The influence of underfill material properties on the fatigue life of Ball Grid Array (BGA) packages that are subjected to thermal cycling is investigated in this study. A finite element model is created using Ansys by assuming the existence of an infinite array of solder interconnects, cylindrical in shape, surrounded by underfill material. Axial stresses in the interconnects are determined as a temperature loading is applied. The results show that these normal stresses are on the same order of magnitude as the hydrostatic compressive stresses induced in the solder upon underfill curing. Therefore it is concluded that for the range of underfill properties tested, these Mode I cyclic stresses need to be considered in the development of a fracture-based fatigue life model. In addition, a guideline is provided to aide researchers in designing experiments that will replicate loads on fractured specimens that are consistent with those seen in aerospace applications.

No description available.

Experimental and numerical analyses were both adopted in the thesis. First, the BGA with three different solder ball components and pads, were investigated and their strength was affected by drop tests and thermal cycling test. Then the concept of numerical simulation to do the follow-up analysis was adopted. the relationships of stress, strain, and creep strain energy density were found. The lead-free solder ball has better resistance to the drop test with lower silver content; on the contrary, it has better properties due to thermal cycling tests with higher silver content. In the drop test, the failure of solder ball were found obviously in the packages that near four corner of the test board, and concentrated in the diagonal screw holes. The failure of solder ball was distributed over the peripheral of the package in the middle cross section of test board. Comparing the different position of 15 packages due to drop test, the amount of failed solder balls showed that the package positions U3, U8, U13 was obviously fractured, and the situation of fracture was relatively slight in the positions of U1, U5, U6, U7, U9, U10, U11, U15. In the fatigue life prediction of thermal cycling test, the simplified model of package in 45¢X direction was mostly close to the experimental data. After the except ion of the solder ball with failure mode A1, the major failure mode in drop test was mode B3. But the mode C was the majority of thermal cycling test. The structure and intensity of SMD play an important role on above experiments; the better choice of SMD can reduce the rate of failure mode A1, and improve the accuracy of the experiment.

Logistics is regard as enterprise's "third profit source" and in the process of global industrialization it plays an important role. Many industries improve logistics conditions to reduce operating costs, and they attempt to obtain a new competitive advantage. With the development of the economy, culture, ideology, public and the gradually strengthen of the awareness of logistic, there is another heat topic attracted a lot of researchers-the environmental logistics. With the effect of the environmental logistic, more and more people realize that they must emphasize and value the natural environment, and inspired by the environmental logistic there are also lots of new topic came to be discussed, i.e. the coordinated development of the green economy. The environmental logistics as the indispensable part in economic development can deal with how to help the economic and the environment harmonious coexistence with each other. Thus, the development of green logistics has become major issue for global economic development nowadays. In this paper, we make a comparison of Chinese and developed country's green logistic statue, then identify the development of green logistics problems and propose solutions. The case companies we choose are COSCO international Freight Co., Ltd and the Panalpian Ltd. company. We connect these two companies and sent out questionnaires, based on their answers, we considered some elements which affect the difference between companies in Chinese and developed countries. We test these elements on SPSS, and carry out elements effecting environmental logistics. Based on this questionnaires,  we find out huge differences between these two companies, meanwhile there are five factors we summarized which influencing the gap between China and developed country in environmental logistics. Therefore, we give some suggestions for China's environmental future logistics.

¡@¡@A high efficient packaging technique was proposed for power InGaN light emitting diodes( LEDs ).In this approach , sub-mounts based on Si bench technology were used to provide a fact heat conducting channel between the LEDs and the cases.Two different structures of the Si sub-mounts were used, namely, a conventional Si block and a Si block with a copper-filled V-groove. ¡@¡@The thermal resistance of the two different sub-mounts were measured and compared. For a 45mil power LED biased at 1W, thermal resistance of 12.77¢J/W and 18.79¢J/W were measured for the Si sub-mount and the Si sub-mount with copper-filled V-groove. We believe the better thermal resistance of the sub-mount with copper-filled V-groove is due to high thermal conductivity of the copper.

In this study, a novel technique (TO-Butterfly package) for butterfly-type laser module packaging based on the coaxial type structure is proposed. By applying the low cost TO packaging technique, the cost and fabrication time can be reduced, and the yield rate can be increased. The achievement can be employed to package the novel butterfly-type laser module in the fiber optics communication. In traditional butterfly-type module package, the PWS was large while saddle clip and fiber ferrule being jointed by laser welding after the fiber ferrule and laser being aligned. Therefore, the coupling efficiency and the yield rate are low with long fabrication time. On the contrary, the TO-Butterfly package, similar to TO-Can laser module, includes upper part and lower part. The direction of the main PWS in TO-Butterfly laser module parallels to the optical axis, in which direction the components are constrained. Therefore, the PWS takes less influence on the coupling efficiency. Furthermore, the aligning process between the fiber and the laser and laser welding process is completed on Newport LW4000 workstation to build up a TO-Butterfly TOSA. After that, the TO-Butterfly TOSA is taken out of the workstation and combined with the case through solder. As a result, the fabrication time can be reduced to one-third. And the coupling efficiency and yield rate can also be improved. After several times of process modification, the coupling efficiency of the 19 TO-Butterfly TOSA modules by applying the novel packaging technology was all over 70%. The average and the highest coupling efficiency were 81.3% and 95.7%, respectively, and the standard deviation was 6.5%.

