TW201718798A - Resin sheet and electronic device - Google Patents

Abstract

A resin sheet of the present invention is used for bonding an electronic component. A tack force at 25 DEG C of the resin sheet is 80 gf/5mm [phi] or more. When a minimum melt viscosity of the resin sheet is measured under the conditions in which a frequency is 62.83 rad/sec and a temperature is 50 to 200 DEG C by using a viscoelasticity measurement apparatus, the minimum melt viscosity is in the range of 300 to 2000 pa.s.

Description

Resin sheet and electronic device

The present invention relates to a resin sheet and an electronic device.

In the manufacture of an electronic device, there is a case where an electronic component is mounted and fixed on one surface of an insulating layer. For example, there is a technique in which an electronic component is formed on a buildup layer when manufacturing a wiring board in which an electronic component such as a ceramic capacitor is built. As such a technique, for example, the technique described in Patent Document 1 can be cited.

Patent Document 1 discloses that in an electronic component-embedded wiring board having an electronic component including a main body portion and an external electrode, at least a part of the external electrode is formed in the opening portion, and the opening portion is formed in the main body portion.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2013-183028

When manufacturing an electronic device in which an electronic component is mounted on an insulating layer, the inventors have studied, for example, a process of forming a resin sheet on a base layer provided with a circuit, and placing the electronic component on the resin sheet. To harden the resin sheet. However, with the miniaturization of the circuit wiring, the circuit of the resin sheet to the base layer Embeddedness becomes more important. On the other hand, it has been found that in the process, it is also required to improve the adhesion to electronic parts of the resin sheet. Heretofore, it has been difficult to realize a resin sheet which can improve the embedding property to the circuit of the underlying layer and the balance with the adhesion to the electronic component.

According to the present invention, there is provided a resin sheet which is used for a resin sheet which is followed by an electronic part, and has an adhesive force of 80 gf/5 mm at 25 ° C. As described above, when the resin sheet is measured using a dynamic viscoelasticity measuring apparatus at a frequency of 62.83 rad/sec and a measurement temperature range of 50 ° C to 200 ° C, the lowest melt viscosity of the resin sheet is 300 Pa. s above and 1000Pa. s below.

Moreover, according to the present invention, there is provided an electronic device comprising the cured film of the resin sheet and an electronic component attached to one surface of the cured film.

According to the present invention, it is possible to realize a resin sheet which can improve the embedding property to a circuit and the balance with the adhesion to an electronic component.

1‧‧‧ circuit substrate

10‧‧‧Resin sheet

12‧‧‧Additional

14‧‧‧1st resin layer

16‧‧‧2nd resin layer

20‧‧‧ Carrier

30‧‧‧ peeling layer

40‧‧‧Wiring

50‧‧‧Ceramic capacitors

52‧‧‧ Body Department

54‧‧‧Electrode

60‧‧‧Prepreg

62‧‧‧Insulation

64, 68‧‧‧ solder mask

70, 72‧‧‧through holes

74, 76‧‧‧ wiring

78‧‧‧Metal plating

80‧‧‧Semiconductor wafer

82‧‧‧Bumps

84‧‧‧ underfill resin

86‧‧‧External connection terminal

90‧‧‧ openings

100‧‧‧Electronic devices

A, B‧‧‧ origin

W, X, Y, Z‧‧‧ plane distance

Fig. 1 is a schematic cross-sectional view showing a resin sheet of the embodiment.

2(a) to 2(c) are schematic cross-sectional views showing a method of manufacturing the circuit board of the embodiment.

3(a) to 3(c) are schematic cross-sectional views showing a method of manufacturing the circuit board of the embodiment.

4(a) to 4(c) are sectional views showing the manufacturing method of the electronic device of the embodiment. schematic diagram.

Fig. 5 is a schematic cross-sectional view showing a modified example of the resin sheet of the embodiment.

Fig. 6 is a schematic plan view showing a method of measuring the positional shift amount.

7(a) to 7(c) are schematic cross-sectional views showing a modification of the ceramic capacitor.

Hereinafter, preferred embodiments of the present invention will be described using the drawings. In the drawings, the same components are denoted by the same reference numerals, and the description is omitted as appropriate.

First, the outline of the resin sheet of the present invention will be described.

The resin sheet of the present invention satisfies the following constituent elements: constituent element A, which has an adhesive force of 80 gf/5 mm at 25 ° C. And the constitutive requirement B is the lowest melt viscosity of 300 Pa when measured by a dynamic viscoelasticity measuring device at a frequency of 62.83 rad/sec and a measurement temperature range of 50 ° C to 200 ° C. s above and 1000Pa. s below.

The resin sheet of the present invention can be used to follow electronic parts on one side thereof. On the other hand, the other side may follow the circuit surface of the substrate on which the circuit pattern is formed.

In the present invention, by satisfying the constitution A, the resin sheet has sufficient adhesion to the electronic component following the upper side. By increasing the adhesive force of the constituent A, the adhesion of the resin sheet to the electronic component can be improved, and the position of the electronic component can be prevented from shifting after the resin sheet is cured.

Further, in the present invention, by satisfying the constitution B, the resin sheet has good embedding characteristics for the circuit disposed on the lower side. By setting the lowest melt viscosity of the constituent B to be within the above range, the resin sheet before curing becomes easy to be inserted into the gap of the circuit or the like.

As a result of research, the inventors have found that the embedding property of the resin sheet on the lower circuit (circuit of the substrate) becomes more important as the circuit wiring is miniaturized. On the other hand, in the process, The adhesion to electronic components must be improved. Further, based on such a finding, the resin sheet having a balance between the embedding property of the substrate and the adhesion to the electronic component is realized by combining the constituent element A and the constituent element B. .

The resin sheet of the present invention can improve the embedding property to the circuit of the substrate and the adhesion to the electronic component, and can achieve a balance between embedding property and adhesion. Further, the circuit board or the electronic device using the resin sheet is highly reliable and excellent in yield.

Hereinafter, the resin sheet, the circuit board, the method of manufacturing the circuit board, and the electronic device of the present embodiment will be described in detail.

[Resin composition for resin sheet]

First, a resin composition for a resin sheet for forming the resin sheet of the present embodiment will be described.

The resin composition for a resin sheet is a varnish-like resin composition. The resin sheet of the present embodiment can be obtained by forming the resin sheet resin composition into a film form. The resin composition for a resin sheet contains a thermosetting resin composition of a thermosetting resin. As the resin sheet of the present embodiment, a resin film formed using the thermosetting resin composition can be used.

The thermosetting resin is not particularly limited, and examples thereof include a phenol resin and a benzoic acid. Ring resin, epoxy resin, melamine resin, unsaturated polyester resin, maleimide resin, polyurethane resin, diallyl phthalate resin, polyoxyn resin, cyanide An acid ester resin, a resin having a methacrylonitrile group, or the like. For example, the thermosetting resin may contain a liquid resin which is liquid at room temperature (25 ° C). These may be used alone or in combination of two or more. In the present embodiment, the thermosetting resin preferably contains an epoxy resin.

