JP2011103325A - Composite layer of insulating layer and wiring layer, circuit board using the same, and semiconductor package - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite layer formed of an insulating layer having a smooth and uniform surface shape on which smooth and good wiring with an orderly wiring width can be formed, and a wiring (a wiring layer) formed on the insulating layer, and provide a circuit board using the composite layer, and a semiconductor package. <P>SOLUTION: The composite layer formed of the insulating layer and wiring layer includes the wiring (the wiring layer) formed by a printing method on curable insulating resin (the insulating layer) formed on the substrate by the printing method, wherein the wiring contains at least one or more elements out of Cu, Ag, Au, Al, Ni, Co, Pd, Sn, Pb, In, and Ga. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a composite layer of an insulating layer and a wiring layer, a circuit board using the same, and a semiconductor package.

  From the advantages of low energy, low cost, high throughput, on-demand production, etc., the formation of wiring patterns by the printing method is considered promising. This object is realized by forming a pattern by a printing method using an ink paste containing a metal element and then imparting metal conductivity to the printed wiring pattern. Conventionally, a conductive paste in which flaky silver or copper is mixed with a binder of a thermoplastic resin or a thermosetting resin together with an organic solvent, a curing agent, a catalyst, or the like has been used. This conductive paste is used by applying it to an object by dispenser or screen printing and drying at room temperature or by heating to about 150 ° C. to cure the binder resin to form a conductive film. It was.

  However, since the material for forming a conductive film made of such a conventional conductive paste contains a binder resin, it is difficult to obtain a low resistance film because the contact of particles is hindered. Further, in the conventional silver paste, since the silver particles are in the form of flakes having a particle diameter of 1 to 100 μm, it is impossible in principle to print a wiring having a line width equal to or smaller than the particle diameter of the flake-like silver particles. For this reason, an ink using particles having a particle size of 500 nm or less has been demanded. From these points, the conventional conductive paste is not suitable for forming a fine wiring pattern.

  In order to overcome such drawbacks of the conductive paste, a wiring pattern forming method using metal nanoparticles has been studied, and a method using gold or silver nanoparticles has been studied. Specifically, a dispersion containing gold or silver nanoparticles of 100 nm or less is applied to a substrate by applying a very fine circuit pattern on a substrate by a printing method, and thereafter sintering metal nanoparticles. A wiring layer formed by

  Furthermore, in recent years, a method for forming a wiring pattern by an inkjet printing method as described in Patent Document 1 and a method for manufacturing a printed wiring board by an offset printing method as described in Patent Document 2 have been proposed. Patent Document 3 proposes a method of manufacturing a multilayer printed wiring board by forming an insulating layer having a hole on a substrate by a printing method and further forming a conductor layer by a printing method. According to these production methods, it is possible to produce a multilayer printed wiring board without using large-scale equipment such as press equipment and plating equipment. In addition, since the insulating material and / or the metal nanoparticle dispersion liquid can be printed only in a necessary place, there is an advantage that the use efficiency of the material is very high. However, when metal nanoparticles are used alone, a nano-size melting point drop occurs alone, so that the metal nanoparticles are covered with an organic protective film to prevent fusion and aggregation when used as printing ink. Is the current situation (for example, Patent Document 4). Also, the printing ink has different drawing characteristics of the wiring pattern depending on the type of substrate and / or surface properties such as unevenness and surface free energy, and it is difficult to form a smooth wiring with a uniform wiring width by a printing method.

JP 2003-80694 A JP-A-11-58921 JP 2003-110242 A JP 2005-81501 A

  The present invention has been made in view of the problems of the prior art. That is, the present invention provides a composite layer composed of an insulating layer having a smooth and uniform surface property capable of forming a smooth and smooth wiring with good wiring width, and a wiring (wiring layer) formed on the insulating layer. The purpose is to provide. It is another object of the present invention to provide a circuit board and a semiconductor package using the composite layer.

As a result of examining the above-mentioned drawbacks in detail, the present inventors have been able to form a smooth and linear wiring by using a metal nanoparticle dispersion that does not use a surface treatment agent. It was found that it becomes a wiring formation surface. By using these metal nanoparticle dispersion liquid and insulating resin liquid, wiring drawing by a printing method typified by an ink jet method is possible, and patterning after film formation is performed on a substrate having a different material and / or surface property. A desired wiring can be formed without processing.
The present invention is as follows.

  In the present invention, at least one of Cu, Ag, Au, Al, Ni, Co, Pd, Sn, Pb, In, and Ga is formed on a curable insulating resin (insulating layer) formed on a substrate by a printing method. The present invention relates to a composite layer of an insulating layer and a wiring layer in which a wiring (wiring layer) containing an element is formed by a printing method.

  According to the present invention, a wiring layer includes at least one element of Cu, Ag, Au, Al, Ni, Co, Pd, Sn, Pb, In, and / or metal nanoparticles of oxides thereof. The wiring layer is a composite layer of the insulating layer and the wiring layer.

  The present invention relates to the composite layer of the insulating layer and the wiring layer, wherein the average particle diameter of primary particles of the metal nanoparticles is 1 to 300 nm.

