Overview
IEC 62899-202-10:2023 - Printed electronics - Part 202-10 - defines standardized terminology and test methods to measure how the electrical resistance of printed conductive ink layers changes as thermoformable substrates are elongated (thermoforming). The standard covers both in‑situ (during elongation) and pre‑ and post‑elongation resistance measurement methods and is applicable to thermoformable substrates that may also include graphic inks and cover/insulation layers. This gives designers, materials engineers and test laboratories a repeatable procedure to quantify resistance changes caused by plastic strain during thermoforming or in‑mould‑electronics (IME) manufacturing.
Key topics and requirements
- Measured value: change in conductive layer resistance as a function of thermoplastic elongation (in‑situ or pre/post).
- Test specimen requirements: definitions for ink stack, specimen shape and conductive layer layout; guidance in informative Annex B for specimen geometry and layouts.
- Measurement apparatus:
- elongation equipment to apply controlled plastic strain,
- precision resistance measurement equipment for low‑resistance printed traces,
- specimen holders and fixtures suitable for thermoformable substrates.
- Measurement parameters: control and reporting of elongation magnitude, elongation speed and elongation temperature.
- Procedures: step‑by‑step measurement workflows for in‑situ and pre/post methods, including how to measure conductive line elongation and when to record electric breaks.
- Data analysis and reporting:
- calculation of resistance change vs. elongation,
- methods for excluding outliers,
- required measurement report contents and example report format (informative Annex A).
Practical applications
Who uses IEC 62899-202-10 and why:
- Printed electronics manufacturers and IME producers - to validate that conductive inks and printed traces tolerate thermoforming without unacceptable resistance increases or open circuits.
- Materials developers (conductive inks, substrates) - to compare formulations under standardized thermoforming strain and report consistent performance metrics.
- Design engineers - to predict circuit performance after forming and design redundancy or compensation for resistance change.
- Quality assurance and test labs - to implement repeatable test methods for supplier qualification, acceptance testing, and failure analysis.
Practical outcomes include selecting suitable ink/substrate combinations, setting process limits for thermoforming, and producing data for component and assembly specifications.
Related standards
- IEC 62899-202 (Printed electronics - Part 202: Materials - Conductive ink) - referenced normative document for conductive ink definitions and properties.
Keywords: IEC 62899-202-10, printed electronics, thermoformable conducting layer, resistance measurement, conductive ink, thermoforming, in‑mould‑electronics, in‑situ measurement, test method.