Nonlinear Response of a Printed Circuit Board in Shock

2009 ◽  
Author(s):  
M. Vujosevic ◽  
P. Raghavan ◽  
G. Ramanathan ◽  
W. Hezeltine ◽  
K. Blue
Keyword(s):  
Printed Circuit Board ◽  
Transfer Functions ◽  
Numerical Approach ◽  
Circuit Board ◽  
Special Importance ◽  
Strain Measurements ◽  
Printed Circuit ◽  
Numerical Finite Element ◽  
Nonlinear Deformations ◽  
The Impact

This work focuses on deformation mechanisms taking place in a Printed Circuit Board (PCB) exposed to high impact shock. A combined experimental, theoretical, and numerical approach has been applied to address both the nature of the observed deformation and its modeling and test metrology implications. Experimental evidence overwhelmingly indicates that a PCB in both test and system applications undergoes nonlinear deformations. Geometric nonlinearity of board response is attributed to the elevated in-plane (membrane) stresses that develop when a drop height and/or inertia forces are significant. The impact of these stresses on deformations (board strain) was quantified using a specially designed test. Membrane stresses were also accounted for in a numerical (Finite Element Method) model developed and carefully validated in the course of this study. The model shows a very good agreement with test data. The nonlinearity of PCB deformation in shock, i.e. the fact that both bending moments and in-plane forces are present in the board has important implications on test metrology development and on correlation between the measured board strain and stresses in interconnects of surface mounted components. Of special importance is the impact that nonlinearity can have on development of transfer functions between strain measurements on system boards and strain measurements on test boards, which is also addressed in the paper.

Numerical Simulation and Experimental Measurement of a Printed Circuit Board Subjected to Drop Test

2009 ◽  
Vol 419-420 ◽  
pp. 37-40
Author(s):  
Shiuh Chuan Her ◽  
Shien Chin Lan ◽  
Chun Yen Liu ◽  
Bo Ren Yao
Keyword(s):  
Finite Element ◽  
Experimental Measurement ◽  
Test Specimen ◽  
Printed Circuit Board ◽  
Drop Impact ◽  
Simulation Technique ◽  
Drop Test ◽  
Circuit Board ◽  
Printed Circuit ◽  
The Impact

Drop test is one of the common methods for determining the reliability of electronic products under actual transportation conditions. The aim of this study is to develop a reliable drop impact simulation technique. The test specimen of a printed circuit board is clamped at two edges on a test fixture and mounted on the drop test machine platform. The drop table is raised at the height of 50mm and dropped with free fall to impinge four half-spheres of Teflon. One accelerometer is mounted on the center of the specimen to measure the impact pulse. The commercial finite element software ANSYS/LS-DYNA is applied to compute the impact acceleration and dynamic strain on the test specimen during the drop impact. The finite element results are compared to the experimental measurement of acceleration with good correlation between simulation and drop testing. With the accurate simulation technique, one is capable of predicting the impact response and characterizing the failure mode prior to real reliability test.

Research on Liberation Mechanism of the Impact Crushing Waste Printed Circuit Board

2010 ◽  
Vol 113-116 ◽  
pp. 730-734 ◽  
Author(s):  
Chen Long Duan ◽  
Yue Min Zhao ◽  
Jing Feng He ◽  
Nian Xin Zhou
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Distribution Model ◽  
Evaluation Indexes ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Waste Printed Circuit Board ◽  
Impact Crushing ◽  
The Impact

The reutilization of waste Printed Circuit Boards (PCB) is a focused topic in the field of environment protection and resource recycling, and the crushing is the crucial process for recycling waste PCB. A hamper impacting crusher was used to achieve metals crushing liberation from non-metals, the liberation mechanism of PCB can be explained by dispersion liberation accompanied disengaging liberation. The Rosin-Rammler distribution model of crushed PCB particle was put forward. The evaluation indexes show that Rosin-Rammler function can accurately describe size distribution of PCB particles because the convergence property R2 is 0.99694 and fitting error E is 4.80658. The selective crushing is appearance with metals concentrated in coarser fraction and non-metals in finer size during comminution processing. The impact crushing is an effective method to metals liberation of PCB particles.

Failure Analysis of Halogen-Free Printed Circuit Board Assembly Under Board-Level Drop Test

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
Hung-Jen Chang ◽  
Chau-Jie Zhan ◽  
Tao-Chih Chang ◽  
Jung-Hua Chou
Keyword(s):  
Printed Circuit Board ◽  
Drop Test ◽  
Circuit Board ◽  
Printed Circuit Board Assembly ◽  
Printed Circuit ◽  
Plastic Ball ◽  
Circuit Board Assembly ◽  
Halogen Free ◽  
Board Level ◽  
The Impact

In this study, a lead-free dummy plastic ball grid array component with daisy-chains and Sn4.0Ag0.5Cu Pb-free solder balls was assembled on an halogen-free high density interconnection printed circuit board (PCB) by using Sn1.0Ag0.5Cu solder paste on the Cu pad surfaces of either organic solderable preservative (OSP) or electroless nickel immersion gold (ENIG). The assembly was tested for the effect of the formation extent of Ag3Sn intermetallic compound. Afterward a board-level pulse-controlled drop test was conducted on the as-reflowed assemblies according to the JESD22-B110 and JESD22-B111 standards, the impact performance of various surface finished halogen-free printed circuit board assembly was evaluated. The test results showed that most of the fractures occurred around the pad on the test board first. Then cracks propagated across the outer build-up layer. Finally, the inner copper trace was fractured due to the propagated cracks, resulting in the failure of the PCB side. Interfacial stresses numerically obtained by the transient stress responses supported the test observation as the simulated initial crack position was the same as that observed.

