KR100989582B1 - Micro pump and method for manufacturing the same - Google Patents

Abstract

A micro pump and a method of manufacturing the same are disclosed. A first cavity in which protrusions are formed to improve heat transfer rate is formed on one surface of the first substrate and the other surface of the first substrate, and a heater heating the volume of the working fluid to be filled in the first cavity. A membrane is bonded to one surface of the first substrate to cover the first cavity, the membrane expands according to the volume change of the working fluid, and a second cavity corresponding to the first cavity is formed on one surface. The micro pump includes a second substrate bonded to the membrane to cover the second cavity, and a valve formed on one surface of the second substrate so that the transfer fluid flowing into and out of the second cavity moves in one direction. The heat transfer rate from the heater to the working fluid can be improved, and the response characteristic can be improved by improving the heat radiation performance of the working fluid. In addition, leakage of the working fluid of the first cavity can be minimized, and the moving state of the conveying fluid can be easily confirmed.

Micro pump, irregularities, deep reactive ion etching

Description

Micro pump and method for manufacturing the same

The present invention relates to a micropump and a manufacturing method thereof.

Micro pumps are devices that supply or control liquids and are one of the key components of micro fluidic systems. The microfluidic system is expected to meet the demand of biofuel, which is emerging with the achievement of the recent genome project and the development of the micro total analysis system (μTAS), and the fuel supply device of the fuel cell, which is emerging as an alternative fuel. As a result, it is attracting attention as the commercialization area of next generation micro electro mechanical system (MEMS) devices.

Micro pumps can be broadly divided into mechanical pumps and nonmechanical pumps. Mechanical pumps convert driving electrical energy into mechanical energy to create a driving force to control the liquid, while non-mechanical pumps generate driving force by directly applying a physical force to a liquid or a liquid interface without converting into mechanical energy.

A representative example of a mechanical pump is a diaphragm pump, which is relatively high in efficiency and easy to manufacture, and is being actively researched. Actuators that generate the driving force of diaphragm pumps include piezoelectric actuators using piezoelectric (PZT) materials that transform electrical energy into mechanical energy.The thermal expansion material is contained in a closed chamber consisting of a membrane on one side. The thermopneumatic actuator, which utilizes the volume change generated by heating the material in the chamber with a heater, deposits electrodes between the body and the membrane, respectively, and then applies the same or different power to both sides to attract and repulse And an electrostatic actuator using the same, an electromagnetic actuator driven by the attraction force and the repulsive force between the permanent magnet and the electromagnet, and the like.

However, the actuator according to the prior art described above has some problems to be applied to the micropump for a portable device. In other words, piezoelectric actuators have a small driving displacement and require a high voltage of several tens of volts or more, and electrostatic actuators have a low driving force and a very high driving voltage, thereby limiting applications. Electromagnetic actuators generate noise, are complicated to manufacture, and have difficulty in miniaturization. have.

On the other hand, the thermopneumatic actuator can be operated at a low driving voltage without a separate voltage conversion device, it is easy to miniaturize, and the driving force and the drive displacement characteristics are relatively good, so it is suitable for application to a portable system. However, due to the time required for heating and cooling, the driving cycle is limited, and the driving determining factor is an analog method of temperature rather than a digital method such as an electric signal, which is affected by the surrounding environment and difficult to control precisely. .

Accordingly, there is a demand for a micropump using a thermopneumatic actuator capable of improving heat transfer rate, excellent response characteristics, and precise control, and a method of manufacturing the same.

The present invention provides a micropump capable of improving a heat transfer rate to a working fluid, and a method of manufacturing a micropump capable of realizing a space filled with a working fluid in a free shape.

According to an aspect of the present invention, a first cavity in which protrusions are formed to improve heat transfer rate is formed on one surface of a first substrate and the other surface of the first substrate, and a working fluid filled in the first cavity is formed in a volume. A heater that heats to change, a membrane bonded to cover the first cavity on one surface of the first substrate, the membrane expanded according to a change in volume of the working fluid, a second corresponding to the first cavity A cavity is formed on one surface, and includes a second substrate bonded to the membrane to cover the second cavity, and a valve formed on one surface of the second substrate so that the transfer fluid flowing into and out of the second cavity moves in one direction. A micro pump is provided.

The first substrate may be made of a material including silicon (Si), and the second substrate may be made of a material including glass.

The membrane may be made of an elastic material including silicon.

On the side opposite to the first cavity of the membrane, a third cavity may be formed to correspond with the first cavity.

The adhesive may further include an adhesive interposed between the first substrate and the membrane.

An adhesive passage may be formed on one surface of the first substrate so that the adhesive is uniformly distributed.

The valve may be a diffuser whose cross sectional area increases from inlet to outlet.

The second substrate may further include a temperature sensor formed adjacent to the heater to sense a temperature of the heater.

In addition, according to another aspect of the invention, the step of forming a first cavity formed with a projection to improve the heat transfer rate on one surface of the first substrate, heating the heater to heat the volume of the working fluid filled in the first cavity first substrate Forming a second cavity corresponding to the first cavity, and a valve on one surface of the second substrate to move the transfer fluid flowing into and out of the second cavity in one direction, so that the second cavity is covered 2. A method of manufacturing a micropump comprising bonding a membrane to a substrate and bonding the membrane to cover a first cavity on one side of the first substrate to expand the membrane corresponding to a change in volume of the working fluid. do.

