• Corrosion Science and Technology
• /
• 제5권3호
• /
• pp.99-105
• /
• 2006

This paper is to investigate feasibility on quantitative aging state of epoxy coating on concrete wall in containment structure under operation of nuclear power plants. For evaluating the physical characteristics of the epoxy coating, adhesion strengths of two kinds of degraded epoxy coating systems on both steel surfaces and concrete surfaces were measured via accelerated aging. Comparatively impedance data taken by ultrasonic test were also taken to relate with adhesion data. After aging, in case of concrete, from half of specimens, aging of epoxy coating was developed. As for steel, on $4^{th}$ inspection day, adhesion force was failed. To improve reliability on quality degradation of epoxy, relationship between adhesion and impedance was analyzed. By tracing to co-respond to these data, it was possible to Fig. out physical state of as-built epoxy coating. The possibility to develop new methodology of time - dependent aging state on epoxy coating was found and discussed.

• 한국표면공학회:학술대회논문집
• /
• 한국표면공학회 2015년도 추계학술대회 논문집
• /
• pp.204-204
• /
• 2015

• 한국재료학회지
• /
• 제19권8호
• /
• pp.437-442
• /
• 2009

This paper describes an improved strategy for controlling the adhesion force using both the antiadhesion and adhesion layers for a successful large-area transfer process. An MPTMS (3-mercaptopropyltrimethoxysilane) monolayer as an adhesion layer for Au/Pd thin films was deposited on Si substrates by vapor self assembly monolayer (VSAM) method. Contact angle, surface energy, film thickness, friction force, and roughness were considered for finding the optimized conditions. The sputtered Au/Pd ($\sim$17 nm) layer on the PDMS stamp without the anti-adhesion layer showed poor transfer results due to the high adhesion between sputtered Au/Pd and PDMS. In order to reduce the adhesion between Au/Pd and PDMS, an anti-adhesion monolayer was coated on the PDMS stamp using FOTS (perfluorooctyltrichlorosilane) after $O_2$ plasma treatment. The transfer process with the anti-adhesion layer gave good transfer results over a large area (20 mm $\times$ 20 mm) without pattern loss or distortion. To investigate the applied pressure effect, the PDMS stamp was sandwiched after 90$^{\circ}$ rotation on the MPTMS-coated patterned Si substrate with 1-${\mu}m$ depth. The sputtered Au/Pd was transferred onto the contact area, making square metal patterns on the top of the patterned Si structures. Applying low pressure helped to remove voids and to make conformal contact; however, high pressure yielded irregular transfer results due to PDMS stamp deformation. One of key parameters to success of this transfer process is the controllability of the adhesion force between the stamp and the target substrate. This technique offers high reliability during the transfer process, which suggests a potential building method for future functional structures.

• 한국구조물진단유지관리공학회 논문집
• /
• 제7권2호
• /
• pp.149-157
• /
• 2003

The purpose of this paper is to quantitatively investigate aging state of epoxy coating on containment structure at nuclear power plant. In order to evaluate an physical bonding of the epoxy coating, adhesion test was performed on a degraded epoxy coating on concrete specimens fabricated by accelerated aging experiment. In addition, impedance data by ultrasonic test were measured to compare with adhesion data. From almost 50 % of the specimens, aging phenomena of epoxy coating such as pin hole, blistering was discovered. To improve reliability on quality degradation of epoxy, co-relation between two kinds of different data was analyzed. By tracing co-related these data, it was possible to figure out physical state of as-built epoxy coating. The possibility to develop new methodology of time - dependent aging state on epoxy coating was found and discussed.

• 한국표면공학회지
• /
• 제56권1호
• /
• pp.77-83
• /
• 2023

The reliability of leadframe-based semiconductor package depends on the adhesion between metal and epoxy molding compound (EMC). In this study, the Ag surface was electrochemically treated in a solution containing silanes in order to improve the adhesion between Ag and epoxy substrate. After electrochemical treatment, the thin silane layer was deposited on the Ag surface, whereby the peel strength between Ag and epoxy substrate was clearly improved. The improvement of peel strength depended on the functional group of silane, implying the chemical linkage between Ag and epoxy.

• 정보저장시스템학회논문집
• /
• 제5권2호
• /
• pp.82-88
• /
• 2009

Understanding the adhesion behavior and characteristics of toner film is required to achieve image and text printing with high quality resolution. Toner can be considered as a thin film coating on a media such as paper or polymer film. Quantitative measurement of adhesion characteristics of the thin film is important to assess the reliability of the system. In this work the main objective was to investigate the adhesion characteristic between the toner and the media by ramp loading scratch test method. The scratch test may be used to obtain quantitative information about the adhesion of the film to the substrate. In the scratch test a diamond tip was used to scratch the surface of the toner film under an increasing normal load until the toner detached or fractured. The critical load (LC) was obtained from the experimental results. Also, the relationship between the critical load and the adhesive strength of the interface between the substrate and the toner was obtained by measuring the normal and tangential forces during the scratch test. Finally, theoretical analysis of the toner scratch characteristics was performed based on Benjamin and Weaver theory, Plowing model, and Laugier model.

