JP2007173381A - Sheet for circuit board and chip buried circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet for circuit board with which a circuit board where a circuit chip is buried for controlling respective pixels of display is efficiently manufactured with sufficient quality and high productivity, and to provide a chip buried circuit board. <P>SOLUTION: The sheet for circuit board for burying the circuit chip includes a non-curing layer formed of an energy line curing polymeric material, and a resin layer which is arranged on a surface of a side where the circuit chip of the non-curing layer is buried and whose glass transfer temperature is 0°C or above. In the chip buried circuit board, the circuit chip is buried in the non-curing layer formed of the energy line curing polymeric material having the resin layer on the surface, the chip is irradiated with an energy line, and it is cured. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a circuit board sheet and a chip-embedded circuit board using the same. More specifically, the present invention relates to a circuit board sheet for efficiently producing a circuit board in which a circuit chip is embedded to control each pixel for display or the like with high quality and high productivity. , And a chip embedded circuit board for a display or the like obtained by using the same.

Conventionally, in a flat display represented by a liquid crystal display, for example, an insulating film, a semiconductor film, etc. are sequentially laminated on a glass substrate by a CVD method (chemical vapor deposition method) or the like to produce a semiconductor integrated circuit. Through the process, a microelectronic device such as a thin film transistor (TFT) is formed in the vicinity of each pixel constituting the screen, thereby controlling on / off and light / dark of each pixel. That is, microelectronic devices such as TFTs are fabricated on the spot on a substrate used for a display. However, in such a technique, it is inevitable that the process is complicated in many steps and the cost is high, and when the display area is enlarged, a CVD apparatus for forming a film on a glass substrate is also large. There is a problem that the cost is drastically increased.
Therefore, for the purpose of cost reduction, a technique is disclosed in which a minute crystalline silicon integrated circuit chip is attached to a printing original plate like printing ink, and is transferred to a predetermined location on a display substrate by means of printing technology or the like. (For example, refer to Patent Document 1). In this case, a polymer film is formed on the display substrate in advance, and a fine crystalline silicon integrated circuit chip is transferred to the display substrate by means of printing technology or the like, and the chip is raised by a method such as thermoforming or heating press. Embedding in a molecular film is performed. However, such a method is not efficient because defects such as distortion and foaming of the polymer film are likely to occur and heating takes time.
JP 2003-248436 A

  Under such circumstances, the present invention is to efficiently produce a circuit board having a circuit chip embedded with high quality and high productivity in order to control each pixel for display or the like. The present invention has been made for the purpose of providing a circuit board sheet and a chip-embedded circuit board for a display obtained by using the circuit board sheet.

As a result of intensive studies to achieve the above object, the present inventors have used a circuit board sheet made of an energy beam curable polymer material for embedding a circuit chip, and the energy beam curable polymer material. When embedding a circuit chip in an uncured layer comprising, if air remains around the circuit chip or on the sheet surface, the flatness of the resulting chip-embedded circuit board is impaired, resulting in display defects, transparent electrodes, metal In the formation of wiring, it was found that problems such as disconnection and increased resistance occur.
Based on this knowledge, the present inventors have further studied and provided a resin layer having a glass transition temperature of a certain value or more on an uncured layer made of an energy ray curable polymer material. It has been found that embedding a circuit chip in the uncured layer can effectively prevent air from remaining around the circuit chip and on the sheet surface.
The present invention has been completed based on such findings.
That is, the present invention
(1) A circuit board sheet for embedding a circuit chip, which is an uncured layer made of an energy ray curable polymer material, and a glass transition temperature provided on the surface of the uncured layer on the side where the circuit chip is embedded. Having a resin layer of 0 ° C. or higher, a circuit board sheet,
(2) The circuit board sheet according to (1), wherein the glass transition temperature of the resin layer is 30 ° C. or higher,
(3) The circuit board sheet according to (1) or (2), wherein the resin layer has a thickness of 0.05 to 25 μm,
(4) The circuit board sheet according to any one of (1) to (3) above, wherein the breaking elongation of the resin layer is 500% or less in the measurement of a thickness of 50 μm, and (5) the above (1) In the circuit board sheet according to any one of the items (4) to (4), a circuit chip is embedded in an uncured layer made of an energy beam curable polymer material having a resin layer on the surface, and then cured by irradiating energy rays on the circuit chip. A chip embedded circuit board, characterized in that
Is to provide.