Forming the first cavity may be performed by deep reactive ion etching.

The first substrate may be made of a material containing silicon (Si), and the second substrate may be made of a material including glass.

The membrane may be made of an elastic material including silicon.

Prior to bonding the membrane to one side of the first substrate, the method may further include forming a third cavity on the side opposite the first cavity of the membrane to correspond to the first cavity.

Forming the third cavity may be performed by deep reactive ion etching.

Bonding the membrane to one surface of the first substrate may be performed at room temperature via an adhesive between the first substrate and the membrane.

Prior to bonding the membrane to one surface of the first substrate, the method may further include forming an adhesive flow path on one surface of the first substrate such that the adhesive is uniformly distributed.

Bonding the second substrate and the membrane may be performed by thermal bonding.

The valve may be a diffuser whose cross sectional area increases from inlet to outlet.

The forming of the heater may include forming a temperature sensor sensing a temperature of the heater so as to be adjacent to the heater on the other surface of the first substrate.

In the micropump according to the embodiment of the present invention, the heat transfer rate from the heater to the working fluid can be improved, and the response characteristic can be improved by improving the heat radiation performance of the working fluid. In addition, leakage of the working fluid of the first cavity can be minimized, and the moving state of the conveying fluid can be easily confirmed.

In addition, the micro-pump manufacturing method according to the embodiment of the present invention can be implemented in a free shape of the space filled with the working fluid, it can be applied to various kinds of valves more precisely. In addition, the process can be simplified and the process time can be shortened.

An embodiment of a micropump according to the present invention and a method for manufacturing the same will be described in detail with reference to the accompanying drawings. The description will be omitted.

1 is a cross-sectional view showing an embodiment of a micro pump according to an aspect of the present invention. 2 is a cross-sectional view showing an embodiment of a heater, a temperature sensor, and a first substrate, which is part of a micro pump according to an aspect of the present invention, and FIG. 3 is a part of the micro pump according to an aspect of the present invention. 4 is a bottom view showing an embodiment of a temperature sensor and a first substrate, and FIG. 4 is a plan view showing an embodiment of a heater, a temperature sensor, and a first substrate, which are part of a micropump according to an aspect of the present invention.

5 is a cross-sectional view showing an embodiment of the membrane, the valve and the second substrate, which is part of the micropump according to one aspect of the invention, and FIG. 6 is a membrane, which is part of the micropump, according to one aspect of the invention. A bottom view of an embodiment of a valve and a second substrate, and FIG. 7 is a plan view of an embodiment of a membrane, a valve, and a second substrate, which is part of a micropump according to an aspect of the present invention.

1 to 8, a micro pump 100, a first substrate 110, an insulating layer 111, a first cavity 112, a protrusion 114, and a working fluid inlet ( 116, the adhesive flow path 118, the heater 120, the membrane 130, the third cavity 132, the second substrate 140, the second cavity 142, and the valve 144. , Conveying fluid inlet 146, conveying fluid outlet 148, adhesive 150, temperature sensor 160, electrode 170, protective layer 180 are shown.

According to the present embodiment, by forming the protrusion 114 in the first cavity 112 formed in the first substrate 110, the micro pump 100 which can improve the heat transfer rate from the heater 120 to the working fluid. Is presented.

In addition, by using a silicon substrate having a high thermal conductivity as the first substrate 110, the response characteristic is improved by improving the heat dissipation performance of the working fluid, and the membrane 130 is made of silicon, thereby removing the first cavity 112 from the first cavity 112. A micropump 100 is presented which can minimize the leakage of the working fluid and can easily check the state of movement of the conveying fluid by using a glass substrate as the second substrate 140.

In addition, by forming an adhesive flow path 118 on one surface of the first substrate 110, by bonding the first substrate 110 and the membrane 130 with the adhesive 150 at room temperature using the adhesive flow path 118. The micropump 100 is presented which can be implemented more precisely in a short time with a simplified process.

In the first substrate 110, a first cavity 112 in which the protrusion 114 is formed may be formed on one surface to improve the heat transfer rate. The first cavity 112 may be filled with a working fluid for inflating the membrane 130 to transport the transport fluid, and the first fluid 112 may be filled with a first fluid to more effectively transfer heat generated by the heater 120. A cavity 114 may be formed in the cavity 112 to increase the surface area of the first cavity 112.

In this case, the first substrate 110 may be a silicon substrate including silicon (Si), and the silicon substrate may have a high thermal conductivity, thereby effectively dissipating heat of the working fluid, and thus, response characteristics of the micropump 100 may be used. This can be improved further.

When the first substrate 110 is made of silicon, the first substrate 110 is formed on the outermost layer of the silicon oxide film for electrical insulation between the heater 120, the temperature sensor 160 and the electrode 170, and the silicon substrate. An insulating layer 111 such as silicon oxidation may be formed, and the insulating layer 111 may be formed by wet oxidation of the surface of the first substrate 110 made of silicon.

