A cutting and forming method for wafer-level laminated plastic-sealed round wafer

Abstract

The present invention relates to a cutting and forming method for wafer-level laminated plastic-sealed discs, and belongs to the technical field of semiconductor packaging jigs. The cutting platform comprises a cutting knife group (50), a chassis (70), a rotating motor (80) and a film scrap suction system (90). The chassis (70) sucks the plastic-sealed disc (20) by vacuum, and the cutting knife I (51), cutting knife II (52), cutting knife III (53), cutting knife IV (54) and a file (58) of the cutting knife group (50) sequentially operate on the plastic-sealed disc (20) to complete the edge trimming of the plastic-sealed disc (20) and the trimming of the alignment notch (13). The present invention trims and constrains the edge of the plastic-sealed disc that has completed the lamination process to form the morphology of a standard disc.

Description

Technical Field

[0001] The invention relates to a cutting and molding method for a wafer-level laminated plastic-sealed round wafer, belonging to the technical field of semiconductor packaging jigs. Background Art

[0002] With the development of the semiconductor industry, wafer-level packaging (wafer WLP) has become a typical low-cost and high-efficiency packaging method, with a large number of mature production lines at home and abroad, but the traditional wafer-level packaging method has also encountered some limiting factors. In the plastic encapsulation process, a lamination process is often used to use curled layered plastic molding compound (sheet mold molding compound) around the chip, on the back and even on the front, and the plastic molding compound is wrapped through the flattening process. The plastic molding compound is generally used as a carrier to continue the subsequent bumping process. In this manufacturing process, the edge of the wafer is not constrained and often deformed, no longer in the shape of a standard wafer, which affects the subsequent bumping production.

[0003] The edge of the wafer needs to be trimmed and constrained to form a standard wafer shape, thereby ensuring that the edge shape will not affect the bump manufacturing process during the bump manufacturing process. Summary of the invention

[0004] Based on this, it is necessary to provide a cutting and forming method for wafer-level laminated plastic-encapsulated wafers. During the manufacturing process, the edges of the plastic-encapsulated wafers that have completed the lamination process are trimmed and constrained to form the morphology of a standard wafer.

[0005] The object of the present invention is achieved in that:

[0006] The present invention provides a cutting and forming method for wafer-level laminated plastic-sealed round wafers, and the process steps are as follows:

[0007] Step 1: preparing a wafer that has completed fan-out packaging through a flip-chip process, wherein the wafer is provided with an alignment notch, wherein the alignment notch is in the form of a V-groove, and an angle A of the V-groove is not greater than 2°;

[0008] Step 2: Pre-treat the wafer surface, which may include plasma cleaning, baking or water washing;

[0009] Step 3: Select a layered plastic film of appropriate thickness, cut it to form a circle of the same size as the disc, and fit it to the front of the disc to form a plastic-sealed disc;

[0010] Step 4: Using a laminating device, in a closed space, setting a suitable temperature, and using an air bag and / or a metal plate to flatten the plastic-sealed disc, the plastic-sealing material of the plastic-sealing material film overflows the edge of the plastic-sealed disc;

[0011] Step 5: Prepare the cutting platform, and vacuum the plastic-sealed disc through the bottom plate of the cutting platform. The cutting knives I, II, III, and IV of the cutting knife group are in the initial state, and the position of the file is aligned with the center line of the alignment notch of the plastic-sealed disc to be trimmed;

[0012] Step 6: The cutters I, II, III, IV and the file operate in sequence: the cutters I and IV trim the edge of the plastic-sealed wafer, the cutters II and III trim the edge of the alignment notch of the plastic-sealed wafer, and the file trims the alignment notch of the plastic-sealed wafer; the tips of the cutters I, II, III and IV move in the tangent direction of the edge of the wafer in sequence;

[0013] Step 7: Remove the cut plastic-encapsulated disc from the cutting platform and transfer it to the next process station.

[0014] Furthermore, the wafer includes, from top to bottom, a plurality of wafers arranged at equal distances according to design conditions, a sticky material for fixing the wafers, and a carrier wafer.

[0015] Furthermore, step three also includes tearing off the upper release film of the plastic encapsulation film, the plastic encapsulation film includes an upper release film, a plastic encapsulation layer and a lower release film, and an upper bonding surface is formed on the upper surface corresponding to the plastic encapsulation layer, and a lower bonding surface is formed on the lower surface corresponding to the plastic encapsulation layer, the material of the plastic encapsulation layer is epoxy resin or a mixture of epoxy resin and filler, the upper release film and the lower release film are ABF films; the plastic encapsulation film is bonded to the front side of the wafer through its upper bonding surface.

