CN217586060U

CN217586060U - Packaging structure capable of enhancing infrared absorption of infrared thermopile detector

Info

Publication number: CN217586060U
Application number: CN202220892227.1U
Authority: CN
Inventors: 关一浩; 雷程; 梁庭; 熊继军; 武学占
Original assignee: North University of China
Current assignee: North University of China
Priority date: 2022-04-18
Filing date: 2022-04-18
Publication date: 2022-10-14
Anticipated expiration: 2032-04-18

Abstract

The utility model belongs to the technical field of infrared thermopile detector encapsulation, when having solved external infrared radiation and having penetrated the light filter and shine the thermopile film, partly reflected, partly see through the film and shine the bottom, only few part radiation is absorbed by the film, leads to the problem that the response rate is low. The utility model provides a can strengthen infrared thermopile detector infrared absorption's packaging structure, including infrared sensor chip, encapsulation pipe cap and encapsulation tube socket, the encapsulation tube socket is located encapsulation pipe cap bottom and constitutes a confined hollow region with the encapsulation pipe cap, the infrared sensor chip arrange in the hollow region and with encapsulate between the tube socket through the reflection base be connected, the position that encapsulation pipe cap upper end corresponds the infrared sensor chip has the radiation mouth, the radiation mouth covers through a protruding transmission filter. The reflection base which can reflect the infrared light penetrating through the film layer of the chip is arranged below the infrared sensor chip, so that the infrared sensor chip absorbs the infrared radiation for the second time, and the performance of the detector is enhanced.

Description

Packaging structure capable of enhancing infrared absorption of infrared thermopile detector

Technical Field

The utility model belongs to the technical field of infrared thermopile detector encapsulation, concretely relates to can strengthen infrared thermopile detector infrared absorbing packaging structure.

Background

The working principle of the MEMS thermopile infrared detector is that based on the Seebeck effect, infrared electromagnetic waves emitted by a target object are detected and converted into measurable electric signals to be output, and the physical temperature is represented by the value of the electric signals; the MEMS infrared thermopile is used as a core working device of modern information detection systems such as a spectrometer, a gas sensor, a remote temperature sensor and the like, and the performance of the thermopile detector directly influences the capability and the precision of the thermopile detector on detecting a tiny signal.

Through retrieval, the chinese patent CN212320923U discloses an infrared temperature measuring sensor device, which comprises a tube cap, a convex lens, an infrared filter, an infrared thermopile sensor and a packaging base; the packaging base is positioned at the bottom of the pipe cap to form a closed hollow area with the pipe cap; the pipe cap is provided with a groove which is sunken towards the hollow area, and the groove is provided with a through hole; the convex lens is embedded in the groove and covers the through hole; the infrared filter is arranged in the hollow area and correspondingly positioned below the through hole; the infrared thermopile sensor is located in the hollow area and correspondingly located below the infrared filter, and a distance is reserved between the infrared thermopile sensor and the infrared filter.

The thermopile chip is directly fixed on the packaging base, when the external infrared radiation penetrates through the optical filter to irradiate the thermopile film, one part is reflected, one part penetrates through the film to irradiate the bottom, only a small part of radiation is absorbed by the film, and the problem of low response rate is caused.

SUMMERY OF THE UTILITY MODEL

When shining the thermopile film to external infrared radiation transmission light filter, partly by the reflection, partly see through the film and shine the bottom, only few part radiation is absorbed by the film, leads to the response rate low and the pipe cap conch wall thickness is unanimous thinner, receives external influence easily not enough, the utility model aims to provide a can strengthen infrared thermopile detector infrared absorption's packaging structure can reflect the reflection base of the infrared light that sees through the chip rete through setting up for infrared sensor chip secondary absorption infrared radiation, and then the performance of reinforcing detector.

For realizing above-mentioned purpose, the utility model discloses a following technical scheme, a can strengthen infrared thermopile detector infrared absorption's packaging structure, including the infrared sensor chip, encapsulation pipe cap and encapsulation tube socket, the encapsulation tube socket is located encapsulation pipe cap bottom and constitutes a confined cavity region with the encapsulation pipe cap, the infrared sensor chip arrange in the cavity region and with the encapsulation tube socket between be connected through the reflection base, the position that encapsulation pipe cap upper end corresponds the infrared sensor chip has the radiation mouth, the radiation mouth covers through a protruding transmission light piece, the pad on infrared sensor chip surface and the pin in the encapsulation tube socket pass through unsettled metal pin and be connected, in order to accomplish drawing forth of the signal of telecommunication.

Preferably, the infrared sensor chip is bonded with the reflection base, the reflection base comprises a silicon substrate and a metal film layer, and the reflection base is provided with a ventilation groove which enables a cavity of the infrared sensor chip to be communicated with a hollow area in the packaging pipe cap.

