Methods for processing sheet materials, thin wafers, and thin components.

Abstract

A sheet material has a plurality of cylindrical or semi-cylindrical structures with a height of 50 to 500 micrometers and a diameter of 10 to 1 mm, or prismatic structures with a length of 100 to 1 mm and a thickness of 10 to 1 mm, on its surface. The sheet material is formed from a thermosetting resin. This provides a sheet material that can easily process thinned wafers or reconfigurable components using molding and sealing, exhibiting excellent chemical resistance; a sheet material for thinning wafer processing including the sheet material; and methods for processing thin wafers and thin components using the sheet material.

Description

[Technical Field]

[0001] This invention relates to a sheet material, a sheet material for thinning wafers, a method for processing thin wafers, and a method for processing thin components. In particular, this invention relates to a bonding sheet material for processing thin silicon wafers, compound semiconductor wafers, or square glass panels and glass wafers thinned to less than 300 micrometers without breakage. [Previous Technology]

[0002] In recent years, in order to increase the density of semiconductor components, efforts have been made to change the previous thickness of more than 500 micrometers to the use of semiconductor components with a wafer thickness of less than 300 micrometers, especially less than 100 micrometers.

[0003] In addition, in order to make semiconductor devices three-dimensional, many manufacturing methods have been developed as follows: on a glass panel that is thinned to less than 1 mm, especially less than 500 micrometers, semiconductor components with a wafer thickness of less than 300 micrometers, especially less than 100 micrometers, are reconfigured into a functionally necessary structure to form a package.

[0004] Regarding the manufacturing of such thin wafers or the packaging manufacturing of thin panels, for example, in the Through Silicon Via (TSV) process, which is an important process for mounting three-dimensional semiconductor components, circuits are formed on both the front and back sides of the silicon wafer. In order to make the circuit conductive, TSV (Through Silicon Via), also known as through electrode formation, is performed. However, in order to form the electrode, the silicon wafer, which becomes a semiconductor component, is bonded to a glass wafer called a carrier for support via a temporary adhesive (temporary glue). Then, the silicon wafer is thinned, and circuits are formed.

[0005] Furthermore, regarding the packaging manufacturing using thin panels, for example, a Field Programmable Gate Array (FPGA) component for Artificial Intelligence (AI) or a High Bandwidth Memory (HBM) component for Multilayer Dynamic Random Access Memory (DRAM) is configured on a thin glass panel to form a function. After the component is configured on the glass panel, the panel is sealed using molding resin or the like, and then thinned and planarized to expose the electrodes, and circuit formation is implemented.

[0006] In the above-described method for processing two thin substrates, during circuit formation, a silicon wafer or glass wafer serving as a carrier becomes a supporting substrate for the implementation of the process. However, after the process is completed, it is necessary to remove the silicon wafer formed by the circuit, which has been thinned to 300 micrometers or, depending on the circumstances, to less than 100 micrometers, or to use a molded and sealed reconfiguration component.

[0007] Previously, when removing the thinned silicon wafer or molding and sealing reconfiguration component, a dicing tape using ultraviolet (UV) stripping was generally used. The dicing tape was attached to the silicon wafer to be removed while it was connected to a glass carrier. In this state, the carrier was generally removed by laser stripping or the like.

[0008] However, on the surface of the thinned silicon wafer formed by circuitry and attached to the dicing tape in this manner, temporary adhesive resin used in the thinning process usually remains. This residual resin needs to be dissolved and removed by solvent cleaning or the like.

[0009] On the other hand, it is known that adhesives for bonding cutting strips mostly use uncured acrylic resins, etc. In the solvent cleaning step of the residual resin of the temporary adhesive, it dissolves in the solvent used, causing problems such as peeling and swelling, and there is a problem that the cleaning solvents that can be used are very limited.

[0010] Patent Document 1 discloses an invention relating to a dry adhesive fiber structure comprising microfibers with mushroom-shaped tips. [Prior Art Documents] [Patent Documents]

[0011] [Patent Document 1] U.S. Patent Application Publication No. 2015 / 0368519 [Summary of the Invention]

[0012] [The problem that the invention aims to solve]

[0013] As previously described, it was desirable to develop a tool for the thinning process of silicon wafers or compound semiconductors, which are mostly used in the three-dimensional mounting and other purposes described above, that can easily process thinned wafers or reconfigurable components sealed by molding, and that has excellent chemical resistance.

