A dicing method for a gallium arsenide wafer

Abstract

The present invention relates to the technical field of wafer cutting, and provides a scribing method for gallium arsenide wafers. During the grinding stage, the grinding plate is used to achieve grinding twice. On the one hand, it can expose the diamond of the grinding wheel blade and generate chip flutes. On the other hand, it can round the grinding wheel blade to ensure the concentricity of the grinding wheel blade and the spindle. Moreover, each time of grinding will cause loss of the edge part in contact with the grinding plate, making the edge of the grinding wheel blade become "V"-shaped, achieving the purpose of trimming the edge shape. In this way, during the scribing process of the product, the contact area with the material is smaller, and the impact breaking force on the material is smaller, which can significantly reduce the chipping and cracking of the particles after segmentation, is beneficial to improving the cutting quality of the wafer, and thus improves the yield of the wafer product; during the scribing stage, it is preferentially segmented into multiple stepped wide strip cutting channels, and then detailed division is carried out, so that the material stress can be initially released, because the large area of the wafer strip is sufficient to resist the problem of crack extension.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer cutting, and in particular to a scribing method for gallium arsenide wafers. Background Art

[0002] With the booming development of the LED industry, innovation is being accumulated in different links. Especially in recent years, small-pitch LEDs have continued to grow, and Mini / Micro LEDs have achieved a qualitative change from quantitative change. With the release of the future Mini / Micro LED market, its upstream LED chips will be the core beneficiary link. There are various substrate materials for LED chips, and different substrates emit different colors of light. Among them, gallium arsenide, as a second-generation semiconductor material, is the most mature compound semiconductor material after "silicon", and has superior characteristics such as high frequency, high electron mobility, high output power, low noise, and good linearity. It is widely used in the LED chip industry and is one of the preferred substrate materials.

[0003] Gallium arsenide belongs to the III-V group compounds, with a zinc blende lattice structure, brittle and hard. Its material also has problems such as crystal orientation in forming at specific angles, making its processing difficulty significantly higher than that of the first-generation semiconductor material "silicon", and it is extremely easy to appear problems such as cracks and chipping during the processing. In addition, the toxicity of gallium arsenide has not been studied very completely because it contains highly toxic As. Although the crystal of gallium arsenide is very stable, the absorption of a small amount of gallium arsenide by the body can be ignored. However, As cannot appear during the entire processing process. Therefore, the laser ablation processing method cannot be used (it is easy to decompose and produce As under high-temperature conditions). At present, the common method in the semiconductor industry to divide materials into small particles is grinding wheel scribing in addition to laser ablation. However, when applied to the LED chip industry, gallium arsenide will be processed into a 4-inch wafer with a thickness of about 150 um. Due to the characteristics of grinding, the gallium arsenide wafer will have a certain degree of warpage. The size of the pattern particles on it is basically between 95 and 170 um, and there is a layer of gold plated on the back of the wafer. Coupled with the fact that the gallium arsenide material is hard and brittle and cannot be divided by laser ablation, the particles are extremely easy to break and chip during the process of scribing and dividing the pattern particles by the grinding wheel, resulting in damage to the wafer. Summary of the Invention

[0004] The purpose of the present invention is to provide a scribing method for gallium arsenide wafers to solve the problem that the existing scribing method for gallium arsenide wafers is prone to cause chipping and breakage of the wafers.

[0005] To solve the above problems, the present invention provides a scribing method for gallium arsenide wafers, including:

[0006] S100, install a sharpening plate with a particle size matching the grinding wheel blade at a predetermined position on the cutting worktable of the scribing machine;

[0007] S200, set the knife grinding parameters and start the dicing machine. First, control the depth of the grinding wheel blade cutting into the knife grinding plate to be not less than the thickness of the gallium arsenide wafer to be cut, and then control the depth of the grinding wheel blade cutting into the knife grinding plate to be 1 / 4 - 1 / 2 of the thickness of the gallium arsenide wafer to be cut;

[0008] S300, remove the knife grinding plate, install the knife grinding silicon wafer at a predetermined position on the cutting worktable, and control the depth of the grinding wheel blade cutting into the knife grinding silicon wafer to be 1 / 2 - 3 / 4 of the thickness of the gallium arsenide wafer to be cut;