  The present invention relates to a composite layer of the insulating layer and the wiring layer, wherein the wiring (wiring layer) is formed and the metal conductivity is imparted at a low temperature of less than 200 ° C.

  The present invention relates to the above-mentioned composite layer of an insulating layer and a wiring layer using a wiring ink for printing method in which the metal nanoparticles are dispersed in a solvent.

  In the present invention, the curable insulating resin (insulating layer) is formed by using a curable insulating resin ink for printing method that is cured by either or both of heating and light irradiation. Related to the composite layer.

  The present invention relates to the composite layer of the insulating layer and the wiring layer, wherein the curable insulating resin ink for printing method contains an epoxy resin, a curing agent, and a solvent.

  The present invention relates to the composite layer of the insulating layer and the wiring layer, wherein the epoxy resin contains a glycidyl etherified product obtained by condensation reaction of a phenol compound and an aldehyde compound.

The present invention relates to the composite layer of the insulating layer and the wiring layer, wherein the vapor pressure of the solvent is less than 1.34 × 10 ³ Pa.

  The present invention relates to the composite layer of the insulating layer and the wiring layer, wherein the printing method is a plateless printing method.

  The present invention relates to a composite layer of the insulating layer and the wiring layer using an inkjet device or a dispenser device as a printing method.

  The present invention relates to a circuit board using the composite layer of the insulating layer and the wiring layer as part or all of the circuit for electric conduction.

  The present invention relates to a semiconductor package in which the composite layer of the insulating layer and the wiring layer is used as part or all of the circuit for electric conduction.

  According to the present invention, a method of covering a substrate with a curable insulating resin by a printing method such as an ink jet printing method, and forming a wiring on the substrate, a smooth and linear shape on a substrate of different materials and surface properties This wiring can be formed. Also, by forming the wiring and imparting metal conductivity at a low temperature of less than 200 ° C., it is possible to form the wiring on the circuit board or semiconductor package after mounting without requiring heat resistance that can withstand high temperature heating. It becomes.

It is sectional drawing which shows an example of the composite layer of the insulating layer and wiring layer of this invention.

Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.
The insulating layer (hereinafter also referred to as curable insulating resin) formed in the present invention will be described. Usually, the curable insulating resin is formed by a printing method such as an inkjet printing apparatus or a dispenser apparatus. An insulating ink applicable to such a printing method is referred to as a curable insulating resin ink for printing method (hereinafter abbreviated as a curable insulating resin ink).

  The curable insulating resin ink contains a resin and, if necessary, a solvent. Moreover, you may mix | blend a hardening accelerator, a coupling agent, antioxidant, a filler, a surface conditioner, etc. A resin used for the insulating ink is obtained by dissolving a monomer, an oligomer, or the like in a solvent as required, and applying the resin to a substrate, followed by heat treatment to remove the solvent and cure the resin to obtain a curable insulating resin (insulating layer).

  The material (resin) used for the curable insulating resin ink may be any material as long as it generally exhibits electrical insulation. For example, epoxy resin, phenol resin, polyimide resin, polyamide resin, polyamideimide resin, silicone-modified polyamide Although there are an imide resin, a polyester resin, a cyanate ester resin, a BT resin, an acrylic resin, a melamine resin, a urethane resin, an alkyd resin, etc., there is no particular limitation. These may be used alone or in combination of two or more. When these curable insulating resin inks are used for printed wiring boards, it is preferable to use a thermosetting resin from the viewpoint of insulation reliability, connection reliability, and heat resistance. Resins are preferred.

  Examples of the epoxy resin contained in the curable insulating resin ink include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenol type epoxy resin, alicyclic epoxy resin, and aliphatic chain epoxy resin. Glycidyl ester type epoxy resin, or glycidyl etherified product of phenol, cresol, alkylphenol, catechol, bisphenol F, bisphenol A, bisphenol S and other aldehydes such as formaldehyde and salicylaldehyde, and other bifunctional phenols Glycidyl etherified products, difunctional alcohol glycidyl etherified products, polyphenols glycidyl etherified products, and hydrogenated products and halides thereof. , Glycidyl ethers of condensation products of phenols and aldehydes are preferred in view of heat resistance and connection reliability. These epoxy resins may have any molecular weight, and several types can be used in combination.

  Examples of the curing agent used together with the epoxy resin contained in the curable insulating resin ink include amines such as diethylenetriamine, triethylenetetramine, metaxylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, m-phenylenediamine, and dicyandiamide, phthalic anhydride Acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl nadic anhydride, pyromellitic anhydride, trimellitic anhydride, etc. acid anhydrides, imidazole, 2-ethyl Imidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 1-benzyl-2-methylimidazole, 2-heptadecylimidazole, 4 5-diphenylimidazole, 2-methylimidazoline, 2-phenylimidazoline, 2-undecylimidazoline, 2-heptadecylimidazoline, 2-isopropylimidazole, 2,4-dimethylimidazole, 2-phenyl-4-methylimidazole, 2- Imidazoles such as ethyl imidazoline, 2-isopropyl imidazoline, 2,4-dimethyl imidazoline, 2-phenyl-4-methyl imidazoline, and imino groups are acrylonitrile, phenylene diisocyanate, toluidine isocyanate, naphthalene diisocyanate, methylene bisphenyl isocyanate, melamine acrylate Such as imidazoles, bisphenol F, bisphenol A, bisphenol S, and polyvinylphenol Lumpur acids, and phenol, cresol, alkylphenol, catechol, bisphenol F, bisphenol A, and condensates and their halides and aldehydes such as phenol with formaldehyde and salicylaldehyde, such as bisphenol S. These compounds may have any molecular weight, and several types can be used in combination.

