JP2013098403A - Manufacturing method of semiconductor device, semiconductor device, adhesive film and pasting method of adhesive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a semiconductor device with which high bonding reliability can be achieved by suppressing voids when pasting an adhesive film and a semiconductor wafer.SOLUTION: A manufacturing method of a semiconductor device includes the steps of confronting an adhesive agent layer of an adhesive film and a semiconductor wafer with a clearance less than or equal to 1 cm therebetween, pasting the adhesive agent layer of the adhesive film and the semiconductor wafer with pressure of 0.1 to 1 MPa at 50 to 100°C under heated vacuum of 10000 Pa or less, obtaining a semiconductor wafer with the adhesive agent layer, individualizing the semiconductor wafer with the adhesive agent layer into a semiconductor chip with the adhesive agent layer, and mounting the semiconductor chip with the adhesive agent layer. In the adhesive agent layer of the adhesive film, a tack value measured according to a probe tack method on its surface pasted to the semiconductor wafer is 100 gf/5 mmφ or more at a pasting temperature.

Description

The present invention relates to a method for manufacturing a semiconductor device capable of suppressing voids when bonding an adhesive film and a semiconductor wafer and realizing high bonding reliability. The present invention also relates to a semiconductor device manufactured by the manufacturing method of the semiconductor device, an adhesive film used in the manufacturing method of the semiconductor device, and a bonding method of the adhesive film.

As semiconductor devices are miniaturized and densified, flip-chip mounting using a semiconductor chip having a large number of bump electrodes formed on the surface has attracted attention as a method for mounting a semiconductor chip on a circuit board. Yes.
In flip chip mounting, as a method for ensuring the connection reliability of the joint portion, after bonding the bump electrode of the semiconductor chip and the pad electrode of the circuit board, the liquid sealing adhesion is performed in the gap between the semiconductor chip and the circuit board. It is a common method to inject and harden an agent (underfill). However, flip-chip mounting using underfill has problems such as high manufacturing cost, time-consuming filling of underfill, and limitations in reducing the distance between bump electrodes and the distance between the semiconductor chip and the circuit board. I have it.

Therefore, in recent years, a method has been proposed in which a paste adhesive (NCP) is applied on a circuit board and then a semiconductor chip is heated and / or pressure bonded. There has also been proposed a method in which a semiconductor chip is heated and / or pressure bonded after a film adhesive (NCF) is bonded to the surface of the semiconductor wafer or semiconductor chip. In this case, the adhesive is applied at the wafer level. Can be supplied in a batch and separated into semiconductor chips by dicing, so a significant process reduction is expected.

In addition, an adhesive film (BG-NCF) in which a back grind tape used in a back grind process for thinning a semiconductor wafer and a film adhesive is integrated has been proposed.
For example, Patent Document 1 discloses a step 1 in which an adhesive layer for an adhesive sheet of a pressure-sensitive adhesive sheet composed of a base material and an adhesive layer for interlayer adhesive formed on the base material is bonded to the wafer, Semiconductor having step 2 for grinding in a state of being fixed to a sheet, and step 3 for obtaining a wafer having an adhesive layer for adhesion between layers removed from the ground wafer by removing the base material while leaving an adhesive layer for interlayer adhesion The manufacturing method is described. According to Patent Document 1, according to the method described in the document, a wafer with a thinly ground interlayer adhesive can be obtained very simply, and a semiconductor device can be obtained using the obtained wafer. Have been described.

When bonding an adhesive film on the surface of a semiconductor wafer, it is important to bond the bump electrodes on the surface of the semiconductor wafer with good followability without causing voids. For this reason, a vacuum lamination method is often used.

As a general method of the vacuum laminating method, there is a method in which heating and evacuation are performed in a state where the adhesive film and the semiconductor wafer face each other, and pressure bonding is performed with a roll, a balloon, a press or the like under a heating vacuum. However, depending on the device, when heating and vacuuming, the adhesive film and the semiconductor wafer may be in contact from the beginning, or the clearance may be narrow and partially in contact. In such a case, there is a problem in that air is entrained between the adhesive film and the semiconductor wafer, and the entrained air is expanded by heating and vacuuming to generate a void (lami void). The void expanded by heating and evacuation is crushed during the subsequent press-bonding step or when the atmospheric pressure is released, and may remain as a crater-like pattern. Eventually, this leads to a decrease in yield of the semiconductor device, a decrease in junction reliability, and the like.

In particular, in BG-NCF, if the adhesion between the adhesive film and the semiconductor wafer is insufficient, defects such as peeling and wafer cracking may occur in the back grinding process, or the adhesive layer may be left behind after the back grinding process. When the material is peeled off, the adhesive may adhere to the substrate side, and the adhesive layer may peel off (delaminate) from the semiconductor wafer.

JP 2008-016624 A

An object of this invention is to provide the manufacturing method of the semiconductor device which can suppress the void at the time of bonding an adhesive film and a semiconductor wafer, and can implement | achieve high joining reliability. Another object of the present invention is to provide a semiconductor device manufactured by the method for manufacturing a semiconductor device, an adhesive film used in the method for manufacturing the semiconductor device, and a method for bonding the adhesive film.