[0009] S400, remove the knife grinding silicon wafer and set the cutting parameters. Fix the gallium arsenide wafer to be cut at a predetermined position on the cutting worktable, and control the grinding wheel blade to perform dicing according to the cutting parameters; the cutting parameters include a cutting process, and the cutting process includes a first channel step, a second channel step, and a third channel step set in sequence; wherein, the first channel step steps at 3 - 7 times the step of the particle theory, the second channel step is perpendicular to the first channel step and performs sequential dicing according to the step of the particle theory; the third channel step is the remaining cutting tracks after completing the first channel step.

[0010] Optionally, before S100, it includes:

[0011] Select a knife grinding plate with a particle size matching that of the grinding wheel blade; the particle size of the knife grinding plate is close to or the same as the size of the hard particles of the grinding wheel blade.

[0012] Optionally, the particle size of the knife grinding plate is 4000# - 5000#, and the particle size of the grinding wheel blade is 4800# - 5000#.

[0013] Optionally, in S100, the step of installing the knife grinding plate with a particle size matching that of the grinding wheel blade at a predetermined position on the cutting worktable of the dicing machine includes:

[0014] Fix the selected knife grinding plate at the central area of the sticky substrate film with an adhesive force greater than 120 N / 25 mm, and fix it with a metal ring matching the cutting worktable, so that the knife grinding plate, the sticky substrate film, and the metal ring form an integral body. The metal ring is magnetically adsorbed by the metal edge on the surface of the cutting worktable, and the sticky substrate film is adsorbed by the vacuum chuck of the dicing machine to realize the fixation of the knife grinding plate.

[0015] Optionally, in S200, the knife grinding parameters specifically include:

[0016] The knife grinding rotation speed setting range is 30000 rpm - 45000 rpm, and the knife grinding dicing speed is 5 mm / s - 40 mm / s.

[0017] Optionally, in S200, the knife grinding parameters further include:

[0018] Set the step of each grinding and cutting according to the thickness of the grinding wheel blade installed on the device, which is 5 to 10 times the thickness of the grinding wheel blade; the cooling water flow rate for the grinding wheel blade cutting is not less than 1 L / min.

[0019] Optionally, in S400, when controlling the grinding wheel blade to perform scribing according to the cutting parameters, it further includes:

[0020] During scribing, it is necessary to precisely control the depth of the grinding wheel blade cutting into the substrate of the gallium arsenide wafer, and at the same time cut through the material layer of the gallium arsenide wafer.

[0021] Optionally, in S400, the cutting parameters specifically include:

[0022] The scribing rotation speed setting range is 30000 rpm to 45000 rpm, and the product scribing speed is 15 mm / s to 60 mm / s.

[0023] Optionally, in S400, the cutting parameters further include:

[0024] The scribing depth is set to cut into the viscous substrate film by 0.5 μm to 4 μm, and the cooling water flow rate during the cutting of the grinding wheel blade is not less than 1 L / min.

[0025] The present invention has at least the following technical effects:

[0026] The scribing method of the gallium arsenide wafer provided by the present invention realizes double grinding on the grinding plate during the grinding plate grinding stage. On the one hand, it can expose the diamond of the grinding wheel blade and generate chip flutes, and on the other hand, it can round the grinding wheel blade to ensure the concentricity of the grinding wheel blade and the spindle. Moreover, each grinding will cause wear on the cutting edge part in contact with the grinding plate. Therefore, after two grindings from deep to shallow, the cutting edge of the grinding wheel blade will become "V"-shaped, achieving the purpose of trimming the cutting edge shape. In this way, during the scribing of the product, the contact area with the material is smaller, the impact and breaking force on the material is smaller, and the area in contact with the metal on the back of the material is smaller. It is especially suitable for materials such as gallium arsenide wafers that are hard, brittle, thin, and have backside metallization. It can significantly reduce the chipping and cracking of particles after dicing, which is beneficial to improving the cutting quality of the wafer, thereby improving the yield of wafer products. In addition, during the scribing stage, the gallium arsenide wafer is preferably divided into multiple stepped wide strip-shaped cutting channels (that is, the spacing between the cutting channels is greater than a single particle), and then detailed division is carried out. In this way, the material stress can be initially released. Since the area of the wafer wide strip is large enough to resist the problem of crack propagation, the cutting quality of the wafer is further improved. Description of the Drawings

[0027] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0028] Figure 1 It is a flowchart of a method for dicing a gallium arsenide wafer provided by an embodiment of the present invention.

