Process method for micron-sized high-precision slotting processing on front and back surfaces of base material

Abstract

The invention relates to a process method for micron-sized high-precision slotting on the front and back surfaces of a substrate, belonging to the technical field of semiconductor substrate grinding process, the process method provided by the invention can utilize the existing equipment to convert the structural characteristics processed by the previous process into mark points used for determining the position in the subsequent processing, so that not only can the processing precision be met, but also the processing efficiency is improved. The existing equipment does not need to be transformed, so that the cost is reduced, and the utilization rate of the whole equipment of a production line is improved; the conditions that after a conventional imaging system is transformed, the compatibility of equipment to other products is reduced, and the transformed equipment is fixed in a certain process, so that the utilization rate of the equipment is reduced, and the cost is increased are effectively avoided. Moreover, the process method can more accurately control the machining precision of the subsequent process, the whole product does not need to be cut into small blocks in advance, machining is performed only by means of precision offset of equipment, the one-time success rate of product production is improved, and meanwhile, the workload can be reduced and the working efficiency can be improved through whole-piece large-block machining.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor substrate grinding processing technology, and specifically relates to a process method for micron-level high-precision grooving on the front and back sides of a substrate. Background Art

[0002] At present, more and more semiconductor, optical, acoustic and other related products need to be grooved on both sides of a substrate, such as implantable neural electrode arrays (UEA / UIEA) and ultrasonic generators of ultrasonic probes. Such products generally have specific requirements for the position of the grooves on the front and back sides, and the accuracy of the groove position and the shape of the groove often determine the performance of the product; therefore, the accuracy of the position of the groove on the back side (the side to be processed later) and the shape of the groove are particularly important. Most of the existing processing technologies for simultaneous grooves on the front and back sides will choose to modify the groove processing equipment on the back side separately, such as: adding lenses with penetrating light sources such as infrared light and X-ray lenses to clearly see the position of the grooves on the front side of the product; or divide the product into small pieces through high-precision cutting, confirm one of the "standard edges", and use the "standard edge" as the reference, relying solely on the accuracy of the equipment itself, to set the processing position offset and processing step; or make a deeper mark on the front side through certain technical means, and grind and thin from the back side until the mark is exposed before processing.

[0003] However, these existing methods have their own limitations, namely: the investment in modifying the imaging module of the equipment is large, and due to technical limitations, the clarity needs to be improved; the efficiency of dividing the product into small pieces through high-precision cutting and confirming a "standard edge" is slow, which will greatly increase the production cost in actual operation, and the processing accuracy is completely dependent on the accuracy of the equipment itself, which introduces a new source of processing error into the product processing process, which is not conducive to mass production; in addition, after making a deeper mark on the surface of the product and then grinding from the back, the premise is that the part ground off from the back is useless to the product itself, and will not affect the performance of the finished product, and the finished product is thinner. Since the currently commonly used methods have many limitations in the actual implementation process, it is necessary to improve the existing processing technology for micron-level precision grooving on both sides of the substrate. Summary of the invention

[0004] The present invention is aimed at the above-mentioned problems and provides a process method for high-precision grooving at the micron level on the front and back sides of the substrate by utilizing the normal cutting mode of a knife wheel dicing machine, which has low cost, is conducive to mass production, is easy to operate, and has high processing accuracy.

