A quartz boat tooth for bending a sheet for a bc process

Abstract

The utility model relates to quartz boat technical field especially relates to a kind of quartz boat teeth for BC process curved wafer, including quartz boat body, protruding tooth, the side of quartz boat body is provided with multiple sets of protruding tooth, protruding tooth is linear equidistance arrangement along the side length direction of quartz boat body, protruding tooth is V type, the sharp side of protruding tooth is close to quartz boat body, and the side of protruding tooth close to quartz boat body is provided with bottom platform, the side of protruding tooth away from quartz boat body is provided with upper platform;The utility model carries out optimization to the protruding tooth shape and size of quartz boat body, removes straight edge on the basis of Y type quartz boat tooth and optimizes the side angle of protruding tooth, simultaneously, the size and angle of bottom platform and upper platform are optimized, more easily to bend silicon wafer overlap and slide into boat tooth bottom, not easy to cause the condition that silicon wafer is hung on upper platform and does not slide, and compared with the design of V type quartz boat, processing difficulty is reduced, and safety is increased.

Description

Technical Field

[0001] This utility model relates to the field of quartz boat technology, and in particular to a quartz boat tooth for BC process bending sheets. Background Technology

[0002] The basic structure of a solar cell typically includes multiple functional layers. A typical crystalline silicon cell structure, from top to bottom, consists of: an anti-reflective coating (such as silicon nitride), a front electrode (silver grid lines), an N-type silicon layer, a P-type silicon layer, a back aluminum electrode, and a back electric field. Thin-film cells employ a stacked design on a glass or flexible substrate, consisting of a transparent conductive layer (TCO), an absorber layer (such as amorphous silicon or cadmium telluride), and a back electrode. The silicon wafer, as the core semiconductor material, plays a crucial role in absorbing sunlight and generating photoelectric conversion. When sunlight shines on the silicon wafer, the built-in electric field of its PN junction separates photogenerated electron-hole pairs, creating a potential difference.

[0003] In the battery manufacturing process, the quartz boat serves as a crucial auxiliary tool, primarily used to support and transport raw materials such as silicon wafers. Quartz material possesses properties such as high temperature resistance, high purity, and chemical stability, protecting the silicon wafers from contamination during high-temperature processes in battery production (such as diffusion and sintering), while simultaneously ensuring process uniformity. Especially in the manufacture of crystalline silicon solar cells, the cleanliness and structural design of the quartz boat directly affect the yield and performance of the cells, serving as a vital carrier connecting raw materials and finished batteries.

[0004] Most existing quartz boat teeth are Y-shaped. The conventional boat tooth design is Y-shaped with a bottom spacing of 1.1±0.05mm. Conventional boat teeth had no problems in the previous PERC process, but they lack compatibility in the BC process, leading to frequent automated breakage. This results in excessive silicon wafer breakage rate, greatly increasing manufacturing costs. In addition, the upper platform is wide, which can cause silicon wafers to get stuck on the upper platform without slipping off. A small number of quartz boats are V-shaped. V-shaped teeth are prone to wrapping and expansion because overlapping silicon wafers cannot fall at the same height at the bottom of the boat teeth, resulting in a height difference between the two overlapping silicon wafers, affecting the process effect. Furthermore, the tips of V-shaped quartz boats are relatively sharp, posing a safety hazard. Utility Model Content

[0005] To overcome the problem that most quartz boats are not compatible with the BC process, resulting in frequent automated breakage and excessive silicon wafer breakage, which greatly increases manufacturing costs.

[0006] The technical solution of this utility model is as follows: a quartz boat tooth for BC process bending sheet, including a quartz boat body (1) and protruding teeth (2). Multiple sets of protruding teeth (2) are provided on one side of the quartz boat body (1). The protruding teeth (2) are arranged equidistantly along the side length direction of the quartz boat body (1). The protruding teeth (2) are V-shaped. The pointed side of the protruding teeth (2) is close to the quartz boat body (1). A bottom platform (201) is provided on the side of the protruding teeth (2) close to the quartz boat body (1). An upper platform (202) is provided on the side of the protruding teeth (2) away from the quartz boat body (1).

[0007] Preferably, the width of the upper platform (202) is 0.1 mm.

[0008] Preferably, the upper platform (202) is parallel to the long side of the quartz boat body (1).

[0009] Preferably, the bottom platform (201) is provided with a beveled edge, and the beveled edge of all bottom platforms (201) is in the same beveled direction.

