Inkjet Printing of Fine-Line Thick-Film Inductors

2010 ◽  
Vol 7 (4) ◽  
pp. 205-213
Author(s):  
Marcel Wassmer ◽  
Waldemar Diel ◽  
Klaus Krueger
Keyword(s):  
Thick Film ◽  
Inkjet Printing ◽  
Digital Fabrication ◽  
Production Method ◽  
Passive Components ◽  
Construction Methods ◽  
Ferrite Particle ◽  
Main Challenge ◽  
The Stability ◽  
New Applications

Inkjet printing is the emerging technology for the deposition of a variety of particles. The reliable printing of nano-silver inks shows the possibilities of digital fabrication of microelectronic circuits and raises the question for further use with other particles. To compete with common thick-film screen printing as a production method it is consequential and necessary to investigate the inkjet printing of all passive electronic thick-film components. Inductors are frequently required in electronic circuits, yet they represent a main challenge for thick-film printing. With the development of new materials, which are suitable for low-temperature cofired ceramic processes, the integration of passive components promises new applications. In a first step, different ferrite particle compositions are dispersed to stabilized inks that can be used with a commercial inkjet print head. The stability of the ink is fundamental for reliable drop formation. In addition, the viscosity must fit to the print heads' operational ranges and the magnetic properties must be taken into account. In a second step, the effect of substrate coating and drop volume variation toward the shape of the printed structures are defined and shown. The fundamental construction methods of inkjet-printed inductors on fired ceramic are investigated. First, silver coils are printed without ferrite to optimize the printing pattern. Subsequently, coils are embedded in inkjet printed ferrite layers. Depending on the geometrical layout, several drying and firing steps are necessary, leading to a more complex production process and influencing the electrical properties. Finally, it is shown that inkjet printing is very effective for built-up of multilayer thick-film inductors, and the high accuracy of the printing process promises accurate electrical values.

Inkjet Printing of Thick-Film Resistors

2010 ◽  
Vol 2010 (1) ◽  
pp. 000771-000778
Author(s):  
Marcel Wassmer ◽  
Waldemar Diel ◽  
Klaus Krueger
Keyword(s):  
Thick Film ◽  
Inkjet Printing ◽  
Digital Fabrication ◽  
Production Method ◽  
Circuit Board ◽  
Passive Components ◽  
Long Term Stability ◽  
Efficient Alternative ◽  
New Applications

The integration of passive components directly into circuit board is an efficient alternative to surface mounted devices. Inkjet printing is the emerging technology for the deposition of a variety of particles and therefore for digital fabrication of microelectronic circuits. Resistors are one of the most frequently required passive components in electronic circuits. In LTCC-technology the integration and additionally the embedding of resistors promises new applications. Integrated resistors are usually screen printed. Inkjet printing has several advantages to compete seriously with screen printing as production method. This study investigates the possibilities and reliability of inkjet printing of thick-film resistors. In a first step, different resistive compositions are characterised towards compatibility with a commercial inkjet print head. The reliability and long term stability in drop formation are fundamental for production process. Further on, the interaction between ink and substrate has to be taken into account to reach the desired morphology. In a second step, the advantages of using inkjet for printing resistors are shown. A measure of ink amount is introduced for exact dosing of the ink. Afterwards, compositions with a wide resistivity range are printed with different print heads. The printed resistors are further passed alternatively through a post-fire or through a co-fire process. The effect of variations in particle composition and ink amount are characterized towards the change in electrical behaviour. Further, the influences of printing conditions on morphology and resistivity are discussed.

Inkjet Printing as Technology for In-Situ Blending of Thick-Film Resistor Inks

2012 ◽  
Vol 2012 (CICMT) ◽  
pp. 000142-000151
Author(s):  
Marcel Waßmer ◽  
Waldemar Diel ◽  
Klaus Krüger
Keyword(s):  
Thick Film ◽  
Inkjet Printing ◽  
Production Method ◽  
Circuit Boards ◽  
Passive Components ◽  
Long Term Stability ◽  
Efficient Alternative ◽  
Thickness Variations ◽  
New Applications