The present invention is a method of manufacturing a semiconductor device using an adhesive film having a resin base layer, an adhesive layer, and an adhesive layer in this order, and the adhesive layer of the adhesive film and the semiconductor wafer are separated by a clearance of 1 cm or less. The process of making it oppose, the process of bonding the adhesive bond layer of the said adhesive film, and the said semiconductor wafer with the pressure of 0.1-1 Mpa under the heating vacuum of 50-100 degreeC and 10000 Pa or less, leaving only an adhesive bond layer A step of peeling the resin base layer and the adhesive layer of the adhesive film to obtain a semiconductor wafer with an adhesive layer, and a semiconductor with an adhesive layer by dicing the semiconductor wafer with the adhesive layer together with the adhesive layer A step of dividing the chip into chips, and a step of mounting the semiconductor chip with the adhesive layer on a substrate or another semiconductor chip via the adhesive layer by thermocompression bonding. The adhesive layer of the tack value was measured by the probe tack method of surface on the side to be bonded to the semiconductor wafer, a method of manufacturing a semiconductor device is 100 gf / 5 mm.phi or more at the bonding temperature.
The present invention is described in detail below.

In the adhesive film having the resin base layer, the pressure-sensitive adhesive layer, and the adhesive layer in this order, the inventor makes the tack value of the adhesive layer at the bonding temperature equal to or higher than a predetermined value, whereby the adhesive film, the semiconductor wafer, It has been found that voids at the time of bonding can be suppressed. By setting the tack value of the adhesive layer at the bonding temperature to a predetermined value or more, even if air is entrained when the adhesive film and the semiconductor wafer are opposed to each other, the adhesive film and the semiconductor wafer once contacted with each other Therefore, it is presumed that the air layer can be prevented from expanding while peeling the adhesive film and the semiconductor wafer under a heating vacuum.
After performing such bonding, the present inventor peels the resin base layer and the adhesive layer to form a semiconductor wafer with an adhesive layer, and then a semiconductor chip with an adhesive layer obtained by dicing is obtained. It has been found that a semiconductor device with high bonding reliability can be manufactured by mounting on a substrate or the like, and the present invention has been completed.

In the method for producing a semiconductor device of the present invention, first, a step of making the adhesive layer of the adhesive film having the resin base layer, the adhesive layer and the adhesive layer in this order and the semiconductor wafer face each other with a clearance of 1 cm or less, Next, a step of bonding the adhesive layer of the adhesive film and the semiconductor wafer at a pressure of 0.1 to 1 MPa under a heating vacuum of 50 to 100 ° C. and 10,000 Pa or less.
These processes are performed by a vacuum laminator (for example, trade name “MVLP-500 / 600II” manufactured by Meiki Seisakusho, trade name “V130” manufactured by Nichigo Morton, trade name “ATM-812M” manufactured by Takatori, etc.) It is preferable to carry out using. By bonding the adhesive layer of the adhesive film and the semiconductor wafer at a pressure in the above range under the heating vacuum as described above, the bonding can be performed while suppressing voids with good followability to the bump electrodes existing on the surface of the semiconductor wafer. It can be carried out.

In addition, the clearance between the adhesive layer of the adhesive film and the semiconductor wafer with a clearance of 1 cm or less means that a clearance may exist between the adhesive layer of the adhesive film and the semiconductor wafer, and the clearance is 1 cm or less. This means that the adhesive layer of the adhesive film and the semiconductor wafer may be in contact or partially in contact with each other.

The adhesive film has a resin base layer, an adhesive layer, and an adhesive layer in this order, but for the purpose of protecting the adhesive layer, the adhesive film is further separated on the side opposite to the side in contact with the adhesive layer. You may have a base material with a mold. Such a substrate with a release agent is peeled off before using the adhesive film.
Although the said base material with a mold release agent is not specifically limited, For example, a PET base material with a silicon mold release agent etc. can be used.

The said adhesive film has a resin base material layer. Examples of the resin base layer include layers made of polyethylene terephthalate (PET), polycarbonate, polymethyl methacrylate, polyethylene naphthalate, polybutylene terephthalate, polyethylene, polypropylene, and the like. Of these, a layer made of PET is preferable.

The minimum with the preferable thickness of the said resin base material layer is 5 micrometers, and a preferable upper limit is 200 micrometers. When the thickness is less than 5 μm, the effect of protecting the semiconductor wafer may be reduced when the semiconductor wafer is ground and thinned after bonding the adhesive layer of the adhesive film and the semiconductor wafer. If the thickness exceeds 200 μm, excessive stress may be generated in the semiconductor wafer when only the adhesive layer is left and the resin base layer and the adhesive layer are peeled off. The more preferable lower limit of the thickness is 10 μm, and the more preferable upper limit is 50 μm.

In the adhesive film, an adhesive layer is laminated on the resin base material layer. The adhesive layer is preferably a layer made of an acrylic polymer.
As the acrylic polymer, for example, a general (meth) acrylic acid alkyl ester resin obtained by polymerizing or copolymerizing one or two or more (meth) acrylic acid alkyl ester monomers, (meth) acrylic acid alkyl ester Examples thereof include a layer made of a copolymer of a monomer and another vinyl monomer that can be copolymerized therewith. Among these, a copolymer of a (meth) acrylic acid alkyl ester monomer and another vinyl monomer that can be copolymerized therewith is preferable.
In addition, (meth) acrylic acid means both acrylic acid and methacrylic acid.

The (meth) acrylic acid alkyl ester monomer preferably has 2 to 12 carbon atoms in the alkyl group. Specifically, for example, ethyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic And acid-2-ethylhexyl. These (meth) acrylic acid alkyl ester monomers may be used alone or in combination of two or more.

