On Thursday May 13th, 2021, Greg Caswell presented “ASQ RRD Series Webinar: Evolution Of Electrolytic Capacitors- Why A Reliability Engineer Should Know This”
Unfortunately no video, but only slides can be shared.
Why would a Reliability practitioner need to know this? Where there is electricity, that is, electrons moving collectively, there is capacitance. In systems, especially complex systems, changes in capacitance, or the incidental formative presence of an undesired capacitance can impose a spurious system response which could lead to a functional failure. In the grand scheme of things, it would be advantageous for the reliability practitioner to have a perspective on capacitance. This presentation provides one such viewpoint.
Electrolytic capacitors have long been identified as a weak link for long term high reliability applications. However, capacitor manufacturers have made significant improvements to the materials and manufacturing processes to enhance their reliability. This webinar will discuss those changes, provide insight into the various failure mechanisms for electrolytic capacitors and describe appropriate accelerated tests to validate performance.
We will take a deeper dive into the methodologies utilized to improve capacitor performance, e.g. foil purity and electrolyte volume. We will also discuss, from a reliability perspective, the impact of changing to a higher temperature electrolyte (from ethylene glycol to DMF, DMA and GBL) and also changes in the bung material (from butyl to EPDM).
There are several environmental factors involved in the aging of electrolytic capacitors. Electrolyte loss due to drying out and leakage current due to oxide degradation are thermally related as is the self-heating associated with ripple current. The impact of the applied voltage level is also a driver as it can cause leakage current increases as well. All of these issues result in a capacitance decrease, an increase in ESR, and a change to the dissipation factor. Many other failure mechanisms associated with manufacturing will also be discussed.
Examples of calculations for life expectancy will be shown to demonstrate the effects of applied voltage, rated temperature, ripple current, and the endurance factor coupled with the application usage profile.
Bio
• Greg has over 50 years of experience in electronics manufacturing focusing on failure analysis and reliability. He is passionate about applying his unique background to enable his clients to maximize and accelerate product design and development while saving time, managing resources, and improving customer satisfaction.
• Greg, a Lead Consulting Engineer for Ansys, is an industry recognized expert in the fields of SMT, advanced packaging, printed board fabrication, circuit card assembly, and bonding solutions using nanotechnology. He has been well-regarded as a leader in the electronics contract manufacturing and component packaging industries for the past 50 years. Prior to joining Ansys Greg was the Vice President of Engineering at Reactive Nanotechnology (RNT), where he led application development for the RNT Nanofoil® and ensured a successful transition of product technology to Indium Corporation. His previous appointments include Vice President of Business Development for Newport Enterprises, Director of Engineering for VirTex Assembly Services, and Technical Director at Silicon Hills Design. He has presented over 270 papers at conferences all over the world and has taught courses at IMAPS, SMTA and IPC events. He helped design the 1st pick and place system used exclusively for SMT in 1978, edited and co-authored the 1st book on SMT in 1984 for ISHM and built the 1st SMT electronics launched into space. Look for his new book entitled “Design for Excellence in Electronics Manufacturing” to be published in April 2021.
• B.A., Management (St. Edwards University)
• B.S., Electrical Engineering (Rutgers University)
