Vacuum encapsulation structure and method of manufacturing the same

Abstract

The application provides a vacuum packaging structure and a preparation method thereof. The vacuum packaging structure comprises a substrate, a conductive pedestal arranged on the surface of the substrate, a first getter layer arranged on the surface of the conductive pedestal, a micro-bridge structure supported and arranged on the surface of the first getter layer, and a second getter layer arranged on the surface of the conductive pedestal and located in a space enclosed by the first getter layer and the micro-bridge structure. The application does not need to weld a getter column or a getter sheet on a component packaging shell, and does not need to provide an additional space for the getter on a cover plate. In the case of reducing the size of the component packaging and the cost of the device, the exposed area of the getter is increased, the vacuum degree of the component is improved, and the service life of the first getter layer and the second getter layer is increased through the electric activation or thermal activation mode.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of infrared sensor, in particular to a vacuum packaging structure and a preparation method thereof. BACKGROUND

[0002] Infrared focal plane sensor can respond to external infrared radiation, and is the core device of infrared thermal imaging equipment. In order to make the infrared focal plane sensor have a higher response rate to the infrared signal of the target object, the sensor must be vacuum packaged to minimize its air heat conduction.

[0003] At present, the focal plane infrared sensor is commonly packaged by metal, ceramic and wafer level. The metal and ceramic packaging uses columnar and sheet-shaped getter, and the getter is welded in the packaging tube shell by laser spot welding process. After the interior of the packaging shell is pumped to vacuum through the exhaust tail pipe, the getter is activated by electric activation or thermal activation, so as to achieve the effect of long-term vacuum packaging in the tube shell. However, in the above packaging method, the getter needs to be placed in the space outside the focal plane array area, resulting in a larger device packaging size, higher cost and complex packaging process. The wafer level packaging uses thin film getter, which is deposited on the cap wafer. The getter on the cap wafer needs to be activated by high temperature first, and then the wafer bonding packaging is completed by eutectic bonding process. However, most of the area of the cap wafer for wafer level packaging is an infrared light passing area, and the getter material cannot be deposited, resulting in very limited getter layout space. In addition, the getter of the wafer level packaged infrared sensor is generally laid on the cap wafer, and there is no electrical activation circuit, so that the getter cannot be activated again to prolong the service life of the device after the vacuum failure.

[0004] Therefore, how to reduce the volume of the infrared focal plane sensor while still ensuring sufficient getter layout space, maintain high vacuum inside the packaging tube shell, and control the activation of the getter, so that the reactivation after packaging can be realized at a controllable activation temperature without affecting the performance of the sensor, to realize low-cost, high-efficiency and long-life packaging is the current research difficulty. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a vacuum packaging structure and a preparation method thereof, which can increase the contact area of the getter and air while reducing the volume of the vacuum packaging structure, and can activate the getter in the packaging again to prolong the service life of the device after the vacuum failure.

[0006] To solve the above problems, the present application provides a vacuum packaging structure, comprising: a substrate; a conductive pedestal arranged on the surface of the substrate; a first getter layer arranged on the surface of the conductive pedestal; a micro-bridge structure supporting the surface of the first getter layer; and a second getter layer arranged on the surface of the conductive pedestal and located in the space enclosed by the first getter layer and the micro-bridge structure.

[0007] In some embodiments, in the direction perpendicular to the substrate, the edge of the orthographic projection of the second getter layer on the substrate protrudes beyond the edge of the orthographic projection of the micro-bridge structure on the substrate.

[0008] In some embodiments, a driving circuit is arranged in the substrate, which is connected to the conductive pedestal to provide activation current for the first getter layer and the second getter layer.

[0009] In some embodiments, a plurality of conductive pedestals are arranged on the surface of the substrate in a relative symmetry.

[0010] In some embodiments, the micro-bridge structure comprises a pier, a micro-cantilever beam, and a bridge deck, the pier comprises an insulating layer covering the first getter layer and a first electrode layer covering the insulating layer, at least one side of the first getter layer is exposed, and the first electrode layer is connected to the conductive pedestal; the micro-cantilever beam is used to connect the pier and the bridge deck; the bridge deck is supported by the micro-cantilever beam and suspended on the surface of the first getter layer, and the second getter layer is located below the micro-cantilever beam.

[0011] In some embodiments, the bridge deck comprises a structural support layer, a thermistor layer, a second electrode layer, and a protective layer, the structural support layer is connected to the corresponding pier through the micro-cantilever beam; the thermistor layer is arranged on the upper surface of the structural support layer and connected to the second electrode layer; the second electrode layer is arranged on the upper surface of the thermistor layer and electrically connected to the driving circuit through the micro-cantilever beam, the first electrode layer, and the conductive pedestal; and the protective layer is arranged on the surface of the thermistor layer and the surface of the second electrode layer and covers the thermistor layer and the second electrode layer.

