The IEEE Electronics Packaging Technology Conference (EPTC) is an annual international event organized by the IEEE RS/EPS/EDS Singapore Chapter and co-sponsored by the IEEE Electronics Packaging Society (EPS). Since its inauguration in 1997, EPTC has been established as a highly reputable international electronics packaging conference and is the IEEE EPS flagship conference in the Asia and Pacific Region. This time, the conference was held for four days from December 3rd to 6th, 2024, at the Hotel Grand Copthorne Waterfront, Singapore. At this conference, more than 800 people were attendees with different academic and industrial backgrounds. There were more than 100 keynote lectures, invited lectures, and exhibitor presentations, including more than 120 oral presentations and more than 100 poster presentations held in several sessions covering a wide range of fields within Semiconductor technology.
The next event is scheduled to be held in Singapore in December 2025.
At this conference, we presented a method to find the areas that possess high failure risk for microvias. In the PCB boards used in Automobile cars, when the thermal loading is applied, the FR4 substrate sheet of PCB containing epoxy resin is very sensitive to glass transition temperature and its coefficient of thermal expansion becomes very high. To understand the effect of substrate materials on microvia interconnect, we have used finite element analysis (FEA). One main challenge of this study includes addressing the imprecise location of microvias in substrate sheets. The substrate sheets contain a nonuniform distribution of woven fiberglass and resin and therefore the substrate layer possesses different resin-fiber concentrations in different positions. For this purpose, we used the design of experiment (DOE) technique using the Taguchi methodology which is a widely used method in DOEs. A detailed model of the substrate layer containing a complex fiberglass structure with resin including microvia interconnects was developed. Simulations were conducted based on the Taguchi L9 Orthogonal array with the chosen design and material parameters. Three microvia locations along with an additional factor i.e., Via-position were introduced to find the substrate location with a high probability of microvia failures. This study shows that the composite substrate material significantly impacts the reliability of microvias during the reflow process. The design of experiments using the important design parameters (location and position) and material parameters (CTE) was conducted. The CTE changed significantly above the glass transition temperature in the thickness direction that affected the microvia structure. On the other hand, Fiberglass provides mechanical strength to the microvia at elevated temperatures preventing microvias from early failures. The microvia at resin-rich regions are less likely to pass 1000 cycles and therefore the resin-rich regions across the substrate layers are the high failure risk areas for microvias. This research provides a strong understanding of the interaction of microvias with their immediate surroundings of substrate layers. The lower the fiberglass content in the microvia surrounding, the higher the risk of getting early failures. Moreover, these findings provide useful insights for the improvement of microvia reliability in the design phase.
During the question-and-answer session, I received a lot of appreciation and useful pieces of advice regarding future research direction, such as extending the study to stacked microvias. I also received the plaque award for the recognition and efforts I put in this research field.
The best experience I gained from participating in this international conference, EPTC, was the opportunity to interact with great researchers who are leading unique research in various fields. I communicated with different researchers by attending their presentations and I was involved in several question-and-answer sessions to enhance my knowledge and contribute to productive thinking. I was able to connect with several researchers who are working in different industries. This is an experience that can only be had at an international conference. Additionally, since the conference had a wide scope of topics in semiconductor industry, I was able to gain new ideas by listening to presentations in research fields that I usually don't encounter.
Finally, I would like to express my deepest gratitude to the Marubun Foundation for the tremendous support they provided me during my overseas travel, enabling me to have this valuable experience.
