• 한국신뢰성학회지:신뢰성응용연구
• /
• 제14권4호
• /
• pp.225-229
• /
• 2014

A one-shot device is defined as a product, system, weapon, or equipment that can be used only once. After use, the device is destroyed or must undergo extensive rebuild. Determining the reliability of a one-shot device poses a unique challenge to the manufacturers and users due to the destructive nature and costs of the testing. This paper presents a reliability growth prediction for a one-shot system. It is assumed that 1) test duration is discrete(i.e. trials or rounds); 2) trials are statistically independent; 3) the number of failures for a given system configuration is distributed according to a binomial distribution; and 4) the cumulative expected number of failures through any sequence of configurations is given by AMSAA model. When the system development is represented by three configurations and the number of trials and failures during configurations are given, the AMSAA model parameters and reliability at configuration 3 are estimated by using a reliability growth analysis software. Further, if the reliability growth predictions do not meet the target reliability, the sample size of an additional test is determined for achieving the target reliability.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제17권3호
• /
• pp.236-245
• /
• 2017

Purpose: There is no established inspection system for composite wind blade during the fabrication stage even though the blades are one of the most important part at wind generation system, but phased array ultrasonic testing method has been continuously studied about wind turbine blade with composite. When wind turbine blade with complex shape by phased array probe is inspected, it is necessary to study for system keeping constant pressure using pressure device. Methods: In this paper, we propose constant pressure device for inspecting wind turbine blade by phased array ultrasonic test method. Design of the device controller is based on Hunt-Crossley model. We evaluate reliability of phased array ultrasonic inspection result that applicated constant pressure device. Result: Defect indication is precise and its error is small when constant pressure mechanism based on Hunt-Crossley model was used. Conclusion: When inspection is progressed using constant pressure mechanism, the reliability of composite wind blade inspection can be improved.

• Journal of Welding and Joining
• /
• 제31권3호
• /
• pp.84-88
• /
• 2013

These days embedded technology may be the most significant development in the electronics industry. The study focused on the development of active device embedding using flexible printed circuit in view of process and materials. The authors fabricated 30um thickness Si chip without any crack, chipping defects with a dicing before grinding process. In order to embed chips into flexible PCB, the chip pads on a chip are connected to bonding pad on flexible PCB using an ACF film. After packaging, all sample were tested by the O/S test and carried out the reliability test. All samples passed environmental reliability test. In the future, this technology will be applied to the wearable electronics and flexible display in the variety of electronics product.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
• /
• pp.129-130
• /
• 2005

The electrical stress has a major effect on the long-term reliability of the thyristor. Therefore, it is needed to analyze the relationship between reliability and stress. In this paper, we investigate the device failure mechanism which induced by the stress. And also investigate the effect of the thermal stress on the device failure and relationship between electrical and thermal stress. Two-dimensional process simulator ATHENA and device simulator ATLAS are used to analyze the failure mechanism of the device.

• 산업경영시스템학회지
• /
• 제35권4호
• /
• pp.1-9
• /
• 2012

Decisions on reliability screening rules and burn-in policies are determined based on the estimated reliability. The variability in a semiconductor manufacturing process does not only causes quality problems but it also makes reliability estimation more complicated. This study investigates the nonuniformity characteristics of integrated circuit reliability according to defect density distribution within a wafer and between wafers then develops optimal burn-in policy based on the estimated reliability. New reliability estimation model based on yield information is developed using a spatial stochastic process. Spatial defect density variation is reflected in the reliability estimation, and the defect densities of each die location are considered as input variables of the burn-in optimization. Reliability screening and optimal burn-in policy subject to the burn-in cost minimization is examined, and numerical experiments are conducted.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제14권3호
• /
• pp.147-151
• /
• 2014

An actuator latch device of a hard disk drive is installed for locking an actuator to hold a magnetic head parked in a parking zone. Applying an external force to the drive, the head can move away from the parking zone and destroy data on the disk. A magnet latching mechanism is used to prevent the actuator from moving when the computer is not in use. A permanent magnet holds the actuator when the head is in the parking zone. When the computer is turned on, the actuator has to overcome the latch magnet in order to move. A stronger latch magnet will hold the actuator adequately, but the actuator will not be released when unlocking is required. A breakthrough solution is needed to improve the reliability of the drive without any deterioration of its performance. In order to obtain the idea for resolving this technical contradiction, we analyse patents for actuator latch device of a hard disk drive. A practical way for solving contradictions in product development using TRIZ is proposed in this paper.

