An infrared chip packaging device

Abstract

The utility model discloses an infrared chip packaging device, including the infrared chip that sets up in turn, support frame board and infrared light -transmitting piece: the upper surface of infrared chip has photosensitive area, and a plurality of infrared photosensitive units are formed in photosensitive area, support frame board is opposite the position of photosensitive area and is provided with the light -transmitting through -hole, infrared light -transmitting piece covers the area of light -transmitting through -hole to make infrared light -transmitting piece, support frame board and infrared chip form the vacuum cavity that contains infrared photosensitive unit in light -transmitting through -hole together, wherein, support frame board includes the epitaxial part of at least one side of light -transmitting through -hole and extends outward, and the upper surface of epitaxial part is provided with information etching structure. The infrared chip packaging device in the application still expands the device function on the basis of guaranteeing device structure volume miniaturization, and then has promoted the convenience of device application.

Description

Technical Field

[0001] This utility model relates to the field of infrared detection device technology, and in particular to an infrared chip packaging device. Background Technology

[0002] Uncooled infrared detectors, with their advantages of wide spectral response and no need for cryogenic cooling, have been widely used in security monitoring, automotive night vision, industrial inspection, and consumer electronics. With the rapid development of intelligent sensing technology, the market has placed more diverse demands on the miniaturization and performance of infrared detectors. Traditional infrared detectors are mostly packaged in alumina ceramic or aluminum nitride ceramic housings. This packaging structure results in a detector package thickness typically exceeding 3mm, making it difficult to adapt to the needs of miniaturized modules. Silicon-based or germanium-based wafer-level packaging (WLP) technology can reduce the package size. This involves wafer-level bonding and vacuum sealing of the infrared transmission window between the infrared transmission window and the chip substrate using a ring frame, overcoming the size limitations and cost bottlenecks of traditional infrared detector packaging technology. However, because wafer-level packaged infrared detectors have a small package size, it is difficult to expand their functionality beyond infrared detection, making it difficult for them to meet more diverse functional requirements in practical applications. Utility Model Content

[0003] The purpose of this invention is to provide an infrared chip packaging device that expands the device's functionality while ensuring its miniaturization, thus providing great convenience for users.

[0004] To address the aforementioned technical problems, this utility model provides an infrared chip packaging device, comprising an infrared chip, a support frame plate, and an infrared light-transmitting sheet stacked sequentially: the upper surface of the infrared chip has a photosensitive area, and a plurality of infrared photosensitive units are formed in the photosensitive area; the support frame plate has a light-transmitting hole at a position opposite to the photosensitive area; the infrared light-transmitting sheet covers the area where the light-transmitting hole is located, so that the infrared light-transmitting sheet, the support frame plate, and the infrared chip together form a vacuum cavity in the light-transmitting hole to accommodate the infrared photosensitive units;

[0005] The supporting frame plate includes an extension portion extending outward from at least one side of the light-transmitting through hole; the upper surface of the extension portion is provided with an information etching structure.

[0006] In one optional embodiment of this application, the information etching structure is at least one of the following etching structures: barcode etching structure, QR code etching structure, and chip model code etching structure.

[0007] In one optional embodiment of this application, the recesses of the information etching structure are filled with a pigment filling layer.

[0008] In one optional embodiment of this application, the upper surface of the information etching structure is covered with a convex lens adhesive layer.

[0009] In one optional embodiment of this application, the thickness of the support frame plate is 0.5mm to 0.7mm.

[0010] In one optional embodiment of this application, a portion of the through-hole area near the outer extension is an ineffective light-transmitting area;

[0011] The wall of the light-transmitting aperture near the outer epitaxial portion is also connected to an inner epitaxial portion located in the ineffective light-transmitting area; the upper surface of the inner epitaxial portion is lower than the upper edge surface of the light-transmitting aperture; a getter is disposed on the upper surface of the inner epitaxial portion; the upper surface of the getter is not higher than the upper edge surface; a conductive activation structure electrically connected to the getter is disposed on the outer epitaxial portion.

[0012] In an optional embodiment of this application, the upper surface of the inner epitaxial portion is provided with two electrode plates respectively connected to both ends of the getter; the support frame plate has two internal through holes extending from the upper surface of the inner epitaxial portion to the upper surface of the outer epitaxial portion; the two conductive activation structures extend from the upper surface of the inner epitaxial portion to the upper surface of the outer epitaxial portion through the two internal through holes; and the ends of the two conductive activation structures located on the upper surface of the inner epitaxial portion are respectively in contact with the two electrode plates.

[0013] In one optional embodiment of this application, the inner extension portion is further connected to a shielding strip that is higher than the upper surface of the inner extension portion but not higher than the upper surface of the edge portion on the side opposite to the outer extension portion.

[0014] In one optional embodiment of this application, a portion of the infrared photosensitive unit on the side closest to the light-transmitting aperture is a reference infrared photosensitive unit;

[0015] The invalid light-transmitting area is directly opposite the area where the reference infrared photosensitive unit is located, and the inner extension covers the area where the reference infrared photosensitive unit is located.

[0016] In an optional embodiment of this application, a portion of the through-hole area near the epitaxial portion is an ineffective light-transmitting area; the ineffective light-transmitting area faces the area outside the photosensitive area on the infrared chip; a thermally activated getter is disposed on the lower surface of the infrared light-transmitting sheet at the position facing the ineffective light-transmitting area.

[0017] The present invention provides an infrared chip packaging device, comprising an infrared chip, a support frame plate, and an infrared light-transmitting sheet stacked sequentially: the upper surface of the infrared chip has a photosensitive area, and a plurality of infrared photosensitive units are formed in the photosensitive area; the support frame plate has a light-transmitting hole at the position opposite to the photosensitive area; the infrared light-transmitting sheet covers the area where the light-transmitting hole is located, so that the infrared light-transmitting sheet, the support frame plate, and the infrared chip together form a vacuum cavity in the light-transmitting hole to accommodate the infrared photosensitive units; wherein, the support frame plate includes an epitaxial portion extending outward from at least one side of the light-transmitting hole; the upper surface of the epitaxial portion is provided with an information etching structure.