[0016] Further, in step six, the cutting platform includes a cutting knife group, a chassis, a rotating motor and a film scrap suction system, the chassis sucks the plastic sealing disc by vacuum, the front of the plastic sealing disc faces upward, and makes it rotate in situ under the action of the chassis; the rotating motor drives the chassis of the cutting platform to rotate clockwise or counterclockwise; the cutting knife group is arranged on one side of the chassis, and the cutting knife I, cutting knife II, file, cutting knife III and cutting knife IV are arranged from left to right in sequence, the cutting knife II and cutting knife III are symmetrical with the file as the center line, and the cutting knife I and cutting knife IV are also symmetrical with the file as the center line; the cutting knife I, cutting knife II, cutting knife III, cutting knife IV and file 58 have their tips arranged in an arc shape, surrounding the chassis to form an arc, and the radius of the arc is R3;

[0017] The angle α between the blades of cutter I and cutter IV is in the range of 90°≤α≤180°, and the angle β between cutter II and cutter III is in the range of 60°≤β≤90°. The film scrap suction system draws waste away from the working area of ​​the cutting knife group. The film scrap suction system includes a plurality of pipes connected to a vacuum cleaner, and the pipes are distributed above cutter I, cutter II, file, cutter III and cutter IV, close to their respective blade tips; it also includes a static-eliminating ion fan and a camera, the static-eliminating ion fan is arranged on the other side of the chassis, and the camera is arranged above the cutting knife group.

[0018] Furthermore, in step six, the operation order of the cutting knife I and the cutting knife IV can be interchanged.

[0019] Furthermore, in step six, the cutting knife II and the cutting knife III alternately cut into the alignment notch of the plastic packaging wafer.

[0020] Furthermore, in step six, the cutter I trims the edge of the plastic-sealed wafer, including the following steps: first, a camera above the cutting knife group captures and locates the center straight line position of the wafer alignment notch, and fine-tunes the chassis to rotate clockwise by a certain angle B, wherein the angle B is not greater than half of the angle A; then, the cutter I extends toward the direction close to the plastic-sealed wafer and makes the cutter I close to the right side of the plastic-sealed wafer alignment notch, and the rotating motor drives the cutting platform, and the plastic-sealed wafer rotates counterclockwise in situ under the action of the chassis, and takes the current position as the starting point and rotates counterclockwise by an angle γ, wherein the value of the angle γ is not less than 363°; during the rotation process, the cutting edge of the cutter I is close to the edge of the wafer, and along the tangent direction of the edge of the wafer, the invalid plastic-sealing material outside the wafer is cut and peeled off through the cutting edge, and the waste material is extracted from the working area of ​​the cutter I through the film scrap suction system; after the work is completed, the cutter I returns to its original position.

[0021] Furthermore, in step six, the cutting knife IV trims the edge of the plastic-sealed wafer, including the following steps: first, a camera above the cutting knife group captures and locates the center straight line position of the wafer alignment notch, and fine-tunes the chassis to rotate counterclockwise by a certain angle B, wherein the angle B is not greater than half of the angle A, and the angle B is adjusted according to the size of the wafer;

[0022] Then: cutter IV extends toward the plastic encapsulation wafer and makes cutter IV close to the left side of the alignment notch of the plastic encapsulation wafer, the rotating motor drives the cutting platform, and the plastic encapsulation wafer rotates clockwise in situ under the action of the chassis, and takes the current position as the starting point, and rotates counterclockwise by an angle θ, and the value of angle θ is not less than 363°; during the rotation process, the cutting edge of cutter I is close to the edge of the wafer, and along the tangent direction of the edge of the wafer, the invalid plastic encapsulation material outside the wafer is cut and peeled off through the cutting edge, and the waste material is sucked away from the working area of ​​cutter IV through the film scrap suction system; after the work is completed, cutter IV returns to its original position.

[0023] Furthermore, in step six, the cutter II and the cutter III perform edge trimming on the alignment notch of the plastic-sealed wafer, including the following steps: first, fine-tuning the chassis to rotate the plastic-sealed wafer to the center straight line position of the wafer alignment notch, and the cutter II and the cutter III cut into the alignment notch of the plastic-sealed wafer from the left and right sides respectively, and cut the plastic sealing material in the alignment notch step by step at a speed of 0.5 microns downwards, and extract the waste material from the working area of ​​the cutter II and the cutter III through the film scrap suction system; the actual cutting distance is not less than 1 mm and is based on reaching the wafer; after the work is completed, the cutter II and the cutter III return to their original positions.

