KR100914938B1 - Micro Heater, micro heater manufacturing method and environment sensor using thereof - Google Patents

Abstract

The micro heating apparatus according to the present invention includes an elastic thin film in which a lower silicon oxide thin film, a silicon nitride thin film and an upper silicon oxide thin film are sequentially deposited; A heating part formed on the elastic thin film and generating heat by an applied current; A heating part electrode formed on a pattern of the elastic thin film to apply a current input from the outside to the heating part; A diffusion plate formed on the elastic thin film to collect heat energy generated from the heating unit; And an insulating layer formed on the heating part, the heating part electrode, and an upper end of the diffusion plate, wherein the heating part is formed in a pattern surrounding the diffusion plate, and the diffusion plate is vertically connected to the heating part. Even though a current is applied from the heating unit, the current does not flow.

Description

Micro heater, micro heater manufacturing method and environment sensor using the same

The present invention relates to a micro heating device, a micro heating device manufacturing method and an environmental sensor using the same.

In particular, the present invention relates to a micro heating device with low power consumption and excellent thermal efficiency, and an environmental sensor using the same.

The present invention is derived from a study performed as part of the IT source technology development project of the Ministry of Information and Communication [Task management number: 2006-S-006-02, Task name: ubiquitous terminal components / modules]

As sensor technology develops, research on micro heating devices used in environmental sensors such as gas sensors has also been developed. In particular, the micro heating device is required to have good thermal efficiency at low power and good isothermal property that is uniformly heated throughout the heating device. The diffusion plate of the conventional micro heating device is formed in a wide plate structure, or is diffused in a different layer from the heating part. A method of forming a plate has been used.

However, the diffuser plate having a wide plate structure has a disadvantage of large heat loss and inferior flexibility, and when the diffuser plate and the heating unit exist in different layers, the process becomes complicated and the thermal efficiency is inferior.

Therefore, there is a need for a micro heating device capable of realizing low thermal power and an environmental sensor using the same for an efficient environmental sensor.

An object of the present invention is to provide a micro heating device, a micro heating device manufacturing method, and an environmental sensor using the same.

It is another object of the present invention to provide a micro heating device, a method of manufacturing a micro heating device, and an environmental sensor using the same, which are relatively simple in process and are excellent in thermal efficiency and isothermal characteristics.

In order to achieve the above objects, a micro heating apparatus according to the present invention, the lower silicon oxide thin film, the silicon nitride thin film and the upper silicon oxide thin film formed by depositing an elastic thin film; A heating part formed on the elastic thin film and generating heat by an applied current; A heating part electrode formed on a pattern of the elastic thin film to apply a current input from the outside to the heating part; A diffusion plate formed on the elastic thin film to collect heat energy generated from the heating unit; And an insulating layer formed on the heating part, the heating part electrode, and an upper end of the diffusion plate, wherein the heating part is formed in a pattern surrounding the diffusion plate, and the diffusion plate is vertically connected to the heating part. Even though a current is applied from the heating unit, the current does not flow.

In a preferred embodiment, the heating unit, the heating electrode, and the diffusion plate are each made of one of polysilicon, tungsten, aluminum, nickel and platinum, and the combination of the diffusion plate and the heating unit is a Wheatstone bridge. Form of circuit coupling characteristics. In addition, the diffusion plate includes a plurality of concentric circles, and the plurality of concentric circles are connected to each other with neighboring concentric circles. In addition, the diffusion plate is composed of a circular disk-shaped plate, the heating portion surrounds the diffusion plate in a gear-shaped pattern and is connected vertically to the diffusion plate. In addition, the pattern of the heating unit may be modified to increase the internal resistance of the heating unit itself.

