JPH1187913A - Manufacture of transfer sheet and multilayered circuit board and image-forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the adhesive force of an image layer to a metal plating film with a safe operation by forming a transfer sheet obtained by superposing a layer of a sheet having an aqueous resin layer formed with a protrusion and recess surface with fine particles each having a specific particle size and provided on a support, and a layer of a photosensitive sheet having an insulating resin layer. SOLUTION: As a support 1, a plastic film is used. Resin used for an aqueous layer 12 is selected from water soluble resin, alkali (water solution) soluble resin, and moisture dispersible resin. It is sufficient that fine particles 12P contained in the layer 12 have a mean particle size of 1 to 10 μm and be selected from any of inorganic fine particles, organic low molecular-weight fine particles and organic polymer fine particles. Roughing of a surface of the aqueous resin layer is for improving adhesive force of the resin layer formed after the aqueous resin layer has been removed and a metal plating film. As an insulating resin layer 13, any material may be used as long as performance necessary for a multilayered circuit board by a build-up method such as process suitability or the like is satisfied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer wiring board, and an image forming method and a transfer sheet which are advantageously used in the method. The present invention particularly relates to a method for manufacturing a multilayer wiring board by a build-up method, and more particularly to a property transfer sheet useful for forming an interlayer insulating film used at that time.

[0002]

2. Description of the Related Art In recent years, the trend of making electronic devices lighter, thinner, smaller, and higher in performance has been rapidly progressing. For this reason, it is necessary to reduce the size of electronic components used in electronic devices, and in order to cope with this, increasing the density of printed wiring boards has become a major issue. The multilayer structure of the multilayer printed wiring board has a structure in which planar conductive layers (wiring patterns) and insulating layers are alternately stacked. By laminating the wiring patterns in this way, it is advantageous to increase the density. Conventionally, in a multilayer wiring board, connection (that is, interlayer connection) of upper and lower circuit patterns (conductive layers) is performed by forming a via hole (forming a hole in an insulating layer) by drilling a hole and forming metal plating on the portion. Was being done. Formation of a via hole by drilling such a hole is difficult to reduce the size of the via hole, and is not suitable for the above-described high density. As one method for increasing the density of printed wiring boards, the build-up method has recently attracted attention. The feature is that holes for interlayer connection are formed by forming fine holes (via holes) using a photosensitive insulating film between layers instead of the conventional method of drilling holes. Further, a technique of forming a via hole by directly irradiating an insulating film with a laser beam without using a photosensitive insulating film has also attracted attention (Japanese Patent Application Laid-Open No. 9-107167).

A specific example of a method of forming an interlayer connection by a via hole using a photosensitive layer insulating film is disclosed in Japanese Patent Laid-Open No. 4-1 / 4-1.
No. 48590. In this method, a photosensitive insulating resin layer is provided on a first circuit pattern having a wiring pattern of a copper layer formed on a substrate, and via holes are formed by photolithography (imagewise exposure and development).
The surface is chemically roughened using a potassium permanganate solution. The chemical roughening treatment at this time is performed in order to increase the adhesion between the insulating resin layer and the copper layer of electroless plating (and the copper layer of electrolytic plating formed thereon). This is thought to be because fine irregularities are formed on the resin surface, and the adhesive force is improved by the so-called anchor effect. Copper is adhered on the insulating resin layer in which the via holes are formed by electroless plating. As a result, copper also adheres to the via hole and the first circuit pattern (copper layer) at the bottom of the via hole, and a copper layer for forming a second circuit pattern connected to the first wiring pattern is formed. This copper layer is patterned to form a second wiring pattern. Hereinafter, similarly, a desired number of wiring patterns can be formed.

However, in the method described in Japanese Patent Application Laid-Open No. 4-148590, that is, the method of forming irregularities on the surface of the insulating resin layer by chemical treatment (surface roughening treatment), the use of potassium permanganate is indispensable for forming the irregularities on the surface. Therefore, such a method is not preferable in terms of safety and environment.