[0024] Furthermore, in step six, the file trims the alignment notch of the plastic-sealed wafer, including the steps of: the file moves forward from the central axis and presses against the alignment notch area of ​​the plastic-sealed wafer, moving up and down, and extracting waste materials from the working area of ​​the file through the film chip suction system; after the work is completed, the file returns to its original position.

[0025] Beneficial Effects

[0026] 1. In the manufacturing process of the present invention, a silicon wafer or glass is used as a carrier, and the plastic sealing material of the plastic sealing wafer is evenly spread on the carrier after the lamination process, and the chip of the wafer on the carrier is coated and packaged;

[0027] 2. The present invention provides a cutting and molding method for wafer-level laminated plastic-sealed discs, which defines the structure of the cutting platform, the operating sequence, operating angle and operating distance of the cutting knife group, and trims the edge of the plastic-sealed disc to ensure that the plastic-sealed disc still maintains a standard size after lamination, thereby ensuring that the edge morphology during the bump manufacturing process of the chip will not affect the bump manufacturing process, and the next step of the process can be smoothly continued. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a flow chart of a method for cutting and molding a wafer-level laminated plastic-sealed round wafer of the present invention;

[0029] Figures 2 to 4 It is a schematic diagram of a cutting platform for wafer-level laminated plastic-sealed round wafers of the present invention;

[0030] Figure 5 is a schematic top view of a wafer in the present invention;

[0031] Figure 6 It is a cross-sectional schematic diagram of the plastic sealing material film in the present invention;

[0032] Figure 7 It is a cross-sectional schematic diagram of the plastic-sealed wafer in the present invention;

[0033] Figures 8A to 8K It is a cross-sectional schematic diagram of a cutting and molding method of a wafer-level laminated plastic-encapsulated wafer of an embodiment;

[0034] In the figure:

[0035] Wafer 10

[0036] Wafer 11

[0037] Viscous material 12

[0038] Position gap 13

[0039] Plastic wafer 20

[0040] Plastic film 30

[0041] Upper release film 31

[0042] Plastic packaging material layer 32

[0043] Lower release film 33

[0044] Upper joint surface 311

[0045] Lower joint surface 331

[0046] Cutting knife set 50

[0047] Cutter I51

[0048] Cutting knife Ⅱ52

[0049] Cutter Ⅲ53

[0050] Cutting knife Ⅳ54

[0051] File 58

[0052] Chassis 70

[0053] Motor 80

[0054] Film scrap suction system 90. DETAILED DESCRIPTION

[0055] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings of the present invention. Based on the embodiments in this application, other similar embodiments obtained by ordinary technicians in this field without making creative work should all fall within the scope of protection of this application. In addition, the directional words mentioned in the following embodiments, such as "up", "down", "left", "right", etc., are only reference to the directions of the accompanying drawings. Therefore, the directional words used are used to illustrate rather than limit the invention.

[0056] The specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings.

[0057] Reference Figure 1 The process of a cutting and forming method of a wafer-level laminated plastic-sealed round wafer of the present invention is as follows:

[0058] Executing step S101: providing a wafer to be laminated;

[0059] Executing step S102: pre-processing the surface of the wafer;

[0060] Executing step S103: cutting the layered plastic film and laminating it with the upper surface of the wafer to form a plastic wafer;

[0061] Execute step S104: the laminating device performs a flattening process on the plastic-sealed wafer, and the plastic-sealing material overflows the edge of the plastic-sealed wafer;

[0062] Execute step S105: prepare a cutting platform, fix the plastic-sealed wafer and align it;

[0063] Execute step S106: the cutting blades I, II, III, IV and the file of the cutting platform sequentially cut the plastic sealing material overflowing the edge of the plastic sealing wafer;

[0064] Execute step S107: remove the cut plastic-encapsulated wafer from the cutting platform and transfer it to the next process station.

[0065] Example

[0066] The present invention provides a wafer-level laminated plastic-sealed round wafer cutting platform, such as Figures 2 to 4 As shown, it includes a cutting knife group 50, a chassis 70, a rotating motor 80 and a film scrap suction system 90. The chassis 70 sucks the plastic packaging wafer 20 by vacuum. The rotating motor 80 drives the chassis 70 of the cutting platform to rotate clockwise or counterclockwise.