  Among the above-mentioned curing agents, a condensate of a phenol compound having a phenolic hydroxyl group and an aldehyde compound is preferable from the viewpoint of heat resistance and connection reliability. Examples of such condensates include hydroquinone, resorcinol, catechol, bisphenol A, bisphenol F, bisphenol S, naphthalenediols, biphenols, phenol novolac resins, resole resins, bisphenol A novolac resins, cresol novolac resins, and halides thereof. , Alkyl group-substituted or nitrogen-containing group-substituted. These can be used alone or in combination of two or more. In addition, the condensate of the phenol compound which has a phenolic hydroxyl group containing the structure shown to a following formula, and an aldehyde compound can be hardened | cured with an epoxy resin, and is preferable at the point from which higher adhesiveness is obtained.

  When using the said epoxy resin (a) and the condensate (b) of the said phenolic compound and an aldehyde compound in combination, both compounding quantity is an equivalent ratio (epoxy equivalent) of an epoxy equivalent and a hydroxyl equivalent from a sclerosing | hardenable viewpoint. / Hydroxyl equivalent) is preferably 0.70 / 0.30 to 0.30 / 0.70, and 0.65 / 0.35 to 0.35 / 0.65 from the viewpoint of solvent resistance and mechanical properties. More preferably, it is 0.60 / 0.40 to 0.40 / 0.60 from the viewpoint of connection reliability, and 0.55 / 0.45 to 0.00 from the viewpoint of heat resistance. The ratio is particularly preferably 45 / 0.55. If the blending amount of both is out of the above equivalent ratio range, the curability tends to be insufficient.

  The weight average molecular weight of the epoxy resin or the curing agent is preferably 20000 or less. Within this range, an increase in viscosity when the insulating ink is used can be sufficiently suppressed.

The solvent contained in the curable insulating resin ink is preferably a solvent having a vapor pressure at 25 ° C. of less than 1.34 × 10 ³ Pa. With such a solvent, an increase in ink viscosity due to the volatilization of the solvent can be suppressed. For example, when only a solvent having a vapor pressure of 25 ° C. of 1.34 × 10 ³ Pa or more is used, the ink viscosity is remarkably increased due to volatilization of the solvent. For example, in the ink jet printing method, droplets may be ejected from the nozzles of the ink jet head. In addition, the ink jet head tends to be clogged.
Note that a solvent having a vapor pressure of less than 1.34 × 10 ³ Pa and a solvent having a vapor pressure of 1.34 × 10 ³ Pa or more may be used in combination, but in that case, the vapor pressure is 1.34 × The blending ratio of the solvent of 10 ³ Pa or more is preferably 60% by mass or less based on the mass of the total amount of the solvent, and more preferably 50% by mass or less from the viewpoint of suppressing an increase in ink viscosity due to solvent volatilization. Further, it is more preferable that the content be 40% by mass or less from the viewpoint of the ability to eject droplets from the nozzles of the inkjet head. Various solvents can be used as long as the vapor pressure is in a desired range and the insulating resin is dispersed or dissolved.

The solvent having a vapor pressure at 25 ° C. of less than 1.34 × 10 ³ Pa may be any solvent that can dissolve the curable resin. Specifically, γ-butyrolactone, cyclohexanone, N-methyl-2-pyrrolidone, Anisole, ethylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol dimethyl ether, diacetone alcohol, 1,3-butylene glycol diacetate, tetradecane, methyl lactate And ethyl lactate. Specific examples of the solvent having a vapor pressure at 25 ° C. of 1.34 × 10 ³ Pa or more include methyl ethyl ketone, methyl isobutyl ketone, toluene, isopropyl alcohol and the like. These solvents can be used alone or in combination of two or more.

  The content ratio of the solvent in the curable insulating resin ink is not particularly limited, and it is preferable to appropriately adjust the viscosity and surface tension of the ink at 25 ° C. to be within the ranges shown below. The content is preferably 30 to 99% by mass.

  The viscosity of the curable insulating resin ink is preferably 50 mPa · s or less at 25 ° C. When the viscosity of the curable insulating resin ink is 50 mPa · s or less, it is possible to more reliably prevent the occurrence of non-ejection nozzles during nozzle printing and the occurrence of nozzle clogging. The viscosity of the curable insulating resin ink is more preferably 1.0 to 30 mPa · s at 25 ° C. By setting the viscosity of the curable insulating resin ink within this range, the droplet diameter can be reduced, the landing diameter of the curable insulating resin ink can be further reduced, and it is easy to cope with fine pattern formation.

