Misc - MIKI Hirofumi

Characteristics of thermal-type fingerprint sensor

Hirofumi Miki (Hiro (J.S). Han), Yauhiro Koshimoto

SPIE Proceedings "Biometric technology for human identification V" 18-19 March 2008 Orlando, Florida, USA ( SPIE )    Proc. of SPIE Vol. 6944 69440P1-12   2008.03  [Refereed]

Magnetic fluid pump by using thermo-magnetic effect

Shinya muraii, Hirofumi Miki (Hiro. Han) and Yasuhiro Koshimoto

電子情報通信学会 2008.3     C-5-13   2008.03

Basic study of photothermal magnetic drive micro actuator

Takashi Ohkawa Hirofumi Miki (Hiro. Han) and Yasuhiro Koshimoto

電子情報通信学会 2008.3     C-5-12   2008.03

Non-contact micro bearing by using eddy current levitaion

T. Nakao, Hirofumi Miki (J. Han), Y.Koshimoto

Digests of the 31th annul conference on MAGNETICS 2007     105   2007.09

Research on micro tweezers driving by electromagnetic

A. Kimura, D Takanaka, Y. Naka, Hirofumi Miki (J. Han), Y. Koshimoto

Digests of the 31th annul conference on MAGNETICS 2007     107   2007.09

Tactile sensor by utilizing magnetic suspension

Tuty Rahiza Sajat, Hirofumi Miki (J. Han), Y. Koshimoto

Digests of the 31th annul conference on MAGNETICS 2007     106   2007.09

Sensitivity improvement of SPR sensor by using double fibers

Masanao saito, Hirofumi Miki (Ji-song Han), Yasuhiro Koshimoto

電子情報通信学会     c-3-23 p179   2007.03

Large displacement novel structure by using MEMS technology

Hiroyuki Honda, Hirofumi Miki (Ji-song Han), Yasuhiro Koshimoto

電子情報通信学会     C-5-10 p10   2007.03

Thermal-type micro sensor array on PI film substrate having wet-etched through-holes for interconnection

JS Han, ZY Tan, K Sato, M Shikida

BOSTON TRANSDUCERS'03: DIGEST OF TECHNICAL PAPERS, VOLS 1 AND 2 ( IEEE )  June 9-12, pp.1614-1617   1614 - 1617   2003

　View Summary

We proposed an ultra-thin structure of thermal-type micro sensor array having excellent thermal isolation and sensitivity by using 25similar to50-mum-thick polyimide (PI) film as the substrate. The device also has the attractive features of mechanical flexibility allowing three-dimensional packaging. For vertical interconnects, microvia holes (diameter <100mum) were made by PI film wet etching. Arrayed heater elements with 0.1-mum-thick nickel film were formed by using lift-off technology, and electrical feed-through with 2-mum-thick Cu film were formed by electroless Cu-plating. Heater elements (front side) and electrical feed-through (backside) were interconnected through the fabricated microvia holes using electroless Cu-plating. Fabricated heater elements (Ni) showed good adhesion with the PI film substrate, and its temperature coefficient of resistance (TCR) was 2600ppm. Because of the small thermal capacity and good thermal isolation, the sensor also showed high thermal response of less than 0.4mus when 280mV/10mus of pulse voltage was applied to the heater elements.

