JP2008072108A - Sheet for forming protecting film for chip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet for forming a protecting film for a chip in which the protecting film of high uniformity can be easily formed on the rear side of the chip, and further, even if fine flaws are formed on the rear side of the chip by mechanical grinding, adverse influences caused by such flaws can be canceled. <P>SOLUTION: A sheet 10 for forming the protecting film for the chip includes a release sheet 1 and a protecting film forming layer 2 which is formed on the release side of the release sheet 1 and constituted of a thermosetting component and/or an energy ray curing component and a binder polymer component. The binder polymer component is constituted of an acrylic polymer, the thermosetting component is constituted of an epoxy resin, and the energy ray curing component is constituted of an ultraviolet curing resin, preferably. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a protective film-forming sheet for a chip that can efficiently form a protective film on the back surface of a semiconductor chip and that can improve the manufacturing efficiency of the chip, and in particular, a semiconductor chip that is mounted by a so-called face down method. It is related with the sheet | seat for protective film formation for chips used for manufacture.

2. Description of the Related Art In recent years, semiconductor devices have been manufactured using a so-called “face down” mounting method. In the face-down method, a chip in which convex portions called bumps are formed on the circuit surface side of the chip is used, and the convex portions on the circuit surface side are connected to the base.

Such a semiconductor device is generally manufactured through the following steps.
(1) A circuit is formed on the surface of the semiconductor wafer by an etching method or the like, and bumps are formed at predetermined positions on the circuit surface.
(2) The back surface of the semiconductor wafer is ground to a predetermined thickness.
(3) The back surface of the semiconductor wafer is fixed to a dicing sheet stretched on a ring frame, and is cut and separated for each circuit by a dicing saw to obtain a semiconductor chip.
(4) A semiconductor chip is picked up and mounted on a predetermined base in a face-down manner, and if necessary, resin sealing or resin coating is applied to the back surface of the chip to obtain a semiconductor device.

Resin sealing is performed by a potting method in which an appropriate amount of resin is dropped and cured on a chip, a molding method using a mold, or the like. However, it is difficult to drop an appropriate amount of resin by the potting method. Also, the mold method requires cleaning of the mold and the equipment and operating costs are expensive.

The resin coating may vary in quality because it is difficult to uniformly apply an appropriate amount of resin.
Therefore, there is a demand for the development of a technique that can easily form a highly uniform protective film on the back surface of the chip.

  Further, in the back grinding in the step (2), minute streak is formed on the back surface of the chip by mechanical grinding. This minute scratch may cause cracking after the dicing step (3) or packaging. For this reason, conventionally, chemical etching for removing minute scratches may be necessary after mechanical grinding. However, chemical etching necessitates equipment and operation costs as well as the cost increase.

  Therefore, even if a minute scratch is formed on the back surface of the chip by mechanical grinding, there is a demand for the development of a technique that eliminates the adverse effects caused by the scratch.

  The present invention has been made in view of the above-described conventional technology, and a highly uniform protective film can be easily formed on the back surface of the chip, and fine scratches are formed on the back surface of the chip by mechanical grinding. However, an object of the present invention is to provide a process capable of eliminating the adverse effects caused by such scratches, and a protective film-forming sheet for chips used in the process.

The first protective film forming sheet for chips according to the present invention is:
It has a release sheet and a protective film forming layer formed on the release surface of the release sheet and made of a thermosetting component or energy ray curable component and a binder polymer component.

The second protective film forming sheet for chips according to the present invention is:
It has a release sheet and a protective film forming layer made of a thermosetting component, an energy ray curable component, and a binder polymer component formed on the release surface of the release sheet.

  In the present invention, the binder polymer component is preferably composed of an acrylic polymer, the thermosetting component is preferably composed of an epoxy resin, and the energy ray curable component is composed of an ultraviolet curable resin. It is preferable.

  When such a protective film forming sheet for a chip according to the present invention is applied to a process described later, a highly uniform protective film can be easily formed on the back surface of the chip, and fine scratches are formed on the back surface of the chip by mechanical grinding. Even if it is formed, the adverse effects caused by such scratches can be eliminated.

A first manufacturing method of a semiconductor chip according to the present invention includes:
After pasting the protective film forming layer of the first or second protective film forming sheet for chips on the back surface of the semiconductor wafer having a circuit formed on the front surface,
The following steps (1) to (3) are performed in an arbitrary order to obtain a semiconductor chip having a protective film on the back surface.
Step (1): peeling the protective film forming layer and the release sheet,
Step (2): Curing the protective film forming layer by heating or energy ray irradiation,
Step (3): The semiconductor wafer and the protective film forming layer are diced for each circuit.

