Silicon wafer carrier machining method

Abstract

According to the silicon wafer carrier processing method provided by the invention, a press is utilized to press a blank for multiple times so as to reach the set hardness and thickness of a product, and then cutting, polishing, grinding and injection molding are carried out on the material subjected to hardness strengthening treatment. According to the processing mode of the silicon wafer carrier, previous heat treatment processing is canceled, abnormal conditions such as deformation of the carrier in the later period are effectively prevented, the stability of the product processing quality is ensured, the processing steps are more concise, the injection mold used in the application is compact and simple in overall structure, a plurality of glue injection parts are adopted to synchronously form a rubber ring structure, and the production efficiency is improved. And the built-in runner with the bent ox horn-shaped structure is used for injecting glue, so that no sprue trace is left on the product.

Description

Technical Field

[0001] The present invention relates to the technical field of silicon wafer carriers, and in particular to a silicon wafer carrier processing method. Background Art

[0002] Grinding and polishing carriers are important workpieces that are indispensable for supporting grinding and polishing components in the polishing process of electronic and optical workpieces. With the development of semiconductor technology, semiconductor silicon wafers are gradually developing towards larger sizes and thinner slices. Grinding and polishing are involved in the production of silicon wafers, and grinding and polishing require the use of special placement carriers. At present, when processing the carrier shown in the figure, the main material used is sheet metal material, and the thickness of the carrier is relatively thin, only 0.7-0.8mm. In the current production method, in order to meet its hardness requirements, it is necessary to perform heat treatment after the shape processing is completed. However, during the heat treatment, the carrier is prone to deformation and other abnormalities, affecting its processing quality. Summary of the invention

[0003] The purpose of the present invention is to provide a silicon wafer carrier processing method to solve the technical problems in the background technology.

[0004] To achieve the aforementioned purpose, the present invention provides the following technical solutions:

[0005] A silicon wafer carrier processing method specifically includes the following processing steps:

[0006] S1. Perform hardness strengthening operation on the rolled raw sheet metal, and send the raw sheet metal into a press for several pressings until it reaches a set thickness;

[0007] S2, rough grinding and rough polishing both sides of the rolled sheet metal material coil obtained in S1;

[0008] S3, cutting the shape and holes of the roughly polished and roughly ground sheet metal coil to form a first semi-finished product, wherein a plurality of retaining holes with internal tooth structures are processed in the first semi-finished product;

[0009] S4, placing the first semi-finished product into an injection mold, performing injection molding on the retaining hole with the inner tooth structure in the semi-finished product, and injecting a rubber ring into the retaining hole, the rubber ring covers the inner tooth structure of the inner hole, and the upper and lower end surfaces of the rubber ring are flush with the end surfaces of the first semi-finished product, thereby forming a second semi-finished product;

[0010] S5, fine grinding and polishing the second semi-finished product according to the dimensional tolerance specified in the assembly parts drawing to form a third semi-finished product;

[0011] S6. Place the third semi-finished product into a coating machine for double-sided coating to obtain a finished product of the carrier.

[0012] In S1, three presses are used to continuously pressurize the raw blank sheet metal.

[0013] The rubber ring is made of PVDF material by injection molding.

[0014] The carrier outer ring of the first semi-finished product has external teeth. In the coating operation in step S6, the external teeth and the rubber ring position of the third semi-finished product are not subjected to coating treatment.

[0015] In the step S6, the thickness of the finished product after coating is less than 4.0 um compared with the thickness before coating.

[0016] The injection mold includes an upper mold and a lower mold. The upper mold is composed of an upper mold bottom plate, a runner plate and an upper mold fixing plate from top to bottom. The upper mold fixing plate is provided with a plurality of injection holes for injecting glue into the lower mold. The lower mold is composed of a lower mold bottom plate, an ejector mechanism and a lower mold fixing plate from bottom to top. A lower mold core is installed in the lower mold fixing plate. A molding part that matches the finished product structure of the carrier is provided on the lower mold core. The molding part includes a storage groove for placing the carrier. Three raised frustums are provided on the molding part, corresponding to the corresponding retaining hole positions on the carrier. The three frustums have the same structure.

