WO1994004832A1

WO1994004832A1 - Micro-miniaturizable valve

Info

Publication number: WO1994004832A1
Application number: PCT/EP1993/002269
Authority: WO
Inventors: Roland Zengerle; Axel Richter
Original assignee: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
Priority date: 1992-08-24
Filing date: 1993-08-24
Publication date: 1994-03-03
Also published as: DE4227998C2; EP0656997A1; DE4227998A1

Abstract

A micro-miniaturizable valve has a pressure compensating chamber (2), a first semi-active valve (3) arranged between the pressure compensation chamber (2) and a first fluid line (L1) and a second semi-active valve (4) arranged between the pressure compensation chamber (2) and a second fluid line (L2).

Description

Micro-miniaturizable valve

Description

The present invention relates to a microminiaturisable valve.

Known pneumatic valves and hydraulic valves consist of a large number of components, which typically consist of plastics and metals. Particularly in the case of so-called booster valves, which can switch a high pressure by means of a comparatively low pneumatic control pressure, considerable sizes and thus also large volumes result in known valves, which in the known valves have comparatively long switching times and a conduct behavior that is unsatisfactory in dynamic terms.

For some time, valve structures and micropumps have also been manufactured using methods of semiconductor technology. For example, the specialist publication Sensors and Actuatores 20 (1989), 163 to 169 shows a microvalve made of silicon by means of a photolithographic method, which is arranged on a silicon wafer with a through hole for the fluid to be controlled, this valve structure having one comprises movable valve body, which is arranged by means of radially extending arms which merge into a fastening ring, above the through hole. The through hole is closed by a piezoelectric actuating element.

From the professional publication Proceedings of IEEE, MEMS-90, February 11-14, 1990, Napa Valley, California: "Micro achined Silicon Microvalve "an electrostatically actuable silicon microvalve is already known, which comprises a base part with an inlet opening, which converges conically to an outlet opening, above which an elastic closure plate made of a dielectric is arranged at a short distance. Both the elastic closure plate and The dielectric region below this sealing plate has electrode plates for the electrostatic opening and closing of the microvalve thus formed. The flow modulation curve of such a microvalve as a function of the control voltage shows a strong hysteresis. Although this known microvalve has a high holding force, that is to say in its closed state Resists even a high pressure difference of approx. 100 mbar, it is not able to operate at high fluid flow velocities and pressure differences of more than 150 mbar in its open position by applying an el electrical control signals to be closed again. Closing is practically only possible if the fluid flow through which the microvalve flows has essentially decreased to zero.

Proceeding from this prior art, the present invention has for its object to provide a microvalve that can be manufactured using the methods of micro-mechanics, has a short response time and improved dynamic behavior and can also switch high and low pressures on and off .

This object is achieved by a microminiaturisable valve according to claim 1.

According to a first aspect of the invention, the valve comprises a pressure compensation chamber and two semi-active valves which are in fluid flow connection with the pressure compensation chamber. A first of the semi-active valves is arranged between the pressure compensation chamber and a first fluid line in such a way that it counteracts a pressure in the first fluid line which is higher than that in the pressure compensation chamber, is stable in its closed state by applying a first voltage to electrically conductive areas of this first semi-active valve. A second one of the semi-active valves is arranged between the pressure compensation chamber and a second fluid line in such a way that it counteracts a pressure in the pressure compensation chamber that is higher than that in the fluid line by applying a second voltage to conductive areas of the second semi-active valve can be kept in its closed state. The flow through the valve from the first fluid line into the second fluid line can be controlled as desired by alternately switching off the voltages applied to the two semi-active valves.

According to an important aspect of the invention, a valve piston is arranged in a manner that can be acted upon by the pressure of the pressure compensation chamber and can be placed against a valve seat in dependence on the pressure in this pressure compensation chamber in order to control a fluid connection between a third and fourth fluid line Way to open and close. With this structure of the microminiaturisable valve, a control pressure can be applied to the first fluid line and the second fluid line can be used to vent the pressure compensation chamber. Corresponding to the electrical control signals for the two semi-active valves, the pressure in the pressure compensation chamber can be set to a selectable pressure level between the control pressure and the venting pressure in the first or second fluid line, so that this can be done by suitable electrical control of the two semi-active valves, the fluid connection between the third and fourth fluid lines can be opened and closed as desired in a controllable manner.