On the other hand, one surface of the first substrate 110, the adhesive flow path 118 may be formed so that the adhesive 150 is uniformly distributed, accordingly, the first substrate (at room temperature) using the adhesive 150 When bonding 110 and membrane 130, the adhesive 150 is distributed along the adhesive flow path 118 and the excess adhesive 150 is discharged out along the adhesive flow path 118, thereby simplifying the process and The time may be shortened, and the first substrate 110 and the membrane 130 may be bonded more precisely without errors. Bonding between the first substrate 110 and the membrane 130 will be described again in the description of the membrane 130.

In addition, the first substrate 110 may be formed with a working fluid inlet 116 for injecting a working fluid for expanding the membrane 130 into the first cavity 112, through the working fluid inlet 116. The working fluid may be injected into the first cavity 112 and sealed with an adhesive at room temperature, for example, using a piece of silicon or the like.

The first cavity 112, the adhesion passage 118, and the working fluid inlet 116 may be formed by deep reactive ion etching, and thus wet etching as in the prior art. Unlike the case, the first cavity 112, the adhesive flow path 118, and the working fluid inlet 116 may be embodied in a free shape without restriction. Hereinafter, a process of forming the first cavity 112, the adhesive passage 118, and the working fluid inlet 116 will be described in detail.

First, an insulating layer 111 such as, for example, a silicon oxide film is formed on both surfaces of the first substrate 110 made of silicon by wet oxidation. Subsequently, except for the region where the first cavity 112, the adhesive flow path 118, and the working liquid injection hole are to be formed on one surface of the first substrate 110 on which the insulating layer 111 is formed by photo-lithography. On the region, a first resist is formed, and the insulating layer 111 except for the region where the first resist is formed is removed by reactive ion etching. Next, a portion of the first substrate 110 is removed by deep reactive ion etching the surface of the first substrate 110 except for the region where the first resist is formed, thereby removing the first cavity 112 and the adhesive flow path 118. It can form part of the working liquid inlet.

Subsequently, in a photolithography method, a second resist is formed on an area of the other surface of the first substrate 110 on which the insulating layer 111 is formed except the area where the working liquid injection hole is to be formed, and except the area on which the second resist is formed. After etching and removing the insulating layer 111, the other surface of the first substrate 110 except for the region where the second resist is formed may be deep reactive ion etched to remove a portion thereof, thereby forming a working liquid injection hole.

The heater 120 is formed using titanium (Ti) and platinum (Pt) on the other surface of the first substrate 110 to correspond to the position of the first cavity 112, and is filled in the first cavity 112. The working fluid can be heated to change volume. That is, the working fluid receives the heat generated from the heater 120 and changes in volume from the liquid to the gas. The working fluid may rapidly change in volume, thereby expanding the membrane 130 that seals the first cavity 112. The transfer fluid introduced into the second cavity 142 may be moved in one direction.

The temperature sensor 160 may be formed to be adjacent to the heater 120 on the other surface of the first substrate 110 to sense the temperature of the heater 120. That is, the temperature sensor 160 detects the temperature of the heater 120 that generates heat by receiving electricity from the outside and transmits a signal thereof to the controller so that the micropump 100 can be more precisely controlled. It will serve as an assistant.

In this case, in order to protect the heater 120 and the temperature sensor 160 from external influences, a protective layer 180 such as silicon nitride may be formed on the heater 120 and the temperature sensor 160. Can be. However, the portion to be used as the electrode 170 in the heater 120 and the temperature sensor 160 may be used as a terminal for receiving electricity from the outside by preventing the protective layer 180 from being formed. .

As described above, the heater 120 and the temperature sensor 160 may be formed after the first cavity 112, the adhesive flow path 118, and the working fluid inlet 116 are formed in the first substrate 110. This can be explained by dividing into the following steps.

First, a third resist is formed on the other surface of the first substrate 110 except for the region where the heater 120 and the temperature sensor 160 are to be formed by photolithography. Subsequently, titanium and platinum are sequentially deposited on the other surface of the first substrate 110, and then the third resist is removed in a lift-off manner, thereby heating the heater corresponding to the position of the first cavity 112. 120 and a temperature sensor 160 adjacent thereto may be formed.

Thereafter, the heater 120 is formed by forming a protective layer 180 such as silicon nitride on the other surface of the first substrate 110 on which the heater 120 is formed, for example, by chemical vapor deposition. It can be protected from the outside, by forming a fourth resist on the other surface of the second substrate 140 except for the region where the electrode 170 is to be formed by photolithography and removing a part of the protective layer 180 by etching. It is possible to form an electrode 170 for supplying electricity from the.

The membrane 130 may be bonded to cover the first cavity 112 on one surface of the first substrate 110, so that the membrane 130 may be expanded according to a change in volume of the working fluid. That is, the membrane 130 may cover the first cavity 112 so that the working fluid filled in the first cavity 112 is sealed in the first cavity 112, and thus, the operation of the heater 120 is prevented. Accordingly, heat is transferred to the working fluid so that the working fluid expands in volume through a phase change, and according to the volume change of the working fluid, the membrane 130 made of an elastic material expands accordingly, and thus, the second cavity 142. It is possible to transport the transport fluid in one direction by pushing the transport fluid introduced into the.

