A Lead Free Graphite Conducting Paste for Screen Printing

2011 ◽  
Vol 284-286 ◽  
pp. 2230-2233
Author(s):  
Shi Yong Luo ◽  
Juan Chen ◽  
Wen Cai Xu ◽  
Li Xia Huo ◽  
Jun Yan Zhao
Keyword(s):  
Sheet Resistance ◽  
Vickers Hardness ◽  
Ethyl Cellulose ◽  
Screen Printing ◽  
Graphite Powder ◽  
Lead Free ◽  
Cellulose Solution ◽  
Melting Glass ◽  
Powder Lead ◽  
Free Glass

A lead free graphite conducting pastes were prepared by using graphite powder, lead free low-melting glass and terpineol ethyl cellulose solution. By analyzing the sheet resistance, Vickers hardness as well as the adhesion strength of the sintered film prepared by the pastes formulated with different composition, the composition of the paste with preferable properties was evaluated as in mass percent: organic vehicle 60, graphite powder 15~20, and low melting glass 20~25. The films, prepared by the pastes using the lead free glass with a glass transition temperature of 476°C, were perfectly flat and compact after fired at a peak temperature within the range from 520°C to 580°C. The sheet resistance of the fired film with glass content of 25wt% was 135Ω/mm2when the thickness of the film was 25±3μm, while the Vickers hardness and the binder force between the sintered film and the substrate were favorable. In addition, the rheological behaviors of the typical paste were characterized by using an ARES (RFS-III) rheometer. It is found that a weak flocculated network structure is formed in the paste for the high solid filler.

A Glass Dielectric Paste for Preparation Transparent Spacers of Vacuum Glass by Screen Printing

2012 ◽  
Vol 519 ◽  
pp. 252-255
Author(s):  
Jun Yan Zhao ◽  
Shi Yong Luo ◽  
Xin Lin Zhang ◽  
Wen Cai Xu ◽  
Man Zhao
Keyword(s):  
Network Structure ◽  
Vickers Hardness ◽  
Ethyl Cellulose ◽  
Screen Printing ◽  
Glass Powder ◽  
Flat Glass ◽  
Sound Insulation ◽  
Cellulose Solution ◽  
Glass Substrates ◽  
Melting Glass

Vacuum glass is a new building material with excellent energy conservation and sound insulation properties. Usually, the spacers between two pieces of flat glass substrates are mini-rings of metal. In the present research, the spacers were prepared with a glass dielectric paste by screen printing, and then sintered till them transparent. The glass dielectric paste for the preparation of transparent spacers of vacuum glass was prepared by using low melting glass powder and terpineol ethyl cellulose solution. The composition of the paste with preferable properties was evaluated as in mass percent: organic vehicle 20-25, and low melting glass powder 73-80. The rheological behaviors of the typical paste were characterized by using an ARES (RFS-III) rheometer. It is found that a weak flocculated network structure is formed in the paste for the high solid filler. The spacers were prepared by screen printing the paste on the glass substrate and then sintered. The transparent, Vickers hardness of the spacers as well as the binder forces between the spacers and the substrate is reported. The reliability of the prepared transparent spacers for the vacuum glass was discussed.

Rheological Behavior of Silver Paste Prepared from Nanoparticles

2011 ◽  
Vol 327 ◽  
pp. 120-123
Author(s):  
Shi Yong Luo ◽  
Juan Chen ◽  
Wen Cai Xu ◽  
Xin Lin Zhang ◽  
Li Xia Huo
Keyword(s):  
Shear Rate ◽  
Low Temperature ◽  
Rheological Behavior ◽  
Ethyl Cellulose ◽  
Screen Printing ◽  
Sintering Temperature ◽  
Cellulose Solution ◽  
Silver Particles ◽  
Pseudoplastic Fluid ◽  
Electrical Components

A paste with as low as 300°C sintering temperature was prepared by using nano silver particles and ethyl cellulose solution. The rheological and thixotropic behaviors of the typical paste were characterized and their effects on the screen printing ability were analyzed in details. The paste demonstrates a typical shear thinning rheological behavior and thixotropic of pseudoplastic fluid. The apparent viscosity decreased rapidly with the increase of the shear rate. The paste is proper for the manufacturing electrical components at a low temperature as low as 300°C.

