Microstructural and Thermal Characterization of Copper Based Composites for Thermal Management in Electronic Packaging

2014 ◽  
Vol 976 ◽  
pp. 148-153 ◽  
Author(s):  
Carlos Alberto León ◽  
Gabriel Rodríguez-Ortiz ◽  
E.A. Aguilar-Reyes ◽  
Makoto Nanko ◽  
M. Takeda
Keyword(s):  
Electronic Packaging ◽  
Coefficient Of Thermal Expansion ◽  
Thermal Characterization ◽  
Electroless Copper Plating ◽  
Pulsed Electric Current ◽  
Alumina Particles ◽  
The Matrix ◽  
Materials Used ◽  
Thermo Physical Properties

Copper based composites with 30, 40, 50 and 60 vol.% Al2O3 were fabricated by powder metallurgy and consolidated by pulsed electric current sintering (PECS). For the purpose of determining the advantage of using coated fillers, composite alumina particles with 18 vol.% copper were prepared by electroless copper plating. Coatings were continuous and homogeneous through alumina surface. Thus, composites consolidated by the modified process increased contact between the matrix and filler, which resulted in superior thermo-physical properties. Thermal conductivities of 210-99 and 227-114 W/mK were obtained for Cu/Al2O3 made by the admixture and the coated filler method, respectively. Such superiority is mainly attributed to the continuity in the matrix phase; the thermal conductivity values observed are similar to those shown by the traditional materials used in electronic packaging. The coefficient of thermal expansion was slight lower in composites fabricated by the coated filler method; values in the ranges of 14-11 and 13-10.5 μm/m°C were obtained for the admixture and the coated filler method, respectively.

Thermal Characterization of Polyurethane from Castor Oil Reinforced Sugarcane Straw Composites

2011 ◽  
Vol 415-417 ◽  
pp. 1103-1106
Author(s):  
Patricia Câmara Miléo ◽  
George Jackson de Moraes Rocha ◽  
Adilson Roberto Gonçalves
Keyword(s):  
Castor Oil ◽  
Thermal Characterization ◽  
Natural Fibre ◽  
Cellulose Fibres ◽  
Sugarcane Straw ◽  
The Matrix ◽  
One Step ◽  
Polyurethane Composites ◽  
Environmental Interests

The development in the area of natural-fibre-reinforced composites has greatly increased in recent years. Using castor oil polyurethane (PU) as matrix for composites reinforced with lignin and cellulose from sugarcane straw is in tune with economical and environmental interests. The aim of this work was the thermal degradation study of castor oil-polyurethane composites reinforced with cellulose from sugarcane straw. For the obtainment of cellulose, sugarcane straw was pretreated by steam explosion, followed by a delignification with NaOH. For the production of the PU, the polyol (castor oil) to diisocyanate mass ratio was 1.5:1.0. Reinforcement of the matrix was done changing the concentration of cellulose fibres (5,10,15,20% w/w). Thermogravimetric analysis of the materials was carried out. The results obtained showed that the process of decomposition of the matrix occurs in one step, while for the composites it occurs in two steps. The addition of reinforcement in the matrix basically did not change the thermal stability of the composite.

On the Thermal Characterization of Fibers Prepared by Cryogenic Grinding of Scrap Tires

2010 ◽  
Vol 636-637 ◽  
pp. 1421-1427
Author(s):  
F. Parrés ◽  
J.E. Crespo ◽  
A. Nadal ◽  
A. Macias-Garcia ◽  
E.M. Cuerda-Correa
Keyword(s):  
Thermal Characterization ◽  
Thermal Transitions ◽  
Recycling Process ◽  
Pyrolysis Gas ◽  
Scrap Tires ◽  
Analysis Techniques ◽  
Reinforcing Fibers ◽  
Materials Used ◽  
Thermal Analysis Techniques

The importance of recovering and valorising the residues generated by industrialized societies is mainly due to the environmental impact that such residues may cause. In this connection, scrap tires constitute a major source of pollution. In the recent years large amounts of scrap tires have been recycled in order to recover the metals contained in this residue. Tires have also been grinded and the small particles produced have found different applications. In addition to metals and rubber particles, reinforcing fibers are also produced in the recycling process of scrap tires. As a previous step for the valorisation of this third constituent of waste tires, a characterization of such fibers is strongly recommended. Thermal analysis techniques make it possible to identify the fibers through the thermal transitions that may take place. Usually, such transitions result mainly in cotton and rayon. Furthermore, the combination of pyrolysis, gas chromatography and mass spectrometry techniques corroborates the identification of several compounds derived from the decomposition of the fibers as well as some materials used in the preparation of tires.