A second manufacturing method of a semiconductor chip according to the present invention is as follows.
Affixing the protective film forming layer of the second chip protective film forming sheet to the back surface of the semiconductor wafer having a circuit formed on the surface,
After curing the protective film formation layer by energy ray irradiation,
The following steps (1) to (3) are performed in an arbitrary order to obtain a semiconductor chip having a protective film on the back surface.
Step (1): peeling the protective film forming layer and the release sheet,
Step (2): The protective film forming layer is further cured by heating,
Step (3): The semiconductor wafer and the protective film forming layer are diced for each circuit.

  According to the present invention, a highly uniform protective film can be easily formed on the back surface of the chip, and even if minute scratches are formed on the back surface of the chip by mechanical grinding, the adverse effects caused by such scratches are eliminated. it can.

Hereinafter, the present invention will be described more specifically with reference to the drawings.
First, a first protective film forming sheet 10 for a chip according to the present invention includes a release sheet 1 and a protective film forming layer 2 formed on the release surface of the release sheet 1 as shown in FIG. .

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, 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, etc. Used. These crosslinked films are also used. Furthermore, these laminated films may be sufficient.

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

  Furthermore, the surface tension of the release sheet 1 is preferably 40 mN / m or less, more preferably 37 mN / m or less, and particularly preferably 35 mN / m or less. Such a release sheet 1 having a low surface tension can be obtained by appropriately selecting the material, or can be obtained by applying a silicone resin or the like to the surface of the sheet 1 and performing a release treatment. it can.

The film thickness of the release sheet 1 is usually about 5 to 300 μm, preferably about 10 to 200 μm, and particularly preferably about 20 to 150 μm.
The protective film forming layer 2 of the first protective film forming sheet for a chip is composed of a thermosetting component or an energy ray curable component and a binder polymer component. The protective film forming layer 2 of the second protective film forming sheet for a chip is composed of a thermosetting component, an energy ray curable component, and a binder polymer component.

  Examples of the thermosetting component include epoxy resins, phenol resins, melamine resins, urea resins, polyester resins, urethane resins, acrylic resins, polyimide resins, benzoxazine resins, and mixtures thereof. Especially in this invention, an epoxy resin, a phenol resin, and these mixtures are used preferably.

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 the present invention is usually 50 to 5000 g / eq. Specific examples of such an epoxy resin include glycidyl ethers of phenols such as bisphenol A, bisphenol F, resorcinol, phenyl novolak, and cresol novolac; glycidyl ethers of alcohols such as butanediol, polyethylene glycol, and polypropylene glycol; Glycidyl ethers of carboxylic acids such as phthalic acid, isophthalic acid and tetrahydrophthalic acid; glycidyl type or alkyl glycidyl type epoxy resins in which active hydrogen bonded to a nitrogen atom such as aniline isocyanurate is substituted with a glycidyl group; vinylcyclohexane diepoxide; 3,4-epoxycyclohexylmethyl-3,4-dicyclohexanecarboxylate, 2- (3,4-epoxy) cyclohexyl-5,5-spiro (3,4-epoxy) cyclohexane-m-di Examples include so-called alicyclic epoxides in which an epoxy is introduced, for example, by oxidizing a carbon-carbon double bond in the molecule, such as oxane. In addition, an epoxy resin having a biphenyl skeleton, a dicyclohexadiene skeleton, or a naphthalene skeleton can be used.

Among these, in the present invention, bisphenol glycidyl type epoxy resin, o-cresol novolak type epoxy resin and phenol novolak type epoxy resin are 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 active species (anions and cations) are generated by a chemical reaction by heating; the epoxy resin is stably dispersed in the epoxy resin at around room temperature and is heated at a high temperature. There are a method of initiating a curing reaction by dissolving and dissolving with a solvent; 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 active latent epoxy resin curing agent used in the present invention include various onium salts, high melting point active hydrogen compounds such as dibasic acid dihydrazide compounds, dicyandiamide, amine adduct curing agents, and imidazole compounds. be able to.

  These thermally activated latent epoxy resin curing agents can be used singly or in combination of two or more. The heat-activatable latent epoxy resin curing agent as described above is preferably 0.1 to 20 parts by weight, more preferably 0.2 to 10 parts by weight, particularly preferably 0. It is used at a ratio of 3 to 5 parts by weight.

  As the phenolic resin, a condensate of phenols such as alkylphenol, polyhydric phenol, naphthol and aldehydes is used without particular limitation. Specific examples of the phenolic resin preferably used in the present invention include phenol novolak resin, o-cresol novolak resin, p-cresol novolak resin, t-butylphenol novolak resin, dicyclopentadiene cresol resin, polyparavinylphenol. Resin, bisphenol A type novolak resin, or modified products thereof are used.

  The phenolic hydroxyl group contained in these phenolic resins 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-type resin.

