System and method for inspecting a wire slot in a rotating shaft of a multi-wire saw for contaminant particles

Abstract

The embodiment of the present application discloses a system and method for checking the contaminated particles in the wire slot of the rotating shaft of a multi-wire cutting machine, wherein the multi-wire cutting machine has at least two rotating shafts, the outer circumferential surface of each rotating shaft is formed with a plurality of circumferentially extending wire slots, the cutting wires are wound on the at least two rotating shafts in a manner of being located in the plurality of wire slots to obtain a plurality of cutting wire segments between the adjacent two rotating shafts, and the plurality of cutting wire segments are in the same plane and parallel to each other when there is no contaminated particle in each wire slot of the adjacent two rotating shafts, the system comprises: a light source for emitting a light beam; a light screen, the light beam is irradiated on the light screen to form a light spot on the light screen, wherein the light beam is blocked by the plurality of cutting wire segments so that a plurality of corresponding shadows are formed in the light spot; a judgment unit for identifying whether the plurality of shadows are parallel to each other, and determining that there is a contaminated particle in at least one wire slot when it is identified that the plurality of shadows are not parallel to each other.

Description

Technical Field

[0001] This invention relates to the field of silicon wafer production, and more particularly to a system and method for inspecting contaminant particles in the grooves of the spindle of a multi-wire dicing machine. Background Technology

[0002] In the silicon wafer manufacturing process, multi-wire dicing machines are typically used to cut single-crystal ingots produced by the Czochralski method to obtain wafers. A multi-wire dicing machine usually includes two opposing rotating shafts. A single dicing wire is wound around the grooves of the two shafts to obtain multiple parallel dicing segments in the same plane. The rotation of the shafts causes these multiple dicing segments to move, thereby completing the cutting of the single-crystal ingot.

[0003] The slots in the spindle can become clogged with contaminating particles such as silicon chips or other impurities. This can prevent the cutting wire from being properly positioned within the slot, or even render the slot ineffective at limiting the cutting wire. Consequently, during the operation of the multi-wire dicing machine, or as the spindle rotates, improperly positioned or uncontrolled cutting wires are prone to skipping, or "jumping" from a slot containing contaminating particles into an adjacent slot. This can increase or decrease the spacing between adjacent cutting wire segments, resulting in wafers that do not meet thickness requirements. It also increases the risk of wire breakage, potentially rendering the entire product being cut unusable. Therefore, it is necessary to determine whether the slots in the spindle of a multi-wire dicing machine are contaminated with particulate matter.

[0004] In the existing judgment method, operators need to visually inspect a series of grooves arranged along the axis of the rotating shaft one by one, which is not only time-consuming and labor-intensive but also has a high labor intensity. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention aims to provide a system and method for inspecting contaminant particles in the grooves of the shaft of a multi-wire cutting machine. This system and method can automate the inspection of contaminant particles in a simple and convenient manner, eliminating the need for operators to visually inspect each groove individually.

[0006] The technical solution of this invention is implemented as follows:

[0007] In a first aspect, embodiments of the present invention provide a system for inspecting contaminant particles in the grooves of the shafts of a multi-wire cutting machine, wherein the multi-wire cutting machine has at least two shafts, each shaft having a plurality of circumferentially extending grooves formed on its outer circumferential surface, and cutting wires are wound around the at least two shafts such that they are located in the plurality of grooves to obtain a plurality of corresponding cutting wire segments between adjacent shafts, and the plurality of cutting wire segments are in the same plane and parallel to each other when there are no contaminant particles in each groove of the adjacent shafts, the system comprising:

[0008] A light source, which is used to emit a light beam;

[0009] A light screen, wherein the light beam shines on the light screen to form a light spot on the light screen, wherein the light beam is blocked by the plurality of dicing segments so that the light spot forms a plurality of corresponding shadows;

[0010] The determination unit is used to identify whether the plurality of shadows are parallel to each other, and when it is identified that the plurality of shadows are not parallel to each other, it determines that at least one wire groove contains contaminant particles.

