Film for forming protective film, sheet for forming protective film, and semiconductor wafer

Abstract

Provided is a film for forming a protective film, which is formed from a resin composition that contains a polymer component, a thermosetting component, a crosslinking agent component, an epoxy-modified silicone oil, and an inorganic filler. The polymer component is an acrylic polymer, the thermosetting component comprises epoxy resin and a thermosetting agent, and the cross-linking agent component comprises a metal chelate and polyisocyanate. In addition, based on the total weight of the resin composition as 100 weight percent, the content of the epoxy modified silicone oil is 0.01 weight percent to 0.2 weight percent. Therefore, according to the film for forming the protective film, the resin composition containing the epoxy modified silicone oil is added, so that the film can be quickly torn off as required after being thermally bonded with a semiconductor wafer, and the film has reworkability.

Description

Technical Field

[0001] The present invention relates to a protective film forming film, a protective film forming sheet, and a semiconductor wafer with a protective film, and more particularly to a protective film forming film, a protective film forming sheet, and a semiconductor wafer with a protective film that have reworkability. Background Art

[0002] In recent years, the industry has used the so-called face-down mounting method to manufacture semiconductor devices, which bonds electrodes such as bumps formed on the circuit surface of the chip to the substrate, thereby exposing the back side of the chip opposite to the circuit surface. Therefore, a protective film is set on the back side of the chip for protection so that it can be directly mounted in the semiconductor device.

[0003] However, if the chip protection film is not properly bonded after thermal bonding, it may be impossible to rework or require additional organic solvents to remove the chip protection film, which is difficult to process and may cause chip breakage.

[0004] In view of this, how to adjust the composition formula of the protective film to improve the problems of poor adhesion and inability to rework the protective film has become the goal of relevant industries. Summary of the Invention

[0005] An object of the present invention is to provide a protective film forming film, a protective film forming sheet, and a semiconductor wafer with a protective film. By adjusting the composition and formulation of the protective film forming film, after thermal bonding to the semiconductor wafer, the protective film forming film that is poorly bonded can be quickly removed, thereby increasing reworkability and improving production yield.

[0006] One embodiment of the present invention provides a film for forming a protective film. The film is formed from a resin composition comprising a polymer component, a thermosetting component, a crosslinking agent component, an epoxy-modified silicone oil, and an inorganic filler. The polymer component is an acrylic polymer, the thermosetting component comprises an epoxy resin and a thermosetting agent, and the crosslinking agent component comprises a metal chelate and a polyisocyanate. Furthermore, the epoxy-modified silicone oil comprises 0.01 to 0.2 weight percent of the total weight of the resin composition as 100 weight percent.

[0007] In the protective film-forming film according to the aforementioned embodiment, the content of the polymer component may be 20 to 30 weight percent based on 100 weight percent of the total weight of the resin composition.

[0008] In the protective film-forming film according to the aforementioned embodiment, the epoxy resin may include a liquid epoxy resin and a solid epoxy resin.

[0009] In the protective film forming film according to the aforementioned embodiment, the liquid epoxy resin may be a bisphenol A epoxy resin, a bisphenol F epoxy resin, resorcinol, a phenyl novolac epoxy resin, a cresol novolac epoxy resin, or a combination thereof.

[0010] In the protective film forming film according to the aforementioned embodiment, the solid epoxy resin may be a naphthalene-based epoxy resin, a dicyclopentadiene-based epoxy resin, or a combination thereof.

[0011] In the protective film forming film according to the aforementioned embodiment, based on the total weight of the epoxy resin being 100 weight percent, the contents of the liquid epoxy resin and the solid epoxy resin may each be 40 weight percent to 60 weight percent.

[0012] In the protective film-forming film according to the aforementioned embodiment, the content of the metal chelate compound may be 0.1 to 2 weight percent based on 100 weight percent of the total weight of the resin composition.

[0013] In the protective film-forming film according to the aforementioned embodiment, the content of the polyisocyanate may be 0.1 to 3 weight percent based on 100 weight percent of the total weight of the resin composition.

[0014] In the protective film-forming film according to the aforementioned embodiment, the content of the inorganic filler may be 40 to 50 weight percent based on 100 weight percent of the total weight of the resin composition.

[0015] In the protective film-forming film according to the aforementioned embodiment, the resin composition may further include an additive, a dispersant, a colorant, a hardening accelerator, or a combination thereof.