  The energy ray curable component is composed of a compound that is polymerized and cured when irradiated with energy rays such as ultraviolet rays and electron beams. This compound has at least one polymerizable double bond in the molecule, and usually has a molecular weight of about 100 to 30,000, preferably about 300 to 10,000. As such energy beam polymerization type compounds, for example, low molecular weight compounds such as those disclosed in JP-A-60-196,956 and JP-A-60-223,139 are widely used. Include trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate or 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate. Acrylates, polyethylene glycol diacrylates, oligoester acrylates, polyester-type or polyether-type urethane acrylate oligomers, polyester acrylates, polyethers Le acrylate, and epoxy-modified acrylate.

Among these, in the present invention, an ultraviolet curable resin is preferably used, and specifically, an oligoester acrylate, a urethane acrylate oligomer, or the like is particularly preferably used. By mixing a photopolymerization initiator in the energy ray curable component, the polymerization curing time and the amount of light irradiation can be reduced.

Specific examples of such a photopolymerization initiator include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, methyl benzoin benzoate, benzoin dimethyl ketal, Examples include 2,4-diethylthioxanthone, α-hydroxycyclohexyl phenyl ketone, benzyldiphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, β-chloranthraquinone, and the like.

The photopolymerization initiator is desirably used at a ratio of about 1.5 to 4.5 parts by weight, preferably about 2.4 to 3.8 parts by weight with respect to 100 parts by weight of the energy ray curable component.
The binder polymer component is used for imparting an appropriate tack to the protective film forming layer 2 and improving the operability of the sheet.

  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, sheet formation will be insufficient, and if it is too high, compatibility with other components will deteriorate, and as a result, uniform sheet formation will 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, and an acrylic polymer is particularly preferably used.

  Examples of the acrylic polymer include (meth) acrylic acid ester copolymers composed of structural units derived from (meth) acrylic acid ester monomers and (meth) acrylic acid derivatives. Here, the (meth) acrylic acid ester monomer is preferably a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 18 carbon atoms, such as methyl (meth) acrylate, ethyl (meth) acrylate, (meth ) Propyl acrylate, butyl (meth) acrylate, etc. are used. Examples of the (meth) acrylic acid derivative include (meth) acrylic acid, glycidyl (meth) acrylate, hydroxyethyl (meth) acrylate, and the like.

  By copolymerizing glycidyl methacrylate and the like to introduce glycidyl groups into acrylic polymers, compatibility with epoxy resin as a thermosetting adhesive component described later is improved, and Tg after curing is increased, resulting in heat resistance. Will also improve. Further, by introducing a hydroxyl group into the acrylic polymer with hydroxyethyl acrylate or the like, it becomes easy to control the adhesion to the chip and the physical properties of the adhesive.

  The weight average molecular weight of the acrylic polymer is preferably 100,000 or more, particularly preferably 150,000 to 1,000,000. The glass transition temperature of the acrylic polymer is usually 20 ° C. or lower, preferably about −70 to 0 ° C., and has adhesiveness at room temperature (23 ° C.).

In the first protective film-forming sheet for chips, when only the thermosetting component is blended in the protective film-forming layer 2, the blending ratio is preferably 100 to 1500 weights with respect to 100 parts by weight of the binder polymer component. Parts, more preferably 150 to 1000 parts by weight, particularly preferably 200 to 800 parts by weight. Moreover, when using only an energy-beam curable component for the protective film formation layer 2, the compounding ratio is preferably 5 to 500 parts by weight, more preferably 10 to 200 parts by weight with respect to 100 parts by weight of the binder polymer component. , Particularly preferably 20-1
50 parts by weight.

  Further, in the protective film forming layer 2 of the second chip protective film forming sheet, the thermosetting component and the energy ray curable component in total are preferably 100 to 1500 parts by weight with respect to 100 parts by weight of the binder polymer component. More preferably, it is used in a proportion of 150 to 1000 parts by weight, particularly preferably 200 to 800 parts by weight. In this case, the weight ratio of the thermosetting component to the energy ray curable component (thermosetting component / energy ray curable component) is preferably 55/45 to 97/3, more preferably 60/40 to 95. / 5, particularly preferably 70/30 to 90/10.

  When the heat or energy ray curable component and the binder polymer component are blended at such a ratio, an appropriate tack is exhibited before curing, the application work can be stably performed, and the film strength is excellent after curing. A protective film is obtained.

  Moreover, the protective film formation layer 2 may be colored. The protective film forming layer 2 is colored by, for example, blending a pigment, a dye or the like. When the protective film forming layer 2 is colored, the appearance is improved.

  Moreover, the following various additives may be mix | blended with the protective film formation layer 2 other than the component mentioned above. For example, the protective film forming layer 2 is further coated with gold, silver, copper, nickel, aluminum, stainless steel, carbon, ceramic, nickel, aluminum, or the like with silver for the purpose of imparting conductivity after die bonding. Conductive fillers such as those may be added, and for the purpose of imparting thermal conductivity, heat conduction of metallic materials such as gold, silver, copper, nickel, aluminum, stainless steel, silicon, germanium, and alloys thereof A sex substance may be added.