[0018] The support frame plate in the infrared chip packaging device of this application differs from the ring-shaped support frame of conventional infrared detector packaging in that, in addition to connecting the infrared light-transmitting sheet and the infrared chip, it also has an outwardly extending epitaxial portion. This epitaxial portion can support information etching structures, allowing users to easily and quickly obtain relevant information characterizing the infrared chip packaging device based on these etching structures. Compared to the current conventional infrared chip packaging devices, which rely on the detector's own storage unit for recording model information, this application directly etches the signal information of the infrared chip packaging device onto the support frame plate using etching structures. Even though the device itself does not have storage capabilities, this ensures the accuracy and reliability of the information markings on the infrared chip packaging device and greatly facilitates users in finding relevant device information. Therefore, the infrared chip packaging device of this application not only ensures miniaturization of the device structure but also improves the ease of application. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of the infrared chip packaging device provided in the embodiments of this application;

[0021] Figure 2 For along Figure 1 Schematic diagram of the cross-sectional structure along the AA direction;

[0022] Figure 3 This is an exploded view of the infrared chip packaging device provided in the embodiments of this application;

[0023] Figure 4A schematic cross-sectional view of a local area with an information etching structure on a support frame plate provided in an embodiment of this application;

[0024] Figure 5 The following are provided for the embodiments of this application: Figure 1 Schematic diagram of the first type of cross-sectional structure in the BB direction;

[0025] Figure 6 The following are provided for the embodiments of this application: Figure 1 Schematic diagram of the second type of cross-sectional structure in the BB direction;

[0026] Figure 7 A schematic diagram of a support frame plate provided in an embodiment of this application;

[0027] Figure 8 This is another structural schematic diagram of the support frame plate provided in the embodiments of this application;

[0028] Figure 9 The following are provided for the embodiments of this application: Figure 1 A schematic diagram of the cross-sectional structure along the CC direction;

[0029] In the attached diagram: 1 is the infrared chip, 11 is the infrared photosensitive unit, 110 is the reference infrared photosensitive unit, 2 is the support frame plate, 200 is the light-transmitting through hole, 201 is the information etching structure, 202 is the conductive activation structure, 203 is the pigment filling layer, 204 is the convex lens adhesive layer, 21 is the epitaxial portion, 22 is the epitaxial portion, 220 is the electrode sheet, 23 is the shielding strip, 3 is the infrared light-transmitting sheet, 31 is the thermally activated getter, 4 is the getter, and 5 is the bonding layer. Detailed Implementation

[0030] The core of this invention is to provide an infrared chip packaging device that can improve the convenience of practical applications of the device to a certain extent.

[0031] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] like Figures 1 to 3 As shown, Figure 1 This is a schematic diagram of the structure of the infrared chip packaging device provided in the embodiments of this application; Figure 2 For along Figure 1 Schematic diagram of the cross-sectional structure along the AA direction; Figure 3This is an exploded view of the infrared chip packaging device provided in an embodiment of this application.

[0033] In one specific embodiment of this application, the infrared chip packaging device may include:

[0034] An infrared chip 1, a support frame plate 2, and an infrared light-transmitting sheet 3 are stacked sequentially. The upper surface of the infrared chip 1 has a photosensitive area, and multiple infrared photosensitive units 11 are formed in the photosensitive area. A light-transmitting hole 200 is opened in the support frame plate 2 opposite to the photosensitive area. The infrared light-transmitting sheet 3 covers the area where the light-transmitting hole 200 is located, so that the infrared light-transmitting sheet 3, the support frame plate 2, and the infrared chip 1 together form a vacuum cavity in the light-transmitting hole 200 to accommodate the infrared photosensitive units 11.

[0035] The support frame plate 2 includes an extension portion 21 extending outward from at least one side of the light-transmitting through hole 200; the upper surface of the extension portion 21 is provided with an information etching structure 201.

[0036] like Figure 1 and Figure 3 As shown, the infrared chip 1 in this embodiment includes a chip substrate, a plurality of infrared photosensitive units 11 arranged in a two-dimensional array on the chip substrate, and a readout circuit structure electrically connected to the infrared photosensitive units 11. Its specific structure and fabrication method are similar to those of a conventional infrared chip 1, and will not be discussed in detail in this embodiment. The difference is that the area where the infrared photosensitive units 11 are distributed on the infrared chip 1, that is, the photosensitive area, is not located at the exact center of the infrared chip 1, but closer to one side of the infrared chip 1, thereby allowing a larger space area to be reserved on the opposite side of the infrared chip 1.

[0037] Furthermore, in this embodiment, the upper surfaces of the support frame plate 2 and the infrared chip 1 (i.e., the surface where the infrared photosensitive unit 11 is located) are bonded together, and at least a light-transmitting hole 200 is provided at the position corresponding to the photosensitive area. That is to say, the light-transmitting hole 200 provided on the support frame plate 2 in this embodiment is at least not smaller than the area where the infrared photosensitive unit 11 is distributed.

[0038] The infrared transparent sheet 3 is a thin sheet structure that can transmit infrared light. This infrared transparent sheet 3 can be fabricated using materials with high transmittance in the infrared band, such as germanium (Ge) wafers, silicon (Si) wafers, or sulfur selenium glass, which can effectively transmit infrared radiation. In practical applications, the wafer can be thinned first, then an infrared antireflective film can be deposited, followed by dicing to obtain an infrared transparent sheet 3 with good optical performance. Optionally, during the fabrication of the infrared transparent sheet 3, after thinning the wafer, a metasurface structure (a microlens structure that increases the transmittance of infrared light) can be created on the wafer surface using photolithography-etching. After removing the resist, dicing is performed to obtain an infrared transparent sheet 3 with even higher optical performance.