[0005] The technical solution adopted by the present invention is: the process method for high-precision micron-level grooving on the front and back sides of the substrate comprises the following steps: Step 1: Selection of consumables: Choose diamond blades of suitable material and mesh size according to the material of the product to be processed, the final groove width and depth of the finished product, and the size of the chipping and burr allowed at the front cut; choose the appropriate fixing method according to the overall size of the product material; Step 2: Process the front of the product. Fix the back of the product with the front facing up on the cutter wheel dicing machine, and grind and cut the groove on the front according to the processing requirements. Set different rotation speeds, feed speeds and blade height parameters according to the processing requirements. After processing the groove, use a 3D surface width meter to randomly test the shape of the side and bottom of the groove, the overall depth of the groove, and use a microscope to measure the technical parameters of the groove spacing. If there is no problem, continue processing. If there is a problem, adjust the process, adjust the consumables, and compensate the accuracy of the equipment until the data is qualified and the front is processed as a whole and in batches. Step 3: Front quality inspection: After the front processing is completed, the front processed products are sampled for various indicators such as edge collapse, groove spacing, groove width, and consistency as needed; if qualified, proceed to the next step; if unqualified, evaluate rework or scrap, and adjust the process and equipment; Step 4: Process the edge of the back side of the product, that is, make a mark on the back side of the substrate with a depth greater than the groove on the front side; fix the front side of the product with the back side facing up, select a wide and coarse blade, select an appropriate mode, set the blade height lower than the cutting depth of the front groove, select an appropriate speed and feed speed, and grind and cut at the edge of the back side of the product. After the grinding and cutting is completed, use the industrial camera built into the equipment to clearly see the front cut mark at the cutting surface position of the back edge of the product; Step 5: Align and process the back mark. According to the product drawing requirements, calculate the offset position, angle and position of the front groove required for back groove opening, as well as the cutting depth required for the back groove. Select the appropriate blade according to the width, depth and chipping requirements of the back groove in the processing drawing; and adapt the appropriate rotation speed and cutting speed. After alignment with the front groove exposed at the bottom of the groove at the edge of the product as the mark point, perform grinding and cutting according to the calculated angle and position offset; Step 6: Finished product inspection: Inspect the processed products according to customer requirements to determine whether they meet the precision standards for processed products. If they meet the standards, the entire processing process is completed. If they fail, it is necessary to determine whether the product can be reworked. If so, proceed to step 5 again. If not, the product must be scrapped and reprocessed.

[0006] In step 1, the blade material should be selected according to the object to be processed and the following principles should be followed: Commonly used grinding wheels are divided into four categories according to the binder: electroforming, sintered metal, resin, and ceramic; When processing silicon, germanium, gallium arsenide, crystal compounds, piezoelectric ceramics, resins, and metal products, use electroforming knives; When processing crystal materials, glass, metal, piezoelectric ceramics, and resin products, use sintered metal knives; When processing glass, metal, and crystal compound products, use resin knives; When processing sapphire products, choose ceramic knives.

[0007] In step 1, the selection of blade mesh should be based on the product thickness, hardness, and edge collapse requirements and follow the following principles: When the product material is fixed, the smaller the chipping edge, the finer the blade mesh should be; if the chipping edge is required to be loose, a coarser blade mesh should be selected; When processing products of different materials, the higher the hardness of the product to be processed, the coarser the mesh of the blade to be selected. Conversely, the lower the hardness of the product to be processed, the finer the mesh of the blade to be selected; When processing products of different thicknesses, the thicker the product to be processed and the deeper the processing depth, the coarser the blade mesh should be selected. Conversely, the thinner the product to be processed and the shallower the processing depth, the finer the blade mesh should be selected.

[0008] In the step 1, when grinding and cutting grooves of different depths, different blade lengths are required. However, when the extension of the blade wheel and the cutting depth are in an incorrect ratio to the blade thickness, wavy cutting or over-wide cutting will occur. The parameters need to be proportional, and the cutting depth should not exceed 3 / 4 of the blade extension. The blade length-width ratio range is as follows: Electroformed and metal grinding wheel blades: blade length-to-width ratio is less than 20; Resin grinding wheel blade: blade length-to-width ratio is less than 10.

[0009] In step 2, the speed setting should not exceed the maximum speed that the blade can withstand. The maximum speeds of various types of blades are as follows: Electroformed grinding wheel blade: 60000rpm; Sintered metal grinding wheel blade: 40000rpm; Resin grinding wheel blade: 30000rpm; Ceramic grinding wheel blade: 10000rpm.

[0010] In the step 4, it is better to choose a blade with a coarse mesh and a wide blade width for the trimming process, without giving too much consideration to the edge chipping effect after cutting, and ensure that the edge chipping after cutting is within the level of 100 microns; in this step, the unprocessed surface of the edge of the product to be processed is ground until the processed part is exposed. After this part is exposed, it is used as a marking point for the subsequent step 5 alignment.

[0011] In the fourth step, the grinding and cutting method is flexibly selected. When the edge of the product to be processed is a straight line, the normal processing mode is selected; when the product to be processed is a circle, the edge trimming mode is selected; when the product to be processed is a circular fragment, the arc edge is processed as a full circle using edge trimming, and the other edges are processed as straight lines using the normal mode.

[0012] In the step 5, when grinding and cutting the back side, the mark used is the groove cut in step 2 exposed after processing in step 4; align and straighten according to the mark point exposed on the back edge, and enter the offset value and offset angle of the groove to be cut in the cutting parameters. The offset value and offset angle are calculated by other data given in the drawing. The specific calculation method is as follows: Offset value: b=ae Where: b – back groove offset; a——the distance between the center point of the product and the front; e——the distance between the center point of the product and the back; Offset angle: α=arcsin(d / c) Where: α – the angle between the back and front grooves in the drawing; d – stepping of the cut; c – the length of the cuts between the intersection points of the cuts.

