• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권11호
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• pp.617-624
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• 1999

The spiral type thin-film inductor performed in high frequency at 2-5[MHz] range is analyzed by 2-dimensional Finite Element Method(2D FEM). The features of micro thin-film inductor have complicated electromagnetic phenomenon such as skin effect, proximity effect and magnetic saturation. To develope miniatured magnetic device considering these features, it is important to predict the property of the thin film inductor according to design parameter. In this paper, we present the 2D FEM analysis for the spiral type thin film inductor. The characteristics of inductor from point of view of inductance, resistance and quality factor are studied according to design parameter and various pattern construction.

• 한국진공학회지
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• 제8권4A호
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• pp.461-464
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• 1999

Planar type thin film inductors have a potential for the application of miniaturized DC-DC converters. For those high current applications, the magnetic film with high current capability is required. The current capability of magnetic films is mainly determined from high saturation magnetization (4$\piM_s$) as well as large anisotropy field $(H_k)$. We fabricated a double rectangular spiral thin film inductor which consist of magnetic layer, coil and insulator. Highest inductance values as well as best frequency characteristics can be obtained from 5 MHz and quality factor exhibit about 7.

• 한국전기전자재료학회논문지
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• 제16권2호
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• pp.138-143
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• 2003

A double spiral thin-film inductor with a NiFe magnetic core is integrated with DC-DC converter IC. The NiFe core is deposited on a polyimide film as the thinckness of NiFe is 2.5~3.5 ${\mu}$m. Then, copper conductor line is deposited on the NiFe core with double spiral structure. Process integration is performed by sequential processes of etching the polyimide film deposited both top and bottom of the NiFe core and electroplation copper conductor line from exposed metal pad of the DC-DC converter IC. Process integration is simplified by elimination planarization process for top core because the proposed thin-film inductor has a bottom NiFe core only. Inductor of the fabricated monolithic DC-DC converter IC is 0.53 ${\mu}$H when the area of converter IC and thin-film inductor are 5X5$\textrm{mm}^2$ and 3.5X2.5$\textrm{mm}^2$, respectively. The efficiency is 72% when input voltage and output voltage are 3.5 V and 6 V, respectively at the operation frequency of 8 MHz.

• ETRI Journal
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• 제25권4호
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• pp.270-273
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• 2003

This paper presents a simple process to integrate thin-film inductors with a bottom NiFe magnetic core. NiFe thin films with a thickness of 2 to 3${\mu}m$ were deposited by sputtering. A polyimide buffer layer and shadow mask were used to relax the stress of the NiFe films. The fabricated double spiral thin-film inductor showed an inductance of 0.49${\mu}H$ and a Q factor of 4.8 at 8 MHz. The DC-DC converter with the monolithically integrated thin-film inductor showed comparable performances to those with sandwiched magnetic layers. We simplified the integration process by eliminating the planarization process for the top magnetic core. The efficiency of the DC-DC converter with the monolithic thin-film inductor was 72% when the input voltage and output voltage were 3.5 V and 6 V, respectively, at an operating frequency of 8 MHz.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.71-71
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• 2009

This paper describes a simple, on-chip CMOS compatible the thin-film inductor applied for the dc-dc converters. A fully CMOS-compatible thin-film inductor with a bottom NiFe core is integrated with the DC-DC converter circuit on the same chip. By eliminating ineffective top magnetic layer, very simple process integration was achieved. Fabricated monolithic thin film inductor showed fairly high inductance of 2.2 ${\mu}H$ and Q factor of 11.2 at 5MHz. When the DC-DC converter operated at $V_{in}=3.3V$ and 5MHz frequency, it showed output voltage $V_{out}=8.0V$, and corresponding power efficiency was 85%.

