Cavity structure and processing equipment
By using a thinner metal shell and replacement layer in the cavity structure, combined with heating parts, the existing vacuum cavity has solved the problem of large weight and low strength, and the cavity structure has been lightened and high strength, meeting the production needs of large semiconductor or photovoltaic materials.
Patent Information
- Application Number
- CN202422136794.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-30
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-08-30
AI Technical Summary
In the preparation of large semiconductors or photovoltaic materials, existing vacuum cavity has problems such as high weight, high cost, low mechanical strength and poor thermal stability, which is difficult to meet the production needs of stability, convenience and high economic efficiency.
By adopting a thinner metal shell and a replacement layer in the cavity structure, the density of the replacement layer is less than that of the metal shell, connected to the outer side wall or inner wall of the metal shell, and connected to the heating element, to achieve lightweight and high strength of the cavity structure.
The overall weight reduction, mechanical strength improvement and thermal stability of the cavity structure are achieved, and the stable, convenient and economical production needs of semiconductor or photovoltaic materials are met.
Smart Images
Figure CN223038907U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of semiconductor or photovoltaic material processing, and particularly to a cavity structure and a processing device. Background Art
[0002] When preparing semiconductor or photovoltaic materials, it is usually necessary to place sheet materials (such as silicon wafers, etc.) in a cavity to perform a heating reaction on the sheet materials in the cavity. Therefore, the cavity needs to have a certain strength and stability. Generally, the cavity is made of solid metal plates through processes such as welding and bending, or is composed of a quartz tube and a flange. However, for the preparation of large-scale semiconductors or photovoltaic materials, the solid metal plates are heavy and costly, while the quartz tubes have low mechanical strength and poor thermal stability, resulting in problems such as inconvenient handling and installation, high production costs, and poor stability in the current vacuum cavities.
[0003] Therefore, there is an urgent need for a vacuum cavity to meet the production requirements of large-scale semiconductors or photovoltaic materials with stability, convenience, and high economic efficiency. Summary of the Utility Model
[0004] In view of this, the present application provides a cavity structure. By pouring a part of the metal material in the replacement layer, compared with the all-metal cavity structure, the problems of the large weight of the metal cavity structure and the low strength of the quartz cavity structure are solved to meet the production requirements of semiconductor or photovoltaic materials with stability, convenience, and high economic efficiency.
[0005] The present application provides a cavity structure including a metal shell, a replacement layer, and a heating element. A cavity for accommodating sheet materials is provided inside the metal shell. The replacement layer is connected to the outer wall or the inner wall of the metal shell, and the density of the replacement layer is less than the density of the metal shell. The heating element is connected to the metal shell or the replacement layer.
[0006] In the above embodiment, with the relatively thin metal shell, compared with the solid metal structure, it helps to reduce the overall weight of the cavity structure, and the replacement layer is used to maintain the overall strength of the cavity structure, and the inside of the metal shell is heated by the heating element to meet the production requirements of semiconductor or photovoltaic materials with stability, convenience, and high economic efficiency.
[0007] In some embodiments, when the replacement layer is connected to the outer wall of the metal shell, the heating element is arranged on the outer wall of the metal shell.
[0008] In some embodiments, the replacement layer is made of a heat-insulating organic material or an inorganic material, and the mechanical strength of the replacement layer when heated to a specified temperature is greater than or equal to the mechanical strength of the quartz material when heated to the specified temperature.
[0009] In some embodiments, when the replacement layer is connected to the inner wall of the metal housing, the replacement layer includes a heat-conducting layer and a heat-insulating layer; the heat-insulating layer is connected to the inner side wall of the metal housing; the heat-conducting layer is connected to the side of the heat-insulating layer away from the metal housing; the heating element is connected to the side of the heat-conducting layer away from the heat-insulating layer, or the heating element is disposed within the heat-conducting layer.
[0010] In some embodiments, the heat-insulating layer is made of a heat-insulating organic material or inorganic material, and the mechanical strength of the heat-insulating layer when heated to a specified temperature is greater than or equal to the mechanical strength of quartz material when heated to the specified temperature.
