IEC 62047-38:2021

Overview

IEC 62047-38:2021 specifies a standardized test method for measuring the adhesion strength of metal powder paste in MEMS interconnection. It applies to metal powder pastes such as anisotropic conductive paste, solder paste, and nanoscale metallic inks, with particle diameters from 10 µm to 500 µm. The method uses a glass lens to apply a uniaxial compression (contact load) and then retracts the lens to measure the maximum pulling force; adhesion strength is calculated as force divided by the measured contact area (S = P / A).

Key topics and technical requirements

• Test principle: Compress metal powder paste with a curved glass lens to form actual contact areas, hold, then retract to measure adhesion during unloading.
• Applicable materials: Metal powder pastes used in MEMS interconnection (e.g., anisotropic conductive paste, solder paste, nanoscale metallic inks).
• Particle size range: Valid for metal powder diameters between 10 µm and 500 µm.
• Test piece design: Circular pattern on a substrate; radius of the test piece must be at least 50 times smaller than lens radius of curvature (R); thickness ≥ 2× single-particle diameter.
• Measurement and instrumentation:
  • Force recorded by a loadcell (maximum pulling force PC).
  • Contact area captured by optical microscope + CCD camera; image capture > 30 Hz with objective ≥20×.
  • Contact area measurement accuracy: ±5% or better.
• Key parameters:
  • Contact load (PL) - predetermined compression force.
  • Separation speed (VSEP) - retract speed (µm/s).
  • Adhesion strength (SC) = maximum pulling force / contact area (N/m² or N/m).
• Test procedure summary: install test piece → record force/images → apply contact load → hold briefly → retract at set separation speed → compute adhesion from maximum pull force and measured contact area.
• Data and reporting: Include contact force/time curves, contact-area images, maximum pulling force, computed adhesion strength, test-piece dimensions and environmental conditions.

Applications and users

• Who uses it: MEMS device manufacturers, electronic packaging engineers, materials suppliers (conductive pastes/inks), reliability and test labs, R&D teams developing MEMS interconnections.
• Practical uses:
  • Evaluate and compare adhesion performance of conductive pastes for MEMS-to-PCB interconnection.
  • Simulate real contact interfaces by considering actual contact area between MEMS electrodes and metal powder particles.
  • Support process development, quality control, failure analysis, and supplier qualification.

Related standards

• Part of the IEC 62047 series (Semiconductor devices – Micro-electromechanical devices).
• References measurement practices from IEC 62047-2:2006 and IEC 62047-3:2006 for dimensional and imaging guidance.

Keywords: IEC 62047-38:2021, adhesion strength, metal powder paste, MEMS interconnection, anisotropic conductive paste, solder paste, nanoscale metallic inks, contact area, glass lens test method.