[0067] The cutting knife group 50 is arranged on one side of the chassis 70, and the cutting knife I 51, the cutting knife II 52, the file 58, the cutting knife III 53 and the cutting knife IV 54 are arranged in sequence from left to right. The cutting knives II 52 and III 53 are symmetrical with the file 58 as the center line, and the cutting knives I 51 and IV 54 are also symmetrical with the file 58 as the center line; the tips of the cutting knives I 51, II 52, III 53, IV 54 and the file 58 are arranged in an arc shape, surrounding the chassis 70 to form an arc, and the radius of the arc is R3.

[0068] The angle α between the blades of the cutting blades I 51 and IV 54 is in the range of 90°≤α≤180°, so as to ensure that the subsequent rotation angle of the wafer 10 can be as small as possible and reduce the arc of rotation. Figure 3 In particular, in order to ensure that the alignment notch 13 of the plastic wafer 20 can be trimmed as close to the outline of the standard wafer as possible, the angle β between the cutting blade II 52 and the cutting blade III 53 is required to be in the range of 60°≤β≤90°, as shown in FIG. Figure 4As shown. The film scrap suction system 90 arranged next to the cutting knife extracts waste materials from the working area of ​​the cutting knife. The film scrap suction system 90 includes a plurality of pipes 91 connected to a vacuum cleaner, and the pipes 91 are distributed above the cutting knife I 51, the cutting knife II 52, the file 58, the cutting knife III 53 and the cutting knife IV 54, close to their respective knife tips. It also includes a static electricity removal ion blower 60 and a camera, the static electricity removal ion blower 60 is arranged on the other side of the chassis 70, and the camera is arranged above the cutting knife group 50.

[0069] The plastic wafer 20 includes a wafer 10 for fan-out packaging through a flip-chip process and a plastic film 30. The wafer 10 includes, from top to bottom, a plurality of chips 11 arranged at equal distances according to design conditions, an adhesive material 12 for fixing the chips 11, and a carrier wafer. The wafer 10 is provided with a positioning notch 13, and the positioning notch 13 is in the form of a V-groove, and the angle A of the V-groove is not greater than 2°. Figure 5 shown.

[0070] The molding material film 30 includes an upper release film 31, a molding material layer 32 and a lower release film 33, and an upper bonding surface 311 is formed on the upper surface corresponding to the molding material layer 32, and a lower bonding surface 331 is formed on the lower surface corresponding to the molding material layer 32. The molding material layer 32 is made of epoxy resin or a mixture of epoxy resin and filler. The upper release film 31 and the lower release film 33 are ABF films, such as Figure 6 After the upper release film 31 is removed, the plastic film 30 is laminated with the front surface of the wafer 10 through its upper bonding surface 311 to form a plastic wafer 20. Figure 7 The front side of the plastic packaging disc 20 faces upwards, and is rotated in place under the action of the bottom plate 70.

[0071] During operation, the camera above the cutting knife group 50 captures and locates the wafer 10 at the center straight line position of the notch 13, and the tips of the cutting knives I 51 , II 52 , III 53 and IV 54 move in the tangent direction of the edge of the wafer 10 in sequence.

[0072] The present invention relates to a cutting and forming method for a wafer-level laminated plastic-sealed round wafer. FIG. 8A to FIG. 8K The figure is a cross-sectional schematic diagram of the cutting and forming method. The process steps are as follows:

[0073] Step 1: Prepare a wafer 10 that has completed fan-out packaging, whose radius is R1. The wafer 10 includes a plurality of chips 11 arranged at equal distances according to design conditions, an adhesive material 12 for fixing the chips 11, and a carrier wafer. Fig. 8A is a top view, Figure 8B The wafer 10 is a partially enlarged cross-sectional schematic diagram. The wafer 10 is of a standard wafer size, which means that the size of the wafer 10 is 200 mm (8 inches) or 300 mm (12 inches).

