Insulating sleeve and graphite boat

Abstract

The utility model provides an insulating sleeve and a graphite boat, belonging to the technical field of solar cell manufacture, comprising a ceramic bushing, a plurality of circles of insulating protective film wound on the outer surface of the ceramic bushing, the width of the insulating protective film being smaller than the axial length of the ceramic bushing, so that the two axial ends of the ceramic bushing abut against adjacent graphite boat sheets. And gaps are formed between the insulating protective film and the graphite boat sheets at the two ends. According to the utility model, a plurality of layers of high-temperature-resistant insulating protective films are wound on the ceramic sleeve, and the axial length of the annular protective layer formed by the insulating protective films is not greater than the lengths of the two ends of the ceramic sleeve, so that the ceramic sleeve is in contact with the graphite boat sheet, and the strength and insulativity of the whole support are ensured; after the graphite boat is used for a certain number of times, the resistance between the adjacent graphite boat sheets is measured, and when the resistance value is close to the minimum resistance value required by use, the outer insulating protective film is removed, and meanwhile, the conductive layer deposited on the insulating protective film is removed, so that the insulating property of the insulating sleeve is recovered.

Description

Technical Field

[0001] The utility model belongs to the technical field of solar cell manufacturing, and particularly relates to an insulating sleeve and a graphite boat with the insulating sleeve. Background Art

[0002] PECVD (Plasma Enhanced Chemical Vapor Deposition) utilizes microwaves or radio frequency to ionize a gas containing the atoms of the film components, forming a localized plasma. This highly reactive plasma readily reacts, depositing the desired thin film on the substrate surface with high quality. Currently, PECVD is commonly used in the industrial fabrication of crystalline silicon cells to deposit thin films with varying properties, such as silicon nitride and silicon oxynitride. In the industrial tubular PECVD coating process, a ceramic sleeve with excellent insulation and high dielectric strength is typically placed over the ceramic rods of a graphite boat, positioned between adjacent boat slices and in close contact with them. The sleeve provides physical support and electrical isolation between adjacent boat slices, and also creates an electric field.

[0003] With the continuous development of battery processes and technologies, PECVD is being used in the preparation of other high-efficiency solar cells, such as tunneling oxide passivated contact cells (Topcon) and amorphous silicon heterojunction cells (HIT). At this time, PECVD needs to be used for the deposition of other thin film materials, including the deposition of amorphous silicon thin films, doped amorphous silicon thin films, etc. With the diversification of the application scenarios of the PECVD coating process, uneven coating, reduced coating rate, and even the inability to continue coating have begun to appear, seriously affecting the quality of the coating. Moreover, the process can only deposit thinner films in one go and cannot meet process requirements such as thick films. In addition, the cleaning frequency of the graphite boat has also increased accordingly, so that the graphite boat needs to be taken offline for cleaning after one or several uses, resulting in low utilization of the graphite boat and increased use costs.

[0004] One of the factors is that the insulation performance of the ceramic sleeves between adjacent boats gradually weakens during the continuous coating process because a layer of conductive film is deposited on the surface, and eventually conductivity is formed, resulting in uneven coating on the substrate. The ceramic sleeves need to be replaced, which not only reduces the quality of the substrate coating, but also leads to low utilization of the graphite boat and increased usage costs.

[0005] At present, in order to increase the primary insulation service life of ceramic bushings and reduce the downtime of replacing ceramic bushings, multiple grooves are generally opened on the outer wall of the ceramic bushing to delay the time for forming a uniform conductive layer on the outer surface of the ceramic bushing. However, this also causes the strength of the ceramic bushing to be reduced and also affects the service life of the ceramic bushing. Utility Model Content

[0006] The embodiments of the present invention provide an insulating sleeve and a graphite boat, which are intended to extend the service life of a ceramic sleeve, reduce the production downtime caused by replacing the ceramic sleeve, and improve the utilization efficiency of the graphite boat and the quality of substrate coating.

