【公開日：2025.06.10】【最終更新日：2025.05.24】
課題データ / Project Data
課題番号 / Project Issue Number
24TT0021
利用課題名 / Title
Lithography for fabrication of heat radiation devices
利用した実施機関 / Support Institute
豊田工業大学 / Toyota Tech.
機関外・機関内の利用 / External or Internal Use
外部利用/External Use
技術領域 / Technology Area
【横断技術領域 / Cross-Technology Area】（主 / Main）加工・デバイスプロセス/Nanofabrication（副 / Sub）-
【重要技術領域 / Important Technology Area】（主 / Main）高度なデバイス機能の発現を可能とするマテリアル/Materials allowing high-level device functions to be performed（副 / Sub）-
キーワード / Keywords
Infrared emission Microtextures ,高品質プロセス材料/技術/ High quality process materials/technique,光リソグラフィ/ Photolithgraphy
利用者と利用形態 / User and Support Type
利用者名（課題申請者）/ User Name (Project Applicant)
相澤 龍彦
所属名 / Affiliation
表面機能デザイン研究所
共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes
ARIM実施機関支援担当者 / Names of Collaborators in The Hub and Spoke Institutes
佐々木 実
利用形態 / Support Type
（主 / Main）技術代行/Technology Substitution（副 / Sub）,共同研究/Joint Research
利用した主な設備 / Equipment Used in This Project
TT-005：マスクレス露光装置
TT-006：マスクアライナ装置
TT-015：デジタルマイクロスコープ群
TT-032：三次元形状測定機
報告書データ / Report
概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)
Metallic micro-textures were regularly aligned onto the copper sheet by the lithographic and wet plating processes. The resin film with the regularly aligned through-holes was first formed onto the copper specimen using the lithographic treatment. Nickel-base micro-pillars were formed by selective nucleation and growth into these through-holes. This regularity controlled micro-textured device with micro-pillar alignment was characterized by thermo-graphic microscppy to investigate the regular alignment effect on the IR-emittance. Heat radiation experiment in vacuum was performed to describe the IR-radiation from the regularly micro-pillared device to a target plate.
実験 / Experimental
A lithographic treatment was utilized to build up the through-hole array into a sacrifice resin film, as illustrated in Figs. 1a and 1b. The height and root diameter of through-holes was controllable for each design of microtextures. In the following experiment, its diameter and height was designed to be 20 mm and 10 mm, respectively. The total current, the current density and the chemical solutions have influence on the nucleation and growth processes of this nickel unit-cell. In the following experiments, they were controlled to drive two dimensional growth in the through-hall array in Fig. 1c. After removal of resin film by chemical treatment, the regularly aligned microtextures are formed on the copper specimen as depicted in Fig. 1d. The thermographic microscope with FTIR (Shimazu, Kyoto, Japan) was utilized to measure the IR-emittance spectra for the regularly aligned microtextures. The optical beam line in this measurement is schematically explained in the following. Two beams from IR and visible sources are introduced into the Cassegrain objective, which consists of concave primary and convex secondary mirrors. The beam from this objective is irradiated onto the specimen surface and reflected back to objective. This beam is selected by an aperture and detected by T2SL (Type II Super-Lattice) sensor as well as the optical microscope. In the following, the aperture is controlled to focus the measured area on the micro-textured specimen.
結果と考察 / Results and Discussion
A through-hole array was formed into the resin film using the lithography, as depicted in Fig. 2. Its average diameter and height were 16 mm and 15 mm, respectively. The wet plating was utilized to selectively deposit the nickel clusters into this through-hole array. Figure 3 depicts the microtextures on the copper substrate after wet-plating and removal of resin film, The cylindrical unit cell with the diameter of 15 mm and the height of 9 mm was formed as a replica of through-hole in resin. As shown in Figs. 3b and 4, the nickel clusters grew in dendritic on the top surface of unit cell. This proves that the dendritically growing nickel clusters deposit, coalescence and fill the through-hole to form this cylindrical unit cell. FT-IR and thermographic microscopy was employed to measure the emittance spectra by controlling the aperture. Four focused areas on the micro-textured copper specimen were selected for IR-emission spectra. Figure 5 compares the IR-emissivity in the function of wavelength (l) from l = 2.5 mm to l = 14.5 mm among four specimens. In case of A-specimen, excluding the effect of copper clearances to the emissivity, the resonance peaks are detected at l = 9 mm, 4.5 mm and 3 mm, respectively. These wavelengths are corresponding to H, H/2, and H/3, respectively. That is, IR waves are selectively emitted at l = 2 x H, H, H/2 and H/3, by resonance. This resonance dependency of emissivity is commonly observed in Fig, 5 among four specimens. The intensity of emissivity is significantly reduced with A -> B -> C -> D, or, with increasing the copper clearance area in the focused area for measurement of emission. The intensity of emissivity for copper is much less than 0.1, irrespective of the wavelength.
図・表・数式 / Figures, Tables and Equations
Fig. 1 Illustration on the nucleation and growth processes of micro-pillars selectively into the through-hole array.
Fig. 2 Regularly aligned through-holes into the sacrifice resin film down to the copper specimen using the lithography. a) An overview on the specimen, b) through-hole array, and c) cross-sectional profile by the laser microscopy.
Fig. 3 Micro-pillar array after nucleation and dendritic growth selectively into the through-holes. a) SEM image on the micro-pillar alignment, and b) cross-sectional view on the micro-pillars using the laser microscopy.
Fig. 4 FE-SEM image on the micro-pillared nickel unit cell on the copper plate.
Fig. 5 Measured emittance of the IR waves from the micro-pillared unit-cells using thermographic microscopy and FT-IR.
その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)
成果発表・成果利用 / Publication and Patents
論文・プロシーディング（DOIのあるもの） / DOI (Publication and Proceedings)
口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.
特許 / Patents
特許出願件数 / Number of Patent Applications：0件
特許登録件数 / Number of Registered Patents：0件