中国物理B ›› 2015, Vol. 24 ›› Issue (6): 68105-068105.doi: 10.1088/1674-1056/24/6/068105

所属专题: TOPICAL REVIEW — III-nitride optoelectronic materials and devices

• TOPICAL REVIEW—III-nitride optoelectronic materials and devices • 上一篇    下一篇

Transient thermal analysis as measurement method for IC package structural integrity

Alexander Hanß, Maximilian Schmid, E Liu, Gordon Elger   

  1. Technische Hochschule Ingolstadt, Esplanade 10, 85049 Ingolstadt, Germany
  • 收稿日期:2015-01-09 修回日期:2015-03-28 发布日期:2015-06-25

Transient thermal analysis as measurement method for IC package structural integrity

Alexander Hanß, Maximilian Schmid, E Liu, Gordon Elger   

  1. Technische Hochschule Ingolstadt, Esplanade 10, 85049 Ingolstadt, Germany
  • Received:2015-01-09 Revised:2015-03-28 Published:2015-06-25
  • Contact: Gordon Elger E-mail:Gordon.Elger@thi.de
  • About author:81.70.Pg; 81.05.Ea; 44.10.+i; 85.60.Bt

摘要:

Practices of IC package reliability testing are reviewed briefly, and the application of transient thermal analysis is examined in great depth. For the design of light sources based on light emitting diode (LED) efficient and accurate reliability testing is required to realize the potential lifetimes of 10^5 h. Transient thermal analysis is a standard method to determine the transient thermal impedance of semiconductor devices, e.g. power electronics and LEDs. The temperature of the semiconductor junctions is assessed by time-resolved measurement of their forward voltage (Vf). The thermal path in the IC package is resolved by the transient technique in the time domain. This enables analyzing the structural integrity of the semiconductor package. However, to evaluate thermal resistance, one must also measure the dissipated energy of the device (i.e., the thermal load) and the k-factor. This is time consuming, and measurement errors reduce the accuracy. To overcome these limitations, an innovative approach, the relative thermal resistance method, was developed to reduce the measurement effort, increase accuracy and enable automatic data evaluation. This new way of evaluating data simplifies the thermal transient analysis by eliminating measurement of the k-factor and thermal load, i.e. measurement of the lumen flux for LEDs, by normalizing the transient Vf data. This is especially advantageous for reliability testing where changes in the thermal path, like cracks and delaminations, can be determined without measuring the k-factor and thermal load. Different failure modes can be separated in the time domain. The sensitivity of the method is demonstrated by its application to high-power white InGaN LEDs. For detailed analysis and identification of the failure mode of the LED packages, the transient signals are simulated by time-resolved finite element (FE) simulations. Using the new approach, the transient thermal analysis is enhanced to a powerful tool for reliability investigation of semiconductor packages in accelerated lifetime tests and for inline inspection. This enables automatic data analysis of the transient thermal data required for processing a large amount of data in production and reliability testing. Based on the method, the integrity of LED packages can be tested by inline, outgoing inspection and the lifetime prediction of the products is improved.

关键词: transient thermal analysis, thermal resistance, reliability, light emitting diode

Abstract:

Practices of IC package reliability testing are reviewed briefly, and the application of transient thermal analysis is examined in great depth. For the design of light sources based on light emitting diode (LED) efficient and accurate reliability testing is required to realize the potential lifetimes of 10^5 h. Transient thermal analysis is a standard method to determine the transient thermal impedance of semiconductor devices, e.g. power electronics and LEDs. The temperature of the semiconductor junctions is assessed by time-resolved measurement of their forward voltage (Vf). The thermal path in the IC package is resolved by the transient technique in the time domain. This enables analyzing the structural integrity of the semiconductor package. However, to evaluate thermal resistance, one must also measure the dissipated energy of the device (i.e., the thermal load) and the k-factor. This is time consuming, and measurement errors reduce the accuracy. To overcome these limitations, an innovative approach, the relative thermal resistance method, was developed to reduce the measurement effort, increase accuracy and enable automatic data evaluation. This new way of evaluating data simplifies the thermal transient analysis by eliminating measurement of the k-factor and thermal load, i.e. measurement of the lumen flux for LEDs, by normalizing the transient Vf data. This is especially advantageous for reliability testing where changes in the thermal path, like cracks and delaminations, can be determined without measuring the k-factor and thermal load. Different failure modes can be separated in the time domain. The sensitivity of the method is demonstrated by its application to high-power white InGaN LEDs. For detailed analysis and identification of the failure mode of the LED packages, the transient signals are simulated by time-resolved finite element (FE) simulations. Using the new approach, the transient thermal analysis is enhanced to a powerful tool for reliability investigation of semiconductor packages in accelerated lifetime tests and for inline inspection. This enables automatic data analysis of the transient thermal data required for processing a large amount of data in production and reliability testing. Based on the method, the integrity of LED packages can be tested by inline, outgoing inspection and the lifetime prediction of the products is improved.

Key words: transient thermal analysis, thermal resistance, reliability, light emitting diode

中图分类号:  (Thermal analysis, differential thermal analysis (DTA), differential thermogravimetric analysis)

  • 81.70.Pg
81.05.Ea (III-V semiconductors) 44.10.+i (Heat conduction) 85.60.Bt (Optoelectronic device characterization, design, and modeling)