(epoxy resin (A))

The epoxy resin (A) may, for example, comprise one or more selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, and bisphenol S type ring. Oxygen resin, bisphenol M type epoxy resin (4,4'-(1,3-phenylene diisopropylidene) bisphenol type epoxy resin), bisphenol P type epoxy resin (4,4' -(1,4-1,4-phenylene diisopropylidene) bisphenol epoxy resin), bisphenol Z epoxy resin (4,4'-cyclohexylene bisphenol epoxy resin) and other bisphenols Epoxy resin; phenol novolak type epoxy resin, cresol novolak type epoxy resin, tetraphenol ethane novolak type epoxy resin, phenolic aldehyde type epoxy resin having a condensed ring aromatic hydrocarbon structure, etc. Varnish type epoxy resin; biphenyl type epoxy resin; arylene type epoxy resin, biphenyl aralkyl type epoxy resin and other aralkyl type epoxy resin; n-naphthyl ether type epoxy resin, naphthalene Phenolic epoxy resin, naphthalene diphenol epoxy resin, 2-functional to 4-functional naphthalene epoxy resin, binaphthyl epoxy resin, naphthalene aralkyl epoxy resin, naphthalene modified cresol novolac epoxy Resin or the like having a naphthalene skeleton Epoxy resin; anthracene-type epoxy resins; phenoxy type epoxy resins; dicyclopentadiene type epoxy resins; drop Ethylene type epoxy resin; adamantane type epoxy resin; bismuth type epoxy resin, allylated epoxy resin, epoxidized epoxide type epoxy resin, propylene acrylate type epoxy resin, alicyclic epoxy resin . In the above, from the viewpoint of improving the embedding property of the resin sheet or the surface smoothness, it is more preferable to include an epoxy resin having a naphthalene skeleton. Thereby, the low-line expansion of the resin sheet and the high elastic modulus can be achieved. Moreover, the rigidity of the circuit board can be improved, the workability can be improved, or the reflow resistance of the semiconductor package can be improved and the warpage can be suppressed. Further, from the viewpoint of improving the embedding property of the resin sheet, an epoxy resin having a trifunctional or higher naphthalene skeleton is particularly preferable.

The epoxy resin (A) is exemplified by an epoxy resin represented by the following formula (1).

(In the formula (1), n is an integer of 0 to 10, and R ₁ and R ₂ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms)

The content of the epoxy resin (A) is preferably 3% by weight or more, and more preferably 5% by weight or more based on the total solid content of the thermosetting resin composition. When the content of the epoxy resin (A) is at least the above lower limit value, it is possible to contribute to improvement in embedding property or smoothness of the resin sheet formed using the thermosetting resin composition. On the other hand, the content of the epoxy resin (A) is preferably 40% by weight or less, and more preferably 35% by weight or less based on the total solid content of the thermosetting resin composition. When the content of the epoxy resin (A) is at most the above upper limit value, the heat resistance or moisture resistance of the resin sheet formed using the thermosetting resin composition can be improved. The epoxy resin (A) may be one containing a liquid epoxy resin. The content of the liquid epoxy resin may be 15% by weight or less, or may be 10% by weight or less, based on the total solid content of the thermosetting resin composition. By reducing the content of the liquid epoxy resin, deterioration of the carrier peelability due to excessive adhesion can be suppressed.

In addition, the total solid content of the thermosetting resin composition means all components except the solvent contained in the thermosetting resin composition. Hereinafter, in this specification with.

Further, the thermosetting resin composition preferably further comprises a cyanate resin, an allylphenol compound, a propenylphenol compound, an active ester compound, an alkoxydecane-modified phenol compound, or a carbodiimide compound. At least one liquid or semi-solid resin. By including these resins, the adhesiveness of the resin sheet can be improved while the lowest melt viscosity of the resin sheet is within the above range. In particular, the thermosetting resin composition preferably contains a cyanate resin in the above resin.

(Cyanate resin (B1))

When the thermosetting resin composition contains a cyanate resin, it is possible to impart a moderate viscosity to the resin sheet, and to achieve a low-line expansion of the resin sheet or an increase in the modulus of elasticity and rigidity. Moreover, it can also contribute to an improvement in heat resistance or moisture resistance of the obtained semiconductor device.

The cyanate resin (B1) is a resin having a cyanate group (-O-CN) in the molecule. It is especially preferable to use a cyanate resin having two or more cyanate groups in the molecule. The cyanate resin (B1) is not particularly limited, and examples thereof include a dicyclopentadiene type cyanate resin, a phenol novolak type cyanate resin, a novolac type cyanate resin, and a bisphenol A. A bisphenol type cyanate resin such as a cyanate resin, a bisphenol E type cyanate resin, a tetramethyl bisphenol F type cyanate resin, or a naphthol aralkyl type cyanate resin.

Further, the cyanate resin (B1) is not particularly limited, and may be obtained, for example, by reacting a cyanogen halide compound with a phenol or a naphthol. Examples of such a cyanate resin include a cyanate resin obtained by a reaction of a phenol novolak type polyphenol and a cyanogen halide, and a reaction of a cresol novolak type polyphenol with a cyanogen halide. The obtained cyanate resin and the reaction of the naphthol aralkyl type polynaphthol and the cyanogen halide are obtained. Cyanate resin and the like. The cyanate resin (B1) may be used alone or in combination of two or more.

In view of the low-line expansion of the resin sheet or the improvement of the modulus of elasticity and the rigidity, the phenol novolac type cyanate resin and the dicyclopentadiene type cyanate resin are more preferably contained. Or a naphthol aralkyl type cyanate resin, particularly preferably a phenol novolac type cyanate resin.

The content of the cyanate resin (B1) is preferably 3% by weight or more, and more preferably 5% by weight or more based on the total solid content of the thermosetting resin composition. When the content of the cyanate resin (B1) is at least the above lower limit value, more effective low-line expansion and high elastic modulus of the resin sheet formed using the thermosetting resin composition can be achieved. . Moreover, it can contribute to the improvement of embedding property or smoothness. On the other hand, the content of the cyanate resin (B1) is preferably 40% by weight or less, and more preferably 35% by weight or less based on the total solid content of the thermosetting resin composition. When the content of the cyanate resin (B1) is at most the above upper limit value, the heat resistance or moisture resistance of the resin sheet formed using the thermosetting resin composition can be improved.

(filling material (C))

The thermosetting resin composition preferably further contains a filler (C).

As the filler (C), an inorganic filler can be used. The inorganic filler is not particularly limited, and examples thereof include talc, calcined clay, uncalcined clay, mica, glass, etc.; titanium oxide, aluminum oxide, bauxite, cerium oxide, and molten cerium oxide. Oxide; carbonate such as calcium carbonate, magnesium carbonate or hydrotalcite; hydroxide such as aluminum hydroxide, magnesium hydroxide or calcium hydroxide; sulfate or sulfite such as barium sulfate, calcium sulfate or calcium sulfite; boric acid Zinc, barium metaborate, aluminum borate, calcium borate, sodium borate, etc. Borate; nitride such as aluminum nitride, boron nitride, tantalum nitride or carbon nitride; titanate such as barium titanate or barium titanate. Among these, talc, alumina, glass, cerium oxide, mica, aluminum hydroxide, magnesium hydroxide, and preferably cerium oxide are preferable.

The cerium oxide is not particularly limited, and may include, for example, at least one of spherical cerium oxide and crushed cerium oxide. It is more preferable to contain spherical cerium oxide from the viewpoint of improving the embedding property or surface smoothness of the resin sheet. Further, the cerium oxide may be, for example, a molten spherical cerium oxide.

The average particle diameter D _{50 of} the filler (C) is not particularly limited, but is preferably 0.01 μm or more and 5.0 μm or less, and more preferably 0.05 μm or more and 2.0 μm or less.

The average particle diameter D _{50 of the} above-mentioned filler (C) can be measured using, for example, a laser diffraction type particle size distribution measuring apparatus (LA-500 manufactured by HORIBA). Further, the filler may contain one type or two or more types.

