Infrared pyroelectric sensor

Abstract

The utility model discloses an infrared pyroelectric sensor comprising a substrate, a first surface of the substrate is provided with a first electrode layer, an infrared radiation collection layer and a second electrode layer in sequence, and a second surface of the substrate is provided with a groove; wherein the first surface and the second surface are opposite surfaces; the infrared radiation collection layer is used for receiving infrared radiation heat, converting the received infrared radiation heat into an electric signal, and transmitting the electric signal to a signal receiving device through the first electrode layer and the second electrode layer. The infrared radiation collection layer of the infrared pyroelectric sensor designed by the utility model keeps higher sensitivity, and further improves the detection accuracy of the infrared pyroelectric sensor.

Description

TECHNICAL FIELD

[0001] The utility model relates to infrared temperature measurement technical field especially relates to a kind of infrared pyroelectric sensor. BACKGROUND

[0002] Infrared pyroelectric sensor is a kind of device that can sense infrared radiation and convert it into electrical signal. It uses the pyroelectric effect of materials, that is, when the material is subjected to infrared radiation, the temperature changes in it, causing the charge distribution of the material to change, thereby generating a voltage signal. This principle makes infrared pyroelectric sensor widely used in human sensing, security monitoring, automatic lighting and other fields.

[0003] However, the infrared pyroelectric sensor in the prior art has low sensitivity to infrared radiation, resulting in poor detection accuracy of the infrared pyroelectric sensor. SUMMARY

[0004] The utility model provides a kind of infrared pyroelectric sensor, to make the infrared radiation collection layer of infrared pyroelectric sensor keep higher sensitivity, and then improve the accuracy of infrared pyroelectric sensor detection.

[0005] According to one aspect of the utility model, an infrared pyroelectric sensor is provided, which comprises:

[0006] a substrate, a first surface of the substrate is provided with a first electrode layer, an infrared radiation collection layer and a second electrode layer in sequence, and a second surface of the substrate is provided with a groove; wherein the first surface and the second surface are opposite surfaces;

[0007] The infrared radiation collection layer is used to receive infrared radiation heat and convert the received infrared radiation heat into an electrical signal, which is transmitted to a signal receiving device through the first electrode layer and the second electrode layer.

[0008] Further, the infrared radiation collection layer includes a thermoelectric film layer.

[0009] Further, the substrate includes an SOI substrate.

[0010] Further, the substrate includes a first silicon layer, a silicon dioxide layer and a second silicon layer.

[0011] The first surface of the first silicon layer is in contact with the first electrode layer, and the silicon dioxide layer is arranged between the first silicon layer and the second silicon layer.

[0012] The groove penetrates through the second silicon layer and the silicon dioxide layer.

[0013] Further, a through hole is provided on the infrared radiation collection layer.

[0014] The through hole exposes part of the first electrode layer, and the through hole does not overlap with the second electrode layer.

[0015] Further, the infrared pyroelectric sensor further comprises:

[0016] A lead portion;

[0017] The lead portion is arranged in the through hole and is in contact with the first electrode layer.

[0018] Further, the thickness of the lead portion is less than the thickness of the infrared radiation collecting layer.

[0019] Further, the vertical projection of the through hole on the substrate does not overlap with the groove.

[0020] Further, the through hole is a circular through hole.

[0021] Further, the material of the pyroelectric thin film layer comprises lead zirconate titanate.

[0022] The infrared pyroelectric sensor designed in the embodiment of the utility model, including substrate, first electrode layer, infrared radiation collecting layer and second electrode layer are sequentially arranged on the first surface of the substrate, and a groove is arranged on the second surface of the substrate, so that the infrared radiation collecting layer can convert the received infrared radiation heat into an electric signal, and the electric signal is transmitted to the signal receiving device through the first electrode layer and the second electrode layer, compared with the infrared pyroelectric sensor designed in the prior art, the infrared pyroelectric sensor designed in the embodiment of the utility model is smaller in size, lower in manufacturing cost and better in product uniformity; a groove is arranged on the second surface of the substrate, which can reduce the thickness of the substrate, because the solid heat conduction speed is fast, the infrared radiation heat received by the infrared radiation collecting layer can be avoided to dissipate too much from the substrate, thereby maintaining the high sensitivity of the infrared radiation collecting layer and improving the accuracy of the infrared pyroelectric sensor detection.

[0023] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the utility model, nor is it used to limit the scope of the utility model. Other features of the utility model will become easy to understand through the following description. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical scheme in the embodiment of the utility model, the drawings needed in the embodiment description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to these drawings without creative labor.

