JPWO2017090439A1 - Resin sheet for connecting circuit members - Google Patents

Abstract

A resin sheet for connecting a circuit member, which is interposed between electrodes facing each other and used to electrically connect the electrodes facing each other. The material constituting the resin sheet is a melt viscosity at 90 ° C. before curing. Is 1.0 * 10 < ⁰ > -5.0 * 10 < ⁵ > Pa * s, The average linear expansion coefficient in 0-130 degreeC of hardened | cured material is 45 ppm or less, The resin sheet for circuit member connection characterized by the above-mentioned. According to such a resin sheet for connecting a circuit member, when the circuit members are connected to each other, the connection resistance at the connection portion hardly changes and has high reliability.

Description

  The present invention relates to a resin sheet, for example, a circuit sheet connecting resin sheet used for bonding a semiconductor chip and a substrate by a so-called flip chip mounting method.

  In recent years, a flip chip mounting method has been adopted from the viewpoint of high integration of a semiconductor integrated circuit (IC) and miniaturization of a semiconductor device (IC package). This flip chip mounting method is a kind of wireless bonding method, in which bumps made of solder or the like are formed on electrodes on the surface of a semiconductor chip, and the semiconductor chip is turned upside down on a substrate such as a printed circuit board or a ceramic substrate. After placing and aligning the bump and the electrode of the substrate, the bump is heated and melted to join the electrode of the semiconductor chip and the electrode of the substrate.

  In such a flip chip mounting type semiconductor device, in order to ensure electrical connection reliability and mechanical connection strength, a resin called an underfill material is generally used between the semiconductor chip and the substrate. Intervene. As a method for using the underfill material, there is known a method in which after a semiconductor chip and a substrate are soldered together, an underfill material made of a liquid resin composition is injected into a gap between the two and cured.

  However, in recent years, with the increase in the number of electrodes due to the high integration of semiconductor integrated circuits, the pitch of electrodes and the thinning of semiconductor devices, the distance between the bumps is extremely narrow, and the distance between the semiconductor chip and the substrate is It is getting very small. Therefore, the above method using a liquid resin composition as the underfill material has a problem that it is difficult to completely fill the gap between the semiconductor chip and the substrate with the underfill material. In order to solve this problem, a method of bonding a semiconductor chip and a substrate using an adhesive film called NCF (Non-Conductive Film) has been proposed (for example, see Patent Document 1).

  By the way, such an underfill material is required to have high reliability such that the connection resistance between the semiconductor chip and the substrate does not change even under a temperature cycle test. In this regard, an adhesive that contains an inorganic filler as an underfill material and has an average coefficient of thermal expansion at 110 to 130 ° C. after curing of 200 ppm or less has been proposed (see Patent Document 2).

JP 2009-277818 A Japanese Patent Laid-Open No. 10-287848

  However, the adhesive of Patent Document 2 has a problem that the coefficient of linear expansion is still large, and good results cannot be secured in the temperature cycle test.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a resin sheet for connecting a circuit member that has a high reliability, in which the connection resistance at the connection portion hardly changes.

In order to achieve the above object, first, the present invention is a resin sheet for connecting a circuit member, which is interposed between electrodes facing each other and used to electrically connect the electrodes facing each other, The material constituting the resin sheet has a melt viscosity of 1.0 × 10 ^{0 to} 5.0 × 10 ⁵ Pa · s at 90 ° C. before curing, and the average linear expansion coefficient of the cured product at 0 to 130 ° C. Provided is a resin sheet for connecting circuit members, which is 45 ppm or less (Invention 1).

  The resin sheet for connecting circuit members according to the above invention (Invention 1) has a melt viscosity at 90 ° C. before curing in the above range. Therefore, when the resin sheet is interposed between the electrodes, a circuit such as a chip or a substrate is used. It follows the unevenness of the surface of the member well. Moreover, since the average linear expansion coefficient of the cured product is 45 ppm or less, the difference in linear expansion coefficient from the adherend (circuit member) is reduced, and the stress that can be generated between the resin sheet and the adherend is reduced. can do. Therefore, the resin sheet for connecting circuit members according to the above invention (Invention 1) can have high connection reliability between the circuit members.

  In the said invention (invention 1), it is preferable that the material which comprises the said resin sheet contains 1 or more types of thermoplastic components selected from the group which consists of a polyvinyl acetal resin and a polyester resin (invention 2).

  In the said invention (invention 2), it is preferable that the material which comprises the said resin sheet contains a phenoxy resin further as the said thermoplastic component (invention 3).

  In the said invention (invention 1-3), it is preferable that the material which comprises the said resin sheet contains an inorganic filler (invention 4).

  In the said invention (invention 4), it is preferable that the said inorganic filler is a silica filler (invention 5), and it is preferable that the average particle diameter of the said inorganic filler is 10-200 nm (invention 6).

  In the said invention (invention 4-6), it is preferable that the material which comprises the said resin sheet contains 35-64 mass% of said inorganic fillers (invention 7).

  In the said invention (invention 1-7), it is preferable that the material which comprises the said resin sheet contains the component which has a flux function (invention 8).

  In the said invention (invention 8), it is preferable to contain the component which has a carboxyl group as a component which has the said flux function (invention 9), and it is preferable that the component which has the said carboxyl group is 2-methylglutaric acid. (Invention 10).