The weight average molecular weight of the acrylic polymer is usually about 200,000 to 2,000,000.

Moreover, it is preferable that the said adhesion layer is a layer which consists of a crosslinked acrylic polymer. The cross-linked acrylic polymer refers to a polymer in which a cross-linked structure is formed between the main chains of the acrylic polymer as described above.
Examples of a method for obtaining the crosslinked acrylic polymer include a method of blending a crosslinking agent with an acrylic polymer having a crosslinkable functional group (hereinafter also referred to as a functional group-containing acrylic polymer).

The functional group-containing acrylic polymer has, as in the case of the acrylic polymer as described above, a (meth) acrylic acid alkyl ester monomer in which the carbon number of the alkyl group is usually in the range of 2 to 18 as the main monomer. It is a polymer having adhesiveness at room temperature, obtained by copolymerizing a monomer, a functional group-containing monomer, and other modifying monomers that can be copolymerized with these if necessary. Is preferred.

Examples of the functional group-containing monomer include a carboxyl group-containing monomer such as (meth) acrylic acid, a hydroxyl group-containing monomer such as hydroxyethyl (meth) acrylate, an epoxy group-containing monomer such as glycidyl (meth) acrylate, (meth ) Isocyanate group-containing monomers such as isocyanate ethyl acrylate, and amino group-containing monomers such as aminoethyl (meth) acrylate.
Examples of the other modifying monomers include various monomers generally used for acrylic polymers such as vinyl acetate, acrylonitrile, and styrene.

Examples of the crosslinking agent include isocyanate crosslinking agents, aziridine crosslinking agents, epoxy crosslinking agents, metal chelate crosslinking agents, and the like. Among these, the isocyanate group of the isocyanate-based crosslinking agent and the alcoholic hydroxyl group in the functional group-containing acrylic polymer react to form a partial three-dimensional structure, leaving only the adhesive layer and the resin base layer. An isocyanate-based cross-linking agent is preferable because an adhesive residue hardly occurs when the adhesive layer is peeled off.

Further, the adhesive layer may be a layer made of an acrylic polymer having a radically polymerizable unsaturated group as a crosslinkable functional group.
As a method for obtaining an acrylic polymer having a radical polymerizable unsaturated bond, for example, a functional group-containing acrylic polymer having a functional group in the molecule is synthesized in advance, and the functional group reacts with the functional group in the molecule and radical polymerization. And a method of reacting a compound having a polymerizable unsaturated group.
In addition, when the adhesion layer contains the acrylic polymer which has a radically polymerizable unsaturated group, it is preferable that an adhesion layer contains a photoinitiator or a thermal polymerization initiator.

The preferable lower limit of the thickness of the adhesive layer is 2 μm, and the preferable upper limit is 100 μm. When the thickness is less than 2 μm, after bonding the adhesive layer of the adhesive film and the semiconductor wafer, the effect of protecting the bump electrode of the semiconductor wafer is reduced when the semiconductor wafer is ground and thinned from the back surface. And the top of the bump electrode may be crushed during bonding and grinding. When the thickness exceeds 100 μm, after bonding the adhesive layer of the adhesive film and the semiconductor wafer, the effect of protecting the semiconductor wafer is reduced when the semiconductor wafer is ground and thinned from the back surface, and the thickness of the semiconductor wafer is reduced. Unevenness, cracks, etc. may occur. The more preferable lower limit of the thickness is 4 μm, the still more preferable lower limit is 5 μm, the more preferable upper limit is 60 μm, and the still more preferable upper limit is 50 μm.

In the adhesive film, an adhesive layer is laminated on the pressure-sensitive adhesive layer.
The adhesive layer has a tack value measured by the probe tack method on the surface bonded to the semiconductor wafer of 100 gf / 5 mmφ or more at the bonding temperature. By setting the tack value of the adhesive layer at the bonding temperature within such a range, voids when bonding the adhesive film and the semiconductor wafer can be suppressed. This is because if the tack value of the adhesive layer at the bonding temperature is in the above range, even if air is caught when the adhesive film and the semiconductor wafer are opposed to each other, the adhesive film and the semiconductor once contacted It is presumed that since the adhesiveness with the wafer is high, the expansion of the air layer can be suppressed while peeling the adhesive film and the semiconductor wafer under a heating vacuum.

The bonding temperature means a temperature at which the adhesive layer of the adhesive film and the semiconductor wafer are bonded together. That is, the bonding temperature is a temperature in the range of 50 to 100 ° C.

When the tack value at the bonding temperature is less than 100 gf / 5 mmφ, the suppression of voids when bonding the adhesive film and the semiconductor wafer becomes insufficient. As a result, unevenness in the thickness of the adhesive layer occurs, a defect occurs in the back grind process, and after the back grind process, only the adhesive layer is left and the resin substrate layer and the adhesive layer are separated from the semiconductor wafer. The adhesive layer may peel off. A preferable lower limit of the tack value at the bonding temperature is 120 gf / 5 mmφ.

