CN217424568U

CN217424568U - Infrared sensor and electronic device

Info

Publication number: CN217424568U
Application number: CN202220870851.1U
Authority: CN
Inventors: 陈华辉; 李晓; 周飞云
Original assignee: Shanghai Xinzhou Technology Co ltd; Chipsea Technologies Shenzhen Co Ltd
Current assignee: Shanghai Xinzhou Technology Co ltd; Chipsea Technologies Shenzhen Co Ltd
Priority date: 2022-04-15
Filing date: 2022-04-15
Publication date: 2022-09-13
Anticipated expiration: 2032-04-15

Abstract

The infrared sensor and the electronic equipment comprise a substrate, a first metal layer arranged on the substrate, an infrared sensing element and a temperature sensing element which are respectively arranged on the first metal layer, and an insulating layer is arranged between the first metal layer and the infrared sensing element; through the mode, the infrared sensing element and the temperature sensing element are arranged on the first metal layer, the first metal layer can be electrically connected with the temperature sensing element and can also be used as a heat conduction layer to enable the heat of the infrared sensing element and the temperature sensing element to be more balanced, the thermal resistance of the temperature sensing element and the infrared sensing element is favorably reduced, the error between the ambient temperature of the infrared sensing element and the ambient temperature measured by the temperature sensing element is reduced, the accuracy of the target temperature to be measured output by the infrared sensor is improved, other devices for reducing the thermal resistance of the temperature sensing element and the infrared sensing element are not needed, and the packaging structure of the infrared sensor is simplified.

Description

Infrared sensor and electronic device

Technical Field

The application relates to the technical field of infrared sensors, in particular to an infrared sensor and electronic equipment.

Background

At present, most of common infrared sensors adopt a thermopile measuring principle, and when the target temperature is obtained, the thermopile only needs to measure the temperature difference of the actual temperature of the target relative to the ambient temperature of the infrared sensor, so that an ambient temperature sensing element is required to be additionally arranged to measure the ambient temperature, and the actual temperature can be finally calculated.

In the prior art, the temperature sensing element and the thermopile are generally arranged on the substrate at intervals, wherein the temperature sensing element generally adopts a thermistor, and the thermal resistances of the temperature sensing element and the thermopile are large, so that the difference between the ambient temperature measured by the thermopile and the ambient temperature measured by the temperature sensing element is large, and the actual temperature of the target to be measured is not favorably and accurately measured.

SUMMERY OF THE UTILITY MODEL

The application aims to provide an infrared sensor and electronic equipment, and aims to solve the technical problem that measurement is inaccurate due to large thermal resistance between a temperature sensing element and an infrared sensing element in the prior art.

The technical scheme of the application is as follows: the utility model provides an infrared sensor, includes the base plate, locates the first metal level of base plate, locate respectively infrared sensing element and the temperature sensing element of first metal level, first metal level with be provided with the insulating layer between the infrared sensing element.

Optionally, the first metal layer includes at least one first metal trace.

Optionally, the infrared sensor further includes a first metal welding layer disposed between the insulating layer and the infrared sensing element, and a second metal welding layer disposed between the first metal layer and the temperature sensing element.

Optionally, the infrared sensor further includes a first electrode disposed between the temperature sensing element and the second metal welding layer, and a second electrode disposed on a side of the temperature sensing element away from the second metal welding layer.

Optionally, the infrared sensor further includes a first metal wire electrically connected to the second electrode.

Optionally, the infrared sensing element comprises at least one thermopile.

Optionally, the infrared sensing element further includes a main body portion provided with the thermopile, a support portion for supporting the main body portion and connected to the insulating layer, and a back cavity extending from one side of the support portion away from the main body portion to the main body portion, and the thermopile is disposed on one side of the main body portion away from the support portion.

Optionally, the infrared sensor further includes a third electrode disposed on the main body portion.

Optionally, the infrared sensor further includes a fourth metal wire connected to the third electrode.

Optionally, the infrared sensor further includes a second metal layer disposed on the substrate and spaced apart from the first metal layer, and a reference resistor, where the reference resistor spans the space between the first metal layer and the second metal layer and is connected to the first metal layer and the second metal layer, respectively.

Optionally, the second metal layer includes at least one second metal trace.

Optionally, the infrared sensor further includes a third metal welding layer connecting the reference resistor and the first metal layer, and a fourth metal welding layer connecting the reference resistor and the second metal layer.