[0039] Obviously, the main purpose of the infrared light-transmitting sheet 3 in this embodiment is to form a vacuum cavity in the light-transmitting hole 200 together with the supporting frame plate 2 and the infrared chip 1 to accommodate the infrared photosensitive unit 11. The vacuum degree of the vacuum cavity is not less than 1 Pa. Therefore, the infrared light-transmitting sheet 3 in this embodiment should be a thin sheet structure with a shape roughly similar to the light-transmitting hole 200 on the supporting frame plate 2, but slightly larger in size. This allows the edge of the infrared light-transmitting sheet 3 to be sealed and bonded to the edge of the light-transmitting hole 200 on the supporting frame plate 2. In short, it is sufficient to ensure that the infrared light-transmitting sheet 3 can seal the light-transmitting hole 200 from the upper end (i.e., the end away from the infrared chip 1).

[0040] In addition, the support frame plate 2 in this embodiment can be a multilayer ceramic structure formed by any one or more ceramics such as alumina, aluminum nitride, and beryllium oxide; the thickness of the support frame plate 2 can be approximately 0.5mm to 0.7mm, which is roughly equivalent to the thickness of the infrared chip 1 and the infrared light-transmitting sheet 3, thereby ensuring that the thickness of the entire infrared chip packaging device is less than 3mm, and realizing the miniaturization of the infrared chip packaging device.

[0041] like Figure 2 As shown, the infrared light-transmitting sheet 3 and the supporting frame plate 2, as well as the supporting frame plate 2 and the infrared chip 1, can be sealed and connected by eutectic welding of the bonding layer 5 or by bonding with conductive adhesive, thereby achieving a sealed connection between the infrared light-transmitting sheet 3, the supporting frame plate 2 and the infrared chip 1 stacked sequentially.

[0042] It is understandable that during the bonding process between the infrared light-transmitting sheet 3 and the infrared chip 1, it is susceptible to contamination by microparticles, which can form optical scattering centers and cause a decrease in the signal-to-noise ratio of the device imaging. In this embodiment, based on the miniaturization of the device using wafer-level packaging (WLP) technology, the position of the infrared light-transmitting sheet 3 on the infrared chip is raised by the support frame plate 2. This increases the distance between foreign objects such as microparticles and the infrared photosensitive pixel 11, thereby reducing the degree of influence on the infrared photosensitive pixel and increasing the signal-to-noise ratio of the device.

[0043] Based on this, the support frame plate 2 in this embodiment also includes an extension portion 21 extending outward from at least one side of the light-transmitting hole 200. That is to say, in addition to having an annular structure surrounding the light-transmitting hole 200, the support frame plate 2 in this application also has a portion of the extension portion 21 with a flat plate structure. In other words, the light-transmitting hole 200 in this application is not located in the central region of the support frame plate 2, but is offset to one side, so the support frame plate 2 is generally asymmetrical U-shaped structure. Obviously, the direction in which the light-transmitting hole 200 is offset to one side on the support frame plate 2 is the same as the direction in which the photosensitive areas distributed by each infrared photosensitive unit 11 are offset to one side on the infrared chip 1. Therefore, the extension portion 21 on the support frame plate 2 is also attached to the area on the infrared chip 1 that does not have infrared photosensitive units 11. Furthermore, in the support frame plate 2 of this embodiment, the upper surface of the extension portion 21 (i.e., the surface facing away from the infrared chip 1) further has an information etching structure 201.

[0044] In this embodiment, the information etching structure 201 is a specific pattern structure formed by laser etching. The information etching structure 201 can be at least one of the following etching structures: barcode etching structure, QR code etching structure, and chip model code etching structure.

[0045] It is understandable that the barcode etching structure is the structure that forms the barcode etching pattern, the QR code etching structure is the structure that forms the QR code etching pattern, and the chip model code etching structure is the structure that forms the etching pattern of numbers and / or letters and other feasible identifiers of the chip model.

[0046] Furthermore, conventional infrared devices carrying unique identification information typically require a built-in storage unit within the device itself. However, for infrared devices lacking built-in storage, users find it difficult to trace the device's model and other data, causing inconvenience. This application, by incorporating an information etching structure 201 on the support frame plate 2, eliminates the need for a dedicated storage unit within the device itself to store unique identifiers such as the model, enabling users to trace the device's model and other information, thus providing greater convenience.

[0047] Taking the QR code etching structure as an example, the pattern formed by the QR code etching structure can be a QR code link. When a user scans the QR code etching structure with an electronic device such as a mobile phone, they can directly access a webpage with various relevant information such as the chip's model, characteristic parameters, and fault repair strategies. This provides users with great convenience when actually using the infrared chip packaged device, as they can obtain various relevant information about the infrared chip packaged device by scanning the QR code etching structure.

[0048] Of course, in practical applications, the barcode etching structure, QR code etching structure, or chip model code etching structure can simply represent the chip model. Users can use the chip model identifier to search online for various relevant information about that chip model. Alternatively, for example, barcode etching structures, QR code etching structures, and chip model code etching structures can be simultaneously etched on the outer epitaxial portion 21 of the same support frame plate 2. The barcode etching structure serves as an anti-counterfeiting mark, the QR code etching structure is an identification code for obtaining the various operating parameters required by the infrared chip package device, and the chip model code etching structure identifies the model of the infrared chip package device, etc. This application does not impose specific limitations on these aspects.

[0049] In this embodiment, the information etching structure 201 can be formed by laser etching on the surface of the extension portion 21 of the support frame plate 2; and the size of the uneven structure of the information etching structure 201 is in the micrometer or even nanometer range, that is to say, it may be very inconspicuous or even negligible to the human eye. Based on this, such as Figure 4 As shown, in another optional embodiment of this application, the recess of the information etching structure 201 may also be filled with a pigment filling layer 203.

