A hot filament assembly for a hot filament chemical vapor deposition apparatus

Abstract

The utility model provides a kind of hot wire assembly of hot filament chemical vapor deposition equipment, it can automatically tension heated lengthened hot wire, to avoid the risk of short circuit of hot wire generated thereby. It includes vertically arranged hot wire, hot wire is connected with power supply, it further includes tensioning mechanism, hot wire is spiral and its bottom is connected with tensioning mechanism, tensioning mechanism includes connecting piece, self-locking mechanism, one end of connecting piece is connected with hot wire, the other end of connecting piece is connected with self-locking mechanism and can move downward relative to self-locking mechanism, self-locking mechanism can prevent connecting piece upward movement.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic cell manufacturing technology, specifically to a hot wire component of a hot wire chemical vapor deposition equipment. Background Technology

[0002] In existing photovoltaic cell manufacturing, heterojunction (HJT) cells are hailed as the next-generation high-efficiency battery technology with the greatest industrial potential due to their advantages such as high conversion efficiency, short process flow, thin silicon wafer application, low temperature coefficient, and bifacial power generation. Chemical Vapor Deposition (CVD) is the core process for HJT cell fabrication. There are two main heterojunction amorphous silicon thin film deposition technologies: Plasma Enhanced CVD (PECVD) and Hot Wire CVD (HWCVD). HWCVD offers advantages such as simple equipment structure, fast deposition rate, smooth film surface, and low radiation damage. Its working principle utilizes the catalytic decomposition reaction of molecules on a heated metal wire, resulting in deposition and polymerization on the substrate surface to form a thin film. However, existing hot wire CVD equipment often uses straight wires as the hot wire. During operation, the hot wire can elongate and deform due to heating, potentially causing short circuits and affecting the process results. Utility Model Content

[0003] To address the problem that existing straight wires may cause short circuits and affect process performance, this invention provides a hot wire assembly for a hot wire chemical vapor deposition (CCVD) apparatus that can automatically tension the heated and extended hot wire, thereby avoiding the risk of hot wire short circuits.

[0004] The technical solution is as follows: a hot wire assembly of a hot wire chemical vapor deposition apparatus, comprising a vertically arranged hot wire connected to a power source, characterized in that: it further comprises a tensioning mechanism, the hot wire is spiral-shaped and its bottom is connected to the tensioning mechanism, the tensioning mechanism comprises a connector and a self-locking mechanism, one end of the connector is connected to the hot wire, the other end of the connector is connected to the self-locking mechanism and is capable of moving downward relative to the self-locking mechanism, the self-locking mechanism being capable of preventing the connector from moving upward.

[0005] Furthermore, each hot filament chemical vapor deposition device is equipped with multiple sets of hot filament assemblies. Each set of hot filament assemblies includes two parallel hot filaments, hot filament one and hot filament two, which are connected to each other at the bottom by a conductive connecting rod. Hot filament one is connected to the positive terminal of the power supply, and hot filament two is connected to the negative terminal of the power supply. Hot filament one and hot filament two are respectively connected to the tensioning mechanism.

[0006] Furthermore, the connector includes a toothed rod located at the bottom, the self-locking mechanism includes a reverse spring and a base, the toothed rod passes through the base vertically and is provided with locking teeth, the reverse spring includes a connecting end and a contact end, the reverse spring is connected to the base through the connecting end, the contact end of the reverse spring can contact the locking teeth, the reverse spring is arranged obliquely downward along the direction from the connecting end to the contact end, the bottom slope of the locking teeth extends obliquely upward along the direction from the tooth root to the tooth tip, and the top slope of the locking teeth extends horizontally or obliquely upward along the direction from the tooth root to the tooth tip.

[0007] Beneficial effects: 1. Compared with straight wire, spiral wire has better resistance to deformation. At the same time, when the hot wire needs to be tensioned due to deformation, the spiral structure has better elasticity, which can prevent straight wire from breaking due to excessive force.

[0008] 2. By setting a tensioning mechanism at the bottom of the hot wire, the hot wire that stretches when heated will be pulled by the gravity of some parts of the tensioning mechanism, and the self-locking mechanism will prevent it from rebounding, thus avoiding a short circuit caused by two parts of the hot wire coming into contact with each other due to rebound. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the structure of this utility model;

[0010] Figure 2 This is a schematic diagram of a set of hot wire components;

[0011] Figure 3 This is a schematic diagram showing the positions of the hot wire assembly and the substrate;

[0012] Figure 4 This is a schematic diagram of the tensioning mechanism;

[0013] Figure 5 for Figure 4 Enlarged diagram of point A in the middle. Detailed Implementation

[0014] like Figure 1 The hot filament assembly of a hot filament chemical vapor deposition apparatus shown includes a vertically arranged hot filament 1 connected to a power source, and a tensioning mechanism 2. The hot filament 1 is spiral-shaped and its bottom is connected to the tensioning mechanism 2. Figure 2 , Figure 4 The tensioning mechanism 2 includes a connector 21 and a self-locking mechanism 22. One end of the connector 21 is connected to the hot wire 1, and the other end of the connector 21 is connected to the self-locking mechanism 22 and can move downward relative to the self-locking mechanism 22. The self-locking mechanism 22 can prevent the connector 21 from moving upward.

