IEC 61760-3:2021

Overview

IEC 61760-3:2021 is an international standard published by the International Electrotechnical Commission (IEC) that defines the standard method for specifying electronic components designed specifically for through-hole reflow (THR) soldering technology. This standard aims to unify the requirements and test conditions for components with leads intended for through-hole reflow soldering, ensuring these components can be handled with the same placement and mounting processes used for surface-mount devices (SMDs).

The purpose of IEC 61760-3:2021 is to provide component manufacturers, users, and assembly line engineers with a consistent reference framework. It establishes essential design requirements, packaging, labelling, storage, and mechanical stress considerations for components supporting THR soldering. Additionally, it specifies recommended process conditions, such as solder paste application methods and reflow soldering profiles, to facilitate reliable assembly and post-assembly quality.

Notably, the 2021 edition updates position tolerance requirements to between 0.2 mm and 0.4 mm and introduces the through-hole vacant method as a solder paste supply technique, reflecting industry advancements.

Key Topics

• Component Design and Specifications
  IEC 61760-3:2021 mandates detailed component outlines including pick-up areas, tilt limits, bottom surface flatness, terminal shape and dimensions, optical recognition, and marking. These ensure components are optimized for automated placement and THR soldering reliability.

• Packaging and Labelling
  Requirements cover packaging types such as tape and tray formats, clearly labelled to support automated handling. Proper packaging minimizes damage and maintains component integrity during transport and storage.

• Process Conditions for THR Soldering
  The standard describes typical THR soldering process steps, including solder paste application, component insertion, reflow soldering methods, and cleaning processes. It supports various solder paste supply methods, emphasizing the newly introduced through-hole vacant technique.

• Test Conditions and Quality Criteria
  IEC 61760-3 outlines relevant tests including wettability, dewetting, resistance to soldering heat and cleaning solvents, soldering profiles, and moisture sensitivity levels. These confirm components meet reliability standards applicable to through-hole reflow processes.

• Compatibility with Lead-Free Soldering
  Additional criteria are specified for ensuring components are compatible with lead-free soldering processes, vital for current environmental regulations and industry practices.

Applications

IEC 61760-3:2021 serves as an essential reference for:

• Electronic Component Manufacturers designing through-hole components intended for modern reflow soldering techniques, guaranteeing compliance with international standards.
• Contract Manufacturers and PCB Assembly Lines aiming to integrate through-hole reflow soldering alongside surface mounting technology, optimizing throughput and minimizing defects.
• Quality Assurance Teams focused on validating component and soldering process performance under standardized conditions.
• Design Engineers selecting components and designing PCB layouts compatible with combined THR and surface mount assembly methods.
• Research and Development organizations improving assembly efficiency and exploring new assembly technologies leveraging through-hole reflow methods.

By standardizing the requirements and testing, manufacturers and users can achieve higher reliability, greater process consistency, and improved interoperability in electronic assembly environments using THR soldering.

Related Standards

IEC 61760-3:2021 is part of the IEC 61760 series on surface mounting technology. Related standards include:

• IEC 61760-1 - Surface mounting technology - Part 1: Generic specification for surface-mount components.
• IEC 61760-2 - Surface mounting technology - Part 2: Specification method for components for surface mounting.
• IPC/JEDEC standards on soldering and component assembly methods, which complement IEC guidance for PCB manufacturing and assembly process control.
• ISO/IEC Directives on standards development and terminology, ensuring consistency in drafting and interpretation of technical requirements.

These related standards collectively support the design, manufacturing, and quality assurance processes for electronic components and assembly technologies worldwide.

Keywords: IEC 61760-3:2021, through-hole reflow soldering, THR soldering standard, component specification, electronic components, surface mounting technology, solder paste supply, soldering process conditions, lead-free soldering compatibility, electronic assembly, PCB manufacturing standard.