TW202330226A - Wire cutting equipment and wire cutting method - Google Patents

Abstract

The embodiment of the invention discloses wire cutting equipment and a wire cutting method, and the wire cutting equipment comprises a bearing module which is used for bearing a silicon rod to move in the feeding direction; the cutting module comprises a cutting line and a cutting line driving unit, and the cutting line driving unit is arranged to drive the cutting line to move so as to cut the silicon rod; the first mortar supply module is arranged to be capable of spraying mortar to the cutting position, cutting the silicon rod, of the cutting line all the time.

Description

Wire cutting device and wire cutting method

Embodiments of the present invention belong to the technical field of wafer processing, and in particular relate to wire cutting equipment and wire cutting methods.

As the carrier of semiconductor circuit manufacturing process, the quality of silicon wafer has a decisive influence on the formation of integrated circuits. At present, the main steps in the preliminary molding process of silicon wafers include: silicon rod cutting, physical and chemical grinding, chemical etching, physical and chemical polishing, etc. Silicon rod cutting is one of the core technologies in silicon wafer forming technology, which mainly includes multi-line mortar (SiC) cutting and inner circle cutting. The mainstream technology currently used is multi-wire cutting, because compared with inner circle cutting, multi-wire cutting has the advantages of high efficiency, good quality, and high production rate.

Multi-wire cutting is the current advanced slicing processing technology. Its principle is to wind the cutting wires in turn in the guide grooves formed on the circumferential surface of the bobbin at intervals so that the cutting wires form an array of cutting line segments. Under the guidance of the cutting line, the abrasive material is brought into the processing area of the material to be cut (such as silicon rod) for grinding by using the high-speed reciprocating motion of the cutting line, and the workpiece to be cut is fed in the vertical direction through the lifting of the worktable, so that the The workpiece is simultaneously cut into several thin slices (such as wafers) of the desired size and shape. Usually the abrasive used in the multi-wire cutting process can be selected as mortar.

At present, during the cutting process, since the cutting wire is fed at high speed along its extension direction, as the cutting wire continuously cuts into the silicon rod, the friction between the cutting wire and the silicon rod will generate a lot of heat. If the heat cannot be taken away in time Walking will have an adverse effect on the flatness of the cut silicon wafer, and as the cutting process continues, the ability of the cutting line to carry sand will decrease, and the amount of mortar that can actually be carried by the cutting line to the cutting position may be lower than expected , which also has a negative impact on cutting efficiency.

In view of this, the embodiment of the present invention expects to provide a wire cutting device and a wire cutting method, which can reduce the influence of temperature on the flatness of cut silicon wafers and improve cutting efficiency.

The technical scheme of the embodiment of the present invention is realized like this: In a first aspect, an embodiment of the present invention provides a wire cutting device, which includes: A carrying module, the carrying module is used to carry the movement of the silicon rod in the feeding direction; A cutting module, the cutting module includes a cutting wire and a cutting wire driving unit, the cutting wire driving unit is configured to drive the cutting wire to move so as to cut the silicon rod; A first mortar supply module, the first mortar supply module is configured to always spray mortar to the cutting position where the silicon rod is cut by the cutting line.

In a second aspect, an embodiment of the present invention provides a wire cutting method, which is performed by using the wire cutting device according to the first aspect.

Embodiments of the present invention provide a wire cutting device and a wire cutting method; the wire cutting device includes a first mortar supply module that can always spray mortar to the cutting position where the wire cuts the silicon rod, and the first mortar supply module directly sends The mortar is sprayed to the cutting position, and the heat generated by the friction between the cutting line and the silicon rod can be taken away by the mortar, and more mortar can be involved in the cutting operation, thereby improving the cutting efficiency.

The above-mentioned features and advantages and other features and advantages of the present invention will be more apparent through the following detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings.

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, but not to limit the present invention.

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is only some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without progressive improvements fall within the protection scope of the present invention.

In addition, it should be noted that the terms “first” and “second” in the embodiments of the present invention are used to distinguish similar items, and are not used to describe a specific order or sequence. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention are capable of practice in sequences other than those illustrated or described herein and that what is distinguished by "first" and "second" are generally As a category, the number of objects is not limited. For example, there may be one or more first objects.