The integration of passive components directly into circuit boards is an efficient alternative to surface mounted devices. Digital printing methods are more and more emerging technologies for the fabrication of microelectronic circuits. Inkjet printing is a technology for the deposition of a variety of particles with the unique selling proposition of in-situ ink blending. Resistors are one of the most frequently required passive components in electronic circuits. In LTCC technology the integration and additionally the embedding of resistors promises new applications. Integrated resistors are usually screen printed. Inkjet printing has several advantages to compete seriously with screen printing as production method. This study investigates the opportunities of in-situ blending in inkjet printing of thick-film resistors. In a first step, the different options of ink blending are analyzed theoretically. In order to have a basis for further calculations five compositions with a wide resistivity range are printed purely. Afterwards the printed resistors are passed through a post-fire process and the electrical properties are recorded. Reliability and long term stability in drop formation are fundamental for production process. In a second step, the different options of ink blending are analyzed. The five compositions are blended to four combinations of neighbouring inks and are printed and blended with two inkjet printheads. The effect of blending is characterized towards the change in electrical behaviour and the different blending techniques are compared. Additionally, the opportunity of layer thickness variations is investigated and its influence is analyzed. Further, the influences of printing conditions on morphology and resistivity are discussed.

In-Situ Blending of Inkjet-Printed Thick-Film Resistors

2013 ◽  
Vol 2013 (CICMT) ◽  
pp. 000211-000220 ◽  
Author(s):  
Dietrich Jeschke ◽  
Mathias Niemann ◽  
Klaus Krüger
Keyword(s):  
Linear Model ◽  
Thick Film ◽  
Circuit Design ◽  
Inkjet Printing ◽  
Passive Components ◽  
Electric Behavior ◽  
Printing System

Thick-film resistors are widely used passive components. Considering circuit design and layout, decoupling the resistance from geometry is desirable. Inkjet printing offers an approach to reach this aim by allowing for in-process blending of resistor inks. To model the electric behavior of printed resistors, a conductance based linear model is derived, that is both, physically plausible and mathematically convenient. Generally the model is based on resistor layers connected in parallel. To allow for fine graduation the parallel layers are not just realized with different decadic inks but with a discrete number of ink mixtures (“virtual inks”) which are generated in-situ during printing. Both, the conductance model and the in-process ink blending are proven by real inkjet-printed resistors. For manufacturing these resistors, the used inkjet printing system was improved.

scholarly journals Iterative stability analysis for general polynomial control systems

2021 ◽  
Author(s):  
Bo Xiao ◽  
Hak-Keung Lam ◽  
Zhixiong Zhong
Keyword(s):  
Stability Analysis ◽  
Lyapunov Function ◽  
Control Systems ◽  
Polynomial System ◽  
Stability Conditions ◽  
General Polynomial ◽  
Main Challenge ◽  
Detailed Simulation ◽  
Feasible Solutions ◽  
The Stability

AbstractThe main challenge of the stability analysis for general polynomial control systems is that non-convex terms exist in the stability conditions, which hinders solving the stability conditions numerically. Most approaches in the literature impose constraints on the Lyapunov function candidates or the non-convex related terms to circumvent this problem. Motivated by this difficulty, in this paper, we confront the non-convex problem directly and present an iterative stability analysis to address the long-standing problem in general polynomial control systems. Different from the existing methods, no constraints are imposed on the polynomial Lyapunov function candidates. Therefore, the limitations on the Lyapunov function candidate and non-convex terms are eliminated from the proposed analysis, which makes the proposed method more general than the state-of-the-art. In the proposed approach, the stability for the general polynomial model is analyzed and the original non-convex stability conditions are developed. To solve the non-convex stability conditions through the sum-of-squares programming, the iterative stability analysis is presented. The feasible solutions are verified by the original non-convex stability conditions to guarantee the asymptotic stability of the general polynomial system. The detailed simulation example is provided to verify the effectiveness of the proposed approach. The simulation results show that the proposed approach is more capable to find feasible solutions for the general polynomial control systems when compared with the existing ones.

scholarly journals Nanomaterials and nanotechnology for the delivery of agrochemicals: strategies towards sustainable agriculture

2022 ◽  
Vol 20 (1) ◽  
Author(s):  
Changcheng An ◽  
Changjiao Sun ◽  
Ningjun Li ◽  
Bingna Huang ◽  
Jiajun Jiang ◽  
...  
Keyword(s):  
Particle Size ◽  
Food Security ◽  
Chemical Composition ◽  
Labor Cost ◽  
Small Particle Size ◽  
Agricultural Systems ◽  
The Stability ◽  
New Applications ◽  
Chemical Pesticides ◽  
Improve Food Security