  Furthermore, a coupling agent can be added to the protective film forming layer 2 for the purpose of improving the adhesion and adhesion between the protective film after curing and the back surface of the chip. The coupling agent can improve adhesion and adhesion without impairing the heat resistance of the protective film, and also improves water resistance (moisture heat resistance).

The coupling agent is preferably a silane (silane coupling agent) because of its versatility and cost merit.
In addition, a crosslinking agent such as an organic polyvalent isocyanate compound, an organic polyvalent imine compound, or an organic metal chelate compound is added to the protective film forming layer 2 in order to adjust the initial adhesive force and cohesive force before curing. You can also.

Further, an antistatic agent can be added to the protective film forming layer 2. By adding an antistatic agent, static electricity can be suppressed, so that the reliability of the chip is improved.
Moreover, the reliability as a package improves by adding a phosphoric acid compound, a bromine compound, a phosphorus compound, etc. and adding a flame retardance performance.

  The protective film-forming sheet 10 for chip body according to the present invention is obtained by directly applying a composition comprising the above components on the release surface of the release sheet 1 according to a generally known method such as a roll knife coater, gravure coater, die coater, reverse coater. Alternatively, it can be obtained by coating by transfer and drying to form the protective film forming layer 2. In addition, said composition can be apply | coated after making it melt | dissolve or disperse | distribute to a solvent as needed.

The thickness of the protective film forming layer 2 thus formed is usually 3 to 100 μm, preferably 10 to 60 μm.
The second chip protective film-forming sheet according to the present invention is the first chip protective film except that the protective film-forming layer comprises both a thermosetting component and an energy ray-curable component as essential components. It is the same as that of the sheet | seat for formation, The preferable aspect is also the same.

  When the first and second protective film forming sheets for chips 10 according to the present invention are applied to a semiconductor device manufacturing process described later, a highly uniform protective film can be easily formed on the back surface of the chip, Moreover, even if minute scratches are formed on the back surface of the chip by mechanical grinding, the adverse effects caused by such scratches can be eliminated.

First, the first method for manufacturing a semiconductor chip according to the present invention will be described more specifically with reference to the drawings.
In the first method for manufacturing a semiconductor chip according to the present invention,
After pasting the protective film forming layer of the first or second protective film forming sheet for chips on the back surface of the semiconductor wafer having a circuit formed on the front surface,
The following steps (1) to (3) are performed in an arbitrary order to obtain a semiconductor chip having a protective film on the back surface.
Step (1): peeling the protective film forming layer and the release sheet,
Step (2): Curing the protective film forming layer by heating or energy ray irradiation,
Step (3): The semiconductor wafer and the protective film forming layer are diced for each circuit.

First, the case where the steps (1), (2), and (3) are performed in this order will be described more specifically with reference to FIG.
First, the protective film forming layer 2 of the chip protective film forming sheet 10 is attached to the back surface of the semiconductor wafer 3 having a circuit formed on the front surface (see FIG. 2A).

Next, as shown in FIG. 2B, the release sheet 1 is peeled from the protective film forming layer 2 to obtain a laminate of the semiconductor wafer 3 and the protective film forming layer 2.
Next, the protective film forming layer 2 is cured by heating or energy ray irradiation, and a protective film is formed on the entire surface of the wafer. FIG. 2C shows the state of heating by the heating device. As a result, the strength is improved as compared with the case of a single wafer, so that damage to the wafer during handling can be reduced. Further, even if a minute flaw is formed on the back surface of the wafer during back surface grinding, the flaw is filled with the protective film, so that damage to the wafer due to the flaw can be reduced.

  In addition, compared to the coating method in which the coating solution for the protective film is applied directly to the back surface of the wafer or chip, the thickness of the protective film is excellent and the yield of the protective film material is also good. Become.

  Next, as shown in FIG. 2D, the laminated body of the semiconductor wafer 3 and the protective film 2 is diced for each circuit formed on the wafer surface. Dicing is performed so as to cut both the wafer and the protective film. The wafer is diced by a conventional method using a dicing sheet. As a result, a semiconductor chip having a protective film on the back surface is obtained.

Finally, the diced chip is picked up by a general-purpose means such as a collet to obtain a semiconductor chip having a protective film on the back surface (FIG. 2E).
According to the present invention, a highly uniform protective film can be easily formed on the back surface of the chip, and even if a minute scratch is formed on the back surface of the chip by mechanical grinding, the scratch is filled with the protective film. Therefore, cracks after the dicing process and packaging are less likely to occur.