At this time, the conveying fluid pushed out by the action of the valve 144 formed on the second substrate 140 to be connected to the second cavity 142 may flow in one direction, which is a part for describing the valve 144. This is explained in detail.

On the other hand, the membrane 130 may be made of an elastic material containing silicon, thereby preventing the working fluid from flowing out of the first cavity 112 may implement a more efficient micro-pump 100.

In addition, a third cavity 132 may be formed on a surface of the membrane 130 that faces the first cavity 112 to correspond to the first cavity 112, thereby providing a space into which the working fluid is injected. It can be increased in a simple manner and at the same time can reduce the thickness of the membrane 130 to be more sensitive to changes in the volume of the working fluid.

The third cavity 132 forms a seventh resist on one surface of the membrane 130 except for the region where the third cavity 132 is to be formed by photolithography, and one surface of the membrane 130 except the seventh resist. Can be formed by deep reactive ion etching to remove a portion thereof.

The membrane 130 may be bonded to the first substrate 110 through the adhesive 150. That is, as described above, since the adhesive flow path 118 may be formed on one surface of the first substrate 110 to uniformly distribute the adhesive 150, the adhesive 150 may be more precise at room temperature. The micro pump 100 can be manufactured by a simple process.

In addition, the membrane 130 may be bonded to the second substrate 140 by thermal bonding, and thus, the membrane 130 may be largely independent of the valve 144 formed on the second substrate 140. The second substrate 140 and the membrane 130 may be bonded more precisely. This will be described later in the following description of the process of forming the second cavity 142 and the valve 144 on the second substrate 140.

The second substrate 140 may be bonded to the membrane 130 such that a second cavity 142 corresponding to the first cavity 112 is formed on one surface thereof, and the second cavity 142 is covered. Accordingly, the membrane 130 expands toward the second cavity 142 formed on the second substrate 140, so that the transfer fluid introduced into the second cavity 142 is pushed by the membrane 130, so that the transfer fluid moves in one direction. I can move it.

That is, a second cavity 142 may be formed on one surface of the second substrate 140, and the transfer fluid inlet 146 and the second cavity into which the fluid flows into the second cavity 142 may be formed. A transfer fluid outlet 148 through which the fluid flows out at 142 is formed, so that the transfer fluid may enter and exit the second cavity 142 as the membrane 130 expands, and the transfer fluid inlet 146 and the transfer fluid A valve 144 is formed between the fluid outlet 148 and the second cavity 142 to allow the transport fluid to be transported in one direction. The one-way transport function of the valve 144 will be described again in the section describing the valve 144.

On the other hand, the second substrate 140 may be a glass substrate made of glass, thereby easily confirming the movement state of the transport fluid contained in the second cavity 142.

The valve 144 may be formed on one surface of the second substrate 140 so that the transfer fluid flowing into and out of the second cavity 142 moves in one direction. That is, the valve 144 has a structure in which fluid can flow only in one direction, between the transfer fluid inlet 146 and the second cavity 142, and between the transfer fluid outlet 148 and the second cavity 142. Each of which may be formed to cause a transfer fluid pressurized by the expanding membrane 130 to flow from the transfer fluid inlet 146 to the transfer fluid outlet 148.

On the other hand, the valve 144 may be a diffuser (diffuser) in which the cross-sectional area is increased from the inlet in which the fluid flows into the valve 144 to the outlet exiting the valve 144, accordingly, the simple structure of the conveying fluid Since the transportation can be made in one direction, it is possible to implement a micro pump 100 of a smaller size.

As described above, the second cavity 142, the valve 144, the transfer fluid inlet 146, and the transfer fluid outlet 148 may be formed on the second substrate 140, and are divided into the following processes. can do.

First, an etch stop layer made of polysilicon is formed on both surfaces of the second substrate 140 made of glass in order to use fluorine (HF) as an etching solution. Subsequently, in a photolithography method, the fifth cavity 142, the valve 144, the transfer fluid inlet 146, and the fifth substrate may be disposed on one surface of the second substrate 140 except for the region where the transfer fluid outlet 148 is to be formed. A resist is formed, and the etch stop layer except for the region where the fifth resist is formed is removed by reactive ion etching. Subsequently, a portion of the second substrate 140 except for the region where the fifth resist is formed is removed by a process such as, for example, wet etching using fluorine, thereby providing the second cavity 142, the valve 144, and the transfer. A portion of the fluid inlet 146 and the transport fluid outlet 148 may be formed, and then the etch stop layer may be removed.

Next, after the sixth resist is formed on the other surface of the second substrate 140 except for the region where the transfer fluid inlet 146 and the transfer fluid outlet 148 are to be formed by photolithography, a region in which the sixth resist is formed is formed. By removing a portion of the second substrate 140 except for a process such as sand blasting (sand blasting), it is possible to form the transfer fluid inlet 146 and the transfer fluid outlet 148.