Micro-heating apparatus manufacturing method according to the present invention comprises the steps of depositing a lower silicon oxide thin film, a silicon nitride thin film and an upper silicon oxide thin film on a silicon substrate in order to form an elastic thin film; A heating part electrode of a conductive material, a heating part for generating heat by a current applied from the heating part electrode, and a diffusion plate for collecting thermal energy generated in the heating part are formed on an upper end of the elastic thin film, wherein the heating part is Forming a diffusion plate surrounding the diffusion plate, wherein the diffusion plate is vertically connected to the heating unit; Forming an insulating layer on top of the heating part electrode, the heating part, and the diffusion plate; And etching the silicon substrate positioned at a lower end of the region in which the heating part electrode, the heating part, and the diffusion plate are not formed.

In an exemplary embodiment, in the etching of the silicon substrate, the silicon substrate, which is located at the bottom of the region in which the heating part electrode, the heating part and the diffusion plate are not formed, is etched using a substrate lower process, or the substrate upper process. Etching to the predetermined thicknesses of the elastic thin film and the silicon substrate positioned at the lower end of the insulating layer located on the upper end of the region in which the heating part electrode, the heating part and the diffusion plate are not formed.

An environmental sensor according to the present invention comprises: an elastic thin film in which a lower silicon oxide thin film, a silicon nitride thin film and an upper silicon oxide thin film are sequentially deposited; A heating part formed on the elastic thin film and generating heat by an applied current; A heating part electrode formed on a pattern of the elastic thin film to apply a current input from the outside to the heating part; A diffusion plate formed on the elastic thin film to collect heat energy generated from the heating unit; An insulating layer formed on an upper end of the heating part, the heating part electrode, and the diffusion plate; And an environmental sensor electrode and an environmental sensing material formed on an upper end of the insulating layer, wherein the heating part is formed in a pattern surrounding the diffusion plate, and the diffusion plate is connected to the heating part vertically to provide a current from the heating part. Even if is applied, it is characterized in that no current flows.

The present invention can provide a micro heating device, a micro heating device manufacturing method, and an environmental sensor using the same.

In addition, the present invention can provide a micro heating device, a micro heating device manufacturing method, and an environmental sensor using the same, the process is relatively simple, and excellent in thermal efficiency and isothermal characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows the cross section of the 1st Example of the micro heating apparatus applied to this invention.

2 is a view showing a plane of a first embodiment of a micro heating device to which the present invention is applied;

3 is a cross-sectional view of a second embodiment of a micro heating device applied to the present invention.

4 is a view showing a plane of a second embodiment of a micro heating device to which the present invention is applied;

5 is a diagram showing the results of simulation of prediction of a micro heating device applied to the present invention.

6 shows an embodiment of an environmental sensor according to the invention;

7 is a view showing an embodiment of a heating unit and a diffusion plate in the micro heating apparatus applied to the present invention.

<Explanation of symbols for main parts of the drawings>

400: micro heating device 100: silicon substrate

300: lower silicon oxide thin film 310: silicon nitride thin film

320: upper silicon oxide thin film 210: heating part electrode

200: heating part 250: diffusion plate

350: insulating layer 270: sensor electrode 600: sensing material

Hereinafter, a micro heating apparatus, a micro heating apparatus manufacturing method, and an environmental sensor using the same according to the present invention will be described in detail with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the cross section of 1st Example of the micro heating apparatus applied to this invention.

Referring to FIG. 1, the micro heating device 400 according to the present invention includes a silicon substrate 100, a lower silicon oxide thin film 300, a silicon nitride thin film 310, an upper silicon oxide thin film 320, and a heating part electrode 210. ), A heating unit 200, a diffusion plate 250, and an insulating layer 350.

The micro heating device is a heating device formed through a semiconductor process and serves to change an electrical signal transmitted from the heating unit electrode 210 into thermal energy in the heating unit 200. The diffusion plate 250 connected to the heating unit 200 collects heat generated by the heating unit 200 and serves to even the temperature distribution. Such micro heating devices can be made compact and are used in various sensors or other heating devices.

The silicon substrate 100 is a substrate for forming the micro heating apparatus of the present invention and is generally the same as the silicon substrate which is often used in a semiconductor process. However, since the micro heating apparatus according to the present invention is configured in a thin film form, after all of the micro heating apparatuses are formed on the upper surface of the silicon substrate, the silicon substrate of the portion where the micro heating apparatus is formed is etched and removed 150 from the rear side.

