JP2004059716A - High-dielectric-constant composite material composition, dielectric transfer sheet, multilayer circuit board having built-in passive element and method for producing the multilayer circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a high-dielectric-constant composite material composition for obtaining a capacitor element having high volume precision and reduced dispersion, a dielectric transfer sheet, a multilayer circuit board having a built-in passive element and to provide a method for producing the multilayer circuit board. <P>SOLUTION: The multilayer circuit board 100 having the built-in capacitor element is obtained by forming a dielectric pattern 51p by a pattern transfer using a dielectric transfer sheet on a lower electrode 41c for a capacitor of a circuit board 20 equipped with first wiring patterns 21a, first wiring patterns 21b, insulating layers 31, second wiring patterns 41a, second wiring patterns 41b and the lower electrode 41c for the capacitor on both sides of an insulating substrate 11, and forming an upper electrode 61a for the capacitor on the dielectric pattern 51p. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a high dielectric constant composite material composition, a dielectric transfer sheet, a multilayer circuit board and a method for producing the same, and more specifically, to prepare a dielectric transfer sheet composed of a high dielectric constant composite material composition, The present invention relates to a multilayer circuit board having a capacitor element built therein by transferring a pattern on a circuit board to form a dielectric pattern and a method of manufacturing the same.
[0002]
[Prior art]
As the miniaturization, high density, and high performance of electronic devices are progressing, the demands for miniaturization, high density, and high speed of the multilayer circuit boards used therein are also increasing. There is a need for multilayer circuit boards.
The multilayer circuit board is formed by laminating a circuit board (inner board) and a prepreg sheet to form a wiring pattern and a via hole to form a multilayer circuit board. It is shifting to a build-up type multilayer circuit board in which circuit patterns are stacked alternately.
[0003]
In recent years, as the performance of electronic devices has become higher, the signal transmission speed has been increased. However, this has caused a problem that electrical noise increases. In order to solve this problem, measures such as providing a decoupling capacitor on a circuit board have been taken.
Further, in order to increase the density and performance of electronic devices, multilayer circuit boards incorporating passive elements such as capacitors, inductors, and resistors, which are circuit components, are being developed.
[0004]
FIG. 6 shows an example of a conventional multilayer circuit board having a built-in capacitor element.
A method of manufacturing a multilayer circuit board with a built-in capacitor element is as follows. A circuit board (inner layer board) in which a first wiring pattern 21a and a first wiring pattern 21b are formed on both surfaces of an insulating base material 11 is provided with an insulating layer 31 interposed therebetween. A method of manufacturing the multilayer circuit board 20 on which the electrode 41c, the second wiring pattern 41a, and the second wiring pattern 41b are formed, and coating the lower electrode 41c for the capacitor and the insulating layer 31 with a resin solution mixed with a dielectric material, or A dielectric layer 52 is formed by a method such as laminating a B-stage dielectric sheet, the surface is polished, a capacitor upper electrode 62 is formed, a capacitor element is formed, and a multilayer circuit board with a built-in capacitor element is produced. It was that.
Here, the B-stage state means a semi-cured state in which adhesion and curing with another layer can be performed by heating and pressing.
[0005]
Since the capacitance of the capacitor element is proportional to the area and inversely proportional to the distance between the electrodes, in order to obtain a capacitor element having a small area and a high capacitance, it is necessary to use a thin and uniform dielectric layer having a high dielectric constant. To form.
In the method of coating the resin solution mixed with the dielectric material, or the method of laminating the B-stage dielectric sheet, the film has uniformity of the film thickness, or has a high dielectric constant and also has the adhesiveness to the lower electrode and the insulating base material. There is a problem that it is difficult to obtain a dielectric layer.
In addition, when a dielectric layer is provided over the entire surface, providing a wiring pattern on the dielectric layer has a high dielectric constant, so that there is a problem that the degree of freedom in designing the wiring pattern is reduced due to signal deceleration and electrical loss. .
