CN218271080U

CN218271080U - Pyroelectric infrared sensor with external signal processing part

Info

Publication number: CN218271080U
Application number: CN202121962836.1U
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 with external signal processing parts relates to the technical field of infrared sensors. It includes a cap, a base assembled with the cap to form a sealed space, the base including a circuit substrate; the infrared sensitive element is fixed on the upper surface of the circuit substrate and is positioned in the sealed space; and the signal processing part is arranged outside the pipe cap and fixed on the circuit substrate, and the signal processing part is electrically connected with the circuit substrate. The base comprises a circuit substrate and a metal shielding bottom plate, and the metal shielding bottom plate is fixedly arranged on the lower end face of the circuit substrate; and the metal shielding bottom plate is provided with an accommodating space for accommodating the signal processing part. By adopting the technical scheme, the signal processing part is external and is designed on the lower surface of the substrate, the hole can be formed in the position of the application circuit board corresponding to the signal processing part, the signal processing part is embedded into the installation mode inside the application circuit board, the ultrathin application of the sensor is realized, meanwhile, the automatic production of the sensor is convenient, the efficiency is improved, and the cost is reduced.

Description

Pyroelectric infrared sensor with external signal processing part

Technical Field

The utility model relates to an infrared sensor technical field, concretely relates to external pyroelectric infrared sensor of signal processing part.

Background

A pyroelectric infrared sensor is a sensor for detecting infrared heat 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 heat 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 market at present 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, a signal processing part and a supporting part for fixing the infrared sensitive element are arranged in the closed space in a stacking mode, a gap is arranged between the infrared sensitive element and the signal processing element to ensure the performance of the infrared sensitive element and the signal processing element, the supporting part and the 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 which is converted by a signal circuit on the PCB circuit substrate and is output outwards. The traditional pyroelectric infrared sensor has the following defects: a certain gap needs to be kept between the infrared sensitive element and the signal processing element, so that the support piece needs to be customized, the structure and the production process of the sensor are complex, the assembly automation of the sensor is not facilitated, the efficiency is low, the cost is high, and the ultra-thin and small-size packaging of the sensor is not facilitated.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to prior art's defect and not enough, provide an external pyroelectric infrared sensor of signal processing part, remove the support component between infrared sensing element and the circuit substrate among the traditional pyroelectric sensor, and seal through the signal processing part is external and through the metal shielding bottom plate, realize can realizing the ultra-thin and small-size encapsulation of sensor when not influencing the basic performance of sensor, satisfy the requirement of application to product mounting height and small-size.

In order to achieve the above object, the utility model adopts the following technical scheme: a pyroelectric infrared sensor with external signal processing parts comprises: the upper surface of the pipe cap is provided with a window; the infrared filter is embedded on the window; a base assembled with the cap to form a sealed space, the base including a circuit substrate; the infrared sensitive element is fixed on the upper surface of the circuit substrate and is positioned in the sealed space; and a signal processing part which is arranged outside the pipe cap and fixed on the circuit substrate, wherein the signal processing part is electrically connected with the circuit substrate.

The base comprises a circuit substrate and a metal shielding bottom plate, and the metal shielding bottom plate is fixedly arranged on the lower end face of the circuit substrate; the metal shielding bottom plate is provided with an accommodating space for accommodating the signal processing part, and the circuit substrate and the metal shielding bottom plate are sealed to form a sealed accommodating space.

The circuit board is provided with a heat dissipation groove at a position corresponding to the infrared sensitive element so as to increase a heat transfer gap between the infrared sensitive element and the circuit board and reduce the thermal stability interference of heat conducted from the application circuit board by the circuit board on the infrared sensitive element.

And a supporting piece for supporting the infrared sensitive element is arranged in the sealed space on the circuit substrate.

The 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 and the sealing space.

And the circuit substrate is provided with a vent hole for communicating the closed space formed by the metal shielding bottom plate and the circuit substrate with the closed space formed by the pipe cap and the circuit substrate.

The electric connecting part of the pyroelectric infrared sensor comprises a plug connector, a BGA ball, a stamp hole array or a bonding pad array which is fixedly arranged on the circuit substrate and electrically connected with the circuit substrate.

The 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 circuit substrate is a multilayer circuit board.

The circuit board 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 a pyroelectric infrared sensor with high integration level and multifunctional integration and an external signal processing part.