An Assessment of the Impact of Interconnect Strategies on Thermal Performance of GaAs Power Amplifier IC Devices

2001 ◽  
Author(s):  
V. H. Adams ◽  
T.-Y. Tom Lee
Keyword(s):  
Thermal Resistance ◽  
Power Amplifier ◽  
Thermal Performance ◽  
Flip Chip ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Printed Circuit ◽  
Wire Bond ◽  
Die Attach ◽  
The Impact

Abstract Alternative interconnect strategies are being considered in place of the standard wire bond interconnect for GaAs power amplifier MMIC devices due to cost and electrical performance improvements. The package/die thermal performance consequences are potentially high-risk issue to these interconnect strategies and requires evaluation. Thermal simulations are conducted to compare and evaluate the thermal performances of three interconnect strategies: wire bond, gold post-flip chip, and through via interconnects. The test vehicle simulated is a three-stage, dual band power amplifier integrated circuit dissipating approximately 5 W steady-state power. Parametric studies are conducted to evaluate the impact of the printed circuit board, die thickness, solid gold vias, and design enhancements on package thermal performance. Best thermal performance is provided by a wire bonded, thin GaAs die attached with solder die attach to a printed circuit board that maximizes the number of plated-through-holes directly under the die. This configuration results in a best case junction-to-heat sink thermal resistance of 12 °C/W. Optimum flip chip and through via designs result in degraded thermal performance compared to the above described wire bond design but may have acceptable thermal performance. For these simulations, predicted junction-to-heatsink thermal resistance is in a range of 15–20 °C/W and is better than a comparable wire bonded design that uses a conductive epoxy die attach material.

scholarly journals Optimization of a Gate Distribution Layout to Compensate the Current Imbalance Generated by the 3D Geometry of a Railway Inverter

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1891
Author(s):  
Andressa Nakahata-Medrado ◽  
Jean-Luc Schanen ◽  
Jean-Michel Guichon ◽  
Pierre-Olivier Jeannin ◽  
Emmanuel Batista ◽  
...  
Keyword(s):  
Time Domain ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Time Domain Simulation ◽  
Optimization Strategy ◽  
Next Generation ◽  
Printed Circuit ◽  
3D Geometry ◽  
The Impact ◽  
Complete Investigation

The impact of the stray inductances originated from interconnects in power electronics becomes crucial with the next generation of SiC devices. This paper shows that the existing layout of a railway inverter, operating with Si IGBTs already exhibits a dynamic current imbalance between paralleled modules. This will not allow using this geometry with SiC MOSFETs. A complete investigation of the electromagnetic origin of this issue has been performed. A generic circuit model has been proposed to establish a cabling rule to design a Gate Distribution Printed Circuit Board (PCB) in such a way that it compensates the power dissymmetry. An optimization strategy has been used to obtain a new geometry of this PCB, which has been validated with a time domain simulation.

Study on Recovery of Metals from Printed Circuit Board Using a Gas-Liquid Fluidized Bed

2014 ◽  
Vol 997 ◽  
pp. 638-641
Author(s):  
Yue Bin Han ◽  
Li De Li ◽  
Guang Ming Li ◽  
Wen Zhi He
Keyword(s):  
Fluidized Bed ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Particle Diameter ◽  
Air Separation ◽  
Circuit Board ◽  
Operation Condition ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
The Impact

Comminuting and enrichment are the key technology to recycle waste printed circuit boards (WPCBs), in this paper the mechanical separation of WPCBs, comminuting by bang comminute and enrichment by air-solid fluidized bed, was studied. Experiments were designed to examine the impact of the airflow velocity and particle diameter to the air separation process, in order to optimize the operation condition. The results illustrated that it is feasible and very effective to apply gas-solid fluidized bed to recycle WPCBs.

scholarly journals Investigation of Impacts on Printed Circuit Board Laminated Composites Caused by Surface Finish Application

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3203
Author(s):  
Denis Froš ◽  
Karel Dušek ◽  
Petr Veselý
Keyword(s):  
Bond Strength ◽  
Thermal Shock ◽  
Surface Finish ◽  
Printed Circuit Board ◽  
Thermomechanical Properties ◽  
Circuit Board ◽  
Printed Circuit ◽  
Surface Finishes ◽  
The Impact ◽  
Selection Of

The purpose of this study was to compare the strength of the bond between resin and glass cloth for various composites (laminates) and its dependence on utilized soldering pad surface finishes. Moreover, the impact of surface finish application on the thermomechanical properties of the composites was evaluated. Three different laminates with various thermal endurances were included in the study. Soldering pads were covered with OSP and HASL surface finishes. The strength of the cohesion of the resin upper layer was examined utilizing a newly established method designed for pulling tests. Experiments studying the bond strength were performed at a selection of laminate temperatures. Changes in thermomechanical behavior were observed by thermomechanical and dynamic mechanical analyses. The results confirmed the influence of the type of laminate and used surface finish on bond strength. In particular, permanent polymer degradation caused by thermal shock during HASL application was observed in the least thermally resistant laminate. A response to thermal shock was detected in thermomechanical properties of other laminates as well, but it does not seem to be permanent.

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