[0025] Figure 1 It is a structure schematic view of an infrared pyroelectric sensor provided by the embodiment of the utility model;

[0026] Figure 2 is a structural schematic diagram of another infrared pyroelectric sensor according to an embodiment of the present application;

[0027] Figure 3 is a structural schematic diagram of another infrared pyroelectric sensor according to an embodiment of the present application;

[0028] Figure 4 is a process flow diagram of an infrared pyroelectric sensor according to an embodiment of the present application;

[0029] Figure 5 is a process flow diagram of an infrared pyroelectric sensor according to an embodiment of the present application;

[0030] Figure 6 is a process flow diagram of an infrared pyroelectric sensor according to an embodiment of the present application;

[0031] Figure 7 is a process flow diagram of an infrared pyroelectric sensor according to an embodiment of the present application;

[0032] Figure 8 is a process flow diagram of an infrared pyroelectric sensor according to an embodiment of the present application;

[0033] Figure 9 is a process flow diagram of an infrared pyroelectric sensor according to an embodiment of the present application;

[0034] Figure 10 is a process flow diagram of an infrared pyroelectric sensor according to an embodiment of the present application;

[0035] Figure 11 is a process flow diagram of an infrared pyroelectric sensor according to an embodiment of the present application;

[0036] Figure 12 is a process flow diagram of an infrared pyroelectric sensor according to an embodiment of the present application;

[0037] Figure 13 is a process flow diagram of an infrared pyroelectric sensor according to an embodiment of the present application;

[0038] Figure 14 is a process flow diagram of an infrared pyroelectric sensor according to an embodiment of the present application;

[0039] Figure 15 is a process flow diagram of an infrared pyroelectric sensor according to an embodiment of the present application;

[0040] Figure 16The utility model discloses a kind of process flow diagram of infrared pyroelectric sensor according to the utility model embodiment. DETAILED DESCRIPTION

[0041] In order to make the person in the art better understand the utility model scheme, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only a part of the embodiments of the utility model, not all. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor shall belong to the scope of protection of the utility model.

[0042] It should be noted that the terms "first", "second" and the like in the specification and claims of the utility model and the above drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the utility model described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0043] The utility model embodiment provides a kind of infrared pyroelectric sensor, Figure 1 It is according to the structure schematic diagram of a kind of infrared pyroelectric sensor according to the utility model embodiment, reference Figure 1 , infrared pyroelectric sensor includes:

[0044] Substrate 1, the first surface of substrate 1 is sequentially provided with first electrode layer 2, infrared radiation collection layer 3 and second electrode layer 4, and the second surface of substrate 1 is provided with a groove a;Wherein, first surface and second surface are opposite surfaces;

[0045] Infrared radiation collection layer 3 is used to receive infrared radiation heat, and converts the received infrared radiation heat into electrical signal, is transmitted to signal receiving device 5 by first electrode layer 2 and second electrode layer 4.

[0046] The substrate 1 can be an SOI substrate, and the infrared radiation collecting layer is a thermoelectric film layer. The infrared pyroelectric sensor designed in the embodiment of the utility model is manufactured by using the MEMS process. The Micro-Electro-Mechanical System (MEMS) is a technology integrating micro-sized mechanical elements, sensors, actuators and electronic elements. The MEMS process is to precisely control materials and structures on a micro scale by using the MEMS technology, so that a complex mechanical / electronic system can be manufactured on a micro chip. The MEMS process usually includes the following steps: 1. Selection of base material: selecting a base material suitable for MEMS manufacturing, such as silicon (Si), glass, metal, etc. 2. Thin film deposition process: using chemical vapor deposition (CVD) or physical vapor deposition (PVD) technology, depositing a thin film on the substrate to build the structure of the MEMS element. 3. Photolithography process: using photolithography technology, defining the structure and shape of the MEMS device by mask and ultraviolet light irradiation. 4. Etching and etching process: using chemical etching or ion etching method, removing the excess material to form the required microstructure. 5. Packaging process: packaging the MEMS device to protect it from the external environment and provide a channel for connecting electronic elements. 6. Test and calibration: strictly test the manufactured MEMS device to ensure that its performance and function meet the design requirements.

[0047] Specifically, the infrared radiation collecting layer 3 in the infrared pyroelectric sensor converts the infrared radiation heat into an electrical signal corresponding to the infrared radiation heat after receiving the infrared radiation heat from the outside world, and transmits the generated electrical signal to the signal receiving device 5 through the first electrode layer 2 and the second electrode layer 4, so that the signal receiving device 5 can realize different control according to the infrared radiation heat from the outside world. For example, the infrared pyroelectric sensor designed in the embodiment of the utility model is applied to an automatic lighting system. The infrared pyroelectric sensor designed in the embodiment of the utility model can detect the activity track of the human body, and realize the on-off control of the lighting tool according to the activity track of the human body, thereby realizing the effective use of energy and avoiding the waste of energy. A groove a is arranged on the second surface of the substrate 1, which can reduce the thickness of the substrate 1 and avoid the excessive dissipation of the infrared radiation heat received by the infrared radiation collecting layer 3 from the substrate 1, thereby improving the detection accuracy of the infrared pyroelectric sensor.

