Academic literature on the topic 'Nendo (Firm)'

There are relatively few smoke saunas in Estonia today. Most are located in the south-eastern parts of the country: Old Võromaa and Setomaa. Unfortunately, skills and knowledge of fire safety in connection with smoke saunas are no longer as widespread as they used to be. As the smoke sauna tradition of the Võromaa people has been presented as a candidate for the UNESCO World Heritage List, the use and construction of smoke saunas has intensified and the protection of the smoke sauna heritage has become particularly topical.The authors provide an overview of the main reasons smoke saunas catch fire and outline the construction and utilisation methods that help prevent fires. In order to do so, it is recommended to keep the wood and stove as far as possible from each other and to make sure that there is nothing else that a fire can ‘latch onto’. It is also good to surround the stove with a structure made of fireproof material. The rocks in the stove must also be periodically re-stacked. Smoke saunas must be kept clean and users must make sure that the flames do not rise up through the rocks in the stove. It is good if the sauna is always heated by the same person: someone who knows its properties and how to heat it.

There are relatively few smoke saunas in Estonia today. Most are located in the south-eastern parts of the country: Old Võromaa and Setomaa. Unfortunately, skills and knowledge of fire safety in connection with smoke saunas are no longer as widespread as they used to be. As the smoke sauna tradition of the Võromaa people has been presented as a candidate for the UNESCO World Heritage List, the use and construction of smoke saunas has intensified and the protection of the smoke sauna heritage has become particularly topical.The authors provide an overview of the main reasons smoke saunas catch fire and outline the construction and utilisation methods that help prevent fires. In order to do so, it is recommended to keep the wood and stove as far as possible from each other and to make sure that there is nothing else that a fire can ‘latch onto’. It is also good to surround the stove with a structure made of fireproof material. The rocks in the stove must also be periodically re-stacked. Smoke saunas must be kept clean and users must make sure that the flames do not rise up through the rocks in the stove. It is good if the sauna is always heated by the same person: someone who knows its properties and how to heat it.

Sotsiaal- ja kodanikupädevuse üks komponent on oskus suhelda teisest rahvusest inimestega. Selle oskuse olulised mõjutajad on hoiakud teiste rahvusrühmade suhtes. Omavahelise vähese suhtlemise tulemusena tekivad teise rahvusrühma suhtes sageli stereotüüpsed negatiivsed hoiakud, mis suhtlemist takistavad. Artiklis käsitletavas uuringus võrreldi 8.–9. klassi eesti ja eestivene õpilaste vastastikuseid hoiakuid enne ja pärast mängustatud koostöötegevuste projektis osalemist. Uuriti Integratsiooni SA tellimisel firma Game Club 2018. aasta sügisel korraldatud neljas neli päeva kestnud lõimumisprojektis osalenud noorte (n = 80) hoiakuid teise rahvusrühma suhtes. Projektis osalejad täitsid enne ja pärast projekti ankeetküsitluse (Likerti tüüpi skaalaküsimused, vabad vastused), millega mõõdeti nende hoiakuid teise rahvusrühmaga suhtlemise suhtes. Ankeetküsitluse tulemusi analüüsiti kvantitatiivselt ja kvalitatiivselt. Uuringu tulemusena selgus, et noorte hoiakud teise rahvusrühma suhtes olid pärast projekti positiivsemad, kuid eri rahvusrühmadel ja eri aspektides eri määral. Teadlikult ja täpselt korraldatud intensiivsetel mängustatud koostöötegevustel võib olla potentsiaali eri rahvusest noorte lähendamisel. Summary

Abstract Objectives In this paper the research on developing convolutional spiking neural networks for traffic signs classification is presented. Unlike classical ones, spiking networks reflect the behaviour of biological neurons much more closely, by taking into account the time dimension and event-based operation. Spiking networks running on dedicated neuromorphic platforms, such as Intel Loihi, can operate with greater energy efficiency, hence they are an interesting approach for embedded solutions. Methods For convolutional spiking neural networks' design and simulation, Nengo and NengoDL libraries for Python language were used. Numerous experiments using the Leaky-Integrate-and-Fire (LIF) neuron model were conducted. The training results, with different augmentation methods and number of time steps for input image presentation were compared. Results Finally, an accuracy of up to 97% on the test set was achieved, depending on the number of time steps the input was presented to the SNN. Conclusions The proposed experiments show that using simple convolutional spiking neural network, one can achieve accuracy comparable to the classical network with the same architecture and trained on the same dataset. At the same time, running on dedicated neuromorphic hardware, such solution should be characterized by low latency and low energy consumption.