[0010] Preferably, the bevel angle of the beveled edge of the bottom platform (201) is three degrees.

[0011] Preferably, the width of the bottom platform (201) is 0.5 mm.

[0012] Preferably, the side angle of the protruding tooth (2) is consistent with the side angle of the existing V-shaped quartz boat.

[0013] The beneficial effects of this utility model are:

[0014] 1. By optimizing the shape and size of the protrusions (2) of the quartz boat body (1), the extended edge is removed and the side angle of the protrusions (2) is optimized based on the Y-shaped quartz boat teeth. At the same time, the size and angle of the bottom platform (201) and the upper platform (202) are optimized, making it easier to bend the silicon wafers and slide them into the bottom of the boat teeth after overlapping. It is less likely that the silicon wafers will be stuck on the upper platform and not slip off. In addition, compared with the design of the V-shaped quartz boat, the processing difficulty is reduced and the safety is increased. Attached Figure Description

[0015] Figure 1 The diagram shown is a planar structural schematic of this utility model;

[0016] Figure 2 The diagram shown is a schematic representation of the planar structure of a Y-shaped quartz boat tooth.

[0017] Figure 3 The diagram shown is a schematic representation of the planar structure of a V-shaped quartz boat tooth.

[0018] Figure 4 The diagram shown is a partially enlarged planar structural schematic of this utility model;

[0019] Figure 5 The diagram shown is a partially enlarged planar structural schematic of a Y-shaped quartz boat tooth.

[0020] Explanation of reference numerals in the attached drawings: 1. Quartz boat body; 2. Teeth; 201. Bottom platform; 202. Upper platform. Detailed Implementation

[0021] A solar cell is a device that directly converts sunlight into electrical energy using the photovoltaic effect of semiconductor materials. Its core structure is typically a PN structure formed by P-type and N-type semiconductors. When sunlight shines on the cell surface, photon energy is absorbed and electron-hole pairs are excited. Under the influence of a built-in electric field, these pairs separate to form a potential difference, which is collected through the upper and lower electrodes to form direct current. Currently, mainstream crystalline silicon cells use silicon wafers as substrates, while thin-film cells use glass or flexible substrates to deposit functional layers. With technological advancements, solar cells have continuously improved in terms of conversion efficiency, cost control, and reliability, becoming an important component of renewable energy power generation and widely used in power plants, building-integrated photovoltaics, and distributed energy systems.

[0022] The basic structure of a solar cell typically consists of multiple functional layers: the top layer is an anti-reflective coating (such as silicon nitride) and metal grid electrodes, used to reduce light reflection and collect current; the middle layer is a core semiconductor layer (such as the PN junction of a crystalline silicon cell or the absorption layer of a thin-film cell), which achieves photoelectric conversion through the photovoltaic effect; the bottom layer is a back electrode and a back field layer (such as an aluminum back field layer), used to form a current loop and enhance carrier collection. Through optimized optical management and electrical performance, each layer works together to achieve efficient absorption of sunlight, charge separation, and current output. The choice of materials and process design directly determine the cell's conversion efficiency and reliability.

[0023] In solar cell structures, silicon wafers, as the core semiconductor substrate, serve as both the medium for photon absorption and the carrier for charge separation and transport. Their PN junction structure creates a built-in electric field through the doping difference between P-type and N-type silicon. When sunlight excites electron-hole pairs, the electric field drives the directional separation of charge carriers, forming a photocurrent. The crystal quality of the silicon wafer (such as the perfect lattice of single-crystal silicon) and surface treatment (such as a textured surface) directly affect light-harvesting efficiency and carrier recombination loss. Thickness optimization requires balancing the contradiction between light absorption (sufficient thickness) and carrier collection (sufficient thinness), ultimately determining the cell's conversion efficiency limit.

[0024] In the battery manufacturing process, the quartz boat serves as a crucial auxiliary tool, primarily used to support and transport raw materials such as silicon wafers. Quartz material possesses properties such as high temperature resistance, high purity, and chemical stability, protecting silicon wafers from contamination during high-temperature processes in battery production (such as diffusion and sintering), while ensuring process uniformity. Especially in the production of high-efficiency batteries using processes like PERC and TOPCon, the cleanliness and structural precision of the quartz boat are critical to battery performance. In the manufacturing of crystalline silicon solar cells, the cleanliness and structural design of the quartz boat directly affect the yield and performance of the cells, serving as a vital carrier connecting raw materials and finished batteries.

