Scribing method and device and storage medium

Abstract

The invention provides a scribing method and device and a storage medium. The scribing method comprises the steps that the radius of a cutter, the maximum cutting depth of the cutter to a wafer and the target cutting groove length are obtained; the initial feeding speed of the cutter and the middle section scribing speed of the cutter are determined, and the middle section scribing speed is larger than the initial feeding speed; calculating the feed stroke of the cutter based on the radius of the cutter and the maximum cutting depth; based on the target grooving length and the feed stroke, calculating the middle stroke of the cutter; calculating acceleration based on the initial feed speed, the middle scribing speed and the feed stroke; the cutter is controlled to cut into the wafer at the initial feeding speed and the accelerated speed in an accelerated mode; the cutter is controlled to cut the wafer at the middle section scribing speed until the cutting stroke of the cutter reaches the middle section stroke; and controlling the cutter to cut the wafer at the middle section scribing speed and the accelerated speed. According to the scribing method, the scribing efficiency can be ensured, the scribing quality is also considered, and edge breakage caused during cutter feeding and cutter discharging is prevented.

Description

Technical Field

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

[0002] The dicing process is an important process in the actual production of semiconductor devices. The dicing process is implemented by a dicing machine, which includes components such as a spindle, a cutter, and a dicing table. The dicing process of the dicing machine is that the spindle drives the high-speed rotating cutter to descend and contact the wafer on the dicing table, and the spindle then drives the cutter to move close to the wafer along a predetermined dicing path, thereby cutting the wafer into a number of grains with predetermined sizes.

[0003] The resistance that the cutter receives during the dicing process is not the same. Specifically, the force on the cutter gradually increases as it enters the wafer. The force on the cutter gradually increases and decreases as it exits the wafer. The force on the cutter remains constant in the middle section of the wafer (i.e., the section between the entry section and the exit section).

[0004] In the existing dicing method, the cutter uses a fixed dicing speed throughout the dicing process, which makes it difficult to balance dicing efficiency and dicing quality. For example, if the dicing speed is set too high, the chip edge will break during the cutting process. If the dicing speed is set too low, the dicing efficiency will be too low. Summary of the invention

[0005] In order to solve the above technical problems, the present application provides a dicing method, which adopts the following technical solutions:

[0006] A dicing method, comprising:

[0007] Obtain the cutter radius, the maximum cutting depth of the cutter on the wafer, and the target cutting groove length;

[0008] Determine the initial feed speed of the cutter and the middle section scribing speed of the cutter, wherein the middle section scribing speed is greater than the initial feed speed;

[0009] Calculate the cutter's feed stroke based on the cutter radius and maximum cutting depth;

[0010] Calculate the middle stroke of the cutter based on the target grooving length and feed stroke;

[0011] Calculate the acceleration based on the initial feed speed, the mid-slice dicing speed and the feed stroke;

[0012] Control the cutter to cut into the wafer at an initial feed speed and acceleration;

[0013] Controlling the cutter to cut the wafer at the middle cutting speed until the cutting stroke of the cutter reaches the middle stroke;

[0014] The cutter is controlled to cut out the wafer at the mid-slicing speed and acceleration deceleration.

[0015] In some embodiments, the feed stroke of the cutter is calculated based on the cutter radius and the maximum cutting depth, according to the following formula: Among them, S is the feed stroke, R is the cutter radius, and d is the maximum cutting depth.

[0016] In some embodiments, based on the target groove length and the feed stroke, the middle stroke of the cutter is calculated according to the following formula: S1=L-2S, where S1 is the middle stroke, L is the target groove length, and S is the feed stroke.

[0017] In some embodiments, the acceleration a is calculated based on the initial feed speed, the middle dicing speed, and the feed stroke, according to the following formula: a=2t(V-V0)(2V0-V) 2 / 9S 2 , where a is the acceleration, V0 is the initial feed speed, V is the middle dicing speed, S is the feed stroke, and t is the time it takes for the cutter to enter the wafer.

[0018] In some embodiments, the acceleration is calculated based on the initial feed speed, the middle dicing speed, and the feed stroke, and is completed according to the following formula: a=(V 2 -V0 2 ) / 2S, where a is acceleration, V0 is initial feed speed, V is middle scribing speed, and S is feed stroke.

[0019] In some embodiments, before controlling the cutter to accelerate into the wafer at an initial feed speed and acceleration, the dicing method of the present application further includes: determining a reserved dicing stroke; controlling the cutter to move toward the wafer at the initial feed speed for the reserved dicing stroke.

[0020] In some embodiments, after controlling the cutter to cut out the wafer at a mid-slicing speed and acceleration deceleration, the dicing method of the present application further includes: controlling the cutter to move away from the wafer at an initial feed speed to reserve a dicing stroke.