• 대한한의진단학회지
• /
• 제9권1호
• /
• pp.125-130
• /
• 2005

Background and purpose: We evaluated the reliability of two electrodermal measurement devices on meridian skin areas; Electro Acupuncture according to Dr. Voll (EAV) method and newly developed MIR-1. Methods: Eighteen volunteers were tested repeatedly on the same condition with each device. To explore the intra-rater, inter-rater, and test-retest reliabilities, one rater tested each subject twice in succession, then the other rater tested the subject in a row. Finally, retests on the subjects with each device were performed 1 week later. The reliability was determined by Pearson correlation and intraclass correlation statistics. Results: EAV method showed poor reliability, while MIR-1 showed good reliability. Conclusion: It is suggested that further research on the reliability and useful device in both fields of clinical practice and biomedical research.

• 한국시뮬레이션학회논문지
• /
• 제25권4호
• /
• pp.77-84
• /
• 2016

본 논문은 시스템에 대한 기능 중심의 신뢰도 예측을 수행하기 위한 모델링 방법론을 제안한다. 신뢰도 예측에 대한 다양한 기존 연구들이 있지만, 이 연구들의 공통점은 하드웨어 중심으로 신뢰도 예측을 수행하였다는 점이다. 신뢰성이 제품이 주어진 사용 조건 아래서 의도하는 기간 동안 정해진 기능을 성공적으로 수행하는 능력이라고 정의되는 점에서 보았을 때, 하드웨어 중심의 신뢰도는 논리적 모순을 가진다. 본 논문에서는 기능 중심의 신뢰도 예측을 위해 4-단계 모델링 절차(four-phase modeling procedure)를 제안하였다. 제안되는 모델링 방법론은 네 개의 모델로 구성된다; 1) 구조적 블록 모델(structure block model), 2) 기능 블록 모델 (function block model), 3) 장치 모델 (device model), 그리고 4) 신뢰성 예측 모델 (reliability prediction model). 본 논문에서는 제안하는 모델링 방법론을 이용하여 전자식 안정기에 대한 기능 중심의 신뢰도 예측을 수행하였으며, 하드웨어의 신뢰도를 결정하기 위해 신뢰도 예측 규격 중 하나인 MIL-HDBK-217F를 이용하였다.

• 마이크로전자및패키징학회지
• /
• 제20권4호
• /
• pp.1-6
• /
• 2013

Recently, various types of flexible devices such as flexible displays, batteries, e-skins and solar cell panels have been reported. Most of the researches focus on the development of high performance flexible device. However, to realize these flexible devices, the long-term reliability should be guaranteed during the repeated deformations of flexible devices because the direct mechanical stress would be applied on the electronic devices unlike the rigid Si-based devices. Among various materials consisting electronics devices, metal electrode is one of the weakest parts against mechanical deformation because the mechanical and electrical properties of metal films degrade gradually due to fatigue damage during repeated deformations. This article reviews the researches of fatigue behavior of thin metal film, and introduces the methods to enhance the reliability of metal electrode for flexible device.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1999년도 하계종합학술대회 논문집
• /
• pp.891-894
• /
• 1999

According to increasing the integration of the device, there are important consideration about the improvement of the reliability in the product. To improve the reliability of the device, the test parameters and test time are increased. There are no pin-to-pin short test and pin-to-pin leakage test in the present test items to analysis the characteristics and reliability of the device. The purpose of the paper is to model the pin-to-pin phenomenon and propose to modify the test method present and to test the new pin-to-pin DC parameters. These modified and additive test items are applied to product test and confirmed to improve the reliability of product test.