[0029] Figure 2 It is a schematic diagram of the step-by-step dicing trajectory according to the first channel in a method for dicing a gallium arsenide wafer provided by an embodiment of the present invention;

[0030] Figure 3 It is a schematic diagram of the step-by-step dicing trajectory according to the second channel in a method for dicing a gallium arsenide wafer provided by an embodiment of the present invention;

[0031] Figure 4 It is a schematic diagram of the step-by-step dicing trajectory according to the third channel in a method for dicing a gallium arsenide wafer provided by an embodiment of the present invention. Specific Embodiments

[0032] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the described embodiments are some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0033] Those skilled in the art of this technology can understand that, unless otherwise defined, all terms used herein (including technical terms and scientific terms) have the same meaning as the general understanding of those of ordinary skill in the art to which the present invention belongs. It should also be understood that terms such as those defined in a general dictionary should be understood to have a meaning consistent with the meaning in the context of the prior art, and will not be interpreted with an idealized or overly formal meaning unless specifically defined as here.

[0034] Those skilled in the art of this technology can understand that, unless specifically stated, the singular forms "a", "an", "the" and "said" used herein may also include the plural forms. It should be further understood that the term "comprising" used in the description of the present invention means the presence of the described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their groups. The term "and / or" used herein includes all or any unit and all combinations of one or more related listed items.

[0035] The grinding process and dicing method of gallium arsenide wafers are a new method based on a dicing machine with a grinding wheel. The dicing mechanism of the dicing machine with a grinding wheel is that the grinding wheel blade is driven by the main shaft to rotate at high speed and impact the brittle material to form the division of the material. In the process of impacting and breaking the material, the main roles are played by the hard particles (i.e., diamonds) exposed on the grinding wheel blade and the chip flutes around them. The advantages and disadvantages of these two points will directly affect the size of the chipping and the crack situation generated after the material is divided. At the same time, due to the characteristics of gallium arsenide wafers such as hardness, brittleness, and thinness, the stress characteristics of the material and the shape of the grinding wheel blade also have a great impact on the chipping and cracks of the divided particles, thus affecting the yield of the wafers. Therefore, the embodiment of the present invention provides a dicing method for gallium arsenide wafers to solve the problem that the existing cutting method is easy to cause wafer breakage and affect the yield.

[0036] The following takes specific embodiments to elaborate in detail on the technical solution of the present invention and how the technical solution of the present invention solves the above technical problems.

[0037] As Figure 1 shown, the embodiment of the present invention provides a dicing method for gallium arsenide wafers, including the following steps S100 to S400:

[0038] S100, install a grinding plate with a particle size matching that of the grinding wheel blade at a predetermined position on the cutting worktable of the dicing machine.

[0039] Specifically, fix the selected grinding plate in the central area of the viscous substrate film with an adhesive force greater than 120 N / 25 mm, and fix it with a metal ring matching the cutting worktable, so that the grinding plate, the viscous substrate film, and the metal ring form an integral body. The metal ring is magnetically adsorbed by the metal edge on the surface of the cutting worktable, and the viscous substrate film is adsorbed by the vacuum chuck of the dicing machine to realize the fixation of the grinding plate.

[0040] Optionally, before S100, it includes:

[0041] Select a grinding plate with a particle size matching that of the grinding wheel blade; the particle size of the grinding plate is close to or the same as the size of the hard particles of the grinding wheel blade. Because if the particle size (hard particle size) of the grinding plate is too large, it will lead to excessive wear during grinding and a short blade life; when the particle size of the grinding plate is too small, it will lead to insufficient exposure of the diamond and poor roundness of the grinding wheel blade. Therefore, correctly selecting the particle size of the grinding plate is an index to ensure good cutting effect after grinding. For example: the particle size of the grinding plate is 4000# - 5000#, and the particle size of the grinding wheel blade is 4800# - 5000#.