  According to the present invention, when a circuit chip is embedded by providing a resin layer having a glass transition temperature of 0 ° C. or higher on the surface on the side where the circuit chip is embedded in an uncured layer made of an energy beam curable polymer material, Since it is possible to prevent air from remaining around the circuit chip and on the surface of the sheet, a circuit board sheet capable of efficiently producing a chip-embedded circuit board with high quality and high productivity, and A chip-embedded circuit board obtained using the circuit board sheet can be provided.

The circuit board sheet of the present invention is a circuit board sheet for embedding a circuit chip, on an uncured layer made of an energy ray curable polymer material, and on the surface of the uncured layer on the side where the circuit chip is embedded. It has the resin layer whose provided glass transition temperature is 0 degreeC or more.
In this way, by providing a resin layer having a glass transition temperature of 0 ° C. or higher on the surface on the side where the circuit chip of the uncured layer made of the energy ray curable polymer material is embedded, when embedding the circuit chip, glass The substrate and the uncured layer can be prevented from coming into close contact with each other, and as a result, air can be effectively prevented from remaining around the embedded circuit chip and on the sheet surface.
When the glass transition temperature of the resin layer is less than 0 ° C., the effect of preventing air from remaining around the embedded circuit chip and the sheet surface is not sufficiently exhibited. A preferable glass transition temperature of the resin layer is 30 ° C. or higher. Although there is no restriction | limiting in particular about the upper limit, Usually, it is about 300 degreeC.
Further, the elongation at break of the resin layer is preferably 500% or less, more preferably 350% or less, and further preferably 150% or less in the measurement of a thickness of 50 μm from the viewpoint of embedding property of the circuit chip. The lower limit is not particularly limited, but is usually about 1%. If the elongation at break is 500% or less, the resin layer is easily broken when the circuit chip is embedded, so that the embedding property is good.
The tensile strength of the resin layer is preferably 20 to 500 MPa.
In addition, the measuring method of the said glass transition temperature, breaking elongation, and tensile strength is demonstrated later.
Further, the resin layer preferably has a transmittance of 80% or more at a wavelength of 400 to 800 nm. In addition, the thickness of the resin layer is preferably 25 μm or less, more preferably 0.05 to 25 μm, from the viewpoints of circuit chip embeddability and the effect of the present invention (preventing air remaining).

As a method for forming the resin layer on the surface of the uncured layer made of energy ray-curable polymer material on the side where the circuit chip is embedded, any method can be used as long as it can form a resin layer having the above properties. There is no. For example, any of a method of laminating a resin layer forming film on the uncured layer and a method of applying a resin layer forming coating solution to the uncured layer can be used.
The resin material constituting the resin layer is not particularly limited as long as it can form the resin layer having the above properties, and various resin materials can be used. Examples of such resin materials include polyester resins, acrylic resins, polyolefin resins, polyester urethane resins, epoxy acrylate ultraviolet curable resins, and urethane acrylate ultraviolet curable resins.
In order to form an uncured layer made of an energy beam curable polymer material, for example, a coating solution having an appropriate concentration containing the energy beam curable polymer material is applied onto a support by a known method such as knife coating. Directly apply and dry to form the uncured layer by the coating method, roll coating method, bar coating method, blade coating method, die coating method, gravure coating method, etc. The method can be used.
Also, on the release agent layer of the release sheet, the coating solution is applied by the above method and dried to form an uncured layer, which is transferred to a support, or peeled off from the coating solution. Using the sheet, an uncured sheet having a release sheet on both sides can be produced. In this case, the order of peeling can be set by varying the peeling force of the release sheets provided on both sides. Further, a plurality of uncured layers may be laminated to obtain a desired thickness.
The thickness of the uncured layer is usually about 50 to 1000 μm, preferably 80 to 500 μm, although it depends on the conditions of use.
The release sheet used in this case is not particularly limited, but a release film such as a silicone resin is applied to a polyolefin film such as a polyethylene film or a polypropylene film, or a polyester film such as polyethylene terephthalate. Etc. The thickness of this release sheet is usually about 20 to 150 μm.