[0012] In some embodiments, a groove is arranged on the side surface of the first getter layer to increase the area of the first getter layer.

[0013] In some embodiments, the cross-sectional shape of the second getter layer is selected from any one of a ring shape, a U shape, and a rectangular shape.

[0014] To solve the above problems, the application provides a preparation method of a vacuum packaging structure, which comprises the following steps: providing a substrate; forming a conductive pedestal on the surface of the substrate; forming a first getter layer and a second getter layer on the surface of the conductive pedestal; and forming a micro-bridge structure on the surface of the first getter layer to support the micro-bridge structure on the surface of the first getter layer.

[0015] In some embodiments, the step of forming the first getter layer and the second getter layer on the surface of the conductive pedestal comprises the following steps: forming a getter material layer on the surface of the conductive pedestal; and patterning the getter material layer to form the first getter layer on a part of the surface of the conductive pedestal and to form the second getter layer on another part of the surface of the conductive pedestal.

[0016] In some embodiments, the specific step of forming the micro-bridge structure on the surface of the first getter layer to support the micro-bridge structure on the surface of the first getter layer comprises the following steps: forming an insulating layer on the surface of the first getter layer and forming a first electrode layer on the surface of the insulating layer; forming a sacrificial layer on the surface of the substrate, wherein the sacrificial layer covers the conductive pedestal, the first getter layer, the insulating layer and the first electrode layer; forming a through hole on the surface of the sacrificial layer, wherein the through hole ends at the surface of the first electrode layer; and sequentially forming a structure support layer, a second electrode layer, a thermistor layer and a protective layer on the sacrificial layer, wherein the second electrode layer is connected with the first electrode layer through the through hole.

[0017] The above technical solution can increase the exposed area of the getter in the packaging space and improve the vacuum degree of the component by forming the first getter layer and the second getter layer in the micro-bridge structure without welding getter columns or getter sheets on the packaging tube of the component and without providing additional space for the getter on the cover plate, thereby reducing the size of the component and the cost of the component.

[0018] Further, the first getter layer is formed below the pier, which can reduce the height of the micro-cantilever beam and improve the stability of the micro-bridge structure. The second getter layer is arranged below the micro-cantilever beam, which makes full use of the longitudinal height of the infrared absorption resonant cavity and the characteristic that the micro-cantilever beam does not need to absorb infrared signals, so that the getter layer is not arranged below the bridge surface, which does not affect the infrared absorption resonant cavity formed between the bridge surface and the substrate and does not affect the infrared absorption effect of the bridge surface.

[0019] Further, the simultaneous formation of the first getter layer and the second getter layer simplifies the etching process of the through hole of the sacrificial layer and can greatly improve the preparation efficiency of the device.

[0020] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application, as claimed. Techniques, methods and devices known to those of ordinary skill in the art can be employed in the practice of the application, and can be deemed to be part of the disclosure herein, to the extent that they are not inconsistent with the specific teachings of the application. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a schematic diagram of a cross section of a vacuum packaging structure according to an embodiment of the present application;

[0022] Figure 2 is a schematic diagram of a top view of a vacuum packaging structure according to an embodiment of the present application;

[0023] Figure 3 is a schematic diagram of a top view of a vacuum packaging structure according to another embodiment of the present application;

[0024] Figure 4 is a schematic diagram of a top view of a bridge of a vacuum packaging structure according to an embodiment of the present application;

[0025] Figure 5 is a schematic diagram of the steps of a method of manufacturing a vacuum packaging structure according to an embodiment of the present application;

[0026] Figures 6A-6D is a schematic diagram of a manufacturing process of a vacuum packaging structure according to an embodiment of the present application;

[0027] Figure 7 is a schematic diagram of the steps of a method of forming a getter layer in a method of manufacturing a vacuum packaging structure according to an embodiment of the present application;

[0028] Figures 8A-8B is a schematic diagram of a method of forming a getter layer in a method of manufacturing a vacuum packaging structure according to an embodiment of the present application;

[0029] Figure 9 is a schematic diagram of the steps of a method of forming a first getter layer in a method of manufacturing a vacuum packaging structure according to an embodiment of the present application;

[0030] Figures 10A-10D is a schematic diagram of a method of forming a first getter layer in a method of manufacturing a vacuum packaging structure according to an embodiment of the present application;

[0031] Figure 11 is a schematic diagram of the steps of a method of forming a second getter layer in a method of manufacturing a vacuum packaging structure according to another embodiment of the present application;

[0032] Figures 12A-12Bis a schematic diagram of a forming method of the second getter layer in the vacuum packaging structure preparation method provided by another embodiment of the present application;

[0033] Figure 13 is a schematic diagram of a forming method of the micro-bridge structure in the vacuum packaging structure preparation method provided by an embodiment of the present application.

