CN218271081U

CN218271081U - Pyroelectric infrared sensor

Info

Publication number: CN218271081U
Application number: CN202121963683.2U
Authority: CN
Inventors: 吴华民; 刘财伟
Original assignee: Shenzhen Huasan Sense Technology Co ltd
Current assignee: Shenzhen Huasan Sense Technology Co ltd
Priority date: 2021-08-19
Filing date: 2021-08-19
Publication date: 2023-01-10
Anticipated expiration: 2031-08-19

Abstract

A pyroelectric infrared sensor relates to the technical field of infrared sensors. The infrared sensor comprises a pipe cap, an infrared filter, a base, an infrared sensitive element and a signal processing part, wherein the pipe cap and the base are assembled to form a sealed space, the base comprises a first circuit substrate, one side of the first circuit substrate, which is positioned in the sealed space, is provided with a mounting groove, the signal processing part is arranged in the mounting groove, and the infrared sensitive element is arranged in the sealed space and is positioned above the signal processing part. The supporting piece used for supporting the infrared sensitive element is arranged on one side, corresponding to the signal processing part, of the first circuit substrate, the mounting groove is formed in one side, located in the sealing space, of the first circuit substrate, the signal processing part is arranged in the mounting groove, the ultrathin standard sheet type element can be used as the supporting piece, the material and packaging cost of the supporting piece is reduced, and meanwhile ultrathin and small-size packaging of the sensor is achieved.

Description

Pyroelectric infrared sensor

Technical Field

The utility model relates to an infrared sensor technical field, concretely relates to pyroelectric infrared sensor.

Background

A pyroelectric infrared sensor is a sensor for detecting infrared thermal radiation, which is made by using a material with good pyroelectric property as a core, and is mainly applied to detecting infrared rays of people and animals or other objects with thermal radiation so as to judge whether people or other animals exist in a certain space. The method is widely applied to the fields of induction type lighting, intrusion type alarming, security protection, intelligent home and the like.

The pyroelectric infrared sensor with mature technology on the current market mainly comprises a pipe cap, a pipe seat forms a closed space, an infrared optical filter is arranged in a window on the surface of the pipe cap, a pyroelectric infrared sensitive element is arranged in the closed space, a supporting component for fixing the infrared sensitive element and a JFET or IC of a signal processing part are fixed on the upper surface of a PCB circuit substrate, and the working principle of the pyroelectric infrared sensor is that an infrared radiation signal received by the infrared sensitive element is converted into a weak voltage signal, and the weak voltage signal is converted by a signal circuit on the substrate and is output outwards.

The height of the supporting part of the existing pyroelectric infrared sensor is larger than the thickness of a signal processing part, and the requirements of an application end on the thickness and the small size of a product cannot be met, so that the improvement is needed.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to prior art's defect and not enough, provide a pyroelectric infrared sensor, it is provided with the mounting groove to lie in sealed space one side on the first circuit substrate, the signal processing part sets up in the mounting groove, infrared sensing element sets up in sealed space and lies in signal processing part top, because the signal processing part is installed in some or all embedding mounting grooves, make and to adopt ultra-thin, the support piece of standard piece formula component as infrared sensing element, support piece's material and encapsulation cost have been reduced, the ultra-thin and the small-size encapsulation of sensor have been realized simultaneously.

In order to achieve the above object, the utility model adopts the following technical scheme: the utility model provides a pyroelectric infrared sensor, includes pipe cap, infrared filter, base, infrared sensing element and signal processing part, the pipe cap with the base assembly is in order to form confined space, the base includes first circuit substrate, be located on the first circuit substrate one side is provided with the mounting groove in the confined space, the signal processing part set up in the mounting groove, infrared sensing element set up in the confined space and be located signal processing part top.

And a supporting piece for supporting the infrared sensitive element is arranged on one side of the first circuit substrate corresponding to the signal processing part, and the signal processing part is inversely arranged in the mounting groove and is electrically connected with the first circuit substrate.

The support piece is a standard chip component, and the chip component is a chip resistor, a chip capacitor or a chip inductor.

The infrared sensing element is arranged on one side, far away from the mounting groove, of the second circuit substrate and is electrically connected with the second circuit substrate.

The second circuit substrate is provided with a heat dissipation groove corresponding to the infrared sensitive element, so that a heat transfer gap between the infrared sensitive element and the second circuit substrate is enlarged, and the thermal stability interference of heat conducted from the application circuit board to the infrared sensitive element by the first circuit substrate and the second circuit substrate is reduced.

And a support is arranged between the second circuit substrate and the infrared sensitive element, and the infrared sensitive element is electrically connected with the second circuit substrate through the support.