  When the circuit members are connected to each other, the circuit member connecting resin sheet of the present invention has a high reliability because the connection resistance at the connecting portion hardly changes.

Hereinafter, embodiments of the present invention will be described.
The resin sheet for connecting circuit members according to the present embodiment is interposed between electrodes facing each other, and is used to electrically connect the electrodes facing each other. The circuit member is not particularly limited as long as it is a member in which an electrode is formed on a circuit. For example, in addition to a semiconductor chip and a semiconductor wafer, an inorganic circuit substrate such as a lead frame, a ceramic circuit substrate, and a glass circuit substrate, an organic rigid circuit Examples thereof include organic circuit boards such as substrates and flexible circuit boards.

1. Physical Properties (1) Melt Viscosity In this embodiment, the material constituting the resin sheet has a melt viscosity at 90 ° C. before curing (hereinafter sometimes referred to as “90 ° C. melt viscosity”) as an upper limit value of 5. It is 0 × 10 ⁵ Pa · s or less, preferably 1.0 × 10 ⁵ Pa · s or less, and particularly preferably 5.0 × 10 ⁴ Pa · s or less. When the 90 ° C. melt viscosity is less than or equal to the above upper limit, when the circuit member connecting resin sheet is interposed between the electrodes, the circuit member and the resin are satisfactorily followed by unevenness on the surface of the circuit member such as a chip or a substrate. It is possible to prevent generation of voids at the interface with the layer made of the sheet. The 90 ° C. melt viscosity is 1.0 × 10 ⁰ Pa · s or more as a lower limit, preferably 1.0 × 10 ¹ Pa · s or more, and particularly preferably 1.0 × 10 ² Pa · s. s or more. When the 90 ° C. melt viscosity is equal to or higher than the lower limit, the material constituting the resin sheet does not flow excessively, and contamination of the apparatus can be prevented when the resin sheet is stuck or when a circuit is connected.
Therefore, the resin sheet for connecting circuit members according to the present embodiment has high reliability when the 90 ° C. melt viscosity of the constituent material is in the above range.

  Here, the 90 degreeC melt viscosity of the material which comprises a resin sheet is the value measured using the flow tester, and the detail of a test method is as showing in the Example mentioned later.

(2) Average linear expansion coefficient In the present embodiment, the material constituting the resin sheet has an average linear expansion coefficient of the cured product at 0 to 130 ° C. (hereinafter sometimes simply referred to as “average linear expansion coefficient”). The upper limit is 45 ppm or less, preferably 35 ppm or less, and particularly preferably 25 ppm or less. If the average linear expansion coefficient is not more than the above upper limit, the difference in linear expansion coefficient between the cured resin sheet and the adherend (circuit member) becomes small, and based on the difference between the resin sheet and the adherend. It is possible to reduce the stress that can be generated between the two. Thereby, the resin sheet for circuit member connection which concerns on this embodiment can make the connection reliability of circuit members high, and shows high connection reliability especially in the temperature cycle test shown in an Example. .

  On the other hand, the lower limit of the average linear expansion coefficient is not particularly limited, but is preferably 5 ppm or more and more preferably 10 ppm or more from the viewpoint of film formability.

  Here, the average linear expansion coefficient of the material constituting the resin sheet is a value measured using a thermomechanical analyzer, and the details of the test method are as shown in Examples described later.

(3) Glass transition temperature In this embodiment, it is preferable that the material which comprises a resin sheet has the glass transition temperature (Tg) of hardened | cured material as 150 degreeC or more as a lower limit, and it is 200 degrees C or more further. The temperature is preferably 240 ° C. or higher. It is preferable for the glass transition temperature of the cured product to be equal to or higher than the above lower limit value because the cured product is not deformed during the temperature cycle test and stress is hardly generated. On the other hand, the upper limit value of the glass transition temperature of the cured product is not particularly limited, but is preferably 350 ° C. or less and more preferably 300 ° C. or less from the viewpoint of suppressing embrittlement of the cured product.
Here, the glass transition temperature of the cured material of the material constituting the resin sheet was measured using a dynamic viscoelasticity measuring instrument (manufactured by TA Instruments, DMA Q800), with a frequency of 11 Hz, an amplitude of 10 μm, and a rate of temperature increase. This is the temperature at the maximum point of tan δ (loss elastic modulus / storage elastic modulus) when the viscoelasticity in the tensile mode is measured by raising the temperature from 0 ° C. to 300 ° C. at 3 ° C./min.

2. Material The resin sheet for connecting circuit members according to the present embodiment satisfies the above-described 90 ° C. melt viscosity and average linear expansion coefficient, and is preferably made of a material that satisfies the above-described glass transition temperature.

(1) Thermoplastic component It is preferable that the material which comprises the said resin sheet contains a thermoplastic component. By containing a thermoplastic component, the 90 ° C. melt viscosity and the average linear expansion coefficient of the material can easily satisfy the numerical range described above.

  Examples of the thermoplastic component include (meth) acrylic resin, phenoxy resin, polyester resin, polyurethane resin, polyimide resin, polyamideimide resin, siloxane-modified polyimide resin, polybutadiene resin, polypropylene resin, and styrene-butadiene-styrene copolymer. Styrene-ethylene-butylene-styrene copolymer, polyacetal resin, polyvinyl acetal resin including polyvinyl butyral resin, butyl rubber, chloroprene rubber, polyamide resin, acrylonitrile-butadiene copolymer, acrylonitrile-butadiene-acrylic acid copolymer , Acrylonitrile-butadiene-styrene copolymer, polyvinyl acetate, nylon and the like, and one kind can be used alone, or two or more kinds can be used in combination.

