Printed Circuit Board Model Research Articles

A modeling method for thermal steady-state simulation of the four-layer printed circuit board.

Thermal simulation of a Printed Circuit Board (PCB) can help identify potential overheating risks in the circuit. The proposed modeling method combines analytical temperature solutions and numerical approximations. Only Fourier-series analytical solutions related to the prepreg-layer surfaces need to be calculated, rather than the entire structure. Heat transfer through the lateral sides of a PCB is approximately considered as part of the compensated heat flux of the insulating-layer surface boundaries. Heat diffusion within or between metal layers is numerically approximated using the finite volume method. The core layer is treated as "thermally-thick". Temperature-dependent boundary conditions are considered through iterations. A test solver was developed based on the method. The modeling accuracy was validated by comparison with COMSOL Multiphysics for a four-layer structure with a moderate degree of discretization. Additionally, a PCB for generating DC 3.3V was designed, tested, and modeled, with the modeling results confirmed by the thermal images. The electro-thermal analysis of the distribution of electric potential and Joule heating in traces and vias was integrated into the PCB model. The layout maps of the PCB were further adjusted to reduce Joule heating in the output circuit, and the improvement on reducing the IR drop and hotspot temperature was examined.

Uncertain process-based data integration and residual lifetime evaluation of PCB in airborne equipment with ADT and field data

Accurately evaluating the lifespan of the Printed Circuit Board (PCB) in airborne equipment is an essential issue for aircraft design and operation in the marine atmospheric environment. This paper presents a novel evaluation method by fusing Accelerated Degradation Testing (ADT) data, degradation data, and life data of small samples based on the uncertainty degradation process. An uncertain life model of PCB in airborne equipment is constructed by employing the uncertain distribution that considers the accelerated factor of multiple environmental conditions such as temperature, humidity, and salinity. In addition, a degradation process model of PCB in airborne equipment is constructed by employing the uncertain process of fusing ADT data and field data, in which the performance characteristics of dynamic cumulative change are included. Based on minimizing the pth sample moments, an integrated method for parameter estimation of the PCB in airborne equipment is proposed by fusing the multi-source data of life, degradation, and ADT. An engineering case illustrates the effectiveness and advantage of the proposed method.

Electromagnetic Modeling of PCB Based on Darwin's Model Combined With Degenerated Prism Whitney Elements

Due to the advancement in the development of semiconductors used in the power converters, the printed circuit boards (PCBs) require an in-depth study of their electromagnetic behavior. To characterize the behavior of the PCBs, the Darwin model is employed, which can take into account all the coupled effects, namely resistive, inductive, and capacitive effects, at the intermediate frequencies. Nevertheless, the study of particular structures having a geometric dimension smaller than the others can create meshing difficulties. The modeling of thin structures by the finite element method requires the optimization of the mesh. To circumvent this issue, the shell elements for both node and edge elements are applied in this work. Finally, to validate the proposed approaches, two PCBs with different geometries are studied in both time and frequency domains, where the measurements for a single PCB are provided to compare with the numerical results.

Finite Element Modeling of Rigid-Flex PCBs for Dynamic Environments

ABSTRACTRigid-flex circuit boards are becoming more prevalent as the limits are pushed on the size, mass, and geometry of electronic systems. A key aspect of designing a rigid-flex printed circuit boards (PCB) system is an assessment of the dynamic properties of the PCB and predicting system performance under dynamic loading. Among current modeling methodologies for rigid-flex PCB, a simplified modeling methodology that adequately captures the system dynamics does not exist. This article presents a novel, computationally efficient approach for modeling rigid-flex PCB systems and the calibration of the material models via modal testing. The resulting simplified model is able to capture system frequencies, mode shapes, and representative force-displacement behavior. The proposed methodology is used to model NASA Jet Propulsion Laboratory’s Pop-Up Flat Folding Explorer Robot (PUFFER) and assess the sensitivity of a system model to input parameters.