[0074] The material of the carrier wafer can be a silicon wafer or a glass wafer, which is equivalent to a carrier plate, and is used to carry the wafer 10. The wafer 10 is a reconstructed wafer completed by flipping, and the mounting accuracy of adjacent chips 11 is within 15 microns. Generally, it is required that the distance S1 between the outermost chip 11 and the outermost side of the carrier wafer after arrangement is not less than 3 mm. The periphery of the wafer 10 is processed with an alignment notch 13 of a specified shape and size, which is the positioning and identification mark of the wafer. Generally, the length of the 8-inch and 12-inch alignment notches 13 is 1.2 mm. The alignment notch 13 can also be a V-groove, and the grinding accuracy of the V-groove is very high, and the shape and position tolerance is required to be within a few wires. The angle A of the V-groove is not greater than 2°.

[0075] Step 2: pre-treating the surface of the wafer 10, such pre-treating methods include but are not limited to plasma cleaning, baking or water washing;

[0076] Step 3: Select a layered plastic film 30 of appropriate thickness and cut it to form a circle of the same size as the wafer 10. Generally, the plastic film 30 includes an upper release film 31, a plastic layer 32 and a lower release film 33, and an upper bonding surface 311 is formed on the upper surface corresponding to the plastic layer 32, and a lower bonding surface 331 is formed on the lower surface corresponding to the plastic layer 32. The plastic layer 32 is made of epoxy resin or a mixture of epoxy resin and filler. The upper release film 31 and the lower release film 33 are ABF films, such as Figure 8C shown.

[0077] To ensure that the wafer is fully wrapped and flows evenly, the cutting size requirement is: the size is not less than 199 mm (corresponding to an 8-inch wafer) or 299 mm (corresponding to a 12-inch wafer). After the cutting is completed, the upper release film 31 on the upper surface of the plastic film 30 is torn off to expose the upper bonding surface 311, which is then bonded to the upper surface of the wafer 10 to form a plastic-encapsulated wafer 20. Fig.8D After the surface of the wafer 10 is processed, the chip 11 can be more tightly combined with the plastic film 30 and the relative position of the chip 11 can be kept fixed.

[0078] Step 4: Use laminating equipment to set a suitable temperature in a closed space, and use air bags and / or metal plates to flatten the plastic film 30. The suitable temperature is usually the temperature point where the plastic layer 32 has the best fluidity after melting. After the plastic wafer 20 is flattened, the plastic of the plastic layer 32 of the plastic film 30 overflows during the lamination process, and after overflowing, it will exceed the edge of the original wafer 10, forming a "large wafer" that exceeds the conventional size, with a radius of R2. The edge of the overflowed plastic is often irregular, and its relative width is S3, which interferes with subsequent operations. Therefore, the overflowed plastic needs to be trimmed accordingly, such as Fig. 8E As shown;

[0079] Step 5: Prepare the cutting platform. When not in operation, the cutters I 51, II 52, III 53 and IV 54 are in their initial state, i.e., their original positions. The plastic-encapsulated wafer 20 is sucked by the bottom plate 70 of the cutting platform by vacuum, and the camera above the cutting knife group 50 is used to grab and position the file 58 so that the position is aligned with the center line of the alignment notch 13 of the plastic-encapsulated wafer 20 to be trimmed. Fig.8F As shown;

[0080] Step 6: The following steps will define the operating sequence of cutter I 51, cutter II 52, cutter III 53, cutter IV 54 and file 58 in sequence.

[0081] The cutting blade I 51 trims the edge of the plastic-sealed wafer 20, such as Figure 8G As shown:

[0082] First, the camera above the cutting knife group 50 captures and locates the wafer 10 to the center straight line position of the notch 13, and the chassis 70 is fine-tuned to rotate clockwise by a certain angle B, which is not greater than half of the angle A. This angle B is adjusted according to the size of the wafer 10. Generally, the angle B of an 8-inch wafer 10 is 0.5° to 0.7°, and the angle B of a 12-inch wafer 10 is 0.6° to 0.7°.

[0083] Then: the cutter I51 extends toward the direction close to the plastic encapsulated wafer 20 and makes the cutter I51 close to the right side of the alignment notch 13 of the plastic encapsulated wafer 20. The rotating motor 80 drives the cutting platform. The plastic encapsulated wafer 20 rotates counterclockwise in situ under the action of the chassis 70. Starting from the current position, it rotates counterclockwise by an angle γ. The value of the angle γ is not less than 363°. For 8-inch or 12-inch wafers, the angle of the alignment notch is not greater than 2°. In order to cut cleanly, it must be rotated more than 363°. During the rotation process, the tip of the cutter I51 is close to the edge of the wafer 10. Along the tangent direction of the edge of the wafer 10, the invalid plastic encapsulation material outside the wafer 10 is cut and peeled off by the tip of the cutter, and the waste material is extracted from the working area of ​​the cutter I51 through the film scrap suction system 90. Repeat the above work several times to ensure the trimming quality. After the work is completed, the cutter I51 returns to its original position