[0025] Quartz boats are typically made of high-purity fused silica and feature a slotted frame structure with Y-shaped or V-shaped grooves for vertically inserting silicon wafers. The groove spacing is precisely designed to ensure uniform flow of process gases. Edge reinforcing ribs enhance overall mechanical strength, while bottom support feet match the diffusion furnace track for stable transport. Special surface treatments (such as polishing or coating) reduce impurity precipitation at high temperatures. This structure meets the requirements for high-density silicon wafer loading while withstanding repeated thermal shocks, making it a key carrier for balancing production efficiency and process stability.

[0026] As a key support tool in the production of crystalline silicon solar cells, the structural design of the quartz boat directly affects production yield and process stability. Currently, the mainstream quartz boat tooth shapes on the market are mainly divided into two types: Y-type and V-type. However, both have limitations to varying degrees in practical applications, especially in the rapidly developing back contact (BC) cell technology, where these traditional designs are revealing increasingly obvious compatibility issues.

[0027] Y-shaped quartz spar teeth, currently the most common type, typically have a bottom spacing of 1.1±0.05mm and a symmetrical "Y"-shaped fork in the tooth shape. This design performs reasonably well in traditional PERC (Passivated Emitter and Rear Cell) processes, mainly due to its stable support performance and moderate contact area. However, when applied to BC (Batch-Based Cell) processes, the inherent defects of the Y-shaped teeth become apparent: First, during automated transport, stress concentration easily occurs at the contact points between the silicon wafer and the spar teeth, leading to a significant increase in the breakage rate during robotic handling. In some production lines, the breakage rate even exceeds the process allowable standard by 2-3 times, resulting in huge hidden cost losses. Second, the width of the upper platform of the Y-shaped teeth is generally designed in the range of 0.8-1.2mm. This size often causes the silicon wafer to fail to slide smoothly to the predetermined position in high-speed production environments, resulting in a "wafer hanging" phenomenon. Specifically, the edge of the silicon wafer gets stuck at the edge of the platform and cannot fall naturally under gravity. This not only affects the production cycle but also leads to uneven temperature fields in subsequent processes, thus affecting the conversion efficiency of the cell.

[0028] In contrast, while V-shaped quartz boat teeth solve the silicon wafer positioning problem to some extent, they present more complex manufacturing challenges. The typical characteristic of V-shaped teeth is their acute-angled triangular shape and continuous sloping contact surface. This design easily leads to two key problems in practical use: First, "overlapping diffusion" (i.e., uneven edge diffusion). Due to the supporting characteristics of the V-shaped teeth, adjacent silicon wafers are difficult to maintain absolute horizontal alignment, typically resulting in a height difference of 0.1-0.3 mm. In high-temperature diffusion processes, this height difference leads to uneven flow of process gases, causing abnormal doping concentration at the wafer edges, ultimately manifesting as edge leakage in the solar cells. Second, there are safety hazards. The tip angle of the V-shaped teeth is typically between 60-75 degrees. This sharp structure can easily scratch the silicon wafer surface in high-speed automated production, and more seriously, it may damage the precision sensors at the end of the robotic arm. Production data from a leading photovoltaic company in 2023 showed that the accident rate on production lines using V-shaped quartz boats was 40% higher than that using Y-shaped boats, mainly due to scratches during equipment maintenance.

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0030] Please see Figures 1-5 This utility model provides an embodiment: a quartz boat tooth for bending wafers in the BC process, comprising a quartz boat body 1 and protruding teeth 2. Multiple sets of protruding teeth 2 are arranged on one side of the quartz boat body 1, with the protruding teeth 2 arranged equidistantly along the side length of the quartz boat body 1. The protruding teeth 2 are V-shaped, with the pointed side of the protruding teeth 2 close to the quartz boat body 1. A bottom platform 201 is provided on the side of the protruding teeth 2 close to the quartz boat body 1, and an upper platform 202 is provided on the side of the protruding teeth 2 away from the quartz boat body 1. By optimizing the shape and size of the protruding teeth 2 of the quartz boat body 1, removing the extended edge and optimizing the side angle of the protruding teeth 2 based on the Y-shaped quartz boat tooth, and simultaneously optimizing the size and angle of the bottom platform 201 and the upper platform 202, it is easier for the bent silicon wafer to slide into the bottom of the boat tooth after overlapping, reducing the likelihood of the silicon wafer getting stuck on the upper platform without slipping off. Furthermore, compared to the V-shaped quartz boat design, this reduces processing difficulty and increases safety.

