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Thermal resistivity properties of LED packages with thermal via Hyo Soo Lee1,a, Hyeong Won Shin1,b, and Seung Boo Jung2,c 1 Advanced Material Division, Korea institute of Industrial Technology, 7-47 Songdo-dong, Yeonsu-gu, Incheon 406-840, Korea 2 Dept. of Adv.
In fact, the heat from an LED package with 1~3W LED chip shows a nearly 60~150℃, which affects thermal damage related to performance, joint failure, crack, etc.
The strucure of thermal via was drawn also as Fig. 1, which was the same as a pin-through hole in printed circuit board formed by mechanical drill process.
Chracterization of thermal properties of the LED were carried out by a 2 type of experiments.
And it was observed that the copper volume of inner layer in thermal via was dominant factor on the heat dissipation, which was also exactly correlated with thermal resistivity of each specimen.

Reviews on Automobile Abnormal Sound Fault Diagnosis Tan Guiling1, a, Miao Dehua1,b*,,Qi Yuming1, c, Deng Sanpeng1, d 1School of Mechanical Engineering, Tianjin University of Technology and Education, Tianjin, 300222, China atanguiling@sina.cn, bmiaodh@126.com, cqiyuming1221@gmail.com, dsanpeng@yeah.net *Author for correspondence: Miao Dehua(1957-), Male , Dr.
As a result, it will reduce the number of traffic accidents, protect human safety and property.
Automotive abnormal sound will not affect the car's driving immediately, but it will seriously affect the ride comfort, causing the passenger irritability, decreasing the attention of the driver or other adverse symptoms.
Lu Jianwei etc, from College of Mechanical and Automotive Engineering of Hefei University of Technology, analyzed the transmission gear abnormal sound failure from the perspective of nonlinear dynamics [9].
Brake abnormal sound The abnormal noise, made by the automobiles when breaking, is probably arose by these factors, such as the improper use of the material or big distortion of Brake Disc or the hardness, the Porosity, Friction Characteristics and squeezing properties of Brake Friction Lining are unqualified.

Ferroelectric properties of the lead-free ceramic behaved a coercive field of 12.5kV/cm and remanent polarization as high as 30uC/cm2.
That is why it could have potential to behave good piezoelectric properties.
The formation of secondary phase which affects the electrical properties a lot was found to be one of the key issues for dopants in lead-free ceramics.
To achieve improved ferroelectric properties, it should be important to reduce the formation of secondary phase.
Haertling, Properties of Hot-Pressed Ferroelectric Alkali Niobate Ceramics.

Changing modes of sintering produces a predetermined surface roughness which is an important factor in adhesion of adjacent layers.
For research cobalt chrome molybdenum powder DSK-F75 was selected, which is used in mechanical engineering to manufacture products of high-temperature assignment.
The alloy has a good combination of mechanical properties such as plasticity limit of 0.65 кН/mm2, density 8,4 g/cm3 combined with moderate hardness.
Characteristic curves, constructed according to this formula, revealed the most significant parameters, affecting the roughness of the sintered layer, as well as the limits of its changes due to technological modes of sintering.
Yakovlev, Mechanical activation of metal powders effect on quality of surface sintered layer, Metal Treatment. 4(2012) 108-110

Key Laboratory of Advanced Textile Composites (Tianjin Polytechnic University), Ministry of Education, Tianjin, 300160, China Correspondence to xgma@tjpu.edu.cn Key words: thermochomic; energy-storage; sol-gel; composite materials Abstract: Composite thermochromic energy-storage materials (CTEM)were prepared by sol-gel method, Factors exerting influence on thermochomic and thermal properties of composite materials were discussed, such as the molar ratio of ester to water, the dosage of thermochomic materials, pH value were optimized via 3 factors and 3 levels of L9 (33) orthogonal design.
It was usually composed by chromophoric reagent, delomorphic reagent and solvent [1], of which chromophoric reagent decided the properties such as the color and stability of the reversible thermochomic materials, delomorphic reagent decided the color shade and the solvent decided the temperature to change color.
Various factors that influence the thermochromic and thermal properties of the CTEM were carefully discussed, such as the molar ratio of ester to water, the dosage of thermochomic materials, pH value and so on, the optimum formulation was successfully acquired at last, subsequently broadening the use of the organic phase change materials and laying the foundation for the development of intelligent textiles.
Tianjin, China), Deionized water. 1.2 Methods 1.2.1 Sol - Gel method mechanism In this experiment, under constant mechanical stirring, TEOS as precursor, was mixed in ethanol solvent to form a homogeneous solution.
(2) The thermochromic energy-storage materials prepared through appropriate formula were tested for reflectivity and thermal properties, the results showed that it had excellent chromogenic and thermal performance