The upper limit of the tack value at the bonding temperature is not particularly limited, but the preferable upper limit is 300 gf / 5 mmφ. When the tack value at the bonding temperature exceeds 300 gf / 5 mmφ, the tack value at 25 ° C. also increases, and the substrate with a release agent laminated on the adhesive layer is peeled off to protect the adhesive layer until use. May cause problems. In addition, in the pick-up process when picking up the separated semiconductor chip with an adhesive layer and mounting it on a substrate or another semiconductor chip, the adhesive layer adheres on the stage, leading to a pickup failure. There is. A more preferable upper limit of the tack value at the bonding temperature is 250 gf / 5 mmφ.

Further, the adhesive layer preferably has a tack value measured by a probe tack method on the surface bonded to the semiconductor wafer of 10 gf / 5 mmφ or less at 25 ° C. When the tack value at 25 ° C. exceeds 10 gf / 5 mmφ, the substrate side with the release agent is used to peel the substrate with the release agent laminated on the adhesive layer to protect the adhesive layer until use. The adhesive may adhere to the adhesive layer, causing the adhesive layer to cohesively break, or may cause interface separation between the adhesive layer and the adhesive layer.

The tack value measured by the probe tack method is a probe tack measuring device (for example, tacking tester TAC-2 (manufactured by RHESCA)), probe diameter 5 mm, contact speed 120 mm / min, test speed 600 mm / It means a tack value measured under the measurement conditions of minute, contact load of 10 mN / mm ² and contact time of 10 seconds.

In order to make the tack value of the adhesive layer at the bonding temperature within the above range, it is effective to lower the melt viscosity of the adhesive layer. However, if the melt viscosity is too low, a void (bonding void) is formed between the adhesive layer and the substrate or another semiconductor chip when the semiconductor chip with the adhesive layer is mounted on the substrate or another semiconductor chip by thermocompression bonding. ).
For this reason, it is preferable that the adhesive layer has a minimum melt viscosity of 3000 Pa · s or more and 30000 Pa · s or less. When the minimum melt viscosity is less than 3000 Pa · s, a void is formed between the adhesive layer and the substrate or another semiconductor chip when the semiconductor chip with the adhesive layer is mounted on the substrate or another semiconductor chip by thermocompression bonding. May occur. When the minimum melt viscosity exceeds 30000 Pa · s, the tack value of the adhesive layer at the bonding temperature may not be within the above range. In addition, when a semiconductor chip with an adhesive layer is mounted on a substrate or another semiconductor chip by thermocompression bonding, a sufficient adhesive force cannot be obtained, leading to a decrease in bonding reliability. The minimum with more preferable minimum melt viscosity is 5000 Pa.s, and a more preferable upper limit is 25000 Pa.s.

In addition, the minimum melt viscosity is a measurement at a temperature rising rate of 5 ° C./min, a frequency of 1 Hz, and a measuring temperature of 30 to 180 ° C. using a melt viscosity measuring device (for example, a rotary rheometer VAR-100 (manufactured by Rheologicala)). It means the lowest melt viscosity measured under the conditions.

As a method of adjusting the tack value and the minimum melt viscosity, a method of adjusting the type and amount of each component contained in the adhesive layer is preferable. Especially, it is preferable that the said adhesive bond layer contains an epoxy resin, the acrylic polymer which has an epoxy group in a side chain, an epoxy hardening agent, and an inorganic filler.

The epoxy resin is preferably an epoxy resin having a polycyclic hydrocarbon skeleton in the main chain. By containing an epoxy resin having a polycyclic hydrocarbon skeleton in the main chain, the cured product of the adhesive layer may be rigid and exhibit excellent mechanical strength and heat resistance because molecular movement is inhibited. In addition, since the water absorption is low, excellent moisture resistance can be exhibited.

Examples of epoxy resins having a polycyclic hydrocarbon skeleton in the main chain include epoxy resins having a dicyclopentadiene skeleton such as dicyclopentadiene dioxide and phenol novolac epoxy resins having a dicyclopentadiene skeleton (hereinafter, dicyclopentadiene). 1-glycidylnaphthalene, 2-glycidylnaphthalene, 1,2-diglycidylnaphthalene, 1,5-diglycidylnaphthalene, 1,6-diglycidylnaphthalene, 1,7-diglycidylnaphthalene, 2 , 7-diglycidylnaphthalene, triglycidylnaphthalene, 1,2,5,6-tetraglycidylnaphthalene and other epoxy resins having a naphthalene skeleton (hereinafter also referred to as naphthalene type epoxy resin), tetrahydroxyphenylethane type epoxy resin , Tetrakis (glycidyloxyphenyl) ethane, 3,4-epoxy-6-methylcyclohexyl-3,4-epoxy-6-methylcyclohexane carbonate, and the like. Of these, dicyclopentadiene dioxide is preferable. These epoxy resins having a polycyclic hydrocarbon skeleton in the main chain may be used alone or in combination of two or more.

The preferable lower limit of the weight average molecular weight of the epoxy resin having the polycyclic hydrocarbon skeleton in the main chain is 500, and the preferable upper limit is 2000. When the weight average molecular weight is less than 500, the mechanical strength, heat resistance, moisture resistance and the like of the cured product of the adhesive layer may not be sufficiently improved. When the weight average molecular weight exceeds 2000, the cured product of the adhesive layer becomes too rigid and may become brittle.