Optionally, the infrared sensor further includes a fourth electrode disposed between the third metal welding layer and the reference resistor and connected to the first metal layer, and a fifth electrode disposed between the fourth metal welding layer and the reference resistor and connected to the second metal layer.

Optionally, the infrared sensor further includes a second metal line electrically connected to the first metal layer and located between the temperature sensing element and the reference resistor, and a third metal line electrically connected to the second metal layer.

Another technical scheme of the application is as follows: an electronic device is provided, which comprises the infrared sensor.

The infrared sensor and the electronic equipment comprise a substrate, a first metal layer arranged on the substrate, an infrared sensing element and a temperature sensing element which are respectively arranged on the first metal layer, and an insulating layer is arranged between the first metal layer and the infrared sensing element; through the mode, the infrared sensing element and the temperature sensing element are arranged on the first metal layer, the first metal layer can be used as a heat conduction layer to enable the heat between the infrared sensing element and the temperature sensing element to be more balanced while being electrically connected with the temperature sensing element, so that the heat resistance of the temperature sensing element and the infrared sensing element is favorably reduced, the error between the environment temperature measured by the infrared sensing element and the environment temperature measured by the temperature sensing element is reduced, the accuracy of the target temperature to be measured output by the infrared sensor is improved, other devices for reducing the heat resistance of the temperature sensing element and the infrared sensing element are not needed, and the packaging structure is favorably simplified; the infrared sensing element is prevented from being influenced by other electric signals conducted on the first metal layer through the arrangement of the insulating layer, and the operation stability of the infrared sensing element is improved.

Drawings

Fig. 1 is a schematic structural diagram of an infrared sensor according to an embodiment of the present application;

FIG. 2 is a schematic structural diagram of an infrared sensor according to another embodiment of the present application;

FIG. 3 is a view of the infrared sensor element of the infrared sensor of FIG. 2 taken along direction A;

FIG. 4 is a schematic circuit diagram of the infrared sensor of FIG. 2;

fig. 5 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

The present application will be further described with reference to the accompanying drawings and embodiments.

In the following, many aspects of the present application will be better understood with reference to the drawings. The components in the drawings are not necessarily to scale. Instead, emphasis is placed on clearly illustrating the components of the present application. Moreover, in the several views of the drawings, like reference numerals designate corresponding parts.

Referring to fig. 1, an infrared sensor 100 includes a substrate 10, a first metal layer 21, an infrared sensing element 30, and a temperature sensing element 40, where the first metal layer 21 is disposed on the substrate 10, the infrared sensing element 30 and the temperature sensing element 40 are disposed on the first metal layer 21 at an interval, the temperature sensing element 40 is directly disposed on the first metal layer 21, and an insulating layer 50 is disposed between the infrared sensing element 30 and the first metal layer 21.

In the present embodiment, the temperature sensing element 40 is electrically connected to the first metal layer 21, and the temperature sensing element 40 can transmit an electrical signal through the first metal layer 21, for example, the electrical signal can be a current signal; the infrared sensor element 30 is insulated from the electrical signal conducted on the first metal layer 21 by the insulating layer 50, preventing the infrared sensor element 30 from being affected by the electrical signal conducted on the first metal layer 21.

In an alternative embodiment, the substrate 10 may be a Circuit substrate, for example, a PCB (Printed Circuit Board) substrate, and the material of the substrate 10 may be a resin substrate, a plastic substrate, a ceramic substrate, or other substrates.

In this embodiment, the first metal layer 21 is made of a metal material, has a heat conduction function, and can be regarded as a heat conduction layer, the infrared sensing element 30 and the temperature sensing element 40 are simultaneously disposed on the first metal layer 21, and heat can be conducted through the first metal layer 21, so that heat between the infrared sensing element 30 and the temperature sensing element 40 is more balanced, thermal resistances of the temperature sensing element and the infrared sensing element are reduced, errors between ambient temperatures respectively measured by the infrared sensing element and the temperature sensing element are reduced, and accuracy of a target temperature to be measured output by the infrared sensor is improved. In this embodiment, the first metal layer 21 has an effect of reducing the thermal resistance between the infrared sensing element 30 and the temperature sensing element 40, and other devices for reducing the thermal resistance do not need to be additionally arranged, which is beneficial to simplifying the package structure.