[0034] Figures 14A-14D is a schematic diagram of a forming method of the micro-bridge structure in the vacuum packaging structure preparation method provided by an embodiment of the present application. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0036] First, a vacuum packaging structure provided by the embodiments of the present application will be introduced below.

[0037] Figure 1 is a schematic diagram of a cross section of a vacuum packaging structure provided by an embodiment of the present application. Please refer to Figure 1 , the vacuum packaging structure comprises a substrate 1, a conductive pedestal 2, a first getter layer 31, a micro-bridge structure 5, and a second getter layer 32.

[0038] In the embodiment, the vacuum packaging structure comprises a plurality of conductive pedestals 2, and the plurality of conductive pedestals 2 are arranged on the surface of the substrate 1 in a relative symmetry. The conductive pedestal 2 is a conductive structure, and the material thereof is one of metal materials such as aluminum, gold, silver, and copper, or an alloy thereof.

[0039] The first getter layer 31 is arranged on the surface of the conductive pedestal 2. The material of the first getter layer 31 can be one of materials such as titanium, zirconium cobalt rhenium, zirconium titanium vanadium, zirconium iron vanadium, and zirconium vanadium.

[0040] The micro-bridge structure 5 is supported on the surface of the first getter layer 31. In the embodiment, the micro-bridge structure 5 comprises a bridge pier 53, a micro-cantilever beam 51, and a bridge deck 52. The bridge pier 53 comprises an insulating layer 531 covering the first getter layer 31, and a first electrode layer 532 covering the insulating layer 531, at least one side of the first getter layer 31 being exposed, and the first electrode layer 532 being connected to the conductive base 2. The micro-cantilever beam 51 is used to connect the bridge pier 53 and the bridge deck 52. The bridge deck 52 is supported by the micro-cantilever beam 51 and suspended on the surface of the first getter layer 31, and the second getter layer 52 is located below the micro-cantilever beam 51.

[0041] The second getter layer 32 is arranged on the surface of the conductive base 2 and located in the space enclosed by the first getter layer 31 and the micro-bridge structure 5. The first getter layer 31 is located on the surface of the outer conductive base 2, and the second getter layer 32 is located on the surface of the inner conductive base.

[0042] In the embodiment, the micro-bridge structure 5 comprises two bridge piers 53.

[0043] The first getter layer 31 and the second getter layer 32 are activated multiple times by thermal activation or electrical activation, thereby increasing the service life of the first getter layer 31 and the second getter layer 32 and achieving high response and high sensitivity detection. The substrate 1 is provided with a driving circuit (not shown in the figure), which is connected to the conductive base 2 and provides an activation current for the first getter layer 31 and the second getter layer 32 to achieve electrical activation of the first getter layer 31 and the second getter layer 32. Moreover, the first electrode layer 532 in the bridge pier 53 is also electrically connected to the corresponding driving circuit through the conductive base 2.

[0044] The vacuum packaging structure further comprises a reflective layer 4 arranged on the upper surface of the substrate 1, and the conductive base 2 is located on both sides of the reflective layer 4. The reflective layer 4 is made of one of aluminum, gold, silver, copper, and other metal materials or an alloy thereof. The reflective layer 4 is an optional structure, which forms a resonant absorption cavity with the bridge deck 52, and the height of the resonant absorption cavity is d, and d = λ / 4, λ being the absorption wavelength.

[0045] In the embodiment, the bridge 52 is suspended above the reflective layer 4 on the upper surface of the substrate 1 through the micro-cantilever beam 51 and the pier 53, and forms a resonant absorption cavity of 1 / 4 absorption wavelength with the reflective layer 4. The second getter layer 32 is arranged below the micro-cantilever beam 51, and no getter layer is arranged below the bridge 52. The longitudinal height of the infrared absorption resonant cavity is fully utilized, and the micro-cantilever beam 51 does not need to absorb infrared signals, which does not affect the infrared absorption resonant cavity formed between the bridge 52 and the substrate 1, and does not affect the infrared absorption effect of the bridge 52.

[0046] In the embodiment, the bridge 52 further includes a structure support layer 521, a thermistor layer 522, a second electrode layer 523, and a protective layer 524. The structure support layer 521 is connected to the corresponding pier 53 through the micro-cantilever beam 51. The thermistor layer 522 is arranged on the upper surface of the structure support layer 521 and connected to the second electrode layer 523. The second electrode layer 523 is arranged on the upper surface of the thermistor layer 522 and electrically connected to the driving circuit through the micro-cantilever beam 51, the first electrode layer 532, and the conductive pedestal 2. The protective layer 524 is arranged on the surface of the second electrode layer 523 and the surface of the thermistor layer 522, and covers the second electrode layer 523 and the thermistor layer 522.

