Surface mount type PIR sensor

Abstract

The utility model provides a surface-mounted PIR sensor. The surface-mounted PIR sensor comprises a PCB substrate, a signal conditioning chip, a supporting structure, a sensitive component, a PCB cover plate and an optical filter, the signal conditioning chip is arranged on the first surface of the PCB substrate and is used for leading out a signal to the second surface of the PCB substrate through a circuit arranged on the PCB substrate; the supporting structure surrounds the signal conditioning chip and is arranged on the first surface of the PCB substrate; the sensitive component is arranged above the signal conditioning chip through the supporting structure, and the sensitive component is electrically connected with the signal conditioning chip; the PCB cover plate surrounds the signal conditioning chip, the supporting structure and the sensitive component and is arranged on the substrate edge of the first surface of the PCB substrate; the optical filter is arranged on the PCB cover plate, and a closed space is defined by the optical filter, the PCB cover plate and the PCB substrate, so that the production cost of the patch type PIR sensor is reduced, and the electromagnetic shielding effect is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of sensors, in particular to a patch type PIR sensor. Background Art

[0002] The PIR (passive infrared sensor) sensor is also called a passive infrared sensor and also a pyroelectric infrared sensor. At present, the patch type PIR sensor is widely used in injection-molded or metal housings. For the patch sensor with an injection-molded housing, due to the complexity of its manufacturing process, the cost of secondary injection molding of the housing is too high. For the patch sensor with a metal housing, a PCB board is used to encapsulate the base. The material of the PCB board has poor high-temperature resistance and a high thermal resistance rate. The metalization process of the housing will have an adverse impact on the PCB substrate used as the base. For the finished product welded by the secondary reflow soldering process, problems such as poor soldering of the bottom pads and poor adhesion between the substrate and the cap are likely to occur. Summary of the Utility Model

[0003] To solve the above technical problems, the utility model provides a patch type PIR sensor.

[0004] A patch type PIR sensor provided by the utility model includes: a PCB substrate, a signal conditioning chip, a support structure, a sensitive component, a PCB cover plate, and a filter;

[0005] The signal conditioning chip is arranged on the first surface of the PCB substrate and is used to lead out the signal to the second surface of the PCB substrate through the circuit arranged on the PCB substrate;

[0006] The support structure is arranged around the signal conditioning chip on the first surface of the PCB substrate;

[0007] The sensitive component is arranged above the signal conditioning chip through the support structure, and is electrically connected between the sensitive component and the signal conditioning chip;

[0008] The PCB cover plate is arranged around the signal conditioning chip, the support structure, and the sensitive component at the edge of the first surface of the PCB substrate;

[0009] The filter is arranged on the PCB cover plate and encloses a sealed space with the PCB cover plate and the PCB substrate.

[0010] In a possible implementation manner, chip pads are arranged on the first surface of the PCB substrate;

[0011] The signal conditioning chip is soldered on the chip pads and is connected to the circuit arranged on the PCB substrate through the chip pads.

[0012] In a possible implementation, an adhesive area is provided on the first surface of the PCB substrate;

[0013] The PCB cover plate is adhered to the adhesive area through a conductive adhesive material.

[0014] In a possible implementation, the adhesive area is closed-shaped.

[0015] In a possible implementation, the support structure includes a first support post and a second support post;

[0016] The first support post and the second support post are oppositely arranged on both sides of the signal conditioning chip, and the sensitive component is supported above the signal conditioning chip.

[0017] In a possible implementation, a space is provided between the signal conditioning chip and the sensitive component.

[0018] In a possible implementation, the first support post and the second support post are made of a conductive material or a material with a low resistivity;

[0019] The sensitive component is electrically connected to the signal conditioning chip through the first support post and the second support post.

[0020] In a possible implementation, the first support post and the second support post are made of a non-conductive material;

[0021] A conductive layer is provided on the surfaces of the first support post and the second support post;

[0022] The sensitive component is electrically connected to the signal conditioning chip through the conductive layer.

