Thermal Strain Analysis of a Flip-Chip Package by a Modified Hybrid Method

介绍一种可用于微电子封装局部应变场分析的实验/计算混合方法,该方法结合了有限元的整体/局部模型和实时的激光云纹干涉技术,利用激光云纹干涉技术所测得的应变场来校核有限元整体模型的计算结果,并用整体模型的结果作为局部模型的边界条件,对实验难以确定的封装结构局部位置的应力、应变场进行分析.用这种方法对可控坍塌倒装封装结构在热载荷作用下焊球内的应变场分布进行了分析,结果表明该方法能够提供封装结构内应力-应变场分布的准确和可靠的结果,为微电子封装的可靠性分析提供重要的依据. For the reliability analysis of electronic packages, strains in very localized areas, such as an interconnection or a corner, need to be determined. In this paper, a modified hybrid method of global/local modeling and real time moire interferometry is presented. In this method, a simplified, coarsely meshed global model is developed to get rough information about the deformation of the microelectronic package. In order to make sure the global model has been reasonably simplified and the material properties ...

Application of Optical Protein-chip in Detecting Phage M13KO7

Abstract: Avidin layer was bound on the substrate surface of Silicon wafer modified with aldehyde. The interaction between avidin and biotin was adopted for the immobilization of mouse monoclonal biotin-anti-M13 (antibody GP3)-labeled biotin. The surface was incubated in a solution containing phage M13KO7, which was trapped by the antibody GP3 with the interaction between phage M13KO7 and antibody GP3, resulting in a variation of layer thickness that was detected by imaging ellipsometry. The results showed a saturated layer of antibody GP3 with a thickness about 6.9 nm on the surface of the silicon wafer. The specific interaction between phage M13KO7 and antibody GP3 resulted in a variation of layer thickness. The layer of phage M13KO7 bound with antibody GP3 was 17.5 nm in the concentration of 1.1×1010 pfu/mL. Each variation of the layer thickness corresponded to a concentration of phage M13KO7 in the range of 0.1×1010–2.5×1010 pfu/mL, with the sensitivity of 109 pfu/mL. Compared with other methods, the optical protein-chip, requiring only short measurement time, label free, is a quantitative test, and can be visualized. This study could be significant on the interactions between the antibody and the virus, showing potential in the early diagnosis of virosis.

Micro-systems for Optical Protein-Chip

Protein-Chip as micro-assays for the determination of protein interaction, the analysis, the identification and the purification of proteins has large potential applications. The Optical Protein-Chip is able to detect the multi-interaction of proteins and multi-bio-activities of molecules directly and simultaneously with no labeling. The chip is a small matrix on solid substrate containing multi-micro-area prepared by microfabrication with photolithography or soft lithography for surface patterning, and processed with surface modification which includes the physical, chemical, and bio-chemical modifications, etc. The ligand immobilization, such as protein immobilization, especially the oriented immobilization with low steric hindrance and high bio-specific binding activity between ligand and receptor is used to form a sensing surface. Each area of the pattern is corresponding to only one bioactivity. The interval between the areas is non-bioactive and optically extinctive. The affinity between proteins is used to realize non-labeling microassays for the determination of protein identification and protein interaction. The sampling of the chip is non-disturbing, performed with imaging ellipsometry and image processing on a database of proteins.

Simultaneous Laser-Induced Fluorescence And Contactless-Conductivity Detection For Microfluidic Chip

A combined detection system involving simultaneous LIF and contactless-conductometric measurements at the same place of the microfluidic chip was described. The LIF measurement was designed according to the confocal principle and a moveable contactless-conductivity detector was used in (CD)-D-4. Both measurements were mutually independent and advantageous in analyses of mixtures. Various experimental parameters affecting the response were examined and optimized. The performances were demonstrated by simultaneous detection of Rhodamine B. And the results showed that the combined detection system could be used sensitively and reliably. (C) 2008 Yong Yu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Soluble Angiopoietin Receptor Tie-2 In Patients With Acute Myocardial Infarction And Its Detection By Optical Protein-Chip

The Tie-2 receptor has been shown to play a role in angiogenesis in atherosclerosis. The conventional method assaying the level of soluble Tie-2 (sTie-2) was ELISA. However, this method has some disadvantages. The aims of this research are to establish a more simple detection method, the optical protein-chip based on imaging ellipsomtry (OPC-IE) applying to Tie-2 assay. The sTie-2 biosensor surface on silicon wafer was prepared first, and then serum levels of sTie-2 in 38 patients with AMI were measured on admission (day 1), day 2, day 3 and day 7 after onset of chest pain and 41 healthy controls by ELISA and OPC-IE in parallel. Median level of sTie-2 increased significantly in the AMI patients when compared with the controls. Statistics showed there was a significant correlation in sTie-2 results between the two methods (r=0.923, P0.01). The result of this study showed that the level of sTie-2 increased in AMI, and OPC-IE assay was a fast, reliable, and convenient technique to measure sTie-2 in serum.