[0006]
[Problems to be solved by the invention]
The present invention has been conceived in view of the above problems, and has a high capacitance accuracy, and a high dielectric constant composite material composition and a dielectric transfer sheet for obtaining a capacitor element with less variation, a multilayer circuit board with a built-in passive element, and It is an object of the present invention to provide a manufacturing method thereof.
[0007]
[Means for Solving the Problems]
To achieve the above object, the present invention first provides a high dielectric constant composite material composition comprising at least a polyfunctional epoxy resin, a thermoplastic resin, and a dielectric filler according to claim 1; A high dielectric constant composite material composition characterized in that the softening point of the resin is 150 ° C. or lower.
[0008]
According to a second aspect of the present invention, there is provided the high dielectric constant composite material composition according to the first aspect, wherein the polyfunctional epoxy resin has an epoxy equivalent of 150 to 300 and a molecular weight of 200 to 1000. .
[0009]
According to a third aspect of the present invention, the thermoplastic resin is blended in an amount of 10 to 50% by weight based on a total solid content of the polyfunctional epoxy resin and the thermoplastic resin. And a high dielectric constant composite material composition described in (1).
[0010]
According to a fourth aspect of the present invention, the dielectric filler is blended in an amount of 30 to 90% by weight based on a total solid content of the polyfunctional epoxy resin, the thermoplastic resin, and the dielectric filler. A high dielectric constant composite material composition according to any one of claims 1 to 3.
[0011]
In a fifth aspect, a dielectric solution is prepared using the high dielectric constant composite material composition according to any one of the first to fourth aspects, and a dielectric solution having a thickness of 5 to 50 μm is formed on the transfer film. A dielectric transfer sheet having a body layer formed thereon.
[0012]
In a sixth aspect, a dielectric pattern is formed on a circuit board by a thermal transfer method using the dielectric transfer sheet according to the fifth aspect, and a capacitor element using the dielectric pattern as a dielectric is formed. And a multilayer circuit board with a built-in passive element.
[0013]
Still further, according to a seventh aspect, there is provided a method of manufacturing a multilayer circuit board according to the sixth aspect, comprising at least the following steps.
(A) A step of manufacturing a circuit board on which a wiring pattern is formed on both surfaces of an insulating base material 11 and a lower electrode for a capacitor is formed.
(B) A dielectric solution is prepared using the high dielectric constant composite material composition according to any one of claims 1 to 4, and the dielectric solution is applied on a support film, heated and dried. Forming a dielectric layer having a predetermined thickness to produce a dielectric transfer sheet;
(C) a step of transferring a pattern on the capacitor lower electrode of the laminated circuit board using the dielectric transfer sheet, heating and curing to form a dielectric pattern having a predetermined thickness.
(D) forming a capacitor element by forming an upper electrode for the capacitor on the dielectric pattern, and fabricating a multilayer circuit board with a built-in passive element;
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
The high dielectric constant composite material composition of the present invention according to claim 1 comprises a polyfunctional epoxy resin, a thermoplastic resin, and a dielectric filler, and the softening point of the thermoplastic resin is 150 ° C. or less. Features.
By setting the melting temperature of the thermoplastic resin to 150 ° C. or lower, the pattern transfer temperature of the dielectric transfer sheet created using the high dielectric constant composite material composition can be set to 150 ° C. or lower, and the dielectric when the pattern is transferred is reduced. It is possible to improve the pattern cut of the layer. In addition, the fluidity of the coating film when the dielectric solution is applied on the transfer film can be given, and a smooth dielectric layer can be formed on the transfer film.
[0015]
Examples of the polyfunctional epoxy resin constituting the high dielectric constant composite material composition include phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin Hydrogenated compounds of epoxy compounds containing an aromatic ring such as biphenyl epoxy resin, biphenyl novolak epoxy resin, trishydroxyphenylmethane epoxy resin, tetraphenylethane epoxy resin, dicyclopentadiene phenol epoxy resin, and fats Examples thereof include cyclic epoxy resins, various derivatives of cyclohexene oxide, halogen-containing epoxy resins such as tetrabromobisphenol A type epoxy resin, and the like, and these can be used alone or in combination.
