Molding, sheet for handling, handling method, handling method for thinned device, extraction method for thinned wafer, extraction method for mold-sealed rearrangement element, method of manufacturing thinned wafer, mold-sealed rearrangement element, and method of manufacturing package

Abstract

To provide a sheet which is capable of easily handling a thinned wafer or a mold-sealed rearrangement element and improved in chemical resistance, a sheet for thinned wafer handling, a handling method for a thinned wafer using the sheet for thinned wafer handling and a handling method for a thinned device.SOLUTION: A sheet 1 of a sheet 10 for thinned wafer handling includes on a surface a plurality of structures 1a in a columnar or semi-columnar shape having a height of 50 microns to 500 microns and a diameter of 10 microns to 1 mm or in a prismatic shape having a length of 100 microns to 1 mm and a thickness of 10 microns to 1 mm. The sheet includes on the surface a structure in which a plurality of structures is disposed at an equal interval or a structure in which a plurality of structures is arrayed in such a manner that a maximum value of an interval becomes less than three times of a minimum value of the interval. The sheet is molded by a thermosetting resin.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a sheet, a sheet for thinning wafer handling, a method for handling a thin wafer, and a method for handling a thin device. In particular, the present invention relates to an adhesive sheet for handling a thin silicon wafer thinned to 300 microns or less, a compound semiconductor wafer, or a rectangular glass panel or glass wafer with a side length of 1 millimeter or less without damage.

Background Art

[0002] In recent years, due to the high density of semiconductor elements, semiconductor element manufacturing using wafers with a thickness of 300 microns or less, particularly 100 microns or less, has been actively carried out, starting from the conventional thickness exceeding 500 microns.

[0003] In addition, for the three-dimensionalization of semiconductor devices, semiconductor elements with a wafer thickness of 300 microns or less, particularly 100 microns or less, are rearranged into a functionally necessary configuration on a glass panel thinned to 1 millimeter or less, particularly 500 microns or less, and packaged. Many manufacturing methods have been developed.

[0004] Regarding the manufacturing of such thin wafers and the manufacturing of packages using thin panels, for example, in the TSV (Through Silicon Via) process, which is an important process for three-dimensional semiconductor element mounting, circuit formation is performed on both the front and back surfaces of a silicon wafer, and in order to conduct it, TSV (Through Silicon Via), so-called through electrode formation, is carried out. For this electrode formation, the silicon wafer serving as a semiconductor element is adhered via a glass wafer called a carrier for support and a temporary adhesive (Temporary Glue agent). Then, thinning of the silicon wafer and further circuit formation are carried out.

[0005] Regarding the manufacture of packages using thin panels, for example, an FPGA element for AI or an HBM element, which is a multi-layer stacked DRAM, is rearranged on a thin glass panel to form a single function. After the rearrangement of the elements on the glass panel, the panel is sealed with a molding resin or the like, and then thinned and flattened, and electrodes are exposed to form a circuit or the like.

[0006] In the method of handling the two thin substrates shown above, during circuit formation, a silicon wafer or a glass wafer as a carrier serves as a support substrate, and the process proceeds. However, after the process is completed, it is necessary to take out the silicon wafer formed with a circuit thinned to 300 microns, or in some cases, 100 microns or less, or the rearranged element sealed with a mold.

[0007] Conventionally, when taking out this thinned silicon wafer or the mold-sealed rearranged element, generally, a dicing tape using a UV peeling method is used, and in a state where a glass carrier is connected, this dicing tape is attached to the silicon wafer to be taken out, and in that state, the carrier is generally removed by a laser peeling method or the like.

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

[0009] On the other hand, the adhesive paste of the dicing tape often uses an uncured acrylic resin or the like, and in the solvent cleaning process of the residual resin of this temporary adhesive, it dissolves in the solvent used, causing problems such as peeling and swelling, and there is a problem that the available cleaning solvents are very limited.