[0047] In the embodiment, the micro-cantilever beam 51 further includes a structure support layer 511, a second electrode layer 512, and a protective layer 514. The structure support layer 511 covers the surface of the first electrode layer. The second electrode layer 512 is arranged on the surface of the structure support layer 511 and electrically connected to the first electrode layer through the structure support layer 511. The protective layer 514 covers the surface of the second electrode layer 512 and the surface of the structure support layer. The structure support layer 521 of the bridge 52 is connected to the corresponding first electrode layer 532 through the structure support layer 511 of the micro-cantilever beam 51. The second electrode layer 523 of the bridge 52 is electrically connected to the second electrode layer 512 of the micro-cantilever beam 51 to connect the second electrode layer 523 of the bridge 52 to the first electrode layer 532, and further connect the thermistor layer 522 to the first electrode layer 532. The protective layer 524 of the bridge 52 and the protective layer 514 of the micro-cantilever beam 51 are the same layer structure.

[0048] The material of the protective layer 524 and the protective layer 514 is one of silicon oxide, silicon nitride, silicon oxynitride, etc., the material of the second electrode layer 523 and the second electrode layer 512 is one of titanium, germanium, platinum, nickel-chromium, titanium nitride, etc., the material of the thermistor layer 522 is one of vanadium oxide, amorphous silicon, copper oxide, manganese oxide, molybdenum oxide, titanium oxide, etc., which is used to convert infrared radiation into an electrical signal, the electrical signal is transmitted to the driving circuit through the conductive base 2, and the driving circuit outputs a result signal to reflect the temperature of the target according to the electrical signal. The material of the structural support layer 521 and the structural support layer 511 is one of silicon oxide, silicon nitride, silicon oxynitride, etc.

[0049] In this embodiment, the structural support layer 521 of the bridge deck 52 and the structural support layer 521 of the micro-cantilever beam 51 are connected to the first electrode layer 532 of the pier 53 and placed on the conductive base 2 through the pier 53. The thermistor layer 522 of the bridge deck 52 is placed on the upper surface of the structural support layer 521 of the bridge deck 52 and connected to the second electrode layer 523, and the second electrode layer 523 is arranged on the upper surface of the thermistor layer 522 of the bridge deck 52 and electrically connected to the driving circuit through the second electrode layer 512 of the micro-cantilever beam 51, the first electrode layer 532, the conductive base 2.

[0050] Figure 2 is a top view schematic diagram of a vacuum packaging structure provided by an embodiment of the present application. In this embodiment, the conductive base 2 is annularly distributed, and the second getter layer 32 is arranged on the surface of the conductive base 2. In the direction perpendicular to the substrate, the edge of the orthographic projection of the second getter layer on the substrate protrudes from the edge of the orthographic projection of the micro-bridge structure on the substrate. The driving circuit arranged in the substrate 1 is connected to the conductive base 2 to provide an activation current for the second getter layer 32. Figure 2 The second getter layer 32 in the middle is shown in a shaded area to show the cross-sectional shape of the second getter layer 32. In this embodiment, the shape of the orthographic projection of the second getter layer 32 on the substrate 1 (i.e., the cross-sectional shape of the second getter layer 32) is a continuous annular shape, and the structures on both sides are symmetrical.

[0051] Figure 3 is a top view schematic diagram of a vacuum packaging structure provided by another embodiment of the present application. In this embodiment, Figure 2The second getter layer 32 is shown in the shadow area to indicate the cross-sectional shape of the second getter layer 32. In the embodiment, the conductive pedestal 2 is symmetrically arranged on both sides of the substrate, the second getter layer 32 is arranged on the surface of the conductive pedestal 2, and the shape of the orthographic projection of the second getter layer 32 on the substrate 1 (i.e. the cross-sectional shape of the second getter layer 32) is a discontinuous rectangle, three on each side, and the structures on both sides are asymmetric.

[0052] The above are two different arrangement modes of the second getter layer 32. In other embodiments, the cross-sectional shape of the second getter layer 32 is selected from any one of a ring shape, a U shape, and a rectangle shape. For example, the second getter layer 32 can also be arranged in a U shape.

[0053] Figure 4 is a top view schematic diagram of a bridge pier of a vacuum packaging structure provided by an embodiment of the present application. Please refer to Figure 4 , the first getter layer 31 has grooves 311 on both sides to increase the effective area of the first getter layer 31 and improve the vacuum degree of the packaging structure. In other embodiments, the grooves 311 of the first getter layer 31 can have other positions and shapes.

[0054] The bridge pier 53 includes an insulating layer 531 made of aluminum oxide, aluminum nitride, silicon oxide, silicon nitride, silicon oxynitride, beryllium oxide, etc. The insulating layer 531 is provided with a first electrode layer 532 on the surface. The first electrode layer 532 spans the first getter layer 31 on both sides and covers 1 / 5 to 1 / 2 of the surface area of the first getter layer 31. The first electrode layer 532 is interconnected with the conductive pedestal 2 on the surface of the substrate 1. The first electrode layer 532 is made of aluminum, copper, etc.