With a suitable dimensioning of the area of the valve piston on the pressure compensation chamber side in relation to the area that results in the area of a valve seat between the third and fourth fluid lines, the invention enables corresponding microminiaturisable valve an amplification effect in that with a comparatively low control pressure in the first fluid line, comparatively high pressures in the third and fourth fluid lines can be controlled.

Further developments of the microminiaturizable valve according to the invention are specified in the subclaims.

Preferred exemplary embodiments of the present invention are explained in more detail below with reference to the accompanying drawings. Show it:

1 shows a cross-sectional view of a first embodiment of the microminiaturisable valve according to the invention;

2 shows a first embodiment of a semi-active valve which can be used in the micro-miniaturizable valve according to the invention;

3a shows a second to fifth embodiment of the up to 3d semi-active microvalve which can be used in the valve according to the invention;

FIG. 4 shows a representation corresponding to FIG. 1 of a second embodiment of the micro-miniaturizable micro-valve according to the invention;

FIG. 5 shows a further representation corresponding to FIG. 1 of a third embodiment of the microminiaturisable valve according to the invention;

FIG. 6 shows a further representation corresponding to FIG. 1 of a fourth embodiment of the microminiaturizable according to the invention Valves;

7 shows a further representation corresponding to FIG. 1 of a fifth embodiment of the microminiaturizable valve according to the invention; and

8 shows a fifth embodiment of the microminiaturizable valve according to the invention.

As can be seen in particular in FIG. 1, the first exemplary embodiment of a microminiaturized valve shown there, which is designated in its entirety by the reference number 1, comprises three essentially plate-shaped bodies K1, K2 which are arranged one above the other and firmly connected to one another , K3. In the preferred embodiment, the three bodies K1, K2, K3 are formed by silicon wafers. The first and second bodies K1, K2 are connected to one another in an electrically conductive manner. The third body K3 is electrically insulated from the second body K2. This electrical insulation is preferably implemented in that the third body K3 is covered over its entire surface with an insulation layer on its side facing the second body K2. The insulation layer can consist of silicon oxide or silicon nitride. The second and third bodies K2, K3 are preferably only very slightly or not at all spaced from one another. In a preferred embodiment, these two bodies K2, K3 are connected by anodic bonding via an electrically insulating pyrex intermediate layer. It is also possible to glue the two bodies K2, K3 laterally in a flat arrangement.

The first and / or the second body K1, K2 are structured by means of photolithographic etching processes in such a way that they define a pressure compensation chamber 2 with one another. In the embodiment shown, the pressure compensation chamber 2 is molded into the first body K1 by etching. However, it is obvious to a person skilled in the field of semiconductor technology that the first body K 1 can also be designed as a flat plate if the pressure compensation chamber 2 is etched into the side of the second body K 2 facing the first body K 1.

Four fluid lines L1, L2, L3, L4 are fastened to the third body K3 on its side facing away from the second body K2. The fluid lines can be attached using a suitable adhesive. However, the entire valve can also be fitted into a special housing, which establishes both the connection of the electrical connections and the connection to the fluid connections.

In the fluid connection between the pressure compensation chamber 2 and the first and second fluid lines L1, L2 are two semi-active valves 3, 4. The first semi-active valve 3 is arranged such that this has a pressure in the first fluid line L1, which is higher than that in the Pressure compensation chamber 2, by applying a first voltage UI to electrically conductive areas (cf. FIG. 2) of the valve, can be kept in a closed state. The second semi-active valve 4 is arranged in the opposite manner with respect to the installation position of the first semi-active valve 3 in such a way that it presses against the pressure in the pressure compensation chamber 2, which is higher than that in the second fluid line L2, by applying a second voltage U2 to conductive Areas (see FIG. 2) of the second valve can be kept in a closed state. As can be clearly seen from the overall view of FIGS. 1 and 2, the first and the second semi-active valves 3, 4 each have a movable valve region, which is designed here as a valve flap 5, which has an opening 6 in an adjacent, fixed one ¬ covering surface area 7 of the respective adjacent body K1 or K2. As already mentioned, the second and third bodies K2, K3 are made of insulation layers 9, 10 μm. give .

The second body K2 has on its fixed surface area 7 facing the third body K3 in the area of the opening 6 a first electrode in the form of a metallization 11.