[0010] Patent Document 1 discloses an invention related to a dry adhesive fiber structure including a microfiber having a mushroom-shaped tip.

Prior Art Documents

Patent Documents

[0011]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0012] In the situation described above, conventionally, a tool that can easily handle a wafer that has already been thinned or a rearranged element sealed with a mold for the thinning process of a silicon wafer or a compound semiconductor, which is frequently used for purposes such as the three-dimensional mounting described above, has been desired to be developed, a tool with excellent chemical resistance.

[0013] The present invention has been made to solve the above problems, and provides a sheet with excellent chemical resistance that can easily handle a wafer that has already been thinned or a rearranged element sealed with a mold, a sheet for thinning wafer handling including the sheet, and a method for handling a thin wafer and a method for handling a thin device using the sheet for thinning wafer handling.

Means for Solving the Problems

[0014] To solve the above problems, in the present invention, a sheet is provided that has a plurality of structures on the surface, the structures being columnar or semi-columnar with a height of 50 microns to 500 microns and a diameter of 10 microns to 1 mm, or prismatic with a length of 100 microns to 1 mm and a thickness of 10 microns to 1 mm, and the plurality of structures are arranged at equal intervals, or the plurality of structures are arranged on the surface such that the maximum value of the intervals is less than three times the minimum value of the intervals, and the sheet is molded by a thermosetting resin.

[0015] With such a sheet, while a wafer can be easily adhered with sufficient adhesive strength, almost no force is required for peeling, so that a wafer that has already been thinned or a repositioning element encapsulated with a mold can be easily handled without being damaged.

[0016] In addition, the sheet of the present invention is formed of a thermosetting resin and is excellent in chemical resistance, so that various resins for cleaning temporary adhesives can be used.

[0017] The thermosetting resin is, for example, at least one selected from the group consisting of acrylic thermosetting elastomers, silicone thermosetting elastomers, urethane thermosetting elastomers, and fluorine thermosetting elastomers.

[0018] By using such a thermosetting elastomer as the thermosetting resin, a sheet with even better chemical resistance can be obtained.

[0019] In addition, in the present invention, a substrate, the sheet of the present invention laminated on the substrate, and A thinning wafer handling sheet is provided, which is characterized by including the above.

[0020] With such a thinning wafer handling sheet, since it includes the sheet of the present invention, a wafer that has already been thinned or a repositioning element encapsulated with a mold can be easily handled without being damaged.

[0021] Furthermore, by using the thinning wafer handling sheet of the present invention, the adhesive portion is excellent in chemical resistance due to the use of a thermosetting elastomer, so that various resins for cleaning temporary adhesives can be used.

[0022] In addition, the present invention provides a method for handling a thin wafer, which is characterized by adhering a silicon wafer or a compound semiconductor wafer having a thickness of 300 microns or less to the thinning wafer handling sheet of the present invention and then handling it.

[0023] In the method for handling a thin wafer of the present invention, since almost no force is required for peeling, even a silicon wafer with a thickness of 300 μm or less can be easily taken out without being damaged.

[0024] Further, the present invention provides a method for handling a thin device, characterized in that a square glass panel or metal panel with a thickness of 1.5 mm or less on which a silicon wafer or compound semiconductor wafer with a thickness of 300 μm or less is mounted is adhered to a sheet for handling a thinned wafer of the present invention and then handled.

[0025] In the method for handling a thin device of the present invention, since almost no force is required for peeling, even a square glass panel or metal panel with a thickness of 1.5 mm or less on which a silicon wafer or compound semiconductor wafer with a thickness of 300 μm or less is mounted can be easily taken out without being damaged.

Effects of the Invention

[0026] As described above, in the case of the sheet of the present invention, while a wafer can be easily adhered with sufficient adhesive force, almost no force is required for peeling. Therefore, a wafer that has already been thinned or a repositioning element sealed with a mold can be easily handled without being damaged. Further, the sheet of the present invention is formed of a thermosetting resin and has excellent chemical resistance, so that various resins for cleaning temporary adhesives can be used.

