Overview
IEC 62899-302-3:2021 - "Printed electronics - Part 302-3: Equipment - Inkjet - Imaging-based measurement of drop direction" specifies in-flight, imaging-based methods for measuring the direction of ink drops jetted from drop-on-demand inkjet print-heads used in printed electronics. The standard describes how to use optical drop watchers (single, double or strobe flash) to determine both 2-D projected angles and full 3-D trajectory angles of jetted drops. It explicitly excludes holographic/interference techniques and any methods that assess deposited (post-impact) drops.
Key technical topics and requirements
- Measurement scope:
- Applies only to in-flight imaging of drops from drop-on-demand print-heads (printed electronics equipment).
- Does not cover holographic/interference methods or deposited-drop assessments.
- Measurement methods:
- Six defined methods: projected-angle measurement using one drop watcher (methods 1–3: double flash, single flash, strobe) and trajectory-angle measurement using two drop watchers (methods 4–6).
- Annex A contains measurement formulae, schematics and image-recording guidance for each method.
- Instrumentation and calibration:
- All trajectory measurement equipment must have a carefully calibrated geometry.
- Image plane alignment: the imaging plane must be aligned precisely orthogonal to the inkjet nozzle plane before measurements.
- Reporting and reproducibility:
- Measurement processes require reporting of conditions (see Clause A.3) and explicit statement of geometry, reference directions and delays used.
- Normative reference:
- Refers to IEC 62899-302-1 for related imaging-based jetting-speed measurement methods.
Practical applications and who uses this standard
- Printed electronics equipment manufacturers: validate print-head performance, ensure accurate drop placement and consistent jetting direction.
- Print-head and ink developers: quantify angular spread under specific ink and waveform conditions to optimize formulation and drive signals.
- Equipment integrators and contract manufacturers: assess whether drop trajectories risk bridging adjacent conductive features (affecting yield and electrical performance).
- Metrology and quality labs: implement standardized in-flight imaging test procedures for QA, acceptance testing and comparative benchmarking.
- R&D teams designing high-resolution printed circuits, sensors or displays where precise drop placement is critical.
Related standards
- IEC 62899-302-1 - Printed electronics - Equipment - Inkjet - Imaging based measurement of jetting speed (normative reference).
- Other parts of the IEC 62899 series cover broader printed-electronics metrology topics (see IEC webstore for the series index).
Keywords: IEC 62899-302-3, printed electronics, inkjet, drop direction, drop watcher, in-flight imaging, drop-on-demand, projected angle, trajectory angles, measurement standard.
Open preview (PDF)Printed electronics - Part 302-3: Equipment - Inkjet - Imaging-based measurement of drop direction