The lower silicon oxide thin film 300, the silicon nitride thin film 310, and the upper silicon oxide thin film 320 are formed of an elastic thin film of the micro heating apparatus of the present invention. The reason why the elastic thin film is composed of three layers instead of one layer is that when the heating is started in the micro heating apparatus, since the warpage occurs due to the heating, the elastic thin film of the micro heating apparatus may be broken or deformed. In order to minimize such denaturation and cracking, a thin film is formed by overlapping a silicon oxide thin film having a compressive stress and a silicon nitride thin film having an elongated stress.

The heating part electrode 210 is a part that plays a role of supplying power to the micro heater according to the present invention, and is a conductive wire which transmits electric power applied from the outside to the heating part 200.

Since the heating unit 200 is a circular conductive wire surrounding the diffusion plate 250 and has a smaller resistance value than that of the heating unit electrode 210, heat is generated by Joule's heat. Since the diffusion plate 250 is parallel to the Wheatstone bridge in circuit with the heating unit 200, there is no flow of current to the diffusion plate 250.

The diffusion plate 250 plays a role of collecting the heat energy transferred from the heating unit 200, and is composed of a plurality of concentric circles. In particular, the junction C coupled to the heating unit 200 is vertically bonded to the heating unit 200, and is configured in the same manner as the parallel state of the Wheatstone bridge from a circuit point of view. Therefore, the current flowing to the diffusion plate 250 is lost, the diffusion plate 250 serves to collect only heat without the flow of current.

In particular, the heating part 200, the diffusion plate 250, and the heating part electrode 210 may be made of polysilicon, tungsten, aluminum, nickel, platinum, and the like, which have good thermal conductivity and electrical conductivity and are suitable for use. If it is not metal, it does not matter much.

The insulating layer 350 serves as a protective film to surround all of the heating part 200, the diffusion plate 250, and the heating part electrode 210 to insulate from the outside.

2 is a view showing a plane of a first embodiment of a micro heating device to which the present invention is applied.

Referring to FIG. 2, it can be seen that the micro heating apparatus according to the present invention is formed by etching the silicon substrate described with reference to FIG. 1 in a circular shape at the rear of the micro heating apparatus 400 of the present invention.

It can be seen that the heating unit electrode 210 is a conductive wire connected from the outside of the micro heating device 400, and the heating unit 200 may be a conductive wire formed in a circular shape surrounding the diffusion plate 250 from the outside. The diffusion plate 250 may include a plurality of concentric circles, and may be vertically bonded to the heating unit 200 at the point where the diffusion plate 250 is joined to the heating unit 200.

By the configuration described above, the diffusion plate 250 serves to collect the heat energy transferred from the heating unit 200, but the current transmitted from the heating unit 200 is not transmitted to the diffusion plate 250 at all.

3 is a view showing a cross section of a second embodiment of a micro heating device applied to the present invention, and FIG. 4 is a view showing a plane of a second embodiment of the micro heating device applied to the present invention.

3 and 4, the micro heating apparatus 400 according to the second embodiment of the present invention may include a silicon substrate 100, a lower silicon oxide thin film 300, a silicon nitride thin film 310, and an upper silicon oxide thin film ( 320, the heating unit electrode 210, the heating unit 200, the diffusion plate 250, the insulating layer 350, and the lower blood vessel 500.

The micro heating device may play the same role as the micro heating device described with reference to FIG. 1.