[0016] Another embodiment of the present invention provides a protective film-forming sheet including the protective film-forming film described in the preceding paragraph, wherein the protective film-forming film is sandwiched between a first release film and a second release film.

[0017] Another embodiment of the present invention provides a semiconductor wafer with a protective film, comprising a semiconductor wafer and a protective film. The protective film is attached to a surface of the semiconductor wafer and is formed by curing the protective film-forming film described in the preceding paragraph.

[0018] Thus, the present invention adjusts the components and content of the resin composition to prepare a protective film forming film, and after thermally bonding it to a semiconductor chip, the interface adhesion between the protective film forming film and the semiconductor chip can be reduced to achieve a rework effect, and the poorly bonded protective film forming film can be quickly torn off. DETAILED DESCRIPTION

[0019] The following will discuss various embodiments of the present invention in more detail. However, this embodiment can be applied to various inventive concepts and can be specifically implemented in various specific scopes. The specific embodiments are for illustrative purposes only and are not intended to limit the scope of the disclosure.

[0020] In the present invention, the term "range from one value to another value" is used as a summary to avoid listing all values ​​within the range in the specification. Therefore, the description of a specific numerical range encompasses any value within that range and any smaller numerical range defined by any value within that range, just as if the arbitrary value and the smaller numerical range were explicitly stated in the specification. For example, the range of "0.1% by weight to 1% by weight" encompasses the range of "0.5% by weight to 0.8% by weight," regardless of whether other values ​​are listed in the specification.

[0021] <Film for forming a protective film>

[0022] The protective film-forming film of the present invention is formed from a resin composition. For example, the resin composition can be applied to a target object and dried to form the protective film-forming film; alternatively, the resin composition can be formed into a film. The resin composition comprises a polymer component, a thermosetting component, a crosslinking agent component, an epoxy-modified silicone oil, and an inorganic filler. Preferably, the resin composition further comprises an additive, a dispersant, a colorant, a curing accelerator, or a combination thereof. The various components described above are described in detail below.

[0023] <Polymer Component>

[0024] In this embodiment, the polymer component is used to impart film-forming properties or flexibility to the protective film-forming film, and the content of the polymer component may be 20 to 30 weight percent based on the total weight of the resin composition being 100 weight percent. Specifically, the polymer component is an acrylic polymer, which may be obtained by copolymerizing one or more (meth)acrylate monomers, wherein the (meth)acrylate monomers may include, but are not limited to, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, isobornyl (meth)acrylate, glycidyl (meth)acrylate, hydroxymethyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, or hydroxybutyl (meth)acrylate.

[0025] <Thermosetting Components>

[0026] In this embodiment, the thermosetting component is used to cure the protective film forming film to form a hard protective film. Specifically, the thermosetting component includes an epoxy resin and a thermosetting agent, and the thermosetting agent can react with the epoxy resin by heating.

[0027] The epoxy resin described above may include a liquid epoxy resin and a solid epoxy resin. The liquid epoxy resin may be, but is not limited to, a bisphenol A epoxy resin, a bisphenol F epoxy resin, resorcinol, a phenyl novolac epoxy resin, a cresol novolac epoxy resin, or a combination thereof. The solid epoxy resin may be, but is not limited to, a naphthalene epoxy resin, a dicyclopentadiene epoxy resin, or a combination thereof. The softening point of the solid epoxy resin is between 80°C and 110°C. Furthermore, based on 100% by weight of the total weight of the epoxy resin, the content of the liquid epoxy resin and the solid epoxy resin is each between 40% and 60% by weight, which improves the film-forming properties of the protective film.

[0028] The aforementioned thermal hardener may be a compound having two or more functional groups reactive with the epoxy groups of the epoxy resin. Examples of such functional groups include phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, or carboxyl groups. Specifically, the thermal hardener may be, but is not limited to, a phenolic hardener such as biphenol, novolac-type phenolic resin, or dicyclopentadiene-type phenolic resin, or an amine-based hardener such as dicyandiamide. The thermal hardener content may be 0.1 to 2 weight percent based on 100 weight percent of the total weight of the resin composition.

[0029] <Crosslinking Agent Component>

[0030] In this embodiment, a crosslinking agent component is used to crosslink with the polymer component having functional groups, thereby imparting good film strength to the protective film-forming film. The crosslinking agent component also adjusts the stress and strain properties of the protective film-forming film, thereby imparting appropriate hardness and softness. Specifically, the crosslinking agent component comprises a metal chelate and a polyisocyanate. Based on 100 weight percent of the total weight of the resin composition, the metal chelate content may be 0.1 to 2 weight percent, and the polyisocyanate content may be 0.1 to 3 weight percent. Using the metal chelate alone would make the protective film-forming film too hard and brittle, while using the polyisocyanate alone would make the protective film-forming film too soft.