The content of the filler (C) is preferably, for example, 40% by weight or more, and more preferably 50% by weight or more based on the total solid content of the thermosetting resin composition. When the content of the filler (C) is at least the above lower limit value, the heat resistance or moisture resistance of the resin sheet obtained by using the thermosetting resin composition can be effectively improved. Further, the resin sheet can be made to have a low linear expansion and a high elastic modulus, which contributes to reduction in warpage of the obtained semiconductor package. On the other hand, the content of the filler (C) is preferably, for example, 90% by weight or less, and more preferably 85% by weight or less based on the total solid content of the thermosetting resin composition. By setting the content of the filler (B) to be equal to or less than the above upper limit value, the embedding property of the resin sheet can be more effectively improved.

(hardening accelerator (D))

The thermosetting resin composition preferably further contains, for example, a curing accelerator (D). Thereby, the hardenability of the thermosetting resin composition can be improved.

As the curing accelerator (D), a curing reaction for promoting the epoxy resin (A) can be used, and the type thereof is not particularly limited. The curing accelerator (D) is not particularly limited, and may, for example, include one or more selected from the group consisting of zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octoate, zinc octoate, and diacetyl hydrazine. An organic metal salt such as acetone cobalt (II), triethyl hydrazine acetone (III); a tertiary amine such as triethylamine, tributylamine or diazabicyclo[2.2.2]octane; such as tetraphenylphosphonium- Tetraphenylborate (TPP-K), tetraphenylphosphonium-tetrakis(4-methylphenyl)borate (TPP-MK), a tetradecyl quinone compound; 2-phenyl-4-methylimidazole , 2-ethyl-4-ethylimidazole, 2-phenyl-4-ethylimidazole, 2-phenyl-4-methyl-5-hydroxyimidazole, 2-phenyl-4,5-dihydroxyimidazole Imidazoles; phenolic compounds such as phenol, bisphenol A, nonylphenol; organic acids such as acetic acid, benzoic acid, salicylic acid, p-toluenesulfonic acid; Among these, it is more preferable to contain an onium salt compound from the viewpoint of more effectively improving the hardenability.

The onium salt compound to be used as the curing accelerator (D) is not particularly limited, and for example, a compound represented by the following formula (2) can be used.

(In the formula (2), P is a phosphorus atom, and R ³ , R ⁴ , R ⁵ and R ⁶ each represent a substituted or unsubstituted organic group having an aromatic ring or a heterocyclic ring, or substituted or unsubstituted Aliphatic groups, which may be the same or different from each other; A ^- represents an anion of an n(n≧1) valence proton donor having at least one or more protons released to the outside of the molecule, or a wrong anion thereof )

The content of the hardening accelerator (D) is preferably 0.1% by weight or more, and more preferably 0.3% by weight or more based on the total solid content of the thermosetting resin composition. When the content of the curing accelerator (D) is at least the above lower limit value, the curability of the thermosetting resin composition can be more effectively improved. On the other hand, the content of the curing accelerator (D) is preferably, for example, 10% by weight or less, and more preferably 5% by weight or less based on the total solid content of the thermosetting resin composition. When the content of the curing accelerator (D) is at most the above upper limit value, the storage stability of the thermosetting resin composition can be improved.

(E) colorant

The thermosetting resin composition may further contain, for example, a color former (E). The colorant (E) contains, for example, one or more selected from the group consisting of dyes, pigments, and pigments such as green, red, blue, yellow, and black. In the above, a green coloring agent or a green dye may be used from the viewpoint of improving the visibility of the opening and the like. The green coloring agent may, for example, comprise one or more of known known coloring agents such as an anthraquinone, a phthalocyanine, and an anthraquinone.

The content of the coloring agent (E) is preferably 0.05% by weight or more, and more preferably 0.1% by weight or more based on the total solid content of the thermosetting resin composition. When the content of the coloring agent (E) is at least the above lower limit value, the visibility or concealability of the opening portion of the resin sheet obtained by using the thermosetting resin composition can be more effectively improved. On the other hand, the content of the coloring agent (E) is preferably 5% by weight or less, and more preferably 3% by weight or less based on the total solid content of the thermosetting resin composition. By setting the content of the colorant (E) to be equal to or less than the above upper limit, the thermosetting tree can be more effectively improved. The hardening property of the lipid composition, and the like.

(Other ingredients (F))

In the thermosetting resin composition, in addition to the above components, a coupling agent, a leveling agent, a hardener, a sensitizer, an antifoaming agent, an ultraviolet absorber, a foaming agent, an antioxidant, and a hardening may be added as needed. One or more additives of a fuel, an ion trapping agent, and the like.

Examples of the coupling agent include a decane coupling agent such as an epoxy decane coupling agent, a cationic decane coupling agent, and an amino decane coupling agent, a titanate coupling agent, and a polyasoxy oil type coupling agent. Examples of the leveling agent include an acrylic copolymer and the like. The content of the above-mentioned coupling agent is not particularly limited, and is, for example, preferably 0.05 to 5% by weight, and more preferably 0.2 to 3% by weight based on the total solid content of the thermosetting resin composition.

Examples of the curing agent include a phenol resin such as a phenol novolak resin, a cresol novolak resin, and an aryl alkylene novolak resin. The content of the curing agent is not particularly limited. For example, it is preferably 0.05 to 10% by weight, and more preferably 0.2 to 5% by weight based on the total solid content of the thermosetting resin composition.

The resin sheet of the present embodiment satisfies the constitutional requirements A and B by using a thermosetting resin composition containing a predetermined amount of each component. In particular, by using 3 to 40% by weight of epoxy resin (A), 3 to 40% by weight of a cyanate resin (B1), an allylphenol compound, a propenylphenol compound, an active ester compound, an alkane At least one liquid or semi-solid resin of the oxydecane-modified phenol compound or the carbodiimide compound, 40 to 80% by weight of the filler (C), and 0.1 to 5% by weight of the hardening accelerator The thermosetting resin composition of (D) can be more reliably satisfied A resin sheet of the parts A and B. Moreover, it is more preferable to use the following thermosetting resin composition from the viewpoint of obtaining a resin sheet which satisfies the constituent elements A and B and which is particularly excellent in the balance between the embedding property and the adhesiveness, that is, it contains: 5 to 35 5% by weight of epoxy resin (A); 10 to 35% by weight selected from the group consisting of cyanate resin (B1), allyl phenol compound, propylene phenol compound, active ester compound, alkoxy decane modified phenol compound, At least one liquid or semi-solid resin of the carbodiimide compound; 50 to 85% by weight of the filler (C); and 0.3 to 5% by weight of the hardening accelerator (D).

Further, the thermosetting resin composition is a varnish-like resin composition. The resin sheet of this embodiment can be obtained by forming a varnish-like thermosetting resin composition into a film form.

The resin sheet of the present embodiment can be obtained, for example, by subjecting a coating film (resin film) obtained by coating a varnish-like thermosetting resin composition to a solvent removal treatment. The resin sheet can be defined as a solvent content ratio of 5% by weight or less based on the total amount of the thermosetting resin composition. In the present embodiment, for example, the solvent removal treatment can be carried out at 100 ° C to 150 ° C for 1 minute to 5 minutes. Thereby, the solvent can be sufficiently removed while suppressing the hardening of the thermosetting resin film.

In the present embodiment, the method of forming the thermosetting resin composition on the carrier substrate is not particularly limited, and the following methods can be mentioned. For example, a method of preparing a resin varnish by dissolving and dispersing a thermosetting resin in a solvent or the like, and applying the resin varnish to a carrier substrate using various coating apparatuses, and drying the resin varnish; A method in which a resin varnish is spray-coated on a carrier substrate using a spray device and then dried. Among these, a method in which a resin varnish is applied onto a carrier substrate by various coating apparatuses such as a comma coater or a die coater, and then dried is used. Thereby, it is possible to efficiently manufacture a void-free device A resin sheet with a carrier substrate of a resin sheet having a uniform thickness.

