DE19920161A1 - Process for the production of micro components with flow channels - Google Patents

Abstract

The invention relates to method for producing microcomponents with flow channels in at least one plane, especially of chemical microreactors, heat exchangers, mixers and evaporators. The inventive method comprises the following steps: A. producing a first metal layer or metal film (1); B. coating at least one surface of the first metal layer or metal film (1) with a structured resist layer (3), whereby the first metal layer or metal film (1) has bare spots (6) which do not correspond to the channels to be produced; C. depositing a second metal layer (7) onto the bare spots (6) of the first metal layer or metal film (1); wherein the sequence of steps A to C is carried out several times to produce several planes and/or the sequence of steps A to C is followed by step A to produce a closing segment for the flow channels; and D. removing the resist layer (3) once the planes have been produced. The resist layer (3) can be a serigraphical coating layer, a photosensitive layer or a perforated film.

Description

The invention relates to a method for producing microcomponents with Flow channels in at least one level, especially chemical micro reactors used in the chemical industry for, among other things, synthesis reactions NEN and in other areas, for example as hydrogen sources for Energy conversion (fuel cells), can be used, as well as Heat exchangers, mixers and evaporators.

Chemical microreactors have been used in the literature for several years aimed towards the conventional production lines for manufacturing chemical compounds have advantages. This is a Arrangement of reaction cells, the dimensions of a few micro meters up to a few millimeters and are therefore much smaller than that of conventional reactors. These reaction cells are designed so that in they have physical, chemical or electrochemical reactions can. In contrast to a conventional porous system (heterogeneous Catalysis) the dimensions of these cells are defined by the construction, that is, can be produced according to plan using a technical process. The An order of individual reaction cells in the ensemble of the reactor is ordered, especially periodically in one, two or three dimensions. To the che Mix microreactors are also the necessary in the broader sense Supply and discharge structures for the fluids (liquids, gases) and sensors and actuators, for example valves that flow through the material control individual cells, and heating elements.

The use of chemical microreactors as hydrogen sources for fuel cells for energy conversion is described, for example, by R. Peters et al. in "Scouting Study about the Use of Microreactors for Gas Supply in a PEM- Fuel Cell System for Traction", Proc. of the 1 ^st Int. Conf. on Microreaction Technology, Frankfurt, 1997.

This concept for chemical microreactors was also based on heat build-up shear applied. In this case there are at least in the heat exchanger two separate fluid channels available for the transmission of Heat from fluid in one channel to fluid in the other channel.

There are a number of proposals for the production of chemical microreactors or heat exchangers:
For example, a chemical microreactor can be produced by stacking several copper foils into which grooves are carved using a diamond tool to form flow channels. Such a manufacturing process is described by D. Hönicke and G. Wiesmeier in "Heterogeneous Catalyzed Reactions in a Microreactor" in DECHEMA Monographs, Volume 132, Papers of the Workshop on Microsystem Technology, Mainz, 20 to 21 February 1995, pages 93 to 107. For the production of acrolein from propene, the inner walls of the reaction channels were partially oxidized to copper (I) oxide.

With the LIGA process (lithography, electroforming, impression) a plastic layer, mostly polymethyl methacrylate (PMMA), using syn exposed to chrotron radiation and then developed. The so generated Structure is filled with metal using an electrolytic process. The Metal structure can then be used in other procedural documents using art replication of the material (plastic injection molding process). This procedure Ren was written by W. Ehrfeld and H. Lehr in Radiat. Phys. Chem., Volume 45, pages 349 to 365.

A technology related to the LIGA process, which is without the very complex The so-called laser LIGA process is sufficient for synchrotron radiation.  

Here, the plastic layer made of PMMA with a powerful UV Structured the laser and then electroplated as in the LIGA process (W. Ehrfeld et al., "Potentials and Realization of Microreactors" in DECHEMA Monographs, Volume 132, pages 1 to 29).