[0007] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: to provide an insulating sleeve, comprising: a ceramic sleeve, with multiple turns of insulating protective film wrapped around the outer surface of the ceramic sleeve, the width of the insulating protective film being smaller than the axial length of the ceramic sleeve, so that the axial ends of the ceramic sleeve abut against adjacent graphite boat sheets, and a gap is formed between the insulating protective film and the graphite boat sheets at both ends.

[0008] In combination with the first aspect, in one achievable manner, two shoulders are provided on the outer surface of the ceramic sleeve, and two ends of the insulating protective film respectively abut against the two shoulders.

[0009] In combination with the first aspect, in one achievable manner, the thickness of the wound insulating protective film does not exceed the radial height of the shaft shoulder.

[0010] In combination with the first aspect, in one achievable manner, the radial height of the shoulder is 1-2 mm.

[0011] In combination with the first aspect, in one feasible manner, the insulating protective film is made of polyimide.

[0012] In combination with the first aspect, in one feasible manner, grooves communicating with the center hole of the ceramic sleeve are respectively provided at both axial ends of the ceramic sleeve, the length direction of the grooves is perpendicular to the axis of the ceramic sleeve, and the grooves also extend to the outer surface of the ceramic sleeve.

[0013] In combination with the first aspect, in one achievable manner, the groove has a shape of a trapezoid, a V-shape, a U-shape or an arc.

[0014] In combination with the first aspect, in one achievable manner, the groove has a depth of 0.5-1.5 mm and a width of 0.5-1.5 mm.

[0015] In combination with the first aspect, in one achievable manner, the ceramic sleeve has an axial length of 10-12 mm, an inner diameter of 6-10 mm, and an outer diameter of 12-20 mm.

[0016] In a second aspect, an embodiment of the present invention further provides a graphite boat, comprising the insulating sleeve.

[0017] Compared with the prior art, the insulating sleeve and graphite boat provided by the utility model have the following beneficial effects: multiple layers of high-temperature resistant insulating protective film are wrapped around the ceramic sleeve, and the axial length of the annular protective layer formed by the insulating protective film is no longer than the length of the two ends of the ceramic sleeve, so that the ceramic sleeve is in contact with the graphite boat sheet, thereby ensuring the strength and insulation of the overall support; after the graphite boat is used a certain number of times, the resistance between adjacent graphite boat sheets is measured. When the resistance value approaches the minimum resistance value required for use, one or two layers of the insulating protective film are removed, and at the same time, the conductive layer deposited on the insulating protective film is removed, thereby restoring the insulation performance of the insulating sleeve.

[0018] The utility model can increase the service life of the graphite boat by extending the primary insulation service life of the insulating sleeve, thereby ensuring the continuity and uniformity of the coating on the substrate; at the same time, when removing part of the insulating protective film, it is not necessary to remove the insulating sleeve, but the insulating protective film deposited with the conductive layer can be removed online, thereby shortening the downtime of the graphite boat and improving the production efficiency of the graphite boat. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The structure of the insulating sleeve provided by the embodiment of the utility model is schematically shown Figure 1 ;

[0020] Figure 2 A schematic side view of the insulating sleeve provided in an embodiment of the present utility model;

[0021] Figure 3 The structure of the insulating sleeve provided by the embodiment of the utility model is schematically shown Figure 2 ;

[0022] Description of reference numerals:

[0023] 1. Ceramic sleeve; 2. Insulation protective film; 3. Groove; 4. Shoulder. DETAILED DESCRIPTION

[0024] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0025] Please also refer to Figures 1 to 3 The insulating sleeve provided by the present invention is now described. The insulating sleeve comprises a ceramic sleeve 1, with 5-10 turns of an insulating protective film 2 wrapped around the outer surface of the ceramic sleeve 1. The width of the insulating protective film 2 is smaller than the axial length of the ceramic sleeve 1, so that the axial ends of the ceramic sleeve 1 abut against adjacent graphite boats, and a gap is left between the insulating protective film 2 and the graphite boats at both ends.