[0084] The cutting blade IV 54 trims the edge of the plastic-encapsulated wafer 20, such as Figure 8H As shown:

[0085] First, the camera above the cutting knife group 50 captures and locates the wafer 10 to the center straight line position of the notch 13, and the fine-tuning chassis 70 rotates counterclockwise by a certain angle B, which is not greater than half of the angle A. The angle B is adjusted according to the size of the wafer 10. Generally, the angle B of an 8-inch wafer 10 is 0.5° to 0.7°, and the angle B of a 12-inch wafer 10 is 0.6° to 0.7°.

[0086] Then: the cutter IV54 extends toward the plastic encapsulated wafer 20 and makes the cutter IV54 close to the left side of the alignment notch 13 of the plastic encapsulated wafer 20. The rotating motor 80 drives the cutting platform. The plastic encapsulated wafer 20 rotates clockwise in situ under the action of the chassis 70. Starting from the current position, it rotates counterclockwise by an angle θ. The value of the angle θ is not less than 363°. For 8-inch or 12-inch wafers, the angle of the alignment notch 13 is not greater than 2°. In order to cut cleanly, it must be rotated more than 363°. During the rotation process, the tip of the cutter I51 is close to the edge of the wafer 10. Along the tangent direction of the edge of the wafer 10, the invalid plastic encapsulation material outside the wafer 10 is cut and peeled off by the tip of the cutter, and the waste material is extracted from the working area of ​​the cutter IV54 through the film scrap suction system 90. Repeat the above work several times to ensure the trimming quality. After the work is completed, the cutter IV54 returns to its original position

[0087] It should be noted that the operation order of the cutting blade I 51 and the cutting blade IV 54 can be interchanged. After the previous cutting blade is completed, the latter is used to trim the ground better.

[0088] The cutting blade II 52 and the cutting blade III 53 perform edge trimming on the alignment notch 13 of the plastic packaging wafer 20, such as Figure 8I and 8J As shown:

[0089] First, the chassis 70 is fine-tuned to rotate the plastic-sealed wafer 20 to the center straight line position of the alignment notch 13 of the wafer 10, and the cutter II 52 and the cutter III 53 cut into the alignment notch 13 of the plastic-sealed wafer 20 from the left and right sides respectively, and the plastic-sealed materials in the alignment notch 13 are cut step by step at 0.5 microns, and the waste materials are extracted from the working area of ​​the cutter II 52 and the cutter III 53 through the film scrap suction system 90; the actual cutting distance is not less than 1 mm and is based on the wafer 10. In order to ensure the working effect, the cutter II 52 and the cutter III 53 alternately cut into the alignment notch 13 of the plastic-sealed wafer 20, and the cutter II 52 and the cutter III 53 repeat the above work several times; after the work is completed, the cutter II 52 and the cutter III 53 return to the original position.

[0090] The file 58 is used to trim the alignment notch 13 of the plastic packaging disc 20. Figure 8K As shown:

[0091] The file 58 moves forward from the central axis and abuts against the alignment notch 13 area of ​​the plastic packaging wafer 20 , and moves up and down, and the waste is sucked away from the working area of ​​the file 58 through the film scrap suction system 90 .

[0092] The file repeats the above work several times to ensure that the plastic sealing material in the alignment gap 13 is completely removed; after the work is completed, the file 58 returns to its original position.

[0093] Step 7: The cut plastic-encapsulated wafer 20 is removed from the cutting platform and transferred to the next process station.

[0094] Generally, the next process includes tearing off the lower release film 33 and baking and curing the plastic encapsulation material. Optionally, if it is necessary to continue to bond the supporting silicon wafer or glass sheet G1 on the lower bonding surface 331, the lower release film 33 is generally torn off to expose the lower bonding surface 331, and the silicon wafer or glass sheet G1 is laminated on the lower bonding surface 331. Because it will be pressed again, the plastic encapsulation material layer 32 may overflow again, and the processes of step 6 need to be repeated. After the cutting of the plastic encapsulation material is completed, baking and curing are performed again.