[0031] Please see Figure 4 In this embodiment, the width of the upper platform 202 is 0.1 mm, the upper platform 202 is parallel to the long side of the quartz boat body 1, the bottom platform 201 is provided with a beveled edge, the beveled direction of all the bottom platform 201 beveled edges is consistent, the beveled angle of the bottom platform 201 beveled edge is three degrees, the width of the bottom platform 201 is 0.5 mm, and the side angle of the protrusion 2 is consistent with the side angle of the existing V-shaped quartz boat; the upper platform 202 is used to guide the silicon wafer into the gap between the protrusion 2, and the bottom platform 201 is used to contact the silicon wafer and limit the silicon wafer.

[0032] Compared to the Y-shaped quartz spar, this patent adjusts the bevel angle at the bottom platform 201 from 2° to 3°, making it easier for the bent silicon wafers to slide into the upper platform 202 at the bottom of the spar after overlapping. The width of the upper platform 202 is reduced to 0.1mm and the bevel is steeper, which is more suitable for the current size of silicon wafers and makes it less likely for the silicon wafers to get stuck on the upper platform without slipping off. At the same time, the width of the bottom platform 201 is designed to be 0.5mm. The current mainstream silicon wafer thickness is 130±5μm, and the sum of the two wafers is no more than 270μm, which is 0.27mm. This width is sufficient for the silicon wafers to fall normally and also serves to gather and bend the silicon wafers.

[0033] Compared to the V-shaped scalloped tooth design, the V-shaped tooth is prone to the phenomenon of wrapping and expanding because the overlapping silicon wafers cannot fall at the same height at the bottom of the scalloped tooth, resulting in a certain height difference between the two overlapping silicon wafers, which affects the process effect. In this application, a bottom platform 201 is designed to accommodate silicon wafers, reducing the height difference between silicon wafers. Although the bottom platform 201 has a beveled edge, it can greatly reduce the height difference between silicon wafers compared to using a V-shaped beveled edge to store silicon wafers. Therefore, the U-shaped top tooth designed in this patent has more advantages.

[0034] In practical applications, after the second poly diffusion, the silicon wafer enters the P diffusion process. At this time, the silicon wafer is required to be a double-insertion process, and the surface curvature of the silicon wafer exceeds 5°. When using the old-style quartz boat with toothed teeth for production, the breakage rate exceeds 4%. After replacing it with a new type of toothed quartz boat, the breakage rate is reduced to 0.08%.

[0035] Through the above steps, by optimizing the shape and size of the protrusions 2 of the quartz boat body 1, removing the extended edge and optimizing the side angle of the protrusions 2 based on the Y-shaped quartz boat teeth, and optimizing the size and angle of the bottom platform 201 and the upper platform 202, it is easier to bend the silicon wafers and slide them into the bottom of the boat teeth after they are overlapped. It is less likely that the silicon wafers will get stuck on the upper platform and not slip off. In addition, compared with the V-shaped quartz boat design, the processing difficulty is reduced and the safety is increased.

Claims

1. A quartz boat tooth for bending a sheet for a BC process, comprising a quartz boat body (1); characterized in that: It also includes protruding teeth (2). Multiple sets of protruding teeth (2) are provided on one side of the quartz boat body (1). The protruding teeth (2) are arranged equidistantly along the side length of the quartz boat body (1). The protruding teeth (2) are V-shaped. The pointed side of the protruding teeth (2) is close to the quartz boat body (1). A bottom platform (201) is provided on the side of the protruding teeth (2) close to the quartz boat body (1). An upper platform (202) is provided on the side of the protruding teeth (2) away from the quartz boat body (1). The width of the upper platform (202) is 0.1 mm.

2. The quartz boat tooth for BC process bent sheets according to claim 1, characterized in that: The upper platform (202) is parallel to the long side of the quartz boat body (1).

3. The quartz boat tooth for BC process bending sheets according to claim 1, characterized in that: The bottom platform (201) is provided with a beveled edge, and the beveled edge of all bottom platforms (201) has the same beveled direction.

4. A quartz boat tooth for BC process bent sheets according to claim 3, characterized in that: The bevel angle of the bottom platform (201) is three degrees.

5. A quartz boat tooth for BC process bent sheets according to claim 1, characterized in that: The width of the bottom platform (201) is 0.5 mm.

6. A quartz boat tooth for BC process bent sheets according to claim 1, characterized in that: The side angle of the protruding tooth (2) is consistent with the side angle of the existing V-shaped quartz boat.

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