[0013] Beneficial effects of the present invention: 1. The process method of the present invention can utilize existing equipment to convert the structural features after previous processing into marking points used for subsequent processing to determine the position, which can not only meet the processing accuracy, but also does not need to modify the existing equipment, thus reducing costs and improving the utilization rate of the overall equipment of the production line; it effectively avoids the situation that after the conventional imaging system is modified, the compatibility of the equipment with other products is reduced, and the modified equipment will be fixed in one or several processes, resulting in reduced equipment utilization and increased costs.

[0014] 2. The process method of the present invention can more accurately control the processing accuracy of subsequent processes (the marking points are exposed, which is convenient for alignment correction). There is no need to cut the entire product into small pieces in advance and rely solely on the equipment's own precision offset processing, which improves the one-time success rate of product production. In addition, processing of large pieces can reduce workload, improve work efficiency, and reduce time and material costs.

[0015] 3. The process method of the present invention can expose the structural features of the product after the previous process as a mark without damaging the entire surface or a large area of ​​each surface (unprocessed surface), creating the possibility for implementing more other processes on the back of the subsequent product; avoiding the existing process method of making alignment marks on the back of the product, which requires making etching marks on the front of the product downward and then grinding the entire back surface until the marking point is exposed. Under the premise of not affecting other areas of the product, the etching limit depth of the etching process is relatively shallow, and the entire back surface grinding will damage the back of the product on a large scale and affect the subsequent processing of the back.

[0016] 4. The process method of the present invention is easier to operate, without any other special consumables and auxiliary materials. The conventional slicing supporting facilities can meet the entire process requirements, saving costs and improving efficiency. In addition, the entire process does not require much operating experience, reducing the difficulty and making it easy for operators to get started. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a flowchart of the process method of the present invention.

[0018] Figure 2 It is a schematic diagram of the process method of the present invention after the entire front surface of the silicon wafer is cut.

[0019] Figure 3 It is a schematic diagram of the edge cutting of the back side (unprocessed side) of the silicon wafer in the process method of the present invention.

[0020] Figure 4 yes Figure 3 Axonometric view (stereoscopic view). DETAILED DESCRIPTION

[0021] In daily production and processing, it is a common requirement to perform grooving on both sides of a substrate. However, when the product has specific requirements for the position and accuracy of the grooves on the front and back sides, the processing difficulty and processing cost of the product will be greatly increased. The common processing methods now often modify the machine, use special lenses and light sources to see the inside through the surface covering, or divide the product into small pieces by high-precision cutting, confirm one of the "standard edges", and use the "standard edge" as a reference, relying solely on the accuracy of the equipment itself, set the processing position offset and processing step, or make a deeper mark on the front side through certain technical means, and then grind and thin from the back side until the mark is exposed before processing; these methods have their own limitations during processing. Therefore, it is necessary to invent a low-cost, batch-producible, easy-to-operate, high-precision process method that can perform micron-level precision grooving on both sides of the substrate. The process method of the present invention uses the normal cutting mode and Edge Trimming mode of the cutter wheel dicing machine to adjust and design the cutting method to achieve micron-level precision grooving on both sides of a substrate, which can be applied to the production and processing of a variety of materials with similar properties.

[0022] The specific steps of the present invention are described in detail. The process method for high-precision micron-level grooving on the front and back sides of a substrate comprises: Step 1: Selection of consumables. According to the material of the product to be processed, the final groove width and depth of the finished product, the size of the chipping and burr allowed at the front cut, select a diamond blade with a suitable material (resin, metal, ceramic, etc.) and mesh size (400# to 5000#). According to the overall size of the product material, select the fixing method (film fixing, wax fixing).

[0023] ① The material of the grinding wheel blade should be selected according to the object to be processed, and generally the following principles should be followed: Comparison table of blade material types and workpieces to be processed type Grinding wheel blade bond material Processed products Electroforming Nickel, etc. Silicon, germanium, gallium arsenide, some crystalline compounds (such as lithium niobate, lithium tantalate), some piezoelectric ceramics, some resins, some metals, etc. Sintered Metal Copper, tin, etc. Some crystal materials, some glass materials, some metal materials, some piezoelectric ceramic materials, some resin materials Resin Resin, metal, etc. Some glasses, some metals, some crystalline compounds ceramics Inorganic non-metallic materials, etc. sapphire Commonly used grinding wheel blades can be divided into four categories according to the binder: electroforming (the main component is metallic nickel), sintered metal (the main component is copper, tin, etc.), resin (the main component is resin, metal, etc.), and ceramic (the main component is inorganic non-metallic materials, etc.).