Li and Mg metals are produced by electrolysis in a molten chloride bath. Currently carbon-based material is used as anode. However, carbon-based anode reacts electrochemically with oxide ions dissolved in the bath, which causes its undesirable consumption. In our laboratory, a new type of inert anode by forming a thin and dense oxide film has been studied. It was shown that a SiO2 film was formed on MoSi2 anode in molten LiCl-KCl melt with Li2O, and that the dissolution of MoSi2 was inhibited by the formation of oxide film. However, sufficient electrolytic current was hardly applied. In this study, the modification of the anodic properties of MoSi2 has been attempted by the addition of Nb or Al in MoSi2. A MoSi2 rod containing Nb(0.1~1.0mol%) or Al(0.1~0.5mol%) was prepared by sintering from MoSi2, Nb and Al powder. The prepared rod was pre-oxidized (1573K, 4h) to form a SiO2 film in advance, and then used as working electrode. An Al plate and Ag/AgCl were used as counter and reference electrode, respectively. The potential of the Ag/AgCl electrode was calibrated against the Li metal deposition potential measured by cyclic voltammetry. Electrolysis was conducted at 700K in an Ar atmosphere. Anodic behavior of MoSi2 was investigated by cyclic voltammetry, and potentio-static electrolysis was performed. The weight change in MoSi2 anode was measured, and the surface and cross section of the MoSi2 electrode were observed and analyzed by SEM-EDX and XRD. The shape of the cyclic voltammogram did not change significantly by the addition of Nb or Al in the MoSi2. Anodic peaks were seen around 2.5V (vs. Li / Li+, the same hereinafter) and around 3.6V. Above 3.6V, anodic current continued to flow with gas bubble formation. The current at 3.6V in the cyclic voltammogram changed with the added amount of Nb or Al as shown in Fig.1, which suggests the Nb or Al addition strongly influenced the anodic property of MoSi2. Current during potentio-static electrolysis at 4.2V increased with current oscillation. It was seen that a black film peeled periodically, and the current oscillation seemed to link the peeling. The quantity of electricity increased with Ni or Al addition in MoSi2. An oxide layer was observed on the MoSi2 surface after potentio-static electrolysis, and a dense layer was formed on MoSi2 containing 0.5~1.0mol% Nb. The weight of MoSi2 decreased by potentio-static electrolysis, and Nb or Al addition in MoSi2 clearly inhibited the weight change. The addition of 0.5~1.0mol%-Nb seemed suitable from the improvement of the anodic property of MoSi2. It was indicated that Nb or Al addition in MoSi2 influenced its anodic property, and that the addition inhibited its anodic consumption in molten LiCl-KCl. However, it was shown that the formation and peeling of the surface film occurred repeatedly, so the formation of a durable surface film should be necessary. The results of this research were obtained as a result of the commissioned work (JPNP 14004) of the New Energy and Industrial Technology Development Organization (NEDO). Figure 1

Polymer electrolyte fuel cells (PEFCs) are used in fuel cell vehicles and households stationary power sources because of their low operating temperatures, small size, and light weight. For further development of PEFCs, it is necessary to reduce the amount of platinum used in the catalyst layers. If the amount of platinum used in the catalyst layers is reduced, the current density per mass of platinum increases. The effect of diffusion polarization then becomes dominant in the overall voltage drop. One factor that causes diffusion polarization is the transport resistance of oxygen molecules in the catalyst layers. Therefore, an understanding of the transport of oxygen molecules in the catalyst layers is necessary to improve the performance of PEFCs under high current density conditions. The catalyst layers comprise porous structures by aggregation of ionomer-coated platinum-supported carbon. The Knudsen number is important for gas diffusion phenomena in porous structures. The Knudsen number is the ratio of the representative length of the system to the mean free path of gas molecules, and when this value is sufficiently small, the gas diffusion phenomenon can be regarded as molecular diffusion. When the Knudsen number is sufficiently large, the gas diffusion phenomenon becomes Knudsen diffusion, in which collisions with solid walls are more dominant than collisions between gas molecules. The Knudsen number is sufficiently large in the porous structure of the catalyst layer. Therefore, the effect of collision with solid surfaces is important in the oxygen transport in the catalyst layer. In previous studies, it has been clarified that the behavior of oxygen molecules incident on an ionomer thin film includes surface scattering, in which diffuse reflection occurs on the surface, and surface diffusion, in which oxygen molecules trapped on the surface move across the surface in a series of multiple collisions. However, the effect of surface diffusion on oxygen transport across the catalyst layer is not clear. The purpose of this study is to analyze the effect of oxygen molecules and ionomer conditions on surface diffusion using the MD simulation. We analyze the behavior of oxygen molecules impinging on ionomers in a computational system that reproduces the pores of the catalyst layer. The simulation system consists of polymer chains, solvent molecules (water molecules and hydronium ions), and oxygen molecules. Periodic boundary conditions were applied in the x-, y-, and z-directions. The behavior of oxygen molecules after they impact the ionomer wall such as their residence time during surface diffusion and the surface diffusion coefficient will be analyzed. Acknowledgments This work was supported by the New Energy and Industrial Technology Development Organization (NEDO) of Japan, Grant number JPNP20003. It was performed on the Supercomputer system “AFI-NITY” at the Advanced Fluid Information Research Center, Institute of Fluid Science, Tohoku University. Figure 1

