Wafer girdling method, wafer girdling equipment and storage medium

Abstract

The invention provides a wafer girdling method, wafer girdling equipment and a storage medium. The wafer girdling method comprises the following steps: acquiring a wafer radius, a girdling length and a workbench circle center coordinate; placing the wafer on a workbench, and determining a first circle center coordinate of the wafer; determining a cutting position of a cutter based on the wafer radius, the girdling length, the center coordinate of the workbench and the first center coordinate; controlling the cutter to abut against the wafer according to the cutting position of the cutter; ring cutting is carried out, the position of the cutter is corrected every preset time in the ring cutting process, and the correction comprises the steps of determining a second circle center coordinate of the wafer; based on the wafer radius, the girdling length, the workbench circle center coordinate and the second circle center coordinate, the correction position of the cutter is determined; and the cutter is controlled to move to the correction position. According to the wafer girdling method and device, in the wafer girdling process, the position of the cutter is corrected, so that the distance between the cutter and the circle center of the wafer is equal to the difference value between the radius of the wafer and the girdling length, and it is ensured that the circular wafer is cut out.

Description

Technical Field

[0001] The present application relates to the field of semiconductor device production, and specifically to a wafer ring cutting method, device and storage medium. Background Art

[0002] As electronic devices develop towards miniaturization, multifunctionality and intelligence, the space for integrated circuit packaging devices on the xy plane becomes limited or even scarce. Therefore, advanced packaging focuses on the third dimension (z-axis), which can not only reduce the package volume but also improve circuit performance. Based on this advantage, a variety of vertical packaging technologies have emerged, such as chip stacking (PiP), package stacking (POP), multi-chip package (MCP) and system-in-package (SIP).

[0003] With the advancement of packaging technology, related processes are also developing towards the upstream wafer process field, and packaging processes are directly implemented on wafers, such as Bumping, TSV, Fan-out, Fan-in, Chiplet and other technologies. However, no matter which process is used, chip thinning is a necessary link.

[0004] Since the edge of the wafer is curved, when it is thinned to an ultra-thin wafer, edge fragmentation leading to wafer breakage is one of the key issues in ultra-thin processing. Therefore, the ring cutting process is very necessary, which can effectively remove the circular shape of the outer edge of the wafer, thereby stabilizing the edge of the wafer, preventing the wafer from breaking, and meeting more precise thinning processes and yields.

[0005] The wafer ring cutting method is to fix the wafer on the rotating table, adjust the position of the cutter, control the cutter to press the edge of the wafer, then control the rotating table to rotate and start the cutter. When the wafer rotates with the rotating table, the high-speed rotating cutter cuts off the outer edge of the wafer.

[0006] However, when placing the wafer to be cut in a circular shape on the rotating table, there will inevitably be a certain deviation between the center of the wafer and the center of the rotating table. During the circular cutting process, if the cutter is always kept in the same position, the distance between the cutter and the center of the wafer will continue to change, and ultimately it will be impossible to cut a qualified circular wafer. Summary of the invention

[0007] In order to solve the above technical problems, the present application provides a wafer ring cutting method, which adopts the following technical solutions:

[0008] A wafer ring cutting method, comprising:

[0009] Obtain the wafer radius, circular cutting length and workbench center coordinates;

[0010] Placing the wafer on a workbench and positioning the wafer to determine the first center coordinate of the wafer;

[0011] Determine the cutting position of the cutting knife based on the wafer radius, the circular cutting length, the coordinates of the center of the worktable and the coordinates of the first center of the worktable;

[0012] According to the lowering position of the cutter, the cutter is controlled to abut against the wafer so that the distance between the cutter and the center of the wafer is equal to the difference between the wafer radius and the circular cutting length;

[0013] Start the workbench and cutter to perform circular cutting;

[0014] During the circular cutting process, the position of the cutter is corrected at predetermined intervals so that the distance between the cutter and the center of the wafer is equal to the difference between the wafer radius and the circular cutting length.

[0015] The wafer ring cutting method provided in the present application continuously corrects the position of the cutter during the ring cutting process of the wafer, so that the distance between the cutter and the center of the wafer is equal to the difference between the wafer radius and the ring cutting length, ultimately ensuring that a circular qualified wafer is cut out.

