Scribing method of back gold wafer

Abstract

The invention belongs to the technical field of semiconductor processing, particularly relates to a scribing method of a back gold wafer, and aims to solve the problem of low qualification rate caused by easy generation of curled edges, burrs, cracks and the like on a back metal layer when the back gold wafer is subjected to diamond grinding wheel scribing. By means of laser back face slotting scribing and laser front face slotting scribing, diamond grinding wheel slicing and cutting-off are carried out finally. According to the method, different technological characteristics of the laser grooving technology and the grinding wheel scribing technology are combined, back gold wafer scribing can be efficiently and stably completed, and the method is simple, practical, easy to implement and high in operability.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor processing, and in particular relates to a slicing method for a gold-backed wafer. Background Art

[0002] Solar cells, LEDs, power devices and other products have high requirements for bonding strength and heat dissipation. The packaging process of such products is generally completed by eutectic welding process. The metallization layer is processed on the back of the wafer by sputtering, evaporation and other methods before dicing to provide better heat dissipation performance and mechanical stability. However, the introduction of metal materials on the back greatly increases the difficulty of dicing back-gold wafers in the integrated circuit packaging production process.

[0003] Back-gold wafer refers to a wafer with one or more layers of metal deposited on the back.

[0004] Slicing is the first step in the entire integrated circuit packaging process. Its purpose is to separate the entire wafer into individual chips with independent electrical properties for subsequent chip packaging. The mainstream slicing processes include diamond wheel slicing process and laser slicing process.

[0005] Circuits with high requirements for bonding strength and heat dissipation mostly use wafer back gold processing. The metal materials on the back are generally titanium (Ti), nickel (Ni), gold (Au) / silver (Ag). The industry generally uses a grinding wheel scribing process to scribing such products. During scribing, the scribing knife is stably controlled at a certain height with the help of equipment and rotates at a high speed of 30,000 to 50,000 revolutions per minute. The workbench carrying the wafer moves in a straight line at a certain speed along the direction of the scribing knife, thereby achieving chip separation.

[0006] However, when the current integrated circuit back-gold wafer is diced using a diamond wheel dicing process, under conventional process conditions, the back metal material itself has good ductility and high fracture toughness, which causes the material to easily wrap around the diamond wheel blade, thereby reducing the cutting ability of the diamond wheel, increasing the stress during the dicing process and exacerbating problems such as curling, burrs, and cracking of the back metal layer. This results in a low pass rate during the packaging process of such products and extremely high product production costs. Summary of the invention

[0007] In order to solve the above-mentioned problem in the prior art, namely, when a gold-backed wafer is diced with a diamond wheel, the back metal layer is prone to curling, burrs, cracks, etc., resulting in a low pass rate, the present invention provides a dicing method for a gold-backed wafer.

[0008] The technical solution of the present invention includes:

[0009] A method for scribing a gold-backed wafer, characterized by comprising the steps of:

[0010] Step (1) Slicing and front film lamination: select a gold-backed wafer and laminate the front side of the gold-backed wafer on the dicing film according to the conventional dicing and laminating method;

[0011] Step (ii) laser back side slotting and scribing: using the visual recognition system under the transmission workbench to determine the position of the wafer front side scribing track, and using the laser slotting and scribing device to slot and scribing the back side of the gold-backed wafer;

[0012] Step (iii) scribing and cleaning: cleaning the wafer after the laser back side grooving and scribing is completed, and the back side grooving and scribing of the gold-backed wafer is completed;

[0013] Step (iv) laminating the back side of the wafer after laser back side slotting and laminating, laminating the back side of the gold-backed wafer on the dicing film according to the conventional laminating method;

[0014] Step (5) laser front side slotting and scribing: using laser slotting and scribing equipment, finding the scribe line position on the front side of the gold-backed wafer, and laser slotting and scribing the front side of the gold-backed wafer;

[0015] Step (six) grinding wheel cutting through scribing: after completing the laser grooving and scribing of the front side of the gold-backed wafer, use a diamond grinding wheel scribing knife to cut through the gold-backed wafer;

[0016] Step (VII) Slicing and cleaning: After the back side of the grinding wheel is cut through and the slicing is completed, the back-gold wafer is cleaned to complete the slicing of the back-gold wafer.