[0055] Based on the same inventive concept, the embodiment of the present application further provides a preparation method of a vacuum packaging structure.

[0056] Figure 5 is an implementation step schematic diagram of a preparation method of a vacuum packaging structure provided by an embodiment of the present application. Please refer to Figure 5 , the preparation method of the vacuum packaging structure includes: step S501, providing a substrate 1; step S502, forming a conductive pedestal 2 on the surface of the substrate 1; step S503, forming a first getter layer 31 and a second getter layer 32 on the surface of the conductive pedestal 2; and step S504, forming a micro-bridge structure 5 arranged on the surface of the first getter layer 31 on the surface of the first getter layer 31.

[0057] Figures 6A-6D is a schematic diagram of a preparation process of a vacuum packaging structure in an embodiment of the present application.

[0058] AppendixFigure 6A As shown in FIG. 1, a substrate 1 is provided according to step S501. The substrate 1 is provided with a driving circuit (not shown in the figure).

[0059] FIG. 1 shows a schematic diagram of a vacuum packaging structure according to an embodiment of the present application. Figure 6B As shown in FIG. 1, a conductive pedestal 2 is formed on the surface of the substrate 1 according to step S502. The conductive pedestal 2 is electrically connected to the driving circuit. The conductive pedestal 2 is made of one of metal materials such as aluminum, gold, silver, copper, and alloys thereof. The surface of the conductive pedestal 2 is exposed on the surface of the substrate 1. In this step, a reflective layer 4 is also formed on the surface of the substrate 1, and the conductive pedestal 2 is arranged on both sides of the reflective layer 4.

[0060] FIG. 1 shows a schematic diagram of a vacuum packaging structure according to an embodiment of the present application. Figure 6C As shown in FIG. 1, a first getter layer 31 and a second getter layer 32 are formed on the surface of the conductive pedestal 2 according to step S503. The material of the first getter layer 31 can be one of titanium, zirconium cobalt rhenium, zirconium titanium vanadium, zirconium iron vanadium, and zirconium vanadium. The material of the second getter layer 32 can be one of titanium, zirconium cobalt rhenium, zirconium titanium vanadium, zirconium iron vanadium, and zirconium vanadium.

[0061] Figure 7 FIG. 2 is an embodiment of the method for forming the getter layers in the method for preparing the vacuum packaging structure according to an embodiment of the present application.

[0062] FIG. 1 shows a schematic diagram of a vacuum packaging structure according to an embodiment of the present application. Figure 7 After the step of forming the conductive pedestal 2, the first getter layer 31 and the second getter layer 32 are simultaneously formed on the surface of the conductive pedestal 2, so as to save the process steps, reduce the cost, and improve the production efficiency. The step of forming the first getter layer 31 and the second getter layer 32 on the surface of the conductive pedestal 2 includes: step S601, forming a getter material layer 12 on the surface of the conductive pedestal 2; and step S602, patterning the getter material layer 12, so as to form the first getter layer 31 on part of the surface of the conductive pedestal 2, and form the second getter layer 32 on another part of the surface of the conductive pedestal 2.

[0063] Figures 8A-8B FIG. 2 is an embodiment of the method for forming the getter layers in the method for preparing the vacuum packaging structure according to an embodiment of the present application.

[0064] FIG. 1 shows a schematic diagram of a vacuum packaging structure according to an embodiment of the present application. Figure 8A As shown in FIG. 1, a getter material layer 12 is formed on the surface of the conductive pedestal 2 according to step S601. The material of the getter material layer 12 can be one of titanium, zirconium cobalt rhenium, zirconium titanium vanadium, zirconium iron vanadium, and zirconium vanadium.

[0065] FIG. 1 shows a schematic diagram of a vacuum packaging structure according to an embodiment of the present application. Figure 8BAs shown, referring to step S602, the getter material layer 12 is patterned to form the first getter layer 31 on a part of the surface of the conductive base 2 and to form the second getter layer 32 on another part of the surface of the conductive base 2.

[0066] In another embodiment, the first getter layer 31 and the second getter layer 32 are formed in different steps, and the heights of the first getter layer 31 and the second getter layer 32 can be independently controlled. Figure 9 is an embodiment of the method for forming the first getter layer in the method for manufacturing the vacuum packaging structure provided by the present application.

[0067] In one embodiment, referring to the accompanying drawings Figure 9 , this step specifically includes: step S701, forming a photoresist material layer 9 on a part of the surface of the conductive base 2; step S702, patterning the photoresist material layer 9 to form a photoresist layer 10; step S703, forming a first getter material layer 8 on the surface of the photoresist layer 10 and the exposed surface of the conductive base 2; and step S704, removing the photoresist layer 10 and the first getter material layer 8 on the surface of the photoresist layer 10, and the first getter material layer 8 on the surface of the conductive base 2 is retained to form the first getter layer 31.