[0016] In some embodiments, the position correction includes:

[0017] Positioning the wafer to determine the second center coordinate of the wafer;

[0018] Determine the corrected position of the cutter based on the wafer radius, the circular cutting length, the worktable center coordinates and the second center coordinates;

[0019] Control the cutter to move to the correction position.

[0020] In some embodiments, positioning the wafer includes: acquiring an image of the wafer; identifying an edge of the wafer using an edge recognition algorithm; and determining a first center coordinate or a second center coordinate of the wafer based on the identified edge of the wafer and the wafer radius.

[0021] In some embodiments, based on the wafer radius, the circular cutting length, the worktable center coordinates and the first center coordinates, determining the cutting position of the cutting knife includes: calculating the first deviation distance and the first deviation angle of the wafer according to the worktable center coordinates and the first center coordinates; calculating the first target distance between the cutting knife and the worktable center according to the first deviation distance, the first deviation angle, the wafer radius and the circular cutting length; and determining the cutting position of the cutting knife according to the first target distance.

[0022] In some embodiments, the first target distance between the cutter and the center of the worktable is calculated according to the first deviation distance, the first deviation angle, the wafer radius, and the circular cutting length, and is completed according to the following formula:

[0023]

[0024] Wherein: S1 is the first target distance between the cutter and the center of the worktable, M1 is the first deviation distance, a1 is the first deviation angle, R is the wafer radius, and L is the circular cutting length.

[0025] In some embodiments, determining the corrected position of the cutter based on the wafer radius, the circular cutting length, the worktable center coordinates and the second center coordinates includes:

[0026] Calculate the second deviation distance and the second deviation angle of the wafer according to the workbench center coordinates and the second center coordinates;

[0027] Calculate the second target distance between the cutter and the center of the worktable according to the second deviation distance, the second deviation angle, the wafer radius, and the circular cutting length;

[0028] The corrected position of the cutter is determined according to the second target distance.

[0029] In some embodiments, the second target distance between the cutter and the center of the worktable is calculated according to the second deviation distance, the second deviation angle, the wafer radius, and the circular cutting length, and is completed according to the following formula:

[0030]

[0031] Wherein: S2 is the second target distance between the cutter and the center of the worktable, M2 is the second deviation distance, a2 is the second deviation angle, R is the wafer radius, and L is the circular cutting length.

[0032] In some embodiments, after placing the wafer on the workbench, the wafer ring cutting method further includes: pre-aligning the wafer using a pre-alignment mechanism.

[0033] The present application also provides a wafer ring cutting device, which includes a memory and a processor, wherein the memory stores at least one program instruction, and the processor implements any of the above-mentioned wafer ring cutting methods by loading and executing at least one program instruction.

[0034] The present application also provides a computer storage medium, in which at least one program instruction is stored, and the at least one program instruction is loaded and executed by a processor to implement any of the wafer ring cutting methods described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Schematic diagram of the circular cutting principle of the cutter in the embodiment of the present application;

[0036] Figure 2 This is a flowchart of the execution of the wafer ring cutting method in an embodiment of the present application. DETAILED DESCRIPTION

[0037] The technical solution of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0038] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0039] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0041] like Figure 1 As shown, as known to those skilled in the art, in order to facilitate the alignment of the wafer, before wafer ring cutting is performed, a rectangular coordinate system XOY is generally established with the center O of the workbench (which is also the rotation center of the workbench) as the origin.

[0042] Before the wafer is ring cut, the wafer 100 is first placed on a workbench, and the center A of the wafer 100 is aligned with the center O of the workbench as much as possible, and the workbench is controlled to adsorb the wafer 100 .

[0043] Then, the cutter is controlled to move along the Y axis so that the distance between the position B of the cutter and the center A of the wafer 100 is equal to the difference between the radius R of the wafer and the circular cutting length L.

[0044] Next, the workbench is controlled to rotate and the cutter is controlled to rotate at high speed. If the center A of the wafer 100 is completely aligned with the center O of the workbench, after the circular cutting, the circular area of ​​the wafer edge with a length of L will be cut off, thereby obtaining a qualified wafer with a radius of RL.

[0045] However, if Figure 1 As shown, when the wafer 100 is placed on the workbench, it is impossible to completely align the center A of the wafer 100 with the center O of the workbench, and there must be a positional deviation between the two. Figure 1 As shown, there is a deviation distance M and a deviation angle a between the center A of the wafer 100 and the center O of the worktable, and the deviation distance M and the deviation angle a change continuously with the rotation of the wafer. Therefore, during the ring cutting process, if the position of the cutter is always kept at B, the distance between the cutter and the center A of the wafer 100 will inevitably change continuously, so that a qualified wafer with a radius of RL cannot be obtained.