  The surface tension at 25 ° C. of the curable insulating resin ink is preferably 20 mN / m or more, and the surface tension can be adjusted with a surface conditioner. When the surface tension of the curable insulating resin ink is less than 20 mN / m, the droplet of the curable insulating resin ink spreads on the substrate after landing and tends to be unable to form a flat film. The surface tension of the curable insulating resin ink is more preferably in the range of 20 to 80 mN / m. This is because when the surface tension of the curable insulating resin ink exceeds 80 mN / m, there is a tendency that inkjet nozzle clogging tends to occur. From the viewpoints of flat film formability and stable inkjet ejection properties, it is more preferably 20 to 40 mN / m.

  As the surface conditioner to be added to the curable insulating resin ink, for example, one of silicone, vinyl, acrylic, and fluorine can be used alone, or two or more can be used in combination.

Various printing methods such as screen printing, letterpress printing, gravure printing, ink jet printing, nanoimprint printing, contact printing, spin coat printing, and printing using dispenser devices The printing method can be applied. Among these, the ink jet printing method is preferable because it can print a desired amount of ink at a desired position without using a special plate, and has features such as material utilization efficiency and ease of adapting to pattern design changes.
As the inkjet printing method, for example, a commonly-known ejection method such as a piezo method for ejecting a liquid by vibration of a piezo element or a thermal method for ejecting a liquid by utilizing the expansion of the liquid by rapid heating can be used. . Among these, the piezo method is preferable from the viewpoint that the ink is not heated. In order to carry out such an ink jet printing method, for example, a normal ink jet apparatus can be used. The optimum nozzle diameter of the head that ejects ink can be selected depending on the desired droplet size.

  As a method of removing the solvent after applying the curable insulating resin ink to the substrate, a heat treatment method of heating the substrate or blowing hot air can be employed. Such heat treatment can be performed, for example, at a heating temperature of 120 to 200 ° C. and a heating time of 0.1 to 2 hours. When a thermosetting resin is used as the resin, the resin can be cured after removing the solvent or simultaneously with removing the solvent. For example, in the case of an ultraviolet curable resin, the resin can be cured by irradiating ultraviolet rays after removing the solvent.

Next, the wiring layer formed in the present invention will be described. The wiring layer formed in the present invention is formed by the following process, for example. That is, the first step of forming the printing method wiring ink on the curable insulating resin (insulating layer) by the printing method, and if necessary, the removal of the solvent of the printing method wiring ink and the firing for imparting conductivity. The electrical wiring is formed by the second process for performing the ligation or reduction treatment.
The wiring layer formed in the present invention is characterized by containing at least one element of Cu, Ag, Au, Al, Ni, Co, Pd, Sn, Pb, In, and Ga.

(Wiring material)
The wiring layer formed in the present invention is usually formed on a curable insulating resin (insulating layer) by a printing method such as an inkjet printing apparatus or a dispenser apparatus. The wiring ink for printing method applicable to such a printing method preferably contains metal nanoparticles and a solvent.

  The metal nanoparticles used in the present invention will be described. As the metal nanoparticles, any of Cu, Ag, Au, Al, Ni, Co, Pd, Sn, Pb, In, Ga and oxides thereof can be used, and metal salts and metal complexes may be contained as a small amount of impurities. Good. The particles may be entirely metal, core-shell metal particles whose surroundings are oxides or almost all of them are oxides (for example, copper oxide), and other elements as long as they can exhibit electrical conductivity after normal processing or treatment. Or a compound thereof. In addition, particles having cuprous oxide and a core / shell structure are more preferable because they can be easily reduced. A commercial item may be used for these metal nanoparticles, and it is also possible to synthesize | combine using a well-known synthesis | combining method. These metal nanoparticles can be used individually by 1 type or in combination of 2 or more types. Moreover, in order to prevent oxidation and aggregation of particles, a dispersant or a surface treatment agent may be used.

  In general, metals have a large specific gravity, and if the particle size is large, the primary particle size of the metal nanoparticles is 1 to 300 nm from the viewpoint that it is easy to settle due to its own weight and it is difficult to stably maintain the dispersed state. Preferably, from the viewpoint of dispersibility when dispersed in a dispersion medium without using a dispersant, it is more preferably 5 to 200 nm, and it is made conductive (reduced resistivity) by continuing good dispersibility and reducing treatment described later. ) Is also easy, and is more preferably 10 to 100 nm. The average primary particle size is calculated by calculating the arithmetic average particle size from the particle size distribution of the volume fraction with respect to the particle size obtained from the intensity of scattered light measured at 25 ° C. by the laser diffraction scattering method, or the nitrogen adsorption BET When the average particle diameter is measured in the powder state, the specific surface area measured by the method is used to calculate the particle diameter based on the specific gravity of the primary particles and assuming that the particle shape is a true spherical particle. Is generally obtained by the latter method.