The valve flap 5 has, at least on its side opposite the fixed surface area 7 of the second body K2, a second electrode which is preferably arranged outside the insulation layer 10 and which can likewise be a metallization. The control voltage UI, U2 is applied to these two electrodes 11, 12, with which the valve flap 5 can be held electrostatically in a position sealing against the opening 6.

The first semi-active valve 3 differs from the second semi-active valve 4 just described only in that it is formed in the reverse position by the second and third bodies K2, K3, the body K2 thus forming a valve flap 13, while the third Body K3 defines the opposite opening 14.

The second body K2 has a recess 15 which extends from its one main surface to almost its other main surface to form a membrane 16, the central part of which preferably forms a valve piston 17 surrounded by the recess 15. The valve piston 17 is resiliently suspended by the membrane 16.

The third body K3 has a central through opening 18 opposite to the valve piston 17, as a result of which the region of the body K3 surrounding the through opening 18, which is adjacent to the valve piston 17, defines a valve seat 19. The third body K3 has a further through-opening 19 which extends from the third fluid line L3 to the recess 15 in the second body K2. In the first control line Ll the control pressure pl, there is a venting pressure p4 in the second fluid line L2, a supply air pressure p2 prevails in the third fluid line L3, while there is an exhaust air pressure p3 in the fourth fluid line L4. A vessel, the pressure of which is to be controlled by valve 1, can be connected to the fourth fluid line.

Before the operation of the valve 1 according to FIG. 1 is explained, the operation of the semi-active valve 3, 4 used in the valve 1 will first be explained with reference to FIG. 2.

By applying an electrical voltage U between the second electrode 12, the flap 5 and the opposite electrode 11 to the fixed surface area 7 of the second body K2, the flap 5 is pressed onto the opposite surface area 7 with the electrostatic pressure p. For the capacitor-like arrangement, p is calculated as follows:

€ ₀ • β, U2

P = ^• d *

In this equation, el denotes the relative dielectric constant of the insulator medium and d the thickness of the dielectric. In the case of an approximately 1 μm thick silicon oxide layer as insulation, electrostatic pressures in the range of a few hundred mbar can be generated at voltages around 30 volts.

The flap 5 can be kept closed by applying a voltage to an overpressure on the side of the opening 6 until there is a balance of forces. The following applies:

(pl - p4) Fl = p F2 In this equation, Fl denotes the area of the opening 6 and F2 the area of the valve flap 5 which extends beyond the opening 6.

Depending on the ratio of the areas F2 / F1, the electrostatic pressure of a few hundred milibars can block significantly higher pneumatic pressure differences (pl-p4).

If the voltage U is switched off, the flap 5 bends away from the fixed surface area 7, so that a fluid (air or an insulating hydraulic medium) can pass through the semi-active valve 3, 4.

Starting from the mode of operation of the semi-active valves 3, 4, the function of the valve 1 (FIG. 1) will now be explained. When the semi-active valve 4 on the venting side, as the side of the second fluid line L2, is closed, the semi-active valve 3 on the control pressure side, ie. H. open the side of the first fluid line L1, which results in a gas flow or generally a fluid flow into the pressure equalization chamber 2 until pressure equalization is achieved. In this state, the semi-active valve 3 can be closed again and held electrostatically by applying the voltage UI.

By switching off the voltage U2 at the second semi-active valve 4 when the first semi-active valve 3 is closed, the pressure compensation chamber 2 can be vented or brought to the lower pressure level p4 within the second fluid line L2. After the pressure equalization has taken place, this semi-active valve 4 can be closed again by applying the voltage U2, whereupon the cycle can begin again. In order to be able to achieve the highest possible operating frequency, the volume of the pressure compensation chamber 2 should be as small as possible. In order to keep the valve 1 closed against the counter pressure, no electrical power is required, since power is only consumed during the switching process.

If there is an overpressure p2 in the third fluid line L3 compared to the pressure p3 in the fourth fluid line and the pressure equalization chamber 2 is under the control pressure p1 from the first fluid line L1, the valve piston 17 becomes on the valve seat 19 of the exhaust air passage opening 18 pressed so that the pneumatic valve 1 is closed.

If the second semi-active valve 4 on the ventilation side is opened by switching off the voltage U2, the pressure in the pressure compensation chamber 2 is reduced from the pressure pl to the pressure p4. The valve piston 17 is deflected upwards by the pressure difference from the piston underside and piston top. Now the third and fourth fluid lines L3, L4 are connected to one another so that the valve 1 is open.

