Wafer cutting method and wafer

Abstract

The present application provides a wafer cutting method and wafer, the cutting method comprises: in the material lifting step, the first material lifting process is carried out, and the first material lifting process comprises: along the first direction, the cutting line network is applied by the force from its outer side to the middle, and is inclined to the material lifting direction, the first direction is parallel to the axis direction of line roller;The first material lifting process comprises: the first spraying process is carried out to the cutting line network, and the spraying medium is applied to the cutting line network by the force.The present application realizes the correction target wafer's inclined posture by applying the above-mentioned force to the cutting line network, widens the wedge-shaped gap, and then effectively alleviates the degree of cutting line being clamped and dragged by two side wafers, reduces the line bow amplitude, reduces the breakage rate, avoids the cutting line to the same part of wafer produces unexpected grinding, reduces wafer surface scratch, and improves product quality.

Description

Technical Field

[0001] This invention relates to the field of semiconductor processing technology, and in particular to a wafer cutting method and a wafer. Background Technology

[0002] Wafer dicing machines are commonly used equipment in the photovoltaic and semiconductor material processing fields. They cut crystals into thin wafers through the high-speed reciprocating motion of a dicing wire. According to conventional processes, thicker wafers are reserved at both ends of the crystal as sacrificial layers, while the thinner wafers in the middle are the normal products.

[0003] As attached Figure 2 As shown, during the actual cutting process, influenced by factors such as the distribution of the cutting fluid flow field and the stress state of the wire saw, the wafer tends to tilt outward along the crystal axis, and the tilt is more pronounced closer to the two ends. The thicker wafers at both ends of the crystal are relatively stable and less prone to tilting, while the thinner wafer adjacent to the thicker wafer tilts the most severely: its top end remains bonded and fixed to the feed seat, but it tilts outward as a whole, and its bottom end moves closer to the thicker wafer side, thus forming a wedge-shaped gap that is wider at the top and narrower at the bottom. During subsequent feeding, the wire mesh height remains constant while the crystal continues to rise. The narrower part of the wedge-shaped gap gradually contacts the cutting wire. At this time, the thin and thick wafers simultaneously clamp the cutting wire and pull it up with the crystal, causing the cutting wire inside the crystal to arch upward, forming a wire bow, which is very easy to break.

[0004] Meanwhile, because the thin and thick wafers rise together with the dicing line, compared to the ideal working condition (i.e., the thin wafer is not tilted), in actual working conditions: along the feeding direction, the surface of the tilted thin wafer provides significant support to the dicing line, resulting in a significantly longer contact time between the same part of the wafer and the dicing line. Since the dicing line itself is still in a continuous routing state, it will produce an unexpected grinding effect at that location, causing scratches on the wafer surface and reducing product quality. Summary of the Invention

[0005] The purpose of this invention is to provide a wafer cutting method and a wafer, thereby overcoming the shortcomings in the aforementioned background art.

[0006] The technical solution of the present invention is: a wafer cutting method, the method comprising: performing a first material lifting process in a material lifting step, the first material lifting process comprising: applying a force to the cutting wire mesh along a first direction, the force pointing from the outside to the middle and inclined toward the material lifting direction, the first direction being parallel to the axial direction of the wire roller.

[0007] In some feasible technical solutions, the first material feeding process includes: performing a first spraying process on the cutting wire mesh, so that the spraying medium applies a force to the cutting wire mesh.

[0008] In some feasible technical solutions, the cutting wire mesh includes a first cutting segment, the first cutting segment being located at both ends of the cutting wire mesh along the first direction, and the first spraying process includes: applying a force A toward the first cutting segment.

[0009] In some feasible technical solutions, the cutting wire mesh includes a first cutting segment and a second cutting segment. The first cutting segment is located at both ends of the cutting wire mesh along the first direction, and the second cutting segment is located between the two first cutting segments. The first spraying process includes: applying a force A toward the first cutting segment and applying a force B toward the second cutting segment; the angle between the force A and the plane where the cutting wire mesh is located is greater than the angle between the force B and the plane where the cutting wire mesh is located.

[0010] In some feasible technical solutions, the cutting wire mesh includes a first wire mesh region located between the wire roller and the crystal; the first material feeding process includes: performing a first spraying process on at least one of the first wire mesh regions.

[0011] In some feasible technical solutions, along the direction perpendicular to the first direction, the cutting mesh includes a second mesh region located between two first mesh regions; when the second mesh region is located within the crystal and the distance between it and the cut surface of the crystal is greater than or equal to 2 mm, the first spraying process is performed.

[0012] In some feasible technical solutions, the injection medium includes liquid and / or gas.

[0013] In some feasible technical solutions, the flow rate of the injection medium is 240L / min to 260L / min, and the injection pressure is 3500Pa to 5000Pa.

[0014] In some feasible technical solutions, the first material feeding process further includes: a second spraying process on the cutting wire mesh, the second spraying process including: spraying liquid from the outside to the center of the cutting wire mesh along a direction perpendicular to the first direction.

[0015] The technical solution of the present invention also includes: a wafer, which is obtained by the above-described wafer cutting method.

[0016] The beneficial effects of this invention include: by applying a force from the outside to the center of the cutting wire mesh in a direction parallel to the axis of the wire roller during the feeding step, the tilt posture of the target wafer is corrected, the wedge gap is widened, and the degree of clamping and dragging of the cutting wire by the wafers on both sides is effectively reduced, the wire bow amplitude is reduced, the wire breakage rate is reduced, and at the same time, the cutting wire avoids unexpected grinding of the same part of the wafer, reducing scratches on the wafer surface and improving product quality. Attached Figure Description

[0017] Figure 1 This is a schematic diagram showing the distribution of the cutting wire roller, cutting wire mesh, and crystal in the prior art;

[0018] Figure 2 This is a schematic diagram of the wafer posture in the crystal after cutting in the prior art;

[0019] Figure 3 This is a process flow diagram of an embodiment of the present invention;

[0020] Figure 4 This is a top view schematic diagram of the material lifting spray device in Embodiment 14 of the present invention;

[0021] Figure 5 This is a schematic diagram of the working condition of the first nozzle in Embodiment 14 of the present invention;

[0022] Figure 6 This is a top view schematic diagram of the material lifting spray device in Embodiment 15 of the present invention;

[0023] Figure 7 This is a top view schematic diagram of the material lifting spray device in Embodiment 17 of the present invention.