[0011] In some embodiments, the thickness ratio among the metal housing, the heat-insulating layer, and the heat-conducting layer is (2 - 5):(7 - 15):(1 - 3).
[0012] In some embodiments, the material of the metal housing is any one of pure molybdenum, aluminum alloy, stainless steel, and titanium alloy.
[0013] In some embodiments, the thickness ratio between the metal housing and the replacement layer is (2 - 5):(7 - 15).
[0014] In some embodiments, the replacement layer is in contact with the metal housing, or a vacuum gap is formed between the replacement layer and the metal housing, and the heating element is located in the vacuum gap.
[0015] In some embodiments, the cavity of the metal housing is a rectangular cavity.
[0016] A processing device includes a carrier and the above-described cavity structure. The carrier is used for carrying a sheet material, and the cavity of the cavity structure is used for accommodating the carrier. Description of the Drawings
[0017] Figure 1 It is a side view of the processing device provided by an embodiment of the present application.
[0018] Figure 2 It is Figure 1 a schematic structural diagram of the cavity structure in
[0019] Figure 3 It is Figure 2 a cross-sectional view of the cavity structure in
[0020] Figure 4 It is Figure 2 a partial schematic structural diagram of the cavity structure of
[0021] Figure 5 It is Figure 1 a schematic structural diagram of another cavity structure in
[0022] Figure 6 It is Figure 5The cross-sectional view after the cavity structure in [it] is cut along the B-B cutting line.
[0023] Description of main component symbols
[0024] Processing equipment 100
[0025] Cavity structure 10
[0026] Metal shell 11
[0027] Cavity 110
[0028] Replacement layer 12
[0029] Heating element 13
[0030] End plate 14
[0031] Thermal conduction layer 15
[0032] Heat insulation layer 16 Specific implementation manners
[0033] Next, the technical solutions in the embodiments of the present application will be described with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments.
[0034] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be an intermediate component at the same time. When a component is considered to be "provided on" another component, it can be directly provided on the other component or there may be an intermediate component at the same time. The terms "top", "bottom", "upper", "lower", "left", "right", "front", "rear", and similar expressions used herein are only for the purpose of illustration.
[0035] The terms "first", "second", etc. are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features.
[0036] The symbols "-" and "~" should be understood to include their end values. For example, if the range value A is 1~2, it should be understood that A is greater than or equal to 1 and less than or equal to 2.
[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in the description of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application.
[0038] The following will describe some embodiments of the present application in conjunction with the accompanying drawings. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.
[0039] In some embodiments, referring to Figure 1 , the present application discloses a processing device 100, including a carrier (not shown) and a cavity structure 10. The carrier carries a sheet material inside the cavity structure 10 so that the sheet material can be processed.
[0040] In some embodiments, during the processing of the sheet material, the processing environment needs to be heated to a specified temperature, and the specified temperature is adjusted according to the actual reaction requirements. Exemplarily, the specified temperature is a temperature higher than room temperature such as 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C or 500°C, etc.
[0041] In some embodiments, the sheet material is a sheet-like component such as a semiconductor, a silicon wafer or a battery cell. The carrier can be a quartz boat, a graphite boat or an aluminum boat, or a combination of a quartz boat, a graphite boat and an aluminum boat plus a boat support.
[0042] In some embodiments, referring to Figure 2 , Figure 3 and Figure 5 , the cavity structure 10 includes a metal shell 11, a replacement layer 12 and a heating element 13. The metal shell 11 is provided with a cavity 110 for accommodating the carrier. The replacement layer 12 is connected to the outer side wall of the metal shell 11. The density of the replacement layer 12 is less than that of the metal shell 11. Since the replacement layer 12 replaces a part of the metal material, compared with the cavity structure 10 made entirely of metal, the overall weight of the cavity structure 10 can be reduced, which helps the cavity structure 10 to be quickly carried, transported and assembled. And through the replacement layer 12 with a certain mechanical strength, the risk of the overall deformation of the cavity structure 10 can be reduced. The heating element 13 is arranged between the replacement layer 12 and the metal shell 11 to heat the cavity 110, so as to heat the sheet material passing through the cavity 110.