[0031] The aforementioned metal chelate compound may be, but is not limited to, aluminum acetylacetonate or zinc acetylacetonate, while the aforementioned polyisocyanate may be, but is not limited to, toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), or hexamethylene diisocyanate (HDI). Furthermore, the isocyanate groups in both the metal chelate compound and the polyisocyanate undergo a cross-linking reaction with the functional groups in the polymer component. Specifically, since the polymer component is an acrylic polymer, which has hydroxyl functional groups, a cross-linked structure can be introduced into the protective film-forming film by reacting the cross-linking agent component with the hydroxyl groups in the polymer component.

[0032] <Epoxy modified silicone oil>

[0033] In this embodiment, the epoxy-modified silicone oil is used to impart a protective film-forming film to a wafer after thermal bonding, thereby reducing the interface adhesion and achieving a rework effect. The content of the epoxy-modified silicone oil is 0.01 to 0.2 weight percent based on the total weight of the resin composition being 100 weight percent.

[0034] Specifically, because the wafer surface is rich in OH groups, and the protective film-forming film is rich in OH and epoxy groups, when the protective film-forming film is thermally bonded to the wafer, its adhesion is enhanced by the wafer surface roughness and the attractive forces of the functional groups. However, epoxy-modified silicone oil has multiple non-polar CH bonds, so adding epoxy-modified silicone oil can reduce the attractive forces of OH groups between the protective film-forming film and the wafer, thereby reducing adhesion and enhancing reworkability. Furthermore, the epoxy-modified silicone oil has epoxy groups in its side chains, which react with the epoxy resin during thermal curing, preventing the entire silicone oil from migrating to the wafer surface and causing poor adhesion and peeling of the cured protective film. Conversely, using conventional silicone oil, which lacks epoxy groups in its side chains, does not react with the epoxy resin during thermal curing. Furthermore, conventional silicone oil has a low molecular weight and will migrate to the wafer surface and precipitate, affecting the adhesion and peeling strength of the cured protective film and generating gas emissions when heated.

[0035] <Inorganic fillers>

[0036] In this embodiment, the inorganic filler is used to impart flame retardancy, low thermal expansion, and low hygroscopicity to the cured protective film. Specifically, the inorganic filler may be, but is not limited to, silicon oxide, talc, calcium carbonate, titanium dioxide, red iron oxide, silicon carbide, or a combination thereof. The inorganic filler content may be 40 to 50 weight percent based on 100 weight percent of the total weight of the resin composition.

[0037] <Hardening Accelerator>

[0038] In this embodiment, a hardening accelerator is used to adjust the curing speed of the resin composition. Specifically, the hardening accelerator may be, but is not limited to, a tertiary amine such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, or tris(dimethylaminomethyl)phenol, or an imidazole such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, or 2-phenyl-4-methyl-5-hydroxymethylimidazole. The content of the hardening accelerator may be 0.1 to 2 weight percent based on 100 weight percent of the total weight of the resin composition.

[0039] <Colorant>

[0040] In this embodiment, a colorant is used to impart laser printability, light-shielding properties, and design properties to the cured protective film. Specifically, the colorant may be, but is not limited to, an inorganic pigment such as carbon black or an organic pigment such as anthocyanin. The colorant content may be 0.2 to 10 weight percent based on 100 weight percent of the total weight of the resin composition.

[0041] In addition, other components such as additives or dispersants may be added as needed, and their types and contents are not particularly limited.

[0042] <Protective Film Forming Sheet>

[0043] The protective film-forming sheet of the present invention comprises the aforementioned protective film-forming film, which is sandwiched between a first release film and a second release film. Specifically, the protective film-forming sheet has the first release film on one surface of the protective film-forming film and the second release film on the other surface. A protective film-forming sheet having such a configuration is preferably stored in a roll form. Furthermore, the first release film and the second release film may both be known release films, and may be the same or different. Furthermore, the release forces required to release the first and second release films from the protective film-forming sheet may differ.