• 한국세라믹학회지
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• 제40권4호
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• pp.375-379
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• 2003

In this paper, a novel design of multilayer ceramic-based Transmit/Receive (T/R) switch using Low Temperature Co-fired Ceramic (LTCC) technology have been presented. Compact T/R switch has been designed by transforming quarter-wave transmission line to its lumped equivalent circuit. Especially, high-Q three dimensional inductors with double strip have been proposed and incorporated. The proposed inductor has been modeled by multi-conductor coupled lines. A measured inductor quality factor (Q) of 80 and a Self-Resonance Frequency (SRF) of 6.6 GHz have been demonstrated. The inductor library has been incorporated into the design of WCDMA T/R switch.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.129-131
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• 2001

This paper represents the method is to design thin film spiral type inductor using the analytic method and to evaluate the characteristics of the high frequency inductors using HFSS simulation program. The magnetic circuit of the thin film inductor can be successfully simulated by the HFSS.

• 한국자기학회지
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• 제10권5호
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• pp.250-255
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• 2000

본 연구에서는 double rectangular spiral형 공심 인덕터를 유사 LIGA공정으로, F $e_{86.7}$Z $r_{3.3}$ $B_{4}$A $g_{6}$ 자성막을 dc magnetron sputtering법으로 각각 제조한 후 인덕터의 구조를 변화시켜, 인덕터의 임피던스 특성에 미치는 자성막의 특성 인자에 대해 연구하였다. 공심 인덕터의 전류 방향과 자성 박막의 자화 용이축이 수직일 경우 인덕터의 인덕턴스가 향상되었고, 공심 인덕터와 F $e_{86.7}$Z $r_{3.3}$ $B_{4}$A $g_{6}$ 자성막 사이 절연막이 없는 경우 자성막의 자속 집속효과가 증가하여 절연막이 있는 경우보다 인덕턴스는 높고, 저항의 증가율이 높았으며, F $e_{86.7}$Z $r_{3.3}$ $B_{4}$A $g_{6}$ 자성막의 투자율이 높을수록 인덕터의 인덕턴스에 기여하는 부분이 증가하므로 인턱턴스는 향상되었다. 또한 인덕터의 주파수 특성은 공심 인덕터의 특성에 지배적인 영향을 받으므로 인덕터의 주파수 특성을 향상시키기 위해서는 자성막의 특성보다 공심 인덕터의 특성을 향상시키는 것이 바람직하다.키는 것이 바람직하다.

• 한국정보전자통신기술학회논문지
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• 제10권5호
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• pp.402-408
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• 2017

본 논문에서는 무선 신호전송을 위한 비접촉 방식의 AC 커플링 기반 육각 나선형 박막 인덕터의 주파수 특성을 분석하였다. 사각 나선형 인덕터와 육각 나선형 인덕터에 대하여 권선수 변화, 도체 선 폭 및 선 간격을 변화에 따른 주파수 특성을 비교 분석하였다. 육각 나선형 인덕터는 사각 나선형 인덕터와 비교하여 동일한 인덕턴스를 갖기 위하여 더 많은 권선수를 갖게 되지만 전체적인 도선의 길이는 짧아지게 된다. 이는 자기인덕턴스는 감소하고 상호인덕턴스가 증가하여 전체적인 인덕턴스는 같은 값을 가질 수 있다. 또한 전체적인 도선의 길이가 짧아지고 자기저항이 감소하므로 품질계수와 자기공진주파수의 성능을 확보할 수 있다. 제안된 육각 나선형 박막 인덕터는 2GHz에서 3.54nH의 인덕턴스와 5.0GHz에서 최댓값 14.00의 품질계수를 가지며, 약 11.3GHz에서 자기공진주파수를 가진다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권5호
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• pp.333-338
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• 1999

Thin film inductors of $10 mm \times 10 mm$ with inner coil type of 14 turns were fabricated by sputtering, photo-masking, and etching processes. Their characteristics of impedances and annealing after were investigated. The properties of impedances of the thin film magnetic core inductors with inner coil type were improved by magnetic field annealing due to the removal of residual stress and the improvement magnetic properties of magnetic films. But the characteristics of frequency of the thin film magnetic core inductors were not improved by magnetic field annealing due to properties of the spiral pattern and inner coil type. The thin film magnetic core inductor annealed by uniaxal field annealing method showed an inductance of 1000 nH and resistance of$ 6 \Omega$ of 1 at 2 MHz.