[0011] Secondly, embodiments of the present invention provide a method for inspecting contaminant particles in the grooves of the shafts of a multi-wire cutting machine, wherein the multi-wire cutting machine has at least two shafts, each shaft having a plurality of circumferentially extending grooves formed on its outer circumferential surface, and cutting wires are wound around the at least two shafts in such a manner that they are located in the plurality of grooves to obtain a plurality of corresponding cutting wire segments between two adjacent shafts, and the plurality of cutting wire segments are in the same plane and parallel to each other when there are no contaminant particles in each groove of the two adjacent shafts, the method comprising:

[0012] Emit a beam of light;

[0013] The light spot formed by the light beam is such that the light beam is blocked by the plurality of cleaving segments, resulting in the formation of a plurality of shadows in the light spot;

[0014] The system identifies whether the multiple shadows are parallel to each other, and determines that at least one groove contains contaminant particles when the multiple shadows are identified as not being parallel to each other.

[0015] This invention provides a system and method for inspecting contaminant particles in the grooves of the shaft of a multi-wire cutting machine. It utilizes the positional influence of contaminant particles on the cutting wire segments and uses optical methods to determine whether contaminant particles are present in the grooves of the shaft of the multi-wire cutting machine. This allows for automated operation in a simple and convenient manner, avoiding the need for operators to visually inspect each groove and reducing labor costs. Attached Figure Description

[0016] Figure 1 This is a top view schematic diagram of the multi-line cutting process to which the present invention is applied;

[0017] Figure 2 Combination Figure 1 The perspective view of the multi-wire cutting machine in the figure shows a schematic diagram of the components of a system according to an embodiment of the present invention;

[0018] Figure 3 Combination Figure 1 The perspective view of the multi-wire cutting machine shows a schematic diagram of the components of a system according to another embodiment of the present invention;

[0019] Figure 4 Combination Figure 1 The perspective view of the multi-wire cutting machine shows a schematic diagram of the components of a system according to another embodiment of the present invention;

[0020] Figure 5 Combination Figure 1 The perspective view of the multi-wire cutting machine shows a schematic diagram of the components of a system according to another embodiment of the present invention;

[0021] Figure 6 This is a schematic diagram of a method according to an embodiment of the present invention. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0023] See Figure 1 and Figure 2 This invention provides a system 1 for inspecting contaminant particles PG in the wire groove 11A of the shaft 10A of a multi-wire cutting machine 1A, wherein, as in Figure 1 As shown in more detail, the multi-wire cutting machine 1A has at least two rotating shafts 10A, each rotating shaft 10A having a plurality of circumferentially extending wire grooves 11A formed on its outer peripheral surface. Cutting wires 20A are wound around the at least two rotating shafts 10A in such a manner that they lie within the plurality of wire grooves 11A to obtain corresponding plurality of cutting wire segments 21A between adjacent rotating shafts 10A, as shown in... Figure 1 As schematically shown by thick solid lines, and when there is no [something] in each groove 11A of the two adjacent rotating shafts 10A as in [something] Figure 2 The multiple cutting line segments 21A shown in the figure are in the same plane P and parallel to each other when the pollution particles PG are in the figure. Figure 1The plane P is schematically shown in the figure through a dashed box. Thus, when, for example, the at least two rotating shafts 10A rotate in the same direction, the plurality of cutting segments 21A will move, such that when, for example, a crystal ingot (not specifically shown in the figure) moves toward the plurality of cutting segments 21A in a direction perpendicular to plane P, the plurality of cutting segments 21A can cut the crystal ingot into multiple wafers. See [the figure for details]. Figure 2 The system 1 may include:

[0024] Light source 10, which is used to emit light beam B;

[0025] A light beam B illuminates a screen 20 to form a light spot S on the screen 20. The light beam B is blocked by the plurality of dicing segments 21A, resulting in the formation of a plurality of corresponding shadows SH within the light spot S. Figure 2 The example shows 6 cutting line segments and 6 corresponding shades;

[0026] The determination unit 30 is used to identify whether the plurality of shadows SH are parallel to each other, and when it is identified that the plurality of shadows SH are not parallel to each other, it determines that at least one wire groove 11A contains contaminant particles PG. Figure 2 As shown, the six shaded areas are not parallel to each other, so the grooves 11A of the two adjacent shafts 10A are contaminated by contaminant particles PG.