[0024] In the picture:

[0025] 1. Wire roller;

[0026] 2. Cutting wire mesh; 21. First wire mesh area; 211. First cutting segment; 212. Second cutting segment; 22. Second wire mesh area;

[0027] 3. Crystal; 31. Sacrificial wafer; 32. First target wafer; 33. Second target wafer;

[0028] 4. Material holder;

[0029] 5. First spray assembly; 51. First piping structure; 52. First spray element; 53. First nozzle;

[0030] 6. Second spray assembly; 61. Second piping structure; 62. Second spray element; 63. Second nozzle;

[0031] aa' represents the first direction. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0033] In the description of the embodiments of this invention, it should be understood that the terms "top," "bottom," etc., indicating orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, it should be noted that unless otherwise explicitly specified and limited, the terms "set" and "connected" should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention through specific circumstances.

[0034] To address the aforementioned problems in the prior art, this technical solution provides a wafer cutting method and a wafer processed using this method. The cutting method employs a first lifting process in which a force is applied to the cutting wire mesh 2 from its outer side to its center in a direction parallel to the axis of the wire roller during the lifting step. This allows the cutting wire mesh 2 to smoothly detach from the crystal 3 with the help of this force, thereby reducing the wire breakage rate and minimizing scratches on the wafer.

[0035] To facilitate understanding of the implementation of this technical solution, the basic structure and cutting process of existing cutting equipment will first be explained. (See attached document.) Figure 1 Existing cutting equipment typically employs three wire rollers 1, two of which are located at the same height, parallel and spaced apart, while the third is located at a lower position, directly below the middle of the two higher rollers 1, forming an inverted triangle distribution. Before cutting, cutting wire is wound around the three rollers 1 as needed, creating a horizontal cutting wire mesh 2 between the two higher rollers 1. This cutting wire mesh 2 directly contacts and cuts the crystal 3. During the cutting step, the material holder 4, carrying the crystal 3, is gradually fed downwards from above the cutting wire mesh 2, causing the crystal 3 to contact the cutting wire mesh 2 between the two higher rollers 1 and be cut. As the feeding continues, the crystal 3 gradually enters the area between the three rollers 1 until the cutting wire mesh 2 between the two higher rollers 1 completely cuts through the crystal 3, completing the cutting process. At this point, the material lifting step can begin.

[0036] In the aforementioned cutting and feeding steps, to ensure that the crystal 3 can smoothly enter and exit the area between the three wire rollers 1, the distance between the two higher wire rollers 1 must be greater than the radial dimension of the crystal 3. Therefore, along the line connecting the centers of the two higher wire rollers 1, the cutting wire mesh 2 must have areas that do not contact the crystal 3 and areas that do contact the crystal 3. These are referred to as the first wire mesh area 21 and the second wire mesh area 22, respectively. For ease of description, the direction parallel to the axis of the wire rollers is defined as the first direction aa'. In the direction perpendicular to the first direction aa', each end of the cutting wire mesh 2 has a first wire mesh area 21, and the second wire mesh area 22 is located between the two first wire mesh areas 21. During the cutting wire travel process, a cutting line segment starts from one wire roller 1, passes through the first wire mesh area 21 on one side, the second wire mesh area 22, and the first wire mesh area 21 on the other side in sequence, and finally reaches another wire roller 1. Furthermore, in the first direction aa', the cutting mesh 2 includes a plurality of the aforementioned cutting segments spaced apart. For ease of description, the cutting segment located at the edge of the first mesh region 21 along the first direction aa' is defined as the first cutting segment 211. Thus, each first mesh region 21 has two first cutting segments 211, and the segment located between the two first cutting segments 211 is defined as the second cutting segment 212, and the number of such segments is several.

[0037] Furthermore, the first wire mesh region 21 that the cutting segment passes through before entering the second wire mesh region 22 is defined as the first wire mesh region 21 before entering the wire mesh region 22, and the first wire mesh region 21 that the cutting segment passes through after leaving the second wire mesh region 22 is defined as the first wire mesh region 21 after exiting the wire mesh region 22; the first cutting segment 211 located in the first wire mesh region 21 before entering the wire mesh region 21 is called the first cutting segment 211 before entering the wire mesh region 21, and the first cutting segment 211 located in the first wire mesh region 21 after exiting the wire mesh region 21 is called the first cutting segment 211 after exiting the wire mesh region 21; the second cutting segment 212 located in the first wire mesh region 21 before entering the wire mesh region 21 is called the second cutting segment 212 before entering the wire mesh region 21, and the second cutting segment 212 located in the first wire mesh region 21 after exiting the wire mesh region 21 is called the second cutting segment 212 after exiting the wire mesh region 21.

[0038] Based on the above equipment structure, cutting steps, and material handling steps, this technical solution provides the following specific embodiments. It should be noted that, with reference to the appendix... Figure 2In this paper, crystal 3 is in a state after being completely cut through. Crystal 3 forms several independent complete wafers. For the sake of clarity, the conventional names used in the existing process will be used in the following text. The thick slices located at both ends of crystal 3 are called sacrificial wafers 31, and the thin slices located between the two thick slices are called target wafers. According to the distribution of the target wafers, the target wafers can be divided into first target wafers 32 and second target wafers 33 that are distributed at intervals along the first direction aa'. The first target wafers 32 are adjacent to the sacrificial wafers 31. There are several second target wafers 33 located between the two first target wafers 32.