Japanese Unexamined Patent Publication (Kokai) No. 63-126297 discloses a method for improving the adhesive strength between an insulating resin layer and electroless plated copper by adding fine particles soluble in an acid or oxidizing agent solution to a photosensitive insulating resin. After the photosensitive insulating resin is cured and hardened, the dispersed fine particles are dissolved with a strong oxidizing agent consisting of strong acid or chromic acid to form irregularities on the surface of the photosensitive insulating resin layer. A method for improving the adhesion to a membrane is described.

However, even in the method disclosed above, since the treating agent used is an oxidizing agent or a strong acid, it is not preferable in terms of safety and environment. Further, in this method, a photosensitive insulating resin layer containing fine particles is formed by coating. If the process is simpler than printing or coating, and if the formed layer is to be provided on an insulating substrate by a lamination (heating, pressure bonding) method with few defects, fine particles will be contained in the photosensitive insulating resin. Since the particles are dispersed, defects such as mixing of bubbles on the insulating base material are likely to occur, and there is a problem that practical use is difficult. Also, when a via hole is formed by directly irradiating a laser beam to an insulating film, there is a similar problem as a method for improving the adhesive strength to a metal film of electroless plating.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a multilayer wiring in which the adhesion between an image layer of an insulating resin layer formed by laser irradiation and a metal plating film is improved in a safe operation without causing environmental pollution. An object of the present invention is to provide a method for manufacturing a substrate. Another object of the present invention is to provide an image forming method that can be advantageously used in the method for manufacturing the multilayer wiring board. Still another object of the present invention is to provide a transfer sheet that can be advantageously used in the method for manufacturing the multilayer wiring board.

[0008]

According to the present invention, there is provided an aqueous resin layer containing fine particles having an average particle diameter of 1 to 10 μm and having fine irregularities formed on the surface by the fine particles on a support. A transfer sheet comprising a sheet and a photosensitive sheet having an insulating resin layer provided on a support, wherein the aqueous resin layer and the insulating resin layer are superposed in contact with each other; An insulating resin layer is laminated on a water-based resin layer of a sheet containing fine particles of 10 μm and provided on a support with a water-based resin layer having fine irregularities formed on the surface by the fine particles. The lamination of the resin layer is generally performed by coating or sticking) on the transfer sheet. The aqueous resin layer is preferably a water-soluble resin or an alkali-soluble resin. Further, the support is preferably transparent.

The above transfer sheet can be advantageously used in the following method for producing a multilayer wiring board and image forming method. The following process: containing fine particles having an average particle diameter of 1 to 10 μm, on the aqueous resin layer of a sheet in which an aqueous resin layer having fine irregularities formed on the surface by the fine particles is provided on a support, A transfer sheet formed by laminating insulating resin layers,
On the insulating substrate on which the first wiring pattern is formed, the first wiring pattern and the insulating resin layer are superimposed so as to be in contact with each other, and heated and pressed, and then the support is peeled off. Removing the resin layer by contacting the aqueous resin layer with an aqueous liquid; exposing the first wiring pattern by irradiating the insulating resin layer with a laser beam to remove the insulating resin layer in the irradiated area; Forming an insulating resin layer having holes to be formed and having fine irregularities on the surface, forming a plating layer on the surface of the insulating resin layer and the holes, and forming a photoresist layer on the plating layer Forming a second wiring pattern by removing the exposed plating layer by etching after imagewise exposing and developing; and the following steps: average particle diameter Fine particles of 1 to 10 μm Contains, by its fine particles on the provided and becomes the seat of the aqueous resin layer on the aqueous resin layer in which fine irregularities are formed the support surface, the transfer sheet insulating resin layer are laminated,
On the insulating substrate on which the first wiring pattern is formed, the first wiring pattern and the insulating resin layer are superimposed so as to be in contact with each other, and heated and pressed, and then the support is peeled off. Contacting the aqueous resin layer with an aqueous liquid to remove the resin layer; and irradiating the insulating resin layer with a laser beam in an image-wise manner to remove the insulating resin layer in the irradiated area, thereby forming a wiring pattern. Forming an insulating resin image having fine irregularities on the surface of an insulating substrate having the same.