(solvent)

The varnish-like thermosetting resin composition may contain, for example, a solvent.

The solvent may, for example, comprise one or more selected from the group consisting of acetone, methyl ethyl ketone, methyl isobutyl ketone, toluene, ethyl acetate, cyclohexane, heptane, cyclohexane. , cyclohexanone, tetrahydrofuran, dimethylformamide, dimethylacetamide, dimethyl hydrazine, ethylene glycol, serotonin, carbitol, anisole, and N-methyl An organic solvent such as pyrrolidone.

In the varnish-like thermosetting resin composition, the solid content of the thermosetting resin composition is, for example, preferably 30% by weight or more and 80% by weight or less, more preferably 40% by weight or more and 70% by weight or less. Thereby, a thermosetting resin composition which is excellent in workability or film formability can be obtained. Further, the varnish-like thermosetting resin composition can be, for example, an ultrasonic dispersion method, a high-pressure collision type dispersion method, a high-speed rotation dispersion method, a bead milling method, a high-speed shear dispersion method, and a self-rotating revolution dispersion method. Each of the above-mentioned mixers was prepared by dissolving, mixing, and stirring the above components in a solvent.

Further, the thermosetting resin composition is preferably a composition which is, for example, a fiber substrate or a paper substrate which does not contain a glass fiber substrate. By not including such a substrate, the embedding property of the circuit is improved, and a thermosetting resin composition which is particularly suitable for forming a resin sheet can be realized.

[Resin sheet]

The resin sheet of the present embodiment may contain the resin composition for the resin sheet described above. The film obtained. In the present embodiment, the resin sheet may have a sheet shape or a roll shape that can be wound up.

As described above, the adhesive sheet of the present embodiment has an adhesion at 25 ° C of 80 gf / 5 mm. the above. The lower limit of the adhesion of the above resin sheet is 80gf/5mm Above, preferably 90gf/5mm Above, more preferably 100gf/5mm the above. The upper limit of the adhesive force of the above resin sheet is not particularly limited, and is preferably, for example, 1000 gf/5 mm. Below, more preferably 900gf/5mm Hereinafter, it is further preferably 800 gf/5 mm the following. By setting the adhesive force to be equal to or higher than the above lower limit value, the adhesion to the electronic component can be improved. Thereby, when manufacturing an electronic device, it is possible to suppress the positional shift of the electronic component due to the influence of the drying or the additional step before the resin sheet is cured. By setting the adhesive force to the above upper limit or less, the carrier or the carrier substrate can be easily peeled off, and the use of the resin sheet becomes good.

In the present embodiment, the adhesion of the resin sheet can be measured, for example, by the following procedure. First, a resin sheet with a carrier substrate is prepared. The resin sheet of the resin sheet with a carrier substrate was bonded to the core material at 80 °C. Next, the resin sheet and the core material of the bonded carrier substrate were cut into about 10 cm square, and the carrier substrate was peeled off to prepare a measurement sample. Subsequently, the measurement sample was placed on a table of a tacking tester (manufactured by Rhesca) set to a temperature of 25 ° C in the following manner, and the probe (5 mm) was placed. ) at 100gf/5mm The condition of 5 sec was pressed against the measurement sample. Thereafter, the probe was detached from the measurement sample under the condition of 2 mm/sec. At this time, the tensile force of the probe from the measured sample is measured, and the peak value is used as the adhesive force (gf/5 mm). ). By the above operation, the adhesion of the peeling surface of the resin sheet after peeling off the carrier substrate can be measured.

In the resin sheet of the present embodiment, by measuring the frequency of 62.83 The minimum melt viscosity of 50~200 °C measured by dynamic viscoelasticity test of rad/sec and heating rate of 3 °C/min is 2000 Pa. s below. The upper limit of the above minimum melt viscosity is 2000 Pa. Below s, preferably 900Pa. Below s, more preferably 800Pa. s below. By setting the minimum melt viscosity to be equal to or less than the above upper limit value, the embedding property of the resin sheet can be improved as described above. On the other hand, the lower limit of the above minimum melt viscosity is 300 Pa. Above s, preferably 400 Pa. Above s, more preferably 500Pa. s above. By setting the minimum melt viscosity to be equal to or higher than the above lower limit value, the surface smoothness of the resin sheet can be improved.

In the present embodiment, the dynamic viscoelasticity test can be carried out under the following conditions using, for example, a dynamic viscoelasticity measuring device. Further, the dynamic viscoelasticity measuring device is not particularly limited, and for example, Physica MCR-301 manufactured by Anton Paar Co., Ltd. can be used.

Frequency: 62.83 rad/sec

Measuring temperature: 50~200°C

Heating rate: 3 ° C / min

Geometric shape: parallel plate

Plate diameter: 10mm

Board spacing: 0.1mm

Load (normal force): 0N (fixed)

Strain: 0.3%

Measuring atmosphere: air

In the present embodiment, for example, the adhesion and the minimum amount can be controlled by appropriately selecting the type or amount of each component contained in the thermosetting resin composition, the preparation method of the thermosetting resin composition, and the like. Melt viscosity. In the above, for example, in a range in which the content of the liquid epoxy resin is small (15% by weight or less based on the total solid content of the thermosetting resin composition), a preparation method such as heating or the like is used. The coupling agent treatment and the stirring method are used to improve the dispersibility of the filler and the like, and are used as elements for setting the adhesion and the minimum melt viscosity to a desired numerical range. Furthermore, the content of the filler is set to be less than or equal to the lower limit value (40% by weight or more based on the total solid content of the thermosetting resin composition) in a range in which the content of the liquid epoxy resin is small. And the dispersibility of the filler material is improved by a suitable stirring method as a particularly important factor for controlling the above adhesion and the lowest melt viscosity.

In the present embodiment, when the resin sheet is heat-treated at 200 ° C for 1 hour to obtain a cured product, the storage modulus at 25 ° C of the cured product of the resin sheet is preferably 7 GPa or more. Thereby, it is possible to achieve the deflection suppression or the strength improvement of the circuit board including the resin sheet obtained by using the thermosetting resin composition, and the warpage suppression of the semiconductor package including the circuit board. The above storage modulus is more preferably 10 GPa or more. On the other hand, the upper limit of the storage modulus is not particularly limited, and may be, for example, 50 GPa or less.

In the present embodiment, when the resin sheet is heat-treated at 200 ° C for 1 hour to obtain a cured product, the glass transition temperature of the cured product of the resin sheet is preferably 160 ° C or higher. Thereby, the heat resistance and the reflow resistance of the resin sheet obtained by using the thermosetting resin composition can be improved. The above glass transition temperature is more preferably 200 ° C or higher. On the other hand, the upper limit of the glass transition temperature is not particularly limited, and may be, for example, 350 ° C or lower.

In the present embodiment, the storage modulus and the glass transition temperature can be calculated, for example, based on measurement results obtained by using a dynamic viscoelasticity measuring device at a frequency of 1 Hz and a temperature increase rate of 5 for the cured product. Dynamic viscoelasticity test was carried out under the conditions of °C/min. The dynamic viscoelasticity measuring device is not particularly limited, and for example, DMS6100 manufactured by Seiko Instruments Co., Ltd. can be used.

In the present embodiment, when the resin sheet is heat-treated at 200 ° C for 1 hour to obtain a cured product, the linear expansion coefficient of the cured product of the resin sheet which is less than the glass transition temperature is preferably 30 ppm/° C. or less. Thereby, warpage suppression of a semiconductor package including a resin sheet obtained by using a thermosetting resin composition can be achieved. The above linear expansion coefficient is more preferably 28 ppm/° C. or less. On the other hand, the lower limit of the linear expansion coefficient is not particularly limited, and may be, for example, 3 ppm/° C. or more.