The energy beam curable polymer material used in the present invention is a polymer material containing a component that crosslinks when irradiated with energy rays. For example, (1) an adhesive acrylic polymer and an energy beam curable oligomer and / or Or a polymer material containing a monomer and, if desired, a photopolymerization initiator, (2) a polymer material containing an adhesive acrylic polymer in which an energy ray-curable functional group is introduced in the side chain, and a photopolymerization initiator if desired And so on.
In addition, an energy ray refers to what has an energy quantum in electromagnetic waves or a charged particle beam, ie, an ultraviolet ray or an electron beam.
In the polymer material of (1), the adhesive acrylic polymer includes (meth) acrylic acid ester having an alkyl group of 1 to 20 carbon atoms in the ester moiety, and a functional group having active hydrogen as required. Preferred examples thereof include a monomer having a monomer and a copolymer with another monomer, that is, a (meth) acrylic acid ester copolymer. In addition, (meth) acrylic acid ester means methacrylic acid ester and / or acrylic acid ester.
Here, examples of the (meth) acrylic acid ester having 1 to 20 carbon atoms in the alkyl group of the ester portion include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and butyl (meth) acrylate. , Pentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, myristyl (meth) acrylate , Palmityl (meth) acrylate, stearyl (meth) acrylate, and the like. These may be used alone or in combination of two or more.

On the other hand, examples of the monomer having a functional group having active hydrogen which is used as desired include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2 -Hydroxyalkyl (meth) acrylate such as hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, monomethylaminoethyl (meth) acrylate, monoethylaminoethyl (meth) acrylate Monoalkylaminoalkyl (meth) acrylates such as monomethylaminopropyl (meth) acrylate and monoethylaminopropyl (meth) acrylate; ethylenic polymers such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid and citraconic acid Such as the sum of the carboxylic acid, and the like. These monomers may be used independently and may be used in combination of 2 or more type.
In the (meth) acrylic acid ester copolymer, (meth) acrylic acid ester is contained in an amount of 5 to 100% by mass, preferably 50 to 95% by mass, and the monomer having a functional group having active hydrogen is 0 to 95% by mass. %, Preferably 5 to 50% by mass.
Examples of other monomers used as desired include vinyl esters such as vinyl acetate and vinyl propionate; olefins such as ethylene, propylene and isobutylene; halogenated olefins such as vinyl chloride and vinylidene chloride; styrene Styrene monomers such as α-methylstyrene; diene monomers such as butadiene, isoprene and chloroprene; nitrile monomers such as acrylonitrile and methacrylonitrile; acrylamide, N-methylacrylamide, N, N- Examples include acrylamides such as dimethylacrylamide. These may be used alone or in combination of two or more. These monomers can be contained in an amount of 0 to 30% by mass in the (meth) acrylic acid ester copolymer.
In the polymer material, the (meth) acrylic acid ester copolymer used as the adhesive acrylic polymer is not particularly limited with respect to the copolymerization form, and may be any of random, block, and graft copolymers. May be. The molecular weight is preferably 300,000 or more in terms of weight average molecular weight.
In addition, the said weight average molecular weight is the value of standard polystyrene conversion measured by the gel permeation chromatography (GPC) method.
In the present invention, this (meth) acrylic acid ester copolymer may be used alone or in combination of two or more.

Examples of the energy ray curable oligomer include a radical curable oligomer that cures by radical polymerization and a cationic curable oligomer that cures by cationic polymerization. Examples of the radical curable oligomer include polyester acrylate, epoxy acrylate, urethane acrylate, polyether acrylate, polybutadiene acrylate, and silicone acrylate. Here, as the polyester acrylate oligomer, for example, by esterifying hydroxyl groups of a polyester oligomer having hydroxyl groups at both ends obtained by condensation of a polyvalent carboxylic acid and a polyhydric alcohol with (meth) acrylic acid, It can be obtained by esterifying the terminal hydroxyl group of an oligomer obtained by adding alkylene oxide to a polyvalent carboxylic acid with (meth) acrylic acid. The epoxy acrylate oligomer can be obtained, for example, by reacting (meth) acrylic acid with an oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolak type epoxy resin and esterifying it. A carboxyl-modified epoxy acrylate oligomer obtained by partially modifying this epoxy acrylate oligomer with a dibasic carboxylic acid anhydride can also be used. The urethane acrylate oligomer can be obtained, for example, by esterifying a polyurethane oligomer obtained by the reaction of polyether polyol or polyester polyol and polyisocyanate with (meth) acrylic acid, and the polyether acrylate oligomer is It can be obtained by esterifying the hydroxyl group of polyether polyol with (meth) acrylic acid.
Examples of the cationic curable oligomer include bisphenol A type epoxy resin, bisphenol F type epoxy resin, alicyclic epoxy resin, epoxidized polyolefin, resorcin type epoxy resin, novolac type epoxy resin, polyethylene glycol dilysidyl ether, polypropylene glycol dilyl. Examples thereof include epoxy resins such as sidyl ether and epoxidized soybean oil, vinyl ethers such as polyethylene glycol divinyl ether, polyester polyvinyl ether and polyurethane polyvinyl ether, and epoxidized polyolefins.
The weight average molecular weight of the curable oligomer is a value in terms of standard polystyrene measured by the GPC method, preferably 500 to 100,000, more preferably 1,000 to 70,000, still more preferably 3,000 to 40,000. It is selected in the range.
This curable oligomer may be used individually by 1 type, and may be used in combination of 2 or more type.

