Low Temperature Die Attach Material

1989 ◽  
Vol 167 ◽  
Author(s):  
Mark A. Blocker ◽  
Tom L. Herrington ◽  
My N. Nguyen

AbstractA new silver lead phosphovanadate glass die attach material is discussed. Its sintering characteristics are examined by dilatometry and the organic system by thermo gravimetric analysis. Sintering is found to occur at lower temperature than conventional silver glass systems. This is caused by reaction between silver and one of the glass components during heat treatment. The vehicle is found to evaporate faster allowing void free processing for large area dice.The new glass combined with a more volatile organic system has produced a single pass die attach material which can be fired as low as 360°C.

Evaluation of consumer properties of polyurethane thermal panels is the goal of the work. Physico-mechanical and operational characteristics of thermal panels are determined to achieve the purpose of the work. Methods of IR spectroscopy and thermo gravimetric analysis were used to study the structure of the samples. Satisfactory consumer properties of the studied thermo panels are brought out: compliance of clinker with the DIN EN 121 standard; absence of visual defects and change of color of thermo panels after 50 cycles of freezing-thawing; absence of changing color of thermo panels after influence of UV of radiation with the wavelength of 240-320 nanometers within 607 hours 30 minutes; high values of coefficients of sound absorption in the frequency range from 600 to 1600 Hz; low heat conductivity of the FPU layer. The influence of UV-radiation on thermal stability of foamed polyurethane is valued. Thermal analysis methods and IR spectroscopy are used to assess the degree of UV - destruction of polyurethane foam. At destruction of foamed polyurethane there is a rupture of chemically weak communication and formation of alcohols, air, olefins. The results of IR-spectroscopy illustrate the beginning of the processes of destruction of samples of FPU under the influence of UV-radiation. Using the thermo gravimetric analysis the research of the FPU thermal properties under the influence of UV - radiations is conducted. It is established that compositions from FPU under the influence of UV- radiation have lower temperature of the beginning of decomposition, than initial material. The influence of UV-radiation on heat stability of the studied compositions is shown. The possible mechanism of destruction of FPU is confirmed in the research. The DSС method has estimated the resistance of FPU to the oxidizing influence characterizing the material operation time. The studied consumer properties of thermal panels show that they can be used in civil engineering as effective protection structures of buildings.


2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Madalina Angelusiu ◽  
Maria Negoiu ◽  
Stefania-Felicia Barbuceanu ◽  
Tudor Rosu

The paper presents the synthesis and characterization of Cu(II), Co(II), Ni(II), Cd(II), Zn(II) and Hg(II) complexes with N1-[4-(4-bromo-phenylsulfonyl)-benzoyl]-N4-(4-methoxyphenyl)-thiosemicarbazide. The new compounds were characterized by IR, EPR, electronic spectroscopy, magnetic moments, thermo-gravimetric analysis and elemental analysis.


Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1728
Author(s):  
Peng Wen ◽  
Teng-Gen Hu ◽  
Yan Wen ◽  
Ke-Er Li ◽  
Wei-Peng Qiu ◽  
...  

An ethyl acetate extract from of Nervilia fordii (NFE) with considerable suppression activity on lipid peroxidation (LPO) was first obtained with total phenolic and flavonoid contents and anti-LPO activity (IC50) of 86.67 ± 2.5 mg GAE/g sample, 334.56 ± 4.7 mg RE/g extract and 0.307 mg/mL, respectively. In order to improve its stability and expand its application in antioxidant packaging, the nano-encapsulation of NFE within poly(vinyl alcohol) (PVA) and polyvinyl(pyrrolidone) (PVP) bio-composite film was then successfully developed using electrospinning. SEM analysis revealed that the NFE-loaded fibers exhibited similar morphology to the neat PVA/PVP fibers with a bead-free and smooth morphology. The encapsulation efficiency of NFE was higher than 90% and the encapsulated NFE still retained its antioxidant capacity. Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD) analysis confirmed the successful encapsulation of NFE into fibers and their compatibility, and the thermal stability of which was also improved due to the intermolecular interaction demonstrated by thermo gravimetric analysis (TGA). The ability to preserve the fish oil’s oxidation and extend its shelf-life was also demonstrated, suggesting the obtained PVA/PVP/NFE fiber mat has the potential as a promising antioxidant food packaging material.


2011 ◽  
Vol 135-136 ◽  
pp. 1057-1059
Author(s):  
Heng Tao Zhou ◽  
Yong Wei

With a thermo gravimetric analysis apparatus combustion characteristics experiments of coal residue cornstalk and mixtures of them were done at 20 C/min heating rate. Then the combustion characteristic Parameters were obtained by above experiments. The c combustion activation energies were acquired by kinetics analysis. The results show those: the ignition characteristic and synthesis combustion characteristic of coal residue are bad. The ignition characteristic and synthesis combustion characteristic of cornstalk are better. The combustion characteristics of the mixture of coal residue and cornstalk are determined by mixing ratio. The ratio of cornstalk is more and the synthesis combustion characteristic is better.


2019 ◽  
Vol 41 (2) ◽  
pp. 240-240
Author(s):  
Nevin Cankaya Nevin Cankaya

In this study, some new chitosan materials were synthesized by the grafting of chitosan with the monomers such as 1-vinylimidazole (VIM), methacrylamide (MAm) and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS). First of all, chitosan methacrylate was prepared by esterification of primary -OH group with methacryloyl chloride a 25.13% yield by mole. The monomers were grafted into chitosan methacrylate via free radical polymerization using 2,2and#39;-Azobisisobutyronitrile as an initiator in N,N-dimethylformamide. The graft copolymers were characterized by FT-IR spectra and elemental analysis. Thermal stabilities of the graft copolymers were determined by TGA (thermo gravimetric analysis) method. The synthesized chitosan methacrylate and its graft copolymers were tested for their antimicrobial activity against bacteria and yeast.


2017 ◽  
Vol 898 ◽  
pp. 2347-2353
Author(s):  
Ahmed Hossamaldin ◽  
Ping Liu ◽  
Ya Du ◽  
Xiao Ze Jiang ◽  
Bin Sun ◽  
...  

To prepare alpha zirconium phosphate (α-ZrP) with high interlayer distance, grafting ratio and thermal stability, 1,2-epoxypropane was used to modify α-ZrP as the epoxy group reacting with P-OH on the external and internal surfaces of α-ZrP to form P-O-C bonds after small amines pre-intercalation. Different characterization techniques were used, including X-ray Powder Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Thermo-Gravimetric Analysis (TGA) and Carbon Mass Nuclear Magnetic Resonance (13C MAS NMR). The results of XRD confirmed the pre-intercalation of amino-propane and the intercalation of 1,2-epoxypropane, as the interlayer distance increased from 7.5 Å to 16.9 Å and 15.3 Å, respectively. FT-IR and 13C MAS NMR results confirmed the formation of P-O-C bonds between 1,2-epoxypropane and α-ZrP. TGA analysis showed that the grafting ratio of 1,2-epoxypropane was 19.44%.


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