The silicon substrate 100 is a substrate for forming the micro heating apparatus of the present invention and is generally the same as the silicon substrate which is often used in a semiconductor process. However, referring to FIG. 4, in the present embodiment, the bottom portion is not etched by etching the unnecessary portion except for the region in which the micro heating device 400 is formed by using a microfabrication technique from the front side without etching the silicon substrate 100 from the rear side. In more detail, in FIG. 4, the regions (two upper and lower semicircular regions) except for the micro heating apparatus 400 in FIG. 4 are the heating electrode 210, the heating 200, and the diffusion plate 250. ) Is an unformed unnecessary region, and the insulating layer 350, the upper silicon oxide thin film 320, the silicon nitride thin film 310, the lower silicon oxide thin film 300 and the silicon formed on this portion by using a microfabrication technique from the front side. When the substrate 100 is sequentially etched to form the lower bleeding blood 500, the micro heating device 400 having a shape around the heating part 200 and the diffusion plate 250 is formed.

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In the case of manufacturing the micro heating device 400 in this manner, there may be a manufacturing process benefit.

FIG. 5 is a diagram showing the results of simulation of prediction of a micro heating device applied to the present invention. FIG.

It is a figure which shows the temperature change distribution of the micro heating apparatus applied to this invention.

5a simulated using a finite element analysis method, the applied power was used 25mW, the diffusion plate was used platinum (Pt). In this case, the maximum temperature of the heating unit 200 was predicted as 713.01K as can be seen in the figure. This shows 440 degrees Celsius, so it can be seen that the micro heating device exhibits sufficient performance. In addition, as can be seen in this figure, it can be seen that the isothermal characteristic of the entire diffusion plate is also sufficiently satisfied.

5B is a diagram showing the current flow in the micro heating device applied to the present invention.

Since the diffusion plate of the present invention serves as a Wheatstone bridge in terms of circuits, the current flowing from the outside does not flow at all, and it is described in the preceding drawings, and the result of the simulation is shown in FIG. 5B.

As can be seen in the drawing of FIG. 5B, it can be seen that the current flowing through the heating unit electrode and the heating unit does not flow to the diffusion plate at all.

6 is a view showing an embodiment of an environmental sensor according to the present invention.

FIG. 6A is a cross-sectional view of a gas sensing device configured by adding a gas sensor electrode 270 and a gas sensing material 600 to an upper end of a micro heating device according to the first embodiment described in FIG. 1 of the present invention. 6B is a cross-sectional view of the gas sensing device configured by adding the gas sensor electrode 270 and the gas sensing material 600 to the top of the micro heating apparatus according to the second embodiment described with reference to FIG. 3.

7 is a view showing an embodiment of the heating unit and the diffusion plate in the micro heating apparatus applied to the present invention.

FIG. 7A is a view of the heating unit 200 and the diffusion plate 250 of the first and second embodiments described with reference to FIGS. 2 and 4 of the present invention. The heating unit 200 has a concentric circle structure, and the diffusion plate 250 is connected to the heating unit 200 by a Wheatstone bridge. The diffusion plate 250 has a shape in which a plurality of concentric circles are connected. Heat energy generated by the heating unit 200 is collected by the diffusion plate 250 and a uniform heat distribution is formed.

FIG. 7B is a view of another type of diffuser plate 250. The diffusion plate 250 is in the form of a circular disk rather than a plurality of concentric circles. In the case of using the diffusion plate 250 having such a structure, there is no need to etch another pattern on the diffusion plate, thereby simplifying the manufacturing process.

FIG. 7C is a view illustrating another type of heating unit 200. The heating unit 200 is a curved shape rather than a concentric structure. Such a curved shape can increase the electrical resistance of the concentric structure. The resistance characteristics vary depending on the shape of the heating part, and the bending pattern does not need to be the shape illustrated in this drawing, and may be configured by any number of deformations in the form of increasing the resistance component. In other words, the resistance component can be made large in the form of longer length or reduced cross-sectional area.

As such, when the gas sensing device is configured using the micro heating device according to the present invention, heat loss is less than that of the conventional micro heating device. It can be remarkably strong even in degeneration.

In addition to the gas detection device described in the above drawings, when the micro heating device of the present invention is applied to many parts of the environmental sensor to which the micro heating device is applied, a more efficient environmental sensor can be configured.

The present invention is not limited to the above embodiments, and many variations are possible by those skilled in the art within the spirit of the present invention.