  In addition, since the metal nanoparticles are applied to a printing method, it is preferable that the average dispersed particle size including secondary aggregates is 500 nm or less. When the average dispersed particle size is 200 nm or less, for example, in the ink jet printing method, problems such as nozzle clogging hardly occur, which is more preferable. Although there may be particles having a dispersed particle diameter of 500 nm or more, it is preferable that the maximum dispersed particle diameter is 2 μm or less because clogging does not occur in ink jet printing.

  Dispersion of the metal nanoparticles to be applied to the printing method includes an ultrasonic disperser, a media disperser such as a bead mill, a cavitation stirrer such as a homomixer or a Silverson stirrer, a counter collision method such as an artemizer, Claire SS5, etc. Can be carried out using an ultra-thin film high-speed rotating disperser, a rotating / revolving mixer, or the like.

Next, the wiring ink for printing method used in the present invention will be described. The wiring ink for printing method preferably contains a solvent having a vapor pressure at 25 ° C. of less than 1.34 × 10 ³ Pa as a solvent. If the solvent has a vapor pressure at 25 ° C. of less than 1.34 × 10 ³ Pa, an increase in the viscosity of the wiring ink for printing method due to the volatilization of the solvent can be suppressed. For example, when only the solvent having a vapor pressure of 25 ° C. of 1.34 × 10 ³ Pa or more is used, the viscosity of the wiring ink for printing method is remarkably increased due to the volatilization of the solvent. It becomes difficult to discharge the ink, and the ink jet head tends to be clogged.
Note that a solvent having a vapor pressure of less than 1.34 × 10 ³ Pa and a solvent having a vapor pressure of 1.34 × 10 ³ Pa or more may be used in combination, but in that case, the vapor pressure is 1.34 × The blending ratio of the solvent of 10 ³ Pa or more is preferably 60% by mass or less based on the mass of the total amount of the solvent, and more preferably 50% by mass or less from the viewpoint of suppressing an increase in ink viscosity due to solvent volatilization. Further, it is more preferable that the content be 40% by mass or less from the viewpoint of the ability to eject droplets from the nozzles of the inkjet head.

Specific examples of the solvent having a vapor pressure of less than 1.34 × 10 ³ Pa at 25 ° C. include γ-butyrolactone, cyclohexanone, N-methyl-2-pyrrolidone, anisole, ethylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, triethylene glycol, Examples include ethylene glycol monomethyl ether, triethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol dimethyl ether, diacetone alcohol, 1,3-butylene glycol diacetate, tetradecane, methyl lactate, and ethyl lactate. Specific examples of the solvent having a vapor pressure at 25 ° C. of 1.34 × 10 ³ Pa or more include methyl ethyl ketone, methyl isobutyl ketone, toluene, isopropyl alcohol and the like. These solvents can be used alone or in combination of two or more.

  The content ratio of the solvent in the wiring ink for printing method is not particularly limited, and it is preferable to adjust appropriately so that the viscosity and surface tension of the ink at 25 ° C. are within the ranges shown below. It is preferable to be 30 to 99% by mass with respect to the mass of the wiring ink for use.

  The viscosity of the wiring ink for printing method is preferably 50 mPa · s or less at 25 ° C. If the viscosity of the wiring ink for printing method is 50 mPa · s or less, it is possible to more reliably prevent the occurrence of non-ejection nozzles during nozzle printing and the occurrence of nozzle clogging. Further, the viscosity of the wiring ink for printing method is more preferably 1.0 to 30 mPa · s at 25 ° C. By setting the viscosity of the wiring ink for printing method within the above range, the diameter of the droplet can be reduced, and the landing diameter of the wiring ink for printing method tends to be further reduced. This facilitates formation of fine wiring.

  The surface tension at 25 ° C. of the wiring ink for printing method is preferably 20 mN / m or more. When the surface tension of the printing method wiring ink is less than 20 mN / m, the printing method wiring ink droplets spread on the curable insulating resin after landing and tend not to form a flat film. The surface tension of the wiring ink for printing method is more preferably in the range of 20 to 80 mN / m. This is because when the surface tension of the wiring ink for printing method exceeds 80 mN / m, there is a tendency that ink jet nozzle clogging tends to occur. From the viewpoint of flat film formation and stable inkjet discharge, it is more preferably 20 to 50 mN / m.

(Wiring formation method)
As a printing method of the wiring ink for the printing method, a printing method similar to the formation of the insulating layer can be used. For example, various printing methods such as a screen printing method, a relief printing method, a gravure printing method, an ink jet printing method, a nanoimprint printing method, a contact print printing method, and a spin coat printing method can be applied. Among these, the ink jet printing method is preferable because it can print a desired amount of ink at a desired position without using a special plate, and has features such as material utilization efficiency and ease of adapting to pattern design changes.

  As a method for removing the solvent after the wiring ink for printing method is deposited on the substrate, a heat treatment method in which the substrate is heated or hot air is blown can be employed. Such heat treatment can be performed, for example, at a heating temperature of 50 to 200 ° C. and a heating time of 0.1 to 2 hours. In addition, the solvent can be removed in a vacuum environment.