On the other hand, examples of the energy beam curable monomer include a radical curable monomer that cures by radical polymerization and a cationic curable monomer that cures by cationic polymerization. Examples of radical curable monomers include monofunctional acrylates such as cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and isobornyl (meth) acrylate. 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, hydroxypivalate neopentyl glycol di ( (Meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, bis [2- (meth) acryloyloxyethyl] -2-hydroxyethyl isocyanurate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) ) Acrylate, tris [2- (meth) acryloyloxyethyl] isocyanurate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. And meth) acrylic acid esters.
Examples of the cationic curable monomer include alkyl-substituted alkenes such as inten and coumarone, styrene derivatives such as styrene and α-methylstyrene, vinyl ethers such as ethyl vinyl ether, n-butyl vinyl ether, cyclohexyl vinyl ether, butanediol divinyl ether, and diethylene glycol divinyl ether. , Glycidyl ethers such as bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, ethylene glycol diglycidyl ether, 3-ethyl-3-hydroxyethyl oxetane, 1,4-bis [(3-ethyl-3-oxetanylmethoxy Oxetane such as methyl] benzene, 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate, bis (3,4- And alicyclic epoxies such as (epoxycyclohexyl) adipate and N-vinylcarbazole.
These curable monomers may be used alone or in combination of two or more.
The amount of these curable oligomers and curable monomers used is selected so that the polymer material after curing has the desired properties by application of energy rays, but usually the (meth) acrylic acid ester copolymer 3-300 mass parts can be mix | blended with respect to 100 mass parts of solid content.

Moreover, although an ultraviolet ray or an electron beam is usually irradiated as an energy ray, when irradiating an ultraviolet ray, a radical polymerization initiator or a cationic polymerization initiator can be used depending on the curable oligomer or monomer to be used. . Examples of the radical polymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2 , 2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2 -Morpholino-propan-1-one, 4- (2-hydroxyethoxy) phenyl-2 (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzopheno Dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2, Benzyl dimethyl ketal such as 4-diethylthioxanthone, 2,2-dimethoxy-1,2-diphenylethane-1-one, acetophenone dimethyl ketal, p-dimethylamine benzoate, oligo [2-hydroxy-2-methyl-1 -[4- (1-propenyl) phenyl] propanone] and the like. Typical examples of the cationic polymerization initiator include allyldiazonium salts, diallyliodonium salts, triallylsulfonium salts having anions such as BF ₄ ⁻ , PF ₆ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ and FeCl ₄ ^−. Can do. Furthermore, a sensitizer can also be added for the purpose of enhancing the activity of these photopolymerization initiators or expanding the wavelength region showing the activity. These may be used alone or in combination of two or more.
A compounding quantity is 0.1-10 mass parts normally with respect to 100 mass parts of solid content of the above-mentioned energy ray hardening-type polymeric material.

