WO2006005487A1

WO2006005487A1 - Microstructured device and production method therefor

Info

Publication number: WO2006005487A1
Application number: PCT/EP2005/007269
Authority: WO
Inventors: Jörg KENTSCH; Martin Stelzle; Manfried Dürr; Wilfried Nisch; Wolfgang Lutz
Original assignee: NMI Naturwissenschaftliches und Medizinisches Institut an der Universität Tübingen
Priority date: 2004-07-08
Filing date: 2005-07-06
Publication date: 2006-01-19
Also published as: DE102004033440A1

Abstract

In order to produce a microstructured device, a microstructured first substrate (11) having at least one elevated area (12) is provided. An adhesive is then applied to a support in order to produce an adhesive layer at that location. The adhesive layer is then transferred from the support to the at least one elevated area (12) of the microstructured substrate (11). Afterwards, a second optionally microstructured substrate (15) is positioned upon the first substrate (11) so that it, via its contact surface (16), rests upon the at least one elevated area (12) of the first substrate (11), said elevated area being provided with the adhesive layer (14). The adhesive layer (14) is then cured.

Description

Microstructured device and method for its production

The present invention relates to a microstructured device, with at least one cavity or microchannel surrounded on all sides by walls, wherein at least one wall is adhesively bonded to a raised area of the remaining device via its contact surface, as well as methods for producing a microstructured device and an adhesive tool for carrying out of the procedure.

Such microstructured devices and processes for their preparation are known in many cases from the prior art be¬.

The known microstructured devices are used, for example, as microfluidic systems, where they are used for the manipulation of small volumes of fluid, as required, for example, in chemical or biochemical analysis. The known devices are used, for example, for manipulating and measuring biological cells, as described in DE 197 12 309. Other application examples of such microstructured devices are printheads of ink jet printers, as described, for example, in US 5,855,713.

DE 41 28 964 A1 also describes microstructured devices having micro cavities which are used in the field of micromechanics and integrated sensor technology.

An example of fluidic microsystems which are produced by structuring of silicon or of layers which are deposited on silicon is known from DE 197 39 717 A1.

WO 98/45693 also describes microchannel structures for micro-fluidic manipulations.

The known devices have dimensions of a few millimeters to a few centimeters, the microstructuring itself being in the micrometer range. The microchannels present in the known devices have, for example, thicknesses of 5 to 50 μm and widths of 50 to 2000 μm, wherein the length of the microchannels may be in the millimeter range.

In the production of such microstructured Vorrichtun¬ gene so the production of channels, cavities, etc. er¬ is necessary, which is generally done with methods of planar technology. In this case, two substrates are patterned by lithography and etching process with trenches and subsequently connected miteinan¬, so that a closed cavity or Kanal¬ structure is formed. Depending on the material of the substrates, the halves of the device formed by the two substrates are joined together by various methods. A common method is the so-called anodic bonding, which however is not applicable if the substrate consists of a polymer or a glass or silicon provided with a temperature-sensitive coating. In addition, the achievable accuracy in anodic bonding is limited by the associated thermal expansion.

Therefore, so-called Klebebondingverfahren durchge set, as they are known for example from the aforementioned WO 98/45693. In the known method, an adhesive is applied by means of stamping, rolling, spraying, doctoring or similar steps on a substrate, whereupon this substrate is then positi¬ on the second substrate on which raised areas are provided through which then the Cavities or microchannels are formed. The cavities or microchannels thus formed are surrounded by three walls of the substrate material and by a fourth wall provided with the adhesive layer.

However, such devices have a whole series of disadvantages, for example the channel walls can not be completely chemically functionalized, ie provided with biomolecules or a protein-repellent coating, because the surface chemistry in the cavity or microchannel is not seen over all four walls homogeneous. In addition, the wetting properties of the adhesive layer can be different from the properties of the remaining channel surface. whereby the fluidic properties of the known device are adversely affected.

Moreover, in the known method, it is not excluded that excess adhesive gets into the cavities or microchannels, so that further sides are provided with an undesired coating and, if necessary, even the clear width of the cavities or microchannels is reduced worst case the microchannels can even clog up. This is a problem in particular when devices with microstructures in the micrometer range are to be produced.

