JP5779260B2 - Protective film forming sheet for chip and manufacturing method of semiconductor chip with protective film - Google Patents

Description

  The present invention relates to a protective film forming sheet for a chip used for forming a protective film on a chip, and a method of manufacturing a semiconductor chip with a protective film in which a protective film is formed on a chip. In particular, the present invention relates to a protective film forming sheet for a chip used for forming a protective film on the back surface of a semiconductor chip mounted by a so-called face-down method, and a method for manufacturing a semiconductor chip with a protective film having a protective film formed on the back surface of the chip. .

  In recent years, semiconductor devices have been manufactured using a so-called face-down mounting method. In this mounting method, a semiconductor chip (hereinafter simply referred to as “chip”) having electrodes such as bumps on a circuit surface is used, and the electrodes are bonded to a substrate. In some cases, the semiconductor device is not sealed. In this case, the surface opposite to the circuit surface of the chip (the back surface of the chip) is exposed.

  In order to protect the exposed back surface of the chip, an organic film may be formed on the back surface of the chip. Conventionally, a protective film made of an organic film is formed by applying a liquid resin to the back surface of a chip by spin coating, drying, and curing. However, the protective film formed in this way has problems such as insufficient thickness accuracy.

  In order to solve the above problems, a protective film with high thickness uniformity can be easily formed on the back side of the chip, and even if a minute scratch is generated on the back side of the chip by mechanical grinding, it can eliminate the adverse effects caused by the scratch. A protective film forming sheet is disclosed (for example, see Patent Documents 1 to 5).

JP 2004-142430 A JP 2004-331728 A JP 2007-158026 A JP 2008-006386 A JP 2008-218930 A

  By the way, in the semiconductor device (chip) in which the protective film is formed, printing is performed on the protective film formed on the back surface of the chip by laser marking in order to impart discrimination (Patent Documents 1 to 3). 5). In particular, Patent Document 4 discloses a protective film-forming sheet for chips having two protective film-forming layers having different colors in order to improve the visibility of laser marking.

  However, these all require a laser marking process. Thus, if one process of laser marking increases, the production efficiency of a semiconductor device will worsen. Further, in a precise semiconductor device sensitive to heat, there is a possibility that the laser marking cannot be performed because the circuit may be destroyed by light or heat at the time of laser marking. Furthermore, in a semiconductor device of the same shape in which a protective film is formed on the back surface of a chip, it is difficult to easily identify what kind of chip the chip is by only printing with laser marking.

  The present invention has been made in view of such a situation, and performs a protective film forming sheet for a chip and a laser marking that can give the chip distinctiveness without performing laser marking. An object of the present invention is to provide a method of manufacturing a semiconductor chip having discriminating properties such as types.

  In order to achieve the above object, first, the present invention provides a protective film-forming sheet for a chip, which is laminated on a chip and forms a protective film for the chip, and includes a release sheet and the release sheet A curable protective film forming layer formed on the surface, and the protective film forming layer includes all chips obtained from the wafer when the protective film forming sheet for chips is attached to the wafer. Provided is a protective film-forming sheet for chips that is colored so as to have two or more colors in the plane direction (Invention 1).

  As the chip, a semiconductor chip can be mainly exemplified, but it is not limited to this. In this specification, “sheet” includes the concept of film, and “film” includes the concept of sheet.

  As the wafer, a semiconductor wafer can be mainly exemplified, but the wafer is not limited thereto.

  According to the above invention (Invention 1), the protective film forming layer colored so as to have two or more colors in the planar direction can impart distinction such as the type to the chip. It is not necessary to perform laser marking for providing distinctiveness.

  In the said invention (invention 1), it is preferable that the said protective film formation layer is colored differently according to the kind of said chip | tip (invention 2). However, the protective film forming layer may be colored differently even for the same type of chip.

  In the said invention (invention 1 and 2), the said protective film formation layer may consist of a resin composition containing a thermosetting resin (A) and a coloring agent (B) (invention 3), or energy ray hardening. It may consist of a resin composition containing a curable resin (C) and a colorant (B) (Invention 4), a thermosetting resin (A), a colorant (B), and an energy beam curable resin (C). (Invention 5).

  In the said invention (invention 1-5), you may have a 2nd peeling sheet on the surface on the opposite side of the surface which contact | connects the said peeling sheet in the said protective film formation layer (invention 6).