[0023] In a possible implementation, the sealed space is a cylinder.

[0024] The technical solution provided by the present utility model has at least the following beneficial effects:

[0025] By applying the PCB substrate and the PCB cover plate to the structure of the sensor, the design and process of the metallized surface can be optimized, which can greatly reduce the material cost and production cost, and can achieve the same or better electromagnetic shielding effect compared with the current similar surface-mounted sensors on the market. Description of the Drawings

[0026] Figure 1 It is a three-dimensional structural schematic diagram of a surface-mounted PIR sensor provided by an embodiment of the present utility model during non-combined assembly;

[0027] Figure 2A three-dimensional structural schematic diagram of a patch-type PIR sensor provided by an embodiment of the present invention during partial combined assembly;

[0028] Figure 3 A three-dimensional structural schematic diagram of the overall patch-type PIR sensor provided by an embodiment of the present invention;

[0029] Figure 4 A front-view structural schematic diagram of a patch-type PIR sensor provided by an embodiment of the present invention;

[0030] Figure 5 A cross-sectional view of a patch-type PIR sensor provided by an embodiment of the present invention passing through a support structure;

[0031] In the drawings, 10, PCB substrate; 11, chip pad; 12, bonding area; 13, fulcrum; 20, signal conditioning chip; 30, support structure; 40, sensitive component; 50, PCB cover; 60, filter. Detailed implementation manners

[0032] To deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with the drawings and embodiments. The embodiments are only used to explain the present invention and do not limit the protection scope of the present invention.

[0033] Please refer to Figures 1 to 5 , a patch-type PIR sensor provided by the present invention includes: a PCB substrate 10, a signal conditioning chip 20, a support structure 30, a sensitive component 40, a PCB cover 50, and a filter 60;

[0034] The signal conditioning chip 20 is disposed on the first surface of the PCB substrate 10 and is used to lead out signals to the second surface of the PCB substrate 10 through the circuit provided on the PCB substrate 10;

[0035] The support structure 30 is disposed around the signal conditioning chip 20 on the first surface of the PCB substrate 10;

[0036] The sensitive component 40 is disposed above the signal conditioning chip 20 through the support structure 30, and the sensitive component 40 is electrically connected to the signal conditioning chip 20;

[0037] The PCB cover 50 surrounds the signal conditioning chip 20, the support structure 30, and the sensitive component 40 and is disposed on the substrate edge of the first surface of the PCB substrate 10;

[0038] The filter 60 is disposed on the PCB cover plate 50, and encloses a sealed space with the PCB cover plate 50 and the PCB substrate 10.

[0039] In this embodiment, the PCB substrate 10 leads out the signals of the signal conditioning chip 20 to the pads on the bottom surface, i.e., the second surface, of the PCB substrate 10, which is equivalent to leading out the (input and output) pins of the signal conditioning chip 20. The bottom pads are the external interfaces of the sensor, such as including an input port and an output port. The upper surface, i.e., the first surface, of the PCB substrate 10 is provided with pads and a copper cladding layer. The pads and the copper cladding layer are not connected, and the copper cladding layer serves as an electromagnetic shielding metal layer. The part of the PCB substrate 10 that fits with the PCB cover plate 50 is also provided with a metal layer, which plays a conductive role and is connected to the PCB cover plate 50 serving as a shielding layer. The signal conditioning chip 20 is a conventional chip for PIR sensors, and is used to filter, amplify and convert the signals of the sensitive component 40. The support structure 30 is a conventional support structure, which is mainly used to support the sensitive component 40 and can also be used to lead out the signals of the sensitive component 40 to the signal conditioning chip 20. The support structure 30 can be multiple support columns, and its material can be made of conductive or insulating materials. The sensitive component 40 is a conventional model, which is mainly used to absorb the infrared light radiated by the human body or other objects and convert the infrared light signal into an electrical signal. The PCB cover plate 50 is a cover plate made of PCB, which can be understood as a ring-shaped PCB, and metal layers are provided on its inner side, upper and lower surfaces. The filter 60 is mainly used to selectively allow infrared light to pass through while filtering out light of other wavelengths. The sealed space enclosed by the filter 60, the PCB cover plate 50 and the PCB substrate 10 can be a cylinder or other shapes. In a specific implementation manner, when the support structure 30 leads out the signals of the sensitive component 40 to the signal conditioning chip 20, if the support structure 30 is made of a conductive material, the electrical connection between the sensitive component 40 and the signal conditioning chip 20 can be directly realized by using the conductivity of the support structure 30; if the support structure 30 is made of an insulating material, corresponding conductive channels can be coated on the support structure 30 with conductive glue to conduct the two ends of the support structure 30, so as to realize the electrical connection between the sensitive component 40 and the signal conditioning chip 20.