Claims (12)

An elastic thin film in which the lower silicon oxide thin film 300, the silicon nitride thin film 310, and the upper silicon oxide thin film 320 are sequentially deposited; A heating part 200 formed on the elastic thin film and generating heat by an applied current; A heating part electrode 210 having a pattern formed on the elastic thin film to apply a current input from the outside to the heating part 200; A diffusion plate 250 having a pattern formed on the elastic thin film to collect thermal energy generated from the heating part 200; And Including the insulating layer 350 formed on the heating unit 200, the heating unit electrode 210, the upper end of the diffusion plate 250, The heating part 200 is formed in a pattern surrounding the diffusion plate 250, and the diffusion plate 250 is vertically connected to the heating part 200 so that a current may be applied from the heating part 200. Micro heating device, characterized in that does not flow. The method of claim 1, The heating unit (200), the heating unit electrode (210), the diffusion plate 250 is a micro heating device, characterized in that each made of any one material of polysilicon, tungsten, aluminum, nickel and platinum. delete delete The method of claim 1, The coupling of the diffusion plate 250 and the heating unit 200 has a circuit coupling characteristic of Wheatstone bridge type. The method of claim 1, The diffusion plate 250 includes a plurality of concentric circles, wherein the plurality of concentric circles are connected to each other with neighboring concentric circles. The method of claim 1, The diffusion plate 250 is a micro heating device, characterized in that consisting of a circular disk-shaped plate. The method of claim 1, The heating unit 200 surrounds the diffuser plate 250 in a cogwheel-shaped pattern and is connected to the diffuser plate 250 vertically. The method of claim 8, The pattern of the heating unit 200 is a micro heating device, characterized in that the deformation in the form of increasing the internal resistance of the heating unit 200 itself. Depositing a lower silicon oxide thin film 300, a silicon nitride thin film 310, and an upper silicon oxide thin film 320 on the silicon substrate 100 in order to form an elastic thin film; The heating unit electrode 210 of the conductive material, the heating unit 200 for generating heat by the current applied from the heating unit electrode 210, the heat energy generated in the heating unit 200 on the upper end of the elastic thin film A diffuser plate 250 is formed to collect, wherein the heating part 200 is formed in a pattern surrounding the diffusion plate 250, and the diffusion plate 250 is formed to be vertically connected to the heating part 200. Making; Forming an insulating layer (350) on top of the heating part electrode (210), the heating part (200) and the diffusion plate (250); And And etching the silicon substrate 100 positioned at the lower end of the region in which the heating part electrode 210, the heating part 200, and the diffusion plate 250 are not formed. Way. The method of claim 10, wherein in the etching of the silicon substrate 100, Etching the silicon substrate 100 positioned at the lower end of the region in which the heating part electrode 210, the heating part 200, and the diffusion plate 250 are not formed by using a lower substrate process, or using an upper substrate process Thus, the elastic thin film and the silicon substrate 100 positioned at the bottom thereof from the insulating layer 350 positioned at the top of the region in which the heating part electrode 210, the heating part 200, and the diffusion plate 250 are not formed. And etching the substrate to a predetermined thickness. An elastic thin film in which the lower silicon oxide thin film 300, the silicon nitride thin film 310, and the upper silicon oxide thin film 320 are sequentially deposited; A heating part 200 formed on the elastic thin film and generating heat by an applied current; A heating part electrode 210 having a pattern formed on the elastic thin film to apply a current input from the outside to the heating part 200; A diffusion plate 250 having a pattern formed on the elastic thin film to collect thermal energy generated from the heating part 200; An insulation layer 350 formed on an upper end of the heating part 200, the heating part electrode 210, and the diffusion plate 250; And Including an environmental sensor electrode 270 and an environmental sensing material 600 formed on the top of the insulating layer 350, The heating part 200 is formed in a pattern surrounding the diffusion plate 250, and the diffusion plate 250 is vertically connected to the heating part 200 so that a current may be applied from the heating part 200. Environmental sensor, characterized in that does not flow.