[0024] Electroforming knives are generally used when processing silicon, germanium, gallium arsenide, some crystalline compounds (such as lithium niobate, lithium tantalate), some piezoelectric ceramics, some resins, and some metal products.

[0025] When processing some crystal materials, some glass, some metals, some piezoelectric ceramics, and some resin products, sintered metal knives are generally used.

[0026] When processing some glass, some metal, and some crystal compound products, resin knives are generally used.

[0027] When processing sapphire products, ceramic knives are generally used.

[0028] ② The selection of grinding wheel blade mesh should generally be based on product thickness, hardness, edge collapse requirements and follow the following principles: When the product material is fixed, theoretically, the smaller the edge chipping is required, the finer the blade mesh (the larger the number) should be. If the edge chipping is required to be loose, a coarser mesh (smaller number) blade can be appropriately selected. However, the mesh should not be too fine in pursuit of small edge chipping. Too fine mesh may cause blade damage, serpentine cuts, and inability to cut products. If the above phenomena occur, the mesh should be appropriately thickened.

[0029] When processing products of different materials, theoretically, the higher the hardness of the product to be processed, the coarser the mesh of the grinding wheel blade should be (the smaller the number). Conversely, the lower the hardness of the product to be processed, the finer the mesh (the larger the number) of the grinding wheel blade should be.

[0030] When processing products of different thicknesses, theoretically, the thicker the product to be processed and the deeper the processing depth, the coarser the grinding wheel blade should be (the smaller the number). Conversely, the thinner the product to be processed and the shallower the processing depth, the finer the grinding wheel blade should be (the larger the number).

[0031] For example: the edge collapse requirement is less than 10um, and the mesh selection needs to be greater than 2000#; The edge collapse requirement is between 10 and 20um, and the mesh selection is generally between 800# and 2000#; The chipping edge requirement is greater than 20um, and the mesh selection can be less than 800#.

[0032] When actually selecting the blade mesh number, you can take the median value within the edge chipping requirement range for testing. If the edge chipping is large, you can replace the grinding wheel blade with a larger mesh number for testing. If other phenomena such as blade damage, product cutting inability, etc. occur, you can replace the grinding wheel blade with a smaller mesh number for testing.

[0033] ③ When grinding and cutting grooves of different depths, it is necessary to match the grinding wheel blade with different blade lengths. However, when the extension of the grinding wheel blade and the cutting depth are in an incorrect ratio to the blade thickness, it will cause wavy cutting or over-wide cutting. Therefore, all parameters must be kept in proportion, and the cutting depth should not exceed 3 / 4 of the blade extension. The blade length-width ratio range is as follows: Electroformed and metal grinding wheel blades: blade length-to-width ratio is less than 20; Resin grinding wheel blade: blade length-to-width ratio is less than 10.

[0034] Step 2: Processing of the front of the product. On the cutter wheel dicing machine, fix the back of the product with the front facing up, and grind and cut the groove on the front according to the processing requirements. The general processing requirements will indicate the groove depth, groove spacing, and edge collapse at the edge of the front groove. In order to ensure the processing effect, different parameters such as speed, feed speed and blade height should be set according to the requirements. The cutting depth is set to the same for the whole piece, and there is automatic height measurement to compensate the cutting depth during the cutting process. However, there is an error in the thickness of the equipment working plate (the plate that fixes the workpiece at the bottom) and the product itself. Therefore, after the groove is processed, it is necessary to test whether the depth is within the tolerance range, that is, use a 3D surface width meter to test the shape of the side and bottom of the groove, the overall depth of the groove, and use a microscope to measure the groove spacing technical parameters. If there is no problem, continue processing; if there is a problem, it is necessary to adjust the process, adjust the consumables, and compensate the accuracy of the equipment until the data is qualified before the front can be processed as a whole and in batches.

[0035] The speed setting should generally not exceed the theoretical maximum speed that the grinding wheel blade can withstand. The theoretical maximum speeds of various types of blades are as follows: Electroformed grinding wheel blade: 60000rpm; Sintered metal grinding wheel blade: 40000rpm; Resin grinding wheel blade: 30000rpm; Ceramic grinding wheel blade: 10000rpm.

