bluuebunny/crossref_metadata_2025_split huggingface dataset:
Embedded Power Modules – A new approach using Power Core and High Power PCB
Authors: Boettcher Lars , Boettcher Lars , Karaszkiewicz S. , Manessis D. , Ostmann A. 
Published: October 2015

Power electronics packaging applications has strong demands regarding reliability and cost. The fields of developments reach from low power converter modules, over single or multichip MOSFET or IGBT packages, up to high power applications, like needed e.g. for solar inverters and automotive applications. This paper will give an overview about these applications and a description of each ones demand.
The spectrum of conventional power electronics packaging reaches from SMD packages for power chips to large power modules. In most of these packages the power semiconductors are connected by bond wires, resulting in large resistances and parasitic inductance. Additionally bond wires result in a high stray inductance which limits the switching frequency.
The embedding of chips using Printed Circuit Board (PCB) technology offers a solution for many of the problems in power packaging. This paper will show today's available power packages and power modules, realized in industrial production as well as in European research projects. All technologies which are used are based on PCB materials and processes. Chips are mounted to Cu foils, lead frames, high power PCBs or even ceramic substrates, embedded by vacuum lamination of laminate sheets and electrically connected by laser drilling and Cu plating.
A new approach for embedded power modules will be presented in detail. In this project, different application fields are covered, ranging from 50 W over 500 W to 50kW power modules for different applications like single chip packages, over power control units for pedelec (Pedal Electric Cycle), to inverter modules for automotive applications. This approach will focus on a power core base structure for the embedded semiconductor, which is then connected to a high power PCB. The connection to the embedded die is realized by direct copper connection only. The technology principle will be described in detail. Frist manufactured demonstrators will be presented. The presented new approach for the realization of a power core structure offers new possibilities for the module manufacturing, avoiding soldering or Ag sintering of the power semiconductors and the handling of thick copper substrates during the embedding process.
Advancements in Through Glass Via (TGV) Technology
Authors: Shorey Aric , Lu Rachel , Pollard Scott , Kuksenkova Ekatarina , Smith Gene 
Published: October 2015

Glass provides many opportunities for advanced packaging. The material properties give many opportunities. As an insulator, glass provides advantages in providing low electrical loss, particularly at high frequencies. The relatively high stiffness and ability to adjust coefficient of thermal expansion gives advantages to manage warp in glass core substrates and bonded stacks.
Forming processes allow the potential to both form in panel format as well as to form at thicknesses as low as 100 um, giving opportunities to provide cost-effective solutions for the industry. Via fabrication technology development continues to advance providing via diameters &lt; 20 um in size in production ready environment. [1–5]
As the industry adopts glass solutions, significant advancements have been made in downstream processes such as glass handling and via/surface metallization. We will provide an update on advancements in these areas as well as handling techniques to achieve desired process flows. There also continues to be increasing amounts of data showing the ability to achieve electrical and thermo-mechanical reliability of substrates with TGV and latest data here will also be provided.
A Random Stimulation Source for Evaluating MEMS Devices using an Exact Solvable Chaotic Oscillator
Authors: Beal Aubrey N. , Dean Robert N. 
Published: October 2015

MEMS devices are nearly ubiquitous, with applications ranging from automobiles to toys, medical equipment to missiles, and cell phones to industrial equipment. At the microscale, fabrication tolerances are significantly less precise than at the scale of traditional machining techniques. This can result in significant differences in the operating characteristics between otherwise identical MEMS devices. A wide bandwidth random excitation source is ideal for evaluating these components, whether used as the forcing function for an electromechanical shaker employed to measure transmissibility, or as a voltage source to evaluate actuator structure resonances and instabilities.
An electronic chaotic oscillator provides an ideal wide bandwidth voltage source which is provably random from first principles and may be simply integrated for the aforementioned MEMS testing. This type of system is easily integrated through standard Si MEMS processes and readily lends itself to application as a built-in-self test (BIST) component. These systems guarantee uniform frequency content from D.C. up to 100kHz due to their characteristically random behavior and serve as a strong candidate for providing uniform spectral density to a device under test.
The proposed system is a simple, electronic circuit that creates a random, wideband excitation voltage for observing characteristics of MEMS devices. This functionality is achieved by the analog, digital or mixed signal computation of nonlinear differential equations that describe various exactly solvable chaotic systems. By creating Si microsystems which perform these computations, these test sources may be readily fabricated as integrated BIST components for MEMS devices or fabricated separately and integrated by flip chip assembly techniques. Furthermore, by considering the iterated map of this particular category of stimulation source, a direct and easy measurement of the stimulation entropy may be monitored and corrected.
This work begins as a theoretical treatment involving the Nonlinear Dynamics of these types of systems including chaotic systems which permit closed form solutions. These systems are described classically through nonlinear differential equations and intuitively through iterated maps. These techniques reveal inherent methods for entropy measurement in these sources which may be implemented and controlled easily using electronic circuits. Subsequently, the simulation, circuit design methodology, circuit simulation, fabrication, testing and hardware verification of these wideband chaotic sources is presented. The development of this work delineates simple, wideband electronic testing circuits which may be fully integrated with MEMS devices using standard Si MEMS processes. The resulting microsystem may be used as the forcing function when measuring transmissibility of MEMS devices, or as a BIST element to evaluate MEMS microstructure characteristics through direct microelectronic fabrication or flip chip integration.
Design and Fabrication of LTCC Catalyst Chambers.
Authors: Towner Tyler W. , Plumlee Donald G. 
Published: October 2015