Modeling flexible/curved PCBs using RBF mesh morphing

In the recent past, flexible printed circuit board (PCB) electronics have seen a significant surge in many electronics products ranging from smartphone/watches that wrap around our wrists, displays that fold out as large television sets, reconfigurable electronics that conform to the roofs/trunks of cars or as flexible implants that can monitor and treat diseases. Whatever the need is, it is quite evident that the near future is bound to see a significant uptick in day-to-day usage of such electronic products and hence as a direct result there is a need for numerical modeling, simulation and analysis of PCB’s that conform to different shapes. However, given the complexity of PCB’s, numerical modeling of such structures remains a challenge and there is a need for a clear and simple methodology to accomplish this. In addition, the developed methodology should also be applicable to both the trace mapping and trace modeling techniques typically used while working with Electronic-CAD files. In this work, the RBF (Radial Basis Function) method has been presented as a capable technology that can morph the flat mesh electronic data to a curved space which can be further used for analysis purposes. Since the morphing is being directly implemented at the mesh level, a lot of obstacles and complexity typically encountered while generating curved PCB CAD files can be avoided. The RBF Morph ACT Extension has been the tool of choice in the current context. This extension was built on the modular architecture of the ANSYS Workbench and is hence deeply integrated into Mechanical which makes it easy to work with. While RBF Morph offers a wide range of morphing capabilities, a 2-step morph process which relies on an auxiliary body and 2D coordinate filtering technique has been identified as most reliable technique of choice for most curved geometries. The morph technique developed has been successfully applied to a wide range of curved structures which include solid PCBs as well.

Compact Simulation of Chip-to-Chip Active Noise Coupling on a System PCB Board

A chip-to-chip active noise coupling demonstrator integrates two identical complementary metal oxide silicon (CMOS) chips on a printed circuit board (PCB), where each chip has the capability of power noise generation by CMOS shift resister array circuits (noise source; NS) and also power noise measurements by on-chip voltage monitoring circuits (OCM). For establishing the noise aware design strategy and methodology, a full-system level noise coupling simulation technique is evaluated on the demonstrator representing a multi-chip mixed-signal PCB. In an experimental scenario, an IC chip (Aggressor IC) operates the NS to generate power noise and the OCM measures the voltage fluctuation of the power delivery network (PDN) within the chip. On the other hand, another IC (Victim IC) holds the NS in no operation while uses the OCM to monitor its PDN voltage fluctuation caused by the conducted noise from the aggressor IC. For the verification of simulation accuracy, two chip power models (CPM), package wire models, discrete de-cap models and a single PCB model are combined into a chip-package-system (CPS) integrated model. The simulation was performed in about 2 hours for CPS integrated noise simulation including S-parameter extraction of the PCB. It is demonstrated that the full-system model with the two CPMs successfully simulates chip-to-chip active noise coupling, namely noise propagation from internal circuits of an aggressor chip to those on a victim chip. The chip-to-chip noise coupling simulation exhibited good agreements with measurements in case studies. The simulation methodology enables conductive noise aware design for multi-chip mixed-signal PCB in its design stage.

Component layout optimization design based on genetic algorithm

When working, electronic equipment is often subjected to a mechanical environment dominated by vibration. The printed circuit board (PCB) in the equipment is prone to deformation and transmits vibration to the components on the board. As the weakest link, the component corner position has a large acceleration, which is one of the important reasons for the failure of components and the entire electronic equipment. Based on the finite element modeling of PCB, the interaction between the finite element analysis software NASTRAN and the programming software MATLAB is realized, and the application of genetic algorithm in component layout optimization becomes possible. The optimization results show that the method adopted in this paper can effectively reduce the acceleration value at the component corner and optimize the mechanical environment when the electronic equipment works.