[0036] When setting parameters, if there is no mature process, you can first test it with the median value within the blade's operating speed range, and then adjust it according to the processing effect. The optimal cutting speed for products of different materials is different; generally, the higher the speed, the better the edge collapse, but too high or too low speed will cause the blade to deform slightly during the cutting process, resulting in a poor groove shape.

[0037] Step 3: Front quality inspection. After the front processing is completed, the front processed products are randomly inspected for other indicators such as edge collapse, groove spacing, groove width, consistency, etc. If qualified, proceed to the next step. If unqualified, rework or scrapping will be evaluated according to the situation, and the process and equipment will be adjusted.

[0038] Step 4: Process the edge of the back side of the product, that is, make a mark on the back side of the substrate with a depth greater than the groove on the front side. Fix the front side (processed side) of the product with the back side facing up, select a wider blade with a coarser mesh, select the mode (edge ​​trimming mode is used for standard circles, standard mode is used for squares and irregular shapes), set the blade height lower than the cutting depth of the front groove, select the appropriate rotation speed and feed speed, and grind and cut at the edge of the back side of the product. After the grinding and cutting is completed, the front cut marks can be clearly seen at the cutting surface position of the back edge of the product through the industrial camera built into the equipment. The purpose of this step is to expose the cut marks on the front side on the back side, and the purpose of grinding on the edge is to maintain the integrity of the product to the greatest extent.

[0039] The choice of blade for trimming process is better with coarser mesh and wider blade width. You don't need to consider the edge collapse effect after cutting too much, just ensure that the edge collapse after cutting is within 100 microns. Grind the unprocessed surface of the edge of the product to be processed until the processed part is exposed; after this part is exposed, it can be used as a marking point for the subsequent step 5 alignment.

[0040] In addition, the grinding and cutting method should be flexibly selected. For example, if the edge of the product to be processed is a straight line, the normal processing mode (left cutting / A mode) can be directly selected; if the product to be processed is a circle, the edge trimming mode can be selected; if the product to be processed is a circular fragment, the arc edge can be processed as a full circle using edge trimming, and the other edges can be processed as straight lines using the normal mode. The principle of selecting the processing method is to damage the unprocessed surface as little as possible.

[0041] Step 5: Align and process the back mark. According to the product drawing requirements, calculate the offset position, angle and other requirements for the back groove and the position of the front groove, as well as the required cutting depth of the back groove. Select the blade according to the width, depth and chipping requirements of the back groove in the processing drawing; and adapt the appropriate rotation speed and cutting speed. Use the front (processed surface) cut exposed at the bottom of the cut at the edge of the product as the mark point for alignment, and then grind and cut according to the calculated angle and position offset.

[0042] The mark used is the groove cut out in step two that is exposed after processing in step four. Without adding other equipment or causing large-scale damage to the product, the results of the previous processing steps can be used to improve the accuracy of this step and accurately locate the part to be processed on the back of the product.

[0043] When grinding and cutting the back side, align and straighten according to the mark point exposed on the back side edge, and enter the offset value and offset angle of the groove to be cut in the cutting parameters. The offset value and offset angle can be calculated from other data given in the drawing. The specific calculation method is as follows: Offset value: b=ae Where: b – the groove offset of the back side (surface to be cut) (parameters need to be set for the equipment); a——The distance between the center point of the product and the front (cut surface); e——The distance between the center point of the product and the back (uncut surface).

[0044] Offset angle: α=arcsin(d / c) Where: α is the angle between the back side (to be cut) and the front side (cut) groove in the drawing (the equipment needs to set the parameter); d – stepping of the cut; c – the length of the cuts between the intersection points of the cuts.

[0045] Step 6: Finished product inspection. Inspect the processed products according to normal customer needs to determine whether they meet the precision standards of the processed products. If qualified, the entire processing process is completed; if unqualified, it is necessary to determine whether the product can be reworked. If it can be reworked, go back to step 5. If it cannot be reworked, it needs to be scrapped and reprocessed.