Next, in the polymer material of (2), as the adhesive acrylic polymer in which the energy ray curable functional group is introduced into the side chain, for example, the adhesive described in the polymer material of (1) described above is used. An active site such as —COOH, —NCO, epoxy group, —OH, —NH ₂ is introduced into the polymer chain of the conductive acrylic polymer, and this active site is reacted with a compound having an energy ray-curable functional group, The thing formed by introduce | transducing an energy-beam curable functional group into the side chain of this adhesive acrylic polymer can be mentioned.
To introduce the active sites in the adhesive acrylic polymer, a functional group in preparing the tacky acrylic polymer, -COOH, -NCO, epoxy groups, -OH, etc. -NH _2, A monomer or oligomer having a radically polymerizable unsaturated group may be present in the reaction system.
Specifically, when the -acrylic polymer described in the polymer material (1) described above is produced, when a -COOH group is introduced, (meth) acrylic acid or the like is substituted with -NCO group. When introducing, 2- (meth) acryloyloxyethyl isocyanate, etc., when introducing an epoxy group, glycidyl (meth) acrylate, etc., when introducing an —OH group, 2-hydroxyethyl. (meth) acrylate, 1,6-hexanediol mono (meth) acrylate, in the case of introducing -NH ₂ groups, or the like may be used N- methyl (meth) acrylamide.
The compound having an energy ray-curable functional group has a functional group that reacts with the active site. Examples of the functional group that reacts with the active site include —COOH, —NCO, an epoxy group, and —OH. The energy ray curable functional group is not particularly limited, and may be a radical polymerizable functional group or a cationic polymerizable functional group. Examples of the radical polymerizable functional group include a (meth) acryloyl group and a vinyl group. Examples of the compound having a radical polymerizable functional group include 2- (meth) acryloyloxyethyl isocyanate, glycidyl (meth) acrylate, pentaerythritol mono (meth) acrylate, dipentaerythritol mono (meth) acrylate, trimethylolpropane mono From (meth) acrylate and the like, it can be appropriately selected and used according to the type of active site.
Examples of the cationic polymerizable functional group include olefins having an electron-emitting substituent, and ring-opening cationic polymerizable functional groups such as cyclic ether, cyclic sulfide, cyclic imine, cyclic disulfide, lactone, cyclic formal, and cyclic imino ether. be able to.
As another method for introducing a cationic polymerizable functional group into the side chain of an adhesive acrylic polymer, both a radical polymerizable unsaturated group and a cationic polymerizable functional group can be used in the production of an adhesive acrylic copolymer. Examples thereof include a method in which a monomer or an oligomer containing it is present in the reaction system.
In this way, an adhesive acrylic polymer in which an energy ray curable functional group is introduced into the side chain of the adhesive acrylic polymer, that is, an energy ray curable (meth) acrylate copolymer is obtained. It is done.
The energy ray curable (meth) acrylic acid ester copolymer preferably has a weight average molecular weight of 100,000 or more, particularly preferably 300,000 or more. In addition, the said weight average molecular weight is the value of standard polystyrene conversion measured by GPC method.
Moreover, as a photoinitiator used as needed, the photoinitiator illustrated in description of the polymeric material of the above-mentioned (1) can be used.
In the energy beam curable polymer materials (1) and (2) described above, a crosslinking agent, a tackifier, an antioxidant, an ultraviolet absorber, light, and the like, as long as the effects of the present invention are not impaired. Stabilizers, softeners, fillers and the like can be added.
Examples of the crosslinking agent include polyisocyanate compounds, epoxy resins, melamine resins, urea resins, dialdehydes, methylol polymers, aziridine compounds, metal chelate compounds, metal alkoxides, metal salts, and the like. A compound is preferably used. This crosslinking agent can be blended in an amount of 0 to 30 parts by mass with respect to 100 parts by mass of the solid content of the (meth) acrylic acid ester copolymer.

Examples of polyisocyanate compounds include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, and isophorone diisocyanate. Nalto, cycloaliphatic polyisocyanates such as hydrogenated diphenylmethane diisocyanate, etc., and their biurets, isocyanurates, and low molecular weights such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, castor oil The adduct body etc. which are a reaction material with an active hydrogen containing compound can be mentioned. These crosslinking agents may be used individually by 1 type, and may be used in combination of 2 or more type.
The energy beam curable polymer material (1) and (2) described above has the energy beam curable polymer material (2) compared to the energy beam curable polymer material (1) in order to control the elastic modulus. A (meth) acrylic ester copolymer can be added. Similarly, the adhesive acrylic polymer of (1), the energy beam curable oligomer, or the energy beam curable monomer can be added to the energy beam curable polymer material of (2).

