대용량 전력변환용 초접합 IGBT 개발에 관한 연구

정헌석,강이구,Chung, Hun-Suk,Kang, Ey Goo 한국전기전자재료학회 2015 전기전자재료학회논문지 Vol.28 No.8

This paper was proposed the theoretical research and optimal design 3000V super junction NPT IGBT for using electrical automotive and power conversion. Because super junction IGBT was showed ultra low on resistance, it was structure that can improve the thermal characteristics of conventional NPT IGBT. The electrical characteristics of super junction NPT IGBT were 2.52 V of on state voltage drop, 4.33 V of threshold voltage and 2,846 V breakdown voltage. We did not obtaing 3,000 V breakdown voltage but we will obtain 3,000 V breakdown voltage through improving p pillar layer. If we are carried this research, This device will be used electrical automotive, power conversiton and high speed train.

複式簿記의 生成過程에 관한 硏究

鄭憲錫 誠信女子大學校 1982 硏究論文集 Vol.16 No.-

經濟的 代理人으로서의 會計監査人에 대한 考察

鄭憲錫 誠信女子大學校 1986 硏究論文集 Vol.24 No.-

The owner of the firm hires an auditor as a second agent who is expected to attest to the assertions made by the manager of the firm, therby inducing the manager to report trvthfully to the owner. Thus, there arises an agency problem between the owner and the auditor similar to the one between the owner and the manager: how to motivate the rational auditor to deliver the contracted level of audit services where their services are not observable by the owner. Moral hazard problems can be arrisen on the auditor`s effort. Therefore, the pareto optimal contract between the principal and agent is then used to determine the form of the liability rule. Amajor factor influencing the incentives of the auditor in carrying out contracted tasks is the manner in which the legalsystem, a) decides if audit failure has occured and b) implements penalties. An auditor uses due care standard to avoid legal liability and chooses the optimal amount of care to maximize his expected utility. Areas of liability in auditing has been analyzed in terms of strict liability and negligence. While a strict liability system is one where the auditor is held liable for all losses without regard for his effort, a negligence system is one where the auditor is held liable if the court determines (on verification) that his effort level is lower than the due care standard. This paper attempted to present a simple model that can address the auditor`s liability problems under the two systems. But this model has some limitations because of tailing to consider the factors such as legal costs, independence, auditor`s reputation and insurance. Through a further study a more fine model inducing pareto optimal contract for the social welfare system should be developed.

산업 파워 모듈용 900 V MOSFET 개발

정헌석 한국전기전자재료학회 2020 전기전자재료학회논문지 Vol.33 No.2

A power device is a component used as a switch or rectifier in power electronics to control high voltages. Consequently, power devices are used to improve the efficiency of electric-vehicle (EV) chargers, new energy generators, welders, and switched-mode power supplies (SMPS). Power device designs, which require high voltage, high efficiency, and high reliability, are typically based on MOSFET (metal-oxide-semiconductor field-effect transistor) and IGBT (insulated-gate bipolar transistor) structures. As a unipolar device, a MOSFET has the advantage of relatively fast switching and low tail current at turn-off compared to IGBT-based devices, which are built on bipolar structures. A superjunction structure adds a p-base region to allow a higher yield voltage due to lower RDS (on) and field dispersion than previous p-base components, significantly reducing the total gate charge. To verify the basic characteristics of the superjunction, we worked with a planar type MOSFET and Synopsys’ process simulation T-CAD tool. A basic structure of the superjunction MOSFET was produced and its changing electrical characteristics, tested under a number of environmental variables, were analyzed. 본 논문에서는 기존의 일반적인 온 저항이 급격히 줄어든 MOSFET 900V 초접합 MOSFET의 최적화를 진행하여, 해당되는 최적의 설계 및 공정 파라미터를 도출하였다. SiC MOSFET이 대체되고 있는 상황에서 Si 기반으로 온 저항을 낮출 수 있는 소자이며, 같은 크기의 웨이퍼에서 생산효율을 높일 수 있는 소자라고 할 수 있다. 이와 같은 파라미터를 이용하여 전기적인 특성을 분석한 결과, 항복전압은 1080V, 온저항은 690mΩ을 갖는 우수한 특성을 보이고 있다. 본 논문에서 제안한 소자는 전기 및 하이브리드 자동차의 부품으로 충분히 활용 가능할 것으로 생각한다.

계측센서의 기술동향

정헌석,Jeong, Heon-Seok 한국전기전자재료학회 2010 전기전자재료 Vol.23 No.1

Analysis of Electrical Characteristics of Shielded Gate Power MOSFET According to Design and Process Parameters

정헌석 한국전기전자재료학회 2018 Transactions on Electrical and Electronic Material Vol.19 No.4

This paper designed a structure of the shielded trench gate power MOSFET device, which has been applied to small capacity(less than or equal to 100 V) and high-speed operation as the next generation power semiconductor device, based onthe optimally developed design and process parameters using 2D device and process simulator, and then compared andanalyzed the electrical characteristics between existing and shielded trench gate power MOSFET devices. The breakdownvoltage characteristic, which was regarded as the core characteristic of power semiconductor device, showed that both ofthe devices had around 120 V, indicating no signifi cant change. However, the threshold voltage characteristic, which wasone of the characteristics present in power semiconductor devices for mobile phone battery, exhibited that turn-on voltagewas comparable with each other but the fl owing current characteristic was signifi cantly improved in the shielded trench gatepower MOSFET. Furthermore, the on-resistance characteristic was analyzed according to the oxide thickness of shieldedMOSFET, and the optimal value was obtained when oxide thickness was 0.3 μm.

Study on Thermal Analysis for Optimization LED Driver Ics

정헌석 한국전기전자재료학회 2017 Transactions on Electrical and Electronic Material Vol.18 No.2

This research was analyzed thermal characteristics that was appointed disadvantage when smart LED driver ICs waspackaged and we applied extracted thermal characteristics for optimal layout design. We confirmed reliability ofsmart LED driver ICs package without additional heat sink. If the package is not heat sink, we are possible to minimizepackage. For extracting thermal loss due to overshoot current, we increased driver current by two and three times. As a result of experiment, we obtained 22 mW and 49.5 mW thermal loss. And we obtained optimal data of 350 mAdriver current. It is important to distance between power MOSFET and driver ICs. If the distance was increased, thetemperature of package was decreased. And so we obtained optimal data of 3.7 mm distance between power MOSFETand driver ICs. Finally, we fabricated real package and we analyzed the electrical characteristics. We obtained constant35 V output voltage and 80% efficiency.

빠찌오리 以後의 會計發達에 관한 硏究

鄭憲錫 誠信女子大學校 1983 硏究論文集 Vol.17 No.-

광복 60주년-한국도시를 다시 본다 그리움으로 다가오는 한국도시의 풍취

정헌석 대한지방행정공제회 2005 도시문제 Vol.40 No.441

Trench 식각각도에 따른 Super Juction MOSFET의 래치 업 특성에 관한 연구

정헌석,강이구,Chung, Hun Suk,Kang, Ey Goo 한국전기전자재료학회 2014 전기전자재료학회논문지 Vol.27 No.9

This paper was showed latch up characteristics of super junction power MOSFET by parasitic thyristor according to trench etch angle. As a result of research, if trench etch angle of super junction MOSFET is larger, we obtained large latch up voltage. When trench etch angle was $90^{\circ}$, latch up voltage was more 50 V. and we got 700 V breakdown voltage. But we analyzed on resistance. if trench etch angle of super junction MOSFET is larger, we obtained high on resistance. Therefore, we need optimal point by simulation and experiment for solution of trade off.