Pressure-Assisted Sintering of Multilayer Transformer Using LTCC-Compatible NiCuZn-Ferrite and Silver Conductor

2012 ◽  
Vol 2012 (CICMT) ◽  
pp. 000476-000483
Author(s):  
Hamid Naghib-zadeh ◽  
Torsten Rabe
Keyword(s):  
Thermal Expansion ◽  
Copper Oxide ◽  
Heating Rate ◽  
Glassy Phase ◽  
Dielectric Material ◽  
Nitrogen Atmosphere ◽  
Divalent Copper ◽  
Nicuzn Ferrite ◽  
Silver Diffusion ◽  
Sintering Behaviour

A low-fired NiCuZn-ferrite and a new LTCC dielectric material with matched sintering shrinkages and coefficients of thermal expansion were used for integration of magnetic function into LTCC. Silver was used as inner conductor material. Silver diffusion during sintering into the surrounding glassy phase modifies the sintering behaviour of LTCC near the silver conductor and generates warping and delamination of the multilayer. Silver diffusion can be prevented by sintering in nitrogen atmosphere. However, sintering in nitrogen atmosphere causes partial decomposition of NiCuZn-ferrite by reduction of divalent copper oxide (CuO) to cuprite (Cu2O). It was found that diffusion of silver and associated deformation can be highly reduced if a higher heating rate during sintering in air is used. A Defect-free multilayer transformer with several silver conductive layers could be manufactured by pressure-assisted sintering only.

Microstructural development of ZnO using a rate-controlled sintering dilatometer

1996 ◽  
Vol 11 (3) ◽  
pp. 671-679 ◽  
Author(s):  
Gaurav Agarwal ◽  
Robert F. Speyer ◽  
Wesley S. Hackenberger
Keyword(s):  
Thermal Expansion ◽  
Heating Rate ◽  
Grain Growth ◽  
Microstructural Development ◽  
Constant Heating Rate ◽  
Temperature Determination ◽  
Grain Sizes ◽  
Rate Controlled ◽  
Temperature Controlled ◽  
Constant Heating

Rate-controlled sintering (RCS) of isostatically pressed particulate compacts of ZnO showed lower average grain sizes and intragranular pore densities than constant heating rate temperature controlled sintering. Valid comparisons of this form could only be made after corrections to hardware and software which reduced specimen creep under dilatometer pushrod load, nonuniform pushrod expansion, reproducible specimen temperature determination, thermal expansion during sintering, and instantaneous termination of sintering at the specified end of RCS. The improved microstructures from RCS were attributed to maximized efficiency of densification, optimizing the time and temperatures permitted for grain growth.

The Effect of Thermal History on Porcelain Expansion Behavior

1989 ◽  
Vol 68 (9) ◽  
pp. 1313-1315 ◽  
Author(s):  
C.W. Fairhurst ◽  
D.T. Hashinger ◽  
S.W. Twiggs
Keyword(s):  
Thermal Expansion ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Heating Rate ◽  
Room Temperature ◽  
Heating Rates ◽  
Thermal Expansion Data ◽  
Temperature Range ◽  
Expansion Behavior

Porcelain-fused-to-metal restorations are fired several hundred degrees above the glass-transition temperature and cooled rapidly through the glass-transition temperature range. Thermal expansion data from room temperature to above the glass-transition temperature range are important for the thermal expansion of the porcelain to be matched to the alloy. The effect of heating rate during measurement of thermal expansion was determined for NBS SRM 710 glass and four commercial opaque and body porcelain products. Thermal expansion data were obtained at heating rates of from 3 to 30°C/min after the porcelain was cooled at the same rate. By use of the Moynihan equation (where Tg systematically increases in temperature with an increase in cooling/heating rate), the glass-transition temperatures (Tg) derived from these data were shown to be related to the heating rate.

Process Optimization of Preparation and Performance Characterization of Oily Sludge-Based Adsorbent Material by Pyrolysis

2009 ◽  
Vol 79-82 ◽  
pp. 1971-1974
Author(s):  
Guang Ying Zhang ◽  
Ying Fei Hou ◽  
Chun Hu Li ◽  
Wei Zhu ◽  
Jian Zhang
Keyword(s):  
Heating Rate ◽  
Flue Gas ◽  
Pyrolysis Temperature ◽  
Influencing Factor ◽  
Nitrogen Atmosphere ◽  
Flue Gas Desulfurization ◽  
Oily Sludge ◽  
Breakthrough Time ◽  
And Performance

The oily sludge-based adsorbents for flue gas desulfurization were prepared by pyrolysis. Based on benzene adsorptivity, the conditions of pyrolysis process were optimized. The optimum prepared conditions of adsorbent material were in nitrogen atmosphere and 550°C, 4h, 10°C/min for the pyrolysis temperature, pyrolysis time and heating rate, respectively. In this case, the maximum benzene adsorbability was 60.12mg/g. Moreover, the main influencing factor was pyrolysis temperature, secondly was pyrolysis time and finally was heating rate. The sludge-based adsorbents were appropriate for flue gas desulfurization. The sulfur capacity of adsorbents via a flue gas desulfurization test after subsequent processing was about 3% and breakthrough time could keep to 109 min.