[0016]
As the thermoplastic resin constituting the high dielectric constant composite material composition, polyamide resin, polyimide resin, polyether ether ketone, polyether sulfone, polyphenylene ether resin, phenoxy resin, polysulfone, polyphenylene sulfide, polyolefin resin and the like and rubber Known components such as components can be used. Examples of the rubber component include polybutadiene rubber and various modified polybutadiene rubbers such as urethane-modified and epoxy-modified.
[0017]
As the dielectric filler constituting the high dielectric constant composite material composition, known dielectric fillers can be used, but those having a relative dielectric constant of 50 or more are preferable. For example, titanium dioxide-based ceramics, barium titanate-based ceramics, calcium titanate-based ceramics, strontium titanate-based ceramics, lead zirconate-based ceramics and the like can be used. These may be used alone or in combination.
However, the present invention is not particularly limited to these.
The average particle diameter of the dielectric filler is preferably 0.1 to 30 μm. The reason for this is that if the thickness exceeds 30 μm, the applicability of the dielectric layer becomes poor when a dielectric transfer sheet is produced, and the dielectric layer having a thickness of 30 μm or less cannot be formed. It becomes difficult to obtain an element.
If the thickness is less than 0.1 μm, the dispersibility of the dielectric filler in the dielectric solution will be poor.
[0018]
The high dielectric constant composite material composition of the present invention according to claim 2 is characterized in that the polyfunctional epoxy resin has an epoxy equivalent of 150 to 300 and a molecular weight of 200 to 1000.
The reason for this is that when the epoxy equivalent of the polyfunctional epoxy resin is 150 or less, the heat resistance of the dielectric layer decreases, and when it is 300 or more, the dielectric layer becomes brittle, and cracks and cracks are formed in the dielectric layer coating. This is because it easily occurs.
If the molecular weight of the polyfunctional epoxy resin is 200 or less, the heat resistance of the dielectric layer decreases, and if the molecular weight is 1000 or more, the pattern cutting becomes poor due to the decrease in fluidity during pattern transfer.
[0019]
In the high dielectric constant composite material composition of the present invention according to claim 3, the thermoplastic resin is blended in an amount of 10 to 50% by weight based on the total solid content of the polyfunctional epoxy resin and the thermoplastic resin. It is characterized by.
The reason for this is that if the blending ratio of the thermoplastic resin is 10% by weight or less based on the total solid content of the polyfunctional epoxy resin and the thermoplastic resin, the dielectric layer coating becomes brittle, and cracks and cracks occur in the dielectric layer. Easier to do. On the other hand, if it is 50% by weight or more, the adhesiveness to the base material when the pattern of the dielectric layer is transferred becomes poor.
[0020]
The high dielectric constant composite material composition of the present invention according to claim 4, wherein the dielectric filler is 30 to 90% by weight based on the total solid content of the polyfunctional epoxy resin, the thermoplastic resin, and the dielectric filler. It is characterized by being blended.
The reason is that if the compounding ratio of the dielectric filler is 30% by weight or less, sufficient high dielectric properties cannot be obtained, and if it is 90% by weight or more, high dielectric properties cannot be obtained. This is because the properties become brittle and sufficient film properties including adhesiveness to the base material cannot be obtained.
[0021]
The dielectric transfer sheet 70 of the present invention according to claim 5 is a method in which a dielectric solution is prepared using the high dielectric constant composite material composition and a solvent, and the dielectric solution is gravure-printed or rolled on the support film 12. It is formed by coating with a coater or the like, forming a dielectric coating film, heating and drying to form a dielectric layer 51 having a thickness of 5 to 50 μm (see FIG. 4).
If the thickness of the dielectric layer after drying is 5 μm or less, it is difficult to make the thickness uniform, and if it is 50 μm or more, the temperature inside the dielectric layer is unlikely to be uniform, resulting in poor pattern cutting during pattern transfer.
[0022]
As the solvent, a solvent in which both the polyfunctional epoxy resin and the thermoplastic resin are dissolved and which does not remain in the cured resin must be used. When a phenoxy resin is used as the thermoplastic resin, toluene, cyclohexanone, dimethylformamide, methyl ethyl ketone, xylene, dioxane, tetrahydrofuran, acetone, butanol and the like can be used.
