KR20020000683A - Driving unit make use of magnetic fluid and manufacture method of the driver - Google Patents

Abstract

PURPOSE: A driving apparatus with magnetic fluid and a manufacturing method thereof are provided to improve driving force at low voltage, and to respond promptly by driving a micro pump with magnetic fluid deformed according to the magnetic field. CONSTITUTION: A driving device is composed of a first board(10) having a magnetic field generating part(12); a second board(20) having a magnetic fluid accommodating space(22) corresponding to the magnetic field generating part on the first board; a second board(30) having an injection port(32) injecting magnetic fluid to the accommodating space, and a magnetic fluid moving space(33) over the second board; and a thin membrane(40) covering the magnetic fluid moving space. The magnetic fluid is deformed according to the magnetic field, and applied to the driving device. The driving force increases at low voltage, and the driving device responds quickly with using magnetic fluid.

Description

Driver using magnetic fluid and manufacturing method of the driver {DRIVING UNIT MAKE USE OF MAGNETIC FLUID AND MANUFACTURE METHOD OF THE DRIVER}

The present invention relates to a micro pump that uses MEMS technology and is applicable to medical applications, in particular, by applying magnetic fluid as a pumping source instead of a valve, which is a mechanical element, to reduce the manufacturing cost of a device and to apply a micro machine. The present invention relates to a driver using a magnetic fluid capable of overcoming the limitations of materials, and a method of manufacturing the driver.

In general, MEMS (Micro Electro Mechanical Systems) is interpreted as a micro precision mechanical technology, and refers to a technology that is made by integrating electrical and mechanical parts into a microminiature. These MEMS are widely applied to information recording devices, medical and biotechnology devices, fluid devices, inertial navigation system devices, optical components and displays.

In particular, a micro actuator such as a micro pump, which is one of the fluid elements, is used in medical applications for bloodless treatment.

These micro pumps are classified into three types according to the driving method.

First, it is a micropump using volume change of piezoelectric material by voltage. This micropump has advantages of large driving force and simple structure, but has a problem of applying a high voltage.

In addition, since there must be a manufacturing process that does not belong to the standard method, such as the bonding process on the piezo film or piezo stack, there is a problem that the manufacturing cost is high.

Second, it is a micro pump using the electrostatic force. This micro-pump is a simple structure in which two electrodes face each other with a small distance.As the size is reduced, the electrostatic force, which is the force acting on the surface, becomes the dominant force compared to gravity, so it has the ability to generate micro displacement, so that the super precise position control is possible. Although it can be implemented, and has advantages such as large driving force and high-speed response, high voltage must be applied, and there is a problem that the fluid is damaged while the transfer fluid is activated by an electric field.

Third, it is a micro pump using volume change in phase change of materials. This micropump has advantages of being driven with a large driving force and low voltage, but there are problems such as high temperature generation and low speed response.

As such micro-pumps currently used have their advantages, but they also have their weaknesses, so there is an urgent need for technology development to overcome them.

The present invention has been made to solve the conventional problems as described above, by using a magnetic fluid to drive the micropump using a low-voltage large deformation, high-speed response, magnetic fluid implantable in the human body and the driver The purpose of this is to provide a method of production.

1 is an exploded perspective view of a driver according to the present invention

Figure 2 is a longitudinal cross-sectional view showing a coupling state of FIG.

3 is a view showing a state in which the magnetic fluid in FIG.

4A to 4E are manufacturing process diagrams of the first substrate constituting the driver according to the present invention.

5a to 5e are manufacturing process diagrams of the third substrate constituting the driver according to the present invention.

<Explanation of symbols for the main parts of the drawings>

1: magnetic fluid 10: first substrate

11: first silicon panel 12: magnetic field generating unit

13 plating base layer 14 thick film photosensitive film

15 coil plating 20 second substrate

21: second silicon panel 22: accommodation space

30: third substrate 31: third silicon panel

32: injection hole 33: magnetic fluid flow space

33a, 33b: upper and lower thermal oxide film 40: thin film

According to the first aspect of the present invention for achieving the above object,

A first substrate having a magnetic field generating portion for generating a magnetic field; A second substrate stacked on the first substrate and having a receiving space accommodating a magnetic fluid reacting by a magnetic field at a position corresponding to the magnetic field generating unit; A third substrate stacked on the second substrate and having an injection hole for injecting magnetic fluid into the accommodation space and having a magnetic fluid moving space in communication with the accommodation space where the injection hole is avoided; It characterized in that it comprises a thin film of a soft material covering the magnetic fluid moving space.

