Dániel Straubinger, Attila Géczy, András Sipos, András Kiss, Dániel Gyarmati, Oliver Krammer, Dániel Rigler, David Bušek and Gábor Harsányi
This paper aims to present a novel approach on investigating critical current densities in the solder joints of chip-size surface-mounted components or device (SMD) components and…
Abstract
Purpose
This paper aims to present a novel approach on investigating critical current densities in the solder joints of chip-size surface-mounted components or device (SMD) components and ball grid array (BGA) lead-free solder joints with the focus of via-in-pad geometries. The investigation involves a numerical approach and a physical validation with selected geometry configurations and high current loads to reveal possible failure sources. The work is a continuation of a previous study.
Design/methodology/approach
Current density was investigated using finite element modeling on BGA joints. Dummy BGA components, 0402 and 0603 zero ohm jumper resistors, were used, both in daisy chain setups on standard FR4 printed circuit boards (PCBs). Respective physical loading experiments were set to find effects of elevated current density at hot zones of the joints. Cross-section analysis, scanning electron microscopy and shear force tests were used to analyze the joints.
Findings
The findings reveal alterations in the joints, while the current loading is not directly affecting the structure. The modeling reveals the current density map in the selected formations with increased current crowding zones. Overall, the degradation does not reach the level of electromigration (EM)-induced voiding due to the limiting factor of the FR4 substrate.
Practical implications
The heavy current load affects joint reliability, but there are limitations of EM-induced failures on PCB-based assemblies due to the thermomechanical weakness of the FR4 material.
Originality/value
The experiments investigate current density from a novel aspect on frequently used BGA surface mounted components with modeling configurations focusing on possible effects of via-in-pad structure.
Details
Keywords
Emmanuel Osafo and Robert M. Yawson
This paper aims to identify ways by which the core functions of human resource development HRD can be used to enhance the university–community partnership (UCP) in lieu of the…
Abstract
Purpose
This paper aims to identify ways by which the core functions of human resource development HRD can be used to enhance the university–community partnership (UCP) in lieu of the “town and gown” era. Furthermore, the paper addresses the need to extend HRD activities beyond the organization and leverage HRD to spearhead the community-development agenda through coalition building between organizations, local universities and the community.
Design/methodology/approach
Literature on UCP is reviewed and analyzed, and the need to extend HRD focus beyond the organization to include community development through coalition building is discussed. A single-case descriptive analysis to illustrate the critical role of human resource and leadership development in UCP is done.
Findings
HRD’s interest in the UCP drive is negligible. UCP presents a new frontier for HRD research and practice because there is both public and private funding that can be assessed through the right contacts and networks.
Originality/value
The need for UCP has been a subject of discussion among scholars for time immemorial. However, the collapse of the “town and gown” era has inspired greater interest in UCP. HRD scholars and practitioners can leverage the expertise in applying andragogy principles, the focus on the adult learner and community leadership development to play a crucial in the UCP drive.