[0027] Further, in the case of the sheet for handling a thinned wafer of the present invention, since it includes the sheet of the present invention, a wafer that has already been thinned or a repositioning element sealed with a mold can be easily handled without being damaged. Furthermore, by using the sheet for handling a thinned wafer of the present invention, the adhesive portion has excellent chemical resistance due to the use of a thermosetting elastomer, so that various resins for cleaning temporary adhesives can be used. Therefore, the sheet for handling a thinned wafer of the present invention is particularly useful for use, for example, in a method for handling a thin wafer and a method for handling a thin device.

[0028] In addition, in the method for handling a thin wafer of the present invention, since almost no force is required for peeling, even a silicon wafer with a thickness of 300 microns or less can be easily taken out without being damaged.

[0029] And in the method for handling a thin device of the present invention, since almost no force is required for peeling, even a rectangular glass panel or metal panel with a thickness of 1.5 millimeters or less on which a silicon wafer or compound semiconductor wafer with a thickness of 300 microns or less is mounted can be easily taken out without being damaged.

Brief Description of the Drawings

[0030]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0031] As described above, it is a tool that can easily handle a thinned wafer or a repositioned element sealed with a mold for the thinning process of a silicon wafer or a compound semiconductor, which is frequently used for purposes such as the three-dimensional mounting described above, and there has been a demand for the development of a tool with excellent chemical resistance.

[0032] As a result of intensive studies on the above problems, the inventors of the present invention have found that a plurality of columnar or semi-columnar structures having a height of 50 to 500 microns, or prismatic structures having a length of 100 microns to 1 mm, and having a diameter or thickness of 10 microns to 1 mm are provided on the surface, and these are arranged at equal intervals, or are arranged such that the maximum value of the intervals is less than three times the minimum value of the intervals. A sheet formed by molding with a thermosetting resin can easily adhere to a wafer with sufficient adhesive force, while hardly requiring any force for peeling. Therefore, a wafer that has already been thinned or a repositioned element sealed in a mold can be easily handled without being damaged, and furthermore, it has been found that excellent chemical resistance can be exhibited, and the present invention has been completed.

[0033] That is, the present invention provides a plurality of columnar or semi-columnar structures having a height of 50 to 500 microns and a diameter of 10 microns to 1 mm, or prismatic structures having a length of 100 microns to 1 mm and a thickness of 10 microns to 1 mm on the surface, and the plurality of structures are arranged at equal intervals, or the plurality of structures are arranged on the surface such that the maximum value of the intervals is less than three times the minimum value of the intervals, and is characterized by being formed by molding with a thermosetting resin.

[0034] Further, the present invention includes a base material and the sheet of the present invention laminated on the base material and is characterized by being a sheet for thinning wafer handling.

[0035] Further, the present invention provides a method for handling a thin wafer, which comprises adhering a silicon wafer or a compound semiconductor wafer having a thickness of 300 microns or less to the sheet for thinning wafer handling of the present invention and then handling it.

[0036] Further, the present invention is a method for handling a thin device, characterized by handling a rectangular glass panel or metal panel with a thickness of 1.5 millimeters or less on which a silicon wafer or compound semiconductor wafer with a thickness of 300 microns or less is mounted, after adhering it to the sheet for thinning wafer handling of the present invention.

[0037] Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

[0038] FIG. 1 is a schematic cross-sectional view showing an example of the sheet of the present invention. The sheet 1 shown in FIG. 1 has a plurality of structures 1a on one surface of a resin base 1b. The sheet 1, that is, the plurality of structures 1a and the base 1b are formed of a thermosetting resin.

[0039] The resin used in the present invention is composed of a thermosetting resin. Specifically, at least one selected from the group consisting of a thermosetting elastomer, more specifically, for example, an acrylic thermosetting elastomer, a silicone thermosetting elastomer, a urethane thermosetting elastomer, and a fluorine thermosetting elastomer is used.

