IEC 61191-3:2017

Overview

IEC 61191-3:2017 - "Printed board assemblies - Part 3: Sectional specification - Requirements for through-hole mount soldered assemblies" - prescribes requirements for assemblies that use through‑hole technology (THT) or the THT portions of mixed-technology assemblies. This 2017 edition (Edition 2.0) updates acceptance and workmanship requirements to align with the acceptance criteria in IPC‑A‑610F.

Key topics

• Scope and applicability
  • Requirements apply to lead-and-hole solder assemblies for fully THT assemblies or THT sections of mixed assemblies.
• Mandatory references
  • Incorporates requirements of IEC 61191‑1 (generic soldered assembly specification) and refers to IEC 60194 terms and definitions.
• Workmanship and acceptability
  • Workmanship must meet IPC‑A‑610 classification requirements; acceptance criteria updated to be compliant with IPC‑A‑610F.
• Placement accuracy
  • Components must be positioned so that final post‑solder placement is correct; Annex A provides detailed placement requirements and mounting configurations.
• Lead forming and preforming
  • Leads must be pre‑formed to final configuration (excluding final clinch/retention bend) and must not damage the lead‑to‑body seal.
  • Leads must extend at least one lead diameter (but not less than 0.8 mm) before the start of the bend radius.
  • Accepts limited exposed core metal if cross‑section reduction ≤10% - treated as a process indicator.
• Through‑hole solder joint requirements
  • Acceptance, control and corrective action clauses cover plated/non‑plated through‑holes, via connections, clinched leads, fillet requirements, and defects.
• Rework
  • Procedures and limits for reworking unsatisfactory solder joints are included to preserve component integrity and board reliability.
• Annexes, figures and tables
  • Annex A contains placement requirements and detailed mounting illustrations; the standard includes figures and tables on lead bends, hole obstruction, fillet requirements, and defect classification.

Applications

IEC 61191‑3:2017 is used by:

• PCB designers and assembly engineers to define THT placement, forming and soldering requirements.
• Contract manufacturers and electronics assemblers for process control, inspection criteria and acceptance sampling.
• Quality/inspection teams and compliance officers to enforce workmanship standards consistent with IPC‑A‑610F.
• Procurement and product documentation to specify THT assembly acceptance in contracts and production drawings.

Related standards

• IEC 61191‑1:2013 - Generic specification for soldered assemblies
• IEC 60194 - Printed board design, manufacture and assembly - Terms and definitions
• IPC‑A‑610 (IPC‑A‑610F) - Acceptability of Electronic Assemblies (acceptance criteria alignment)

Keywords: IEC 61191-3:2017, through-hole, THT, printed board assemblies, through-hole mount soldered assemblies, IPC-A-610F, lead forming, placement accuracy, plated through-holes, clinched leads, rework.