[0048] The infrared pyroelectric sensor designed in the embodiment of the utility model, including substrate 1, first electrode layer 2, infrared radiation collection layer 3 and second electrode layer 4 are sequentially arranged on the first surface of substrate 1, and a groove a is arranged on the second surface of substrate 1, so that infrared radiation collection layer 3 can convert the received infrared radiation heat into an electric signal, and the electric signal is transmitted to signal receiving device 5 through first electrode layer 2 and second electrode layer 4, compared with the infrared pyroelectric sensor designed in the prior art, the infrared pyroelectric sensor designed in the embodiment of the utility model is smaller in size, lower in manufacturing cost and better in uniformity of product; and the groove a arranged on the second surface of substrate 1 can reduce the thickness of substrate 1, because the solid heat conduction speed is fast, the infrared radiation heat received by infrared radiation collection layer 3 can be prevented from dissipating too much from substrate 1, thereby maintaining the high sensitivity of infrared radiation collection layer 3 and improving the accuracy of infrared pyroelectric sensor detection.

[0049] Further, the infrared radiation collection layer includes a thermoelectric film layer.

[0050] Illustratively, the material of the thermoelectric film layer can be lead zirconate titanate, i.e., the thermoelectric film layer is a PZT film layer.

[0051] Further, the substrate includes an SOI substrate.

[0052] Further, Figure 2 is a structural schematic view of another infrared pyroelectric sensor according to the embodiment of the utility model, referring to Figure 2 , the substrate includes a first silicon layer 11, a silicon dioxide layer 12 and a second silicon layer 13;

[0053] The first surface of the first silicon layer 11 is in contact with the first electrode layer 2, and the silicon dioxide layer 12 is arranged between the first silicon layer 11 and the second silicon layer 13.

[0054] The groove a penetrates the second silicon layer 13 and the silicon dioxide layer 12.

[0055] Specifically, the groove a in the substrate penetrates the second silicon layer 13 and the silicon dioxide layer 12, which can prevent the infrared radiation heat received by the infrared radiation collection layer 3 from dissipating too much due to the fast solid heat conduction speed, thereby maintaining the high sensitivity of the infrared radiation collection layer 3 and improving the accuracy of infrared pyroelectric sensor detection.

[0056] Further, Figure 3 is a structural schematic view of another infrared pyroelectric sensor according to the embodiment of the utility model, referring to Figure 3 , the infrared radiation collection layer 3 is provided with a through hole 31;

[0057] The through hole 31 exposes part of the first electrode layer 2, and the through hole 31 does not overlap the second electrode layer 4.

[0058] Specifically, the first electrode layer 2 can be connected with the signal receiving device 5 through the through hole 31, so that the signal receiving device 5 can receive the electric signal transmitted by the infrared radiation collecting layer 3 through the first electrode layer 2 and the second electrode layer 4.

[0059] Further, with reference to Figure 3 , the infrared pyroelectric sensor further comprises:

[0060] the lead part b;

[0061] The lead part b is arranged in the through hole 31, and the lead part b is in contact with the first electrode layer 2.

[0062] Specifically, the lead part b is arranged in the through hole 31, so that the first electrode layer 2 can be connected with the signal receiving device 5 through the lead part b, the connection between the first electrode layer 2 and the signal receiving device 5 is more convenient, and the signal receiving device 5 can receive the electric signal transmitted by the infrared radiation collecting layer 3 through the first electrode layer 2 and the second electrode layer 4 more conveniently.

[0063] Further, with reference to Figure 3 , the thickness of the lead part b is less than the thickness of the infrared radiation collecting layer 3.

[0064] Specifically, the thickness of the lead part b is designed to be less than the thickness of the infrared radiation collecting layer 3, so that the lead part b does not contact the second electrode layer 4 due to the excessive thickness of the lead part b, the first electrode layer 2 and the second electrode layer 4 are not short-circuited, and the electric signal transmitted by the infrared radiation collecting layer 3 to the signal receiving device 5 is accurate.

[0065] Further, the vertical projection of the through hole on the substrate does not overlap the groove.

[0066] Further, the through hole is a circular through hole.

[0067] Further, the material of the thermoelectric film layer comprises lead zirconate titanate.

[0068] Specifically, the lead zirconate titanate has excellent thermoelectric performance, so that the sensing assembly has high sensitivity, and the infrared pyroelectric sensor designed in the embodiment of the utility model is more sensitive and reliable in detecting infrared radiation.