[0050] The pigment filling layer 203 preferably uses a filling material that is distinctly different from the color of the upper surface of the support frame plate 2. Taking the support frame plate 2 as a gray-black ceramic as an example, the pigment filling layer 203 can be a milky white filling layer. For example, milky white pigment can be mixed into transparent glue to form milky white glue. This milky white glue is then filled into the recesses of the information etching structure 201, thereby making the color contrast between the protrusions and recesses in the information etching structure 201 obvious. This ensures that the information etching structure 201 is more eye-catching and easier for electronic devices to scan.

[0051] Building upon this, to further enhance the visibility of the information etching structure 201, a convex lens adhesive layer 204 can be formed on the surface of the area where the information etching structure 201 is located. Specifically, adhesive can be applied at the location of the information etching groove. Due to its viscosity, the liquid adhesive automatically forms a transparent adhesive structure that is thick in the middle and thin at the edges, with an outwardly convex curved surface. Once this transparent adhesive structure cures, it serves as a convex lens structure to magnify the etching pattern of the information etching groove. Because of the magnifying effect of the convex lens adhesive layer 204, the information etching structure 201 can be made more prominent, and the scanning difficulty of the information etching structure 201 by the electronic scanning equipment can be reduced, thus lowering the resolution requirements of the electronic scanning equipment.

[0052] Based on any of the above embodiments, in an optional embodiment of this application, the infrared chip packaging device may include:

[0053] The portion of the through-hole area near the outer extension 21 within the light-transmitting through-hole 200 is an ineffective light-transmitting area;

[0054] The wall of the light-transmitting through-hole 200 near the outer epitaxial portion 21 is also connected to an inner epitaxial portion 22 located in the ineffective light-transmitting area; the upper surface of the inner epitaxial portion 22 is lower than the edge upper surface of the light-transmitting through-hole 200; a getter 4 is provided on the upper surface of the inner epitaxial portion 22; the upper surface of the getter 4 is not higher than the edge upper surface; a conductive activation structure 202 electrically connected to the getter 4 is provided on the outer epitaxial portion 21.

[0055] like Figure 5 As shown, an inner epitaxial portion 22 extending away from the outer epitaxial portion 21 is connected to the hole wall near the outer epitaxial portion 21 inside the light-transmitting aperture 200. Obviously, on the infrared chip 1, the area directly below the inner epitaxial portion 22 is blocked by the inner epitaxial portion 22 and is not irradiated by infrared light. Therefore, the area covered by the inner epitaxial portion 22 in the light-transmitting aperture 200 is also an ineffective light-transmitting area.

[0056] In practical applications, a light-transmitting hole 200 with an area larger than the photosensitive area on the infrared chip 1 can be opened on the support frame plate 2. That is, the projection of the light-transmitting hole 200 on the infrared chip 1 covers not only the photosensitive area but also a part of the area outside the photosensitive area. The area opposite to the photosensitive area in the light-transmitting hole 200 is the side of the light-transmitting hole 200 near the outer extension 21, which is the area where the inner extension 22 is set. In other words, the inner extension 22 can be for the area outside the photosensitive area on the infrared chip 1.

[0057] like Figure 2 and Figure 6As shown, in another optional embodiment of this application, the infrared photosensitive unit 11 on the infrared chip 1 may further include a portion of the infrared photosensitive unit 11 as a reference infrared photosensitive unit 110, that is, located as shown in the figure. Figure 2 Within the dashed box on the mid-infrared chip 1; in practical applications, the reference infrared photosensitive unit 110 does not need to receive infrared light radiation, but serves as a reference for other units that can receive infrared light radiation. When determining the infrared signals generated by the infrared light sensed by other infrared photosensitive units 11, the output signal of the reference infrared photosensitive unit 110 can be used as a benchmark for calculation. This can eliminate noise caused by the characteristics of the infrared photosensitive unit 11 itself and the chamber environment within the light-transmitting aperture 200 to a certain extent, thereby improving the accuracy and reliability of the infrared data measured by each infrared photosensitive unit 11 other than the reference infrared photosensitive unit 110.

[0058] Since the reference infrared photosensitive unit 110 does not need to receive infrared light irradiation, in this embodiment, the inner extension portion 22 can be further disposed in the area of ​​the light-transmitting through hole 200 directly opposite the reference infrared photosensitive unit 110. That is to say, in this embodiment, the inner extension portion 22 serves both as a carrier of the getter 4 and as a light shield for the reference infrared photosensitive unit 110.

[0059] Obviously, in this embodiment, the shape and size of the light-transmitting aperture 200 can be the same as the shape and size of the area covered by all infrared photosensitive units 11, while the inner extension 22 is approximately the same as or the same as the shape and size of the area where the reference infrared photosensitive unit 110 is located.

[0060] Furthermore, the proportion of the reference infrared photosensitive unit 110 among all infrared photosensitive units 11 is generally relatively small. Therefore, if the size of the epitaxial portion 22 is only similar to the size of the area where the reference infrared photosensitive unit 110 is located, the upper surface of the epitaxial portion 22 may not have enough space to carry the getter 4. Based on this, in practical applications, the area of ​​the light-transmitting aperture 200 can be slightly larger than the photosensitive area where the infrared photosensitive unit 11 is located, and the epitaxial portion 22 can be partially located directly above the reference infrared photosensitive unit 110, while the other part is directly opposite the area on the infrared chip 1 other than the photosensitive area (generally the area adjacent to the reference infrared photosensitive unit 110).

[0061] Based on the above discussion, the inner extension portion 22 in this embodiment can be integrally formed with the supporting frame plate 2, and the upper surface of the inner extension portion 22 is lower than the upper edge surface of the light-transmitting hole 200. That is to say, a gap is left between the upper surface of the inner extension portion 22 and the lower surface of the infrared light-transmitting sheet 3. Thus, a getter 4 can be further provided on the upper surface of the inner extension portion 22. Obviously, the upper surface of the getter 4 should not be higher than the upper edge surface of the light-transmitting hole 200. Therefore, the getter 4 is located in the vacuum space inside the light-transmitting hole 200, thereby achieving the function of absorbing gas in the vacuum space where the infrared photosensitive unit 11 is located.