By containing the acrylic polymer having an epoxy group in the side chain, the cured product of the adhesive layer can exhibit excellent flexibility. Therefore, for example, when an epoxy resin having a polycyclic hydrocarbon skeleton in the main chain and an acrylic polymer having an epoxy group in the side chain are used in combination, the cured product of the adhesive layer has a polycyclic hydrocarbon skeleton as the main chain. It has excellent mechanical strength, heat resistance and moisture resistance derived from the epoxy resin in the chain, and excellent flexibility derived from the acrylic polymer having an epoxy group in the side chain, and excellent cold and heat cycle resistance In addition, solder reflow resistance, dimensional stability, bonding reliability, and the like can be realized.

Examples of the acrylic polymer having an epoxy group in the side chain include a copolymer composed of glycidyl (meth) acrylate and alkyl (meth) acrylate. Especially, the copolymer which consists of glycidyl (meth) acrylate and alkyl (meth) acrylate and whose epoxy equivalent is about 300 g / eq is preferable.

The preferable lower limit of the weight average molecular weight of the acrylic polymer having an epoxy group in the side chain is 10,000, and the preferable upper limit is 1,000,000. If the weight average molecular weight is less than 10,000, it may be difficult to form an adhesive layer, or the adhesive force of the cured product of the adhesive layer may be insufficient. If the weight average molecular weight exceeds 1,000,000, it may be difficult to form an adhesive layer having a certain thickness.

As for the compounding quantity of the acrylic polymer which has an epoxy group in the said side chain, the preferable minimum with respect to 100 weight part of epoxy resins is 20 weight part, A preferable upper limit is 200 weight part. If the blending amount is less than 20 parts by weight, the flexibility of the cured product of the adhesive layer may be lowered. If the blending amount exceeds 200 parts by weight, the mechanical strength, heat resistance, moisture resistance, etc. of the cured product of the adhesive layer may be lowered.

Examples of the epoxy curing agent include thermosetting acid anhydride curing agents such as trialkyltetrahydrophthalic anhydride, phenolic curing agents, amine curing agents, latent curing agents such as dicyandiamide, and cationic catalyst curing agents. Etc. These epoxy curing agents may be used alone or in combination of two or more. Of these, thermosetting acid anhydride curing agents are preferred. The thermosetting acid anhydride curing agent has a high thermosetting speed. Therefore, by using such a curing agent, a void is formed when a semiconductor chip with an adhesive layer is mounted on a substrate or another semiconductor chip by thermocompression bonding. Can be effectively suppressed.

When using an epoxy curing agent that reacts with the functional group of the epoxy resin in an equivalent amount, the preferable lower limit for the functional group amount of the epoxy resin is 0.8 equivalent, and the preferable upper limit is 1.2 equivalent. It is. When the blending amount is less than 0.8 equivalent, the adhesive layer may not be sufficiently cured even when heated. Even if the blending amount exceeds 1.2 equivalents, it may not contribute to the thermosetting property of the adhesive layer in particular, and may cause voids due to volatilization of an excessive epoxy curing agent.

The adhesive layer may further contain a curing accelerator for the purpose of adjusting the curing speed or the physical properties of the cured product.
Examples of the curing accelerator include imidazole-based curing accelerators and tertiary amine-based curing accelerators. These hardening accelerators may be used independently and may use 2 or more types together. Among these, an imidazole-based curing accelerator is preferable because it is easy to control the reaction system for adjusting the curing speed or the physical properties of the cured product.

Examples of the imidazole-based curing accelerator include 1-cyanoethyl-2-phenylimidazole in which the 1-position of imidazole is protected with a cyanoethyl group, and an imidazole-based curing accelerator whose basicity is protected with isocyanuric acid (trade name “2MA-OK”). , Manufactured by Shikoku Kasei Kogyo Co., Ltd.), liquid imidazole (trade name “FUJICURE 7000”, manufactured by T & K TOKA), 2-ethyl-4-methylimidazole, 1-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazo 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-benzyl-2-ethylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl 2-phenyl-4,5-di- (cyanoethoxymethyl) imidazole, Examples include imidazole compounds such as 1,8-diazabicyclo (5.4.0) undecene-7, and derivatives thereof. These imidazole type hardening accelerators may be used independently and may use 2 or more types together.

As for the compounding quantity of the said hardening accelerator, the preferable minimum with respect to 100 weight part of epoxy hardeners is 5 weight part, and a preferable upper limit is 50 weight part. When the blending amount is less than 5 parts by weight, the adhesive layer may not be sufficiently cured even when heated. Even if the amount exceeds 50 parts by weight, it does not particularly contribute to the thermosetting of the adhesive layer.

Examples of the inorganic filler include silica particles, glass particles, and alumina. By blending an inorganic filler in the adhesive layer, the mechanical strength of the cured product of the adhesive layer can be ensured, and the linear expansion coefficient of the cured product is reduced to achieve high bonding reliability. be able to. Of these, silica particles are preferable, and spherical silica is particularly preferable from the viewpoint of fluidity and bonding reliability.

The minimum with the preferable average particle diameter of the said inorganic filler is 0.01 micrometer, and a preferable upper limit is 1 micrometer. When the average particle size is less than 0.01 μm, the viscosity of the adhesive solution for forming the adhesive layer increases, and the fluidity and the coating property may decrease. In addition, when the viscosity of the adhesive solution increases, the followability of the adhesive film to the surface of the semiconductor wafer decreases, and voids may not be sufficiently suppressed when the adhesive film and the semiconductor wafer are bonded together. When the average particle diameter exceeds 1 μm, the transparency of the adhesive layer is impaired, and when mounting a semiconductor chip with an adhesive layer on a substrate or another semiconductor chip by thermocompression bonding, bump electrodes and alignment on the semiconductor chip The mark may not be recognized. The more preferable lower limit of the average particle diameter is 0.02 μm, the more preferable upper limit is 0.5 μm, the still more preferable lower limit is 0.05 μm, and the still more preferable upper limit is 0.3 μm.
In addition, in order to achieve both the improvement of the coating property of the adhesive solution and the improvement of the transparency of the adhesive layer, two or more kinds of inorganic fillers having different average particle diameters may be used in combination.