In the present embodiment, for example, the cured product can be measured using a thermomechanical analyzer (TMA) (thermal analyzer) at a temperature increase rate of 10 ° C/min, and the coefficient of linear expansion obtained thereby can be calculated. The average of 25 to 50 ° C is taken as the above linear expansion coefficient at a glass transition temperature.

In the present embodiment, for example, the storage can be controlled by appropriately selecting the type or amount of each component contained in the thermosetting resin composition, the preparation method of the thermosetting resin composition, and the like. Modulus, the above glass transition temperature, and the above linear expansion coefficient.

Further, the resin sheet of the present embodiment can be laminated on the carrier substrate to form a resin sheet with a carrier substrate. Thereby, the rationality of the resin sheet can be improved.

In the present embodiment, as the carrier substrate, for example, a polymer film can be used. The polymer film is not particularly limited, and examples thereof include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, and polycarbonate. A release paper such as a xenon sheet, a thermoplastic resin sheet having heat resistance such as a fluorine resin or a polyimide resin. Among these, the sheet containing polyethylene terephthalate is preferable because it is inexpensive and the peel strength is easily adjusted. Thereby, it becomes easy to peel from the said resin sheet with moderate intensity|strength.

The thickness of the carrier substrate is not particularly limited, and may be, for example, 10 to 100 μm or 10 to 70 μm. Thereby, it is rational and preferable to manufacture a resin sheet.

The resin sheet of the present invention may be a single layer or a plurality of layers, and may contain one or more of the above films. When the resin sheet is a plurality of layers, it may be composed of the same kind or may be composed of different types.

The resin sheet of the present embodiment may have a configuration including a first resin sheet (first resin layer) and a second resin sheet (second resin layer) disposed under the first resin sheet. In addition, the first resin sheet and the second resin sheet have the same configuration as the above resin sheet.

The first resin sheet may have higher adhesion to the electronic component than the second resin sheet. In other words, in the present embodiment, the adhesion of the first resin sheet can be made larger than the adhesion of the second resin sheet. On the other hand, the second resin sheet may have higher embedding characteristics to the lower layer circuit than the first resin sheet. That is, in the present embodiment, the lowest melt viscosity of the second resin sheet can be made larger than the lowest melt viscosity of the first resin sheet. By using two or more resin sheets, the adhesion between the upper layer and the electronic component can be further improved, and the lower layer can be better embedded in the circuit. That is, the balance between the adhesion to the electronic component and the embedding property to the circuit of the lower layer can be further improved.

In the present embodiment, a method of forming a resin sheet (resin layer) of two or more layers is not particularly limited. For example, first, a first resin layer obtained by applying a thermosetting resin composition onto a carrier substrate is used. The second resin layer is bonded to the first resin layer and the second resin layer, and dried. Thereafter, the carrier substrate is removed from the first resin layer and the second resin layer to obtain a resin sheet having a two-layer structure. Further, a method of applying a thermosetting resin composition onto a carrier substrate and It was dried to obtain a first resin sheet. Thereafter, the thermosetting resin composition is applied onto the first resin sheet and dried to form the second resin sheet on the first resin sheet. Further, a method in which two layers are simultaneously coated on a carrier substrate and dried to obtain two layers of a resin sheet can be used.

Further, in the present embodiment, in the production of the second resin sheet, the second resin can be improved by further reducing the content of the epoxy resin to the first resin sheet or without disposing the liquid epoxy resin. Peelability of the sheet from the carrier substrate.

[circuit board]

The circuit board of the present embodiment may include a cured film of the resin sheet and an electronic component that is next to one surface of the cured film.

Fig. 3 (c) shows an example of the circuit board 1 of the present embodiment. The circuit board 1 may include a buildup layer 12, an insulating layer 62, a wiring 40, and an electronic component (ceramic capacitor 50). The wiring 40 is embedded in the buildup layer 12 of the lower layer. A ceramic capacitor 50 is fixed to the upper surface of the buildup layer 12 of the lower layer. On the buildup layer 12 of the lower layer, the ceramic capacitor 50 and the insulating layer 62 are disposed so as to form the same layer. As the insulating layer 62, a cured product of a prepreg can be used. The prepreg may also be free of a substrate. On the ceramic capacitor 50 and the insulating layer 62, an upper layer 12 is disposed. In the circuit board 1 of the present embodiment, an electronic component is housed, and the insulating layer 62 may be formed of a coreless layer without using a core layer including a substrate. The hollow substrate embedded in the electronic component can be made.

In the present embodiment, since the buildup layer 12 includes the resin sheet, the wiring is well embedded, and the positional deviation of the electronic component is suppressed. Therefore, a circuit board having a structure excellent in reliability can be obtained.

[electronic device]

The electronic device of the present embodiment can be used for an electronic device in which an electronic component is mounted on the circuit board. Examples of the electronic component include a semiconductor device and the like.

FIG. 4(c) shows an example of the electronic device 100 described above. This is an example in which the semiconductor wafer 80 is flip-chip bonded to the circuit board 1. The electronic device 100 may include a circuit board 1, a wiring layer, external connection terminals, a connection portion (wiring 74, metal plating layer 78) connected to the electrode bumps of the semiconductor element, and a semiconductor wafer 80.

A wiring layer is formed on both surfaces of the circuit board 1. The number of layers of the wiring layer is arbitrary. The wiring 76 of the lower wiring layer is electrically connected to the external connection terminal 86. The wiring 74 of the upper wiring layer is electrically connected to the bump 82 of the semiconductor wafer 80. The periphery of the wirings 74, 76 is covered by the solder resist films 64, 68, respectively. In the gap between the semiconductor wafer 80 and the solder resist film 64, an underfill resin 84 is filled.

In the present embodiment, an electronic device having a structure in which reliability is obtained stably and excellent in yield can be realized by using a circuit board having a structure excellent in reliability.

[Method of Manufacturing Circuit Board]

The manufacturing steps of the circuit board of the present embodiment will be described with reference to Figs.

1 is a cross-sectional view showing a structure of a resin sheet 10 of the present embodiment, and FIGS. 2 and 3 are step sectional views showing a manufacturing procedure of the circuit board 1 of the present embodiment.

First, the resin sheet 10 shown in Fig. 1 is prepared. As the resin sheet 10, the resin sheet 10 formed of the resin composition for a resin sheet of the present embodiment can be used. The resin sheet 10 is formed on one surface of a carrier substrate (not shown).

Then, the carrier 20 having the peeling layer 30 formed on one surface is prepared. As a carrier 20 is not particularly limited as long as it is a substrate having high strength, and for example, a metal plate such as a copper plate can be used. On the carrier 20, a patterned resist is formed by lithography. Subsequently, a metal barrier layer is formed, and an electrolytic plating film is formed by electrolytic plating. Subsequently, the resist is removed using a resist stripper, thereby forming a patterned wiring 40 (wiring pattern) functioning as a conductive circuit (FIG. 2(a)).

Next, the resin sheet 10 is pressure-bonded to the release layer 30 in a state in which one surface of the resin sheet 10 on which the carrier substrate is not disposed and the wiring on which the wiring 40 of the carrier 20 are formed are faced. Thereby, the resin sheet 10 is bonded to the carrier 20. That is, the resin sheet is bonded to the surface of the substrate (carrier 20) on the side where the conductive circuit (wiring 40) is formed. Thereby, the resin sheet 10 can be embedded in the periphery of the wiring 40 or in the gap between the wirings. Thereafter, the carrier substrate is peeled off from the resin sheet 10 (Fig. 2(b)).

