IEC TR 62899-304-2:2026

• Abstract:

  IEC TR 62899-304-2:2026 provides information on methods for determining the sample temperature during the thermal treatment process in the production of PE products.; This document also compares the characteristics of contact and non-contact temperature measurement methods.

• Status: Published
• Publication Date: 28-Sep-2026
• ICS: 19.080 - Electrical and electronic testing
• ICS: 37.100.10 - Reproduction equipment
• Technical Committee: TC 119 - Printed Electronics
• Drafting Committee: WG 3 - TC 119/WG 3
• Current Stage: PPUB - Publication issued
• Start Date: 29-Sep-2026
• Completion Date: 23-Oct-2026

IEC TR 62899-304-2:2026 is an IEC Technical Report on temperature measurement during thermal treatment in printed electronics production. It explains how to determine sample temperature during sintering and related post-processes, and it compares contact and non-contact measurement methods. The report is intended for people who set up, measure, or control thermal treatment equipment for PE products.

What does IEC TR 62899-304-2:2026 specify?

IEC TR 62899-304-2:2026 gives information on measuring sample temperature during thermal treatment of PE products. It focuses on how to select and use measurement methods so the temperature at the sample, not only the equipment setpoint, is understood.

The document is organized into six clauses: scope, references, terms, temperature-measurement issues, measurement examples, and the information needed for reproducible conductive layers. It also includes a bibliography with supporting standards and background publications.

Clause	What it covers
1	Scope
2	Normative references
3	Terms and definitions
4	Issues of temperature measurement for thermal treatment
5	Examples of measurement
6	Items important for reproduction of the conductive layer

What are the key requirements of IEC TR 62899-304-2:2026?

IEC TR 62899-304-2:2026 is guidance rather than a prescriptive test method, but it highlights the practical points that matter when measuring temperature in PE thermal treatment.

• Clause 4 explains that thermal treatment in PE includes evaporation, annealing, curing, and sintering, and that heating may use resistance heating, infrared radiation, laser, flash lamp, and similar sources. In practice, this means the measurement method must match the process type, whether batch or continuous.

• Clause 4.2 warns that the temperature entered into the equipment is often a space temperature, not the actual sample temperature. It also notes that temperature inside the equipment may be non-uniform, so users need to measure near the sample and not assume the setpoint is the true process temperature.

• Clause 4.3 links sintering temperature to ink conductivity and resistivity. The practical point is that each ink can have a different best temperature window, so process control has to be tied to the ink being used.

• Clause 5.1 says temperature sensors should be calibrated and kept in a condition that allows accurate measurement, with calibration handled by a calibration agency or laboratory. For users, this means sensor validity is part of process control, not just a one-time setup issue.

• Clause 5.2 and 5.3 describe contact methods: thermocouples and resistance temperature detectors (RTD). The report stresses choosing the measurement position close to the area of interest and fixing the sensor properly, because poor contact, bad placement, and thermal gradients can distort the reading.

• Clause 5.4 to 5.6 describe non-contact and indicator methods: temperature labels, laser methods, and IR cameras. These methods are useful when direct contact is difficult, but the report points out common error sources such as emissivity changes, irradiation angle, ambient light, focus, reflectivity, and environmental conditions.

• Clause 6 says reproducibility depends on communicating the assessment date and place, the sensor and its calibration information, the thermal treatment equipment, the method used, the results, and related standards or laws. In practice, this is the information needed to compare runs, troubleshoot defects, and repeat a process reliably.

What terms does IEC TR 62899-304-2:2026 define?

IEC TR 62899-304-2:2026 does not list formal terms in Clause 3, but it uses several key terms and abbreviations throughout the document.

• Printed electronics (PE) - Electronics made by printing processes, where the printed features often need later thermal treatment to develop their properties.
• Thermal treatment - A post-process such as evaporation, annealing, curing, or sintering that uses heat to change the printed material.
• Thermocouple - A contact temperature sensor used when fast response and a wide temperature range are needed.
• Resistance temperature detector (RTD) - A contact sensor based on resistance change, used when high precision and stability are important.
• Temperature label - A label with inks that change colour at a specific temperature and show the highest temperature reached.
• Infrared (IR) camera - A non-contact device that measures temperature over an area by sensing emitted radiation.
• Emissivity - A surface property that affects radiated intensity and therefore influences non-contact temperature measurement.