Further, in the dielectric solution, if necessary, additives such as a thermal polymerization inhibitor, a plasticizer, a leveling agent, an antifoaming agent, an ultraviolet absorber, a flame retardant, a coloring pigment, and the like are added. be able to.
[0023]
As the support film 12, a known film such as polyethylene terephthalate (PET) can be used. In particular, when the heating temperature is high, a film having high heat resistance such as polyimide or polytetrafluoroethylene (PTFE) is preferable. is there.
Further, a release layer may be provided on the support film 12 in order to improve the pattern transferability of the dielectric layer. Silicone treatment or the like can be used as the release layer.
[0024]
The multilayer circuit board 100 with a built-in passive element of the present invention according to claim 6 is configured such that the second wiring is formed on a core substrate (inner layer substrate) in which the first wiring patterns 21a and the first wiring patterns 21b are formed on both surfaces of the insulating base material 11 in advance. The circuit board 20 is prepared by forming the pattern 41a, the second wiring pattern 41b, and the lower electrode 41c for the capacitor, and is pressed and heated by the pressing die 80 using the dielectric transfer sheet 70 to obtain a dielectric material. The body layer 51 is pattern-transferred to form a dielectric pattern 51p on the capacitor lower electrode 41c on the circuit board 20 (see FIGS. 5A and 5B). The capacitor 61 is formed by forming the electrode 61a (see FIG. 1).
Here, the case where the capacitor element is formed on the uppermost layer of the four-layer circuit board has been described, but the capacitor element can be formed on any wiring pattern layer of the circuit board, and the number of wiring pattern layers of the circuit board is particularly limited. Not something.
As for the built-in passive element, not only a capacitor element but also an inductor element and a resistance element can be provided as necessary.
[0025]
Hereinafter, a method of manufacturing a multilayer circuit board with a built-in passive element according to the present invention will be described.
2 (a) to 2 (e) and 3 (f) to 3 (i) are schematic partial cross-sectional views showing one embodiment of a method for manufacturing a multilayer circuit board according to claim 7 in the order of steps.
First, the core substrate 10 in which the first wiring patterns 21a and the first wiring patterns 21b are formed on both surfaces of the insulating base material 11 is manufactured (see FIG. 2A).
Next, an insulating layer 31 is formed on both surfaces of the core substrate 10 (see FIG. 2B), and a via hole 32 is formed at a predetermined position of the insulating layer 31 by laser processing or a photoetching process (FIG. 2). (C)).
[0026]
Next, a thin-film conductor layer (not particularly shown) is formed on the insulating layer 31 and in the via hole 32 by electroless copper plating or the like, electrolytic copper plating is performed using the thin-film conductor layer as a cathode, and a predetermined thickness is formed. The conductor layer 41 and the filled via 42 are formed (see FIG. 2D).
Next, the conductor layer 41 is patterned to form the second wiring pattern 41a, the second wiring pattern 41b, and the capacitor lower electrode 41c, thereby manufacturing the circuit board 20 (see FIG. 2E).
[0027]
Next, the dielectric transfer sheet 70 and the pressing die 80 are set on the circuit board 20 on which the capacitor lower electrode 41c is formed (see FIG. 5A), and the pressing die 80 and the capacitor lower electrode 41c are set. Are aligned and pressurized for a predetermined time by a press die 80 heated to a predetermined temperature to form a dielectric pattern 51p on the capacitor lower electrode 41c, thereby producing the circuit board 30 on which the dielectric pattern 51p is formed. (See FIGS. 5B and 3F).
Here, the pressing surface of the press die 80 is formed to have the same size as the capacitor lower electrode 41c or smaller than the capacitor lower electrode 41c.
