectronDevices1This standard is issued under the fixed designation F18;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 and test method cover acceptancerequirements for headers used in electron devices and describesprocedures for determining conformance to these require-ments.1.2 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 The following safety hazard caveat pertains only to thetest method(Sections 7-13)described in this specification.Thisstandard does not purport to address all of the safety concerns,if any,associated with its use.It is the responsibility of the userof this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use.2.Terminology2.1 Definitions of Terms Specific to This Standard:2.1.1 The header may be described as an external metalmember of cylindrical,oval,or other shape into which is sealedone or more wire leads or metal tubulations through a glassmedium.The metal parts may be plated or unplated and theglass may be clear or opaque.3.Significance and Use3.1 This standard covers procedures for conducting me-chanical and vacuum leak tests on glass-to-metal headers andis suitable for quality control and research and developmentuse.3.2 This standard is suitable for assessing both the quality ofmaterials as well as the manufacturing techniques used.4.Acceptance Requirements4.1 The headers shall conform to the requirements asspecified in 4.1.1 and 4.1.2 when tested in accordance with theprescribed methods of test(Sections 5-13).4.1.1 Visual:4.1.1.1 Cracks around the lead shall be restricted axially andradially to one lead diameter.Specimens showing any othertype of crack shall be rejected.4.1.1.2 The glass shall be free of inclusions exceeding onehalf of the smallest lead diameter.Gas bubbles entirelyenclosed by glass are permissible up to a diameter notexceeding that of the smallest lead.4.1.1.3 Metallic parts shall be as free of draw lines orgrooves longer(by visual estimate)than one half of the seallength as best commercial practice will permit.4.1.1.4 In the case of clear glass seals,reference is made tothe seal area only.4.1.1.5 In the case of opaque glass seals,reference is madeto any portion of the exposed metal parts.4.1.2 Leak:4.1.2.1 With the header sealed to the mass spectrometer leakdetector,the number of detectable leaks in a sample lot shall beless than the limit agreed upon between the purchaser and theseller.TEST METHODS5.Apparatus5.1 Microscope,of 10 power magnification,unless other-wise specified,in combination with suitable incandescentwhite light source.5.2 Mass Spectrometer Leak Detector,adjusted to respondto a tracer gas such as helium and capable of detecting leaks of109mL/s at standard temperature and pressure.5.3 Hood,having a volume of approximately 250 cm3(2.5 104m3),to cover the test specimen completely with thetracer gas.(The hood should be flushed with the tracer gas forat least 10 s).5.4 Fixture,suitable for making a seal between the headerunder test and the lead detector.A suggested jig is shown inFig.1.1This specification and test method are under the jurisdiction of ASTMCommittee F01 on Electronics and are the direct responsibility of SubcommitteeF01.03 on Metallic Materials.Current edition approved Feb.1,2012.Published March 2012.Originallyapproved in 1961 as F18 61 T.Last previous edition approved in 2006 as F18 64(2006).DOI:10.1520/F0018-12.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.5 Bath,two constant temperature water baths,and animmersion bath maintained at a temperature of 80Cto 70C.5.6 Torque Fixture,capable of holding the header in a fixedposition and capable of rotating a lead about its axis.5.7 Bending Fixture,capable of rotating the header throughan arc of 90,+0 5,about an axis of the lead under test andthrough the exit point of the lead from the glass.A weight isattached to the lead at a point close to the extremity.5.8 Megohmmeter,for testing electric insulation.5.9 Furnace,capable of heating parts to a temperature of450C maximum.5.10 Lead Pull Tester,capable of holding the header in afixed position while applying a load along the axis of the leadin a direction perpendicular to the plane containing the rim ofthe header.The displacement of one constraining member ofthe tester shall increase at a constant rate with respect to thesecond constraining member of the tester.6.Co