[0014] This invention was made to solve the aforementioned problems, and its object is to provide a sheet material with excellent chemical resistance that can easily process thinned wafers or reconfigurable components sealed by molding, a sheet material for thinning wafer processing including the sheet material, a method for processing thin wafers using the sheet material for thinning wafer processing, and a method for processing thin components. [Means for Solving the Problem]

[0015] In order to solve the aforementioned problem, the present invention provides a sheet material characterized in that it has a plurality of cylindrical or semi-cylindrical structures with a height of 50 micrometers to 500 micrometers and a diameter of 10 micrometers to 1 mm, or prismatic structures with a length of 100 micrometers to 1 mm and a thickness of 10 micrometers to 1 mm on its surface, and the plurality of structures are arranged at equal intervals on the surface, or the plurality of structures are arranged in such a way that the maximum value of the interval is less than three times the minimum value of the interval, and the sheet material is formed by thermosetting resin.

[0016] If it is such a sheet, the wafer can be easily and with sufficient adhesion. On the other hand, peeling requires almost no force, so the thinned wafer or the reconfigured component using the molded seal can be easily processed without damage.

[0017] In addition, the sheet of the present invention is formed from a thermosetting resin and has excellent chemical resistance, so it can be used with various temporary adhesive cleaning resins.

[0018] The thermosetting resin is, for example, at least one selected from the group consisting of acrylic thermosetting elastomers, silicone thermosetting elastomers, carbamate thermosetting elastomers and fluorinated thermosetting elastomers.

[0019] By using this thermosetting elastomer as a thermosetting resin, a sheet with superior chemical resistance is produced.

[0020] In addition, the present invention provides a sheet for thinning wafer processing, characterized in that it comprises: a substrate; and the sheet of the present invention, which is laminated on the substrate.

[0021] If it is a sheet for thinning wafer processing, then it includes the sheet of the present invention, so that thinned wafers or reconfigured components using molding seals can be easily processed without damage.

[0022] Furthermore, by using the thin wafer processing sheet of the present invention, the bonding portion uses a thermosetting elastomer, which has excellent chemical resistance, and therefore can be used with various temporary adhesive cleaning resins.

[0023] In addition, the present invention provides a method for processing thin wafers, characterized in that a silicon wafer or compound semiconductor wafer with a thickness of 300 micrometers or less is followed by a thin wafer processing sheet of the present invention for processing.

[0024] In the thin wafer processing method of the present invention, almost no force is required for peeling, so even silicon wafers with a thickness of less than 300 micrometers can be easily removed without damage.

[0025] In addition, the present invention provides a method for processing thin components, characterized in that a square glass panel or metal panel with a thickness of 1.5 mm or less and a silicon wafer or compound semiconductor wafer with a thickness of 300 micrometers or less is attached to the thin wafer processing sheet of the present invention for processing.

[0026] In the thin-film component processing method of the present invention, peeling requires almost no force. Therefore, even square glass panels or metal panels with a thickness of 1.5 mm or less and mounting silicon wafers or compound semiconductor wafers with a thickness of 300 micrometers or less can be easily removed without damage. [Effects of the Invention]

[0027] As described above, with the sheet of the present invention, wafers can be easily and with sufficient adhesion. On the other hand, peeling requires almost no force, so thinned wafers or reconfigured components using molded seals can be easily processed without damage. In addition, the sheet of the present invention is molded from a thermosetting resin and has excellent chemical resistance, so various temporary adhesive cleaning resins can be used.

[0028] Furthermore, if the wafer thinning sheet of the present invention is included, then the wafer thinned by the present invention can be easily processed or the reconfigured component sealed by molding can be easily processed without damage. Moreover, by using the wafer thinning sheet of the present invention, the bonding portion, by using a thermosetting elastomer, exhibits excellent chemical resistance, thus allowing the use of various temporary adhesive cleaning resins. Therefore, the wafer thinning sheet of the present invention is particularly useful, for example, in methods for processing thin wafers and thin components.

