IEC 60749-15:2020

Overview

IEC 60749-15:2020 - Semiconductor devices - Mechanical and climatic test methods - Part 15: Resistance to soldering temperature for through‑hole mounted devices - defines a reproducible solder dip test to determine whether encapsulated solid‑state devices with through‑hole leads can withstand soldering temperatures encountered during printed wiring board assembly. The procedure evaluates whether soldering heat (conducted through leads from the reverse side of the board) degrades electrical characteristics or internal connections. The test is destructive and intended for qualification, lot acceptance and product monitoring.

Key topics and technical requirements

• Test method: Solder dip (preferred for reproducibility); an alternative uses a controlled soldering iron per IEC 60068‑2‑20 when dip is impracticable.
• Temperature:
  • Typical solder bath for Sn–Pb: 260 ± 5 °C.
  • Typical bath for Pb‑free alloys: ~270 ± 5 °C (document provides Pb‑free parameters).
  • Soldering‑iron condition may use higher local temperature (table indicates condition B example at 350 ± 5 °C).
• Immersion parameters:
  • Dwell time: 10 ± 5 s.
  • Immersion/emersion rates: ≈ 25 mm/s.
  • Number of immersions: up to 2.
  • Distance from solder bath to device body: ~1.5 ± 0.5 mm.
• Materials and flux:
  • Specifies solder compositions for Sn–Pb and typical Pb‑free alloys (Ag, Cu, Sn balance).
  • Flux example: 25% colophony in 75% isopropyl alcohol, unless otherwise specified.
• Pre‑conditioning:
  • Option to use accelerated ageing (steam ageing, damp heat, dry heat, etc.) per IEC 60068‑2‑20 before solder exposure.
• Failure criteria and measurements:
  • Post‑dip inspection and electrical testing to detect degradation or internal failures (visual and electrical criteria referenced to relevant device specifications).
• Scope limitations:
  • Heat is applied through leads from the reverse side; the test does not simulate wave/reflow exposure on the same side as the package body.

Applications and who uses it

• Used by semiconductor manufacturers, test labs, quality engineers and contract manufacturers for:
  • Product qualification and reliability screening.
  • Lot acceptance and production monitoring.
  • Verifying robustness of through‑hole devices to assembly solder processes (wave soldering, soldering‑iron operations).
• Practical value: standardized, reproducible method to assess soldering heat resistance and avoid latent failures introduced during PCB assembly.

Related standards

• IEC 60068‑2‑20 - environmental testing; solderability and resistance to soldering heat methods
• IEC 60749‑3 - external visual examination
• IEC 60749‑8 - sealing

Keywords: IEC 60749-15:2020, solder dip, resistance to soldering heat, through-hole mounted devices, solderability, wave soldering, lead-free solder, solder bath, soldering iron, accelerated ageing.