Miniature heater

Abstract

The utility model discloses a miniature heater, comprising a substrate provided with an etching groove; the supporting layer comprises a silicon dioxide layer arranged on the upper surface of the substrate and a supporting upper layer arranged on the upper surface of the silicon dioxide layer; the heating layer is provided with a heating disc deposited on the upper surface of the supporting upper layer and a connecting electrode led out, and the heating disc is provided with a patterned structure; the protective layer covers the heating disc of the heating layer; a passivation layer covering the heating layer and the protective layer; and the metal heat dissipation layer is arranged in the passivation layer. The defects that a traditional micro heater is fragile in film structure and poor in thermal response performance are overcome.

Description

Technical Field

[0001] The utility model relates to the technical field of MEMS, in particular to a micro heater. Background Art

[0002] MEMS Heater is a miniature heating element based on MEMS (Micro-Electro-Mechanical Systems) technology, which is widely used in advanced technology fields such as gas sensors, microfluidic systems, environmental monitoring, and broadband infrared emission. With their advantages such as small size, fast response, and low power consumption, they have become an indispensable component in modern technology. By integrating micro-resistance heating elements, MEMS Heater can achieve precise temperature control and efficient thermal management. In recent years, with the continuous advancement of MEMS technology, the design and performance of these heaters have been significantly improved. They not only perform well in traditional application fields, but also show their unique advantages in emerging broadband infrared emission applications.

[0003] There are two mature structural models in MEMS heater design: the void structure and the cantilever beam structure. The void structure uses a complete supporting film with an insulating air cavity designed below the film. This design provides effective thermal insulation through the air cavity, reducing heat conduction to the substrate, thereby improving heating efficiency. The cantilever beam structure connects the heating area to the silicon substrate through several cantilever beams and uses deep silicon etching (DSI) technology to remove material on the back of the silicon substrate to reduce heat loss through the substrate.

[0004] Currently, gap-type microheaters suffer from high heat loss and long thermal response times. Cantilever-type microheaters, on the other hand, suffer from fragile film structures and poor device stability. While improved cantilever-type microheaters typically utilize a thicker silicon dioxide layer deposited on top to protect the membrane structure, this also introduces problems such as prolonged heat dissipation time and increased thermal stress. While a thicker silicon dioxide layer provides physical protection, it affects the rate of heat dissipation, resulting in longer cooling response times and increased thermal stress in the structure, which negatively impacts the stability of the microheater. Utility Model Content

[0005] In view of the above defects in the prior art, the present invention provides a micro heater to solve the defects of the traditional micro heater, such as fragile film structure and poor thermal response performance.

[0006] The utility model is implemented by the following technical solutions:

[0007] A micro heater, comprising:

[0008] a substrate having an etched groove;

[0009] a support layer comprising a silicon dioxide layer disposed on the upper surface of the substrate and a support upper layer disposed on the upper surface of the silicon dioxide layer;

[0010] a heating layer comprising a heating plate deposited on the upper surface of the supporting layer and a connecting electrode led out, wherein the heating plate has a patterned structure;

[0011] A protective layer, which is used to cover the heating plate of the heating layer;

[0012] a passivation layer, which is used to cover the heating layer and the protective layer;

[0013] The metal heat dissipation layer is arranged inside the passivation layer.

[0014] Furthermore, the metal heat dissipation layer is located in the middle of the passivation layer and directly above the protective layer.

[0015] Furthermore, the heating plate is made of molybdenum.

[0016] Furthermore, the supporting upper layer and the protective layer are both made of aluminum nitride.

[0017] Furthermore, the metal heat dissipation layer is made of molybdenum.

[0018] Furthermore, the heating plate is circular in shape, and the circular heating plate is composed of a plurality of arc lines.

[0019] Furthermore, the heating disk is a double heating electrode, each of the heating electrodes includes a plurality of arc-shaped portions and a plurality of connecting portions configured to connect the arc-shaped portions, and the double heating electrodes are combined into a circular shape.