  In addition, “(meth) acrylic acid” in the present specification means both acrylic acid and methacrylic acid. The same applies to other similar terms such as “(meth) acrylic resin”.

  Among the thermoplastic components described above, it is preferable to use one or more selected from the group consisting of polyvinyl acetal resins and polyester resins. The material constituting the resin sheet contains these thermoplastic components, so that both the 90 ° C. melt viscosity and the average linear expansion coefficient are both low, and as a result, these values are within the numerical range described above. Becomes easier.

  Here, the polyvinyl acetal resin is obtained by acetalizing polyvinyl alcohol obtained by saponifying polyvinyl acetate with aldehyde. Examples of the aldehyde used for acetalization include n-butyraldehyde, n-hexylaldehyde, n-valeraldehyde and the like. As the polyvinyl acetal resin, it is also preferable to use a polyvinyl butyral resin acetalized with n-butyraldehyde.

  Examples of polyester resins include polyester resins obtained by polycondensation of dicarboxylic acid components and diol components such as polyethylene terephthalate resin, polybutylene terephthalate resin, and polyethylene oxalate resin; urethane obtained by reacting these with a polyisocyanate compound. Modified polyester resins such as modified polyester resins; polyester resins grafted with acrylic resins and / or vinyl resins, and the like can be used, and one kind can be used alone or two or more kinds can be used in combination.

  Moreover, when the material which comprises the said resin sheet contains a polyvinyl acetal resin or a polyester resin as a thermoplastic component, it is especially preferable to contain a phenoxy resin further. In the case of further containing a phenoxy resin, the material constituting the resin sheet is more likely to satisfy the numerical range described above in terms of 90 ° C. melt viscosity and average linear expansion coefficient.

  Although it does not specifically limit as a phenoxy resin, For example, a bisphenol A type, a bisphenol F type, a biphenol type, a biphenyl type etc. are illustrated.

  The thermoplastic component preferably has a lower limit of the softening point of 50 ° C. or higher, more preferably 100 ° C. or higher, and particularly preferably 120 ° C. or higher. Moreover, the upper limit value of the softening point of the thermoplastic component is preferably 200 ° C. or less, more preferably 180 ° C. or less, and particularly preferably 150 ° C. or less. By including a thermoplastic component having a softening point equal to or higher than the lower limit, the average linear expansion coefficient of the material constituting the resin sheet can be reduced, and the above-described numerical range is easily satisfied. Moreover, the embrittlement of a sheet | seat can be suppressed as a softening point is below the said upper limit. The softening point is a value measured based on ASTM D1525.

  The thermoplastic component preferably has a glass transition temperature lower limit value of 50 ° C. or higher, more preferably 60 ° C. or higher, and particularly preferably 80 ° C. or higher. The upper limit of the glass transition temperature of the thermoplastic component is preferably 250 ° C. or lower, more preferably 200 ° C. or lower, and particularly preferably 180 ° C. or lower. By including a thermoplastic component having a glass transition temperature of the lower limit value or more, the average linear expansion coefficient of the material constituting the resin sheet can be reduced, and the above-described numerical range is easily satisfied. Moreover, it becomes what was excellent in compatibility with another material as a glass transition temperature is below the said upper limit. In addition, the glass transition temperature of a thermoplastic component is the value measured using the differential scanning calorimeter, and a specific measuring method is shown in the Example mentioned later.

  The thermoplastic component preferably has a weight average molecular weight of 10,000 or more, more preferably 30,000 or more, and particularly preferably 50,000 or more. Further, the upper limit is preferably 1,000,000 or less, more preferably 700,000 or less, and particularly preferably 500,000 or less. It is preferable for the weight average molecular weight to be not less than the above lower limit value, since the film viscosity can be maintained and the melt viscosity can be lowered. Moreover, since a compatibility with low molecular weight components, such as a thermosetting component, improves that a weight average molecular weight is below the said upper limit, it is preferable. In addition, the weight average molecular weight in this specification is the value of standard polystyrene conversion measured by the gel permeation chromatography (GPC) method.

  The lower limit of the content of the thermoplastic component in the material constituting the resin sheet is preferably 3% by mass or more, more preferably 5% by mass or more, and particularly preferably 7% by mass or more. preferable. The upper limit of the thermoplastic component content is preferably 95% by mass or less, more preferably 90% by mass or less, and particularly preferably 80% by mass or less. When the content of the thermoplastic component is equal to or more than the lower limit value, the 90 ° C. melt viscosity of the material constituting the resin sheet can be further lowered, and the above-described numerical range is easily satisfied. On the other hand, when the content of the thermoplastic component is not more than the upper limit value, the average linear expansion coefficient of the material constituting the resin sheet can be further reduced, and the above-described numerical range is easily satisfied.

(2) Inorganic filler It is preferable that the material which comprises the said resin sheet contains an inorganic filler. Since the material constituting the resin sheet contains an inorganic filler, the average linear expansion coefficient becomes a low value. Therefore, when the resin sheet for connecting circuit members according to this embodiment is used, the connection reliability between the circuit members is The property can be made high.