Next, the case where the steps (1), (3), and (2) are performed in this order will be described more specifically with reference to FIG.
This manufacturing method is
The protective film forming layer 2 of the chip protective film forming sheet 10 is attached to the back surface of the semiconductor wafer 3 on which a circuit is formed on the front surface (FIG. 3A),
The release sheet 1 is peeled from the protective film forming layer 2 (FIG. 3B),
The semiconductor wafer 3 and the protective film 2 are diced for each circuit (FIG. 3C),
The protective film forming layer 2 is cured by heating or energy ray irradiation (FIG. 3D),
A semiconductor chip having the protective film 3 on the back surface is obtained (FIG. 3E).

That is, it is the same as the manufacturing method shown in FIG. 2 (the manufacturing method performed in the order of (1), (2), and (3)) except that the protective film forming layer 2 is cured after dicing.
When the protective film forming layer 2 contains a thermosetting component, the protective film forming layer 2 is cured by heating. Therefore, the dicing sheet is required to have heat resistance that does not deteriorate due to heat during curing.

Next, the case where the steps (2), (1), and (3) are performed in this order will be described more specifically with reference to FIG.
This manufacturing method is
Affixing the protective film forming layer 2 of the chip protective film forming sheet 10 to the back surface of the semiconductor wafer 3 having a circuit formed on the surface (FIG. 4A),
The protective film forming layer 2 is cured by heating or energy ray irradiation (FIG. 4B),
Release the release sheet 1 from the cured protective film forming layer 2 (FIG. 4C),
The semiconductor wafer 3 and the protective film 2 are diced for each circuit (FIG. 4D),
A semiconductor chip having the protective film 3 on the back surface is obtained (FIG. 4E).

That is, the manufacturing method is the same as that in the order of (1), (2), and (3) except that the release sheet 1 is peeled after the protective film forming layer 2 is cured.
When the protective film forming layer 2 contains a thermosetting component, the protective film forming layer 2 is cured by heating. Therefore, the release sheet 1 is required to have heat resistance that does not deteriorate due to heat during curing. For this reason, as the release sheet 1, a polymethylpentene film, a polyethylene naphthalate film, a polyimide film or the like having excellent heat resistance is used.

Next, the case where the steps (2), (3), and (1) are performed in this order will be described more specifically with reference to FIG.
This manufacturing method is
The protective film forming layer 2 of the chip protective film forming sheet 10 is pasted on the back surface of the semiconductor wafer 3 having a circuit formed on the front surface (FIG. 5A),
The protective film forming layer 2 is cured by heating or energy ray irradiation (FIG. 5B),
The semiconductor wafer 3 and the cured protective film forming layer 2 are diced for each circuit (FIG. 5C),
The cured protective film forming layer 2 and the release sheet 1 are peeled off (FIG. 5D),
A semiconductor chip having the protective film 3 on the back surface is obtained. In this method, the release sheet 1 is peeled off simultaneously with chip pickup. That is, by picking up the chip, the release sheet and the chip are peeled off, and a semiconductor chip having a protective film on the back surface is obtained.

  When the protective film forming layer 2 contains a thermosetting component, the protective film forming layer 2 is cured by heating. Therefore, the release sheet 1 is required to have heat resistance that does not deteriorate due to heat during curing. For this reason, as the release sheet 1, a polymethylpentene film, a polyethylene naphthalate film, a polyimide film or the like having excellent heat resistance is used.

Next, the case where the steps (3), (1), and (2) are performed in this order will be described more specifically with reference to FIG.
This manufacturing method is
Affixing the protective film forming layer 2 of the chip protective film forming sheet 10 to the back surface of the semiconductor wafer 3 having a circuit formed on the surface,
The semiconductor wafer 3 and the protective film forming layer 2 are diced for each circuit,
The protective film forming layer 2 and the release sheet 1 are peeled off,
The protective film forming layer 2 is cured by heating or energy ray irradiation,
A semiconductor chip having a protective film on the back surface is obtained.

  In this method, as shown in FIGS. 6A to 6C, the wafer 3 may be diced with the wafer 3 held and fixed to the protective film forming layer 2. Therefore, in this case, the chip protective film forming sheet 10 also has a function as a so-called dicing sheet. However, at the time of mounting on the chip mounting substrate, the protective film forming layer is already cured and does not have a die bonding function. For this reason, the sheet | seat used for the manufacturing method of the semiconductor chip of this invention is not what is called a dicing die-bonding sheet | seat.

  6D to 6F, the chip protective film forming sheet 10 holding and fixing the wafer 3 to the protective film forming layer 2 is further fixed to the dicing sheet, and the above steps are performed. Also good.

According to the present invention, a highly uniform protective film can be easily formed on the back surface of the chip.
Next, the case where the steps (3), (2), and (1) are performed in this order will be described more specifically with reference to FIG.