From DE 41 28 964 Al a method is known in which initially a two-dimensional adhesive layer is applied, which is fotostrukturierbar. After appropriate Beliσhtungs- and etching process are then only on the desired raised areas of the first substrate adhesive areas with which the contact surfaces of the second substrate are bonded. However, in the known method it is disadvantageous that it requires many method steps, wherein in particular the structuring of the adhesive layer requires a precise alignment between the shadow mask and the substrate having the raised areas.

DE 100 56 908 A1 describes a method for joining microstructured plastic parts, in which the adhesive is applied to a carrier film and precured there before it is then transferred to the microstructured component. Pre-curing on the carrier film is intended to increase the viscosity in order to prevent the application of the adhesive Material on the component adhesive flows into the microstructuring.

However, since then there is a risk that the adhesive layer is completely transferred from the carrier film to the component, where the non-raised areas would then be undesirably covered, it is further proposed to treat this with compressed air after transferring the adhesive to the microstructured component, in order to blow off the adhesive layer possibly above the channel structure.

In the known method it is disadvantageous that two procedural steps are required in order to ensure that adhesive is applied only on the raised areas. This is once the precuring of the adhesive on the carrier film and on the other blowing off the component after transferring the adhesive and before placing the second component.

These process steps are not only time-consuming, they are also unreliable and therefore require a very precise coordination of the individual process parameters, in order to prevent the penetration of the adhesive into undesired areas and, on the other hand, nevertheless to ensure a good connection between the components. According to the inventors of the present application, it is not possible with the known method, on the one hand, to completely provide the raised areas with an adhesive layer and, on the other hand, to keep the walls free of adhesive on their free surfaces and the channels.

From the published after the earliest priority date of the present application DE 103 38 967 Al is a method It is known in which a transfer film with granular or powdery adhesive adhering thereto or a film of the hotmelt adhesive itself is applied to the raised regions of the microstructured first substrate. It is also possible to apply a suspension or dispersion of a hotmelt adhesive to the surface of the substrate by means of a roller.

The production of an adhesive layer on a support is not known from this document.

Against this background, the object of the present invention is to further develop the known methods in such a way that microstructured devices can be produced without the above-mentioned disadvantages in the case of rapid, simple and reproducible passage.

In the method mentioned in the introduction, this object is achieved according to the invention by the steps:

a) providing a microstructured first substrate having at least one raised area,

b) applying an adhesive to a support to form an adhesive layer thereon,

σ) transferring the adhesive layer from the carrier to the at least one raised region of the microstructured substrate, d) positioning a second, optionally microstructured substrate on the first substrate so that it comes into contact with its contact surface with the at least one raised region of the first substrate provided with the adhesive layer, and

e) curing the adhesive layer.

In the known microstructured device, this object is achieved in that the at least one raised region is completely coated with adhesive and the walls are free of adhesive on their free surfaces.

The object underlying the invention is completely solved in this way.

In fact, the inventors of the present application have recognized that, contrary to the expectation of the experts and contrary to all the methods described in the prior art, it is possible to completely cover the raised regions of the microstructured first substrate with the adhesive layer, but so to do form that when joining with the second substrate, no adhesive flows into the microchannels or cavities, but still the Kontaktflä¬ surfaces of the second substrate over the entire surface with the raised Be¬ be glued. As a result, the microchannels and cavities in the device produced by the new method are surrounded on all sides by adhesive-free surfaces, but on the other hand, the two substrates are very firmly connected to one another. It is preferred if in step b) an adhesive with a dynamic viscosity is applied which is less than 1000 mPa s, preferably 200 to 500 mPa s, wei¬ ter preferably about 300 mPa s.

The inventors of the present application have recognized that an adhesive having such a dynamic viscosity can be applied to the support in a sufficiently thin layer, wherein when transferring the adhesive layer from the support to the raised areas, it is ensured that the adhesive is only on adheres to the raised areas and flows into neither the transfer of the adhesive layer nor the subsequent pressing of the second substrate in the channels and cavities. In other words, the adhesive wets either the raised areas or remains on the support, which can be pressed for example directly onto the first substrate, so that only the raised areas are provided by Ab¬ pressure with an adhesive layer.