[0015] In a hot-filament CVD system, the reactant gas is first passed through a high-temperature hot filament (typically above 1000°C, and sometimes exceeding 2000°C; the material can be tantalum wire, and the specific setting depends on the HWCVD process). The hot filament itself also acts as a catalyst. The reactant gas (which can be alkanes and hydrogen, and sometimes other gases) decomposes under the influence of high temperature and catalysis. The reaction products are deposited on the substrate 3 directly opposite the hot filament 1 (in conjunction with...). Figure 3 (As shown). Using an appropriate number of hot wires and a suitable distance between the hot wires and the substrate can achieve a relatively uniform coating quality. Their arrangement within the process chamber is as follows: Figure 3 The distance "X" from the hot wire to the substrate and the spacing "Y" between the hot wires can be determined experimentally to a relatively optimal value. Under high-temperature conditions, the hot wire will deform, causing changes in the distances X and Y, which leads to poor uniformity in film growth. Furthermore, due to the irregularity of the hot wire deformation, the process precision is difficult to control. Compared to straight wires, using elastic spiral wires in conjunction with the tensioning mechanism 2 provides better resistance to deformation, thus providing a stable thermal field to the substrate 3. This ensures process stability and extends the service life of the hot wires.

[0016] Specifically, in combination Figure 2 Each hot filament chemical vapor deposition equipment is equipped with multiple hot filament assemblies. Each hot filament assembly includes two parallel hot filaments, 11 and 12, which are connected to each other at the bottom by a conductive connecting rod 4. Hot filament 11 is connected to the positive terminal of the power supply through a retainer, and hot filament 12 is connected to the negative terminal of the power supply through a retainer. The two hot filaments are connected to a power supply to form a circuit. Hot filament 11 and hot filament 12 are respectively connected to a tensioning mechanism 2. Of course, the separately connected tensioning mechanism 2 can also be replaced by a common tensioning mechanism 2.

[0017] For tensioning mechanism 2, its connecting member 21 can be as follows: Figure 4 The omnidirectional rotating ring 211 and toothed rod 212 shown are described. The omnidirectional rotating ring 211 can be made of insulating ceramic material or can be connected to the hot wire in a non-conductive manner by spraying an insulating layer. The top of the omnidirectional rotating ring 211 is hung on a hook at the bottom of the hot wire, and the bottom is rotatably connected to the toothed rod 212. The self-locking mechanism 22 can be an existing self-locking mechanism that allows the toothed rod 212 to move smoothly downwards and prevents it from moving upwards. After the hot wire is heated, it will have extended metallic thermal properties. Relying on the weight of the ring, the hot wire is stretched downwards along its own gravity. The self-locking mechanism prevents the spring from rebounding, thus ensuring the resistance to deformation and preventing short circuits caused by partial contact due to deformation of the hot wire.

[0018] Specifically, in combination Figure 5The self-locking mechanism 22 includes a reverse spring 221 and a base 222. The toothed rod 212 passes through the base 222 vertically and is provided with locking teeth. The reverse spring 221 includes a connecting end and a contact end. The reverse spring is connected to the base 222 through the connecting end. The contact end of the reverse spring 221 can contact the locking teeth. Along the direction from the connecting end to the contact end, the reverse spring is set in a downward direction. The bottom slope of the locking teeth extends upward along the direction from the tooth root to the tooth tip. The top slope of the locking teeth extends horizontally or upward along the direction from the tooth root to the tooth tip. In this way, when the toothed rod 212 moves downward, the bottom slope of the locking teeth can push the reverse spring 221 downward and cause it to elastically deform and flip downward to pass over the current locking teeth, so as not to prevent the toothed rod 212 from moving downward. However, when the toothed rod 212 needs to move upward, the reverse spring 221 can abut against the top slope of the current locking teeth to prevent the toothed rod 212 from moving upward and thus prevent the hot wire from rebounding.

[0019] The above are merely preferred embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the scope of protection of this utility model. Therefore, the scope of protection of this utility model should be determined by the scope of the claims.

Claims

1. A hot filament assembly for a hot filament chemical vapor deposition apparatus, comprising a vertically arranged hot filament connected to a power source, characterized in that: It also includes a tensioning mechanism, wherein the hot wire is spiral-shaped and its bottom is connected to the tensioning mechanism. The tensioning mechanism includes a connector and a self-locking mechanism. One end of the connector is connected to the hot wire, and the other end of the connector is connected to the self-locking mechanism and is capable of moving downward relative to the self-locking mechanism. The self-locking mechanism is capable of preventing the connector from moving upward.

2. The hot filament assembly of a hot filament chemical vapor deposition apparatus according to claim 1, characterized in that: Each hot-wire chemical vapor deposition equipment is equipped with multiple sets of hot-wire assemblies. Each set of hot-wire assemblies includes two parallel hot-wires, hot-wire one and hot-wire two, which are connected to each other at the bottom by a conductive connecting rod. Hot-wire one is connected to the positive terminal of the power supply, and hot-wire two is connected to the negative terminal of the power supply. Hot-wire one and hot-wire two are respectively connected to the tensioning mechanism.

3. The hot filament assembly of a hot filament chemical vapor deposition apparatus according to claim 1 or 2, characterized in that: The connector includes a toothed rod at the bottom, and the self-locking mechanism includes a reverse spring and a base. The toothed rod passes through the base vertically and has locking teeth. The reverse spring includes a connecting end and a contact end. The reverse spring is connected to the base through the connecting end, and the contact end of the reverse spring can contact the locking teeth. The reverse spring is arranged obliquely downward along the direction from the connecting end to the contact end. The bottom slope of the locking teeth extends obliquely upward along the direction from the tooth root to the tooth tip, and the top slope of the locking teeth extends horizontally or obliquely upward along the direction from the tooth root to the tooth tip.

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