A silicon wafer cutting apparatus and a cyclic processing method of a main roller thereof

Abstract

The present application relates to the field of photovoltaic cell manufacturing, discloses a kind of silicon wafer cutting equipment and its main roller circulation processing method, wherein the method comprises the following steps: S1: rough turning is carried out to the coating on main roller;S2: the main roller after rough turning is weighed, and the main roller is grouped according to the weight, the deviation of the weight of each main roller in each group from the average weight of all main rollers in the group is located in the second interval, and the main roller in each group is bound together;S3: one of the main roller is taken out, and each main roller is respectively finished fine turning, and after processing, the main roller in the same group is re-bound together;S4: one of the main roller is taken out, and a plurality of circumferential grooves are engraved on the coating of each main roller, and after grooving, the main roller after grooving is re-bound together for use.The method weighs and groups the circulating main roller, and the same group is used when in use, which can reduce the shaking of wire net during cutting and improve the consistency of silicon wafer thickness.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic cell manufacturing technology, specifically to a silicon wafer cutting equipment and a method for the cyclic processing of its main roller. Background Technology

[0002] With the development of photovoltaic technology, the application of photovoltaic cells is becoming increasingly widespread, and the market demand for monocrystalline silicon, one of the raw materials for photovoltaic cells, is also increasing. In the production process of monocrystalline silicon wafers, the monocrystalline silicon rods grown in a monocrystalline furnace need to be cut into wafers using a wire mesh composed of cutting wires. Currently, because tungsten wire can achieve thinner wafer cutting compared to high-carbon steel wire, the cutting wires in current silicon wafer cutting equipment are gradually replacing high-carbon steel wire. However, in existing silicon wafer cutting equipment, the inconsistent weight of the main rollers leads to inconsistent rotational inertia during the cutting process. When using tungsten wire as the cutting wire, the wire mesh wobbles significantly, resulting in inconsistent thickness of the produced silicon wafers and affecting product yield. Furthermore, the rigidity of the grooves on the existing main rollers used to accommodate the tungsten wires is insufficient, leading to a high rate of wire skipping and breakage during slicing, thus impacting production efficiency. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a circulating processing method for the main roller of a silicon wafer cutting equipment, which can improve the weight consistency of the main roller on the equipment, avoid excessive wire mesh shaking during the cutting process, and improve the thickness consistency of the product.

[0004] To solve the above problems, the technical solution adopted by the present invention is as follows: a method for cyclic processing of the main roller of a silicon wafer cutting equipment, characterized by comprising the following steps:

[0005] S1: Rough machining of the coating layer on the main roller so that the outer diameter of the main roller falls into the first interval;

[0006] S2: Weigh the main rolls after roughing, group the main rolls according to the weighing weight, and ensure that the deviation of the weight of each main roll in each group from the average weight of all main rolls in the group is within the second interval, and then bundle the main rolls in each group together.

[0007] S3: Take out one set of main rollers that have been rough-machined, and finish-machine each main roller separately to make the outer diameter of the main rollers meet the equipment requirements. After processing, re-bundle the main rollers in the same set together.

[0008] S4: Take out one set of precision-machined main rollers, and engrave several circumferential grooves on the coating of each main roller. After the grooves are engraved, re-bundle the main rollers together for later use.

[0009] Compared to existing technologies, the advantages of this invention are as follows: When regrooving old master rollers, all old master rollers are weighed and grouped. Master rollers with high weight consistency are grouped together and bundled and solidified. Master rollers in the same group are also bundled and solidified after subsequent precision turning and grooving processes, avoiding mixing between groups and ensuring a high degree of weight consistency of master rollers in the same group throughout the entire cycle. When the master rollers are loaded onto the machine, only master rollers from the same group are selected for use, ensuring a high degree of weight consistency of the master rollers on the equipment, thereby avoiding wire mesh swaying and improving the thickness consistency of the cut silicon wafers.

