JP2010118444A - Circuit board, and method of manufacturing circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-reliability circuit board used to control respective pixels for a display, especially, a flat panel display. <P>SOLUTION: There is provided the circuit board constituted so that a circuit chip is buried in a resin sheet for the circuit board made of an energy-beam curing type polymeric material, and the resin sheet is irradiated with an energy beam to be cured, wherein the silicon atom content of a sheet surface after curing on the side where the circuit chip is buried is ≤5 atm%. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a circuit board and a method for manufacturing the circuit board. More specifically, the present invention relates to a highly reliable circuit board and a circuit board manufacturing method that do not cause malfunction or circuit destruction.

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 steps, 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, a microelectronic device such as a TFT is fabricated on the glass substrate on the spot. 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 microcrystalline silicon integrated circuit chip is attached to a printing original plate like printing ink, and it is moved to a predetermined location on a glass substrate for display and fixed by means such as printing technology. A technique is disclosed (for example, see Patent Document 1). In this case, a polymer film is formed in advance on a glass substrate, and a microcrystalline silicon integrated circuit chip is transferred to the glass 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.

In addition, by using a resin sheet for a circuit board made of an energy beam curable polymer material instead of the polymer film, by controlling the storage elastic modulus at the time of circuit chip embedding and after embedding to a predetermined range, heating is performed. There has been disclosed a circuit board sheet that can be embedded without circuit chip (for example, see Patent Document 2).
JP 2003-248436 A JP 2006-323335 A

However, in the resin sheet for a circuit board in Patent Document 2, when a photoresist for forming a circuit wiring pattern is applied to the surface of a cured sheet in which circuit chips are embedded, pinholes or As a result, inconveniences such as repellency occur, and as a result, the finally formed wiring pattern is different from the design, and problems such as malfunction and circuit destruction due to excessive current occur. I found out through research.
In addition, in order to avoid the above problem, applying the photoresist solution a plurality of times causes a complicated process and affects the yield.
The present invention has been made under such circumstances, and an object of the present invention is to provide a highly reliable circuit board used for controlling each pixel for a display, particularly a flat display, and a method for manufacturing the circuit board. And

As a result of intensive research to achieve the above object, the present inventors used a resin sheet for a circuit board for producing a circuit board, obtained from an energy ray curable polymer material, and It has been found that by setting the silicon atom content on the sheet surface after curing to a specific value or less, it is possible to provide a high-quality circuit board and achieve its purpose. It came to complete.
That is, the present invention
[1] A circuit board in which a circuit chip is embedded in a resin sheet for a circuit board obtained from an energy beam curable polymer material and cured by irradiating it with energy rays, on the side where the circuit chip is embedded A circuit board having a silicon atom content of 5 atomic% or less on the surface of the sheet after curing;
[2] The circuit board according to the above item [1], wherein a wiring is formed on a surface on which the circuit chip is embedded,
[3] A circuit chip is disposed between a circuit board resin sheet obtained from an energy beam curable polymer material and a facing film bonded to a surface of the circuit board resin sheet on which the circuit chip is embedded. The circuit board resin sheet is embedded in a circuit chip, irradiated with energy rays to cure the circuit board resin sheet, and the facing film is peeled off. [1] or [2] [4] The method for producing a circuit board according to the above item [3], wherein the surface bonded to the circuit board resin sheet of the facing film has no silicone release agent layer,
Is to provide.

  According to the present invention, it is possible to provide a highly reliable circuit board in which a circuit chip is embedded in order to control each pixel for a display, particularly for a flat display.

First, the resin sheet for circuit boards used for the circuit board of this invention is demonstrated.
[Resin sheet for circuit board]
The resin sheet for a circuit board used in the present invention (hereinafter sometimes simply referred to as a resin sheet) is a resin sheet obtained from an energy ray curable polymer material for embedding a circuit chip.

(Energy ray curable polymer material)
In the present invention, the energy beam curable polymer material refers to a polymer material that has an energy quantum in an electromagnetic wave or a charged particle beam, that is, a polymer material that is cross-linked by irradiation with ultraviolet rays or electron beams.
Examples of the energy beam curable polymer material used in the present invention include a (meth) acrylate polymer, an energy beam curable polymerizable oligomer and / or a polymerizable monomer, and a photopolymerization initiator as required. Mention may be made of molecular materials.
In the polymer material, the (meth) acrylic acid ester-based polymer includes a (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 that is used as desired. Preferred examples include a monomer having a monomer and a polymer with another monomer, that is, a (meth) acrylic acid ester polymer. In the present invention, "(meth) acrylic acid ..." means both "acrylic acid ..." and "methacrylic acid ...".