[0017] As an optional technical solution, in step (a), the diameter of the gold-backed wafer includes 4, 5, 6, 8, and 12 inches, the wafer thickness is 100 μm to 775 μm, and the minimum width of the dicing road is 80 μm.

[0018] As an optional technical solution, in step (a) and step (d), the substrate material of the dicing film is polyolefin with a thickness of ≤120μm, and the adhesive layer material is acrylic with a thickness of ≤20μm, thereby ensuring the stability of the gold-backed wafer during the dicing process; the dicing film has the characteristic of UV debonding, and the pre-UV viscosity is ≥5000mN / 25mm, thereby ensuring that the gold-backed wafer is firmly bonded during the dicing process.

[0019] As an optional technical solution, in step (ii), the transmission workbench includes a transparent workbench made of aluminosilicate glass, the dicing film is vacuum adsorbed on the transmission workbench, and a visual recognition system is arranged under the workbench, and the visual recognition system is used to identify the dicing line position on the front side of the back-gold wafer, and correspondingly generate the back side cutting position of the back-gold wafer based on this position.

[0020] As an optional technical solution, in step (ii), the laser grooving and scribing device includes a purple picosecond laser, the laser wavelength of which is 355nm, the maximum power is 25W, the pulse width is 80ns to 150ns, and the frequency is 40KHz to 200KHz.

[0021] As an optional technical solution, in step (ii), the back side of the back-gold wafer is laser grooved and scribed, the laser groove cutting depth is set to 2-5μm, the groove width is selected to be 35-45μm, the cutting speed is set to 250-400mm / s, the number of cutting times is set to 2-6 times, and the cutting power is set to 1-5W.

[0022] The cutting depth is set to 2-5 μm, which minimizes the amount of groove removal, ensures that the back metal material is effectively removed, and produces a smaller heat-affected area and thermal effect.

[0023] The slot width is selected to be 35 to 45 μm, so that the slotting mark has an appropriate width, ensuring that the mark is larger than the width of the cutting blade. When the back-gold wafer is cut through, the cutting blade can completely enter the cut without contacting the side wall of the cut, preventing secondary damage to the chip during the cutting process.

[0024] The cutting speed is set to 250-400 mm / s, which increases the cutting speed per unit time within a reasonable range and improves the cutting efficiency.

[0025] The number of cutting times is set to 2 to 6 times, and the number of cutting times is increased within a reasonable range to effectively remove the cutting material and prevent the problem of residual metal burrs.

[0026] The cutting power is set to 1-5W. The cutting power is increased within a reasonable range to improve the material removal capability and avoid residual metal burrs during cutting.

[0027] As an optional technical solution, in step (iii) and step (vii), the cleaning is an air-water two-fluid cleaning method, the cleaning water flow rate is 0.15-0.30 L / min, and the injection gas pressure is 0.15-0.40 MPa.

[0028] The air-water two-fluid cleaning method uses a scribing equipment cleaning unit to spray a supersonic water-air mixture to bombard the wafer surface, thereby removing various silicon debris and dust generated during scribing. The cleaning water flow rate is 0.15-0.30 L / min, and the spraying gas pressure is 0.15-0.40 MPa, which effectively removes contamination generated on the wafer surface during the scribing process.

[0029] As an optional technical solution, the front side of the gold-backed wafer described in step (v) is laser grooved and scribed, the laser groove cutting depth is set to 5-15 μm, the groove width is selected to be 35-45 μm, the cutting speed is set to 300-600 mm / s, the number of cutting times is set to 4-8 times, and the cutting power is set to 3-7 W.

[0030] The cutting depth is set to 5-15 μm, which can minimize the amount of groove removal while ensuring that the metal material on the back is effectively removed, thereby generating a smaller heat-affected area and thermal effect.

