IEC 60749-30:2020

Overview

IEC 60749-30:2020 - "Semiconductor devices - Mechanical and climatic test methods - Part 30: Preconditioning of non‑hermetic surface mount devices prior to reliability testing" - defines a standardized preconditioning procedure for non‑hermetic surface mount devices (SMDs) before they undergo in‑house reliability or qualification testing. The standard prescribes representative preconditioning flows that simulate typical industry multiple solder reflow operations and the moisture‑related stresses that plastic‑encapsulated or moisture‑permeable packages experience during storage and assembly.

Key topics and requirements

• Preconditioning objective: Reproduce moisture absorption and soldering stresses that can cause package cracking or electrical failure when vapor pressure rises during reflow.
• Preconditioning flows: Defined sequences covering moisture soak, optional temperature cycling, drying (bake‑out), one or more solder reflow cycles, and final electrical and visual inspection. Different flows apply to dry‑packed and non‑dry‑packed SMDs (Methods A, B, C referenced).
• Moisture soak and chamber conditions: Specifies controlled humidity/temperature soak environments (examples in the standard include combinations such as 85 °C/85 % RH, 30 °C/70 % RH, etc.) and tolerances for chamber performance.
• Solder reflow: Expanded in this edition (Clause 6.7) with guidance on simulating industry multiple reflow operations and monitoring the temperature at the package top to correlate moisture sensitivity level (MSL) and actual assembly conditions.
• Measurements and inspections: Initial and final electrical testing and visual inspection, plus optional flux application simulation and cleaning/drying steps.
• Defined terminologies: New Clause 3 introduces standardized terms (e.g., MSL, floor life, dead‑bug/live‑bug orientation) to ensure consistent interpretation.

Practical applications and users

Who uses IEC 60749-30:

• Semiconductor manufacturers establishing device qualification and reliability protocols.
• Contract manufacturers and PCB assemblers validating solder process compatibility and avoiding moisture‑induced failures.
• Test laboratories and OEM reliability engineers performing lot qualification, process audits, and long‑term reliability monitoring. How it’s used:
• To determine the correct preconditioning flow (MSL correlation) before subjecting devices to HAST, temperature cycling, or other reliability tests.
• To set bake, soak and reflow parameters that reflect real assembly practices and ensure consistent, reproducible stress conditions.

Related standards

• IEC 60749-20 (moisture sensitivity levels for plastic‑encapsulated SMDs)
• Other IEC 60749 parts referenced for reliability tests (HAST, moisture resistance, temperature cycling)

Keywords: IEC 60749-30, SMD preconditioning, non‑hermetic surface mount devices, moisture sensitivity level (MSL), solder reflow, reliability testing, preconditioning flow, dry‑pack, bake out, semiconductor test method.