  Although the inorganic filler which can be used in this embodiment is not specifically limited, A silica, an alumina, glass, a titanium oxide, mica etc. can be illustrated, These are used individually by 1 type or in combination of 2 or more types. Can do. Among these, silica filler is preferable. The shape of the silica filler is preferably spherical.

  The lower limit of the average particle diameter of the inorganic filler is preferably 10 nm or more, more preferably 20 nm or more, and particularly preferably 30 nm or more. The average particle size of the inorganic filler is preferably 200 nm or less, more preferably 150 nm or less, and particularly preferably 100 nm or less. When the average particle size of the inorganic filler is not less than the above lower limit, both the transparency of the sheet and the low melt viscosity can be achieved. Moreover, 90 degreeC melt viscosity in the material which comprises the said resin sheet can be maintained to a low value as the average particle diameter of an inorganic filler is below the said upper limit.

  The lower limit of the content of the inorganic filler in the material constituting the resin sheet is preferably 35% by mass or more, more preferably 40% by mass or more, and particularly preferably 50% by mass or more. . The upper limit of the content of the inorganic filler is preferably 64% by mass or less, more preferably 60% by mass or less, and particularly preferably 56% by mass or less. In the material which comprises a resin sheet, the average linear expansion coefficient of the said material can be reduced more as content of an inorganic filler is more than the said lower limit, and it will become easy to satisfy | fill the numerical range mentioned above. On the other hand, when the content of the inorganic filler is not more than the above upper limit value, the 90 ° C. melt viscosity of the material can be maintained at a low value, and the above-described numerical range is easily satisfied.

(3) Component having a flux function In the present embodiment, when the electrodes of the circuit member are joined by solder, the material constituting the resin sheet for connecting a circuit member of the present embodiment is a component having a flux function (hereinafter referred to as “flux”). It is preferable to contain a "component". The flux component has an action of removing the metal oxide film formed on the electrode surface, makes the electrical connection between the electrodes by solder more reliable, and can improve the connection reliability at the solder joint. .

  Although it does not specifically limit as a flux component, It is preferable that it is a component which has a phenolic hydroxyl group and / or a carboxyl group, and it is especially preferable that it is a component which has a carboxyl group. The component having a carboxyl group has a flux function and also has a function as a curing agent when an epoxy resin described later is used as a thermosetting component. For this reason, the component having a carboxyl group reacts and is consumed as a curing agent after the solder bonding is completed, so that it is possible to suppress problems caused by excessive flux components.

Specific flux components include, for example, glutaric acid, 2-methylglutaric acid, orthoanisic acid, diphenolic acid, adipic acid, acetylsalicylic acid, benzoic acid, benzylic acid, azelaic acid, benzylbenzoic acid, malonic acid, 2, 2-bis (hydroxymethyl) propionic acid, salicylic acid, o-methoxybenzoic acid, m-hydroxybenzoic acid, succinic acid, 2,6-dimethoxymethylparacresol, benzoic hydrazide, carbohydrazide, malonic dihydrazide, succinic dihydrazide Glutaric acid dihydrazide, salicylic acid hydrazide, iminodiacetic acid dihydrazide, itaconic acid dihydrazide, citric acid trihydrazide, thiocarbohydrazide, benzophenone hydrazone, 4,4′-oxybisbenzenesulfonylhydrazide, adipic acid dihydride A hydrazide, a rosin derivative, etc. are mentioned, These can be used individually by 1 type or in combination of 2 or more types.
Examples of rosin derivatives include gum rosin, tall rosin, wood rosin, polymerized rosin, hydrogenated rosin, formylated rosin, rosin ester, rosin modified maleic resin, rosin modified phenolic resin, rosin modified alkyd resin, and the like.

  Among these, 2-methylglutaric acid and rosin derivatives are particularly preferable. 2-Methylglutaric acid is a material constituting the resin sheet for connecting circuit members, and has two carboxyl groups in the molecule although the molecular weight is relatively small. In the embodiment, it can be particularly preferably used. Since the rosin derivative has a high softening point and can impart a flux property while maintaining a low linear expansion coefficient, it can be used particularly suitably in this embodiment.

  In the present embodiment, the lower limit of the content of the flux component in the material constituting the resin sheet is preferably 1% by mass or more, more preferably 3% by mass or more, and 5% by mass or more. Is particularly preferred. The upper limit of the content of the flux component is preferably 20% by mass or less, more preferably 15% by mass or less, and particularly preferably 10% by mass or less. In the material constituting the resin sheet, when the content of the flux component is equal to or higher than the lower limit, the electrical connection between the electrodes by solder can be made more reliable, and the connection reliability at the solder joint can be further improved. . On the other hand, when the content of the flux component is not more than the above upper limit value, it is possible to prevent problems such as ion migration due to an excessive flux component.

(4) Thermosetting component It is preferable that the material which comprises the resin sheet for circuit member connection of this embodiment contains a thermosetting component.
The thermosetting component is not particularly limited as long as it is an adhesive component usually used for connecting circuit members such as semiconductor chips. Specific examples include epoxy resins, phenol resins, melamine resins, urea resins, polyester resins, urethane resins, acrylic resins, polyimide resins, benzoxazine resins, and the like. These may be used alone or in combination of two or more. Can be used. Among these, from the viewpoint of adhesiveness and the like, an epoxy resin and a phenol resin are preferable, and an epoxy resin is particularly preferable.