[0040] In a possible implementation manner, a chip pad 11 is provided on the first surface of the PCB substrate 10;

[0041] The signal conditioning chip 20 is soldered on the chip pad 11 and is connected to the circuit provided on the PCB substrate 10 through the chip pad 11.

[0042] In this embodiment, the chip pad 11 is a conventional pad for soldering. The chip pad 11 can be electrically connected to the pad provided on the second surface through the circuit provided in the PCB substrate 10. The circuit provided in the PCB substrate 10 can be a simple copper-clad via, that is, the chip pad 11 on the first surface is directly electrically connected to the pad on the second surface through the copper-clad via. The signal conditioning chip 20 can thus be electrically connected to the pad on the second surface through the chip pad 11. In specific implementation, a fulcrum 13 is further provided on the first surface of the PCB substrate 10, and the fulcrum 13 serves as the support point of the support structure 30 on the PCB substrate 10. The fulcrum 13 can adopt the form of a pad, and the fulcrum 13 is electrically connected to the corresponding chip pad 11 through the circuit provided in the PCB substrate 10. The sensitive component 40 can thus be electrically connected to the signal conditioning chip 20 through the fulcrum 13.

[0043] In a possible implementation manner, an adhesive area 12 is provided on the first surface of the PCB substrate 10;

[0044] The PCB cover plate 50 is adhered to the adhesive area 12 through a conductive adhesive material.

[0045] In this embodiment, a metal layer is provided in the adhesive area 12. The conductive adhesive material can adopt silver paste and epoxy resin. In specific implementation, assuming that the contact position between the PCB cover plate 50 and the adhesive area 12 is circular, the silver paste is in the inner layer of the circular adhesive area 12, and the epoxy resin is in the outer layer of the circular adhesive area 12. As Figure 4 , when the PCB cover plate 50 is adhered to the PCB substrate 10, the conductive adhesive material is coated into an adhesive layer with a certain thickness, and a gap is left outside the adhesive area 12 between the PCB cover plate 50 and the PCB substrate 10 due to the existence of the adhesive layer.

[0046] In a possible implementation manner, the adhesive area 12 is closed.

[0047] In this embodiment, the closed shape can be a closed circular ring or other closed shapes, which can effectively ensure the closed-loop connection between the PCB substrate 10 and the PCB cover plate 50 and improve the electromagnetic shielding performance.

[0048] In a possible implementation manner, the support structure 30 includes a first support column 31 and a second support column 32;

[0049] The first support column 31 and the second support column 32 are oppositely arranged on both sides of the signal conditioning chip 20, and the sensitive component 40 is supported above the signal conditioning chip 20.

[0050] In this embodiment, the first support column 31 and the second support column 32 are symmetrically arranged on both sides of the signal conditioning chip 20. The first support column 31 and the second support column 32 can be made of conductive materials or low-resistance materials, or non-conductive materials with conductive layers on their surfaces.

[0051] In a possible implementation, there is a gap between the signal conditioning chip 20 and the sensitive component 40.

[0052] In this embodiment, a certain space is reserved between the signal conditioning chip 20 and the sensitive component 40 to prevent interference between the two and avoid affecting the overall performance of the sensor.