[0010] In the above-mentioned cyclic processing method of the main roller of the silicon wafer cutting equipment, in step S4, the rotational speed of the main roller during grooving is proportional to the outer diameter of the main roller.

[0011] In the above-mentioned cyclic processing method of the main roller of the silicon wafer cutting equipment, in step S4, during the processing of each groove on the main roller, after each entry of the cutter, the cutter moves along the preset groove contour, and exits after completing a complete groove contour.

[0012] In the above-mentioned circulating processing method of the main roller of the silicon wafer cutting equipment, in step S4, the groove is V-shaped and the bottom of the groove is an arc tangent to the groove wall.

[0013] A method for cyclic processing of the main roller of a silicon wafer dicing machine includes the following steps:

[0014] S1: Sandblasting the surface of the roller core increases the adhesion between the roller core and the coating layer;

[0015] S2: Weigh the sandblasted roller cores, group the roller cores according to the weighing weight, and ensure that the deviation of the weight of each roller core in each group from the average weight of all roller cores in the group is within the third interval, and then bundle the roller cores in each group together.

[0016] S3: Take out one set of roller cores, apply a coating layer to the circumference of each roller core to form a main roller, and after the coating is completed, re-bundle the main rollers of the same set together.

[0017] S4: Take out one set of main rollers and rough machine the coating layer of each main roller so that the outer diameter of the main roller falls into the first interval. After processing, re-bundle the main rollers in the same set together.

[0018] S5: Take out one set of main rollers that have been rough-machined, and finish machine the coating layer of each main roller to make the outer diameter of the main roller meet the equipment requirements. After processing, re-bundle the main rollers in the same set together.

[0019] S6: Take out one set of precision-machined main rollers, and engrave several circumferential grooves on the coating of each main roller. After the grooves are engraved, re-bundle the main rollers together for later use.

[0020] In the above-mentioned cyclic processing method of the main roller of the silicon wafer cutting equipment, in step S6, the rotational speed of the main roller during grooving is proportional to the outer diameter of the main roller.

[0021] In the above-mentioned cyclic processing method of the main roller of the silicon wafer cutting equipment, in step S6, during the processing of each groove on the main roller, after each entry of the cutter, the cutter moves along the preset groove contour, and exits after completing a complete groove contour.

[0022] In the above-mentioned circulating processing method of the main roller of the silicon wafer cutting equipment, in step S6, the groove is V-shaped and the bottom of the groove is an arc tangent to the groove wall.

[0023] The above-mentioned circulating processing method for the main roller of the silicon wafer cutting equipment, before step S1, further includes:

[0024] S1.1: The main roller that has been coated and has been repeatedly grooved more than a predetermined number of times is machined to remove the coating layer on the circumference of the main roller, exposing the roller core.

[0025] A silicon wafer cutting device includes at least two main rollers, a plurality of cutting wires sleeved between the two main rollers, and a drive device for driving the main rollers to rotate. The main rollers are taken from the same group of main rollers after being processed by the above-mentioned silicon wafer cutting device main roller cyclic processing method. The deviation between the weight of each main roller and the average weight of all the main rollers on the device is within a second interval.

[0026] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0027] Figure 1 This is a flowchart of the cyclic processing method of the main roller of the silicon wafer cutting equipment according to the first embodiment of the present invention;

[0028] Figure 2 A schematic diagram of the grooving on the main roller of an existing silicon wafer cutting equipment;

[0029] Figure 3 This is a schematic diagram of the grooving on the main roller of the silicon wafer cutting equipment according to an embodiment of the present invention;

[0030] Figure 4 This is a flowchart of the cyclic processing method of the main roller of the silicon wafer cutting equipment according to the second embodiment of the present invention;

[0031] Figure 5 A graph showing the silicon wafer thickness processing capability under the existing main roller circulation processing method;

