학술논문

Considerations on a Smart Strategy for Simultaneously Testing Multiple PCB Assemblies in Board Level Vibration
Document Type
Conference
Source
2020 IEEE 70th Electronic Components and Technology Conference (ECTC) Electronic Components and Technology Conference (ECTC), 2020 IEEE 70th. :793-800 Jun, 2020
Subject
Components, Circuits, Devices and Systems
Vibrations
Stress
Fixtures
Testing
Reliability
Finite element analysis
Soldering
Board Level Reliability
Vibration Test Method
PCB dynamic response
modal analysis
Wafer Level Chip Scale Package
Vibration Fixture
Harsh Environment Reliability
Language
ISSN
2377-5726
Abstract
Board level vibration testing is an important characterization aspect that has to be considered during development and release of electronic components in applications involving harsh environments. Industrial reliability test standards prescribed by JEDEC recommend to stress a statistical representative sample size of at least 30 components. Consequently, the test execution time is undesirably long when testing all components sequentially. This paper provides a solution by developing a vibration test approach for simultaneously stressing multiple PCB assemblies. To start with, multiple boards are evaluated via vibrational spectrum analysis that is combined with a Finite Element Model (FEM) to calculate the strain at solder joint level. Limited variation is seen in calculated strain levels from PCB to PCB. This permits simultaneous testing of multiple PCB assemblies. Consequently, three test capacity expansion arrangements, namely One Dimensional (1D), Two Dimensional (2D: Stacked & Side by Side) & Three Dimensional (3D) test methods are evaluated. When comparing the investigated test extension strategies, it is found that test approach with stacked PCB levels alter the stress transferred to the component and can lead to a false reliability prediction. Depending upon the allowed mass load limit of the shaker system and stress levels involved, both 1D and 3D techniques can be used as complementary to one another. Outcomes of this study can further be used to provide guidance for future board level vibration test method.