[0043] In addition, due to the certain flexibility of the metal shell 11, during the process of heating the sheet material, the risk of structural damage of the cavity structure 10 under the action of thermal stress can be reduced.
[0044] In some embodiments, the cavity 110 of the metal shell 11 is a rectangular cavity, and the cavity 110 is configured to receive at least one carrier having a substantially rectangular cross-section. Thus, the volume of the cavity 110 is optimally adapted to the profile of the workpiece carrier.
[0045] In some embodiments, the metal housing 11 is made of a lightweight and high-strength metal plate, having good compressive and bending resistance. For example, the material of the metal housing 11 is any one of a pure molybdenum plate, an aluminum alloy plate, a stainless steel plate, and a titanium alloy plate.
[0046] In some embodiments, the replacement layer 12 is attached to the outer sidewall of the metal housing 11.
[0047] In some embodiments, the replacement layer 12 is made of a heat-insulating organic or inorganic material, thereby reducing the risk of heat dissipation inside the metal housing 11. And compared with a quartz tube with relatively low strength, the mechanical strength of the replacement layer 12 when heated to a specified temperature is greater than that of quartz glass when heated to the specified temperature, thereby helping to improve the overall structural stability of the cavity structure 10. Herein, the mechanical strength refers to the ability to resist deformation and damage under the action of a load.
[0048] In some embodiments, the material of the replacement layer 12 is a non-metallic material such as ceramic, quartz, PI, polyurethane, and epoxy resin, which has good heat insulation, sealing, heat resistance, and mechanical strength when heated to a specified temperature. When the replacement layer 12 is ceramic, the clay used to form the ceramic is sequentially filled into the metal housing 11, and then the cavity structure 10 is heated to form the replacement layer 12.
[0049] In other embodiments, the material of the replacement layer 12 is quartz. The replacement layer 12 is wrapped around the outer sidewall of the metal housing 11, and the quartz is supported by the metal housing 11, strengthening the strength of the replacement layer 12. Compared with the setting method of an overall quartz tube, it helps to improve the overall strength of the cavity structure 10 to meet the requirement of stably heating a sheet material by the processing device in a vacuum state.
[0050] In some embodiments, the thickness ratio of the metal housing 11 to the replacement layer 12 is A∶B.
[0051] Among them, A is 2 to 5 unit thicknesses. When the thickness of the metal housing 11 is less than 2 unit thicknesses, the compressive and bending resistance of the cavity structure 10 is insufficient. When the thickness of the metal housing 11 is greater than 5 unit thicknesses, the weight of the cavity structure 10 is too large.
[0052] B is 7 to 15 unit thicknesses. When the thickness of the replacement layer 12 is less than 7 unit thicknesses, the heat insulation effect of the cavity structure 10 is poor. When the thickness of the replacement layer 12 is greater than 15 unit thicknesses, the overall volume of the cavity structure 10 will be too large.
[0053] Exemplarily, the thickness ratio of the metal housing 11 to the replacement layer 12 is 3:8 or 3:10 or 3:12 or 4:8 or 4:10 or 4:12, etc., so as to achieve a lower weight and smaller volume of the cavity structure 10 while maintaining good compressive, bending and heat insulation properties, etc.
[0054] In some embodiments, the thickness ratio of the metal housing 11 to the replacement layer 12 can be correspondingly adjusted according to different performance requirements of the cavity structure 10.
[0055] In some embodiments, please refer to Figure 3 , the heating element 13 is in contact with the outer side wall of the metal housing 11, and heat is conducted to the heating element 13 through the metal housing 11, so that the heat of the heating element 13 can be evenly diffused into the interior of the metal housing 11, which helps the cavity structure 10 to heat the sheet material fully and evenly. At the same time, the heat of the heating element 13 is quickly guided into the interior of the cavity structure 10 through the metal housing 11, which helps to reduce the risk of deformation of the cavity structure 10 caused by thermal stress concentration, and helps to ensure the sealing performance of the cavity structure 10.
[0056] In some embodiments, please refer to Figure 3 and Figure 4 , the heating element 13 includes a resistance wire or a resistance sheet evenly wound around the outer side wall of the metal housing 11. The evenly distributed resistance wire or resistance sheet helps to improve the uniformity of heating the sheet material by the heating element 13.