[0020] Furthermore, the connecting portion includes a transverse connecting portion and a longitudinal connecting portion that are connected vertically, and an end of the transverse connecting portion away from the longitudinal connecting portion and an end of the longitudinal connecting portion away from the transverse connecting portion are respectively connected to a connecting electrode, and one side of the transverse connecting portion and the longitudinal connecting portion are both connected with a first arc portion formed in a circular arc shape, a first connecting portion bent at one end of the first arc portion to extend inwardly toward the center of the circle, and a second arc portion formed in a circular arc shape to extend from the end of the first connecting portion and spaced inwardly from the first arc portion, and the other side of the transverse connecting portion and the longitudinal connecting portion are both connected with a third arc portion formed in a circular arc shape, a second connecting portion bent at one end of the third arc portion to extend inwardly toward the center of the circle, and a fourth arc portion formed in a circular arc shape to extend from the end of the second connecting portion and spaced inwardly from the third arc portion, and the arc lengths of the first arc portion, the second arc portion, the third arc portion and the fourth arc portion gradually decrease from the outside to the inside.

[0021] Furthermore, a spacing distance between the first arc-shaped portion and the second arc-shaped portion is the same as a spacing distance between the third arc-shaped portion and the fourth arc-shaped portion.

[0022] Furthermore, a Pad layer is included, the passivation layer is provided with a window exposing the connection electrode of the heating layer, and the Pad layer is used to cover the connection electrode of the heating layer through the window.

[0023] Compared with the prior art, the beneficial effects of the present invention include at least:

[0024] The micro heater of the present invention adds multiple heat dissipation structures to the thick film structure of the traditional micro heater, which are a supporting upper layer, a protective layer and a metal heat dissipation layer. The added supporting upper layer, protective layer and metal heat dissipation layer not only further thicken the thin film structure and enhance the stability of the micro heater, but also speed up the heat dissipation time, improve the heat dissipation effect, and shorten the thermal response time, thereby increasing the thermal response rate. In addition, the supporting upper layer and the protective layer not only play a role in heat dissipation, but also play a role in thermal stress protection, effectively reducing the stress problem caused by thermal expansion of the heating layer, further improving the stability of the structure, and effectively solving the defects of the traditional micro heater, such as fragile thin film structure and poor thermal response performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is an exploded view of a micro heater according to an embodiment of the present invention;

[0026] Figure 2 Schematic diagram of the heating pattern of the heating plate of an embodiment of the present utility model;

[0027] In the figure: 1. substrate; 11. etching groove; 2. supporting layer; 3. heating layer; 31. heating plate; 3100. horizontal connecting part; 3101. longitudinal connecting part; 3102. first arc portion; 3103. first connecting part; 3104. second arc portion; 3105. third arc portion; 3106. second connecting part; 3107. fourth arc portion; 32. connecting electrode; 4. protective layer; 5. passivation layer; 51. window; 6. metal heat dissipation layer; 7. Pad layer. DETAILED DESCRIPTION

[0028] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make this disclosure more comprehensive and complete and to fully convey the concepts of the example embodiments to those skilled in the art. Identical reference numerals in the figures denote identical or similar structures, and thus repeated descriptions thereof will be omitted.

[0029] The words expressing positions and directions described in this utility model are all explained with reference to the accompanying drawings as examples, but they can be changed as needed, and all such changes are included in the protection scope of this utility model.

[0030] like Figure 1 and Figure 2 As shown, a micro heater provided by the utility model includes:

[0031] A substrate 1 having an etched groove 11;

[0032] A support layer 2, comprising a silicon dioxide layer disposed on the upper surface of the substrate 1 and a support upper layer disposed on the upper surface of the silicon dioxide layer;

[0033] The heating layer 3 has a heating plate 31 deposited on the upper surface of the supporting upper layer and a connecting electrode 32 drawn out, wherein the heating plate 31 has a patterned structure;

[0034] The protective layer 4 is used to cover the heating plate 31 of the heating layer 3

[0035] a passivation layer 5, which is used to cover the heating layer 3 and the protective layer 4;

[0036] The metal heat dissipation layer 6 is arranged inside the passivation layer 5 .

[0037] In this embodiment, by providing an etching groove 11 on the substrate 1, the heat generated by the heating layer 3 can be locally concentrated, which can significantly reduce heat loss, improve energy efficiency, and show better thermal performance in applications requiring precise temperature control. The support layer 2 is a support structure that integrates a silicon dioxide layer (not shown) and a supporting upper layer (not shown). The silicon dioxide layer can play an isolating and protective role. Since the supporting upper layer has good thermal conductivity, the supporting upper layer allows heat to be conducted more efficiently to increase the thermal response rate, while also improving the effect of thermal stress management. In this way, the support layer 2 can improve the stability of the micro heater and avoid the influence of thermal stress on device performance and service life. Therefore, the support layer 2 can serve as the heat dissipation structure and thermal stress protection structure of the bottom layer. The protective layer 4 covers the heating plate 31 of the heating layer 3, which can play a role in heat dissipation and serve as a heat dissipation structure of the middle layer. At the same time, the protective layer 4 and the supporting upper layer together play a role in thermal stress protection; the metal heat dissipation layer 6 is arranged inside the passivation layer 5. Since the passivation layer 5 is thick, the heat dissipation performance is poor. Therefore, the metal heat dissipation layer 6 is added in the middle of the passivation layer 5 as the top heat dissipation structure. Since the metal heat dissipation layer 6 is wrapped by the passivation layer 5, the chemical stability and electrical insulation of the material can be maintained, and the metal heat dissipation layer 6 can be prevented from being oxidized or other environmental influences. Therefore, the metal heat dissipation layer 6 can serve as an additional heat dissipation structure to make up for the problem of longer thermal response time caused by the thicker passivation layer 5.