Also the methods used in the semiconductor industry for structuring sili cium surfaces have also been developed for the production of Microreactors taken over. For example, J.J. Lerou et al. in "Microfabricated Minichemical Systems: Technical Feasibility", DECHEMA Monographs, Volume 132, pages 51 to 69 described a method in which three etched silicon wafers and two end wafers on the outside were connected. Furthermore, one with polycrystalline silver particles filled heat exchanger, which was also designed as a microreactor, used.

EP 0 212 878 A1 describes a method for producing a heat exchanger described in which the flow channels of the heat medium in steel plates can be formed by chemical etching. The steel plates are then welded together by diffusion bonding.

WO-A-9215408 describes a method for producing microsieves ben, in a flat carrier coated with an etch-resistant layer Holes and other depressions with a certain pattern through plasma technology can be etched. Several of these perforated beams are then made connected with each other.

DE 197 08 472 A1 describes a manufacturing process for chemical microreactors described, in which fluid channels are formed in individual levels by substrates provided with metal surfaces by means of photolithographic tech structured or screen printing process and the channel structures obtained be formed by metal removal or deposition processes. The one by one produced levels are then combined into a stack and firmly connected. For example, the channels can pass through partial etching away of the metal layer on the substrate are generated.  

The previously known methods for producing the chemical microreactor Ren and heat exchanger have many disadvantages. For example are complicated and / or expensive techniques for making the channels conducive. In some cases, the manufacture of the reactors is strictly on Silicon limited as a material.

A particular disadvantage is that for specific applications in the chemical reaction technology certain sensitive functional surfaces layers destroyed or at least destroyed when the individual layers are joined together can be damaged, especially if a high temperature process is applied. As a possible remedy, it has also been suggested to glue the individual layers together. This technique However, there are limits and risks to the fact that the adhesive gets into the fine channels and clogged and / or that the adhesive connection under operating conditions is not strong enough to do so in general high pressure which occurs when the fluids are passed through the reactor or heat exchange occurs, to withstand. In addition, adhesives are in the general low heat and chemical resistance for manufacture the microreactors are only suitable in special cases.

Functional surfaces are used in chemical reaction technology layers, for example, for the catalysis of chemical reactions. One after However, slow coating of the flow channels in the levels is common not possible because the functional layers in this case because of the elec trical shielding by the reactor or heat exchanger itself not can be applied electrolytically. Also at the stromlo Sen metallization has been found that a safe coating is not is possible because the metallization baths usually used on below different flow rate of the metallization liquid to the coating surfaces react very sensitively. Under these conditions Such surface areas are electrolessly metallized where the metallizing liquid flows slowly while Ober  areas where the liquid passes at high speed flows, not be covered with metal.

Another disadvantage of the known methods is that they are considerable in practice Difficulty assembling the stacked reactors too are winds and occur when the microcomponents are encased. This difficult There are leaks when joining and material distortion at ther mixer load. The more seams a component has, the higher the risk of leaks, so usually with a high rejects in the manufacture of the reactors must be expected when using this technique.

The present invention is therefore based on the problem of micro-building le with flow channels in at least one level, especially chemical Microreactors, heat exchangers, mixers and evaporators to manufacture the for a variety of different applications in chemical reak tion technology, for heat exchange, for mixing substances or for mixing vaporization of liquids are suitable. In particular, it should be possible for different applications of the micro component different coatings to apply to the channel surfaces. Furthermore, the manufacturing process be inexpensive and quick to implement without high failure rates arise when manufacturing the microcomponents. Such microreactors, heat Exchangers, mixers and evaporators should also be in large quantities be easy and inexpensive to manufacture.

This problem is solved by the method according to claim 1. Preferred Embodiments of the invention are specified in the subclaims.

The method according to the invention is used to manufacture micro components Flow channels in at least one level, especially chemical Microreactors, heat exchangers, mixers and evaporators. The currents Mung channels preferably have dimensions of a few micrometers up to a few millimeters.  