In principle, two different cases can be distinguished in the operating mode of such a valve:

In a first operating mode, the pressure in the fluid lines L3 and L4 can in each case be constant, so that a specific, stationary fluid flow can be switched with the valve. If this operating case is present, no time-variable pressures are necessary for the calculation of the control pressure Pl, and the valve can be switched by switching the pressure in the pressure compensation chamber between the control pressure Pl and the venting pressure P4 by means of the two semi-active valves.

In a second operating mode, for example, a closed container can be connected to the fluid line L4, in which the pressure increases from the initial pressure P3 to the higher final pressure P2 through the valve described above becomes. The pressure in one of the two fluid lines L3 or L4 is thus variable over time, as is the pressure flow. In order to be able to reduce the pressure in the container back to P3 and thus be able to reach the initial state again, a second valve is therefore necessary. The supply air line L3 of the second valve is connected to the container and the container can be vented again by opening the second valve. The initial state has thus been restored. The variable pressures in the fluid lines L3 and L4 must be taken into account for the size of the control pressure, which must close the respective valves again.

Depending on the dimensioning of the area A _{3 of} the exhaust air passage opening 18 and the area A ^ of the membrane 16, the simple logic element shown in FIG. 1 can be operated as a simple switch in which the control pressure p 1 and the supply air pressure p 2 are identical. or operate as an amplifier element, in which one can switch a large supply air pressure p2 with a low control pressure pl. A minimum switching pressure pl _mj _ _{n is} required to switch the valve. The following applies:

A ₂

P ⁱ min = P ^{3 () +} P ^{2 (} -

^A l H

with AL = A ₃ + A ₂

When choosing the areas A ₃ , A ^ one is limited to an area A ₃ smaller than A _{] ^} , from which it can be seen from the above equation that the control pressure pl min must always be greater than the exhaust air pressure p3. On the other hand, it can also be seen that the minimum control pressure pl min can be significantly lower than the supply air pressure p2 to be switched by suitable selection of the areas A _lf A ₃ , which results in the amplification function described results.

The semi-active valves 3, 4 are not limited to the shape shown in FIG. 2. 3a to 3d show variants of semi-active valves in which the embodiment shown in FIG. 3a has a valve flap 5 which lies smoothly against the fixed surface area 7. Instead of the flap 5 according to FIG. 3a, a bar (not shown) clamped on two sides can be used. As is shown in FIG. 3b, the fixed surface area 7 can have support webs 20 which are fixed by corresponding surface recesses 21 and against which the valve flap 5 rests. With this configuration, the risk of contamination can be reduced and a more favorable flow resistance of the semi-active valve can be achieved. The lowering of the surface recesses 21 should, however, not be more than 1 μm in order not to reduce the electrostatic pressure that can be generated too much.

It is also possible, instead of the flap 5, to form a membrane 22 which can include a central membrane reinforcement 23. In this embodiment, openings 24 in the membrane will be arranged at a distance from the opening 6 in the counter body. According to the configuration in FIG. 3b, a surface recess 25 can also be provided in this membrane-like embodiment of the movable valve region.

A second embodiment of the valve 1 is shown in FIG. 4. Parts which correspond to the embodiment in FIG. 1 are identified by the same reference numerals, so that their repeated description can be omitted. In the embodiment according to FIG. 4, the recess 15 'has an enlarged lateral extent, as a result of which the lateral extent of the valve piston 17' is correspondingly reduced. This results in wider membrane areas 16 '.

In the third embodiment of the valve 1 according to FIG. 5 differs from the first exemplary embodiment according to FIG. 1 in that here the membrane 16 ″ is set back against the main surface of the second body K2 facing the first body K1 by a surface recess 26. Correspondingly, the recess 15 ″, which surrounds the valve piston 17 ″, is made with a smaller depth.

The fourth embodiment of the valve according to the invention explained below corresponds to the second embodiment with the exception of the differences explained below, so that here too, the same reference numerals of the second embodiment according to FIG. 4 and the fourth embodiment according to FIG. 6 designate the same parts. In this embodiment of the valve 1, the third body K3 has an annular recess 28 in the region of the valve seat 19, which defines a narrow support edge 27 for the valve piston 17 '. This narrow support edge 27 not only reduces the susceptibility of the valve 1 to contamination, but also results in a clear definition of the area A ₂ over which the pressure p2 acts, in contrast to the area A ₃ over which the pressure p3 acts. With the areas A _v A ₂ , A ₃ defined in this way, the balance of forces which acts on the valve piston 17 'can be drawn up as a function of the pressures pl, p2, p3 and p4 and the areas mentioned.