Freestanding optical fibers fabricated in a glass chip by femtosecond laser micromachining for lab-on-a-chip application (vol 13, pg 7225, 2005)

An erratum is presented to correct the propagation loss of the freestanding optical fibers fabricated in glass chip. (c) 2006 Optical Society of America.

Surface planar ion chip for linear radio-frequency Paul traps

We propose a surface planar ion chip which forms a linear radio frequency Paul ion trap. The electrodes reside in the two planes of a chip, and the trap axis is located above the chip surface. Its electric field and potential distribution are similar to the standard linear radio frequency Paul ion trap. This ion trap geometry may be greatly meaningful for quantum information processing.

A single-layer magnetic atom chip for trapping an array of Bose-Einstein condensate

We propose a simple single-layer magnetic microtrap configuration which can trap an array of magnetically-trapped Bose-Einstein condensate. The configuration consists of two series of parallel wires perpendicular to each other and all of the crossing points are cut off for maintaining the uniformity of the current. We analyse the trapping potential, the position of trapping centres and the uniformity of the array of the traps. The trapping depth and trapping frequency with different parameters are also calculated. Lastly, the effect of the cut-off crossing points, dissipate power, chip production are introduced concisely.

Guiding neutral atoms with two current-carrying wires and a vertical bias field on the atom chip

We demonstrate the guiding of neutral atoms with two parallel microfabricated current-carrying wires on the atom chip and a vertical magnetic bias field. The atoms are guided along a magnetic field minimum parallel to the current-carrying wires and confined in the other two directions. We describe in detail how the precooled atoms are efficiently loaded into the two-wire guide. We present a detailed experimental study of the motional properties of the atoms in the guide and the relationship between the location of the guide and the vertical bias field. This two-wire guide with vertical bias field can be used to realize large area atom interferometer.

TWO-DIMENSIONAL ARRAY OF ION TRAPS ON A PLANAR CHIP

We investigate a planar ion chip design with a two-dimensional array of linear ion traps for the scalable quantum information processor. The segmented electrodes reside in a single plane on a substrate and a grounded metal plate, a combination of appropriate rf and DC potentials are applied to them for stable ion confinement, and the trap axes are located above the surface at a distance controlled by the electrodes' lateral extent and the substrate's height as discussed. The potential distributions are calculated using static electric field qualitatively. This architecture is conceptually simple and many current microfabrication techniques are feasible for the basic structure. It may provide a promising route for scalable quantum computers.

Identification and characterization of Bacillus anthracis by multiplex PCR on DNA chip

Bacillus anthracis can be identified by detecting virulence factor genes located on two plasmids, pXO1 and pXO2. Combining multiplex PCR with arrayed anchored primer PCR and biotin-avidin alkaline phosphatase indicator system, we developed a qualitative DNA chip method for characterization of B. anthracis, and simultaneous confirmation of the species identity independent of plasmid contents. The assay amplifies pag gene (in pXO1), cap gene (in pXO2) and Ba813 gene (a B. anthracis specific chromosomal marker), and the results were indicated by an easy-to-read profile based on the color reaction of alkaline phosphatase. About 1 pg of specific DNA fragments on the chip wells could be detected after PCR. With the proposed method, the avirulent (pXO1(+)/2(-), pXO1(-)/2(+) and pXO1(-)/2(-)) strains of B. anthracis and distinguished 'anthrax-like' strains from other B. cereus group bacteria were unambiguously identified, while the genera other than Bacillus gave no positive signal. (C) 2004 Elsevier B.V. All rights reserved.

Oligonucleotide ligation assay-based DNA chip for multiplex detection of single nucleotide polymorphism

An oligonucleotide ligation assay-based DNA chip has been developed to detect single nucleotide polymorphism. Synthesized nonamers, complementary to the flanking sequences of the mutation sites in target DNA, were immobilized onto glass slides through disulfide bonds on their 5' terminus. Allele-specific pentamers annealed adjacent to the nonamers on the complementary target DNA, containing 5'-phosphate groups and biotin labeled 3'-ends, were mixed with the target DNA in tube. Ligation reactions between nonamers and pentamers were carried out on chips in the presence of T4 DNA ligase. Ligation products were directly visualized on chips through enzyme-linked assay. The effect of G:T mismatch at different positions of pentamers on the ligation were evaluated. The results showed that any mismatch between pentamer and the target DNA could lead to the decrease of ligation, which can be detected easily. The established approach was further used for multiplex detection of mutations in rpoB gene of rifampin-resistant Mycobacterium tuberculosis clinical isolates. (C) 2003 Elsevier B.V. All rights reserved.