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This chapter discusses the cooling technologies for microelectronic equipment from the viewpoint of their efficiency in space-constrained heat transfer, focusing on the flow boiling cooling. Also, some practical issues involved in the design of microchannel cooling systems are discussed. The flow boiling cooling system has large heat transfer capacity and advanced characteristics that can be used to realize very low thermal resistances. The chapter discusses various cooling methods. They are low-velocity air cooling, heat sinking with low speed air flow, heat sinking with high-speed impinging air flow, direct single-phase liquid cooling, heat pipe and direct phase-change cooling. In order to contain the discussion within a manageable length, a simple situation is assumed and the emphasis is placed on forced boiling cooling. Riehl et al. made a comprehensive review of the recent literature on micro-channel cooling. They compared the correlations for single-phase and phase-change heat transfer proposed by various investigators and found considerable divergence among the predicted heat transfer coefficients.

In my career as a lens designer, IODC lens design problems have been offering very important occasions. I would like to explain how I tackled the problems.

Axially asymmetric optical systems treated in this paper contain both freeform surfaces and spheres. In these systems, freeform surfaces need to be allocated at the most effective position. The problem can be elegantly solved with the method of traveling freeform surfaces. The purpose of this paper is to show that the sensitivity control can be included in this design process.

New advantage must be added to Japanese manufacturing (monozukuri) for which Japan has held the leading position. To do so, it is necessary to build a new mechanism for research and development and innovation. We heard from the people who have led the Japanese manufacturing about the new strategy for monozukuri, the importance of synthesis, and the role of Full Research that AIST is trying to achieve.

We have researched and simulated the BTL (biomass to liquid process) in which woody biomass is converted to transportation liquid fuels. In the present study, methanol (MeOH) was considered as a liquid fuel. The BTL-MeOH was designed and the environmental and economic analysis of the process was performed from the viewpoint of CO2 emission and capital and operating costs. A case study focusing on heat and power resources was conducted. The result revealed that the process required an independent case of heat and power for CO2 reduction; however, the cost of this was high due to the cogeneration with a steam turbine. Therefore, the introduction of a low-cost cogeneration, e.g., with a gas turbine, was required for commercialization.

In order to develop guidelines for developing lubricants of high performance for aluminum die casting, we conducted tribological evaluation tests on the thermal and lubricating characteristics of inorganic powders and waxes. Specifically, we measured the thermal conductivity of various inorganic powders and then selected powders superior in heat insulation. Next, we investigated the thermal behavior of the waxes contained in powder lubricants by thermogravimetry. In addition, by using a friction tester, we evaluated the lubrication performance of the composite lubricants at high temperatures of 250ºC and 350ºC. With all of these results, we proposed composite lubricants for aluminum die casting.

In this report a novel optical system for very thin zoom lenses is shown. The key point of this system is the use of the intermediate image. The system consists of 3 lens groups with the positive optical power. The possibility of the zooming and focusing types is investigated, as well as the possibility of the power distribution of 3 lens groups. Finally the procedure to realize such an unprecedented optical system is shown.

A new road map of future trends in micro-engineering and nano-engineering was established from the viewpoints of manufacturing and mechanical engineering. This road map was made by evaluating the results of questionnaires given to the leading engineers including elected trustees of the JSME, and by considering the discussions during the “International Symposium of Micro-Mechanical Engineering (ISMME2003)” held on December 2003 in Tsuchiura and Tsukuba, Japan. The micro- and nano-engineering were categorized from the manufacturing viewpoint. The road map shows the important trends in micro- and nano-engineering, which include new technological areas, as well as technical development, new manufacturing processes, and new kinds of mechanical engineering. The road map also estimates, from the engineering standpoint, the expected time for practical application and technological breakthroughs.