[0095] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for cutting and molding a wafer-level laminated plastic-sealed wafer, the process steps of which are as follows: Step 1: preparing a wafer (10) that has completed fan-out packaging through a flip-chip process, wherein the wafer (10) is provided with an alignment notch (13), wherein the alignment notch (13) is in the form of a V-groove, and an angle A of the V-groove is not greater than 2°; Step 2: pre-treating the surface of the wafer (10), wherein the pre-treatment methods include plasma cleaning, baking or water washing; Step 3: Select a layered plastic film (30) of suitable thickness, cut it into a circle of the same size as the disc (10), and fit it to the front side of the disc (10) to form a plastic-sealed disc (20); Step 4: Using a laminating device, in a closed space, setting a suitable temperature, and using an air bag and / or a metal plate to flatten the plastic-sealed disc (20), so that the plastic-sealed material of the plastic-sealed material film (30) overflows the edge of the plastic-sealed disc (20); Step 5: Prepare a cutting platform, hold the plastic-sealed disc (20) by vacuum through the bottom plate (70) of the cutting platform, and place the cutting blades I (51), II (52), III (53), and IV (54) of the cutting blade group (50) in an initial state, and align the position of the file (58) with the center line of the alignment notch (13) of the plastic-sealed disc (20) to be trimmed; Step 6: The cutter I (51), the cutter II (52), the cutter III (53), the cutter IV (54) and the file (58) operate in sequence: the cutter I (51) and the cutter IV (54) trim the edge of the plastic-sealed wafer (20), the cutter II (52) and the cutter III (53) trim the edge of the alignment notch (13) of the plastic-sealed wafer (20), and the file (58) trims the alignment notch (13) of the plastic-sealed wafer (20); the tips of the cutters I (51), the cutter II (52), the cutter III (53) and the cutter IV (54) move in sequence along the tangent direction of the edge of the wafer (10); Step 7: The cut plastic-encapsulated disc (20) is removed from the cutting platform and transferred to the next process station.

2. The cutting and forming method according to claim 1, characterized in that: The wafer (10) comprises, from top to bottom, a plurality of wafers (11) arranged at equal distances according to design conditions, an adhesive material (12) for fixing the wafers (11), and a carrier wafer.

3. The cutting and forming method according to claim 2, characterized in that: Step three also includes tearing off the upper release film (31) of the plastic encapsulation film (30), wherein the plastic encapsulation film (30) includes an upper release film (31), a plastic encapsulation layer (32) and a lower release film (33), and forming an upper bonding surface (311) on the upper surface corresponding to the plastic encapsulation layer (32), and forming a lower bonding surface (331) on the lower surface corresponding to the plastic encapsulation layer (32), wherein the material of the plastic encapsulation layer (32) is epoxy resin or a mixture of epoxy resin and filler, and the upper release film (31) and the lower release film (33) are ABF films; the plastic encapsulation film (30) is bonded to the front side of the wafer (10) via its upper bonding surface (311).

4. The cutting and forming method according to claim 3, characterized in that: In step six, the cutting platform comprises a cutting knife group (50), a chassis (70), a rotating motor (80) and a film scrap suction system (90); the chassis (70) sucks the plastic-sealed disc (20) by vacuum, with the front side of the plastic-sealed disc (20) facing upward, and makes it rotate in situ under the action of the chassis (70); the rotating motor (80) drives the chassis (70) of the cutting platform to rotate clockwise or counterclockwise; the cutting knife group (50) is arranged on one side of the chassis (70), and is arranged in sequence from left to right A cutting knife I (51), a cutting knife II (52), a file (58), a cutting knife III (53) and a cutting knife IV (54), wherein the cutting knife II (52) and the cutting knife III (53) are symmetrical with the file (58) as the center line, and the cutting knife I (51) and the cutting knife IV (54) are also symmetrical with the file (58) as the center line; the cutting knife tips of the cutting knife I (51), the cutting knife II (52), the cutting knife III (53), the cutting knife IV (54) and the file (58) are arranged in an arc shape, surrounding the bottom plate (70) to form an arc shape, and the radius of the arc shape is R3; The angle α between the blades of the cutting knife I (51) and the cutting knife IV (54) is in the range of 90°≤α≤180°, and the angle β between the cutting knife II (52) and the cutting knife III (53) is in the range of 60°≤β≤90°. The film scrap suction system (90) extracts waste materials from the working area of ​​the cutting knife group. The film scrap suction system (90) includes a plurality of pipes (91) connected to a vacuum cleaner. The pipes (91) are distributed above the cutting knife I (51), the cutting knife II (52), the file (58), the cutting knife III (53) and the cutting knife IV (54), close to their respective blade tips. The system also includes a static electricity removal ion blower (60) and a camera. The static electricity removal ion blower (60) is arranged on the other side of the chassis (70), and the camera is arranged above the cutting knife group (50).