Here, examples of the (meth) acrylic acid ester having 1 to 20 carbon atoms of the alkyl group in the ester portion include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth ) Butyl acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, Examples include 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, as a monomer having a functional group having active hydrogen, which is used as desired, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate Hydroxyl-containing monomers such as (meth) acrylic acid hydroxyalkyl esters such as (meth) acrylic acid 2-hydroxybutyl, (meth) acrylic acid 3-hydroxybutyl, (meth) acrylic acid 4-hydroxybutyl, ) Monomethylaminoethyl acrylate, monoethylaminoethyl (meth) acrylate, monomethylaminopropyl (meth) acrylate, monoalkylaminoalkyl (meth) acrylate such as monoethylaminopropyl (meth) acrylate; acrylic acid, Ethylene such as methacrylic acid, crotonic acid, maleic acid, itaconic acid, citraconic acid Such emissions unsaturated carboxylic acids can be used as appropriate.

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. In the (meth) acrylic acid ester-based polymer, these monomer units can be contained in an amount of 0 to 30% by mass.
In the polymer material, the (meth) acrylic acid ester polymer used as the acrylic polymer is not particularly limited as to its copolymerization form, and may be any of random, block, and graft copolymers. . The molecular weight is preferably 50,000 to 2,000,000 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-based polymer may be used alone or in combination of two or more.

Examples of the energy ray curable polymerizable oligomer include oligomers such as 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 reaction of polyether polyol or polyester polyol with polyisocyanate with (meth) acrylic acid. It can be obtained by esterifying the hydroxyl group of ether polyol with (meth) acrylic acid.
The weight average molecular weight of the polymerizable 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 polymerizable oligomer may be used individually by 1 type, and may be used in combination of 2 or more type.

  On the other hand, as the energy ray-curable polymerizable monomer, for example, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isobornyl (meth) acrylate, etc. Monofunctional acrylic acid esters, di (meth) acrylic acid 1,4-butanediol ester, di (meth) acrylic acid 1,6-hexanediol ester, di (meth) acrylic acid neopentyl glycol ester, di ( (Meth) acrylic acid polyethylene glycol ester, di (meth) acrylic acid neopentyl glycol adipate ester, di (meth) acrylic acid hydroxypivalic acid neopentyl glycol ester, di (meth) acrylic acid dicyclopentanyl, di (meth) acrylic Acid caprolactone-modified dicyclopentenyl, di (meth) acrylate Ethylene oxide modified phosphoric acid ester, di (meth) acrylic acid allylated cyclohexyl, di (meth) acrylic acid isocyanurate, di (meth) acrylic acid dimethylol tricyclodecane, tri (meth) acrylic acid trimethylolpropane ester, Tri (meth) acrylic acid dipentaerythritol ester, tri (meth) acrylic acid propionic acid modified dipentaerythritol ester, tri (meth) acrylic acid pentaerythritol ester, tri (meth) acrylic acid propylene oxide modified trimethylolpropane ester, isocyanuric Acid tris (acryloxyethyl), penta (meth) acrylic acid propionic acid modified dipentaerythritol ester, hexa (meth) acrylic acid dipentaerythritol ester, hepta (meth) acrylic acid trierythritol ester Le, hexa (meth) acrylic acid caprolactone-modified dipentaerythritol ester, polyfunctional acrylates such as caprolactone-modified tris (acryloyloxyethyl) isocyanurate. These polymerizable monomers may be used alone or in combination of two or more.

Moreover, although an ultraviolet-ray or an electron beam is normally irradiated as an energy ray, when irradiating an ultraviolet-ray, a photoinitiator can be used. Examples of the photopolymerization 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, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl)- Butanone-1, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2,2-dimethoxy-1,2-diphenylethane-1 -On, 2,2-diethoxy- 2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-hydroxy-1- [4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl ] -2-Methyl-propan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 4- (2-hydroxy Ethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4′-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethi Ruthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethyl ketal, acetophenone dimethyl ketal, p-dimethylamine benzoate, oligo [2-hydroxy-2-methyl-1- [4- (1-propenyl) phenyl] propanone] and the like. These may be used alone or in combination of two or more.
A compounding quantity is 0.01-10 mass parts normally with respect to 100 mass parts of solid content of the above-mentioned energy ray hardening-type polymeric material.

