Modeling the Effects of the PCB Motion on the Response of Microstructures Under Mechanical Shock

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Abdallah H. Ramini ◽  
Mohammad I. Younis ◽  
Ronald Miles
Keyword(s):  
Printed Circuit Board ◽  
Microelectromechanical Systems ◽  
Element Model ◽  
Higher Order ◽  
Circuit Board ◽  
Mechanical Shock ◽  
Lumped Model ◽  
Distributed Models ◽  
Mems Device ◽  
Cantilever Microbeam

Microelectromechanical systems (MEMS) are often used in portable electronic devices that are vulnerable to mechanical shock or impact, such as that induced due to accidental drops on the ground. This work presents a modeling and simulation effort to investigate the effect of the vibration of a printed circuit board (PCB) on the dynamics of MEMS microstructures when subjected to shock. Two models are investigated. In the first model, the PCB is modeled as an Euler-Bernoulli beam to which a lumped model of a MEMS device is attached. In the second model, a special case of a cantilever microbeam is studied and modeled as a distributed-parameter system, which is attached to the PCB. These lumped-distributed and distributed-distributed models are discretized into ordinary differential equations, using the Galerkin method, which are then integrated numerically over time to simulate the dynamic response. Results of the two models are compared against each other for the case of a cantilever microbeam and also compared to the predictions of a finite-element model using the software ANSYS. The influence of the higher order vibration modes of the PCB, the location of the MEMS device on the PCB, the electrostatic forces, damping, and shock pulse duration are presented. It is found that neglecting the effects of the higher order modes of the PCB and the location of the MEMS device can cause incorrect predictions of the response of the microstructure and may lead to failure of the device. It is noted also that, for some PCB designs, the response of the microstructure can be amplified significantly causing early dynamic pull-in and hence possibly failure of the device.

Dynamic – Thermal Analyses of a Structurally Reconfigured Electronics Package Onboard Mini Satellite

2014 ◽  
Vol 592-594 ◽  
pp. 2117-2121 ◽  
Author(s):  
P. Veeramuthuvel ◽  
S. Jayaraman ◽  
Shankar Krishnapillai ◽  
M. Annadurai ◽  
A.K. Sharma
Keyword(s):  
Finite Element ◽  
Printed Circuit Board ◽  
Thermal Environment ◽  
Thermal Analyses ◽  
Simulation Models ◽  
Element Model ◽  
Circuit Board ◽  
Element Analysis ◽  
Transfer Path ◽  
Vibration Responses

The electronics package in a spacecraft is subjected to a variety of dynamic loads during launch phase and suitable thermal environment for the mission life. The dynamic and thermal analyses performed for a structurally reconfigured electronics package. Two different simulation models are developed to carry out the analyses. This paper discusses in two parts, in part-1, the vibration responses are determined at various critical locations, including on the Printed Circuit Board (PCB) for the vibration loads specified by launch vehicle using Finite Element Analysis (FEA). The mechanical properties of PCB are determined from the test specimens, which are then incorporated in the finite element model. In part-2, the steady-state temperature distributions on the components and on the PCB are determined, to check the effectiveness of heat transfer path from the components to the base of the package and to verify the predicted values are within the acceptable temperature limits specified. The predicted temperature values are then compared with on-orbit observations.

Low-Density Fan-Out Heterogeneous Integration of MEMS Tunable Capacitor and RF SOI Switch

2019 ◽  
Vol 2019 (1) ◽  
pp. 000051-000055
Author(s):  
Rameen Hadizadeh ◽  
Anssi Laitinen ◽  
Niko Kuusniemi ◽  
Volker Blaschke ◽  
David Molinero ◽  
...  
Keyword(s):  
High Voltage ◽  
Microelectromechanical Systems ◽  
Performance Metrics ◽  
Circuit Board ◽  
Low Density ◽  
Rf Switch ◽  
Tunable Capacitor ◽  
Esd Protection ◽  
Mems Device ◽  
The Impact