This manufacturing method is
Affixing the protective film forming layer 2 of the chip protective film forming sheet 10 to the back surface of the semiconductor wafer 3 having a circuit formed on the surface,
The semiconductor wafer 3 and the protective film forming layer 2 are diced for each circuit,
The protective film forming layer 2 is cured by heating or energy ray irradiation,
The cured protective film forming layer 2 and the release sheet 1 are peeled off,
A semiconductor chip having a protective film on the back surface is obtained.

  That is, except that the protective film forming layer 2 and the release sheet 1 are peeled after the protective film forming layer 2 is cured, the manufacturing method (steps (3), (1), (2) shown in FIG. Order).

  As described above, in the first manufacturing method according to the present invention, the order of the steps (1) to (3) is not particularly limited, but in particular the order of the steps (1), (2), (3), It is preferable to perform the steps (2), (1), (3), the steps (3), (1), (2) or the steps (3), (2), (1) in this order.

  In FIGS. 2 to 7, the protective film forming layer is cured by a heating device. However, when an energy beam curable component is used as the curable component, an energy beam irradiation device (an ultraviolet ray as an energy beam) is used. In the case of using UV, an ultraviolet irradiation device) is used.

  In the case of using the second protective film forming sheet for a chip that uses a thermosetting component and an energy ray curable component in combination with the curable component, the step of curing the protective film forming layer involves heating and energy ray irradiation simultaneously. May be performed, or may be performed sequentially. In particular, it is preferable to provide a protective film forming layer on the wafer and then irradiate energy rays to semi-harden the protective film forming layer and then completely cure the protective film forming layer by heating to form a protective film.

That is, the second manufacturing method of the semiconductor chip according to the present invention is as follows.
Affixing the protective film forming layer of the protective film forming sheet for a chip to the back surface of the semiconductor wafer having a circuit formed on the surface,
After curing the protective film formation layer by energy ray irradiation,
The following steps (1) to (3) are performed in an arbitrary order to obtain a semiconductor chip having a protective film on the back surface:
Step (1): peeling the protective film forming layer and the release sheet,
Step (2): The protective film forming layer is further cured by heating. (3): The semiconductor wafer and the protective film forming layer are diced for each circuit.

  Similarly to the first manufacturing method, in the second manufacturing method according to the present invention, the order of the steps (1) to (3) is not particularly limited, but the steps (1), (2), ( 3), step (2), (1), (3), step (3), (1), (2) or step (3), (2), (1) Preferably it is done.

  By semi-curing the protective film forming layer with energy rays in this way, the protective film forming layer loses tack, and under normal storage conditions, the protective film forming layer does not adhere even if it contacts other members. Transfer between processes can be performed reliably and workability can be improved.

〔Example〕
EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. The composition of the protective film forming layer used in the examples, the wafer, the apparatus, and the like are shown below.

(Protective film forming layer 1)
The protective film forming layer 1 was formed from the following formulation.
Acrylic polymer (weight average molecular weight 900,000 obtained by copolymerizing 55 parts by weight of butyl acrylate, 15 parts by weight of methyl methacrylate, 20 parts by weight of glycidyl methacrylate and 15 parts by weight of 2-hydroxyethyl acrylate, glass transition temperature 15 parts by weight of a binder polymer comprising a -28 ° C copolymer),
Mixture of epoxy resins (liquid bisphenol A type epoxy resin (epoxy equivalent 180 to 200) 30 parts by weight, solid bisphenol A type epoxy resin (epoxy equivalent 800 to 900) 40 parts by weight, o-cresol novolac type epoxy resin (epoxy equivalent 210) ˜230) 10 parts by weight) of thermosetting component,
Thermally active latent epoxy resin curing agent (amine adduct system) 0.6 parts by weight,
A blend comprising 1.3 parts by weight of a black pigment (azo) and a diluent solvent.