[0062] like Figure 5 and Figure 6 As shown, in this embodiment, the getter 4 is disposed on the support frame plate 2, which can, to a certain extent, avoid the problem that the getter 4, being disposed on the upper surface of the infrared chip 1, would affect the layout of the reading circuit on the infrared chip 1, thus reducing the difficulty of the circuit layout on the infrared chip 1. Furthermore, in this embodiment, a step-like surface is formed between the inner extension portion 22 of the support frame plate 2 and the hole wall of the light-transmitting hole 200 to support the getter 4. This ensures that even with a relatively small thickness, the upper surface of the inner extension portion 22 can provide a sufficiently large supporting area for the getter 4. This avoids the problem that the thickness of the support frame plate 2 is limited due to device miniaturization, thus limiting the area of ​​the getter 4. It ensures that with a sufficiently large getter area, there is sufficient gas-gathering capacity, thereby guaranteeing good device performance.

[0063] In this embodiment, the getter 4 can be prepared by powder sintering, and the specific process is as follows:

[0064] 1) Powder preparation: The selected getter alloy material is made into powder by atomization and other methods to ensure that the powder has a suitable particle size distribution, so as to ensure the uniformity and getter performance of the subsequent sintering process.

[0065] 2) Mold forming: The prepared getter powder is placed into a specific mold and a certain pressure is applied to make it initially form a getter blank. The shape and size of the mold are determined according to the area and shape of the getter 4 on the inner extension of the support frame plate 2.

[0066] 3) Sintering treatment: The formed getter blank is placed in a high-temperature furnace for sintering. The sintering temperature, time and atmosphere parameters in the high-temperature furnace are reasonably controlled to make the powder particles metallurgically bonded to form getter elements with certain strength and pore structure. The appropriate pore structure in the getter element is conducive to gas diffusion and adsorption, thereby improving the getter efficiency.

[0067] 4) Cleaning and testing: The sintered getter element is cleaned to remove impurities and contaminants from the surface; then the getter performance is tested, such as by measuring the getter rate, getter capacity and other indicators, to screen out qualified getters.

[0068] 5) Installation and activation: Install the qualified getter 4 onto the upper surface of the inner extension 22 of the support frame plate 2, and connect it to the conductive activation structure 202 through the electrode plate 220. After the encapsulation is completed, the getter 4 is activated by energizing the conductive activation structure, and it can start to perform the getter function.

[0069] The getter 4 prepared above has stable performance and good mechanical properties and getter properties.

[0070] In this embodiment, the getter 4 can be prepared by thin film deposition, and the specific process is as follows:

[0071] 1) Substrate treatment: The upper surface of the inner extension 22 of the support frame plate 2 is cleaned and pretreated to improve the adhesion between the film and the substrate. Pretreatment methods include chemical cleaning, plasma treatment, etc.

[0072] 2) Thin Film Deposition: A getter film is deposited on the pretreated substrate surface using methods such as physical vapor deposition (PVD) or chemical vapor deposition (CVD). During the deposition process, deposition parameters, such as deposition rate, temperature, and gas flow rate, are precisely controlled to obtain a film with uniform thickness and good getter performance.

[0073] 3) Annealing treatment: The deposited getter film is annealed. By controlling the annealing temperature and time, the crystal structure and surface morphology of the film are improved, thereby enhancing its getter activity.

[0074] 4) Performance testing: Perform getter performance testing on the annealed getter film to evaluate its getter effect and stability; if the test results do not meet the requirements, appropriate adjustments or redeposition can be made; if the test results meet the requirements, getter 4 is prepared and formed.

[0075] 5) Encapsulation and activation: After the preparation and testing of getter 4 are completed, the encapsulation operation is carried out. The support frame plate 2 is welded to the infrared chip 1 and the infrared light-transmitting sheet 3 to form a vacuum cavity. Then, the getter 4 is activated by energizing the electrode sheet 220 and the conductive activation structure 202.

[0076] The above-mentioned method of preparing getter 4 enables the getter 4 to be ultra-thin and integrated, which is beneficial to further reduce the thickness of the support frame plate 2, and thus better suited for miniaturized infrared detectors.

[0077] As described above, the getter 4 in this embodiment requires electrical activation. Therefore, a conductive activation structure 202 for activating the getter 4 can be further provided on the epitaxial portion 21. This conductive activation structure 202 is electrically connected to the getter 4, thereby enabling electrical activation of the getter 4 by means of this conductive activation structure 202. The end of the conductive activation structure 202 on the epitaxial portion 21 can be located on the upper surface or the side surface of the epitaxial portion 21; this application does not limit this.

[0078] like Figure 5 and Figure 6 As shown, in an optional embodiment of this application, the upper surface of the inner extension portion 22 is provided with two electrode sheets 220 respectively connected to both ends of the getter 4; the support frame plate 2 is provided with two internal through holes extending from the upper surface of the inner extension portion 22 to the upper surface of the outer extension portion 21; two conductive activation structures 202 extend from the upper surface of the inner extension portion 22 to the upper surface of the outer extension portion 21 through the two internal through holes; and the ends of the two conductive activation structures 202 located on the upper surface of the inner extension portion 22 are respectively in contact with the two electrode sheets 220.

[0079] like Figure 5 and Figure 6 As shown, the conductive activation structure 202 extends from the upper surface of the inner epitaxial portion 22 to the upper surface of the outer epitaxial portion 21, thus providing a conductive circuit for the getter 4 and the external power supply circuit. In practical applications, an internal through hole can be formed on the support frame plate 2 first, and then a conductive paste can be injected into the internal through hole. Once the conductive paste has solidified, the conductive activation structure 202 can be formed.