[0039] Example 1

[0040] Reference Appendix Figure 3 This embodiment provides a wafer dicing method for a process where both crystal feeding and lifting are in the vertical direction. The dicing method includes a dicing step S1 and a lifting step S2. In the dicing step, the feed holder 4 moves the crystal 3 in a vertically downward feeding direction, causing the crystal 3 to gradually contact the dicing wire mesh 2, thereby being diced into two sacrificial wafers 31 and several target wafers located between the two sacrificial wafers. In the lifting step, the feed holder 4 moves the crystal 3 in a vertically upward lifting direction, gradually separating it from the dicing wire mesh 2. During this process, a first lifting process is performed, which includes applying a force from the outside to the center of the first wire mesh region 21 before wire entry along a first direction aa'. In this embodiment, the force is applied using a jetting method. Based on this, the first lifting process provided in this embodiment includes performing a first jetting process on the first wire mesh region 21 before wire entry, causing the jetting medium to apply a force in the horizontal direction to the first wire mesh region 21 before wire entry.

[0041] Based on the cutting method provided in this embodiment, in the feeding step, the sprayed medium can apply a horizontal force to the cutting segments of the first mesh region 21. Since the cutting lines are continuous, this force can be transmitted from the cutting segments of the first mesh region 21 to the cutting segments of the second mesh region 22, and further act on the target wafer. Specifically, the direction of this force is horizontal and along the first direction aa' from the outside of the first mesh region 21 to the middle of the first mesh region 21. Under this action, the cutting segments of the first mesh region 21 will drive the cutting segments of the second mesh region 22 to shift along the first direction aa', thereby: the cutting segments of the second mesh region 22 push against the target wafer along the first direction aa', causing the target wafer to move towards the middle of the crystal 3, thereby correcting the tilt posture of the target wafer. As a result, the wedge-shaped gap between the target wafer and the sacrificial wafer 31, as well as between adjacent target wafers, can approach the ideal rectangular gap.

[0042] It should be noted that, due to the limitations of the liquid supply system (such as the pump body and pipelines), the output of the jetting medium cannot achieve an absolutely continuous and stable state, and there is an objectively certain pulse frequency. When the pulsed jetting medium acts on the cutting line, the cutting line undergoes a slight displacement, slightly correcting the orientation of the target wafer, at which point the wafer gap increases. During the pulse interval, the above-mentioned force temporarily disappears, and the cutting line returns to its original position and orientation along the first direction aa'. As the cutting line resets, the clamping and dragging force of the wafers on both sides of the cutting line decreases, and may even fail to form an effective drag. As the crystal 3 continues to be fed, the cutting line re-enters the narrower area of ​​the wedge-shaped gap. At this time, the subsequent pulsed jetting medium arrives, causing the cutting line to shift again along the first direction aa' and push against the target wafer. By repeating the above process, the width of the lower end of the wedge gap can be continuously widened, and the intensity and degree of the cutting wire being clamped and pulled upward by the wafers on both sides can be reduced, so that the cutting wire and the wafer can be separated more smoothly. This achieves the effects of reducing wire bowing, reducing the incidence of wire breakage, reducing continuous grinding of the same part of the wafer relative to the cutting wire (reducing scratches), and improving product quality.

[0043] In actual operation: the sacrificial wafer 31, due to its large thickness and strong adhesion, basically does not tilt; the first target wafer 32 tilts the most; the tilt of the multiple second target wafers 33 gradually decreases from both ends of the crystal 3 towards the middle. Therefore, in the material handling step of the existing cutting method, the bowing generated by the first cutting segment 211 located between the sacrificial wafer 31 and the first target wafer 32 is larger, more prone to wire breakage, and causes more severe scratches on the wafer. Therefore, the first jetting process provided in this embodiment includes: applying a horizontal force A towards the first cutting segment 211 before wire entry.

[0044] Example 2

[0045] This embodiment provides a wafer dicing method for a process where both crystal feeding and lifting are in the vertical direction. The dicing method includes a dicing step S1 and a lifting step S2. In the dicing step, the feed holder 4 moves the crystal 3 in a vertically downward feeding direction, causing the crystal 3 to gradually contact the dicing wire mesh 2, thereby being diced into two sacrificial wafers 31 and several target wafers located between the two sacrificial wafers. In the lifting step, the feed holder 4 moves the crystal 3 in a vertically upward lifting direction, gradually separating it from the dicing wire mesh 2. During this process, a first lifting process is performed, which includes applying a force from the outside to the center of the first wire mesh region 21 after wire exit along a first direction aa'.

[0046] In this embodiment, the aforementioned force is applied using a jetting method. Based on this, the first material handling process provided in this embodiment includes: performing a first jetting process on the first wire mesh area 21 after the wire exits, so that the jetting medium applies a horizontal force A to the first cutting segment 211 after the wire exits.

[0047] Example 3

[0048] This embodiment provides a wafer dicing method for a process where both crystal feeding and lifting are in the vertical direction. The dicing method includes a dicing step S1 and a lifting step S2. In the dicing step, the feed holder 4 moves the crystal 3 in a vertically downward feeding direction, causing the crystal 3 to gradually contact the dicing wire mesh 2, thereby being diced into two sacrificial wafers 31 and several target wafers located between the two sacrificial wafers. In the lifting step, the feed holder 4 moves the crystal 3 in a vertically upward lifting direction, gradually separating it from the dicing wire mesh 2. During this process, a first lifting process is performed, which includes applying a force from the outside to the center of the first wire mesh region 21 before wire entry and the first wire mesh region 21 after wire exit along a first direction aa'.

[0049] In this embodiment, the aforementioned force is applied using a jetting method. Based on this, the first material handling process provided in this embodiment includes: performing a first jetting process on the first wire mesh area 21 before entering the line and the first wire mesh area 21 after exiting the line, so that the jetting medium applies a horizontal force A to the first cutting segment 211 before entering the line and the first cutting segment 211 after exiting the line, respectively.

