Compensation type pyroelectric detector

Abstract

The utility model discloses a compensation type pyroelectric detector, and relates to the technical field of compensation type pyroelectric detectors. The compensation type pyroelectric detector comprises a pin, the top of the pin penetrates through a packaging base to be connected with a circuit board, the top of the circuit board is provided with a pyroelectric compensation sensitive element, and the top of the pyroelectric compensation sensitive element is provided with a pyroelectric detection sensitive element; and a packaging cap is connected to the packaging base and covers the circuit board, the pyroelectric compensation sensitive element and the pyroelectric detection sensitive element. According to the compensation type pyroelectric detector, the pyroelectric compensation sensitive element and the pyroelectric detection sensitive element are arranged, and the pyroelectric compensation sensitive element and the pyroelectric detection sensitive element adopt a crossed and laminated compensation structure, so that the compensation type pyroelectric detector is different from a traditional parallel compensation structure; according to the utility model, the cavity space is saved, and at the same time, the offset effect of the compensation element in the detector on the pyroelectric signal is effectively suppressed.

Description

Technical Field

[0001] The utility model belongs to the technical field of compensated pyroelectric detectors, and in particular relates to a compensated pyroelectric detector. Background Art

[0002] A pyroelectric detector is a thermal-sensitive infrared detector that works by utilizing the effect that the spontaneous polarization intensity of pyroelectric materials changes with temperature.

[0003] The above device does not have a structure for improving the sensitivity of the detection device when in use, so that when the existing pyroelectric detector is in use, the compensation element in the traditional pyroelectric detector is easy to offset the pyroelectric signal, thereby causing the sensitivity of the traditional pyroelectric detector to be reduced to a certain extent when in use. Based on the shortcomings of the existing technology, the utility model designs a compensated pyroelectric detector. Utility Model Content

[0004] In order to solve the above problems existing in the prior art, the utility model provides a compensating pyroelectric detector, which has the characteristic of improving the sensitivity of the detection device.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a compensated pyroelectric detector, comprising a pin, the top of the pin passes through the packaging base to connect to the circuit board, the top of the circuit board is provided with a pyroelectric compensation sensitive element, and the top of the pyroelectric compensation sensitive element is provided with a pyroelectric detection sensitive element; a packaging cap is connected to the packaging base to cover the circuit board, the pyroelectric compensation sensitive element and the pyroelectric detection sensitive element.

[0006] As an optimal technical solution of a compensated pyroelectric detector of the utility model, the circuit board includes a field effect tube and a double-sided PCB board, the field effect tube is connected to the center of the lower end surface of the double-sided PCB board, and the double-sided PCB board is connected to the top of the pin.

[0007] As a preferred technical solution of a compensated pyroelectric detector of the utility model, filters are arranged on the tops of the pyroelectric detection sensitive element and the pyroelectric compensation sensitive element.

[0008] As a preferred technical solution of a compensated pyroelectric detector of the utility model, the pyroelectric compensation sensitive element and the pyroelectric detection sensitive element are stacked on the circuit board in a cross shape, and the sensitive coating is only distributed in the cross-stacked portion.

[0009] As a preferred technical solution of a compensated pyroelectric detector of the utility model, the pyroelectric compensation sensitive element and the pyroelectric detection sensitive element are bonded to the circuit board by silver glue.

[0010] As a preferred technical solution of a compensated pyroelectric detector of the utility model, the double-sided PCB board is provided with a conductive channel penetrating the upper and lower surfaces, and the conductive channel is used for welding with the pins.

[0011] Compared with the prior art, the beneficial effects of the utility model are:

[0012] 1. When the utility model is in use, a pyroelectric compensation sensitive element and a pyroelectric detection sensitive element are arranged. The pyroelectric compensation sensitive element and the pyroelectric detection sensitive element adopt a cross-stacked compensation structure. Different from the traditional parallel compensation structure, the detection element and the compensation element of the utility model are located in different planes, but are stacked together in a cross-cross manner. While saving cavity space, the compensation element in the detector effectively suppresses the offsetting effect of the pyroelectric signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0014] Figure 1 This is a schematic diagram of the pin structure of the utility model;

[0015] Figure 2 This is a schematic diagram of the field effect tube structure of the utility model;

[0016] Figure 3 This is a schematic diagram of the packaging base structure of the utility model;

[0017] Figure 4 This is a schematic diagram of the filter structure of the utility model.