As such, after the second cavity 142, the valve 144, the transfer fluid inlet 146, and the transfer fluid outlet 148 are formed on the second substrate 140, the second substrate 140 may be thermally bonded to the second substrate 140. The membrane 130 may be bonded, and at this time, a processing process for the membrane 130 may be performed. This can be explained by dividing as follows.

First, by thermal bonding, the elastic membrane 130 made of, for example, 400 micrometers of silicon may be bonded to the second substrate 140, and thus, a valve formed on the second substrate 140 may be bonded. The second substrate 140 and the membrane 130 may be bonded to each other more precisely without restricting the shape of the 144.

Next, the above-mentioned elastic membrane 130 is thinly processed to, for example, 80 micrometers by, for example, a chemical mechanical polishing (CMP) method, and as described above, the third cavity is formed by deep reactive ion etching. 132 may be formed.

Thereafter, according to the bonding process of the first substrate 110 and the membrane 130 described above, the first substrate 110 may be bonded to the membrane 130 by using the adhesive 150, and accordingly, Micro pump 100 can be manufactured.

Next, an embodiment of a micropump manufacturing method according to another aspect of the present invention will be described.

8 is a flow chart showing an embodiment of a micro pump manufacturing method according to another aspect of the present invention, Figures 9 to 30 is a cross-sectional view showing each process of an embodiment of a micro pump manufacturing method according to another aspect of the present invention.

8 to 30, the micro pump 200, the first substrate 210, the insulating layer 211, the first cavity 212, the protrusion 214, the working fluid inlet 216, and the adhesive flow path ( 218, a first resist 291, a second resist 292, a third resist 293, a fourth resist 294, a fifth resist 295, a sixth resist 296, and a seventh Resist 297, heater 220, membrane 230, third cavity 232, second substrate 240, etch stop layer 241, second cavity 242, valve 244, transfer fluid inlet 246, conveying fluid outlet 248, adhesive 250, temperature sensor 260, electrode 270, and protective layer 280 are shown.

According to the present embodiment, when the first cavity 212 and the third cavity 232 are formed by deep reactive ion etching, the wet cavity is formed by wet etching according to the related art. Unlike the present invention, a method of manufacturing the micro pump 200 capable of freely implementing a space filled with a working fluid is provided.

In addition, by bonding the second substrate 240 and the membrane 230 by thermal bonding, a method of manufacturing the micropump 200 that can apply various types of valves 244 more precisely is proposed. .

In addition, by bonding the first substrate 210 and the membrane 230 at room temperature using the adhesive 250 and the adhesive flow path 218, the micro pump 200 may simplify the process and shorten the process time. A manufacturing method is presented.

First, as shown in FIGS. 9 to 12, the first cavity 210 having the protrusion 214 formed thereon so as to improve the heat transfer rate and the adhesive flow path 218 may be subjected to the deep reactive ion etching of the first substrate 210 ( It is formed on one surface of the silicon substrate (S110). The working fluid inlet 216 for injecting the working fluid in the present process may also be formed. As the deep reactive ion etching is used in the present process, it may be different from the case of wet etching as in the prior art. Alternatively, the first cavity 212, the adhesive passage 218, and the working fluid inlet 216 may be implemented in a free shape without restriction. Hereinafter, a process of forming the first cavity 212, the adhesive flow path 218, and the working fluid inlet 216 will be described in detail.

First, as shown in FIGS. 9 and 10, an insulating layer 211, such as a silicon oxide film, is formed by wet oxidation on both surfaces of the first substrate 210 made of silicon. Subsequently, as illustrated in FIG. 11, the first cavity 212, the adhesive flow path 218, and the operation of one surface of the first substrate 210 on which the insulating layer 211 is formed are formed by photo-lithography. The first resist 291 is formed on the region excluding the region where the liquid injection hole is to be formed, and the insulating layer 211 except for the region where the first resist 291 is formed is etched and removed. Next, as shown in FIG. 12, the first cavity is removed by deep reactive ion etching of one surface of the first substrate 210 except for the region where the first resist 291 is formed, thereby removing a portion of the first substrate 210. 212 and adhesive flow path 218 and a portion of the working liquid inlet can be formed.

Subsequently, as shown in FIGS. 13 and 14, in the photolithography method, the second resist (on the other surface of the first substrate 210 on which the insulating layer 211 is formed except the region where the working liquid injection hole is to be formed) is formed. 292 is formed, the insulating layer 211 except for the region where the second resist 292 is formed is removed by etching, and then the other surface of the first substrate 210 except for the region where the second resist 292 is formed is deeply reactive. The working liquid inlet can be formed by ion etching to remove a portion thereof.

In this case, the first substrate 210 may be a silicon substrate including silicon, and the silicon substrate may have a high thermal conductivity, thereby effectively dissipating heat of a working fluid, thereby improving response characteristics of the micropump 200. Can be.

When the first substrate 210 is made of silicon, the first substrate 210 is formed of silicon on the outermost layer for electrical insulation between the heater 220, the temperature sensor 260, and the electrode 270 and the silicon substrate. An insulating layer 211 such as an oxide layer may be formed, and the insulating layer 211 may be formed by wet oxidation of the surface of the first substrate 210 made of silicon.

