A5053829893- Electronic Packaging and Soldering Technologies
- Adhesion, Friction, and Surface Interactions
- Advanced Measurement and Metrology Techniques
- Optical measurement and interference techniques
- Transport Systems and Technology
- Engineering Applied Research
- Superconducting Materials and Applications
- Physics of Superconductivity and Magnetism
- Metallurgy and Material Forming
- 3D IC and TSV technologies
- Metal Forming Simulation Techniques
- Structural Health Monitoring Techniques
- Mechanical Behavior of Composites
- Sensor Technology and Measurement Systems
- Laser and Thermal Forming Techniques
- Advanced MEMS and NEMS Technologies
- Surface Roughness and Optical Measurements
- Advanced machining processes and optimization
- Optical Systems and Laser Technology
- Probabilistic and Robust Engineering Design
- IoT-based Smart Home Systems
- Welding Techniques and Residual Stresses
- Industrial Vision Systems and Defect Detection
- Industrial Automation and Control Systems
- Vibration and Dynamic Analysis
Chungbuk National University
2002-2024
Kwangshin University
1998
Argonne National Laboratory
1992-1994
In microelectromechanical system (MEMS) devices, the deformation of MEMS structure caused by packaging induced stress is great concern since it directly affects performance device. this paper, behavior gyroscope package subjected to temperature change investigated using a high-sensitivity moire interferometry. Temperature dependent analyses warpage and extension/contraction are presented. Analysis reveals that global bending occurs due mismatch coefficient thermal expansion between chip,...
Dense, bulk Bi2Sr2CaCu2Ox bars were fabricated by sinter forging. The exhibited strong textures in which the c axes of platelike grains preferentially aligned parallel to pressing direction. Fracture strength was measured four-point bending, and compression at angles 0, 45, 90 degrees Maximum tension gas 100 MPa average 84 MPa. compression, depended on orientation, 180 maximum 120-135
A robust scheme of moire´ interferometry for real-time observation is employed to study the temperature dependent thermo-mechanical behavior a ceramic ball grid array package assembly. The implemented with convection-type environmental chamber that provides rapid control required in accelerated thermal cycling. Thermal deformations are documented at various temperatures. Thermal-history analyses global and local presented. significant nonlinear due complete stress relaxation maximum...
The role of Ag additions in the microstructural evolution and related mechanical properties YBCO has been studied. Various amounts have added to by two different mixing techniques, i.e. form metallic powder solution. strength fracture toughness specimen increased with increasing content, probably because strengthening mechanisms resulting from addition. In addition, YBCO-Ag composites showed higher values when was solution compared those it powder. Specifically, an addition 10 vol% Ag, made...
In this study, a Bayesian framework is outlined for the parameter estimation that arises during uncertainty quantification in numerical simulation as well prognosis of structural performance. framework, parameters are estimated form posterior distribution conditional on provided data. Several case studies implement presented to illustrate concept. First one an inverse estimation, which unknown input inversely based finite number measured response Next metamodel problem when original function...
The reliability concerns of solder interconnections in flip chip PBGA packages are produced mainly by the mismatch coefficient thermal expansion(CTE) between module and PCB. Finite element analysis has been employed extensively to simulate loading for joint deformation electronic packages. objective this paper is study thermo-mechanical behavior FC-PBGA package assemblies subjected temperature change, with an emphasis on effect finite model, material models conditions. Numerical results...
In this study, a method of computer model calibration is applied to quantify the uncertainties arising in material characterization solder joint microelectronics package subject thermal cycle. all are addressed by using Bayesian approach. A special specimen that characterizes property due shear deformation prepared, from which Moire´ fringe measured running Viscoplastic finite element analysis procedure constructed for based on Anand model. Gaussian process known as Kriging employed...
This paper presents the effective technique to design a six-axis load cell by using experimental with an orthogonal array. A binocular structure is used as basic sensing element for instead of parallel plate structure. The finite method adopted obtain strain distributions element, and doing analysis variances, its results are utilized in determining factor which more influential output strain. Calibration test show that developed loa maximum capacities 196 N forces 19.6 N. m moments...
Moire interferometry is an optical method, providing whole field contour maps of in-plane displacements with high resolution. The demand for enhanced sensitivity in displacement measurements leads to the technique microscopic moire interferometry. method extension interferometry, and employs microscope required spatial In this paper, by order magnitude using immersion optical/digital fringe multiplication(O/DFM) method. patterns, interval represents 52 ㎚ per order. estimate reliability...
반도체 패키지는 여러 가지 다양한 재료로 구성되어 있으며, 제조시나 사용 환경에서 온도가 변하면 각 재료의 열팽창 계수의 차이로 인하여 굽힘변형이 발생하게 된다. 그림자 무아레 방법은 비접촉으로 전체 영역에 걸친 면외변위를 측정하는 광학적 방법이지만 측정 감도가 <TEX>$50{\mu}m/fringe$</TEX> 이상이어서 패키지의 굽힘변형을 측정하기에는 적당하지 않은 면이 있었다. 본 논문에서는 시스템에 위상이동 기법을 적용하여 <TEX>$12.5{\mu}m/fringe$</TEX>의 향상된 감도를 갖는 측정장치를 구성하였다. 측정에서 나타나는 탈봇 현상을 고려하여 1/2 영역에서 변형을 측정할 수 있도록 실험을 수행하였다. 위상이동에 의해 기록되는 4장의 무늬를 영상처리하여 4배 얻어내었다. 논문에서 개발한 측정방법을 기존의 섬유강화 패키지 기판과 무섬유 기판에 상온과 약 <TEX>$100^{\circ}C$</TEX>의 발생하는 측정하였다. Electronic...
This paper describes an experimental study and finite element analysis (FEA) carried out for investigating thermal deformation behavior of solders, resulting from temperature change in the solder. With such a goal mind, shear specimen that was composed two metal bars having different coefficient expansion solder blocks placed between designed fabricated. Two types blocks, eutectic (Sn/36Pb/ 2Ag) lead-free (Sn/3.0Ag/0.5Cu) were tested as well. Fringe patterns several steps recorded analyzed...
Abstract Plastic ball‐grid array (PBGA) package assembly comprises various materials with different thermo‐mechanical properties, and the solder patterns can significantly influence deformation ball stress. This study utilizes moiré interferometry to investigate behavior of wire bonded plastic (WB‐PBGA) packages under varying temperatures. Real‐time experiments were conducted capture fringe representing at temperature stages. Experiments for three distinct configurations: full grid...
Cracks and defects in the ITO (Indium tin oxide) sputtering target process arise from uneven strain distribution stress concentration, which are caused by differences coefficients of thermal expansion elastic moduli between materials, as well improper bonding setup conditions. This study investigates optimal conditions for through shear tests. The tests were conducted on specimens bonded under 24 different results indicate that surface roughness adhesive thickness most significant factors...