In the above method for manufacturing a multilayer wiring board, the insulating resin layer is preferably a photocurable or thermosetting insulating resin layer. In this case, before or after (preferably after) the step of removing the aqueous resin layer, for curing,
Exposure and heat treatment or heat treatment is preferred. The aqueous liquid for removing the aqueous resin layer is preferably a dilute acid aqueous solution. The plating layer is preferably formed by an electroless plating process and an electrolytic plating process.

Further, the present invention also relates to a method for manufacturing a multilayer wiring board and an image forming method. The following steps: a step of providing an insulating resin layer on the first wiring pattern on the insulating substrate on which the first wiring pattern is formed, containing fine particles having an average particle diameter of 1 to 10 μm, A transfer sheet having an aqueous resin layer having fine irregularities formed on a support is superimposed on the insulating substrate so that the aqueous resin layer and the insulating resin layer are in contact with each other, and heated and heated. Pressure bonding, removing the support after peeling off the support, removing the resin layer by contacting an aqueous liquid with the aqueous resin layer; irradiating the insulating resin layer with laser light to insulate the irradiated area. Removing the resin layer to form an insulating resin layer having a hole through which the first wiring pattern is exposed and having fine irregularities on the surface; and forming a plating layer on the surface of the insulating resin layer and the hole. Forming a photolithography layer, and photolithography on the plating layer. Forming a strike layer, imagewise exposure,
Forming a second wiring pattern by removing the exposed plating layer by etching after developing, and a method of manufacturing a multilayer wiring board; and an insulating substrate on which the first wiring pattern is formed A step of providing a photosensitive insulating resin layer on the first wiring pattern above, wherein the aqueous resin layer containing fine particles having an average particle diameter of 1 to 10 μm and having fine irregularities formed on the surface by the fine particles is transparent; A sheet provided on a support is superimposed on the insulating substrate so that the aqueous resin layer and the photosensitive insulating resin layer are in contact with each other, and a step of applying pressure by heating and pressing is performed. Removing the resin layer by contacting the aqueous resin layer with an aqueous liquid after removing; and irradiating the insulating resin layer with a laser beam imagewise to remove the insulating resin layer in the irradiated area. , With wiring pattern The image forming method comprising steps of, forming an insulating resin image on the surface on an insulating substrate having fine irregularities that.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The transfer sheet of the present invention contains fine particles, and the insulating resin layer comprises a sheet in which an aqueous resin layer having fine irregularities formed on the surface by the fine particles is provided on a support. A transfer sheet provided on a support,
It is obtained by overlapping the aqueous resin layer and the photosensitive insulating resin layer in a contact state. That is, FIG. 1 shows the configuration of the transfer sheet of the present invention. As shown in (1-1) of FIG. 1, a sheet in which an aqueous resin layer 12 having fine irregularities on the surface including fine particles 12p is provided on a support 11, and an insulating resin is provided on another support 14 A sheet provided with the layer 13 is prepared, and as shown in (1-2), two sheets are overlapped so that the water-soluble resin layer 12 and the photosensitive insulating resin layer 13 face each other (usually by lamination). Done). Thereby, the transfer sheet of the present invention is obtained. When the transfer sheet is used in an image forming method and a method for manufacturing a multilayer wiring board, another transfer member 14 is peeled off from the transfer sheet. Further, another support 14 is obtained from this transfer sheet.
The transfer sheet (1--) of the present invention in which a water-soluble resin layer 12 and an insulating resin layer 13 are sequentially provided on a support 11 is provided.
3), and the surface of the insulating resin layer 13 can be further coated with a protective film made of a plastic film such as a polypropylene film to be used as a photosensitive transfer sheet. Further, the insulating resin layer 13 can be provided by a coating method instead of the transfer as described above.