  Epoxy resins have the property of forming a three-dimensional network upon heating and forming a hardened product. As such an epoxy resin, various conventionally known epoxy resins are used. Specifically, glycidyl ethers of phenols such as bisphenol A, bisphenol F, resorcinol, phenyl novolac, cresol novolac; butanediol, Glycidyl ether of alcohols such as polyethylene glycol and polypropylene glycol; Glycidyl ether of carboxylic acid such as phthalic acid, isophthalic acid and tetrahydrophthalic acid; Glycidyl type in which active hydrogen bonded to nitrogen atom such as aniline isocyanurate is substituted with glycidyl group Or an alkyl glycidyl type epoxy resin; vinylcyclohexane diepoxide, 3,4-epoxycyclohexylmethyl-3,4-dicyclohexanecarboxylate, 2- (3,4- So-called alicyclic in which epoxy is introduced by, for example, oxidizing a carbon-carbon double bond in the molecule, such as (poxy) cyclohexyl-5,5-spiro (3,4-epoxy) cyclohexane-m-dioxane. Mention may be made of type epoxides. In addition, an epoxy resin having a biphenyl skeleton, a dicyclohexadiene skeleton, a naphthalene skeleton, or the like can also be used. These epoxy resins can be used alone or in combination of two or more.

  In this embodiment, the lower limit of the content of the thermosetting component in the material constituting the resin sheet is preferably 5% by mass or more, and more preferably 10% by mass or more. The upper limit of the content of the thermosetting component is preferably 75% by mass or less, more preferably 60% by mass or less, and particularly preferably 55% by mass or less. When the content of the thermosetting component is within the above range, the connection strength between the circuit members can be sufficiently ensured, and the 90 ° C. melt viscosity and the average linear expansion coefficient in the material constituting the resin sheet can be obtained. It becomes easy to adjust to the numerical range mentioned above.

(5) Curing Agent / Curing Catalyst When the material constituting the resin sheet for connecting circuit members of this embodiment contains the thermosetting component described above, the material preferably further contains a curing agent and a curing catalyst.

  Although it does not specifically limit as a hardening | curing agent, Phenols, amines, thiols, etc. are mentioned, According to the kind of thermosetting component mentioned above, it can select suitably. For example, when an epoxy resin is used as the curable component, phenols are preferable from the viewpoint of reactivity with the epoxy resin.

  Examples of phenols include bisphenol A, tetramethyl bisphenol A, diallyl bisphenol A, biphenol, bisphenol F, diallyl bisphenol F, triphenylmethane type phenol, tetrakisphenol, novolac type phenol, cresol novolac resin, and the like. Can be used singly or in combination of two or more.

  In addition, the curing catalyst is not particularly limited, and examples thereof include imidazole-based, phosphorus-based, and amine-based, and can be appropriately selected according to the type of the thermosetting component described above. For example, when an epoxy resin is used as the curable component, an imidazole-based curing catalyst is preferable from the viewpoint of reactivity with the epoxy resin.

  In the present embodiment, the lower limit of the content of the curing catalyst in the material constituting the resin sheet is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and 0.4 It is particularly preferable that the content is at least mass%. The upper limit of the content of the curing catalyst is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 3% by mass or less. In the material which comprises a resin sheet, a thermosetting component can fully be hardened as content of a curing catalyst is more than the said lower limit. On the other hand, when the content of the curing catalyst is not more than the above upper limit value, the storage stability of the resin sheet becomes good.

(6) Other components The resin sheet for connecting circuit members according to the present embodiment further includes a plasticizer, a stabilizer, a tackifier, a colorant, a coupling agent, and an antistatic agent as a material constituting the resin sheet. Further, it may contain an antioxidant, conductive particles and the like.

  For example, when the material constituting the resin sheet contains conductive particles and the like, and anisotropic conductivity is imparted to the resin sheet for connecting circuit members, in an aspect that complements solder bonding, or with solder bonding The circuit members can be electrically joined in different manners.

3. Other Configurations The resin sheet for connecting circuit members according to the present embodiment may be further laminated with a release sheet. Also, a dicing sheet integrated sheet (dicing / die bonding sheet) obtained by further laminating a dicing sheet on the circuit member connecting resin sheet according to the present embodiment, or a back grind sheet integrated adhesive sheet obtained by further laminating a back grind sheet. It is good.

  When the release sheet is further laminated in the resin sheet for circuit member connection according to the present embodiment, the configuration of the release sheet is arbitrary, for example, a polyester film such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polypropylene, Examples thereof include a plastic film such as a polyolefin film such as polyethylene. It is preferable that a peeling treatment is performed on these peeling surfaces (surfaces in contact with the resin sheet). Examples of the release agent used for the release treatment include silicone-based, fluorine-based, and long-chain alkyl-based release agents.

  When laminating release sheets on both sides of the resin sheet for connecting circuit members, one release sheet may be a heavy release release sheet having a high release force, and the other release sheet may be a light release release sheet having a low release force. preferable.

  Although there is no restriction | limiting in particular about the thickness of a peeling sheet, Usually, it is about 20-250 micrometers.