Finite element modeling technique for avionics PCB with electronic components in random vibration environment

Electronic components normally experience functional failure due to vibration loads. To envisage the episode of this failure, it is necessary to estimate the vibration response of electronic components mounted on the printed circuit board (PCB). As a continuation to the research work which commenced with PCB level that unravelled the modeling mysteries concerned with accurate modeling of PCBs and their appropriate boundary conditions, the present work addressed the modeling issues allied to PCB with various electronic components having distinguished mounting configurations and are brought to reality with the abetment of Finite Element Analysis (FEA) and experimentation. Modeling approaches used in practice to address modeling part with regard to electronic components limit their scope to the extent of modal analysis. Unfortunately, information about a modeling option which yields to accurate prediction of vibration experienced by the electronic components is not available. Hence, objective of the current research work is to identify accurate & appropriate modeling approach for electronic components with the aid of FEA and experimentation. Comparison of frequencies and vibration response results is made for different modeling methodologies, including their ability of fetching the results swiftly and consistently in assortment with different component mounting configurations.

Fault detection using thermal image based on soft computing methods: Comparative study

This paper presents Integrated Circuit (IC) fault detection of a Printed Circuit Board (PCB) model using thermal image processing. The thermal image is captured and processed from the PCB model by the finite element method (FEM). The histogram features are extracted from the ICs hotspots which are used as inputs in a classifier model. The effective features are minimized by the principal component analysis method. In this work, a comparative study for image classification and detection is performed based on three soft computing techniques: multilayer perceptron, support vector machine, and adaptive neuron-fuzzy inference system. The effectiveness of the models is evaluated by comparing the performance and accuracy of the classification. To validate the model, the experimental evaluation is performed on Arduino UNO in order to detect the fault condition on the real time operating PCB.

Parametric Design and Rapid Prototyping of Installation Box for Vehicle Terminal PCB

Installation box for vehicle terminal PCB (Printed Circuit Board) was took as research object, which is encountered in the process of project developing. Vehicle terminal PCB in actual development process was set as an example, point cloud data were acquired by three coordinate measuring method; Imageware software was used to reconstruct the vehicle terminal PCB model, basic size parameters of vehicle terminal PCB can be got and then design parameters of installation box for vehicle terminal PCB can be determined. Design of the installation box for vehicle terminal PCB was completed based on Solidworks software, then 3D modeling and 2D drawing of installation box for vehicle terminal PCB was gained. Up Plus 2 rapid prototype machine was used to manufacture installation box for vehicle terminal PCB rapidly based on 3D printing technology, then prototype of installation box for vehicle terminal PCB was obtained. It is of certain engineering significant for single (small amount) manufacturing of installation box for general PCB.

Anisotropic viscoelastic shell modeling technique of copper patterns/photoimageable solder resist composite for warpage simulation of multi-layer printed circuit boards

In this study, the warpage simulation of a multi-layer printed circuit board (PCB) was performed as a function of various copper (Cu) patterns/photoimageable solder resist (PSR) composite patterns and their anisotropic viscoelastic properties. The thermo-mechanical properties of Cu/PSR patterns were obtained from finite element analysis (virtual test) and homogenized with anisotropic composite shell models that considered the viscoelastic properties. The multi-layer PCB model was simplified based on the unit Cu/PSR patterns and the warpage simulation during the reflow process was performed by using ABAQUS combined with a user-defined subroutine. From these results, it was demonstrated that the proposed anisotropic viscoelastic composite shell simulation technique can be successfully used to predict warpage of multi-layer PCBs during the reflow process.

Modeling of Order Oriented Planning for Printed Circuit Board Assembly Line

Printed circuit board (PCB) assembly planning problem has been given lot of attention to efficiently manage the orders of different PCB products. However, little effort has been paid to describe its comprehensive model which can demonstrate all the planning problems collectively considering in the surface mount technology (SMT) lines. A mixed integer model for PCB assembly line which includes the integration of different levels of the planning problems and considered component allocation problem (line balancing), PCB model sequencing problem (mixed model sequencing problem), feeder arrangement problem and component placement sequencing problem on different SMT machines collectively. Current research is significant to solve different planning problems of the PCB assembly line simultaneously to get the overall global solution of the problem in future.

