scholarly journals Fabrication, response and stability of miniature piezoresistive force-sensing thick-film cantilevers

2016 ◽  
Vol 2016 (CICMT) ◽  
pp. 000024-000031
Author(s):  
Thomas Maeder ◽  
Caroline Jacq ◽  
Stefane Caseiro ◽  
Peter Ryser
Keyword(s):  
Thick Film ◽  
Low Cost ◽  
Substrate Material ◽  
Force Sensing ◽  
Second Step ◽  
Ceramic Substrates ◽  
Plastic Deformations ◽  
Self Heating ◽  
Signal Drift ◽  
Micro Cracks

Abstract Miniature ceramic cantilevers have been successfully applied to the fabrication of simple and low-cost piezoresistive thick-film force-sensing cells, using different thick-film and LTCC (low-temperature co-fired ceramic) substrates. The availability of thin substrates for some materials allows much improved sensitivity compared to classical thick-film technology, with LTCC also featuring rather low substrate elastic modulus and fine structurability. However, practical applicability may be hindered by processing difficulties, such as printing and handling very thin fired substrates, or, in the case of co-fired tapes, warpage during firing. Also, signal drift is observed with some devices. In this work, we show that most of the previously-observed signal drift in some LTCC sensors is not due to self-heating, and therefore stems from defects such as micro-cracks within the ceramic cantilevers or plastic deformations in internal conductors. In a second step, we explore manufacturability of thick-film cantilevers on very thin substrates, and show that it is possible to print a single-sided design on substrates with thickness as low as 45 μm, although a lower limit of ~100 μm, depending on substrate material, is more practical.

Advanced DBC - Highly Reliable and Conductive Copper Ceramic Substrates

2016 ◽  
Vol 2016 (CICMT) ◽  
pp. 000073-000078
Author(s):  
Paul Gundel ◽  
Anton Miric ◽  
Kai Herbst ◽  
Melanie Bawohl ◽  
Jessica Reitz ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Cycling ◽  
Power Electronics ◽  
Thick Film ◽  
Low Cost ◽  
Automotive Applications ◽  
Ceramic Substrates ◽  
Hybrid Technologies

Abstract So far Direct Bonded Copper (DBC) substrates have been the standard for power electronics. They provide excellent electrical and thermal conductivity at low cost. Weaknesses of DBC technology are the inevitable warpage and the relatively low reliability under thermal cycling. The low reliability poses a significant hurdle in particular for automotive applications with high lifetime requirements. Thick Print Copper (TPC) substrates with low warpage and excellent reliability overcome these weaknesses, but also provide a reduced conductivity at a higher cost. We present two thick-film/DBC hybrid technologies which combine the best properties of DBC and TPC: excellent conductivity, low cost, reduced warpage and excellent reliability.

scholarly journals A Novel Electrically Small Ground-Penetrating Radar Patch Antenna with a Parasitic Ring for Respiration Detection

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 1930
Author(s):  
Di Shi ◽  
Taimur Aftab ◽  
Gunnar Gidion ◽  
Fatma Sayed ◽  
Leonhard M. Reindl
Keyword(s):  
Ground Penetrating Radar ◽  
Patch Antenna ◽  
Low Cost ◽  
Substrate Material ◽  
Geometric Parameters ◽  
Gas Explosions ◽  
Aerial Vehicle ◽  
Electromagnetic Characteristics ◽  
Ground Penetrating ◽  
Quick Search

An electrically small patch antenna with a low-cost high-permittivity ceramic substrate material for use in a ground-penetrating radar is proposed in this work. The antenna is based on a commercial ceramic 915 MHz patch antenna with a size of 25 × 25 × 4 mm3 and a weight of 12.9 g. The influences of the main geometric parameters on the antenna’s electromagnetic characteristics were comprehensively studied. Three bandwidth improvement techniques were sequentially applied to optimize the antenna: tuning the key geometric parameters, adding cuts on the edges, and adding parasitic radiators. The designed antenna operates at around 1.3 GHz and has more than 40 MHz continuous −3 dB bandwidth. In comparison to the original antenna, the −3 and −6 dB fractional bandwidth is improved by 1.8 times and 4 times, respectively. Two antennas of the proposed design together with a customized radar were installed on an unmanned aerial vehicle (UAV) for a quick search for survivors after earthquakes or gas explosions without exposing the rescue staff to the uncertain dangers of moving on the debris.

scholarly journals A novel biosensor based on Blu-ray disc coating film for determination of total amino acid content in tea leaves

RSC Advances ◽  
2021 ◽  
Vol 11 (63) ◽  
pp. 39666-39671
Author(s):  
Lanling Chu ◽  
Yunzheng Wang ◽  
Yu Zhou ◽  
Xuejun Kang
Keyword(s):  
Low Cost ◽  
High Surface ◽  
Amino Acid Content ◽  
Substrate Material ◽  
Total Amino Acid ◽  
Coating Film ◽  
The Novel ◽  
Total Amino Acid Content ◽  
High Surface Activity

The novel biosensor substrate material based on a simple BD coating film displayed preferable merits with high surface activity, low cost, easy making, easy using, and extensive application prospect.

