JP2010056531A - Method of manufacturing semiconductor chip laminated body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor chip laminated body extremely easily providing a semiconductor chip with an interlayer adhesive adhering thereto, and manufacturing a high lamination type semiconductor chip laminated body high in connection reliability even by semiconductor chips each having a projecting electrode. <P>SOLUTION: This method of manufacturing the semiconductor chip laminated body includes processes of: sticking an interlayer sticking adhesive layer 22 of an adhesive sheet and a wafer 1 having projecting electrodes 12 on a surface thereof to each other; grinding the wafer; half-curing the interlayer sticking adhesive layer by irradiating the adhesive sheet with an energy ray; providing the wafer with a half-cured interlayer sticking adhesive layer stuck thereto by peeling a base material film 21 from the adhesive sheet; segmenting the wafer by dicing it; and providing a semiconductor chip laminated body by sticking the semiconductor chip with the half-cured interlayer sticking adhesive layer stuck thereto to a substrate or another semiconductor through the half-cured interlayer sticking adhesive layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention makes it possible to obtain a semiconductor chip to which a thinly ground interlayer adhesive is adhered very easily, and a highly laminated semiconductor chip laminate having a high connection reliability even with a semiconductor chip having a convex electrode. The present invention relates to a method for manufacturing a semiconductor chip laminate that can be manufactured.

In recent years, high integration of semiconductors has progressed, and a stacked chip in which a plurality of thinly ground IC chips are stacked has been proposed. At the same time, various methods for highly integrated mounting of semiconductors have been proposed, and at present, bonding between IC chips is usually performed using an interlayer adhesive (Patent Documents 1 and 2, etc.).

Such a stacked chip is usually manufactured as follows. First, an adhesive tape called a back grind tape is attached to the wafer, and in this state, the wafer is ground to a predetermined thickness. The back grind tape is peeled off after grinding. Next, an interlayer adhesive is applied to the surface of the wafer, and then laminated with another wafer, a substrate, or the like. However, such a process has a problem that it is extremely complicated.

On the other hand, Patent Document 3 discloses a process 1 for bonding 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 to the wafer. Step 2 of grinding with the adhesive sheet fixed to the pressure-sensitive adhesive sheet, Step of removing the substrate from the ground wafer, leaving the adhesive layer for the interlayer adhesive, and obtaining the wafer having the adhesive layer for the interlayer adhesive attached thereto 3 is described. According to the method of Patent Document 3, it is possible to obtain a wafer with an interlayer adhesive that has been thinly ground easily and surely.

However, when a semiconductor chip laminate is manufactured by the method of Patent Document 3, when the wafer with the interlayer adhesive is diced into individual pieces, the interlayer adhesive layer cannot be cut cleanly, or the interlayer adhesive There was a case where the beard due to the layer was generated, or the cutting waste adhered to the interlayer adhesive layer. Moreover, the adhesive force of the interlayer adhesive layer may be reduced by water used during dicing. In particular, in the case of a semiconductor chip having a convex electrode on the surface, there is also a problem that the electrode is not well exposed from the interlayer adhesive layer, and the connection reliability is inferior.

JP 2005-126658 A JP 2003-231875 A JP 2008-016624 A

The present invention makes it possible to obtain a semiconductor chip to which a thinly ground interlayer adhesive is adhered very easily, and a highly laminated semiconductor chip laminate having a high connection reliability even with a semiconductor chip having a convex electrode. It aims at providing the manufacturing method of the semiconductor chip laminated body which can be manufactured.

The present invention is a method for producing a semiconductor chip laminate in which semiconductor chips having convex electrodes on the surface are laminated using an adhesive sheet comprising a base film and an adhesive layer for interlayer adhesion, A process 1 for bonding an adhesive layer for interlayer adhesion and a surface of the wafer having a convex electrode on the surface thereof on which the convex electrode is formed, and a process 2 for grinding the wafer while being fixed to the adhesive sheet. From the step 3 of semi-curing the adhesive layer for interlayer adhesion by irradiating the adhesive sheet bonded to the ground wafer with energy rays, and from the adhesive sheet bonded to the ground wafer The base film is peeled off to obtain a wafer to which a semi-cured interlayer adhesive layer is adhered, and the wafer to which the semi-cured interlayer adhesive layer is diced and semi-cured. Step 5 for separating the semiconductor chip to which the indirect wearing adhesive layer is attached, and the semiconductor chip to which the semi-cured interlayer adhesive adhesive layer is attached through the semi-cured interlayer adhesive adhesive layer to the substrate or And a step 6 of obtaining a semiconductor chip laminate by bonding to another semiconductor.
The present invention is described in detail below.

In the method for producing a semiconductor chip laminate of the present invention, an adhesive sheet comprising a base film and an interlayer adhesive layer (hereinafter also simply referred to as “adhesive layer”) is used.
Although it does not specifically limit as said base film, For example, the sheet | seat which consists of transparent resin, such as an acryl, an olefin, a polycarbonate, vinyl chloride, ABS, a polyethylene terephthalate (PET), nylon, urethane, a polyimide, It has a network-like structure. Examples thereof include a sheet and a sheet having holes.