The chemical microreactors are preferably used in chemical indu for example, for synthesis reactions and in other fields for example as hydrogen sources for energy conversion (fuel cells), used.

Devices with flow channels are used as chemical microreactors understood at least one reactor location, which in addition to the actual Re action zones may also have auxiliary zones which are used for mixing, Dosing, heating, cooling or analyzing the raw materials, intermediate products or end products. Each zone is assigned to the respective one Characterized adapted structure. During heating and cooling zones NEN either as a heat exchanger or as with electrical resistance heaters tongues or electrical cooling elements equipped reactor compartments are formed, analysis zones have adapted sensors. Dosing zones contain for example micro valves and mixing zones, for example channels with appropriately shaped internals for swirling the merged Fluids.

In the microreactors, heat exchangers, mixers and evaporators Flow channels included in at least one level. The flow channels in the individual levels can also be partially connected to one another.

For the following explanation of the method, reference is made to FIGS. 1 and 2. Show it:

Fig. 1 is a schematic representation of the process for the Her adjusting method in a first embodiment;

Fig. 2 is a schematic representation of the process for the manufacturing process in a second embodiment.

In the first embodiment of the invention ( FIG. 1), a first metal layer 1 is first produced to produce the multilayer microcomponents (method step A). This metal layer can either be formed on a carrier 2 , for example on a plastic plate or a metal plate, using a galvanotechnical or physical metal deposition process, or a self-supporting film can be produced. Such films are known from printed circuit board technology. All conventional vacuum processes can be used for coating with a physical metal deposition process, namely the CVD (chemical vapor deposition), PECVD (plasma enhanced chemical vapor deposition), vapor deposition and sputtering processes. Before preferably this metal layer is formed by electrolytic metal deposition. It usually consists of copper, nickel, cobalt, zinc, tin, chromium, iron (steel, stainless steel), aluminum or alloys of these metals with one another or with other elements, for example phosphorus or boron. In principle, however, it can also consist of another metal. For electrolytic metal deposition, in which an external power source for metal deposition is required, the deposition of an electrically conductive starting layer is first necessary. This can be formed, for example, by electroless metal deposition after prior activation of the non-catalytic surface with palladium seeds. The thickness of the metal layer 1 is preferably at least 0.1 μm in order to ensure sufficient electrical conductivity for subsequent manufacturing steps. A thickness of 5 µm to 1 mm is common.

The first metal layer or metal foil is then coated in a first process variant on at least one of the two surfaces with a photosensitive layer 3 (method step B). The thickness of this layer is determined by the height of the flow channels to be formed later. Usually, positive or negative photoresists known from printed circuit board technology, microsystem technology and from chip manufacturing techniques are used for this purpose. After drying, the photosensitive layer formed is exposed to the pattern of the channels, for example through a mask 4 (light rays 5 ; method step B1) and the underlying metal layer or metal foil 1 is subsequently exposed in the development process at all locations 6 which do not correspond to the channels to be formed (Process step B2).

In another variant (not shown in the figure), at least one surface of the first metal layer or metal foil 1 is coated with a screen printing lacquer layer at the locations on the surface which correspond to the channels to be formed.

In a third process variant, a foil, preferably a plastic foil, is laminated onto at least one surface of the first metal layer or metal foil 1 , the foil being provided with perforations at all points 6 of the surface which do not correspond to the channels to be formed. The use of such a film is advantageous when particularly high flow channels are to be formed, so that the resist structure must be very thick. Therefore, foils with a thickness of 50 µm and more are used.

Both when coating with a photosensitive resist and when subsequent exposure and development of the resist as well as when coating hen with a screen printing lacquer layer or a perforated film is a structure obtained with the first metal layer or metal foil at all points the resist or the film is covered, the flow channels to be formed correspond.