[0021] The dicing method provided by the present application controls the cutter to start feeding at a relatively low initial feed speed. During the feed stage, the cutting speed of the cutter is steadily increased with acceleration. After the feed is completed, the cutting speed of the cutter reaches a relatively large middle-section cutting speed. Subsequently, the cutter maintains the middle-section cutting speed to complete the middle section of the wafer. During the exit stage, the cutting speed of the cutter is steadily reduced with acceleration. After the exit is completed, the cutting speed of the cutter is reduced to the initial feed speed.

[0022] The dicing method provided in the present application uses a low speed for dicing at the beginning of the knife feed, then steadily accelerates to a high speed, and uses a high and uniform speed for dicing after the knife force is stable. When the knife is removed, it is steadily decelerated from a high speed to the initial feed speed until the dicing is completed. In this way, the dicing efficiency can be ensured, while the dicing quality can be taken into account, and the edge collapse caused by the knife feed and knife removal can be prevented.

[0023] The present application also provides a dicing 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 dicing methods by loading and executing at least one program instruction.

[0024] 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 above-mentioned dicing methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the dicing process of the cutting knife in the embodiment of the present application;

[0026] Figure 2 This is a flowchart of the execution of the cutting method in the embodiment of the present application. DETAILED DESCRIPTION

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] The resistance the cutter receives during the cutting process is not the same. Specifically, the force on the cutter gradually increases as it cuts into the wafer, and if the cutter feeds in too fast, it can easily cause chipping of the wafer edge. The force on the cutter gradually increases and decreases as it cuts out of the wafer, and similarly, if the cutter exits too fast, it can easily cause chipping of the wafer edge. When the cutter is cutting the middle section of the wafer (i.e., the section between the feed section and the exit section), the force on the cutter is the greatest and remains constant, and there is no chipping of the wafer edge when the cutter is cutting the middle section of the wafer.

[0032] In view of the above rules, it is possible to consider controlling the cutter to cut into or out of the wafer at a lower speed, and to implement the cutting of the middle section of the wafer at a higher speed. During the cutting process, as the cutter continues to cut in, the force on the cutter gradually increases, and the risk of wafer edge collapse gradually decreases. Therefore, it is possible to consider gradually increasing the cutting speed, so that after the cutting is completed, the speed of the cutter increases to a higher middle section cutting speed. During the cutting process, as the cutter continues to cut out, the force on the cutter gradually decreases, and the risk of wafer edge collapse gradually increases. Therefore, it is possible to consider gradually reducing the cutting speed.

[0033] Based on the above considerations, the inventive concept of this application is as follows:

[0034] The cutter is controlled to start feeding at a preset lower initial feed speed V0. During the feed stage, the cutting speed of the cutter is steadily increased at an acceleration a. The feed stroke S during the feed stage can be determined according to the radius R of the cutter and the maximum cutting depth d of the cutter on the wafer.

[0035] After the cutting is completed (ie, the cutting depth of the cutter on the wafer reaches the maximum cutting depth d), the cutting speed of the cutter reaches a preset larger middle-section cutting speed V.

[0036] Then, the cutter maintains the middle-segment dicing speed V to complete the middle-segment dicing of the wafer, and the middle-segment length is S1. The middle-segment length is S1 = the length of the target cut groove L-the infeed stroke S-the outfeed stroke. Since the outfeed stroke is equal to the infeed stroke S, therefore, S1 = L-2S.

[0037] In the knife exit stage, the cutting speed of the cutter decreases steadily at an acceleration a (which is exactly the opposite of the speed change in the knife entry stage). After the knife exit is completed (i.e., the cutter is separated from the wafer), the cutting speed of the cutter decreases to the initial knife entry speed V0. In addition, the knife exit stroke in the knife exit stage is equal to the knife entry stroke S.

[0038] The above-mentioned initial feed speed V0 and mid-section scribing speed V are pre-set values ​​according to the material of the wafer and the scribing requirements. Therefore, the key to this application is to determine the acceleration a.

[0039] Acceleration a setting strategy 1:

[0040] In order to make the speed control process simpler, the acceleration a is set to a constant value, that is, the feed process is a uniform acceleration process, and the exit process is a uniform deceleration process.

[0041] In this case, acceleration a=(V 2 -V0 2 ) / 2S, where a is acceleration, V0 is initial feed speed, V is middle scribing speed, and S is feed stroke.

[0042] Acceleration a setting strategy 2:

[0043] As those skilled in the art know, as the cutter cuts into the wafer, the force applied to it does not increase along a straight line, but along a curve. Therefore, setting the acceleration a to a non-constant value can improve the dicing quality and efficiency. The following will deduce the setting process of the acceleration a in detail.

