Overview
SIST EN ISO 9455-14:2018 is an international standard specifying a qualitative test method for assessing the tackiness of flux residues left after the soft soldering process. This standard applies broadly to all types of soft soldering fluxes, including solder pastes and flux cored solder wires. The assessment of flux residue tackiness is vital for applications where flux residues remain on electrical and electronic equipment, as tacky residues can affect reliability and functionality.
Developed under the collaboration of ISO Technical Committee 44 and CEN Technical Committee 121, this standard ensures consistent evaluation methods aligned with industry requirements across Europe and internationally. It supersedes the earlier EN ISO 29455-14:1993 edition, reflecting editorial updates and improved test reporting.
Key Topics
- Scope of Testing: The method is designed for qualitative evaluation of tackiness in flux residues post-soldering. It is suitable for liquid, solid, paste fluxes, solder pastes, and flux cored solder wires.
- Test Principle: Flux and solder materials are melted together on a copper test piece allowing residues to form naturally. Once cooled, the residue is dusted with chalk powder and brushed to observe adhesion.
- Materials and Apparatus:
- Copper test pieces with a depressed center to hold solder.
- Solder baths maintained at specific temperatures depending on solder alloys (e.g., Sn60Pb40 at 235°C).
- Powedered chalk and soft brushes for residue examination.
- Degreasing solvents, acid cleaning solutions, and drying ovens.
- Test Procedure:
- Test pieces are cleaned, flux applied, solder melted, and allowed to cool.
- Residues are dusted with chalk powder and brushed gently.
- Observation of chalk removal determines tackiness: easy removal indicates "not tacky", while strong adhesion indicates tackiness.
- Reporting: Results are recorded qualitatively, enabling manufacturers and users to assess the suitability of flux for specific applications and equipment longevity.
Applications
The SIST EN ISO 9455-14:2018 standard is widely used in industries reliant on soft soldering processes, especially where electrical or electronic assemblies must retain flux residues without adverse effects. Applications include:
- Electronics Manufacturing: Ensuring flux residues on printed circuit boards (PCBs) are non-tacky to prevent contamination and mechanical issues.
- Electrical Equipment Assembly: Assessing flux residues on connectors and terminals where residue tackiness can affect conductor connections.
- Solder Material Quality Control: Qualification of new flux formulations and solder pastes during development and production stages.
- Quality Assurance Testing: Routine testing by manufacturers to maintain consistent product performance and compliance with international standards.
By applying this standard, companies can minimize risks related to flux residue performance, such as corrosion, contamination, and impaired electrical insulation.
Related Standards
SIST EN ISO 9455-14:2018 works in conjunction with several other standards within the ISO 9455 series and related soldering norms:
- ISO 9455-1 & ISO 9455-2: Methods for determination of non-volatile matter in soft soldering fluxes, supporting sample preparation for Part 14 testing.
- ISO 9453: Specifies chemical compositions and forms of soft solder alloys, ensuring correct material specifications for testing.
- ISO 197-1: Provides terms and definitions for copper and copper alloys used as test piece materials in soldering applications.
- Additional parts of ISO 9455 series cover flux test methods such as activity and corrosion testing, complementing the tackiness assessment.
These standards collectively support comprehensive evaluation and quality control of fluxes and soldering materials in manufacturing environments.
By adhering to SIST EN ISO 9455-14:2018, manufacturers and quality professionals can ensure consistent, reliable evaluation of flux residue tackiness, enhancing product quality and operational reliability in soft soldering applications. This standard is a critical reference for industries focused on electronics and electrical assembly where flux residues are a key process parameter.