[0044] <Semiconductor Wafer with Protective Film>

[0045] The semiconductor wafer with a protective film of the present invention comprises a semiconductor wafer and a protective film. The protective film is attached to one surface of the semiconductor wafer and is formed by curing the aforementioned protective film-forming film. Specifically, the protective film-forming film is attached to the back surface of the semiconductor wafer, opposite the circuit surface, and then cured to form a protective film that protects the semiconductor wafer from external impacts. The semiconductor wafer may be, but is not limited to, a silicon wafer, a wafer made of gallium arsenide, silicon carbide, gallium nitride, or the like, or a glass wafer.

[0046] The present invention is further illustrated by the following specific examples, which are intended to facilitate those skilled in the art to which the present invention relates, so that they can fully utilize and practice the present invention without excessive interpretation. These examples should not be construed as limiting the scope of the present invention, but are intended to illustrate how to implement the materials and methods of the present invention.

[0047] <Examples / Comparative Examples>

[0048] The types of components used in the resin compositions of Examples 1 to 5 of the present invention and Comparative Examples 1 to 4 are as follows.

[0049] Polymer composition: Acrylic polymer (weight-average molecular weight: 690,000 g / mol; glass transition temperature: -1°C) copolymerized with 65 parts by weight of n-butyl acrylate (BA), 15 parts by weight of methyl acrylate (MA), 12 parts by weight of glycidyl methacrylate (GMA), and 8 parts by weight of hydroxyethyl acrylate (2-HEA).

[0050] Epoxy resin (I): bisphenol A type epoxy resin.

[0051] Epoxy resin (II): naphthalene type epoxy resin.

[0052] Epoxy resin (III): dicyclopentadiene type epoxy resin.

[0053] Thermal hardener: dicyandiamide.

[0054] Crosslinking agent component (I): zinc acetylacetonate.

[0055] Crosslinking agent component (II): HDI polyisocyanate.

[0056] Inorganic filler: silica filler (average particle size 0.586 μm).

[0057] Additive (I): (3-glycidoxypropyl)triethoxysilane.

[0058] Additive (II): (3-glycidoxypropyl)trimethoxysilane.

[0059] Additive (III): organosilicone alkoxy oligomer.

[0060] Additive (IV): 2,4-pentanedione.

[0061] Hardening accelerator: imidazole type epoxy resin hardener.

[0062] Colorant: carbon black (particle size 23 nm).

[0063] Dispersant: EFKA PX4701 (available from BASF).

[0064] The resin compositions of Examples 1 to 5 of the present invention are formed by mixing according to the components and contents in Table 1.

[0065]

[0066]

[0067] The resin compositions of Comparative Examples 1 to 4 of the present invention are formed by mixing according to the components and contents in Table 2.

[0068]

[0069] <Manufacture of Film for Forming Protective Film>

[0070] The resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4 are mixed with a solvent to form a glue with a solid content of 30% to 40% and a viscosity of 200 cps to 600 cps. The glue is coated on a 50-μm heavy release film by a slot coater. After baking in an oven, the glue becomes a 25-μm film for forming a protective film, and then it is covered with a 38-μm light release film to form a film for forming a protective film with a sandwich structure, so as to facilitate the storage of the film for forming a protective film.

[0071] <Chip Adhesion Test>

[0072] Align and stick the film for forming a protective film formed by the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4 with 3M 681 tape. Then, heat-attach the adhered film for forming a protective film to the polished surface of a #8000 polished silicon wafer (diameter 200 mm, thickness 280 μm) at 80°C, and let it stand at room temperature for 5 minutes. After that, conduct a tensile test at a speed of 300 mm / min and an angle of 180 degrees with a universal tensile testing machine.

[0073] <Reworkability Test>

[0074] Heat-attach the film for forming a protective film formed by the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4 to the polished surface of a #8000 polished silicon wafer (diameter 200 mm, thickness 280 μm) at 80°C with a roller, and then cold-attach a Siwei Lutou brand MYAGR green Mara high-temperature resistant tape with a roller. Manually tear off the adhered film for forming a protective film, and confirm whether there is any residue of the film for forming a protective film on the silicon wafer. If it can be torn off cleanly at one time, it is marked as A. If it cannot be torn off cleanly at one time and needs to be torn off twice, it is marked as B. If it cannot be torn off, it is marked as C.

[0075] <Wafer Cross-Cut Test>

[0076] The film for forming a protective film formed from the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4 was hot-attached to the polished surface of a #8000 polished silicon wafer (diameter 200 mm, thickness 280 μm) at 80°C using a roller, and then thermally cured at 130°C for 2 hours to form a protective film. After cooling, the interface between the silicon wafer and the protective film was subjected to a cross-hatch test using a grid cutter. The test method and judgment were based on ASTM D3359 specifications. If the edges of the cuts were completely smooth and there was no peeling at the edges of the grids, the grade was 2B.

