NBN EN 60539-2 : 2005 AMD 1 2010

1 General
   1.1 Scope
   1.2 Normative references
   1.3 Information to be given in a detail specification
       1.3.1 Outline drawing and dimensions
       1.3.2 Mounting
       1.3.3 Ratings and characteristics
   1.4 Terminology
2 Preferred ratings and characteristics
   2.1 Tolerances on rated zero-power resistance
   2.2 Climatic categories
3 Quality assessment procedures
   3.1 Primary stage of manufacture
   3.2 Structurally similar components
   3.3 Qualification approval procedures
       3.3.1 The manufacturer shall comply with 3.4 of IEC 60539-1
   3.4 Quality conformance inspection
       3.4.1 Qualification approval on the basis of the fixed
             sample size procedure
   3.5 Quality conformance inspection
       3.5.1 Formation of inspection lots
       3.5.2 Test schedule
       3.5.3 Delayed delivery
       3.5.4 Assessment level
4 Test and measurement procedures
   4.1 Mounting
   4.2 Drying and recovery
       4.2.1 Drying
       4.2.2 Recovery
   4.3 Visual examination and check of dimensions
       4.3.1 Visual examination
       4.3.2 Requirements
       4.3.3 Marking
       4.3.4 Dimensions
   4.4 Electrical tests
       4.4.1 Zero-power resistance
       4.4.2 B-value or resistance ratio
       4.4.3 Resistance/temperature characteristic
   4.5 Thermal tests
       4.5.1 Dissipation factor (delta)
       4.5.2 Thermal time constant by cooling after self-heating (Tau[c])
   4.6 Resistance to soldering heat
       4.6.1 Initial measurement
       4.6.2 Test conditions
       4.6.3 Recovery
       4.6.4 Final inspection, measurements and requirements
  4.7 Solderability
       4.7.1 Test conditions
       4.7.2 Recovery
       4.7.3 Final inspection, measurements and requirements
  4.8 Rapid change of temperature
  4.9 Thermal shock
  4.10 Climatic sequence
       4.10.1 Initial measurements
       4.10.2 Dry heat
       4.10.3 Damp heat (cyclic), first cycle
       4.10.4 Cold
       4.10.5 Damp heat (cyclic), remaining cycles
       4.10.6 Final measurements
  4.11 Damp heat, steady state
  4.12 Endurance
       4.12.1 Endurance at Theta[3] and P[max.]
       4.12.2 Endurance at upper category temperature
  4.13 Shear (adhesion) test
  4.14 Substrate bending test
  4.15 Component solvent resistance
  4.16 Solvent resistance of marking
Annex A (normative) Guide for the specification and coding of
        dimensions of surface mount negative temperature
        coefficient thermistors
Annex ZA (normative) Normative references to international
         publications with their corresponding European
         publications

Applies to surface mount directly heated negative temperature coefficient thermistors, typically made from transition metal oxide materials with semiconducting properties. These thermistors have metallized connecting pads or soldering strips and are intended to be mounted directly on to substrates for hybrid circuits or on to printed boards.