[0044] The acceleration a increases with the time it takes for the cutter to enter the wafer. The acceleration a can be represented by a=At+B, where: t is the time it takes for the cutter to enter the wafer, and A and B are constants to be determined.

[0045] When t=0, the cutter has just touched the wafer and has not yet started to accelerate, the acceleration a=0, and therefore B=0, that is, the acceleration a can ultimately be represented as a=At.

[0046] Due to variable acceleration, the velocity is the integral of the acceleration over time:

[0047]

[0048] When t=0, the cutter just touches the wafer and the speed of the cutter is V0, so it can be deduced that C=V0.

[0049] Therefore, we can get formula (1):

[0050] In the feeding stage, the cutter stroke S is the integral of the speed over time:

[0051]

[0052] When t=0, the cutter just touches the wafer, S=0, so it can be deduced that D=0.

[0053] Therefore, we get formula (2):

[0054] In addition, if Figure 1 As shown, the radius R of the cutter, the half-stroke of the feed stroke S / 2, the difference between the radius R of the cutter and the maximum cutting depth d satisfies the Pythagorean theorem, that is: (S / 2) 2 =R 2 -(Rd) 2 , so we can get,

[0055] Finally, solving the equations formed by the above formula (1) and formula (2), we can obtain: A = 2(V-V0)(2V0-V) 2 / 9S 2 .

[0056] Substituting A into the acceleration formula a=At, the acceleration a of the cutter is obtained as:

[0057] a=2t(V-V0)(2V0-V) 2 / 9S 2 , where: t is the acceleration time, V is the middle section scribing speed, V0 is the initial feed speed, and S is the feed stroke S of the cutter.

[0058] Based on the above invention concept, the present invention finally proposes a dicing method. Figure 1 and Figure 2 As shown, the dicing method in the embodiment of the present invention includes the following steps:

[0059] Step 101 , obtaining a cutter radius R, a maximum cutting depth d of the cutter on the wafer, and a target cutting groove length L.

[0060] The cutter radius R and the target groove length L are both fixed values ​​obtained through measurement, and the maximum cutting depth d of the cutter on the wafer is a predetermined value based on the wafer thickness and cutting requirements.

[0061] Step 102, determining an initial feed speed V0 of the cutter and a middle section scribing speed V of the cutter, wherein the middle section scribing speed V is greater than the initial feed speed V0.

[0062] The initial feed speed V0 and the mid-section scribing speed V are set according to the material of the wafer and the scribing requirements, and are generally empirical values.

[0063] Step 103: Calculate the cutter feed stroke S based on the cutter radius R and the maximum cutting depth d.

[0064] As described above,

[0065] Step 104 : Based on the target grooving length L and the feed stroke S, calculate the middle stroke S1 of the cutter.

[0066] As described above, S1=L-2S.

[0067] Step 105 , calculating the acceleration a based on the initial feed speed V0 , the middle scribing speed V and the feed stroke S.

[0068] Optionally, the acceleration a is set to a constant value, that is, the process of cutting in is a uniform acceleration process, and the process of cutting out is a uniform deceleration process. Acceleration a = (V 2 -V0 2 ) / 2S.

[0069] Optionally, the acceleration a is set to a non-constant changing value, acceleration a = 2t(V-V0)(2V0-V) 2 / 9S 2 .

[0070] Step 106 , controlling the cutter to accelerate into the wafer at an initial feed speed V0 and an acceleration a.

[0071] After the acceleration is completed, the speed of the cutter reaches the mid-section dicing speed V, and the cutting depth of the cutter reaches the maximum cutting depth d.

[0072] Step 107 , controlling the cutter to cut the wafer at the middle cutting speed V until the cutting stroke of the cutter reaches the middle stroke S1 .

[0073] Step 108 , controlling the cutter to decelerate and cut out the wafer at a mid-slicing speed V and an acceleration a.

[0074] Since the speed changes in the knife exit stage and the knife entry stage in step 105 are exactly opposite, the speed of the cutter after leaving the wafer just drops to the initial knife entry speed V 0。

[0075] The dicing method provided in the embodiment of the present application first controls the cutter to start feeding at a relatively low initial feed speed. During the feed stage, the cutting speed of the cutter is steadily increased at a preset acceleration. After the feed is completed, the cutting speed of the cutter reaches a relatively large middle-section cutting speed. Subsequently, the cutter maintains the middle-section cutting speed to complete the middle-section cutting of the wafer. During the exit stage, the cutting speed of the cutter is steadily reduced at a preset acceleration. After the exit is completed, the cutting speed of the cutter is reduced to the initial feed speed.

