Hot Embossing

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Modeling of Large Area Hot Embossing

Modeling of Large Area Hot Embossing

The surface area of the foil covers the structured part of the tool. The tool and substrate are heated to the polymer molding temperature under vacuum. When the constant molding temperature is reached, embossing starts. At a constant embossing rate (in the order of 1 mm/min), tool and substrate are moved towards each other until the pre-set maximum embossing force is reached. Then, relative movement between the tool and substrate is controlled by the embossing force. The force is kept constant for an additional period (packing time, holding time), the plastic material flows under constant force (packing pressure). At the same time, tool and substrate move further towards each other, while the thickness of the residual layer decreases with packing time. During this molding process, temperature remains constant. This isothermal embossing under vacuum is required to completely fill the cavities of the tool. Air inclusions or cooling during mold filling already may result in an incomplete molding of the microstructures, in particular at high aspect ratios. Upon the expiry of the packing time, cooling of the tool and substrate starts, while the embossing force is maintained. Cooling is continued until the temperature of the molded part drops below the glass transition temperature or melting point of the plastic. When the demolding temperature of the polymer is reached, the molded part is demolded from the tool by the opening movement, i.e. the relative movement between tool and substrate. Demolding only works in connection with an increased adhesion of the molded part to the substrate plate. Due to this adhesion, the demolding movement is transferred homogeneously and vertically to the molded part. Demolding is the most critical process step of hot embossing. Depending on the process parameters selected and the quality of the tool, demolding forces may vary by several factors. In extreme cases, demolding is no longer possible or the structures are destroyed during demolding. Apart from the one-sided molding described above, the process is also used for double-sided positioned embossing. The principle of the process remains the same. Instead of the substrate, however, another tool is applied. To demold the molded part from one of both tool halves, special demolding mechanisms, such as ejector pins or pressurized-air demolding, are used. For a better understanding, the schematic representation of embossing in Figure 1 is limited to the major process steps. Depending on the tool and polymer, the process and process parameters have to be adapted accordingly.
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Design and measurement analysis of hot embossing system for high aspect ratio microfluidics

Design and measurement analysis of hot embossing system for high aspect ratio microfluidics

The focus of this work was to develop a hot embossing machine capable of prototyping the key aspects of Daktari's microfluidic card and to determine a method to[r]

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Modeling and Optimization of the Hot Embossing Process for Micro and Nanocomponent Fabrication

Modeling and Optimization of the Hot Embossing Process for Micro and Nanocomponent Fabrication

Hot embossing may be analyzed theoretically by means of process simulation. Today, finite element method 共FEM兲 simulation tools are state of the art in the field of plastic molding. However, no simulation tool exists that satisfac- torily reproduces the entire process chain of hot embossing. Complete FEM modeling of a typical LIGA mold insert using PC-based FEM systems is not yet possible due to excessively high computational resources required to per- form such analyses. Flow behavior of polymers during em- bossing has already been studied for a simple microstructure. 10,11 However, not only the individual free- standing microstructure is of interest, but also the structural field, and the type of arrangement of the individual micro- structures. Modeling of structural fields allows statements to be made with respect to the arrangement and mutual influence of individual structures, and thus, a tool can be designed in advance. 9,12,13
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Rapid fabrication of tooling for microfluidic devices via laser micromachining and hot embossing

Rapid fabrication of tooling for microfluidic devices via laser micromachining and hot embossing

https://doi.org/10.1088/0960-1317/18/2/025012 Access and use of this website and the material on it are subject to the Terms and Conditions set forth at Rapid fabrication of tooling for microfluidic devices via laser micromachining and hot embossing

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Numerical modeling and experimental study of hot embossing process for manufacturing of microcomponents

Numerical modeling and experimental study of hot embossing process for manufacturing of microcomponents

Access and use of this website and the material on it are subject to the Terms and Conditions set forth at Numerical modeling and experimental study of hot embossing process for manufacturing of microcomponents Marcotte, Jean-Philippe; Kabanemi, Kalonji K.; Hétu, Jean-Francois

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Hot Embossing Lithography: Release-Layer Characterization by Chemical Force Microscopy

Hot Embossing Lithography: Release-Layer Characterization by Chemical Force Microscopy

NRC Publications Archive Archives des publications du CNRC Access and use of this website and the material on it are subject to the Terms and Conditions set forth at Hot Embossing Lithography: Release-Layer Characterization by Chemical Force Microscopy

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Chemical force microscopy for hot-embossing lithography release layer characterization

Chemical force microscopy for hot-embossing lithography release layer characterization

for hot embossing lithography. Acknowledgements Some of the preliminary work was performed at the Cornell Nanofabrication Facility (a member of the National Nanofabrication Users Network) which is supported by the National Science Foundation under Grant ECS-9731293, its users, Cornell University and Industrial Affiliates. The authors are also grateful for collaborations with Quantiscript Inc. and Micralyne Inc, which contribute to the context for this study. NSC is particularly grateful for helpful discussions and useful interactions with Prof. L. Cuccia (Concordia University, Montreal), Dr. G. Cross (Trinity College, Dublin), Dr. M. Geissler (NRC) and our reviewers who provided many constructive comments.
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Demolding strategy to improve the hot embossing throughput

Demolding strategy to improve the hot embossing throughput

Figure 1. Standard hot embossing process. The pressure is released after freezing of the resist. To understand how this thermal cycle can be shortened, two points have been highlighted. First, it is noticeable that from a cost-effectiveness point of view, the embossing time (figure 1) should be the shortest as possible. Subsequently, steps where mold is not really used to print (i.e. cooling time to reach temperature below T g ) should be