The base includes circuit substrate and metal shielding bottom plate, the pipe cap with the metal shielding bottom plate forms airtight space, the metal shielding bottom plate is used for improving the whole heat capacity of sensor, in order to improve the thermal stability ability of sensor and improve the anti-electromagnetic interference performance of sensor.

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

1. by adopting the design that the signal processing part is arranged externally and the heat dissipation groove is arranged between the circuit substrate and the infrared sensitive element, the supporting part of the infrared sensitive element can be omitted, the process is simplified, the automatic production of the sensor is facilitated, the cost is reduced, the thickness of the sensor is reduced, and the ultrathin and small-size packaging of the sensor is realized.

2. The signal processing part is external and sets up in the circuit substrate lower surface, when customer's actual application, can be at the position trompil that the application circuit board corresponds to the signal processing part, adopts the mounting means of embedding the signal processing part inside the application circuit board, has further reduced the height that the sensor was surperficial from customer application circuit board to the sensor, has realized the ultra-thin application of sensor.

3. 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 sectional view of embodiment 1 of the present invention;

FIG. 2 is a sectional view of embodiment 2;

FIG. 3 is a sectional view of a first embodiment of embodiment 3;

FIG. 4 is a schematic structural view of a second embodiment of embodiment 3;

FIG. 5 is a sectional view of a third embodiment of embodiment 3;

FIG. 6 is a sectional view of embodiment 4.

Description of the reference numerals: 1. a pipe cap; 2. an infrared filter; 3. a circuit board; 4. an infrared-sensitive element; 5. a signal processing part; 6. a metal shielding chassis; 7. a plug-in unit; 71. an electrode; a. a groove; 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 an external pyroelectric infrared sensor for signal processing parts, as shown in fig. 1, including: the device comprises a pipe cap 1, an infrared filter 2, a base, an infrared sensitive element 4 and a signal processing part 5.

The upper surface of the pipe cap 1 is provided with a window; the infrared filter 2 is embedded on the window; the base and the pipe cap 1 are assembled to form a sealed space, and the pipe cap 1 is glued on the base; the base comprises a circuit substrate 3, an infrared sensitive element 4 is fixed on the upper surface of the circuit substrate 3 and is positioned in a sealed space, and the infrared sensitive element 4 is glued on the circuit substrate 3; the signal processing part 5 sets up outside the pipe cap 1 and is fixed in on the circuit substrate 3, the signal processing part 5 is connected with the circuit substrate 3 electricity, the signal processing part 5 is external and sets up in the 3 lower surfaces of circuit substrate, when customer's actual application, can be at the position trompil that the application circuit board corresponds to the signal processing part 5, adopt the mounting means of embedding the signal processing part 5 inside the application circuit board, the height of sensor from customer application circuit board surface to sensor surface has further been reduced, the ultra-thin application of sensor has been realized.

Preferably, the base comprises a circuit substrate 3 and a metal shielding bottom plate 6, wherein the metal shielding bottom plate 6 is fixedly arranged on the lower end face of the circuit substrate 3; the metal shield chassis 6 is provided with an accommodating space for accommodating the signal processing component 5, and the circuit board 3 and the metal shield chassis 6 are sealed to form a sealed accommodating space. In this embodiment, the circuit substrate 3 is an epoxy PCB circuit board, the signal processing part 5 is a JFET, an amplifier, an MCU or an intelligent integrated circuit or an ADC device, the circuit substrate 3 is respectively bonded to the infrared sensitive element 4, the signal processing part 5, the cap 1 and the metal shielding bottom plate 6, and the cap 1 and the infrared filter 2 by gluing or welding, and the conventional resistive energy storage sealing process in the manufacturing process is eliminated, so that the process is simplified, the efficiency is improved, and the cost is reduced.

It should be noted that, the signal processing part 5 of the pyroelectric infrared sensor is externally arranged and shielded by the accommodating space of the metal shielding bottom plate 6, and meanwhile, the sensitive element supporting part between the sensitive element and the circuit substrate 3 in the traditional pyroelectric sensor is removed, the pyroelectric infrared sensor is mounted on the client through hole application circuit board with the metal shielding bottom plate 6 for embedding, so that the height between the top of the pyroelectric infrared sensor and the bottom of the external circuit board is conveniently reduced, the ultrathin application and mounting of the pyroelectric infrared sensor can be realized, the requirements of the application end on the thickness and the small size of the product are met, and the miniature electronic device with the pyroelectric infrared sensor is conveniently manufactured.