[0018] In the figure: 1. Pin; 2. Package base; 3. Circuit board; 4. Pyroelectric compensation sensitive element; 5. Pyroelectric detection sensitive element; 6. Package cap; 201. Field effect transistor; 202. Double-sided PCB board; 501. Filter. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0020] Example 1

[0021] See also Figure 1-4The utility model provides the following technical solutions: a compensated pyroelectric detector, comprising a pin 1, the top of the pin 1 passes through a packaging base 2 and is connected to a circuit board 3, a pyroelectric compensation sensitive element 4 is arranged on the top of the circuit board 3, and a pyroelectric detection sensitive element 5 is arranged on the top of the pyroelectric compensation sensitive element 4; a packaging cap 6 is connected to the packaging base 2, covering the circuit board 3, the pyroelectric compensation sensitive element 4 and the pyroelectric detection sensitive element 5.

[0022] The circuit board 3 includes a field effect transistor 201 and a double-sided PCB board 202 . The field effect transistor 201 is connected to the center of the lower end surface of the double-sided PCB board 202 , and the double-sided PCB board 202 is connected to the top of the pin 1 .

[0023] A filter 501 is disposed on the top of the pyroelectric detection sensitive element 5 and the pyroelectric compensation sensitive element 4 .

[0024] The pyroelectric compensation sensitive element 4 and the pyroelectric detection sensitive element 5 are stacked on the circuit board 3 in a cross shape.

[0025] It needs to be further explained that the top of the pyroelectric detection sensitive element 5 is an absorption coating, the top of the pyroelectric compensation sensitive element 4 is a compensation coating, and the overlapping portion of the top coatings of the pyroelectric detection sensitive element 5 and the pyroelectric compensation sensitive element 4 is called a sensitive coating; because the compensation coating is placed at the high end, it can be completely shielded, thereby avoiding the influence of the external real flame signal on the sensitive coating, and on the other hand, saving the cost of material use.

[0026] The pyroelectric compensation sensitive element 4 and the pyroelectric detection sensitive element 5 are bonded to the circuit board 3 by silver glue.

[0027] The double-sided PCB board 202 is provided with a conductive channel running through the upper and lower surfaces, and the conductive channel is used for welding with the pin 1 .

[0028] It needs to be further explained that the filter 501 is usually selected as 6-15μm (micrometers) to make the pyroelectric detector work in the mid-infrared band. Since the pyroelectric detection sensitive element 5 has a wide response spectral range, a suitable 3-2 can be selected according to actual needs.

[0029] There is no exact value for the size of the accommodating cavity of the packaging cap 6, and the height is preferably 0.1-0.5 mm (millimeter), which is slightly larger than the pyroelectric compensation sensitive element 4 to avoid squeezing the sensitive element and affecting the compensation effect.

[0030] The heightening bolts are used to place and fix the double-sided PCB board 202. The fixing method of the sensitive element and the circuit board 3 is a conventional technical means in the field, and the present utility model does not limit this.

[0031] The pyroelectric detection sensitive element 5 and the pyroelectric compensation sensitive element 4 are made of pyroelectric materials, but are not limited to ceramic materials such as lead zirconate titanate, lithium tantalate, lithium niobate, etc., single crystal materials or composite materials.

[0032] The appropriate readout circuit can be selected according to the modulation frequency of the incident light. If the modulation frequency of the incident light is low, the readout circuit can be designed based on a junction field effect transistor or a common operational amplifier; if the modulation frequency of the incident light is high, a radio frequency amplifier circuit or a coaxial line can be selected as the readout circuit.

[0033] The cross-stacked compensation structure is different from the traditional parallel compensation structure. The detection element and the compensation element of the utility model are located in different planes, but are stacked together in a cross-cross manner. While saving cavity space, it effectively suppresses the offsetting effect of the compensation element in the detector on the pyroelectric signal.