[0046] Therefore, during the ring cutting process of the wafer, it is necessary to correct the position of the cutter according to the actual position of the center A of the wafer 100 to ensure that the distance between the cutter and the center A of the wafer 100 remains RL.

[0047] Please continue to refer to Figure 1 As shown, the foot of the perpendicular from the center A of the wafer 100 to the Y axis is D.

[0048] The distance OB between the center O of the worktable and the cutter position B is OD=OD+DB. Furthermore, OD=Msina.

[0049]

[0050] therefore,

[0051] The wafer radius R and the ring cutting length L are both known values. Therefore, during the ring cutting process, if the deviation distance M and the deviation angle a between the center A of the wafer 100 and the center O of the worktable can be obtained, the position B of the cutter can be corrected to ensure that the distance between the cutter and the center A of the wafer 100 remains RL.

[0052] Based on the above invention concept, the present invention finally proposes a wafer ring cutting method. Figure 1 As shown, the wafer ring cutting method in the embodiment of the present invention includes the following steps:

[0053] Step 101, obtaining the coordinates of the wafer radius R, the circular cutting length L and the center O of the workbench.

[0054] Among them, the wafer radius R is a fixed value that can be obtained through measurement, the ring cutting length L is a preset value required by the ring cutting process, and the coordinates of the center O of the worktable are the coordinates of the origin of the pre-established rectangular coordinate system XOY.

[0055] Step 102 : placing the wafer 100 on a workbench and positioning the wafer to determine the first center coordinates of the wafer 100 .

[0056] The first center coordinate is the coordinate of the initial position of the center A of the wafer.

[0057] Step 103 : Determine the cutting position of the cutter based on the wafer radius R, the circular cutting length L, the coordinates of the center of the worktable O and the first center coordinates.

[0058] Step 104 , according to the lower cutting position of the cutter, control the cutter to abut against the wafer, so that the distance between the cutter and the center A of the wafer 100 is equal to the difference between the wafer radius R and the circular cutting length L.

[0059] That is, the cutter is controlled to move along the Y axis until it reaches the lowering position, and then the cutter is controlled to descend and abut against the wafer, so as to ensure that the distance between the cutter and the center O of the worktable is equal to the difference between the wafer radius R and the circular cutting length L.

[0060] Step 105, start the workbench and the cutter to perform circular cutting.

[0061] The speed of the workbench and the rotation speed of the cutter can be set according to specific needs. The cutter is generally installed on the spindle, which controls the high-speed rotation of the cutter.

[0062] Step 106 , during the circular cutting process, the position of the cutter is corrected at predetermined intervals so that the distance between the cutter and the center A of the wafer 100 is equal to the difference between the wafer radius R and the circular cutting length L.

[0063] Optionally, the position correction process includes:

[0064] Step 1061: Position the wafer to determine the second center coordinates of the wafer.

[0065] The second center coordinates are the coordinates of the current position of the center A of the wafer 100 .

[0066] Step 1062: Determine the corrected position of the cutter based on the wafer radius R, the circular cutting length L, the coordinates of the worktable center O and the second center coordinates.

[0067] Step 1063: Control the cutter to move to the correction position so that the distance between the cutter and the center A of the wafer 100 is equal to the difference between the wafer radius R and the circular cutting length L.

[0068] That is, the cutter is controlled to move from the current position along the Y axis to the correction position. In this way, it can be ensured that the distance between the cutter and the center O of the worktable is restored to be equal to the difference between the wafer radius R and the circular cutting length L.

[0069] It should be noted that during the ring cutting process, the time interval between two adjacent corrections (i.e., the predetermined time) can be specifically set according to factors such as the rotation speed of the turntable, the size of the wafer, and the ring cutting accuracy requirements. Of course, the shorter the predetermined time is set, the higher the ring cutting accuracy, that is, the rounder the wafer obtained after ring cutting.

[0070] The wafer ring cutting method provided in the embodiment of the present application continuously corrects the position of the cutter during the ring cutting process of the wafer, so that the distance between the cutter and the center of the wafer is equal to the difference between the wafer radius R and the ring cutting length L, ultimately ensuring that a circular qualified wafer is cut out.