A second metal layer 7 is then deposited at the exposed or exposed locations 6 of the first metal layer or metal foil 1 (method step C1). Typically, an electroplating process is used for this, preferably an electrolytic metal deposition process in which an external power source is used for metal deposition. Of course, the second metal layer can also be produced by electroless metallization. If a selective deposition of the second metal layer is desired only at the exposed or exposed positions 6 of the first metal layer or metal foil 1 , but not on the screen printing lacquer layer, the photosensitive layer or the perforated film 3 , then this must be taken care of separately when using the currentless method that the second metal layer 7 is formed only on the first metal layer or the metal foil, for example by applying a negative electrical potential to the first metal layer or the metal foil during the deposition of the second metal. If, on the other hand, an electrolytic metal deposition process is selected, this metal is automatically and selectively deposited only on the exposed areas of the first metal layer or metal foil. The metal of the second metal layer can be identical to the metal of the first metal layer or metal foil. Another metal can also be applied to form the second metal layer. In the finished microreactor, heat exchanger, mixer or evaporator, the second metal layer forms the walls of the flow channels. This metal layer must therefore have a thickness which corresponds to the height of the flow channels. The second metal layer should preferably be as thick as the screen printing lacquer layer, the photosensitive layer or the perforated film.

Before the formation of further channel levels or a termination segment for The first channel level formed can be closed, if so required - by a mechanical or other surface treatment can be leveled, for example by micro milling or polishing.

To form the second and further channel levels, the process sequence A to C described above is carried out several times in succession. This means that a further first metal layer 1 'is then again applied to the surface of the photoresist layer, screen printing resist layer or to the perforated film 3 and to the second metal layer 7 in a method step A'. This further first metal layer 1 ', like the corresponding metal layer or metal foil 1 in the first level, represents a base layer on which the individual flow channels of the next channel level are formed. To produce this base metal layer in the second level as well as to form the first metal layer or metal foil 1 in the first channel level, a thin conductive starting layer made of metal must first be deposited when this first metal layer is electrolytically deposited. If this starting layer is formed in an electroless manner, a catalytic layer for electroless metal deposition must first be separated. Palladium colloids, for example, are suitable for this. These are used to prepare the electrically non-conductive surfaces for the deposition of the thin conductive starting layer, which forms the basis for an electrolytically deposited metal layer. The second base layer can also be formed using a physical metal deposition process, for example by sputtering.

After the formation of this second base layer 1 ', a photosensitive layer, a structured screen printing lacquer layer or perforated film is again applied. The photosensitive layer, screen printing lacquer layer or perfo rized film is then dried. The photosensitive layer is then exposed to the image of the flow channels and developed. The screen printing lacquer or film structure also has the image of the flow channels. The second metal is then again formed on the exposed metal surfaces. Then further levels are applied in the manner described.

After completion of each level, the top reactor or Heat exchanger level covered by a final layer of metal to the close the top channel level. This metal layer is also used as a finish called segment. If necessary, front panels can be attached to the both end faces of the reactor, heat exchanger, mixer or Ver steamer are provided, which are screwed together, for example to absorb the forces that occur during the flow.

If a microcomponent is produced with only one flow channel level, then following the aforementioned method sequence with steps A to C, with which a flow channel level is formed, method step A is carried out to form an end segment for the flow channels. In this case, the metal layer 1 'brought up after the formation of the first channel level represents the end segment.

After completion of the micro component with one or more flow the photoresist, screen printing resist or the perforated film is made out of the channels the flow channels kept free during the metallization removed.  