[0028]
The heating temperature of the pressing die 80 is preferably from 80 to 150 ° C. If the temperature is lower than 80 ° C., the dielectric layer becomes poor in fluidity, so that the dielectric pattern 51p is not transferred with good shape onto the capacitor lower electrode 41c of the circuit board 20. If the temperature is higher than 150 ° C., the fluidity is too high, so that the thickness of the transferred dielectric pattern 51p cannot be made constant. Alternatively, heat is transmitted to the transfer peripheral portion, and burrs are generated in the transfer pattern 51p.
[0029]
Next, a resin film is formed by a method such as laminating a prepreg film or the like on the surface of the circuit board 30 on which the dielectric pattern 51p is formed, heated and cured at a predetermined temperature, and then flush with the surface of the dielectric pattern 51p. The insulating layer 33 having a predetermined thickness is formed by mechanical polishing until the thickness becomes (see FIG. 3G).
Next, a thin-film conductor layer is formed on the insulating layer 33 and the dielectric pattern 51p by electroless plating or the like (not shown in particular), and electrolytic copper plating is performed using the thin-film conductor layer as a cathode. A conductor layer 61 having a predetermined thickness is formed on the body pattern 51p (see FIG. 3H).
[0030]
Next, a photosensitive layer is formed by a method such as laminating a dry film on the conductor layer 61, and a series of patterning processes such as pattern exposure and development are performed to form a resist pattern. The layer 61 is etched, the capacitor upper electrode 61a is formed on the dielectric pattern 51p to form the capacitor element 50, and the passive element built-in multilayer circuit board 100 on which the capacitor element 50 is formed is obtained (FIG. 3 (i)). reference).
[0031]
The multilayer board with a built-in passive element manufactured using the dielectric transfer sheet made of the high dielectric constant composite material composition of the present invention can incorporate a capacitor element having a high dielectric constant, excellent capacitance accuracy, and little variation. This makes it possible to obtain a high-density, high-reliability multilayer circuit board.
[0032]
【Example】
Hereinafter, the present invention will be described in detail with reference to examples.
First, a first wiring layer 21a and a first wiring layer 21b are formed by patterning using a copper-clad laminate in which 18 μm copper foil is bonded to both surfaces of an insulating base material 11 in which non-woven glass is impregnated with an epoxy resin. The manufactured core substrate 10 was manufactured. Further, a B-stage (semi-curable) epoxy-based thermosetting insulating resin film is attached to both surfaces of the core substrate 10 to form an insulating layer 31 having a thickness of 40 μm, and a predetermined position of the insulating layer 31 is laser-processed. Via holes 32 were formed (see FIGS. 2A to 2C).
[0033]
Next, a thin-film conductor layer is formed on the insulating layer 31 and in the via hole 32 by electroless copper plating or the like, electrolytic copper plating is performed using the thin-film conductor layer as a cathode, and a 10 μm-thick conductor layer 41 and a filled via 42 are formed. And the conductor layer 41 is patterned to produce a four-layer circuit board 20 in which the second wiring layer 41a, the second wiring layer 41b, and the capacitor lower electrode 41c are formed (FIGS. 2D to 2D). e)).
[0034]
Next, 99.8 parts by weight of an epoxy resin having an epoxy equivalent of 190 g / eq (Epicoat 828: manufactured by Yuka Shell Epoxy) as a polyfunctional epoxy resin, and a phenoxy resin (Fenote YP-50: Toto Kasei Co., Ltd.) as a thermoplastic resin. 100 parts by weight), 800 parts by weight of barium titanate (BT-05: manufactured by Sakai Chemical Industry Co., Ltd.) as a dielectric filler, and 0.2 parts by weight of a curing catalyst (2-ethyl-4-methylimidazole). Was dispersed and kneaded with a kneading roll, followed by stirring and defoaming treatment to obtain a dielectric solution A comprising a high dielectric constant composite material composition.
