Effects of Pd Alloying and Coating on the Galvanic Corrosion between Cu Wire and Bond Pads for a Semiconductor Packaging

Round 1

Reviewer 1 Report

In this article the authors investigate the effects of Pd alloying and coating on the galvanic corrosion between Cu wire and bond pads within semiconductor packaging, focusing on the impact of chloride contaminants from the PCB manufacturing process.

·       The authors should discuss what are the  are the next steps in investigating the effects of Pd alloying and coating on galvanic corrosion in semiconductor packaging.

·       The authors should explain better how Pd alloying or coating influences the anodic and cathodic reactions compared to unalloyed Cu.

·       The authors should highlight  the potential long-term implications for semiconductor devices using these materials. How might the galvanic corrosion observed influence device failure rates over time?

·       The scale bars are not visible in Figures 5 and 6.

moderate revision 

Author Response

We attached the answer file.

Author Response File: Author Response.pdf

Reviewer 2 Report

1.     Pd is sure to be nobler in corrosion than Cu. However, 1wt%Pd addition to Cu can make substantial improvement for Cu in the corrosion resistance, which is hard to believe. What is your designing rule at the beginning?

2.     For the units of “hours” and “^oC”, they have not been presented in the unified manner.

3.     In Fig. 2, the y axis of “corrosion rate of Al” is set to the largest value of 100. It is too high, the value of 40 is quite enough. The y axis of “corrosion rate of wire” is set to the largest value of 1. It is too high, the value of 0.4 is quite enough. Then, the readers can see the clearer tendency for both cases, especially for “corrosion rate of wire”.

4.     In Fig. 4, the Cu-Al couple has a much higher value of corrosion rate of Al at 1%NaCl+1%HCl, than any other values shown in this Figure. Are you sure for this higher value? Is there any explanation for this phenomenon?

5.     The layout of this manuscript is a problem. There is much empty place in certain pages, which should be avoided.

6.     The “3. Results and Discussion” has presented much information as a whole. It is better to show some sub-titles to help readers follow your work.

7.     The authors suggested the corrosion products of Cu oxide, Al oxide, or Si oxide. However, there is none of the chemical reaction showing how these products form?

8.     In Figures 2, 4, 8, 16, the experimental result of each point should have the error bar.

9.     In Figure 8a-b, the Cu-Al and Cu1Pd-Al have very similar tendencies in the experimental values. But, their tendencies are suddenly different in Figure 8d. Why?

Can be further polished after eliminating several typo errors.

Author Response

We attached the answer file.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I recommend the publication of this article.