With the method according to the invention, the individual micro component parts are thus produced in a sequential manner, in contrast to the known methods. This eliminates the disadvantage that the individual levels must be connected to one another and to the end segment in a joining process after their separate production. On the other hand, no leaks can occur in the finished micro-component due to an inadequate joining process. In addition, basically all metals that can be deposited by means of electroplating processes can be used as materials. For the manufacture of the flow channel walls, for example, copper, nickel, cobalt, zinc, tin, chromium and iron and their alloys can be used. Precious metals such as platinum, gold, silver, ruthenium and palladium are particularly suitable for the functional layers. When using the known manufacturing processes, the individual layers initially produced separately are subsequently connected to one another by diffusion welding or soldering. However, this presupposes that materials are also used that can be diffusion welded or soldered. In addition, in the manufacture of the microcomponents according to the invention, in contrast to the components produced by the known methods, there is no material distortion. Such a disadvantageous effect is usually unavoidable when joining the conventional micro components due to the large amount of heat. Another advantage of the method according to the invention is that no special measures have to be taken to ensure good adhesion between the second and further base layers 1 '(or 1 '', 1 ''',...) And the To ensure photoresist layer, screen printing resist layer or the perforated film.

It is also advantageous that already in the course of the formation of the individual levels functional, for example catalytic, layers on the flow channel walls de can be applied. The functional layers could are basically also generated after the manufacture of the micro component. in the In the case of the joined components, however, the solder connections between the individual channel levels, since this is the electroless metallization can deactivate baths for the production of the functional layers. Except which can be a metallization process using an external current not be used to apply these layers after the  Reactor is completed.

To produce the functional layers, a third metal layer 8 is produced in an additional method step C2 ( FIG. 1) by electrolytic or electroless metal deposition or with a physical metal deposition method, for example a sputter, vapor deposition, CVD or PECVD, after carrying out process step C1 . Procedure. Alternatively, molecular layers which have specific catalytic properties can also be chemisorbed or adsorbed, or plastic or ceramic layers can be formed. The ceramic layers are particularly advantageous when a large surface on the flow channel walls is to be created. Porous ceramic layers are formed for this purpose, for example oxide layers by sputtering. A vapor-deposited aluminum layer is also particularly suitable and can subsequently be converted to an aluminum oxide layer by anodizing or treatment, for example with nitric acid. Such a layer can serve as a support for catalysts with which this layer can be impregnated.

Layer 8 in turn can also be made up of different layers. These layers can also serve as supported catalysts. For this purpose, the surfaces of the screen printing lacquer layer, the photosensitive layer or the perforated film and the second metal layer are first cleaned. The cleaned surfaces can then be brought into contact with an activation solution, for example a palladium colloid solution, which has a catalytic effect for the subsequent electroless metal deposition in order to be able to electrolessly deposit metal on the non-catalytic surfaces of the screen printing lacquer layer, photosensitive layer or the perforated film . The layer 8 can also be selectively applied exclusively to the screen printing lacquer, the photosensitive layer or the perforated film by suitable mask processes in order to prevent layers 8 deposited on the metal layer 7 from impairing the adhesive strength of metal layers subsequently applied to the layer 7 .

Activation solutions of this type are known per se. Usually this by mixing palladium chloride, tin (II) chloride and hydrochloric acid or of palladium sulfate, an aminopyridine and alkali or of palladium sulfate, an organic protective colloid such as polyvinylpyrrolidone, and sodium hypophosphite formed. Then the activated surfaces with brought into contact with a metallization solution, for example an acidic one Solution containing palladium ions. One that can be used well for this purpose Palladium plating solution also contains an oxidizing agent, e.g. Na triumperoxodisulfate. Alternatively, for example, corrosion protection layer can be deposited from a nickel / phosphorus alloy. For this commercial baths are available, in which in addition to a nickel salt Carboxylic acids as complexing agents for nickel ions and additionally sodium hypo phosphite are contained as a reducing agent.

In a further process variant ( FIG. 2), the second metal layer 7 is modified to the previously described method in a reactor, heat exchanger, mixer or evaporator level according to method step C and the first metal layer 1 'in the subsequent level or as Conclusion segment-serving first metal layer 1 'according to process step A' formed in a single combined process step. This eliminates a separate process step. The metals of the first and second metal layers are preferably identical.