Preparation and luminescent properties of the coating of phosphor in lead-free glass by multilayer screen-printing

2016 ◽  
Vol 684 ◽  
pp. 372-378 ◽  
Author(s):  
Hong Li ◽  
Xujia Xu ◽  
Yun Li ◽  
Shuang Wu ◽  
Peijing Tian ◽  
...  
Keyword(s):  
Screen Printing ◽  
Luminescent Properties ◽  
Lead Free ◽  
Free Glass

Design and Optimization of Chronotherapeutic Dosage Form for the Treatment of Angina Pectoris

2020 ◽  
Vol 10 ◽  
Author(s):  
Rupali Singh ◽  
Rishabha Malviya
Keyword(s):  
Drug Delivery ◽  
Angina Pectoris ◽  
Ethyl Cellulose ◽  
Dosage Form ◽  
Cellulose Solution ◽  
Specific Drug ◽  
Pharmaceutical Dosage Form ◽  
Weight Variation ◽  
Short Period ◽  
Time Specific

Background: The chronotherapy concept attains considerable focus towards itself due to its pulsatile fashion rather than continuous delivery. The delivery of the right amount of drug to the target organ at the most appropriate time is fulfilled by using the chronotherapeutic dosage form. Aim: The present study aims to develop and evaluate a chronotherapeutic drug delivery system by using natural polymer for time specific drug delivery at the target site. Material and Method: Tamarind seed polysaccharide was extracted and used in the preparation of core tablets. Nine formulations of core tablets were prepared with nifedipine at 5 tonnes of pressure on 6 mm punch. The core tablets were prepared by using the compression coating method. The three batches F1, F2 and F3 were prepared by using tamarind gum in different concentration i.e. 45%, 22.5% and 67.5% respectively and compressed at 8 tonnes of pressure on 12 mm of punch. The finally compressed tablet was coated with different concentrations of ethyl cellulose in which isopropyl alcohol used as a solvent. In a controlled medium, a stability study was performed to evaluate the physical appearance, drug content and release of the prepared core tablet. Result: All the nine formulations of tablets were prepared successfully and the evaluation studies (thickness, weight variation, hardness, friability etc.) revealed that all the formulations were within the official range. The release study of the drug revealed that the formulation F7 containing 67.5% of tamarind polymer, coated with 2%, 4% and 5% of ethyl cellulose solution released 59.68±1.03% (Q50%) drug within 5 h whereas, 87.09±2.08% (Q80%) within 6 h and within 12 h 97.74±2.19% of the drug was released. The formulation F7 was found to be more effective as it released the maximum amount of drug in a short period as compared with other formulations. Conclusion: The coating of core tablets allowed to prepare pharmaceutical dosage form for time specific drug delivery. These chronotherapeutic core tablets can be used for the treatment of angina pectoris and hypertension etc.

scholarly journals Development and Characterization of a Novel Low-Cost Water-Level and Water Quality Monitoring Sensor by Using Enhanced Screen Printing Technology with PEDOT:PSS

Micromachines ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 474 ◽  
Author(s):  
Bei Wang ◽  
Manuel Baeuscher ◽  
Xiaodong Hu ◽  
Markus Woehrmann ◽  
Katharina Becker ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Level ◽  
Sheet Resistance ◽  
Screen Printing ◽  
Low Cost ◽  
Conductive Polymer ◽  
Water Quality Monitoring ◽  
Physical Treatment ◽  
Printing Technology ◽  
Screen Printing Technology

A novel capacitive sensor for measuring the water-level and monitoring the water quality has been developed in this work by using an enhanced screen printing technology. A commonly used environment-friendly conductive polymer poly(3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS) for conductive sensors has a limited conductivity due to its high sheet resistance. A physical treatment performed during the printing process has reduced the sheet resistance of printed PEDOT:PSS on polyethylenterephthalat (PET) substrate from 264.39 Ω/sq to 23.44 Ω/sq. The adhesion bonding force between printed PEDOT:PSS and the substrate PET is increased by using chemical treatment and tested using a newly designed adhesive peeling force test. Using the economical conductive ink PEDOT:PSS with this new physical treatment, our capacitive sensors are cost-efficient and have a sensitivity of up to 1.25 pF/mm.