The reduction in satellite size and mass presents the need to develop a proportionally smaller propulsion system for orbital station keeping. A liquid, monopropellant micropropulsion device made from Low Temperature Co-Fired Ceramics (LTCC) has been developed at Boise State University. This robust, simple design uses an embedded silver catalyst chamber to decompose a rocket-grade hydrogen peroxide monopropellant into a hot gas, which is then expelled out through a nozzle to generate thrust. Using LTCC eliminates the planar geometry fabrication constraint commonly found in silicon MEMS processing.
This report presents the design and fabrication, and optimization of the hydrogen peroxide catalyst chamber used in these monopropellant microthrusters. Using the standard fabrication process for LTCC an initial prototype was developed. The design of this initial device was developed to measure the efficiency of the catalyst chamber by evaluating the ability of the device to decompose hydrogen peroxide. Catastrophic cracking within the device substrate was observed during initial testing. In order to obtain sufficient data, it was assumed that the cracking was due to thermal expansion and so a new functional design was implemented that decreased the overall cross sectional area of the device and decreased failure rates. To ensure that this assumption is correct, an investigation of device failure will be presented using an embedded resistor to simulate the catalytic reaction occurring inside the substrate. The results from this investigation will be documented. Additionally, optical microscope images will be used to document the failure investigation process. Several conclusions will be presented to improve the ability to use LTCC for high temperature applications.
An Assembly-Based Structural Model for LTCC Package Design and Reliability
Authors: Young Nathan , Massad Jordan , Ewsuk Kevin 
Published: October 2015

Packaging a high power radio frequency integrated circuit (RFIC) in low temperature cofired ceramic (LTCC) presents many challenges. Within the constraints of LTCC fabrication, the design must provide the usual electrical isolation and interconnections required to package the IC, with additional consideration given to RF isolation and the structural integrity issues. While iterative design and prototyping is an option for RFIC packaging development, it is a tedious and expensive process that would most likely be unsuccessful due to the complexity of the problem. To facilitate package design and optimization, thermo-mechanical assembly simulations were used to identify and manage the critical process parameters to control solder failures in the LTCC package assembly. The modeling results were confirmed through comparisons to prototype testing. This paper summarizes an assembly-based modeling approach to RFIC package design and solder failure analysis, and presents some results and key findings to date.
Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000
An Investigation of the Process Stability of RF SiP Made of DuPont 943 and 9K7
Authors: Bartnitzek Thomas , Purtova Tatyana , Rusch Christian , Kaminski Slawomir , Feger Till 
Published: October 2015

RF packaging is one of the most challenging topics in LTCC technology. Today LTCC is particularly capable for advanced packages and systems-in-package because of its electrical, functional, thermomechanical properties as well as its excellent long-term stability and reliability. LTCC combines the potential for miniaturization, low loss handling of high frequencies up to 110 GHz and offers the opportunity to integrate additional features. Therefore it has to go through various manufacturing steps and several refirings without any performance degradation or loss of dimensional accuracy.
This paper discusses the impact of thermal post processing on RF characteristics and geometrical properties of LTCC. Ceramic substrates with radar front ends, calibration structures and other test vehicles made of Du Pont Green Tape® 943 and 9k7 were cofired following the recommended conditions and refired several times in order to investigate and compare the influence of the postfiring. The flatness, dimensions and RF performance of the ceramics up to 110 GHz were evaluated and compared.
Continuous Manufacture of Submicron Thick Ceramic Green Tapes and Coatings Demonstrated for TCO Nano Particles
Authors: Straue Nadja , Roosen Andreas 
Published: October 2015