Thermal Characterization of Bi-Material Microcantilevers: Thermal Conductance and Microscale Convection

2009 ◽  
Author(s):  
Arvind Narayanaswamy ◽  
Ning Gu
Keyword(s):  
Heat Transfer ◽  
Thermal Environment ◽  
Coefficient Of Thermal Expansion ◽  
Ambient Pressure ◽  
Thermal Conductance ◽  
Thermal Characterization ◽  
Temperature Changes ◽  
Atomic Force ◽  
The Heat Transfer Coefficient

Bi–material atomic force microscope cantilevers have been used extensively over the last 15 years as physical, chemical, and biological sensors. As a thermal sensor, the static deflection of bi–material cantilevers due to the mismatch of the coefficient of thermal expansion between the two materials has been used to measure temperature changes as small as 10−5 K, heat transfer rate as small as 40 pW, and energy changes as small as 10 fJ. Bi–material cantilevers have also been use to measure “heat transfer - distance” curves a heat transfer analogy of the force–distance curves obtained using atomic force microscopes. In this work, we concentrate on characterization of heat transfer from the microcantilever. The two quantities that we focus on are the thermal conductance of the cantilever, Gcant (units WK−1), and the thermal conductance due to microscale convection from the cantilever to the ambient fluid, Gconv (units WK−1). The deflection of the cantilever to changes in its thermal environment is measured using the shift in position, on a position sensitive detector, of a laser beam focused at the tip of the cantilever. By determining the response of the microcantilever to (1) uniform temperature rise of the ambient, and (2) change in power absorbed at the tip, the thermal conductance of heat transfer from the cantilever can be determined. When the experiment is performed at low enough ambient pressure so that convection is unimportant (¡ 0.1 Pa), Gcant can be measured. When the experiment is performed at atmospheric pressure the heat transfer coefficient due to convection from the cantilever can be determined.

scholarly journals Physical and Thermal Characterization of Alkali Treated Rice Husk Reinforced Polypropylene Composites

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Ismat Zerin Luna ◽  
Krishna Chandra Dam ◽  
A. M. Sarwaruddin Chowdhury ◽  
Md. Abdul Gafur ◽  
Nuruzzaman Khan ◽  
...  
Keyword(s):  
Rice Husk ◽  
Sodium Hydroxide Solution ◽  
Thermal Characterization ◽  
Sem Analysis ◽  
Morphological Properties ◽  
Electron Microscopic ◽  
Polypropylene Composites ◽  
The Matrix ◽  
The Fourier Transform

Rice husk (RH) reinforced polypropylene- (PP-) based composites were prepared by compression molding. The RH was treated with sodium hydroxide solution (1 wt%); then composites were prepared using varying percentages of RH (5 to 20 wt%). The thermomechanical, spectroscopic, and morphological properties of the prepared composites (RH-PP) were investigated. The scanning electron microscopic (SEM) analysis showed better interfacial adhesion between alkali treated RH and the matrix PP. The Fourier Transform Infrared (FTIR) spectra confirmed the chemical bonding.The results revealed that physical properties as well as thermal stability of the composites improved significantly with the addition of alkali treated RH in PP matrix.

