Fretting wear remains a critical reliability challenge in electrical contacts, leading to increased contact resistance and intermittent failures. While electroplated gold (EPG) has been the standard finish for noble metal contacts, its non-uniform microstructure can adversely affect electrical performance and reliability. This has motivated the exploration of electroless gold (EG) as a potential substitute.

CALCE's comparative study evaluates these gold finishes under fretting conditions, focusing on their electrical and tribological performance. EG’s contact performance was compared with EPG’s, supported by data on contact resistance evolution, wear mechanisms, and contact lifetime.

Tuesday, September 9, 2025
11:00 a.m. to 12:00 noon US Eastern Time

On October 15 and 16, 2025, the Center for Advanced Life Cycle Engineering will hold its biannual Reliability Science Symposium. The meeting will include an overview of CALCE's research activities, followed by several detailed presentations of research projects. The meeting will be open to all CALCE members.

Registration opens soon.

CALCE is offering a four-day course on failure analysis of electronics from November 18–21, 2025, at the University of Maryland, College Park. Through lectures, case studies, demos, and hands-on labs, you'll explore failure mechanisms, specimen preparation, physics of failure, root cause analysis, and materials analysis. It’s a great opportunity to gain practical insight into the latest methods in electronic failure analysis.

Register Here
November 18-21, 2025
For more information contact Dr. Michael Osterman

Organizations at all levels in the electronics product supply chain need organizational policies to reduce their exposure to the risk of procuring counterfeit parts. Creating, implementing, validating, and updating organizational policies and ensuring that all business units are trained in the policies and understand their responsibilities are essential for the organization.

Over the past two decades, many industry organizations have developed, updated, and fine-tuned counterfeit avoidance standards for electronic (and some non-electronic) components. These standards provide frameworks for organizations to establish robust counterfeit mitigation programs, emphasizing supply chain control, risk assessment, verification processes, and reporting mechanisms to protect against the influx of counterfeits. This new course from CALCE covers the practical implementation of the standards, and it is fully customizable based on the type of organization.

The advantages of Printed Hybrid Electronic assemblies are of considerable interest to designers of electro-mechanical systems, especially for applications in extreme environments. This study considered the reliability of electrical components embedded into polymeric substrates and interconnected with printed conductors as elements of PHE assemblies subject to extreme acceleration levels experienced during mechanical shock. ...

Fatigue model constants of a board level reliability model are obtained for Bi-based SAC305 hybrid solder joints. Three tasks are performed to achieve the goal. In the first task, the constitutive properties (the Anand model constants) of hybrid solders are obtained as a function of Bi concentration from the constant strain rate tests at various temperatures. In the second task, ideal package assemblies containing hybrid solder joints are assembled using a metal-core PCB on the top and an FR-4 PCB at the bottom....

When a linear viscoelastic (LVE) analysis is to be implemented, the time-dependent shear and bulk moduli, G(t) and K(t), are required. In practice, however, only the time-dependent behavior under uniaxial loading, E(t), is often available for the analysis simply because it can be measured routinely using commercial tools such as a dynamic mechanical analyzer or a universal tensile testing machine. When only E(t) is available for an LVE analysis, some assumption has to be made to satisfy the input requirements of an LVE analysis. ...

Additive manufacturing provides a pathway for manufacturing of printed hybrid electronic (PHE) assemblies in novel non-planar (curvilinear and 3D) form factors. In particular, PHEs may combine conventionally manufactured microelectronics components and circuit elements with additively manufactured features. Aerosol jet printing (AJP) is one of the leading additive manufacturing methods for PHEs. It is therefore critical to better understand the reliability aspects of using AJP-based PHEs to fully leverage the possibilities offered by this technology. ...