Moreover, according to the 2nd aspect of this invention,

Depositing a plating base layer on the first silicon panel; Coating a thick film photoresist film on the plating base layer; Patterning a portion of the thick film photoresist; Coil-coating a portion where the thick film photoresist is opened; Removing the remaining thick film photoresist except for the coil plated portion; Manufacturing a first substrate by removing the remaining plating base layer except for the coil plated portion;

A second substrate is fabricated by forming an accommodating space for accommodating the magnetic fluid at a position corresponding to the coil-plated portion of the second silicon panel;

Depositing upper and lower thermal oxide films on upper and lower surfaces of a third silicon panel, respectively; first patterning a portion of the lower thermal oxide film to be removed; First etching to form an injection hole corresponding to the patterning size of the lower thermal oxide film on the third silicon panel, and removing the upper thermal oxide film remaining on the injection hole; Depositing a free-deformable thin film on the upper thermal oxide film; Second patterning so that a portion of the area avoided by the primary patterning of the lower thermal oxide film is removed; Fabricating a third substrate by secondary etching to form a magnetic fluid flow space having a size corresponding to a second patterned area in the third silicon panel;

The first, second and third substrates are characterized in that it comprises a step of sequentially bonding by bonding.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, since the present invention uses a magnetic fluid, it will be briefly described as to what is a magnetic fluid and its characteristics.

Magnetic fluid or ferrofluid is a colloidal solution in which ferromagnetic particles are uniformly dispersed in a medium (water or oil) .The colloid adsorbs a surfactant to ferromagnetic ultrafine particles to prevent aggregation and sedimentation in the liquid phase. It is manufactured by dispersing. It is completely stable and does not settle or aggregate even by gravity or magnetic gradient, and has macroscopic properties similar to single-phase fluids.

Therefore, unlike an electroheological or magnetorheological fluid whose volume varies with piezoelectric material or a magnetic field or electric field whose volume is changed by an applied voltage, a magnetic fluid deforms the shape of the fluid itself by an applied magnetic field. Has the characteristic of becoming.

Such magnetic fluids have been proposed and tried in all fields such as specific gravity screening, magnetic seals, speaker cooling materials, magnetic recording materials, waste oil treatment, and various devices.

A configuration of a driver using such a magnetic fluid will be described with reference to FIGS. 1 to 3.

1 is an exploded perspective view of a driver according to the present invention, and FIG. 2 shows a combined state of FIG. 1. According to the drawings, the present invention may include a first substrate 10 and a second substrate 20, and a third substrate 30. This configuration is achieved by stacking sequentially.

The first substrate 10 includes a first silicon panel 11 and a coil-shaped magnetic field generator 12 provided on an upper surface thereof to generate a magnetic field according to the application of power.

In addition, the second substrate 20 is formed by forming an upper / lower open receiving space 22 at a position corresponding to the magnetic field generator 12 of the second silicon panel 21. In this case, the accommodation space 22 is a place where the magnetic fluid 1 is accommodated.

The third substrate 30 is formed by forming an injection hole 32 for injecting the magnetic fluid 1 into the accommodation space 22 of the second silicon panel 21 in the third silicon panel 31. do. In addition, in the third silicon panel 31, a magnetic fluid flow space 33 communicating with the accommodation space 22 is formed where the injection hole 32 is avoided.

In this case, the magnetic fluid flow space 33 is a space in which the magnetic fluid 1 reacts.

In addition, a thin film 40 of a soft material covering the magnetic fluid flow space 33 is deposited. The thin film 40 is deformed upward by the reaction force of the magnetic fluid 1, and can be freely deformed when the magnetic fluid 1 is unreacted.

Therefore, in a state in which no power is applied to the magnetic field generating unit 12, the magnetic fluid 1 remains in a non-reactive state as shown in FIG. 2, and when power is applied to the magnetic field generating unit 12, the magnetic field generating unit ( As the magnetic fluid 1 accommodated in the receiving space 22 of the second substrate 20 reacts with the magnetic field generated by 12), a force to be discharged through the magnetic fluid flow space 32 of the third substrate 30 is reacted. Will occur.

At this time, the thin film 40 covering the magnetic fluid flow space 32 is deformed convex upward as shown in FIG. 3 by the force P to be discharged from the magnetic fluid 1. As the thin film 40 is deformed by the reaction or no reaction of the magnetic fluid 1, it is possible to provide power for transferring the fluid (not shown) flowing over the thin film 40 to an appropriate point.

Meanwhile, the manufacturing process of the driver will be described with reference to FIGS. 4 and 5 as follows. 4 is a manufacturing process diagram of the first substrate constituting the driver according to the present invention, and FIG. 5 shows a manufacturing process diagram of the third substrate constituting the driver according to the present invention.

First, a manufacturing process of the first substrate 10 will be described with reference to FIGS. 4A to 4E.