Secondly, in the present invention, after the protective film forming layer of the protective film forming sheet for chips (Inventions 1 to 6) is pasted on the back surface of the semiconductor wafer having a circuit formed on the surface, the following step (1) A method of manufacturing a semiconductor chip with a protective film is provided, wherein a semiconductor chip having a protective film having two or more colors in the plane direction on the back surface is obtained by performing steps (3) to (3) in any order (invention) 7).
(1) Step of peeling protective film forming layer and release sheet (2) Step of curing protective film forming layer (3) Step of dicing semiconductor wafer and protective film forming layer

  According to the said invention (invention 7), the semiconductor chip with a protective film obtained by the protective film colored on the back surface of the semiconductor chip so as to have two or more colors in the plane direction is obtained by laser marking. Even if it does not perform, it will have the discriminating property of a kind etc. However, the present invention may include a step of laser marking as necessary, and does not exclude a semiconductor chip with a protective film subjected to laser marking from the scope of the present invention.

  Thirdly, the present invention is a semiconductor chip with a protective film in which a protective film is formed on the back surface of the semiconductor chip, and the protective film cures a curable protective film forming layer having two or more colors in a planar direction. Thus, a semiconductor chip with a protective film is provided.

  In the semiconductor chip with a protective film according to the invention, the protective film colored so as to have two or more colors in the planar direction has a distinction such as the type without performing laser marking. However, the present invention does not exclude a laser-marked semiconductor chip with a protective film. For example, a semiconductor chip with a protective film in which a lot number or the like that is not related to chip type discrimination is laser-marked is also provided. It is included in the scope of the invention.

  According to the present invention, it is possible to obtain a semiconductor chip with a protective film having discriminating properties such as a type and excellent design without performing laser marking.

It is sectional drawing of the sheet | seat for protective film formation for chips which concerns on one Embodiment of this invention. It is a top view of the sheet | seat for chip | tip protective film formation which concerns on one Embodiment of this invention. It is a top view of the semiconductor chip with a protective film which concerns on one Embodiment of this invention. It is a side view of the semiconductor chip with a protective film which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.
[Sheet for forming protective film for chip]
FIG. 1 is a cross-sectional view of a protective film-forming sheet for chips according to an embodiment of the present invention. FIG. 2 is a plan view of the protective film-forming sheet for chips according to one embodiment of the present invention.

  The chip protective film forming sheet 4 according to the present embodiment is, as an example, attached to a semiconductor wafer and for forming a protective film on a semiconductor chip, but is not limited thereto, and is various. Can be used as an adherend, and various chips can be used as an object to be protected.

  As shown in FIG. 1, the chip protective film forming sheet 4 according to the present embodiment includes a (first) release sheet 1 and a protective film forming layer 3 provided on the release surface of the release sheet 1. Become.

  The protective film forming layer 3 is colored so as to have two or more colors in the planar direction. In the present embodiment, when the chip protective film forming sheet 4 is affixed to the semiconductor wafer, each of the chips obtained from the semiconductor wafer has two or more colors in the plane direction so that the protective film forming layer 3 is present. Is colored (see FIG. 2).

  In the present embodiment, the protective film forming layer 3 is color-coded as a checkered pattern (see FIGS. 2, 3 and 4), but is not limited to this. The protective film forming layer 3 is preferably colored so as to have a different color depending on the type of chip. Thereby, even if it does not perform laser marking, the semiconductor chip with a protective film which has discriminability according to the kind of chip | tip is obtained. In addition, such a semiconductor chip with a protective film has excellent design properties due to the protective film having two or more colors.

  Examples of the release sheet 1 include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, and polybutylene terephthalate film. , Polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene / (meth) acrylic acid copolymer film, ethylene / (meth) acrylic acid ester copolymer film, polystyrene film, polycarbonate film, polyimide film, fluororesin film A liquid crystal polymer film or the like is used. These crosslinked films are also used. Furthermore, these laminated films may be sufficient.

  In particular, when the release sheet 1 is peeled after the protective film forming layer 3 is heat-cured, a polymethylpentene film, a polyethylene naphthalate film, a polyimide film or the like excellent in heat resistance is preferably used.

  The film surface (particularly the surface in contact with the protective film forming layer 3) may be subjected to a peeling treatment. Examples of the release agent used for the release treatment include alkyd-based, silicone-based, fluorine-based, unsaturated polyester-based, polyolefin-based, and wax-based release agents. In particular, in terms of excellent heat resistance, alkyd-based, Silicone-based and fluorine-based release agents are preferred.

  In order to facilitate peeling between the protective film forming layer 3 and the release sheet 1, the surface tension of the release sheet 1 is preferably 40 mN / m or less, more preferably 37 mN / m or less, particularly preferably 35 mN / m. It is as follows. Thus, the release sheet 1 having a low surface tension can be obtained by appropriately selecting the material, and can also be obtained by applying a release agent to the surface of the release sheet and performing a release treatment.

  The thickness of the release sheet 1 is usually 5 to 300 μm, preferably 10 to 200 μm.

  The protective film forming layer 3 is curable and made of a colored material. In addition, "curability" in this specification shall mean the property hardened | cured by triggers, such as a heating and energy beam irradiation.