Laser-induced backside wet etching (LIBWE) of silica glass plates was performed by the excitation of a pure toluene solution with an ns-pulsed KrF excimer laser at 248 nm. Well-defined grid micro-pattern was fabricated without debris and micro-crack around the etched area. The etch rate, which increased linearly with laser fluence, was 30% higher than that in the case of acetone solution of pyrene dye at a concentration of 0.4 mol dm −3 . To understand the etching mechanism, the formation and propagation of shock wave and bubble were monitored by time-resolved optical microscopy at the interface between the silica glass and the toluene solution during etching process. Transient high pressure as well as high temperature generated by UV laser irradiation plays a key role in the etching process.

Laser-induced backside wet etching of fused-silica plates using an aqueous solution of naphthalene-1,3,6-trisulfonic acid trisodium salt (Np(SO3Na)3) is reported. A KrF excimer laser was employed as a light source. The etch rate varied greatly with the concentration of the solution and the laser fluence. For lower concentration solutions, the etch rate increased linearly with laser fluence. For highly concentrated solutions, however, the etch rate increased abruptly at higher fluence. Well-defined line-and-space and grid micropatterns were fabricated using a low etch rate. The etched surface was as flat as the surface of the virgin plates and the etched pattern was free of debris and microcracks. The formation and propagation of shockwaves and bubbles in the solution during the etch process were monitored. High pressure, as well as the high temperature generated by the photothermal process, plays a key role in the etching process.

KrF excimer laser ablation of polyethylene terephthalate (PET), polyimide (PI) and polycarbonate (PC) in air was studied by an in situ monitoring technique using a microphone. The microphone signal generated by a short acoustic pulse represented the etch rate of laser ablation depending on the laser fluence, i.e., the ablation “strength”. From a linear relationship between the microphone output voltage and the laser fluence, the single-pulse ablation thresholds were found to be 30 mJ cm −2 for PET, 37 mJ cm −2 for PI and 51 mJ cm −2 for PC (20-pulses threshold). The ablation thresholds of PET and PI were not influenced by the number of pulses per spot, while PC showed an incubation phenomenon. A microphone technique provides a simple method to determine the excimer laser ablation threshold of polymer films.

The laser-induced back-side wet etching of fused silica with aqueous solutions of pyranine (8-hydroxy-1,3,6-pyrenetrisulfonic acid trisodium salt) is reported. KrF and XeF excimer lasers were employed as light sources. Well-defined line-and-space and grid micropatterns, free of debris and microcracks, were obtained. Compared with other organic solutions, the aqueous pyranine etching medium etches more slowly but produces a higher quality etched surface. With the KrF laser, the etch rate ranged from 0.02 to 0.12 nm pulse-1, depending on the dye concentration and the fluence of the laser. The etch rate decreased dramatically when the XeF laser was employed, which was partially attributed to the lower absorption efficiency of the aqueous pyranine solution at the XeF laser wavelength.

We have investigated time evolution of the plume produced during laser ablation of ZnO under ArF-excimer-laser irradiation in He atmosphere. The plume luminescence is mainly due to excited Zn atoms. The plume propagates straightforwardly within 1 μs after ablation, and then it expands and forms an anchor-like shape due to the plasma confinement by the surrounding He gas. After the disappearance of the plume luminescence at high He pressure, a second excitation with a XeCl-excimer-laser causes a luminescence that can be explained in terms of condensation and formation of oxygen molecules and ZnO nanoparticles in the plume.

Nitrogen solid film deposited on a copper plate at 10 K was irradiated with a picosecond UV laser at 263 nm in vacuum. Photo-dissociation of nitrogen molecule in the solid film was confirmed by the optical emissions, which were ascribed to atomic nitrogen, during the laser irradiation at the fluence of 5 J cm −2 pulse −1 . This photolysis was discussed by the comparison with laser-induced breakdown of nitrogen gas. At the fluence over ca. 10 J cm −2 pulse −1 , the ablation of the frozen nitrogen film was observed. Employing the ablation plume including a reactive species such as nitrogen atoms, the surface reaction of a graphite (highly oriented pyrolytic graphite (HOPG)) plate and silicon wafer was studied. XPS analysis indicated that nitrides were formed on the surfaces by the treatment. The ps-laser ablation of nitrogen solid film provides a novel technique for surface modification of materials.

