• 한국정밀공학회지
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• 제25권6호
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• pp.7-12
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• 2008

• 항공우주시스템공학회지
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• 제12권6호
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• pp.1-8
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• 2018

투명 전극에 사용되는 필름인 이방성전도필름은 전도성 입자를 재료로 하여 열 압착법으로 제조되고 있다. 하지만 열 압착법은 낭비되는 재료가 많고 공정이 복잡하다는 단점을 가지고 있으며, 이와 같은 단점을 극복하기 위해 전도성 입자 잉크를 이용한 잉크젯 프린팅 기술을 제안하였다. 잉크의 특성 및 프린팅 조건은 패터닝 선 두께에 영향을 주게 되며, 미세 패터닝을 위한 최적 조건 도출이 중요하다. 본 논문에서는 전도성 입자 잉크를 제작하였으며, 노즐의 두께와 유량을 변화하여 패터닝 결과물을 제작하였고, 전도성 입자 잉크의 토출에 따른 전기전도도를 도출하였다.

• 대한기계학회논문집A
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• 제28권9호
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• pp.1408-1414
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• 2004

The use of flip-chip technology has many advantages over other approaches for high-density electronic packaging. ACF (anisotropic conductive film) is one of the major flip-chip technologies, which has short chip-to-chip interconnection length, high productivity, and miniaturization of package. In this study, thermal fatigue lift of ACF bonding flip-chip package has been predicted. Elastic and thermal properties of ACF were measured by using DMA and TMA. Temperature dependent nonlinear hi-thermal analysis was conducted and the result was compared with Moire interferometer experiment. Calculated displacement field was well matched with experimental result. Thermal fatigue analysis was also conducted. The maximum shear strain occurs at the outmost located bump. Shear stress-strain curve was obtained to calculate fatigue life. Fatigue model for electronic adhesives was used to predict thermal fatigue life of ACF bonding flip-chip packaging. DOE (Design of Experiment) technique was used to find important design factors. The results show that PCB CTE (Coefficient of Thermal Expansion) and elastic modulus of ACF material are important material parameters. And as important design parameters, chip width, bump pitch and bump width were chose. 2$^{nd}$ DOE was conducted to obtain RSM equation far the choose 3 design parameter. The coefficient of determination ($R^2$) for the calculated RSM equation is 0.99934. Optimum design is conducted using the RSM equation. MMFD (Modified Method for feasible Direction) algorithm is used to optimum design. The optimum value for chip width, bump pitch and bump width were 7.87mm, 430$\mu$m, and 78$\mu$m, respectively. Approximately, 1400 cycles have been expected under optimum conditions. Reliability analysis was conducted to find out guideline for control range of design parameter. Sigma value was calculated with changing standard deviation of design variable. To acquire 6 sigma level thermal fatigue reliability, the Std. Deviation of design parameter should be controlled within 3% of average value.