[0040] These resins are preferably moldable into the shapes described below and have no transfer of resin components when peeled from the adhesion target, but there are no restrictions on their range and use.

[0041] The sheet 1 of the present invention has minute structures 1a on the surface of a resin (base portion 1b), specifically, a plurality of structures 1a having a columnar or semi-columnar shape with a height of 50 to 500 microns and a diameter of 10 to 1 mm, or a prismatic shape with a length of 100 to 1 mm and a thickness of 10 to 1 mm. In the present invention, when the structure 1a is prismatic, the thickness refers to the diameter of the circumscribed circle 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, or a structure in which a plurality of structures 1a are arranged such that the maximum value 1c of the intervals is less than three times the minimum value 1d of the intervals on the surface. The maximum value 1c of the intervals is larger than the minimum value 1d of the intervals.

[0042] Further, as shown in FIG. 2, it is common to use the sheet 1 in a form bonded to a film (base material 2) such as a PET or polyolefin resin sheet.

[0043] The sheet 10 after bonding can be used, for example, as a sheet for thinning wafer handling. The sheet 10 for thinning wafer handling shown in FIG. 2 includes the base material 2 and the sheet 1 of the present invention laminated on the base material 2. The sheet 1 shown in FIG. 2 has the same structure as the sheet 1 shown in FIG. 1.

[0044] The structures 1a of the sheet 1 formed on the base material 2 such as a resin sheet preferably have a uniform height and a flat surface of the structures. Further, although the size and pitch (the size of the structure 1a and the interval between the structures 1a) can be arbitrarily selected, it is desirable that, for example, a circuit-formed silicon wafer or a compound semiconductor wafer to be bonded can be held.

[0045] Next, an example of using the thinning wafer handling sheet 10 of the present invention will be described. FIG. 3 shows a schematic cross-sectional view showing an example of the use site of the sheet for thinning wafer handling of the present invention.

[0046] After a part of the surface of the plurality of structures 1a of Sheet 1 of the thinning wafer handling sheet 10 is adhesively formed on a frame (for example, a metal frame) 4 such as a dicing frame, a processed thinning wafer (for example, a silicon wafer, a compound semiconductor wafer) 3 with a carrier 5 is adhered by another part of the surface of the plurality of structures 1a. The thinning wafer 3 to be adhered is temporarily adhered to the carrier 5 via a temporary adhesive layer 6 containing a temporary adhesive. Thereafter, for example, a glass wafer as the carrier 5 is peeled off by a laser peeling method or the like according to the properties of the temporary adhesive of the temporary adhesive layer 6. After the carrier 5 is peeled off, the temporary adhesive residue remaining on the thinned wafer 3 is washed with an appropriate organic solvent-based cleaning agent, so that the thinned wafer 3 adhered on the thinning wafer handling sheet 10 according to the present invention can be taken out. Here, since Sheet 1 of the present invention is molded from a thermoplastic resin, it has high chemical resistance. Therefore, in the handling method using Sheet 1 of the present invention, various solvents and resins for cleaning the temporary adhesive can be used to remove the temporary adhesive residue.

[0047] Through the above steps, a thinned wafer 3 stretched on the thinning wafer handling sheet 10 is obtained. The adhesion between the thinning wafer handling sheet 10 and the thinning wafer 3 can exhibit sufficient strength to withstand handling due to the presence of the plurality of structures 1a on the surface of Sheet 1. On the other hand, after handling, for example, by applying a slight force to the edge portion of the wafer, the thinned wafer 3 can be easily taken out from the thinning wafer handling sheet 10. Due to the plurality of structures 1a formed on the surface of the thinning wafer handling sheet 10, almost no force is required for this peeling, and even a 300 mm silicon wafer 3 with a thickness of 300 microns or less, and further a thickness of 30 microns or less, can be easily taken out without being damaged.

[0048] Further, after the thinned wafer 3 is taken out, since there is no transfer of resin to its surface, an additional cleaning process or the like is not required.