The base film may or may not be subjected to a release treatment on the surface. Usually, it is easier to peel off after being subjected to a mold release treatment. However, in the method for producing a semiconductor chip laminate of the present invention, after the adhesive layer is semi-cured as described later even if the mold release treatment is not performed. Therefore, it is possible to peel the substrate film. Further, when the mold release treatment is not performed, the mold release agent is not transferred to the adhesive by not performing the treatment using the mold release agent, and the adhesive layer exhibits a higher adhesive force. be able to.

Although it does not specifically limit as thickness of the said base film, A preferable minimum is 12 micrometers and a preferable upper limit is 300 micrometers. If the thickness of the substrate film is less than 12 μm, the ability to protect or flatten the wafer as a protective tape may be insufficient. When the thickness of the base film exceeds 300 μm, excessive stress may be generated on the wafer when the base film is peeled off.

The adhesive layer is not particularly limited as long as it has sufficient adhesive force and can be semi-cured by irradiation with energy rays. The adhesive layer is preferably one that can be completely cured by further heating after semi-curing.
As such an adhesive layer, for example, a layer made of a photothermosetting adhesive composition containing a photocurable compound, a thermosetting compound, a photopolymerization initiator and a thermosetting agent is suitable.

Although it does not specifically limit as said photocurable compound, The acrylic resin which has a photocurable functional group is preferable.
The acrylic resin having the photocurable functional group is not particularly limited. For example, isobornyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, butyl (meth) acrylate, methyl (meth) acrylate, hydroxyethyl (meth) Linkage group such as urethane bond, ester bond, ether bond, etc. to a polymer or copolymer having a molecular weight of about 50,000 to 600,000 consisting of acrylic components such as acrylate, 4-hydroxybutyl (meth) acrylate, (meth) acrylic acid, etc. Through which a photocurable functional group such as an allyl group or a (meth) acryl group is introduced.
Examples of the photocurable compound include pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane (meth) acrylate di (meth) acrylate, dipentaerythritol tri (meth) acrylate, Low molecular polyfunctionality such as ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate An acrylic resin may be used.
These acrylic resins having a photocurable functional group may be used alone or in combination of two or more.

The acrylic resin having the photocurable functional group preferably has a double bond equivalent of 0.1 to 5 meq / g. When the double bond equivalent is less than 0.1 meq / g, the adhesive layer may not be sufficiently semi-cured even when irradiated with energy rays. When the double bond equivalent exceeds 5 meq / g, the adhesive layer may not be able to exert a sufficient adhesive force when adhered to a substrate or other semiconductor described later.

The acrylic resin having a photocurable functional group preferably further has a thermosetting functional group. By having the thermosetting functional group, the acrylic resin having the photocurable functional group reacts with the thermosetting compound described later when adhering to the substrate or other semiconductor described later, and a more uniform cured product. Can be obtained. Therefore, the heat resistance and adhesiveness of the cured product are improved, and a semiconductor chip laminated body with higher connection reliability can be manufactured.
The thermosetting functional group is not particularly limited, and examples thereof include a hydroxyl group, a carboxylic acid group, an amino group, an imino group, an oxetanyl group, an epoxy group, a mercapto group, and an isocyanate group. Of these, an epoxy group is particularly preferable.
Although it does not specifically limit as an acrylic resin which has such a photocurable functional group and a thermosetting functional group, For example, in addition to the acrylic component mentioned above as a copolymerization component, the copolymer containing glycidyl (meth) acrylate etc. To the polymer, a resin having a photocurable functional group introduced via a linking group as described above, or a polymer or copolymer composed of the above-described acrylic component, a linking group such as a urethane bond, an ester bond, or an ether bond is added. And a resin having an epoxy group introduced in addition to the photocurable functional group. These acrylic resins may be used independently and 2 or more types may be used together.

Although it does not specifically limit as said thermosetting compound, It is preferable to contain an epoxy resin.
Although it does not specifically limit as said epoxy resin, It is preferable to contain the epoxy resin which has a polycyclic hydrocarbon frame | skeleton in a principal chain. The cured product of the photothermosetting adhesive composition containing an epoxy resin with a polycyclic hydrocarbon skeleton in the main chain is rigid and impedes molecular movement, and exhibits excellent mechanical strength and heat resistance. In addition, since the water absorption is also reduced, excellent moisture resistance can be exhibited.