[0035]
Similarly, as a polyfunctional epoxy resin, 54.2 parts by weight of an epoxy resin having an epoxy equivalent of 190 g / eq (Epicoat 828: manufactured by Yuka Shell Epoxy Co.) and an epoxy resin having an epoxy equivalent of 160 g / eq (830 LVP: Dainippon Ink and Chemicals, Inc.) 45.6 parts by weight), 100 parts by weight of a phenoxy resin (Fenote YP-50: manufactured by Toto Kasei) as a thermoplastic resin, and barium titanate (BT-05: Sakai Chemical Industry) as a dielectric filler Of the curing catalyst (2-ethyl-4-methylimidazole) was dispersed and kneaded with a kneading roll, followed by stirring and defoaming to obtain a high dielectric constant. A dielectric solution B comprising the composite material composition was obtained.
[0036]
Similarly, as a polyfunctional epoxy resin, 54.2 parts by weight of an epoxy resin having an epoxy equivalent of 190 g / eq (Epicoat 828: manufactured by Yuka Shell Epoxy) and an epoxy resin having an epoxy equivalent of 160 g / eq (830 LVP: Dainippon Ink and Chemicals, Inc.) 45.6 parts by weight), 100 parts by weight of epoxidized polybutadiene rubber (Nadex R-45EPT: manufactured by Nagase ChemteX Corporation) as a thermoplastic resin, and barium titanate (BT-) as a dielectric filler. 05: Sakai Chemical Industry Co., Ltd.) (800 parts by weight) and a curing catalyst (2-ethyl-4-methylimidazole) (0.2 parts by weight) were kneaded and dispersed and kneaded with a roll, followed by stirring and defoaming. As a result, a dielectric solution C composed of the high dielectric constant composite material composition was obtained.
[0037]
<Example 1>
First, the dielectric solution A obtained in the above example is coated on a support film 12 made of a polyethylene terephthalate film having a thickness of 50 μm by a roll coater, heated and dried to form a dielectric layer 51a having a thickness of 20 μm. A dielectric transfer sheet 70a was produced (see FIG. 4).
[0038]
Next, the dielectric transfer sheet 70a and the circuit board 20 are overlapped, and the pressing die 80 heated to 150 ° C. is aligned with the capacitor lower electrode 41a of the circuit board 20 (see FIG. 5A). ) 5kg / cm ² The circuit board 30a in which the dielectric pattern 51ap was formed on the capacitor lower electrode 41a of the circuit board 20 was produced for 10 seconds (see FIGS. 5B and 3F).
[0039]
Next, a dry film (ABF-45H: manufactured by Ajinomoto Fine Techno Co., Ltd.) composed of a B-stage film is formed on the surface of the circuit board 30a on which the dielectric pattern 51p is formed, using a vacuum pressurized laminator at a temperature of 110 ° C. , Pressure: 3kg / cm ² After laminating under a condition of vacuum degree: 0.4 Torr, heating and curing at 170 ° C. for 1 hour, and mechanically polishing until the same surface as the surface of the dielectric pattern 51ap to form an insulating layer 33 (FIG. 3 ( g)).
[0040]
Next, a 1 μm thick thin-film conductor layer is formed on the insulating layer 33 and the dielectric pattern 51ap by electroless copper plating (not shown in particular), and electrolytic copper plating is performed using the thin-film conductor layer as a cathode. A conductor layer 61 having a thickness of 10 μm was formed on the dielectric pattern 33 and the dielectric pattern 51ap (see FIG. 3H).
[0041]
Next, a dry film is laminated on the conductor layer 61 to form a photosensitive layer, and a series of patterning processes such as pattern exposure and development are performed to form a resist pattern, and the conductor layer 61 is formed using the resist pattern as an etching mask. Was etched to form a capacitor upper electrode 61a on the dielectric pattern 51ap, thereby obtaining a multilayer circuit board 100a on which the capacitor element 50 was formed (see FIG. 3 (i)).
[0042]
<Example 2>
First, in the same process as in Example 1, the dielectric solution B was applied on a support film 12 made of a 50 μm-thick polyethylene terephthalate film by a roll coater, heated and dried to form a 20 μm-thick dielectric layer 51b. The dielectric transfer sheet 70b was formed (see FIG. 4).