[0049] Thus, the sheet 10 for thinning wafer handling of the present invention can be used, for example, in a method for handling a thin wafer that handles a silicon wafer or a compound semiconductor wafer 3 with a thickness of 300 microns or less. In the method for handling a thin wafer of the present invention, the silicon wafer or the compound semiconductor wafer 3 can be handled after being adhered to the sheet 10 for thinning wafer handling of the present invention. Thereby, even a silicon wafer or a compound semiconductor wafer 3 with a thickness of 300 microns or less can be easily taken out without being damaged.

[0050] On the other hand, if the plurality of structures 1a are columnar or semi-columnar structures and the height is less than 50 microns, the height exceeds 500 microns, the diameter is less than 10 microns, or the diameter exceeds 1 mm, it is impossible to achieve both the adhesive force required for handling and excellent peelability. Similarly, if the plurality of structures 1a are prismatic structures and the length is less than 100 microns, the length exceeds 1 mm, the thickness is less than 10 microns, or the diameter exceeds 1 mm, it is impossible to achieve both the adhesive force required for handling and excellent peelability.

[0051] Also, if the plurality of structures 1a are arranged such that the maximum value of the interval exceeds three times the minimum value of the interval, the adhesive force required for handling cannot be exhibited.

[0052] The present invention can obtain a sheet 10 for thinning wafer handling with excellent chemical resistance and other process compatibility by processing a sheet 1 made of a thermoplastic resin, preferably a thermosetting elastomer, more preferably a thermosetting elastomer of acrylic, silicone, urethane, or fluorine type, into a target shape and adhering it to a thinned wafer.

[0053] The use of the sheet 10 for thinning wafer handling of the present invention is not limited to the method of handling thin wafers. For example, the sheet 10 for thinning wafer handling of the present invention can also be used in the method of handling thin devices. In the method of handling thin devices of the present invention, for example, a rectangular glass panel or metal panel with a thickness of 1.5 millimeters or less on which a silicon wafer or compound semiconductor wafer with a thickness of 300 microns or less is mounted can be adhered to the sheet for thinning wafer handling of the present invention and then handled. Thereby, even a rectangular glass panel or metal panel with a thickness of 1.5 millimeters or less on which a silicon wafer or compound semiconductor wafer with a thickness of 300 microns or less is mounted can be easily handled without breakage.

[0054] The lower limit of the thickness of the silicon wafer or compound semiconductor wafer adhered to the sheet 10 for thinning wafer handling of the present invention and handled is not particularly limited. For example, a silicon wafer or compound semiconductor wafer with a thickness of 10 microns or more and 300 microns or less can be handled. Also, the lower limit of the thickness of the rectangular glass panel or metal panel adhered to the sheet 10 for thinning wafer handling of the present invention and handled is not particularly limited. For example, a rectangular glass panel or metal panel with a thickness of 0.1 millimeter or more and 1.5 millimeters or less on which a silicon wafer or compound semiconductor wafer with a thickness of 10 microns or more and 300 microns or less is mounted can be handled.

Example

[0055] Hereinafter, the present invention will be specifically described using examples, but the present invention is not limited thereto.

[0056] [Example] A urethane resin, which is a thermosetting elastomer, was molded on a PET sheet with a thickness of 100 microns into a cylindrical structure with a height of 200 microns and a diameter of 500 microns so that the interval was 500 - micron intervals (equidistant) and the total thickness was 500 microns. Thereby, a sheet for thinning wafer handling was obtained.

[0057] On one hand, a 300 mm glass wafer (700 microns thick) was used as a carrier, and a wafer with a thickness of 775 microns on which TSVs had been formed was adhered to this glass carrier using a UV laser peelable temporary material (SPIS-TA401 + SPIS-TA501) manufactured by Shin-Etsu Chemical Co., Ltd. as an adhesive layer. Subsequently, the wafer on which TSVs had been formed was thinned to a thickness of 50 microns to form the terminals of the TSVs. Further, a SiO2 film was formed by plasma CVD using TEOS to obtain a thinned silicon wafer. After forming the sheet for handling the thinned wafer obtained above on a dicing frame, the thinned silicon wafer was bonded to the sheet.