The surface of the aqueous resin layer 12 on the support 11 is
The particles are roughened (roughened) by the fine particles, and the vicinity of the surface of the insulating resin layer 13 on the aqueous resin layer 12 side formed thereon is also roughened following the unevenness. Support 11
Is peeled off, the insulating resin layer 13 of the transfer sheet is laminated on the insulating substrate, and then, for example, a via hole (hole) is formed.
Before irradiating a laser beam to form a layer, the aqueous resin layer 12 is removed, and along with that, the fine particles also fall off or elute. As a result, irregularities are formed on the surface of the insulating resin layer, and good adhesion to the metal plating film is obtained. When the insulating resin layer 13 is formed on the surface of the aqueous resin layer 12 by coating, since the surface of the water-soluble resin layer is roughened, foaming may occur on the surface. This is preferable because such a phenomenon is not observed. In the case of the coating method, the thickness of the photosensitive insulating resin layer may be non-uniform, but the above-described transfer method does not have such a disadvantage.

The transfer sheet of the present invention will be described in detail. As the support 11, a plastic film such as a polyethylene terephthalate film can be used. The thickness of the film is preferably from 10 to 200 μm. 1
When the thickness is less than 0 μm, handling of the film becomes difficult, and wrinkles and the like are easily generated. When the thickness is more than 200 μm, when performing pattern exposure through a support,
Resolution degradation due to light scattering of the support is increased. Further, in consideration of the ability to follow the substrate surface during lamination on an insulating substrate, the thickness is particularly preferably 100 μm or less. The same material as described above can be used for the material of the other support 14.

Aqueous resin layer 12 provided on the support
Can be selected from water-soluble resins, alkali (aqueous solution) -soluble resins, and water-dispersible resins. A resin soluble in water or a resin soluble in alkali (aqueous solution) is preferred. Generally, an aqueous solution of a resin,
Used in the form of aqueous dispersions and emulsions. Preferred examples of the resin material include polyvinyl alcohol and its derivatives, polyvinylpyrrolidone and its derivatives,
Cellulose and its derivatives, gelatin and its derivatives,
Examples thereof include polyacrylic acid and derivatives thereof.
These may be used alone or in combination.

Fine particles 12p contained in the aqueous resin layer 12
Any particles having an average particle diameter of 1 to 10 μm may be used, and any fine particles such as inorganic fine particles, organic low-molecular fine particles, and organic high-molecular fine particles may be used. Preferred examples of the material of the fine particles include silica, calcium silicate, calcium carbonate, zinc oxide, titanium dioxide, zirconia, mullite, calcium hydroxide, talc, aluminum hydroxide, diatomaceous earth, and barium sulfate. These fine particles may be used alone or in combination of two or more. The average particle diameter is particularly preferably in the range of 1 to 7 μm. The particle diameter of the fine particles 12p is represented by an average particle diameter in the present invention. In the present invention, the average aggregated particle diameter (average secondary particle diameter) is expressed as the average particle diameter, if the particles are easily aggregated particles such as ultrafine silica particles and exist in an aggregated state in the layer.

The weight ratio of the fine particles to the aqueous resin is preferably in the range of 0.5 to 5 (fine particles / aqueous resin).
From the viewpoint of the stability of the aqueous resin solution in which the fine particles are dispersed, 4 or less is particularly preferable. If the weight ratio is less than 0.5, the number of irregularities on the surface of the aqueous resin layer is reduced, and the number of irregularities formed on the surface of the edge resin layer applied thereon is also reduced. It is difficult to obtain a high adhesion to the film.