Those skilled in the art will understand that the singular forms "a", "an", "said" and "the" used herein may also include plural forms unless otherwise specified. It should be further understood that the word "comprising" used in the description of the present invention refers to the presence of the stated features, integers, steps, operations, elements and/or components, but does not exclude the presence or addition of one or more other features, Integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Additionally, "connected" or "coupled" as used herein may include wireless connection or wireless coupling. The expression "and/or" used herein includes all or any elements and all combinations of one or more associated listed items.

The term "and/or" in the embodiment of the present invention describes the relationship between associated objects, indicating that there may be three relationships, for example, A and/or B, which may mean: A exists alone, A and B exist simultaneously, and B exists alone. three conditions. The character "/" generally indicates that the contextual objects are an "or" relationship.

The term "plurality" in the embodiments of the present invention refers to two or more, and other quantifiers are similar.

"Determine B based on A" in the present invention means that the factor A should be considered when determining B. It is not limited to "B can be determined only based on A", but also includes: "Determine B based on A and C", "Determine B based on A, C and E", "determine C based on A, further determine B based on C" wait. In addition, it may also include A as the condition for determining B, for example, "when A meets the first condition, use the first method to determine B"; another example, "when A meets the second condition, determine B"; another example , "when A satisfies the third condition, determine B based on the first parameter" and so on. Of course, it may also be a condition that takes A as a factor for determining B, for example, "when A satisfies the first condition, use the first method to determine C, and further determine B based on C" and so on.

Referring to FIG. 1, it shows a schematic diagram of a wire cutting device 1 in the related art. It can be understood that the structure shown in FIG. In a specific implementation state, elements are added or subtracted from the composition structure shown in FIG. 1 , which is not specifically limited in this embodiment of the present invention. As shown in FIG. 1, the wire cutting device 1 can include a wire cutting unit 11 and a carrier unit 12; the wire cutting unit 11 can be placed below the vertical direction of the carrier unit 12 as shown in FIG. As shown in FIG. 2, it is placed above the vertical direction of the carrying unit 12. Specifically, the wire cutting unit 11 may include a plurality of bobbins 111 and cutting wires 112, and the cutting wires 112 are wound on the bobbins 111 to form an array of mutually parallel cutting wire segments; in FIG. 1, the number of bobbins 111 is 2 Take this as an example, and the reciprocating direction of the bobbin 111 and the cutting line 112 toward and away from the carrying unit 12 is shown by the solid arrow in FIG. 1 , and the reciprocating speed can be 10m/s to 15m/s for example. The carrying unit 12 is used to load and fix the silicon rod 2 to be processed. In the example shown in FIG. 1 and FIG. As for the abutment 121 , for example, the silicon rod to be processed can be fixed to the abutment by bonding its peripheral surface to the lower surface ( FIG. 1 ) or the upper surface ( FIG. 2 ) of the abutment with resin.

For the wire cutting equipment 1 shown in Fig. 1 and Fig. 2, by moving the wire cutting unit 11 or the carrying unit 12 so that the cutting wire 112 and the silicon rod 2 to be processed move toward each other along the vertical direction, the wire to be cut 112 After being in contact with the silicon rod 2 to be processed, the cutting of the silicon rod 2 to be processed is realized by using the movement of the cutting line 112 along its extending direction. In the example shown in Figure 1, the wire cutting unit 11 can be moved along the direction shown by the black arrow, and the carrying unit 12 can also be moved along the direction of the dotted white arrow, so as to realize the distance between the cutting line 112 and the silicon rod 2 to be processed. Relative motion in the vertical direction. In the example shown in Figure 2, the carrying unit 12 can be moved along the direction shown by the black arrow, and the wire cutting unit 11 can also be moved along the direction of the dotted white arrow, so as to realize the gap between the cutting line 112 and the silicon rod 2 to be processed. Relative motion in the vertical direction. It should be noted that the embodiment of the present invention implements the movement of the wire cutting unit 11 or the carrying unit 12 by adding a lifting device (not shown in the figure). It can be understood that those skilled in the art can also And the implementation scenario implements the movement of the wire cutting unit 11 or the carrying unit 12 in other ways, which will not be described in this embodiment of the present invention.