(Reduction method)
The reduction or sintering of the wiring layer is not particularly limited as long as it is a method suitable for each wiring layer. The volume resistivity after reduction or sintering is desirably 1 × 10 ⁻⁵ Ω · m or less. If the volume resistivity is higher than this, it may not be used as electrical wiring. From the viewpoint of electrical conductivity as electrical wiring, the volume resistivity is more preferably 1 × 10 ⁻⁶ Ω · m or less, and from the viewpoint of use as a suitable fine wiring with little electrical resistance loss, the volume resistivity is More preferably, it is 1 × 10 ⁻⁷ Ω · m or less.

As a reduction method, for example, in the case of a wiring layer using copper particles containing copper oxide in metal nanoparticles, a reduction method using atomic hydrogen, or a reduction method of heating in a reducing gas atmosphere such as hydrogen or ammonia Is an example. Examples of the method for generating atomic hydrogen include a method using a hot wire apparatus. For example, the pressure in the apparatus is reduced to 10 ⁻³ Pa or less to remove the air in the system. Next, a raw material gas containing hydrogen such as hydrogen, ammonia or hydrazine is sent from a gas inlet to a shower head for diffusing the gas in the chamber. The gas diffused from the shower head passes through a high-temperature catalyst body (e.g., energized and heated to a high temperature, for example, 1700 ° C.) made of tungsten wire, for example, and the source gas is decomposed to generate atomic hydrogen. The copper oxide particles are reduced by the atomic hydrogen, and sintering proceeds. It is also possible to insert a shutter or a shielding plate with a gap that does not block the gas between the catalyst body heated to a high temperature and the sample substrate so that the substrate does not directly receive the radiant heat from the catalyst body. During this process, the temperature of the substrate is kept at 50 ° C. or lower unless directly receiving the radiant heat from the catalyst body or heating the substrate holder. Fusion progresses.
In the present invention, by forming the wiring (wiring layer) and imparting the metal conductivity at a low temperature of less than 200 ° C., it is not necessary to require the substrate or the insulating layer to have a characteristic (heat resistance) that can withstand high-temperature heating. ,preferable.

  In addition, it can be reduced by atomic hydrogen generated by a vacuum plasma apparatus or an atmospheric pressure plasma apparatus using RF or microwave. Other than this, alkylamine borane, hydrazine, hydrazine compound, formaldehyde, aldehyde compound, phosphorous acid compound, hypophosphorous acid compound, adipic acid, formic acid, alcohol, tin (II) compound, metallic tin, hydroxyamines, A wiring layer having a desired volume resistivity can be obtained by a reduction method using a reducing liquid selected from ascorbic acid. In any method, it is possible to form a wiring (wiring layer) and impart metal conductivity at a low temperature of less than 200 ° C.

  The composite layer of the insulating layer and the wiring layer of the present invention is suitable as a circuit board or a circuit for electrical conduction of a semiconductor package. It can be used as a circuit board or a part or all of a circuit for electric conduction of a semiconductor package.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.
The viscosity of the insulating ink (curable insulating resin ink for printing method) in each example is 25 ° C. using a small vibration viscometer SV-10 (trade name) manufactured by A & D Co., Ltd. It was measured. The surface tension of the ink is measured at 25 ° C. using a fully automatic surface tension meter (trade name: CBVP-Z) manufactured by Kyowa Interface Chemical Co., Ltd., which is a surface tension measuring device by the Wilhelmy method (platinum plate method). did.

(Curable insulating resin ink 1)
Bisphenol A novolac type epoxy resin (N-865: Dainippon Ink Chemical Co., Ltd., trade name) 5.79 g, using aminotriazine-containing cresol novolac resin (LA-3018-50P only solid: Dainippon Ink and Chemicals, Inc. Co., Ltd., trade name) 4.21 g, 2-ethyl-4-methylimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.) 0.004 g is changed to 30.50 g of gamma butyrolactone (vapor pressure 2.3 × 10 ² Pa at 25 ° C.) A curable insulating resin ink 1 having a viscosity of 8 mPa · s was obtained by dissolution. Further, the surface tension of the curable insulating resin ink 1 was 44 mN / m.

(Curable insulating resin ink 2)
Bisphenol A novolac type epoxy resin (N-865: Dainippon Ink Chemical Co., Ltd., trade name) 5.79 g, using aminotriazine-containing cresol novolac resin (LA-3018-50P only solid: Dainippon Ink and Chemicals, Inc. Co., Ltd., trade name) 4.21 g, 2-ethyl-4-methylimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.) 0.004 g, surface conditioner (BYK310: product of BYK Chemie, trade name) 0.05 g gamma-butyrolactone (Vapor pressure at 25 ° C. 2.3 × 10 ² Pa) Dissolved in 30.45 g to obtain a curable insulating resin ink 2 having a viscosity of 8 mPa · s. Further, the surface tension of the curable insulating resin ink 2 was 22 mN / m.