• Journal of Welding and Joining
• /
• 제18권4호
• /
• pp.64-69
• /
• 2000

Reliability of PBGA(Plastic Ball Grid Array) package is very weak compared with normal plastic packages. The reliability are the lower resistance to popcorn cracking, which is reduced by moisture absorption in PCB(Printed Circuit Board). This paper adapts plasma treatment process and analyzes their effect. The contents of C and Cl decrease after plasma treatment but O, Ca and N relatively increase. The Plasma treatment to improve the adhesion between EMC(Epoxy Molding Compound) and PCB(solder mask). The degree of improvement was over 100% Max., which is depend on the properties of EMC. Ar+H$_2$as plasma gas show good result. There is a little difference in RF power and treatment time.

• 마이크로전자및패키징학회지
• /
• 제26권4호
• /
• pp.101-105
• /
• 2019

칩 패키지에는 생산 공정 및 운송, 보관 과정에서 발생하는 외부 환경 변화로부터 인쇄 회로 기판(printed circuit board, PCB)을 보호하기 위해 에폭시 몰딩(epoxy molding compound, EMC)이 사용된다. PCB와 EMC의 접합 신뢰성은 제품의 품질 및 수명에 중요한 요소이며 이를 보증하기 위해 제품 설계 및 생산 단계에서 그 접합 에너지를 정밀하게 측정하고, 이에 영향을 끼치는 요소를 통제하여 공정을 최적화 시켜야 한다. 본 논문은 이중 외팔보(double cantilever beam, DCB) 시험을 이용하여 휨(warpage)이 있는 칩 패키지의 EMC와 PCB의 계면 접합 에너지를 측정하고 보정하는 방법에 대해 소개한다. DCB 시험법은 이종 재료의 계면 접합 에너지를 측정하는 전통적인 방법이며 정밀한 접합 에너지 측정을 위해 평평한 기판이 필수적이다. 그러나 칩 패키지는 내부 구성 요소들의 열팽창 계수 차이로 인해 휨이 발생하기 때문에 평평한 기판을 제작하여 정밀한 접합 에너지를 측정하는데 어려움이 있다. 이를 극복하고자 본 연구에서는 휨이 있는 칩 패키지로 DCB 시험법을 위한 시편을 제작하고, 기판의 복원력을 보정하여 접합 에너지를 계산하였다. 보정된 접합에너지는 동일 조건에서 제작된 칩 패키지 중 휨이 없는 시편을 선별하여 측정한 접합 에너지와 비교, 검증하였다.

• 한국재료학회지
• /
• 제19권3호
• /
• pp.119-124
• /
• 2009

In the microelectronics packaging industry, the adhesion strength between Cu and polyimide and the thermal stability are very important factors, as they influence the performance and reliability of the device. The three different buffer layers of Cr, 50%Cr-50%Ni, and Ni were adopted in a Cu/buffer layer/polyimide system and compared in terms of their adhesion strength and thermal stability at a temperature of $300^{\circ}C$ for 24hrs. A 90-degree peel test and XPS analysis revealed that both the peel strength and thermal stability decreased in the order of the Cr, 50%Cr-50%Ni and Ni buffer layer. The XPS analysis revealed that Cu can diffuse through the thin Ni buffer layer ($200{\AA}$), resulting in a decrease in the adhesion strength when the Cu/buffer layer/polyimide multilayer is heat-treated at a temperature of $300^{\circ}C$ for 24hrs. In contrast, Cu did not diffuse through the Cr buffer layer under the same heat-treatment conditions.

• 센서학회지
• /
• 제33권2호
• /
• pp.86-92
• /
• 2024

Flexible electronic devices are exposed to repeated mechanical deformation; therefore, electrode performance is an important element. Recently, a new technology has been developed to improve the adhesion strength between polymer substrates and metal thin films through the cross-linking reaction of bovine serum albumin (BSA) bioconjugation proteins; however, additional performance evaluation as an electrode is necessary. Therefore, in this study, we investigated the effect of adhesive strength between a flexible substrate and a metal thin film on the performance of a flexible electrode. Cracks and changes in the electrical resistance of the electrode surface were observed through outer bending fatigue tests and tensile tests. As a result of a bending fatigue test of 50,000 cycles and a tensile test at 10% strain, the change in the electrical resistance of the flexible electrode with a high adhesion strength was less than 40%, and only a few microcracks were formed on the surface; thus, the electrical performance did not significantly deteriorate. Through this study, the relationship between the adhesion strength and electrical performance was identified. This study will provide useful information for analyzing the performance of flexible electrodes in the commercialization of flexible electronic devices in the future.