Abstract Using Low-Density Fan-Out (LDFO) packaging technology, a radio frequency (RF) microelectromechanical systems (MEMS) tunable capacitor array composed of electrostatically actuated beams on 180nm high-voltage CMOS silicon was heterogeneously integrated with a single-pole four-terminal (SP4T) RF switch on 180nm CMOS silicon-on-insulator (SOI). The primary objective of this study was to determine the manufacturability of this System-in-Package (SiP) design, which is proven at time zero through survival of the MEMS device based on acceptable MEMS performance metrics. In addition, the RF SOI switch provides high-voltage electrostatic discharge (ESD) protection for the MEMS device. Capacitive MEMS structures are particularly sensitive to unpredictable electrostatic charging scenarios, such as handling after package assembly and printed circuit board (PCB) surface mount processing. Consequently, resistance to dielectric breakdown by means of robust ESD protection is a very desirable quality. Integrating the RF switch in close proximity with the MEMS device not only enables the ability to withstand charging scenarios in excess of 1kV (human body model), it mitigates the impact of parasitics on RF performance by minimizing interconnect lengths and complexity.

I/O Printed Circuit Board Assemblies; Recent Learning in Mechanical Stress Analysis, Verification Testing, and Post-test Analysis Techniques and Results

2015 ◽  
Vol 2015 (1) ◽  
pp. 000169-000178
Author(s):  
John Torok ◽  
Shawn Canfield ◽  
Suraush Khambati ◽  
Robert Mullady ◽  
Budy Notohardjono ◽  
...  
Keyword(s):  
Printed Circuit Board ◽  
Measurement Techniques ◽  
Form Factors ◽  
Mechanical Analysis ◽  
Circuit Board ◽  
Mechanical Shock ◽  
Test Analysis ◽  
Printed Circuit ◽  
Analysis Techniques ◽  
Post Test

Recent high-end server designs have included new Input / Output (I/O) printed circuit board (PCB) assemblies consisting of a variety of form factors, electronic design layouts, and packaging assembly characteristics. To insure the required functional and reliability aspects are established and maintained, new mechanical analysis and verification testing techniques have been recently devised. A description of the design application set, the analysis tools and techniques applied, and the verification testing completed, including the associated measurement techniques as well as post-testing analysis methods and results are presented. Also included are the recent PCB raw card characterization efforts whose results have been applied as material property inputs to the analysis to improve analytical-to-empirical correlation. Included within the application set are both the use of custom designed cards as well as industry standard, original equipment manufacturer (OEM) cards that are packaged within custom enclosures. Given packaged and unpackaged (i.e., as installed in a higher-level rack system assembly) fragility testing requirements, new analysis techniques exploiting the capabilities of LS-DYNA have been used to provide a predictive means to support both initial as well as iterative design levels. In addition, these analysis results are also used to identify locations for measurement sensor placement employed during mechanical verification testing. Thermal shock and mechanical shock and vibration verification testing details and results are provided describing the conditions applied to simulate assembly shipping conditions, both as packaged as well as in situ to the higher-level of assembly. Included with this is a discussion with respect to post-test analysis techniques and results, including the use of both microscopic cross-section analysis as well as dye-pry assessments. Concluding, continued and future activities are described as “best practices” for the application of this methodology as part of the end-to-end development process.

Comparison of Different Methods for Stress and Deflection Analysis in Embedded Die Packages during the Assembly Process

2014 ◽  
Vol 2014 (1) ◽  
pp. 000355-000360
Author(s):  
K. Macurova ◽  
R. Bermejo ◽  
M. Pletz ◽  
R. Schöngrundner ◽  
T. Antretter ◽  
...  
Keyword(s):  
Printed Circuit Board ◽  
Plastic Material ◽  
Three Dimensional ◽  
Diffraction Method ◽  
Element Model ◽  
Analytical Investigation ◽  
Circuit Board ◽  
Curvature Radius ◽  
Assembly Process ◽  
Deflection Analysis

Important topics for electronic packages are thermally induced stresses created during package manufacturing and their role in mechanical failure. In the present paper, an analytical and a numerical analysis of the assembly process (component attached with an adhesive to a copper foil) is investigated. This process is prior to the lamination of the printed circuit board. Stresses develop due to a mismatch of coefficients of thermal expansion and particularly to shrinkage associated with adhesive polymerization. The analytical investigation is based on the classical laminate theory and an interfacial model. The three-dimensional numerical finite element model is capable to use geometric and material properties which are not possible to investigate analytically. In particular, the influence of the adhesive meniscus and plastic material models for copper and adhesive are investigated. The models are validated experimentally by an X-ray diffraction method (Rocking-Curve-Technique) showing a good agreement of the calculated and measured curvature radius values.