[0050] Compared to Example 1, this example applies force A to the first cutting line segment 211 both before and after the wire enters the circuit. This means that a lateral thrust in the same direction is applied simultaneously from both ends of the cutting line. This creates a superposition effect of force A on the cutting line, significantly enhancing the lateral thrust transmitted to the second mesh region 22. Therefore, the pushing effect of the cutting line on the target wafer is more effective, allowing for a greater push towards the center of the crystal 3, thus correcting the wafer's tilt posture more quickly and thoroughly. Furthermore, the increase in the size of the lower end of the wedge-shaped gap is more pronounced, further reducing the clamping and dragging force between the cutting line and the wafer, further reducing wire bowing, decreasing the wire breakage rate, and further reducing scratches on the wafer surface.

[0051] It should be noted that this embodiment only limits the direction of the force A, not the magnitude of the force A. In actual implementation, the force A applied to the first cutting segment 211 before the wire enters the line can be equal to or unequal to the force A applied to the first cutting segment 211 after the wire exits the line, by adjusting the flow rate or injection pressure of the injection medium according to actual needs.

[0052] Example 4

[0053] In actual operation: Due to the relatively large initial tilt of the first target wafer 32 and the relatively small initial tilt of the second target wafer 33, the initial gap between the first target wafer 32 and the second target wafer 33, as well as the initial gap between adjacent second target wafers 33, are relatively wide. This makes it difficult for the second cutting segment 212 to be clamped and dragged upward by the wafers on both sides during the initial feeding stage. However, as mentioned earlier, as the force A is continuously applied, the tilt of the first target wafer 32 is gradually corrected, and the gap between it and the second target wafer 33 will decrease accordingly. Therefore, it is still necessary to appropriately correct the orientation of the second target wafer 33 to prevent the second cutting segment 212 from being clamped after the gap decreases.

[0054] Based on the above, this embodiment provides a wafer cutting method for a process where both crystal feeding and lifting are in the vertical direction. The cutting method includes a cutting step S1 and a lifting step S2. Specifically: In the cutting step, the feed holder 4 moves the crystal 3 in a vertically downward feeding direction, causing the crystal 3 to gradually contact the cutting wire mesh 2, thereby being cut into two sacrificial wafers 31 and several target wafers located between the two sacrificial wafers; In the lifting step, the feed holder 4 moves the crystal 3 in a vertically upward lifting direction, gradually separating it from the cutting wire mesh 2, and in this process, a first lifting process is performed. The first lifting process includes: applying a force from the outside to the center of the first wire mesh region 21 before wire entry along a first direction aa'.

[0055] In this embodiment, the aforementioned force is applied using a jetting method. Based on this, the first material handling process provided in this embodiment includes: performing a first jetting process on the first wire mesh area 21 before entering the line, so that the jetting medium applies a horizontal force A to the first cutting segment 211 before entering the line and a horizontal force B to the second cutting segment 212 before entering the line, wherein the magnitudes of force A and force B are equal or unequal.

[0056] Example 5

[0057] This embodiment provides a wafer dicing method for a process where both crystal feeding and lifting are in the vertical direction. The dicing method includes a dicing step S1 and a lifting step S2. In the dicing step, the feed holder 4 moves the crystal 3 in a vertically downward feeding direction, causing the crystal 3 to gradually contact the dicing wire mesh 2, thereby being diced into two sacrificial wafers 31 and several target wafers located between the two sacrificial wafers. In the lifting step, the feed holder 4 moves the crystal 3 in a vertically upward lifting direction, gradually separating it from the dicing wire mesh 2. During this process, a first lifting process is performed, which includes applying a force from the outside to the center of the first wire mesh region 21 after wire exit along a first direction aa'.

[0058] In this embodiment, the aforementioned force is applied using a jetting method. Based on this, the first material feeding process provided in this embodiment includes: performing a first jetting process on the first wire mesh area 21 after the wire exits, so that the jetting medium applies a horizontal force A to the first cutting segment 211 after the wire exits and a horizontal force B to the second cutting segment 212 after the wire exits, wherein the magnitudes of force A and force B are equal or unequal.

[0059] Example 6

[0060] This embodiment provides a wafer dicing method for a process where both crystal feeding and lifting are in the vertical direction. The dicing method includes a dicing step S1 and a lifting step S2. In the dicing step, the feed holder 4 moves the crystal 3 in a vertically downward feeding direction, causing the crystal 3 to gradually contact the dicing wire mesh 2, thereby being diced into two sacrificial wafers 31 and several target wafers located between the two sacrificial wafers. In the lifting step, the feed holder 4 moves the crystal 3 in a vertically upward lifting direction, gradually separating it from the dicing wire mesh 2. During this process, a first lifting process is performed, which includes applying a force from the outside to the center of the first wire mesh region 21 before wire entry and the first wire mesh region 21 after wire exit along a first direction aa'.

[0061] In this embodiment, the aforementioned force is applied using a jetting method. Based on this, the first material handling process provided in this embodiment includes: performing a first jetting process on the first wire mesh area 21 before entering the line and the first wire mesh area 21 after exiting the line, so that the jetting medium applies a horizontal force A to the first cutting segment 211 before entering the line and the second cutting segment 212 before entering the line and the second cutting segment 212 after exiting the line, and the magnitudes of force A and force B are equal or unequal.

[0062] Example 7

[0063] This embodiment provides a wafer dicing method for a process where both crystal feeding and retraction are in the vertical direction. The dicing method includes a dicing step S1 and a retraction step S2. In the dicing step, the feed holder 4 moves the crystal 3 in a vertically downward feeding direction, causing the crystal 3 to gradually contact the dicing wire mesh 2, thereby being diced into two sacrificial wafers 31 and several target wafers located between the two sacrificial wafers. In the retraction step, the feed holder 4 moves the crystal 3 in a vertically upward retraction direction, gradually separating it from the dicing wire mesh 2. During this process, a first retraction process is performed, which includes applying a force from the outside to the center of the first wire mesh region 21 before wire entry along a first direction aa'.