[0031] The slot width is selected to be 35 to 45 μm so that the slot cut has an appropriate width. On the one hand, it ensures that there is a certain safety distance between the cut and the chip isolation wall to reduce the thermal effect on the chip active area; on the other hand, it ensures that the cut is larger than the width of the cutting blade. When the back-gold wafer is cut through, the cutting blade can completely enter the cut but does not contact the side wall of the cut, thereby preventing secondary damage to the chip caused by the cutting process.

[0032] The cutting speed is set to 300-600 mm / s, within a reasonable range, to increase the cutting speed per unit time and improve the cutting efficiency.

[0033] The number of cutting times is set to 4 to 8 times. Within a reasonable range, the number of cutting times can be increased to effectively remove materials and prevent the problem of residual metal burrs.

[0034] The cutting power is set to 3-7W. Within a reasonable range, the cutting power is increased to improve the material removal capability and avoid residual metal burrs during cutting.

[0035] As an optional technical solution, in step (six), the back-gold wafer is cut through to completely cut through the back-gold wafer and cut 20 to 30 μm thick downward from the surface of the film to ensure that the back-gold wafer is completely separated into single independent chips; when cutting through, the grinding wheel spindle speed is set to 30,000 to 50,000 r / min, and the feed speed is set to 10 to 20 mm / s.

[0036] As an optional technical solution, when the back-gold wafer is cut through, the cutting blade used is a nickel-plated diamond grinding wheel dicing knife, whose width is 10 to 15 μm thinner than the laser grooving width, the cutting blade blade length is selected to be 350 to 550 μm, the diamond mesh number of the cutting blade is selected to be 3000 to 4000 mesh, the diamond concentration of the cutting blade is selected to be 50 to 70, and the diamond adhesive strength of the cutting blade is selected to be a soft binder.

[0037] The diamond grinding wheel slicing knife is a metal electroplated knife, and its main electroplating component is nickel. The nickel-plated diamond grinding wheel slicing knife can be made thinner, has higher slicing and cutting accuracy, and has strong cutting ability.

[0038] The key technical indicators for selecting the through-cut blade used in the diamond wheel scribing process include: blade width, blade length, diamond mesh number, concentration and adhesive strength.

[0039] The blade width is 10-15 μm thinner than the laser slotting width, and the through-cutting blade can completely enter the cut without contacting the side wall of the cut, thereby preventing secondary damage to the chip caused by the through-cutting process.

[0040] The blade length is selected to be 350-550 μm. Within the blade processing capacity range, a blade with a smaller length is selected to reduce the cutting stress caused by the blade shaking during the cutting process.

[0041] The diamond mesh number of the blade is selected to be 3000-4000 mesh, and the diamond particles on the surface of the blade have an appropriate size, which reduces the cutting stress while making the blade edge have a certain size to prevent the blade edge from being blocked by silicon powder during the cutting process, causing a surge in cutting stress due to a decrease in the cutting ability of the blade.

[0042] The diamond concentration of the blade is selected to be 50-70, and the density of diamond particles is reasonably controlled to ensure the cutting ability of the blade while making the blade have a larger blade edge to prevent the blade edge from being wrapped and blocked by silicon powder during the grooving process, which causes a surge in cutting stress caused by a decrease in the cutting ability of the blade.

[0043] The diamond adhesive strength of the blade is selected as a soft adhesive, which ensures that the diamond particles can be quickly updated during the blade grooving process and has a continuous and stable cutting ability.

[0044] Conventional diamond wheel dicing equipment is used to perform a through-cut process on the front side of the gold-backed wafer. The key process parameters of the dicing equipment include: cutting depth, spindle speed and feed speed.

[0045] The cutting depth is the penetration depth. The blade needs to completely cut through the gold-backed wafer and cut 20 to 30 μm thick from the surface of the film to completely separate the gold-backed wafer into individual independent chips.

[0046] The spindle speed is set to 30,000-50,000 r / min. Within the range allowed by the equipment capacity, the amount removed per revolution is reduced, the cutting stress is reduced, and the probability of cracking is reduced.

[0047] The feed speed is set to 10-20 mm / s, within a reasonable range, to reduce the amount removed per unit time, reduce cutting stress, and reduce the probability of cracking.