The DC electric-field effect on the crystallinity of II–VI semiconductor in composite systems has been investigated for CdS–ITO films fabricated via alternative pulsed laser deposition (PLD) of CdS and indium tin oxide (ITO) on electric-field-applied substrates. The alternative laser ablation was performed under irradiation of ArF excimer laser in mixture gas of helium and oxygen. The application of electric-field facilitated the preferential crystal-growth of CdS in nanometer scale at low pressure, whereas all the films grown without the field were amorphous. There is a large difference in the crystallization between the films grown on field-applied and heated substrates; the latter showed the crystal-growth with random orientations. This difference indicates that the existence of electric-field has an influence on the transformation from amorphous to crystalline phase of CdS. The driving force for the field-induced crystallization is also discussed in the light of the Joule heat.

Epitaxially grown Pb(Zr,Ti)O 3 (PZT) thin films have been successfully prepared by the coating photolysis process using ArF excimer laser at room temperature. Starting materials lead-2-ethylhexanoate, zirconium-2-ethylhexanoate oxide and titanium-2-ethyl-1-hexanolate were mixed and diluted with toluene, spin-coated on the single crystal SrTiO 3 (STO)(0 0 1) substrate and dried at 150 °C. When dried films were irradiated by ArF excimer laser at a fluence of 50–80 mJ/cm 2 at a repetition rate of 10 Hz for 1 min (600 shots), epitaxially PZT perovskite phase films were obtained. Single crystal LaAlO 3 (LAO)(0 0 1) and quartz were also used as the substrate, PZT thin films which were grown on STO showed best crystallinity.

Scanning tunneling microscopy (STM) was used to investigate the surface morphology of ice crystals containing adsorbed poly(vinyl alcohol) (PVOH) molecules inside a cold room at −7.0°C. PVOH was used as a substitute for antifreeze protein (AFP) type I, which is an effective additive for making ice slurries resistant to recrystallization. The STM images revealed microscale grooves on ice crystals made from PVOH solutions, indicating that PVOH molecules significantly influence the surface structure of the ice crystal. The length of each groove was similar to that of a PVOH molecule, indicating that PVOH molecules were adsorbed on the ice crystal surfaces. The interaction force between PVOH molecules and the ice surface was discussed by assuming a molecular structure of PVOH on the ice crystal surface, and the depression of the local freezing point was analyzed based on the surface curvature of ice revealed by STM.

TEA CO2 laser induced ablation of solid amorphous silicon monoxide in H2 and H2O atmosphere results in deposition of hydrogenated SiOx films, which reveals that ablated silicon monoxide fragments are reactive towards H2 and H2O. The films analyzed by FTIR and XP spectroscopy are revealed as rich in H, composed of Si0 and several SixOyHz configurations and containing both Si–OH and Si–H bonds. The films produced in H2O have (Si)H mostly bonded in the (O3)Si–H unit and those produced in H2 have H attached to Si which is bonded to 1–3 oxygen atoms.

Toward direct observation of benzdiynes, we investigated the wavelength-selective photolyses of five kinds of benzenetetracarboxylic dianhydride derivatives in nitrogen matrixes at 13 K. In the first step of the photolyses, all dianhydrides were converted into benzynedicarboxylic anhydrides with loss of CO and CO2 upon irradiation at 308 nm. In the second step, the benzyne intermediates were photolyzed at 266 nm. In these photolyses, the generation of two kinds of benzdiynes, 3,6-difluoro-1,4-benzdiyne and 3,6-bis(trifluoromethyl)-1,4-benzdiyne, was confirmed by good correspondence between observed and calculated IR spectra. These benzdiynes were converted into the corresponding hexatriynes upon further irradiation at 266 nm. Benzdiynes were not observed in the photolyses of the other three dianhydrides: only hexatriynes were observed as major photoproducts. These results suggested that benzdiynes were generated first and then converted into hexatriynes and that the efficiency of the decomposition of benzdiynes depended on the substituents. The dynamics of the generation and decomposition of benzdiynes in the matrixes was analyzed by using a successive reaction scheme.