Flipchip Bonding of Si Chip on Flexible PEN Foil using Novel Electronic 100 μm Pitch Fan-out Circuitry

2007 ◽  
Vol 1030 ◽  
Author(s):  
Jeroen van den Brand ◽  
Erik Veninga ◽  
Roel Kusters ◽  
Tomas Podprocky ◽  
Andreas Dietzel
Keyword(s):  
Thick Film ◽  
Low Cost ◽  
Cost Effective ◽  
High Density ◽  
Polyethylene Naphthalate ◽  
Electronic Circuitry ◽  
Effective Technology

AbstractA novel, cost effective technology to manufacture high density embedded electronic circuitry is demonstrated. The process consists of laser photoablation of the circuitry into a substrate through a mask and subsequent filling using a polymer thick film paste. Because the volume of the substrate is used it is possible to make thick and thereby highly conductive lines using low cost materials and processes. The process is demonstrated for a fan out circuitry in 100 µm thick polyethylene naphthalate (PEN). The fan out circuitry has linewidths of 50 µm and line spacings of 100 µm. The usability of the circuitry is demonstrated by the successful flipchip bonding of a thinned Si daisy chain dummy chip with 176 IO's.

Improving Performance of Laser-Printed Conductive Silver Lines

2012 ◽  
Vol 2012 (CICMT) ◽  
pp. 000377-000384
Author(s):  
Dustin Büttner ◽  
Klaus Krüger
Keyword(s):  
Thick Film ◽  
Screen Printing ◽  
Printed Electronics ◽  
Production Method ◽  
Silver Particles ◽  
Ceramic Substrates ◽  
High Speeds ◽  
Conductive Line ◽  
Ink Jet ◽  
Jet Printing

Within the last decade, large efforts were made to implement digital printing as a production method for printed electronics. Especially in production of thick-film electronics, innovation is pushed forward to overcome the lacks of established screen-printing regarding flexibility and tooling. Besides the numerous approaches in using ink-jet printing for printed electronics, researchers at Helmut Schmidt University already showed huge progress in applying electrophotography (“laser printing”) as a method to print conductive silver lines in order to form a conductive layout for thick-film circuits. Electrophotography is a solvent-free method, able to directly print silver toner onto ceramic substrates, forming a conductive line after firing. Benefits are high speeds and flexibility and a huge potential regarding precision. Now, after the feasibility of the method was proven and even functional conductive layouts like RFID coils were printed, the next steps have to be taken towards developing electrophotography to an applicable method in a thick-film production process. Thus, this paper describes the efforts in improving the method's performance. Different kinds of silver particles are tested towards their possibility of forming a silver toner. The resulting silver lines are examined regarding conductivity and printing precision. Also, surface treatment of substrates is considered as a method to reduce the number of required print cycles. Corresponding tests are performed. Furthermore, different firing profiles are tested towards their influence onto the resulting silver lines. Combining the results of these examinations, the performance of conductive silver lines could be improved significantly.

Chemical selective coating of nickel / palladium / gold metallization on screen-printed thick film on LTCC and Al2O3 ceramic for high temperature applications

2012 ◽  
Vol 2012 (CICMT) ◽  
pp. 000334-000338
Author(s):  
Jens Müller ◽  
Thomas Mache ◽  
Torsten Thelemann
Keyword(s):  
High Temperature ◽  
Thick Film ◽  
Low Cost ◽  
Gold Wire ◽  
Wire Bonding ◽  
Pure Gold ◽  
Al2o3 Ceramic ◽  
Selective Coating ◽  
Silver Palladium ◽  
Silver Silver

Electroless plating on silver is a low cost alternative to printing of mixed metals or pure gold paste systems on LTCC. It overcomes the necessity to have material transitions from inner to outer layers or from conductor lines to wire bonding- or solder-pads. Since no commercial process and material set for silver thick film conductors has been available on the market a proprietary Ni/Pd/Au coating technology was developed for the use on silver inks for LTCC and Al2O3-ceramic as a base for both soldering and wire bonding. The work included the screening of different chemicals as well as several silver paste systems from two commercial vendors. Conductor adhesion, plating layer thicknesses, plating accuracy, (lead free) solderability and gold wire-bondability were assessed to optimize the process. Layers of about 5 microns Ni, (0.1 to 0.3) microns Pd and (0.05 to 0.15) microns Au were electrolessly deposited. The developed Ni-Pd-Au finish is an economical alternative with only about a quarter of the cost compared to the conventional use of silver, silver / palladium and gold compounds for ceramic substrates. This technology allows coating of the structures down to a fine pad size of 200×200 microns and a minimum line width of 100 microns, without reducing the adhesion mechanism between thick-film metallization and ceramic substrate. By covering of pure conductors with high temperature glass or dielectrics, further material saving is possible. Besides, the process offers also very good coating of structures in cavities.