Thermal warpage analysis of PBGA mounted on PCB during reflow process by FEM and experimental measurement

Purpose – The purpose of this paper is to study the thermal warpage of a plastic ball grid array (PBGA) mounted on a printed circuit board (PCB) during the reflow process. Design/methodology/approach – A thermal-mechanical coupling method that used finite-element method software (ANSYS 13.1) was performed. Meanwhile, a shadow moiré apparatus (TherMoiré PS200) combined with a heating platform was used for the experimental measurement of the warpage of PBGA according to the JEDEC Standard. Findings – The authors found that the temperature profiles taken from the simulated results and experimental measurement are consistent with each other, only with a little and acceptable difference in the maximum temperatures. Furthermore, the maximum warpage measurements during the reflow process are 0.157 mm and 0.149 mm for simulation and experimental measurements, respectively, with a small 5.37 per cent difference. The experimental measurement and simulated results are well correlated. Based on the validated finite element model, two factors, namely, the thickness and dimension of PCB, are explored about their effect on the thermal warpage of PBGA mounted on PCB during the reflow process. Practical implications – The paper provides a thorough parametrical study of the thermal warpage of PBGA mounted on PCB during the reflow process. Originality/value – The findings in this paper illustrate methods of warpage study by combination of thermal-mechanical finite element simulation and experimental measurement, which can provide good guidelines of the PCB design in the perspective of thermal warpage during the reflow process.

Reliability Analysis and Accelerated Statistical Model of CNC PCB for Electrochemical Migration

The effect of conductor spacing and applied voltage on the insulation performance of printed circuit board (PCB) has been investigated under temperature-humidity-bias (THB) conditions in this paper. Based on the electrochemical migration failure mechanism, this paper proposes an accelerated statistical model, which includes a life-stress relationship model and a life distribution model. The accelerated statistical model can effectively quantify the effect of concurrent conductor spacing and applied voltage on the characteristic life of the PCB. Because THB test can produce less life data in limited test period, an accelerated degradation theory is applied for the modeling research. In addition, a methodology on how to verify the accelerated statistical model for the CNC PCB is introduced. In the case of small samples, the least square regression method is applied for parameter calculation due to its high precision. Furthermore, the residual analysis is carried out to check the fitting effect. The results show that the accelerated statistical model can describe the life characteristics of CNC PCBs preferably under the comprehensive action of conductor spacing stress and applied voltage stress.

Accuracy of simplified printed circuit board finite element models

Electronic components are prone to failure due to shock or vibration loads. To predict when this failure may occur it is necessary to calculate the vibration response of the printed circuit board (PCB); this is most usually achieved through use of simplified finite element (FE) models. The accuracy of these FE models will be mainly dependant on various sources of error, including: manufacturing variability, which will cause supposedly identical printed circuit boards to behave differently (including variability in materials and assembly, as well as dimensional tolerances); inaccuracy in the model input parameters, which is caused by either the modelling assumptions used or poor measurement technique; and errors in the solution process (e.g. linear solutions in non-linear situations). This paper investigates experimentally the contribution of these effects, this is achieved by first looking at measurement of input parameters and to what accuracy a PCB can reasonably be modelled, and then secondly measuring the extent of manufacturing and assembly induced variability. When these contributions have been defined, it will be possible to assess the confidence in any FE PCB model.