In the present invention, the energy ray-curable material can contain inorganic fine particles for the purpose of suppressing volume shrinkage at the time of curing by energy rays of the obtained resin sheet for circuit boards and improving heat resistance. .
Examples of the inorganic fine particles include oxides and carbides of various metal elements such as titanium, zirconium, tin, aluminum, and iron.
In the present invention, these inorganic fine particles may be used alone or in combination of two or more. The average particle diameter is preferably in the range of 3 to 50 nm, more preferably in the range of 5 to 30 nm, from the viewpoints of transparency, uniform dispersibility, volume shrinkage suppression effect, and the like. The average particle size in the present invention is based on a value calculated by the BET method.

In the energy ray curable polymer material, a crosslinking agent, a tackifier, an antioxidant, a UV absorber, a light stabilizer, a softening agent, and the like are added as desired as long as the effects of the present invention are not impaired. be able to.
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 above-mentioned (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.

(Production of resin sheet for circuit board)
Hereinafter, a method for producing a resin sheet for circuit boards used in the present invention will be described, but the present invention is not particularly limited thereby.
On the release agent layer of the release sheet, a coating solution adjusted to an appropriate concentration containing the energy ray curable polymer material is applied to a known method such as knife coating, roll coating, bar coating, blade coating. A resin sheet for a circuit board having a single-layer structure is formed by applying and drying to a predetermined thickness by a method, a die coating method, a gravure coating method, or the like. The release sheet may remain laminated for storage and protection of the circuit board resin sheet. Furthermore, on the other surface of the resin sheet for circuit boards, a release sheet having a different release force from that of the release sheet may be laminated, or it may be used as it is for producing a circuit board sheet to be described later without being laminated. Also good.
Here, although the thickness of the resin sheet for circuit boards is based also on the use conditions, it is about 50-1000 micrometers normally, Preferably it is 80-500 micrometers. In addition, when enlarging the thickness of the resin sheet for circuit boards, it can be set as the resin sheet for circuit boards by laminating | stacking the resin layer produced with the manufacturing method of the said resin sheet for circuit boards.

For the release sheet, there is no particular limitation on the release sheet on the side to be bonded to the support described later in the resin sheet for circuit board, polyolefin film such as polyethylene film or polypropylene film, polyester film such as polyethylene terephthalate, The thing etc. which apply | coated release agents, such as a silicone resin, and provided the release agent layer can be used.
On the other hand, as the release sheet on the side of embedding the circuit chip in the resin sheet, a polyolefin film such as a polyethylene film or a polypropylene film from the viewpoint of setting the silicon atom content of the resin sheet for a circuit board after curing to 5 atom% or less, Polyester film such as polyethylene terephthalate provided with non-silicone release agent layer such as alkyd resin release agent layer, polybutadiene release agent layer, polyethylene release agent layer, or silicone release agent with little silicone migration What provided the layer etc. can be used. Examples of the silicone-based release agent with a small amount of silicone migration include those that do not substantially contain a migration component such as a release control agent (silicone resin) or silicone oil.
The thickness of this release sheet is usually about 20 to 150 μm.

The resin sheet for circuit boards of the present invention may be formed on a support. (Hereinafter referred to as circuit board sheet)
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 substrate, a plate-like or film-like plastic support, and the like. As the glass substrate, 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.

Although there is no restriction | limiting in particular in the method of producing the sheet | seat for circuit boards of this invention, From the surface of productivity, the following 1st method and 2nd method are preferably employable, for example.
As a first method, as a resin sheet used for manufacturing the circuit board sheet, a resin sheet in which a light release type release sheet is laminated on one side and a heavy release type release sheet is laminated on the other side Using the sheet, first, the light release type release sheet is peeled off, and the peeled surface is bonded to the support to produce a circuit board sheet.
As a second method, a circuit board resin sheet is prepared on the release sheet by the above-described method, and then directly bonded to a support to prepare a circuit board sheet.