[0057] In some embodiments, the heating element 13 is made of materials such as nickel-chromium alloy, iron-chromium-aluminum alloy, molybdenum, tungsten, platinum, tantalum, silicon carbide or graphite.
[0058] In other embodiments, a vacuum gap is formed between the replacement layer 12 and the metal housing 11, and the heating element 13 is located in the vacuum gap. Since the heat loss of the heating element 13 is low in a vacuum environment, the thermal efficiency is improved. In addition, the heating element 13 works in a vacuum environment, which can reduce the risk of oxidation and corrosion of the heating element 13.
[0059] In some embodiments, please refer to Figure 1 and Figure 3 , the metal housing 11 has opposite ends. The cavity structure 10 further includes two end plates 14. One end plate 14 is connected to one end of the metal housing 11, and the other end plate 14 is connected to the other end of the metal housing 11. The replacement layer 12 is located between the two end plates 14.
[0060] In some embodiments, the replacement layer 12 is formed by injection molding or filling molding. The two end plates 14 and the outer side wall of the metal housing 11 semi-wrap the replacement layer 12, so that during the injection molding or filling molding process of the replacement layer 12, the replacement layer 12 can be supported, which helps to reduce the risk of deformation of the replacement layer 12 and improves the quality of the cavity structure 10.
[0061] In some embodiments, along a direction perpendicular to the extension direction of the cavity structure 10, the edge of the end plate 14 extends toward the outside of the replacement layer 12. Connection holes (not shown) are formed on the plate surface of the end plate 14, so that the end plate 14 forms a flange structure. When the end plate 14 of one cavity structure 10 contacts the end plate 14 of another cavity structure 10, the two cavity structures 10 are fixedly connected by bolts passing through the connection holes on the two end plates 14.
[0062] In some embodiments, the end plate 14 and the metal housing 11 are integrally formed.
[0063] In other embodiments, please refer to Figure 5 and Figure 6 , the replacement layer 12 is connected to the inner side wall of the metal housing 11. The replacement layer 12 includes a heat insulation layer 16 and a heat conduction layer 15. The heat insulation layer 16 is connected to the metal housing 11, and the heat conduction layer 15 is provided on the side of the heat insulation layer 16 away from the metal housing 11. The heating element 13 is provided in the heat conduction layer 15 or between the heat conduction layer 15 and the heat insulation layer 16. Under the heat conduction of the heat conduction layer 15, the heating element 13 can be protected from damage by the external environment and the purpose of uniform heating can be achieved.
[0064] In some embodiments, the heat insulation layer 16 is made of heat-insulating organic or inorganic materials, so as to reduce the risk of heat dissipation inside the metal housing 11. And compared with the quartz tube with lower strength, the mechanical strength of the cavity structure 10 at the specified heating temperature is greater than that of the quartz glass at the specified heating temperature, which helps to improve the stability of the overall structure of the cavity structure 10. Among them, the mechanical strength refers to the ability to resist deformation and damage under the action of load.
[0065] In some embodiments, the material of the heat insulation layer 16 is a non-metallic material such as ceramic, quartz, PI, polyurethane, epoxy resin, etc., which has good heat insulation, sealing, heat resistance and mechanical strength at the specified heating temperature.
[0066] When the heat insulation layer 16 is ceramic, the clay used to form the ceramic is filled into the metal housing 11 in sequence, and then the cavity structure 10 is heated to realize the processing and forming of the heat insulation layer 16.
[0067] In other embodiments, the material of the thermal insulation layer 16 is quartz. The thermal insulation layer 16 is disposed on the inner sidewall of the metal housing 11, and the outer sidewall of the thermal insulation layer 16 is supported by the metal housing 11, strengthening the strength of the thermal insulation layer 16. Compared with the setting method of the overall quartz tube, it helps to improve the overall strength of the cavity structure 10.
[0068] In some embodiments, the thermal insulation layer 16 fits against the inner wall of the metal housing 11.