Screen Printing Fine Pitch Stretchable Silver Inks onto a Flexible Substrate for Wearable Applications

2018 ◽  
Vol 2018 (1) ◽  
pp. 000665-000671
Author(s):  
Jianbiao Pan ◽  
Malcolm Keif ◽  
Joshua Ledgerwood ◽  
Xiaoying Rong ◽  
Xuan Wang
Keyword(s):  
Sheet Resistance ◽  
Flexible Electronics ◽  
Screen Printing ◽  
Flexible Substrate ◽  
Thermoplastic Polyurethane ◽  
Organic Substrate ◽  
Printing Process ◽  
Silver Ink ◽  
Fine Pitch

Abstract The lightweight and bendable features of printed flexible electronics are increasingly attractive. Currently stretchable silver inks are formulated for wide traces, typically larger than 2 mm. To attach ultra-thin silicon chips that have fine pitch onto printed organic substrate, it is necessary to print fine trace width/space that matches the pitch of the chips, which may be less than 200 microns. This paper presents the development and optimization of the screen printing process for printing stretchable silver ink onto stretchable thermoplastic polyurethane (TPU) substrate. A test vehicle was designed including 50 μm/5 mm (line width/line length) to 350 μm/35 mm lines (at 4 biases). The stretchable ink selected was DuPont PE 873 and Dupont's PE 5025 ink (non-stretchable conductive flake silver) was used as a “control” to baseline the printing process. The substrate used was Bemis TPU ST604. The experiment was done on a DEK Horizon 03i printer. A DEK squeegee 200 (Blue) and a DEK 265 flood bar (200 mm) were used. A 2-level factorial design with three replicates was selected to investigate the effect of process parameters on the quality of prints. The quality of the prints is characterized by 1) resistance of traces, 2) sheet resistance, 3) z-axis height, and 4) trace width/spacing. We observed significant noise in the z-axis printed silver ink height measured by profilometry and concluded z-axis height is not a good response variable for characterizing screen printing stretchable silver ink onto TPU substrate, mainly due to high roughness of the TPU substrate. We proposed calculated sheet resistance based on the measured resistance value, trace width, and trace length, which can replace trace height measurements on rough profile substrates. We found that squeegee pressure and emulsion thickness have statistically significant effects on calculated sheet resistance of print traces while print speed does not have statistically significant effects. In our experiment setting levels, the lower the squeegee pressure, the lower the calculated sheet resistance that is achieved. The emulsion with higher emulsion over mesh (EOM) is better than the emulsion with lower EOM since it can achieve lower sheet resistance. After optimizing the screen printing process, we were able to print 100 μm (4 mils) trace width and spacing with high consistency.

Evaluation of Glass Frits for Development of Lead-Free Thick Film Resistor

2010 ◽  
Vol 2010 (1) ◽  
pp. 000752-000759
Author(s):  
Xudong Chen ◽  
W. Kinzy Jones
Keyword(s):  
Electrical Properties ◽  
Temperature Coefficient ◽  
Thick Film ◽  
Glass Frit ◽  
Lead Free ◽  
Temperature Coefficient Of Resistance ◽  
Film Resistor ◽  
Thick Film Resistor ◽  
Glass Compositions ◽  
Free Glass

Glass frit is a major component of thick film resistor (TFR) for the production of hybrid circuits. More than thirty commercial lead-free glass frits with different compositions have been evaluated for developing a lead-free thick film resistor that is compatible with typical industry thick film processing and has comparable electrical properties as the lead bearing counterpart. Two glass compositions were selected out of 33 candidates for preparation of RuO2 based TFR inks, which were screen printed on alumina substrates and fired at 850°C. The preliminary results of these resistors showed that the sheet resistance spanned from 400 ohms per square (Ω/□) to 0.4 mega-ohms per square (MΩ/□) with 5–15% RuO2 and the hot temperature coefficient of resistance (HTCR) fell in a range of ±350ppm/°C.

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