Comparison of Different Methods for Stress and Deflection Analysis in Embedded Die Packages During the Assembly Process

2015 ◽  
Vol 12 (2) ◽  
pp. 80-85 ◽  
Author(s):  
K. Macurova ◽  
R. Bermejo ◽  
M. Pletz ◽  
R. Schöngrundner ◽  
T. Antretter ◽  
...  
Keyword(s):  
Printed Circuit Board ◽  
Plastic Material ◽  
Three Dimensional ◽  
Diffraction Method ◽  
Element Model ◽  
Analytical Investigation ◽  
Circuit Board ◽  
Curvature Radius ◽  
Assembly Process ◽  
Deflection Analysis

Important topics for electronic packages are thermally induced stresses created during package manufacturing and their role in mechanical failure. In the present paper, an analytical and a numerical analysis of the assembly process (component attached with an adhesive to a copper foil) is investigated. This process is prior to the lamination of the printed circuit board. Stresses develop due to a mismatch of coefficients of thermal expansion and particularly to shrinkage associated with adhesive polymerization. The analytical investigation is based on the classical laminate theory and an interfacial model. The three-dimensional, numerical, finite element model is capable of using geometric and material properties not possible to investigate analytically. In particular, the influence of the adhesive meniscus and plastic material models for copper and adhesive are investigated. The models are validated experimentally by an x-ray diffraction method (rocking-curve technique) showing a good agreement of the calculated and measured curvature radius values.

Mechanical Stress Analysis and Evaluation of Hybrid Land Grid Array Attached Large Form Factor Organic Modules

2012 ◽  
Vol 2012 (1) ◽  
pp. 000818-000824
Author(s):  
John Torok ◽  
Shawn Canfield ◽  
Yuet-Ying Yu ◽  
Jiantao Zheng
Keyword(s):  
Form Factor ◽  
Stress Analysis ◽  
Mechanical Stress ◽  
Printed Circuit Board ◽  
Organic Substrate ◽  
Circuit Board ◽  
Bottom Surface ◽  
Mechanical Shock ◽  
Analysis And Evaluation ◽  
Pcb Assembly

Recent industry trends to continue enabling increased server system performance and packaging density has driven the need to implement larger form factor hybrid land grid array (LGA) attached organic modules. In addition, given the need to package multiple modules on a single printed circuit board (PCB) assembly, PCB cross-sections and their corresponding physical properties (e.g., flatness, etc.) as well as module bottom surface metallurgy (BSM) co-planarity require a more detailed understanding of impacts to the compliant as well as the soldered connector interfaces. Lastly, the migration to lead (Pb)-free solders has further complicated the issue given both the change in material properties as well as processing temperatures. In this paper we will discuss the mechanical stress analysis and evaluation tests assessment of a recently developed 50 mm square organic processor module, hybrid LGA attached to a multiple site PCB. The analysis presented will highlight the methodology to identify both connector soldered stress and predicted contact load variation across the module's mated interface. Key parameters discuss will include the PCB flatness, Organic substrate BSM co-planarity (both predicted and measured) and the Hybrid LGA as-soldered contact co-planarity. Corroborating predicted analytical results, we will discuss various evaluation tests performed to validate the design's integrity. Key tests include, pressure sensitive film (PSF) studies and environment stress exposures, including thermal shock, mechanical shock and vibration and seismic exposure. Post test electrical integrity and test sample construction analysis, including 3D x-ray and mechanical cross-section, will also be described. The analysis process and testing described will provide a method to evaluate more challenging hybrid LGA applications as both module sizes and/or number applied per PCB assembly increase and Pb-free assembly is introduced in future applications.