[0071] Optionally, the implementation process of step 102 is:

[0072] First, a camera disposed above a workbench is used to acquire an image of the wafer 100. In order to align the camera coordinates with a pre-established rectangular coordinate system XOY, optionally, the imaging axis of the camera is perpendicular to the workbench and passes through the center O of the workbench.

[0073] Next, an edge recognition algorithm is used to identify the circular edge of the wafer. Edge recognition is a mature technology commonly used in the field of image processing. Common edge recognition algorithms include Canny algorithm, Sobel algorithm, grayscale histogram-based algorithm, etc. In the embodiment of the present application, a suitable edge recognition algorithm can be selected as needed to identify the edge of the wafer.

[0074] Finally, the first center coordinates of the wafer are determined based on the identified circular edge of the wafer and the wafer radius R. The first center coordinates are the coordinates of the initial position of the center A of the wafer.

[0075] The specific process of determining the coordinates of the second center of the wafer in step 1061 is the same as that in step 102 and will not be repeated in this specification.

[0076] Optionally, the specific implementation process of step 103 is:

[0077] First, according to the coordinates of the center O of the worktable and the coordinates of the first center, the first deviation distance M1 and the first deviation angle a1 of the wafer 100 are calculated. The first deviation distance M1 is the distance deviation of the initial position of the center A of the wafer relative to the center O of the worktable, and the first deviation angle a1 is the angle deviation of the initial position of the center A of the wafer relative to the center O of the worktable.

[0078] Next, the first target distance between the cutter and the center of the table O is calculated according to the first deviation distance M1, the first deviation angle a1, the wafer radius R, and the circular cutting length L. According to the above-mentioned inventive concept, the first target distance can be calculated and obtained according to the following formula:

[0079]

[0080] Wherein: S1 is the first target distance between the cutter and the center of the worktable, M1 is the first deviation distance, a1 is the first deviation angle, R is the wafer radius, and L is the circular cutting length.

[0081] Finally, the cutting position of the cutter is determined according to the first target distance S1.

[0082] After determining the cutting position, the cutter is controlled to move along the Y axis until the distance between the cutter and the center O of the worktable is the first target distance S1, and then the cutter is controlled to descend and abut against the wafer, ensuring that the distance between the cutter and the center O of the worktable is equal to the difference between the wafer radius R and the circular cutting length L.

[0083] Optionally, the implementation process of step 1062 is:

[0084] First, according to the coordinates of the center O of the worktable and the coordinates of the second center, the second deviation distance M2 and the second deviation angle a2 of the wafer 100 are calculated. The second deviation distance M2 is the distance deviation of the current position of the center A of the wafer relative to the center O of the worktable, and the second deviation angle a2 is the angle deviation of the current position of the center A of the wafer relative to the center O of the worktable.

[0085] Next, the second target distance between the cutter and the center of the table O is calculated according to the second deviation distance M2, the second deviation angle a2, the wafer radius R, and the ring cutting length L. According to the above-mentioned inventive concept, the second target distance can be calculated and obtained according to the following formula:

[0086]

[0087] Wherein: S2 is the second target distance between the cutter and the center of the worktable, M2 is the second deviation distance, a2 is the second deviation angle, R is the wafer radius, and L is the circular cutting length.

[0088] Finally, the corrected position of the cutter is determined according to the second target distance S2.

[0089] After the correction position is determined, the cutter is controlled to move from the current position along the Y axis to the correction position, so that the distance between the cutter and the center of the table O is the second target distance S2. In this way, it can be ensured that the distance between the cutter and the center of the table O is restored to be equal to the difference between the wafer radius R and the circular cutting length L.

[0090] Optionally, after placing the wafer on the workbench, the wafer ring cutting method in the embodiment of the present application further includes:

[0091] A pre-alignment mechanism is used to pre-align the wafer.

[0092] By pre-aligning the wafer, the center A of the wafer can be aligned with the center O of the workbench as closely as possible.

[0093] An embodiment of the present application also provides a wafer ring cutting device, which includes a memory and a processor, wherein the memory stores at least one program instruction, and the processor implements the wafer ring cutting method in any of the above embodiments by loading and executing at least one program instruction.