(Curable insulating resin ink 3)
Bisphenol A novolac type epoxy resin (N-865: Dainippon Ink Chemical Co., Ltd., trade name) 5.79 g, using aminotriazine-containing cresol novolac resin (LA-3018-50P only solid: Dainippon Ink and Chemicals, Inc. Co., Ltd., trade name) 4.21 g, 2-ethyl-4-methylimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.) 0.004 g, surface conditioner (polyflow WS-314: trade name, manufactured by Kyoeisha Chemical Co., Ltd.) 03 g was dissolved in 30.47 g of gamma butyrolactone (vapor pressure 2.3 × 10 ² Pa at 25 ° C.) to obtain a curable insulating resin ink 3 having a viscosity of 8 mPa · s. Further, the surface tension of the curable insulating resin ink 3 was 38 mN / m.

(Curable insulating resin ink 4)
Bisphenol A novolac type epoxy resin (N-865: Dainippon Ink Chemical Co., Ltd., trade name) 5.79 g, using aminotriazine-containing cresol novolac resin (LA-3018-50P only solid: Dainippon Ink and Chemicals, Inc. Co., Ltd., trade name) 4.21 g, 2-ethyl-4-methylimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.) 0.004 g, surface conditioner (BYK307: manufactured by BYK Chemie, trade name) 0.01 g of gamma butyrolactone (Vapor pressure at 25 ° C. 2.3 × 10 ² Pa) Dissolved in 30.49 g to obtain a curable insulating resin ink 4 having a viscosity of 8 mPa · s. Further, the surface tension of the curable insulating resin ink 4 was 25 mN / m.

(Wiring ink A for printing method)
Copper oxide particles having a primary particle size of 60 nm were dispersed in gamma-butyrolactone so as to have a concentration of 27% by mass to obtain a dispersion having an average dispersed particle size of 100 nm. A wiring ink A having a viscosity of 6 mPa · s and a surface tension of 44 mN / m was obtained.

(Wiring ink B for printing method)
Cobalt oxide particles having a primary particle size of 30 nm were dispersed in gamma-butyrolactone so as to have a concentration of 27% by mass to obtain a dispersion having an average dispersed particle size of 100 nm. A wiring ink B having a viscosity of 10 mPa · s and a surface tension of 44 mN / m was obtained.

(Wiring ink C for printing method)
An α-phase ferric oxide having a primary particle size of 10 nm was dispersed in gamma-butyrolactone so as to have a concentration of 15% by mass to obtain a dispersion having an average dispersed particle size of 800 nm. A wiring ink C having a viscosity of 10 mPa · s and a surface tension of 44 mN / m was obtained.

(Examples 1-5, Comparative Example 1)
(Formation of insulating layer)
A molded encapsulant (CEL-9700ZHF10, manufactured by Hitachi Chemical Co., Ltd., trade name) is heated in an explosion-proof dryer at 180 ° C. for 1 hour, and a UV dry processor (PL16-110A: manufactured by Sen Engineering Co., Ltd., trade name). Was used, and the distance between the UV lamp and the sealing material was adjusted to 1.5 cm, followed by UV irradiation treatment for 3 minutes. The curable insulating resin inks 1 to 4 were respectively applied using an inkjet printing apparatus (MJP-1500V, manufactured by Microjet Co., Ltd.). The set amount of the curable insulating resin was 43 g / m ² .
Each curable insulating resin ink was applied to a substrate (CEL-9700ZHF10) and then cured under the conditions of a heating temperature of 180 ° C. and a heating time of 1 hour to form an insulating layer.

(Insulation layer surface roughness (Ra))
The surface roughness (Ra) of the formed insulating layer was measured using a three-dimensional non-contact surface shape measurement system (Micromap, trade name) manufactured by Ryoka Systems Co., Ltd. The results are shown in Table 1 below.

(Formation of wiring layer)
On the formed insulating layer, the wiring ink for printing method was applied using an inkjet printing apparatus (MJP-1500V, manufactured by Microjet Co., Ltd.). The wiring inks A and B could be discharged well without causing clogging of the inkjet head, but the wiring ink C was clogged. The wiring width was 200 μm and the wiring thickness was 1 μm.

(Reduction / Sintering)
The wiring printed by the ink jet apparatus was dried on a hot plate at 100 ° C. for 30 minutes to remove the solvent. Then, it reduced with the hot wire apparatus. Tungsten wire was used as the catalyst of the hot wire apparatus, and the treatment was performed at a wire temperature of 1800 ° C., a hydrogen flow rate of 70 sccm, a chamber pressure of 3 Pa, and a stage temperature of 60 ° C. or less.

(Wiring formability)
The wiring formability is a value obtained by measuring the wiring width using a 3D non-contact surface shape measurement system (micromap, product name) manufactured by Ryoka Systems Co., Ltd. and dividing the maximum wiring width by the minimum wiring width. A case of a good wiring shape with a wiring width of less than 1.2 times was evaluated as ◯, a case where disconnection did not occur at 1.2 times or more was evaluated as Δ, and a case where disconnection occurred was evaluated as ×. The results are shown in Table 1 below.

(Volume resistivity of wiring layer)
The volume resistivity of the wiring layer is determined by measuring the surface resistance with a 4-probe microresistance measuring device (Loresta MCP-T610, manufactured by Mitsubishi Chemical Corporation), and using the layer thickness obtained by FIB / SIM cross-sectional observation. The resistivity was determined. The results are shown in Table 1 below.