[0080] Understandably, because the upper surface area of ​​the epitaxial portion 21 is large enough, the exposed end face of the conductive activation structure 202 on the upper surface of the epitaxial portion 21 can be large enough, thereby improving the ability of the conductive pin that energizes the conductive activation structure 202 to make easier and more reliable contact electrical connection with the conductive activation structure 202 during the activation of the getter 4, and improving the success rate of mass production of the device to activate the getter 4.

[0081] Furthermore, considering that the heating of the getter 4 during the activation process of the conductive activation structure 202 may affect the infrared photosensitive unit 11, therefore, as Figure 7 As shown, the support frame plate 2 in this application may further include:

[0082] The inner extension 22 is connected to a shielding strip 23 on the side opposite to the outer extension 21, which is higher than the upper surface of the inner extension 22 but not higher than the upper surface of the edge.

[0083] Reference Figure 7The lower side of the shielding strip 23 is connected to the inner extension 22, and the upper side can be flush with or slightly lower than the upper edge of the light-transmitting hole 200, while the two ends are left with gaps between them and the light-transmitting hole 200. Thus, the shielding strip 23, the inner extension 22, and the hole wall of the light-transmitting hole 200 together form a concave space for the adsorbent 4, and this concave space is in air communication with the space where the infrared photosensitive unit 11 is located. That is to say, the shielding strip 23 can block the heat generated when the getter 4 is activated by electricity from affecting the infrared photosensitive unit 11 to a certain extent, and also ensure the adsorption of gas in the space where the infrared photosensitive unit 11 is located by the getter 4.

[0084] It is understandable that, in practical applications, structures such as the shielding strip 23, the inner extension 22, and the supporting frame plate 2 can be integrally formed.

[0085] Based on the above discussion, in embodiments where a conductive activation structure 202 needs to be formed inside the support frame plate 2, the support frame plate 2 can be an alumina ceramic frame plate or a low-temperature co-fired ceramic frame plate; ceramic materials have excellent insulation properties, enabling more complex high-density wiring, and excellent airtightness. In practical applications, the preparation process of using ceramics as the material to form the support frame plate 2 may include:

[0086] 1) Mix ceramic powder (such as alumina or LTCC material) with organic binder and cast it into a green ceramic tape. Use a precision mold to punch out the frame structure and internal cavity on the green ceramic tape (in order to form light-transmitting through holes 200).

[0087] 2) Through-hole filling and circuit printing: Vertical interconnected through-holes are formed on the green ceramic sheet by laser drilling, and tungsten or molybdenum metal paste is used to fill them to form a structural segment of conductive activation structure 202 extending in the vertical direction; then, the wire pattern corresponding to the segment of conductive activation structure 202 extending in the horizontal direction is printed on each layer of green ceramic sheet by thick film printing technology.

[0088] 3) Lamination and co-firing: The printed multi-layered green ceramic sheets are aligned, stacked, and pressed together to form an integral three-dimensional green structure; then co-fired in a high-temperature reducing atmosphere to densify the ceramic and sinter the metal conductor to form an integral ceramic framework.

[0089] 4) Post-processing and surface metallization: After co-firing, nickel / gold layers are deposited in the welding area of ​​the frame (i.e., the annular area on the trademark surface that is welded to the infrared light-transmitting sheet 3 and the infrared chip 1 respectively through the bonding layer 5) and the external pin area (the end of the conductive activation structure 202 exposed on the epitaxial portion 21) by electroplating or chemical plating to provide excellent solderability and corrosion resistance; then, laser etching is used to form the information etching structure 201 on the epitaxial portion 21.

[0090] Based on any of the above embodiments, the adsorbent 4, which requires electrical activation, is not necessarily used in this application. For example... Figure 8 As shown, in another optional embodiment of this application, the infrared chip packaging device may further include:

[0091] The portion of the through-hole area near the epitaxial portion 21 within the light-transmitting through-hole 200 is an ineffective light-transmitting area; the ineffective light-transmitting area faces the area outside the photosensitive area on the infrared chip 1; a heat-activated getter 31 is provided on the lower surface of the infrared light-transmitting sheet 3 at the position facing the ineffective light-transmitting area.

[0092] In this embodiment, there is also an ineffective light-transmitting area in the light-transmitting hole 200. This ineffective light-transmitting area is located outside the photosensitive area on the infrared chip 1, and no inner extension portion 22 is provided in the ineffective light-transmitting area. A thermally activated getter 31 is provided on the lower surface of the infrared light-transmitting sheet 3 at the location of the ineffective light-transmitting area. In this embodiment, the thermally activated getter 31 is activated by heating. In practical applications, the thermally activated getter 31 can be activated before the infrared light-transmitting sheet 3 is connected to the support frame plate 2.

[0093] In addition, Figure 8 In the embodiments described above, the inner extension portion 22 is not provided in the ineffective photosensitive area. However, it is understood that in practical applications, this application does not exclude the possibility that the location of the thermally activated getter 31 on the infrared light-transmitting sheet 3 is directly opposite the reference infrared photosensitive unit 110 in the infrared photosensitive unit 11. In this case, the inner extension portion 22 can also be provided in the ineffective photosensitive area corresponding to the reference infrared photosensitive unit 110 to block the light from the reference infrared photosensitive unit 110.

[0094] Based on the above discussion, the activating getter 31 in this embodiment is disposed on the lower surface of the infrared light-transmitting sheet 3. Therefore, in this embodiment, the support frame plate 2 can be made of ceramic plate or Kovar alloy frame plate. For infrared chips 1 formed on silicon substrates, the thermal expansion coefficient of Kovar alloy material matches well with that of silicon substrates, making it easy to metallize and weld. In practical applications, a frame substrate with an asymmetric loop structure having light-transmitting holes 200 can be formed by precision stamping or wet / dry etching of the Kovar alloy plate. The surface of the area on the support frame plate 2 where the information etching structure 201 needs to be formed can be coated with an insulating ceramic layer by thermal oxidation or spraying.