[0043]
Next, the dielectric transfer sheet 70b and the circuit board 20 are overlapped, and the pressing die 80 heated to 150 ° C. is aligned with the capacitor lower electrode 41a of the circuit board 20 (see FIG. 5A). ) 5kg / cm ² , And a dielectric pattern 51 bp was formed on the capacitor lower electrode 41 a of the circuit board 20 to fabricate the circuit board 30 b (see FIGS. 5B and 3F).
[0044]
Next, a dry film (ABF-45H: manufactured by Ajinomoto Fine Techno Co., Ltd.) made of a B-stage film is formed on the surface of the circuit board 30b on which the dielectric pattern 51bp is formed, using a vacuum pressurizing laminator at a temperature of 110 ° C. , Pressure: 3kg / cm ² After laminating under the condition of vacuum degree: 0.4 Torr, heating and curing at 170 ° C. for 1 hour, and mechanically polishing until the same surface as the surface of the dielectric pattern 51 bp to form the insulating layer 33 (FIG. 3 ( g)).
[0045]
Next, a 1 μm thick thin film conductor layer is formed on the insulating layer 33 and the dielectric pattern 51 bp by electroless copper plating (not shown in particular), and electrolytic copper plating is performed using the thin film conductor layer as a cathode. A conductor layer 61 having a thickness of 10 μm was formed on the dielectric layer 33 and the dielectric pattern 51 bp (see FIG. 3H).
[0046]
Next, a dry film is laminated on the conductor layer 61 to form a photosensitive layer, and a series of patterning processes such as pattern exposure and development are performed to form a resist pattern, and the conductor layer 61 is formed using the resist pattern as an etching mask. Was etched to form a capacitor upper electrode 61a on the dielectric pattern 51bp, thereby obtaining a multilayer circuit board 100b on which the capacitor element 50 was formed (see FIG. 3 (i)).
[0047]
<Example 3>
First, in the same process as in Example 1, the dielectric solution C was applied on a support film 12 made of a polyethylene terephthalate film having a thickness of 50 μm by a roll coater, heated and dried to obtain a dielectric layer 51 c having a thickness of 20 μm. Was formed to produce a dielectric transfer sheet 70c (see FIG. 4).
[0048]
Next, the dielectric transfer sheet 70c and the circuit board 20 are overlapped, and the pressing die 80 heated to 150 ° C. is aligned with the capacitor lower electrode 41a of the circuit board 20 (see FIG. 5A). ) 5kg / cm ² , And a dielectric pattern 51cp was formed on the capacitor lower electrode 41a of the circuit board 20 to fabricate the circuit board 30c (see FIGS. 5B and 3F).
[0049]
Next, a dry film (ABF-45H: manufactured by Ajinomoto Fine Techno Co., Ltd.) made of a B-stage film is formed on the surface of the circuit board 30c where the dielectric pattern 51cp is formed, using a vacuum pressurizing laminator at a temperature of 110 ° C. , Pressure: 3kg / cm ² After laminating under a condition of vacuum degree: 0.4 Torr, heating and curing at 170 ° C. for 1 hour, and mechanically polishing until the surface becomes the same as the surface of the dielectric pattern 51 cp to form an insulating layer 33 (FIG. g)).
[0050]
Next, a thin film conductor layer having a thickness of 1 μm is formed on the insulating layer 33 and the dielectric pattern 51cp by electroless copper plating (not shown in particular), and electrolytic copper plating is performed using the thin film conductor layer as a cathode. A conductor layer 61 having a thickness of 10 μm was formed on the dielectric layer 33 and the dielectric pattern 51cp (see FIG. 3H).
[0051]
Next, a dry film is laminated on the conductor layer 61 to form a photosensitive layer, and a series of patterning processes such as pattern exposure and development are performed to form a resist pattern, and the conductor layer 61 is formed using the resist pattern as an etching mask. Was etched to form a capacitor upper electrode 61a on the dielectric pattern 51cp to obtain a multilayer circuit board 100c on which the capacitor element 50 was formed (see FIG. 3 (i)).
[0052]
In the pattern transfer using the dielectric transfer sheets of Examples 1 to 3, a dielectric pattern with good pattern cutting and excellent pattern accuracy was obtained, and a capacitor element with little variation was obtained.