[0053] In a possible implementation, the first support column 31 and the second support column 32 are made of conductive materials or materials with low resistivity;

[0054] The sensitive component 40 is electrically connected to the signal conditioning chip 20 through the first support column 31 and the second support column 32.

[0055] In this embodiment, the conductive materials or materials with low resistivity used for the first support column 31 and the second support column 32 are all conventional types of materials. The first support column 31 and the second support column 32 can respectively serve as transmission wires. The sensitive component 40 is electrically connected to the PCB substrate 10 through the first support column 31 and the second support column 32, and is electrically connected to the signal conditioning chip 20 through the PCB substrate 10.

[0056] In a possible implementation, the first support column 31 and the second support column 32 are non-conductive materials;

[0057] The surfaces of the first support column 31 and the second support column 32 are provided with conductive layers;

[0058] The sensitive component 40 is electrically connected to the signal conditioning chip 20 through the conductive layer.

[0059] In this embodiment, the conductive layer can be formed by coating the surfaces of the first support column 31 and the second support column 32 with conductive glue. The sensitive component 40 can be electrically connected to the PCB substrate 10 through the conductive layer, and is electrically connected to the signal conditioning chip 20 through the PCB substrate 10.

[0060] In a possible implementation, the enclosed space is a cylinder.

[0061] In this embodiment, a closed cylindrical space is formed among the optical filter 60, the PCB cover plate 50, and the PCB substrate 10, which is convenient for processing and manufacturing. Both the PCB cover plate 50 and the PCB substrate 10 are made of PCB material with a metal layer provided thereon, so as to construct a cylindrical metallized shielding layer, effectively improving the electromagnetic shielding effect.

[0062] The above embodiments shall not limit the present utility model in any way, and all technical solutions obtained by means of equivalent replacement or equivalent conversion fall within the protection scope of the present utility model.

Claims

1. A patch type PIR sensor, characterized in that: include: PCB substrate, signal conditioning chip, support structure, sensitive components, PCB cover, filter; The signal conditioning chip is arranged on the first surface of the PCB substrate, and is used to lead the signal to the second surface of the PCB substrate through the circuit arranged on the PCB substrate; The support structure is arranged on the first surface of the PCB substrate around the signal conditioning chip; The sensitive component is arranged above the signal conditioning chip through the supporting structure, and the sensitive component is electrically connected to the signal conditioning chip; The PCB cover plate surrounds the signal conditioning chip, the support structure, and the sensitive components and is arranged on the substrate edge of the first surface of the PCB substrate; The filter is arranged on the PCB cover plate, and forms a closed space with the PCB cover plate and the PCB substrate.

2. The patch type PIR sensor according to claim 1, characterized in that: The first surface of the PCB substrate is provided with a chip pad; The signal conditioning chip is soldered on the chip pad and connected to a circuit arranged on the PCB substrate through the chip pad.

3. The patch type PIR sensor according to claim 1, characterized in that: The first surface of the PCB substrate is provided with a bonding area; The PCB cover plate is bonded to the bonding area by means of a conductive bonding material.

4. The patch type PIR sensor according to claim 3, characterized in that: The bonding area is closed.

5. The patch type PIR sensor according to claim 1, characterized in that: The support structure includes a first support column and a second support column; The first supporting column and the second supporting column are relatively arranged on two sides of the signal conditioning chip, and support the sensitive component to be arranged above the signal conditioning chip.

6. The patch type PIR sensor according to claim 5, characterized in that: The signal conditioning chip is spaced apart from the sensitive components.

7. The patch type PIR sensor according to claim 5, characterized in that: The first support column and the second support column are made of conductive material or low resistivity material; The sensitive component is electrically connected to the signal conditioning chip through the first supporting column and the second supporting column.

8. The patch type PIR sensor according to claim 5, characterized in that: The first support column and the second support column are made of non-conductive material; A conductive layer is provided on the surfaces of the first supporting column and the second supporting column; The sensitive component is electrically connected to the signal conditioning chip through the conductive layer.

9. The patch type PIR sensor according to claim 1, characterized in that: The enclosed space is a cylinder.

Images