[0069] In other embodiments, a vacuum gap is formed between the thermal insulation layer 16 and the metal housing 11. Since the heat conduction efficiency in a vacuum is relatively low, it helps to reduce the heat transfer efficiency from the replacement layer 12 to the metal housing 11, so as to improve the heating effect of the heating element 13 and the heat preservation effect of the thermal insulation layer 16.
[0070] In some embodiments, the thermal insulation layer 16 and the heat conduction layer 15 are made by injection molding or filling molding. The two end plates 14 and the inner sidewall of the metal housing 11 semi-wrap the thermal insulation layer 16 and the heat conduction layer 15. Thus, during the injection molding or filling molding process of the thermal insulation layer 16 and the heat conduction layer 15, the thermal insulation layer 16 and the heat conduction layer 15 can be supported, which helps to reduce the risk of deformation of the thermal insulation layer 16 and improve the quality of the cavity structure 10.
[0071] In some embodiments, the heating element 13 is disposed in the heat conduction layer 15 to facilitate the speed of heat transfer from the heating element 13 towards the sheet material in the heat conduction layer 15. Before the heat conduction layer 15 is processed and formed, the heating element 13 is disposed on the inner wall of the thermal insulation layer 16, and then the heat conduction layer 15 is injected onto the sidewall of the thermal insulation layer 16 in the metal housing 11, so that the heat conduction layer 15 wraps the heating element 13 and is integrally formed with the heating element 13, thereby improving the stability of the heating element 13.
[0072] In some embodiments, the heat conduction layer 15 is a heat-conducting ceramic, and the thermal insulation layer 16 is a heat-insulating ceramic. The special clay for forming the heat-insulating ceramic and the heat-conducting ceramic is filled into the metal housing 11 in sequence, and then the cavity structure 10 is heated, so as to realize the processing and forming of the thermal insulation layer 16 and the heat conduction layer 15.
[0073] In other embodiments, the material of the heat conduction layer 15 is a metal material. The heating element 13 is disposed between the heat conduction layer 15 and the thermal insulation layer 16. The heat of the heating element 13 is quickly guided into the cavity 110 of the metal housing 11 through the heat conduction layer 15, which helps to reduce the risk of deformation of the cavity structure 10 caused by thermal stress concentration in the cavity structure 10 and helps to ensure the sealing performance of the processing device. When the sheet material passes through the cavity structure 10, through the metal heat conduction layer 15, the risk of damage to the cavity structure 10 when the sheet material comes into contact with the cavity structure 10 can be reduced.
[0074] In addition, since the metal housing 11 and the heat-conducting layer 15 have a certain flexibility, the risk of structural damage to the cavity structure 10 under the action of thermal stress can be reduced during the process of heating the sheet material.
[0075] In other embodiments, when the heat-conducting layer 15 is made of a metal material, the heating element 13 contacts the side of the heat-conducting layer 15 facing the heat-insulating layer 16, and the metal heat-conducting layer 15 conducts heat to the heating element 13, so that the heat of the heating element 13 can be evenly diffused into the interior of the metal housing 11, which helps the cavity structure 10 to heat the sheet material fully and evenly.
[0076] In other embodiments, the heat-conducting layer 15 can also be made of a non-metal material. For example, the non-metal material is graphene, silicon carbide, or the like.
[0077] In some embodiments, when the thickness of the cavity structure 10 is a certain value, the thickness ratio of the metal housing 11, the heat-insulating layer 16, and the heat-conducting layer 15 is a∶b∶c.
[0078] Among them, a is 2 to 5 unit thicknesses. When the thickness of the metal housing 11 is less than 2 unit thicknesses, the compressive and bending resistance of the cavity structure 10 is insufficient. When the thickness of the metal housing 11 is greater than 5 unit thicknesses, the weight of the cavity structure 10 is too large.
[0079] b is 7 to 15 unit thicknesses. When the thickness of the heat-insulating layer 16 is less than 7 unit thicknesses, the heat-insulating effect of the cavity structure 10 is poor. When the thickness of the heat-insulating layer 16 is greater than 15 unit thicknesses, since the volume of the cavity 110 needs to be maintained at a specified size, the overall volume of the cavity structure 10 will be too large.