[0042] S200. Set the grinding parameters and start the dicing machine. First, control the depth of the grinding wheel blade cutting into the grinding plate to be not less than the thickness of the gallium arsenide wafer to be cut, and then control the depth of the grinding wheel blade cutting into the grinding plate to be 1 / 4 - 1 / 2 of the thickness of the gallium arsenide wafer to be cut.

[0043] Two - stage grinding is achieved through the grinding plate. On the one hand, it can expose the diamond of the grinding wheel blade and generate chip flutes. On the other hand, it can round the grinding wheel blade to ensure the concentricity between the grinding wheel blade and the spindle. Moreover, each grinding will cause wear on the cutting edge part in contact with the grinding plate. Therefore, after two - stage grinding from deep to shallow, the cutting edge of the grinding wheel blade will become "V" - shaped, achieving the purpose of trimming the cutting edge shape. Compared with the conventional "U" - shaped grinding wheel cutting edge, the "V" - shaped grinding wheel cutting edge has less contact area with the material during the dicing process, smaller impact force on the material for impact fragmentation, and smaller contact area with the metal on the back of the material. It is especially suitable for hard, brittle, thin and back - metal materials such as gallium arsenide wafers, which can significantly reduce the chipping and cracking of particles after dicing, and is beneficial to improving the cutting quality of the wafer, thus improving the yield of wafer products.

[0044] Optionally, the grinding speed setting range is 30000 rpm - 45000 rpm, and the grinding dicing speed is 5 mm / s - 40 mm / s. Too low a speed will cause the risk of tool breakage, while too high a speed will generate a large impact force resulting in a snake - shaped cutting edge. The grinding dicing speed is also a key parameter. Too slow a grinding dicing speed affects efficiency, and too fast a grinding dicing speed will cause excessive load on the blade and is prone to tool breakage.

[0045] According to the thickness of the grinding wheel blade installed in the equipment, set the step of each grinding cut to be 5 - 10 times the thickness of the grinding wheel blade. Too small a step distance will affect the grinding effect, but too large a step distance will cause waste of the grinding plate and increase costs. The cooling water flow rate for the grinding wheel blade cutting is not less than 1 L / min, which is beneficial to improving the cutting edge formation. The setting of the cutting depth and grinding sequence refers to the key parameters of the above - mentioned grinding plate, and select the corresponding cutting mode for dicing according to the direction of the linear velocity of the blade rotation.

[0046] S300. Remove the grinding plate, install the grinding silicon wafer at a predetermined position on the cutting worktable, and control the depth of the grinding wheel blade cutting into the grinding silicon wafer to be 1 / 2 - 3 / 4 of the thickness of the gallium arsenide wafer to be cut.

[0047] Specifically, first perform two - stage grinding through the grinding plate in step S200, and then perform the third - stage grinding through the grinding silicon wafer in step S300, aiming to further improve the cutting edge state and end shape of the grinding wheel blade, making the diamond better exposed and generating more chip flutes, so that the current cutting edge and shape of the grinding wheel blade are more suitable for cutting hard, brittle and thin materials such as gallium arsenide wafers.

[0048] When sharpening the knife with a sharpening silicon wafer, the sharpening parameters can be referred to those in step S200 when sharpening the knife on the sharpening board, which will not be repeated here.

[0049] S400. Remove the sharpening silicon wafer and set the cutting parameters. Fix the gallium arsenide wafer to be cut at a predetermined position on the cutting workbench, and control the grinding wheel blade to perform scribing according to the cutting parameters. The cutting parameters include the cutting process, and the cutting process includes the first channel step, the second channel step, and the third channel step set in sequence. Among them, the first channel step is 3 to 7 times the step of the particle theory step, the second channel step is perpendicular to the first channel step, and scribing is performed in sequence according to the particle theory step. The third channel step is the remaining cutting channels after completing the first channel step. The particle theory step can be understood as a single particle (the side length of the smallest wafer unit).

