Processing math: 100%
  • 제목/요약/키워드: Hybrid joining

검색결과 162건 처리시간 0.025초

Micro-bump Joining Technology for 3 Dimensional Chip Stacking (반도체 3차원 칩 적층을 위한 미세 범프 조이닝 기술)

  • Ko, Young-Ki;Ko, Yong-Ho;Lee, Chang-Woo
    • Journal of the Korean Society for Precision Engineering
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    • 제31권10호
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    • pp.865-871
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    • 2014
  • Paradigm shift to 3-D chip stacking in electronic packaging has induced a lot of integration challenges due to the reduction in wafer thickness and pitch size. This study presents a hybrid bonding technology by self-alignment effect in order to improve the flip chip bonding accuracy with ultra-thin wafer. Optimization of Cu pillar bump formation and evaluation of various factors on self-alignment effect was performed. As a result, highly-improved bonding accuracy of thin wafer with a 50μm of thickness was achieved without solder bridging or bump misalignment by applying reflow process after thermo-compression bonding process. Reflow process caused the inherently-misaligned micro-bump to be aligned due to the interface tension between Si die and solder bump. Control of solder bump volume with respect to the chip dimension was the critical factor for self-alignment effect. This study indicated that bump design for 3D packaging could be tuned for the improvement of micro-bonding quality.

Prediction of Tensile Strength for Plasma-MIG Hybrid Welding Using Statistical Regression Model and Neural Network Algorithm (통계적 회귀 모형과 인공 신경망을 이용한 Plasma-MIG 하이브리드 용접의 인장강도 예측)

  • Jung, Jin Soo;Lee, Hee Keun;Park, Young Whan
    • Journal of Welding and Joining
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    • 제34권2호
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    • pp.67-72
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    • 2016
  • Aluminum alloy is one of light weight material and it is used to make LNG tank and ship. However, in order to weld aluminum alloy high density heat source is needed. In this paper, I-butt welding of Al 5083 with 6mm thickness using Plasma-MIG welding was carried out. The experiment was performed to investigate the influence of plasma-MIG welding parameters such as plasma current, wire feeding rate, MIG-welding voltage and welding speed on the tensile strength of weld. In addition we suggested 3 strength estimation models which are second order polynomial regression model, multiple nonlinear regression model and neural network model. The estimation performance of 3 models was evaluated in terms of average error rate (AER) and their values were 0.125, 0.238, and 0.021 respectively. Neural network model which has training concept and reflects non -linearity was best estimation performance.

Effect of Spew Fillet on Failure Strength Properties of Natural Fiber Reinforced Composites Including Adhesive Bonded Joints (접착제 접합된 자연섬유강화 복합재료의 파괴강도 특성에 미치는 접착제 필릿의 영향)

  • Yoon Ho-Chel;Choi Jun-Yong;Kim Yong-Jig;Lim Jae-Kyoo
    • Journal of Welding and Joining
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    • 제23권6호
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    • pp.67-71
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    • 2005
  • This paper is concerned with a study on fracture strength of composites in an adhesive single lap joint. The tests were carried out on joint specimens made with hybrid stacked composites consisting of the polyester and bamboo natural fiber layer. The main objective of this work was to evaluate the fracture properties adjacent to adhesive bonded joint of natural fiber reinforced composite specimens. From the results, natural fiber reinforced composites have lower tensile strength than the original polyester. But tensile-shear strength of natural fiber reinforced composites with bamboo layer far from adhesive bond is as high as that of the original polyester adhesive bonded joints. Spew filet at the end of the overlap reduced the stress concentration at the bonded area. Spew fillet and position of bamboo natural fiber layer have a peat effect on the tensile-shear strength of natural fiber reinforced composites including adhesive bonded joints.

APPLYING LASER-ARC HYBRID WELDING TECHNOLOGY FOR LAND PIPELINES

  • Booth, G-S;Howse, D-S;Woloszyn, A-C;Howard, R-D
    • Proceedings of the KWS Conference
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    • 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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    • pp.169-175
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    • 2002
  • World demand for natural gas has generated the need for many new land transmission pipelines to be installed in the next decade or so. Although mechanized gas metal arc welding is well developed, there are opportunities for cost savings by using alternative welding processes. Hybrid Nd:YAG laser - gas metal arc welding enables fibre optic delivery of the laser energy to a robotic welding head to be combined with the addition of extra energy and a consumable to produce good quality, deep penetration welds in a single pass. The present paper describes initial procedure development to optimize the laser and gas metal arc welding parameters for making joints in pipeline steel. Satisfactory joint quality was obtained and it is intended to develop the process to prototype field trials.

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