Controlling warpage of molded package for inkjet manufacturing

A system consisting of four silicon dies and several discrete components was encapsulated with epoxy mold material and the package was used for the evaluation of inkjet manufacturing in electronics. Experimental samples showed that the molding process induces thermo-mechanical stresses that warp the package after the mold resin is cured at elevated temperature. The molding process was modeled using the finite element method (FEM), and different package structures were simulated to see how those affect the final warpage of the package. Material properties of the mold material were measured and used in the FE model. The viscoelastic behavior of mold material was modeled with a sum of Prony series terms and a time-temperature shift factor was used to include the temperature effect. To verify the modeling assumptions, the surface profile of an experimental package was measured with an optical profilometer and the measurements were compared with the simulated profile. A good correlation was found between the measured and simulated profile of the package. The simulations with different package structures showed that e.g. an additional film placed on top of the mold resin reduces significantly the warpage of the package.     

Die L?slichkeit der kohlensauren Magnesia in kohlens?urehaltigem Wasser

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Ueber Indicatoren zur Alkalimetrie und Acidimetrie

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Improved lower bound for locating-dominating codes in binary Hamming spaces

Designs, Codes and Cryptography - In this article, we study locating-dominating codes in binary Hamming spaces $$mathbb {F}^n$$ . Locating-dominating codes have been widely studied since their...     

Analysis of selective androgen receptor modulators by gas chromatography-microchip atmospheric pressure photoionization-mass spectrometry

A gas chromatography-microchip atmospheric pressure photoionization-mass spectrometric (GC-μAPPI-MS) method was developed and used for the analysis of three 2-quinolinone-derived selective androgen receptor modulators (SARMs). SARMs were analyzed from spiked urine samples, which were hydrolyzed and derivatized with N-methyl-N-(trimethylsilyl)trifluoroacetamide before analysis. Trimethylsilyl derivatives of SARMs formed both radical cations (M^+•) and protonated molecules ([M + H]⁺) in photoionization. Better signal-to-noise ratios (S/N) were obtained in MS/MS analysis using the M^+• ions as precursor ions than using the [M + H]⁺ ions, and therefore the M^+• ions were selected for the precursor ions in selected reaction monitoring (SRM) analysis. Limits of detection (LODs) with the method ranged from 0.01 to 1 ng/mL, which correspond to instrumental LODs of 0.2–20 pg. Limits of quantitation ranged from 0.03 to 3 ng/mL. The mass spectrometric response to the analytes was linear (R ≥ 0.995) from the LOQ concentration level up to 100 ng/mL concentration, and intra-day repeatabilities were 5%–9%. In addition to the GC-μAPPI-MS study, the proof-of-principle of gas chromatography-microchip atmospheric pressure chemical ionization-Orbitrap MS (GC-μAPCI-Orbitrap MS) was demonstrated.     

Feasibility of capillary liquid chromatography/microchip atmospheric pressure photoionization mass spectrometry in analyzing anabolic steroids in urine samples

We examined the feasibility of capillary liquid chromatography/microchip atmospheric pressure photoionization tandem mass spectrometry (capLC/µAPPI‐MS/MS) for the analysis of anabolic steroids in human urine. The urine samples were pretreated by enzymatic hydrolysis (with β‐glucuronidase from Helix pomatia), and the compounds were liquid‐liquid extracted with diethyl ether. After separation the compounds were vaporized by microchip APPI, photoionized by a 10 eV krypton discharge lamp, and detected by selected reaction monitoring. The capLC/µAPPI‐MS/MS method showed good sensitivity with detection limits at the level of 1.0 ng mL^?1, good linearity with correlation coefficients between 0.9954 and 0.9990, and good repeatability with relative standard deviations below 10%. These results demonstrate that microchip APPI combined with capLC/MS/MS provides a new potential method for analyzing non‐polar and neutral compounds in biological samples. Copyright © 2010 John Wiley & Sons, Ltd.     

Universal gates with wires in a row

Journal of Algebraic Combinatorics - Koornwinder polynomials are q-orthogonal polynomials equipped with extra five parameters and the $$B C_n$$ -type Weyl group symmetry, which were introduced by...     

Passivation of black silicon boron emitters with atomic layer deposited aluminum oxide

The nanostructured surface – also called black silicon (b‐Si) – is a promising texture for solar cells because of its extremely low reflectance combined with low surface recombination obtained with atomic layer deposited (ALD) thin films. However, the challenges in keeping the excellent optical properties and passivation in further processing have not been addressed before. Here we study especially the applicability of the ALD passivation on highly boron doped emitters that is present in crystalline silicon solar cells. The results show that the nanostructured boron emitters can be passivated efficiently using ALD Al₂O₃ reaching emitter saturation current densities as low as 51 fA/cm². Furthermore, reflectance values less than 0.5% after processing show that the different process steps are not detrimental for the low reflectance of b‐Si. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)