Ken Kaminishi

Prediction of the Fatigue Crack Growth Life in Microelectronics Solder Joints

In order to predict the crack growth life in microelectronics solder joints, an FE A (finite element analysis) program employing a new scheme for crack growth analysis is developed. Also some experimental data necessary for the practical application of this program are obtained. Above all, the data related to the crack growth rate play a key role and are obtained in terms of the maximum opening stress range Δσθ max as

Contact Width Analysis of Corrugated Metal Gasket Based on Surface Roughness

{{da} \mathord{\left/ {\vphantom {{da} {dN = }}} \right. \kern-\nulldelimiterspace} {dN = }}\beta \left[ {\Delta \sigma _{\theta max} - \gamma } \right]^\alpha ,

Optimized design of cab frame to improve energy absorption performance

where α = 2.0 and β = 2.5 x 10-9 mm 5/N 2 are independent of the test conditions, and γ is dependent on the solder material. The calculated values of the crack growth life by the FEA are in good agreement with the experimental ones. This indicates at the same time that the crack growth rate and path are certainly controlled, through the above equation, by Δσθ max measured at a certain radial distance from the crack tip.

Study on Bending Characteristics for Square Tube Using Energy Absorption Part

Previous studies on corrugated metal gaskets have established that the contact width, contact stress, and surface roughness are important design parameters for optimizing gasket performance. However, the contact stress and contact width considering the surface roughness when the leakage occur did not defined yet. In this study, we determined the real contact stress and contact width when leakage started on 25A-size metal gasket. The contact width determined through a comparison between simulation and experimental results. The contact stress determined through a simulation analysis. The experiment involves a helium leakage test using new metal gaskets having different surface roughness levels. The result justified that the real contact width and average contact stress when the leakage started occur were 0.195mm and 800MPa, respectively. There is a good agreement for contact width both by simulation and experiment result. The contact width for flange having surface roughness 1.5μm is longest than the others.

Evaluation Grain Homogeneity of Aluminium after ECAP Process by ECAP Geometry Analysis Using Taguchi Method

Contact width is important design parameter for optimizing design of new metal gasket. The contact width was found have relationship with helium leak quantity. Increasing axial force, the contact width will increase and helium leakage will decrease. This study we conducted the surface roughness evaluation of 25A-size metal gasket before and after use. The results denote the real contact width after contact with flange having different surface roughness. The real contact width for the flange having smoother surface roughness is wider than the rougher one.

Deformation Characteristic of Thin Stainless Gasket Material

In the previous study, the relationship between leakage and the contact width size that prevent leakage for 25A size of new metal gasket has been examined. In this study, large size of new metal gasket which are 50A, 80A and 100 A sizes were evaluated by using same approach of leak measurement and the relationship between leakage and the contact width. A new approach of leak measurement was performed to clarify the relationship between the presence of leak produced by the water pressure test and the amount of helium leak rate using helium leak test. Moreover, comparing the evaluation results of the relationship between the clamping load and the contact width by using the finite element method (FEM) analysis with the experimental results of the clamping load and the leakage, the contact width which affects the occurrence of leakages on new metal gasket was clarified. The results obtained for these gaskets indicated that the contact width is similar.

Optimization of New Metal Gasket Design Based on Contact Width Involving Contact Stress Consideration

Heavy operating vehicle was used in many surfaces condition, sometimes in heavy terrain with high possibilities of rollover accident. Rollover is a fatal condition where the equipment shifted from its stability and move toward the ground. Consequently, the use of a rollover protecting structure or cab frame as a standard safety was an effort to protect operator from the accident. Numerical approach using finite element method generated a simple square of cab frame combined with design experiment of Taguchi’s orthogonal array. A set of 11 single bars compiled into entire cab frame where each bar has 2 thickness levels and total 12 simulations were required. Furthermore, every simulation compares each other to produce the highest energy absorption during collision. Finally, the highest result then optimized using Taguchi’s control chart. Thickness is known as a prime factor in structural design which can increase energy absorption and reduce buckling at certain area. The highest energy absorption obtained in the optimized model was valuable for prototyping development of cab frame.Heavy operating vehicle was used in many surfaces condition, sometimes in heavy terrain with high possibilities of rollover accident. Rollover is a fatal condition where the equipment shifted from its stability and move toward the ground. Consequently, the use of a rollover protecting structure or cab frame as a standard safety was an effort to protect operator from the accident. Numerical approach using finite element method generated a simple square of cab frame combined with design experiment of Taguchi’s orthogonal array. A set of 11 single bars compiled into entire cab frame where each bar has 2 thickness levels and total 12 simulations were required. Furthermore, every simulation compares each other to produce the highest energy absorption during collision. Finally, the highest result then optimized using Taguchi’s control chart. Thickness is known as a prime factor in structural design which can increase energy absorption and reduce buckling at certain area. The highest energy absorption obtained i...

Deformation Evaluation of Solder Ball Joints by Electromotive Force

Abstract—In the square tube subjected to the bending load, the rigidity of the entire square tube is reduced when a collapse occurs due to local stress concentration. Therefore, in this research, the influence of bending load on the square tube with attached energy absorbing part was examined and reported. The analysis was conducted by using Finite Element Method (FEM) to produced bending deflection and buckling points. Energy absorption was compared from rigidity of attached part and square tube body. Buckling point was influenced by the rigidity of attached part and the thickness rate of square tube.