VCR 주행장치의 2축 플랜지 반력 측정장치 개발

주진원,김승환,김갑순,이경원,Joo, Jin-Won,Kim, Seung-Hwan,Kim, Gap-Soon,Lee, Kyeong-Won 대한기계학회 1996 大韓機械學會論文集A Vol.20 No.7

This paper presents the design process and evaluaation results of a two-axis force transducer for measuring flange reaction forces. A double-cantilever beam structure is used as a sensing element, and its optimal configuration is determined based on the derived strain equations to maximize the sensitivity and minimize the regid body displacements. To reduce the coupling errors between two-axis forces, strain distributions by finite elemetns analysis are utilized and the Wheaststone bridge cricuits composed of strain gages are built such that the output voltage should be zero, although strains of four strain gages are not zero. Calibration test shows that the two-azxis force transducer developed in this paper is useful in measuring flange reaction forces within the coupling error of 5.53%.

병렬판구조를 이용한 소형 6축 힘/토크센서의 설계 및 특성평가

주진원,나기수,김갑순,Joo, Jin-Won,Na, Gi-Su,Kim, Gap-Sun 대한기계학회 1998 大韓機械學會論文集A Vol.22 No.2

This paper describes the design processes and evaluation results of a small-sized six-axis force/torque sensor. The new six-axis force/torque sensor including S-type structure has been developed using a parallel plate structure as a basic sensing element. In order tominimize coupling errors, the location of strain gages has been determined based on the finite element analysis and the connections of strain gages have been made such that the bridge circuit with 4 strain gages becomes balanced. Several design modifications result in a similar strain sensitivity for six-axis forces and moments, and the reduced coupling errors of 2.6% FS between each forces and moments. Calibration test results show that the six-axis load cell developed which has light weight of 135g and the maximum capacities of 196 N in forces and 19.6 N.m in moments is estimated to be within 7.1% FS in coupling error.

Wire Bonding PBGA 패키지의 솔더볼 그리드 패턴에 따른 열-기계적 거동

주진원,Joo, Jin-Won 한국마이크로전자및패키징학회 2009 마이크로전자 및 패키징학회지 Vol.16 No.2

모아레 간섭계를 이용하여 와이어 본딩 플라스틱 볼 그리드 (WB-PBGA) 패키지의 열-기계적인 거동 특성을 연구하였다. 실시간 모아레 간섭계를 이용하여 각 온도단계 에서 변위분포를 나타내는 간섭무늬를 각각 얻고, 그로부터 굽힘변형 거동 및 솔더볼의 변형률에 대한 해석을 비교하여 수행하였다. 본 실험에서는 full grid와 perimeter with central connections 및 perimeter의 배열 형태를 갖는 세 가지 패키지를 사용하였으며, 이 배열 형태를 비교하여 굽힘변형 및 솔더볼의 평균변형률을 자세하게 해석하였다. 솔더볼의 유효변형률은 WB-PBGA-FG의 경우 칩 가장자리 바로 바깥쪽 솔더볼에서, WB-PBGA-P/C의 경우 가운데 연결 솔더볼의 가장 바깥 솔더볼에서, WB-PBGA-P의 경우는 칩과 가장 기까운 안쪽 솔더볼에서 최대값을 가지는 것으로 나타났다. Thermo-mechanical behaviors of wire-bond plastic ball grid array (WB-PBGA) package assemblies are characterized by high-sensitivity moire interferometry. Using the real-time moire setup, fringe patterns are recorded and analyzed for several temperatures. Experiments are conducted for three types of WB-PBGA package that have full grid pattern and perimeter pattern with/without central connections. Bending deformations of the assemblies and average strains of the solder balls are investigated, with an emphasis on the effect of solder interconnection grid patterns, Thermal strain distributions and the location of the critical solder ball in package assemblies are quite different with the form of solder ball grid pattern. For the WB-PBGA-PC, The largest of effective strain occurred in the inner solder ball of perimeter closest to the chip solder balls. The critical solder ball is located at the edge of the chip for the WB-PBGA-FG, at the most outer solder ball of central connections for the WB-PBGA-P/C, and at the inner solder ball closest to the chip for the WB-PBGA-P.