[0017] A single truncated table has several groups of injection parts with the same structure in a circular array along its axis, and the injection parts include two insert grooves with the same structure, a first flow channel is provided between the two insert grooves for connecting the two insert grooves, an insert is embedded in the insert groove, a second flow channel is provided in the insert, and a glue outlet is provided on the side of the insert, and the glue outlet is on the outer end face of the truncated table.

[0018] A glue inlet channel is arranged above the insert, a longitudinal section of a second flow channel in the insert is in a curved horn shape, and the glue inlet channel and the glue outlet are connected through the second flow channel.

[0019] The insert includes a first insert and a second insert, wherein a first concave through groove is provided on the top of the first insert, and a second concave through groove is provided on the top of the second insert, and the first through groove and the second through groove are spliced ​​to form a glue entry channel; the first insert is provided with a third concave through groove toward the second insert, and the second insert is correspondingly provided with a fourth through groove, and the third through groove and the fourth through groove are spliced ​​to form a second horn-shaped flow channel; a first concave groove is provided below the first insert, and a first protrusion extending toward the first insert is provided below the second insert, and the first protrusion is in the first groove, and a mounting hole is provided on the first insert for mounting screws to fix it to the round table.

[0020] The ejector mechanism includes an ejector base plate, an ejector panel, a plurality of ejectors and two spacer blocks. The ejector base plate is below the ejector panel. One end of the ejector is mounted on the ejector panel, and the other end is inserted into the lower die core. A plurality of guide rods are also mounted on the ejector panel. The guide rods are inserted into the lower die fixing plate. Compression springs are sleeved on the guide rods. The compression springs are squeezed between the lower die plate and the ejector panel. The two spacer blocks are respectively on the left and right sides of the ejector base plate and between the lower die fixing plate and the lower die base plate.

[0021] Compared with the prior art, the present invention provides a method for processing a silicon wafer carrier, which eliminates the need for heat treatment of the product and utilizes a press to strengthen the hardness of the material to reach a set value, thereby effectively reducing the defective rate of carrier production. In addition, the carrier produced in the present application has a rubber ring injected at the position of its retaining hole, and the rubber ring and the retaining hole are injection molded as one piece in a mutually interlocking manner, making the connection between the rubber ring and the retaining hole more stable, thereby effectively ensuring the service life of the carrier. The injection mold used in the present application has a compact and simple overall structure, and utilizes several injection parts to simultaneously mold the rubber ring structure, and utilizes a built-in curved horn-shaped structure runner for injection, so that the product does not have any remaining gate marks. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 : Structural diagram of the injection mold in this application;

[0023] Figure 2 : Three-dimensional structure diagram of the lower mold;

[0024] Figure 3 : Three-dimensional structure diagram of upper mold;

[0025] Figure 4 : Three-dimensional structure diagram of the lower mold core;

[0026] Figure 5 : Figure 4 A magnified image of point A;

[0027] Figure 6 : Bottom structure diagram of lower mold core;

[0028] Figure 7 : Three-dimensional structure diagram of insert;

[0029] Figure 8 : Three-dimensional structure diagram of the insert from another direction;

[0030] Fig. 9 : A three-dimensional structural diagram of the first inlay block;

[0031] Fig.10 : The third block structure diagram;

[0032] Fig.11 : Three-dimensional structure diagram of the lower mold fixing plate;

[0033] Fig.12 : The front view of the carrier processed in this application;

[0034] Fig.13 : Fig.12 Enlarged view of point B:

[0035] Fig.14 : Schematic diagram of the coating area of ​​the carrier processed in this application. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0037] Specific embodiment 1: Please refer to Figures 1 to 14 A method for processing a silicon wafer carrier 11 of this embodiment specifically includes the following processing steps:

[0038] S1. Perform hardness strengthening operation on the rolled raw sheet metal. Send the raw sheet metal into a press for several pressings until it is pressed to a set thickness. According to the strengthening requirements, an additional press can be added to roll and shape the material to achieve the required hardness. In this embodiment, three presses are used to continuously press the raw sheet metal and then coil it for subsequent processing.