In a related solution, the bobbin 111 is provided with a plurality of guide grooves for guiding the cutting wire 112, and the cutting wire 112 is wound in each guiding groove of each bobbin 111 in turn, so that the cutting wire 112 is formed by a plurality of An array of cutting line segments, in which each cutting line segment is parallel to each other so as to cut a silicon rod into a plurality of silicon wafers at one time. At the beginning of the cutting operation, before the wire cutting unit 11 and the carrier unit 12 move towards each other, the wire cutting unit 11 is first started to run, so that the cutting wire winding shaft 111 performs high-speed reciprocating motion, and at the same time sprays the cutting wire through the mortar nozzle Cutting mortar, this process is called "preheating process", usually, the two ends of the cutting wire are respectively wound on the pay-off reel and the take-up reel, and the reciprocating motion of the cutting wire is driven by the cooperation of the pay-off reel and the take-up reel. Once the reciprocating motion of the cutting wire is smooth and the cutting wire has been evenly sprayed with mortar, the preheating process ends. Then, the wire cutting unit 11 and the carrier unit 12 are moved toward each other to perform the cutting operation while the cutting wire continues the high-speed reciprocating motion.

In the cutting process using the wire cutting equipment in the related art, because the cutting wire reciprocates at high speed, it will quickly generate a large amount of heat when it rubs against the silicon rod. As the cutting position continues to deepen, these heats become more and more A lot of it accumulates inside the silicon rod being cut, and continues to affect the silicon rod throughout the cutting process until the end of the cutting process, eventually resulting in poor flatness of the silicon wafer that has just been cut out due to the influence of this part of the heat . In addition, as the cutting process continues, the silicon slag generated by the cutting may accumulate near the cutting position on the silicon rod, and the extrusion of the crystal rod to the cutting position will also increase with the increase of the cutting depth, and the cutting line will be sandy due to wear. These factors result in the cutting wire not being able to carry sufficient mortar to the cutting position, resulting in reduced cutting capacity and overall cutting efficiency.

In view of the above situation, the embodiment of the present invention expects to provide a wire cutting device and a wire cutting method; which can reduce the influence of temperature on the flatness of cut silicon wafers and improve cutting efficiency.

Based on this, referring to Fig. 3, it shows a kind of wire cutting equipment 200 provided by the implementation of the present invention. Movement; cutting module 202, the cutting module 202 includes a cutting line 2021 and a cutting line driving unit 2022, the cutting line driving unit 2022 is set to drive the cutting line 2021 to move to cut the silicon rod S; the first mortar Supply module 203 , the first mortar supply module 203 is configured to always spray mortar to the cutting position where the silicon rod S is cut by the cutting line 2021 .

As shown in Figure 3, the wire cutting equipment 200 includes a carrying module 201, a cutting module 202 and a first mortar supply module 203, the carrying module 201 carries a silicon rod S and can drive the silicon rod S along the direction of the cutting module 202. At the same time, the cutting line drive unit 2022 of the cutting module 202 moves the cutting line 2021 in the direction of extension of the cutting line, such as reciprocating motion, so as to contact the silicon rod S with the silicon rod S Carry out cutting, in Fig. 3, cutting line drive unit 2022 is take-up wheel and pay-off wheel, in the cutting process, first mortar supply module 203 always sprays mortar to the cutting position where cutting line 2021 cuts silicon rod S, that is That is to say, the mortar is sprayed on both the cutting line section that is performing the cutting operation and the part of the silicon rod that is being cut, so that the mortar can directly reach the cutting position to participate in the cutting operation, and the cutting efficiency is improved, and the mortar that has participated in the cutting operation will flow through gravity Leaving the silicon rod and the cutting line, so as to take away part of the heat generated by the cutting operation, and reduce the accumulation of heat at the silicon rod.

The embodiment of the present invention provides a kind of wire cutting equipment 200; 203 directly sprays the mortar to the cutting position, and the heat generated by the friction between the cutting line 2021 and the silicon rod S at the cutting position can be taken away by the mortar, and more mortar can be involved in the cutting operation, thereby improving the cutting efficiency.

When the carrying module 201 drives the silicon rod S to feed downward toward the cutting line 2021 in the vertical direction, the cutting line 2021 starts cutting from the bottom of the silicon rod S. For this, refer to FIG. 3 . Optionally, the first The mortar supply module 203 is arranged below the silicon rod and the cutting line 2021 and includes a nozzle 2031 for spraying mortar upwards, that is to say, the first mortar supply module 203 is fed from the silicon rod and the cutting operation through the nozzle 2031. The downward direction of the cutting line section sprays mortar upwards. This setting can make the mortar directly reach the cutting position with a short path, not only in the initial stage of cutting, but also in any stage of the cutting process. The nozzle 2031 can spray the mortar from the The cut and formed adjacent silicon wafers are sent to the cutting position, which has better ejection efficiency. Optionally, the first mortar supply module 203 is disposed directly below the silicon rod and the cutting line 2021 .

