DE19921659A1 - Microvalve assembly, e.g. for pneumatic system, has housing with molded interconnect device structure for electrically connecting electronic drive components and microvalves - Google Patents

Abstract

The microvalve arrangement has a housing (2) containing at least one microvalve (8, 8'), which may be of piezoelectric, magnetostrictive, or shape memory type. Associated electronic components (32) for operating the valves are also included and the housing is at least partially formed as a molded interconnect device (MID), with a conductor structure (34) for electrically contacting the valve electronic components (33) and/or the microvalve(s).

Description

The invention relates to a microvalve arrangement, which has at least one microvalve through which a fluid flow control is controllable.

US Pat. No. 5,640,995 describes a modular microven valve arrangement, which has several micro valves, which can be controlled by valve electronics. The valve electronics sits on a circuit board with a suitable electrical conductor structure is provided. The lei terplatte itself is between individual components of the Mi kroventilanordnung built and has all to accommodate necessary electronic components and links a relatively large space requirement.

It is the object of the present invention to create a microven tilanordnung to create a simpler and space-saving construction.

A microvalve arrangement is provided to solve this problem seen that has a housing that with at least one Micro valve and a valve electronics assigned to it is equipped and at least partially as a MID body ("Molded Interconnect Device"), whereby it is  indirectly with one for electrical contacting of the valve electronic components and / or the at least one microven tils serving conductor structure is provided.

In this way, there is a microvalve arrangement in which the housing itself as a carrier for the electrical conductor structure is used for electrical contacting the valve electronic components and / or the at least one Micro valve is used. The case is, at least as far as the components having the conductor structure are concerned reaches, as a so-called Molded Interconnect Device, So practically as a plastic component with structured lei picture. This makes it possible, in contrast to the convention planar PCB technology, the required Conductors such as conductor tracks or electrical contact surfaces or shielding surfaces in three-dimensional plastic structure to realize what through the practically arbitrary shape optimal utilization of the available standing space allows. Because the housing itself can also act as a ladder support additional separate components can be saved, which in turn to reduce the space requirement, but also to reduce it which contributes to manufacturing costs.

Advantageous developments of the invention go from the Un claims.

The housing of the microvalve arrangement can be inside least have an intermediate wall, the at least part of the ladder structure. So the MID structure is not open  the outer wall of the housing is limited, but can become alternatively or in addition to any existing twos Extend walls that are present, for example, around to enlarge the assembly area for electronic components.

The valve electronics components are conveniently located at least partially and preferably in their entirety a partition. However, the interior can also side of the outer wall with electronic components or at least components of the current-carrying conductor structure wear that for contacting the electrical components the microvalve arrangement are required.

The micro valves of the micro valve arrangement are more expedient only with the interposition of a valve carrier only medium fixed on the housing. The valve carrier includes on the one hand a Fluidka cooperating with the microvalves nalsystem and serves for mechanical and / or thermal decoupling from the aforementioned housing. Thereby the microvalve arrangement is particularly suitable for Operations in the field of industrial fluid technology, ins special of industrial pneumatics, where the valves used very often in an inhospitable environment, for example in Shape of fluctuating temperatures or shock loads and vibrations. The on the case Exposed loads are therefore effective from the micro valves shielded.

In this context, it is advantageous if the valve Carrier made of a material that has a high mechanical  Strength, a low coefficient of thermal expansion, a high thermal conductivity and electrical insulation gene. The use of a ceramic is recommended here materials, especially aluminum oxide. The Ma is preferred material selection made so that the modulus of elasticity of Valve carrier equal to or preferably larger than that of the basic body of the microvalves fixed to it is.

It is already known from WO 92/20 942, a micro to implement valve arrangement in that several microven tile can be arranged laterally on a central block, the has a fluid channel system inside. This well-known Microvalve arrangement is suitable due to the lack of protective measures not readily for industrial use sentences in a harsh environment.

Several micro valves can be operated on one and the same at the same time Valve support to be fixed, the use of a recommends plate-like valve carrier, the on opposite set sides with at least one micro valve each pieces. It is possible to use the existing Wed. kroventile fluidly with each other via the fluid channel system to link other that building on micro valves low more functionality, for example with a 2/2 valve function, an overall higher quality valve function, at for example in the form of a 3/2-functionality, the micro valve arrangement is reached. Building on a plurality In this way extremely complex valve functions.  