온도변화에 따른 MEMS 자이로스코프 패키지의 미소변형 측정

주진원,최용서,좌성훈,김종석,정병길,Joo Jin-Won,Choi Yong-seo,Choa Sung-Hoon,Kim Jong-Seok,Jeong Byung-Gil 한국마이크로전자및패키징학회 2004 마이크로전자 및 패키징학회지 Vol.11 No.4

MEMS 소자의 패키지는 일반적으로 패키징 과정에서 큰 온도변화를 받게 되는데, 이에 의한 패키지의 변형은 패키지 및 소자의 신뢰성에 큰 영향을 미칠 수 있다. 본 논문에서는 진동형 MEMS 자이로스코프 센서의 패키지를 대상으로 하여, 온도변화로 인한 열변형 거동에 대한 광학실험과 해석을 수행하였다. 이를 위하여 실시간 모아레 간섭계를 이용하여 각 온도단계에서 변위분포를 나타내는 간섭무늬를 얻고, 그로부터 MEMS 패키지의 굽힘변형 거동 및 인장변형에 대한 해석을 수행하였다. MEMS 칩과 EMC 및 PCB의 열팽창계수 차이로 인하여 패키지는 $125^{\circ}C$ 이하에서는 전체적으로 아래로 볼록한 굽힘변형이 발생하였으며, 온도 $140^{\circ}C$를 정점으로 그 이상의 온도에서는 반대의 굽힘변형이 발생하였다. MEMS의 주파수에 영향을 줄 수 있는 칩 자체의 수축변형률은 약 $481{\times}10^{-6}$로 측정되어서 MEMS 설계시 이를 고려하여야 함을 알 수 있다. In MEMS devices, packaging induced stress or stress induced structure deformation become increasing concerns since it directly affects the performance of the device. In this paper, deformation behavior of MEMS gyroscope package subjected to temperature change is investigated using high-sensitivity moire interferometry. Using the real-time moire setup, fringe patterns are recorded and analyzed at several temperatures. Temperature dependent analyses of warpages and extensions/contractions of the package are presented. Linear elastic behavior is documented in the temperature region of room temperature to $125^{\circ}C$. Analysis of the package reveals that global bending occurs due to the mismatch of thermal expansion coefficient between the chip, the molding compound and the PCB. Detailed global and local deformations of the package by temperature change are investigated, concerning the variation of natural frequency of MEMS gyro chip.

Flip Chip PBGA 패키지의 온도변화에 대한 변형거동 해석

주진원,김도형,Joo, Jin-Won,Kim, Do-Hyung 한국마이크로전자및패키징학회 2006 마이크로전자 및 패키징학회지 Vol.13 No.4

본 논문에서는 FC-PBGA 패키지를 대상으로 하여 온도변화에 따른 열변형에 대한 실험과 해석을 수행하였다. 모아레 간섭계를 이용하여 각 온도단계에서 변위분포를 나타내는 간섭무늬를 얻고, 그로부터 굽힘변형 거동 및 솔더볼의 변형률에 대한 해석을 수행하였다. 한 개의 패키지가 PCB에 연결되어 있는 단면 패키지 결합체와 두 개의 패키지가 PCB의 양쪽에 연결되어 있는 양면 패키지 결합체의 변형 거동을 비교하였다. FC-PBGA의 단면 패키지 결합체 패키지의 최대 굽힘변위는 결합되지 않은 패키지보다 20%정도 작게 발생된 것으로 나타났으며 앙면 패키지의 경우는 대칭성으로 인하여 칩 윗면의 최대 굽힘변위가 단면패키지보다 반 정도 작게 발생되었다. 솔더볼의 파손에 큰 영향을 미치는 유효변형률은 단면 패키지 결합체의 경우 칩 가장자리의 바로 바깥쪽 솔더볼에서, 양면 패키지 결합체의 경우는 칩 가장자리의 바로 안쪽 솔더볼에서 가장 큰 값을 가졌으며, 그 최대값은 양면패키지 결합체의 경우가 50%정도 더 큰 것으로 나타났다. Thermo-mechanical behavior of flip-chip plastic ball grid array (FC-PBGA) packages are characterized by high sensitive $moir\'{e}$ interferometry. $Moir\'{e}$ fringe patterns are recorded and analyzed for several temperatures. Deformation analysis of bending displacements of the packages and average strains in the solder balls for both single and double-sided package assemblies are presented. The bending displacement of the double-sided package assembly is smaller than that of the single-sided one because of its symmetric structure. The largest effective strain occurred at the solder ball located on the edge of the chip and its magnitude of the double-sided package assembly is greater than that of single-sided one by 50%.