[0050] Specifically, refer to Figures 2 to 4 , first fix the LED gallium arsenide wafer on a plastic film with a PVC substrate, place it in the central area of the plastic film, and fix it with a metal ring matching the workbench of the dicing machine. The wafer, plastic film, and metal ring form a whole. Then, adjust the viscosity of the plastic film by heating and baking the plastic film. Finally, magnetically adsorb the metal ring through the metal edge on the surface of the dicing machine workbench, and the vacuum chuck of the dicing machine adsorbs the plastic film with a negative pressure of not less than 80 kPa, so as to fix the gallium arsenide wafer.

[0051] During the specific cutting process, the whole cutting process is divided into three stages: as Figure 2 shown, for example, first scribe and cut at large intervals along the first direction every 3 to 7 times the particle theory step (for example: 5 times the particle theory step), which is conducive to the initial release of stress; as Figure 3 shown, then scribe in sequence along the second direction according to the particle theory step, and the second direction is perpendicular to the first direction; as Figure 4 shown, finally, subdivide and scribe the particles within the large interval to obtain multiple single grains. It can be understood that the interval of the first channel step is 3 to 7 times the particle theory step. If the interval is too small, it will cause stress and edge chipping, but if the interval is too large, it will not be able to release stress well.

[0052] It should be noted that, since most common LED gallium arsenide wafers are 4-inch round wafers, they will have a certain amount of deformation (i.e., stress) after the grinding process. The final particle size of this type of wafer material is relatively small (generally, particles of 90 to 140 um square). If the particles are cut according to the step size, they will be too small and will most likely cause cracks or serious chipping due to resistance to stress release. Therefore, the present invention preferentially divides the gallium arsenide wafer into a plurality of stepped wide strip cutting paths (i.e., the spacing between the cutting paths is greater than that of a single particle). In this way, the material stress can be initially released because the wide strip area is large enough to resist the problem of crack extension.

[0053] In addition, because the LED gallium arsenide wafer is hard, brittle and thin and has a layer of gold plating on the back, the grinding wheel blade will contact the metal and film on the back when cutting the wafer. Both materials pose a risk of blade clogging, which seriously affects the sharpness of the blade and causes chipping or cracking on the back of the particle. When cutting, the depth of the grinding wheel blade cutting into the substrate of the gallium arsenide wafer must be precisely controlled, and the material layer of the gallium arsenide wafer must be cut through at the same time. This can effectively solve the problem of the metal layer on the back of the material and the substrate film wrapping the blade during the continuous cutting process of the gallium arsenide wafer, resulting in reduced blade cutting ability.

[0054] Optionally, the cutting parameters in this embodiment specifically include: the cutting speed setting range is 30000rpm~45000rpm, the product cutting speed is 15mm / s~60mm / s; the cutting depth is set to cut into the sticky substrate film 0.5μm~4μm, and the cooling water flow rate during cutting of the grinding wheel blade is not less than 1L / min.

[0055] The gallium arsenide wafer dicing method provided by the embodiment of the present invention is used to process LED gallium arsenide wafers, without high-temperature melting and other destructive effects on crystal materials, and will not produce thermal decomposition to generate toxic substances. The physical dicing method has low pollution and is more conducive to green and sustainable development. In addition, the dicing accuracy can be controlled within the micron range, which can meet the precision processing requirements of various industries, and the product size obtained by dicing is high in precision and strong in practicality. The entire dicing operation process is simple, the process flow is coherent, and can meet the needs of gallium arsenide materials of various sizes and thicknesses. Compared with the laser cutting method, there is no subsequent manual splitting process, which is suitable for industrial production, can reduce the risks caused by manual operation errors, and has higher work efficiency. In addition, the consumables in the entire dicing process are low in price, low in consumption, and less in subsequent processes, which can reduce unnecessary labor costs. The early power supply and the later emission detection equipment are simple to build, which can greatly reduce the production cost, and significantly improve the quality and yield of LED chips, indirectly greatly reduce the manufacturing cost of chips, and provide a favorable guarantee for the mass industrial production of LED chips.