To connect the fluid duct system to external fluid lines to be able, the housing of the microvalve arrangement is appropriate Usually equipped with connecting channels that under Interposition of suitable sealing measures with the fluid channel system communicate. This conveniently comes in sealing channel sealing all channel transitions at the same time used between the valve carrier and the Ge housing is interposed.

Has at least one micro valve of the micro valve arrangement expediently via a micromechanically structured Structure and is particularly due to common etching and / or Ab molding techniques. Particularly advantageous designs Micro valves are those that are on a pie zoelectric and / or a magnetostrictive function principle, or based on a memory metal Function.

The invention based on the accompanying drawing tion explained in more detail. In this show:

FIG. 1 kroventilanordnung a preferred design of the Mi invention, the housing only partially depicted example, to visualize the be inside the case-sensitive components,

Fig. 2 shows the housing used in the micro-valve arrangement according to FIG. 1 and again shown only in partial view in individual representation,

Fig. 3, the housing of FIG. 2, in addition to instal profiled valve electronics and sealing measures for the fluid connection to the valve carrier,

Fig. 4 is a side view of the micro valve assembly looking in the direction according to arrow IV of FIG. 1 on the terminal side of the assembly,

Fig. 5 the valve carrier used in the microvalve arrangement according to FIGS. 1 to 4 in a perspective individual representation, with dash-dotted lines the micro valves seated on it are indicated and

Fig. 6 shows an alternative design of the valve carrier.

The microvalve arrangement 1 of the embodiment has a housing 2 with a preferably cuboid and in particular re cube-like outer contour. In the drawing, the outer wall 3 of the housing 2 , which normally forms a coherent hollow body that defines an interior 4 , only partially in order to improve the clarity. Visible is a bottom wall 5 and a side wall 6 oriented to the connection side of the microvalve arrangement 1 and at right angles to the bottom wall 5 .

The housing 2 has a further dividing the interior space 4 intermediate wall. 7 It is firmly connected to the outer wall 3 , preferably an integral construction is provided.

In the exemplary embodiment the intermediate wall 7, both the bottom wall 5 connected as well as one piece with the side wall ver. 6

Adjacent to the intermediate wall 7 , two micro valves 8 , 8 ′, which are only indicated schematically, are accommodated in the interior 4 . You are in the embodiment in a first ( 12 ) of the two by the intermediate wall 7 abge divided partitions 12 , 13 of the interior 4th

The two microvalves 8 , 8 'have a one-part or multi-part base body 14 , for example in a layered construction, each of which contains at least one valve member (not shown in more detail) and an associated actuator system. It can be, for example, piezo valves or Ven tiles whose activation is caused by magnetostriction or on the basis of the so-called memory metal effect. The valve member can be designed, for example, as a bending element or as a membrane element, an electrostatic actuation being conceivable as well. The processes known from microsystem technology are used in particular for production, for example using a silicon etching technique or a plastic molding process.

The microvalves 8 , 8 'are not placed directly on the housing 2 , the housing-fixed fixation takes place rather only with telbar with the interposition of an intermediate body designated as valve carrier 15 be. The microvalves 8 , 8 'are fastened to the valve carrier 15 , which in turn is fixed on the housing 2 . Between the micro valves 8 , 8 'and the Ge housing 2 there is expediently an all-round distance, which can be very small and is therefore not shown in detail in the drawing.

The valve carrier 15 contains a fluid channel system 16 composed of a plurality of fluid channels, which is also clearly visible from FIGS . 5 and 6. It opens with connection openings 17 , 17 'to two outer mounting surfaces 18 , 18 ' of the Ven tilträger 15 , on which the two micro valves 8 , 8 'fi xed. Via the connection openings 17 , 17 ', the fluid channel system 16 communicates with valve channels of the microvalves 8 , 8 ', which are not shown in detail.

For optimal use of the available installation space, the valve carrier 15 is designed in the manner of a plate, the ones in the assembly surfaces 18 , 18 'being located on the two larger plate surfaces oriented opposite one another. This results in a sandwich-like structure, the two micro-valves 8 , 8 'enclosing the valve carrier 15 between them.

The arrangement is expediently such that the plane of expansion of the valve carrier 15 extends parallel to the plane of expansion of the intermediate wall 7 .

