ASTM_F_542_-_02.pdf

Designation:F 542 02An American National StandardStandard Test Method forExothermic Temperature of Encapsulating Compounds forElectronic and Microelectronic Encapsulation1This standard is issued under the fixed designation F 542;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 provides results that are related to themaximum temperature reached in a specific volume by areacting liquid encapsulating compound,and the time frominitial mixing to the time when this peak exothermic tempera-ture is reached.1.2 This test method provides a means to measure the peakexothermic temperature of an encapsulating compound.1.3 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 hazardstatements see Section 8.NOTE1There is no equivalent IEC standard.2.Referenced Documents2.1 ASTM Standards:D 1711 Terminology Relating to Electrical Insulation2D 5423 Specification for Forced-Convection LaboratoryOvens for Evaluation of Electrical Insulation33.Terminology3.1 Definitions:For definitions of terms used in this testmethod,refer to Terminology D 1711.3.2 Definition of Term Specific to This Standard:3.2.1 encapsulating compound,na resin system used toencase electronic components.3.2.1.1 DiscussionThese resins are generally used to pro-vide protection from the operating environment and mechani-cal damage.4.Summary of Test Method4.1 A thermocouple is used to measure the highest tempera-ture at the geometric center of a volume of encapsulatingcompound in order to characterize the heat generated by thechemical exothermic reaction.5.Significance and Use5.1 Heat generated by a reacting liquid encapsulating com-pound may cause damage to heat-sensitive electronic compo-nents.Degradation of the encapsulating compound may alsooccur at high temperatures.Proper selection of an encapsulatemust include knowledge of its exothermic temperature topreclude damage to components.5.2 Since the exothermic temperature of a reacting encap-sulating compound varies with the volume and geometry ofmaterial,it is essential that the volume and geometry bespecified in any determination.By selection of an appropriatevolume and geometry,the exothermic temperature may bemeasured in sufficiently precise and reproducible form forapplication evaluation,quality control,and encapsulating com-pound characterization.5.3 Materials may be compared by testing equal volumes ofeach material using the same geometry.Two different volumesof the same material in similar geometries may be tested todetermine the effect of volume on the exothermic temperature.6.Interferences6.1 Under normal electronic system encapsulation,the heatsink of the components would reduce the maximum heatgenerated in the encapsulating compound.Since the volumeand geometry of the electronic system,plus the heat sink of thecomponents,affect the exothermic temperature of the encap-sulating compound,it is recommended that actual hardware betested in cases in which temperature-sensitive electronics areutilized.7.Apparatus7.1 Specimen Containers for specific test volumes,as fol-lows:7.1.1 For 50-mL test,borosilicate glass beaker,Griffin,1This test method is under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials,and is the direct responsibility ofSubcommittee D 09.01 on Electrical Insulating Varnishes,Powders and Encapsu-lating Compounds.Current edition approved Sept.10,2002.Published October 2002.Originallypublished as F 542 77 T.Last previous edition F 542 98.2Annual Book of ASTM Standards,Vol 10.01.3Annual Book of ASTM Standards,Vol 10.02.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.7.1.2 For 125-mL test,“No.202 3 204”standard canningindustry 130 mL can,54.0 mm in diameter by 57.1 mm inheight,7.1.3 For 150-mL test,borosilicate glass beaker,Griffin,low-form,7.1.4 For 200-mL test,“No.202 3 314”standard canningindustry 225 mL can,54.0 mm in diameter by 98.4 mm inheight,or7.1.5 For 300-mL test,“No.211 3 400”standard canningindustry No.1“soup”can,68.2 mm in diameter by 101.6 mmin height.7.2 Glass Tubing,of sufficient length and diameter tosupport the thermocouple wire into the geometric center of thespecimen container.7.3 Thermocouple,expendable,one for each specimen,capable of measuring temperatures from 23 to 260C(73 to500F),inclusive.7.4 Temperature-Indicating Device,utilizing thermo-couples,and accurate to 6 3C(6 5F)(see Note 2).NOTE2Automatic temperature recorders have been used success-fully.7.5 Balance,capab