In addition, a first cavity 212 on which a protrusion 214 is formed may be formed on one surface of the first substrate 210 to improve heat transfer rate. The first cavity 212 may be filled with a working fluid for expanding the membrane 230 to transport the conveying fluid, and in order to more efficiently transfer heat generated by the heater 220 to the working fluid. A cavity 214 may be formed in the cavity 212 to increase the surface area of the first cavity 212.

Meanwhile, an adhesive channel 218 may be formed on one surface of the first substrate 210 so that the adhesive 250 may be uniformly distributed. Accordingly, the adhesive substrate 250 may be used to form the first substrate (at room temperature). When bonding the 210 and the membrane 230, the adhesive 250 is distributed along the adhesive channel 218 and the excess adhesive 250 is discharged to the outside along the adhesive channel 218 to simplify the process. The time may be shortened, and the first substrate 210 and the membrane 230 may be bonded more precisely without errors.

In addition, the first substrate 210 may be formed with a working fluid inlet 216 for injecting a working fluid for expanding the membrane 230 into the first cavity 212, through the working fluid inlet 216. The working fluid may be injected into the first cavity 212 and sealed with an adhesive at room temperature, for example, using a piece of silicon or the like.

Next, as illustrated in FIGS. 15 to 17, the heater 220 heating the volume of the working fluid charged in the first cavity 212 and the temperature sensor sensing the temperature of the heater 220 ( 260 is formed on the other surface of the first substrate 210 (S120). Thereafter, a protective layer 280 may be formed to protect the heater 220 and the temperature sensor 260, and the process of forming the heater 220, the temperature sensor 260, and the protective layer 280 is as follows. You can explain by dividing them together.

First, as shown in FIG. 15, the third resist 293 is formed on the other surface of the first substrate 210 except for the region in which the heater 220 and the temperature sensor 260 are to be formed. Subsequently, as illustrated in FIG. 16, titanium and platinum are sequentially deposited on the other surface of the first substrate 210, and then, as illustrated in FIG. 17, the third resist is formed according to a lift-off method. By removing 293, the heater 220 corresponding to the position of the first cavity 212 and the temperature sensor 260 adjacent thereto may be formed.

18 and 19, a protective layer such as silicon nitride may be formed on the other surface of the first substrate 210 on which the heater 220 is formed, for example, by chemical vapor deposition. 280 may be formed to protect the heater 220 from the outside, and the fourth resist 294 may be formed and etched on the other surface of the second substrate 240 except for the region where the electrode 270 is to be formed by photolithography. By removing a portion of the protective layer 280 by the electrode 270 for supplying electricity from the outside can be formed.

Here, the heater 220 is formed by using titanium and platinum on the other surface of the first substrate 210 to correspond to the position of the first cavity 212, the volume of the working fluid filled in the first cavity 212 Can be heated to change. That is, the working fluid receives the heat generated from the heater 220 and changes in volume from liquid to gas and rapidly changes in volume. Accordingly, the membrane 230 enclosing the first cavity 212 is expanded to The transfer fluid introduced into the second cavity 242 may be moved in one direction.

In addition, the temperature sensor 260 may be formed to be adjacent to the heater 220 on the other surface of the first substrate 210 to detect the temperature of the heater 220. That is, the temperature sensor 260 detects the temperature of the heater 220 which generates heat by receiving electricity from the outside, and transmits a signal thereof to the controller so that the micro pump 200 can be more precisely controlled. It will serve as an assistant.

In this case, a protective layer 280 such as silicon nitride may be formed on the heater 220 and the temperature sensor 260 to protect the heater 220 and the temperature sensor 260 from external influences. Can be. However, the portion to be used as the electrode 270 in the heater 220 and the temperature sensor 260 may be used as a terminal for receiving electricity from the outside by preventing the protective layer 280 from being formed. .

Next, as shown in FIGS. 20 to 23, a valve 244 for moving the second cavity 242 corresponding to the first cavity 212 and the transfer fluid flowing in and out of the second cavity 242 in one direction. (Diffuser) is formed on one surface of the second substrate 240 (glass substrate) (S130). At this time, a transfer fluid inlet 246 and a transfer fluid outlet 248 for the inlet and outlet of the transfer fluid may also be formed, and the second cavity 242, the valve 244, the transfer fluid inlet 246, and the transfer fluid outlet The process of forming (248) can be explained by dividing as follows.

First, as shown in FIGS. 20 and 21, an etch stop layer 241 made of polysilicon is formed on both surfaces of the second substrate 240 made of glass in order to use fluorine (HF) as an etching solution. Subsequently, as shown in FIG. 22, the second substrate excluding a region in which the second cavity 242, the valve 244, the transfer fluid inlet 246, and the transfer fluid outlet 248 is to be formed (as shown in FIG. 22). The fifth resist 295 is formed on one surface of the 240, and the etch stop layer 241 except for the region where the fifth resist 295 is formed is etched and removed. Subsequently, as shown in FIG. 23, a portion of the second substrate 240 except for the region where the fifth resist 295 is formed is removed by a process such as, for example, wet etching using fluorine. The cavity 242, the valve 244, and the portion of the conveying fluid inlet 246 and the conveying fluid outlet 248 may be formed, and then the etch stop layer may be removed.