[0048] Beneficial effects of the present invention:

[0049] (1) The back-gold wafer dicing method of this method is different from the conventional grinding wheel dicing process. First, a laser grooving and dicing device is used to remove the metallization layer on the back of the back-gold wafer. Then, a combination of laser grooving and grinding wheel dicing equipment is used to cut the front of the back-gold wafer, finally achieving high-reliability dicing of the back-gold wafer.

[0050] (2) The back-gold wafer dicing method of the present invention utilizes a laser grooving process, which can instantly sublimate and evaporate the metal material on the back of the back-gold wafer, effectively controlling the heat-affected zone and thermal effect during the dicing process, while ensuring the cutting quality of the front side of the back-gold wafer, thereby improving the packaging qualification rate of such products.

[0051] (3) By utilizing various process parameters in the dicing method of the present invention, the heat-affected zone and thermal effect of the dicing process are further controlled, effectively solving the serious problems of metal curling, burrs, and edge collapse on the back side of the back-gold wafer after dicing;

[0052] (4) The back-gold wafer dicing method of the present invention is combined with the different process technology characteristics of the laser grooving process and the grinding wheel dicing process to efficiently and stably complete the back-gold wafer dicing. The method is simple, practical, easy to implement and highly operational. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0054] Figure 1 This is a schematic diagram of the transmission workbench principle of the present invention;

[0055] Figure 2 It is a schematic diagram of laser grooving on the back side of a gold-backed wafer of the present invention;

[0056] Figure 3 It is a schematic diagram of cutting a gold-backed wafer of the present invention;

[0057] Figure 4 It is a process flow chart of back-gold wafer scribing of the present invention;

[0058] Reference numerals include:

[0059] 1-Laser, 2-Diamond wheel dicing knife, 3-Transmission workbench, 4-Visual recognition system, 5-Front side of wafer, 6-Back side of wafer, 7-Wafer, 8-Laser grooving marks, 9-Grinding wheel cutting marks. DETAILED DESCRIPTION

[0060] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the relevant invention are shown in the accompanying drawings.

[0061] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0062] The present invention provides a method for dicing a gold-backed wafer. Figure 4 As shown, the steps include:

[0063] Step (1) Slicing and front film lamination: select a gold-backed wafer and laminate the front side of the gold-backed wafer on the dicing film according to the conventional dicing and laminating method;

[0064] Step (ii) laser back side slotting and scribing: using the visual recognition system under the transmission workbench to determine the position of the wafer front side scribing track, and using the laser slotting and scribing device to slot and scribing the back side of the gold-backed wafer;

[0065] Step (iii) scribing and cleaning: cleaning the wafer after the laser back side grooving and scribing is completed, and the back side grooving and scribing of the gold-backed wafer is completed;

[0066] Step (iv) laminating the back side of the wafer after laser back side slotting and laminating, laminating the back side of the gold-backed wafer on the dicing film according to the conventional laminating method;

[0067] Step (5) laser front side slotting and scribing: using laser slotting and scribing equipment, finding the scribe line position on the front side of the gold-backed wafer, and laser slotting and scribing the front side of the gold-backed wafer;

[0068] Step (six) grinding wheel cutting through scribing: after completing the laser grooving and scribing of the front side of the gold-backed wafer, use a diamond grinding wheel scribing knife to cut through the gold-backed wafer;

[0069] Step (VII) Slicing and cleaning: After the back side of the grinding wheel is cut through and the slicing is completed, the back-gold wafer is cleaned to complete the slicing of the back-gold wafer.

[0070] Among them, Figure 1 Shown is a schematic diagram of the transmission workbench principle of the present invention.

[0071] The invention comprises a transmission workbench 3, a visual recognition system 4 is arranged below the transmission workbench 3, the transmission workbench 3 comprises a transparent workbench made of transparent material, a scribing film is vacuum-adsorbed on the workbench, a front side 5 of a back-gold wafer is attached to the scribing film downward, a back side 6 of the back-gold wafer is upward, the visual recognition system 4 determines the scribing path position of the front side of the back-gold wafer, and correspondingly determines the scribing path position of the back side of the back-gold wafer, the laser 1 performs laser grooving according to the determined scribing path position, and the back side of the back-gold wafer after laser grooving is as shown in FIG. Figure 2 shown.