(Protective film forming layer 2)
The protective film forming layer 2 was formed from a blend obtained by adding the following to the protective film forming layer 1.
Energy ray (ultraviolet ray) curable component (trimethylolpropane triacrylate) 15 parts by weight, photopolymerization initiator (α-hydroxycyclohexyl phenyl ketone) 4.5 parts by weight (protective film forming layer 3)
The protective film forming layer 3 was formed from the following formulation.
Acrylic polymer (weight average molecular weight of 800,000 copolymerized with 65 parts by weight of butyl acrylate, 10 parts by weight of methyl methacrylate, 10 parts by weight of methyl acrylate and 15 parts by weight of 2-hydroxyethyl acrylate, glass transition temperature 100 parts by weight of a binder polymer comprising a -33 ° C copolymer),
50 parts by weight of energy ray (ultraviolet) curable component (trimethylolpropane triacrylate),
1.5 parts by weight of a photocurable component (α-hydroxycyclohexyl phenyl ketone),
A composition comprising 0.5 parts by weight of a crosslinking agent (organic polyvalent isocyanate crosslinking agent (Coronate L, manufactured by Nippon Polyurethane Co., Ltd.)) and a diluent solvent.
(Wafer): A 6-inch unpolished wafer using a grinding device (DFG-840, DFG-840) with # 2000 polishing to a thickness of 200 μm (sheet pasting device): Lintec Corp. Adwill RAD3500m / 12
(Sheet peeling device): Adwill RAD3000m / 12, manufactured by Lintec Corporation
(Dicing tape mounter): Adwill RAD2500m / 8, manufactured by Lintec Corporation
(Ultraviolet irradiation device): manufactured by Lintec Corporation, Adwill RAD2000m / 8
(Dicing machine): Tokyo Seimitsu Co., Ltd., AWD-4000B
(Blower constant temperature thermostat): Yamato Science Co., Ltd., DN610
(Dicing sheet): Adwill G-11, manufactured by Lintec Corporation
[Example 1]
The composition of the protective film forming layer 1 is applied to the release-treated surface of a polyethylene terephthalate film (SP-PET3811, manufactured by Lintec Co., Ltd., thickness 38 μm, surface tension less than 30 mN / m) subjected to release treatment on one side as a release sheet. Then, it was applied and dried so that the thickness after removal of the solvent was 30 μm, and a protective film-forming sheet for chips was prepared. In order to protect the coated surface, a peeled polyethylene terephthalate film (SP-PET3801 manufactured by Lintec Corporation) was laminated.

Remove the polyethylene terephthalate film (SP-PET3801) from the prepared protective film-forming sheet for chips, and apply the protective film-forming layer to the polished surface of the wafer using a sheet application device. (FIG. 2, step A).
Next, after peeling a peeling sheet using a sheet peeling apparatus (FIG. 2, process B),
Heating is performed at 160 ° C. for 1 hour using an air constant temperature thermostat (FIG. 2, step C),
The protective film forming layer was cured to prepare a wafer with a protective film.

  Next, a dicing tape mounter is used to attach a dicing sheet on the protective film of the wafer, and a dicing machine is used to divide the wafer into individual chips (10 mm × 10 mm) together with the protective film. (FIG. 2, steps D and E).

[Example 2]
The composition of the protective film forming layer 1 is applied to the release-treated surface of a polyethylene naphthalate film (made by Teijin Ltd., Teonex, thickness 25 μm, surface tension of less than 30 mN / m) subjected to a release treatment on one side as a release sheet. Then, it was applied and dried so that the thickness after removal of the solvent was 30 μm, and a protective film-forming sheet for chips was prepared. In order to protect the coated surface, a peeled polyethylene terephthalate film (SP-PET3801 manufactured by Lintec Corporation) was laminated.

  The polyethylene terephthalate film was peeled off from the obtained protective film-forming sheet for chips, the sheet was affixed to the wafer polishing surface in the same manner as in Example 1, and the outer periphery of the sheet was removed along the wafer (FIG. 4, step). A). Subsequently, heating was performed at 160 ° C. for 1 hour using an air constant temperature thermostat (FIG. 4, Step B) to cure the protective film forming layer and form a protective film on the polished surface of the wafer.

  Next, the release sheet is peeled off using a sheet peeling device (FIG. 4, step C), the dicing sheet is pasted on the protective film of the wafer using a dicing tape mounter, and the wafer together with the protective film is used using the dicing apparatus. Was divided into individual chips (10 mm × 10 mm), and desired chips with protective film were prepared (FIG. 4, steps D and E).

[Example 3]
As a release sheet, the composition of the protective film forming layer 3 is applied to the release-treated surface of a polyethylene terephthalate film (SP-PET3811, manufactured by Lintec Co., Ltd.) on one side so that the thickness after removal of the solvent is 30 μm. Coating and drying were performed to prepare a protective film-forming sheet for chips. In order to protect the coated surface, a peeled polyethylene terephthalate film (SP-PET3801 manufactured by Lintec Corporation) was laminated.

  The polyethylene terephthalate film (SP-PET3801) is peeled off from the obtained protective film-forming sheet for chips, and the sheet is attached to the polished surface of the wafer in the same manner as in Example 1, and the outer periphery of the sheet is removed along the wafer. (FIG. 4, step A). Subsequently, ultraviolet rays were irradiated from the sheet side using an ultraviolet irradiation device to completely cure the protective film forming layer, and a wafer with a protective film was prepared (not shown).

  Next, the release sheet is peeled off using a sheet peeling device (FIG. 4, step C), the dicing sheet is pasted on the protective film of the wafer using a dicing tape mounter, and the wafer together with the protective film is used using the dicing apparatus. Was divided into individual chips (10 mm × 10 mm), and desired chips with protective film were prepared (FIG. 4, steps D and E).