The fine particle-dispersed aqueous resin solution (aqueous resin solution containing fine particles dispersed therein) is usually mixed with an aqueous solution in which a water-soluble resin is dissolved or a mixed solution of water and a solvent such as methanol, followed by mixing and stirring. It can be obtained by: The water-soluble resin solution containing the fine particles is strongly stirred or dispersed by a dissolver, a homogenizer, a paint shaker, a dyno mill, or the like, so that the particle diameter of the fine particles is reduced to obtain a water-soluble resin solution containing the fine particles dispersed therein. Can be. It is also possible to obtain a fine particle dispersion prepared in advance and an aqueous resin by stirring. The preparation method of the fine particle-dispersed aqueous resin solution is not limited to the above method. In addition, a surfactant may be added, or a solvent such as methanol may be mixed with water to be applied onto the support in a good surface condition. Further, a dispersant or the like can be added for the purpose of preventing the sedimentation of the fine particles.

The fine particle-dispersed aqueous resin solution is, for example,
Plastic film (first support) by bar coating etc.
Applied on top. The thickness of the coating film after drying at this time is usually
It is desirable that the thickness be in the range of 2 to 15 μm as measured by a film thickness meter. When the thickness is smaller than 2 μm, the height of the irregularities on the surface of the insulating resin layer becomes small, and the adhesive strength with the metal plating film is reduced. On the other hand, when the thickness is larger than 15 μm, the processing time becomes longer to dissolve or peel off and remove the aqueous resin layer containing the fine particles. In particular, it is preferably 10 μm or less.

In the transfer sheet of the present invention, the surface of the aqueous resin layer is roughened to improve the adhesion between the insulating resin layer formed on the insulating substrate after the transfer and the removal of the aqueous resin layer and the metal plating film. It is to make it. If the surface of the aqueous resin layer is flat, it is easily peeled off even if a metal plating layer is formed thereon, and a circuit board cannot be formed by the build-up method. In the present invention, “roughening” refers to J
Evaluation was performed according to the method specified in IS-K5400, and 5
It is necessary to perform the test to such an extent that at least 8 evaluations can be obtained in the grid test at mm intervals. Also, 9
The peel strength, which is a value obtained by the 0 degree peel test, is 0.
It is preferably at least 55 kg / cm.

Next, the insulating resin layer of the transfer sheet will be described. As the insulating resin, the present invention satisfies the performance required for a multilayer wiring board by a build-up method, such as processability such as insulation properties, pattern forming properties, adhesion, strength, electroless plating resistance, and electroplating resistance. As long as any material can be used. As the insulating resin of the insulating resin layer,
Epoxy resins, acrylic resins, resins modified with amines (such as benzylamine and cyclohexylamine) of a styrene / maleic anhydride copolymer, and the like can be given.
It is preferable that the insulating resin further has a photo-curing property or a thermosetting property. In this case, it is preferable to perform exposure and heat treatment or heat treatment for curing before or after (preferably after) a step of removing the aqueous resin layer described below. Preferable examples of the photocurable insulating resin are disclosed in JP-A-7-17-1.
No. 10577, JP-A-7-209866 and the like, a photopolymerization initiator or an addition-polymerizable monomer having a photopolymerization initiator system and an ethylenically unsaturated double bond, and styrene / maleic anhydride A photosensitive insulating resin containing a resin modified with an amine (benzylamine, cyclohexylamine, etc.) of the copolymer can be used.

The sheet for laminating the insulating resin layer on the aqueous resin layer is formed by applying an insulating resin solution on a support different from the support on which the aqueous resin layer is formed, and drying to form the insulating resin layer. It is obtained by doing. A surfactant, a mat material (fine particles), and the like may be added to the insulating resin solution as needed to impart coating suitability. The coating solvent is not particularly limited, but methyl ethyl ketone, cyclohexanone and the like are preferably used. After applying and drying the photosensitive insulating resin solution,
A polypropylene film or the like may be laminated to protect the surface. As shown in FIG. 1, the transfer sheet of the present invention is obtained by laminating the sheet and the sheet generally by lamination.