[0046] After a large amount of data measurement and processing using this method, the position accuracy of the front and back grooves can be within 20um when the equipment accuracy is normal and there is no abnormality in operation. Some data are intercepted as follows (to facilitate the measurement of data accuracy, the product is selected as a product with different sizes of front and back grooves that need to be aligned): Measurement data table Sheet 1 Sheet 1 Sheet 1 Sheet 2 Sheet 2 Sheet 2 Slice 3 Slice 3 Slice 3 Slice 4 Slice 4 Slice 4 Measurement area Point 1 in the region Point 2 in the region Point 3 in the area Point 1 in the region Point 2 in the region Point 3 in the area Point 1 in the region Point 2 in the region Point 3 in the area Point 1 in the region Point 2 in the region Point 3 in the area superior 7.01 um 4.09 um 2.79 um 7.72 um 4.76 um 5.73 um 5.32 um 8.32 um 6.32 um 6.97 um 6.74 um 6.23 um middle 3.67 um 4.48 um 4.42 um 5.13 um 7.38 um 7.51 um 7.68 um 9.03 um 6.83 um 6.95 um 8.49 um 7.17 um Down 7.41 um 3.31 um 4.33 um 6.79 um 6.64 um 7.94 um 3.91 um 5.56 um 3.74 um 2.45 um 5.24 um 7.14 um Left 3.52 um 2.91 um 3.46 um 8.13 um 5.73 um 7.95 um 5.79 um 2.68 um 5.39 um 8.33 um 7.31 um 5.71 um right 3.14 um 2.29 um 2.09 um 9.56 um 5.58 um 4.09 um 7.58 um 2.72 um 5.36 um 13.30 um 11.82 um 8.71 um The above measurement data table shows that 4 pieces without abnormalities in production were randomly selected from the continuously processed products, and three more places were randomly selected from each of the five areas of the product, namely the top, bottom, left, right and middle, to measure the overlap of the front and back processing groove positions. From the data in the table, it can be seen that the processing accuracy of the front and back overlap positions of the four products is within 20um, which meets the processing requirements of 20um accuracy.

[0047] Example: The embodiment is the grooving of thick hard materials with double-sided machining.

[0048] The industrialization / mass production process of some processes in the production of implantable neural electrode arrays (UEA / UIEA) is as follows: a: epitaxial wafer, 75 mm p-type c-Si (100) wafer, resistivity 0.01-0.05 Ω·cm; b: Back cutting, use a thinner blade (50um for this product), cut with a depth of 0.5mm, and make grooves at intervals of 400um, both horizontally and vertically, forming 7×7 chips, each chip has 13×13 grooves. The horizontal and vertical parameters are consistent, the depth error may be within plus or minus 20um, and the chipping edges on both sides are 10um each; c: vitrification (pour glass into the groove) + grinding (grind this surface flat); d: Back metallization, evaporation and sputtering of metal on the exposed silicon surface; e: Front cutting: This product uses a 250um or 150um thick blade to cut grooves from the uncut side (front) of the epitaxial wafer, with a step length of 400um and a depth of 1.5mm. The center offset of the grooves on both sides cannot exceed 30um; f: Wet etching to etch the front silicon pillar into a cone shape; g: Tip metallization, metal is plated on the surface of the silicon cone; h: array segmentation, dividing the array into individual chips; i: Parylene deposition, depositing insulating material on the entire front surface; j: Insulation of the end of polyparaxylene, remove the insulation material at the front tip; k: The carrier is removed, and the back substrate material is removed; after further processing, it finally becomes a finished product.

[0049] In the above process flow, the method of the present invention can be used for the process of grooving the front and back surfaces and offsetting by no more than 30um. The specific implementation method is as follows: Grinding wheel dicing machine: Use the dicing machine model DS9260 produced by Shenyang Heyan Technology Co., Ltd.; Grinding wheel blades: Blades of Shanghai Xinyang Semiconductor Materials Co., Ltd., model “SYB5M-MM-2045-P4, 53, 1190”; blades of Zhengzhou Abrasives and Grinding Tools Research Institute Co., Ltd., model “M1A8-SD1500-C100-H5255.55*0.5*40”; blades of Shanghai Xiyue Machinery Technology Co., Ltd., model “4000# 1A8 58*0.25*40”.

[0050] 1. Film pasting: Place the material on the automatic film pasting machine for film pasting. After the film pasting is completed, the material, UV film, and metal ring are bonded into a unified whole, and then placed on the workbench of the dicing machine and fixed by vacuum adsorption.

[0051] 2. Cutting and processing on one side: Use the conventional cutting function of the DS9260 dicing machine and the blade model "SYB5M-MM-2045-P4, 53, 1190", spindle speed 30000rpm, cutting depth 0.5mm, cutting speed CH1: 3mm / s, CH2: 2mm / s, cutting water flow 1L / min front and back spray, 1.5L / min side spray, 1.5L / min cleaning spray, cutting water temperature 20℃, cut the entire surface of the silicon wafer according to the required step size, remove it, clean it, pour glass into the material cutting seam, and do other surface treatments (such as Figure 2 as shown).