[0026] Compared with the prior art, the insulating sleeve and graphite boat provided by the present invention have the following beneficial effects: multiple layers of high-temperature resistant insulating protective film 2 are wrapped around the ceramic sleeve 1, and the axial length of the annular protective layer formed by the insulating protective film 2 is no longer than the length of the two ends of the ceramic sleeve 1, so that the ceramic sleeve 1 is in contact with the graphite boat sheet, thereby ensuring the strength and insulation of the overall support; after the graphite boat is used a certain number of times, the resistance between adjacent graphite boat sheets is measured. When the resistance value approaches the minimum resistance value required for use, one or two layers of the insulating protective film 2 are removed, and at the same time, the conductive layer deposited on the insulating protective film 2 is removed, thereby restoring the insulation performance of the insulating sleeve.

[0027] The utility model does not destroy the overall structure of the ceramic sleeve 1, thereby ensuring the overall supporting strength of the ceramic sleeve 1; and the ceramic sleeve 1 is wrapped with the insulating protective film 2. When the outermost film coated with the insulating protective film 2 reaches the conductive state, the outermost insulating protective film 2 can be removed to expose the uncoated insulating protective film 2, which can continue to play the insulating function. This can increase the service life of the graphite boat by extending the one-time insulating service life of the insulating sleeve, and ensure the continuity and uniformity of the coating on the substrate; at the same time, when removing part of the insulating protective film 2, it is not necessary to remove the insulating sleeve, but the insulating protective film 2 with the conductive layer deposited can be removed online, thereby shortening the downtime of the graphite boat and improving the production efficiency of the graphite boat.

[0028] The outer ends of the insulating protective film 2 can be bonded with insulating tape; the stickiness of the inner surface of the insulating protective film 2 can also enable them to be tightly wound together.

[0029] In some embodiments, see Figure 3 Two shaft shoulders 4 are provided on the outer surface of the ceramic sleeve 1, and the two ends of the insulating protective film 2 are respectively in contact with the two shaft shoulders 4. The provided shaft shoulders 4 have the function of axially positioning the wound insulating protective film 2.

[0030] In some embodiments, see Figure 3 The thickness of the insulating protective film 2 wrapped does not exceed the radial height of the shaft shoulder 4, so that the insulating protective film 2 can be well positioned in the axial direction.

[0031] In some embodiments, see Figure 3 , the radial height of the shoulder 4 is 1-2 mm. The radial height of the shoulder 4 has certain restrictions to ensure the strength of the shoulder 4, because the axial width of the shoulder 4 will not be too wide, generally 1-2 mm.

[0032] In some embodiments, the insulating protective film 2 is made of polyimide. Polyimide (PI) has excellent high-temperature resistance over a wide temperature range. Polyimide exhibits exceptional thermal stability at high temperatures, with a thermal decomposition temperature of up to 600°C, making it one of the most thermally stable polymers to date. Specifically, polyimide has a long-term operating temperature range of -200°C to 300°C and maintains its performance in air at temperatures between 250°C and 280°C.

[0033] Polyimide is not only heat-resistant but also possesses other outstanding properties. It is an organic polymer material with the best overall performance, boasting corrosion resistance, fatigue resistance, damage resistance, impact resistance, low density, and low noise. Furthermore, polyimide exhibits excellent electrical insulation properties, with a dielectric constant of 4.0 and a dielectric loss of only 0.004 to 0.007. These properties have led to its widespread application in aerospace, microelectronics, nanotechnology, liquid crystals, separation membranes, lasers, and other fields.

[0034] The insulating protective film 2 can also be modified polyoxymethylene (POM), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyphenylene ester (PPOB), polyphenylene ether (PPO), liquid crystal polymer (LCP), etc. These materials also have high heat resistance and insulation, and are suitable for insulation needs in high-temperature environments. They can maintain good insulation performance in high-temperature environments above 400 degrees and are widely used in automotive parts, semiconductor industry, aerospace industry, petrochemical industry, machinery industry, medical industry, electronic appliances and other fields.