The formation of the combined layer 7 , 1 'according to method step C + A', which also represents the base layer for the next channel level, is followed by the method described above for forming the next level. Then the surface is first structured by means of a screen printing varnish, a photosensitive layer or a perforated film, and then another metal layer is applied in accordance with process steps C and A '. The reference numerals given in FIG. 2 otherwise correspond to those in FIG. 1.

In this case too, the metal layer 1 'serves as a termination segment, the formation of which is not followed by any further process steps if only one flow channel plane is to be formed.

Functional layers 8 are also deposited in the production of microcomponents according to this process scheme. These are applied to the resist surfaces (method step B3 in FIG. 2). For this purpose, the same process technologies are used as in the process variant according to FIG. 1 described first.

Furthermore, further metal layers can be deposited, if speci fish requirements of the respective application require this. So For example, wear-resistant layers can be counteracted Corrosion and abrasion, e.g. from chrome, a nickel / phosphor Deposit alloy or palladium, or surfaces from catalytically active Form metal (platinum, palladium) electrolytically or without current. Also magne table layers, for example made of a ferromagnetic nickel / cobalt Alloy can be used for certain applications, such as Use of solenoid valves as actuators may be necessary. Furthermore, the Surface structure also through chemical or electrolytic etching techniques be roughened or smoothed.

After the desired number of channel levels has been formed, the screen printing lacquer layer, photosensitive layer or perforated film in a further process step D removed. The structure created can be used for this for example with a solvent for the screen printing lacquer layer, the photo sensitive layer or the perforated film under simultaneous action brought into contact by ultrasound and heat. The solvent preferably contains a surfactant with a low surface tension. The choice of solvent depends on the type of solvent to be dissolved Plastic material (screen printing varnish, photosensitive layer, perforated Foil). For example, for polymethyl methacrylate as plastic material Acetone, chloroform, butanone, 1,4-dioxane and N, N-dimethylformamide and their Mixtures and for photoresists N-methylpyrrolidone, trichloroethane, dimethyl sulfate  oxide and methylene chloride and mixtures thereof. You can also aqueous alkaline systems with suitable cosolvents are used.

Alternatively, the screen printing lacquer layer, photosensitive layer or perfo film can also be removed by pyrolysis. For this, the educated Micro-component structure transferred to an oven and the screen printing varnish that Photosensitive layer or the perforated film thermally decomposed. Even Residual residues of the decomposed organic material can then in be removed with a solvent, again preferably under the action by ultrasound and in the presence of a suitable wetting agent.

In a further process variant, the plastic can also be made with a plastic be removed. For this, the finished micro component structure brought into a glow discharge zone of a plasma reactor.

In a still further process alternative, the screen printing lacquer layer, photosensitive layer or perforated film can be removed in accordance with process step D using supercritical liquids. For this purpose, the micro component structure is brought into contact under suitable pressure and temperature conditions, for example in an autoclave, with carbon dioxide, ethylene, propane, ammonia, dinitrogen dioxide, water, toluene, nitrogen heterocycles or other substances which are in a supercritical state. Supercritical fluids that can be converted into the supercritical state at room temperature are particularly suitable. A well suited supercritical fluid is carbon dioxide. The suitable conditions for this are T ≈ 40 ° C and P = 80.10 ³ to 200.10 ³ hPa (80 to 200 bar).

After completion of the reactor, heat exchanger, mixer or evaporator the necessary fluid connections to external components, for example, pumps and containers.

To further explain the invention, micro component levels are exem plotted. Show it:  

Figure 3 is a schematic representation of a cross section through a heat exchanger.

Fig. 4 is a schematic representation of a cross section of several channel levels in a multiple use for six continuous reactors.