Next, as shown in FIG. 24, the sixth resist 296 is formed on the other surface of the second substrate 240 except for the region where the transfer fluid inlet 246 and the transfer fluid outlet 248 are to be formed by photolithography. After the formation, the portion of the second substrate 240 except for the region where the sixth resist 296 is formed is removed by a process such as sand blasting, so that the transfer fluid inlet 246 and the transfer fluid outlet ( 248).

Here, a second cavity 242 corresponding to the first cavity 212 is formed on one surface of the second substrate 240, and the second substrate 240 includes the membrane 230 to cover the second cavity 242. And may be bonded. Accordingly, the membrane 230 expands toward the second cavity 242 formed on the second substrate 240, so that the transfer fluid introduced into the second cavity 242 is pushed onto the membrane 230 so that the transfer fluid is in one direction. Can be moved.

That is, a second cavity 242 may be formed on one surface of the second substrate 240, and the transfer fluid inlet 246 and the second cavity into which the fluid flows into the second cavity 242. A transfer fluid outlet 248 through which fluid flows out at 242 is formed, so that the transfer fluid may enter and exit the second cavity 242 as the membrane 230 expands, and the transfer fluid inlet 246 and transfer A valve 244 is interposed between the fluid outlet 248 and the second cavity 242 to allow the transport fluid to be transported in one direction.

On the other hand, the second substrate 240 may be a glass substrate made of glass (glass), thereby, it is possible to easily check the movement state of the transport fluid contained in the second cavity 242.

In addition, the valve 244 may be formed on one surface of the second substrate 240 so that the transfer fluid flowing into and out of the second cavity 242 moves in one direction. That is, the valve 244 has a structure in which fluid can flow only in one direction, and is provided between the transfer fluid inlet 246 and the second cavity 242 and between the transfer fluid outlet 248 and the second cavity 242. Each of which may be formed to cause a transfer fluid pressurized by the expanding membrane 230 to flow from the transfer fluid inlet 246 to the transfer fluid outlet 248.

On the other hand, the valve 244 may be a diffuser (diffuser) in which the cross-sectional area increases from the inlet flows into the valve 244 to the outlet flows into the valve 244, and thus, the simple structure of the conveying fluid Since the transport can be made in one direction, it is possible to implement a micro pump 200 of a smaller size.

Next, as illustrated in FIGS. 26 and 27, the second substrate 240 and the membrane 230 are bonded to each other so that the second cavity 242 is covered by thermal bonding (S140). Accordingly, the second substrate 240 and the membrane 230 may be bonded more precisely without restriction on the shape of the valve 244 formed on the second substrate 240.

That is, as shown in FIG. 26, an elastic membrane 230 made of, for example, 400 micrometers of silicon may be bonded to the second substrate 240 by thermal bonding, and then shown in FIG. 27. As described above, the above-described elastic membrane 230 may be thinly processed to, for example, 80 micrometers by, for example, a chemical mechanical polishing (CMP) method.

Here, the membrane 230 may be bonded to cover the first cavity 212 on one surface of the first substrate 210, and may be expanded to correspond to a change in volume of the working fluid. That is, the membrane 230 may cover the first cavity 212 to seal the working fluid filled in the first cavity 212 into the first cavity 212, and thus, to operate the heater 220. Accordingly, the heat is transferred to the working fluid so that the working fluid expands in volume through a phase change, and the membrane 230 made of an elastic material expands correspondingly according to the volume change of the working fluid, and thus, the second cavity 242. It is possible to transport the transport fluid in one direction by pushing the transport fluid introduced into the.

At this time, as described above, the transport fluid pushed out by the action of the valve 244 formed on the second substrate 240 to be connected to the second cavity 242 may flow in one direction.

On the other hand, the membrane 230 may be made of an elastic material including silicon, thereby preventing the working fluid from flowing out of the first cavity 212 may implement a more efficient micro pump 200.

Next, as shown in FIGS. 28 and 29, the third cavity 232 to correspond to the first cavity 212 on the surface opposite the first cavity 212 of the membrane 230 by deep reactive ion etching. ) Is formed (S150). That is, the third cavity 232 forms the seventh resist 297 on one surface of the membrane 230 except for the region where the third cavity 232 is to be formed by photolithography, and the seventh resist 297 is formed. One surface of the membrane 230 except for may be formed by deep reactive ion etching to remove a portion thereof.

Here, the third cavity 232 may be formed to correspond to the first cavity 212 on a surface of the membrane 230 that faces the first cavity 212, thereby providing a space into which the working fluid is injected. While increasing in a simple manner, the thickness of the membrane 230 can be reduced to more sensitively respond to changes in volume of the working fluid.

Next, as shown in FIG. 30, in order to expand the membrane 230 corresponding to the change in the volume of the working fluid, the membrane 230 is connected to one surface of the first substrate 210 through the adhesive 250 at room temperature. Bonding to cover the first cavity 212 (S160).

That is, as described above, since the adhesive flow path 218 may be formed on one surface of the first substrate 210 to uniformly distribute the adhesive 250, the adhesive 250 may be more precise at room temperature. The micro pump 200 can be manufactured by a simple process.