[0029] In addition, in the thin wafer processing method of the present invention, almost no force is required for peeling, so even silicon wafers with a thickness of less than 300 micrometers can be easily removed without damage.

[0030] Moreover, in the thin element processing method of the present invention, peeling requires almost no force. Therefore, even square glass panels or metal panels with a thickness of 1.5 mm or less and mounting silicon wafers or compound semiconductor wafers with a thickness of 300 micrometers or less can be easily removed without damage.

Implementation Method

[0032] As described above, there is a need to develop a tool for the thinning process of silicon wafers or compound semiconductors, which are mostly used in the three-dimensional mounting and other purposes described above, and which can easily process thinned wafers or reconfigurable components using molding and sealing, and has excellent chemical resistance.

[0033] The inventors have repeatedly and diligently studied the aforementioned problem and have found that if the sheet has a plurality of cylindrical or semi-cylindrical structures with a height of 50 to 500 micrometers or a prismatic structure with a length of 100 to 1 mm and a diameter or thickness of 10 to 1 mm, and the structure is arranged at equal intervals or with the maximum value of the interval being less than three times the minimum value of the interval, and the sheet is molded from a thermosetting resin, then the wafer can be easily and with sufficient adhesion. On the other hand, peeling requires almost no force, so the thinned wafer or the reconfigured component sealed by molding can be easily processed without damage, thereby exhibiting excellent chemical resistance, thus completing the present invention.

[0034] That is, the present invention is a sheet material, characterized in that it has a plurality of cylindrical or semi-cylindrical structures with a height of 50 micrometers to 500 micrometers and a diameter of 10 micrometers to 1 mm, or prismatic structures with a length of 100 micrometers to 1 mm and a thickness of 10 micrometers to 1 mm on its surface, and the plurality of structures are arranged at equal intervals on the surface, or the plurality of structures are arranged in such a way that the maximum value of the interval is less than 3 times the minimum value of the interval, and the sheet material is formed by thermosetting resin.

[0035] In addition, the present invention is a sheet for thinning wafer processing, characterized in that it comprises: a substrate; and the sheet of the present invention, which is laminated on the substrate.

[0036] In addition, the present invention is a method for processing thin wafers, characterized in that a silicon wafer or compound semiconductor wafer with a thickness of 300 micrometers or less is attached to the thin wafer processing sheet of the present invention for processing.

[0037] In addition, the present invention is a method for processing thin components, characterized in that a square glass panel or metal panel with a thickness of 1.5 mm or less and a silicon wafer or compound semiconductor wafer with a thickness of 300 micrometers or less is attached to the thin wafer processing sheet of the present invention for processing.

[0038] Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

[0039] FIG1 is a schematic cross-sectional view showing an example of the sheet material of the present invention. The sheet material 1 shown in FIG1 has a plurality of structures 1a on one surface of a resin-based base 1b. The sheet material 1, namely the plurality of structures 1a and the base 1b, is formed of a thermosetting resin.

[0040] The resin used in this invention includes thermosetting resins, specifically thermosetting elastomers, and more specifically, for example, at least one selected from the group consisting of acrylic thermosetting elastomers, silicone thermosetting elastomers, carbamate thermosetting elastomers and fluorinated thermosetting elastomers.

[0041] These resins are preferably capable of being molded into the shapes described below, and there is no transfer of resin components when peeled off from the adhered object, but their scope or use is not limited.

[0042] The sheet 1 of the present invention has a plurality of minute structures 1a on the surface of the resin (base 1b), specifically cylindrical or semi-cylindrical structures 1a with a height of 50 to 500 micrometers and a diameter of 10 micrometers to 1 mm, or prismatic structures 1a with a length of 100 to 1 mm and a thickness of 10 to 1 mm. Furthermore, in the present invention, when the structure 1a is prismatic, its thickness refers to the diameter of the circumcircle of the cross-section of the structure 1a. The sheet 1 has a structure in which a plurality of structures 1a are arranged at equal intervals on its surface, or a structure in which a plurality of structures 1a are arranged such that the maximum value 1c of the interval is less than three times the minimum value 1d of the interval. The maximum value 1c of the interval is greater than the minimum value 1d of the interval.