[0068] Figures 10A-10D is a schematic diagram of the method for forming the first getter layer in the method for manufacturing the vacuum packaging structure provided by the present application.

[0069] In one embodiment, referring to the accompanying drawings Figure 10A As shown, referring to step S701, a photoresist material layer 9 is formed on a part of the surface of the conductive base 2. The photoresist material layer 9 can be formed by coating and other processes. In this step, the photoresist material layer 9 is only formed on a part of the surface of the conductive base 2, and another part of the surface of the conductive base 2 is not covered by the photoresist material layer 9.

[0070] In one embodiment, referring to the accompanying drawings Figure 10B As shown, referring to step S702, the photoresist material layer 9 is patterned to form a photoresist layer 10. In this step, the photoresist material layer 9 can be patterned by the method of exposure and development. The photoresist layer 10 formed by patterning the photoresist material layer 9 exposes a part of the surface of the conductive base 2.

[0071] In one embodiment, referring to the accompanying drawings Figure 10CAs shown, referring to step S703, a first getter material layer 8 is formed on the surface of the photoresist layer 10 and the exposed surface of the conductive base 2. The material of the first getter material layer 8 can be one of titanium, zirconium cobalt rhenium, zirconium titanium vanadium, zirconium iron vanadium, and zirconium vanadium. In this step, the first getter material layer 8 can be deposited by a chemical vapor deposition process or the like.

[0072] Figure 2 is a schematic diagram of the formation of a second getter layer in a method for manufacturing a vacuum packaging structure according to another embodiment of the present application. Figure 10D As shown, referring to step S704, the photoresist layer 10 and the first getter material layer 8 on the surface of the photoresist layer 10 are removed, and the first getter material layer 8 on the surface of the conductive base 2 is retained to form the first getter layer 31. In this step, a stripping process is used to remove the photoresist layer 10, which includes but is not limited to laser stripping, stripping liquid stripping, and the like. When the photoresist layer 10 is removed, the first getter material layer 8 on the surface of the photoresist layer 10 is also removed, and the first getter material layer 8 on the surface of the conductive base 2 is retained as the first getter layer 31.

[0073] Figure 11 Figure 2 is a schematic diagram of the formation of a second getter layer in a method for manufacturing a vacuum packaging structure according to another embodiment of the present application.

[0074] In this embodiment, the vacuum packaging structure further includes a second getter layer 32, which is disposed on the surface of the conductive base 2 and located within the space enclosed by the first getter layer 31 and the micro-bridge structure 5. As shown in Figure 2, referring to step S801, a second getter material layer 7 is formed on another part of the surface of the conductive base 2. The material of the second getter material layer 7 can be one of titanium, zirconium cobalt rhenium, zirconium titanium vanadium, zirconium iron vanadium, and zirconium vanadium. In this step, the second getter material layer 7 can be deposited by a chemical vapor deposition process or the like. Figure 11 Before the step of forming a photoresist layer 10 on the surface of the conductive base 2, the method further includes: step S801, forming a second getter material layer 7 on another part of the surface of the conductive base 2; and step S802, patterning the second getter material layer 7 to form a second getter layer 32, which is located within the space enclosed by the first getter layer 31 and the micro-bridge structure 5.

[0075] Figures 12A-12B Figure 2 is a schematic diagram of the formation of a second getter layer in a method for manufacturing a vacuum packaging structure according to another embodiment of the present application.

[0076] Figure 2 is a schematic diagram of the formation of a second getter layer in a method for manufacturing a vacuum packaging structure according to another embodiment of the present application. Figure 12A As shown, referring to step S801, a second getter material layer 7 is formed on another part of the surface of the conductive base 2. The material of the second getter material layer 7 can be one of titanium, zirconium cobalt rhenium, zirconium titanium vanadium, zirconium iron vanadium, and zirconium vanadium. In this step, the second getter material layer 7 can be deposited by a chemical vapor deposition process or the like.

[0077] Figure 2 is a schematic diagram of the formation of a second getter layer in a method for manufacturing a vacuum packaging structure according to another embodiment of the present application. Figure 12BAs shown, referring to step S802, the second getter material layer 7 is patterned to form a second getter layer 32, which is located in the space enclosed by the first getter layer 31 and the micro-bridge structure 5.

[0078] After the second getter layer 32 is formed, step S701 is performed to form the first getter layer 31 on the surface of the conductive pedestal 2, thereby forming the first getter layer 31 and the second getter layer 32 on the surface of the substrate 1, effectively increasing the area of the getter. In this embodiment, the first getter layer 31 and the second getter layer 32 are formed in different steps, which enables independent control of the height of the first getter layer 31 and the second getter layer 32.