In this case, it is further preferred if, in step b), an adhesive layer having a thickness of less than 10 μm, preferably less than 5 μm, more preferably less than 3 μm, is produced.

The inventors have further recognized that with such a thickness of the adhesive layer it is prevented that during the transfer of the adhesive layer to the raised areas and / or during the pressing on of the second substrate, adhesive beads are formed which enter the cavities or microchannels and partially or completely close. In one exemplary embodiment, for example, an adhesive having a viscosity of 300 mPa s and a thickness of the adhesive layer is from 1 to 3 μm. used. For example, the adhesive sold by Panacol-Elosol GmbH in 61440 Ober¬ ursel has proven to be an adhesive under the trade name "Vitralit 1558".

It is further preferred if, in step e), the curing of the adhesive is supported by suitable measures, preferably by pressure and / or temperature treatment and / or UV irradiation.

In this measure, it is advantageous that the adhesive is cured in a defined manner in a manner known per se, so that a secure and firm connection is created.

For example, when the above-mentioned adhesive Vitralit 1558 is used, it can be cured by irradiation with UV light in the spectral range 320-370 nm for 300 seconds with a radiation power of 10 mW / cm ² .

In general, it is preferred in this case if, in step b), the adhesive is applied to a planar surface. ,

Here is an advantage that the new process can be carried out very quickly and easily. The thin layer of adhesive must first be spun onto the planar surface of the carrier, then transferred by imprinting onto the microstructured first substrate. Due to the properties of the adhesive and the thickness of the adhesive layer, only the raised areas of the first substrate are wetted. Alternatively, the adhesive layer can be removed from the carrier with an intermediate punch and transferred to the substrate.

On the other hand, it is preferred if in step b) the adhesive is applied to a curved surface.

In this measure, it is advantageous that large-area contact with the surface to be wetted is avoided, which avoids strong adhesion and excessively high forces during detachment of the adhesive layer from the microstructured substrate compared with full-area transfer with the intermediate punch or directly to the planar support ,

In this case, it is particularly preferred if the support is flexible, so that it can preferably be bulged in step c) and rolled on the raised area of the first substrate.

This measure combines the above-mentioned advantages, since the adhesive layer can first be applied to the planar support by known methods, whereupon the support is then bulged and rolled on the first substrate, so that a defined transfer of the adhesive layer is ensured only on the raised areas ,

In another embodiment, it is preferred if in step b) the adhesive is applied to at least one roller. This roller can be regarded as a curved surface in the sense of the above embodiments, so that the already mentioned advantage of the small contact surface between the adhesive layer and the microstructured device results if the roller unrolls on the at least one raised region of the first substrate becomes.

In a further development, it is preferred if in step b) the adhesive is applied to two adjoining rollers and in step c) the adhesive layer is produced by oppositely rotating the two rollers, preferably in step c) an adhesive forming between the two rollers ¬ bead serves as an adhesive reservoir or alternatively can be removed, wherein the adhesive layer is optionally homogenized by another reverse rotation of the two rolls. The removal of adhesive bead and homogenization of the adhesive layer is preferably repeated several times until no or no appreciable bead of adhesive is formed any more.

In this measure, it is advantageous that a very defined adhesive layer is formed, wherein furthermore the metering of the adhesive for the reproducibility of the new process no longer plays a decisive role. It merely has to be ensured that at least as much adhesive is applied to the rollers as is necessary for the formation of homogeneous adhesive layers of sufficient thickness on both rollers. However, an overdosing is harmless, because then an adhesive bead forms between the oppositely rotating rollers, which either serves as an adhesive reservoir, ie serves to "fill in" the adhesive layer which is transferred from the underside of one of the two rollers to the substrate, or removed, for example, can be stripped. The inventors of the present application have found that in this way an adhesive layer is produced which is so thin that no bead formation and accordingly no contamination of the channels with adhesive can occur even when transferred to the microstructured substrate.