[0052] 3. Pre-cutting treatment of the other side: Place the product on the automatic film laminating machine to laminat the processed side. After laminating, use the "Edge Trimming" function of DS9260, with the blade model "M1A8-SD1500-C100-H5255.55*0.5*40", spindle speed 30000rpm, θ axis feed speed 1° / s, Z axis feed speed 1mm / s, cut in 1.6mm, diameter 75mm, perform circular trimming of the silicon wafer, and clean it. After cutting, it is equivalent to opening a groove of about 0.5mm wide and 1.6mm deep on the edge of the unprocessed side of the product, which can just expose the glass in the groove of the processed surface as a marking point for the processing alignment of this surface (such as Figure 3 and Figure 4 as shown).

[0053] 4. Cutting and processing on the other side: Use the conventional cutting function of the DS9260 dicing machine and the blade model "4000#1A8 58*0.25*40", spindle speed 23000rpm, cutting depth 1.5mm, cutting speed CH1: 1mm / s, CH2: 1mm / s, cutting water flow 0.5L / min front and back spray, 0.5L / min side spray, 0.5L / min cleaning spray, cutting water temperature 20℃, focus on the step height of the product edge, you can clearly see the front groove and glass filling, and the image boundary is clear, take the front groove and glass filling as the mark point, straighten the product and cut it at the front groove and glass filling. After cutting, clean the silicon powder on the surface of the product, remove the silicon wafer, and complete the remaining product process.

[0054] 5. Cutting into particles: stick the completed silicon wafer on the UV film, cut it according to the reserved cutting position with a blade of model "4000# 1A8 58*0.25*40", the cutting parameters are spindle speed 23000rpm, cutting depth 2mm, cutting speed CH1: 1mm / s, CH2: 1mm / s, cutting water flow 0.5L / min front and back spray, 0.5L / min side spray, 0.5L / min cleaning spray, cutting water temperature 20℃. After cutting, remove the particles and it is done.

[0055] 6. Inspection: Stand the cut particles side up and observe under a measuring microscope. The upper and lower grooves of the product can correspond to each other, and the center deviation does not exceed 30um, which meets the use requirements.

Claims

1. A process for high-precision micron-level grooving on the front and back sides of a substrate, characterized in that: The steps include: Step 1: Selection of consumables: Choose diamond blades of suitable material and mesh size according to the material of the product to be processed, the final groove width and depth of the finished product, and the size of the chipping and burr allowed at the front cut; choose the appropriate fixing method according to the overall size of the product material; Step 2: Process the front of the product. Fix the back of the product with the front facing up on the cutter wheel dicing machine, and grind and cut the groove on the front according to the processing requirements. Set different rotation speeds, feed speeds and blade height parameters according to the processing requirements. After processing the groove, use a 3D surface width meter to randomly test the shape of the side and bottom of the groove, the overall depth of the groove, and use a microscope to measure the technical parameters of the groove spacing. If there is no problem, continue processing. If there is a problem, adjust the process, adjust the consumables, and compensate the accuracy of the equipment until the data is qualified and the front is processed as a whole and in batches. Step 3: Front quality inspection: After the front processing is completed, the front processed products are sampled for various indicators such as edge collapse, groove spacing, groove width, and consistency as needed; if qualified, proceed to the next step; if unqualified, evaluate rework or scrap, and adjust the process and equipment; Step 4: Process the edge of the back side of the product, that is, make a mark on the back side of the substrate with a depth greater than the groove on the front side; fix the front side of the product with the back side facing up, select a wide and coarse blade, select an appropriate mode, set the blade height lower than the cutting depth of the front groove, select an appropriate speed and feed speed, and grind and cut at the edge of the back side of the product. After the grinding and cutting is completed, use the industrial camera built into the equipment to clearly see the front cut mark at the cutting surface position of the back edge of the product; Step 5: Align and process the back mark. According to the product drawing requirements, calculate the offset position, angle and position of the front groove required for back groove opening, as well as the cutting depth required for the back groove. Select the appropriate blade according to the width, depth and chipping requirements of the back groove in the processing drawing; and adapt the appropriate rotation speed and cutting speed. After alignment with the front groove exposed at the bottom of the groove at the edge of the product as the mark point, perform grinding and cutting according to the calculated angle and position offset; Step 6: Finished product inspection: Inspect the processed products according to customer requirements to determine whether they meet the precision standards for processed products. If they meet the standards, the entire processing process is completed. If they fail, it is necessary to determine whether the product can be reworked. If so, proceed to step 5 again. If not, the product must be scrapped and reprocessed.