[0076] It can be seen that the dicing method provided in the embodiment of the present application uses a low speed for dicing at the beginning of the knife feed, then steadily accelerates to a high speed, and uses a high and uniform speed for dicing after the knife force is stable. When the knife is removed, it is steadily decelerated from the high speed to the initial feed speed until the dicing is completed. In this way, the dicing efficiency can be ensured, and the dicing quality can be taken into account, and the edge collapse caused by the knife feed and the knife exit can be prevented.

[0077] Optionally, before controlling the cutter to accelerate into the wafer at the initial feed speed V0 and the acceleration a in step 105, the dicing method of the embodiment of the present application further includes:

[0078] A reserved dicing stroke S0 is determined, and the cutter is controlled to move toward the wafer at a uniform speed of the reserved dicing stroke S at an initial feed speed V0, so that the cutter contacts the wafer.

[0079] By setting the reserved dicing stroke S0, it is possible to avoid the blade from being directly brought down onto the workpiece and causing impact damage to the blade. In addition, the blue film supporting the wafer can also be diced.

[0080] Similarly, optionally, after controlling the cutter to decelerate at the mid-slicing speed V and acceleration a to cut out the wafer in step 107, the dicing method of the embodiment of the present application further includes: controlling the cutter to move away from the wafer at an initial feed speed V0 to reserve a dicing stroke S0.

[0081] An embodiment of the present application also provides a dicing device, which includes a memory and a processor, wherein the memory stores at least one program instruction, and the processor implements the dicing method in any of the above embodiments by loading and executing at least one program instruction.

[0082] An embodiment of the present application further 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 dicing method in any of the above embodiments.

[0083] 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 dicing method, characterized in that: The dicing method comprises: Obtain the cutter radius, the maximum cutting depth of the cutter on the wafer, and the target cutting length; Determine an initial feed speed of the cutter and a middle-segment scribing speed of the cutter, wherein the middle-segment scribing speed is greater than the initial feed speed; Calculating the feed stroke of the cutter based on the cutter radius and the maximum cutting depth; Calculating the middle stroke of the cutter based on the target groove length and the feed stroke; Calculating acceleration based on the initial feed speed, the middle scribing speed and the feed stroke; Controlling the cutter to cut into the wafer at the initial feed speed and the acceleration; Controlling the cutter to cut the wafer at the middle-stage cutting speed until the cutting stroke of the cutter reaches the middle-stage stroke; The cutting blade is controlled to cut out the wafer at the middle dicing speed and the acceleration deceleration.

2. The dicing method according to claim 1, wherein: The calculation of the cutter feed stroke based on the cutter radius and the maximum cutting depth is completed according to the following formula: Among them, S is the feed stroke, R is the cutter radius, and d is the maximum cutting depth.

3. The dicing method according to claim 1, wherein: The calculation of the middle stroke of the cutter based on the target groove length and the feed stroke is completed according to the following formula: S1=L-2S, Among them, S1 is the middle stroke, L is the target groove length, and S is the feed stroke.

4. The dicing method according to claim 2, wherein: The acceleration is calculated based on the initial feed speed, the middle dicing speed and the feed stroke, and is completed according to the following formula: a=2t(V-V0)(2V0-V) 2 / 9S 2 , Among them, a is the acceleration, V0 is the initial feed speed, V is the middle dicing speed, S is the feed stroke, and t is the time it takes for the cutter to enter the wafer.

5. The dicing method according to claim 2, wherein: The acceleration is calculated based on the initial feed speed, the middle dicing speed and the feed stroke, and is completed according to the following formula: a=(V 2 -V0 2 ) / 2S, Among them, a is the acceleration, V0 is the initial feed speed, V is the middle section scribing speed, and S is the feed stroke.

6. The dicing method according to claim 1, wherein: Before controlling the cutter to accelerate into the wafer at the initial feed speed and the acceleration, the dicing method further includes: Determine the reserved dicing stroke; The cutting knife is controlled to move toward the wafer at the initial cutting speed to the reserved dicing stroke.

7. The dicing method according to claim 6, wherein: After controlling the cutter to decelerate and cut out the wafer at the middle-segment dicing speed and acceleration, the dicing method further includes: The cutting knife is controlled to move the reserved dicing stroke away from the wafer at the initial cutting speed.

8. A dicing device, characterized in that: The dicing device includes a memory and a processor, wherein the memory stores at least one program instruction, and the processor implements the dicing method according to any one of claims 1 to 7 by loading and executing the at least one program instruction.

9. 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 dicing method according to any one of claims 1 to 7.

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