[0032] Figure 6 This is a report diagram illustrating the silicon wafer thickness and thickness process capability under the main roller circulation processing method of this invention. Detailed Implementation

[0033] The embodiments of the present invention are described in detail below:

[0034] Existing silicon wafer cutting equipment uses thousands of cutting wires evenly spaced on at least two main rollers to form a wire mesh. This wire mesh is driven through the silicon rod to cut it into multiple thin wafers. Due to market demand for thinner wafers, and given that tungsten wire has better strength than carbon steel wire of the same diameter, current silicon wafer cutting equipment has begun to use diamond-encrusted tungsten wire instead of carbon steel wire as the cutting wire.

[0035] The main roller that drives the cutting wire consists of a roller core and a coating layer. The roller core is generally made of metal, while the coating layer is made of a plastic material with a certain strength, typically polyurethane. Evenly spaced circumferential grooves are etched into the coating layer to accommodate the cutting wire, ensuring that the cutting wires do not skip lines when the main roller rotates, preventing wire wobbling, and guaranteeing consistent silicon wafer thickness. Because the grooves on the main roller wear down after multiple cuts, they can no longer effectively restrain the cutting wire. Therefore, after a certain period of use, the grooves on the main roller need to be machined off and re-grooved to achieve recycling of the main roller.

[0036] Example 1: Refer to Figure 1 The present invention provides a method for the cyclic processing of the main roller of a silicon wafer cutting equipment, comprising the following steps:

[0037] S1: Rough machining of the coating layer on the main roller so that the outer diameter of the main roller falls into the first interval;

[0038] S2: Weigh the main rolls after roughing, group the main rolls according to the weighing weight, and ensure that the deviation of the weight of each main roll in each group from the average weight of all main rolls in the group is within the second interval, and then bundle the main rolls in each group together.

[0039] S3: Take out one set of main rollers that have been rough-machined, and finish-machine each main roller separately to make the outer diameter of the main rollers meet the equipment requirements. After processing, re-bundle the main rollers in the same set together.

[0040] S4: Take out one set of precision-machined main rollers, and engrave several circumferential grooves on the coating of each main roller. After the grooves are engraved, re-bundle the main rollers together for later use.

[0041] The aforementioned method of circulating the main roller involves weighing and grouping the main rollers before precision machining. Rollers with similar weight deviations are grouped together, and each subsequent use involves using the same roller from the same group. This ensures that the rotational inertia of the main rollers during production is essentially consistent, guaranteeing uniform speed during acceleration and deceleration. This prevents the tungsten wire from wobbling during cutting due to speed variations in the main rollers, which would otherwise result in significant differences in the thickness of the cut silicon wafers. This circulating method improves the stability of the wire mesh during cutting, thereby enhancing the consistency of the cut silicon wafer thickness.

[0042] During implementation, when weighing and grouping, the number of main rollers in each group should be an integer multiple of the number of main rollers required on the equipment. When a group of main rollers is full, the main rollers in that group should be bundled together immediately to avoid repeated weighing of the already weighed and grouped main rollers, thus improving the efficiency of grooving. Furthermore, during subsequent precision turning and grooving of the main rollers, processing should also be carried out in groups. After processing, the main rollers in the same group should be bundled together for later use to avoid mixing of main rollers from different groups, which would affect the grouping effect.