Preferably, the metal film layer is a layer of gold thin film sputtered on the upper surface of the silicon substrate, the number of the vent grooves is four, the vent grooves are respectively located in the centers of the four sides of the reflection base, and the length of each vent groove is larger than the width of a silicon window of the infrared sensor chip.

Preferably, a hollow area formed between the packaging pipe cap and the packaging pipe seat is in a truncated cone shape with a narrow top and a wide bottom, the packaging pipe cap body is made of brass, and a layer of gold thin film can be sputtered on the inner wall of the packaging pipe cap body.

Preferably, the central position of the upper end of the packaging pipe cap is provided with an accommodating groove which is concave towards the infrared sensor chip, the radiation port is positioned at the bottom of the accommodating groove, and the convex transmission filter is adhered and embedded in the accommodating groove and covers the radiation port.

Preferably, one side of the convex transmission filter is a plane, and the other side is a convex surface, wherein the plane is positioned at one side far away from the infrared sensor chip.

Preferably, an NTC resistor is arranged in a hollow area formed by the packaging tube seat and the packaging tube cap, and the NTC resistor is installed on the packaging tube seat and connected with the pins through metal leads to complete the extraction of the electric signals.

Compared with the prior art, the method has the following beneficial effects:

1. the reflection base which can reflect the infrared light penetrating through the film layer of the chip is arranged below the infrared sensor chip, so that the infrared sensor chip can absorb the infrared radiation for the second time, the performance of the detector is further enhanced, and the response efficiency of the infrared thermopile detector is improved;

2. the hollow area formed between the packaging tube cap and the packaging tube seat is in a round table shape with a narrow top and a wide bottom, so that the packaging tube cap is ensured to have enough strength while the infrared sensor chip is not hindered from receiving external radiation.

3. The ventilation groove ensures that the cavity of the chip is in the same pressure intensity with the external environment, and avoids the damage of temperature change gas expansion to the chip suspension film in the closed environment.

The parts of the device not involved are the same as or can be implemented using prior art.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments will be briefly described below, and 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 creative efforts.

FIG. 1 is an exploded view of the overall structure of the present embodiment;

fig. 2 is a schematic structural diagram of a package base in the present embodiment;

FIG. 3 is a schematic sectional view showing the overall structure of the present embodiment;

fig. 4 is a schematic structural diagram of the reflection base of the present embodiment.

In the figure: 1-an infrared sensor chip; 2-packaging the tube cap; 2.1-radiation opening; 2.2-accommodating the groove; 3-packaging the tube seat; 3.1-pin; 4.1-a silicon substrate; 4.2-metal film layer; 4.3-venting grooves; 5-a convex transmission filter; 6-metal lead; 7-NTC resistance.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments.

In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

The utility model provides an embodiment:

as shown in fig. 1 to 3, a package structure capable of enhancing infrared absorption of an infrared thermopile detector comprises an infrared sensor chip 1, a package cap 2 and a package tube seat 3, wherein the package tube seat 3 is located at the bottom of the package cap 2 and forms a sealed hollow area with the package cap 2, the infrared sensor chip 1 is arranged in the hollow area and is connected with the package tube seat 3 through a reflection base, a radiation opening 2.1 is formed in the upper end of the package cap 2 corresponding to the infrared sensor chip 1, the radiation opening 2.1 is covered by a convex transmission filter 5, and a bonding pad on the surface of the infrared sensor chip 1 is connected with a pin 3.1 in the package tube seat 3 through a suspended metal lead 6 to complete leading-out of an electric signal.

As shown in fig. 4, the infrared sensor chip 1 is bonded to the reflection base, the reflection base includes a silicon substrate 4.1 and a metal film layer 4.2, and the reflection base is provided with a ventilation groove 4.3 for communicating the cavity of the infrared sensor chip 1 with the hollow region in the encapsulation cap 2.

In this embodiment, the metal film layer 4.2 is a gold film sputtered on the upper surface of the silicon substrate 4.1, the thickness of the metal film layer is not too thin, i.e. 40nm, the material of the film can also be metal aluminum, and the metal film layer 4.2 is a chip film layer for reflecting infrared light penetrating through the chip film layer by the base, so that the infrared sensor chip 1 absorbs infrared radiation for the second time, and the performance of the detector is enhanced.

The four ventilation grooves 4.3 are respectively positioned in the centers of the four sides of the reflection base, and are prepared by photoetching and etching, the length of each ventilation groove 4.3 is larger than the width of a silicon window of the infrared sensor chip 1, so that the cavity of the infrared sensor chip 1 is ensured to be at the same pressure with the external environment, and the chip suspension membrane is prevented from being damaged by temperature change gas expansion in a closed environment.