The study on thermal energy transport system by synthesis and decomposition reactions of methanol was reviewed. To promote energy conservation and global environment protection, a two-step liquid-phase methanol synthesis process, which starts with carbonylation of methanol to methyl formate, then followed by the hydrogenolysis of the formate, was studied to recover wasted or unused discharged heat from industrial sources for the thermal energy demands of residential and commercial areas by chemical reactions. The research and development of the system were focused on the following three points. ( 1 ) Development of low-temperature decomposition and synthetic catalysts, ( 2 ) Development of liquid phase reactor (heat exchanger accompanying chemical reaction), ( 3 ) Simulation of the energy transport efficiency of entire system which contains heat recovery and supply sections. As the result of the development of catalyst, promising catalysts which agree with the development purposes for the methyl formate decomposition reaction and the synthetic reaction are being developed though some studies remain for the methanol decomposition and synthetic reactions. In the fundamental development of liquid phase reactor, the solubilities of CO and H 2 gases in methanol and methyl formate were measured by the method of total pressure decrease due to absorption under pressures up to 1 500 kPa and temperatures up to 140°C. The diffusivity of CO gas in methanol was determined by measuring the diameter and solution time of single CO bubbles in methanol. The chemical reaction rate of methanol synthesis by hydrogenolysis of methyl formate was measured using a plate-type of Raney copper catalyst in a reactor with rectangular channel and in an autoclave reactor. The reaction characteristics were investigated by carrying out the experiments at various temperatures, flow rates and at various catalyst development conditions. We focused on the effect of Raney copper catalyst thickness on the liquid-phase chemical reaction by varying the development time of the catalyst. Investigation results of the catalyst such as surface area, pore radius, lattice size, and photographs of scanning electron microscope (SEM) were also given. In the simulation of energy transport efficiency of this system, by simulating the energy transfer system using two-step liquid phase methanol decomposition and synthetic reactions, and comparing with the technology so far, it can be expected that an innovative energy transfer system is possible to realize.

本研究では，蟻酸メチル分解・合成反応を利用した排熱回収用ケミカルヒートポンプシステムを設計する為の基礎研究として，気液平衡条件下における化学平衡が実現する3成分系の反応である蟻酸メチル分解・合成反応に対して，各成分のモル分率の平衡値を理論的に導出し，流通式実験データの解釈に適用した．測定範囲は，分解反応で温度283–343K，圧力0.6–1.5MPa，合成反応で温度333–393K，圧力3.0–5.0MPaである．気液平衡条件下の化学平衡が実現した状態の計算値を流通式実験データの解釈に適用した結果，圧力0.6MPaにおける蟻酸メチル分解反応では，323K程度以上で計算値に近づき，343Kで平衡状態に近づくことを明らかにした．また圧力5.OMPaにおける蟻酸メチル合成反応では，363K程度以上で計算値から正に偏椅し，393Kで平衡状態に近づくことを明らかにした．

The adhesion of the PTFE substrate whose surface was modified by photochemical reaction upon the irradiation of an ArF excimer laser and Xe2* excimer lamp under a hydrazine and ammonia atmosphere was examined by a peel-off test for the sample prepared by jointing the PTFE substrate and a copper plate through chemical adhesives. These surface-modified PTFE samples were improved in adhesive property, which was 7-20 times higher than that of original PTFE. The chemical modification on the surface of PTFE was discussed on the basis of XPS and static SIMS analyses.