The catalyst layer (CL) was an important component in polymer electrolyte fuel cells (PEFCs). In the CL, Nafion ionomers coated the Pt particles on the carbon surface for the proton transfer assistance, and therefore the structure optimization of ionomer films is very important for the improvement of catalytic utilization and proton transport performance. The microscopic structure of ionomer covered carbon and Pt particles in the solution was related to the final structural characteristics of the ionomer film determining the performance of CL. In order to elucidate the structural evolution and drying process of the catalyst ink, in the present study, we carried out coarse-grained molecular dynamics (CGMD) simulations to investigate the adsorption behavior of ionomers and morphology evolution of Nafion ionomer from the aqueous solutions to the Pt/C substrate surface under various solution conditions including ionomer concentration and I/C ratio, and substrate conditions including the size and distribution of Pt particles, and Pt/C ratio. We found that the ionomers formed a cylindrical aggregate in the solution and are easily attracted by Pt particles due to their hydrophilic ionic shells. Although ionomer aggregates are easily to adsorb onto Pt particles, it tended to unfold and spread onto the carbon substrate finally, which is resulted from the hydrophobic attraction of the exposed ionomer backbone to the carbon surface and the hydrophilic attraction of ionomer sulfonate groups to the aqueous solution. The ionomer adsorption displayed a strong correlation with the ionomer concentration in the dilute solution. However, the I/C ratio had little effect on ionomer adsorption. This adsorption phenomenon of ionomers in the dilution solution was found to fit the Langmuir adsorption model very well but failed when the concentration of ionomer became higher. A wettability switching behavior of ionomers is observed because the morphology of ionomers changed from the solution to the surface. Two types of the adsorption behavior of ionomer aggregates in the aqueous solution were observed. The first adsorption behavior was the direct adsorption of ionomer aggregate to the carbon substrate without any interaction with Pt particles. For the ionomer aggregate, exposed apolar backbones of ionomers that were close to the carbon could help the ionomer aggregate adsorb on the hydrophobic carbon surface. During the adsorption process, cylindrical-like shape ionomer aggregates gradually spread onto the carbon surface. Finally, the ionomers were entirely distributed on the carbon surface without aggregating together. The second adsorption behavior was indirect adsorption of ionomer aggregate, where the ionomer aggregates firstly adsorbed onto the Pt particles from solution, and finally to the carbon substrate. In the solution, the apolar backbones of ionomer aggregates located at the core of the aggregate were difficult to contact with the substance outside such as carbon surface, while the anionic groups located at the aggregate-solvent interface were easy to contact with the substance outside. When such Nafion aggregates were close to the Pt particles, the anionic shells of the cylindrical aggregates were easily to adsorb onto hydrophilic Pt particles. When the Nafion aggregate adsorbed onto Pt particles, Nafion still presents a cylinder-like aggregate state until it started to approach the carbon surface. When the Nafion aggregate begin to move onto the carbon substrate, it gradually unfolded due to the strong hydrophobic interaction between the ionomer backbone and the carbon surface. During this process, Nafion ionomers gradually relieved their internal hydrophobic associations between their backbones because the unfolded ionomers created more surface contacts and better anchored themselves to the surface. Therefore, when the exposed carbon surface was large enough, increasing the number and sizes of Pt particles could increase the surface area of Pt particles, which favors the ionomer adsorption. When the space between Pt particles was too small to create enough carbon surface contacts anchoring the ionomer backbone, the coverage of the ionomer dropped rapidly. The present study provided insight into ionomer adsorption from solutions to Pt/C surface, which could contribute to the catalyst ink design to improve the structure of catalyst layers. Acknowledgments This work was supported by the New Energy and Industrial Technology Development Organization (NEDO) of Japan, Grant number JPNP20003. It was performed on the Supercomputer system “AFI-NITY” at the Advanced Fluid Information Research Center, Institute of Fluid Science, Tohoku University. We also thank W. Shirakawa for her assistance with the simulations.