  As the material, firstly, a resin composition (I) containing a thermosetting resin (A) and a colorant (B), and secondly, an energy ray curable resin (C) and a colorant (B). The resin composition (II) containing the resin composition (II), and thirdly the thermosetting resin (A), the colorant (B) and the energy beam curable resin (C) are preferred.

  The first resin composition (I) is advantageous in that the material is inexpensive and a hard protective film can be formed. Furthermore, in the case where photocuring is difficult due to the presence of the colorant (B) and the electron beam adversely affects the chip, the second resin composition (II) and the third resin composition (III ) Cannot be used, the first resin composition (I) is useful.

  According to the second resin composition (II), since no heating is required when the protective film forming layer 3 is cured, it is possible to prevent adverse effects on the chip due to heat. Therefore, the second resin composition (II) is particularly useful when applied to a chip having low heat resistance.

  The third resin composition (III) can form a hard protective film with the thermosetting resin (A), and also contains the energy ray curable resin (C), so that the release sheet is irradiated at the time of energy ray irradiation. There is an advantage that the peelability from 1 can be improved.

A thermosetting resin (A) is resin which has the characteristic to harden | cure by heating.
Examples of the thermosetting resin (A) include epoxy resins, phenol resins, melamine resins, urea resins, polyester resins, urethane resins, acrylic resins, polyimide resins, benzoxazine resins, and the like. Or in combination of two or more. In particular, in this embodiment, an epoxy resin, a phenol resin, or a mixture thereof is preferably used.

  Epoxy resins have the property of forming a three-dimensional network upon heating and forming a strong film. As such an epoxy resin, conventionally known various epoxy resins are used. Usually, those having a molecular weight of about 300 to 2,000 are preferable, and in particular a molecular weight of 300 to 500, preferably 330 to 400 in a normal state. It is desirable to use an epoxy resin blended with an epoxy resin that has a molecular weight of 400 to 2500, preferably 500 to 2000, and is solid at room temperature. Moreover, the epoxy equivalent of the epoxy resin preferably used in this embodiment is 50-5000 g / eq normally.

  Specific examples of such epoxy resins include glycidyl ethers of phenols such as bisphenol A, bisphenol F, resorcinol, phenyl novolac, and cresol novolac; glycidyl ethers of alcohols such as butanediol, polyethylene glycol, and polypropylene glycol; Glycidyl ether of carboxylic acid such as phthalic acid, isophthalic acid, tetrahydrophthalic acid; glycidyl type or alkyl glycidyl type epoxy resin in which active hydrogen bonded to nitrogen atom such as aniline isocyanurate is substituted with glycidyl group; vinylcyclohexane diepoxide, 3,4-epoxycyclohexylmethyl-3,4-dicyclohexanecarboxylate, 2- (3,4-epoxy) cyclohexyl-5,5-spiro (3,4 As the epoxy) cyclohexane -m- dioxane, carbon in the molecule - epoxy is introduced by for example oxidation to carbon double bonds, so-called alicyclic epoxides and the like. In addition, an epoxy resin having a biphenyl skeleton, a dicyclohexadiene skeleton, or a naphthalene skeleton can also be used. Among these, in this embodiment, a bisphenol glycidyl type epoxy resin, an o-cresol novolak type epoxy resin, or a phenol novolak type epoxy resin is preferably used. These epoxy resins can be used alone or in combination of two or more.

  When using an epoxy resin, it is preferable to use a thermally activated latent epoxy resin curing agent in combination as an auxiliary agent. The thermally activated latent epoxy resin curing agent is a type of curing agent that does not react with the epoxy resin at room temperature but is activated by heating at a certain temperature or more and reacts with the epoxy resin.

  The heat activated latent epoxy resin curing agent is activated by a method in which an active species (anion / cation) is generated by a chemical reaction by heating; it is stably dispersed in the epoxy resin near room temperature, and the epoxy is cured at a high temperature. There are a method of starting a curing reaction by dissolving and dissolving with a resin; a method of starting a curing reaction by elution at a high temperature with a molecular sieve encapsulated type curing agent; a method using a microcapsule, and the like.

  Specific examples of the thermally activated latent epoxy resin curing agent used in the present embodiment include various onium salts, dibasic acid dihydrazide compounds, dicyandiamide, amine adduct curing agents, high melting point active hydrogen compounds such as imidazole compounds, and the like. Can be mentioned. These thermally activated latent epoxy resin curing agents can be used singly or in combination of two or more.