It is preferred if the at least one roller has on its surface microcavities which serve as an adhesive reservoir.

Here, it is advantageous that when applying the adhesive and forming the adhesive layer, adhesive is introduced into the microcavities, which can be arranged in a high lateral density. The microcavities then serve as a kind of adhesive reservoir, so that the amount of adhesive on the roller can be adjusted reproducibly and defined. The microstructuring has the further advantage that when the roll rolls off on the raised regions of the substrate, no adhesive bead is formed in front of the roll which could partially or completely fill the microstructuring. Instead, it is ensured that adhesive is transferred from the roll, which is so microstructured, only to the raised regions of the substrate, which come into contact with the rolling roll and are wetted by the adhesive.

Of course, it is also possible to carry out the method with more than two rolls, wherein one or more of the inserted rolls can be used to transfer the adhesive layer to the first substrate. It is also possible to provide only one roll with the microstructure and to use the other roll or the other rolls for the homogenized introduction of the adhesive into the microstructuring.

In general, it is preferred if in step c) the adhesive layer is transferred under pressure to the at least one raised region, wherein the pressure is preferably greater than 1 × 10 ⁵ Pa, preferably greater than 3 × 10 ⁵ Pa.

Experiments by the inventors have shown that at this pressure, in particular in connection with the above-mentioned adhesive Vitralit 1558, a very reproducible, sufficiently thin adhesive layer which completely covers the raised areas after the transfer is produced, which does not melt when the second substrate is pressed the cavities or microchannels penetrates.

It is further preferred if, in step d), the second substrate is positioned under pressure on the first substrate, this pressure being in the range of 0 to 20 × 10 ⁵ Pa.

Here, it is advantageous that, on the one hand, a very good adhesive bond is produced between the two substrates in this pressure region, on the other hand, it is prevented that adhesive gets into the cavities or microchannels.

It is understood that the viscosity of the adhesive, the thickness of the adhesive layer and the pressure with which the adhesive layer is transferred to the raised areas, as well as the pressure with which the second substrate on the first substrate is pressed, must be adjusted in dependence on each other. At lower viscosity, for example, a smaller thickness of the adhesive layer and a lower pressure in the transfer and assembly is required, while at a slightly higher viscosity, the thickness and the pressure can be greater or each. In any case, however, it must be ensured that neither an adhesive bead forms during the transfer of the adhesive layer nor during the joining of the two substrates, and that it can get into the cavities or microchannels as an impurity.

On the whole, it is preferred if the substrate and / or the carrier are pretreated on its surface with an oxygen plasma in order to ensure wetting of the surface with the adhesive film.

In this measure, it is advantageous that substrate and roller are safely wetted so that actually forms a film and not a collection of small droplets. In this context, the pretreatment of surfaces with an oxygen plasma offers particular advantages.

Against this background, the present invention further relates to an adhesive tool for carrying out the new method, comprising a holder on which a holding region for microstructured substrates is provided, with a first roller, which is rotatably mounted on the holder, and with at least a second roller, which is rotatably and so adjustably mounted on the holder, that it can be brought into contact both with the first roller and with a substrate arranged in the holding region, wherein preferably at least one of the rollers its surface microcavities, which serve as an adhesive reservoir.

It is preferred if one of the two rollers has a harder surface than the other roller, wherein one roller preferably has a surface made of metal, further preferably steel or aluminum, and the other roller preferably has a surface made of plastic Material, more preferably made of silicone.

The arrangement of a hard and a soft roll has two advantages over two existing metal rollers hin¬ with respect to the adjustment advantages, because both rollers can now be aligned exactly to each other, so that in a simple manner over the entire width of the roll evenly thin adhesive film can be produced. Because of the deformability of the second roller even thinner adhesive films can be produced than with two hard rolls.

Further advantages will become apparent from the description and the accompanying drawings.

It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the particular combinations indicated, but also in other combinations or in isolation, without departing from the scope of the present invention.

Embodiments of the invention are illustrated in the drawing and will be explained in more detail in the following description. Show it: 1 shows the production of a microstructured Vorrich¬ device in which the walls surrounding a cavity are free of adhesive on their free surfaces.