Next, the circuit board will be described.
[Circuit board]
The circuit board of the present invention is obtained by embedding a circuit chip in the resin sheet surface for a circuit board produced as described above, irradiating it with energy rays and curing it, and after curing on the side where the circuit chip is embedded. The silicon atom content on the sheet surface is 5 atomic% or less.
The circuit board of the present invention is a surface of the circuit board resin sheet obtained from the following method of the present invention, that is, the circuit board resin sheet obtained from the energy beam curable polymer material described above, and the circuit board resin sheet embedded surface. A circuit chip is placed between the facing film to be bonded to the circuit board, the circuit chip is embedded in the resin sheet for circuit board, and the resin sheet for circuit board is cured by irradiating the energy ray to peel off the facing film. Can be manufactured.
Specifically, a circuit chip to be embedded is placed on a facing film that is used by being bonded so as to face a surface on which a circuit chip of the circuit board resin is embedded, and the circuit board sheet is placed on the circuit board. Place the resin sheet surface (if the resin sheet for circuit board is attached to the release sheet, peel it off in advance) so that it comes into contact with the circuit chip, and apply it under a load of about 0.05 to 2.0 MPa. The chip is embedded at a temperature of preferably 0 to 150 ° C., more preferably 5 to 100 ° C., and the resin film for circuit board is cured by irradiating energy rays, and then the facing film on which the circuit chip is placed is peeled off By doing so, the circuit board of the present invention is obtained. When the circuit chip is embedded by heating, the energy ray irradiation may be performed while the circuit board resin sheet 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. For example, in the case of ultraviolet rays, the irradiation amount of this energy beam is preferably 100 to 5000 mJ / cm ² , and in the case of an electron beam, it is preferably about 10 to 1000 krad.

The facing film is not particularly limited as long as it has a certain degree of rigidity and can be peeled off from the cured resin sheet for circuit boards. For example, a polyolefin film such as polyethylene, polypropylene, cyclopolyolefin film, etc. Examples thereof include a film, a polyester film such as a polyethylene terephthalate film and a polyethylene naphthalate film, a resin sheet such as a polyimide film, and a glass plate. The thickness of the facing film is usually about 10 to 1000 μm, preferably 20 to 500 μm.
Further, when a release sheet provided with a silicone release agent layer is used as the release sheet on the side where the circuit chip is embedded, even if the silicon is transferred to the resin sheet surface for the circuit board and Si remains, After pasting a film that does not have a silicone release agent layer as a film and curing the resin sheet for circuit board, the facing film is peeled off to transfer the silicone to the facing film, and the cured resin for circuit board The Si content on the surface of the sheet on which the circuit chip is embedded can be reduced. If the Si content exceeds 5 atomic%, the resist applied to the circuit board at the time of wiring formation will cause repelling and pinholes, making it difficult to form wiring as designed. The Si content is preferably 4 atomic percent or less, and more preferably 3.5 atomic percent or less. As a method for setting the Si atom content to such a value, as described above, a release sheet on the side where the circuit chip is embedded is provided with a non-silicone release agent layer, or a silicone release agent layer with a small silicone migration amount. And a method of transferring using a facing film. As will be described later, the Si content is measured by measuring the cured resin surface of the circuit board on the side where the circuit is embedded using X-ray electron spectroscopy, and the amount of silicon (Si) and carbon (C). From the following equation.
{Si / (Si + C)} × 100 (atomic%)

FIG. 1 is a process explanatory view showing an example of a method of embedding a circuit chip using a circuit board sheet.
First, a circuit board resin sheet 2 obtained from an uncured energy beam curable polymer material formed on the support 1 is prepared, and the circuit chip 3 is placed on the facing film 4 [( a)]. Next, the circuit board resin sheet 2 is placed so as to be in contact with the circuit chip 3, and the chip is embedded under load, and cured by irradiating energy rays [(b)]. By this operation, the uncured circuit board resin sheet 2 becomes a cured layer, in which the circuit chip 3 is embedded and fixed, and the circuit board 5 of the present invention is easily peeled from the facing film 4. [(C)].
According to such a method, instead of heating the polymer film to embed the circuit chip, the circuit chip is embedded by using an energy ray curable polymer material and then cured to fix the circuit chip. Therefore, problems when using the polymer film are less likely to occur, and the operation time can be shortened, which is efficient.