스트레인 게이지를 이용한 열팽창계수의 측정

주진원 ( Jin Won Joo ),양희걸 ( Hee Gul Yang ) 충북대학교 산업과학기술연구소 2011 산업과학기술연구 논문집 Vol.25 No.1

Measurement of the coefficient of thermal expansion (CTE, or thermal expansion coefficient) is of considerable importance in developing new or special alloys, composite, etc. This paper describes a simple, straightforward technique of measuring the coefficient of a test material relative to that of reference material using strain gages. The technique uses two well-matched strain gages, with one bonded to a specimen of the reference material, and the second to aspecimen of the test material. To verify the applicability of this technique, two well-known material, steel and aluminium are chosen and evaluations are performed in the temperature range of room temperature (24℃) to 100 ℃. The results show that the method can be used to quickly and easily measure CTE with sufficient accuracy.

다분력 힘을 받는 트러스 구조물의 유한요소 해석

주진원 ( Joo Won Joo ),강성일 ( Seong Ll Kang ) 충북대학교 산업과학기술연구소 2012 산업과학기술연구 논문집 Vol.26 No.2

The task of representing a real structure by an idealized model is an important aspect of engineering work. Most of the structure consisting of slender members like bridges, towers and ladders are assembled by bolting and welding. On the finite element analysis (FEA) of these structures, LINK elements which is assumed to be axially loaded are widely used. This paper presents the effect of element type used in the FEA of large scale structure. FEAs modeled with LINK element and BEAM element are conducted for several structures to compare the solutions and investigate the bending effect. In order to verify the results calculated by FEA, structural test by using strain gage apparatus is conducted for a 52 meter-high ladder structure for fire protection. Stresses at selected locations are compared with those by FEA.

항공기 스포일러의 구조 안전성 시험

주진원 ( Jin Won Joo ),유현창 ( Hyun-chang Ryu ),김갑순 ( Gap-soon Kim ) 충북대학교 건설기술연구소 2015 建設技術論文集 Vol.34 No.2

In this paper, the structural test and safety evaluation of aeronautical structures of a composite spoiler were performed for 100% limit load and 150% ultimate load. Supporting jig structures and a loading system were set. up for the test, and 26 rosette gages were attached on the surface of the specimen. In limit load test and ultimate load tests, all principal strains were measured to be below the permissible strain and linear relationships between load and strain ere retained at all load levels. The nonlinear relationship was observed above 160% load level 160%, and the failure of the spoiler was found at the load level of 200% or greater, which indicated that the structure was optimally designed and fabricated.

다분력 로드셀을 이용한 지능형 크레인 시스템 개발

주진원 ( Jin Won Joo ),신규하 ( Kyu Ha Shin ) 충북대학교 산업과학기술연구소 2013 산업과학기술연구 논문집 Vol.27 No.2

마이크로 무아레 간섭계를 이용한 초정밀 변형 측정

주진원(Jin-Won Joo),김한준(Han-Jun Kim) 대한기계학회 2008 大韓機械學會論文集A Vol.32 No.2

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 of microscopic moire interferometry. The method is an extension of the moire interferometry, and employs an optical microscope for the required spatial resolution. In this paper, the sensitivity of moire interferometry is enhanced by an order of magnitude using an immersion interferometry and the optical/digital fringe multiplication(O/DFM) method. In fringe patterns, the contour interval represents the displacement of 52 ㎚ per fringe order. In order to estimate the reliability and the applicability of the optical system implemented, the measurements of rigid body displacements of grating mold and the coefficient of thermal expansion(CTE) for an aluminium block are performed. The system developed is applied to the measurement of thermal deformation in a flip chip plastic ball grid array package.