The Special Supplemental Nutrition Program for Women, Infants, and Children (The WIC Program), began in 1974, and has not seen any major changes to its food packages since then. In 2009, the WIC Program began implementing changes that mandated the inclusion of whole grains, fruits and vegetables, and low-fat dairy, among other changes. These changes aim to better align the food package benefits of the WIC Program with the Dietary Guidelines for Americans, 2005, and the American Academy of Pediatrics Child Feeding Recommendations. The objective of this research was to develop a culturally appropriate original questionnaire for The Texas WIC Program, which aimed to assess the dietary/feeding behaviors of Texas WIC participants both before and after the new WIC food package was implemented. The present study aims to present the methodology of how said survey was developed including pilot study and literature review. A mixed methods, biphasic approach was used to draft, edit and finalize the survey. The first phase consisted of item development, which involved literature review, and expert panel (n= 14) review to refine the instrument prior to piloting. Phase 2 of this research included recruitment of participants, a timed classroom administration of the survey, data collection, analysis and substantive reasoning based on the results of items to be included in the final survey. Quantitative data from survey piloting at two WIC local agency offices was used. Participants (n=54) completed two survey versions during piloting. The final questionnaire included measures of behaviors, attitudes and self-efficacy. Results from piloting showed that the "bubble" survey format had fewer errors and was more easily understood by participants. Incorporating relevant and recent scientific literature as related to survey design within a diverse population with social behavioral theory and mixed methods study design yielded a psychometrically sound instrument that has been used on a large scale and provided relevant data.

In this thesis, voltage-controlled oscillators (VCOs) with improved phase noise are designed and implemented. In the design of the resonant circuit varactor diodes are employed. In practice, a real VCO has to be packaged. The parasitic effect of the package may generate crosstalk inside the VCO and result in frequency shifting. To obtain an accurate prediction, a full wave model is developed. A simulation procedure is established combining High Frequency Structure Simulator (HFSS) with Advance Design System (ADS) software to predict the frequency response at the initial stage of the VCO design. Prototypes have been constructed and the characteristics measured. The simulation agrees with the measured results well. The obtained result show that our study can be used to cut the development time and cost.

The fiber alignment shifts induced by the post-weld-shift (PWS) in laser-welded TO(Transistor outline)-Can type laser module packages is studied experimentally and numerically. The PWS induced fiber alignment shifts were quantitatively determined by four geometrical parameters: the lateral shift(r), the position angle(£\), the tilt angle(£Z), and the swing angle(£c). The measured coupling powers in laser module packages before welding, after welding, and after a compensation clearly confirmed with the measured fiber alignment shifts determined by the dominant parameters of the r and £\ that the fiber shifts due to the PWS could be realigned back closer to their original optimum position after applying a welding compensation, and hence the coupling powers loss due to the PWS could be regained. The measured coupling efficiency after laser welding was from 68% to 95%, and the overall coupling efficiency after the PWS compensation was from 77% to 97%. The increased coupling efficiency after this PWS compensation was from 2% to16%. A coupled thermal-elasto-plasticity model of finite-element method (FEM) analysis was performed to evaluate the effects of PWS on fiber alignment shifts in laser module packages. The measured fiber alignment shifts determined by the dominant parameters of the r and £\ were in good agreement with the numerical calculation of the FEM analysis. In this study, the combination of the experimental and numerical results have significantly provided a practical design guideline for fabricating reliable laser-welded TO-Can type laser module packages with a high yield and high performance for use in low-cost lightwave transmission systems. A novel measurement and compensation technique employing a high-magnification camera with image capturing system (HMCICS) to probe the post-weld-shift (PWS) induced fiber alignment shifts in high-performance butterfly-type laser module packages is investigated. The results show that the direction and magnitude of the fiber alignment shifts induced by the PWS in laser-welded butterfly-type laser module packaging can be quantitatively determined and then compensated. The measured coupling powers in laser module packages after welding and compensation clearly confirmed the measured fiber alignment shifts determined by the translational and rotational parameters that the fiber shifts due to the PWS could be realigned back closer to their original optimum position after applying a welding compensation, and hence the coupling powers loss due to the PWS could be regained. The measured coupling efficiency after laser welding was from 63% to 79%, and the overall coupling efficiency after the PWS compensation was from 69% to 89%. The increased coupling efficiency after this PWS compensation was from 3% to 10%. In comparison with previous studies of the PWS compensation by a qualitatively estimated technique in butterfly-type laser module packages, this novel HMCICS technique has significantly provided an important tool for quantitative measurement and compensation to the effect of the PWS on the fiber alignment shifts in laser module packages. Therefore, the reliable butterfly-type laser modules with a high yield and a high performance used in lightwave transmission systems can be developed and fabricated.

Abstract¡G The main aim of this paper is to utilizing the Shadow Moirè method to study the moisture effect on the warpage of PBGA IC package under the IR-reflow process. An environmental controlled box is designed and built. Three combinations of different moisture and temperature status are chosen for the purpose of study. The result shows that the moisture and temperature change do yielding the change of the warpage of the IC package.