Next, an electronic component (for example, a ceramic capacitor 50) is laminated on the peeling surface of the resin sheet 10 (Fig. 2(c)).

Next, a prepreg 60 is laminated on the resin sheet 10 and the ceramic capacitor 50. Thereafter, an opening portion 90 through which the ceramic capacitor 50 is exposed is formed in the prepreg 60 by, for example, laser irradiation, plasma etching, or mechanical drilling (Fig. 3(a)). Thereby, the opening treatment of the resin sheet 10 which is most suitable for the B-stage state can be selected. For the prepreg 60, for example, a prepreg obtained by semi-curing a conventional thermosetting resin composition, or a prepreg using a resin composition for a resin sheet constituting the resin sheet 20 of the present embodiment may be used. body. The film thickness of the prepreg 60 is preferably, for example, 10 to 100 μm, more preferably 10 to 70 μm.

Next, on the ceramic capacitor 50 and the prepreg 60, the resin sheet 10 with the carrier substrate is laminated by thermocompression bonding. Thereby, the periphery and the upper portion of the ceramic capacitor 50 in the inside of the opening can be buried in the resin sheet 10. Also, can be pre- The resin sheet 10 is placed on the infusion body 60. Thereafter, the carrier substrate is peeled off from the resin sheet 10. The peeling layer 30 remains on the peeling surface of the resin sheet 10 (FIG. 3 (b)). At this time, as the carrier substrate of the resin sheet 10, a metal foil can also be used. As the metal foil, for example, a copper foil or the like can be used. Further, instead of the resin sheet 10 used in Fig. 3(b), a general prepreg containing a composition different from the resin composition for the resin sheet constituting the resin sheet 10 may be used. The prepreg can be used in the form of a resin sheet of a carrier substrate. For example, a prepreg with a copper foil may be used to embed the ceramic capacitor 50.

Next, the structure shown in Fig. 3(b) is subjected to heat treatment. Thereby, the resin sheet 10 of the lower layer, the prepreg 60, and the resin sheet 10 of the upper layer can be hardened once. In the present embodiment, the resin sheet 10 on the lower layer of the ceramic capacitor 50 and the resin sheet 10 embedded in the upper layer of the ceramic capacitor 50 can be hardened at one time, so that the number of steps, the manufacturing time, and the like can be reduced to improve the production process. Sex. In addition, the resin sheet 10 of the lower layer is effective in suppressing ceramics even in an unhardened state by setting not only the adhesive force to the lower limit or more but also the lowest melt viscosity. The positional offset of the capacitor 50. Therefore, in the process of FIGS. 2(c) to 3(b), in other words, during the period from when the ceramic capacitor 50 is disposed on the resin sheet 10 until the resin sheet 10 is hardened, it is not hardened. The resin sheet 10 can suppress the positional shift of the ceramic capacitor 50.

In the above description, an example in which primary hardening is performed in FIG. 3(b) has been described, but the invention is not limited thereto. For example, when the ceramic capacitor 50 is placed on the resin sheet 10 (Fig. 2(c)), the resin sheet 10 can be slightly cured. For example, in the state shown in Fig. 2(c), heat treatment is performed to such an extent that the resin sheet 10 is not completely cured. Thereby, the positional deviation of the resin sheet 10 can be further reduced. Further, compared with the case where it is completely hardened, the time for the process can be shortened and the productivity can be improved.

Further, in FIG. 2(c), the resin sheet 10 on which the ceramic capacitor 50 is placed may be completely cured. Thereby, the positional shift of the ceramic capacitor 50 can be further suppressed.

Here, when the resin sheet 10 is used as the resin sheet 10 having the lowest melt viscosity, the lower layer of the resin is formed by the thermocompression bonding of the prepreg 60 or the upper resin sheet 10 or the like. The viscosity of the sheet 10 becomes low, and the ceramic capacitor 50 becomes easy to shift. In this case, the positional shift can be suppressed by performing the complete hardening in FIG. 2(c), but if it is completely cured, a gap is formed in the interface between the lower portion of the ceramic capacitor 50 and the resin sheet 10. Worry. On the other hand, in the case where the primary curing is performed, when the resin is buried in the space around the capacitor, the resin layer of the upper layer and the resin sheet of the lower layer are both reduced in viscosity and flow, so that there is less concern that voids are generated. .

In the present embodiment, the conditions of the thermosetting treatment are not particularly limited, and for example, it can be set to 200 to 220 ° C for about 1 hour. By the hardening treatment, the buildup layer 12 (insulating layer) including the cured product of the resin sheet 10, and the insulating layer 62 containing the cured product of the prepreg 60 are formed. Thereby, the ceramic capacitor 50 can be fixed on the buildup layer 12 of the lower layer. Next, the carrier 20 is peeled off from the peeling layer 30 (Fig. 3(c)).

By the above processing, the circuit board 1 of the present embodiment can be obtained. Further, in the case where the prepreg 60 does not contain a substrate, the coreless circuit substrate 1 having no core layer can be obtained.

[Manufacturing method of electronic device]

The manufacturing steps of the electronic device 100 of the present embodiment will be described with reference to Fig. 4 .

4 is a cross-sectional view showing the steps of manufacturing the electronic device 100 of the present embodiment. Figure.

The circuit board 1 obtained by the above-described manufacturing steps of the circuit board is used. First, the openings (through holes 70, 72) are formed by, for example, performing laser irradiation on both surfaces of the circuit board 1 (FIG. 4(a)). At the bottom of the via 70, a portion of the electrode 54 of the ceramic capacitor 50 is partially exposed. On the other hand, at the bottom of the through hole 72, a part of the wiring 40 is partially exposed.

Next, a wiring layer is formed on both sides of the circuit board 1. In the present embodiment, the wiring layer is one layer. However, the number of layers of the wiring layer can be arbitrarily set (FIG. 4(b)).

The method of forming the wirings 74 and 76 of the wiring layer is not particularly limited, and for example, a method of forming wiring by lithography and selective etching can be used.

Next, a solder resist film 64 is formed on the upper surface side of the circuit substrate 1. An opening portion exposing a portion of the wiring 74 is formed in the solder resist film 64 by, for example, laser irradiation, plasma etching, chemical etching, or lithography. Next, a metal plating layer 78 is formed on the upper surface of the wiring 74 in the opening portion by a plating treatment or the like. The metal plating layer 78 functions as a connection portion to the electrode bumps (bumps 82) of the semiconductor wafer 80.

On the other hand, on the lower surface side of the circuit board 1, a solder resist film 68 is also formed. Similarly, an opening portion for exposing a portion of the wiring 76 is formed in the solder resist film 68. Next, an external connection terminal 86 is formed by mounting a solder ball or the like on the wiring 76 in the opening.

Next, the bumps 82 of the semiconductor wafer 80 are flip-chip bonded to the connection portions (wiring 74, metal plating layer 78) on the upper surface side of the circuit board 1. Further, the underfill resin 84 is filled on the lower side of the semiconductor wafer 80. With the above processing, half can be obtained Conductor device (electronic device 100) (Fig. 4(c)).

In the manufacturing step of the present embodiment, an example in which the resin sheet 10 is a single layer has been described with reference to FIG. 1. However, the resin sheet 10 is not limited to a single layer, and may be two or more layers. Fig. 5 shows an example in which the resin sheet of the present embodiment has two layers. The resin sheet 10 includes a first resin layer 14 (first resin sheet) and a second resin layer 16 (second resin sheet). The first resin layer 14 of the upper layer has the property of stably fixing the ceramic capacitor 50, and the second resin layer 16 of the lower layer has characteristics of being easily embedded in a circuit pattern such as the wiring 40. By setting the resin sheet to two or more layers, the balance between the embedding property to the lower layer and the adhesion to the electronic component of the upper layer can be further improved.

