• Tribology and Lubricants
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• 제24권5호
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• pp.255-263
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• 2008

Adhesion tests were conducted to investigate the adhesion characteristics between mold and thermoplastic polymer film. Coating of anti-sticking layer (ASL), a kind of polymer material, imprint pressure, and separation velocity were considered as the process conditions. A piece of fused silica without patterns on its surface was used as a mold and the thermoplastic polymer films were made on Si substrate by spin-coating the commercial polymer solution such as mr-I PMMA and mr-I 7020. The ASL was derived from (1H, 1H, 2H, 2H - perfluorooctyl) trichlorosilane($F_{13}$-OTS) and coated on the fused silica mold in vapor phase. The pull-off force was measured in various process conditions and the surfaces of the mold and the polymer film were observed after separation. It was found that the adhesion characteristics between the mold and the thermoplastic polymer film and the release performance of ASL were changed according to the process conditions. The ASL was effective to reduce the pull-off force and the damage of polymer film. In cases of the mold coated with ASL, the pull-off force did not depend on imprint pressure and separation velocity.

• Design & Manufacturing
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• 제6권2호
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• pp.79-83
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• 2012

Inner part is used as an insulator in wire fuses. After injection molding, inner part has been showed flashes, filling defects and deformation. After production, operators have to cut off flashes, one by one. this process leads to continuous low productivity and loss of source materials. This study focuses on identifying the causes for flashes, filling defects, clamping force of injectors, mold adhesion, resin of liquidity and others, and on resolving those issues.

• 한국표면공학회지
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• 제56권5호
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• pp.328-334
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• 2023

The carbon-based films have various properties, which have been widely applied in industrial application. However, it has critical drawback for poor adhesion between films and metal substrate. In the present work, we have deposited carbon-based films on injection mold steel by plasma assisted chemical vapor deposition (PACVD). In order to improve adhesion, prior to film deposition, the substrate was nitriding-treated using PACVD. And its effect on the adhesion was investigated. Due to the pre-nitriding, the amorphous carbon nitride (a-CN:H) films presented 10 times higher adhesion (34.9 N) than that of un-nitirided. In addition, a friction coefficient was decreased from 0.29 to 0.15 for the amorphous carbon (a-C:H) due to improved adhesion. The obtained results demonstrated that pre-nitriding considerably improved the adhesion, and the relationship among adhesion, hardness, and surface roughness was discussed in detail.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1030-1035
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• 2003

The nanoimprint lithography technology makes higher density of semiconductor device and larger capacity of storage media. In this technology the induced damage while detaching polymer pattern from mold should be minimized. In order to analyze the problem, the basic knowledge of adhesion between the polymer and the mold is required. In this study a contact experiment of polyisobutylene specimen with spherical steel tip and polyisobutylene bead tip was conducted using nano indenter. During the contact experiment with various loading rate under load control the contact behavior of viscoelastic material was measured, i.e., the load and displacement between the tip and the specimen were measured. The data was analyzed by HBK model to obtain the stress intensity factor of contact edge and the contact radius as a function of time. Also the adhesion energies between steel/polyisobutylene and polyisobutylene/polyisobutylene were obtained employing the analysis of the crack of viscoelastic material by Schapery.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.489-490
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• 2012

• 소성∙가공
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• 제20권1호
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• pp.64-72
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• 2011

In this study, we have investigated bonding of metal and plastic parts with single planar interface. This is facilitated by surface processing of aluminum sheet, which consists of slitting and punching, followed by insert-molding of polybuthylelne terephthalate(PBT). An injection mold has been built to fabricate specimen. After processing of the specimen, tensile and bending shear adhesion tests have been fulfilled according to KS M3734 and KS M3723, respectively. We also have conducted simulation of tensile and bending shear adhesion tests. Based on the tests results, the proposed bonding method outperforms existing methods based on adhesion.

• 한국표면공학회지
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• 제42권4호
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• pp.173-178
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• 2009

DLC film was synthesized on plastic injection mold(SKD11, $30\;mm\;{\times}\;19\;mm\;{\times}\;0.5\;mm$) and Si(100) wafer for 2 h at $130^{\circ}C$ under 6 mTorr using hybrid method of rf sputtering and ion source. The obtained film was analysed by Raman spectroscopy, AFM, TEM, Nano indenter and scratch tester, etc. The film was defined as an amorphous phase. In the Raman spectrum, broad peak of $sp^2$-bonded carbon attributed to graphite at $1550\;cm^{-1}$ were observed, and the ratio of ID($sp^3$ diamond intensity)/IG($sp^2$ graphite intensity) was approximately 0.54. The adhesion of DLC film was more than 80 N with scratch tester when $0.2\;{\mu}m$ thickness Cr was coated as interlayer. The micro-hardness was distributed at 35~37 GPa. The friction coefficient was 0.02~0.07, and surface roughness(Ra) was 0.34~1.64 nm. The lifetime of DLC coated plastic injection mold using as a connector part in computer was more than 2 times of non-coated mold.

• 한국재료학회지
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• 제15권1호
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• pp.6-13
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• 2005

Copper based leadframe sheets were immersed in two kinds of hot alkaline solutions to form brown-oxide or blackoxide layer on the surface. The oxide-coated leadframe sheets were molded with epoxy molding compound (EMC). After post mold curing, the oxide-coated EMC-leadframe joints were machined to form sandwiched double-cantilever beam (SDCB) specimens. The SDCB specimens were used to measure the fracture toughness of the EMC/leadframe interfaces under quasi-Mode I loading conditions. After fracture toughness testing, the fracture surface were analyzed by various equipment to investigate failure path. An adhesion model was suggested to explain the failure path formation. The adhesion model is based on the strengthening mechanism of fiber-reinforced composite. The present paper deals with the introduction of the adhesion model. The explanation of the failure path with the proposed adhesion model was introduced in the companion paper.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.759-762
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• 2005

A tray inserting machine is developed for automation of inserting plastic mold tray into a cardboard box. Plastic mold tray is used for protecting breakdown of glass bottles. In this paper, two types of processes to divide the plastic mold tray are proposed. As a result, adhesion method by vacuum pad is accepted. And also, static and modal analysis for the machine are carried out to check the machine design using the commercial software, CATIA V5.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 추계학술대회논문집
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• pp.367-370
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• 2003

In this study, application of SAM (self-assembled monolayer) to nano replication process as an anti-adhesion layer was presented to reduce the surface energy between the nano mold and the replicated polymeric nano patterns. The electron beam lithography was used for master nano patterns and the electorforming process was used to fabricate the nickel nano stamper. Alkanethiol SAM as an anti-adhesion layer was deposited on metallic nano stamper using solution deposition method. To analyze wettability and adhesion force of SAM, contact angle and LFM (Lateral Force Microscopy) were measured at the actual processing temperature and pressure for the case of nano compression molding and at the actual UV dose for the case of nano UV molding. It was found that the surface energy due to SAM deposition on the nickel nano stamper markedly decreased and the quality of SAM on the nickel stamper maintained under the actual molding environments.