[0056] The above contents of the present invention are specifically described below by taking specific embodiments as examples:

[0057] Example 1

[0058] An embodiment of the present invention provides a dicing method for a gallium arsenide wafer, comprising the following steps:

[0059] S100, install a sharpening plate with a particle size matching the grinding wheel blade at a predetermined position on the cutting worktable of the dicing machine.

[0060] S200, set the sharpening parameters and start the dicing machine. First, control the depth of the grinding wheel blade cutting into the sharpening plate to be not less than the thickness of the gallium arsenide wafer to be cut, and then control the depth of the grinding wheel blade cutting into the sharpening plate to be 1 / 3 of the thickness of the gallium arsenide wafer to be cut.

[0061] Specifically, when using the sharpening plate F50 to sharpen the knife for the first time, the blade cuts into the sharpening plate by 150 μm, the rotation speed is 35000 rpm, the feed speed is 20 mm / s, and the number of cutting strips is 20; when using the sharpening plate F50 to sharpen the knife for the second time, the blade cuts into the sharpening plate by 50 μm, the rotation speed is 35000 rpm, the feed speed is 20 mm / s, and the number of cutting strips is 15.

[0062] S300, remove the sharpening plate, install the sharpening silicon wafer at a predetermined position on the cutting worktable, and control the depth of the grinding wheel blade cutting into the sharpening silicon wafer to be 2 / 3 of the thickness of the gallium arsenide wafer to be cut.

[0063] Specifically, when using the sharpening silicon wafer to pre-cut and sharpen the knife for the third time, it should cut into the silicon wafer by 100 μm, the rotation speed is 40000 rpm, the feed speed is 20 mm / s, and the number of cutting strips is 50.

[0064] S400, remove the sharpening silicon wafer and set the cutting parameters. Fix the gallium arsenide wafer to be cut at a predetermined position on the cutting worktable, and control the grinding wheel blade to perform dicing according to the cutting parameters; the cutting parameters include a cutting process, and the cutting process includes a first-channel step, a second-channel step, and a third-channel step set in sequence; among them, the first-channel step is 5 times the step according to the particle theory step, the second-channel step is perpendicular to the first-channel step and performs dicing in sequence according to the particle theory step; the third-channel step is the remaining cutting channels after completing the first-channel step.

[0065] Specifically, taking the gallium arsenide wafer for LED to be cut with a specification size of 4 inches (inches), a thickness of 0.15 mm, back gold, and a single product particle size of 0.1 mm * 0.1 mm (i.e., a single particle is a square with a side length of 0.1 mm) as an example for illustrative description.

[0066] First, perform dicing in the first direction (determined according to the design angle of the customer wafer). The spindle speed is 40,000 rpm, the feed rate of the grinding wheel is 35 mm / s, the cutting height of the grinding wheel dicing tool is 0.072 mm (cutting 3 um into the film), and the step is 0.4 mm (4 times the particle theory step).

[0067] Then, perform dicing in the second direction. The spindle speed is 40,000 rpm, the feed rate of the grinding wheel is 55 mm / s, the cutting height of the grinding wheel dicing tool is 0.072 mm, and the step is 0.1 mm.

[0068] Finally, repeat the dicing in the first direction, but the position is different from the dicing position in the first direction. The cutting start point is offset by 0.1 mm from the overall dicing position in the first direction, that is, one step. The spindle speed is 40,000 rpm, the feed rate of the grinding wheel is 25 mm / s, the cutting height of the grinding wheel dicing tool is 0.072 mm, and the steps are 0.1 mm and 0.2 mm respectively, that is, fill in the cutting that was not done in the first direction. The coolant flow rate of the grinding wheel is 1.3 L / min.

[0069] Example 2

[0070] Refer to the method of Example 1. The difference is that in step S200, control the depth of the grinding wheel blade cutting into the sharpening plate to be 1 / 4 of the thickness of the gallium arsenide wafer to be cut. Compared with the depth in Example 1, it is smaller, and the "V" shape trimmed is not obvious enough, and the sharpness is limited.