FIG. 7 is a view showing a modification of the ceramic capacitor 50. In the above description, as shown in FIG. 3(c), the ceramic capacitor 50 in which the electrodes 54 are formed at both ends in the longitudinal direction of the main body portion 52 is shown. However, the present invention is not limited thereto, and various types of materials can be used. A ceramic capacitor 50 is constructed. For example, a capacitor 50 having a configuration in which the electrode 54 is disposed only on one surface side of the main body portion 52, that is, a configuration in which the electrode 54 is disposed on the lower side of the main body portion 52 (FIG. 7(a)), Or the electrode 54 is disposed on the upper side of the main body portion 52 (Fig. 7(b)). The electrodes 54 have an electrode pattern. Further, as shown in FIG. 7(c), a capacitor 50 in which the electrode 54 is formed on both surfaces of the main body portion 52 and formed integrally over the entire surface thereof may be used.

In the present embodiment, an example of flip chip connection has been described. However, the present invention is not limited thereto, and various connection methods can be utilized. For example, a wire bonding method can also be utilized.

Further, the present invention is not limited to the above-described embodiments, and modifications, improvements, etc. within the scope of the object of the invention are included in the present invention.

[Examples]

Next, an embodiment of the present invention will be described. Furthermore, the present invention It is not limited to this.

(Preparation of thermosetting resin composition)

For each of the examples and the comparative examples, a varnish-like thermosetting resin composition was prepared. The varnish-like thermosetting resin composition was obtained by dissolving and dispersing the raw materials of the respective components prepared in accordance with Table 1 in the following solvent 1, followed by stirring for 1 hour using a high-speed stirring device. In addition, the numerical value of the compounding ratio of each component in Table 1 shows the compounding ratio (% by weight) of each component with respect to the solid content of the thermosetting resin composition.

The details of the raw materials of the respective components in Table 1 are as follows.

(thermosetting resin)

Thermosetting resin 1: naphthalene modified cresol novolac epoxy resin (HP-5000 manufactured by DIC Corporation)

Thermosetting resin 2: Naphthyl ether type epoxy resin (HP-6000 manufactured by DIC Corporation)

Thermosetting resin 3: 4-functional naphthalene type epoxy resin (EPICLON HP-4710 manufactured by DIC Corporation)

Thermosetting resin 4: bisphenol F type epoxy resin (EPICLON, 830S manufactured by DIC Corporation)

Thermosetting resin 5: phenol novolac type cyanate resin (Primaset PT-30 manufactured by LONZA Corporation)

Thermosetting resin 6: carbodiimide (V-05 manufactured by Nisshinbo Chemical Co., Ltd.)

Thermosetting resin 7: 3-functional alkoxy decane modified phenol novolac (Arakawa Learned by the company P501)

Thermosetting Resin 8: Acrylate Compound (2-Acetyl-2-[4-(ethyloxy)phenyl]ethyl)

(Filler)

Filler 1: spherical cerium oxide (SO-C4 manufactured by Admatechs, average particle size 1.0 μm, treated with phenylamino decane)

Filler 2: Spherical cerium oxide (SO-C4 manufactured by Admatechs, average particle size 1.0 μm, untreated)

(hardening accelerator)

Hardening accelerator 1: tetraphenylphosphonium-tetrakis(4-methylphenyl)borate (TPP-MK)

(coupling agent)

Coupling agent 1: epoxy decane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.)

(solvent)

Solvent 1: methyl ethyl ketone

(Production of resin sheet)

In Examples 1 to 8 and Comparative Examples 1 to 4, the obtained thermosetting resin composition was applied to a polyethylene terephthalate (PET) film as a carrier substrate (38 μm thick). After the above, the solvent was removed at 140 ° C for 2 minutes to form a resin sheet of a carrier substrate having a thickness of 30 μm.

Further, in Example 4, a resin sheet was produced in the following manner. After the obtained thermosetting resin composition was applied onto a PET film (38 μm thick) as a carrier substrate, the solvent was removed at 140 ° C for 2 minutes to form a first resin layer of the first layer. Similarly, the second resin layer of the second layer was obtained. Two layers of the resin layer are formed by bonding the first resin layer and the second resin layer. Then, the carrier substrate is peeled off from the second resin layer, and a resin sheet with a carrier substrate obtained by laminating a first resin sheet having a thickness of 30 μm and a second resin sheet having a thickness of 30 μm is formed.

(adhesion)

The adhesion of the resin sheet was measured in the following manner for each of the examples and the comparative examples. First, the resin sheet with a carrier substrate was bonded to a core material (FR-4 substrate) at 80 °C. Next, the resin sheet and the core material of the bonded carrier substrate were cut into about 10 cm square, and the carrier substrate (PET film) was peeled off to prepare a measurement sample. Subsequently, the measurement sample was placed on a table of an adhesion tester (manufactured by Rhesca Co., Ltd.) set to 25 ° C in a manner that the core material was the next, at 100 gf / 5 mm. 5 sec conditions probe (5mm ) pressed against the assay sample. Thereafter, the probe was detached from the measurement sample under the condition of 2 mm/sec. At this time, the tensile force of the probe from the measured sample is measured, and the peak value is used as the adhesive force (gf/5 mm). ). By the above operation, the adhesion of the peeling surface of the resin sheet after peeling off the PET film was measured. The results are shown in Table 1.

(lowest melt viscosity)

For each of the examples and the comparative examples, the lowest melt viscosity of the resin sheet was measured in the following manner. First, a resin sheet obtained by peeling off a PET film as a carrier substrate from the resin sheet with a carrier substrate obtained above was prepared as a measurement sample. Subsequently, a dynamic viscoelasticity measuring apparatus (device name Physica MCR-301 manufactured by Anton Paar Co., Ltd.) was used for the measurement sample, and the melt viscosity was measured under the following conditions. Based on the obtained measurement results, the lowest melt viscosity (Pa.s) of 50 to 200 ° C was calculated. The results are shown in Table 1.

Frequency: 62.83 rad/sec

Measuring temperature: 50~200°C

Heating rate: 3 ° C / min

Geometric shape: parallel plate

Plate diameter: 10mm

Board spacing: 0.1mm

Load (normal force): 0N (fixed)

Strain: 0.3%

Measuring atmosphere: air

(glass transfer temperature, storage modulus)

For each of the examples and the comparative examples, a resin sheet obtained by peeling off a PET film as a carrier substrate from a resin sheet with a carrier substrate obtained was laminated to prepare a resin sheet having a thickness of 90 μm. Subsequently, the resin sheet was heated at 200 ° C for 1 hour. After the heat treatment, a measurement sample was prepared by cutting out a width of 8 mm, a length of 50 mm, and a thickness of 90 μm. A dynamic viscoelasticity test was carried out on the measurement sample using a dynamic viscoelasticity measuring apparatus (DMS6100 manufactured by Seiko Instruments Co., Ltd.) at a frequency of 1 Hz and a temperature elevation rate of 5 ° C/min. Subsequently, based on the obtained measurement results, the glass transition temperature (° C.) and the storage modulus (GPa) at 25° C. were calculated. The glass transition temperature is determined based on the peak of tan β. The results are shown in Table 1.