FIG. 2 shows an intermediate punch for transferring an adhesive layer from a carrier to raised regions of the device from FIG. 1; FIG.

3 shows a flexible carrier for transferring an adhesive layer to raised areas of the device according to FIG. 1;

Fig. 4 shows two oppositely rotating rollers for producing an adhesive layer, which is transferred to the raised portions of the apparatus of FIG. 1; and

5 shows an adhesive tool for producing an adhesive layer and for applying the adhesive layer to the raised regions of the device from FIG. 1.

FIG. 1 shows the production of a microstructured device 10 in three steps.

At the top in Fig. 1, a substrate 11 is provided, which may be spielsweise of glass or silicon. On the substrate 11, for example, three raised areas 12 are arranged, which are formed by spacers made of a suitable polymer. On the raised areas 12, an adhesive layer 14 is applied according to the central illustration in Fig. 1, which cover the raised areas 12 almost completely.

At the bottom of FIG. 1, a second substrate 15 is applied to the first substrate 11 in such a way that it lies with its contact surfaces 16 on the raised areas 12, so that the two substrates 11 and 15 are firmly joined together by the adhesive layers 14 become.

Pointing to the first substrate 11, two microelectrodes, indicated at 17, are arranged on the second substrate 15 and project into the microchannels 18 formed in this way.

The microchannels 18 are surrounded by four walls formed by the first and second substrates 11, 15 and the raised regions 12. On the second substrate 15, the first substrate 11 and the raised areas 12, free surfaces 19, 21 and 22 are provided, which are adhesive-free due to the special Auftra¬ type of adhesive layer 14, so that all four walls surrounding the microchannels 18 the same Be¬ wettability and Oberflächenσhemie have.

It should be noted that the device 10 of FIG. 1 is a microstructured device, the raised areas 12 have, for example, a height of 20 microns and a width of 50 microns, wherein they have a distance of 100 microns auf¬. The microchannels 18 accordingly have a width of 100 μm and a height of 20 μm. The numerical data are to be understood merely as an example, the representation of FIG. 1 furthermore not being true to scale.

The Klebschiσht 14 is formed by an adhesive having a viscosity of 300 mPa s, as can be found for example in the adhesive Vitralit 1558 of Panacol-Elosol GmbH, 61440 Oberursel.

The adhesive layer has a thickness of 1 to 3 .mu.m, this thickness being determined inter alia by the quality of the planarity of the raised areas 12 and the contact surfaces 16.

After the two substrates 11 and 15 have been joined together, as shown in FIG. 1, the adhesive layer is cured by irradiation with UV light in the spectral range 320-370 nm for 300 sec, the irradiation power being included about 10 mW / cm ² , wherein the substrates 11 and 15 are joined together at a pressure of less than 10 ⁵ Pa.

As the application of the adhesive layer 14 takes place, will now be explained with reference to the following figures.

FIG. 2 shows a carrier 24 which has a planar surface on which an adhesive layer 25 is spun in a manner known per se. This adhesive layer 25 has, for example, a thickness of 3 μm.

With the aid of a schematically indicated intermediate punch 26, the adhesive layer 25 is now removed from the carrier 24 and onto the raised regions 12 of the substrate 11 from FIG. 1 stamped on top. Due to the viscosity of the adhesive in the adhesive layer 25 and the thickness of the adhesive layer 25 and the pressure with which the intermediate punch is pressed onto the first substrate 11, in this way the adhesive layer 25 is raised onto the raised area only in the region of the raised areas 12 Transfer areas 12 where they form the Klebstoff¬ layer 14. The pressure used in this transfer is, for example, in the range of 0.1 to 5 × 10 ⁵ Pa.

In Fig. 3, a flexible carrier 28 is shown, on which an adhesive layer 29 has been applied in a conventional manner. Under the support 28 is a holder 31, on which the first substrate 11 of FIG. 1 is arranged. Due to the differences in size, the substrate 11 is shown by way of example only; FIG. 3 is just as little true to scale as FIGS. 1 and 2.