(Wiring formation)
Thus, the circuit board in which the circuit chip is embedded, fixed by being cured is usually provided with wiring (circuit) on the surface thereof.
There is no particular limitation on the method of forming the wiring, and any method can be appropriately selected from the conventionally performed methods. For example, the wiring can be formed using a photolithography technique. As an example, a positive or negative photoresist solution is first applied on a circuit board in which a circuit chip is embedded and cured, thereby forming a photoresist layer. The thickness of the photoresist layer is usually 0.1 to 1 μm. Next, after exposing the photoresist layer through a predetermined mask pattern, the photoresist layer is developed using an alkaline developer such as an aqueous tetramethylammonium hydroxide solution to form a resist pattern.
Next, after a chromium or aluminum film having a predetermined thickness is formed on the resist pattern by, for example, sputtering using a chromium target or an aluminum target as a wiring material, the circuit board sheet is made of ethanol or the like. The resist is etched by dipping in an etching solution. When the circuit board of the present invention is used, pinholes and repellency do not occur in the photoresist layer, so that a desired wiring can be formed.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
In addition, the various characteristics in each example were calculated | required according to the method shown below.
(1) Surface Si content The Si content (atomic%) on the surface of the cured resin on the side where the circuit of the circuit board was embedded was measured using X-ray photoelectron spectroscopy (XPS) under the following conditions.
Measuring device: “Quantum-2000” manufactured by ULVAC-PHI
X-ray source: AlKα (1486.6 eV)
Extraction angle: 45 degrees Measurement elements: silicon (Si) and carbon (C)
The amount of Si was expressed in “atomic%” by multiplying the value of Si / (Si + C) by 100.
(2) Wiring formation Wiring formation was performed using a photolithography method. A positive resist solution [manufactured by Tokyo Ohka Kogyo Co., Ltd., trade name “OFPR-800”] is uniformly applied on the entire surface of the circuit board with a spin coater at a rotational speed of 3000 rpm for 40 seconds, and then at 100 ° C. It was dried for 5 minutes to form a resist film having a thickness of 0.5 μm. Next, it exposed using the photomask whose light transmission part is a wiring pattern with a width | variety of 200 micrometers. After the exposure, the circuit board is immersed in a developer [trade name “NMD-3” manufactured by Tokyo Ohka Kogyo Co., Ltd.] for 1 minute to remove the resist in the exposed area, washed with purified water, and dried at 100 ° C. for 5 minutes. And developed. Thereafter, an aluminum (Al) film having a thickness of 15 nm was formed on the circuit board by sputtering using an aluminum (Al) target. Sputtering was performed using a magnetron type sputtering apparatus “manufactured by Rock Giken Co., Ltd., apparatus name“ PVS-WS ”” under the conditions of power: 2500 W, pressure: 2.0 × 10 ⁻¹ Pa, time: 10 seconds. Finally, it was immersed in ethanol for 10 minutes, the resist was etched, and A1 wiring was formed between the chips. Using a digital microscope [manufactured by Keyence Co., Ltd., trade name “Digital Microscope VHX-200”], observation was performed at a magnification of 250 times, and the wiring width was measured at arbitrary 10 points to calculate an average value.
(3) Uneven coating of resist solution Uneven coating of the resist solution was visually observed.

Example 1
A photopolymerization initiator 2,2-dimethoxy-1,2-diphenylethane-1-one [Ciba Specialty Chemicals Co., Ltd.] with respect to 100 parts by mass of poly (methyl methacrylate) solid content having a weight average molecular weight of 100,000 Product name “Irgacure 651”] solid content of 9.0 parts by mass and dimethylol tricyclodecane diacrylate [manufactured by Kyoeisha Chemical Co., Ltd., product name “Light Acrylate DCP-A”] solids content of 200 parts by mass are added. Methyl ethyl ketone was added to adjust the solid content concentration to 38% by mass, and the mixture was stirred until a uniform solution was obtained to obtain an energy ray curable polymer material coating solution.
The prepared coating solution was applied by a knife coater to the release-treated surface of a heavy release type release sheet [trade name “PET50C” manufactured by Lintec Co., Ltd.] having a silicone release agent layer on one side of a polyethylene terephthalate film. Heat drying at 90 ° C. for 90 seconds to form a 50 μm thick resin layer made of an energy ray curable polymer material. Similarly, a light release type release sheet [manufactured by Lintec Corporation, trade name “PET38GS”] having a silicone release agent layer provided on one side of a polyethylene terephthalate film has a thickness made of an energy ray curable polymer material on the release treated surface. A resin layer having a thickness of 50 μm was formed.
Laminator is laminated so that these resin layers are in contact with each other, a resin sheet for a circuit board having a thickness of 100 μm is prepared, and the light release type release sheet is further peeled and bonded to a glass support for circuit board use. A sheet was used. Two circuit chips (thickness 50 μm, length 3 mm, width 3 mm) are placed on a 100 μm-thick cyclopolyolefin film [trade name “Zeonor ZF-16” manufactured by Optes, Inc.] as a facing film, and a circuit board sheet The heavy release type release sheet is peeled off and placed so as to be in contact with the circuit chip, embedded under a load of 0.2 MPa at 70 ° C., and an ultraviolet ray using a fusion H bulb as a light source (illuminance condition: 400 mW / cm ² and light quantity conditions: 300 mJ / cm ² ) to cure the resin sheet for circuit board and obtain a circuit board. Thereafter, the cyclopolyolefin film was peeled off, the Si content on the cured sheet surface of the circuit board was measured, and the wiring was formed, and the wiring width and uneven application of the resist solution were observed. The results are shown in Table 1.