[0043] To avoid tungsten wire skipping during the cutting process due to insufficient rigidity of the wire groove, which would require machine downtime for maintenance, reduce product yield, and impact production efficiency, a reference is needed. Figure 3 In this embodiment, the groove is a V-shaped groove, and the bottom of the groove is an arc tangent to the groove wall. Compared to Figure 2 Existing main roller troughs have an arc-shaped bottom that is angled relative to the trough wall, resulting in an uneven transition between the bottom and the wall. The trough in this embodiment can more stably accommodate tungsten wire, thereby reducing the probability of wire skipping. (Refer to...) Figure 2 Meanwhile, in existing main roller grooving processes, the cutter only travels halfway along the groove contour before exiting, resulting in defects in the groove wall and affecting its strength. (Refer to...) Figure 3 In this embodiment, during grooving, the cutting tool follows the preset groove contour, completing the entire contour of each groove before exiting the cut, thus avoiding defects in the grooves. Furthermore, in this embodiment, to further improve the grooving process, the rotational speed of the main roller is proportional to its outer diameter. This ensures that the cutting speed of the tool relative to main rollers with different outer diameters remains consistent on the main roller surface, guaranteeing the stability of the grooving process and ensuring the consistency of the grooves between main rollers, thereby further reducing skipping during main roller use.

[0044] In this embodiment, the weight deviation of the main roller in the same group from the average weight of the group should be less than 0.5KG. When grooving, a small-angle tool of 22 degrees is used to groove the groove to further improve the strength of the groove.

[0045] Example 2: Refer to Figure 4 For roller cores used for the first time, a coating layer needs to be applied to the roller core surface. Before applying the coating layer, the circumferential surface of the roller core needs to be sandblasted to improve the adhesion between the roller surface and the coating material. For roller cores used for the first time, group weighing should be carried out after sandblasting.

[0046] The coated main roller can only be grooved a limited number of times because the old grooves need to be removed each time it is regrooved. When the number of groovings exceeds a predetermined value, the coating layer needs to be completely removed, exposing the roller core. In actual operation, a portion of the roller core surface needs to be removed while the coating layer is being removed. The roller core after the coating layer is removed is weighed and grouped after re-sandblasting, just like the roller core used for the first time. In this embodiment, the coated roller core can be grooved 7 times. After grooving 7 times, the coating layer needs to be removed and recoated. It can be understood that the specific number of groovings that can be repeated is determined by the coating layer thickness and the amount of machining during roughing and finishing. The grooving process for the coated grooves is the same as in Embodiment 1 of this invention.

[0047] After the main roller undergoes multiple cycles, a portion of the roller core is also removed each time the coating is peeled off. Therefore, the diameter of the roller core decreases with each cycle. When the minimum diameter of the roller core is reached, it needs to be scrapped. During production, the roller core may be damaged due to unforeseen circumstances. If the diameter of the damaged roller core is not yet at the minimum scrap diameter, several other roller cores with the same diameter after coating removal (e.g., three) need to be selected and dynamically balanced together. If the result is within a certain range, the damaged roller core is bundled with the roller cores that underwent dynamic balancing.

[0048] In the silicon wafer cutting equipment of this invention, the main rollers are taken from one group at a time, and it is strictly forbidden to transfer them from different groups. This ensures that the weight and rotational inertia of the main rollers on the machine are basically consistent. Simultaneously, the high strength of the wire grooves effectively binds the tungsten wire within them. During the cutting process, this reduces the probability of wire skipping and wire mesh sway, thereby improving the yield and thickness control of the silicon wafers.

[0049] Reference Figure 5 and Figure 6 The figures show the thickness and thinning process capability reports for the original main roller circulation processing method and the circulation processing method according to this invention, respectively. As can be seen from the figures, the thickness and thinning process capability CPK increases from 0.38 to 0.54 compared to the original method using the improved main roller circulation processing method, and the upper limit of the thickness specification after the improvement is smaller than that before the improvement. The main roller circulation processing method of this invention can improve the consistency of the thickness of the processed silicon wafers.

[0050] It should be noted that in the description of this invention, any descriptions of orientation, such as up, down, front, back, left, right, etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings. They are only for the purpose of facilitating the description of this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and should not be construed as a limitation of this invention.