[0035] The insulating protective film 2 can also be made of commercially available high-temperature resistant insulating tape or high-temperature resistant electrical insulating tape, for example, Teflon high-temperature resistant tape, PET green high-temperature tape, etc.

[0036] In some embodiments, see Figures 1 to 3 The ceramic sleeve 1 is provided with grooves 3 at both axial ends, each connected to the central hole of the sleeve 1. The length of the grooves 3 is perpendicular to the axis of the sleeve 1 and extends to the outer surface of the sleeve 1. The symmetrical grooves 3 at both axial ends of the sleeve 1 facilitate the detection of residual liquid in the insulating sleeve cavity during drying of the graphite boat after cleaning, thereby reducing drying time.

[0037] In some embodiments, see Figures 1 to 3 The shape of the groove 3 is trapezoidal, V-shaped, U-shaped or arc-shaped.

[0038] In some embodiments, the groove 3 has a depth of 0.5-1.5 mm and a width of 0.5-1.5 mm.

[0039] In some embodiments, see Figures 1 to 3The axial length of the ceramic sleeve 1 is 10-12 mm, the inner diameter is 6-10 mm, and the outer diameter is 12-20 mm. The material of the ceramic sleeve 1 is generally 99 alumina ceramic material, 95 porcelain alumina ceramic material, etc.

[0040] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0041] Based on the same inventive concept, an embodiment of the present application further provides a graphite boat including the aforementioned insulating sleeve. The graphite boat includes a plurality of graphite boat sheets, and an insulating sleeve is provided between any two adjacent graphite boat sheets, and the insulating sleeve is provided on a ceramic rod.

[0042] The utility model can increase the service life of the graphite boat by extending the primary insulation service life of the insulating sleeve, thereby ensuring the continuity and uniformity of the coating on the substrate; at the same time, when removing part of the insulating protective film, it is not necessary to remove the insulating sleeve, but the insulating protective film deposited with the conductive layer can be removed online, thereby shortening the downtime of the graphite boat and improving the production efficiency of the graphite boat.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An insulating sleeve, characterized in that: include: A ceramic sleeve (1) is provided, wherein a plurality of turns of an insulating protective film (2) are wound around the outer surface of the ceramic sleeve (1), wherein the width of the insulating protective film (2) is smaller than the axial length of the ceramic sleeve (1), so that the axial ends of the ceramic sleeve (1) abut against adjacent graphite boat sheets, and a gap is formed between the insulating protective film (2) and the graphite boat sheets at the two ends.

2. The insulating sleeve according to claim 1, wherein: Two shaft shoulders (4) are provided on the outer surface of the ceramic sleeve (1), and the two ends of the insulating protective film (2) respectively abut against the two shaft shoulders (4).

3. The insulating sleeve according to claim 2, wherein: The thickness of the wound insulating protective film (2) does not exceed the radial height of the shaft shoulder (4).

4. The insulating sleeve according to claim 2, wherein: The radial height of the shaft shoulder (4) is 1-2 mm.

5. The insulating sleeve according to claim 1, wherein: The insulating protective film (2) is made of polyimide.

6. The insulating sleeve according to claim 1, wherein: Grooves (3) communicating with the central hole of the ceramic sleeve (1) are respectively provided at both axial ends of the ceramic sleeve (1); the length direction of the groove (3) is perpendicular to the axis of the ceramic sleeve (1); and the groove (3) also extends to the outer surface of the ceramic sleeve (1).

7. The insulating sleeve according to claim 6, wherein: The shape of the groove (3) is trapezoidal, V-shaped, U-shaped or arc-shaped.

8. The insulating sleeve according to claim 6, wherein: The groove (3) has a depth of 0.5-1.5 mm and a width of 0.5-1.5 mm.

9. The insulating sleeve according to claim 1, wherein: The ceramic sleeve (1) has an axial length of 10-12 mm, an inner diameter of 6-10 mm, and an outer diameter of 12-20 mm.

10. A graphite boat, characterized in that: The insulating sleeve comprises the insulating sleeve according to any one of claims 1 to 9.

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