[0043] Additionally, as shown in FIG2, the sheet 1 is generally provided in the form of a film (substrate 2) such as polyethylene terephthalate (PET) or polyolefin resin sheet.

[0044] The laminated sheet 10 can be used, for example, as a sheet for wafer thinning. The wafer thinning sheet 10 shown in FIG2 includes a substrate 2 and the sheet 1 of the present invention laminated on the substrate 2. The sheet 1 shown in FIG2 has the same structure as the sheet 1 shown in FIG1.

[0045] The structure 1a of the sheet 1 formed on the substrate 2 such as the resin sheet is preferably of uniform height and has a flat surface. In addition, its size or spacing (the size of the structure 1a and the interval between the structures 1a) can be arbitrarily selected, but ideally it can be a silicon wafer or compound semiconductor wafer formed by circuitry that is the bonding object.

[0046] Next, an example of using the thinned wafer processing sheet 10 of the present invention will be described. FIG3 shows a schematic cross-sectional view of an example of the application area of ​​the thinned wafer processing sheet of the present invention.

[0047] After a portion of the surface of a plurality of structures 1a of the sheet 1 of the thinning wafer processing sheet 10 is formed on a frame (e.g., a metal frame) 4, such as a dicing frame, the processed thinned wafer (e.g., a silicon wafer, a compound semiconductor wafer) 3 with a carrier 5 is attached to another portion of the surface of the plurality of structures 1a. The thinned wafer 3, which is the object of attachment, is temporarily attached to the carrier 5 via a temporary adhesive layer 6 containing a temporary adhesive. Thereafter, depending on the characteristics of the temporary adhesive in the temporary adhesive layer 6, the carrier 5, such as a glass wafer, is peeled off by means of laser peeling or the like. After the carrier 5 is peeled off, the temporary adhesive residue remaining on the thinned wafer 3 is cleaned with a suitable organic solvent-based cleaning agent, and the thinned wafer 3 attached to the thinning wafer processing sheet 10 based on the present invention can be removed. Here, the sheet 1 of the present invention is molded from a thermoplastic resin, and therefore has high chemical resistance. Therefore, in the processing method of the sheet 1 of the present invention, various solvents or resins for cleaning temporary adhesive materials can be used to remove temporary adhesive residues.

[0048] After the above steps, a thinned wafer 3 is obtained and attached to the thinned wafer processing sheet 10. The adhesion between the thinned wafer processing sheet 10 and the thinned wafer 3 exhibits sufficient strength to withstand processing due to the presence of multiple structures 1a on the surface of the sheet 1. Furthermore, after processing, the thinned wafer 3 can be easily removed from the thinned wafer processing sheet 10, for example, by applying a light force to the edge of the wafer. Because of the multiple structures 1a formed on the surface of the thinned wafer processing sheet 10, the peeling requires almost no force, and even 300 mm silicon wafers with a thickness of 300 micrometers or less, and further, 30 micrometers or less, can be easily removed without damage.

[0049] In addition, after the thinned wafer 3 is removed, no resin transfer occurs on its surface, so no additional cleaning steps are required.

[0050] Thus, the wafer thinning sheet 10 of the present invention can be used, for example, in a wafer thinning method for processing silicon wafers or compound semiconductor wafers 3 with a thickness of 300 micrometers or less. In the wafer thinning method of the present invention, the silicon wafer or compound semiconductor wafer 3 can be processed after being attached to the wafer thinning sheet 10 of the present invention. Therefore, even silicon wafers or compound semiconductor wafers 3 with a thickness of 300 micrometers or less can be easily removed without damage.

[0051] On the other hand, if the plurality of structures 1a are cylindrical or semi-cylindrical structures, and their height is less than 50 micrometers, or their height is more than 500 micrometers, or their diameter is less than 10 micrometers, or their diameter is more than 1 mm, then it is impossible to simultaneously achieve the required adhesion and excellent peelability. Similarly, if the plurality of structures 1a are prismatic structures, and their length is less than 100 micrometers, or their length is more than 1 mm, or their thickness is less than 10 micrometers, or their diameter is more than 1 mm, then it is impossible to simultaneously achieve the required adhesion and excellent peelability.

