Mechanical Characterization of Sintered Silver Materials for Power Device Packaging: A Review

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In this review paper, the authors conducted a comprehensive review of recent advancements in sintered silver (s-Ag) die attach technologies for silicon carbide (SiC) device packaging. The authors systematically reviewed the characteristics of s-Ag materials, detailing the sintering process and the microstructural properties that make them suitable for high power density applications. They discussed the mechanical properties and failure mechanisms of s-Ag films under various conditions, highlighting their superior thermal conductivity and high melting point compared to traditional solder materials. Additionally, the authors presented experimental methodologies and results from tensile tests, providing insights into the degradation mechanisms of s-Ag die layers during thermal shock tests. Some minor improvements are needed for the final publication. Overall, I suggest the manuscript to be published in Energies.

1.      Besides the higher requirements from WBG device, due to the increased power density, is there any material-wise difference that can cause more challenges in applying s-Ag on WBG than the conventional Si power device. Such discussion will make the introduction section of the manuscript more complete.

2.      P4, L137-138. Could authors explain why a redox reaction accelerate the mobility of Ag particles. In the cited paper [37], Akio Hirose et al., mentioned that the redox reaction coverts the metal-organic particles into Ag nanoparticles and therefore, increases the surface energy per volume. I cannot find any discussion about the mobility issue. I believe that will also confuses many other readers.

Author Response

Dear Reviewer 1

Thank you for giving us useful comments. Please confirm the attached file as a response letter.

Sincerely yours,

 

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

Comments to manuscript “Mechanical Characterization of Sintered Silver Materials for Power Device Packaging: A Review”

My statement about this manuscript is of interest for mechanical properties of materials. Many references from own authors (10) were cited, where mechanical properties were evoked. This work is original idea, and the results are the interest in the develop of materials for energy applications. However, some points may be enhanced; sintering methodology was not expanded, the authors given some conditions process, pressure and temperature parameters are provided to carry out the “pastes”. But it is worth to have little bite more information about sintering process. Moreover, it is needed to give some details about Ag films synthesis, for example devices used to sinter the materials?, how was the preparation of the samples for TST and bending tests, and similar experiments.

Moreover, the summary is too poor, and not evidences the aims reached trough of the manuscript.

Author Response

Dear Reviewer 2

Thank you for giving us useful comments. Please confirm the attached file as a response letter.

Sincerely yours,

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Authors,

your review is comprehensive and well-organized. After reading your article I have some comments, which I listed below:

1) It is currently popular to test the reliability of bonded and encapsulated power transistors using power cycling. I think that this test should be mentioned in section 3.

2) High thermal conductivity of the material is important, but essential is thermal resistance. Bonding using different materials and methods (soldering, glueing or sintering) have different thicknesses. Secondly, the quality of the bonding, e.g. mentioned in the paper porosity, causes the obtained thermal resistance to be always lower than expected following thermal conductivity and dimensions of bonding. Sometimes, the correlation between the thermal conductivity of the used material and the thermal resistance of the bonded transistor is poor, as in e.g. doi.org/10.1109/TCPMT.2021.3108468.

3) mentioned in the l. 415 number of cycles (1000) is relatively low from the point of view of the transistor application. Please include in the paper an interpretation of this number, and how it could be compared to the number obtained using power cycling, which is often included in the datasheet of the high power modules.

Author Response

Dear Reviewer 3

Thank you for giving us useful comments. Please confirm the attached file as a response letter.

Sincerely yours,

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Authors,

thank you for the comprehensive responses to my comments. I recommend the publication of the article in its present form.