Modal analysis of board-level electronic package

The reliability of board-level electronic package subjected to drop impact is one of the most concerned issues. After drop impact, the Printed Circuit Board (PCB) experiences free vibration which leads to the deformation of PCB, hence the failure of solder joints. The free vibration is dependent on the inherent parameters of PCB. So it is necessary to study the inherent parameters of board-level package. Modal analysis is a common way to characterize the inherent dynamic parameters of a system. By modal analysis, we can understand the inherent vibration features of board-level package system. In this paper, the theoretical vibration model of the JEDEC standard PCB assembled with three Chip Size Packages (CSPs) is performed. Then the results of theoretical analysis are validated by that of finite element analysis (FEA) and modal test. A series of modal parameters are obtained during the modal analysis such as the mode shapes, the natural frequencies and the damping ratios. These parameters are useful for studying the dynamic response of PCB and the strain rate of solder joints during drop test. The Modal Assurance Criterion (MAC) value is used to validate the correlation between two modal shapes obtained from two different modal parameters estimation methods during modal analysis. The MAC value is computed for the first two order mode shapes, indicating the high correlation between the experimental and predicted (including theoretical and FE results) mode shapes.

Using both linear and non‐linear dimensional analysis, correction and prediction to improve PCB yields

PurposeTo present an update and the latest results from work on a project aimed at enabling printed circuit board (PCB) manufacturing to reduce the effect upon production yields by material distortions during the manufacturing process.Design/methodology/approachMeasurement data was collated from inspection steps within the PCB manufacturing process and analysed to provide data describing the distortions of materials used. The data was used to generate a self‐learning model which can be used to predict material movement prior to manufacture.FindingsThe data collated enabled CAM engineers at the design introduction stage to model the PCB build and simulate the material movement that will take place during the manufacturing processes. With this knowledge, the correct compensations to counter the material movement can be applied to the production tooling, eliminating the need to run manufacturing test batches.Research limitations/implicationsThe technology has been used to ensure inner‐layer designs with nominal dimensions after the lamination stage. Further, development work should be undertaken to collate measured data from other parts of the PCB manufacturing process and model the material movement around all registration critical processes.Originality/valueThe paper details how data collated by production processes can be utilised to train mathematical models and provide modified‐tooling information to increase yields in the manufacturing process.

Application of eddy-current testing technique for high-density double-Layer printed circuit board inspection

High-density double-layer printed circuit board (PCB) inspection based on the eddy-current testing (ECT) technique is proposed in this paper. The ECT probe, which consisted of a planar meander exciting coil and spin-valve giant magnetoresistance (SV-GMR) sensor array, is used for this propose. Defects on both the top- and bottom-layer of the high-density double-layer PCB are examined by the ECT technique with scanning over either the top or bottom layer. The characteristics of the proposed ECT probe for high-density double-layer PCB inspection are studied. The inspection results of the high-density double-layer PCB model verify that applying the ECT technique enables identification of the defects of both the top and bottom layer with one-side scanning.

Modeling and simulation for a drop-impact analysis of multi-layered printed circuit boards

Multi-layered printed circuit boards (PCBs) contain a multi-layered structure that is suitable for high-speed and high-frequency applications. Hence, they are used extensively in electronic packaging assemblies for high-density applications. However, numerous composite parts and complex material properties of multi-layer PCBs complicate the reliability simulation of PCB model. This paper deals with a finite element analysis intended to describe numerically the behavior of multi-layered multi-materials PCB model (combination of metallic and composite plies) in the drop-impact performance. Through the comparison of physical drop test results, the fully multi-layered model illustrates higher accuracy if compared with that of the traditional simplified isotropic model and orthotropic model. The effects of material properties for the multi-layer PCB under drop-impact shock have also been investigated.

1305 熱異方性を考慮したプリント基板の熱解析

This paper describes the thermal analysis of Printed Circuit Board (PCB). Because the modeling of PCB has hitherto been very poor, the thermal simulation results cannot satisfy the required accuracy. To solve this problem, we divide into each layer that constitutes the PCB, and considers that each layer is a homogeneous material. And the thermal conductivity of every layer is computed with reference to the wiring area ratio. However, by this method, the anisotropic thermal conductivity of PCB cannot be modeled. Then we divide the PCB into a set of blocks and computed each thermal conductivity in consideration of the wiring area ratio and the wiring direction with reference to the wiring diagram, and created the analysis model reflecting the anisotropic thermal conductivity of PCB.