AbstractNanomaterials (NMs) have received considerable attention in the field of agrochemicals due to their special properties, such as small particle size, surface structure, solubility and chemical composition. The application of NMs and nanotechnology in agrochemicals dramatically overcomes the defects of conventional agrochemicals, including low bioavailability, easy photolysis, and organic solvent pollution, etc. In this review, we describe advances in the application of NMs in chemical pesticides and fertilizers, which are the two earliest and most researched areas of NMs in agrochemicals. Besides, this article concerns with the new applications of NMs in other agrochemicals, such as bio-pesticides, nucleic acid pesticides, plant growth regulators (PGRs), and pheromone. We also discuss challenges and the industrialization trend of NMs in the field of agrochemicals. Constructing nano-agrochemical delivery system via NMs and nanotechnology facilitates the improvement of the stability and dispersion of active ingredients, promotes the precise delivery of agrochemicals, reduces residual pollution and decreases labor cost in different application scenarios, which is potential to maintain the sustainability of agricultural systems and improve food security by increasing the efficacy of agricultural inputs. Graphical Abstract

scholarly journals Adaptive Strategies for Mud Shell Robotic Fabrication

2018 ◽  
Vol 3 (2) ◽  
pp. 64
Author(s):  
Chaltiel Stephanie ◽  
Bravo Maite ◽  
Ibrahim Abdullah
Keyword(s):  
Spray Deposition ◽  
Sustainable Use ◽  
Adaptive Strategies ◽  
Computational Design ◽  
Digital Fabrication ◽  
Construction Methods ◽  
Robotic Fabrication ◽  
Material Deposition ◽  
Physical Tests ◽  
Full Scale Tests

The digital fabrication of monolithic shell structures is presenting some challenges related to the interface between computational design, materialist, and fabrication techniques. This research proposes a singular method for the sequential robotic spray deposition in layers of diverse clay mixes over a temporary fabric form-work pulled in between peripheral and cross section arches. This process relies mainly on the continuity of the construction phases for stability and durability but has encountered some challenges in physical tests related to sagging, displacement, and deformations during the robotic deposition of the material. Adaptive strategies during the digital fabrication stages are proposed for a sequential exploration of the geometry, structural analysis, and construction techniques. Alternative adjustments of protocols for the robotic material deposition include both predictable and unsuspected behaviors preventing the structure to reach non-viable geometric thresholds. Two case studies of physical tests describe, analyze, and simulate some of these strategies and identify specific parameters inquiring the sequential adjustments of the robotic material deposition. These strategies will drive future full-scale tests within a sustainable use of materials and adaptive construction methods, seeking an optimized structural performance that could open a new chapter for the digital fabrication of earthen shells.

scholarly journals Poly(catecholamine) Coating and Biofunctionalization of CsPbBr3 Microcrystals

2021 ◽  
Author(s):  
Sangyeon Cho ◽  
Seok-Hyun Yun
Keyword(s):  
Lipid Bilayers ◽  
Environmental Stability ◽  
Live Cells ◽  
Functional Coatings ◽  
Common Strategy ◽  
Novel Method ◽  
Halide Perovskites ◽  
The Stability ◽  
New Applications

<p>Lead halide perovskites (LHP) microcrystals are promising materials for various optoelectronic applications. Surface coating on particles is a common strategy to improve their functionality and environmental stability, but LHP is not amenable to most coating chemistries because of its intrinsic weakness against polar solvents. Here, we describe a novel method of synthesizing LHP microcrystals in a super-saturated polar solvent using sonochemistry and applying various functional coatings on individual microcrystals <i>in situ</i>. We synthesize cesium lead bromine perovskite (CsPbBr<sub>3</sub>) microparticles capped with organic poly-norepinephrine (pNE) layers. The catechol group of pNE coordinates to bromine-deficient lead atoms, forming a defect-passivating and diffusion-blocking shell. The pNE layer enhances the stability of CsPbBr<sub>3</sub> in water by 2,000-folds, enabling bright luminescence and lasing from single microcrystals in water. Furthermore, the pNE shell permits biofunctionalization with proteins, small molecules, and lipid bilayers. Luminescence from CsPbBr<sub>3</sub> microcrystals is sustained in water over 1 hour and observed in live cells. The functionalization method may enable new applications of LHP particles in water-rich environments.<b></b></p>

A Cloud Platform for Sharing Educational Digital Fabrication Resources Over the Internet