[0052] In addition, if multiple structures 1a are arranged such that the maximum value of the interval is more than three times the minimum value of the interval, the adhesion force required for processing cannot be displayed.

[0053] Moreover, the present invention processes a thermoplastic resin, preferably a thermosetting elastomer, more preferably an acrylic, silicone, carbamate, or fluorine thermosetting elastomer into a target shape and then attaches it to a thinned wafer, thereby producing a thinned wafer processing sheet 10 with excellent chemical resistance or other process suitability.

[0054] The application of the wafer thinning sheet 10 of the present invention is not limited to the wafer thinning process. For example, the wafer thinning sheet 10 of the present invention can also be used in the thin device process. In the thin device process of the present invention, for example, a square glass panel or metal panel with a thickness of 1.5 mm or less and mounting a silicon wafer or compound semiconductor wafer with a thickness of 300 micrometers or less can be processed after the wafer thinning sheet of the present invention. In this way, even a square glass panel or metal panel with a thickness of 1.5 mm or less and mounting a silicon wafer or compound semiconductor wafer with a thickness of 300 micrometers or less can be easily processed without damage.

[0055] The lower limit of the thickness of the silicon wafer or compound semiconductor wafer subsequently processed by the wafer thinning sheet 10 of the present invention is not particularly limited. For example, silicon wafers or compound semiconductor wafers with a thickness of 10 micrometers or more and 300 micrometers or less can be processed. Furthermore, the lower limit of the thickness of the square glass panel or metal panel subsequently processed by the wafer thinning sheet 10 of the present invention is not particularly limited. For example, square glass panels or metal panels with a thickness of 0.1 mm or more and 1.5 mm or less, on which silicon wafers or compound semiconductor wafers with a thickness of 10 micrometers or more and 300 micrometers or less are mounted, can be processed. [Example]

[0056] Hereinafter, the present invention will be specifically described using examples, but the present invention is not limited thereto.

[0057] [Example] On a PET sheet with a thickness of 100 micrometers, a urethane resin, which is a thermosetting elastomer, is molded into a cylindrical structure with a height of 200 micrometers and a diameter of 500 micrometers, with the spacing between the cylindrical structures being 500 micrometers (equal spacing) and the total thickness being 500 micrometers. This yields a sheet for thinning wafer processing.

[0058] On the other hand, a 300 mm glass wafer (700 micrometers thick) is used as a carrier. A UV laser-release temporary material (SPIS-TA401+SPIS-TA501) manufactured by Shin-Etsu Chemical Industry Co., Ltd. is used as a temporary adhesive layer on this glass carrier, followed by the formation of a 775-micrometer thick TSV wafer. Next, the TSV-formed wafer is thinned to 50 micrometers to form TSV terminals. Then, a SiO2 film is formed using tetraethyl orthosilicate (TEOS) via chemical vapor deposition (CVD) to obtain a thinned silicon wafer. The thinned wafer processing sheet obtained above is formed on a dicing frame and then bonded to the thinned silicon wafer.

[0059] For the laminate comprising the glass carrier, the temporary adhesive layer, the thinned silicon wafer, and the sheet for thinning the wafer, firstly, a UV laser is irradiated from the front surface of the glass carrier to peel off the glass carrier. Subsequently, the temporary adhesive resin residue remaining on the silicon wafer is dissolved and cleaned using a cleaner SPIS-TA-Cleaner-25 manufactured by Shin-Etsu Chemical Co., Ltd.

[0060] At this time, no abnormalities such as peeling or floating were found on the wafer thinning sheet supporting the thinned silicon wafer. That is, the bonding between the wafer thinning sheet and the thinned silicon wafer is strong enough to withstand the processing of thin wafers.

[0061] Finally, if the sheet is peeled off from the back side of the thinned wafer processing sheet and from the edge of the thinned silicon wafer, the sheet is easily peeled off, and no damage such as cracks occurs on the 50-micrometer thick wafer. In addition, no resin paste residue is produced.