By a laser-induced backside wet etching method using a pyrene/acetone solution, a fused silica plate was etched upon irradiation with a conventional XeCl excimer laser. The etch rate was about 50% lower than that obtained with a KrF excimer laser under the same experimental conditions. The threshold fluence for etching was estimated to be below 0.5 J cm −2 and a typical etch rate was around 10 nm pulse −1 at a fluence of 1 J cm −2 . After producing the sample having the 10 μm lines and space by irradiation with the first 200 pulses, the second 400 pulses were irradiated to the target sample rotated at right angle. As a result, a square dotted pattern was given without damages for the first etched pattern. Micrographs of the etched surfaces show that this process is a remarkably gentle process free from crack and debris, and favorable for microcrack-free etching of transparent materials.

The preparation of TiO2, In2O3, SnO2 doped In2O3 (ITO) and PbZr0.5Ti0.5O3 (PZT) films have been investigated by the metallorganic (MO) laser photolysis. TiO2 anatase phase was successfully obtained from Ti-2-ethylhexanolate by a two-step irradiation method, while rutile was formed from TiOacac under the same irradiation conditions. In2O3 and ITO films were crystallized by ArF irradiation above the laser fluence of 10 mJ/cm2. The resistivity of the In2O3 film irradiated by further ArF laser in a vacuum and air atmosphere was 2.2×10−2 and 2.2×10 −1 Ω cm , respectively. The lowest resistivity of the ITO film irradiated by the ArF laser in a vacuum was 6.0×10 −4 Ω cm . Epitaxial PZT film on a SrTiO3 substrate was successfully obtained by MO laser photolysis.

A method to actively control the supercooling of water is a critical issue in cold-energy storage and transport systems that use ice slurries. We experimentally studied the use of ultrasonic vibration to control the phase change from supercooled water to ice, and simulated the phase change assuming that ultrasonic-induced cavitation influences ice nucleation. The experimental results indicate that ultrasonic vibration strongly promotes the phase change from supercooled water to ice and that a reliable method to actively control the phase change by ultrasonic vibration can be realized. The results of the simulation agreed well with the experimental results.

An effective and reliable method to generate ice slurry is necessary for cold-energy storage and transport systems. First we found that ice slurries were generated in supercooled water by ultrasonic vibration. Then we experimentally studied the effect of bubble nuclei on the phase change from supercooled water to ice induced by ultrasonic vibration. Our results show that the phase change is closely related to acoustic cavitation, and the probability of the phase change increases as the total number of bubble nuclei increases. Finally, simulation results based on the cavitation-induced nucleation of solid qualitatively agree with the experimental results.

Photolyses of 1,2;5,6- and 2,3;6,7-naphthalenetetracarboxylic dianhydrides ( 1 and 2 ), which would be precursors of 1,5- and 2,6-naphthdiynes, respectively, were studied by matrix isolation and wavelength-selective irradiation techniques in order to directly observe intermediates produced stepwise. The photolyzed products in the matrices were characterized by FT-IR and UV–Vis spectroscopies with the aid of density functional theory calculations. As a result of decarboxylation and decarbonylation of dianhydride precursors, the generation of naphthyne intermediates was confirmed in both the cases of 1 and 2 . The photolyses of these naphthyne intermediates resulted in the formation of acetylenic compounds as in the case of benzdiynes. In the photolysis of 1 , the final compound was assigned to deca-5-ene-1,3,7,9-tetrayne, although it was unidentified in the case of 2 .

An organosilicon compound, hexamethylcyclotrisilazane (HMCTS), was photolyzed in a solid film at 84 K with an ArF excimer laser. A polymeric film was prepared as a result of polymerization and/or crosslinking using a reactive species such as 1-(methylsilyl)methanimine, generated by photolysis. At room temperature in air, the film changed into a polymer having siloxane units. However, fragments generated by laser irradiation of HMCTS in the frozen film made a similar polymer film having a siloxane structure on a PVA film in air. The polymeric film with siloxane units prepared by the cryogenic laser ablation method displayed hydrophobic properties.