In Fig. 3, a channel is presented in a heat exchanger 10 degrees. This individual layer consists of two superimposed metallic layers (dark area) on the respective base (delimited by dash-dotted lines), which were produced according to one of the methods described above. For example, these two metallic layers can have been produced on the substrate by electrolytic deposition of copper in accordance with process steps A to C. Several of these layers form a heat exchanger.

In the position 10 there are channels 11 through which a fluid (liquid or gas) is passed during operation of the heat exchanger. In the present case, the channels are produced by a photolithographic process. These channels extend in the upper of the two layers and have a width of approximately 400 μm and a height of approximately 100 μm. The channels 11 end in connection spaces 12 ', 12 ''', which are used to connect the chemical micro reactor to corresponding feed and discharge lines for the fluid to be passed through. The fluid flowing through the heat exchanger can be passed in operation, for example, via the connection space 12 'shown in the figure above into the channels 11 and, after passing through the channels, leave the micro-reactor through the connection space 12 ''' shown below in the figure.

Several layers of the type shown are one in the other in the heat exchanger. The layers above and below the layer shown have channels which are rotated by 90 ° with respect to the channels of the layer shown. This results in a stacking sequence. . .ABABAB. . ., where A means the layers with the orientation shown and B the adjacent layers with orientation rotated by 90 °. Characterized lie on the one hand the connecting space 12 'and 12' '' above the other of the layers with the label A and at the other hand, the terminal spaces 12 '' and 12 '''' of the layers with the label B on each other. The channels in the layers with the designation A are connected to one another via the respective connection spaces. The same applies to the channels with the designation B. There is no fluid connection between the flow channels in the two layer types A and B. This makes it possible to pass two fluids independently of one another through the heat exchanger, for example a hot and a cold liquid. In operation, the hot liquid in the heat exchanger is cooled by the cold and the cold is warmed up by the hot.

Screw connections are provided, for example, for the gas and liquid-tight connection of the connection spaces 12 ', 12 '', 12 ''', 12 '''' with corresponding supply and discharge lines. The channel plane areas 13 delimiting the connection spaces serve as sockets for the screw connections and are processed in such a way that circular projections with external threads are formed from the respective end face of the reactor, so that supply and discharge pipes are connected to these sockets, for example with union nuts, in a gas-tight and liquid-tight manner can be. The supply and discharge lines are connected to the outwardly open connection spaces 12 ', 12 '', 12 ''', 12 . Of course, the connections to the supply and discharge pipes can also be made by welded or soldered connections. In this case, however, it must again be taken into account that heat-sensitive functional layers in the heat exchanger channels could be damaged or even destroyed during the joining. Therefore, a mechanical method of making the connections is preferable.

A microcomponent according to the invention typically has outer side lengths which are in the range from one to a few centimeters. The connection spaces 12 ', 12 '', 12 ''', 12 '''' of the layer 10 shown in Fig. 3 has in the present case side lengths of 1 cm each.

Of course, the layers can also have channels with a different shape have, for example for systems in the counterflow principle, and through  refractions to neighboring layers. Breakthroughs can be metal deposition in forming the first and second metal layers be formed. The breakthroughs can also be chemical or electrochemically etching the first and second metal layers formed be generated.

Further functions can also be provided on the metallic layer of a layer 10 . On the one hand, so-called actuators and sensors can be integrated into a microreactor. The actuators are switching elements that can be controlled externally or automatically by measuring signals, for example valves, but also electrical resistance heating or cooling elements that function according to the Peltier. Microreactors, in which actuators and sensors are provided, can be locally optimized with a suitable control-technical connection of actuators and sensors. At the same time, the sensor outputs can be used for external monitoring of the reactor condition (such as aging, poisoning of catalysts and similar parameters).

For the actuators and sensors there may also be electrical connections cables for control or for the detection of measurement signals on the To provide substrates. Suitable structures must be used for these elements tion elements are taken into account in the photo process.