The pressure P _auSg i _eι - _ct , _/ which prevails in the pressure compensation _chamber 2, for which the valve piston 17 'does not move upwards or downwards, is calculated as follows:

compensation Ai - _P 3 A ₃ + _P 2

The following relationship applies to areas AA ₂ and A ₃ : A, = A ₂ + A ₃

If the current pressure p in the pressure balancing chamber SSER grö¬ than the equilibrium pressure P _ausgteιch resulting from the above equation, the valve piston 'is pressed onto the exhaust opening 18 against the supporting edge 27 17 and the connection between exhaust air, that the fourth fluid ¬ line L4, and supply air, ie the third fluid line L3, interrupted. Otherwise there is a connection between the third and fourth fluid lines L3, L4.

With a fixed supply air pressure p2 and a fixed exhaust air pressure p3, the control pressure pl and the ventilation pressure p4 must meet the following criteria:

_P 4 A ₁ <p3 A ₃ + _P 2 (criterion for open valve)

p3 A ₃ + p2 A ₂ <pl (criterion for closed valve)

Overall, the following applies:

p4 <p ^{3 (} Ai ^{) + 2 (} V ^A 1> P ¹

In the exemplary embodiments described above, the third fluid line L3 is provided for the supply air, while the fourth fluid line L4 is used for the exhaust air. Furthermore, for reasons of space, area A2 is generally significantly larger than area A3. In this case there is an even more favorable operating behavior of the valve 1 according to the invention if the supply air is supplied through the fourth fluid line L4 and the third fluid line L3 is used as an exhaust air line. In this case, the ratios of the areas A ₂ and A ₃ to one another are higher, with the ratios remaining unchanged Reinforcing effect, ie the switchability of a higher supply air pressure in the fourth fluid line L4 based on the control pressure pl.

FIG. 7 shows a further modification of the valve according to the invention, in which, in turn, parts that are the same or comparable with the preceding exemplary embodiments are identified by the same or similar reference numerals. This embodiment comprises four bodies KO, K1, K2, K3, of which the third and fourth bodies K2, K3 fix together the two semi-active valves 3, 4, to which the supply air line L1 and the exhaust air line L2 adjoin. The pressure compensation chamber 2 is defined by the cavity between the second and third bodies K 1, K 2 and adjoins a membrane region 29 of the second body K 1, this membrane region 29 forming a valve piston 30 on its side facing away from the pressure compensation chamber 2. The valve piston 30 is opposite a support edge 31 of a valve seat 32, which is formed within the first body KO by a corresponding ring recess 33. The third and fourth fluid lines L3, L4 are connected to the outer surface of the first body KO and, as is also evident from the description of the exemplary embodiments explained above, can be connected to or separated from one another depending on the position of the membrane 29 which in turn depends on the pressure in the pressure compensation chamber 2 that can be controlled by the two semi-active valves 3, 4.

Although this configuration of the valve according to the invention requires an additional layer KO compared to the previously described exemplary embodiments, it is classified as technologically more favorable. In this valve structure, the third and fourth layers K2, K3 only have to be optimized with regard to the implementation of the semi-active valves 3, 4 with regard to the choice of technological steps for valve implementation, while the other two layers or bodies KO, Kl have to be optimized the choice of process steps only have to be optimized for the implementation of the diaphragm function and valve seat function. The separation of the functions of the semi-active valves or the membrane enables a higher degree of freedom in the selection of the process parameters.

A more modified variant of the valve according to the invention will now be described with reference to FIG. 8. This valve according to the invention is a simple switch for a pressure p1 prevailing in the supply air line L1 compared to a pressure p2 prevailing in the exhaust air line L2 which is lower than the pressure p1 to be switched. Compared to the previous exemplary embodiments, the third and fourth fluid lines and the membrane and valve piston structure within the second body K2 are omitted.