[0064] In this embodiment, the aforementioned force is applied using a jetting method. Based on this, the first material lifting process provided in this embodiment includes: performing a first jetting process on the first wire mesh area 21 before entering the line, so that the jetting medium applies a force A inclined towards the lifting direction to the first cutting segment 211 before entering the line.

[0065] Based on the cutting method provided in this embodiment, in the material lifting step, the force A applied by the jetting medium to the first cutting segment 211 before the wire entry has two directional components: one is the component along the first direction aa', which is used to form the lateral pushing action described in the aforementioned embodiment, thereby correcting the tilt posture of the target wafer; the other is the component along the material lifting direction, which causes the first cutting segment 211 before the wire entry to not only undergo lateral displacement under the action of the pulse jetting medium, but also to move upward, so that the first cutting segment 211 before the wire entry pushes the target wafer to correct its posture while escaping towards a higher and wider area of ​​the wedge gap, thereby preventing it from being clamped and dragged by the wafers on both sides after entering the crystal 3 as the wiring process progresses.

[0066] It should be noted that although the upward component of force A will cause a certain degree of wire bowing in the dicing segment, its impact on the dicing wire is negligible. This is because: the active upward displacement makes it less likely for the dicing wire to be clamped tightly by the wafers on both sides, thus avoiding larger wire bowing caused by clamping and dragging; at the same time, the dicing wire has continuity and a certain tension, and under its own gravity, it will automatically fall back to its original height during the pulse interval, so the wire bowing is always kept within a small, safe range. The alternating process of the above-mentioned active upward displacement and automatic fall causes a slight up-and-down jump phenomenon in the dicing wire, thereby avoiding the dicing wire always contacting the same part of the wafer, reducing continuous grinding of the same position on the wafer.

[0067] When executing the cutting method of this embodiment, the above-mentioned process of "actively moving upward and laterally pushing against the target wafer → automatically falling back" is repeated multiple times. In each cycle, the cutting wire, driven by force A, laterally pushes against the target wafer and actively moves upward, gradually widening the wedge gap; subsequently, the cutting wire automatically falls back to its original position under the action of gravity and its own tension. Since crystal 3 continues to be lifted upward during the falling process of the cutting wire, the cut wire is now at a lower position relative to crystal 3, thus entering a relatively narrower gap section, and is driven again by force A in the next cycle, repeating the lateral pushing against the target wafer and actively moving upward. This cycle is repeated multiple times, and the cutting wire is always difficult to be completely clamped by the wafers on both sides, eventually successfully detaching from the ever-widening wedge gap.

[0068] Example 8

[0069] This embodiment provides a wafer dicing method for a process where both crystal feeding and lifting are in the vertical direction. The dicing method includes a dicing step S1 and a lifting step S2. In the dicing step, the feed holder 4 moves the crystal 3 in a vertically downward feeding direction, causing the crystal 3 to gradually contact the dicing wire mesh 2, thereby being diced into two sacrificial wafers 31 and several target wafers located between the two sacrificial wafers. In the lifting step, the feed holder 4 moves the crystal 3 in a vertically upward lifting direction, gradually separating it from the dicing wire mesh 2. During this process, a first lifting process is performed, which includes applying a force from the outside to the center of the first wire mesh region 21 after wire exit along a first direction aa'.

[0070] In this embodiment, the aforementioned force is applied using a jetting method. Based on this, the first material lifting process provided in this embodiment includes: performing a first jetting process on the first wire mesh area 21 after the wire exits, so that the jetting medium applies a force A inclined towards the material lifting direction to the first cutting segment 211 after the wire exits.

[0071] Similar to Embodiment 7, the force A provided in this embodiment also includes components in two directions: a component along the first direction aa' and a component along the lifting direction. The component along the first direction aa' can exert a lateral pushing effect on the target wafer to correct the tilting posture of the target wafer; the component along the lifting direction can cause the first cutting segment 211 after the wire exits to produce a slight upward displacement, and based on the continuity of the cutting line, it is transmitted to the cutting segment located inside the crystal 3 at this time.

[0072] However, compared to Embodiment 7, the technical effect of this embodiment is slightly inferior. The reason is that: during the cutting process, the cutting wire continues to move. When an inclined force A is applied to the first cutting segment 211 before the wire enters, the first cutting segment 211 gradually enters the interior of the crystal 3 as the wire moves. Its active upward escape behavior can continue to the cutting segment inside the crystal 3, rather than just transmitting the force based on the continuity of the cutting wire. Therefore, it effectively avoids the cutting wire being clamped and dragged by the wafers on both sides. However, when an inclined force A is applied to the first cutting segment 211 after the wire exits, the first cutting segment 211 has already been led out of the crystal 3. Its active upward displacement behavior gradually dissipates as the cutting wire continues to move. It can only transmit weak vibrations to the cutting segment located inside the crystal 3 based on the continuity of the cutting wire. Therefore, the technical effect of Embodiment 7 is better than that of this embodiment.

[0073] Example 9

[0074] This embodiment provides a wafer dicing method for a process where both crystal feeding and lifting are in the vertical direction. The dicing method includes a dicing step S1 and a lifting step S2. In the dicing step, the feed holder 4 moves the crystal 3 in a vertically downward feeding direction, causing the crystal 3 to gradually contact the dicing wire mesh 2, thereby being diced into two sacrificial wafers 31 and several target wafers located between the two sacrificial wafers. In the lifting step, the feed holder 4 moves the crystal 3 in a vertically upward lifting direction, gradually separating it from the dicing wire mesh 2. During this process, a first lifting process is performed, which includes applying a force from the outside to the center of the first wire mesh region 21 before wire entry and the first wire mesh region 21 after wire exit along a first direction aa'.

