Real time investigation of the effect of thermal expansion coefficient mismatch on film-substrate strain partitioning in Ag/Si systems

2016 ◽  
Vol 120 (13) ◽  
pp. 135301 ◽  
Author(s):  
Debolina Das ◽  
Nasrin Banu ◽  
Bhaskar Bisi ◽  
J. C. Mahato ◽  
V. Srihari ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Real Time ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Strain Partitioning ◽  
Substrate Strain ◽  
Film Substrate ◽  
Thermal Expansion Coefficient Mismatch

Thermal Effects Analysis of Flip Chip LED Packages with through Silicon via (TSV) by Using Numerical Simulation

2013 ◽  
Vol 459 ◽  
pp. 289-294
Author(s):  
Chi Hui Chien ◽  
Bo Syun Chen ◽  
Yii Der Wu
Keyword(s):  
Thermal Expansion ◽  
Integrated Circuits ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Flip Chip ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Optical Efficiency ◽  
Through Silicon Via ◽  
Thermal Expansion Coefficient Mismatch

With advancement of technology, package sizes and products are becoming smaller due to miniaturization. Separate light-emitting diode (LED) chips and control integrated circuits with through silicon via (TSV) structurescan be combined to achieve reduced size. LED chipswithFlip Chip structureare capable of higher optical efficiency and heat dissipation. Analysis of LED chip structure after heat-related destruction of the chip indicated that the chip suffered stress from heating and cooling. The material used for TSV structures is copper, sincethis provides good electrical conductivity and high thermal conductivity. However, the thermal expansion coefficient of copper is higher than for other materials and can result in thermal expansion coefficient mismatch. Hence, the use of this material is likely to cause stress concentration and thus cause damage. In this study, molybdenum and tungsten were tested as replacements for copper in TSV, and the modified TSV was subjected to simulation analysis.The results indicate that replacement of TSV materials can reduce thermal expansion coefficient mismatch and consequent stress fracture and that the performance of different materials can be simulated by Fatigue Analysis and Load.

Design and Simulation of a Micromachined CMOS Temperature Sensor

2009 ◽  
Vol 60-61 ◽  
pp. 334-338
Author(s):  
Hong Yu Ma ◽  
Qin Gan Huang ◽  
Ming Qin
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Low Cost ◽  
Wheatstone Bridge ◽  
Cmos Process ◽  
Piezoresistive Effect ◽  
Working Principle ◽  
Thermal Expansion Coefficient Mismatch ◽  
Mismatch Effect

A design and simulation of a fully CMOS compatible micromachined multilayer cantilevers-based environmental thermometer are presented. The operation principle of the structure is depending on the mismatch effect of thermal expansion coefficient and the piezoresistive effect of polysilicon in CMOS process. Upon temperature variation, the deformation of the multilayer cantilever resulted from the large thermal expansion coefficient mismatch of different materials can be sensed and translated to an electrical voltage output by using a symmetric piezoresistive Wheatstone bridge. The mechanical characteristics of the device are analyzed with the extension of bi-layer Timoshenko model and the output of the read-out circuit is also simulated. The calculation and simulation show that the device with bi-direction deformation may have wide temperature range from -100 to 100°C and sensitivity about 0.15mV/°C, which fit the demand of radiosonde for environmental temperature measurement. This sensor may also have other favorable features, such as micro size, low-cost due to its working principle and compatibility with commercial CMOS process.

EFFECTS OF THERMAL EXPANSION COEFFICIENT MISMATCH ON STRUCTURE AND ELECTRICAL PROPERTIES OF TiO2 FILM DEPOSITED ON Si SUBSTRATE

2008 ◽  
Vol 15 (04) ◽  
pp. 487-491 ◽  
Author(s):  
CHEN YANG ◽  
HUIQING FAN ◽  
SHAOJUN QIU ◽  
YINGXUE XI ◽  
JIN CHEN
Keyword(s):  
Thermal Expansion ◽  
Electrical Properties ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Ion Beam ◽  
Electron Beam Evaporation ◽  
Si Substrate ◽  
Cte Mismatch ◽  
Deposited Film ◽  
Thermal Expansion Coefficient Mismatch

Effects of thermal expansion coefficient (CTE) mismatch on structure and electrical properties of TiO 2 film deposited on Si substrate by ion beam assistant electron beam evaporation have been investigated. Because of a high CTE mismatch between TiO 2 film and Si substrate, microcracks appeared in the TiO 2 film deposited directly on Si substrate after the as-deposited film was annealed at 600°C. In order to decrease the CTE mismatch, TiO 2 film was deposited on Si substrate which was covered by a ZrO 2 thin layer. As a result, crack–free TiO 2 film after annealed at the same temperature was obtained. Meanwhile, corresponding to the crack–free structure, the TiO 2 thin film has more stable dielectric properties and excellent I–V characteristics.

Thermal Spraying On Graphite

1998 ◽  
Author(s):  
N. Mesrati ◽  
H. Ajhrourh ◽  
N. Du ◽  
D. Treheux
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Thermal Spraying ◽  
Ceramic Coatings ◽  
Work Of Adhesion ◽  
Metal Carbide ◽  
Thermodynamic Work ◽  
Thermodynamic Work Of Adhesion ◽  
Thermal Expansion Coefficient Mismatch

Abstract In order to expand the fields of application and to improve the performance of graphite (Cg), it is necessary to reduce its permeability towards of oxygen and to limit its reactivity and especially its oxidation. It is, therefore, essential to protect it from the environment through the use of ceramic coatings. Adhesion between ceramic coatings and graphite is controlled by the mechanical stresses in the coatings and the thermodynamic work of adhesion. Different metal-graphite systems were examined which showed that the adhesion particularly depended on the thermal expansion coefficient mismatch between the two materials and on metal carbide stability. Thus, the rote of the addition on the graphite surface of elements such as Cr, Mo, Al, Si, O on the adhesion of metals or ceramics to graphite has been identified.

scholarly journals Out-of-Plane Thermal Expansion Coefficient and Biaxial Young’s Modulus of Sputtered ITO Thin Films

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 153
Author(s):  
Chuen-Lin Tien ◽  
Tsai-Wei Lin
Keyword(s):  
Thin Films ◽  
Thermal Expansion ◽  
Thermal Stress ◽  
Young’S Modulus ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Young's Modulus ◽  
Heating Temperature ◽  
Glass Substrates ◽  
Ito Thin Films

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.

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