2020 ◽  
pp. 103-130
Author(s):  
Gianluca Cornetta ◽  
Abdellah Touhafi ◽  
Gabriel-Miro Muntean
Keyword(s):  
Resource Sharing ◽  
Business Processes ◽  
Learning Experience ◽  
Remote Sensing Data ◽  
Digital Fabrication ◽  
Remote Access ◽  
The Internet ◽  
Technology Enhanced Learning ◽  
Industry And Education ◽  
New Applications

Cloud and IoT technologies have the potential to enable a plethora of new applications that are not strictly limited to remote sensing, data collection, and data analysis. In such a context, the IoT paradigm can be seen as an empowering technology rather than a disruptive one since it has the capability to improve the standard business processes by fostering more efficient and sustainable implementations and by reducing the running costs. Cloud and IoT technologies can be applied in a broad range of contexts including entertainment, industry, and education, among others. This chapter presents part of the outputs of the NEWTON H2020 European project on technology-enhanced learning; more specifically, it introduces the concept of fabrication as a service in the context of educational digital fabrication laboratories. Fab Labs can leverage cloud and IoT technologies to enable resource sharing and provide remote access to distributed expensive fabrication resources over the internet. Both platform architecture and impact on learning experience of STEM subjects are presented in detail.

Thick Film Pastes for Power Applications

2013 ◽  
Vol 2013 (CICMT) ◽  
pp. 000155-000161
Author(s):  
Christina Modes ◽  
Melanie Bawohl ◽  
Jochen Langer ◽  
Jessica Reitz ◽  
Anja Eisert ◽  
...  
Keyword(s):  
Thick Film ◽  
Electric Vehicles ◽  
Hybrid Electric Vehicles ◽  
Thermal Dissipation ◽  
Automotive Applications ◽  
Electrical Systems ◽  
Electronic Circuitry ◽  
And Performance ◽  
New Applications ◽  
Thick Film Technology

Electronic circuits made by thick film technology are commonly used today in electronic circuitry for automotive applications. Densely packed multi-layer hybrid circuits are very well established for motor and transmission management in standard gasoline fuelled vehicles. As automotive technology shifts from mechanical systems to electrical systems and toward more electrically driven vehicles, such as hybrid electric vehicles and full electric vehicles, thick film systems need to be adapted to fit the challenges and needs of these new applications. The following is a description of a new set of thick film pastes, both precious and base metal, which have attributes and performance suitable for power electronics in automotive applications. The materials provide a means to use common thick film technology to build power circuits to meet the new needs, such as high current carrying capacity and thermal dissipation.

Reliability of Au-Ti for High Temperature Termination on Ferrite LTCC Inductors

2013 ◽  
Vol 2013 (HITEN) ◽  
pp. 000039-000045 ◽  
Author(s):  
James Galipeau ◽  
Matt Gerlach
Keyword(s):  
High Temperature ◽  
Thermal Shock ◽  
Thick Film ◽  
Thermal Ageing ◽  
Wire Bonding ◽  
Sputter Deposited ◽  
Commercial Applications ◽  
The Stability ◽  
Terminal Structure ◽  
Pull Tests

While ferrite Low Temperature Co-fired Ceramic (LTCC) inductor and transformer developments have undergone thermal shock and high temperature aging that focused on the stability of their electrical characteristics (resistance, inductance), little attention has been paid to their termination reliability at high temperatures. Testing has been done on AgPt and AgPd terminations with Ag5Cd95 and Pb88Sn10Ag2 solders for 2000 and 25 hrs, respectively. However, Ag5Cd95 is unusable in commercial applications due to ROHS restrictions while Pb88Sn10Ag2 is undesirable because of the high lead content. Sn96 solder and wire bonding are common attachment methods that have not been vetted. Initial investigations show that high Sn solders may interfere with bonding between the AgPt and AgPd termination materials and the ferrite bulk of the part. An alternative terminal structure for using Sn96 solder is created by electroplating Au and Ni; however, electroplating to ferrite is challenging due to the masking involved. Also, the preferred materials for wire bonding are thick film, thin film or electroplated Au. To this end an alternative termination structure using Au sputter deposited onto sputter deposited Ti is being investigated. This structure was chosen for its potential to be a lower cost alternative to thick film Au and for its potential for simpler manufacturing than electroplating. Tests involved measuring bond strength and resistance after thermal ageing and thermal shock. Baseline solder joint pull tests show strength comparable to other termination methods. Some issues with solder wetting of the terminals have been noted.

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