(Comparative Example 2)
The molded sealing material (CEL-9700ZHF10: manufactured by Hitachi Chemical Co., Ltd., trade name) is heated in an explosion-proof dryer at 180 ° C. for 1 hour, and a UV dry processor (PL16-110A: product name of Sen Engineering Co., Ltd.) is used. The distance between the UV lamp and the sealing material was adjusted to 1.5 cm, and UV irradiation treatment was performed for 3 minutes.
The surface roughness (Ra) of the substrate (CEL-9700ZHF10) was measured using a three-dimensional non-contact surface shape measurement system (micromap, trade name) manufactured by Ryoka Systems Co., Ltd. The results are shown in Table 1 below.
The wiring ink for printing method was applied onto the substrate using an inkjet printing apparatus (MJP-1500V, manufactured by Microjet Co., Ltd.). The ink could be ejected satisfactorily without clogging the inkjet head. The wiring width was 200 μm and the wiring thickness was 1 μm.
The wiring printed by the ink jet apparatus was dried on a hot plate at 100 ° C. for 30 minutes to remove the solvent. Then, it reduced with the hot wire apparatus. Tungsten wire was used as the catalyst of the hot wire apparatus, and the treatment was performed at a wire temperature of 1800 ° C., a hydrogen flow rate of 70 sccm, a chamber pressure of 3 Pa, and a stage temperature of 60 ° C. or less.
Evaluation of wiring formability and measurement of the volume resistivity of the wiring layer were performed in the same manner as in the examples. The results are shown in Table 1 below.

As shown in Table 1, a wiring layer having a smooth and excellent linearity could be formed by the method described in the present invention.
In particular, in Examples 3 to 5 where the surface roughness (Ra) of the insulating layer is 0.1 μm or less, the wiring formability is excellent, and the volume resistivity of the wiring layer is low and the insulating property is also excellent. . Moreover, the formation of wiring and the provision of metal conductivity could be performed at a low temperature of less than 200 ° C. (100 ° C. hot plate, stage temperature of 60 ° C. or less).
In the case of Comparative Example 1 using the wiring ink C in which ferric oxide was dispersed, the average dispersed particle size was 800 nm, so that clogging of the ink occurred and wiring formation was difficult.

  As is apparent from the above experimental results, according to the present invention, when the substrate is covered with a curable insulating resin (insulating layer) having a small surface roughness (Ra) by a printing method such as an ink jet printing method, A wiring layer having a smooth and excellent linearity can be formed, and a wiring board and a semiconductor package using the wiring layer can be manufactured.

1. 1. wiring layer, 2. electrodes, Insulating layer, 4 substrates

Claims (13)

  A wiring containing at least one element of Cu, Ag, Au, Al, Ni, Co, Pd, Sn, Pb, In, and Ga on a curable insulating resin (insulating layer) formed on a substrate by a printing method A composite layer of an insulating layer and a wiring layer, in which (wiring layer) is formed by a printing method.   A wiring (wiring layer) in which the wiring layer contains at least one element of Cu, Ag, Au, Al, Ni, Co, Pd, Sn, Pb, In, Ga and / or metal nanoparticles of those oxides The composite layer of an insulating layer and a wiring layer according to claim 1.   The composite layer of an insulating layer and a wiring layer according to claim 2, wherein the average particle size of the primary particles of the metal nanoparticles is 1 to 300 nm.   The composite layer of an insulating layer and a wiring layer according to any one of claims 1 to 3, wherein the formation of the wiring (wiring layer) and the provision of metal conductivity are performed at a low temperature of less than 200 ° C.   The composite layer of an insulating layer and a wiring layer according to any one of claims 2 to 4, wherein a wiring ink for a printing method in which metal nanoparticles are dispersed in a solvent is used.   The insulation according to any one of claims 1 to 5, wherein the curable insulating resin (insulating layer) is formed using a curable insulating resin ink for a printing method that is cured by either or both of heating and light irradiation. Composite layer of wiring layer and wiring layer.   The composite layer of an insulating layer and a wiring layer according to claim 6, wherein the curable insulating resin ink for printing method contains an epoxy resin, a curing agent, and a solvent.   The composite layer of an insulating layer and a wiring layer according to claim 7, wherein the epoxy resin contains a glycidyl etherified product obtained by condensation reaction of a phenol compound and an aldehyde compound. The composite layer of an insulating layer and a wiring layer according to claim 7 or 8, wherein the vapor pressure of the solvent is less than 1.34 × 10 ³ Pa.   The composite layer of an insulating layer and a wiring layer according to any one of claims 1 to 9, wherein the printing method is a plateless printing method.   The composite layer of an insulating layer and a wiring layer according to any one of claims 1 to 10, wherein an inkjet device or a dispenser device is used as a printing method.   The circuit board which used the composite layer of the insulating layer and wiring layer in any one of Claim 1 to 11 for the part or all as an electric conduction circuit.   12. A semiconductor package using the composite layer of an insulating layer and a wiring layer according to claim 1 as part of or all of an electric conduction circuit.

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