[0038] Therefore, the micro heater of the present invention adds multiple heat dissipation structures to the thick film structure of the traditional micro heater, namely the support layer 2, the protective layer 4 and the metal heat dissipation layer 6. The added support layer 2, the protective layer 4 and the metal heat dissipation layer 6 not only further thicken the thin film structure and enhance the stability of the micro heater, but also speed up the heat dissipation time, improve the heat dissipation effect, and shorten the thermal response time, thereby increasing the thermal response rate. The support layer 2 and the protective layer 4 serve not only as heat dissipation structures, but also as thermal stress protection structures, which can effectively reduce the stress problem caused by thermal expansion of the heating layer 3, further improve the stability of the structure, and effectively solve the defects of the traditional micro heater, such as fragile thin film structure and poor thermal response performance.

[0039] It should be noted that the method for generating the support layer 2 is: first, a silicon dioxide layer is generated on the upper surface of the substrate 1 by a thermal oxidation method, and then a plasma-enhanced chemical vapor deposition method is used to continue to deposit a support upper layer on the upper surface of the silicon dioxide layer. The silicon dioxide layer and the support upper layer together constitute the support layer 2.

[0040] As a preferred embodiment, the metal heat dissipation layer 6 is located in the middle of the passivation layer 5 and directly above the protective layer 4 .

[0041] In this embodiment, the passivation layer 5 is relatively thick, resulting in poor heat dissipation performance. Therefore, the metal heat dissipation layer 6 is positioned in the middle of the passivation layer 5 to help evenly distribute heat from top to bottom and reduce local overheating. Furthermore, the metal heat dissipation layer 6 located in the middle of the passivation layer 5 can also reduce the heat dissipation effect of the passivation layer 5 and provide better protection for the structure.

[0042] As a preferred embodiment, the upper support layer and the protective layer 4 are both made of aluminum nitride. In this embodiment, since the upper support layer and the protective layer 4 both serve as thermal stress protection, both are made of aluminum nitride. Due to the good thermal conductivity of aluminum nitride, heat can be conducted more efficiently, while also improving the thermal stress management effect. At the same time, aluminum nitride has good heat dissipation performance, further accelerating heat dissipation efficiency.

[0043] As a preferred embodiment, the heating plate 31 is made of molybdenum.

[0044] In this embodiment, since the supporting upper layer is made of aluminum nitride and the heating disk 31 is made of molybdenum, the combination of the supporting upper layer of aluminum nitride and the heating disk 31 made of molybdenum performs better than traditional silicon nitride materials. Although molybdenum is an uncommon resistor material, its thermal expansion coefficient does not match that of commonly used MEMS materials such as silicon, which may cause stress during the thermal cycle, resulting in material layer peeling or structural failure. At the same time, molybdenum is easily oxidized at high temperatures and is not suitable as a high-temperature heating material. However, the advantages of molybdenum are also quite obvious. Molybdenum has a high melting point and has sufficiently high thermal stability. Its resistivity and temperature resistance coefficient are higher than those of traditional resistor materials, and it consumes less power. At the same time, the manufacturing cost of molybdenum is low, which effectively controls the overall cost of the device. This embodiment fully utilizes the advantages of molybdenum while effectively compensating for its shortcomings.

[0045] Furthermore, the heating plate 31 is made of molybdenum, which not only offers low cost and excellent thermal conductivity, but also maintains greater stability and consumes less power at high temperatures. Compared to conventional microheater heating materials, this reduces power consumption and manufacturing costs without sacrificing thermal stability. Furthermore, the similar thermal expansion coefficients of aluminum nitride and molybdenum at high temperatures make the entire microheater more robust and durable, making it particularly suitable for high-performance applications requiring efficient thermal management.