[0034] Working principle: When a compensated pyroelectric detector is used, a circuit board 3 for a readout circuit is first arranged on the top of the package base 2, and the pyroelectric compensation sensitive element 4 and the pyroelectric detection sensitive element 5 are fixed at the center of the circuit board 3 in an up-and-down stacking manner to form a cross-layered structure. The empty space at the intersection can be used to weld the pin 1. Conductive channels are arranged on the circuit board 3 to pass through its upper and lower surfaces. The conductive channels are distributed in the four corners of the cross-structure that do not cover the sensitive element. The conductive channels are used for pin 1 welding. The upper surfaces of the pyroelectric compensation sensitive element 4 and the pyroelectric detection sensitive element 5 are not completely covered with sensitive materials. The sensitive materials that make up the sensitive elements are mainly divided into Arranged in the cross-overlapping part, the pyroelectric compensation sensitive element 4 and the pyroelectric detection sensitive element 5 can be directly bonded to the circuit board 3 using silver glue. Since the pyroelectric detection sensitive element 5 is stacked on the upper end of the pyroelectric compensation sensitive element 4 in a cross-over manner, the mechanical support parts at both ends of the pyroelectric detection sensitive element 5 are slightly padded with silver glue or other conductive materials. The circuit board 3 is also provided with resistors, capacitors, and voltage or current amplifiers. The amplifiers are respectively connected to the pyroelectric detection sensitive element 5 and the pyroelectric compensation sensitive element 4 through conductive traces. The pyroelectric detection sensitive element 5 and the pyroelectric compensation sensitive element 4 are made of pyroelectric materials, including ceramics or thin film materials such as lead zirconate titanate and lithium tantalate.

[0035] The compensation type pyroelectric detector adopts the following manufacturing method:

[0036] 1. If Figure 2 As shown, the field effect tube 201 is embedded into the through hole at the lower end of the double-sided PCB board 202, so that the bottom of the field effect tube 201 is flush with the lower surface of the double-sided PCB board 202, and then the pin 1 at the bottom of the field effect tube 201 is sequentially soldered to the corresponding pads on the lower surface of the double-sided PCB board 202;

[0037] 2. Fix the short sides of the pyroelectric compensation sensitive element 4 on the upper surface of the double-sided PCB board 202 using silver glue;

[0038] 3. Stack the pyroelectric detection sensitive element 5 and the pyroelectric compensation sensitive element 4 on the upper surface of the double-sided PCB board 202 in a cross-shaped manner, slightly pad and fix the two short sides with silver glue, and put them in a 150°C oven for heating and drying;

[0039] 4. Insert the pin 1 into the package base 2 and fix it by soldering, and then connect it to the double-sided PCB board 202 circuit by using the heightening bolts;

[0040] 5. Use energy storage welding to package the packaging cap 6 with the filter 501 and the packaging base 2.

[0041] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions described in the above embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A compensated pyroelectric detector, comprising a pin (1), characterized in that: The top of the pin (1) passes through the package base (2) and is connected to the circuit board (3); a pyroelectric compensation sensitive element (4) is arranged on the top of the circuit board (3); and a pyroelectric detection sensitive element (5) is arranged on the top of the pyroelectric compensation sensitive element (4); a package cap (6) is connected to the package base (2) to cover the circuit board (3), the pyroelectric compensation sensitive element (4) and the pyroelectric detection sensitive element (5).

2. The compensated pyroelectric detector according to claim 1, characterized in that: The circuit board (3) comprises a field effect tube (201) and a double-sided PCB board (202), the field effect tube (201) being connected to the center of the lower end surface of the double-sided PCB board (202), and the double-sided PCB board (202) being connected to the top of the pin (1).

3. The compensated pyroelectric detector according to claim 1, characterized in that: Optical filters (501) are arranged on the tops of the pyroelectric detection sensitive element (5) and the pyroelectric compensation sensitive element (4).

4. The compensated pyroelectric detector according to claim 1, characterized in that: The pyroelectric compensation sensitive element (4) and the pyroelectric detection sensitive element (5) are stacked on the circuit board (3) in a cross shape, and the sensitive coating is only distributed in the cross-stacked portion.

5. The compensated pyroelectric detector according to claim 4, characterized in that: The pyroelectric compensation sensitive element (4) and the pyroelectric detection sensitive element (5) are bonded to the circuit board (3) by silver glue.

6. The compensated pyroelectric detector according to claim 2, characterized in that: The double-sided PCB board (202) is provided with a conductive channel penetrating the upper and lower surfaces, and the conductive channel is used for welding with the pin (1).

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