## 4 Conclusions  
In this study, we evaluated heat generation and electrical degradation in DRAM packages under DC voltage stress (2.5-3.1 V) in air and single-phase immersion cooling environments. The results demonstrated that immersion cooling significantly reduced heat accumulation and suppressed the leakage current approximately 59% compared to air cooling. At 3.0 V and 3.1 V, the leakage current in air increased up to three times more than that in immersion cooling, confirming the electrical stability of immersion cooling. These findings provide essential data for assessing DRAM reliability and establish design criteria for stable data center operations. Based on the observed leakage current behavior and thermal trends, it is analytically evident that DRAM packages experience accelerated degradation when stressed above 3.0 V. While the recommended operating voltage remains at 1.2 V, our findings highlight 2.8 V as a critical stress threshold beyond which reliability rapidly declines. These results offer valuable insights for determining safe stress margins and reliability limits in package-level design and accelerated testing frameworks, particularly for systems evaluated under overvoltage conditions.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app15094668/s1](https://www.mdpi.com/article/10.3390/app15094668/s1)]([https://www.mdpi.com/article/10.3390/app15094668/s1](https://www.mdpi.com/article/10.3390/app15094668/s1)), Figure S1: Tape detachment under thermal conditions during contact-based temperature measurements; Figure S2: Comparison of temperature measurements using an infrared camera and a contact thermometer under different voltage conditions; Figure S3: IV curve characteristics with 2.5 V, 2.8 V applied over time in coolant and air; Figure S4: IV curve characteristics with 3.0 V, 3.1 V applied over time in coolant and air.  
Figure 6: (**a**) Rate of leakage current increase at 1.2 V compared with a fresh package under different voltage and environmental conditions. Schematics describing of leakage current reduction mechanisms due to cooling performance (**b**) in air and (**c**) in an immersion environment.  
**Author Contributions:** Conceptualization, K.M. and J.-B.P.; methodology, K.M.; validation, K.M.; formal analysis, K.M., T.K. and J.-B.P.; investigation, K.M. and T.K.; resources, J.-B.P.; writing--original draft preparation, K.M., T.Y.K. and J.-B.P.; writing--review and editing, T.K., T.Y.K. and J.-B.P.; supervision, T.Y.K. and J.-B.P.; project administration, J.-B.P.; funding acquisition, J.-B.P. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This work was supported by the research grant of Kongju National University in 2022, \"Regional Innovation Strategy (RIS)\", through the National Research Foundation of Korea (NRF), funded by the Ministry of Education (MOE) (No. 2021 RIS-004), the Korea Institute of Energy Technology Evaluation and Planning (KETEP), and the Ministry of Trade, Industry, and Energy (MOTIE) of the Republic of Korea (No. RS-2024-00394769).  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The original contributions presented in the study are included in the article. Further inquiries can be directed to the corresponding authors.  
**Conflicts of Interest:** The authors declare no conflicts of interest.