[0027] In the system 1 according to the present invention, the influence of contaminant particles PG on the orientation of the cutting wire segment 21A is utilized, and optical methods are used to determine whether there are contaminant particles PG in the wire groove 11A of the rotating shaft 10A of the multi-wire cutting machine 1A. The automated operation can be completed in a simple and convenient manner, avoiding the need for operators to check the wire groove one by one with the naked eye, thus reducing labor costs.

[0028] For system 1 according to the above embodiment of the present invention, it can be determined that there are contaminant particles PG in the wire groove 11A of the rotating shaft 10A. In this case, the rotating shaft 10A can be cleaned to remove the contaminant particles PG, thereby preventing wire skipping. However, the above cleaning needs to be done on the entire rotating shaft 10A, because it is impossible to determine which one or more wire grooves of the rotating shaft 10A contain contaminant particles PG. This leads to waste of cleaning fluid and high production costs for cleaning. Therefore, in the preferred embodiment of the present invention, see still Figure 2The system 1 may further include a determining unit 40, which is used to check the position of the non-parallel shadow SH' among the plurality of shadows SH, and determine the position of the trough 11A' containing the contaminant particle PG among the plurality of troughs 11A based on the checked position. For example, in Figure 2 In the 3D diagram shown, the third shading from top to bottom among the six shaded areas is a non-parallel shading SH'. Therefore, contaminant particles PG are present in the third groove from front to back among the six grooves 11A corresponding to the six cutting line segments 21A. This allows for the determination of the specific location of the groove 11A' containing contaminant particles PG within the plurality of grooves 11A. Consequently, cleaning can be performed only on the grooves 11A containing contaminant particles PG, eliminating the need to clean the other grooves 11A without contaminant particles PG. This saves cleaning fluid and the time potentially required for cleaning, reducing costs while improving production efficiency.

[0029] For situations where only contaminant particles PG can be determined in the groove 11A of the rotating shaft 10A, it is easy to understand that identifying whether the multiple shadows SH are parallel to each other is quite difficult, because it is necessary to determine the direction of extension of each shadow SH. In order to make this determination process simpler and easier, in the preferred embodiment of the present invention, see Figure 3 The light source 10 emits the light beam B parallel to the path as shown in the image. Figure 1 As shown in the diagram, the determination unit 30 can identify whether the plurality of shadows SH are parallel to each other by determining whether they overlap. That is, as in... Figure 3 As shown, the determination unit 30 can determine the number of shadows SH actually formed on the light screen 20. When the number of shadows SH actually formed is 1, the multiple shadows SH overlap or are parallel to each other, and it can be said that no groove 11A is contaminated by contamination particles PG. When the number of shadows SH actually formed is 2 or more, the multiple shadows SH do not overlap or are not parallel to each other, and it is certain that some grooves 11A are contaminated by contamination particles PG. It is understandable that it is easier to simply determine the number of shadows SH actually formed on the light screen 20 than to determine the direction of extension of each shadow SH.