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Numerical simulation of a thermoviscoelastic frictional problem with application to the hot-embossing process for manufacturing of microcomponents

Numerical simulation of a thermoviscoelastic frictional problem with application to the hot-embossing process for manufacturing of microcomponents

https://doi.org/10.3139/217.2227 Access and use of this website and the material on it are subject to the Terms and Conditions set forth at Numerical simulation of a thermoviscoelastic frictional problem with application to the hot-embossing process for manufacturing of microcomponents

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High fidelity, high yield production of microfluidic devices by hot embossing lithography : Rheology and stiction

High fidelity, high yield production of microfluidic devices by hot embossing lithography : Rheology and stiction

Introduction The increasing demand for polymer-based devices as well as for low-cost micro- and nano-fabrication technologies requires the development of reproducible protocols for manufacturing using inexpensive materials. Replication of micro- and nanostructures with polymers is an active area of research, often employing injection moulding and hot embossing. 1 A good example of the utility of hot embossing is in the fabrication of chips for micro total analysis systems (mTAS), where flow channels, reservoirs and mixing chambers can be designed and fabricated directly in a single-layer polymer chip. The micro electromechanical systems (MEMS) research community has recently adopted these technologies for the replication of precision plastic/metallic microstructures, and to develop low cost mass-production-compatible microfabrica- tion techniques for the commercialization of MEMS devices. 2 Many thermoplastic polymers have been investigated as candidate materials for such applications, including poly- (methyl methacrylate) (PMMA), poly(cyclic olefin) (PCO or COC), polycarbonate (PC), poly(tetrafluoroethylene) (PTFE), polystyrene (PS) and others (Table 1). 3–5
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Numerical simulation of a thermoviscoelastic frictional problem with application to the hot embossing process for microstructure fabrication

Numerical simulation of a thermoviscoelastic frictional problem with application to the hot embossing process for microstructure fabrication

/ La version de cette publication peut être l’une des suivantes : la version prépublication de l’auteur, la version acceptée du manuscrit ou la version de l’éditeur. Access and use of [r]

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Design and process optimization of a hot embossing machine for microfluidics with high aspect ratios

Design and process optimization of a hot embossing machine for microfluidics with high aspect ratios

Another limitation, and Daktari's biggest concern, is that this process does not produce parts that are representative of production parts, meaning both the geometry of the pa[r]

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3D cyclic olefin copolymer (COC) microfluidic chip fabrication using hot embossing method for cell culture platform

3D cyclic olefin copolymer (COC) microfluidic chip fabrication using hot embossing method for cell culture platform

Figure 2-2: Schematic of microfluidic device and experimental images for endothelial cell and hepatocyte co-culture to study transport-mediated angiogenesis [5].. 2.2 Lim[r]

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Modeling and Optimization of the Hot Embossing Process for Micro and Nanocomponent Fabrication

Modeling and Optimization of the Hot Embossing Process for Micro and Nanocomponent Fabrication

/ La version de cette publication peut être l’une des suivantes : la version prépublication de l’auteur, la version acceptée du manuscrit ou la version de l’éditeur. Access and use of [r]

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Numerical modeling of hot embossing process for manufacturing of microcomponents

Numerical modeling of hot embossing process for manufacturing of microcomponents

/ La version de cette publication peut être l’une des suivantes : la version prépublication de l’auteur, la version acceptée du manuscrit ou la version de l’éditeur. Access and use of [r]

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Micro and Nano Replication Using Hot Embossing and Applications

Micro and Nano Replication Using Hot Embossing and Applications

L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB. READ THESE T[r]

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Demolding of hot embossed polymer microstructures

Demolding of hot embossed polymer microstructures

The high-fidelity replication of nano-scale surface textures often observed in hot embossing also suggests that mechanical interaction of asperities contributes to adhesion. If mold features are undercut (Figure 2.4), the part can become “locked” onto the mold, and deformation or failure will occur during demolding. This failure can occur in the part (Figure 2.4 and Figure 1.5) or the mold (Figure 1.4). Although the sidewalls of silicon molds produced by the Bosch process (deep reactive ion etching or DRIE) are often nearly vertical, the scalloped texture will produce some undercut areas that can serve to “lock” the polymer onto the mold. Sidewall roughness can also contribute to friction between the part and mold that must be overcome during demolding. It has been observed that molds with a draft angle such as silicon molds produced by KOH etching can be demolded more easily [84, 86], further suggesting that friction related to mechanical asperity interaction is involved in mold-part adhesion.
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Corrosion Investigation Domestic Hot Water Tanks

Corrosion Investigation Domestic Hot Water Tanks

L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB. Report (Nati[r]

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Creep of olivine during hot-pressing.

Creep of olivine during hot-pressing.

The final density reached by any specimen is determined by the grain size, temperature, and stress conditions of the. test; as a final density is approached for any gi[r]

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Venus : Observe it while it's hot !

Venus : Observe it while it's hot !

VENUS: OBSERVE IT WHILE IT’S HOT! K.L. Jessup , Southwest Research Institute, Boulder, CO, USA (jessup@boulder.swri.edu), F. Mills, Space Science Institute, Boulder, CO, USA, S. Limaye, University of Wisconsin-Madison, Madison, WI, USA E. Marcq, J.L. Bertaux, LATMOS, Versailles, France. C. Wilson, Atmospheric Physics, Oxford, UK. T. Imamu-

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