[Example 4]
The compound of the protective film forming layer 2 is applied to the surface of the release-treated polyethylene terephthalate film (SP-PET3801 manufactured by Lintec Corporation) so that the thickness after removal of the solvent is 50 μm. After drying, a linear low-density polyethylene film (thickness 110 μm, surface tension 32 mN / m) was bonded as a release sheet on the coated surface to prepare a protective film-forming sheet for chips.

Using the obtained sheet dicing tape mounter for forming a protective film for chips, a protective film forming layer was stuck on the polished surface of the wafer and fixed to the ring frame (FIG. 6, step A).
Next, the protective film forming layer was semi-cured (not shown) by irradiating ultraviolet rays from the sheet side using an ultraviolet irradiation device.

Subsequently, using a dicing apparatus, the wafer was divided into individual chips (10 mm × 10 mm) together with the protective film to obtain a desired chip with a protective film forming layer (FIG. 6, steps B and C).
Thereafter, each chip was heated at 160 ° C. for 1 hour with a blast constant temperature thermostat to cure the protective film forming layer (FIG. 6, Step G), and a desired chip with a protective film was prepared.

[Example 5]
The composition of protective film forming layer 2 was applied to the surface of the release-treated polyethylene terephthalate film (SP-PET3801 manufactured by Lintec Corporation) so that the thickness after removal of the solvent would be 30 μm. After drying, a linear low-density polyethylene film (thickness 110 μm, surface tension 32 mN / m) was bonded as a release sheet on the coated surface to prepare a protective film-forming sheet for chips.

  The polyethylene terephthalate film of the obtained protective film-forming sheet for chips was peeled off, and a protective film-forming layer was applied to the polished wafer surface in the same manner as in Example 1, and the outer periphery of the sheet was removed along the wafer (FIG. 2). Step A). Next, ultraviolet rays were irradiated from the sheet side using an ultraviolet irradiation device, and the protective film forming layer was semi-cured to eliminate the tack (not shown).

  Subsequently, the release sheet was peeled off using a sheet peeling apparatus (FIG. 2, step B), and then heated at 160 ° C. for 1 hour using a blower constant temperature thermostat to completely harden the protective film forming layer, and the wafer with protective film (FIG. 2, step C), and then, in the same manner as in Example 1, the wafer with the protective film was divided into individual chips (10 mm × 10 mm) together with the protective film to produce the desired chip with the protective film. (FIG. 2, steps D and E).

Sectional drawing of the protective film formation sheet | seat for chips which concerns on this invention is shown. The process drawing of the manufacturing method of the semiconductor chip concerning this invention is shown. The process drawing of the manufacturing method of the semiconductor chip concerning this invention is shown. The process drawing of the manufacturing method of the semiconductor chip concerning this invention is shown. The process drawing of the manufacturing method of the semiconductor chip concerning this invention is shown. The process drawing of the manufacturing method of the semiconductor chip concerning this invention is shown. The process drawing of the manufacturing method of the semiconductor chip concerning this invention is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Release sheet 2 ... Protective film formation layer 3 ... Semiconductor wafer 10 ... Protective film formation sheet for chips

Claims (7)

  A protective film-forming sheet for chips, comprising a release sheet and a protective film-forming layer comprising a thermosetting component or an energy ray-curable component and a binder polymer component formed on the release surface of the release sheet.   A protective film-forming sheet for a chip, comprising a release sheet and a protective film-forming layer comprising a thermosetting component, an energy ray-curable component, and a binder polymer component formed on a release surface of the release sheet.   The protective film-forming sheet for chips according to claim 1, wherein the binder polymer component comprises an acrylic polymer.   The protective film-forming sheet for chips according to claim 1, wherein the thermosetting component is made of an epoxy resin.   The protective film-forming sheet for chips according to claim 1, wherein the energy ray-curable component is made of an ultraviolet curable resin. After affixing the protective film-forming layer of the protective film-forming sheet for chips according to any one of claims 1 to 5 to the back surface of a 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 on the back surface:
Step (1): peeling the protective film forming layer and the release sheet,
Step (2): Curing the protective film forming layer by heating or energy ray irradiation,
Step (3): The semiconductor wafer and the protective film forming layer are diced for each circuit. The protective film forming layer of the chip protective film forming sheet according to claim 2 is pasted on the back surface of the semiconductor wafer having a circuit formed on the surface, and the protective film forming layer is cured by energy ray irradiation. A method of manufacturing a semiconductor chip, wherein the steps (1) to (3) are performed in an arbitrary order to obtain a semiconductor chip having a protective film on the back surface:
Step (1): peeling the protective film forming layer and the release sheet,
Step (2): The protective film forming layer is further cured by heating,
Step (3): The semiconductor wafer and the protective film forming layer are diced for each circuit.

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