  As the phenol resin, a condensate of phenols such as alkylphenol, polyhydric phenol, naphthol and aldehydes is used without particular limitation. Specific examples of the phenol resin preferably used in the present embodiment include a phenol novolak resin, o-cresol novolak resin, p-cresol novolak resin, t-butylphenol novolak resin, dicyclopentadiene cresol resin, polyparavinylphenol. Examples thereof include resins, bisphenol A type novolak resins, and modified products thereof. These phenol resins can be used individually by 1 type or in combination of 2 or more types.

  The phenolic hydroxyl group contained in the phenol resin can easily undergo an addition reaction with the epoxy group of the epoxy resin by heating to form a cured product having high impact resistance. For this reason, you may use together an epoxy resin and a phenol resin.

  As the colorant (B), an organic pigment, an inorganic pigment, or a dye can be used. As the black pigment, for example, carbon black, copper oxide, iron tetroxide, manganese dioxide, aniline black, activated carbon and the like are used. Examples of yellow pigments include chrome yellow, zinc yellow, cadmium yellow, yellow iron oxide, mineral fast yellow, nickel titanium yellow, navel yellow, naphthol yellow S, Hansa Yellow, benzidine yellow G, benzidine yellow GR, quinoline yellow lake, Permanent yellow NCG, tartarine lake, etc. are used. Examples of the orange pigment include red chrome yellow, molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, indanthrene brilliant orange RK, benzidine orange G, indanthrene brilliant orange GKM and the like. Examples of red pigments include bengara, cadmium red, red lead, mercury sulfide, cadmium, permanent red 4R, risor red, pyrozolone red, watching red, calcium salt, lake red D, brilliant carmine 6B, eosin lake, rhodamine. Lake B, alizarin lake, brilliant carmine 3B, etc. are used. Examples of purple pigments include manganese purple, fast violet B, and methyl violet lake. As the blue pigment, for example, bitumen, cobalt blue, alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partially chlorinated product, first sky blue, indanthrene blue BC and the like are used. Examples of the green pigment include chrome green, chromium oxide, pigment green B, malachite green lake, final yellow green G, and the like. Examples of white pigments include zinc white, titanium oxide, antimony white, and zinc sulfide. Examples of extender pigments include barite powder, barium carbonate, clay, silica, white carbon, talc, and alumina white.

  Examples of the dye that can be used include basic dyes, acid dyes, disperse dyes, and direct dyes. Examples of such dyes include nigrosine, methylene blue, rose bengal, quinoline yellow, and ultramarine blue.

  The energy ray curable resin (C) is a resin having a property of being cured by irradiating energy rays such as ultraviolet rays and electron beams. As the energy ray curable resin (C), an acrylic copolymer having a polymerizable double bond and a weight average molecular weight of 50,000 or more, or a weight average molecular weight having at least one polymerizable double bond in the molecule is 100. Monomers and / or oligomers in the range of ˜30,000 are preferred, and the acrylic copolymer and the monomer and / or oligomer may be used in combination.

  An acrylic copolymer having a polymerizable double bond and a weight average molecular weight of 50,000 or more has a polymerizable double bond in the main chain or side chain of the acrylic copolymer. Examples of the polymerizable double bond include a vinyl group, an allyl group, an acryloyl group, a methacryloyl group, an acryloylamide group, a methacryloylamide group, and preferably an acryloyl group and a methacryloyl group.

  A copolymer having a polymerizable double bond in the side chain is prepared, for example, by the following procedure. First, a polymerizable monomer having at least one selected from butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and isooctyl (meth) acrylate, and active hydrogen such as hydroxyethyl acrylate and acrylic acid And radically copolymerizing with other polymerizable monomer having no active hydrogen as necessary, so that the main chain has a skeleton derived from each polymerizable monomer and the side chain has active hydrogen. A copolymer having is obtained. Next, by reacting the active hydrogen of the side chain in the copolymer with an isocyanate group of a monoisocyanate compound having a (meth) acryloyl group such as 2-methacryloyloxyethyl isocyanate, for example, An acrylic copolymer having a polymerizable double bond ((meth) acryloyl group) can be obtained.

  The weight average molecular weight of the acrylic copolymer having a polymerizable double bond is preferably 50,000 or more, particularly preferably 100,000 to 2,000,000.

  Examples of the monomer / oligomer having at least one polymerizable double bond in the molecule and having a weight average molecular weight in the range of 100 to 30,000 include trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, and pentaerythritol triacrylate. , Dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, oligoester acrylate, polyester type or polyether type urethane Examples include acrylate oligomers, polyester acrylates, polyether acrylates, and epoxy-modified acrylates. Among these, an ultraviolet curable type is particularly preferable. Specifically, epoxy-modified acrylates, oligoester acrylates, urethane acrylate oligomers, and the like are preferable, and epoxy-modified acrylates are most preferable in terms of hardness, heat resistance, adhesiveness, and the like. The said monomer or oligomer can be used individually by 1 type or in combination of 2 or more types.