[0094] An embodiment of the present application also provides a computer storage medium, in which at least one program instruction is stored, and the at least one program instruction is loaded and executed by a processor to implement the wafer ring cutting method in any of the above embodiments.

[0095] The present application is described in sufficient detail above with certain particularity. It should be understood by those skilled in the art that the description in the embodiments is merely exemplary, and all changes made without departing from the true spirit and scope of the present application should fall within the scope of protection of the present application. The scope of protection claimed in the present application is defined by the claims, rather than by the above description in the embodiments.

Claims

1. A wafer ring cutting method, characterized in that: The wafer ring cutting method comprises: Obtain the wafer radius, circular cutting length and workbench center coordinates; Placing the wafer on a workbench and positioning the wafer to determine the first center coordinate of the wafer; Determining a cutting position of a cutting knife based on the wafer radius, the circular cutting length, the center coordinates of the worktable and the first center coordinates; According to the lowering position of the cutter, the cutter is controlled to abut against the wafer so that the distance between the cutter and the center of the wafer is equal to the difference between the radius of the wafer and the circular cutting length; Start the workbench and cutter to perform circular cutting; During the circular cutting process, the position of the cutter is corrected at predetermined intervals so that the distance between the cutter and the center of the wafer is equal to the difference between the wafer radius and the circular cutting length.

2. The wafer ring cutting method according to claim 1, characterized in that: The position correction includes: Positioning the wafer to determine the second center coordinate of the wafer; Determining a corrected position of a cutter based on the wafer radius, the circular cutting length, the worktable center coordinates and the second center coordinates; Control the cutter to move to the correction position.

3. The wafer ring cutting method according to claim 1, characterized in that: Positioning the wafer includes: Acquire an image of the wafer; The edge recognition algorithm is used to identify the edge of the wafer; Based on the identified edge of the wafer and the wafer radius, the first center coordinates or the second center coordinates of the wafer are determined.

4. The wafer ring cutting method according to claim 1, characterized in that: The step of determining the cutting position of the cutting knife based on the wafer radius, the circular cutting length, the center coordinates of the worktable and the first center coordinates includes: Calculating a first deviation distance and a first deviation angle of the wafer according to the workbench center coordinates and the first center coordinates; Calculating a first target distance between a cutting knife and a center of a worktable according to the first deviation distance, the first deviation angle, the wafer radius, and the circular cutting length; The lowering position of the cutter is determined according to the first target distance.

5. The wafer ring cutting method according to claim 4, characterized in that: The first target distance between the cutter and the center of the worktable is calculated according to the first deviation distance, the first deviation angle, the wafer radius, and the circular cutting length, and is completed according to the following formula: Wherein: S1 is the first target distance between the cutter and the center of the worktable, M1 is the first deviation distance, a1 is the first deviation angle, R is the wafer radius, and L is the circular cutting length.

6. The wafer ring cutting method according to claim 1, characterized in that: The method of determining the corrected position of the cutter based on the wafer radius, the circular cutting length, the worktable center coordinates and the second center coordinates includes: Calculating a second deviation distance and a second deviation angle of the wafer according to the workbench center coordinates and the second center coordinates; Calculating a second target distance between the cutting knife and the center of the workbench according to the second deviation distance, the second deviation angle, the wafer radius, and the circular cutting length; The corrected position of the cutter is determined according to the second target distance.

7. The wafer ring cutting method according to claim 6, characterized in that: The second target distance between the cutter and the center of the worktable is calculated according to the second deviation distance, the second deviation angle, the wafer radius, and the circular cutting length, and is completed according to the following formula: Wherein: S2 is the second target distance between the cutter and the center of the worktable, M2 is the second deviation distance, a2 is the second deviation angle, R is the wafer radius, and L is the circular cutting length.

8. The wafer ring cutting method according to claim 1, characterized in that: After placing the wafer on the workbench, the wafer ring cutting method further comprises: A pre-alignment mechanism is used to pre-align the wafer.

9. A wafer ring cutting device, characterized in that: The wafer ring cutting device includes a memory and a processor, wherein the memory stores at least one program instruction, and the processor implements the wafer ring cutting method as described in any one of claims 1 to 8 by loading and executing the at least one program instruction.

10. A computer storage medium, characterized in that: The computer storage medium stores at least one program instruction, and the at least one program instruction is loaded and executed by the processor to implement the wafer ring cutting method as described in any one of claims 1 to 8.

Images