Because the substrate 28 is flexible, it can be provided with the adhesive layer 29 in the planar state, after which it is then bulged as seen in FIG. The carrier 28 is then rolled on the substrate 11, which is indicated by an arrow 32. In this way, the contact surface between the substrate 11 and the carrier 28 is relatively low, which, when transferring the adhesive layer 29 to the substrate 11, supports the desired effect, namely that only in the region of the raised regions 12 from FIG an adhesive layer 14 is formed.

Instead of a flexible carrier 28, a roller may also be used as the carrier, as will now be discussed with reference to FIGS. 4 and 5. In Fig. 4, two oppositely rotating rollers 34, 35 are shown, of which at least one is provided on its surface with an indicated at 36 microstructuring by microcavities. The microcavities serve to receive adhesive which is applied to the rollers 34, 35.

It is sufficient if one of the two rollers 34, 35 has the microstructure 36, the other roller may, for example, have a smooth surface. The adhesive layer is then formed on the microstructured roll and transferred to the raised areas 12 of the first substrate 11 in a manner to be described.

In this case, the microcavities have transverse dimensions ranging from 0.1 μm × 0.1 μm to 50 μm × 50 μm, wherein the microcavities do not necessarily have to be square. In the exemplary embodiment shown, the microcavities have dimensions of 5 μm × 5 μm. The number of microcavities per mm ² is in the range of 10 ¹⁰ to 400, with a number of diameters of 40,000 / mm ^{2 being} preferred. The volume of the individual microcavities then lies in the range from 1 nl (with dimensions of 50 μm × 50 μm) to 1 attoliter (with dimensions of 0.1 μm × 0.1 μm).

The microcavities can be uniform or randomly distributed, they can also be designed as porosity.

After application of the adhesive, the rollers 34, 35 are rotated in opposite directions to each other, so that the adhesive forms a homogeneous layer on at least one of the two rollers 34, 35 and is pressed into the microstructure 36. At the beginning, adhesive is applied in excess to the rollers 34, 35 so that an adhesive bead, indicated at 37, forms between them, which serves as an adhesive reservoir. The adhesive layer 38 formed, for example, on the roller 34 is transferred from the underside to the raised regions 12 of the substrate 11, the adhesive layer 38, so to speak, being raised again when the two rollers 34, 35 are further rotated from the adhesive bead 37 ¬ is filled.

On the other hand, it is also possible to remove the adhesive bead 37 and again to rotate the rollers 34, 35 in opposite directions so that the adhesive layer 38 is distributed homogeneously. Should it again form an adhesive bead 37, this is stripped off again. This process is repeated until, when the rolls 34, 35 rotate in opposite directions, no new bead of adhesive 37 is formed, so that a thin, homogeneous layer of adhesive 38 is formed on the rolls 34, 35, which on the surface of the rolls 34, 35 and / or is formed in the microcavities 36 serving as an adhesive reservoir.

When unrolling, for example, the roller 34 on the substrate 11, the adhesive layer 38 is then transferred in the region of the raised regions 12 and forms the adhesive layer 14 there.

For this purpose, an adhesive tool shown schematically at 41 in FIG. 5 is provided, which comprises a holder 42 on which a holding region for the substrate 11 is provided at 43. On the holder 42, a longitudinally displaceable block 44 is angeord¬ net, which can be moved in the direction of an arrow 45 to the substrate 11 back and away from this. Pivotally mounted on the bracket 44 is an arm 46 which rotatably supports the roller 34 at its outer end and can be pivoted in the direction of an arrow 47 so that the roller 34 in FIG. 5 either to the left or to the right of the bracket 44 on the Holder 42 rests.

On the holder 42 is still a fixed block 48, on which the roller 35 is rotatably mounted.

This adhesive tool 41 is now used to apply the adhesive layer 14 to the raised areas 12 of the substrate 11 from FIG. 1 as follows.

First, the arm 46 is pivoted to the right in the direction of the arrow 47, so that the rollers 34 and 35 come to lie next to each other as shown in Fig. 4. Adhesive is then applied to the rollers 34, 35 and, according to the method described above, the adhesive layer 38 is formed on the rollers 34, 35.