[0051] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," "exceeding," etc. are understood to exclude the stated number, while "above," "below," "within," etc. are understood to include the stated number. If "first" or "second" is mentioned, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0052] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0053] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A method for cyclic processing of the main roller of a silicon wafer cutting equipment, characterized in that, Includes the following steps: S1: Rough machining of the coating layer on the main roller so that the outer diameter of the main roller falls into the first interval; S2: Weigh the main rolls after roughing, group the main rolls according to the weighing weight, and ensure that the deviation of the weight of each main roll in each group from the average weight of all main rolls in the group is within the second interval, and then bundle the main rolls in each group together. S3: Take out one set of main rollers and precision machine each main roller to make the outer diameter of the main roller meet the equipment requirements. After processing, re-bundle the main rollers in the same set together. S4: Take out one set of precision-machined main rollers, and engrave several circumferential grooves on the coating of each main roller. After the grooves are engraved, re-bundle the main rollers together for later use.

2. The circulating processing method of the main roller of the silicon wafer cutting equipment according to claim 1, characterized in that, In step S4, the rotational speed of the main roller during grooving is proportional to the outer diameter of the main roller.

3. The circulating processing method of the main roller of the silicon wafer cutting equipment according to claim 1, characterized in that, In step S4, during the processing of each groove on the main roller, after each entry of the tool, it moves along the preset groove contour and exits after completing a full groove contour.

4. The circulating processing method of the main roller of the silicon wafer cutting equipment according to claim 1, characterized in that, In step S4, the groove is V-shaped, and the bottom of the groove is an arc tangent to the groove wall.

5. A method for cyclic processing of the main roller of a silicon wafer cutting equipment, characterized in that, Includes the following steps: S1: Sandblasting the surface of the roller core increases the adhesion between the roller core and the coating layer; S2: Weigh the sandblasted roller cores, group the roller cores according to the weighing weight, and ensure that the deviation of the weight of each roller core in each group from the average weight of all roller cores in the group is within the third interval, and then bundle the roller cores in each group together. S3: Take out one set of roller cores, apply a coating layer to the circumference of each roller core to form a main roller, and after the coating is completed, re-bundle the main rollers of the same set together. S4: Take out one set of main rollers and rough machine the coating layer of each main roller so that the outer diameter of the main roller falls into the first interval. After processing, re-bundle the main rollers in the same set together. S5: Take out one set of main rollers that have been rough-machined, and finish machine the coating layer of each main roller to make the outer diameter of the main roller meet the equipment requirements. After processing, re-bundle the main rollers in the same set together. S6: Take out one set of precision-machined main rollers, and engrave several circumferential grooves on the coating of each main roller. After the grooves are engraved, re-bundle the main rollers together for later use.

6. The circulating processing method of the main roller of the silicon wafer cutting equipment according to claim 5, characterized in that, In step S6, the rotational speed of the main roller during grooving is proportional to the outer diameter of the main roller.

7. The circulating processing method of the main roller of the silicon wafer cutting equipment according to claim 5, characterized in that, In step S6, during the processing of each groove on the main roller, after each entry of the tool, it moves along the preset groove contour and exits after completing a full groove contour.

8. The circulating processing method of the main roller of the silicon wafer cutting equipment according to claim 5, characterized in that, In step S6, the groove is V-shaped, and the bottom of the groove is an arc tangent to the groove wall.

9. The circulating processing method of the main roller of the silicon wafer cutting equipment according to claim 5, characterized in that, Before step S1, the method further includes: S1.1: The main roller that has been coated and has been repeatedly grooved more than a predetermined number of times is machined to remove the coating layer on the circumference of the main roller, exposing the roller core.

10. A silicon wafer dicing apparatus, comprising at least two main rollers, a plurality of dicing wires sleeved between the two main rollers, and a drive device for driving the main rollers to rotate, characterized in that, The main roller is taken from the same group of main rollers after being processed by the cyclic processing method of the main roller of the silicon wafer cutting equipment according to any one of claims 1 to 9, and the deviation of the weight of each main roller from the average weight of all the main rollers on the equipment is within a second interval.

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