[0072] After laser front and back grooved back gold wafer Figure 3 As shown, diamond wheel slicing and cutting are performed, and the diamond wheel dicing knife 2 scribes and cuts on the laser slotting marks 8 on the wafer 7, and the grinding wheel cutting marks 9 are cutting marks, which divide the wafer 7 into independent chips.

[0073] Example

[0074] The back-gold wafer scribing method of the present invention is used to scribing a back-gold wafer of a certain type of integrated circuit, and the specific steps are as follows:

[0075] (1) Slicing and front film application

[0076] A certain type of integrated circuit back-gold wafer with a thickness of 200μm was selected. The conventional method of wafer lamination was followed, but the direction of the back-gold wafer lamination was changed, and the front side of the back-gold wafer was attached to the dicing film.

[0077] The dicing film substrate material is polyolefin with a thickness of 110μm, the adhesive layer material is acrylic with a thickness of 15μm, and the pre-UV viscosity is 7500mN / 25mm.

[0078] (2) Laser backside grooving and scribing

[0079] Use laser grooving and scribing equipment to scribing the back of the gold-backed wafer. The cutting position is determined according to the scribing track position identified on the front of the gold-backed wafer. The cutting depth is set to 3μm, the grooving width is set to 40μm, the cutting speed is set to 300mm / s, the number of cuts is set to 4 times, and the cutting power is set to 2W.

[0080] (3) Slice cleaning

[0081] After laser grooving and scribing, the back-gold wafer is cleaned to complete the scribing.

[0082] (4) Film on the back of the slicing

[0083] For the gold-backed wafer after the back side is grooved, the back side of the gold-backed wafer is attached to the dicing film according to the conventional dicing film attaching method.

[0084] (5) Laser front side grooving and scribing

[0085] Use laser slotting and scribing equipment to scribing the front side of the gold-backed wafer. The cutting position is the scribing line on the front side of the gold-backed wafer. The cutting depth is set to 10μm, the slot width is set to 40μm, the cutting speed is set to 500mm / s, the number of cuts is set to 6 times, and the cutting power is set to 5W.

[0086] (6) Grinding wheel cutting through the slice

[0087] The diamond wheel cutting knife is a nickel-plated diamond wheel slicer, the cutting blade width is 30μm, the blade length is selected as 350μm, the blade diamond mesh is selected as 3500 mesh, the blade diamond concentration is selected as 50, and the blade diamond adhesive strength is selected as a soft binder.

[0088] Use a diamond wheel cutting knife to scribing the front side of the gold-backed wafer, with a cutting depth of 20 μm from the film surface downward, the spindle speed is set to 30,000 r / min, and the feed speed is set to 10 mm / s.

[0089] (7) Slice cleaning

[0090] After the through-cut dicing is completed, the back-gold wafer is cleaned to complete the back-gold wafer dicing.

[0091] In the description of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0092] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0093] The term "comprise" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that includes a list of elements includes not only those elements but also other elements not expressly listed, or also includes elements inherent to such process, method, article, or apparatus / device.

[0094] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A method for scribing a gold-backed wafer, characterized in that Includes steps: Step (1) Slicing and front film lamination: select a gold-backed wafer and laminate the front side of the gold-backed wafer on the dicing film according to the conventional dicing and laminating method; Step (ii) laser back side slotting and scribing: using the visual recognition system under the transmission workbench to determine the position of the wafer front side scribing track, and using the laser slotting and scribing device to slot and scribing the back side of the gold-backed wafer; Step (iii) scribing and cleaning: cleaning the wafer after the laser back side grooving and scribing is completed, and the back side grooving and scribing of the gold-backed wafer is completed; Step (iv) laminating the back side of the wafer after laser back side slotting and laminating, laminating the back side of the gold-backed wafer on the dicing film according to the conventional laminating method; Step (5) laser front side slotting and scribing: using laser slotting and scribing equipment, finding the scribe line position on the front side of the gold-backed wafer, and laser slotting and scribing the front side of the gold-backed wafer; Step (six) grinding wheel cutting through scribing: after completing the laser grooving and scribing of the front side of the gold-backed wafer, use a diamond grinding wheel scribing knife to cut through the gold-backed wafer; Step (VII) Slicing and cleaning: After the back side of the grinding wheel is cut through and the slicing is completed, the back-gold wafer is cleaned to complete the slicing of the back-gold wafer.