[0046] As a preferred embodiment, the metal heat dissipation layer 6 is made of molybdenum. Since the metal heat dissipation layer 6 mainly dissipates heat from the passivation layer 5 to improve the thermal response time, the metal heat dissipation layer 6 can also be replaced by any metal or material with good heat dissipation performance, such as platinum, tungsten, etc.

[0047] As a preferred embodiment, the heating plate 31 is circular in shape, and the circular heating plate 31 is composed of a plurality of arc lines.

[0048] Compared with the traditional micro heater whose heating plate 31 is mostly spiral in shape, the heating plate 31 of the present invention is circular in shape, and the circular shape is composed of multiple arc lines. The arc lines increase the heating area, so that the micro heater can obtain a larger area and high-quality heating area when working.

[0049] As a preferred embodiment, the heating disk 31 is a double heating electrode, each of the heating electrodes includes a plurality of arc-shaped portions and a plurality of connecting portions configured to connect the arc-shaped portions, and the double heating electrodes are combined into a circular shape.

[0050] In this embodiment, a molybdenum material can be deposited using a PECVD method to form a heating disk 31, wherein the heating disk 31 can be patterned using wet etching or dry etching, and ultimately the heating disk 31 plays a role in heating. Compared to traditional heating electrodes that mostly use a single resistor and are mostly spiral in shape, the heating disk 31 of the present invention uses a dual heating electrode structure, and the dual heating electrodes are circular in shape, and the circular shape is composed of multiple arc portions and multiple connecting portions. The arc portions and connecting portions increase the heating area, so that the micro-heater can obtain a large area and high-quality uniform temperature area during operation, with higher reliability, and can reduce local overheating caused by current concentration, thereby extending the life of the device. Therefore, the use of the above-mentioned heating disk 31 can improve thermal efficiency and response speed, significantly enhance the performance of the micro-heater, and ensure that the heater can achieve excellent performance under various working conditions, thereby meeting higher application requirements.

[0051] As a preferred embodiment, the connecting portion includes a transverse connecting portion 3100 and a longitudinal connecting portion 3101 that are vertically connected, and one end of the transverse connecting portion 3100 away from the longitudinal connecting portion 3101 and one end of the longitudinal connecting portion 3101 away from the transverse connecting portion 3100 are respectively connected to a connecting electrode 32, and one side of the transverse connecting portion 3100 and the longitudinal connecting portion 3101 are connected to a first arc portion 3102 formed in an arc shape, a first connecting portion 3103 bent at one end of the first arc portion 3102 and extending toward the inner side of the center of the circle, and a first arc portion 3104 formed in an arc shape to extend from the end of the first connecting portion 3103 and from the inner side of the center of the circle. The first arc portion 3102 is spaced inward from the second arc portion 3104, and the other sides of the transverse connecting portion 3100 and the longitudinal connecting portion 3101 are connected to a third arc portion 3105 formed in a circular arc shape, a second connecting portion 3106 bent at one end of the third arc portion 3105 to extend inwardly toward the center of the circle, and a fourth arc portion 3107 formed in a circular arc shape to extend from the end of the second connecting portion 3106 and spaced inward from the third arc portion 3105. The arc lengths of the first arc portion 3102, the second arc portion 3104, the third arc portion 3105 and the fourth arc portion 3107 gradually decrease from the outside to the inside.

[0052] In this embodiment, a first arc portion 3102, a second arc portion 3104, a third arc portion 3105 and a fourth arc portion 3107 are provided, and the above arc portions are connected through a transverse connecting portion 3100, a longitudinal connecting portion 3101, a first connecting portion 3103 and a second connecting portion 3106, and the arc lengths of the above arc portions gradually decrease from the outside to the inside, the first arc portion 3102 and the second arc portion 3104 are spaced apart, and the third arc portion 3105 and the fourth arc portion 3107 are spaced apart. After the double heating electrodes are combined, a circular pattern with multiple circles spaced apart that expands from the inside to the outside is formed, which can provide a more uniform current distribution, achieve a more uniform heating effect, and ensure the uniformity of the heating temperature.

[0053] As a preferred embodiment, the distance between the first arc portion 3102 and the second arc portion 3104 is the same as the distance between the third arc portion 3105 and the fourth arc portion 3107. In this way, the uniformity of the heating temperature is further improved.