The thickness of the adhesive layer is preferably adjusted according to the height of the bump electrode, and is preferably equal to or less than the height of the bump electrode, but the preferred lower limit is 5 μm and the preferred upper limit is 100 μm. is there. If the thickness is less than 5 μm, the adhesive strength of the cured product of the adhesive layer may be insufficient. When the thickness exceeds 100 μm, the mounting body may be too thick when the semiconductor chip with the adhesive layer is mounted on a substrate or another semiconductor chip by thermocompression bonding.

As a method for producing the adhesive film, for example, an adhesive solution obtained by producing a film composed of a resin base layer and an adhesive layer and then diluting the adhesive composition to be the adhesive layer with an appropriate solvent Obtained by diluting an adhesive composition to be an adhesive layer with an appropriate solvent after a method of coating on the adhesive layer and drying, or after producing a film comprising a resin base layer and an adhesive layer Examples include a method in which an adhesive solution is applied onto a substrate with a release agent and dried, and then the pressure-sensitive adhesive layer and the adhesive layer are bonded together.
Such an adhesive film used in the method for producing a semiconductor device of the present invention is also one aspect of the present invention.

As a method for producing a film comprising the resin base layer and the adhesive layer, for example, a method of laminating a film to be an adhesive layer using a laminator on at least one surface of the film to be the resin base layer, a coextrusion apparatus And a method of applying a resin coating solution to be an adhesive layer on a resin base layer and drying.
Examples of the method for applying the adhesive solution on the pressure-sensitive adhesive layer include coating methods such as comma coating, gravure coating, and die coating, and casting methods.

The semiconductor wafer is not particularly limited, and examples thereof include a semiconductor wafer made of a semiconductor such as silicon or gallium arsenide and having bump electrodes made of gold, copper, silver-tin solder, aluminum, nickel, or the like on the surface.

In the method for manufacturing a semiconductor device of the present invention, after the step of bonding the adhesive layer of the adhesive film and the semiconductor wafer, a step of grinding and thinning the semiconductor wafer from the back surface may be performed.
As a method for grinding the semiconductor wafer, a conventionally known method is used. For example, a commercially available grinding apparatus (for example, DFG8540 (manufactured by Disco)) is used to grind at 10 to 0.1 μm / s at a rotation of 2400 rpm. There is a method in which grinding is performed under the condition of the amount, and finally the finish is performed by CMP.

In the method for manufacturing a semiconductor device of the present invention, the step of separating the resin base material layer and the pressure-sensitive adhesive layer of the adhesive film, leaving only the adhesive layer, and obtaining a semiconductor wafer with an adhesive layer is then performed.
As a method for separating the resin base material layer and the adhesive layer while leaving only the adhesive layer, for example, after bonding a dicing tape to the surface of the semiconductor wafer where the adhesive film is not bonded, the adhesive layer For example, a method of separating the resin base material layer and the pressure-sensitive adhesive layer while leaving only the ink.

In the method for manufacturing a semiconductor device according to the present invention, the process of dicing the semiconductor wafer with the adhesive layer together with the adhesive layer into the semiconductor chips with the adhesive layer is then performed.
Examples of a method of dicing the semiconductor wafer with the adhesive layer together with the adhesive layer include a method of cutting and separating using a conventionally known grindstone, a laser, or the like.

In the method for manufacturing a semiconductor device of the present invention, a step of mounting the semiconductor chip with the adhesive layer on a substrate or another semiconductor chip through the adhesive layer by thermocompression bonding is then performed.
The method for manufacturing a semiconductor device of the present invention includes both a case where a semiconductor chip is mounted on a substrate and a case where a semiconductor chip is further mounted on one or more semiconductor chips mounted on the substrate.

In the method for manufacturing a semiconductor device of the present invention, after the semiconductor chip with the adhesive layer is mounted on a substrate or another semiconductor chip by thermocompression bonding, heating is performed in order to further completely cure the adhesive layer. As a result, a more stable bonding state can be realized, and a semiconductor device having excellent bonding reliability can be obtained.

In the above description, the semiconductor wafer with the adhesive layer is diced together with the adhesive layer and separated into semiconductor chips with the adhesive layer, and then the semiconductor chip with the adhesive layer is replaced with a substrate or another semiconductor. Although mounted on the chip by thermocompression bonding, as another aspect, a semiconductor wafer with an adhesive layer is stacked on another semiconductor wafer via the adhesive layer, and the obtained stacked body is diced to obtain a semiconductor chip. A mounting body may be obtained.

According to the method for manufacturing a semiconductor device of the present invention, it is possible to suppress a void when bonding an adhesive film and a semiconductor wafer, and to manufacture a semiconductor device with high bonding reliability.
A semiconductor device obtained by such a semiconductor device manufacturing method of the present invention is also one aspect of the present invention.