  Although it will not restrict | limit especially if it is generally used as a dicing sheet, For example, the sheet | seat with which the adhesive layer was laminated | stacked on the single side | surface of a base material can be illustrated.

  The material constituting the substrate of the dicing sheet is not particularly limited. For example, polyethylene, polypropylene, polybutene, polybutadiene, polymethylpentene, polyvinyl chloride, vinyl chloride copolymer, polyethylene terephthalate, polybutylene terephthalate, polyurethane, ethylene acetate Vinyl copolymers, ionomers, ethylene / (meth) acrylic acid copolymers, ethylene / (meth) acrylic acid ester copolymers, polystyrene, vinyl polyisoprene, polycarbonate, polyolefins, etc., one of these Alternatively, a mixture of two or more kinds can be used.

  Moreover, it does not specifically limit as a constituent material of the adhesive layer of a dicing sheet, For example, what is comprised with the resin composition containing an acrylic adhesive, a rubber adhesive, etc. can be used. Examples of the acrylic pressure-sensitive adhesive include resins composed of (meth) acrylic acid and esters thereof, (meth) acrylic acid and esters thereof, and unsaturated monomers copolymerizable therewith (for example, vinyl acetate, Copolymers with styrene, acrylonitrile, etc.) are used. Two or more kinds of these copolymers may be mixed.

  When the dicing sheet and the resin sheet for connecting a circuit member of the present embodiment are used as the dicing sheet integrated adhesive sheet, the circuit member connecting resin sheet is laminated on the surface of the dicing sheet on the pressure-sensitive adhesive layer side. . Here, an adhesive layer and the layer which consists of a resin sheet for circuit member connection are peeled after the dicing process mentioned later. Therefore, the pressure-sensitive adhesive layer preferably has a pressure-sensitive adhesive force that is lowered by energy ray irradiation, heating, or the like.

  Although it will not restrict | limit especially if it is generally used as a back grind sheet, For example, the sheet | seat with which the adhesive layer was laminated | stacked on the single side | surface of a base material can be illustrated.

  Although the constituent material of the base material of the back grind sheet is not particularly limited, for example, a material made of a resin such as polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), ethylene / vinyl acetate copolymer (EVA), etc. Can be mentioned.

  Further, the constituent material of the pressure-sensitive adhesive layer of the back grind sheet is not particularly limited, but for example, a material composed of a resin composition containing an acrylic pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, or the like can be used. Examples of the acrylic pressure-sensitive adhesive include resins composed of (meth) acrylic acid and esters thereof, (meth) acrylic acid and esters thereof, and unsaturated monomers copolymerizable therewith (for example, vinyl acetate, Copolymers with styrene, acrylonitrile, etc.) are used. Two or more kinds of these copolymers may be mixed.

  When the back grind sheet and the resin sheet for connecting circuit members of the present embodiment are used as the back grind sheet integrated adhesive sheet, the circuit member connecting resin sheet is placed on the surface of the back grind sheet on the pressure-sensitive adhesive layer side. Laminated. Here, an adhesive layer and the layer which consists of a resin sheet for circuit member connection are peeled after a back surface grinding process. Therefore, the pressure-sensitive adhesive layer preferably has a pressure-sensitive adhesive force that is lowered by energy ray irradiation, heating, or the like.

4). Manufacturing method of resin sheet for circuit member connection The resin sheet for circuit member connection which concerns on this embodiment can be manufactured similarly to the conventional resin sheet for circuit member connection. For example, when producing a laminate of a resin sheet for connecting a circuit member and a release sheet, a coating liquid containing a material constituting the resin sheet for connecting a circuit member and, if desired, further containing a solvent or a dispersion medium is prepared and peeled off. On one surface of the sheet, a coating film is formed by applying the coating liquid with a die coater, curtain coater, spray coater, slit coater, knife coater, etc. A resin sheet can be formed as a part of the laminate. The properties of the coating liquid are not particularly limited as long as it can be applied. The coating liquid may contain a component for forming a resin sheet as a solute or a dispersoid. The release sheet in the laminate may be peeled off as a process material, or the resin sheet may be protected until being attached to an adherend such as a semiconductor wafer or a ceramic green sheet laminate.

  In addition, as a method for producing a laminate in which two release sheets are laminated on both sides of a resin sheet for connecting circuit members, a coating liquid is formed on the release surface of the aforementioned release sheet by forming a coating film. Then, it is dried to form a laminate composed of a resin sheet and a release sheet, and the surface opposite to the release sheet side of the resin sheet of this laminate is applied to the release surface of another release sheet, A laminate comprising a release sheet / resin sheet / release sheet can be obtained. The release sheet in the laminate may be peeled off as a process material, or the resin sheet may be protected until being attached to an adherend such as a semiconductor wafer or a substrate.

  When manufacturing a dicing sheet integrated adhesive sheet (dicing / die bonding sheet) or a back grind sheet integrated adhesive sheet, a laminate of the above-described circuit member connecting resin sheet and release sheet is formed, and the lamination is performed. By attaching the surface of the body on the resin sheet side to the surface of the dicing sheet or back grind sheet on the pressure-sensitive adhesive layer side, a dicing sheet integrated adhesive sheet or a back grind sheet integrated adhesive sheet can be obtained.

5. Next, a method for using the resin sheet for connecting a circuit member according to the present embodiment will be described with reference to a case where it is used for flip chip mounting.