The epoxy resin having a polycyclic hydrocarbon skeleton in the main chain is not particularly limited. For example, an epoxy resin having a dicyclopentadiene skeleton such as dicyclopentadiene dioxide and a phenol novolac epoxy resin having a dicyclopentadiene skeleton ( (Hereinafter referred to as “dicyclopentadiene type epoxy resin”), 1-glycidylnaphthalene, 2-glycidylnaphthalene, 1,2-diglycidylnaphthalene, 1,5-diglycidylnaphthalene, 1,6-diglycidylnaphthalene, 1, Epoxy resins having a naphthalene skeleton such as 7-diglycidylnaphthalene, 2,7-diglycidylnaphthalene, triglycidylnaphthalene, 1,2,5,6-tetraglycidylnaphthalene (hereinafter referred to as “naphthalene type epoxy resin”), Tetrahydroxyph Niruetan type epoxy resins, tetrakis (glycidyloxyphenyl) ethane, 3,4-epoxy-6-methylcyclohexyl-3,4-epoxy-6-methylcyclohexane carbonate, and the like. Of these, epoxy resins having a dicyclopentadiene skeleton and epoxy resins having a naphthalene skeleton are suitable. These epoxy resins having a polycyclic hydrocarbon skeleton in the main chain may be used singly or in combination of two or more, and also include Bis-A type epoxy resin and Bis-F type epoxy resin. It may be used in combination with a commonly used epoxy resin.

The epoxy resin having a naphthalene skeleton preferably contains a compound represented by the following general formula (1). By using the compound represented by the following general formula (1), the linear expansion coefficient of the adhesive layer can be lowered, the heat resistance and adhesiveness of the cured product are improved, and a semiconductor chip with higher connection reliability. A laminate can be manufactured.

In General Formula (1), R ¹ and R ² each represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, or a phenyl group, and n and m are 0 or 1, respectively.

When the said thermosetting compound contains the compound represented by the said General formula (1), it is not specifically limited as a compounding quantity of the compound represented by the said General formula (1), Of the whole thermosetting compounds 3 to 90% by weight is preferable. If the compounding amount of the compound represented by the general formula (1) is less than 3% by weight, the effect of lowering the linear expansion coefficient of the adhesive layer may not be sufficiently obtained, or the adhesive force may be reduced. is there. When the compounding amount of the compound represented by the general formula (1) exceeds 90% by weight, the compound represented by the general formula (1) and the other compounding components in the photothermosetting adhesive composition are in phase. It may separate and the applicability | paintability at the time of producing an adhesive sheet may fall, or the water absorption rate of an adhesive bond layer may become high. As for the compounding quantity of the compound represented by the said General formula (1), it is more preferable that it is 5 to 80 weight% among the whole thermosetting compounds.

The compounding ratio of the photocurable compound and the thermosetting compound is not particularly limited, but the preferable lower limit of the compounding amount of the photocurable compound with respect to 100 parts by weight of the thermosetting compound is 20 parts by weight, and the preferable upper limit is 40 parts by weight. If the amount of the photocurable compound is less than 20 parts by weight, the shape retention effect due to semi-curing may be insufficient even when irradiated with energy rays. When the compounding quantity of the said photocurable compound exceeds 40 weight part, the heat resistance of the hardened | cured material obtained may be insufficient.

Although it does not specifically limit as said photopolymerizable initiator, For example, what is activated by irradiating light with a wavelength of 250-800 nm is mentioned. Examples of such a photopolymerization initiator include acetophenone derivative compounds such as methoxyacetophenone, benzoin ether compounds such as benzoin propyl ether and benzoin isobutyl ether, ketal derivative compounds such as benzyldimethyl ketal and acetophenone diethyl ketal, Phosphine oxide derivative compound, bis (η5-cyclopentadienyl) titanocene derivative compound, benzophenone, Michler ketone, chlorothioxanthone, todecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, α-hydroxycyclohexyl phenyl ketone, 2-hydroxymethylphenylpropane And photo radical polymerization initiators such as These photoinitiators may be used independently and 2 or more types may be used together.

The blending amount of the photopolymerization initiator is not particularly limited, but a preferable lower limit is 0.05 parts by weight and a preferable upper limit is 5 parts by weight with respect to 100 parts by weight of the photocurable compound. If the amount of the photopolymerization initiator is less than 0.05 parts by weight, it may not be possible to be semi-cured even when irradiated with energy rays. Even if it mixes more than 5 weight part, the said photoinitiator does not contribute to photocurability especially.

The thermosetting agent is not particularly limited. For example, when the thermosetting compound contains an epoxy resin, a thermosetting acid anhydride-based curing agent such as trialkyltetrahydrophthalic anhydride, a phenol-based curing agent. And latent curing agents such as amine-based curing agents and dicyandiamide, and cationic catalyst-type curing agents. These epoxy resin curing agents may be used alone or in combination of two or more. Of these, acid anhydride curing agents are preferred. When an acid anhydride-based curing agent is contained as a thermosetting agent, since the thermosetting speed is high, generation of voids in the cured product can be effectively reduced, and the resulting semiconductor chip laminate can be bonded reliably. Can be expensive.

