Properties of Glass Substrates for Poly-Si Amlcd Technology

1995 ◽  
Vol 377 ◽  
Author(s):  
Dawne M. Moffatt

ABSTRACTA major force for change in substrate requirements in the late 90's may well be the commercialization of poly-silicon thin film transistor (TFT) Active Matrix Liquid Crystal Display (AMLCDs) technology. The processes necessary for “poly-Si” occur at temperatures that are 150–300°C higher than the current amorphous-Si LCD processes. This impacts the thermal shrinkage and thermal gravimetric warp requirements of the glass, particularly as display resolutions tighten, as enabled by poly-Si. In addition, the expected integration of more components (e.g. chip-on-glass) impacts the requirements for the thermal expansion of the substrate.One approach for meeting the poly-Si demands for greater thermal-dimensional stability is to use glasses with higher temperature capability. A new glass, Code 1737, with the highest strain point commercially available at over 660°C, now enables poly-Si processing with acceptable sag and shrinkage after annealing. A logical goal for the next significant glass advancement would be to eliminate annealing altogether, but it is unclear what temperature capability is required. In this study, various glasses with strain points ranging from 600–800°C have been evaluated in terms of their density, thermal expansion, and thermal shrinkage following poly-Si thermal process simulations. It has been confirmed that the magnitude of shrinkage decreases with increasing strain point for glasses in this compositional family. In addition, future new insight into the effect of thermal expansion coefficient has been developed; the lower the thermal expansion coefficient (for a given strain point), the lower the magnitude of the shrinkage for a given strain point and high temperature thermal cycle. This is important new learning in the area of substrates for flat panel displays that will help in further design and development of glasses for future AMLCDs.

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 153
Author(s):  
Chuen-Lin Tien ◽  
Tsai-Wei Lin

This paper proposes a measuring apparatus and method for simultaneous determination of the thermal expansion coefficient and biaxial Young’s modulus of indium tin oxide (ITO) thin films. ITO thin films simultaneously coated on N-BK7 and S-TIM35 glass substrates were prepared by direct current (DC) magnetron sputtering deposition. The thermo-mechanical parameters of ITO thin films were investigated experimentally. Thermal stress in sputtered ITO films was evaluated by an improved Twyman–Green interferometer associated with wavelet transform at different temperatures. When the heating temperature increased from 30 °C to 100 °C, the tensile thermal stress of ITO thin films increased. The increase in substrate temperature led to the decrease of total residual stress deposited on two glass substrates. A linear relationship between the thermal stress and substrate heating temperature was found. The thermal expansion coefficient and biaxial Young’s modulus of the films were measured by the double substrate method. The results show that the out of plane thermal expansion coefficient and biaxial Young’s modulus of the ITO film were 5.81 × 10−6 °C−1 and 475 GPa.


The Thin Film Transistor (TFT) is the key active components of emerging large area and flexible microelectronics (LAFM) which includes a flexible display, robotics skin, sensor & disposable electronics. Different semiconducting or organic conducting materials could be used in the fabrication of TFTs. The material used for the active layer also influences the performance of the TFT uniquely[1]. Silicon based thin film transistors have made possible the development of the active-matrix liquid crystal display within cell-touch technology [2,3,4]. Modern-day simulation software does not support the older SPICE code models, and rather rely on the new drag and drop concepts. The TFT(Thin Film Transistor) Model device wasn't readily available on the LT-Spice Tool which was simulated and the circuit level simulation for basic gates using the TFT was carried out successfully. The model symbol shall be useful for analysis and simulation of the TFT based circuits which require continuous behavioral study and analysis. For a device to be simulated that way, a “.lib” file containing a symbol of the device is necessary. This paper focuses on circuit-level simulation of user-defined device parameters from reported experimental data.


2020 ◽  
Vol 59 (1) ◽  
pp. 523-537
Author(s):  
Chaturaphat Tharasana ◽  
Aniruj Wongaunjai ◽  
Puwitoo Sornsanee ◽  
Vichasharn Jitprarop ◽  
Nuchnapa Tangboriboon

AbstractIn general, the main compositions of porcelain and bone china composed of 54-65%wt silica (SiO2), 23-34% wt alumina (Al2O3) and 0.2-0.7%wt calcium oxide (CaO) suitable for preparation high quality ceramic products such as soft-hard porcelain products for teeth and bones, bioceramics, IC substrate and magneto-optoelectroceramics. The quality of ceramic hand mold is depended on raw material and its properties (pH, ionic strength, solid-liquid surface tension, particle size distribution, specific surface area, porosity, density, microstructure, weight ratio between solid and water, drying time, and firing temperatures). The suitable firing conditions for porcelain and bone china hand-mold preparation were firing at 1270°C for 10 h which resulted in superior working molds for making latex films from natural and synthetic rubber. The obtained fired porcelain hand molds at 1270°C for 10 h provided good chemical durability (10%NaOH, 5%HCl and 10%wtNaCl), low thermal expansion coefficient (5.8570 × 10−6 (°C−1)), good compressive (179.40 MPa) and good flexural strength (86 MPa). While thermal expansion coefficient, compressive and flexural strength of obtained fired bone china hand molds are equal to 6.9230 × 10−6 (°C−1), 128.40 and 73.70 MPa, respectively, good acid-base-salt resistance, a smooth mold surface, and easy hand mold fabrication. Both obtained porcelain and bone china hand molds are a low production cost, making them suitable for natural and synthetic rubber latex glove formation.


2020 ◽  
Vol 45 (46) ◽  
pp. 24883-24894 ◽  
Author(s):  
Ba Nghiep Nguyen ◽  
Daniel R. Merkel ◽  
Kenneth I. Johnson ◽  
David W. Gotthold ◽  
Kevin L. Simmons ◽  
...  

1998 ◽  
Vol 12 (02) ◽  
pp. 191-205 ◽  
Author(s):  
Vu Van Hung ◽  
Nguyen Thanh Hai

By the moment method established previously on the basis of the statistical mechanics, the thermodynamic properties of a strongly anharmonic face-centered and body-centered cubic crystal with point defect are considered. The thermal expansion coefficient, the specific heat Cv and Cp, the isothermal and adiabatic compressibility, etc. are calculated. Our calculated results of the thermal expansion coefficient, the specific heat Cv and Cp… of W, Nb, Au and Ag metals at various temperatures agrees well with the measured values. The anharmonic effects in extended X-ray absorption fine structure (EXAFS) in the single-shell model are considered. We have obtained a new formula for anharmonic contribution to the mean square relative displacement. The anharmonicity is proportional to the temperature and enters the phase change of EXAFS. Our calculated results of Debye–Waller factor and phase change in EXAFS of Cu at various temperatures agrees well with the measured values.


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