2. The process for high-precision micron-level grooving on the front and back sides of a substrate according to claim 1, characterized in that: In step 1, the blade material should be selected according to the object to be processed and the following principles should be followed: Commonly used grinding wheels are divided into four categories according to the binder: electroforming, sintered metal, resin, and ceramic; When processing silicon, germanium, gallium arsenide, crystal compounds, piezoelectric ceramics, resins, and metal products, use electroforming knives; When processing crystal materials, glass, metal, piezoelectric ceramics, and resin products, sintered metal knives are used; When processing glass, metal, and crystal compound products, use resin knives; When processing sapphire products, choose ceramic knives.

3. The process for high-precision micron-level grooving on the front and back sides of a substrate according to claim 1, characterized in that: In step 1, the selection of blade mesh should be based on the product thickness, hardness, and edge collapse requirements and follow the following principles: When the product material is fixed, the smaller the chipping edge, the finer the blade mesh should be; if the chipping edge is required to be loose, a coarser blade mesh should be selected; When processing products of different materials, the higher the hardness of the product to be processed, the coarser the mesh of the blade to be selected. Conversely, the lower the hardness of the product to be processed, the finer the mesh of the blade to be selected; When processing products of different thicknesses, the thicker the product to be processed and the deeper the processing depth, the coarser the blade mesh should be selected. Conversely, the thinner the product to be processed and the shallower the processing depth, the finer the blade mesh should be selected.

4. The process for high-precision micron-level grooving on the front and back sides of a substrate according to claim 1, characterized in that: In the step 1, when grinding and cutting grooves of different depths, different blade lengths are required. However, when the extension of the blade wheel and the cutting depth are in an incorrect ratio to the blade thickness, wavy cutting or over-wide cutting will occur. The parameters need to be proportional, and the cutting depth should not exceed 3 / 4 of the blade extension. The blade length-width ratio range is as follows: Electroformed and metal grinding wheel blades: blade length-to-width ratio is less than 20; Resin grinding wheel blade: blade length-to-width ratio is less than 10.

5. The process for high-precision micron-level grooving on the front and back sides of a substrate according to claim 1, characterized in that: In step 2, the speed setting should not exceed the maximum speed that the blade can withstand. The maximum speeds of various types of blades are as follows: Electroformed grinding wheel blade: 60000rpm; Sintered metal grinding wheel blade: 40000rpm; Resin grinding wheel blade: 30000rpm; Ceramic grinding wheel blade: 10000rpm.

6. The process for high-precision micron-level grooving on the front and back sides of a substrate according to claim 1, characterized in that: In the step 4, it is better to choose a blade with a coarse mesh and a wide blade width for the trimming process, without giving too much consideration to the edge chipping effect after cutting, and ensure that the edge chipping after cutting is within the level of 100 microns; in this step, the unprocessed surface of the edge of the product to be processed is ground until the processed part is exposed. After this part is exposed, it is used as a marking point for the subsequent step 5 alignment.

7. The process for high-precision micron-level grooving on the front and back sides of a substrate according to claim 1, characterized in that: In the step 4, the grinding and cutting method is flexibly selected. When the edge of the product to be processed is a straight line, the normal processing mode is selected; when the product to be processed is a circle, the edge trimming mode is selected; when the product to be processed is a circular fragment, the arc edge is processed as a full circle using edge trimming, and the other edges are processed as straight lines using the normal mode.

8. The process for high-precision micron-level grooving on the front and back sides of a substrate according to claim 1, characterized in that: In the step 5, when grinding and cutting the back side, the mark used is the groove cut in step 2 exposed after processing in step 4; align and straighten according to the mark point exposed on the back edge, and enter the offset value and offset angle of the groove to be cut in the cutting parameters. The offset value and offset angle are calculated by other data given in the drawing. The specific calculation method is as follows: Offset value: b=ae Where: b – back groove offset; a——the distance between the center point of the product and the front; e——the distance between the center point of the product and the back; Offset angle: α=arcsin(d / c) Where: α – the angle between the back and front grooves in the drawing; d – stepping of the cut; c – the length of the cuts between the intersection points of the cuts.

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