• Title/Summary/Keyword: adhesion process

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Analysis of Residual Stresses Induced during Adhesion Process of Chip and Leadframe (칩과 리드페임의 접착과정에서 발생하는 잔류 응력 해석)

  • 이상순
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.13 no.1
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    • pp.97-103
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    • 2000
  • This paper deals with residual stresses induced at the viscoelastic adhesive layer between the semiconductor chip and the leadframe during adhesion process. The adhesive layer has been assumed to be“thermorheologically simple”. The time-domain boundary element method(BEM) has been employed to investigate the behavior of interface stresses. Numerical results show that very large stress gradients are present at the interface corner and such singularity might lead to local yielding or edge delamination.

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A Study on the Evaluation and Quality Control of Adhesives Applicable to the Style of Ladies' Leather Shoe according to the Cementing Process. (시멘트 제법의 숙녀화 적용에 대한 접착제 평가와 품질관리에 관한 연구)

  • 양대용;이상신;이종철
    • Journal of the Society of Korea Industrial and Systems Engineering
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    • v.17 no.32
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    • pp.137-144
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    • 1994
  • According to the cementing process, adhesive for dress shoe applicable to the style of ladies' has steadily been developed. In the study on the evaluation, mathematical model is presented. In the study on the quality control, a list of test results from field application and a model of manufacturing process including adhesion process are introduced.

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Development of Curved Shape Piezoelectric Unimorph Using Pre-stressed Substrate (초기응력을 가진 기저구조물을 이용한 곡면형 압전 유니모프 개발)

  • Kang, Lae-Hyong;Lee, Jong-Won;Han, Jae-Hung;Chung, Sang-Joon;Ko, Han-Young
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.1
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    • pp.94-100
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    • 2009
  • This paper proposes a novel curved shape piezoelectric unimorph using a new fabrication method. Instead of using thermal coefficient mismatch, which has been used for conventional processes for curved shape unimorphs, we used pre-stressed substrates and the room temperature adhesion process. A difference of the mechanical strains between the substrate and the piezoelectric layer makes the final manufactured unimorph get curved. Several performance tests of the proposed unimorph actuators were accomplished and the test results showed the proposed unimorph actuator got comparable actuation capability compared with conventional curved shape actuators.

Stability of Tip in Adhesion Process on Atomic Force Microscopy Studied by Coupling Computational Model

  • Senda, Yasuhiro;Blomqvist, Janne;Nieminen, Risto M.
    • Applied Science and Convergence Technology
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    • v.26 no.1
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    • pp.6-10
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    • 2017
  • We investigated the stability of ionic configurations of the tip of the cantilever in non-contact AFM.; For this, we used a computational model that couples the ionic motion of the MgO surface and the oscillating cantilever. The motion of ions was connected to the oscillating cantilever using a coupling method that had been recently developed. The adhesive process on the ionic MgO surface leads to energy dissipation of the cantilever. It is shown that limited types of ionic configurations of the tip are stable during the adhesive process. Based on the present computational model, we discuss the adhesive mechanism leading to energy dissipation.

A Proposal of Analysis Modeling on the Transfer and Adhesion of Incoming Salt to RC Structure (비래염분 전송 및 RC조 구조물 부착과정에 관한 분석 모델링 제안)

  • Cho, Gyu-Hwan;Kim, Woo-Jae;Ahn, Jae-Cheol;Park, Dong-Cheon
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.05a
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    • pp.91-92
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    • 2012
  • RC structure which is located at shoreline has more serious damages compared with inland structure, because it is directly exposed to chlorine ion which is called incoming salt. In the transmission of incoming salt, differences in transmitted volume of incoming salts could occur according to the influences of local shoreline topography which includes surrounding weather conditions, types of building placements, obstacles of wind tunnel etc. And therefore, for the application of boundary conditions for durable offshore structure design against the salt attack, comparative analysis through wind tunnel test and fluid value simulation are executed in order to investigate the moving and adhesion process of incoming salt to offshore structure.

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A study on exposure of organic solvents in manufacturing industry (제조업 산업장의 유기용제 노출에 관한 연구)

