EN 140402:2015/A1:2016

Overview

EN 140402:2015/A1:2016 is a European Amendment to the standard EN 140402:2015, issued by the CLC (European Committee for Electrotechnical Standardization). This amendment specifically adds a new Annex D to the existing document, which presents a blank template and editorial guidelines related to the fixed low power wirewound surface mount (SMD) resistors specification. These resistors are crucial components in electronic circuits requiring reliable fixed resistance with low power dissipation.

The amendment focuses on addressing the unique mounting and testing requirements for wirewound SMD resistors, which differ from regular chip resistors due to their construction and dissipation characteristics. This amendment enables manufacturers and users to apply consistent technical criteria for mechanical, electrical, and thermal handling.

Key Topics

• Blank Detail Specification Template: Annex D provides a structured template designed for documenting specifications related to fixed low power wirewound SMD resistors. This serves as a guideline for manufacturers to standardize product documentation.

• Mounting Provisions: Special emphasis is placed on mounting techniques for wirewound SMD resistors. Unlike other standard chip resistors, these components have:

  • Distinct outline dimensions.
  • Different solder termination footprints.
  • Higher dissipation levels requiring tailored mounting approaches.

• Testing Requirements: Annex D highlights differentiated rules for:

  • Mechanical testing suitability.
  • Electrical testing where temperature rise is insignificant.
  • Electrical endurance tests involving temperature rise due to dissipation.
  • Thermal testing without electrical excitation.

These provisions ensure the integrity and reliability of resistors under various physical and operational stresses.

• Compatibility and Compliance: By following this amendment, manufacturers comply with CENELEC regulations, ensuring that the standard is uniformly implemented across member countries without alteration.

Applications

This standard and its amendment are indispensable for:

• Electronics Manufacturing: Ensuring fixed low power wirewound SMD resistors meet quality and mounting standards in the production of electronic devices.

• Component Specification: Assisting designers and engineers in specifying resistors that require precise mechanical and thermal handling conditions.

• Quality Assurance and Testing: Providing testing laboratories with clear guidelines for conducting mechanical, electrical, and thermal endurance tests on wirewound SMD resistors.

• Standardization Efforts: Enabling national standard bodies within Europe to adopt and incorporate uniform specifications for these resistor types.

Typical applications include telecommunication equipment, consumer electronics, automotive electronics, and industrial control systems where precision resistors with stable characteristics under low power conditions are essential.

Related Standards

• EN 60115-8:2012: Covers general mounting provisions for chip and cylindrical resistors. Annex D clarifies why these provisions are generally not applicable to wirewound SMD resistors.

• EN 140402:2015: The base standard amended by A1 in 2016 to include the additional mounting and testing provisions regarding wirewound fixed resistors.

• CENELEC Internal Regulations: Governs the adoption and implementation process for amendments and standards within member states, ensuring harmonized electrical component regulations.

Keywords: fixed low power resistors, wirewound SMD resistors, surface mount resistors, resistor mounting standards, electrical testing, mechanical testing, thermal testing, European standard EN 140402, CENELEC standards, resistor specification template.