[0080] c is 1 to 3 unit thicknesses. When the thickness of the heat-conducting layer 15 is less than 1 unit thickness, the heat-conducting effect of the heat-conducting layer 15 is poor. When the thickness of the heat-insulating layer 16 is greater than 3 unit thicknesses, the overall weight of the cavity structure 10 will increase.
[0081] Exemplarily, the thickness ratio of the metal housing 11, the heat-insulating layer 16, and the heat-conducting layer 15 is 3∶10∶2 or 4∶10∶2 or 3∶8∶2 or 3∶12∶2, etc., so as to achieve a lower weight and a smaller volume of the cavity structure 10 while maintaining good compressive, bending, heat-insulating, and heat-conducting performances.
[0082] In some embodiments, the thickness ratio of the metal housing 11, the heat-insulating layer 16, and the heat-conducting layer 15 can be correspondingly adjusted according to different performance requirements of the cavity structure 10.
[0083] In some embodiments, the unit thickness is adjusted according to the actual requirements of the cavity structure 10. Exemplarily, the unit thickness is 0.1 cm, 0.2 cm, 0.3 cm, 0.4 cm, 0.5 cm, 1 cm, 1.5 cm, 2 cm, 2.5 cm, 3 cm, 3.5 cm, 4 cm, 4.5 cm or 5 cm.
[0084] In addition, those of ordinary skill in the art should recognize that the above embodiments are only used to illustrate the present application and are not intended to limit the present application. As long as it is within the substantial scope of the present application, appropriate changes and variations made to the above embodiments fall within the scope disclosed in the present application.
Claims
1. A cavity structure, characterized in that: include: A metal shell, wherein a cavity for accommodating a sheet material is provided in the metal shell; A replacement layer, the replacement layer is connected to the outer wall or the inner wall of the metal shell, and the density of the replacement layer is less than the density of the metal shell; A heating element is connected to the metal shell or the replacement layer.
2. The cavity structure according to claim 1, characterized in that: In the case where the replacement layer is connected to the outer side wall of the metal shell, the heating element is arranged on the outer side wall of the metal shell.
3. The cavity structure according to claim 1, characterized in that: The replacement layer is made of a heat-insulating organic material or an inorganic material, and the mechanical strength of the replacement layer when heated to a specified temperature is greater than or equal to the mechanical strength of a quartz material when heated to a specified temperature.
4. The cavity structure according to claim 1, characterized in that: When the replacement layer is connected to the inner wall of the metal shell, the replacement layer includes a heat-conducting layer and a thermal insulation layer; the thermal insulation layer is connected to the inner wall of the metal shell; the heat-conducting layer is connected to a side of the thermal insulation layer away from the metal shell; the heating element is connected to a side of the heat-conducting layer away from the thermal insulation layer, or the heating element is arranged in the heat-conducting layer.
5. The cavity structure according to claim 4, characterized in that: The thermal insulation layer is made of a thermal insulation organic material or an inorganic material, and the mechanical strength of the thermal insulation layer when heated to a specified temperature is greater than or equal to the mechanical strength of a quartz material when heated to a specified temperature.
6. The cavity structure according to claim 4, characterized in that: The thickness ratio of the metal shell, the thermal insulation layer and the heat conducting layer is (2-5):(7-15):(1-3).
7. The cavity structure according to claim 1, characterized in that: The material of the metal shell is any one of pure molybdenum, aluminum alloy, stainless steel and titanium alloy.
8. The cavity structure according to claim 2, characterized in that: The thickness ratio of the metal shell and the replacement layer is (2-5):(7-15).
9. The cavity structure according to claim 1, characterized in that: The replacement layer is in contact with the outer wall or inner wall of the metal shell; or A vacuum gap is formed between the replacement layer and the outer wall or the inner wall of the metal shell, and the heating element is located in the vacuum gap.
10. The cavity structure according to claim 1, characterized in that: The cavity of the metal shell is a rectangular cavity.
11. A processing equipment, characterized in that: It comprises a carrier and a cavity structure as described in any one of claims 1 to 10, wherein the carrier is used to carry the sheet material, and the cavity of the cavity structure is used to accommodate the carrier.