First, the circuit member connecting resin sheet according to the present embodiment is attached to the circuit surface of the semiconductor wafer on which the circuit and the solder bumps are formed. Specifically, a laminate of a resin sheet for connecting a circuit member and a release sheet is prepared, and the surface of the laminate on the side of the resin sheet for connecting a circuit member is attached to the circuit surface of the semiconductor wafer, and the release sheet is peeled off. The method of doing is mentioned. Thereby, the circuit surface of a semiconductor wafer will be in the state protected by the resin sheet for circuit member connection. Here, since the resin sheet for connecting a circuit member according to the present embodiment has a 90 ° C. melt viscosity of 1.0 × 10 ^{0 to} 5.0 × 10 ⁵ Pa · s before curing of the material constituting the circuit sheet, It is possible to satisfactorily follow the unevenness of the circuit surface and suppress the generation of voids at the interface between the resin sheet layer and the circuit surface. In this state, semiconductor wafer back surface grinding or other back surface processing may be performed.

  Next, the semiconductor wafer is cut into individual chips (dicing process). The method for cutting the wafer is not particularly limited, and it is performed by various conventionally known dicing methods. For example, a normal dicing sheet is affixed to the back side of the semiconductor wafer (the side opposite to the side where the circuit sheet connecting resin sheet is affixed), and is fixed to the ring frame via the dicing sheet. There is a method of cutting a semiconductor wafer using a dicing blade. Also, other dicing methods such as laser dicing may be employed. By such a dicing process, an individual semiconductor chip can be obtained in a state where the layer made of the resin sheet for connecting circuit members is fixed to the circuit surface of the semiconductor chip.

  After the dicing process, pick-up is performed to collect the separated semiconductor chips. If necessary, the dicing sheet may be expanded to increase the interval between the semiconductor chips and then pick up.

  Subsequently, the collected semiconductor chip is placed on a circuit board. The semiconductor chip is placed on the circuit board by using a flip chip bonder so that the electrodes on the semiconductor chip side and the electrodes on the circuit board face each other.

  Further, using a flip chip bonder, the semiconductor chip and the circuit board are heated and pressurized, and then cooled. Thereby, the semiconductor chip and the circuit board are bonded via the cured product of the resin sheet for connecting the circuit member, and the electrode of the semiconductor chip and the electrode of the chip mounting portion are connected via the solder bump formed on the semiconductor chip, Electrically joined. Although the conditions for solder bonding depend on the metal composition used, for example, in the case of Sn-Ag, it is preferable to heat at 200 to 300 ° C. for 1 to 30 seconds.

  When soldering is performed, the layer made of the resin sheet for connecting circuit members, which is interposed between the semiconductor chip and the circuit board, is cured. Curing conditions can be performed, for example, by heating at 100 to 200 ° C. for 1 to 120 minutes. Moreover, you may perform this hardening process by pressurization conditions.

In this way, it is possible to obtain a laminate in which the semiconductor chip and the circuit board are bonded with the cured product of the resin sheet for connecting circuit members. In such a laminate, the material constituting the resin sheet for connecting circuit members has a 90 ° C. melt viscosity of 1.0 × 10 ^{0 to} 5.0 × 10 ⁵ Pa · s and an average linear expansion coefficient of 45 ppm or less. Therefore, generation of voids is prevented, and generation of stress between the semiconductor chip or the circuit board and the cured product of the resin sheet for connecting circuit members is suppressed. Therefore, for example, even after being subjected to a long-term reliability test such as a temperature cycle test, the connection resistance at the connection portion hardly changes and has high reliability.

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

  For example, in the above embodiment, the circuit member connecting resin sheet has been described as an example of the connection between the semiconductor chip and the circuit board, but the circuit connected by the circuit member connecting resin sheet of the present embodiment. The member is not limited to this combination. For example, a combination of a semiconductor chip and a semiconductor chip, a combination of a semiconductor wafer and a semiconductor wafer, a combination of a semiconductor chip and a semiconductor wafer, a combination of a semiconductor chip and a flexible circuit board, and the like can be given.

  Hereinafter, the present invention will be described in more detail by showing examples and test examples, but the present invention is not limited to the following test examples.

[Examples 1-5, Comparative Example 1]
The composition containing the components shown in Table 1 was diluted with methyl ethyl ketone so that the solid content concentration was 40% by mass, and applied on a silicone-treated release film (SP-PET 381031 manufactured by Lintec Corporation). The obtained coating film was dried in an oven at 100 ° C. for 1 minute to form a coating film having a thickness of 45 μm, and a film-like resin composition formed on the release film was obtained. Then, the resin sheet for circuit member connection was obtained by transcribe | transferring a film-form resin composition on a polyolefin base material.