[0053]
【The invention's effect】
The capacitor element manufactured by using the high dielectric constant composite material composition and the dielectric transfer sheet of the present invention has a high dielectric constant, excellent capacitance accuracy, and a capacitor element with little variation. A multilayer circuit board with a built-in reliable capacitor element can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic partial sectional view showing one embodiment of a multilayer circuit board according to the present invention according to claim 6;
2 (a) to 2 (e) are schematic partial sectional views showing a part of steps in a method for manufacturing a multilayer circuit board according to the present invention.
3 (f) to 3 (i) are schematic partial sectional views showing a part of the steps in the method for manufacturing a multilayer circuit board according to the present invention.
FIG. 4 is a schematic partial sectional view showing one embodiment of the dielectric transfer sheet according to claim 5;
FIG. 5A is an explanatory diagram showing a state in which a circuit board, a transfer sheet, and a press die are set in order to form a dielectric pattern. (B) is a schematic partial configuration sectional view showing an example of a circuit board on which a dielectric pattern is formed.
FIG. 6 is a schematic partial sectional view showing an example of a conventional multilayer circuit board with a built-in capacitor element.
[Explanation of symbols]
10 core substrate
11 ... insulating base material
12 Support film
21a, 21b... First wiring layer
20, 30, 30a, 30b, 30c ... circuit board
31 ... Insulating layer
32: Via hole
33a ... resist pattern
33b resist
34 ... opening
41, 61 ... conductor layer
41a, 41b... Second wiring layer
41c: Lower electrode for capacitor
42 ... Fildovia
50 ... Capacitor element
51, 51a, 51b, 51c, 52 ... dielectric layer
51p, 51ap, 51bp, 51cp: dielectric pattern
61a, 62: Upper electrode for capacitor
70, 70a, 70b, 70c ... dielectric transfer sheet
80 ... Press type
100, 100a, 100b, 100c ... multilayer circuit board

Claims (7)

A high dielectric constant composite material composition comprising at least a polyfunctional epoxy resin, a thermoplastic resin, and a dielectric filler, wherein the thermoplastic resin has a softening point of 150 ° C. or less. Composite material composition. The high dielectric constant composite material composition according to claim 1, wherein the polyfunctional epoxy resin has an epoxy equivalent of 150 to 300 and a molecular weight of 200 to 1000. The high dielectric constant composite material according to claim 1 or 2, wherein the thermoplastic resin is blended in an amount of 10 to 50% by weight based on a total solid content of the polyfunctional epoxy resin and the thermoplastic resin. Composition. 4. The dielectric filler according to claim 1, wherein said dielectric filler is contained in an amount of 30 to 90% by weight based on a total solid content of said polyfunctional epoxy resin, said thermoplastic resin and said dielectric filler. A high dielectric constant composite material composition according to any one of the preceding claims. A dielectric solution is prepared using the high dielectric constant composite material composition according to any one of claims 1 to 4, and a dielectric layer having a thickness of 5 to 50 μm is formed on the transfer film. Dielectric transfer sheet. A passive element, wherein a dielectric pattern is formed on a circuit board by a thermal transfer method using the dielectric transfer sheet according to claim 5, and a capacitor element using the dielectric pattern as a dielectric is formed. Built-in multilayer circuit board. The method for manufacturing a multilayer circuit board according to claim 6, comprising at least the following steps.
(A) A step of manufacturing a circuit board in which a wiring pattern and a lower electrode for a capacitor are formed on both surfaces of an insulating base material 11.
(B) A dielectric solution is prepared using the high dielectric constant composite material composition according to any one of claims 1 to 4, and the dielectric solution is applied on a support film, heated and dried. Forming a dielectric layer having a predetermined thickness to produce a dielectric transfer sheet;
(C) a step of transferring a pattern on the capacitor lower electrode of the circuit board using the dielectric transfer sheet, and heating and curing to form a dielectric pattern having a predetermined thickness.
(D) forming a capacitor element by forming an upper electrode for the capacitor on the dielectric pattern, and fabricating a multilayer circuit board with a built-in passive element;

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