The dissolution of co-clusters in AlMgSi-alloys by a short term heat treatment can be used to locally adjust the mechanical properties of a blank for a following forming operation.
The concept is based on a local, short term heat treatment by which the mechanical properties of the material are adjusted for subsequent forming steps.
Thus, to fully benefit from the tailored mechanical properties forming should be performed as close as possible to the heating step.
In addition also inherent properties such as alloy composition, type and amount of solutes and dislocation density are reported to affect the PLC effect [9].
Conclusion and Outlook Various influence factors on the PLC effect of AlMgSi-THTB have been investigated.

The increasing sintering temperature and soaking time affect the phase composition obviously, which lead to the obvious variations of microstructure, mechanical, dielectric and thermal properties of this glass-ceramic.
Moreover, LAS-type glass-ceramic can show a high mechanical property of ~150 MPa for β-spodumene.
Fig. 5 Dielectric properties of LAS glass-ceramics sintered at different sintering temperatures.
The influence of sintering conditions on the microstructure, crystallization behavior, CTE, mechanical and dielectric properties of the LAS glass-ceramic has been studied.
The prepared LAS glass-ceramic exhibits dense microstructure, low sintering temperature of 800 °C, high density of ~2.6, excellent dielectric properties (εr: ~6.9, tan δ: ~2*10-3), good mechanical property of 143 MPa and adjustable CTE from 1.1 to 2.7 *10-6 K-1 close that of silicon.

These ions can be exchanged with other ions relatively easily, without affecting the structure of clay mineral [9].
They have specific characteristics such as high specific surface area, cation exchange capacity and hydrating properties [11].
The factors used were: concentration (10, 30 and 50 ppm) and pH (3, 4 and 5).
The oxides with contents lower than 1%, generally do not significantly influence the properties of clay.
There was influence of initial concentration and the interaction of factors only in response removal capacity (qeq).

These transformations can be related to intrinsic characteristics of the materials and/or to exogenous factors and have visual manifestations that are the basis for its surveying and typology [1][2][4].
They can also affect recent constructions [4].
Underground Metro stations constitute particularly interesting research places for the study of natural stone changes over time since the influence of one of the main factors usually considered (exposition conditions) is minimized.
There are occurrences of surface irregularities in biotite-rich coarse-grained porphyritic granitic rocks applied in pavements (Fig. 3) that seem to specially affect yellowish slabs (yellowish discolouration in these rocks indicates weathering inherited from the quarry that affect physical properties of stones, causing, among other effects, physical weakening and increased porosity).
Fig. 6: Irregularities affecting dark greyish limestone applied in steps risers at the Oriente station (inaugurated in 1998, [7][8]).

In [15-17], the authors determined that the addition of ultrafine natural diamond powders to the melt of tin bronze in an amount of 2-3% by weight has a positive effect on the physical, mechanical and operational properties of the metal bond.
The combination of these factors ultimately reduces the residual porosity in the material.
Yan, Effect of Ti addition on the microstructure and mechanical properties of cast Mg-Gd-Y-Zn alloys, Materials science and engineering a-structural materials properties microstructure and processing. 708 (2017) 482-491
Liu, Reinforcement size dependence of mechanical properties and strengthening mechanisms in diamond reinforced titanium metal matrix composites, Composites Part B: Engineering. 167 (2019) 7-19
Leparoux, Microstructure and mechanical properties of near net shaped aluminium/alumina nanocomposites fabricated by powder metallurgy, Journal of Alloys and Compounds. 714 (2017) 133-143