Evaluation of screen-printable type S (Pt-PtRh) thermocouples on different ceramic substrates

2016 ◽  
Vol 2016 (CICMT) ◽  
pp. 000053-000057
Author(s):  
Jaroslaw Kita ◽  
Sven Wiegärtner ◽  
Alistair Prince ◽  
Peter Weigand ◽  
Ralf Moos
Keyword(s):  
High Temperature ◽  
Thick Film ◽  
Screen Printing ◽  
Temperature Sensors ◽  
Electrical Characteristics ◽  
Buried Structures ◽  
Ceramic Substrates ◽  
Temperature Characteristics ◽  
Film Type ◽  
Thick Film Technology

Abstract The application of thermocouples as temperature sensors has been well known and has already been established for many years. However, for classical thick-film technology using screen-printing and firing, no standardized solutions exist. The here-presented newly developed PtRh thick-film compositions (90% Pt,10% Rh) allows to construct thick-film type S thermocouples (Pt/PtRh), following the IEC temperature characteristics. They can be fired in air, and therefore can be easily integrated into existing thick-film components and devices. In an earlier study, the new Pt-Rh composition was successfully tested on alumina substrates. Their electrical characteristics is equal with classical wire type S thermocouples. This study continues the investigations of thick-film thermocouples. We tested the newly developed pastes for high temperature applications on alumina substrates and evaluated the application of the new screen-printable type S thermocouples on LTCC ceramics. Three possible configurations were investigated: deposited on already fired LTCC substrates (post-fired), screen-printed and co-fired with LTCC tapes on the top surface as well as as buried structures. The paper presents the results of our evaluation and discusses further possible applications.

Formation of Through-Glass-Via (TGV) by Photo-Chemical Etching with High Selectivity

2012 ◽  
Vol 2012 (1) ◽  
pp. 000785-000792
Author(s):  
Zingway Pei ◽  
Jui-Po Sun ◽  
Hsin-Chen Lai ◽  
Pei-Jer Tzeng ◽  
Cha-Hsin Lin ◽  
...  
Keyword(s):  
Chemical Etching ◽  
High Selectivity ◽  
Laser Energy ◽  
Low Cost ◽  
Etching Rate ◽  
Ultra Violet ◽  
Amorphous Region ◽  
Large Area ◽  
Micro Cracks ◽  
Via Hole

In this work, we utilize a photo-chemical etching (PCE) method to form through-glass-via (TGV). The PCE is a low cost, damage-free and potentially large-area method for TGV formation. An ultra-violet (355 nm) pulse laser was used to illuminate the glass surface. The illuminated region will crystallize after thermal annealing in a furnace. The crystallized glass shows much faster etching rate than the amorphous region in HF solution. For a relatively thick (600 nm) glass, a via-hole with diameter of around 60 μm was demonstrated in laser energy of 11 J/cm2. No laser damages were observed. In comparison, at least 10 times higher energy was required to drill a glass directly. Micro-cracks were form around the glass-via. In addition, a 40 selectivity was achieved to the crystallized and amorphous region. This simple and useful method paves a straight road for 3-D integration.

scholarly journals The Role of Sacrificial and/or Protective Layers to Improve the Sintering of Electroactive Ceramics: Application to Piezoelectric PZT-Printed Thick Films for MEMS

Ceramics ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 453-475
Author(s):  
Hélène Debéda ◽  
Maria-Isabel Rua-Taborda ◽  
Onuma Santawitee ◽  
Simon Grall ◽  
Mario Maglione ◽  
...  
Keyword(s):  
Thick Film ◽  
Sacrificial Layer ◽  
Low Cost ◽  
Thick Films ◽  
Protective Layer ◽  
Protective Layers ◽  
Plasma Sintering ◽  
Wide Range ◽  
Spark Plasma ◽  
Pros And Cons

Piezoelectric thick films are of real interest for devices such as ceramic Micro-ElectroMechanical Systems (MEMS) because they bridge the gap between thin films and bulk ceramics. The basic design of MEMS includes electrodes, a functional material, and a substrate, and efforts are currently focused on simplified processes. In this respect, screen-printing combined with a sacrificial layer approach is attractive due to its low cost and the wide range of targeted materials. Both the role and the nature of the sacrificial layer, usually a carbon or mineral type, depend on the process and the final device. First, a sacrificial layer method dedicated to screen-printed thick-film ceramic and LTCC MEMS is presented. Second, the recent processing of piezoelectric thick-film ceramic MEMS using spark plasma sintering combined with a protective layer approach is introduced. Whatever the approach, the focus is on the interdependent effects of the microstructure, chemistry, and strain/stress, which need to be controlled to ensure reliable and performant properties of the multilayer electroceramics. Here the goal is to highlight the benefits and the large perspectives of using sacrificial/protective layers, with an emphasis on the pros and cons of such a strategy when targeting a complex piezoelectric MEMS design.

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