Since mid-infrared (MIR) wavelengths have a great potential for optical communication, sensing, and quantum information, Si-based MIR photonic integrated circuits (PICs) have been developed by leveraging Si photonics technology for near-infrared wavelengths. However, the transparency wavelength window of Si is from 1.2 µm to 8 µm, limiting the available wavelengths in the MIR spectrum. Ge is emerging as a waveguide material to overcome this difficulty because Ge is transparent in the entire MIR spectrum. A Ge-on-Si waveguide is one of the promising platform for a MIR PICs. We have also proposed a Ge-on-insulator (GeOI) platform for MIR integrated photonics [1]. The strong optical confinement in a GeOI waveguide enables an ultracompact MIR PIC. Using wafer bonding and smart-cut, a GeOI wafer was successfully fabricated [2]. As a result, we have demonstrated various Ge passive devices, thermo-optic phase shifters, and modulators on a GeOI platform [3][4]. The propagation loss of a GeOI waveguide is one of the issues. The crystal defects induced by hydrogen implantation for smart-cut generates holes in a Ge film. As a result, evening using an n-type Ge donor wafer for smart-cut, a final Ge layer tends to be p-type. Since free-hole absorption in Ge is significant, the propagation loss of a p-type GeOI becomes large. To suppress hole generation, the optimization of the hydrogen implantation conditions was conducted. We found that the higher the implantation energy was, the deeper the center of the defect position was from a Ge surface [5]. When the implantation energy increases from 80 keV to 160 keV, the defects can be removed from a 300-nm-thick Ge device layer, enabling an n-type GeOI wafer. As a result, a low-loss GeOI waveguide with a propagation loss of 2.3 dB/cm was demonstrated. The monolithic integration of Ge passive waveguides and photodetectors (PDs) is also essential for a MIR PIC. We examined the defect-assist photodetection mechanism in a GeOI waveguide with a lateral PIN junction. When a reverse voltage was applied to the PIN junction, the substantial photocurrent was observed at a wavelength of 2 µm for which Ge is transparent. The defect-assist photodetection is expected to be enhanced due to the large intrinsic carrier density in Ge. As a result, the responsivity of 0.25 A/W was obtained at -5 V. In conclusion, we have developed a GeOI photonics platform for MIR wavelengths. We have achieved a low-loss Ge waveguide, PDs, and optical modulators, the indispensable building blocks for large-scale MIR PICs. The functionality of a GeOI platform can be extended with emerging materials including graphene and phase change materials. This work was partly based on the results from the project JPNP13004, commissioned by the New Energy and Industrial Technology Development Organization (NEDO) and supported by JST-Mirai Program Grant Number JPMJMI20A1, JSPS KAKENHI Grant Number JP20H02198, and the Canon Foundation. Reference [1] Z. Zhao, C.-M. Lim, C. Ho, K. Sumita, Y. Miyatake, K. Toprasertpong, S. Takagi, and M. Takenaka, “Low-loss Ge waveguide at the 2-µm band on an n-type Ge-on-insulator wafer,” Opt. Mater. Express, vol. 11, no. 12, pp. 4097–4106, 2021. [2] J. Kang, X. Yu, M. Takenaka and S. Takagi, “Impact of thermal annealing on Ge-on-Insulator substrate fabricated by wafer bonding,” Materials Science in Semiconductor Processing, vol. 42, Part 2, pp. 259-263, 2016. [3] M. Takenaka et al., “Heterogeneous CMOS Photonics Based on SiGe/Ge and III–V Semiconductors Integrated on Si Platform,” IEEE J. Sel. Top. Quantum Electron., vol. 23, no. 3, pp. 64–76, May 2017. [4] T. Fujigaki, S. Takagi, and M. Takenaka, “High-efficiency Ge thermo-optic phase shifter on Ge-on-insulator platform,” Opt. Express, vol. 27, no. 5, p. 6451, Mar. 2019. [5] Z. Zhao et al., “Low-loss Ge waveguide at the 2-µm band on an n-type Ge-on-insulator wafer,” Opt. Mater. Express, OME, vol. 11, no. 12, pp. 4097–4106, Dec. 2021. [6] Z. Zhao, C.-P. Ho, K. Toprasertpong, S. Takagi, and M. Takenaka, “Monolithic Germanium PIN Waveguide Photodetector Operating at 2 μm Wavelengths,” Optical Fiber Communication Conference (OFC2020), W4G.3, San Diego, 8–12 March 2020.