Preferably, in order to extend the functionality of the sensor. Peripheral components are arranged on the circuit substrate 3, and the peripheral components are positioned inside or outside the pipe cap 1. The peripheral component parts include at least: 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 and a passive device. The output signal control component comprises any one or more of a triode, a field effect tube, a controllable silicon and a relay, and the passive component at least comprises any one or more of a resistor, a capacitor and an inductor.

Example 2:

the main difference between this embodiment and embodiment 1 is that, as shown in fig. 2, a heat dissipation groove a is provided on the circuit substrate 3 at a position corresponding to the infrared sensitive element 4, so as to increase a heat transfer gap between the infrared sensitive element 4 and the circuit substrate 3, so as to reduce the thermal stability interference of heat conducted from the application circuit board by the circuit substrate 3 on the infrared sensitive element 4, thereby improving the thermal stability of the pyroelectric infrared sensor. In some embodiments, a support member for supporting the infrared sensor 4 is disposed in the sealed space on the circuit substrate 3, the infrared sensor 4 is electrically connected to the circuit substrate 3 through the support member, and the support member is fixed to the infrared sensor 4 and the circuit substrate 3 by gluing. To match the optical focal length height. The support is a standard chip component, and the chip component comprises a chip resistor, a chip capacitor, a chip inductor or a chip diode.

Example 3:

the present embodiment is mainly different from embodiment 1 and/or embodiment 2 in that, as shown in fig. 3, 4, and 5, the electrical connection member of the pyroelectric infrared sensor includes a plug 7, a BGA ball 8, a stamp hole array, or a pad array, which is fixedly provided on the circuit substrate 3 and electrically connected to the circuit substrate 3. When the electrical connection component is the plug 7, the plug 77 is used for realizing external electrical connection and assembly of the pyroelectric infrared sensor, the plug 77 is a patch vertical plug 77, and 6 electrodes 7171 are arranged on one side of the plug 77, which is far away from the circuit substrate 3. In some embodiments, the connector 77 is provided with a receiving groove on a side close to the circuit substrate 3, and the receiving groove is used for receiving the metal shielding chassis 6 therein. In some embodiments, connector 77 is disposed on the lower surface of circuit substrate 3 in parallel with metal shield chassis 6.

When the electrical connection components are BGA balls 8. The BGA balls 8 are provided in plurality. The BGA ball 8 is a tin ball, a copper ball, a steel ball or an aspherical block or a column, the surface of the BGA ball 8 is an object easy to be coated with tin, and the ball is a metal conductor or a nonconductor with a conductive layer plated on the surface. The BGA is called Ball Grid Array Package, the Chinese name is Ball Grid Array Package, and the BGA balls 8 are arranged on the mounting side of the sensor circuit substrate 3, so that the automatic production of SMT (surface mount technology) patches is realized to improve the efficiency and reduce the cost when the sensor is applied, and the reflow soldering quality of the patches is ensured; meanwhile, due to the existence of the BGA balls 8, a gap exists between the sensor circuit substrate 3 and the application board where the sensor circuit substrate is located, the contact area is small, the thermal resistance between the application board and the sensor circuit substrate 3 is greatly increased, heat on the application board is reduced to be conducted to the sensor circuit substrate 3, the capacity of the sensor for resisting the temperature change of the space environment where the sensor is located is improved, and the thermal stability of the sensor is improved.

Example 4:

in this embodiment, based on any of the above embodiments, as shown in fig. 6, the 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 sealing the vent hole and the sealed space. In this embodiment, the sealing plug 9 is a sealant. The sealant is fixedly arranged in the vent hole. The arrangement of the vent holes 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 at multiple positions such as the infrared sensitive element 4, the circuit substrate 3, the signal processing part 5, the metal shielding bottom plate 6, the pipe cap 1 and the like 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.

Example 5:

in this embodiment, on the basis of any of the above embodiments, the circuit substrate 3 is provided with an anti-electromagnetic interference structure, and the anti-electromagnetic interference structure includes a metallized covered edge copper-clad layer and/or a metallized open groove 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:

on the basis of any of the above embodiments, the base includes the circuit substrate 3 and the metal shielding bottom plate 6, the cap 1 and the metal shielding bottom plate 6 form an enclosed space, and the metal shielding bottom plate 6 is used to improve 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 shield bottom plate 6 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 3 and protrude out of the metal shielding bottom plate 6, and SMT reflow soldering and welding fixation of the sensor are achieved.