Thereafter, the arm 46 is pivoted ge in the position shown in Fig. 5 and at the same time the block 44 in Fig. 5 moved to the left, so that the roller 35 comes to rest on the substrate 11. Upon further displacement of the bracket 44 in Fig. 5 to the left, the roller 34 then rolls on the substrate 11, wherein the adhesive layer 38 is transferred to the raised portions 12 of the Substra¬ tes 11 of FIG. 1 and there forms the adhesive layer 14. In order to effect a sufficient transfer of the adhesive layer 38 to the raised areas 12, the roller 34 is pressed onto the substrate 11 at a pressure of 5 × 10 ⁵ Pa.

In a preferred embodiment, the roller 35 has a metal surface, for example made of aluminum or steel, or is made entirely of metal, that is to say, for example, steel or aluminum.

On the other hand, the roller 34 has a surface made of a plastic material, such as, for example, silicone, or is entirely made of this material. Of course, this plastic material must be compatible with the adhesive used, so be inert.

It is also possible to form the roller 34 with a harder and the roller 35 with a softer surface. Cavities may be provided on one or both rollers, but it is also possible, given the proper nature of the rollers 34 and 35, to completely dispense with the cavities.

This combination of hard roller and soft roller has the advantage that both rollers can be adjusted exactly adjacent to each other so that a uniformly thin adhesive film is formed over the entire width of the roller, whereby thinner adhesive films are produced because of the deformability of the soft roller 34 can be as with two hard rollers.

An important aspect is the wetting of substrate and roller, so that not small droplets are formed, but actually forms an adhesive film. For this purpose, the surfaces are treated with an oxygen plasma, wherein By choosing a suitable roll material, wetting with a specific adhesive can also be ensured.

The treatment with an oxygen plasma takes place, for example, in a PE-CVD system (plasma enhanced chemical vapor deposition), for example of the Piccolo type from the company plasma electronic. In this system, a plasma can be ignited at low pressure and with the supply of oxygen, which contains ions and oxygen radicals which generate surface charges on the surface of the substrate and / or the roller, remove contaminants and generally change the surface chemistry to such an extent. that the surface becomes wettable.

The above plant is, for example, with a pressure of 0.1 to 5 Pa, with a power of 300 W and an oxygen flow of 5 to 50 sccm (standard σubic centimeters) with a Behandlungs¬ duration of 30 to 60 seconds, typically from 30 Seconds operated.

For the combination of SU-8 type epoxy-based UV-structurable polymer with polyimide, Vitralit® 4731 light curing adhesive and Vitralit 1558 light-curing adhesive for SU-8 adhesive bonding with glass are used to obtain both adhesives Company Panacol Elosol GmbH in 61440 Oberursel.

Claims

claims

1. A method for producing a microstructured Vor¬ direction (10), comprising the steps:

a) providing a microstructured first substrate (11) with at least one raised area (12),

b) applying an adhesive to a carrier (24, 28, 34) in order to produce an adhesive layer (25, 29, 38) there,

c) transferring the adhesive layer (25, 29, 38) from the carrier (24, 28, 34) to the at least one raised region (12) of the microstructured substrate (11),

d) positioning a second, optionally microstructured substrate (15) on the first substrate (11), so that it with its contact surface (16) with the at least one provided with the Klebstoffschiσht (14) erha¬ benen region (12) of the first Substrate (11) comes in An¬ situation, and

e) curing the adhesive layer (14).

2. The method according to claim 1, characterized in that in step b) an adhesive having a dynamic viscosity is applied, which is less than 1000 mPa s, vor¬ preferably at 200 to 500 mPa s, more preferably about 300 mPa s is. 3. The method according to claim 1 or 2, characterized in that in step b) an adhesive layer having a thickness of less than 10 microns, preferably less than 5 microns, wei¬ ter preferably less than about

3 microns is generated.

4. The method according to any one of claims 1 to 3, characterized ge indicates that in step e) the curing of the adhesive is supported by suitable measures, preferably by pressure and / or temperature treatment and / or UV irradiation.