[0075] In this embodiment, the aforementioned force is applied using a jetting method. Based on this, the first material lifting process provided in this embodiment includes: performing a first jetting process on the first wire mesh area 21 before entering the line and the first wire mesh area 21 after exiting the line, so that the jetting medium applies an inclined force A to the first cutting segment 211 before entering the line and the first cutting segment 211 after exiting the line, respectively, in the direction of material lifting.

[0076] It should be noted that this embodiment only limits the direction of the force A, and does not limit the specific angle and magnitude of the force A. In actual implementation, the angle of the force A applied to the first cutting segment 211 before the wire enters the line can be the same or different from that applied to the first cutting segment 211 after the wire exits the line, by adjusting the injection angle of the injection medium according to actual needs; and the magnitude of the force A applied to the first cutting segment 211 before the wire enters the line can be equal or unequal to that applied to the first cutting segment 211 after the wire exits the line, by adjusting the flow rate or injection pressure of the injection medium.

[0077] Example 10

[0078] This embodiment provides a wafer dicing method for a process where both crystal feeding and retraction are in the vertical direction. The dicing method includes a dicing step S1 and a retraction step S2. In the dicing step, the feed holder 4 moves the crystal 3 in a vertically downward feeding direction, causing the crystal 3 to gradually contact the dicing wire mesh 2, thereby being diced into two sacrificial wafers 31 and several target wafers located between the two sacrificial wafers. In the retraction step, the feed holder 4 moves the crystal 3 in a vertically upward retraction direction, gradually separating it from the dicing wire mesh 2. During this process, a first retraction process is performed, which includes applying a force from the outside to the center of the first wire mesh region 21 before wire entry along a first direction aa'.

[0079] In this embodiment, the aforementioned force is applied using a jetting method. Based on this, the first material lifting process provided in this embodiment includes: performing a first jetting process on the first wire mesh area 21 before entering the line, so that the jetting medium applies a force A inclined towards the lifting direction to the first cutting segment 211 before entering the line and applies a force B inclined towards the lifting direction to the second cutting segment 212 before entering the line.

[0080] It should be noted that this embodiment only limits the directions of force A and force B, and does not limit the specific angles and magnitudes of force A and force B. In actual implementation, the angles of force A and force B can be made the same or different by adjusting the injection angle of the injection medium, and the magnitudes of force A and force B can be made equal or unequal by adjusting the flow rate or injection pressure of the injection medium.

[0081] This embodiment provides a preferred implementation scheme in which the angle between force A and the plane (i.e., the horizontal plane) where the cutting mesh 2 is located is greater than the angle between force B and the plane where the cutting mesh 2 is located. The reason for this is that the initial wafer gap where the second cutting segment 212 is located is relatively wide, making it less susceptible to being clamped and dragged by the wafers on both sides. Therefore, the primary objective is to simultaneously perform sufficient attitude adjustment on the second target wafer 33 while adjusting the attitude of the first target wafer 32. The degree to which the cutting line corresponding to the second target wafer 33 actively escapes upwards does not affect the main technical effect of this scheme.

[0082] Based on the above requirements, this embodiment uses a force B with a smaller angle between the second cutting line segment 212 and the plane where the cutting wire mesh 2 is located, so that the component of the force B in the first direction aa' is larger, ensuring that sufficient lateral pushing force is provided to the second target wafer 33, and effectively adjusting the attitude of the second target wafer 33.

[0083] Example 11

[0084] This embodiment provides a wafer dicing method for a process where both crystal feeding and lifting are in the vertical direction. The dicing method includes a dicing step S1 and a lifting step S2. In the dicing step, the feed holder 4 moves the crystal 3 in a vertically downward feeding direction, causing the crystal 3 to gradually contact the dicing wire mesh 2, thereby being diced into two sacrificial wafers 31 and several target wafers located between the two sacrificial wafers. In the lifting step, the feed holder 4 moves the crystal 3 in a vertically upward lifting direction, gradually separating it from the dicing wire mesh 2. During this process, a first lifting process is performed, which includes applying a force from the outside to the center of the first wire mesh region 21 before wire entry and the first wire mesh region 21 after wire exit along a first direction aa'.

[0085] In this embodiment, the aforementioned force is applied using a jetting method. Based on this, the first material lifting process provided in this embodiment includes: performing a first jetting process on the first wire mesh area 21 before entering the line and the first wire mesh area 21 after exiting the line, so that the jetting medium applies a force A inclined towards the lifting direction to the first cutting segment 211 before entering the line and after exiting the line, and applies a force B inclined towards the lifting direction to the second cutting segment 212 before entering the line and after exiting the line; the angle between the force A and the plane where the cutting wire mesh 2 is located is greater than the angle between the force B and the plane where the cutting wire mesh 2 is located.

[0086] Example 12

[0087] This embodiment is an optimization based on any one of embodiments 1 to 11. Compared with the aforementioned embodiments, the difference in this embodiment is that the first material feeding process further includes a second spraying process on the diced wire mesh 2. The second spraying process includes: spraying liquid from the outside to the center of the diced wire mesh 2 along a direction perpendicular to the first direction aa', so that it enters the gaps between the wafers to achieve the functions of lubrication and cooling.

[0088] In any of the specific implementations of Examples 1 to 11, the injection medium used includes at least one of liquid and gas. When a liquid is selected as the injection medium, the liquid injected by the second injection process can be the same as or different from the liquid injection medium used in the first injection process. When the liquid injection medium used in the first injection process is the same as the liquid injected by the second injection process, the first injection process and the second injection process can be started simultaneously or not simultaneously through pipeline connection.