Next, an image forming method and a method of manufacturing a multilayer wiring board according to the present invention will be described with reference to FIGS. First, as shown in (2-1) of FIG. 2, on an insulating substrate 21 on which a first wiring pattern 22 made of a copper layer is formed, the transfer sheet from which the support 14 has been removed is placed on the insulating resin layer 13. Are overlapped so as to contact the first wiring pattern side surface of the insulating substrate, and press-bonded by heating and pressing. This is usually performed using a laminator. If the surface of the photosensitive insulating resin layer is covered with a protective film such as a polypropylene film or a polyethylene film, the protective film is peeled off to expose the insulating resin layer.

As the material of the insulating substrate, various materials such as an insulating material and a metal material can be used. Examples of the insulating substrate include an organic substrate, an inorganic substrate, and a composite thereof. A glass epoxy substrate (epoxy substrate containing glass fiber), a ceramic substrate, or the like is preferable.

After the pressure bonding, the support 11 is peeled off, and then a laminate in which the insulating resin layer 13 and the aqueous resin layer 12 are formed on the insulating substrate 21 as shown in FIG. In order to form irregularities on the surface of the insulating resin layer 13, the aqueous resin layer 12 is removed. The removal of the aqueous resin layer 12 is performed by contacting an aqueous liquid. As the aqueous liquid, an aqueous solution of a dilute acid is preferable. The aqueous liquid can optionally contain a surfactant and an organic solvent having an affinity for water. By the above process, as shown in (2-3) of FIG. 2, a laminate in which the insulating resin layer 13 having the unevenness formed on the surface is formed on the insulating substrate 21 is obtained.

Next, as shown in FIG. 2 (2-3),
By irradiating the insulating resin layer 13 with a laser beam and removing the insulating resin layer in the irradiated area, the first wiring pattern was exposed on the insulating resin layer 13 as shown in (2-4) of FIG. Via hole (interlayer (wiring pattern) connection hole) 2
Form 3 Excimer laser,
A CO ₂ laser and a YAG laser are generally used, and an excimer laser and a CO ₂ laser are preferable. In the case of a CO ₂ laser, a short-pulse CO ₂ laser is preferable, and the pulse width is particularly preferably in the range of 10 ⁻⁴ to 10 ⁻⁸ seconds.

In the case where the insulating resin layer is photo-curable or thermo-curable, after the laser beam irradiation, exposure or exposure and heating is performed to sufficiently cure the insulating resin layer. The curing (post-bake) conditions were 200 to 5000 using an exposure machine.
Exposure under conditions of mj / cm ² and 120 ° C. to 200
Heating in the range of ° C. is preferred. Thereby, the curing of the insulating resin sufficiently proceeds, and the heat resistance and the strong alkali resistance during electroless plating are further improved. When the insulating resin layer is photocurable, the entire surface may be exposed before laser light irradiation. The surface of the insulating resin layer 13 in which the via hole is formed is formed with irregularities, and the anchor effect obtained by this shape is considered to be the effect of the metal layer (second layer) formed by electroless plating and electrolytic plating in a subsequent step. Of the wiring pattern). The above exposure is generally performed by ultraviolet light.
As the light source, an ultra-high pressure mercury lamp or the like can be used, and any of diffused light and parallel light may be used.

Subsequently, by performing electroless plating and electrolytic plating, as shown in FIG. 3 (2-5), the insulating resin layer 13 and the hole thereof are also covered with the electroless plating layer and the electrolytic plating layer. A plating layer 24 is formed, and the plating layer serving as the second wiring pattern is connected to the first wiring pattern (interlayer connection portion 25 is formed). When performing electroless plating, pretreatment such as degreasing, applying a catalyst, or activating a catalyst is performed before the electroless plating. This step is not particularly limited, and a commercially available processing solution known to those skilled in the art can be appropriately used. Further, the degreasing treatment does not necessarily have to be performed. As the metal for the electroless plating, copper, nickel, or the like can be used.
It is about 2 to 0.5 μm.