  The weight average molecular weight of the monomer or oligomer having at least one polymerizable double bond in the molecule is preferably from 100 to 30,000, particularly preferably from 300 to 10,000.

  The energy ray curable resin (C) can reduce the polymerization curing time and the light irradiation amount by mixing a photopolymerization initiator therein. Such photopolymerization initiators include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin benzoic acid methyl, benzoin dimethyl ketal, 2,4-diethyl Examples include thioxanthone, α-hydroxycyclohexyl phenyl ketone, benzyldiphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, β-chloranthraquinone, acylphosphine oxide, and the like. One kind can be used alone, or two or more kinds can be used in combination. Among these, an acylphosphine oxide that absorbs light in a long wavelength region and is curable even in a system to which a colorant (B) is added is particularly preferable.

  The content of the colorant (B) in the resin compositions (I) to (III) varies depending on the type of the colorant (B), and is arbitrary in order to obtain a desired color. It is preferable that it is 20 mass%, and it is especially preferable that it is 0.1-10 mass%.

  The mass ratio of the thermosetting resin (A) and the energy beam curable resin (C) in the third resin composition (III) (thermosetting resin (A) / energy beam curable resin (C)) is 55/45 to 97/3, preferably 60/40 to 95/5, and more preferably 70/30 to 90/10.

  The protective film-forming layer 3 is, as necessary, a film-forming resin (binder polymer), a thermoplastic resin, a crosslinking agent, a filler, a coupling agent, a plasticizer, an antioxidant, a flame retardant, and a stress relaxation agent. Further, it may contain an antistatic agent or the like.

  When the protective film forming layer 3 contains an appropriate amount of the binder polymer, it becomes easy to form a film on the release sheet 1, exhibits an appropriate tack before curing, and has excellent film strength after curing. . If the protective film forming layer 3 shows tack before curing, the sticking operation can be performed stably, and therefore, the alignment of the chip protective film forming sheet 4 with the semiconductor wafer can be easily performed. Further, even if the sticking position is shifted, the sticking can be easily performed.

  The weight average molecular weight of the binder polymer is usually 50,000 to 2,000,000, preferably 100,000 to 1,500,000, particularly preferably 200,000 to 1,000,000. If the molecular weight is too low, the formation of the protective film forming layer 3 may be insufficient. If the molecular weight is too high, the compatibility with other components is deteriorated, resulting in the formation of a uniform protective film forming layer 3. May be hindered.

  As such a binder polymer, for example, an acrylic polymer, a polyester resin, a urethane resin, a silicone resin, a rubber polymer, and the like are used. In particular, an acrylic polymer having no polymerizable double bond in the molecule is preferably used. It is done.

  As said acrylic polymer, the (meth) acrylic acid ester copolymer which consists of a structural unit induced | guided | derived from a (meth) acrylic acid ester monomer and a (meth) acrylic acid derivative is mentioned, for example.

  The thickness of the protective film forming layer 3 is preferably 3 to 300 μm, and particularly preferably 10 to 60 μm.

  Here, the surface opposite to the surface in contact with the first release sheet 1 of the protective film forming layer 3 of this embodiment may be protected by the second release sheet until it is used. As the second release sheet, the same one as the first release sheet 1 can be used. In this case, it is preferable that the peel force of the second release sheet to the protective film forming layer 3 is smaller than the peel force of the first release sheet 1.

[Method for Manufacturing Sheet for Forming Protective Film for Chip]
The chip protective film forming sheet 4 can be manufactured by a conventional method. For example, a coating agent containing a material (resin composition) constituting the protective film forming layer 3 and optionally a solvent is prepared, and a die coater having a plurality of coating heads on the release surface of the release sheet 1 Apply by pattern coating with micro die coater, curtain coater, spray coater, slit coater, knife coater, etc. or by pattern printing such as screen printing, gravure printing, offset printing, inkjet printing, etc. The protective film forming layer 3 having two or more colors is formed.

  The color of the protective film forming layer 3 is not particularly limited, and for example, colors relating to various hues such as black, yellow, orange, red, purple, blue, green, white, intermediate colors or mixed colors thereof, The color which changed those saturation and / or the brightness, various metal colors, various fluorescent colors, etc. are mentioned.

  As the color-coded pattern of the protective film forming layer 3, for example, in addition to the checkered pattern shown in FIG. 2, two or more stripes, two or more triangular patterns, hexagonal pattern, lattice pattern, houndstooth pattern, polka dot pattern, Examples include various patterns such as geometric patterns, various figures or pictures, and combinations thereof. The pattern size can also be set to a desired size. Furthermore, the color coding may be clearly made with a boundary, or the color may be changed by gradation.