And the first circuit substrate is fixedly provided with a bonding pad array, a plug connector, a stamp hole array or a BGA ball which are electrically connected with the first circuit substrate and used for electrically connecting and assembling the pyroelectric infrared sensor externally.

And the first circuit substrate is provided with a vent hole communicated with the sealing space, and the vent hole is provided with a sealing plug for sealing the vent hole.

The first circuit substrate is provided with an anti-electromagnetic interference structure, and the anti-electromagnetic interference structure comprises a metalized edge copper coating and/or a metalized open groove copper coating.

The first circuit substrate is a multilayer circuit board.

The first circuit substrate is provided with additional parts, and the additional parts at least comprise any one or more of a power supply voltage stabilizing chip, an output signal control component, a photosensitive component, an analog or digital signal processing chip, a diode, a triode and a passive device; the additional parts are used for forming the high-integration and multifunctional integrated pyroelectric infrared sensor.

The base includes first circuit substrate and metal bottom plate, metal bottom plate fixed set up in the lower terminal surface of first circuit substrate, metal bottom plate is used for improving the bulk heat capacity of sensor to improve the thermal stability performance of sensor, and be used for improving the anti-electromagnetic interference performance of sensor.

After the technical scheme is adopted, the utility model discloses beneficial effect does:

1. the first circuit substrate is provided with a mounting groove at one side in the sealed space, the signal processing part is arranged in the mounting groove, the infrared sensitive element is arranged in the sealed space and above the signal processing part, and the signal processing part is partially or completely embedded into the mounting groove for mounting, so that an ultrathin standard sheet element can be adopted as a support member of the infrared sensitive element, the cost of the support member is reduced, and the assembly process of the support member is optimized; meanwhile, the ultrathin standard sheet type supporting piece is adopted, so that the infrared sensitive element and the pipe cap can be simultaneously subjected to glue brushing, assembling, baking and glue discharging, compared with the existing process of separately dispensing, baking and glue discharging, the process is simplified, the process time is shortened, the automatic production is greatly facilitated, and the material and packaging cost is reduced; and meanwhile, ultrathin and small-size packaging of the sensor is realized.

2. The design of the vent hole is adopted, so that various adhesives of the sensor can be conveniently baked, discharged and cured at one time, the process time is greatly shortened, and the automatic operation of assembling and packaging the sensor is facilitated.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

Fig. 1 is a schematic structural view of embodiment 1 of the present invention;

FIG. 2 is a cross-sectional view corresponding to FIG. 1;

FIG. 3 is a cross-sectional view in another direction corresponding to FIG. 1;

FIG. 4 is a sectional view of embodiment 2;

FIG. 5 is an exploded schematic view of one embodiment of example 3;

FIG. 6 is a sectional view of another embodiment of example 3;

FIG. 7 is a sectional view of embodiment 4.

Description of the reference numerals: 1. a pipe cap; 2. an infrared filter; 3. a first circuit substrate; 4. an infrared-sensitive element; 5. a signal processing part; 6. a support member; 61. a second circuit substrate; a. mounting grooves; 7. a plug-in unit; 71. an electrode; b. accommodating grooves; 8. BGA balls; 9. and (4) sealing the plug.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications to the present embodiment as required without making a contribution, but all the embodiments are protected by the patent law within the scope of the claims of the present invention.

Example 1:

the present embodiment relates to a pyroelectric infrared sensor, as shown in fig. 1, 2, and 3, which includes an infrared filter 2, a base, an infrared sensing element 4, and a signal processing component 5, wherein a cap 1 is assembled with the base to form a sealed space, and the cap 1 is adhered to the base. The base comprises a first circuit substrate 3, a mounting groove a is formed in one side, located in the sealed space, of the first circuit substrate 3, a signal processing part 5 is arranged in the mounting groove a, and an infrared sensitive element 4 is arranged in the sealed space and located above the signal processing part 5. The thin sensor is produced by forming a mounting groove a on the first circuit substrate 3, wherein the mounting groove a is used for placing the signal processing part 5. In this embodiment, the cap 1 has a window on its upper surface. The infrared filter 2 is embedded on the window. The first circuit substrate 3 is an epoxy resin PCB circuit board. The signal processing component 5 is a JFET, an amplifier, a MCU or an intelligent integrated circuit or an ADC device, and in other embodiments, the first circuit substrate 3 may be a ceramic circuit substrate.