[0054] As a preferred embodiment, a Pad layer 7 is further included. The passivation layer 5 is provided with a window 51 exposing the connection electrode 32 of the heating layer 3 . The Pad layer 7 is used to cover the connection electrode 32 of the heating layer 3 through the window 51 .

[0055] In this embodiment, a window 51 is etched in the passivation layer 5 to expose the connecting electrode 32 of the heating layer 3, which is convenient for connecting the metal lead during testing. The exposed connecting electrode 32 is covered with the Pad layer 7 to prevent oxidation of the heating layer 3. At the same time, the Pad layer 7 can seal the heating layer 3, isolate oxygen, and prevent oxidation of the molybdenum material at high temperatures, thereby effectively compensating for the shortcomings of the molybdenum material.

[0056] As a preferred embodiment, the Pad layer 7 is made of gold. Of course, in other embodiments, the Pad layer 7 can also be made of other conductive materials that isolate oxygen.

[0057] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are illustrative and cannot be understood as limiting the present invention. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the utility model without departing from the principles and purpose of the utility model. All of these changes should fall within the scope of protection of the claims of the present invention.

Claims

1. A micro heater, characterized in that: include: A substrate (1) having an etched groove (11); A support layer (2), comprising a silicon dioxide layer disposed on the upper surface of the substrate (1) and a support upper layer disposed on the upper surface of the silicon dioxide layer; A heating layer (3) comprising a heating plate (31) deposited on the upper surface of the supporting upper layer and a connecting electrode (32) drawn out, wherein the heating plate (31) has a patterned structure; A protective layer (4) for covering the heating plate (31) of the heating layer (3) a passivation layer (5), which is used to cover the heating layer (3) and the protective layer (4); A metal heat dissipation layer (6) is arranged inside the passivation layer (5).

2. The micro heater according to claim 1, wherein: The metal heat dissipation layer (6) is located in the middle of the passivation layer (5) and directly above the protective layer (4).

3. The micro heater according to claim 1, wherein: The supporting upper layer and the protective layer (4) are both made of aluminum nitride.

4. The micro heater according to claim 1, wherein: The heating plate (31) is made of molybdenum.

5. The micro heater according to claim 1, wherein: The metal heat dissipation layer (6) is made of molybdenum.

6. The micro heater according to claim 1, wherein: The heating plate (31) is circular in shape, and the circular heating plate (31) is composed of a plurality of arc lines.

7. The micro heater according to claim 1, wherein: The heating disc (31) is a double heating electrode, each of the heating electrodes comprises a plurality of arc-shaped portions and a plurality of connecting portions configured to connect the arc-shaped portions, and the double heating electrodes are combined into a circular shape.

8. The micro heater according to claim 7, wherein: The connecting portion includes a transverse connecting portion (3100) and a longitudinal connecting portion (3101) connected in a vertical manner, wherein one end of the transverse connecting portion (3100) away from the longitudinal connecting portion (3101) and one end of the longitudinal connecting portion (3101) away from the transverse connecting portion (3100) are respectively connected to a connecting electrode (32), and one side of each of the transverse connecting portion (3100) and the longitudinal connecting portion (3101) is connected to a first arc-shaped portion (3102) formed in an arc shape, a first connecting portion (3103) bent at one end of the first arc-shaped portion (3102) and extending toward the inner side of the center of the circle, and a first connecting portion (3103) formed in an arc shape to extend from the end of the first connecting portion (3103) and from the first arc-shaped portion. (3102) is spaced inwardly from a second arc portion (3104), the other sides of the transverse connecting portion (3100) and the longitudinal connecting portion (3101) are connected with a third arc portion (3105) formed in an arc shape, a second connecting portion (3106) bent at one end of the third arc portion (3105) to extend inwardly toward the center of the circle, and a fourth arc portion (3107) formed in an arc shape to extend from the end of the second connecting portion (3106) and spaced inwardly from the third arc portion (3105), and the arc lengths of the first arc portion (3102), the second arc portion (3104), the third arc portion (3105) and the fourth arc portion (3107) gradually decrease from the outside to the inside.

9. The micro heater according to claim 8, characterized in that The spacing distance between the first arc-shaped portion (3102) and the second arc-shaped portion (3104) is the same as the spacing distance between the third arc-shaped portion (3105) and the fourth arc-shaped portion (3107).

10. The micro heater according to claim 1, wherein: It also includes a Pad layer (7), the passivation layer (5) is provided with a window (51) exposing the connection electrode (32) of the heating layer (3), and the Pad layer (7) is used to cover the connection electrode (32) of the heating layer (3) from the window (51).

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