The amount of the thermosetting agent is not particularly limited, but when using a thermosetting agent that reacts with the functional group of the thermosetting compound in an equivalent amount, the preferred lower limit is relative to the functional group amount of the thermosetting compound. 90 equivalents and a preferred upper limit is 110 equivalents. When the blending amount of the thermosetting agent is less than 90 equivalents, it may not be cured sufficiently even when heated. Even if it mix | blends the said thermosetting agent exceeding 110 equivalent, it does not contribute to thermosetting especially.
Moreover, when using the thermosetting agent which functions as a catalyst, the preferable minimum is 1 weight part and a preferable upper limit is 20 weight part with respect to 100 weight part of thermosetting compounds. . When the blending amount of the thermosetting agent is less than 1 part by weight, it may not be cured sufficiently even when heated. Even if it mix | blends the said thermosetting agent exceeding 20 weight part, it does not contribute to thermosetting especially.

The photothermosetting adhesive composition may further contain a solid polymer having a functional group that reacts with the epoxy resin.
Although it does not specifically limit as a solid polymer which has a functional group which reacts with the said epoxy resin, For example, resin which has an amino group, a urethane group, an imide group, a hydroxyl group, a carboxyl group, an epoxy group etc. is mentioned, Especially, an epoxy group is mentioned. High molecular polymers having When a polymer having an epoxy group is contained, the cured product can exhibit excellent flexibility. By performing adhesion with an adhesive layer comprising such a photothermosetting adhesive composition, excellent mechanical strength derived from an epoxy resin having the above polycyclic hydrocarbon skeleton in the main chain, excellent heat resistance, Excellent moisture resistance, etc. and excellent flexibility derived from the above polymer having an epoxy group are exhibited, and the obtained semiconductor chip laminated body has a thermal cycle resistance, solder reflow resistance, and dimensional stability. Etc., and high adhesion reliability and high connection reliability will be exhibited.

The polymer having an epoxy group is not particularly limited as long as it is a polymer having an epoxy group at a terminal and / or side chain (pendant position). For example, an epoxy group-containing acrylic rubber And epoxy group-containing butadiene rubber, bisphenol-type high molecular weight epoxy resin, epoxy group-containing phenoxy resin, epoxy group-containing acrylic resin, epoxy group-containing urethane resin, epoxy group-containing polyester resin, and the like. These polymer polymers having an epoxy group may be used alone or in combination of two or more. Among them, an epoxy group-containing acrylic resin is suitable because a polymer containing a large amount of epoxy groups can be obtained and the cured product has better mechanical strength and heat resistance.

The photothermosetting adhesive composition may further contain a curing accelerator for the purpose of adjusting the curing rate of the adhesive layer and the physical properties of the cured product.
It does not specifically limit as said hardening accelerator, For example, an imidazole series hardening accelerator, a tertiary amine type hardening accelerator, etc. are mentioned. 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 and the physical properties of the cured product.

The imidazole curing accelerator is not particularly limited, and examples thereof include 1-cyanoethyl-2-phenylimidazole in which the 1-position of imidazole is protected with a cyanoethyl group, and those whose basicity is protected with isocyanuric acid (trade name “2MA- OK ”, manufactured by Shikoku Kasei Kogyo Co., Ltd.). These imidazole type hardening accelerators may be used independently and may use 2 or more types together.

Although it does not specifically limit as thickness of the said adhesive bond layer, A preferable minimum is 5 micrometers and a preferable upper limit is 150 micrometers. If the thickness of the adhesive layer is less than 5 μm, sufficient adhesive strength may not be obtained. When the thickness of the adhesive layer exceeds 150 μm, the resulting semiconductor chip laminate may be thick.

The method for producing the adhesive sheet is not particularly limited, and the photothermosetting adhesive composition diluted with a solvent is applied onto the base film by a method such as comma coating, gravure coating, casting, The method of drying etc. are mentioned.
Although it does not specifically limit as said solvent, Solvents with comparatively low boiling points, such as methyl ethyl ketone, ethyl acetate, acetone, methyl isobutyl ketone, 2-ethoxyethanol, toluene, methanol, ethanol, are preferable. For the purpose of improving the coatability, these relatively low boiling solvents may be used in combination with high boiling solvents such as dimethylacetamide, dimethylformamide, methylpyrrolidone, cyclohexane, and ethyl lactate. Furthermore, you may add a small amount of surfactant as needed.

FIG. 1 shows a schematic diagram for explaining a method for producing a semiconductor chip laminate according to the present invention. The manufacturing method of the semiconductor chip laminated body of the present invention will be described with reference to FIG. 1 as appropriate.
In the method for producing a semiconductor chip laminated body of the present invention, first, the step of bonding the adhesive layer for interlayer adhesion of the adhesive sheet and the surface of the wafer having the convex electrode on the surface thereof to which the convex electrode is formed. 1 is done.