The fluid channel system 16 has further connection openings 22 , which represent the interface of the fluid channel system 16 to the surroundings of the microvalve arrangement 1 . They are located on an outer surface of the valve carrier 15 and in the present case on the narrow side of the valve carrier 15 facing the inner surface of the side wall 6 .

If the housing 2 in the region of the further calculations Verbindungsöff 22 have appropriate recesses, which further connection openings 22 could be used directly for the connection of continuing fluid lines or fluid conduits. In the exemplary embodiment, however, it is provided that the outer wall 3 of the housing 2 is penetrated by connecting channels 23 , which on the one hand open out via connection openings 24 on the outer surface of the outer wall 3 and on the other hand open out on the other side of the further connecting openings 22 in such a manner that they lie opposite on the inner surface of the side wall 6 that there is a connection to the fluid channel system 16 . The fluidic interface between the valve carrier 15 and the housing 2 is sealed, which is done in the exemplary embodiment by interposing a sealing element 25 consisting of a suitable sealing material. This has a mask-like structure with a number of holes corresponding to the number of channel transitions, so that it serves for simultaneous sealing of all channel transitions. In this way, a number of individual seals are saved.

The valve carrier 15 is fixed to the housing 2 by suitable fastening measures. In the exemplary embodiment, it engages with an edge-side holding section 26 in a form-fitting manner in egg ne on the inner surface of the outer wall 3 recessed holding recess 27 , which contributes to the exact positioning or centering. In addition, the Ventilträ ger 15 is firmly bonded to the housing 2 by gluing. But other, for example non-positive and / or positive connections, for example by screwing or pinning, are also conceivable. In any case, the two micro valves 8 , 8 'are advantageously not directly influenced by the chosen fastening measures.

The valve carrier 15 thus has a multiple function. In addition to the provision of the supply and discharge of the fluid channel system 16 to be controlled by the micro-valves to be controlled, it has the function of a decoupling body, which has the micro-valves 8 , 8 ′ attached to it from mechanical and / or thermal influences acting externally on the housing 2 decoupled. In this way it is prevented that the environmental influences acting on the microvalve arrangement 1 during operation - for example temperature fluctuations, shocks or vibrations - are transmitted to the microvalves 8 , 8 'to a harmful extent.

The valve carrier 15 essentially fulfills these requirements by choosing a material that is matched to the structure of the microvalves 8 , 8 ′. In the exemplary embodiment, it consists of ceramic material, alumina material having proven particularly expedient. Material of this type is characterized by high mechanical strength, low thermal expansion coefficient, high thermal conductivity and electrically insulating properties. The modulus of elasticity (E-modulus) of the valve carrier 15 is preferably equal to or greater than the elastic modulus of the base body 14 of the carrier to the valve 15 attached micro-valves 8, 8 '.

The micro valves 8 , 8 'are expediently glued to the valve carrier 15 . The adhesive can move here in Siebdruckver or be brought onto valve carrier 15 with a dispenser. Also in the screen printing process, electrically conductive surfaces or conductor tracks made of conductive paste can be applied to the valve carrier 15 in order to obtain electrical conductors 28 , 28 'which are used for connection to the electrically actuated actuators of the micro valves 8 , 8 '.

The actuation of the microvalves 8 , 8 'as required takes place through the intermediation of valve electronics 32 , which is conveniently placed in the interior 4 of the housing 2 . Ver different components 33 of the valve electronics are exemplified in FIGS . 1 and 3. In connection with the Mikroven valves 8 , 8 'formed in the exemplary embodiment as piezo valves, the valve electronics 32 expediently includes an auxiliary voltage module, a DC / DC converter and a discharger module. The central element is the DC / DC converter, through which the voltage conversion of the regularly available input voltage of 24 volts to the required actuator drive voltage takes place. The auxiliary voltage module connected upstream of this converter serves to reduce the input voltage to a constant supply voltage of approximately 10 to 11 volts u in order to prevent negative effects of tolerance-related fluctuations in the input voltage. The unloader module has the task of switching off the DC / DC converter when the input voltage is switched off and discharging the actuator formed by a piezo bender, which has a capacitive effect here. For this purpose, the input voltage is continuously measured by the discharger module and a transistor circuit is activated when the voltage falls below 15 volts, which triggers this discharge and switch-off process (not shown).