[0030] In cases where it may be necessary to both easily determine whether cable tray 11A is contaminated by contaminating particles PG, and to identify which cable trays 11A are contaminated by contaminating particles PG, in a preferred embodiment of the present invention, see [reference needed]. Figure 4The light source 10 can be movably disposed in the system 1 to move between a first position in which the emitted light beam B is parallel to the plane P and a second position in which the emitted light beam B is not parallel to the plane P, such as in Figure 4 As specifically shown, the light source can rotate about pivot 60, and Figure 4 The image shows a light source 10 in a first position, in which case the light source 10 emits a beam B parallel to plane P, shown as a shaded area, and the light spot S formed by the beam B is shown in a solid-line box. For clarity, the light source 10 in a second position is not shown; instead, only the beam B emitted by the light source 10 in this case, shown as a dotted area, is shown, and the light spot S formed by the beam B is shown in a dashed-line box. Furthermore, the system 1 may also include a stop 50, which is configured to prevent the light source 10 from moving away from the second position when the light source 10 is in the first position, for example in… Figure 4 In the configuration shown, the light source 10 can rotate forward about the pivot 60 to be in a second orientation emitting a beam B that is not parallel to the plane P, while the stop 50 prevents the light source 10 from rotating backward about the pivot 60. In this way, the light source 10 can be moved to switch between the first and second orientations while being in the first orientation in a simple and convenient manner.

[0031] Regarding the manner in which the light source 10 moves, in a preferred embodiment of the present invention, as described above, the system 1 may further include a pivot 60 for hinged connection of the light source 10, such that the light source 10 is arranged in the system 1 in a manner that allows it to rotate about the pivot 60.

[0032] Regarding the aforementioned motion mode of the light source 10, see [link to relevant documentation]. Figure 4 It is understandable that if the cross-sectional area of ​​beam B is not large enough, when the light source 10 rotates, one or more of the plurality of cutting line segments 21A may not be illuminated by beam B, thus making it impossible to complete the inspection. In other words, for each cutting line segment 21A to be illuminated by beam B when the light source 10 rotates, the cross-sectional area of ​​beam B needs to be large enough. Therefore, the volume of the light source 10 emitting beam B also needs to be large enough, resulting in the need for a more expensive light source 10. In a preferred embodiment of the present invention, see... Figure 5 The system 1 may also include Figure 5 The slide rail 70 is schematically shown in the diagram. The slide rail 70 guides the light source 10, such that the light source 10 is positioned in the system 1 in a manner capable of moving along the slide rail 70. Figure 5The light source 10 at the first position is shown by a solid line, and the light source 10 moving from the first position to the second position along the slide rail 70 is shown by a dashed line. In this way, the inspection can be completed using a smaller and therefore less expensive light source 10, reducing production costs.

[0033] Preferably, the light screen 20 can be planar. This allows the determination unit 30 or the confirmation unit 40 to identify or verify the plurality of shadows SH in any direction, rather than having to identify or verify them in the direction in which the light beam B propagates.

[0034] It is readily understood that the system 1 according to an embodiment of the present invention may further include means for rotating the shaft, so that the inspection of the contaminant particle PG can be completed regardless of where the contaminant particle PG is located in the circumferential direction in the groove 11A.

[0035] See Figure 6 and combined Figure 1 and Figure 2 The present invention also provides a method for inspecting contaminant particles PG in the grooves 11A of the shafts 10A of a multi-wire cutting machine 1A, wherein the multi-wire cutting machine 1A has at least two shafts 10A, each shaft 10A having a plurality of circumferentially extending grooves 11A formed on its outer peripheral surface, and cutting wires 20A are wound around the at least two shafts 10A in such a manner that they are located in the plurality of grooves 11A to obtain a plurality of corresponding cutting wire segments 21A between adjacent shafts 10A, and when there are no contaminant particles PG in each groove 11A of the adjacent shafts 10A, the plurality of cutting wire segments 21A are in the same plane P and parallel to each other, the method may include:

[0036] S601: Emit beam B;

[0037] S602: A light spot S is formed in the light beam B, wherein the light beam B is blocked by the plurality of cutting line segments 21A, so that a plurality of shadows SH are formed in the light spot S;

[0038] S603: Identify whether the plurality of shadows SH are parallel to each other, and when it is identified that the plurality of shadows SH are not parallel to each other, determine that at least one wire groove 11A contains contaminant particles PG.