In the circuit board sheet of the present invention, a support may be provided on the side opposite to the side on which the circuit chip is embedded.
There is no restriction | limiting in particular about the said support body, From the transparent support body normally used as a support body for a display, arbitrary things can be selected suitably and can be used. Examples of such a support include a glass plate or a plate-like or film-like plastic support. As the glass plate, for example, a support made of soda lime glass, barium / strontium-containing glass, aluminosilicate glass, lead glass, borosilicate glass, barium borosilicate glass, quartz or the like can be used. On the other hand, as a plate-like or film-like plastic support, for example, a support made of polycarbonate resin, acrylic resin, polyethylene terephthalate resin, polyether sulfide resin, polysulfone resin, polycycloolefin resin, or the like can be used. The thickness of these supports is appropriately selected depending on the application, but is usually about 20 μm to 5 mm, preferably 50 μm to 2 mm.
The chip-embedded circuit board of the present invention is the uncured layer having the resin layer provided on the uncured layer made of the energy beam curable polymer material in the circuit board sheet obtained as described above. It is possible to fabricate the circuit chip by embedding it in the substrate and irradiating it with energy rays to cure it.
A specific method will be described. An embedded circuit chip is placed on a glass plate or the like, and a circuit board sheet is placed thereon such that the resin layer on the uncured layer is in contact with the circuit chip. The glass plate is filled with the chip under a load of about 2.0 MPa, preferably at 150 ° C. or less, more preferably at a temperature of 0-100 ° C., and the uncured layer is cured by irradiating energy rays. The chip-embedded circuit board of the present invention is obtained by peeling from the chip. When the circuit chip is embedded by heating, the energy ray irradiation may be performed while the uncured layer is heated, or may be performed after cooling to room temperature.

As energy rays, ultraviolet rays or electron beams are usually used. Ultraviolet rays are obtained with a high-pressure mercury lamp, a fusion H lamp, a xenon lamp or the like, while an electron beam is obtained with an electron beam accelerator or the like. Among these energy rays, ultraviolet rays are particularly preferable. The irradiation dose of the energy ray may be appropriately selected, for example when the ultraviolet rays, the light quantity is 100 to 500 mJ / cm ^2, the illuminance is preferably 10~500mW / cm ^2, in the case of electron rays, 10 About ~ 1000 krad is preferable.
Such a technique of the present invention fixes the circuit chip by embedding the circuit chip using an energy ray curable polymer material and then curing it, instead of heating the polymer film and embedding the circuit chip. Therefore, problems associated with the use of a polymer film hardly occur, the operation time can be shortened, and it is efficient. Also, the embedding property is excellent.
Furthermore, in the present invention, when embedding a circuit chip by providing a resin layer having a glass transition temperature of 0 ° C. or higher on the surface of the uncured layer made of an energy beam curable polymer material on the side where the circuit chip is embedded. Since air can be prevented from remaining around the circuit chip and on the sheet surface, the chip-embedded circuit board can be efficiently manufactured with high quality and high productivity.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
In addition, about the circuit board sheet | seat obtained in each example, each characteristic, ie, the physical property and embedding property of the resin material used for formation of a resin layer, were calculated | required by the method shown below.
(1) Glass transition temperature of resin layer forming material In accordance with JIS K 7121, an extrapolated glass transition start temperature is measured using an input compensated differential scanning calorimeter [manufactured by PerkinElmer, apparatus name “Pyrisl DSG”]. And the glass transition temperature (Tg).
(2) Elongation at break of resin layer forming material Tensile fracture strain or tensile fracture nominal strain measured according to JIS K 7161 and JIS K 7127 was defined as elongation at break. At this time, a test piece having a thickness of 50 μm was used, and the test speed was 50 mm / min.
(3) Tensile strength of resin layer forming material Measured in accordance with JIS K 7161 and JIS K 7127. At this time, a test piece having a thickness of 50 μm was used, and the test speed was 50 mm / min.
(4) Embeddability FIG. 1 is an explanatory diagram of an embeddability test. FIG. 1 (a) shows a state before embedding, and FIG. 1 (b) shows a state after embedding (after curing).
The heavy release type release sheet of the circuit board sheet was peeled off, and the uncured layer 4 was laminated on the glass substrate 2a of 5 cm × 5 cm (thickness 0.7 mm). A separate glass substrate 2b of 5 cm × 5 cm (thickness 0.7 mm) is prepared, on which a circuit chip (silicon chip) 3 (length 600 μm × width 300 μm × thickness 50 μm) becomes a 3 cm × 3 cm square. The resin layer 5 provided on the uncured layer 4 of the circuit board sheet on the glass substrate 2 a is pressed against the circuit chip 3, and the flat press machine 1 is used at 25 ° C. and 0.3 MPa. Was pressed at a pressure of 5 minutes. After returning to normal pressure, the uncured layer was cured by irradiating with ultraviolet light using a fusion H bulb as a light source under the conditions of an illuminance of 400 mW / cm ² and a light amount of 315 mJ / cm ² to obtain a cured layer 4 ′.
The case where the remaining of air was confirmed visually was evaluated as x, and the case where it could not be confirmed was evaluated as ◯. Further, the glass plate placed on the circuit chip side is peeled off, and the embedding state of the circuit chip is observed with a confocal microscope [manufactured by Lasertec, product name “HD100D”], and the protruding amount h shown in FIG. Evaluated.