5. The method according to any one of claims 1 to 4, characterized ge indicates that in step b) the adhesive is applied to a planar surface (23).

6. The method according to any one of claims 1 to 4, characterized ge indicates that in step b) the adhesive is applied to a curved surface (27).

7. The method according to claim 5 or 6, characterized in that the carrier (28) is flexible.

8. The method according to claim 7, characterized in that in step c) the carrier (28) bulges and on the erhabe¬ nen region (12) of the first substrate (11) is rolled.

9. The method according to claim 5, characterized in that in step c), the adhesive layer (25) with an intermediate punch (26) removed from the carrier (24) and transferred to the substrate (11).

10. The method according to claim 6, characterized in that in step b) the adhesive is applied to at least one roller (34, 35).

11. The method according to claim 10, characterized in that in step c), the roller (34) on the at least one erha¬ benen region (12) of the first substrate (11) is unrolled.

12. The method according to claim 10 or 11, characterized gekennzeich¬ net, that in step b) the adhesive applied to two adjacent rollers (34, 35) and in step c) the adhesive layer (38) by oppositely rotating the two rollers (34 , 35) is generated.

13. The method according to claim 12, characterized in that in step c) between the two rollers (34, 35) forming the adhesive bead (37) is used as an adhesive reservoir or removed, wherein the adhesive layer (38), if necessary, by another reverse rotation the two rollers (34, 35) is homogenized.

14. The method according to claim 13, characterized in that the removal of adhesive bead (37) and homogenization of adhesive layer (38) is repeated several times until no or no appreciable adhesive bead (37) forms more.

15. The method according to any one of claims 10 to 14, characterized in that the at least one roller (34, 35) on its surface microcavities (36), which serve as an adhesive reservoir.

16. The method according to any one of claims 1 to 15, characterized ge indicates that in step c) the adhesive layer (25, 29, 38) is transferred under pressure to the at least one raised area Be¬ (12).

17. The method according to claim 16, characterized in that the pressure is greater than 1 x 10 ^s Pa, preferably greater than 3 x 10 ⁵ Pa.

18. The method according to any one of claims 1 to 17, characterized ge indicates that in step d) the second substrate (15) is positioned under pressure on the first substrate (11), wherein the pressure preferably in the range of 0 to 20 x 10 ⁵ Pa lies.

19. The method according to any one of claims 1 to 18, characterized ge indicates that the substrate (11) and / or the carrier (24, 28, 34) are treated on its surface with a Sauerstoffplas- ma to wetting the surface with an adhesive film.

20. Adhesive tool for carrying out the method according to one of claims 1 to 19, comprising a holder (42) on which a holding portion (43) for microstructured substrates (11) is provided, with a first roller (35) rotatably mounted on the Holder (42) is mounted, and with at least one second roller (34) which is rotatably and so adjustably mounted on the holder (42) that it can be brought into contact both with the first roller (35) and with a substrate (11) arranged in the holding area (43) is.

21. Adhesive tool according to claim 20, characterized in that at least one of the two rollers (34, 35) on its surface microcavities (36), which serve as Kleb¬ substance reservoir.

22. Sticking tool according to claim 20 or claim 21, characterized in that one of the two rollers (34, 35) has a harder surface than the other roller (35, 34).

23. Adhesive tool according to claim 22, characterized in that the one roller (34, 35) has a metal surface, for example. Made of aluminum or steel, or made of metal, for example. Made of aluminum or steel.

24. Adhesive tool according to claim 22 or 23, characterized gekenn¬ characterized in that the other roller (35, 34) has a surface of a plastic material, for example. Made of silicone or is made of this material.

25. Microstructured device comprising at least one cavity surrounded by walls (11, 12, 15) or microchannel (18), at least one wall (15) being provided with a raised area (12) via its contact surface (16). the remaining device is glued, characterized gekennzeich¬ net that the at least one raised portion (12) voll¬ constantly with an adhesive layer (14) is provided and the walls (11, 12, 15) on their free surfaces (19, 21, 22) are adhesive-free.