New structure and fabrication process for thermal-type microsensors

JS Han, T Kadowaki, K Sato, M Shikida

MICROMACHINING AND MICROFABRICATION PROCESS TECHNOLOGY VII ( SPIE-INT SOC OPTICAL ENGINEERING )  4557   386 - 394   2001

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We describe the structure and fabrication of a one-dimensionally arrayed high density thermal-type micro fingerprint sensor. To provide thermal isolation, we designed and fabricated two sets of insulation cavities for each heater element, one for reducing the heat-transfer from the heater to the substrate, and the other one for that of heat to the wiring. The first set of cavities were etched under each heater bridge, leaving an SiO2 diaphragm with the heater bridge on it, and laterally penetrating with the cavities of neighboring heater bridges. The second ones were etched at the both ends of each heater element, leaving a set of SiO2-wiring bridges. This SiO2-wiring bridge structure was used as a thermal isolator when performing a metal-film wiring. The wiring (an electrical feed-through) was formed by a lift-off method, and runs on the SiO2 insulation surface from the heater element to the bonding pad through the SiO2-wiring bridges. The fabricated sensor device was made on a (100) SOI (silicon-on-insulator) wafer. Each heater element was 5x17x50 ( mum(3)) with a pitch of 80 gm. Because of its small thermal capacity and effective thermal isolation, the sensor element was very sensitive. When a 0.4-V/20-mus pulse-voltage was applied to the heater elements, their resistance reached a steady maximum value in about 4similar to5 p. This level of sensitivity will be useful in variety of thermal sensors, such as micro temperature sensors and micro flow sensors, in addition to the thermal-type fingerprint sensors.

Analysis of Strcture & Material-Property Effects On a Thermal Type Fingerprint Sensor

Electrical Society micromachining conference   MM-00-2   7 - 12   2000

アレイしたマイクロヒーター素子を持つ熱型指紋センサーの加工プロセスおよび実験研究

センサー、マイクロマシンと応用システム第17回シンポジュウム2000     345 - 350   2000

Thermal type fingerprint sensor having arrayed heater elements : Ji-song Han, T.Kadowaki, K.Sato, M.Shikida

Technical Digest of the 17^th Sensor Symposium 2000 Kawasaki, May 30-31   pp.345-350   2000

Analysis of structure & material-property effects on a thermal type fingerprint sensor : Ji-song Han, T.Kadowaki, K.Sato, M.Shikida

電気学会研究会資料 MM-00-1~8（マイクロマシン研究会）   2002.2.28, pp.7-12   2000

熱型指紋センサーにおける構造と物性の効果解析

マイクロマシン研究会   MM-00-2   7 - 12   2000

Thermal Type Fingerprint Sensor Having Arrayed Heater Elements

Technical Digest of the 17th Sensor Symposium 2000     345 - 350   2000

Thermal analysis of fingerprint sensor having a micro-heater array : Ji-song Han, T.Kadowaki, K.Sato, M.Shikida

International Symposium on Micromechtronics and Human Science (MHS'99) Nagoya Congress Center & Nagoya Municipal Industrial research Institute   Novenber 23-26, pp.199-205   1999

Thermal Analysis of Fingerprint Sensor Having a Microheater Array

Ji Song Han, Tadashi Kadowaki, Kazuo Sato, Mitsuhiro Shikida

IEEE, MHS'99 ( IEEE )    199 - 205   1999

　View Summary

For the purpose of properties security, in particular of information systems, demands for portable fingerprint sensors are increasing. We proposed a new type of fingerprint sensor having an arrayed microheater, and successfully fabricated one-dimensional array of sensor elements on a silicon wafer using micromachining technologies. Electric resistance of each heater element is measured as signals of temperature difference between elements that are in contact or non-contact with ridges of the fingerprints. In this paper, we analyzed thermal characteristics of our sensor device using computer modeling. Effects of the following parameters were investigated
cavity under heater, SiO2 film between heater and sensor base, heater size, input power and pulse time duration applied to the heater, material properties contacting to sensor surface etc. We concluded that making cavities under the microheater elements and having SiO2 film layer between heater element and sensor base both for the purpose of thermal insulation, is necessary to realize the performance of the proposed sensor system. From the simulation results, it was clarified that such a miniaturized heater element will work quite effective for detecting fingerprint patterns.

Fingerprint sensor with arrayed micro-heater elements : K.Sato, T.Kadowaki, Ji-song Han, M.Shikida

Tech. Dig. Of The 10^th International Conference on Solid-State Sensors and Acuators (Transducers'99)Sendai, Japan   June, 7-10, pp.1874-1875   1999

アレーしたマイクロヒーター素子を持つ指紋センサーの熱特性解析

マイクロメカトロニクストヒューマンサイエンス     199 - 205   1999