[0079] Please continue to refer to the accompanying Figure 5 and the accompanying Figure 6D , referring to step S504, the micro-bridge structure 5 is formed on the surface of the first getter layer 31. The micro-bridge structure includes the bridge piers 53 and the bridge surface 52, and the micro-cantilever beam 51. The bridge surface 52 is suspended on the upper surface of the substrate 1 by the micro-cantilever beam 51 and the bridge piers 53. In this embodiment, the bridge surface 52 is suspended above the reflective layer 4 by the micro-cantilever beam 51 and the bridge piers 53, and forms a resonant absorption cavity with the reflective layer 4 with a quarter of the absorption wavelength.

[0080] Figure 13 is an embodiment of the method for forming a micro-bridge structure in the method for preparing a vacuum packaging structure provided by the present application. The specific steps for forming the micro-bridge structure 5 on the surface of the first getter layer 31 include: step S901, forming an insulating layer 531 on the surface of the first getter layer 31, and forming a first electrode layer 532 on the surface of the insulating layer 531; step S902, forming a sacrificial layer 11 on the surface of the substrate 1, covering the conductive pedestal 2, the first getter layer 31, the insulating layer 531, and the first electrode layer 532; step S903, forming a via hole 13 on the surface of the sacrificial layer 11, which terminates at the surface of the first electrode layer 532; step S904, sequentially forming a structure support layer 521, a thermistor layer 522, a second electrode layer 523, and a protective layer 524 on the sacrificial layer 11, the second electrode layer 512 being connected to the first electrode layer 532 through the via hole 13; step S905, removing the sacrificial layer 11 to form the micro-bridge structure 5.

[0081] Figures 14A-14D is a schematic diagram of the method for forming a micro-bridge structure in the method for preparing a vacuum packaging structure provided by the present application.

[0082] Appendix Figure 14A As shown, referring to step S901, an insulating layer 531 is formed on the surface of the first getter layer 31, and a first electrode layer 532 is formed on the surface of the insulating layer 531. The first electrode layer 532 is interconnected with the conductive base 2 located on the surface of the substrate 1. The material of the first electrode layer 532 is aluminum, copper, etc. In this step, a portion of the surface of the conductive base 2 is covered by the first getter layer 31, and the other portion of the surface not covered by the first getter layer 31 is connected to the first electrode layer 532. In this step, a second getter layer 32 is also provided on the surface of the conductive base 2, and the second getter layer 32 is located inside the first getter layer 31.

[0083] Appendix Figure 14B As shown, referring to step S902, a sacrificial layer 11 is formed. The sacrificial layer 11 is formed on the surface of the substrate 1 and covers the conductive base 2, the first getter layer 31, the insulating layer 531, and the first electrode layer 532. The sacrificial layer is one of organic polymers such as polyimide, styrene, and acrylic homopolymer, or one of amorphous silicon, silicon oxide, and phosphosilicate glass. In this step, the sacrificial layer 11 also covers the second getter layer 32.

[0084] Appendix Figure 14C As shown, referring to step S903, a through-hole 13 is formed on the surface of the sacrificial layer 11, and the through-hole 13 terminates on the surface of the first electrode layer 532. In this step, the through-hole 13 exposes a portion of the surface of the first electrode layer 532.

[0085] Appendix Figure 14D As shown, referring to step S904, a structural support layer, a thermistor layer, a second electrode layer, and a protective layer are sequentially formed on the sacrificial layer 11. In this embodiment, in this step, the structural support layer, the thermistor layer, the second electrode layer, and the protective layer extend laterally to form the bridge deck and micro cantilever beam of the microbridge structure. Specifically, the bridge deck includes a structural support layer 521, a thermistor layer 522, a second electrode layer 523, and a protective layer 524, and the micro cantilever beam includes a structural support layer 511, a second electrode layer 512, and a protective layer 514.

[0086] Please see Figure 6D Referring to step S905, the sacrificial layer 11 is removed to form the microbridge structure 5. The microbridge structure 5 includes the bridge pier 53, the microcantilever beam 51, and the bridge deck 52. The bridge deck 52 is suspended and supported on the upper surface of the substrate 1 by the microcantilever beam 51 and the bridge pier 53.

[0087] The technical scheme is characterized in that the first getter layer 31 and the second getter layer 32 are arranged in the micro-bridge structure 5, without welding getter columns or getter sheets on the device package shell, and without providing additional space for the getter on the cover plate, so that the exposure area of the getter in the package space is increased, the vacuum degree of the device is improved, the device package size is reduced, and the device cost is reduced. The first getter layer 31 and the second getter layer 32 are arranged on the conductive pedestal 2, and the first getter layer 31 and the second getter layer 32 can be activated multiple times by electric activation or thermal activation, so that the service life of the first getter layer 31 and the second getter layer 32 is increased, and high-response and high-sensitivity detection is realized.