Here, the detail of the component shown in Table 1 is as follows.
Thermoplastic component , polyvinyl acetal resin, glass transition temperature: 86 ° C., weight average molecular weight: 130,000, polyvinyl butyral resin, glass transition temperature: 71 ° C., weight average molecular weight: 110,000 polyester resin, glass transition temperature: 83 ° C. Weight average molecular weight: 40,000 · Bisphenol A (BisA) type phenoxy resin, glass transition temperature: 84 ° C, weight average molecular weight: 60,000 · acrylic ester, glass transition temperature: -28 ° C, weight average molecular weight: 800,000
Thermosetting component / bisphenol A (BisA) type epoxy resin, epoxy equivalent: 180-190 g / eq
Inorganic filler / silica filler, average particle size: 100 nm

  Here, the glass transition temperature (Tg) of the thermoplastic component is measured with a temperature profile of −70 ° C. to 150 ° C. at a heating / cooling rate of 10 ° C./min using DSC (PYRIS Diamond DSC) manufactured by PerkinElmer. In practice, the inflection point was confirmed and the glass transition temperature was determined. Moreover, the weight average molecular weight (Mw) of the said structural component was the weight of standard polystyrene conversion measured on the following conditions (GPC measurement) using the gel permeation chromatograph apparatus (the Tosoh company make, product name "HLC-8020"). Average molecular weight.

<GPC measurement conditions>
-Column: "TSK guard column HXL-L", "TSK gel G2500HXL", "TSK gel G2000HXL", "TSK gel G1000HXL" (both manufactured by Tosoh Corporation)-Column temperature: 40 ° C
・ Developing solvent: Tetrahydrofuran ・ Flow rate: 1.0 mL / min
・ Detector: Differential refractometer ・ Standard sample: Polystyrene

[Test Example 1] Measurement of 90 ° C. melt viscosity A sample for measurement having a thickness of 15 mm was prepared by laminating the resin sheets for connecting circuit members prepared in Examples and Comparative Examples. About the obtained sample for a measurement, melt viscosity was measured on the conditions of load 50kgf, temperature range 50-120 degreeC, and temperature increase rate 10 degree-C / min using the flow tester (Shimadzu Corporation make, CFT-100D). Table 1 shows the values of melt viscosity at 90 ° C.

[Test Example 2] Measurement of average linear expansion coefficient The resin sheet for connecting circuit members prepared in Examples and Comparative Examples was cut into 15 x 4.5 mm to obtain measurement samples. The obtained sample was cured by treating at 160 ° C. for 1 hour. About the obtained hardened | cured material, a linear expansion coefficient was measured on the conditions of load 2g, temperature range 0-300 degreeC, and temperature increase rate 5 degree-C / min using a thermomechanical analyzer (the Bruker Ax company make, TMA4030SA). did. From the obtained results, the average linear expansion coefficient at 0 to 130 ° C. was calculated. The results are shown in Table 1.

[Test Example 3] Temperature cycle test The circuit member connecting resin sheet prepared in the examples and comparative examples was laminated on a diced 100 μm chip (TEG wafer manufactured by Waltz: CC80-0101JY Model I), and a TEG chip with a resin sheet Got. The obtained TEG chip with a resin sheet was flip-chip bonded to a substrate using an FC bonder (manufactured by Toray Engineering Co., Ltd., FC3000W) to manufacture a semiconductor device. The obtained semiconductor device is subjected to 1000 cycles in an environment where −55 ° C. for 10 minutes and 125 ° C. for 10 minutes is one cycle, and the connection resistance value between the semiconductor chip and the circuit board for the tested semiconductor device is a digital multimeter. The connection reliability was evaluated according to the following evaluation criteria. The results are shown in Table 1.
○: Change rate of connection resistance value is 20% or less ×: Change rate of connection resistance value exceeds 20%

  As can be seen from Table 1, the circuit member connecting resin sheets obtained in the examples had good results of the temperature cycle test and had high connection reliability.

  Since the circuit member connecting resin sheet according to the present invention has high connection reliability when the circuit members are connected to each other, the resin sheet can be suitably used for joining various circuit members.

Claims (10)

A resin sheet for connecting a circuit member, which is interposed between electrodes facing each other and used to electrically connect the electrodes facing each other,
The material constituting the resin sheet has a melt viscosity of 1.0 × 10 ^{0 to} 5.0 × 10 ⁵ Pa · s at 90 ° C. before curing, and an average linear expansion coefficient of the cured product at 0 to 130 ° C. Is a resin sheet for connecting circuit members, characterized by being 45 ppm or less.   2. The resin sheet for connecting a circuit member according to claim 1, wherein the material constituting the resin sheet contains one or more thermoplastic components selected from the group consisting of a polyvinyl acetal resin and a polyester resin. .   3. The resin sheet for connecting circuit members according to claim 2, wherein the material constituting the resin sheet further contains a phenoxy resin as the thermoplastic component.   The material which comprises the said resin sheet contains an inorganic filler, The resin sheet for a circuit member connection as described in any one of Claims 1-3 characterized by the above-mentioned.   The resin sheet for connecting circuit members according to claim 4, wherein the inorganic filler is a silica filler.   The resin sheet for connecting circuit members according to claim 4 or 5, wherein the inorganic filler has an average particle size of 10 to 200 nm.   The material which comprises the said resin sheet contains 35-64 mass% of said inorganic fillers, The resin sheet for a circuit member connection as described in any one of Claims 4-6 characterized by the above-mentioned.   The material which comprises the said resin sheet contains the component which has a flux function, The resin sheet for a circuit member connection as described in any one of Claims 1-7 characterized by the above-mentioned.   The resin sheet for connecting circuit members according to claim 8, comprising a component having a carboxyl group as the component having the flux function.   The resin sheet for connecting circuit members according to claim 9, wherein the component having a carboxyl group is 2-methylglutaric acid.