[0095] In summary, the support frame plate in the infrared chip packaging device of this application differs from the ring-shaped support frame of conventional infrared detector packaging in that, in addition to connecting the infrared light-transmitting sheet and the infrared chip, it also has an outwardly extending epitaxial portion. This epitaxial portion can support information etching structures, allowing users to easily and quickly obtain relevant information characterizing the infrared chip packaging device based on these etching structures. Compared to the current conventional infrared chip packaging devices, which rely on the detector's own storage unit for recording model information, this application directly etches the signal information of the infrared chip packaging device onto the support frame plate using etching structures. Even though the device itself does not have storage capabilities, this ensures the accuracy and reliability of the information markings on the infrared chip packaging device and greatly facilitates users in finding relevant device information. Therefore, the infrared chip packaging device of this application not only ensures miniaturization of the device structure but also improves the ease of application.

[0096] Based on any of the above embodiments, a specific fabrication process for the infrared chip packaging device of this application may include the following steps.

[0097] (1) Preparation of infrared transparent sheet 3: The whole wafer is thinned, an infrared band antireflection film is deposited by vapor deposition, and then the wafer is diced, as follows:

[0098] a. Select germanium (Ge) or silicon (Si) wafers as the substrate and thin the entire wafer;

[0099] b. Use an ultrasonic cleaner to clean the wafer surface in acetone, ethanol and deionized water in sequence, and finally dry it with nitrogen to achieve wafer surface cleaning and remove impurities and oxides.

[0100] c. Place the cleaned wafer substrate into the cavity of the vacuum evaporation equipment. Ensure the cavity is well sealed and evacuate to below 10⁻⁶ Pa to reduce the impact of gas on the film quality.

[0101] d. Select antireflective coating materials suitable for the infrared band, such as magnesium fluoride ( Zinc sulfide (ZnS), etc., are used to place the vapor deposition material into an evaporation source (such as a tungsten wire or electron beam evaporation source), heat the evaporation source, and cause the vapor deposition material to evaporate and deposit on the surface of the substrate;

[0102] e. Control the evaporation rate (typically 0.1-1 nm / s) and film thickness (typically between tens and hundreds of nanometers, depending on optical design requirements). Monitor the film thickness in real time using a quartz crystal oscillator; after evaporation, slowly restore the chamber to atmospheric pressure and remove the wafer substrate;

[0103] f. Anneal the vapor-deposited film (temperature 200-300℃, time 1-2 hours) to improve the film's density and adhesion; dicing the wafer substrate after vapor-depositing the infrared antireflective coating.

[0104] (2) Fabrication of the support frame plate 2; Based on the dimensions of the infrared chip 1 and the infrared light-transmitting sheet 3, a three-dimensional structure of the multilayer alumina ceramic frame plate is designed, with a light-transmitting through hole 200 reserved inside to accommodate the infrared photosensitive unit 11 of the infrared chip 1, and a special gold-plated area is designed for subsequent welding and conductivity, as follows:

[0105] a. Alumina ceramic green belts are prepared using a tape casting process, and the alumina ceramic green belts are precisely punched and cut to form green sheets of each layer;

[0106] b. Using precision screen printing technology, tungsten or molybdenum-manganese metal paste is printed on specific green sheets to form interlayer interconnections and gold-plated area patterns on the surface;

[0107] c. The printed green sheets are precisely aligned in the design order and laminated under high temperature and high pressure to form a whole green block;

[0108] d. The laminated green block is placed in a high-temperature sintering furnace and co-fired in a reducing atmosphere (such as nitrogen-hydrogen mixture). The temperature profile is precisely controlled (peak temperature is usually 1500-1650℃) to densify the ceramic and form a strong bond with the metallized pattern to obtain a ceramic framework.

[0109] e. The co-fired ceramic frame is cleaned and activated. A 2-5 μm thick nickel layer is deposited in the metallized area (including the area where the support frame plate 2 needs to be welded to the bonding layer 5, and the end surface area of ​​the conductive activation structure 202) as a barrier layer and a base layer. A 0.5-1.5 μm thick pure gold layer is electroplated or electrolessly plated on the nickel layer to form the final solderable surface.

[0110] (3) The manufacturing and welding of the getter are as follows:

[0111] a. Select an alloy foil with zirconium (Zr) as the matrix and containing other active metals (such as V and Fe), and use precision die stamping technology to stamp the alloy foil into a sheet structure as required by the design.

[0112] b. Clean the stamped sheet structure to remove oil and particulate matter to obtain a getter;

[0113] c. Fix the ceramic support frame onto the special fixture, and use a laser welding machine to weld the getter to the support frame;

[0114] (4) The integration and welding of the infrared light-transmitting sheet 3, the supporting frame plate 2 and the infrared chip 1 are as follows:

[0115] a. Select the appropriate solder based on the material of the welding interface (Ge window, Au plating, chip back gold) and the required sealing strength and operating temperature. For example, use gold-based solder (such as Au80Sn20) or gold-germanium (AuGe) solder, as they have excellent thermal conductivity, electrical conductivity and high strength.

[0116] b. Prepare the solder into a solder preform ring (i.e., bonding layer 5), the shape and size of which match the welding surfaces of the support frame plate 2 and the infrared light transmittance sheet 3;

[0117] c. Precisely place the infrared chip 1 (with the surface of the infrared photosensitive unit 11 facing upwards) on a special welding fixture; place the solder preformed ring on the bottom gold-plated area of ​​the support frame plate 2; flip the support frame plate 2 with the getter 4 already soldered on so that the bottom solder is aligned with the gold back of the infrared chip 1 and place it; place another solder preformed ring on the window welding gold-plated area at the top of the support frame plate 2; place the infrared light-transmitting sheet 3 with the anti-reflection coating already deposited on the top solder preformed ring;

[0118] f. Transfer the stacked components into the cavity of the vacuum reflow oven, close the oven door, and start the vacuum process to evacuate the cavity to a vacuum level of 10⁻³ Pa or higher to effectively remove gases and volatiles from the welding interface and prevent the formation of porosity. Execute the precisely set reflow soldering temperature profile:

[0119] Heating zone: Slow heating ensures even heating of the components and allows appropriate evaporation of flux (if used) in the solder paste.