[0058] With respect to the laminate composed of this glass carrier, the adhesive layer, the thinned silicon wafer, and the sheet for handling the thinned wafer, first, a UV laser was irradiated onto the front surface from the glass carrier surface to peel off the glass carrier. After that, the residual adhesive resin residue remaining on the silicon wafer was dissolved and washed with a cleaner SPIS-TA-Cleaner-25 manufactured by Shin-Etsu Chemical Co., Ltd.

[0059] At this time, no abnormalities such as peeling or floating were observed in the sheet for handling the thinned wafer that supported the thinned silicon wafer. That is, the adhesion between the sheet for handling the thinned wafer and the thinned silicon wafer had sufficient strength to withstand the handling of the thin wafer.

[0060] Finally, when the sheet was peeled off from the edge portion of the thinned silicon wafer from the back surface of the sheet for handling the thinned wafer, the sheet was easily peeled off, and no damage such as cracks occurred in the 50-micron-thick wafer, and no resin residue or the like was generated.

[0061] Note that the present invention is not limited to the above-described embodiment. The above-described embodiment is an example, and any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits the same operational effects is included in the technical scope of the present invention.

Claims

1. It has a plurality of structures on the surface, which are columnar or semi-columnar with a height of 50 microns to 500 microns and a diameter of 10 microns to 1 mm, or prismatic with a length of 100 microns to 1 mm and a thickness of 10 microns to 1 mm, and the plurality of structures are arranged at equal intervals, or the plurality of structures are arranged on the surface such that the maximum value of the intervals is less than 3 times the minimum value of the intervals, and it contains a cured product of a resin, A molded article characterized by being used for handling a thinned wafer or a mold-sealed repositioning element.

2. The molded article according to claim 1, wherein the resin is a curable resin.

3. The molded article according to claim 1, wherein the resin is at least one selected from the group consisting of an acrylic resin, a silicone resin, a urethane resin, and a fluororesin.

4. A base material, The molded article according to any one of claims 1 to 3 laminated on the base material, A handling sheet characterized by comprising the above.

5. A handling method characterized by handling a thinned wafer or a mold-sealed repositioning element with a thickness of 300 microns or less after adhering it to the molded article according to any one of claims 1 to 3.

6. A handling method for a thin device, characterized by handling a square glass panel or a metal panel with a thickness of 1.5 mm or less on which a silicon wafer or a compound semiconductor wafer with a thickness of 300 microns or less is mounted, after adhering it to the molded article according to any one of claims 1 to 3.

7. A method for taking out a thinned wafer, characterized by peeling the carrier from the thinned wafer in a state where the thinned wafer supported by the carrier is adhered to the molded article according to any one of claims 1 to 3.

8. A method for taking out a mold-sealed repositioning element, characterized by peeling the carrier from the mold-sealed repositioning element in a state where the mold-sealed repositioning element supported by the carrier is adhered to the molded article according to any one of claims 1 to 3.

9. A method for manufacturing a taken-out thinned wafer, characterized by including peeling the carrier from the thinned wafer in a state where the thinned wafer supported by the carrier is adhered to the molded article according to any one of claims 1 to 3.

10. A method for manufacturing a removed molded encapsulation repositioning element, comprising peeling the carrier from the molded encapsulation repositioning element in a state where the molded encapsulation repositioning element supported by the carrier is adhered to the molded article according to any one of claims 1 to 3.

11. A method for manufacturing a package, comprising a step of peeling the carrier or the molded encapsulation repositioning element from the thinned wafer in a state where the thinned wafer or the molded encapsulation repositioning element supported by the carrier is adhered to the molded article according to any one of claims 1 to 3.

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