The wafer is not particularly limited, and examples thereof include those made of a semiconductor such as silicon or gallium arsenide.
A convex electrode made of gold, copper, silver-tin solder, aluminum, nickel or the like is formed on the wafer. According to the method for manufacturing a semiconductor chip laminated body of the present invention, even a wafer having a convex electrode on the surface can exhibit high connection reliability.
In FIG. 1, convex electrodes 12 are formed on the surface of a wafer 1 (FIG. 1 (a)).

Bonding may be performed at normal temperature and normal pressure, but in order to further improve the adhesion, it is preferable that the bonding is performed under a vacuum of about 1 torr while heating at a temperature in the range of room temperature to 100 ° C. . Moreover, it is preferable to use a laminator for bonding.
In FIG. 1, the adhesive sheet 2 in which the base film 21 and the adhesive layer 22 for interlayer adhesion were formed is affixed on the surface in which the convex electrode 12 of the wafer 1 was formed using the laminator 3 ( FIG. 1 (b)).

In the method for manufacturing a semiconductor chip laminated body according to the present invention, next, the step 2 of grinding in a state where the wafer is fixed to the adhesive sheet is performed.
In step 2, the wafer is ground to a desired thickness. The grinding method is not particularly limited, and a conventionally known method can be used. For example, using a commercially available grinding device (for example, DFG 8540 manufactured by Disco Corporation), grinding is performed at a rotation amount of 2400 rpm and a grinding amount of 0.2 to 3 μm / s, and finally, it is finished by CMP. And the like.
In FIG. 1, the wafer 1 is ground to a predetermined thickness by using a grinding device 4 (FIGS. 1C and 1D).

The wafer has a convex electrode on the surface, and the convex electrode is buried in the adhesive layer of the adhesive sheet, and the shape of the convex electrode affects the shape of the surface of the adhesive layer. However, the adhesive is removed from the surface of the convex electrode by pressing during grinding in step 2, the adhesive layer is flattened, and the height of the electrode is substantially equal to the thickness of the adhesive layer. Thereby, the surface of a convex electrode tends to be exposed on an adhesive bond layer after peeling a base film, and the connection reliability of the obtained semiconductor chip laminated body improves.

In the method for producing a semiconductor chip laminate of the present invention, next, Step 3 is performed in which the adhesive sheet bonded to the ground wafer is irradiated with energy rays to semi-cure the adhesive layer for interlayer adhesion (FIG. 1). (E)).
By irradiating energy rays and semi-curing the adhesive layer, the adhesive strength of the adhesive layer is reduced and the substrate film can be easily peeled off. On the other hand, since it is “semi-cured”, the adhesive layer can exhibit a sufficient adhesive force when adhered to a substrate or other semiconductor described later.

In the present specification, semi-cured means that the gel fraction is 10 to 60% by weight. If the gel fraction is less than 10% by weight, the shape retention force as the adhesive layer may be insufficient, or adhesive residue may be easily left when the base film is peeled off. If the gel fraction exceeds 60% by weight, the fluidity of the adhesive layer becomes insufficient and bonding becomes difficult.
The gel fraction is, for example, infiltrated with a semi-cured composition in a solvent that has sufficient solubility to dissolve the photothermosetting adhesive composition, such as methyl acetate or methyl ethyl ketone, stirred for a sufficient time, and filtered through a mesh Then, it can be calculated from the amount of undissolved material obtained by drying.

Such a semi-cured state is easily achieved, for example, by adjusting the dose of energy rays when the adhesive layer contains an acrylic resin having the photocurable functional group as a photocurable compound. can do. That is, radicals generated by irradiation with energy rays are chain-reacted with the photocurable functional group to form a three-dimensional network structure and gel.

The dose of the energy ray is not particularly limited, preferable lower limit is 100 mJ / cm ^2, the upper limit is preferably 10000 mJ / cm ^2. When the irradiation amount of the energy rays is less than 100 mJ / cm ² , the gel fraction of the adhesive layer is lowered, and the shape retention force as the adhesive layer may be insufficient. When the irradiation amount of the energy rays exceeds 10,000 mJ / cm ² , the saturated state is reached, so that the physical properties of the adhesive layer are hardly affected, which is not preferable from the viewpoint of manufacturing tact.
Moreover, the method of irradiating the energy beam is not particularly limited. For example, from the base film side, using an ultrahigh pressure mercury lamp, the illuminance is set so that the illuminance on the wafer surface becomes 60 mW / cm ² with ultraviolet light around 365 nm. Examples include a method of adjusting and irradiating for 20 seconds (integrated light amount 1200 mJ / cm ² ).

In the method for producing a semiconductor chip laminate of the present invention, the base film is then peeled from the adhesive sheet bonded to the ground wafer to obtain a wafer to which a semi-cured adhesive layer for interlayer adhesion is adhered. Step 4 is performed (FIG. 1 (f)).
Since the adhesive layer of the said adhesive sheet is semi-hardened by irradiation of the energy beam of process 3, a base film can be peeled off very easily. At this time, it is also possible to remove the adhesive layer remaining on the electrode surface.