In some embodiments, the infrared sensor 100 further includes a second metal layer 22 disposed on the substrate 10 and a reference resistor 60, the first metal layer 21 and the second metal layer 22 are disposed at an interval, and an orthogonal projection of the first metal layer 21 on the substrate 10 does not overlap with an orthogonal projection of the second metal layer 22 on the substrate 10, that is, the first metal layer 21 and the second metal layer 22 do not overlap. The reference resistor 60 spans the interval between the first metal layer 21 and the second metal layer 22, and the reference resistor 60 is connected to the first metal layer 21 and the second metal layer 22, respectively.

In the present embodiment, one end of the reference resistor 60 connected to the first metal layer 21 is electrically connected to the first metal layer 21, and one end of the reference resistor 60 connected to the second metal layer 22 is electrically connected to the second metal layer 22. Further, the first metal layer 21 includes at least one first metal trace, the second metal layer 22 includes at least one second metal trace, the infrared sensing element 30 and the temperature sensing element 40 are electrically connected through the first metal trace, one end of the reference resistor 60 connected to the first metal layer 21 is electrically connected through the first metal trace, and one end of the reference resistor 60 connected to the second metal layer 22 is electrically connected through the second metal trace, so that signal transmission can be realized, and temperature detection of a target to be detected is completed.

In some embodiments, continuing to refer to fig. 2, the infrared sensing element 30, the temperature sensing element 40 and the reference resistor 60 are fixed by welding, and the infrared sensor 100 further includes a first metal welding layer 71 disposed between the insulating layer 50 and the infrared sensing element 30, a second metal welding layer 72 disposed between the first metal layer 21 and the temperature sensing element 40, a third metal welding layer 73 connecting the reference resistor 60 and the first metal layer 21, and a fourth metal welding layer 74 connecting the reference resistor 60 and the second metal layer 22. The first metal welding layer 71, the second metal welding layer 72, the third metal welding layer 73 and the fourth metal welding layer 74 have a conductive function respectively. In addition, the first metal soldering layer 71 and the second metal soldering layer 72 have a heat conducting function, respectively, and the arrangement of the first metal soldering layer 71, the second metal soldering layer 72 and the first metal layer 21 can reduce the thermal resistance between the infrared sensor element 30 and the temperature sensor element 40.

In some embodiments, the infrared sensor 100 further comprises a first electrode 81 disposed between the temperature sensing element 40 and the second metal bonding layer 72 and a second electrode 82 disposed on a side of the temperature sensing element 40 remote from the second metal bonding layer 72.

In some embodiments, the infrared sensor 100 further comprises a fourth electrode 83 disposed between the third metal welding layer 73 and the reference resistor 60, and a fifth electrode 84 disposed between the fourth metal welding layer 74 and the reference resistor 60.

In some embodiments, metal solder layers and electrodes are disposed on a side of the reference resistor 60 perpendicular to the substrate 10, the third metal solder layer 73 and the fourth electrode 83 are perpendicular to the first metal layer 21, respectively, and the fourth metal solder layer 74 and the fifth electrode 84 are perpendicular to the second metal layer 22, respectively. Further, the fourth electrode 83 is connected to the first metal layer 21, and the fifth electrode 84 is connected to the second metal layer 22.

It will be appreciated by those skilled in the art that in other embodiments, metal solder layers and electrodes are provided on the side of the reference resistor 60 facing the substrate 10, the third metal solder layer 73 and the fourth electrode 83 are parallel to the first metal layer 21, respectively, and the fourth metal solder layer 74 and the fifth electrode 84 are parallel to the second metal layer 22, respectively.