[0039] S2, rough grinding and rough polishing both sides of the rolled sheet metal material coil obtained in S1;

[0040] S3, cutting the rough-polished and roughly-ground sheet metal coil into a shape and holes to form a first semi-finished product, wherein the first semi-finished product includes a disc-shaped body, and three retaining holes 12 with inner teeth are processed in the first semi-finished product, wherein the inner teeth 1201 are dovetail-shaped convex blocks, and at the same time, the outer ring of the carrier 11 of the first semi-finished product is processed with outer teeth 1101;

[0041] S4, placing the first semi-finished product into an injection mold, performing injection molding on the retaining hole 12 with the inner tooth structure in the semi-finished product, and injecting a rubber ring 13 into the retaining hole 12, wherein the rubber ring 13 is made of PVDF material, and the rubber ring 13 covers the inner tooth 1201 structure of the retaining hole, that is, a dovetail groove 1301 is formed on the rubber ring, and the rubber ring and the inner tooth 1201 of the retaining hole 12 are mutually interlocking structures, and the upper and lower end surfaces of the rubber ring are flush with the end surfaces of the first semi-finished product, thereby forming a second semi-finished product;

[0042] S5, fine grinding and polishing the second semi-finished product according to the dimensional tolerance specified in the assembly parts drawing to form a third semi-finished product;

[0043] S6. Place the third semi-finished product into a coating machine for double-sided coating, and do not coat the outer teeth 1101 and the rubber ring 13 of the third semi-finished product (refer to Fig.14 ), that is, the film layer 14 does not cover the outer teeth 1101 and the rubber ring 13, and the finished product of the carrier 11 is obtained. In addition, the thickness difference between the finished product after coating and the thickness before coating is less than 4.0um.

[0044] The injection mold used in the present application comprises an upper mold and a lower mold. The upper mold comprises, from top to bottom, an upper mold base plate 1, a runner plate 2 and an upper mold fixing plate 3. The upper mold fixing plate 3 is provided with a plurality of injection holes 301 for injecting glue into the lower mold. The lower mold comprises, from bottom to top, a lower mold base plate 4, an ejector mechanism 5 and a lower mold fixing plate 6. A lower mold core 7 is installed in the lower mold fixing plate 6. Three positioning grooves 701 are provided below the lower mold core 7. The lower mold fixing plate 6 is provided with a raised positioning block 601 which is plugged into the positioning groove 701 for positioning and installation. The lower mold core 7 in the present embodiment is a regular octagonal structure.

[0045] The lower mold core 7 is provided with a forming part that matches the finished product structure of the carrier 11. The forming part includes a storage groove 8 for placing the carrier 11. The forming part is provided with three raised round cones 9 corresponding to the positions of the corresponding retaining holes 12 on the carrier 11. The structures of the three round cones 9 are the same.

[0046] A single truncated cone 9 has several groups of injection parts with the same structure in a circular array along its axis. In the present embodiment, six groups of injection parts are provided on a single truncated cone 9 to perform injection molding of the rubber ring. The injection parts include two insert 10 grooves 902 with the same structure. A first flow channel 901 is provided between the two insert 10 grooves 902 for connecting the two insert 10 grooves 902. An insert 10 is embedded in the insert 10 groove 902. A second flow channel is provided in the insert 10. A glue outlet 1004 is provided on the side of the insert 10. The glue outlet 1004 is on the outer end face of the truncated cone 9.