A method of laminating an adhesive film having a resin base layer, an adhesive layer, and an adhesive layer in this order, wherein the adhesive layer of the adhesive film and the semiconductor wafer face each other with a clearance of 1 cm or less; And bonding the adhesive layer of the adhesive film and the semiconductor wafer at a pressure of 0.1 to 1 MPa under a heating vacuum of ˜100 ° C. and 10,000 Pa or less, and the adhesive layer of the adhesive film is a semiconductor wafer A method for laminating an adhesive film in which the tack value measured by the probe tack method on the surface to be bonded to the substrate is 100 gf / 5 mmφ or more at the bonding temperature is also one aspect of the present invention.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the semiconductor device which can suppress the void at the time of bonding an adhesive film and a semiconductor wafer, and can implement | achieve high joint reliability can be provided. Moreover, according to this invention, the semiconductor device manufactured with the manufacturing method of this semiconductor device, the adhesive film used for the manufacturing method of this semiconductor device, and the bonding method of an adhesive film can be provided.

Examples of the present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

The material used for the adhesive layer in Examples and Comparative Examples is shown below.
(Epoxy resin)
Epicron HP-7200 (Dicyclopentadiene type epoxy resin, manufactured by DIC Corporation)
Epicron HP-4710 (Naphthalene type epoxy resin, manufactured by DIC)
(Acrylic polymer having an epoxy group in the side chain)
Marproof G-2050 (manufactured by NOF Corporation)
(Epoxy curing agent)
YH-309 (anhydride, manufactured by Mitsubishi Chemical Corporation)
(Curing accelerator)
FUJICURE 7000 (liquid imidazole compound, manufactured by T & K TOKA)
(Inorganic filler)
SE1050-SPE (spherical silica, average particle size 0.3 μm, manufactured by Admatechs)
YA050C-MJF (spherical silica, average particle size 0.05 μm, manufactured by Admatex)
(Silane coupling agent)
KBM-573 (Phenylaminosilane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.)
(Other)
AC-4030 (stress relaxation rubber polymer, manufactured by Ganz Kasei Co., Ltd.)

Example 1
(1) Manufacture of adhesive film 100 parts by weight of acrylic polymer (SK Dyne 1495C, manufactured by Soken Chemical Co., Ltd.) on one side of a PET film (Teijin Tetron film HPE, thickness 50 μm, manufactured by Teijin DuPont Films) as a resin substrate layer A coating solution containing 1.6 parts by weight of Coronate L-45 (isocyanate-based crosslinking agent, manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent was applied using a comma coater to form an adhesive layer having a thickness of 30 μm.
Subsequently, according to the composition of Table 1, each material was mixed with MEK and stirred and mixed using a homodisper to prepare a 50 wt% solution of the adhesive composition. A 50% by weight solution of the obtained adhesive composition was dried on the silicon release agent side of a PET film with a silicone release agent (A-31, thickness 50 μm, manufactured by Teijin DuPont) by the comma coating method. The film was applied to a thickness of 60 μm and dried at 100 ° C. for 5 minutes to form an adhesive layer.
An adhesive film was obtained by laminating the obtained pressure-sensitive adhesive layer and adhesive layer.

Table 1 shows the tack value of the adhesive layer at the bonding temperature and 25 ° C., and the minimum melt viscosity of the adhesive layer.
The tack value is measured using a probe tack measuring device (tacking tester TAC-2 (manufactured by RHESCA)), probe diameter 5 mm, contact speed 120 mm / min, test speed 600 mm / min, contact load 10 mN / mm ² , The measurement was performed under measurement conditions with a contact time of 10 seconds. Further, the minimum melt viscosity is measured using a melt viscosity measuring device (rotary rheometer VAR-100 (manufactured by Rheological Corporation)) under the measurement conditions of a heating rate of 5 ° C./min, a frequency of 1 Hz, and a measuring temperature of 30 to 180 ° C. did.

(2) Manufacturing of semiconductor device A semiconductor wafer having a diameter of 20 cm and a thickness of 750 μm, and a large number of spherical Ag—Sn solder balls having an average height of 80 μm and a diameter of 110 μm at a pitch of 250 μm was prepared. The PET film with a silicone release agent that protects the adhesive layer of the adhesive film is peeled off, and a vacuum laminator (trade name “MVLP-500 / 600II”, manufactured by Meiki Seisakusho Co., Ltd.) is used to form the adhesive layer of the adhesive film and the semiconductor. The surface of the wafer on which the solder balls are formed is faced with a clearance of 4 mm, and the adhesive layer and the semiconductor are subjected to a heating vacuum of 80 ° C. and 200 Pa (vacuum arrival time of 30 seconds) under a pressure of 0.5 MPa for 30 seconds. The wafer was bonded.
Next, this was attached to a grinding apparatus, and the semiconductor wafer was ground from the back surface until the wafer thickness became about 100 μm. At this time, the operation was performed while water was sprayed on the semiconductor wafer so that the temperature of the semiconductor wafer did not increase due to frictional heat of grinding. After grinding, the surface was mirror-finished by polishing with an alkaline silica dispersion aqueous solution by a CMP process.