The above description is only for the purpose of illustration and not limitation, and other modifications or equivalent replacements made by those skilled in the art to the technical solution of the present invention should be covered by the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. A pyroelectric infrared sensor with external signal processing parts is characterized by comprising: the pipe cap (1), the upper surface of the pipe cap (1) is provided with a window;

an infrared filter (2) embedded on the window;

a base assembled with the cap (1) to form a sealed space, the base including a circuit substrate (3);

the infrared sensitive element (4) is fixed on the upper surface of the circuit substrate (3) and is positioned in the sealed space; and the number of the first and second groups,

the signal processing part (5) is arranged outside the pipe cap (1) and fixed on the circuit substrate (3), and the signal processing part (5) is electrically connected with the circuit substrate (3).

2. The pyroelectric infrared sensor externally arranged on the signal processing part as claimed in claim 1, wherein the base comprises a circuit substrate (3) and a metal shielding bottom plate (6), and the metal shielding bottom plate (6) is fixedly arranged on the lower end face of the circuit substrate (3); the metal shielding bottom plate (6) is provided with an accommodating space for accommodating the signal processing part (5), and the circuit substrate (3) and the metal shielding bottom plate (6) are sealed to form a sealed accommodating space.

3. The pyroelectric infrared sensor with external signal processing parts as claimed in any one of claims 1-2, wherein the circuit substrate (3) is provided with heat dissipation grooves (a) at positions corresponding to the infrared sensitive elements (4) to increase the heat transfer gap between the infrared sensitive elements (4) and the circuit substrate (3) so as to reduce the thermal stability interference of the infrared sensitive elements (4) caused by heat conducted from the application circuit board by the circuit substrate (3).

4. The pyroelectric infrared sensor with the external signal processing part as claimed in any one of claims 1 to 2, characterized in that a support member for supporting the infrared sensitive element (4) is arranged in the sealed space on the circuit substrate (3).

5. The pyroelectric infrared sensor with the external signal processing component as claimed in any one of claims 1 to 2, wherein a vent hole communicated with the sealed space is arranged on the circuit substrate (3), and a sealing plug (9) for sealing the vent hole and the sealed space is arranged on the vent hole.

6. The pyroelectric infrared sensor externally arranged on the signal processing part as claimed in claim 2, wherein the circuit substrate (3) is provided with a vent hole for communicating the sealed space formed by the metal shielding bottom plate (6) and the circuit substrate (3) with the sealed space formed by the tube cap (1) and the circuit substrate (3).

7. The pyroelectric infrared sensor with external signal processing parts as claimed in any one of claims 1 to 2, wherein the electrical connection part of the pyroelectric infrared sensor comprises a plug connector (7), a BGA (ball grid array) ball (8), a stamp hole array or a pad array fixedly arranged on the circuit substrate (3) and electrically connected with the circuit substrate (3).

8. The pyroelectric infrared sensor with the external signal processing part as claimed in any one of claims 1 to 2, characterized in that the circuit substrate (3) is provided with an anti-electromagnetic interference structure, and the anti-electromagnetic interference structure comprises metalized edge copper cladding and/or metalized open-groove copper cladding.

9. The pyroelectric infrared sensor externally arranged on the signal processing part as claimed in any one of claims 1 to 2, characterized in that the circuit substrate (3) is a multilayer circuit board.

10. The pyroelectric infrared sensor with the external signal processing parts as claimed in any one of claims 1 to 2, wherein additional parts are arranged on the circuit substrate (3), 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 a pyroelectric infrared sensor with high integration level and multifunctional integration and an external signal processing part.

11. The pyroelectric infrared sensor with external signal processing parts as claimed in any one of claims 1-2, wherein the base comprises a circuit substrate (3) and a metal shielding bottom plate (6), the cap (1) and the metal shielding bottom plate (6) form a closed space, and the metal shielding bottom plate (6) is used for improving the overall heat capacity of the sensor, improving the thermal stability of the sensor and improving the anti-electromagnetic interference performance of the sensor.