[0047] A glue inlet channel 1003 is provided above the insert 10. When the mold is closed, the glue injection hole 301 of the upper mold is connected to the glue inlet channel 1003 for injecting glue into the lower mold. The longitudinal cross-section of the second flow channel in the insert 10 is a curved horn shape, and the glue inlet channel 1003 and the glue outlet 1004 are connected through the second flow channel.

[0048] The insert 10 includes a first insert 1001 and a second insert 1002, wherein the first insert 1001 is provided with a first concave through groove 1001-1, and the second insert 1002 is provided with a second concave through groove 1002-1, and the first through groove 1001-1 and the second through groove 1002-1 are spliced ​​to form a glue entry channel 1003; the first insert 1001 is provided with a third concave through groove 1001-2 toward the second insert 1002, and the second insert 1002 is provided with a fourth through groove 1002-2 correspondingly, and the third through groove 1001-2 and the fourth through groove 1002-2 are spliced ​​to each other to form a horn-shaped third through groove 1001-2. Second flow channel; a first concave groove 1001-3 is provided under the first insert 1001, and a first protrusion 1002-3 extending toward the first insert 1001 is provided under the second insert 1002. The first protrusion 1002-3 is in the first groove 1001-3. The first insert 1001 is provided with a mounting hole 1001-4 for mounting screws and fixedly connected to the round table 9. In the present application, the insert 10 adopts a split mounting structure, which can effectively reduce the difficulty of processing the shape of the second flow channel. At the same time, when the insert 10 is partially damaged, the damaged insert can be replaced separately, thereby reducing the mold maintenance cost.

[0049] The ejector mechanism 5 includes an ejector base plate 501, an ejector panel 502, a plurality of ejectors 503 and two spacer blocks 504. The ejector base plate 501 is below the ejector panel 502. One end of the ejector 503 is mounted on the ejector panel 502, and the other end thereof is inserted into the lower die core 7. A plurality of guide rods are also mounted on the ejector panel 502. The guide rods are inserted into the lower die fixing plate 6. Compression springs 505 are sleeved on the guide rods. The compression springs 505 are squeezed between the lower die fixing plate 6 and the ejector panel 502. The two spacer blocks 504 are respectively on the left and right sides of the ejector base plate 501 and between the lower die fixing plate 6 and the lower die base plate 4. The ejector is arranged at the position of the storage slot 8 for ejecting products.

[0050] Compared with the prior art, the present invention provides a method for processing a silicon wafer carrier, which eliminates the need for heat treatment of the product and utilizes a press to strengthen the hardness of the material to reach a set value, thereby effectively reducing the defective rate of carrier production. In addition, the carrier produced in the present application has a rubber ring injected at the position of its retaining hole, and the rubber ring and the retaining hole are injection molded as one piece in a mutually interlocking manner, making the connection between the rubber ring and the retaining hole more stable, thereby effectively ensuring the service life of the carrier. The injection mold used in the present application has a compact and simple overall structure, and utilizes several injection parts to simultaneously mold the rubber ring structure, and utilizes a built-in curved horn-shaped structure runner for injection, so that the product does not have any remaining gate marks.

[0051] It will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing exemplary embodiments and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0052] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A silicon wafer carrier processing method, characterized in that: The specific processing steps include: S1. Perform hardness strengthening operation on the rolled raw sheet metal, and send the raw sheet metal into a press for several pressings until it reaches a set thickness; S2, rough grinding and rough polishing both sides of the rolled sheet metal material coil obtained in S1; S3, cutting the shape and holes of the roughly polished and roughly ground sheet metal coil to form a first semi-finished product, wherein a plurality of retaining holes with internal tooth structures are processed in the first semi-finished product; S4, placing the first semi-finished product into an injection mold, performing injection molding on the retaining hole with the inner tooth structure in the semi-finished product, and injecting a rubber ring into the retaining hole, the rubber ring covers the inner tooth structure of the inner hole, and the upper and lower end surfaces of the rubber ring are flush with the end surfaces of the first semi-finished product, thereby forming a second semi-finished product; S5, fine grinding and polishing the second semi-finished product according to the dimensional tolerance specified in the assembly parts drawing to form a third semi-finished product; S6. Place the third semi-finished product into a coating machine for double-sided coating to obtain a finished product of the carrier.