Who uses IEC TR 62899-304-2:2026?

IEC TR 62899-304-2:2026 is used by researchers and developers working on thermal treatment for PE products, especially conductive inks. It is also relevant to process engineers, equipment suppliers, quality managers, and laboratory staff who need to choose a measurement method, install sensors, interpret temperature data, or document reproducible production conditions.

Which standards are used with IEC TR 62899-304-2:2026?

Standard	What it contributes
IEC TR 62899-304-1	Details on temperature measurement for photonic sintering systems, including IR camera-related information
IEC 60584-1	Thermocouple EMF specifications and tolerances
IEC 60751	Industrial platinum resistance thermometers and platinum temperature sensors
ISO/IEC 17025	Good practice for calibration and competence of testing and calibration laboratories
ASTM E230	Standardized thermocouple specification and emf tables
ASTM E1137	Industrial platinum resistance thermometers
JIS C 1602	Thermocouples
JIS C 1604	Platinum resistance thermometers
JIS C 60068-3-5	Example reference for temperature distribution in a convection oven

What does the IEC TR 62899-304-2:2026 document contain?

The document includes examples of temperature gradients in heating equipment, an example showing how sintering temperature affects resistivity, and illustrations of sensor placement and fixation. It also presents the laser measurement principle using Planck’s law and distinguishes between dichroic and monochromatic laser methods.

Table 1 summarizes the measurement methods and their main sources of error, which helps users choose a method and judge its limitations. The figures and summary table make the report useful for process design, measurement setup, testing, and quality control in printed electronics.

IEC TR 62899-304-2 ®
Edition 1.0 2026-09
TECHNICAL
REPORT
Printed electronics -
Part 304-2: Equipment - Sintering - Temperature measurement method for
thermal treatment system
ICS 19.080; 37.100.10 ISBN 978-2-8327-1508-6

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CONTENTS
CONTENTS . 1
FOREWORD . 2
INTRODUCTION . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Issues of temperature measurement for thermal treatment . 5
4.1 General . 5
4.2 Equipment for thermal treatment . 5
4.3 Inks . 6
5 Examples of measurement . 7
5.1 General . 7
5.2 Thermocouples . 7
5.3 Resistance temperature detectors . 8
5.4 Temperature label . 9
5.5 Laser . 9
5.6 IR camera . 10
5.7 Summary of the measurement methods . 10
6 Items that are important for reproduction of the conductive layer . 10
Bibliography . 11

Figure 1 – Example of temperature distribution in the convection oven set at 100 °C
(according to JIS C 60068-3-5 [5]) . 6
Figure 2 – Example of temperature distribution in the cross-section of the tube furnace
(1 in diameter) set at 900 °C [6] . 6
Figure 3 – Relationship between sintering temperature and resistivity of each ink. 7
Figure 4 – Example of ink printed directly on a thermocouple . 8
Figure 5 – Example of fixing a temperature sensor with polyimide tape . 8
Figure 6 – Example of fixing a temperature sensor with eyelet and bolt . 8
Figure 7 – T-SMILS L15570 series manufactured by Hamamatsu Photonics K.K. . 9

Table 1 – Measurement methods and their sources of error . 10

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Printed electronics -
Part 304-2: Equipment - Sintering -
Temperature measurement method for thermal treatment system

FOREWORD
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IEC TR 62899-304-2 has been prepared by IEC technical committee 119: Printed Electronics.
It is a Technical Report.
The text of this Technical Report is based on the following documents:
Draft Report on voting
119/578/DTR 119/595/RVDTR
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this Technical Report is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 62899 series, published under the general title Printed electronics,
can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
– reconfirmed,
– withdrawn, or
– revised.
INTRODUCTION
Printed electronics (PE) has made significant progress, and its market has expanded
considerably. It has numerous applications, including electrical and electronic products, textiles,
and healthcare. In particular, conductive ink has the widest range of applications.
The functionality of conductive ink depends on the quality of the conductive layer that is formed
by thermal treatment after printing the desired pattern. The thermal treatment process greatly
influences the properties of the conductive layer. For example, uneven heating can lead to
problems such as uneven conductivity, substrate distortion, and peeling of the conductive layer
from the substra
...