  When the protective film forming layer 3 is applied as described above, when the chip protective film forming sheet 4 is affixed to the semiconductor wafer, each chip obtained from the semiconductor wafer has two or more colors in the plane direction. It is preferable to form the protective film forming layer 3 so as to have (see FIGS. 2 and 3). Thereby, each chip | tip (the back surface) obtained by dicing of a semiconductor wafer is provided with a specific color, a pattern, etc., and has specific identification property.

  The chip protective film forming sheet 4 produced as described above may be cut according to the shape of the semiconductor wafer as the adherend, if desired (see FIG. 2). By cutting the chip protective film forming sheet 4 in accordance with the shape of the semiconductor wafer before being attached to the semiconductor wafer, the pattern of the protective film forming layer 3 is applied to the individual pattern on the semiconductor wafer when the semiconductor wafer is attached. It becomes easy to match the circuit. However, the cutting can also be performed after the chip protective film forming sheet 4 is attached to the semiconductor wafer.

[Method of manufacturing semiconductor chip with protective film]
FIG. 3 is a plan view of a semiconductor chip with a protective film according to an embodiment of the present invention. FIG. 4 is a side view of a semiconductor chip with a protective film according to an embodiment of the present invention.

  In order to manufacture the semiconductor chip 5 with a protective film according to the present embodiment, first, the protective film forming layer 3 of the protective film forming sheet 4 for a chip is pasted on the back surface of the semiconductor wafer having a circuit formed on the front surface. To do. At this time, after the semiconductor wafer is diced, each semiconductor chip 6 is positioned so that a protective film 3 ′ having a specific identification property is formed, and the protective film forming layer 3 is attached to the back surface of the semiconductor wafer.

Thereafter, by performing the following steps (1) to (3) in an arbitrary order, as shown in FIGS. 3 and 4, the protective film 3 ′ having two or more colors in the plane direction is formed on the semiconductor chip 6. A semiconductor chip 5 with a protective film on the back surface is obtained.
(1) Step of peeling protective film forming layer and release sheet (2) Step of curing protective film forming layer (3) Step of dicing semiconductor wafer and protective film forming layer

  As an example, the case where the said process is performed in order of (1)-(2)-(3) is demonstrated concretely. First, the release sheet 1 is peeled off from the protective film forming layer 3 of the chip protective film forming sheet 4 attached to the back surface of the semiconductor wafer to obtain a laminate of the semiconductor wafer and the protective film forming layer 3.

  Next, the protective film forming layer 3 is cured to form a protective film 3 ′ on the entire back surface of the semiconductor wafer. By curing the protective film forming layer 3, the protective film 3 'is firmly bonded to the back surface of the semiconductor wafer.

  In order to cure the protective film forming layer 3, heating and / or energy beam irradiation may be performed according to the material constituting the protective film forming layer 3. As energy rays, ultraviolet rays, electron beams, etc. are usually used.

  Thereafter, the stacked body of the semiconductor wafer and the protective film 3 ′ is diced for each circuit formed on the surface of the semiconductor wafer. Dicing in the present embodiment is performed so as to cut both the semiconductor wafer and the protective film 3 ′. The dicing of the semiconductor wafer is performed by a conventional method using a dicing sheet. At this time, the laminate may be fixed by sticking the semiconductor wafer surface to the dicing sheet, or may be fixed by sticking the protective film surface to the dicing sheet. As a result, as shown in FIGS. 3 and 4, the semiconductor chip 5 with a protective film having the protective film 3 ′ on the back surface of the semiconductor chip 6 is obtained. What is necessary is just to pick up the semiconductor chip 5 with a protective film obtained by dicing by general means, such as a collet.

  The process of manufacturing the semiconductor chip 5 with a protective film includes the order of (1)-(3)-(2), (2)-(1) in addition to the order of (1)-(2)-(3). )-(3), (2)-(3)-(1), (3)-(1)-(2), or (3)-(2)-(1) It may be.

  The semiconductor chip 5 with protective film obtained as described above is identified without laser marking because the protective film 3 ′ formed on the back surface of the semiconductor chip 6 has two or more colors in the plane direction. Have excellent design properties. Also, the visibility is very high by appropriately selecting the color to be colored on the protective film 3 ′ and the color-coded pattern.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  For example, in the above-described embodiment, a specific pattern is given to the protective film forming layer 3 in accordance with the type of the circuit (chip), so that the type of the circuit can be distinguished from the chip (for example, 1 on one semiconductor wafer). When a plurality of types of circuits are formed, the chip of the circuit a obtained from the semiconductor wafer A on which a plurality of circuits a are formed and the chip of the circuit b obtained from the semiconductor wafer B on which a plurality of circuits b are formed However, the present invention is not limited to this.