2. A method for scribing a gold-backed wafer as claimed in claim 1, characterized in that: In step (a), the diameter of the gold-backed wafer includes 4, 5, 6, 8, and 12 inches, the wafer thickness is 100 μm to 775 μm, and the minimum width of the scribe line is 80 μm.

3. A method for scribing a gold-backed wafer as claimed in claim 1, characterized in that: In step (a) and step (d), the substrate material of the dicing film is polyolefin with a thickness of ≤120 μm, and the adhesive layer material is acrylic with a thickness of ≤20 μm, thereby ensuring the stability of the gold-backed wafer during the dicing process; the dicing film has the characteristic of UV debonding, and the pre-UV viscosity is ≥5000 mN / 25 mm, thereby ensuring that the gold-backed wafer is firmly bonded during the dicing process.

4. A method for scribing a gold-backed wafer as claimed in claim 1, characterized in that: In step (ii), the transmission workbench includes a transparent workbench made of aluminosilicate glass, the dicing film is vacuum adsorbed on the transmission workbench, and a visual recognition system is arranged under the workbench. The visual recognition system is used to identify the dicing position of the front side of the back-gold wafer and generate the back side cutting position of the back-gold wafer accordingly.

5. A method for scribing a gold-backed wafer as claimed in claim 1, characterized in that: In step (ii), the laser grooving and scribing device includes a purple picosecond laser, the laser wavelength of which is 355nm, the maximum power is 25W, the pulse width is 80ns-150ns, and the frequency is 40KHz-200KHz.

6. A method for scribing a gold-backed wafer as claimed in claim 5, characterized in that: In step (ii), the back side of the gold-backed wafer is laser grooved and scribed, the laser groove cutting depth is set to 2-5 μm, the groove width is selected to be 35-45 μm, the cutting speed is set to 250-400 mm / s, the number of cutting times is set to 2-6 times, and the cutting power is set to 1-5 W.

7. A method for scribing a gold-backed wafer as claimed in claim 1, characterized in that: In step (iii) and step (vii), the cleaning is an air-water two-fluid cleaning method, the cleaning water flow rate is 0.15-0.30 L / min, and the injection gas pressure is 0.15-0.40 Mpa.

8. A method for scribing a gold-backed wafer as claimed in claim 1, characterized in that: In step (five), the front side of the gold-backed wafer is laser grooved and scribed, the laser groove cutting depth is set to 5-15 μm, the groove width is selected to be 35-45 μm, the cutting speed is set to 300-600 mm / s, the number of cutting times is set to 4-8 times, and the cutting power is set to 3-7 W.

9. A method for scribing a gold-backed wafer as claimed in claim 1, characterized in that: In step (six), the back-gold wafer is cut through to completely cut through the back-gold wafer and cut 20 to 30 μm thick downward from the surface of the film to ensure that the back-gold wafer is completely separated into single independent chips; when cutting through, the grinding wheel spindle speed is set to 30000 to 50000 r / min, and the feed speed is set to 10 to 20 mm / s.

10. A method for scribing a gold-backed wafer as claimed in claim 9, characterized in that: When the back-gold wafer is cut through, the cutting blade used is a nickel-plated diamond grinding wheel dicing knife, whose width is 10-15 μm thinner than the laser grooving width, the cutting blade blade length is selected to be 350-550 μm, the diamond mesh number of the cutting blade is selected to be 3000-4000 mesh, the diamond concentration of the cutting blade is selected to be 50-70, and the diamond adhesive strength of the cutting blade is selected to be a soft binder.

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