An inhomogeneous magnetic field exerts a magnetization force on all materials, including electrically conducting and non-conducting fluids. A recent experiment demonstrated that this force can enhance or suppress convection in a paramagnetic aqueous solution heated from either below or above. In this paper, to clarify the mechanism of the observed phenomena, we numerically simulated the effect of a vertical magnetic field gradient on thermal convection in paramagnetic fluids. These simulated results agree with experimental observations. Our study shows that the magnetic buoyancy force has potential applications for controlling convection and enhancing the heat transfer efficiency in either electrically non-conducting or low-conducting fluids.

The generation of 1- and 2-naphthynes by the photolyses of 1,2- and 2,3-naphthalenedicarboxylic anhydrides (1, 2), respectively, was investigated by means of Fourier transformed infrared (FT-IR) and ultraviolet−visible (UV−Vis) absorption spectroscopies and theoretical calculations. Consecutive decarboxylation and decarbonylation of 1 were quantitatively analyzed on the basis of UV−Vis absorption spectra. The quantum efficiencies of these processes were estimated as 2 × 10-4 and 0.1, respectively. An isotopomer experiment showed that a cyclopropanone intermediate formed by the decarboxylation showed four CO stretching bands due to anharmonic resonance. Benzocyclopentadienylideneketene was formed from 1-naphthyne and CO, whereas 2-naphthyne did not react with CO to form the corresponding ketene. This different behavior was discussed on the basis of the geometries and energies calculated at the B3LYP/6-31G** level. Moreover, it was shown that the UV−Vis absorption spectra of reactive intermediates generated...

KrF excimer-laser ablation of sintered-powder polytetrafluoroethylene (PTFE) targets is used for the deposition of high-quality PTFE films on metallic microstructures and metal backplates for electroacoustic applications. The films are found to be highly crystalline, consisting of large spherulites with diameters up to 1 mm. X-ray photoelectron spectroscopy of the films revealed the chemical similarity of press-sinter target pulsed-laser-deposited films with bulk PTFE. Negatively charged PTFE films on stainless steel backplates exhibit an exceptional charge stability with practically no decrease of the surface potential up to 225 °C in open-circuit thermally stimulated discharge.

Ab initio and density functional theory (DFT) studies were performed on three isomers of tetradehydrobenzene (benzdiynes). Four different density functionals (BPW91, BLYP, B3LYP, and B1LYP) and two higher levels of theory [QCISD and CCSD(T)] incorporating basis sets up to Dunning's correlation-consistent polarized valence triple-ζ (cc-pVTZ) were utilized for this purpose. Stability tests showed that more stable solutions were available for 1,4-benzdiyne with unrestricted than with restricted DFT, while solutions obtained with later descriptions of 1,3-benzdiyne and 1,2,3,5-tetradehydrobenzene were stable. UB3LYP provided better geometry for 1,4-benzdiyne. Unlike in an earlier study, the energy difference between 1,2,3,5-tetradehydrobenzene and 1,4-benzdiyne calculated with the B3LYP functional coincided well with that calculated at CCSD(T): 13.07 and 14.32 kcal/mol at the B3LYP/cc-pVTZ and CCSD(T)/cc-pVTZ levels, respectively. 1,2,3,5-Tetradehydrobenzene was 8 kcal/mol more stable than 1,3-benzdiyne at the CCSD(T)/cc-pVTZ level. The heats of formation of benzdiynes were obtained by using the G2, CBS-Q, and CBS-QB3 methodologies. The heats of formation calculated for 1,3-benzdiyne and 1,2,3,5-tetradehydrobenzene were 208.6 and 197.9 kcal/mol, respectively, at the CBS-QB3 level of theory. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 923–930, 2001