Example 1
(1) Formation of uncured layer Acrylic ester copolymer solution (solid) obtained by reacting 80 parts by mass of butyl acrylate and 20 parts by mass of acrylic acid in a mixed solvent of ethyl acetate / methyl ethyl ketone (mass ratio 50:50) 2-methacryloyloxyethyl isocyanate is added to a concentration of 35% by mass to 30 equivalents relative to 100 equivalents of acrylic acid in the copolymer, and the reaction is allowed to proceed for 48 hours at 40 ° C. in a nitrogen atmosphere. An energy ray-curable acrylic acid acrylic copolymer having an energy ray-curable functional group in the chain and having a weight average molecular weight of 850,000 was obtained. 2,2-dimethoxy-1,2-diphenylethane-1-one [Ciba Specialty] which is a photopolymerization initiator with respect to 100 parts by mass of the solid content of the obtained energy ray-curable acrylic ester copolymer solution.・ Composition made by Chemicals, trade name “Irgacure 651”] 3.0 parts by mass, energy ray-curable polyfunctional monomer and oligomer [trade name “14-29B (NPI), made by Dainichi Seika Kogyo Co., Ltd.] ] 100 parts by mass and a cross-linking agent comprising a polyisocyanate compound [trade name “Olivein BHS-8515” manufactured by Toyo Ink Manufacturing Co., Ltd.] 1.2 parts by mass are dissolved, and finally methyl ethyl ketone is added to obtain a solid content concentration. Was adjusted to 40% by mass and stirred until a uniform solution was obtained to obtain a coating solution (a).
This coating solution was applied to the release-treated surface of a heavy release type release sheet [trade name “SP-PET3811” manufactured by Lintec Corporation] in which a silicone release agent layer was provided on one side of a polyethylene terephthalate film using a knife coater, Heat-dried at 90 ° C. for 90 seconds to form an uncured layer made of an energy ray-curable polymer material having a thickness of 50 μm. Similarly, an uncured layer having a thickness of 50 μm is formed on the release-treated surface of a light release type release sheet [trade name “SP-PET3801” manufactured by Lintec Corporation] in which a silicone release agent layer is provided on one side of a polyethylene terephthalate film. The sheet | seat which has is produced. The process of laminating the uncured layer on the light release type release sheet on the uncured layer on the heavy release type release sheet and peeling the light release type release sheet was repeated, and finally the heavy release type on one side. A release sheet and a sheet having an uncured layer made of an energy ray curable polymer material having a thickness of 200 μm and provided with a light release release sheet on the opposite surface were obtained.
(2) Production of Sheet for Circuit Board A polyethylene terephthalate (PET) film [manufactured by Toray, product number “C60”] having a thickness of 2 μm was prepared as a resin layer. The light release release sheet of the sheet having an uncured layer obtained in (1) above is peeled off, the PET film is laminated on the uncured layer using a rubber roll, and the PET layer is provided on one side of the uncured layer. A circuit board sheet was obtained. Table 1 shows the characteristics of the circuit board sheet.
Example 2
In Example 1, a circuit board sheet was produced in the same manner as in Example 1 except that a PET film having a thickness of 12 μm was used as the resin layer. Table 1 shows the characteristics of the circuit board sheet.
Examples 3-5
A circuit board sheet was prepared in the same manner as in Example 1 except that a polymethyl methacrylate (PMMA) film was used instead of the PET film as the resin layer.
The PMMA film was prepared by dissolving a PMMA powder (manufactured by Aldrich) so as to be 20% by mass in ethyl acetate, a release sheet in which a silicone release agent layer was provided on one side of a polyethylene terephthalate film [Lintec Corporation. Manufactured and trade name “SP-PET381031”] and dried at 90 ° C. for 1 minute. The thickness of the PMMA film is 1 μm (Example 3), 5 μm (Example 4), and 12 μm (Example 5).
Table 1 shows the characteristics of each circuit board sheet.
Examples 6 and 7
A circuit board sheet was produced in the same manner as in Example 1 except that a polyester urethane resin [trade name “Byron UR-1400” manufactured by Toyobo Co., Ltd.] film was used as the resin layer. In addition, the polyester urethane resin film was produced like Example 3-5. The thickness of this film is 1 μm (Example 6) and 5 μm (Example 7).
Table 1 shows the characteristics of each circuit board sheet.
Example 8
100 parts by mass of epoxy acrylate [manufactured by Daicel-Cytec, Inc., trade name “Ebecryl 600”] and 2-hydroxy-2-methyl-1-phenylpropan-1-one [manufactured by Ciba Specialty Chemicals, trade name “ Darocur 1173 "] A composition consisting of 3 parts by mass was applied to the above heavy release type release sheet, and the above light release type release sheet was laminated thereon. Thereafter, the resin film was cured by irradiating with ultraviolet rays under conditions of 100 mJ / cm ² and 200 mW / cm ² to prepare a resin film having a thickness of 1 μm.
A circuit board sheet was produced in the same manner as in Example 1 except that the resin film was used as the resin layer. Table 1 shows the characteristics of the circuit board sheet.
Examples 9, 10
In Example 8, a circuit board sheet was produced in the same manner as in Example 8, except that urethane acrylate [manufactured by Nippon Synthetic Chemical Co., Ltd., trade name “purple UV-3520TL”] was used instead of epoxy acrylate. The thickness of the resin film is 1 μm (Example 9) and 5 μm (Example 10).
Table 1 shows the characteristics of each circuit board sheet.
Examples 11 and 12
In Example 8, a circuit board sheet was produced in the same manner as in Example 8, except that urethane acrylate [manufactured by Nippon Synthetic Chemical Co., Ltd., trade name “purple light UV-7000B”] was used instead of epoxy acrylate. The thickness of the resin film is 1 μm (Example 11) and 5 μm (Example 12).
Table 1 shows the characteristics of each circuit board sheet.
Comparative Example 1
In Example 1, a circuit board sheet was produced in the same manner as in Example 1 except that the resin layer was not provided on the uncured layer. Table 1 shows the characteristics of the circuit board sheet.
Comparative Example 2
In Example 6, instead of the polyester urethane resin “Byron UR-1400”, a polyester urethane resin [manufactured by Toyobo Co., Ltd., trade name “Byron UR-3200”, Tg = −3 ° C.] was used. A circuit board sheet was prepared in the same manner as described above. Table 1 shows the characteristics of the circuit board sheet.

