This paper is dealing with the field simulation problems of MEMS structures. Both thermal and electro-static fields are considered. Two simulation algorithms are investigated in details: the Fourier transformation method applied to multi-layer structures and the successive node reduction algorithm belonging to the family of FDM methods. Extensions of these methods are discussed, e.g. the application of the Fourier method to mixed lateral boundary conditions and methods for physical level/network model level co-simulation.
The paper presents an algorithm for the thermal simulation of MEMS problems for the cases when certain parts of the MEMS structure are given with their detailed structural description while others are given with the RC network compact models. The presented co-siumulation algorithm enables fast simulation in the frequency or in the time domain, and can be a very useful extension of any kind of field solvers. The thermal simulation of a hot-plate problem demonstrates the advantages and the simpli8city of the method.
Co-simulation of MEMS and their packages is indispensable if the thermal behavior of the MEMS device is critical. For the co-simulation we need a reduced order thermal model of the package in the form of either behavioral or network model form. The paper presents a method for the automated generation of dynamic thermal multi-port models of packages, based on simulation results. The method is general, in will be applicable also for the direct generation of package multi- port network models of thermal transient testers.
This paper is dealing with design, simulation and test of microsystems. Both existing tools and open research areas are addressed. All through the paper, similarities between the present development of MEMS and the development of microelectronics decades ago are pointed out, including the migration from point tools to Computer-Aided Design frameworks, testing, foundries/fabless business or IP issues. Specific aspects such as thermal simulation of microstructures and thermomechanical design at the package level. The conclusion is depicting a possible global simulation scheme integrating thermomechanical design at the package level. The conclusion is depicting a possible global simulation scheme integrating the needs of Systems on Chip multi language simulation together with the needs of MEMS multipurpose simulation.
This paper present a tool and a method for the generation of reduce order thermal models, in order to assure modeling the effect of the package on the thermal behavior of the packaged device. The method is generic, and can be based either on the simulated or on the measured thermal transient response of the real packages. It is based on the generation of the time constant density spectrum of the thermal response function, from which we automatically generate a reduced order thermal model in the form of an RC ladder network model. Beyond presenting the generic methodology experimental results are also presented, based both on the simulation and measurement of MEMS elements and packages.
This paper presents a new concept for the thermal transient measurement of IC packages. The TTMK thermal transient test kit described here consists of a test chip, a dedicated software running on a PC and a special cable connecting the PC to the IC package which encapsulates the test chip. The function of the thermal transient test equipment is realized partly by the test chip itself and partly by the measuring software. The software performs both the control of the measurements and the evaluation of the results. The output of the evaluation software may be a compact model network or the structure function describing the properties of the heat conduction path. The use of the TTMK kit and the capabilities of the evaluation software are presented in this paper.
In recent years great attention has been paid to the thermal issues in electronics design on system, board, package and chip level, including thermal and electro-thermal simulation of integrated circuits and MCM-s, or even integrated microsystems. In this paper we address some algorithmic issues regarding the method of simultaneous iteration. With the node reduction algorithm outlined here electro-thermal simulation of large problems becomes feasible. Besides this algorithmic innovation we provide a specification for a modular, platform independent electro-thermal simulator.
The recently reported 2D successive network reduction (SUNRED) algorithm has been extended to solve thermal or electro-static fields in 3D. The paper presented the models and the solution algorithm of the 3D version and discusses in details the efficiency of the new 3D-field solver. Comparisons with other solvers demonstrate the superior features of SUNRED. The tool extensively supports the compact thermal model generation of the analyzed structure. A novel type of analysis, the time constant analysis is introduced in the paper.
In this paper, we report on the recent advances in building an integrated environment for the design and simulation of microsystems based on commercially available CAD tools. The environment allows a continuous design flow from front-end to back-end for both monolithic and hybrid microsystems. Based on the FEM simulation results in a pre-design phase, simulation models of available standard components are developed in a system level and coupled to layout generators. A multi-level, mixed-mode, multi-technology simulation is ensured and a schematic driven layout is generated. Tools for anisotropic etching simulation are integrated in order to predict the etching procedure of full-custom microstructures.
Besides foundry facilities, Computer-Aided Design (CAD) tools are also required to move microsystems from research prototypes to an industrial market. This paper describes a Computer-Aided-Design Framework for microsystems, based on selected existing software packages adapted and extended for microsystem technology, assembled with libraries where models are available in the form of standard cells described at different levels (symbolic, system/behavioral, layout). In microelectronics, CAD has already attained a highly sophisticated and professional level, where complete fabrication sequences are simulated and the device and system operation is completely tested before manufacturing. In comparison, the art of microsystem design and modelling is still in its infancy. However, at least for the numerical simulation of the operation of single microsystem components, such as mechanical resonators, thermo-elements, elastic diaphragms, reliable simulation tools are available. For the different engineering disciplines (like electronics, mechanics, optics, etc) a lot of CAD-tools for the design, simulation and verification of specific devices are available, but there is no CAD-environment within which we could perform a (micro-)system simulation due to the different nature of the devices. In general there are two different approaches to overcome this limitation: the first possibility would be to develop a new framework tailored for microsystem-engineering. The second approach, much more realistic, would be to use the existing CAD-tools which contain the most promising features, and to extend these tools so that they can be used for the simulation and verification of microsystems and of the devices involved. These tools are assembled with libraries in a microsystem design environment allowing a continuous design flow. The approach is driven by the wish to make microsystems accessible to a large community of people, including SMEs and non-specialized academic institutions.
Integrated microsystems raise new problems in thermal simulation. The frequently used structures such as cantilevers, membranes have quite different heat transfer properties than the simple silicon cubes of conventional ICs. Furthermore numerous functions are realized on these structures based on thermal principle. Quick and correct thermal simulation of these structures is needed during the design process. The paper presents the (mu) S-THERMANAL thermal simulation tool which is capable to simulate cantilever, bridge etc. microsystem structures both in steady-state and in the frequency-domain case. The algorithms of the program, based on the Fourier method, are detailed in the paper and numerous examples illustrate the capabilities of the tool.
Besides foundry facilities, CAD-tools are also required to move microsystems from research prototypes to an industrial market. CAD tools of microelectronics have been developed for more than 20 years, both in the field of circuit design tools and in the area of TCAD tools. Usually a microelectronics engineer is involved only in one side of the design: either he deals with application design or he participates in the manufacturing design, but not in both. This is one point that is to be followed in case of microsystem design, if higher level of design productivity is expected. Another point is that certain standards should also be established in case of microsystem design too: based on selected technologies a set of standard components should be predesigned and collected in a standard component library. This component library should be available from within microsystem design frameworks which might well be established by a proper configuration and extension of existing IC design frameworks. A very important point is the development of proper simulation models of microsystem components that are based on e.g. the FEM results of the predesign phase and are provided in the form of an analog VHDL script. After detailing the above mentioned considerations we discuss the development work concerning a microsystem design framework. Its goal is to provide a set of powerful tools for microsystem application designers. This future framework will be composed of different industry-standard CAD programs and different design databases which in certain cases are completed with special interfaces and special purpose simulation tools.