In this embodiment, the hollow region that forms between encapsulation pipe cap 2 and the encapsulation tube socket 3 is under the narrow round platform form of width, 2 main parts materials of encapsulation pipe cap are brass and the film that the inner wall can sputter one deck gold material, compare conventional encapsulation pipe cap, 2 upper portions of encapsulation pipe cap are thicker in this structure, the below is thinner relatively, the below space enough place infrared sensor chip 1 can, the thickest department in top do not hinder the chip accept external radiation can, guaranteed that encapsulation pipe cap 2 has sufficient intensity.

The central point of the upper end of encapsulation pipe cap 2 puts and has holding recess 2.2 towards infrared sensor chip 1 sunken, radiation mouth 2.1 is located the bottom of holding recess 2.2, 5 bonding inlays of convex optical filter and establishes in holding recess 2.2 and cover radiation mouth 2.1, 5 one sides of convex optical filter are the plane, the one side is the convex surface, one side of 5 convex surfaces of convex optical filter directly pastes on encapsulation pipe cap 2 through epoxy or glue down, form a cavity between convex edge and the holding recess 2.2, make and be more than glue and exist here, prevent to spill over and pollute infrared sensor chip 1.

An NTC resistor 7 is arranged in a hollow area formed by the packaging tube seat 3 and the packaging tube cap 2, the NTC resistor 7 is arranged on the packaging tube seat 3 and is connected with a pin 3.1 through a metal lead 6 to complete the leading-out of an electric signal, and the ambient temperature in the packaging tube cap 2 is calibrated; in this embodiment, the package socket 3 is integrated with 4 pins 3.1, two of which are connected to the bonding pad on the surface of the infrared sensor chip 1, and one of which is connected to the NTC resistor 7.

The above, only be the concrete implementation of the preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art is in the technical scope of the present invention, according to the technical solution of the present invention and the utility model, the concept of which is equivalent to replace or change, should be covered within the protection scope of the present invention.

Claims

1. The utility model provides a can strengthen infrared thermopile detector infrared absorption's packaging structure, includes infrared sensor chip (1), encapsulation pipe cap (2) and encapsulation tube socket (3), its characterized in that: the packaging tube seat (3) is located at the bottom of the packaging tube cap (2) and forms a closed hollow area with the packaging tube cap (2), the infrared sensor chip (1) is arranged in the hollow area and is connected with the packaging tube seat (3) through a reflection base, a radiation opening (2.1) is formed in the position, corresponding to the infrared sensor chip (1), of the upper end of the packaging tube cap (2), the radiation opening (2.1) is covered through a convex transmission optical filter (5), a bonding pad on the surface of the infrared sensor chip (1) is connected with a pin (3.1) in the packaging tube seat (3) through a suspended metal lead (6), and therefore leading-out of an electric signal is completed.

2. The package structure for enhancing infrared absorption of an infrared thermopile detector of claim 1, wherein: the infrared sensor chip (1) is in bonding connection with the reflection base, the reflection base comprises a silicon substrate (4.1) and a metal film layer (4.2), and the reflection base is provided with a ventilation groove (4.3) which enables a cavity of the infrared sensor chip (1) to be communicated with a hollow area in the packaging pipe cap (2).

3. The package structure for enhancing infrared absorption of an infrared thermopile detector of claim 2, wherein: the metal film layer is a layer of gold film sputtered on the upper surface of the silicon substrate (4.1), the number of the vent grooves (4.3) is four, the vent grooves are respectively positioned in the centers of the four sides of the reflection base, and the length of each vent groove (4.3) is larger than the width of a silicon window of the infrared sensor chip (1).

4. The package structure for enhancing infrared absorption of infrared thermopile detector according to any one of claims 1 to 3, wherein: the packaging tube cap is characterized in that a hollow area formed between the packaging tube cap (2) and the packaging tube seat (3) is in a truncated cone shape with a narrow top and a wide bottom, the main body of the packaging tube cap (2) is made of brass, and a layer of gold thin film can be sputtered on the inner wall of the packaging tube cap.

5. The package structure for enhancing infrared absorption of infrared thermopile detector of claim 4, wherein: the central point of the upper end of encapsulation pipe cap (2) puts holding recess (2.2) that have orientation infrared sensor chip (1) sunken, and radiation mouth (2.1) are located the bottom of holding recess (2.2), and protruding transmission filter (5) bonding inlays to be established in holding recess (2.2) and cover radiation mouth (2.1).

6. The package structure for enhancing infrared absorption of an infrared thermopile detector of claim 5, wherein: one side of the convex transmission filter (5) is a plane, the other side of the convex transmission filter is a convex surface, and the plane is positioned on one side far away from the infrared sensor chip (1).

7. The package structure for enhancing infrared absorption of an infrared thermopile detector of claim 1, wherein: an NTC resistor (7) is arranged in a hollow area formed by the packaging tube seat (3) and the packaging tube cap (2), and the NTC resistor (7) is installed on the packaging tube seat (3) and connected with the pin (3.1) through a metal lead (6) to complete leading-out of an electric signal.