The plating base layer 13 is deposited on the first silicon panel 11 (see FIG. 4A).

Next, a thick photoresist film (photo resist) 14 is coated on the plating base layer 13 (see FIG. 4B).

Next, patterning is performed to remove a part of the thick film photosensitive film 14 by exposure (see Fig. 4C).

Next, the coil plating 15 is applied to the portion A removed by patterning (see FIG. 4D). The portion of the coil plating 15 corresponds to the magnetic field generator 12 described above.

Next, a process of removing the remaining thick film photoresist film 14 except for the coil plating 15 part by chemical and removing the remaining plating base layer 13 except the coil plating 15 part (see FIG. 4E). ), The fabrication of the first substrate 10 is completed.

On the other hand, the second substrate 20 is formed by forming an accommodating space 22 on the second silicon panel 21 by opening or forming the upper and lower portions by etching or molding (see Fig. 1).

In addition, the third substrate 30 deposits upper and lower thermal oxide films 33a and 33b on the upper and lower surfaces of the third silicon panel 31 as shown in FIGS. 5A to 5E (see FIG. 5A). .

Next, first patterning is performed so that a portion of the lower thermal oxide film 33b is removed (B) (see FIG. 5B).

Next, in order to form an injection hole 32 corresponding to the first patterning size of the lower thermal oxide layer 33b on the third silicon panel 31, the third silicon panel 31 is first etched. The upper thermal oxide film 33a remaining on the injection hole 32 is removed (see FIG. 5C).

Next, a thin film 40 of soft material is deposited on the upper thermal oxide film 33a (see FIG. 5D).

Next, the second patterning is performed so that a part of the portion which avoids the portion removed by the primary patterning of the lower thermal oxide film 33b is removed (C) (see FIG. 5E).

Next, in order to form a magnetic fluid flow space 33 having a size corresponding to the area of the second patterned area in the third silicon panel 31, an upper row of a size corresponding to the second etching is performed. By removing the oxide film 33a (D), the fabrication of the third substrate 30 is completed (see FIG. 5E).

Thereafter, the first, second and third substrates 10, 20 and 30 are sequentially laminated and bonded by bonding to complete the manufacturing process of the driver using the magnetic fluid 1.

The present invention as described above has a number of advantages that the magnetic fluid is applied to the driver by using the characteristic that the shape is deformed by the magnetic field, so that a large driving force can be obtained, and a fast response and low voltage can be driven.

Claims (2)

A first substrate 10 having a magnetic field generator 12 for generating a magnetic field; A second substrate 20 stacked on the first substrate 10 and having a receiving space 22 in which a magnetic fluid 1 reacting by a magnetic field is received at a position corresponding to the magnetic field generating unit 12. ; The accommodation space 22 is stacked on the second substrate 20 and has an injection hole 32 for injecting the magnetic fluid 1 into the accommodation space 22 and avoids the injection hole 32. A third substrate 30 having a magnetic fluid flow space 33 in communication therewith; Actuator using a magnetic fluid, characterized in that it comprises a thin film (40) of the soft material covering the magnetic fluid flow space (33). Depositing a plating base layer 13 on the first silicon panel 11; Coating a thick film photosensitive film (14) on the plating base layer (13); Patterning a portion of the thick film photosensitive film (14); Coil plating (15) the open portion (A) of the thick film photosensitive film (14); Removing the thick film photoresist film 14 except for the coil plated portion 15; Manufacturing a first substrate (10) by removing the remaining plating base layer (13) except the coil plating (15) portion; A second substrate 20 is fabricated by forming an accommodating space 22 for accommodating the magnetic fluid 1 at a position corresponding to the coil plated portion 15 of the second silicon panel 21; Depositing upper and lower thermal oxide films 33a and 33b on the upper and lower surfaces of the third silicon panel 31, respectively; First patterning the portion of the lower thermal oxide layer 33b to be removed; Primary etching is performed to form an injection hole 32 corresponding to the patterning size of the lower thermal oxide film 33b on the third silicon panel 31, and the upper thermal oxide film 33a remaining on the injection hole 32 is formed. Removing); Depositing a freely deformed thin film (40) on the upper thermal oxide film (33a); Second patterning (C) a portion of the portion avoiding the portion B removed by the primary patterning of the lower thermal oxide film 33b; Secondary etching is performed to form a magnetic fluid flow space 33 having a size corresponding to the area of the second patterned pattern in the third silicon panel 31, and an upper thermal oxide film having a size corresponding to the second etching is formed. 33D) fabricating a third substrate 30 by removing (D); The first, second and third substrates (10, 20, 30) of the manufacturing method of the driver using a magnetic fluid, characterized in that it comprises a step of sequentially bonding by bonding.