In some embodiments, referring to fig. 2 and 3, an infrared sensing area is disposed on a side of the infrared sensing element 30 away from the substrate 21, and the infrared sensing area can absorb infrared rays incident to the infrared sensing area by using a thermal electromotive force (seebeck effect) and generate and output an electrical signal. At least one thermopile 33 is arranged on the side of the infrared sensor element 30 remote from the substrate 10, the thermopile 33 being arranged in the infrared sensing region of the infrared sensor element 30. The thermopile 33 includes a plurality of thermocouples (not shown) connected in series and an electrode (not shown) for detecting an output signal of the thermopile 33. Further, the infrared sensing element 30 further includes a main body portion 31, a supporting portion 32 and a back cavity 34, the infrared sensing element 30 is manufactured by a semiconductor manufacturing process, the main body portion 31 is a portion formed on a silicon substrate, the supporting portion 32 is a portion of the silicon substrate, the back cavity 34 extends from a side of the supporting portion 32 away from the main body portion 31 to the main body portion 31, and the back cavity 34 is formed by etching from a side of the silicon substrate facing away from the main body portion 31. The thermopile 33 is disposed on a side of the main body 31 away from the support portion 32, and an area of the main body 31 where the thermopile 33 is located is an infrared sensing area, so that the main body 31 is also called a hot end of the infrared sensing element 30, the support portion 32 is also called a cold end of the infrared sensing element 30, and a temperature of the cold end of the infrared sensing element 30 (i.e., a temperature of the support portion 32) is an ambient temperature of the infrared sensing element 30.

In fig. 2, the support portion 32 and the temperature sensing element 40 conduct heat through the first metal layer 21, so that the thermal resistance between the support portion 32 and the temperature sensing element 40 is reduced, the temperature between the support portion 32 and the temperature sensing element 40 is closer, that is, the ambient temperature measured by the infrared sensing element 30 is closer to the ambient temperature measured by the temperature sensing element 40, and the accuracy of the target temperature output by the infrared sensor 100 is greatly improved.

In some embodiments, referring to fig. 2, the Temperature sensing element 40 includes a thermistor, such as an NTC (Negative Temperature Coefficient) thermistor or a thermistor made of other thermal sensitive material, for measuring an ambient Temperature at which the infrared sensing element 30 is located, i.e., a cold end Temperature of the infrared sensing element 30.

In some embodiments, the infrared sensor 100 further includes a third electrode 85 disposed on the main body 31 for detecting an output signal of the thermopile 33, and a fourth metal wire 94 connected to the third electrode 85, wherein the fourth metal wire 94 is connected to an input port of an analog-to-digital converter.

In some embodiments, as shown in fig. 2, the infrared sensor 100 further includes a first metal line 91 electrically connected to the second electrode 82, a second metal line 92 electrically connected to the first metal layer 21 and located between the temperature sensing element 40 and the reference resistor 60, and a third metal line 93 electrically connected to the second metal layer 22. The second electrode 82 detects an output signal of the temperature sensing element 40, and the first metal wire 91 is connected to the second electrode 82 to output the output signal. The second metal line 92 is electrically connected to the first electrode 81 and the fourth electrode 83 through the first metal layer 21, respectively, the first electrode 81 detects an output signal of the temperature sensing element 40, and the fourth electrode 83 detects an output signal of the reference resistor 60. The third metal line 93 is electrically connected to the fifth electrode 84 through the second metal layer 22, the fifth electrode 84 detects an output signal of the reference resistor 60, wherein the first metal line 91 is respectively connected to the excitation source output port and the reference source input port, the second metal line 92 is connected to the input port of the analog-to-digital converter, and the third metal line 93 is connected to the reference ground.

Referring To fig. 2 and 4, VS represents the pump output port, Vref represents the reference input port, ADC (Analog To Digital Converter) represents the input port of the Analog-To-Digital Converter, GND represents ground reference, and IR +/IR-represents the input port of the Analog-To-Digital Converter.

In some embodiments, the infrared sensor 100 further includes an Integrated Circuit chip, which may also be disposed on the substrate 10 and located in a region where the first metal layer 21 and the second metal layer 22 are not disposed on the substrate 10, and the Integrated Circuit chip may include an ASIC (Application Specific Integrated Circuit) chip, on which an ADC is disposed, and the Integrated Circuit chip is configured to perform analog-to-digital conversion on analog signals output by the infrared sensing element 30 and the temperature sensing element 40 through the ADC and process the analog signals through other modules to output digital signals.

In this embodiment, after the infrared sensing element 30, the temperature sensing element 40 and the reference resistor 60 are powered on, after the infrared sensing element 30 receives infrared rays of a target to be detected, the infrared sensing element 30 may input a measured first target temperature into the ADC through the fourth metal wire 94, where the first target temperature includes a temperature of the target to be detected and an ambient temperature measured by the infrared sensing element 30, the temperature sensing element 40 may input the measured ambient temperature into the ADC through the second metal wire 92, and the ADC performs analog-to-digital conversion on the first target temperature and the ambient temperature, processes the first target temperature and the ambient temperature through the integrated circuit chip, and finally outputs the temperature of the target to be detected. Furthermore, the integrated circuit chip can also acquire the group value of the reference resistor, and process and output the temperature of the target to be detected by combining the first target temperature and the ambient temperature.