(Linear expansion coefficient)

For each of the examples and the comparative examples, a resin sheet obtained by peeling off a PET film as a carrier substrate from a resin sheet with a carrier substrate obtained was laminated to prepare a resin sheet having a thickness of 90 μm. Subsequently, the resin sheet was heat-treated at 200 ° C for 1 hour, and then a width of 4 mm × a length of 20 mm × a thickness of 90 μm was cut out to prepare a measurement sample. For the measurement sample, TMA (manufactured by TA Instruments) was used, and the linear expansion coefficient was measured under the conditions of a temperature increase rate of 10 ° C/min. Subsequently, the average of the measurement results at 25 to 50 ° C was calculated, and this was taken as the linear expansion coefficient (ppm / ° C) which did not reach the glass transition temperature. The results are shown in Table 1.

(Circuit embedding evaluation, adhesion evaluation)

For each of the examples and the comparative examples, the circuit embedding property and the adhesion to the multilayer ceramic capacitor were evaluated as follows. First, a patterned resist is formed by lithography on a copper plate as a carrier. Subsequently, a nickel barrier layer was formed, and then an electrolytic copper plating film (thickness: 12 μm) was formed by electrolytic plating to form a wiring pattern of L/S = 12/12 μm. Next, the resist is removed using a resist stripper. Next, the resin sheet with the carrier substrate obtained above is laminated in such a manner that the resin sheet is embedded in the wiring. After peeling off the layer, the carrier substrate was peeled off from the resin sheet. Subsequently, a ceramic capacitor was placed on the resin sheet. Subsequently, the resin sheet was cured at 200 ° C for 1 hour to form an insulating layer containing a cured product of the resin sheet. Thereby, an evaluation sample was obtained.

The surface of the insulating layer was observed with a microscope by observing the surface of the insulating layer in any of the ten portions of the evaluation sample obtained above, and the circuit embedding property was evaluated based on the following criteria.

◎: No void was observed at all in the wiring pattern between the wiring patterns.

○: No void was observed between the wiring patterns in all portions of the sample, but several undulations were observed on the surface of the insulating layer.

×: A void was observed between the wiring patterns at at least one portion of the sample.

The results are shown in Table 1.

Further, with respect to the evaluation sample obtained above, the adhesion of the multilayer ceramic capacitor was evaluated by the wafer shear strength measurement by the push-pull test according to the following criteria.

◎: 20 N/mm ² or more.

○: 15 N/mm ² or more and less than 20 N/mm ² .

×: Less than 15 N/mm ² .

The results are shown in Table 1.

(carrier peelability)

The carrier peelability of the resin sheet was evaluated in the following manner for each of the examples and the comparative examples. First, a PET film having a thickness of 25 μm was laminated on the surface of the resin sheet with a carrier substrate on the side where the PET film (thickness: 38 μm) was not provided, and a laminate was obtained. Subsequently, the laminate was cut out to a thickness of about 10 cm to prepare a measurement sample. Subsequently, A PET film having a thickness of 38 μm in the measurement sample was fixed to the stage. Subsequently, at a temperature of 25 ° C, one of the four corners was stretched by 5 cm in the vertical direction with respect to the measurement sample for the PET film having a thickness of 25 μm in the measurement sample, and the carrier peelability was evaluated in accordance with the following criteria.

◎: Peeling occurred between the PET film having a thickness of 25 μm and the resin sheet.

○: Partial peeling occurred between the PET film having a thickness of 38 μm and the resin sheet, but peeled off between the PET film having a thickness of 25 μm and the resin sheet.

X: The PET film having a thickness of 25 μm and the resin sheet were not peeled off, and the PET film having a thickness of 38 μm was peeled off from the resin sheet, or the sample was peeled off from the fixing table. The results are shown in Table 1.

(position offset)

For each of the examples and the comparative examples, the positional shift amount of the ceramic capacitor was measured as follows. First, the resin sheet with the carrier substrate was laminated on the copper plate so that the copper plate and the resin sheet were opposed to each other, and vacuum suction was performed for 30 seconds using a batch type vacuum pressure bonding machine. Thereafter, pressurization was carried out using a pressure resistant rubber under the conditions of 30 seconds and a pressure of 1 kg/cm ² . Subsequently, the resin sheet attached to the carrier substrate peels off the carrier substrate. Subsequently, a ceramic capacitor (size 1608) was placed on the resin sheet.

Subsequently, a prepreg having an opening portion formed corresponding to the ceramic capacitor portion is placed on the resin sheet.

Subsequently, the laminated resin sheet was treated by a vacuum press at a pressure of 30 kg/cm ² and 200 ° C for 30 minutes to fix the ceramic capacitor to the resin sheet and to cure the resin sheet. Thereby, a measurement sample is obtained.

Fig. 6 is a schematic plan view showing a method of measuring the positional shift amount. to After the prepreg was placed, the plane distances (X, Y, Z, W) of the four corners of the origins A and B and the ceramic capacitor were measured. The opening portion 90 in Fig. 6 indicates an opening formed in the prepreg.

Next, the resin sheet is hardened. The plane distances (X, Y, Z, W) of the origins A and B of the sample after hardening and the four corners of the ceramic capacitor were measured again. Then, the offset amount is set as the position shift amount for the position of any of the four corners of the capacitor in which the maximum deviation occurs in the above-described step of hardening the resin sheet in X, Y, Z, and W. The results are shown in Table 1.

Further, in Comparative Example 3, since the adhesive sheet was high, the resin sheet was laminated on the copper plate, and after peeling off the carrier substrate from the resin sheet, the copper sheet and the resin sheet were peeled off, or the resin sheet was peeled off. Since the inside is ruptured and peeled off, peeling of the carrier substrate cannot be performed normally. Therefore, the positional shift amount of Comparative Example 3 was regarded as unevaluable.

10‧‧‧Resin sheet

Claims (13)

A resin sheet for a resin sheet that is followed by an electronic component, characterized in that the adhesion at 25 ° C is 80 gf / 5 mm As described above, when the resin sheet is measured using a dynamic viscoelasticity measuring apparatus at a frequency of 62.83 rad/sec and a measurement temperature range of 50 ° C to 200 ° C, the lowest melt viscosity of the resin sheet is 300 Pa. s above and 2000Pa. s below. The resin sheet according to claim 1, wherein when the resin sheet is heat-treated at 200 ° C for 1 hour to obtain a cured product, the cured glass has a glass transition temperature of 160 ° C or higher. The resin sheet according to claim 1, wherein when the resin sheet is heat-treated at 200 ° C for 1 hour to obtain a cured product, the linear expansion coefficient of the cured product which is less than the glass transition temperature is 30 ppm / ° C or less. The resin sheet according to claim 1, wherein when the resin sheet is heat-treated at 200 ° C for 1 hour to obtain a cured product, the cured product has a storage modulus at 25 ° C of 7 GPa or more. The resin sheet of claim 1, wherein the adhesion is 1000 gf/5 mm the following. The resin sheet according to claim 1, comprising: a first resin layer having one surface adjacent to the electronic component and a surface facing the one surface; and a second resin layer provided on the first resin layer 1 the other side of the resin layer. The resin sheet according to claim 6, wherein the minimum melt viscosity of the second resin layer is greater than that of the first resin layer Minimum melt viscosity. The resin sheet according to claim 1, wherein the resin sheet contains a thermosetting resin composition containing a thermosetting resin and a filler. The resin sheet according to claim 8, wherein the thermosetting resin comprises an epoxy resin. The resin sheet of claim 8, wherein the filler material comprises cerium oxide. The resin sheet according to claim 8, wherein the thermosetting resin composition further contains a cyanate resin. The resin sheet of claim 1, wherein the electronic component is a ceramic capacitor. An electronic device comprising: the cured film of the resin sheet according to any one of claims 1 to 12; and the electronic component, which is attached to one surface of the cured film.