  For example, when a protective film forming layer 3 composed of a random pattern of two or more colors is attached to a semiconductor wafer and diced into individual chips, different patterns are given to the obtained individual chips. Recognizing with a camera or the like and associating the chip with the pattern, it is possible to give distinctiveness such as individual numbers to each chip. That is, when a single type of circuit is formed on a single semiconductor wafer, even chips of the same circuit a obtained from the semiconductor wafer A on which a plurality of circuits a are formed can be separated into the chips. Individual identities can be given.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further more concretely, the scope of the present invention is not limited to these Examples etc.

[Preparation Example 1] (Coating liquid 1 for protective film forming layer)
30 parts by mass of liquid bisphenol A type epoxy resin (epoxy equivalent: 180 to 200 g / eq), 40 parts by mass of solid bisphenol A type epoxy resin (epoxy equivalent: 800 to 900 g / eq), and o-cresol novolac type epoxy resin ( Epoxy equivalent: 210 to 230 g / eq) 10 parts by mass was mixed to obtain a thermosetting resin (A).

  Also, 55 parts by mass of butyl acrylate, 15 parts by mass of methyl methacrylate, 20 parts by mass of glycidyl methacrylate, and 15 parts by mass of 2-hydroxyethyl acrylate are copolymerized to give an acrylic system having a weight average molecular weight of 900,000. A copolymer was obtained. This acrylic copolymer was used as a binder polymer.

  80 parts by mass of the thermosetting resin (A), 0.6 parts by mass of a thermally activated latent epoxy resin curing agent (imidazole compound), and 1.3 parts by mass of a colorant (B) (blue pigment; cobalt blue) And 15 parts by mass of the above binder polymer were mixed to obtain a coating solution 1 for a protective film forming layer.

[Preparation Example 2] (Coating liquid 2 for protective film forming layer)
The coating liquid for the protective film forming layer was the same as the coating liquid 1 for the protective film forming layer in Preparation Example 1 except that 1.5 parts by mass of the yellow pigment (cadmium yellow) was used as the colorant (B). 2 was prepared.

[Preparation Example 3] (Coating liquid 3 for protective film forming layer)
Acrylic copolymer having a weight average molecular weight of 800,000 is copolymerized with 65 parts by mass of butyl acrylate, 10 parts by mass of methyl methacrylate, 10 parts by mass of methyl acrylate, and 15 parts by mass of 2-hydroxyethyl acrylate. Coalescence was obtained. This acrylic copolymer was used as a binder polymer.

  50 parts by mass of the first energy beam curable resin (C) (trimethylolpropane triacrylate), 1.5 parts by mass of the second energy beam curable resin (C) (α-hydroxycyclohexyl phenyl ketone), and coloring Agent (B) (red pigment; cadmium red) 1.0 part by weight, 100 parts by weight of the above binder polymer, and 0.5 part by weight of a crosslinking agent (organic polyvalent isocyanate-based crosslinking agent) are mixed and protected. It was set as the coating liquid 3 for film forming layers.

[Preparation Example 4] (Coating liquid 4 for protective film forming layer)
The coating solution for the protective film forming layer was the same as the coating solution 3 for the protective film forming layer in Preparation Example 3 except that 1.8 parts by weight of the green pigment (chrome green) was used as the colorant (B). 4 was prepared.

[Example 1]
On the release treatment surface (release surface) of a polyethylene terephthalate film (thickness: 38 μm, surface tension: 30 mN / m) on one side as a release sheet, for the protective film forming layer coating solution 1 and the protective film forming layer Each of the coating solutions 2 was dried using a screen printer so that the thickness after drying was 30 μm and a checkered pattern of 4 mm × 4 mm in plan view was formed to form a protective film forming layer. Thus, a protective film-forming sheet for chips was obtained.

  The protective film forming layer of the obtained protective film forming sheet for chip is protected on the polishing surface of the semiconductor wafer A having a diameter of 200 mm and a thickness of 200 μm, on which the surface a plurality of circuits a is formed and the back surface is polished by # 2000 It stuck using the sheet sticking apparatus so that the intersection of the checkered pattern of a film formation layer might be located in the center of each circuit a (8 mm x 8 mm square) on the surface of a semiconductor wafer. Then, the protective film forming sheet for chips was cut along the outer periphery of the semiconductor wafer A, and the portion protruding from the semiconductor wafer A was removed.

  Next, the release sheet is peeled off from the protective film forming sheet for chips affixed to the semiconductor wafer A, and heated at 160 ° C. for 1 hour using a blower constant temperature thermostat to cure the protective film forming layer, thereby protecting the wafer with the protective film. Got.

  Then, using a dicing tape mounter, a dicing sheet is affixed on the protective film of the wafer with the protective film, and then using a dicing apparatus, the semiconductor wafer together with the protective film is combined with individual chips (8 mm × 8 mm). 8 mm square). The separated chip was picked up to obtain a semiconductor chip with a protective film having a blue and yellow checkered pattern formed on the back surface of the chip.