  As can be seen from Table 1, in the sheet for circuit board of the present invention (Examples 1 to 12), no air residue was observed, and the amount of protrusion was less than 10 μm except Examples 2, 5, and 10. It was.

  The circuit board sheet of the present invention provides a resin layer having a glass transition temperature of 0 ° C. or higher on the surface of the uncured layer on the side where the circuit chip is embedded, so that when the circuit chip is embedded, Since air can be prevented from remaining on the sheet surface, the chip-embedded circuit board can be efficiently manufactured with high quality and high productivity.

It is explanatory drawing of an embeddability test. It is explanatory drawing which shows the embedding state of a chip | tip.

Explanation of symbols

1 plane press machine 2a, 2b glass plate 3 circuit chip 4 uncured layer 4 'cured layer 5 resin layer

Claims (5)

  A circuit board sheet for embedding a circuit chip, having an uncured layer made of an energy ray curable polymer material and a glass transition temperature of 0 ° C. provided on the surface of the uncured layer on the side where the circuit chip is embedded A circuit board sheet comprising the above resin layer.   The circuit board sheet according to claim 1, wherein the resin layer has a glass transition temperature of 30 ° C. or higher.   The circuit board sheet according to claim 1 or 2, wherein the resin layer has a thickness of 0.05 to 25 µm.   The circuit board sheet according to any one of claims 1 to 3, wherein the breaking elongation of the resin layer is 500% or less in a measurement of a thickness of 50 µm.   The circuit board sheet according to any one of claims 1 to 4, wherein a circuit chip is embedded in an uncured layer made of an energy ray-curable polymer material having a resin layer on the surface, and is cured by irradiation with energy rays. A chip embedded circuit board characterized by being made.

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