• Title/Summary/Keyword: Ferrite devices

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A Study on the Low Temperature Preparation and the Practical Application of Ferrite Films by New Techniques. (신 기술에 의한 페라이트 막의 저온 제작과 그 응용에 관한 연구)

  • 최동진
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.8
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    • pp.658-663
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    • 1998
  • Ferrite plating enables were grown by ferrite by plating method in solution at low temperature(<10$0^{\circ}C$). This faciltates the fabrication of new ferrite thin film devices using non- heat-resistant materials(plastic, GaAs ect) as substrates. Combining the ferrite plating with sonochemistry, application of power ultrasonic waves to stimulate chemical reactions, the crystallinity and qualities of films were improved. Modifying the reactions cell and plating conditions further improved the film quality.

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An Effective Wireless Power Transfer Technique using Permalloy (Permalloy를 이용한 효율적 인 무선 전력송신 기술)

  • Hwang, Jae-Young;Chung, Yeon-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.3
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    • pp.678-683
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    • 2010
  • This paper presents a wireless (contactless) charging technique with a new core material called permalloy. For charging portable devices wirelessly, ferrosilicon or ferrite has been conventionally used. Due to high permeability of permalloy, charging efficiency can be significantly improved and subsequently this high efficiency increases charging distance between charger and portable devices. Comparative experimental studies demonstrate that the charging performance and efficiency with permalloy employed are significantly improved. The proposed wireless charging techniques can be used to charge portable devices efficiently.

Effect of Solid Loading and Lamination Process on the Properties of Ni-Zn Ferrite Made by Tape Casting Method (분말의 함량 및 적층공정이 Tape Casting법으로 제조된 Ni-Zn Ferrite의 물성에 미치는 영향)

  • 이창호;김경용;이창호;김경용
    • Journal of the Korean Ceramic Society
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    • v.31 no.6
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    • pp.595-600
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    • 1994
  • Ni0.3Zn0.7Fe2O4 ferrite specimens were fabricated by dry pressing and tape casting method. The properties of each specimen were measured and compared. In order to design and manufacture the chip devices effectively, one important criterion can be that the sintered density of the laminated body should approach close to that of the dry pressed body which is regarded as standard. This requirement could be satisfied by controlling the solid loading of the ferrite sheet, lamination temperature and pressure. Using the optimum conditions (solid loading 55 wt%, lamination temperature 6$0^{\circ}C$, lamination pressure 400 kg/$\textrm{cm}^2$, sintered at 125$0^{\circ}C$ 2h) a sintered ferrite, with the density of 5.18g/㎤ and permeability of 1390 at 0.5 MHz, were obtained.

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The effect of powder characteristics on the behavior of Co-firing of ferrite and varistor (Ferrite/varistor의 동시소성 거동에 대한 분체특성의 영향)

  • Han, Ik-Hyun;Lee, Yong-Hyun;Myoung, Seong-Jae;Chun, Myoung-Pyo;Cho, Jeong-Ho;Kim, Byung-Ik;Choi, Duck-Kyun
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.17 no.2
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    • pp.63-68
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    • 2007
  • A number of process problems should be solved in the multi-layered ceramic devices such as EMI filter. In particular, it is essential to control the sintering shrinkage in co-firing of different materials for obtaining defect-free samples such as crack, camber, and delamination which usually occur near the surface and interface. We studied the effect of the powder properties of ferrite on the co-firing behavior of green ceramic layers composed of ferrite and varistor. Three kind of ferrite powder samples as a function of milling time (24, 48, and 72 hr) were prepared. Varistor and ferrite ceramic green sheet were made by means of doctor blade process using slurry (ceramic powder and binder solution). Here, slurry was prepared by mixing 55 wt% powder with 45wt% binder solution. Varistor and ferrite green sheets were laminated at $80 kg/cm^2$, and co-fired at $900^{\circ}C$ and $1000^{\circ}C$ for 3 hr. We obtained the camber-free and co-fired ferrite/varistor layer structure by controlling the milling time and sintering temperature.