This presentation introduces a new technique to manufacture continuously submicron thick ceramic green tapes and coatings from nano particulate suspensions. A profiled steel rod is used to coat large areas with a very low film thickness of down to 250 nm. This technique can easily be scaled up and is therefore suitable for mass production at high throughput and low cost. The profile rod technique could be a method to overcome the limit of the tape casting process and therefore this technique exhibits an enormous economical potential.
The technique is demonstrated at the example of nano particulate indium tin oxide (ITO) and zinc oxide (ZnO) particles, which are both transparent conductive oxides (TCOs) and therefore interesting materials for printed displays etc. Nano particles from Evonik Degussa GmbH were first dispersed and stabilized in organic solvents. Subsequently, dispersions as well as slurries were prepared. Their rheological and wetting behavior were studied and the effect on the microstructure of the resulting layer was evaluated. Furthermore, the influence of the processing parameters during coating on the layer quality was analyzed. Finally, the functionality of the printed layers was proven by electrical measurements as well as the assembly of electron devices.
Study of self-actuated screen-printed PZT-cantilevers
Authors: LAKHMI Riadh , CASTILLE Christophe , DEBEDA Hélène , MAGLIONE Mario , LUCAT Claude 
Published: October 2015

Usually, resonating cantilevers come from silicon technology and are generally activated with pure bending mode. In this work, we suggest to combine high sensitive cantilever structure with full self-actuated piezoelectric thick-film for high electrical-mechanical coupling. This cantilever is realized through the screen-printing deposition associated with a sacrificial layer. The beam part of the cantilever is composed of a PZT layer between two gold electrodes.
Optimum performances of ferroelectric ceramics strongly rely on their composition and microstructure which imply generally the use of mechanical pressure and very high sintering temperature. These conditions are not compatible with the screen-printing process. As already shown with ceramics, addition of eutectic composition Li2CO3-CuO-Bi2O3 or borosilicate glass-frit to PZT powder and application of isostatic pressure, the sintering temperature of cantilevers may be decreased. Screen-printed piezoelectric samples are thus fired at 850°C, 900°C and 950°C. SEM analyses show the densification of the microstructure while increasing the sintering temperature. Electrical and mechanical characterizations are then achieved after poling the self-actuated cantilevers of different dimensions. In addition to the bending mode observed with a vibrometer, we pointed out other resonances related to the piezoelectric properties of the PZT cantilevers. Indeed, the three first orders of “in-plane” 31-longitudinal vibration mode and the first order “out-of-plane” 33-thickness resonance mode are revealed. The resonance frequencies deduced from analytical modeling are linked to the cantilever dimensions and thus confirm the experimental results. The piezoelectric parameters of PZT cantilevers approach those of ceramics. Quality factors of 300 to 400 associated to the unusual 31-longitudinal mode make self-actuated screen-printed PZT cantilevers good candidates for detection in liquid and gaseous media.
Ceramic-Based Planar Heat Pipe (Plate) for Passive Electronics Cooling
Authors: Wilson M. , Anderson H. , Fellows J. , Lewinsohn C. 
Published: October 2015

Heat dissipation has become a major hurdle for the electronics industry, especially as higher performance integrated circuits are being developed for the power industry. Two of the primary hurdles in dissipating this heat are:The thermal contact resistance between the IC and the cooling device.The ability to effectively spread the heat, such that traditional cooling technologies can be effective.By selecting ceramic materials that are thermo-mechanically matched (CTE) to IC materials, the proposed heat plate can be directly bonded by typical solder or braze techniques to the back-side of the IC. This eliminates thermal resistances due to contact and thermal interface materials. Within these heat plates, a three dimensional network of gas channels and fluid wicks spread the high-flux heat loads from localized hot spots to the surrounding regions via phase change fluids and mass transport. Like traditional heat pipes, these heat plates operate at nearly uniform temperature due to the phase change. The internal networks provide for multidimensional heat and mass flow, increasing their dissipating capability.
By using matched ceramic materials, and the inclusion of a heat plate, these primary hurdles for heat dissipation can be mitigated. The performance of prototypical planar heat plates will be presented.
Z-, Y- and M-type Hexagonal Ferrites for High-Frequency Inductive Multilayer Devices
Authors: Töpfer J. , Bierlich S. , Barth S. , Pawlowski B. , Bechtold F. , M¨ller J. 
Published: October 2015

