Heraeus Electronics | Thick Film Whitepaper: Large-Format Printing of PTC 4980 Self-Regulating Heater Inks
- khashayar Ghaffarzadeh
- Aug 11
- 6 min read
Updated: Aug 29
Zachary Kelly, PhD. - Senior Research Scientist, Heraeus Electronics, Conshohocken, Pennsylvania
Case Study: Improving Large-Format PTC Heater Performance
5.1 Initial Challenges Identified
5.2 Optimized Design and Manufacturing Process
5.3 Key Takeaways and Industry Implications
This paper has been carefully compiled by Heraeus Electronics. Although the content is considered accurate, we cannot guarantee that this paper is suitable for any application. The descriptions and engineering data shown here have been compiled by Heraeus Electronics using commonly accepted procedures, in conjunction with modern testing equipment, and have been compiled as according to the latest factual knowledge in our possession.
1. Introduction
Printed electronics have revolutionized heating solutions across industries by enabling cost-effective, scalable, and customizable manufacturing processes. One of the critical advancements in this field is the use of Positive Temperature Coefficient (PTC) resistor pastes for self-regulating heaters. These materials offer inherent temperature control, reducing the need for external regulation mechanisms and ensuring safer, more energy-efficient heating solutions.
Heraeus Electronics has developed PTC4980, a new family of carbon and polymer-based resistor pastes designed specifically for self-regulating heaters. With applications ranging from industrial heating to automotive and medical sectors, these pastes leverage a PTC effect to provide precise thermal management. This white paper explores the principles behind PTC heater inks, design methodologies, and the improvements in large-format printing enabled through collaboration between Heraeus Electronics and Boyd Corporation, preeminent experts in medium to high volume manufacturing for custom user interface and printed electronics.
2. Understanding PTC 4980 and Its Benefits
PTC4980 is a specially engineered carbon-polymer paste formulated for applications requiring self-regulating heating. The paste exhibits a positive temperature coefficient of resistance (PTC), meaning that as temperature increases, the electrical resistance also rises. This property enables a self-limiting effect, preventing overheating and reducing the need for complex control circuitry.
3. Key Features of PTC 4980
Designed for operation in the 65°C - 90°C temperature range
Blendable high and low resistance variants for tailored performance and tighter engineering tolerances in
manufacturing
Provides uniform heating across surfaces
Scalable to large-format printing applications
Reduces energy consumption due to self-regulating properties
By leveraging these characteristics, industries can achieve more reliable, safer, and energy-efficient heating solutions tailored to their specific requirements.
4. Design Principles for PTC Heating Solutions
Heraeus Electronics works closely with customers to help them optimize their PTC heater design based on specific requirements. To develop an effective PTC heater, a systematic design approach is followed. The process begins with defining the application’s requirements and then optimizing the PTC formulation and print layout for the best performance.
Step 1: Define the Application
Before designing a heater, it is crucial to determine:
Target temperature: The target temperature required for the application
Heating area: The surface area in contact with the heating elements
Driving voltage: The operating voltage that will be applied
Desired heating power: The power needed to achieve optimal performance
Thermal load: The type and amount of material that will absorb heat for an application
Step 2: Optimizing PTC Paste and Circuit Design
This optimization process includes:
a.) Blending High (H) and Low (L) Resistance PTC Pastes: Different heating applications require different resistance characteristics. By blending high and low resistance pastes, designers can fine-tune the heater’s resistance to combat the common problem of carbon conductivity drifts, ensuring precise temperature control.
b.) Defining the Conductor Bus Bar and Cell Pattern: The arrangement of the heating elements significantly impacts performance. The design must consider:
Width, length, and thickness of conductor bus bars
Spacing and width of conductor fingers
PTC resistors print thickness
Number and arrangement of PTC resistor cells
By configuring these parameters, a uniform heating profile can be achieved with minimal unwanted heat accumulation.
5. Case Study: Improving Large-Format PTC Heater Performance
Heraeus Electronics collaborated with Boyd Corporation to enhance the design and manufacturing of large-format printed heaters. The initial customer prototype exhibited issues related to conductor bus bar heating, which led to overheating, non-uniform temperature distribution, and performance inconsistencies.