Damage and Failures of CGA/BGA Assemblies Under Thermal Cycling and Dynamic Loadings

2013 ◽  
Author(s):  
Reza Ghaffarian
Keyword(s):  
Thermal Cycling ◽  
Mechanical Loading ◽  
Test Data ◽  
Printed Circuit Board ◽  
High Reliability ◽  
Circuit Board ◽  
Design Parameters ◽  
Mechanical Shock ◽  
Space Applications ◽  
High Processing

Commercial-off-the-shelf column/ball grid array packaging (COTS CGA/BGA) technologies in high-reliability versions are now being considered for use in high-reliability electronic systems. For space applications, these packages are prone to early failure due to the severe thermal cycling in ground testing and during flight, mechanical shock and vibration of launch, as well as other less severe conditions, such as mechanical loading during descent, rough terrain mobility, handling, and ground tests. As the density of these packages increases and the size of solder interconnections decreases, susceptibility to thermal, mechanical loading and cycling fatigue grows even more. This paper reviews technology as well as thermo-mechanical reliability of field programmable gate array (FPGA) IC packaging developed to meet demands of high processing powers. The FPGAs that generally come in CGA/PBGA packages now have more than thousands of solder balls/columns under the package area. These packages need not only to be correctly joined onto printed circuit board (PCB) for interfacing; they also should show adequate system reliability for meeting thermo-mechanical requirements of the electronics hardware application. Such reliability test data are rare or none for harsher environmental applications, especially for CGAs having more than a thousand of columns. The paper also presents significant test data gathered under thermal cycling and drop testing for high I/O PBGA/CGA packages assembled onto PCBs. Damage and failures of these assemblies after environmental exposures are presented in detail. Understanding the key design parameters and failure mechanisms under thermal and mechanical conditions is critical to developing an approach that will minimize future failures and will enable low-risk insertion of these advanced electronic packages with high processing power and in-field re-programming capability.

scholarly journals Sensitivity Analysis of a Portable Wireless PCB-MEMS Permittivity Sensor Node for Non-Invasive Liquid Recognition

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1068
Author(s):  
Javier Meléndez-Campos ◽  
Matias Vázquez-Piñón ◽  
Sergio Camacho-Leon
Keyword(s):  
Laser Ablation ◽  
Sensor Node ◽  
Microelectrode Array ◽  
Printed Circuit Board ◽  
Microelectromechanical Systems ◽  
Circuit Board ◽  
Wireless Sensor Node ◽  
Liquid Sample ◽  
Radio Communication ◽  
Interdigitated Microelectrode

Dielectric characteristics are useful to determine crucial properties of liquids and to differentiate between liquid samples with similar physical characteristics. Liquid recognition has found applications in a broad variety of fields, including healthcare, food science, and quality inspection, among others. This work demonstrates the fabrication, instrumentation, and functionality of a portable wireless sensor node for the permittivity measurement of liquids that require characterization and differentiation. The node incorporates an interdigitated microelectrode array as a transducer and a microcontroller unit with radio communication electronics for data processing and transmission, which enable a wide variety of stand-alone applications. A laser-ablation-based microfabrication technique is applied to fabricate the microelectromechanical systems (MEMS) transducer on a printed circuit board (PCB) substrate. The surface of the transducer is covered with a thin layer of SU-8 polymer by spin coating, which prevents it from direct contact with the Cu electrodes and the liquid sample. This helps to enhance durability, avoid electrode corrosion and contamination of the liquid sample, and to prevent undesirable electrochemical reactions to arise. The transducer’s impedance was modeled as a Randles cell, having resistive and reactive components determined analytically using a square wave as stimuli, and a resistor as a current-to-voltage converter. To characterize the node sensitivity under different conditions, three different transducer designs were fabricated and tested for four different fluids, i.e., air, isopropanol, glycerin, and distilled water—achieving a sensitivity of 1.6965 +/− 0.2028 εr/pF. The use of laser ablation allowed the reduction of the transducer footprint while maintaining its sensitivity within an adequate value for the targeted applications.

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