[0071] Example 3

[0072] Refer to the method of Example 1. The difference is that in step S200, control the depth of the grinding wheel blade cutting into the sharpening plate to be 1 / 2 of the thickness of the gallium arsenide wafer to be cut. Compared with the depth in Example 1, it is larger, and the "V" shape trimmed is too obvious, which will significantly reduce the blade strength to a certain extent and is prone to tool breakage during cutting.

[0073] Example 4

[0074] Refer to the method of Example 1. The difference is that in step S300, control the depth of the grinding wheel blade cutting into the sharpening silicon wafer to be 1 / 2 of the thickness of the gallium arsenide wafer to be cut.

[0075] Example 5

[0076] Refer to the method of Example 1. The difference is that in step S400, the first channel step cuts according to 7 times the particle theory step.

[0077] Comparative Example 1

[0078] Different from Example 1, in Comparative Example 1, only the sharpening plate is used for sharpening once.

[0079] Comparative Example 2

[0080] Different from Example 1, in Comparative Example 2, the cutting method is that the particles only step forward by a single time along the first direction.

[0081] Comparative Example 3

[0082] Different from Example 1, in step S200 of Comparative Example 3, the depth of the grinding wheel blade cutting into the sharpening plate is controlled to be 1 / 6 of the thickness of the gallium arsenide wafer to be cut.

[0083] Comparative Example 4

[0084] Different from Example 1, in step S200 of Comparative Example 4, the depth of the grinding wheel blade cutting into the sharpening plate is controlled to be 2 / 3 of the thickness of the gallium arsenide wafer to be cut.

[0085] Comparative Example 5

[0086] Different from Example 1, in step S300 of Comparative Example 5, the depth of the grinding wheel blade cutting into the sharpening silicon wafer is controlled to be 1 / 4 of the thickness of the gallium arsenide wafer to be cut.

[0087] Test Example

[0088] After observing the particle samples after cutting in each of the above-mentioned examples and comparative examples under a microscope, the corresponding front edge chipping and back edge chipping conditions are obtained, as shown in Table 1 below.

[0089] Table 1 Edge chipping statistics of each example and comparative example

[0090]

[0091] From the above results, it can be seen that compared with the comparative examples, adopting the embodiment scheme of the present invention can significantly reduce the edge chipping size, which is beneficial to improving the wafer qualification rate. Further, according to Example 1 and Examples 2 to 5, adopting the preferred dicing method of the present invention can reasonably control the edge chipping, and is more conducive to improving the wafer dicing quality on the premise of ensuring the dicing efficiency.

[0092] Those skilled in the art of the present technology can understand that the various operations, methods, steps, measures, and solutions in the processes discussed in the present invention can be alternated, changed, combined, or deleted. Further, other steps, measures, and solutions in the various operations, methods, and processes discussed in the present invention can also be alternated, changed, rearranged, decomposed, combined, or deleted. Further, those in the prior art having steps, measures, and solutions in the various operations, methods, and processes disclosed in the present invention can also be alternated, changed, rearranged, decomposed, combined, or deleted.

[0093] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention 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 should not be construed as a limitation of the present invention.