The necessary electrical circuit is convenient in partial functions or completely in an ASIC on one Silicon chip summarized.

The valve electronic components 33 are seated on an electrically conductive conductor structure 345, which can be clearly seen in FIG. 2 and which also serves for contacting the microvalves 8 , 8 'by being connected to the electrical conductors 28 of the valve carrier 15 .

A great advantage of the exemplary microvalve arrangement 1 now consists in the fact that the entire conductor structure 34 is provided directly on the housing 2 of the microvalve arrangement 1 , which in this case is embodied as a MID body, at least in the region of the conductor structure 34 , wherein "MID "stands for" Molded Interconnect Device ", in other words for a regularly injection molded part with a structured conductor pattern.

The MID technology makes it possible to carry out the conductor structure 34 more than two-dimensionally than in the conventional planar circuit-board technology, and in particular to implement three-dimensional solutions such as are shown in the drawing. This makes it much easier to implement the required conductor structures in the smallest of spaces, with virtually unlimited design freedom. Since the housing 2 itself forms the MID body, it is also possible to dispense with separate conductor structure carriers, which results in further savings potential in terms of manufacturing and material costs.

In the exemplary embodiment, the conductor structure 34 extends both over the intermediate wall 7 and also over the inner surface of the outer wall 3 , it expediently running on both opposite wall surfaces of the intermediate wall 7 . However, it goes without saying that, depending on the design of the housing 2, any components of the same can act as a carrier for the conductor structure 34 . It is also possible in particular a multi-part housing structure in such a way that a part comprising the conductor structure 34 as an MID body and the other components are designed in conventional housing technology.

The valve electronics components are expediently in their entirety on the intermediate wall 7 , whereby they are distributed over the two wall surfaces in order to obtain optimal space utilization.

As is apparent from Fig. 2, some conductors of the conductor structure 34 extend on the inner surface of the side wall 6 and in the first connecting sections 35 , which are connected to second connecting sections 36 of the electrical conductors 28 of the valve carrier 15, in order in this way the Ven electronics electronics 32 to link the actuation of the micro valves 8 , 8 'control technology.

Finally, electrical connection means 37 are also provided on the outer surface of the side wall 6 , which are also connected to the conductor structure 34 of the housing 2 and which enable the connection of an external control device and / or power supply device.

Various methods can be used in the manufacture of the MID housing 2 . For example, two-component injection molding processes, hot stamping processes, laser direct structuring or 3D mask exposure are possible. When applying a two-component injection molding process, for example, the procedure is such that first a body made of metalizable plastic is injected, which forms the structures for the later conductor tracks. In an intermediate step, this pre-molded part is pickled and activated with palladium seeds. After this chemical treatment, a non-metallizable plastic is injected around the first mold in a white injection process, which fills the gaps between the pre-molded parts and produces the final shape of the MID body. In the subsequent chemical metallization, no metal is deposited on the non-germinated surface of the second spraying process, so that conductor tracks are only formed on the exposed surface of the first spraying process, which can be galvanically reinforced in a further step and which form the conductor structure 34 .

The two microvalves 8 , 8 'present in the exemplary embodiment are designed as 2/2-way valves, in one case it is a design of the "normally closed" type and in the other case it is a "normally open" design . These two microvalves 8 , 8 'are now controllable by the valve electronics 32 such that, in conjunction with a corresponding fluidic connection by means of the fluid channel system 16 at the outer connection openings 24, a 3/2-valve function can be performed. Building on two identical valves with a simple, low functionality, a microvalve arrangement with higher valve functionality can be realized in this way. As a rule, this enables a simpler and more cost-effective construction than a comparative solution in which only a single microvalve is installed, which already includes a 3/2-valve function.

Regarding the valve carrier 15, it should also be noted that the fluid channel system 16 can also be realized at least partially in the form of groove-like surface depressions 38 of the valve carrier 15 , as is exemplified in FIG. 6. The surface depressions 38 are covered here by the respectively placed microvalve 8 , 8 'to form fluid channels.