Preferably, in order to ensure clearance between the signal processing part 5 and the infrared sensitive element 4, a supporting member 6 for supporting the infrared sensitive element 4 is disposed on the first circuit substrate 3 corresponding to one side of the signal processing part 5, the signal processing part 5 is inversely installed in the installation groove a and electrically connected to the first circuit substrate 3, and the signal processing part 5 is adhered or welded to the first circuit substrate 3. The infrared sensitive element 4 is electrically connected with the first circuit substrate 3 through the supporting member 6, and the top and bottom ends of the supporting member 6 are respectively glued or welded with the first circuit substrate 3 and the infrared sensitive element 4.

It should be noted that, the mounting groove a is formed on the first circuit substrate 3 at one side of the sealed space, so that an ultra-thin and standard chip component can be used as the supporting component 6 of the infrared sensitive component 4, thereby reducing the cost of the supporting component 6 and optimizing the assembly process of the supporting component 6; meanwhile, the ultrathin standard sheet type supporting piece 6 is adopted, so that the infrared sensitive element 4 and the pipe cap 1 can be simultaneously brushed, assembled, baked and discharged with glue, compared with the existing separated glue dispensing, baking and glue discharging process, the process is simplified, the process time is shortened, the automatic production is greatly facilitated, and the material and packaging cost is reduced; and meanwhile, ultrathin and small-size packaging of the sensor is realized. In the present embodiment, at least two supporting members 6 are provided, and some of the supporting members 6 with a tapered shape are provided, and the supporting members 6 are standard chip components, such as chip resistors, chip capacitors, or chip inductors. The first circuit substrate 3 is respectively glued or welded with the support piece 6, the signal processing part 5 and the tube cap 1, the tube cap 1 and the infrared filter 2, and the support piece 6 and the infrared sensitive element 4, and the resistance energy storage sealing welding process in the traditional manufacturing process is removed, so that the working procedures are simplified, the efficiency is improved, and the cost is reduced. In the present embodiment, the first circuit substrate 3 may have a circular shape, a polygonal shape, an elliptical shape, or a special shape. The pipe cap 1 is circular or rectangular.

Preferably, in order to expand the use scenes and functions of the sensor. The first circuit substrate 3 is provided with additional parts, and the additional parts at least comprise any one or more of a power supply voltage stabilization chip, an output signal control component, a photosensitive component, an analog or digital signal processing chip, a diode, a triode and a passive device; the additional parts are used for forming the high-integration and multifunctional integrated pyroelectric infrared sensor.

Example 2:

the main differences between this embodiment and embodiment 1 are: as shown in fig. 4, a second circuit substrate 61 is disposed between the infrared sensor 4 and the signal processing component 5, and the second circuit substrate 61 is an epoxy PCB. The signal processing component 5 is inversely installed in the mounting groove a and electrically connected to the second circuit substrate 61, the second circuit substrate 61 is covered on the mounting groove a and electrically connected to the first circuit substrate 3, and the second circuit substrate 61 is glued or welded to the first circuit substrate 3. The infrared sensor 4 is disposed on the second circuit substrate 61 away from the mounting groove a, and electrically connected to the second circuit substrate 61. The infrared sensor 4 and the signal processing component 5 are connected to the second circuit substrate 61. The infrared sensor 4 is glued to the face of the second circuit substrate 61, and the signal processing component 5 is glued or soldered to the bottom of the second circuit substrate 61. The second circuit substrate 61 can adopt a reference PCB design, and the assembly of the signal processing part 5 and the second circuit substrate 61 and the assembly of the second circuit substrate 61 and the first circuit substrate 3 can adopt a standard SMT reflow soldering process, so that the sensor can be conveniently automatically produced, the assembly process is optimized, and the cost is reduced; the sensor signal processing part 5 is embedded in the mounting groove of the first circuit substrate 3, so that the ultra-thin and small-size packaging of the sensor is realized; meanwhile, the infrared sensitive element 4 is arranged on the upper surface of the second circuit substrate 61, the second circuit substrate 61 is designed by adopting a standard PCB, the height of the infrared sensitive element 4 is adjusted by selecting the thickness of different standard circuit boards, the focal length matching of the sensor sensitive element and a Fresnel lens in application can be conveniently realized, and the structural problem of the focal length matching of the lens by an application end is solved to a certain extent.

In some embodiments, the second circuit substrate 61 is provided with a heat dissipation groove corresponding to the infrared sensitive element 4, so as to increase a heat transfer gap between the infrared sensitive element 4 and the second circuit substrate 61, and reduce thermal stability interference of heat conducted from the application circuit board by the first circuit substrate 3 and the second circuit substrate 61 on the infrared sensitive element 4. In some embodiments, in order to match the optical focal length, a supporting member 6 is disposed between the second circuit substrate 61 and the infrared sensor 4, and the infrared sensor 4 is electrically connected to the second circuit substrate 61 through the supporting member 6. The infrared sensor 4 is glued to the second circuit substrate 61, and the infrared sensor 4 is electrically connected to the second circuit substrate 61. The supporting component is a standard chip component, and the chip component comprises a chip resistor, a chip capacitor and a chip inductor.