[0077] <PCT Wafer Cross-Hatch Test>

[0078] The film for forming a protective film formed from the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4 was hot-attached to the polished surface of a #8000 polished silicon wafer (diameter 200 mm, thickness 280 μm) at 80°C using a roller, and then thermally cured at 130°C for 2 hours to form a protective film. After cooling, the silicon wafer was placed in a pressure cooker tester (PCT) for testing (121°C; humidity 100%, 168 H). After the test, it was taken out and subjected to a cross-hatch test using a grid cutter. The test method and judgment were based on ASTM D3359 specifications. If the edges of the cuts were completely smooth and there was no peeling at the edges of the grids, the grade was 2B.

[0079] Regarding the above tests, the test results of Examples 1 to 5 and Comparative Examples 1 to 4 of the present invention are listed in Table 3 below.

[0080]

[0081] As can be seen from Table 3, for the film for forming a protective film of Examples 1 to 5 of the present invention, by adding epoxy-modified silicone oil, the adhesion after thermal lamination to the semiconductor wafer can be decreased, and it can be torn off at one time, and thus has reworkability. In addition, the protective film formed after the film for forming a protective film is cured has good adhesion to the semiconductor wafer, and can reach a grade of 5B after the cross-hatch test.

[0082] In summary, the present invention adjusts the composition and content of the resin composition so that the film for forming a protective film formed can be torn off at one time after thermal lamination to the semiconductor wafer and has reworkability, and the protective film after curing has good adhesion to the semiconductor wafer and can protect the semiconductor wafer from external impacts.

[0083] Although the present invention has been disclosed as above in the embodiments, it is not intended to limit the present invention. Any person skilled in this art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be defined by the appended claims.

Claims

1. A film for forming a protective film, characterized in that It is formed from a resin composition, which includes: a polymer component which is an acrylic polymer; a thermosetting component comprising an epoxy resin and a thermosetting agent; a crosslinker component comprising a metal chelate and a polyisocyanate; an epoxy-modified silicone oil, wherein the content of the epoxy-modified silicone oil is 0.01 to 0.2 weight percent based on the total weight of the resin composition being 100 weight percent; and - Inorganic filler.

2. The protective film-forming film according to claim 1, wherein Taking the total weight of the resin composition as 100 weight percent, the content of the polymer component is 20 weight percent to 30 weight percent.

3. The protective film-forming film according to claim 1, wherein The epoxy resin includes a liquid epoxy resin and a solid epoxy resin.

4. The protective film-forming film according to claim 3, wherein The liquid epoxy resin is a bisphenol A epoxy resin, a bisphenol F epoxy resin, resorcinol, a phenyl novolac epoxy resin, a cresol novolac epoxy resin or a combination thereof.

5. The protective film-forming film according to claim 3, wherein The solid epoxy resin is a naphthalene epoxy resin, a dicyclopentadiene epoxy resin or a combination thereof.

6. The protective film-forming film according to claim 3, wherein Taking the total weight of the epoxy resin as 100 weight percent, the contents of the liquid epoxy resin and the solid epoxy resin are respectively 40 weight percent to 60 weight percent.

7. The protective film-forming film according to claim 1, wherein Taking the total weight of the resin composition as 100 weight percent, the content of the metal chelate is 0.1 weight percent to 2 weight percent.

8. The protective film-forming film according to claim 1, wherein Taking the total weight of the resin composition as 100 weight percent, the content of the polyisocyanate is 0.1 weight percent to 3 weight percent.

9. The protective film-forming film according to claim 1, wherein Taking the total weight of the resin composition as 100 weight percent, the content of the inorganic filler is 40 weight percent to 50 weight percent.

10. The protective film-forming film according to claim 1, wherein The resin composition further includes an additive, a dispersant, a colorant, a hardening accelerator or a combination thereof.

11. A sheet for forming a protective film, characterized in that: The protective film-forming film according to any one of claims 1 to 10 is included, wherein the protective film-forming film is sandwiched between a first release film and a second release film.

12. A semiconductor wafer with a protective film, characterized in that: Include: a semiconductor chip; and A protective film is attached to a surface of the semiconductor wafer, wherein the protective film is formed by curing the protective film-forming film according to any one of claims 1 to 10.

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