[0062] Furthermore, the present invention is not limited to the described embodiments. The described embodiments are illustrative examples, and any embodiments having a structure that is substantially the same as the technical concept described in the claims of the present invention and performing the same effect are included within the technical scope of the present invention. [Simplified Explanation of the Diagram]

[0031] FIG1 is a schematic cross-sectional view showing an example of the sheet material of the present invention. FIG2 is a schematic cross-sectional view showing an example of the sheet material for wafer thinning processing of the present invention. FIG3 is a schematic cross-sectional view showing an example of the application area of ​​the sheet material for wafer thinning processing of the present invention.

Claims

1. A sheet for processing reconfigurable components of thin wafers or molded seals, characterized in that it has a plurality of cylindrical or semi-cylindrical structures with a height of 50 to 500 micrometers and a diameter of 10 to 1 mm, or prismatic structures with a length of 100 to 1 mm and a thickness of 10 to 1 mm, on its surface, and the plurality of structures are arranged at equal intervals or arranged in a manner where the maximum value of the interval is less than three times the minimum value of the interval, and the sheet is formed from a thermosetting resin.

2. A sheet for processing reconfigurable components of thinned wafers or molded seals, characterized in that it has a plurality of cylindrical or semi-cylindrical structures with a height of 50 to 500 micrometers and a diameter of 10 to 1 mm, or prismatic structures with a length of 100 to 1 mm and a thickness of 10 to 1 mm, on its surface, and the plurality of structures are arranged at equal intervals or arranged in a manner where the maximum value of the interval is less than three times the minimum value of the interval, and the sheet comprises a thermosetting elastomer.

3. A sheet for processing reconfigurable components of thin wafers or molded seals, characterized in that it has a plurality of cylindrical or semi-cylindrical structures with a height of 50 to 500 micrometers and a diameter of 10 to 1 mm, or prismatic structures with a length of 100 to 1 mm and a thickness of 10 to 1 mm, on its surface, and the plurality of structures are arranged at equal intervals or arranged in a manner where the maximum value of the interval is less than three times the minimum value of the interval, and the sheet is made of resin and is molded to prevent the transfer of resin components when peeled off from the adhered object.

4. The sheet as described in claim 2, wherein, The thermosetting elastomer is at least one selected from the group consisting of acrylic thermosetting elastomers, silicone thermosetting elastomers, carbamate thermosetting elastomers, and fluorinated thermosetting elastomers.

5. The sheet as described in claim 3, wherein the sheet does not require a cleaning step when peeled from the self-attached object.

6. A processing sheet, characterized in that it comprises: a substrate; and a sheet as claimed in any one of claims 1 to 5, laminated on the substrate.

7. A processing method characterized in that a thinned wafer or a molded sealed reconfiguration component with a thickness of less than 300 micrometers is attached to a sheet as claimed in any one of claims 1 to 5 for further processing.

8. A method for processing a thin component, characterized in that a square glass panel or metal panel with a thickness of 1.5 mm or less and a silicon wafer or compound semiconductor wafer with a thickness of 300 micrometers or less is followed by processing after the sheet as described in any one of claims 1 to 5.

9. A method for removing a thinned wafer, wherein the carrier is peeled off from the thinned wafer while the thinned wafer supported by a carrier is attached to a sheet as described in any one of claims 1 to 5.

10. A method for removing a molded seal reconfiguration member, wherein the carrier is peeled off from the molded seal reconfiguration member while the molded seal reconfiguration member supported by a carrier is attached to a sheet as described in any one of claims 1 to 5.

11. A method of manufacturing a thinned wafer, comprising peeling the carrier off the thinned wafer while the thinned wafer supported by a carrier is attached to a sheet as described in any one of claims 1 to 5.

12. A method of manufacturing a removed molded seal reconfiguration member, comprising peeling the carrier from the molded seal reconfiguration member while the carrier-supported molded seal reconfiguration member is attached to a sheet as described in any one of claims 1 to 5.

13. A method of manufacturing a package, comprising the step of peeling the carrier or the molded reconfiguration member from the thin wafer while the thin wafer supported by the carrier or the molded reconfiguration member is attached to a sheet as described in any one of claims 1 to 5.

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