Warpage issues are of concern for flip chip Ball Grid Array (FCBGA) package reliability on thin substrates. Despite advantages in electrical performance of thin substrates, FCBGA warpage hampers reliability of the solder balls making up the ball grid array. Warpage and plastic strain of both the FCBGA package and solder balls are calculated under assembly conditions. Temperature dependent material properties were investigated using finite element analysis. FEM calculations of thermal deformation and equivalent plastic strain of solder balls considered to determine overall reliability of the solder balls. Solder ball plastic strain decreased with substrate core thickness. This can explain why solder ball reliability decreases with substrate thickness. Substrate surface warpage fluctuated significantly as core thickness decreased due to reduced stiffness. In addition, it is possible that solder balls and surface mounted components can be affected by surface fluctuations. Although thinner substrates have advantages in terms of electrical performance, high warpage is a critical root cause of package failure. Despite these tradeoffs, developing thinner substrates while avoiding warpage is a forefront issue.

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Article history:Computer-Aided Engineering (CAE) durability analysis and experiments of an aluminum alloy brake pedal were carried out for the car lighter by die casting method. In the CAE analysis, KS standards and criteria of the Volvo Car Corporation were applied, and in the experiment, KS standards were applied. The CAE analysis results show that aluminum alloy brake pedals are stronger than the conventional steel brakes pedals because the yield strength of the aluminum alloy increased by almost 97% over that of steel. Further, the structures of the cylinder and the frame were reinforced with increasing thickness of flame and were changed to suit the die-casting process. Through a durability test based on the KS standard, the strength of a prototype of the aluminum alloy brake pedal was confirmed to be sufficient. , 알루미늄, 마그네슘 등과 같은 비철합금

ARTICLE INFO ABSTRACT Article history:This study analyzed the amount of displacement of window wipers according to pressure by using finite element analysis (FEA) with KS standards for aluminum alloy window wipers manufactured by die-casting method. The product design was changed over four steps considering the die-casting process to achieve strength greater than that of the conventional steel window wiper. According to the FEA results, the strength of final aluminum alloy window wiper improved by 55% over that of a steel window wiper, and the weight of the former was less by approximately 45%. Therefore, there is the possibility of module downsizing for driving motor capacity. Further, the cost competitiveness improved, and the manufacturing process of aluminum alloy window wipers was simplified. , 비철합금의 적용 [4][5][6] , 제조공법의 변화 [7,8] 등이 지속적으로 이루어 지고 있다 [9][10][11][12] .최근에는 자동차 샤시 뿐만 아니라 부품 경량화를 위해 Al의 적 용이 연구되고 있다.이와 같은 Al의 한계를 극복하기 위하여 자동차 부품에 적용이 가능한 Al-Mg 합금이 개발된 바 있다 [13] . 일반적인 스틸 윈도우 와 이퍼는