  • Moon, Deog-Hwan;Kim, Jeong-Ha;Kim, Pil-Ja;Park, Myung-Hee;Hwang, Yong-sik;Lee, Chae-Kwan;Lee, Chang-Hee
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.11 no.3
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    • pp.219-228
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    • 2001
  • Objective : For the purpose of preparing the fundamental data and health promotion and control program on organic solvents in air of manufacturing industry. Methods : The author surveyed number of organic solvent components which was used in working site and also determined the organic solvents concentration in air of 927 manufacturing industries and 1,267 working process with gas chromatography(NIOSH manual) for five years from 1995 to 1999. Results : Mean number of solvents components by type of industry, working process was number of 12. There were exceeded to TLV of 1,2-dichloroethane in textile manufacturing industry N,N-dimethyl furan in tanning and dressing of leather ; luggage, handbags, saddlery, harness and footwear manufacturing industry and chemical and chemical product manufacturing industry by type of industry. There were exceeded to TLV of 1,2-dichloroethane in handwriting and drawing process, cellosolve in adhesive spreading process, N,N-dimethly furan in production of solvent process and adhesion process by working process Total exceeded rate to threshold limit values of organic solvents mixture were 12.9% for EI(Exposure index) and 10.0% for Em(Estimation of mixture) by type of industry, 11.3% for EI and 8.2% for Em by type of working process. The highest exceed rate was 36.7% for EI in tanning and dressing of leather ; luggage handbags, saddlery, harness and footwear manufacturing industry and 29.0% for Em in textile manufacturing industry. The highest exceeded rate was 23.1% for EI and 12.5% for Em in adhesive spreading process by working process. Mean values of total subjects by type of industry and type of working process were $0.7{\pm}1.8$ for EI and $0.7{\pm}1.7$ for Em respectively. Conclusions : As above results, the author suggest that it makes the environmental control program on 1.2-dichloroethane, N,N-dimethyl furan, cellosolve by kind of organic solvent and on textile manufacturing industry, tanning and dressing of leather ; luggage, handbags, saddlery harness and footwear manufacturing industry by type of industry, and on handwriting, drawing process and adhesive spreading process and adhesion process by type of working process.

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Viscoelastic Properties of MF/PVAc Hybrid Resins as Adhesive for Engineered Flooring by Dynamic Mechanical Thermal Analysis

  • Kim, Sumin;Kim, Hyun-Joong;Yang, Han-Seung
    • Journal of the Korean Wood Science and Technology
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    • v.34 no.2
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    • pp.37-45
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    • 2006
  • The viscoelastic properties of blends of melamine-formaldehyde (MF) resin and poly(vinyl acetate) (PVAc) for engineered flooring used on the Korean traditional ONDOL house floor heating system were investigated by dynamic mechanical thermal analysis (DMTA). Because MF resin is a thermosetting adhesive, the effect of MF rein was shown across all thermal behaviors. The addition of PVAc reduced the curing temperature. The DMTA thermogram of MF resin showed that the storage modulus (E') increased as the temperature was further increased as a result of the cross-linking induced by the curing reaction of the resin. The storage modulus (E') of MF resin increased both as a function of increasing temperature and with increasing heating rate. From isothermal DMTA results, peak $T_{tan{\delta}}$ values, maximum value of loss modulus (E") and the rigidities (${\Delta}E$) of MF/PVAc blends at room temperature as a function of open time, peak $T_{tan{\delta}}$ and maximum loss modulus (E") values were found to increase with blend MF content. Moreover, the rigidities of the 70:30 and 50:50 MF/PVAc blends were higher than those of the other blends, especially of 100% PVAc or MF. We concluded that blends the MF/PVAc blend ratios correlate during the adhesion process.

Fabrication and Evaluation of Metal-Supported SOFC (금속지지체식 SOFC 제작 및 평가)

  • Choi, Jin-Hyeok;Lee, Tae-Hee;Choi, Mi-Hwa;Yoo, Young-Sung
    • Transactions of the Korean hydrogen and new energy society
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    • v.22 no.1
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    • pp.77-82
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    • 2011
  • In this study, a metal-supported SOFC was fabricated using a relatively cheap and simple process. The adhesion process between ceramic cell and metal support was performed in high temperature over $1400^{\circ}C$ and the deformation of large metal-supported cell happened in this process. Using bi-layered metal support fabricated by diffusion bonding, the deformation of the metal-supported cell can be minimized and the sealing efficiency of anode and cathode was improved. The flatness of the cell was improved by over 20% and the maximum power density of over 0.5 $Wcm^{-2}$ was obtained at the operation condition of $800^{\circ}C$.

A Study on Adhesion Characteristics for Rubber Parts of Footwear Containing Plasma Treatment (플라즈마 처리에 의한 신발용 고무부품의 접착특성 연구)

  • Jeong, Booyoung;Cheon, Jungmi;Lee, Sangjin;Moon, Jinbok;Chun, Jaehwan
    • Journal of Adhesion and Interface
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    • v.14 no.3
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    • pp.111-116
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    • 2013
  • In this study, we studied surface and adhesion properties with plasma treatment for substitution of buffing and solvent-cleaning in footwear adhesion process. The distance between nozzle and rubber parts was decreased with decreasing the contact angle. And when a speed of plasma treatment increased, the contact angle increased. The result of surface roughness, Ra and Rz increased in 20% and 16% after the plasma treatment. The distance of between nozzle and rubber parts was decreased with decreasing the peel strength. And the speed of plasma treatment was increased with decreasing the peel strength.