[0120] Insulation zone: This zone remains below the melting point of the solder to ensure uniform temperature.

[0121] Reflow zone: Rapidly heat to above the solder liquidus line (e.g., the peak temperature of Au80Sn20 is about 300-320℃) to completely melt the solder, wet all solder surfaces, and form an airtight seal;

[0122] Cooling zone: Controls the cooling rate to form uniform and reliable solder joints and reduce thermal stress;

[0123] After welding is completed, once the temperature inside the furnace has dropped to a safe range, high-purity nitrogen is introduced into the cavity, and the finished component is removed after the pressure is restored to normal.

[0124] g. Perform a visual inspection on the components after welding to confirm that the solder filling is uniform and there are no significant deviations or defects; perform helium mass spectrometry leak detection to verify whether the hermeticity of the packaging meets the requirements, and perform necessary electrical tests and preliminary functional tests. If the tests are qualified, the infrared chip packaging device is completed.

[0125] In this embodiment, although silicon-based or germanium-based wafer-level packaging (WLP) technology can reduce the package size, the infrared light-transmitting sheet 3 is easily contaminated by microparticles during the bonding process, forming optical scattering centers and causing a decrease in the imaging signal-to-noise ratio. Therefore, in this embodiment, the infrared light-transmitting sheet 3, the support frame plate 2, and the infrared chip 1 are vacuum reflow soldered in a vacuum environment to avoid contamination of the infrared light-transmitting sheet 3.

[0126] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that the elements inherent in a process, method, article, or apparatus that includes a list of elements are included. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Additionally, portions of the technical solutions provided in the embodiments of this application that are consistent with the implementation principles of corresponding technical solutions in the prior art have not been described in detail to avoid excessive elaboration.

[0127] This article uses specific examples to illustrate the principles and implementation methods of this utility model. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principles of this utility model, and these improvements and modifications also fall within the protection scope of this utility model.

Claims

1. An infrared chip packaging device, characterized in that, The device includes an infrared chip (1), a support frame plate (2), and an infrared light-transmitting sheet (3) stacked sequentially. The upper surface of the infrared chip (1) has a photosensitive area, and multiple infrared photosensitive units (11) are formed in the photosensitive area. The support frame plate (2) has a light-transmitting hole (200) in front of the photosensitive area. The infrared light-transmitting sheet (3) covers the area where the light-transmitting hole (200) is located, so that the infrared light-transmitting sheet (3), the support frame plate (2), and the infrared chip (1) together form a vacuum cavity in the light-transmitting hole (200) to accommodate the infrared photosensitive units (11). The supporting frame plate (2) includes an extension portion (21) extending outward from at least one side of the light-transmitting through hole (200); the upper surface of the extension portion (21) is provided with an information etching structure (201).

2. The infrared chip packaging device as described in claim 1, characterized in that, The information etching structure (201) is at least one of the following etching structures: barcode etching structure, QR code etching structure, and chip model code etching structure.

3. The infrared chip packaging device as described in claim 2, characterized in that, The recesses of the information etching structure (201) are filled with a pigment filling layer (203).

4. The infrared chip packaging device as described in claim 2, characterized in that, The upper surface of the information etching structure (201) is covered with a convex lens adhesive layer (204).

5. The infrared chip packaging device as described in claim 1, characterized in that, The thickness of the support frame plate (2) is 0.5mm~0.7mm.

6. The infrared chip packaging device according to any one of claims 1 to 5, characterized in that, The portion of the through-hole area (200) near the extension portion (21) is an ineffective light-transmitting area; The wall of the light-transmitting through-hole (200) near the outer epitaxial portion (21) is also connected to an inner epitaxial portion (22) located in the ineffective light-transmitting area; the upper surface of the inner epitaxial portion (22) is lower than the upper edge surface of the light-transmitting through-hole (200); a getter (4) is provided on the upper surface of the inner epitaxial portion (22); a conductive activation structure (202) electrically connected to the getter (4) is provided on the outer epitaxial portion (21).

7. The infrared chip packaging device as described in claim 6, characterized in that, The upper surface of the inner epitaxial portion (22) is provided with two electrode plates (220) that are respectively connected to both ends of the getter (4); the support frame plate (2) is provided with two internal through holes extending from the upper surface of the inner epitaxial portion (22) to the upper surface of the outer epitaxial portion (21); the two conductive activation structures (202) extend from the upper surface of the inner epitaxial portion (22) to the upper surface of the outer epitaxial portion (21) through the two internal through holes; and the ends of the two conductive activation structures (202) located on the upper surface of the inner epitaxial portion (22) are respectively in contact with the two electrode plates (220).

8. The infrared chip packaging device as described in claim 6, characterized in that, The inner extension (22) is connected to a shielding strip (23) on the side opposite to the outer extension (21), which is higher than the upper surface of the inner extension (22) and not higher than the upper surface of the edge.

9. The infrared chip packaging device as described in claim 6, characterized in that, The portion of the infrared photosensitive unit (11) near the extension portion (21) is a reference infrared photosensitive unit (110). The invalid light-transmitting area is directly opposite the area where the reference infrared photosensitive unit (110) is located, and the inner extension (22) covers the area where the reference infrared photosensitive unit (110) is located.

10. The infrared chip packaging device according to any one of claims 1 to 5, characterized in that, The portion of the through-hole area (200) near the epitaxial portion (21) is an ineffective light-transmitting area; the ineffective light-transmitting area is directly opposite the area outside the photosensitive area on the infrared chip (1); a thermally activated getter (31) is provided on the lower surface of the infrared light-transmitting sheet (3) at the position opposite the ineffective light-transmitting area.

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