Claims (21)

1. Micro valve arrangement, with a housing ( 2 ), which is equipped with at least one micro valve ( 8 , 8 ') and associated valve electronics ( 32 ) and which is at least partially as a MID body ("Molded Interconnect De vice") is implemented, it being provided directly with a conductor structure ( 34 ) serving for electrical contacting of the valve electronic components ( 33 ) and / or the at least one microvalve ( 8 , 8 '). 2. Microvalve arrangement according to claim 1, characterized in that the conductor structure ( 34 ) has a three-dimensional expansion. 3. Microvalve arrangement according to claim 1 or 2, characterized in that the housing ( 2 ) inside has at least one intermediate wall ( 7 ) which carries at least a part of the Lei ter structure ( 34 ). 4. Micro valve arrangement according to claim 3, characterized in that the conductor structure ( 34 ) on both of the opposite wall surfaces of the intermediate wall ( 7 ) it stretches. 5. Microvalve arrangement according to claim 3 or 4, characterized in that the valve electronic components ( 33 ) are arranged at least partially and preferably in their entirety on the inter mediate wall ( 7 ). 6. Microvalve arrangement according to one of claims 1 to 5, characterized in that the housing ( 2 ) has an outer wall ( 3 ) which is provided on the inner surface with at least one part of the conductor structure ( 34 ). 7. Micro valve arrangement according to one of claims 1 to 6, characterized in that the at least one micro valve ( 8 , 8 ') with the interposition of a valve carrier ( 15 ) is fixed to the housing, the valve carrier ( 15 ) on the one hand with the micro valve ( 8 , 8 ') cooperating fluid channel system ( 16 ) defines and on the other hand decouples the microvalve ( 8 , 8 ') from mechanical and / or thermal influences acting on the housing ( 2 ). 8. Micro valve arrangement according to claim 7, characterized by a valve carrier ( 15 ) which is simultaneously equipped with a plurality of micro valves ( 8 , 8 '). 9. Microvalve arrangement according to claim 8, characterized in that the valve carrier ( 15 ) on opposite sides are each equipped with at least one microvalve ( 8 , 8 '). 10. Microvalve arrangement according to claim 7 or 8, characterized in that a plurality of microvalves ( 8 , 8 ') are linked via the fluid channel system ( 16 ) in such a way that, when actuated accordingly, overall a valve functionality results which is greater than that of the individual microvalves ( 8th , 8 '). 11. Micro valve arrangement according to one of claims 8 to 10, characterized in that several and preferably all existing micro valves ( 8 , 8 ') are constructed as 2/2-way valves. 12. Micro valve arrangement according to claim 11, characterized by connecting two 2/2-way Micro valves received 3/2-way valve functionality. 13. Microvalve arrangement according to one of claims 7 to 12, characterized in that the elastic modulus (modulus of elasticity) of the valve carrier is equal to or preferably greater than that of the base body ( 14 ) of the at least one micro valve ( 8 , 8 ') attached to it . 14. Microvalve arrangement according to one of claims 7 to 13, characterized in that the valve carrier ( 15 ) consists of ceramic material, preferably of aluminum oxide material. 15. Micro valve arrangement according to one of claims 7 to 14, characterized in that the at least one micro valve ( 8 , 8 ') is glued to the valve carrier ( 15 ). 16. Microvalve arrangement according to one of claims 7 to 15, characterized in that the valve support ( 15 ) on its with a microvalve ( 8 , 8 ') equipped assembly surface ( 18 , 18 ') via at least one groove-like belonging to the fluid channel system ( 16 ) Surface recess ( 38 ) has. 17. Microvalve arrangement according to one of claims 7 to 16, characterized by a positive and / or non-positive and / or integral fastening of the valve carrier ( 15 ) on the housing. 18. Micro valve arrangement according to one of claims 7 to 17, characterized in that the at least one micro valve ( 8 , 8 ') is placed with all-round spacing from the housing ( 2 ). 19. Microvalve arrangement according to one of claims 7 to 18, characterized in the housing ( 2 ) extending connecting channels ( 23 ) which communicate with the fluid channel system ( 16 ) of the Ventilträ gers ( 15 ), wherein at the fluidic interface between the valve carrier ( 15 ) and the housing ( 2 ) a sealing element ( 25 ) sealing all channel transitions at the same time is provided. 20. Micro valve arrangement according to one of claims 1 to 19, characterized by a micromechanically structured structure of at least one micro valve ( 8 , 8 '). 21. Microvalve arrangement according to one of claims 1 to 20, characterized in that at least one microvalve ( 8 , 8 ') is based on a piezoelectric and / or a magnetostrictive functional principle or on a memory metal functional principle.