Introduction The oxygen permeation resistance of ionomer determines the limiting current density, that is, cell performance. In order to analyze governing factors of the oxygen reduction reaction (ORR) rate, oxygen permeation resistance should be formulated[1]. In this study, instead of commercial supported catalyst, platinum slits were prepared by coating the platinum slabs with ionomer. Oxygen permeance per side area of platinum slits catalyst was determined by measuring current and analyzing other mass transfer resistances. The objective of this study is to establish measurement and analysis methods of oxygen permeation resistance of ionomer. Theory In our previous study[2], the current density is expressed as i = 4F δ (C) k vcm p Oc F e [A/m2], (1) where δ (C) is the cathode catalyst layer (CCL) thickness, k vc is the reaction rate constant per unit volume of CCL which does not include through-plane mass transport resistances but oxygen permeation resistance of ionomer [mol/(Pa·m3·s)]. p O is the oxygen partial pressure [Pa]. The subscript m and c denote PEM–CCL boundary and CCL–gas diffusion layer boundary, respectively. F e is effectiveness factor, a function of the following 4 dimensionless moduli, M Om , M pm , P Om , and y Oc . F e is defined as the ratio of the observed reaction rate to the reaction rate which does not have the influence of through-plane mass transfer resistance which is in parallel with reaction resistance as shown in Fig. 1. F e includes the influence of oxygen permeation resistance of ionomer, which is in series with reaction resistance as follows: 1/k vcm = 1/k ° vcm + 1/a v k (I) pO (2) where k ° vcm denotes the reaction rate constant which does not include the influence of neither parallel resistances nor series resistance with reaction resistance. a v k (I) pO denotes the oxygen permeance. These two parameters are per unit volume of CCL [mol/(Pa·m3·s)]. In this study, new dimensionless moduli, O O (I) and F u, are proposed in order to separate a v k (I) pO and k ° vcm from k vcm . Define O O (I) as the ratio of the oxygen permeation resistance to the reaction resistance and the platinum utilization factor, F u, as the ratio of observed reaction rate to the reaction rate which does not have the influence of mass transfer resistance through plane nor oxygen permeation resistance of ionomer. In order to explain the influence of the oxygen permeation resistance on the ORR rate, F u and k ° vcm were applied to Eq. (1) instead of F e and k vcm . The current density is expressed as i = 4F δ (C) k ° vcm p Oc F u = 4F δ (C) k vcm p Oc (1+O O (I)) F u [A/m2]. (3) Results and Discussion F u and F e can be calculated by solving dimensionless equations of 1D isothermal homogeneous medium model with assuming no condensation[3]. Fig. 2 shows the calculation results of F u at fixed Peclet number P Om , y Oc and dimensionless oxygen transport resistance M Om . Increasing dimensionless proton transfer resistance M pm and oxygen permeation resistance O O (I) leads to the decrease in F u.When δ (C), E cm , temperature, ionomer thickness and relative humidity are fixed, F u and M pm is proportional to i/p Oc and p Oc 1/2, respectively. M pm and O O (I) can be determined just by fitting experimental data of i/p Oc plotted against p Oc 1/2 to the theoretical curves. To determine O O (I), the current should be measured at fixed P Om , y Oc and M Om . Since it is difficult to fix these three parameters in case of using Pt supported catalyst, platinum slits catalyst coated with ionomer film is applied to the CCL alternatively. The Pt slits catalyst structure which has the high voidage as shown in Fig. 3 enables oxygen to transfer fast through plane compared with Pt supported catalyst layer. That means M Om and P Om can be regarded as 0 because the oxygen diffusion is much faster than oxygen reduction reaction and convection. If P Om and M Om are approximately zero, the influence of y Oc on F u is negligible. Fig. 4 shows the measured ORR rate dependency on RH. The current density at fixed E cm increases by raising RH due to the increase in proton conductivity, oxygen permeability[4] and catalytic activity[5]. By measuring the ORR rate dependency on p Oc in the same way, O O (I) can be determined. k (I) pO can be obtained when O O (I) is determined. Conclusions Determination method of the ratio of the oxygen permeation resistance to the reaction resistance, O O (I), using platinum slits to obtain oxygen permeance through ionomer is proposed. By measuring the ORR rate dependency on oxygen partial pressure, M pm and O O (I) can be obtained. Acknowledgement This work was supported by the FC-Platform Program: Development of design-for-purpose numerical simulators for attaining long life and high performance project (FY 2020–2024) conducted by the New Energy and Industrial Technology Development Organization (NEDO), Japan. Figure 1