In this embodiment, when the temperature sensing element is used for detecting the ambient temperature, the formula can be used

Obtaining the resistance value of the thermistor, and then obtaining the ambient temperature (also called cold end temperature) according to the relationship between the resistance value of the thermistor and the temperature, wherein Zntc represents the resistance value of the thermistor, Zref represents the resistance value of the reference resistor, Zref has a known value, ADC _ ref represents an ADC code value read by an analog-to-digital converter corresponding to the temperature sensing element, and n represents the resolution of the analog-to-digital converter corresponding to the temperature sensing element.

In this embodiment, an electronic device is further provided in the embodiments of the present application, please refer to fig. 5, in which the electronic device 200 includes an infrared sensor 100, and the infrared sensor 100 specifically refers to the embodiments described above, which are not described in detail herein.

In some embodiments, the electronic device 200 may be a wearable device or a mobile terminal, for example, a wearable device including, but not limited to, a smart watch, a smart bracelet, a smart garment, a smart headset, and the like. If the wearable device is a smart watch, the infrared sensor 100 is used to detect infrared radiation from the skin of the wrist of the wearer. As another example, the wearable device is a TWS (True Wireless Stereo) headset, and the infrared sensor 100 is used for detecting infrared rays radiated from the skin of the ear of the wearer.

In some embodiments, the electronic device 200 can also be any device with communication and storage functions, such as: personal Computers (PCs), notebook computers, smart phones, tablet computers, electronic readers, remote controllers, vehicle-mounted devices, network televisions and other terminal devices.

While the foregoing is directed to embodiments of the present application, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims.

Claims

1. The infrared sensor is characterized by comprising a substrate, a first metal layer arranged on the substrate, an infrared sensing element and a temperature sensing element which are respectively arranged on the first metal layer, and an insulating layer arranged between the first metal layer and the infrared sensing element.

2. The infrared sensor as set forth in claim 1, wherein the first metal layer includes at least one first metal trace.

3. The infrared sensor as set forth in claim 1, further comprising a first metal solder layer disposed between said insulating layer and said infrared sensing element and a second metal solder layer disposed between said first metal layer and said temperature sensing element.

4. The infrared sensor as set forth in claim 3, further comprising a first electrode disposed between said temperature sensing element and said second metal bonding layer and a second electrode disposed on a side of said temperature sensing element remote from said second metal bonding layer.

5. The infrared sensor as set forth in claim 4, further comprising a first metal wire electrically connected to the second electrode.

6. The infrared sensor of claim 1, characterized in that the infrared sensing element comprises at least one thermopile.

7. The infrared sensor as claimed in claim 6, wherein the infrared sensing element further comprises a main body portion provided with the thermopile, a support portion for supporting the main body portion and connected to the insulating layer, and a back cavity extending from a side of the support portion away from the main body portion to the main body portion, the thermopile being provided on a side of the main body portion away from the support portion.

8. The infrared sensor as set forth in claim 7, further comprising a third electrode provided on said main body portion.

9. The infrared sensor as set forth in claim 8, further comprising a fourth metal wire connected to the third electrode.

10. The infrared sensor of claim 1, further comprising a second metal layer disposed on the substrate and spaced apart from the first metal layer, and a reference resistor spanning the space between and connected to the first and second metal layers, respectively.

11. The infrared sensor of claim 10, characterized in that the second metal layer comprises at least one second metal trace.

12. The infrared sensor as set forth in claim 10, further comprising a third metal solder layer connecting said reference resistance and said first metal layer and a fourth metal solder layer connecting said reference resistance and said second metal layer.

13. The infrared sensor as set forth in claim 12, further comprising a fourth electrode disposed between said third metal bonding layer and said reference resistance and connected to said first metal layer and a fifth electrode disposed between said fourth metal bonding layer and said reference resistance and connected to said second metal layer.

14. The infrared sensor as set forth in claim 13, further comprising a second metal line electrically connected to said first metal layer and located between said temperature sensing element and said reference resistor, and a third metal line electrically connected to said second metal layer.

15. An electronic device characterized by comprising the infrared sensor of any one of claims 1 to 14.