Microchips, for example, can also be used in the interior of microreactors Control of actuators and sensors can be integrated by the microchips be electrically insulated from the metallic layers. For this, the Chips, for example, on the screen printing lacquer layer, photosensitive layer or perforated film. The electrical connections too Corresponding control and signal lines can be made using bonded wires or other known connection techniques, such as by soldering or gluing.

Furthermore, in addition to the actual reac at the same time, peripheral reactor components, such as feed lines,  Mixing zones, heating or cooling circuits are formed, so that the manufacture effort is reduced. Therefore, these elements are in photo structuring already to be provided. In addition, the commonly occurring ones Sealing problems minimized.

In Fig. 4, an ensemble of six channel levels for several Durchflußreak gates is shown in a multiple use. The benefit is given so-called tooling holes 15 in the vicinity of the corners, which are used for the precise alignment of masks for producing structures in successive layers.

Compared to the channel position in FIG. 3, the layers shown here differ in that only recesses for connection spaces 12 ', 12 ''' are provided on two mutually opposite sides of the layers, while in the case of the layer of FIG. 3 also by 90 ° there are twisted recesses.

In order to make the production of the reactors particularly economical, whoever made the individual elements of the reactors in this case in a multiple use at the same time. The individual reactors are then separated from one another along the dashed lines 14 .

Claims (9)

1. A method for producing microcomponents with flow channels in at least one level, in particular chemical microreactors, heat exchangers, mixers and evaporators, with the following method steps:

• A. Making a first metal layer or foil;
• B. coating at least one surface of the first metal layer or metal foil with a photosensitive layer, exposing the photosensitive layer with the pattern of the channels and exposing the first metal layer or metal foil at all locations which do not correspond to the channels to be formed; or
  Covering at least one surface of the first metal layer or metal foil with a screen printing lacquer layer at the locations on the upper surface which correspond to the channels to be formed; or
  Laminating a perforated foil onto at least one surface of the first metal layer or metal foil, the perforations of the foil being provided at all locations on the surface which do not correspond to the channels to be formed;
• C. depositing a second metal layer at the exposed or exposed positions of the first metal layer or metal foil,

characterized in that the method sequence A to C for forming the multiple levels is carried out several times in succession and / or method step A for forming a closing segment for the flow channels follows the method sequence A to C and

• D. that the screen printing lacquer layer, the photosensitive layer or the perforated film is only removed after the layers have been formed.

2. The method according to claim 1, characterized in that on the first Metal layer or the metal foil and the screen printing lacquer layer, photosensitive Chen layer or perforated film after performing the step B or on the second metal layer and on the screen printing lacquer layer, photo sensitive layer or perforated film after performing procedure Step C a third metal layer, a molecular layer, a plastic layer or a ceramic layer is formed. 3. The method according to claim 1, characterized in that the second metal layer in one plane according to method step C and the first metal layer in the subsequent level according to method step A in a single Ver driving step are formed, the metals of the first metal layer and the second metal layer are identical. 4. The method according to claim 3, characterized in that between the Process step B and process step C a third metal layer, a Molecular layer, a plastic layer or a ceramic layer on the sieve printing varnish layer, photosensitive layer or perforated film applied becomes. 5. The method according to any one of the preceding claims, characterized net that the screen printing lacquer layer, photosensitive layer or perforated Film according to process step D with a solvent under the action of Ultrasound is removed. 6. The method according to any one of claims 1 to 4, characterized in that the screen printing lacquer layer, photosensitive layer or perforated film according to process step D is removed by pyrolysis.   7. The method according to any one of claims 1 to 4, characterized in that the screen printing lacquer layer, photosensitive layer or perforated film according to process step D is removed by a plasma process. 8. The method according to any one of claims 1 to 4, characterized in that the screen printing lacquer layer, photosensitive layer or perforated film is removed according to process step D with supercritical liquids. 9. The method according to any one of the preceding claims, characterized net that the first metal layer or the metal foil and the second metal layer be formed by electrolytic metal deposition.