5. The cutting and forming method according to claim 4, characterized in that: In step six, the operation order of the cutting knife I (51) and the cutting knife IV (54) can be interchanged.

6. The cutting and forming method according to claim 5, characterized in that: In step six, the cutting blade II (52) and the cutting blade III (53) are alternately cut into the alignment notch (13) of the plastic sealing disc (20).

7. The cutting and forming method according to claim 6, characterized in that: In step six, the cutting knife I (51) trims the edge of the plastic-sealed disc (20), including the following steps: first, the camera above the cutting knife group (50) captures and locates the center straight line position of the disc (10) to align the notch (13), and fine-tunes the bottom plate (70) to rotate clockwise by a certain angle B, wherein the angle B is not greater than half of the angle A; Then, the cutter I (51) extends toward the plastic encapsulation disc (20) and makes the cutter I (51) close to the right side of the alignment notch (13) of the plastic encapsulation disc (20), the rotary motor (80) drives the cutting platform, and the plastic encapsulation disc (20) rotates counterclockwise in the original position under the action of the chassis (70), and takes the current position as the starting point, and rotates counterclockwise by an angle γ, and the value of the angle γ is not less than 363°; during the rotation process, the cutting edge of the cutter I (51) is close to the edge of the disc (10), and along the tangent direction of the edge of the disc (10), the invalid plastic encapsulation material outside the disc (10) is cut and peeled off through the cutting edge, and the waste material is sucked out of the working area of ​​the cutter I (51) through the film scrap suction system (90); after the work is completed, the cutter I (51) returns to the original position.

8. The method according to claim 7, characterized in that: In step six, the cutting knife IV (54) trims the edge of the plastic-sealed wafer (20), including the following steps: first, the camera above the cutting knife assembly (50) captures and locates the center straight line position of the wafer (10) and the alignment notch (13), and the base plate (70) is fine-tuned to rotate counterclockwise by a certain angle B, wherein the angle B is not greater than half of the angle A, and the angle B is adjusted according to the size of the wafer (10); Then, the cutter IV (54) extends toward the plastic encapsulation disc (20) and makes the cutter IV (54) close to the left side of the alignment notch (13) of the plastic encapsulation disc (20). The rotary motor (80) drives the cutting platform. The plastic encapsulation disc (20) rotates clockwise in the original position under the action of the chassis (70). With the current position as the starting point, the cutter rotates counterclockwise by an angle θ, and the value of the angle θ is not less than 363°. During the rotation process, the cutting edge of the cutter I (51) is close to the edge of the disc (10). The cutter cuts and peels off the invalid plastic encapsulation material outside the disc (10) along the tangent direction of the edge of the disc (10), and the waste material is sucked out of the working area of ​​the cutter IV (54) through the film scrap suction system (90). After the work is completed, the cutter IV (54) returns to its original position.

9. The cutting and forming method according to claim 8, characterized in that: In step six, the cutter II (52) and the cutter III (53) perform edge trimming on the alignment notch (13) of the plastic encapsulation wafer (20), comprising the following steps: first, the base plate (70) is finely adjusted to rotate the plastic encapsulation wafer (20) to the center straight line position of the alignment notch (13) of the wafer (10), the cutter II (52) and the cutter III (53) cut into the alignment notch (13) of the plastic encapsulation wafer (20) from the left and right sides respectively, and the plastic encapsulation material in the alignment notch (13) is cut stepwise downward by 0.5 microns respectively, and the waste material is extracted from the working area of ​​the cutter II (52) and the cutter III (53) through the film scrap suction system (90); the actual cutting distance is not less than 1 mm and is based on the contact with the wafer (10); after the work is completed, the cutter II (52) and the cutter III (53) return to their original positions.

10. The cutting and forming method according to claim 9, characterized in that: In step six, the file (58) trims the alignment notch (13) of the plastic-sealed disc (20), including the steps of: the file (58) moves forward from the central axis and presses against the alignment notch (13) area of ​​the plastic-sealed disc (20), moving up and down, and extracting waste materials from the working area of ​​the file (58) through the film scrap suction system (90); after the work is completed, the file (58) returns to its original position.

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