[0069] Exemplarily, the embodiment of the utility model further provides a preparation method of an infrared pyroelectric sensor, Figures 4-16 is a process flow chart of an infrared pyroelectric sensor according to the embodiment of the utility model, with reference to Figures 4-16 , the specific description is as follows:

[0070] provides asFigure 4 The substrate 1 is shown, and then a first electrode layer 2 is made on the substrate 1 by sputtering, forming a structure as shown in Figure 5 The structure is shown, and then an infrared radiation collecting layer 3 is made on the first electrode layer 2 by sputtering, forming a structure as shown in Figure 6 The structure is shown, and then a photoresist layer 6 is made on the infrared radiation collecting layer 3 by photoresist spin coating, forming a structure as shown in Figure 7 The structure is shown, and the photoresist layer 6 is subjected to photoetching and developing, forming a structure as shown in Figure 8 The structure is shown, and then the infrared radiation collecting layer 3 is subjected to etching on the basis of the structure shown in Figure 8 The structure is shown, and then the structure shown in Figure 9 The structure is shown, and then the structure shown in Figure 9 The structure is shown, and then the structure shown in Figure 10 The structure is shown, and the surface exposed away from the substrate 1 in the structure shown in Figure 10 The structure is shown, and the surface exposed away from the substrate 1 in the structure shown in Figure 11 The structure is shown, and then the second electrode layer 4 is made on the surface exposed away from the substrate 1 in the structure shown in Figure 11 The structure is shown, and then the structure shown in Figure 12 The structure is shown, and then the photoresist layer 6 is removed by Lift-off process on the surface exposed away from the substrate 1 in the structure shown in Figure 12 The structure is shown. Then photoresist spin coating is performed on the surface of the substrate 1, and after the photoresist spin coating, the photoresist surface formed is subjected to photoetching and developing, forming the photoresist layer 6, i.e. a structure as shown in Figure 13 The structure is shown, and then the substrate 1 is subjected to etching on the basis of the structure shown in Figure 14 The structure is shown, and then the structure shown in Figure 14 The structure is shown, and then the structure shown in Figure 15 The structure is shown, and then the structure shown in Figure 15 The structure is shown, and then the structure shown in Figure 16 The structure is shown, i.e. a schematic diagram of the internal structure of the infrared pyroelectric sensor.

[0071] It should be understood that the various forms of flow shown above can be used to reorder, add or delete steps. For example, the steps recorded in the present application can be executed in parallel or in sequence or in different order, as long as the desired results of the technical solution of the present application can be achieved, which is not limited herein.

[0072] The specific embodiments described above do not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An infrared pyroelectric sensor, characterized by, Comprising: a substrate, a first surface of the substrate is provided with a first electrode layer, an infrared radiation collecting layer and a second electrode layer in sequence, a second surface of the substrate is provided with a groove; wherein the first surface and the second surface are opposite surfaces; the infrared radiation collecting layer is used for receiving infrared radiation heat and converting the received infrared radiation heat into an electrical signal, which is transmitted to a signal receiving device through the first electrode layer and the second electrode layer.

2. The infrared pyroelectric sensor according to claim 1, characterized in that: the infrared radiation collecting layer comprises a thermoelectric film layer.

3. The infrared pyroelectric sensor according to claim 1, characterized in that: the substrate comprises an SOI substrate.

4. The infrared pyroelectric sensor according to claim 3, characterized in that: the substrate comprises a first silicon layer, a silicon dioxide layer and a second silicon layer; a first surface of the first silicon layer is provided in contact with the first electrode layer, the silicon dioxide layer is provided between the first silicon layer and the second silicon layer; the groove penetrates through the second silicon layer and the silicon dioxide layer.

5. The infrared pyroelectric sensor according to claim 1, characterized in that: a through hole is provided on the infrared radiation collecting layer; the through hole exposes part of the first electrode layer, and the through hole does not overlap with the second electrode layer.

6. The infrared pyroelectric sensor of claim 5, wherein, Further comprising: a lead part; the lead part is provided in the through hole, and the lead part is provided in contact with the first electrode layer.

7. The infrared pyroelectric sensor according to claim 6, characterized in that: a thickness of the lead part is less than a thickness of the infrared radiation collecting layer.

8. The infrared pyroelectric sensor according to claim 5, characterized in that: a vertical projection of the through hole on the substrate does not overlap with the groove.

9. The infrared pyroelectric sensor according to claim 5, characterized in that: the through hole is a circular through hole.

10. The infrared pyroelectric sensor according to claim 2, characterized in that: a material of the thermoelectric film layer comprises lead zirconate titanate.

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