[0089] In any of the specific implementations of Examples 1 to 11, the injection medium used includes at least one of liquid and gas. When the injection medium is liquid, the liquid injected by the second injection process can be the same as or different from it. When the liquid is the same, the first injection process and the second injection process can be started simultaneously by connecting pipelines, or they can be started at different times.

[0090] Example 13

[0091] This embodiment modifies the design concept of any one of embodiments 1 to 11. Compared with the aforementioned embodiments, the difference in this embodiment is that, for the cutting line with an easily magnetized metal material as the substrate, force A and force B are applied by adding a magnet with variable magnetic poles outside the cutting line. The easily magnetized metal material includes, but is not limited to, nickel.

[0092] Taking the application of force A as an example, electromagnets are added on both sides of the first cutting segment 211, with opposite magnetic poles. The two electromagnets are spaced apart from the first cutting segment 211 in the first direction aa', and their heights in the lifting direction can be the same or different: when the two electromagnets are at the same height in the lifting direction, they are used to apply force A in the horizontal direction; when the two electromagnets are at different heights in the lifting direction, they are used to apply force A inclined towards the lifting direction. During the lifting step, by periodically changing the magnetic poles of the two electromagnets, the cutting line vibrates due to the abrupt change in the direction of the magnetic force, thereby applying force A.

[0093] It should be noted that during the cutting process, a downward bow is generated in the middle of the cutting wire. To ensure that crystal 3 is completely cut through, the middle of the cutting wire must exit through the top surface of crystal 3. Therefore, the cutting wire enters the carrier plate (the carrier plate refers to the necessary consumable material located between crystal 3 and material holder 4 in the prior art) located above crystal 3 upon completion of the cutting. During the subsequent material lifting process, due to the change in the direction of crystal 3's movement, an upward bow is generated in the middle of the cutting wire. As the material lifting stroke progresses, there is a transition phase in which part of the cutting wire remains inside the carrier plate, while another part has entered the crystal 3. Since the carrier plate and crystal 3 are different media, the contact state and interaction force characteristics between the cutting wire and both are fundamentally different. If the aforementioned force is applied to the cutting wire during this transition phase, when the cutting wire vibrates at the interface of the different media, the driving force and resistance it experiences are inconsistent, which can easily lead to wire breakage.

[0094] For the reasons stated above, when implementing any embodiment provided by the present invention, the following implementation method is preferred: the first spraying process is performed when the second mesh region 22 is located within the crystal 3 and the distance between the second mesh region 22 and the cut surface of the crystal 3 (i.e., the top surface of the crystal 3 mentioned above) is greater than or equal to 2 mm. This implementation method ensures that the cutting line has completely detached from the carrier plate when the first spraying process is performed.

[0095] Example 14

[0096] This embodiment provides a material lifting spray device for a process in which the crystal lifting direction is vertically upward and the routing direction of the cutting line remains unchanged during the lifting step, in order to execute the wafer cutting method provided in Embodiment 10.

[0097] With attachment Figure 1 The direction shown is for reference only. In this embodiment, the routing direction in the material feeding step is from left to right, and this direction remains unchanged throughout. Based on this, refer to the attached diagram. Figure 4-5The material lifting spray device provided in this embodiment includes a first pipe structure 51 and a first spray assembly 5. The first pipe structure 51 is used to supply liquid spray medium to the first spray assembly 5. The first spray assembly 5 is correspondingly arranged with the first wire mesh area 21 on the left side of the cutting wire mesh 2. The first wire mesh area 21 on the left side is the first wire mesh area 21 before the wire enters.

[0098] The first spray assembly 5 includes a first nozzle 53, which is a fan-shaped nozzle used to form a first output end facing the cutting wire mesh 2, for outputting liquid spray medium. The fan-shaped spray surface of the fan-shaped nozzle is perpendicular to the plane where the cutting wire mesh 2 is located, spraying the cutting wire segments in the first wire mesh area 21 before the wire enters, and has a spray direction one that is inclined upward toward the first cutting wire segment 211 before the wire enters, and a spray direction two that is inclined upward toward the second cutting wire segment 212 before the wire enters. Both spray direction one and spray direction two are directed along the first direction aa' toward the middle of the cutting wire mesh 2; the angle α formed between spray direction one and the plane where the cutting wire mesh 2 is located is greater than the angle b formed between spray direction two and the plane where the cutting wire mesh 2 is located.

[0099] To optimize the force application effect, the installation position and spray parameters of the first nozzle 53 are configured as follows: In the horizontal direction perpendicular to the first direction aa', the distance between the first nozzle 53 and the second mesh area 22 is controlled between 18mm and 22mm; in the first direction aa', the distance between the first nozzle 53 and the first mesh area 21 is controlled between 10mm and 50mm. These spacing settings are used to avoid insufficient force due to excessive momentum loss caused by an excessively long spray path, and to avoid adverse effects due to excessive impact caused by an excessively short spray path.

[0100] Based on the above structure and position configuration, the preferred flow rate of the injection medium of the first nozzle 53 is 240L / min to 260L / min, and the preferred injection pressure is 3500Pa to 5000Pa.

[0101] To facilitate the description of the cutting process, the vertical distance between the cutting surface of crystal 3 (i.e., the bottom surface of crystal 3) and the cutting mesh 2 is defined as the feed position. When the cutting surface is flush with the cutting mesh 2, the feed position is 0; when the cutting surface is below the cutting mesh 2, the feed position is positive; when the cutting surface is above the cutting mesh 2, the feed position is negative.

[0102] Based on the above definition, the specific implementation process of this embodiment is as follows: When the cutting is completed, the feed position is 266mm, at which time the second wire mesh area 22 is located inside the carrier plate. When the material is lifted and the feed position changes to 260mm, the first spray assembly 5 is turned on, spraying the first wire mesh area 21 before the wire entry with a flow rate of 255L / min and a spray pressure of 4200Pa. As the material lifting process continues, the feed position gradually decreases, and the cutting wire mesh 2 gradually separates from the crystal 3 with a small wire bow. When the feed position changes to -2mm, the middle part (top of the wire bow) of the cutting wire mesh 2 is completely separated from the crystal 3. No wire breakage or wafer scratches occurred during the above process, and the surface quality of the target wafer was good.