The ground semiconductor wafer is removed from the polishing apparatus, and a dicing tape (trade name “PE tape # 6318-B”, manufactured by Sekisui Chemical Co., Ltd.) is attached to the surface of the semiconductor wafer where the adhesive film is not bonded. Mounted on the frame. Next, the resin base material layer and the adhesive layer of the adhesive film were peeled off leaving only the adhesive layer, and a semiconductor wafer with an adhesive layer was obtained. Using a dicing machine (trade name “DFD651”, manufactured by Disco Corporation), the semiconductor wafer with the adhesive layer is diced into a chip size of 10 mm × 10 mm together with the adhesive layer at a feed rate of 50 mm / second, and the adhesive layer It was divided into individual semiconductor chips. The obtained semiconductor chip with an adhesive layer was dried in a hot air drying oven at 80 ° C. for 10 minutes, and then a pressure of 0.15 MPa using a bonding apparatus (trade name “DB-100”, manufactured by Kasuya Kogyo Co., Ltd.) A semiconductor device was obtained by pressure bonding at 230 ° C. for 10 seconds and mounting on a substrate.

(Examples 2-5 and Comparative Examples 1-2)
An adhesive film and a semiconductor device were produced in the same manner as in Example 1 except that the adhesive composition was prepared according to the composition shown in Table 1.

<Evaluation>
The following evaluations were performed on the semiconductor devices and the like obtained in Examples and Comparative Examples. The results are shown in Table 1.

(1) Evaluation of Lami Void The state after bonding the adhesive film and the semiconductor wafer was visually observed. A case where a crater-like pattern was generated due to a ramie void was evaluated as x, and a case where there was no crater-like pattern and the adhesive film was uniformly bonded to the entire surface of the semiconductor wafer was rated as ◯.

(2) Bonding void evaluation The obtained semiconductor device was subjected to void observation with an ultrasonic imaging device (manufactured by Hitachi Construction Machinery Co., Ltd.). The case where the area of the void generation portion with respect to the semiconductor chip area was less than 5% was evaluated as “◯”, the case where it was 5% or more and less than 10%, and the case where it was Δ10% or more.

(3) Temperature cycle test The obtained semiconductor device is subjected to a temperature cycle test (one cycle at 30 minutes) at -55 ° C for 9 minutes and 125 ° C for 9 minutes, and the semiconductor after 1000 cycles The apparatus was observed as to whether or not the layers were separated using an ultrasonic flaw detector (trade name “SAT”, manufactured by SONOSCAN). Thereafter, the adhesive layer of the semiconductor device was removed with a mixed acid, and an observation was made as to whether or not the silicon nitride protective film on the surface of the semiconductor chip was cracked.
When no peeling between layers or cracking of the protective film was observed, ◯ when the peeling between layers or cracking of the protective film was slightly observed, and when marked peeling was observed between the layers, or protection The case where conspicuous cracks were observed in the film was evaluated as x.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the semiconductor device which can suppress the void at the time of bonding an adhesive film and a semiconductor wafer, and can implement | achieve high joint reliability can be provided. Moreover, according to this invention, the semiconductor device manufactured with the manufacturing method of this semiconductor device, the adhesive film used for the manufacturing method of this semiconductor device, and the bonding method of an adhesive film can be provided.

Claims (7)

A method of manufacturing a semiconductor device using an adhesive film having a resin base layer, an adhesive layer and an adhesive layer in this order,
A step of facing the adhesive layer of the adhesive film and the semiconductor wafer with a clearance of 1 cm or less;
Bonding the adhesive layer of the adhesive film and the semiconductor wafer at a pressure of 0.1 to 1 MPa under a heating vacuum of 50 to 100 ° C. and 10,000 Pa or less;
Removing the resin base layer and the adhesive layer of the adhesive film leaving only the adhesive layer, and obtaining a semiconductor wafer with an adhesive layer;
The step of dicing the semiconductor wafer with the adhesive layer together with the adhesive layer into individual chips with the adhesive layer;
Mounting the semiconductor chip with the adhesive layer on the substrate or another semiconductor chip via the adhesive layer by thermocompression bonding, and
The method for manufacturing a semiconductor device, wherein the adhesive layer of the adhesive film has a tack value measured by a probe tack method on a surface bonded to a semiconductor wafer of 100 gf / 5 mmφ or more at a bonding temperature. The method for manufacturing a semiconductor device according to claim 1, wherein the adhesive layer of the adhesive film has a minimum melt viscosity of 3000 Pa · s to 30000 Pa · s. 3. The method of manufacturing a semiconductor device according to claim 1, wherein the adhesive layer of the adhesive film contains an epoxy resin, an acrylic polymer having an epoxy group in a side chain, an epoxy curing agent, and an inorganic filler. 4. The semiconductor device according to claim 1, further comprising a step of grinding and thinning the semiconductor wafer from the back surface after the step of bonding the adhesive layer of the adhesive film and the semiconductor wafer. 5. Production method. A semiconductor device manufactured by the method for manufacturing a semiconductor device according to claim 1. An adhesive film used in the method for manufacturing a semiconductor device according to claim 1, 2, 3 or 4. A method for laminating an adhesive film having a resin base layer, an adhesive layer and an adhesive layer in this order,
A step of facing the adhesive layer of the adhesive film and the semiconductor wafer with a clearance of 1 cm or less;
Bonding the adhesive layer of the adhesive film and the semiconductor wafer at a pressure of 0.1 to 1 MPa under a heating vacuum of 50 to 100 ° C. and 10,000 Pa or less,
The adhesive layer of the adhesive film has a tack value measured by a probe tack method on the surface bonded to the semiconductor wafer of 100 gf / 5 mmφ or more at the bonding temperature. .