Hexagonal ferrites can be used as soft magnetic materials for multilayer inductors for high frequency applications up to 3 GHz. We report on the preparation, thermal stability and magnetic properties of Z-, Y- and M-type hexagonal ferrites.
Co2Z-type ferrite Ba3Co2Fe24O41 and iron excess Ba3Co2−yFe24+yO41 (0 ≤ y ≤ 0.8) were prepared by the mixed oxide route. Single phase Z-type ferrites were obtained after sintering at 1300°C. The permeability of a sample with y = 0.6 sintered at 1300°C is μ = 30 with a resonance frequency of 1 GHz. The addition of Bi2O3 as sintering aid shifts the maximum shrinkage down to 950°C and dense samples were sintered at 950°C; however, their permeability is only μ = 3…5. It is shown that Co2Z ferrites are not stable under LTCC conditions. Cu-substituted Z-type ferrites Ba3Co2-xCuxFe24O41 exhibit enhanced sintering ability, but sintering at 950°C also results in low permeability.
Y-type hexagonal ferrites Ba2Co2−x−yZnxCuyFe12O22 were prepared at 1100°C and a permeability of μ = 20 was found for x = 1.2 and y = 0.8. Samples with Bi2O3 addition were sintered at 950 and 900°C exhibiting a permeability of μ = 10. Similar values were measured for M-type ferrites BaFe12-2yCoyTiyO19 with y = 1.2 which were sintered at 900°C using additives. Co/Ti co-substitution is an essential prerequisite for tailoring the magneto-crystalline anisotropy. Co/Ti- substituted M-type materials are stable under LTCC conditions.
Ferrite multilayer devices were fabricated by screen printing coils onto ferrite tapes, stacking and lamination. Firing was performed between 1300°C and 900°C, i.e. at HTCC and LTCC conditions, respectively. The inductance behavior of the devices was evaluated and modeled. It is shown that hexagonal ferrites are suitable materials for the high-frequency multilayer inductors; however, Y- and M-type ferrites are preferred for LTCC-type inductors cofired at 900°C with Ag metallization.
Wide Frequency Characterization of Magnetic Properties of Commercial LTCC Ferrite Material
Authors: Blaž Nelu , Marić Andrea , Radosavljević Goran , Mitrović Nebojša , Atassi Ibrahim , Smetana Walter , Živanov Ljiljana 
Published: October 2015

Complex magnetic permeability and hysteresis characteristic are key parameters that determine properties of ferrite components. This paper offers effective, accurate and simple method for complex permeability determination of LTCC (Low Temperature Co-fired Ceramic) ferrite sample at wide frequency range (up to 1 GHz). Presented research can be found to be of importance in fields of ferrite components design and application, as well as RF and microwave engineering.
The characterization sample is a stack of LTCC tapes forming a toroidal shape structure. Commercially available ferrite tape ESL 40012 was used and standard LTCC processing applied for the sample fabrication. Permeability is determined in the frequency range from 10 kHz to 1 GHz and characterization procedure is divided in two segments - for low and high frequencies. Low frequency measurements (from 10 kHz to 1000 kHz) are performed using LCZ meter and discrete turns of wire, while a short coaxial sample holder and Vector Network Analyzer were used for the higher frequency range (from 1000 kHz to 1 GHz).
Hysteresis properties of this material are also determined. B-H hysteresis loops were measured with BROCKHAUS Tester MPG 100D system using the maximum excitation of 2 kA/m and frequencies of 50 Hz, 500 Hz and 1000 Hz. In addition, we presented another important factor in the practical design, the temperature variation of the permeability dispersion parameters.
Obtained results show good agreement with datasheet values given by the manufacturer at lower frequencies and are in good correlation with results extracted from developed dispersion model at higher frequencies.
Fine-Line Structuring of Microwave Components on LTCC Substrates
Authors: Stöpel D. , Drüe K.-H. , Humbla S. , Mache T. , Rebs A. , Reppe G. , Schulz A. , Vogt G. , Hein M. , Müller J. 
Published: October 2015

Low temperature co-fired ceramics (LTCC) are used in a wide range of RF and microwave applications. The ceramic multilayer technology provides a truly three-dimensional circuit technology, hermetical sealing, hybrid integration, and favorable microwave properties at moderate costs. In order to take full advantage of millimeter wave frequencies, resolutions of lines and spaces below the typical, screen printable 50 μm are desired.
This paper describes the technological development of a fine-line structuring process based on resinate thin films and electroplating on LTCC. A combination of thin-film technology and thick-film technology leads to a novel resinate technology. This new process replaces the commonly used expensive sputtered layers, usually required for thin-film structuring combined with standard LTCC technology.
The initial layer is replaced by a screen-printed metallo-organic paste (resinate paste). Resinate pastes consist of metallo-organic noble metal compounds (e.g. gold and silver), which are dissolved in organic suspensions. The film thickness after firing is typically below 1 μm. This layer can be used to define structures with high precision using photolithography and electroplating followed by an etching process. The etching processes investigated here showed promising resolutions of 25 μm for lines and spaces. But wet-chemical processes can be applied to sintered LTCC surfaces only. Buried fine structures may be achieved with tape-on-substrate (ToS) technology which allows for laminating and subsequent sintering of structured greensheets onto sintered ceramics.
The benefits of this technology for microwave applications are obvious, given an improved resolution and parameter spread, and an accordingly reduced variation of the resulting structures.