EPS M & P Technical Committee will meet regularly to discuss plans and strategy to improve the communication and engagement within the community.

Upcoming webinars:

Attend through webex link: https://ibm.webex.com/meet/dangbing

Chair: Dr. Yang Liu, Nokia Bell Lab, 600 Mountain Avenue, Murray Hill, NJ 07974-0636

December 6th 10AM ~11AM EST: Reliable Metallized Through-Glass Vias for High Hermeticity and High Frequency Microelectronic Devices

Speaker: Dr. Chukwudi Okoro, Senior Research Scientist at Corning Incorporated


One of the primary ways to increase transmission speed of microelectronic packages is by decreasing their electrical path length, which led to the development of the through-silicon vias (TSV) technology. This interconnect type has in recent times enabled high performing microelectronic packages such as the 3D and the 2.5D stacked die architectures. Additionally, the ever-increasing need for higher data transmission speed has led to the continuous demand for better performing high frequency electronic devices. For high frequency (HF) applications, one of the most critical properties that influences signal transmission speed is the dielectric properties of the substrate. In most microelectronic packages, silicon is the predominant substrate material, which unfortunately does not have the preferred dielectric properties needed in high frequency applications. Therefore, the continuous requirement for higher frequency operating electronic devices, would require substrates with better dielectric properties than silicon. The use of glass as an alternative substrate in microelectronic packages possess many enticing attributes for use in HF applications that includes excellent dielectric properties and low surface roughness, while also enabling high volume manufacturing due to its panel size capability.

This makes the use of metallized through-glass vias (TGVs) for high frequency applications very attractive. However, similar to copper (Cu) TSVs, the metallization of TGVs presents significant thermo – mechanical challenges due to the mismatch in the material properties between glass and copper. For instance, the CTE of Corning® HPFS® fused silica glass is 0.52ppm/0C, while that of the via filling material, Cu, is 16.7ppm/0C. Many applications require the use of extreme processing temperatures of up to 400 ̊C, which is expected to lead to high stress build up, due to the high CTE mismatch. This may result in the formation of thermo-mechanically induced cracks. Predominantly, two crack systems are formed; radial cracks that form during heating and circumferential cracks that form during cooling.

While it is critical to resolve processing induced crack formation in Cu TGVs, it is also paramount to determine their expected in-service reliability performance through accelerated tests. For many applications such as MEMS devices, the electronic package is required to be helium hermetic during the service life of the device. As such, it becomes important to determine the expected in-service He hermeticity reliability performance of Cu TGVs under various extreme environmental conditions.

Therefore, today’s presentation aims at understanding and mitigating both processing and in-service reliability concerns associated with the use of Cu TGVs, thereby paving the way for its adoption for high hermeticity and high frequency electronic applications.

Past webinars:

July 16th, 2021: “Second Phase and IMC Variation of Solder Joint under Eelctromigration

Speaker: Prof. Kwang-Lung Lin, Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan, R. O. C. Email: matkllin@mail.ncku.edu.tw

Date: 7/16 Time: 9-10am (New York) / 9-10pm (Taipei)

Abstract: The solder joint, due to its shrinking dimension between the joined items, experiences high current density during application. The athermal electromigration force in combining with the Joule heat will cause a variety of variations to the relatively small dimension solder joint. This talk will present and discuss the effect of electromigration on the recrystallization of second phase and IMC, the effect of current direction on the interfacial IMC formation, and the transformation of IMC under electromigration in solder joint .