[0103] Example 15

[0104] This embodiment provides a material lifting spray device for processes where the crystal lifting direction is vertically upward and the routing direction of the cutting line changes during the lifting step, in order to execute the wafer cutting method provided in Embodiment 10.

[0105] With attachment Figure 1 The directions shown are for reference only. In this embodiment, the routing direction in the material lifting step includes two modes: left-to-right and right-to-left. These two modes can be switched according to the needs of the material lifting process. Based on this, refer to the attached... Figure 6 The material lifting spray device provided in this embodiment includes two first spray components 5, which are respectively arranged in a one-to-one correspondence with two first wire mesh areas 21 on both sides of the cutting wire mesh 2. The structural configuration of each first spray component 5 is the same as that in embodiment 14. When the wire routing direction changes, the first spray component 5 corresponding to the first wire mesh area 21 before the wire enters the current state is activated.

[0106] With the above configuration, regardless of the routing direction, the required force can always be applied to the first cutting segment 211 and the second cutting segment 212 before the current entry line, thereby ensuring that the attitude correction effect of the target wafer is continuously effective during the feeding process.

[0107] Example 16

[0108] This embodiment uses the material lifting spray device described in Embodiment 15 to execute the wafer cutting method provided in Embodiment 11. Compared to Embodiment 15, the difference in this embodiment is that, regardless of whether the wiring direction changes during the material lifting step, both first spray components 5 remain continuously open, ensuring that both first spray components 5 are always in working condition during the material lifting step. That is, both first spray components 5 simultaneously apply force to the first mesh area 21 before wire entry and the first mesh area 21 after wire exit.

[0109] By adopting the above configuration, forces can be applied to the two first wire mesh regions 21 simultaneously during the feeding step, further enhancing the correction effect on the target wafer posture.

[0110] Example 17

[0111] This embodiment is an improvement on the material lifting spray device provided in Embodiment 15, used to execute the wafer cutting method provided in Embodiment 12.

[0112] Compared with the material lifting spray device provided in Example 15, the difference in this example is: (Refer to the attached document) Figure 7 The material feeding spray device is further equipped with a second spray assembly 6. The second spray assembly 6 includes a second pipe structure 61 and a second spray element 62. The second pipe structure 61 is used to supply liquid to the second spray assembly 6, and the first pipe structure 51 is connected to the second pipe structure 61, which can be controlled to start and stop in a unified manner. The second spray element 62 includes a second nozzle 63, which is used to form a second output end. In the horizontal direction perpendicular to the first direction aa', the second output end is arranged towards the cutting wire mesh 2, and is used to spray liquid onto the cutting wire segments in the wafer gap to achieve lubrication and cooling functions.

[0113] Compared with the prior art, the beneficial effects of the present invention include: by applying a force from the outside to the center of the cutting wire mesh 2 in a direction parallel to the axis of the wire roller during the feeding step, the tilt posture of the target wafer is corrected, the wedge gap is widened, and the degree of clamping and dragging of the cutting wire by the wafers on both sides is effectively reduced, the wire bow amplitude is reduced, the wire breakage rate is reduced, and at the same time, the cutting wire avoids unexpected grinding of the same part of the wafer, reducing scratches on the wafer surface and improving product quality.

[0114] The above are preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A wafer cutting method, comprising a feeding step, characterized in that, The first material lifting process is performed in the material lifting step. The first material lifting process includes: applying a force to the cutting wire mesh along a first direction, pointing from its outer side to its middle part and inclined towards the material lifting direction, wherein the first direction is parallel to the axis of the wire roller.

2. The wafer cutting method according to claim 1, characterized in that, The first material feeding process includes: performing a first spraying process on the cutting wire mesh, so that the spraying medium applies a force to the cutting wire mesh.

3. The wafer cutting method according to claim 2, characterized in that, The cutting wire mesh includes a first cutting segment, which is located at both ends of the cutting wire mesh along the first direction. The first spraying process includes applying a force A toward the first cutting segment.

4. The wafer cutting method according to claim 2, characterized in that, The cutting wire mesh includes a first cutting segment and a second cutting segment. The first cutting segment is located at both ends of the cutting wire mesh along the first direction, and the second cutting segment is located between the two first cutting segments. The first spraying process includes: applying force A toward the first cutting segment and applying force B toward the second cutting segment; The angle between the force A and the plane where the cutting wire mesh is located is greater than or equal to the angle between the force B and the plane where the cutting wire mesh is located.

5. The wafer cutting method according to claim 2, characterized in that, The cutting wire mesh includes a first wire mesh region located between the wire roller and the crystal; The first material feeding process includes: performing a first spraying process on at least one of the first wire mesh areas.

6. The wafer cutting method according to claim 5, characterized in that, Along a direction perpendicular to the first direction, the cutting mesh includes a second mesh region located between two first mesh regions; when the second mesh region is located within the crystal and the distance between it and the cut surface of the crystal is greater than or equal to 2 mm, the first spraying process is performed.

7. The wafer cutting method according to claim 2, characterized in that, The injection medium includes liquid and / or gas.

8. The wafer cutting method according to claim 2, characterized in that, The flow rate of the injection medium is 240L / min to 260L / min, and the injection pressure is 3500Pa to 5000Pa.

9. The wafer cutting method according to any one of claims 1-8, characterized in that, The first material feeding process further includes: performing a second spraying process on the cutting wire mesh, the second spraying process including: spraying liquid from the outside to the center of the cutting wire mesh along a direction perpendicular to the first direction.

10. A chip, characterized in that, The wafer is obtained by wafer cutting method according to any one of claims 1-9.

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