5.1 Initial Challenges Identified
When the prototype was tested, thermal imaging indicated hotspots along the conductor bars well above the target temperature. To determine the cause, the PTC cells were first individually investigated. Microscopy and thickness measurements determined that the prints were excellent quality, and the thickness was highly consistent within the cell, from cell-to-cell and from print-to-print. Individual PTC cells were isolated for power testing and performed as expected with consistent regulating profiles. So, everything on an individual component level was working as expected.
The root cause was found in the overall design. The conductor bus bars heated above the target temperature before the PTC units reached the target regulating temperature due to a mismatch in overall resistance values between the conductor bars and the PTC resistor cells.
5.2 Optimized Design and Manufacturing Process
Through mathematical modeling, testing, and design improvements, the following modifications were made:
a.) Model: Calculate the required resistance difference between the conductor trace and the PTC trace to mitigate Joule heating in the conductor bus bars.
b.) Increase Bus Bar Width/Thickness: By increasing the conductor cross-sectional volume along the trace, it reduces the overall resistance of the conductor trace.
c.) Increase PTC trace resistance: The new design ensured that each sub-unit within the heater had the right dimensions to resistance match the conductor with the given input voltage requirements.
d.) The improved prototype demonstrated significant enhancements in performance with:
Reduced unwanted heating at the conductor bars
More uniform heat distribution
Improved efficiency and reliability
5. Case Study: Improving Large-Format PTC Heater Performance
5.3 Key Takeaways and Industry Implications
The collaboration between Heraeus Electronics and Boyd Corporation highlights the importance of precision design in PTC heater manufacturing. The key insights from this research include:
Heater design plays a crucial role in PTC performance: Proper selection of resistance values, conductor patterns, and material thickness ensures efficiency.
Avoiding unwanted bus bar heating: High resistance in unintended areas can lead to undesired heating and performance issues. Optimizing conductor layouts prevents this problem.
High-volume manufacturing requires robust material formulations: Heraeus Electronics’ PTC resistor pastes are designed to be compatible with large-scale production, enabling cost-effective and high-quality manufacturing.
Customization is key: Different applications require different resistance values and power configurations. Heraeus Electronics and Boyd Corporation offer tailored solutions to meet specific industry needs.
6. Conclusion
The development of PTC 4980 self-regulating heater inks represents a significant advancement in printed electronics. By providing a scalable, energy-efficient, and safe heating solution, these materials are unlocking new possibilities across industries. This collaboration between Heraeus Electronics and Boyd Corporation has demonstrated the importance of optimizing material formulations and design parameters to achieve superior performance in largeformat printing.
As demand for smart heating solutions continues to grow, innovations in PTC resistor pastes will play a vital role in enabling high-performance, cost-effective, and sustainable heating applications. Heraeus Electronics remains committed to advancing the field through continuous research, material development, and collaboration with industry leaders.
About Heraeus Electronics
Heraeus Electronics is one of the leading manufacturers of materials for packaging technology in the electronics industry. The operating company develops sophisticated material solutions for the automotive industry, power electronics, and advanced packaging in development centers and production facilities in Asia, the USA, and Europe. As a solution provider, Heraeus Electronics offers its customers a broad product portfolio - from materials and material systems to components and services.
For more information and product details please visit heraeus-electronics.com
The descriptions and engineering data shown here have been compiled by Heraeus using commonly-accepted procedures, in conjunction with modern testing equipment, and have been compiled as according to the latest factual knowledge in our possession. The information was up-to date on the date this document was printed (latest versions can always be supplied upon request). Although the data is considered accurate, we cannot guarantee accuracy, the results obtained from its use, or any patent infringement resulting from its use (unless this is contractually and explicitly agreed in writing, in advance). The data is supplied on the condition that the user shall conduct tests to determine materials suitability for particular application. The Heraeus logo and Heraeus are trademarks or registered trademarks of Heraeus Holding GmbH or its affiliates. All rights reserved.
Contact Us:
China
Phone +86 53 5815 9601
Europe, Middle East and Africa
Phone +49 6181 35 4370
We are Exhibiting in Berlin.
Visit our booth at the TechBlick event on 22-23 October 2025 in Berlin
Contact us for your special discount coupon to attend
Comments