In the method for manufacturing a semiconductor chip laminate according to the present invention, the wafer to which the semi-cured interlayer adhesive adhesive layer is then diced is separated into semiconductor chips to which the semi-cured interlayer adhesive adhesive layer is adhered. Step 5 is performed (FIG. 1G).
The dicing method is not particularly limited, and for example, a method of cutting and separating using a conventionally known grindstone or the like can be used.

Since the adhesive layer of the adhesive sheet is semi-cured by the irradiation of energy rays in step 3, the adhesive layer can be cut cleanly and easily without generating the beard due to the adhesive layer. it can. Moreover, it can suppress that the cutting waste adheres to an adhesive bond layer because the adhesive bond layer is semi-hardened. Furthermore, the adhesive layer is not deteriorated by water used during dicing.

In the method for producing a semiconductor chip laminate of the present invention, the semiconductor chip to which the semi-cured interlayer adhesive adhesive layer is adhered is then bonded to a substrate or another semiconductor through the semi-cured interlayer adhesive adhesive layer. Then, Step 6 for obtaining a semiconductor chip laminated body is performed (FIG. 1H).
Since the semi-cured adhesive layer still has sufficient adhesive strength, the obtained semiconductor chip to which the semi-cured adhesive layer is adhered is attached to the substrate or other semiconductor via the adhesive layer. Adhesion is sufficiently possible.
In this specification, the semiconductor chip stacked body includes both a structure in which only one semiconductor chip is bonded to a substrate and a structure in which a plurality of semiconductor chips are bonded and stacked.

More stable adhesion can be realized by performing Step 7 of further completely curing the adhesive layer by heating the semiconductor chip laminated body obtained in Step 6 after the adhesion.

In the above description, after performing step 4 of obtaining a wafer to which a semi-cured interlayer adhesive adhesive layer is adhered, the wafer to which the semi-cured interlayer adhesive adhesive layer is adhered is diced and semi-cured. Step 5 was performed to separate the semiconductor chip to which the adhesive layer for interlayer adhesion was attached.
As another embodiment, the wafer having the semi-cured adhesive layer for interlayer adhesion obtained in Step 4 was laminated on another wafer through the adhesive layer to produce a wafer laminate. The wafer laminated body may be diced collectively to obtain a semiconductor chip laminated body having a semi-cured adhesive layer for interlayer adhesion attached thereto.

According to the present invention, a semiconductor chip to which a thinly ground interlayer adhesive is attached can be obtained very easily, and a highly laminated semiconductor chip stack having high connection reliability even for a semiconductor chip having a convex electrode. The manufacturing method of the semiconductor chip laminated body which can manufacture a body can be provided.

It is a schematic diagram explaining the manufacturing method of the semiconductor chip laminated body of this invention.

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Examples 1-3)
(1) Preparation of photothermosetting adhesive composition According to the composition shown in Table 1, the materials shown below were added to methyl ethyl ketone and stirred and mixed using a homodisper to prepare a photothermosetting adhesive composition.
(Thermosetting compound)
・ Dicyclopentadiene type epoxy resin (HP-7200HH, manufactured by DIC)
-Naphthalene type epoxy resin (in the above general formula (1), R ¹ and R ² are H, m and n are 1 compounds, EXA-4710, manufactured by DIC)
Resorcinol type epoxy resin (EX201P, manufactured by Nagase ChemteX Corporation)

(Photocurable compound)
-Acrylic resin having a photocurable functional group (2-ethylhexyl acrylate, isobornyl acrylate, hydroxyethyl acrylate copolymer added with 2-methacryloyloxyethyl isocyanate, molecular weight 300,000, double (Binding equivalent 0.9 meq / g, SK-2-37, manufactured by Shin-Nakamura Chemical Co., Ltd.)
-Acrylic resin having a photocurable functional group and a thermosetting functional group (2-methacryloyloxyethylisocyanate is a copolymer of 2-ethylhexyl acrylate, isobornyl acrylate, hydroxyethyl acrylate, and glycidyl methacrylate. Added, molecular weight 520,000, double bond equivalent 0.9 meq / g, epoxy equivalent 1650, SK-2-78, manufactured by Shin-Nakamura Chemical Co., Ltd.)

(Photopolymerization initiator)
Photoradical generator (Esacure 1001, manufactured by Lamberti)

(Thermosetting agent)
・ Acid anhydride (YH-307, manufactured by Japan Epoxy Resin Co., Ltd.)

(Other)
・ Acrylic resin (copolymer of isobutyl methacrylate and hydroxyethyl methacrylate, molecular weight 100,000, SK-2-47, manufactured by Shin-Nakamura Chemical Co., Ltd.)
・ Imidazole compound (2MA-OK, manufactured by Shikoku Chemicals)
・ Stress relaxation rubber polymer (AC4030, manufactured by Ganz Kasei Co., Ltd.)
-Fumed silica (MT10, manufactured by Tokuyama)
・ Imidazolesilane coupling agent (SP-1000, manufactured by Nikko Materials)

(2) Preparation of adhesive sheet On a base film made of polyethylene terephthalate (PET) having a thickness of 50 μm, a photothermographic adhesive composition obtained by a comma coating method was applied to a thickness of 40 μm, An adhesive sheet was obtained by drying. Until use, the surface of the adhesive layer composed of the photothermosetting adhesive composition was protected with a PET film.