[0039] In a preferred embodiment of the present invention, combined with Figure 2 The method may further include checking the position of the non-parallel shadow SH' in the plurality of shadows SH, and determining the position of the groove 11A' containing the contaminant particle PG in the plurality of grooves 11A based on the checked position.

[0040] In a preferred embodiment of the present invention, combined with Figure 3 The light beam B is parallel to the plane P, and the parallelism of the multiple shadows SH can be determined by judging whether the multiple shadows SH overlap.

[0041] It should be noted that the technical solutions described in the embodiments of the present invention can be combined arbitrarily without conflict.

[0042] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention 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 the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A system for inspecting contaminating particles in the wire groove of a multi-wire cutting machine spindle, wherein, The multi-wire cutting machine has at least two rotating shafts, each shaft having a plurality of circumferentially extending grooves formed on its outer circumferential surface. Cutting wires are wound around the at least two rotating shafts in such a manner that they lie within the grooves to obtain a plurality of corresponding cutting wire segments between adjacent rotating shafts. The plurality of cutting wire segments are coplanar and parallel to each other when there are no contaminating particles in each groove of the adjacent rotating shafts. The system is characterized by comprising: A light source, which is used to emit a light beam; A light screen, wherein the light beam shines on the light screen to form a light spot on the light screen, wherein the light beam is blocked by the plurality of dicing segments so that the light spot forms a plurality of corresponding shadows; The determination unit is used to identify whether the plurality of shadows are parallel to each other, and when it is determined that the plurality of shadows are not parallel to each other, it determines that at least one wire groove contains contaminant particles. The system further includes a determining unit, which is used to check the position of non-parallel shadows among the plurality of shadows, and determine the position of the groove containing the contaminant particles among the plurality of grooves based on the checked position. The light source and the screen are respectively disposed on both sides of the plurality of cutting line segments. The light source emits a light beam parallel to the plane. The determination unit identifies whether the plurality of shadows are parallel to each other by judging whether the plurality of shadows overlap. The light source is movably disposed in the system to move between a first position in which the emitted light beam is parallel to the plane and a second position in which the emitted light beam is not parallel to the plane, and the system further includes a stop member configured to prevent the light source from moving away from the second position when the light source is in the first position.

2. The system for inspecting contaminant particles in the wire groove of the shaft of a multi-wire cutting machine according to claim 1, characterized in that, The system also includes a pivot for hinged connection of the light source, such that the light source is positioned in the system in a manner that allows it to rotate about the pivot.

3. The system for inspecting contaminant particles in the wire groove of the shaft of a multi-wire cutting machine according to claim 1, characterized in that, The system also includes a slide rail for guiding the light source, such that the light source is positioned in the system in a manner that allows it to move along the slide rail.

4. The system for inspecting contaminant particles in the wire groove of the spindle of a multi-wire cutting machine according to any one of claims 1 to 3, characterized in that, The light screen is planar.

5. A method for inspecting contaminant particles in the wire groove of a multi-wire cutting machine's spindle, characterized in that, The method is performed using the system for inspecting contaminant particles in the wire groove of the spindle of a multi-wire cutting machine according to claim 1, the method comprising: Switch the light source to the first position and use a stop to limit it, so that the light beam emitted by the light source is parallel to the plane; The light spot formed by the light beam is such that the light beam is blocked by the plurality of cleaving segments, resulting in the formation of a plurality of shadows in the light spot; The system identifies whether the multiple shadows overlap on the screen, and determines that at least one wire groove contains contaminant particles when the multiple shadows do not overlap. When the presence of polluting particles is detected, the light source is switched to a second position so that the beam emitted by the light source is not parallel to the plane. The position of the non-parallel shadows in the plurality of shadows is checked, and the position of the groove containing the contaminant particles in the plurality of grooves is determined based on the checked position.

Images