Effect of Barium Stearate on the Thermal Stability of Polyvinyl Chloride

2013 ◽  
Vol 395-396 ◽  
pp. 371-376 ◽  
Author(s):  
Yi Heng Lu ◽  
Wei Long Liu ◽  
Feng Wei ◽  
Shuang Chun Ma
Keyword(s):  
Heating Rate ◽  
Decomposition Reaction ◽  
Decomposition Temperature ◽  
Nitrogen Atmosphere ◽  
Initial Reaction ◽  
Third Phase ◽  
Barium Stearate ◽  
Degradation Reaction ◽  
Three Stages ◽  
Kinetics Of

Thermal degradation reaction kinetics of PVC stabilized by barium stearate were studied by means of the non-isothermal weight-loss technique under a nitrogen atmosphere. The results show that the lowest decomposition temperature is greater than 203.6°C and 217.2°C in the conversion rate of 5% and 10% respectively. When the heating rate β is 10°C/min, at 200°C and 225°C the remaining mass from the sample with barium stearate was 99.1% and 95.3%, respectively. The thermal decomposition process occurred in three stages, the results calculated by various methods show that the average apparent activation energy in first, second and third phase is 79.88kJ/mol, 89.37kJ/mol and 187.34kJ/mol respectively. In the initial reaction ( α<18%), as heating rate is 20°C/min, the decomposition reaction is controlled by the (A1.5) mechanism.

The Abnormal Melting of Raw Rubber

1949 ◽  
Vol 22 (2) ◽  
pp. 299-309
Author(s):  
Akira Isihara
Keyword(s):  
Thermal Expansion ◽  
Relaxation Time ◽  
Heating Rate ◽  
Relaxation Times ◽  
Previous History ◽  
Time Interval ◽  
Time Rate ◽  
Vulcanized Rubber ◽  
Rate Of Heating ◽  
Amorphous Particles

Abstract The experimental results on the abnormal melting of crystallized raw rubber by Wood and Bekkedahl are studied theoretically. The effect can be explained by the fact that the relaxation time for the thermal expansion of crystalline particles differs from that of amorphous particles. At the point where the melting begins, the time interval of observation becomes comparable to the relaxation time of amorphous particles. The point becomes higher as the time rate of heating increases, and also as the relaxation time itself becomes larger. The point at which fusion is complete is determined by the relaxation times of the amorphous and crystallized states, heating rate, and previous history. This effect becomes large at a suitable heating rate, and is larger in natural rubber than in vulcanized rubber.

Yttrium barium copper oxide-filled polystyrene as a dielectric material

2010 ◽  
Vol 120 (4) ◽  
pp. 2233-2241 ◽  
Author(s):  
Rosalin Abraham ◽  
Soosy Kuryan ◽  
Jayakumari Isac ◽  
Ajesh K. Zacharia ◽  
Sabu Thomas
Keyword(s):  
Yttrium Barium Copper Oxide ◽  
Copper Oxide ◽  
Dielectric Material ◽  
Barium Copper Oxide ◽  
Barium Copper ◽  
Yttrium Barium

Thermal Stress and Failure Location Analysis for Through Silicon via in 3D Integration

2015 ◽  
Vol 32 (1) ◽  
pp. 47-53 ◽  
Author(s):  
H.-Y. Tsai ◽  
C.-W. Kuo
Keyword(s):  
Thermal Expansion ◽  
Thermal Stress ◽  
High Temperature ◽  
Stress Distribution ◽  
Surface Area ◽  
Dielectric Material ◽  
Three Dimensional ◽  
3D Integration ◽  
Element Analysis ◽  
Through Silicon Via

AbstractThrough silicon via (TSV) is the critical structure for three dimensional (3D) integration, which provides vertical interconnection between stacking dies. In TSV structure, large coefficient differences of thermal expansion exist between silicon substrate, dielectric material, and filled metal. Due to the large thermal mismatch, the high thermal stress occurring at the interface of different materials would result in delamination. Therefore, thermal-mechanical reliability is a key issue for 3D integration. In this study, we investigated the thermal-mechanical stress distribution of TSV under the condition of the accelerated thermal cycling loading by finite element analysis based on a 3D model of TSV structure. Due to the thermal expansion, that the TSV structure squeezed the surface area between TSVs at a high temperature resulted in compressive stresses at the surface area between TSVs. Therefore, a proper distance between the stress-sensitive device and the TSV should be kept. The stress analysis shows that the maximum thermal stress occurs in the outside region of TSV interface and in the annular region of TSV at a high temperature and at a low temperature, respectively. This study helps to obtain a clear thermal stress distribution of TSV and possible failure regions can be determined.

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