[Example 2]
On the release treatment surface (release surface) of a polyethylene terephthalate film (thickness: 38 μm, surface tension: 30 mN / m) from which one side as a release sheet is release-treated, and for the protective film-forming layer Each of the coating solutions 4 was dried using a micro die coater so that the thickness after drying was 30 μm, and a stripe pattern having a width of 4 mm / 4 mm in a plan view was dried, and a protective film forming layer was formed. Thus, a protective film-forming sheet for chips was obtained.

  The protective film forming layer of the obtained protective film forming sheet for chip is protected on the polishing surface of the semiconductor wafer B having a diameter of 200 mm and a thickness of 200 μm, on which the circuit b is formed on the front surface and the back surface is polished by # 2000 The film forming layer was pasted by using a sheet pasting apparatus so that the boundary line of the stripe pattern passed through the center of each circuit b (8 mm × 8 mm square) on the surface of the semiconductor wafer. Then, the chip protective film forming sheet was cut along the outer periphery of the semiconductor wafer B, and the portion protruding from the semiconductor wafer B was removed.

Next, the release sheet is peeled off from the chip protective film forming sheet affixed to the semiconductor wafer B, and ultraviolet rays are irradiated from the sheet side in a nitrogen atmosphere using an ultraviolet irradiation device (irradiation conditions: illuminance: 310 mW / cm ^2). , 300 mJ / cm ² ), and the protective film forming layer was cured to obtain a wafer with a protective film.

  Then, using a dicing tape mounter, a dicing sheet is affixed on the protective film of the wafer with the protective film, and then using a dicing apparatus, the semiconductor wafer together with the protective film is aligned with individual circuits (8 mm × 8 mm). 8 mm square). The separated chip was picked up to obtain a semiconductor chip with a protective film in which red and green stripe patterns were formed on the back surface of the chip.

[Test example]
The semiconductor chips with protective films obtained in Examples 1 and 2 were each mounted on a substrate by the face-down method. Each semiconductor chip with a protective film is not marked by laser and has the same shape, but it can be easily identified by the difference in their patterns, and it is suitable for the appropriate position on the substrate. It was easy to confirm that was implemented.

  Furthermore, the semiconductor chip with a protective film obtained in Examples 1 and 2 does not need to be resin-sealed to protect the semiconductor chip, and since a pattern appears, the appearance is beautiful and the design is excellent. there were.

  The protective film forming sheet for a chip of the present invention is suitably used for a semiconductor chip mounted by a face-down method. Moreover, the semiconductor chip with a protective film of the present invention is suitable as a semiconductor chip mounted by a face-down method.

DESCRIPTION OF SYMBOLS 1 ... (1st) peeling sheet 3 ... Protective film formation layer 3 '... Protective film 4 ... Sheet | seat for protective film formation 5 for chips ... Semiconductor chip 6 with protective film ... Semiconductor chip

Claims (7)

A protective film forming sheet for a chip for forming a protective film of the chip laminated on the chip,
A release sheet;
A curable protective film forming layer formed on the release surface of the release sheet;
The protective film forming layer is colored so that when the chip protective film forming sheet is attached to a wafer, all chips obtained from the wafer have two or more colors in the planar direction. A protective film-forming sheet for chips.   The protective film forming layer according to claim 1, wherein the protective film forming layer is colored differently according to the type of the chip.   The said protective film formation layer consists of a resin composition containing a thermosetting resin (A) and a coloring agent (B), The protective film formation sheet for chips | tips of Claim 1 or 2 characterized by the above-mentioned.   The said protective film formation layer consists of a resin composition containing energy-beam curable resin (C) and a coloring agent (B), The protective film formation sheet for chips | tips of Claim 1 or 2 characterized by the above-mentioned.   The said protective film formation layer consists of a resin composition containing a thermosetting resin (A), a coloring agent (B), and energy-beam curable resin (C), The Claim 1 or 2 characterized by the above-mentioned. A protective film forming sheet for chips.   The protective film-forming sheet for chips according to any one of claims 1 to 5, further comprising a second release sheet on a surface opposite to a surface in contact with the release sheet in the protective film-forming layer. . After affixing the protective film forming layer of the protective film forming sheet for a chip according to any one of claims 1 to 6 to the back surface of the semiconductor wafer having a circuit formed on the surface, the following steps (1) to (3 ) In any order to obtain a semiconductor chip having a protective film having two or more colors in the plane direction on the back surface.
(1) Step of peeling protective film forming layer and release sheet (2) Step of curing protective film forming layer (3) Step of dicing semiconductor wafer and protective film forming layer

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