In order to enable enough mortar to participate in the cutting operation, optionally, the nozzle 2031 is set so that the sprayed mortar can always cover the cutting position, specifically, the nozzle 2031 is set not only to the cutting line where the cutting operation is being performed A certain point or a certain area on the segment and the part of the silicon rod being cut is sprayed with mortar so that the mortar can cover the above-mentioned cutting line segment and part of the silicon rod to ensure sufficient cutting capacity.

During the cutting process, the cutting position where the cutting line 2021 cuts the silicon rod always changes with the cutting process. Continue to take the case where the silicon rod S is fed downwards in the vertical direction toward the cutting line 2021 as an example. The cutting position starts from the bottom of the silicon rod. The edge gradually deepens, and the length of the cutting position changes in a way that first becomes longer and then becomes shorter. In order to provide mortar adaptively according to the change of the cutting position, optionally, see FIG. 4 and FIG. 5 , the wire cutting device 200 Also includes a controller 204, the controller 204 is used to control the pressure and injection range of the nozzle 2031 according to the change of the cutting position. Specifically, when the cutting position is closer to the nozzle 2031, the nozzle 2031 can be lower The pressure sprays the mortar, and as the cutting position gradually moves away from the nozzle 2031, the injection pressure of the nozzle 2031 is gradually increased; when the cutting position is short, for example, in the initial stage and the end stage of cutting, the divergence angle θ of the nozzle 2031 can be made smaller , see Figure 5, and when the cutting position is long, for example, when cutting to the diameter position of the silicon rod, it is necessary to expand the divergence angle of the nozzle 2031, so that throughout the cutting process, the mortar can always cover the cutting position, by In this way, not only can the mortar be accurately delivered to the cutting position, but also the amount of mortar can be used reasonably, avoiding the occurrence of mortar waste or insufficient mortar.

In order to realize multi-wire cutting, referring to FIG. 3 , the wire cutting device 200 also includes a wire shaft 205, a plurality of guide grooves 2051 extending along the circumferential direction of the wire shaft 205 are formed on the peripheral surface of the wire shaft 205, the cutting The wire 2021 is wound in the plurality of guiding slots 2051 of the bobbin 205 to form an array composed of a plurality of cutting wire segments SE parallel to each other.

For the situation of multi-wire cutting, in order to provide sufficient mortar to the cutting position corresponding to each cutting line segment SE, optionally, referring to FIG. 3 , the first mortar supply module 203 includes A plurality of the nozzles 2031, so that the ejected mortar can cover the cutting position where each cutting line segment SE cuts the silicon rod. As an example and not limiting, the number of nozzles 2031 can be the same as or greater than the number of cutting line segments SE The number of the cutting line SE, and the position of each nozzle 2031 is set to correspond to each cutting position, such as corresponding to each cutting line SE on the reel 205 on the winding line, thus for one cutting line SE can be composed of one or more The nozzle 2031 sprays the mortar to prevent the mortar from being blocked on the spraying path and unable to reach the cutting position.

In order to ensure that sufficient mortar can participate in the cutting operation, optionally, referring to FIG. Part of the cutting line is sprayed with mortar. Optionally, the second mortar supply module 206 is disposed above the spool 205 and the cutting line 2021 along the axial direction of the spool 205 .

As shown in Fig. 6, a second mortar supply module 206 arranged along the axial direction of the bobbin 205 is respectively provided above the two spools 205, the second mortar supply module 206 is roughly in the shape of a cuboid, and its length is greater than The length of the portion of the bobbin 205 that is wound with the cutting wire and is provided with a downwardly open spray port (not shown), so that a part of the bobbin 205 positioned below and each cutting wire segment SE on the bobbin 205 can be sprayed. Spraying mortar, by means of the spool 205, the mortar can stay on the cutting line segment SE for a period of time, so that the mortar can fully contact the cutting line segment SE, which is more conducive to the cutting line segment SE carrying more mortar to the cutting position to participate in the cutting operation.