Example 2
In Example 1, it carried out similarly to Example 1 except having used the 38-micrometer-thick polyethylene terephthalate film [Mitsubishi Chemical Polyester Film Co., Ltd. make, brand name "T-700"] as a facing film. The results are shown in Table 1.
Example 3
In Example 1, it carried out similarly to Example 1 except having used the polyethylene terephthalate film [Mitsubishi Chemical Polyester Film Co., Ltd. make, brand name "T-100"] as a facing film. The results are shown in Table 1.
Example 4
In Example 1, a non-silicone release sheet in which a low-density polyethylene release agent layer was provided on a polyethylene terephthalate film instead of a heavy release release sheet [trade name “PET50C” manufactured by Lintec Corporation] [Lintec Corporation This was carried out in the same manner as in Example 1, except that a product name “PET38NA” having a thickness of 60 μm was used. The results are shown in Table 1.

Comparative Example 1
In Example 1, the facing film was the same as Example 1 except that a heavy release type release sheet [trade name “PET382020” manufactured by Lintec Corporation] in which a silicone release agent layer was provided on one side of a polyethylene terephthalate film was used. Implemented. The results are shown in Table 1.
Comparative Example 2
In Example 1, the facing film was the same as Example 1 except that a heavy release type release sheet [trade name “PET3801” manufactured by Lintec Corporation] in which a silicone release agent layer was provided on one side of a polyethylene terephthalate film was used. Carried out. The results are shown in Table 1.

From the results shown in Table 1, when a sheet without a silicone release agent layer is used as the facing film, the surface Si content after curing of the resin sheet for circuit boards is 5 atomic% or less, and the resist solution is applied. It was found that a wiring pattern having a designed width was obtained without any unevenness (Examples 1 to 3). On the other hand, in Comparative Examples 1 and 2 in which the Si content exceeds 5 atomic%, uneven application of the resist solution occurs, and the wiring width becomes much larger than the design value, so that usable wiring is formed. It was impossible. In order to form the wiring, a process such as re-application of a resist solution is required, and according to the present invention, it is expected that the process will be simplified in manufacturing the circuit board.
In addition, as in Example 4, a release agent layer other than the silicone release agent layer is provided on the release sheet on the side of the circuit board resin sheet on which the circuit chip is embedded (the side on which the facing film is bonded). When the release sheet was used, Si was not detected, and a wiring pattern having a designed width was obtained.

  The circuit board of the present invention can provide a circuit board in which the Si content of the sheet surface is 5 atomic% or less and the circuit chip is embedded to control each pixel for display, particularly for flat display. .

It is process explanatory drawing which shows one example of the method of manufacturing the circuit board of this invention using the resin sheet for circuit boards.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Support body 2 Resin sheet | seat for circuit boards 3 Circuit chip 4 Face-to-face film 5 Circuit board

Claims (4)

  A circuit board embedded with a circuit chip in a resin sheet for a circuit board obtained from an energy ray curable polymer material, and cured by irradiating it with energy rays, after curing on the side where the circuit chip is embedded A circuit board having a silicon atom content of 5 at% or less on a sheet surface.   The circuit board according to claim 1, wherein wiring is formed on a surface on the side where the circuit chip is embedded.   A circuit chip is disposed between a resin sheet for a circuit board obtained from an energy ray curable polymer material and a facing film bonded to a surface on which the circuit chip of the resin sheet for a circuit board is embedded, The circuit board manufacturing method according to claim 1 or 2, wherein the circuit board resin sheet is embedded in the circuit board resin sheet, irradiated with energy rays to cure the circuit board resin sheet, and the facing film is peeled off.   The manufacturing method of the circuit board of Claim 3 in which the surface bonded to the resin sheet for circuit boards of a facing film does not have a silicone type release agent layer.

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