A hot topic: die attach thermal testing for power electronics components

By Katie Tormala

Power electronics components improve the energy efficiency of electric machines and motors across all industries and applications. These power electronic components are increasingly being more densely packed together, positioned close to or on the motor itself and impacted by harshness and vibration in the vibration. Efficient removal of heat dissipation from these components is critical to prevent premature failure or thermal runaway.

Impact of temperature fluctuations on early life failures in semiconductor devices

Temperature fluctuations can result in the solder die attach breaking, the die attach delaminating from the die, or the die attach separating from the substrate. Like a domino effect, this leads to higher temperatures, further damaging the device until complete failure.

Continuous improvements in quality and reduction in early life failures are critical goals for semiconductor manufacturers and their customers. Historically, semiconductor companies would deploy early life failure reduction efforts with electrical tests or geospatial techniques to reject or test out potential failures. Burn-in and predictive test techniques like average part testing have been around for a long time. Additionally, other geospatial methods, such as visual defect screening and algorithmic yield clustering looking for abnormal patterns, are used to predict early life failures.

Inline thermal resistance measurements add another road to quality for semiconductor companies. Thermal transient testing can measure semiconductor junction temperature responses to short pulses and provide insights into potential manufacturing defects. The technology can reveal inconsistencies in the heat conduction path, quantify their effect on thermal resistance and highlight their location. Problems such as thermal interface material (TIM1) or die attach voids, or delamination can be found in a fraction of seconds, but problems outside of the package, such as TIM2 quality can also be measured with short pulses.

Introduction to die attach thermal testing in semiconductor devices

Transient die attach thermal testing helps ensure the quality and performance of semiconductor devices, particularly those used in high-power applications such as power electronics and microprocessors.
Teams can use transient die attach thermal testing to check the die attach material that connects the chip to the package or substrate. This testing involves generating heat with a pulse of electrical energy, causing the temperature of the die and the surrounding environment to increase. Thermal sensors monitor the temperature, and teams can analyze the temperature response over time.

With this information, teams can determine various thermal properties of the die attach material, such as thermal conductivity, heat capacity and thermal resistance, to optimize the device’s design and ensure it operates reliably under different operating conditions.

Improving semiconductor device quality with thermal testing 

Transient die attach thermal testing can improve the quality of semiconductor devices by:

  1. Improving device performance and reliability via quality control: Ensure products meet required thermal specifications and minimize the risk of future failures.
  2. Extending the life of the product with optimal design: Optimize the device’s layout and material selection using thermal properties of the die attach material, resulting in better reliability and longer operating lifetimes.
  3. Preventing early life failure: Evaluate the thermal safety margins of devices to ensure optimal operation and prevent overheating that results in device failure.
  4. Faster time-to-market with simulation models: Improve the accuracy of thermal simulation models used to predict the temperature behavior of semiconductor devices during behavior.

Transient die attach thermal testing plays an important role in semiconductor device design and manufacturing process.

Advanced simulation tools for die attach thermal testing

Teams can design more effective die attach thermal testing programs by predicting temperature distributions, heat flow patterns, and other critical parameters. Simulation can provide a predictive model of the device’s behavior under different operating conditions. These simulations can:

  1. Optimize testing parameters: to ensure the device reaches the desired temperature without causing damage, resulting in reduced testing time and cost and minimized risk of device failure.
  2. Evaluate design options: to help make informed decisions about material selection, layout and other design factors, helping teams evaluate different design options and determine the thermal performance faster.
  3. Interpret experimental results: to compare the simulated and experimental temperature data to validate simulation models and understand thermal properties of the device.
  4. Predict device behavior: to see how the device will behave under different operating conditions such as ambient temperature or current load, enabling designers to optimize the device thermal performance and ensuring it operates reliability under a wide range of conditions.

Simulation can optimize the transient die attach thermal testing process, improve device design, and ensure that devices operate safely and reliably in various environments.

Learn more about die attach thermal testing

Want to learn more about power electronics die attach and thermal performance? Check out the following webinar and white paper.

Advanced thermal testing and die attach techniques

The “Optimizing semiconductor packaging with advanced thermal testing and die attach techniques” webinar explains how to use thermal transient testing to measure temperature changes in semiconductor packaging and identify potential manufacturing defects.

Key takeaways:

  • The role of thermal transient testing to support package model analysis
  • Application of structure functions for defect identification
  • Testing use cases and limits for package thermal quality
  • Different ways of integrating a test system into a semiconductor production environment

Die attach solutions to meet unique power electronics requirements

ON Semiconductor creates and supplies its clients with power electronic components, like wide band gap semiconductors, that perform optimally when exposed to high and low temperatures. The “Understanding die attach thermal performance for power electronics” white paper discusses testing procedures and solutions to prevent future device failure due to harsh temperatures.

Evaluating the effect of the voids on the thermal impedance of the die-attach, requires a sensitive measuring device and a method for determining the impact of the die attach on the overall measured thermal resistance. Siemens Simcenter POWERTESTERTM tool can measure current, voltage, and die temperature while utilizing structure-function analysis to document package structure changes or defects. Coupled with the integrated structure-function analysis of the Zth curve, it can determine the partial thermal impedance caused by die attach.

Read this whitepaper to see how ON Semiconductor:

  • Explains how the thermal performance of the package is affected by the size, location, and distribution of voids
  • Determines the most accurate method and tools for calculating the junction-to-case resistance
  • Analyzes the implications of die attach layer voids on the junction-to-case resistance
  • Measures ten samples, a through j, using the temperature versus time derivative method

About Siemens Simcenter PowerTESTER

Simcenter Powertester, combines active power cycling with transient thermal characterization and thermal structure investigation. Perform the non-destructive structure-function assessment while the device is mounted, providing a complete electrical and structural evaluation of the device.

About ON Semiconductor
ON semiconductor is a leading semiconductor manufacturer with more than 80,000 different parts and a global supply chain, serving tens of thousands of customers across hundreds of markets.

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This article first appeared on the Siemens Digital Industries Software blog at