[0094] The terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0095] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected" and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0096] In the description of this specification, specific features, structures, materials, or characteristics may be combined in a suitable manner in any one or more embodiments or examples. It should be understood that although the steps in the flowchart of the drawings are shown in sequence according to the indication of the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise clearly stated in this article, the execution of these steps is not strictly limited in order, and they may be executed in other orders. Moreover, at least a part of the steps in the flowchart of the drawings may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same moment, but may be executed at different moments, and their execution order is not necessarily sequential, but may be executed alternately or in turn with at least a part of other steps or sub-steps or stages of other steps.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or equivalently replace some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A gallium arsenide wafer dicing method, characterized in that: include: S100, installing a grinding plate with a particle size matching the grinding wheel blade at a predetermined position of a cutting work disk of a dicing machine; S200, setting the sharpening parameters and starting the dicing machine, first controlling the grinding wheel blade to cut into the sharpening plate to a depth not less than the thickness of the gallium arsenide wafer to be cut, and then controlling the grinding wheel blade to cut into the sharpening plate to a depth of 1 / 3 of the thickness of the gallium arsenide wafer to be cut, and through two sharpenings from deep to shallow, the edge of the grinding wheel blade becomes a "V" shape, thereby achieving the purpose of trimming the blade shape; S300, remove the grinding plate, install the grinding silicon wafer on the predetermined position of the cutting work disc, control the grinding wheel blade to cut into the grinding silicon wafer to a depth of 2 / 3 of the thickness of the gallium arsenide wafer to be cut, further improve the cutting edge state and end shape of the grinding wheel blade, make the diamond better exposed and generate more chip grooves, so that the current blade and shape of the grinding wheel blade are more suitable for cutting hard, brittle and thin materials such as gallium arsenide wafers; S400, remove the grinding silicon wafer and set the cutting parameters, fix the gallium arsenide wafer to be cut at a predetermined position of the cutting work disk, and control the grinding wheel blade to cut according to the cutting parameters; the cutting parameters include a cutting process, and the cutting process includes a first channel step, a second channel step, and a third channel step set in sequence; wherein, the first channel step is 5 times the particle theoretical step, the second channel step is perpendicular to the first channel step, and the cutting is sequentially performed according to the particle theoretical step; the third channel step is to complete the remaining cutting path of the first channel step; the particle theoretical step is the side length of the smallest wafer unit; when cutting, the material layer of the gallium arsenide wafer must be cut through, and the cutting depth is set to cut into the sticky substrate film on the vacuum suction cup of the dicing machine by 0.5μm~4μm, which effectively solves the problem that the metal layer on the back of the material and the substrate film wrap the blade during the continuous cutting process of the gallium arsenide wafer, resulting in a reduction in the cutting ability of the blade; In S200, the knife sharpening parameters also include: According to the thickness of the grinding wheel blade installed on the equipment, set the step size for each grinding cut to 5 to 10 times the thickness of the grinding wheel blade.

2. The gallium arsenide wafer dicing method according to claim 1, characterized in that: Prior to S100, these included: A sharpening plate with a particle size matching that of the grinding wheel blade is selected; the particle size of the sharpening plate is close to or consistent with the hard particle size of the grinding wheel blade.

3. The gallium arsenide wafer dicing method according to claim 2, characterized in that: The particle size of the grinding plate is 4000#~5000#, and the particle size of the grinding wheel blade is 4800#~5000#.

4. The gallium arsenide wafer dicing method according to claim 1, characterized in that: In S100, the step of installing a grinding plate having a particle size matching that of a grinding wheel blade at a predetermined position of a cutting work disk of a dicing machine includes: The selected grinding plate is fixed on the central area of ​​the sticky substrate film with an adhesive force greater than 120N / 25mm, and fixed with a metal ring matching the cutting work disk, so that the grinding plate, the sticky substrate film and the metal ring form a whole. The grinding plate is fixed by magnetically adsorbing the metal ring through the metal edge of the cutting work disk surface and adsorbing the sticky substrate film through the vacuum suction cup of the dicing machine.

5. The gallium arsenide wafer dicing method according to claim 1, characterized in that: In S200, the knife sharpening parameters specifically include: The setting range of the sharpening speed is 30000rpm~45000rpm, and the sharpening cutting speed is 5mm / s~40mm / s.

6. The gallium arsenide wafer dicing method according to claim 1, characterized in that: In S200, the knife sharpening parameters also include: The cooling water flow rate of the grinding wheel blade cutting shall not be less than 1L / min.

7. The gallium arsenide wafer dicing method according to claim 1, characterized in that: In S400, the step of controlling the grinding wheel blade to perform cutting according to the cutting parameters further includes: When scribing, the depth of the grinding wheel blade cutting into the substrate of the gallium arsenide wafer must be accurately controlled, and the material layer of the gallium arsenide wafer must be cut through at the same time.

8. The gallium arsenide wafer dicing method according to claim 1, characterized in that: In S400, the cutting parameters specifically include: The cutting speed setting range is 30000rpm~45000rpm, and the product cutting speed is 15mm / s~60mm / s.

9. The gallium arsenide wafer dicing method according to claim 1, characterized in that: In S400, the cutting parameters also include: The cooling water flow rate of the grinding wheel blade during cutting shall not be less than 1L / min.

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