Example 3:

in this embodiment, as shown in fig. 5 and 6, a pad array, a connector 7, a stamp hole array or BGA balls 8 electrically connected to the first circuit substrate 3 are fixed on the first circuit substrate 3, and are used for electrically connecting and assembling the pyroelectric infrared sensor to the outside. When the connector 7 is arranged on the first circuit substrate 3, the connector 7 is used for electrically connecting the real-time pyroelectric infrared sensor with an external electronic element, the connector 7 is a patch

vertical connector

7, and 6 electrodes 71 are arranged on one side, far away from the first circuit substrate 3, of the connector 7.

When the BGA balls 8 are disposed on the first circuit substrate 3, a plurality of protruding BGA balls 8 are disposed on the lower surface of the first circuit substrate 3, and the BGA balls 8 are electrically connected to the first circuit substrate 3. In the present embodiment, the BGA ball 8 is a solder ball, a copper ball, a steel ball or an aspheric block or pillar, the surface of the BGA ball 8 is an easy-to-solder material, and the ball is a metal conductor or a non-conductor plated with a conductive layer. The BGA is called Ball Grid Array Package, the Chinese name is Ball Grid Array packaging, and the BGA balls 8 are arranged on the mounting side of the first circuit substrate 3 of the sensor, so that SMT (surface mount technology) patch automatic production is realized during application of the sensor to improve efficiency and reduce cost, and the quality of reflow soldering of the patch is ensured. Meanwhile, due to the existence of the BGA balls 8, a gap exists between the first circuit substrate 3 of the sensor and the application board where the first circuit substrate is located, the contact area is small, the thermal resistance between the application board and the first circuit substrate 3 of the sensor is greatly increased, the heat on the application board is reduced to be conducted to the first circuit substrate 3 of the sensor, the capacity of the sensor for resisting the change of the temperature of the space environment where the sensor is located is improved, and the thermal stability of the sensor is improved.

Example 4:

in the present embodiment, as shown in fig. 7, in addition to any of the above embodiments, the first circuit board 3 is provided with a vent hole communicating with the sealed space, and the vent hole is provided with a sealing plug 9 for sealing the vent hole. In this embodiment, the sealing plug 9 is a sealant. The sealant is fixedly arranged in the vent hole. The arrangement of the vent hole is convenient for discharging the glue discharging waste gas staying in the sealed space out of the sealed space in a vacuumizing mode when possible adhesives such as the infrared sensitive element 4, the first circuit substrate 3, the signal processing part 5 and the pipe cap 1 are baked and cured at one time, and meanwhile, inert or dry gas is conveniently injected into the sealed space. The air holes are added to enable a plurality of possible adhesives of the sensor to be baked and cured at one time, the process time of the sensor is greatly shortened, the sensor is beneficial to realizing automatic packaging, and meanwhile, the rubber discharge waste gas in the sealing space of the sensor is completely replaced by inert gas or dry gas, so that the performance of the sensor is also beneficial to improving. Thereby improving the accuracy of the inductor.

Example 5:

in this embodiment, on the basis of any of the above embodiments, the first circuit substrate 3 is provided with an anti-electromagnetic interference structure, and the anti-electromagnetic interference structure includes a metalized edge copper-clad layer and/or a metalized open-slot copper-clad layer. The substrate is reduced from being exposed in a space capacitance environment, and the anti-electromagnetic interference capability of the sensor is improved, so that the sensor can be suitable for being used in strong electromagnetic interference or application occasions with Bluetooth and WIFI communication. Furthermore, the first circuit substrate 3 is a multilayer circuit board, which is a circuit board containing more than two layers of copper foil circuits, and compared with a single-sided or double-sided circuit board, the multilayer circuit board has better electromagnetic interference resistance, so that the electromagnetic interference resistance of the sensor is improved, and the sensor can be applied to application occasions requiring particularly strong electromagnetic interference resistance.