In the field of online cutting, mortar can be recycled. For this, optionally, the first mortar supply module 203 also includes a mortar recovery part, which is used to recover the ejected mortar for recycling, specifically In other words, when the first mortar supply module 203 is arranged under the silicon rod, the mortar ejected from the nozzle 2031 will fall back to the first mortar supply module 203 due to gravity, as shown in FIG. As shown, the first mortar supply module 203 includes a collection part 2032 located at the bottom and a recovery port 2033 communicating with the collection part 2032. The collection part 2032 is in the shape of an arc plate for collecting the ejected mortar and can drain the collected mortar. To the recovery port 2033, the mortar flowing into the recovery port 2033 can be used for subsequent cutting operations after filtering, performance adjustment, etc., thereby reducing the cost of wire cutting operations.

The embodiment of the present invention also provides a wire cutting method, which is executed by using the wire cutting device 200 described in the present invention.

It should be noted that each embodiment in this specification is described in a progressive manner, the same and similar parts of each embodiment can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, as for the embodiment, since it is basically similar to the product embodiment, the description is relatively simple, and for related parts, please refer to the description of the product embodiment.

In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in an appropriate manner.

It is obvious that those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the patent scope of the present invention and the scope of equivalent technologies, the present invention is also intended to include these modifications and variations.

1: Wire cutting equipment 11: Wire cutting unit 111: Spool 112: cutting line 12: Bearing unit 121: Abutment 122: Intermediary software 2: Silicon rod to be processed 200: wire cutting equipment 201: carrying module 202: Cutting module 2021: Cutting Lines 2022: Cutting wire drive unit 203: The first mortar supply module 2031: nozzle 2032: Collection Department 2033: Recovery port 204: Controller 205: Spool 2051: guide groove 206: The second mortar supply module S: silicon rod SE: cut line segment θ: Diffusion angle

Fig. 1 is a schematic diagram of a wire cutting device in the related art; Fig. 2 is the schematic diagram of the wire cutting equipment in another kind of related art; 3 is a schematic diagram of a wire cutting device provided by an embodiment of the present invention; 4 is a schematic diagram of a wire cutting device provided by another embodiment of the present invention; 5 is a schematic diagram of a wire cutting device provided by another embodiment of the present invention; 6 is a schematic diagram of a wire cutting device provided by another embodiment of the present invention; Fig. 7 is a schematic structural diagram of a first mortar supply module provided by an embodiment of the present invention.

200: wire cutting equipment

201: carrying module

202: Cutting module

2021: Cutting Lines

2022: Cutting wire drive unit

203: The first mortar supply module

2031: nozzle

205: Spool

2051: guide groove

S: silicon rod

SE: cut line segment

Claims (10)

A wire cutting device, comprising: A carrying module, the carrying module is used to carry the movement of the silicon rod in the feeding direction; A cutting module, the cutting module includes a cutting wire and a cutting wire driving unit, the cutting wire driving unit is configured to drive the cutting wire to move so as to cut the silicon rod; A first mortar supply module, the first mortar supply module is configured to always spray mortar to the cutting position where the silicon rod is cut by the cutting line. The wire cutting device as claimed in claim 1, wherein the first mortar supply module is disposed below the silicon rod and the cutting wire and includes a nozzle for spraying mortar upward. The wire cutting equipment as claimed in claim 2, wherein the nozzle is arranged such that the sprayed mortar can always cover the cutting position. The wire cutting device as claimed in claim 3, wherein the wire cutting device further comprises a controller, the controller is used for controlling the change of the nozzle pressure and spraying range according to the change of the cutting position. The wire cutting device according to any one of claims 2 to 4, wherein the wire cutting device further comprises a wire shaft, and a plurality of guides extending along the circumferential direction of the wire shaft are formed on the peripheral surface of the wire shaft. The cutting wire is wound in the plurality of guiding grooves of the bobbin to form an array composed of a plurality of cutting wire segments parallel to each other. The wire cutting equipment according to claim 5, wherein the first mortar supply module includes a plurality of nozzles arranged along the axial direction of the silicon rod, so that the sprayed mortar can cover each cutting line segment and cut the Cutting position of the silicon rod. The wire cutting device as claimed in claim 5, wherein the wire cutting device further comprises a second mortar supply module, and the second mortar supply module is configured to spray mortar to the part of the wire spool where the cutting wire is wound. The wire cutting equipment according to claim 7, wherein the second mortar supply module is arranged above the wire shaft and the cutting line along the axial direction of the wire shaft. The wire cutting device according to any one of claims 1 to 4, wherein the first mortar supply module further includes a mortar recovery part, and the mortar recovery part is used to recover the ejected mortar for recycling. A wire cutting method performed by using the wire cutting device described in any one of Claims 1 to 8.

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