(3) Manufacturing of semiconductor chip laminate A semiconductor wafer (silicon wafer) having a diameter of 20 cm, a thickness of 700 μm, and a large number of square copper bumps having a height of 40 μm and a width of 100 μm × 100 μm formed at a pitch of 400 μm was prepared. .

The PET film that protects the adhesive layer of the adhesive sheet was peeled off and attached to the semiconductor wafer under vacuum (1 torr) using a laminator.
Next, this was attached to a grinding apparatus and ground until the thickness of the semiconductor wafer 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 polishing, mirror polishing was performed by polishing with an aqueous solution of silica dispersed in an alkali in a CMP (Chemical Mechanical Polishing) process.

The semiconductor wafer is removed from the polishing apparatus, and a dicing tape “PE tape # 6318-B” (manufactured by Sekisui Chemical Co., Ltd., thickness 70 μm, base polyethylene, adhesive rubber-based adhesive is applied to the surface of the semiconductor wafer where the adhesive sheet is not attached. Material 10 μm) was pasted and mounted on a dicing frame.
From the base film side of the adhesive sheet, using an ultra-high pressure mercury lamp, ultraviolet rays of around 365 nm were irradiated for 20 seconds while adjusting the illuminance so that the illuminance on the semiconductor wafer surface was 60 mW / cm ² (integrated light amount 1200 mJ / cm ² ).
The base film was peeled from the adhesive layer semi-cured by ultraviolet rays, and a wafer was obtained in which the adhesive layer was transferred onto a ground semiconductor wafer.

Using a dicing machine DFD651 (manufactured by Disco Corporation), the semiconductor wafer was divided into 10 mm × 10 mm chip sizes at a feed rate of 50 mm / second, and a semiconductor chip with a semi-cured adhesive layer adhered was obtained. .

The semiconductor chip to which the semi-cured adhesive layer was adhered was dried at 80 ° C. for 10 minutes in a hot air drying furnace, and then a load of 0.15 MPa and a temperature using a bonding apparatus (DB-100, manufactured by Shibuya Kogyo Co., Ltd.) The laminate was formed by pressure bonding at 230 ° C. for 10 seconds. This was repeated, and 5 layers of semiconductor chips were stacked and then cured at 180 ° C. for 60 minutes to obtain a semiconductor chip stack.

(Evaluation)
The wafer, the semiconductor chip, or the obtained semiconductor chip laminated body obtained in the manufacturing process of the semiconductor chip laminated body was evaluated according to the following criteria. The results are shown in Table 1.
(1) Dicing performance evaluation The semiconductor chip to which the separated semi-cured adhesive layer was adhered was observed using a microscope. When each chip and adhesive layer are cut cleanly along the dicing, there is no whisker due to the adhesive layer, and cutting waste does not adhere to the adhesive layer, “○”, and each chip and adhesive If the layer is cut cleanly along the dicing, but there is a beard due to the adhesive layer, or if cutting scraps are attached to the adhesive layer, "△", each chip and the adhesive layer Was not cut cleanly, there was a beard due to the adhesive layer, and a case where cutting waste adhered to the adhesive layer was evaluated as “x”.

(2) Bonding evaluation of semiconductor chip A semiconductor chip with a semi-cured adhesive layer adhered was bonded on a plastic substrate under the conditions of 230 ° C., 100 N for 10 seconds using a bonding apparatus, and the adhesion performance was confirmed. . If the air does not flow between the chip and the substrate, a clean adhesive surface is created, and if the adhesive layer does not rise on the surface of the chip, “○” indicates that there is no air between the chip and the substrate. Although it does not matter, if the adhesive layer rises on the surface of the chip and the adhesive is contaminating the bonder head, “△” indicates that air is trapped between the chip and the substrate, and the chip surface The case where the adhesive layer was raised and the bonder head was contaminated with the adhesive was evaluated as “x”.

(3) Solder heat resistance evaluation The semiconductor chip laminate was dried at 125 ° C. for 6 hours, then subjected to a wet treatment for 48 hours under conditions of 30 ° C. and 80% humidity, and then solder reflow at 260 ° C. for 30 seconds. Processing was performed under conditions. With respect to the layers of each semiconductor chip laminated body after the reflow treatment, whether or not the layers were separated was observed with an ultrasonic flaw detector (SAT).
When the presence or absence of peeling was confirmed with respect to 10 semiconductor chip laminate samples, the case where peeling was found was 0, and the case where peeling was found was 1 or 2 Was evaluated as “Δ”, and the case where three or more samples were observed to be peeled off was evaluated as “×”.