[0088] Further, the first getter layer 31 is formed below the bridge pier 53, which can reduce the height of the micro-cantilever beam 51, thereby improving the stability of the micro-bridge structure 5. The second getter layer 32 is arranged below the micro-cantilever beam 51, fully utilizes the longitudinal height of the infrared absorption resonant cavity, and utilizes the characteristic that the micro-cantilever beam 51 does not need to absorb infrared signals, so that the getter layer is not arranged below the bridge surface 52, which does not affect the infrared absorption resonant cavity formed between the bridge surface 52 and the substrate 1, and does not affect the infrared absorption effect of the bridge surface 52.

[0089] Further, the simultaneous formation of the first getter layer 31 and the second getter layer 32 simplifies the via etching process of the sacrificial layer 11, and can greatly improve the device preparation efficiency.

[0090] The above only describes the preferred embodiments of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should be considered as the protection scope of the present application.

Claims

1. A vacuum packaging structure, characterized in that, include: Substrate; A conductive base, wherein the conductive base is disposed on the surface of the substrate; A first getter layer is disposed on the surface of the conductive base; A microbridge structure is supported on the surface of the first getter layer. The microbridge structure includes a pier, which includes an insulating layer covering the first getter layer and a first electrode layer covering the insulating layer. At least one side of the first getter layer is exposed, and the first electrode layer is connected to the conductive base. The second getter layer is disposed on the surface of the conductive base and is located within the space enclosed by the first getter layer and the microbridge structure. A reflective layer is disposed on the upper surface of the substrate, and the conductive base is located on both sides of the reflective layer.

2. The vacuum packaging structure according to claim 1, characterized in that, In a direction perpendicular to the substrate, the edge of the orthogonal projection of the second getter layer onto the substrate protrudes beyond the edge of the orthogonal projection of the microbridge structure onto the substrate.

3. The vacuum packaging structure according to claim 1, characterized in that, A driving circuit is disposed within the substrate and is connected to the conductive base to provide an activation current for the first getter layer and the second getter layer.

4. The vacuum packaging structure according to claim 1, characterized in that, It includes a plurality of conductive bases, which are symmetrically disposed on the surface of the substrate.

5. The vacuum packaging structure according to claim 1, characterized in that, The microbridge structure also includes microcantilever beams and a bridge deck. The micro cantilever arm is used to connect the bridge pier and the bridge deck; The bridge deck is supported by the microcantilever beam and suspended above the surface of the first getter layer, and the second getter layer is located below the microcantilever beam.

6. The vacuum packaging structure according to claim 5, characterized in that, The bridge deck includes: a structural support layer, a thermistor layer, a second electrode layer, and a protective layer. The structural support layer is connected to the corresponding bridge pier via the micro cantilever beam; The thermistor layer is disposed on the upper surface of the structural support layer and connected to the second electrode layer; The second electrode layer is disposed on the upper surface of the thermistor layer and is electrically connected to the driving circuit through the microcantilever beam, the first electrode layer, and the conductive base; The protective layer is disposed on the surface of the thermistor layer and the surface of the second electrode layer, and covers the thermistor layer and the second electrode layer.

7. The vacuum packaging structure according to claim 1, characterized in that, The first getter layer has grooves on its side to increase the area of ​​the first getter layer.

8. The vacuum packaging structure according to claim 1, characterized in that, The cross-sectional shape of the second getter layer is selected from any one of annular, U-shaped, and rectangular shapes.

9. A method for preparing a vacuum packaging structure as described in claim 1, characterized in that, Includes the following steps: Provide a substrate; A conductive base is formed on the surface of the substrate; A first getter layer and a second getter layer are formed on the surface of the conductive base; A microbridge structure is formed on the surface of the first getter layer to support the microbridge structure.

10. The method according to claim 9, characterized in that, The step of forming the first getter layer and the second getter layer on the surface of the conductive base includes: A getter material layer is formed on the surface of the conductive base; The getter material layer is patterned to form the first getter layer on a portion of the surface of the conductive substrate and the second getter layer on another portion of the surface of the conductive substrate.

11. The method according to claim 9, characterized in that, The specific steps for forming a microbridge structure supporting the surface of the first getter layer include: An insulating layer is formed on the surface of the first getter layer, and a first electrode layer is formed on the surface of the insulating layer; A sacrificial layer is formed on the surface of the substrate and covers the conductive base, the first getter layer, the insulating layer, and the first electrode layer. A through-hole is formed on the surface of the sacrificial layer, and the through-hole terminates at the surface of the first electrode layer; A structural support layer, a thermistor layer, a second electrode layer, and a protective layer are sequentially formed on the sacrificial layer, and the second electrode layer is connected to the first electrode layer through the through hole; The sacrificial layer is removed to form the microbridge structure.

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