2. A method for processing a silicon wafer carrier according to claim 1, characterized in that: In S1, three presses are used to continuously pressurize the raw blank sheet metal.

3. The method for processing a silicon wafer carrier according to claim 1, characterized in that: The rubber ring is made of PVDF material by injection molding.

4. The method for processing a silicon wafer carrier according to claim 1, characterized in that: The carrier outer ring of the first semi-finished product has external teeth. In the coating operation in step S6, the external teeth and the rubber ring position of the third semi-finished product are not subjected to coating treatment.

5. The method for processing a silicon wafer carrier according to claim 1, characterized in that: In the step S6, the thickness of the finished product after coating is less than 4.0 um compared with the thickness before coating.

6. The method for processing a silicon wafer carrier according to claim 1, characterized in that: The injection mold includes an upper mold and a lower mold. The upper mold is composed of an upper mold bottom plate, a runner plate and an upper mold fixing plate from top to bottom. The upper mold fixing plate is provided with a plurality of injection holes for injecting glue into the lower mold. The lower mold is composed of a lower mold bottom plate, an ejector mechanism and a lower mold fixing plate from bottom to top. A lower mold core is installed in the lower mold fixing plate. A molding part that matches the finished product structure of the carrier is provided on the lower mold core. The molding part includes a storage groove for placing the carrier. Three raised frustums are provided on the molding part, corresponding to the corresponding retaining hole positions on the carrier. The three frustums have the same structure.

7. A method for processing a silicon wafer carrier according to claim 6, characterized in that: A single truncated table has several groups of injection parts with the same structure in a circular array along its axis, and the injection parts include two insert grooves with the same structure, a first flow channel is provided between the two insert grooves for connecting the two insert grooves, an insert is embedded in the insert groove, a second flow channel is provided in the insert, and a glue outlet is provided on the side of the insert, and the glue outlet is on the outer end face of the truncated table.

8. The method for processing a silicon wafer carrier according to claim 7, characterized in that: A glue inlet channel is arranged above the insert, a longitudinal section of a second flow channel in the insert is in a curved horn shape, and the glue inlet channel and the glue outlet are communicated through the second flow channel.

9. The method for processing a silicon wafer carrier according to claim 8, characterized in that: The insert includes a first insert and a second insert, wherein a first concave through groove is provided on the top of the first insert, and a second concave through groove is provided on the top of the second insert, and the first through groove and the second through groove are spliced ​​to form a glue entry channel; the first insert is provided with a third concave through groove toward the second insert, and the second insert is correspondingly provided with a fourth through groove, and the third through groove and the fourth through groove are spliced ​​to form a second horn-shaped flow channel; a first concave groove is provided below the first insert, and a first protrusion extending toward the first insert is provided below the second insert, and the first protrusion is in the first groove, and a mounting hole is provided on the first insert for mounting screws to fix it to the round table.

10. The method for processing a silicon wafer carrier according to claim 9, characterized in that: The ejector mechanism includes an ejector base plate, an ejector panel, a plurality of ejectors and two spacer blocks. The ejector base plate is below the ejector panel. One end of the ejector is mounted on the ejector panel, and the other end is inserted into the lower die core. A plurality of guide rods are also mounted on the ejector panel. The guide rods are inserted into the lower die fixing plate. Compression springs are sleeved on the guide rods. The compression springs are squeezed between the lower die plate and the ejector panel. The two spacer blocks are respectively on the left and right sides of the ejector base plate and between the lower die fixing plate and the lower die base plate.

Images