Example 6:

in this embodiment, on the basis of any of the above embodiments, the base includes the first circuit substrate 3 and a metal bottom plate, the metal bottom plate is fixedly disposed on the lower end surface of the first circuit substrate 3, and the metal bottom plate is sealed with the cap 1. The metal base plate is used for improving the overall heat capacity of the sensor so as to improve the thermal stability of the sensor and improve the anti-electromagnetic interference performance of the sensor. Pipe cap 1 and metal bottom plate form airtight space for the sensor is basically sealed completely in metal casing, has further reduced the base plate and has exposed in space capacitance environment, has promoted the anti-electromagnetic interference's of sensor ability, makes this sensor applicable to use at the application occasion of strong electromagnetic interference or taking bluetooth, WIFI communication. In the embodiment, the electrical connecting parts are BGA balls 8, the BGA balls 8 are arranged on the lower end face of the circuit substrate and protrude out of the metal base plate, and SMT reflow soldering and welding fixation of the sensor are achieved.

Above, the technical solutions of the present invention are only used for illustration and not for limitation, and other modifications or equivalent replacements made by the technical solutions of the present invention by those of ordinary skill in the art should be covered in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solutions of the present invention.

Claims

1. The utility model provides a pyroelectric infrared sensor, includes pipe cap (1), infrared filter (2), base, infrared sensing element (4) and signal processing part (5), pipe cap (1) with the base assembly is in order to form confined space, its characterized in that, the base includes first circuit substrate (3), lie in on first circuit substrate (3) one side is provided with mounting groove (a) in the confined space, signal processing part (5) set up in mounting groove (a), infrared sensing element (4) set up in the confined space and lie in signal processing part (5) top.

2. The pyroelectric infrared sensor according to claim 1, characterized in that a support member (6) for supporting the infrared sensitive element (4) is disposed on the first circuit substrate (3) at a side corresponding to the signal processing part (5), and the signal processing part (5) is flip-mounted in the mounting groove (a) and is electrically connected to the first circuit substrate (3).

3. The pyroelectric infrared sensor according to claim 2, characterized in that the support (6) is a standard chip element being a chip resistor, a chip capacitor or a chip inductor.

4. The pyroelectric infrared sensor according to claim 1, wherein a second circuit substrate (61) is disposed between the infrared sensitive element (4) and the signal processing part (5), the signal processing part (5) is flip-mounted in the mounting groove (a) and electrically connected to the second circuit substrate (61), the second circuit substrate (61) is disposed on the mounting groove (a) and electrically connected to the first circuit substrate (3), and the infrared sensitive element (4) is disposed on the second circuit substrate (61) at a side away from the mounting groove (a) and electrically connected to the second circuit substrate (61).

5. The pyroelectric infrared sensor according to claim 4, wherein the second circuit substrate (61) is provided with heat dissipation grooves corresponding to the infrared sensitive element (4) to increase a heat transfer gap between the infrared sensitive element (4) and the second circuit substrate (61) and reduce the thermal stability interference of heat conducted from the application circuit board by the first circuit substrate (3) and the second circuit substrate (61) on the infrared sensitive element (4).

6. The pyroelectric infrared sensor according to claim 4, characterized in that a support (6) is arranged between the second circuit substrate (61) and the infrared sensitive element (4), and the infrared sensitive element (4) is electrically connected with the second circuit substrate (61) through the support (6).

7. The pyroelectric infrared sensor of any one of claims 1 to 6, characterized in that a bonding pad array, a plug connector (7), a stamp hole array or a BGA ball (8) electrically connected with the first circuit substrate (3) is fixedly arranged on the first circuit substrate (3) and used for externally electrically connecting and assembling and fixing the pyroelectric infrared sensor.

8. The pyroelectric infrared sensor according to any one of claims 1 to 6, characterized in that a vent hole communicating with the sealing space is provided on the first circuit substrate (3), and a sealing plug (9) sealing the vent hole is provided on the vent hole.

9. The pyroelectric infrared sensor according to any of the claims 1 to 6, characterized in that the first circuit substrate (3) is provided with an anti-electromagnetic interference structure comprising a metalized copper-clad and/or a metalized copper-clad-grooved.

10. The pyroelectric infrared sensor according to any of claims 1 to 6, characterized in that the first circuit substrate (3) is a multilayer circuit board.

11. The pyroelectric infrared sensor according to any one of claims 1 to 6, characterized in that additional components are arranged on the first circuit substrate (3), wherein the additional components at least comprise any one or more of a power supply voltage stabilization chip, an output signal control component, a photosensitive component, an analog or digital signal processing chip, a diode, a triode and a passive device; the additional parts are used for forming the high-integration and multifunctional integrated pyroelectric infrared sensor.

12. The pyroelectric infrared sensor of claim 1, wherein the base comprises a first circuit substrate (3) and a metal bottom plate, the metal bottom plate is fixedly arranged on the lower end face of the first circuit substrate (3), and the metal bottom plate is used for improving the overall heat capacity of the sensor, so as to improve the thermal stability of the sensor and improve the anti-electromagnetic interference performance of the sensor.