AbstractRapid progresses are achieved in catalytic CVD (Cat-CVD), often called hot-wire CVD, in the past 3-years NEDO national project in Japan. Cat-CVD technology presents many advantages in thin-film formation processes; high-efficiency of gas use, large-area deposition, no ion bombardment and low-temperature deposition even below 200°C. All of the elemental techniques for the industrially applicable Cat-CVD apparatuses, such as the suppression of the metal contamination, the precise control of the substrate temperature, the life extension of the catalyzer, 1-m size uniform deposition and the chamber cleaning, have been completely developed. Sophisticatedly designed substrate holder with electrostatic chuck and showerhead equipped with catalyzers are both key technologies for these achievements. High reproducibility for film properties is also obtained by controlling the reaction between high-density radicals and chamber walls. Prototype mass-production apparatus for SiNx passivation films in GaAs devices has been already developed and this will be probably the first application of Cat-CVD in industry. These recent movements appear to promise the drastic revolution in semiconductor and flat-panel display industries by introducing Cat-CVD in very near future.

Micro-fabricated or Nano-fabricated Printed Circuit Boards (PCB) using environmental friendly materials and processes will be desirable candidates for future electronic packaging technologies. To investigate the ionic migration for thus developed PCB, quite new measurement method has been developed by the authors, which enables real time monitoring of the growth process of ionic migration using QCM (Quartz Crystal Microbalance) and Electrochemical Impedance Spectroscopy (EIS). First part of this research has focused on the QCM method and EIS to study the process of ion migration (hereinafter we call it simply “migration”) in various types of lead-free solder plating and the effects of the reflow (Heat treatments) processing and flux residue of soldering processes. In addition, we investigated the anodic dissolution characteristics of the elements in each type of solder alloy by measuring the current-potential curves in 0.1 kmol m−3 KNO3 solution. When using Sn-3.5 mass%Ag solder plating, reflow processing segregate the stable compound Ag3Sn layer and Sn layer. The Sn layer selectively promotes the anodic dissolution reaction, increasing the occurrence of migration. When using Sn-9 mass%Zn solder plating, the Sn effectively prevents the excessive dissolution reaction of Zn. However, since reflow processing causes each element to separate out, reflow processing lessens the effectiveness of Sn, thus promoting the occurrence of migration. The flux processing of lead-free solders suppresses anodic dissolution and effectively prevents the occurrence of migration. However, with Sn-9 mass%Zn, the lowered adhesion between the flux film and the electrodes is a factor in speeding the growth of migration. The ionic migration of lead free solder in severe NOx circumstance will be commented. Next, electric reliability of the newly developed copper printed boards by NEDO project (L/S = 4/6, 8/12, 12/16 μ□) using polyimide as the substrate have been evaluated under 85 °C, 85%RH. The generation of the migration was tested by conventional time dependence of current under bias of 5.0 V. The progress of the migration could be investigated by EIS (Cole-Cole plots of the impedance). The degradation of the diameter of the impedance loop suggested the intimation of migrations. Finally, in order to establish the micro-fabricated printed circuit boards, “semi-additive” process will be one of the candidates. The process involves the copper etching processes by use of FeCl3 or CuCl2 aqueous solution. But even after the cleansing of such etched substrate, some residue of the iron or copper contaminants will affect the electric reliability of the boards. Such effects have been evaluated by the QCM method. The obtained results suggested that scarce residue of iron contaminants will diminish the reliability rather than residue of copper contaminants.