IEC 60068-2-20:2021 pdf free download

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IEC 60068-2-20:2021 pdf free download

IEC 60068-2-20:2021 pdf free download Environmental testing – Part 2-20: Tests – Tests Ta and Tb: Test methods for solderability and resistance to soldering heat of devices with leads
1 Scope
This part of lEC 60068 outlines Tests Ta and Tb, applicable to devices with leads and leadsthemselves. Soldering tests for surface mounting devices (SMD) are described inIEC 60068-2-58.
This document provides procedures for determining the solderability and resistance to solderingheat of devices in applications using solder alloys,which are eutectic or near eutectic tin lead(Pb),or lead-free alloys.
The procedures in this document include the solder bath method and soldering iron method.
The objective of this document is to ensure that component lead or termination solderabilitymeets the applicable solder joint requirements of lEC 61191-3 and lEC 61191-4. In addition,test methods are provided to ensure that the component body can be resistant to the heat loadto which it is exposed during soldering.
NOTE Information about wetting time and wetting force can be obtained by test methods using a wetting balance.IEC 60068-2-69(solder bath and solder globule method) can be consulted.
2Normative references
The following documents are referred to in the text in such a way that some or all of their contentconstitutes requirements of this document. For dated references, only the edition cited applies.For undated references,the latest edition of the referenced document (including anyamendments) applies.
IEC 60068-1,Environmental testing – Part 1 : General and guidance
IEC 60068-2-2,Environmental testing – Part 2-2: Tests – Test B: Dry heat
IEC 60068-2-66,Environmental testing – Part 2:Test methods -Test Cx: Damp heat, steadystate (unsaturated pressurized vapour)
IEC 60068-2-78,Environmental testing – Part 2-78:Tests -Test Cab: Damp heat,steady stateIEC 61191-3,Printed board assemblies – Part 3: Sectional specification – Requirements forthrough-hole mount soldered assemblies
IEC 61191-4,Printed board assemblies – Part 4: Sectional specification – Requirements forterminal soldered assemblies
3 Terms and definitions
For the purposes of this document, the following.terms. and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
IEC Electropedia: available at http://www.electropedia.org/
ISO Online browsing platform: available at http://www.iso.org/obp
3.1
colophony
natural resin obtained as the residue after removal of turpentine from the oleo-resin of the pine tree, consisting mainly of abietic acid and related resin acids, the remainder being resin acid esters
Note 1 to entry: ”Rosin” is a synonym for colophony, and is deprecated because of the common confusion with the generic term “resin”.
3.2
contact angle
in general, the angle enclosed between two planes, tangent to a liquid surface and a solid/liquid interface at their intersection (see Figure 1 ); in particular, the contact angle of liquid solder in contact with a solid metal surface