(4) TCT evaluation The obtained semiconductor chip laminated body is subjected to a temperature cycle test in which one cycle is −55 ° C., 9 minutes, and 125 ° C., 9 minutes. The body was taken out and the change in conduction resistance value was confirmed. The number of cycles when the conduction resistance value changed by 10% or more was evaluated.

(5) Adhesive strength evaluation The wafer to which the semi-cured adhesive layer was adhered was separated into 5 mm × 5 mm by dicing, and a semiconductor chip to which the semi-cured adhesive layer was adhered was obtained. This semiconductor chip was bonded on a semiconductor wafer at 230 ° C. for 10 seconds using a bonding apparatus, and further cured at 180 ° C. for 60 minutes to obtain a sample. About the obtained sample, the die shear strength in 260 degreeC was measured at the speed | rate of 100 micrometers / s using the die shear tester.

(Comparative Example 1)
According to the composition of Table 1, each of the materials shown above was added to methyl ethyl ketone and stirred and mixed using a homodisper to prepare a curable adhesive composition. This is obtained by adding an acrylic resin (SK-2-47, manufactured by Shin-Nakamura Chemical Co., Ltd.) that is not cured with ultraviolet rays, except for the components that are cured with ultraviolet rays from the compositions of Examples 1 to 3.
Using the obtained curable adhesive composition, except that the step of irradiating ultraviolet rays was omitted, an adhesive sheet was prepared in the same manner as in Examples 1 to 3, and a semiconductor chip laminate was produced using this, Evaluation was performed.

According to the present invention, a semiconductor chip to which a thinly ground interlayer adhesive is attached can be obtained very easily, and a highly laminated semiconductor chip stack having high connection reliability even for a semiconductor chip having a convex electrode. The manufacturing method of the semiconductor chip laminated body which can manufacture a body can be provided.

DESCRIPTION OF SYMBOLS 1 Wafer which has convex electrode on surface 12 Convex electrode 2 Adhesive sheet 21 Base film 22 Adhesive layer for interlayer adhesion 3 Laminator 4 Grinding device 5 Grinding stone 6 Substrate or other semiconductor

Claims (9)

A method for producing a semiconductor chip laminate in which a semiconductor chip having a convex electrode on the surface is laminated using an adhesive sheet comprising a base film and an adhesive layer for interlayer adhesion,
Bonding the adhesive layer for interlayer adhesion of the adhesive sheet and the surface on which the convex electrode of the wafer having the convex electrode is bonded to the surface;
Grinding 2 in a state where the wafer is fixed to the adhesive sheet;
Step 3 of semi-curing the adhesive layer for interlayer adhesion by irradiating the adhesive sheet bonded to the ground wafer with energy rays;
Step 4 of removing the base film from the adhesive sheet bonded to the ground wafer to obtain a wafer to which a semi-cured adhesive layer for interlayer adhesion is attached;
A step 5 of dicing the wafer to which the semi-cured interlayer adhesive adhesive layer is attached, and separating the wafer into individual semiconductor chips to which the semi-cured interlayer adhesive adhesive layer is attached;
A step 6 of obtaining a semiconductor chip laminate by adhering the semiconductor chip to which the semi-cured interlayer adhesive layer is adhered to a substrate or another semiconductor through the semi-cured interlayer adhesive layer. A method for producing a semiconductor chip laminate, comprising: 2. The method of manufacturing a semiconductor chip laminate according to claim 1, further comprising a step 7 of completely curing the adhesive layer for interlayer adhesion by heating the semiconductor chip laminate obtained in step 6. . The adhesive layer for interlayer adhesion consists of a photothermosetting adhesive composition containing a photocurable compound, a thermosetting compound, a photopolymerization initiator, and a thermosetting agent, according to claim 1 or 2. Manufacturing method of semiconductor chip laminated body. 4. The method for producing a semiconductor chip laminate according to claim 3, wherein the photocurable compound is an acrylic resin having a photocurable functional group. The method for producing a semiconductor chip laminate according to claim 4, wherein the acrylic resin having a photocurable functional group further has a thermosetting functional group. The method for producing a semiconductor chip laminate according to claim 3, wherein the thermosetting compound contains an epoxy resin. 7. The method for producing a semiconductor chip laminate according to claim 6, wherein the epoxy resin is an epoxy resin having a polycyclic hydrocarbon skeleton in the main chain. 8. The semiconductor chip laminate according to claim 7, wherein the epoxy resin having a polycyclic hydrocarbon skeleton in the main chain contains an epoxy resin having a dicyclopentadiene skeleton and / or an epoxy resin having a naphthalene skeleton. Production method. The method for producing a semiconductor chip laminate according to claim 8, wherein the epoxy resin having a naphthalene skeleton contains a compound represented by the following general formula (1).

In General Formula (1), R ¹ and R ² each represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, or a phenyl group, and n and m are 0 or 1, respectively.

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