Thermal characterization of coal using piezoelectric photoacoustic microscopy

1986 ◽  
Vol 64 (9) ◽  
pp. 1184-1189 ◽  
Author(s):  
A. Biswas ◽  
T. Ahmed ◽  
K. W. Johnson ◽  
K. L. Telschow ◽  
J. C. Crelling ◽  
...  
Keyword(s):  
Elastic Properties ◽  
Coefficient Of Thermal Expansion ◽  
Thermal Characterization ◽  
Photoacoustic Signal ◽  
Photoacoustic Microscopy ◽  
Piezoelectric Detection ◽  
Theoretical Predictions ◽  
Coal Macerals

The organic constituents that make up the heterogeneous coal mass are called macerals. Vitrinite and pseudovitrinite are two of the most abundantly occurring macerals in North American coals. Photoacoustic microscopy using piezoelectric detection offers a useful technique for probing the thermal-elastic properties of these coal macerals. The experimental and theoretical conditions under which photoacoustic microscopy can be used to characterize the in situ thermal-elastic properties of macerals, as a function of the percentage of carbon or "rank" of coal, are investigated in this paper. Existing piezoelectric photoacoustic theory has been applied to our sample–transducer configuration to arrive at an expression for the voltage measured from the piezoelectric transducer. The theory indicates that the photoacoustic signal is related to the following sample properties: coefficient of thermal expansion a, bulk modulus B, density ρ, and specific heat c. These properties are coupled together into a dimensionless parameter given by aB/ρc, to which the measured voltage is proportional. Some experimental results used to test the validity of the theoretical predictions are presented. Photoacoustic data gathered on 10 Appalachian Basin coals are plotted as a function of the coal rank. These results are shown to compare favourably with a calculated curve, constructed using independently measured values of a, B, ρ, and c.

scholarly journals Thermal characterization of archaeological pot sherds recently excavated in Nedunkur, Tamilnadu, India

Cerâmica ◽  
2012 ◽  
Vol 58 (347) ◽  
pp. 338-341 ◽  
Author(s):  
S. Meyvel ◽  
P. Sathya ◽  
G. Velraj
Keyword(s):  
Raw Materials ◽  
Thermal Characterization ◽  
Inert Atmosphere ◽  
Firing Process ◽  
Linear Temperature ◽  
Thermal Reactions ◽  
Mineralogical Characteristics ◽  
Temperature Ramp ◽  
Materials Used

The archaeological pottery sherds excavated recently in Nedunkur, Tamilnadu, were analysed using Thermogravimetric (TG) and Differential Thermal analysis (DTA) with an objective of identifying the mineralogical characteristics of the raw materials used for their production. Besides, the thermal reactions associated over the linear temperature ramp from room temperature to 1200 °C in an inert atmosphere were also realized by TG-DTA. The characterization studies were able to indicate the conditions of firing process adopted and firing temperature attained by the artisans at the time of manufacture.

Microwave Synthesis and Characterization of Magnesium Based Composites Containing Nanosized SiC and Hybrid (SiC+Al2O3) Reinforcements

2006 ◽  
Vol 129 (2) ◽  
pp. 194-199 ◽  
Author(s):  
Sanjay Kumar Thakur ◽  
K. Balasubramanian ◽  
Manoj Gupta
Keyword(s):  
Brittle Failure ◽  
Failure Strain ◽  
Coefficient Of Thermal Expansion ◽  
Microwave Sintering ◽  
Hot Extrusion ◽  
Magnesium Matrix ◽  
The Matrix ◽  
Al2o3 Particles ◽  
Powder Metallurgy Route

In the present study, monolithic magnesium, nanosized SiC reinforced magnesium and nanosized hybrid (SiC+Al2O3) reinforced magnesium materials have been synthesized by using powder metallurgy route involving microwave sintering followed by hot extrusion. The results show that the monolithic and the reinforced magnesium materials have minimal porosity and the reinforced magnesium materials have fairly well distributed nanosized SiC and SiC+Al2O3 particles in the matrix. The thermo-mechanical property measured in terms of coefficient of thermal expansion of the reinforced magnesium shows dimensionally more stable magnesium as compared to monolithic magnesium. The hardness 0.2% YS and UTS were found to improve significantly after addition of nanosized SiC and nanosized hybrid SiC+Al2O3 particles to the magnesium, However, ductility measured in terms of failure strain was found to be marginally reduced. Fractography results showed the presence of brittle failure mode with cleavage steps on the fractured surface of the magnesium matrix.

Sign in / Sign up

Export Citation Format

Share Document