Many embodiments other than the above-described embodiments are within the scope of the claims of the present invention.

1 is a cross-sectional view showing an embodiment of a micro pump according to an aspect of the present invention.

2 is a cross-sectional view of one embodiment of a heater, a temperature sensor, and a first substrate, which is part of a micropump according to one aspect of the present invention;

3 is a bottom view of one embodiment of a heater, a temperature sensor, and a first substrate, which is part of a micropump according to one aspect of the present invention;

4 is a plan view of an embodiment of a heater, a temperature sensor, and a first substrate, which is part of a micropump according to one aspect of the present invention;

5 is a cross-sectional view of one embodiment of a membrane, a valve and a second substrate, which is part of a micropump according to one aspect of the present invention.

6 is a bottom view showing one embodiment of a membrane, a valve and a second substrate, which is part of a micropump according to one aspect of the present invention.

7 is a plan view showing one embodiment of a membrane, a valve and a second substrate, which is part of a micropump according to one aspect of the present invention.

8 is a flow chart showing an embodiment of a method for manufacturing a micropump according to another aspect of the present invention.

9 to 30 are cross-sectional views showing each process of the micropump manufacturing method according to another aspect of the present invention.

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

100: micro pump 110: first substrate

111: insulating layer 112: first cavity

114: projection 116: working fluid inlet

118: adhesive flow path 120: heater

130: membrane 132: third cavity

140: second substrate 142: second cavity

144: valve 146: transfer fluid inlet

148: conveying fluid outlet 150: adhesive

160: temperature sensor 170: electrode

180: protective layer

Claims (21)

A first substrate having a first cavity formed on one surface thereof, and an inner wall of the first cavity having a plurality of protrusions having a plurality of protrusions for improving a heat transfer rate; A heater which is formed on the other surface of the first substrate and heats the working fluid filled in the first cavity to change volume; Bonded to cover the first cavity on one surface of the first substrate to expand in accordance with the volume change of the working fluid, the surface facing the first cavity corresponds to the shape and arrangement of the first cavity The membrane is formed with a third cavity (membrane); A second substrate formed on one surface of the first cavity corresponding to the shape and arrangement of the first cavity and bonded to the membrane to cover the second cavity; And And a valve formed on one surface of the second substrate so that the transfer fluid flowing into and out of the second cavity moves in one direction. The method of claim 1, The first substrate is a micro pump, characterized in that made of a material containing silicon (Si). The method of claim 1, And the second substrate is made of a material including glass. The method of claim 1, And the membrane is made of an elastic material including silicon. delete The method of claim 1, The micro pump further comprises an adhesive interposed between the first substrate and the membrane. The method of claim 6, On one surface of the first substrate, the micro-pump characterized in that the adhesive flow path is formed so that the adhesive is uniformly distributed. The method of claim 1, The valve is a micro pump, characterized in that the diffuser (diffuser) increases in cross-sectional area from the inlet to the outlet. The method of claim 1, And a temperature sensor formed on the other surface of the first substrate so as to be adjacent to the heater to sense a temperature of the heater. Forming a first cavity on one surface of the first substrate, the first cavity having a plurality of protrusions formed on the inner wall to improve a heat transfer rate; Forming a heater on the other side of the first substrate, the heater heating the volume of the working fluid charged in the first cavity to change in volume; Forming a second cavity corresponding to the shape and arrangement of the first cavity, and a valve on one surface of the second substrate to move the transfer fluid flowing into and out of the second cavity in one direction; Forming a third cavity on a side of the membrane opposite the first cavity, the third cavity corresponding to the shape and placement of the first cavity; Bonding the second substrate and the membrane such that the second cavity is covered; And Bonding the membrane to cover the first cavity on one side of the first substrate to expand the membrane corresponding to a change in volume of the working fluid. The method of claim 10, Forming the first cavity is performed by deep reactive ion etching. The method of claim 10, The first substrate is a micropump manufacturing method, characterized in that made of a material containing silicon (Si). The method of claim 10, The second substrate is a micropump manufacturing method, characterized in that made of a material containing glass (glass). The method of claim 10, The membrane is a micropump manufacturing method, characterized in that made of an elastic material containing silicon. delete The method of claim 10, The forming of the third cavity is a micro pump manufacturing method, characterized in that performed by deep reactive ion etching (deep reactive ion etching). The method of claim 10, Bonding the membrane to one surface of the first substrate, Method of producing a micropump, characterized in that carried out at room temperature via an adhesive between the first substrate and the membrane. The method of claim 17, Prior to bonding the membrane to one side of the first substrate, And forming an adhesive flow path on one surface of the first substrate such that the adhesive is uniformly distributed. The method of claim 10, Bonding the second substrate and the membrane is performed by thermal bonding. The method of claim 10, The valve is a micropump manufacturing method characterized in that the diffuser (diffuser) increases in cross-sectional area from the inlet to the outlet. The method of claim 10, Forming the heater, And forming a temperature sensor sensing the temperature of the heater so as to be adjacent to the heater on the other surface of the first substrate.

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