The pressure in the pressure chamber 2 can be switched between the supply pressure pl and the exhaust air pressure p2 by means of the two semi-active valves 3, 4, by opening one of the two semi-active valves 3, 4 by switching off its control voltage UI, U2 while the other semi-active valve remains closed by applying its control voltage UI, U2. The structure shown in Fig. 8 is only suitable as a pneumatic valve. It can be used as a hydraulic valve if the volume of the pressure compensation chamber 2 can be varied, for example by an elastic membrane on the outwardly facing surface of the first body K 1, so that the pressure compensation chamber can accommodate a variable hydraulic volume.

With this valve, the membrane can form the part of a pump which has a pump chamber adjacent to the elastic membrane. The membrane can also be connected to the piston of a pump structure.

Although the valves according to the invention are preferably implemented in silicon, for the purposes of the invention other materials that are suitable for microstructuring can also be used.

Claims

1. Microminiaturisable valve, characterized by

a pressure compensation chamber (2),

a first semi-active valve (3) arranged between the pressure compensation chamber (2) and a first fluid line (L1) in such a way that it is against a pressure in the first fluid line (L1) which is higher than that in the pressure line ¬ equal chamber (2), by applying a first voltage (UI) to electrically conductive areas (11, 12) of the first semi-active valve (3) can be kept in a closed state, and

an electrostatically stable, second semi-active valve (4) arranged between the pressure compensation chamber (2) and a second fluid line (L2) in such a way that it counteracts a pressure in the pressure compensation chamber (2) that is higher than that in the second fluid ¬ line (L2), by applying a second voltage (U2) to conductive areas (II, 12) of the second semi-active valve (4) can be kept in a closed state.

2. microminiaturisable valve according to claim 1, marked by

a valve piston (17, 17 ', 17 ",) acted upon by the pressure in the pressure compensation chamber (2) and depending on the pressure in the pressure compensation chamber (2) against a valve seat (19, 27) between a third and fourth fluid line (L3 , L4) can be created.

Micro-miniaturizable valve according to claim 1 or 2, characterized by

a control device which generates the first and second voltage (UI, U2) for the control of the first and second semiactive valve (3, 4) in such a way that at any time during the operation of the microminiatizable valve (1) at least on one of the two valves (2,

4) a voltage (UI, U2) is applied.

a valve piston (17, 17 ', 17' ',) acted upon by the pressure in the pressure compensation chamber (2) and depending on the pressure in the pressure compensation chamber (2) against a valve seat (19, 27) between a third and fourth fluid line ( L3, L4) can be created.

Micro-miniaturizable valve according to claim 3, characterized in that

that the valve piston (17, 17 ', 17 ") is guided by a membrane (16) adjoining the pressure compensation chamber (2).

5. microminiaturisable valve according to claim 3 or 4, characterized in

that the area (A ₃ ) enclosed by the valve seat (17, 27) in the area of the fourth fluid line (L4) is smaller than the area (A _χ ) of the valve piston (17, 17 ') acted upon by the pressure in the pressure compensation chamber (2) , 17 ").

6. microminiaturisable valve according to one of claims 1 to 5, characterized in

that the first and second semi-active valves (3, 4) each have a movable valve area (5, 22) which covers an opening (6) in an adjacent, fixed surface area (7), and

that the movable valve area (5, 22) and the fixed surface area (7) each comprise the aforementioned electrically conductive areas (10, 11).

7. microminiaturisable valve according to claim 6, characterized in that

that the area (F ₃ ) of the movable valve area (5, 22) is larger than the area (F _{j of} the opening (6).

Micro-miniaturizable valve according to one of claims 1 to 7, characterized by

three superposed, interconnected, substantially plate-shaped bodies (K1, K2, K3) which are designed such that the first and second bodies (K1, K2) define the pressure compensation chamber (2) with one another, and

that the two semi-active valves (3, 4) are fixed by the second and third body (K2, K3) such that the movable valve area (5) of the first semi-active valve (3) and the fixed surface area (7) of the second semi-active valve (4) are formed by the second body (K2) and that the movable valve area (5) of the second semi-active valve (4) and the fixed surface area (7) of the first semi-active valve (3) are formed by the third body ( K3) are formed.

9. microminiaturisable valve according to claim 8, characterized in

that the valve piston (17, 17 ', 17 ") and the diaphragm (16) guiding it are formed by the second body (K2).

10. microminiaturisable valve according to claim 8 or 9, characterized in

that at least two of the three bodies (Kl, K2, K3) are manufactured using methods of semiconductor technology.