Electroplating is preferred because copper is usually suitable for wiring. As the electrolytic copper plating solution, a copper sulfate bath, a copper pyrophosphate bath, or the like can be used. Of course, it is not limited to these.

After electrolytic plating (eg, copper plating), wiring is formed by a normal subtractive method. At this time, the photoresist layer is formed on the plating layer by laminating a commercially available film-like photoresist (DFR) or applying a liquid photoresist. As shown in (2-6) of FIG. 3, exposure (UV exposure) is performed on the photoresist layer PR provided on the plating layer 24 via a mask M2 for forming a second wiring pattern. .

After the development, the exposed plating layer is removed by etching. As a result, (2-7) in FIG.
As shown in (2), a second wiring pattern 26 and an interlayer connection region 27 having via holes for connecting the second wiring pattern and the first wiring pattern are formed. Note that known photoresist materials, developing solutions, and etching solutions can be used.

By repeating the above steps, a multilayer wiring board is formed.

Next, another example of the method of forming an image and the method of manufacturing a multilayer wiring board of the present invention using an aqueous resin layer containing fine particles will be described with reference to FIGS. As shown in (4-1) of FIG. 4, the first wiring pattern 52
And an insulating substrate 51 having an insulating resin layer 53,
A transfer sheet provided with an aqueous resin layer 42 containing fine particles 42p on 1 is superposed so that the insulating resin layer 53 and the aqueous resin layer 42 are in contact with each other. The surface of the aqueous resin layer 42 on the support 41 is roughened (roughened) by fine particles, and the aqueous resin layer 4 of the insulating resin layer 53 laminated thereon is formed.
The vicinity of the surface on the second side is also roughened following the irregularities. For example, before irradiating the insulating resin layer 53 formed on the insulating substrate with a laser beam to form a via hole (hole), the aqueous resin layer 42 is removed. Or elute. As a result, irregularities are formed on the surface of the photosensitive insulating resin layer, and good adhesion to the metal plating film is obtained.

After the pressure bonding, the support 41 is peeled off, and then a laminate in which an insulating resin layer 53 and an aqueous resin layer 42 are formed on an insulating substrate 51 as shown in FIG. In order to form irregularities on the surface of the insulating resin layer 53, the aqueous resin layer 42 is removed. The removal of the aqueous resin layer 42 is performed by contacting an aqueous liquid. As the aqueous liquid, an aqueous solution of a dilute acid is preferable. The aqueous liquid can optionally contain a surfactant and an organic solvent having an affinity for water. By the above processing, as shown in (4-3) in FIG. 4, a laminate in which the insulating resin layer 53 having the unevenness formed on the surface is formed on the insulating substrate 51 is obtained.

Next, by irradiating the insulating resin layer 53 with laser light to remove the insulating resin layer in the irradiated area,
As shown in (4-4) of FIG. 4, via holes (interlayer (wiring pattern) connection holes) 54 where the first wiring pattern is exposed are formed in the insulating resin layer 53. As the laser light, those described above can be used.

In the case where the insulating resin layer is photo-curable or thermo-curable, the insulating resin layer is sufficiently cured (post-cured) by irradiating the laser beam and then performing exposure or exposure and heating as described above.

Subsequently, by performing the electroless plating and the electrolytic plating, as shown in FIG. 5 (4-5), the electroless plating layer and the electrolytic plating layer are formed on the insulating resin layer and also in the holes thereof. A plating layer 55 is formed, and the plating layer serving as the second wiring pattern is connected to the first wiring pattern (interlayer connection portion 56 is formed).

After electrolytic plating (eg, copper plating), wiring is formed by a usual subtractive method. At this time, the photoresist layer is formed on the plating layer by laminating a commercially available film-like photoresist (DFR) or applying a liquid photoresist. As shown in (4-6) of FIG. 5, the photoresist layer PR2 provided on the plating layer 55 is exposed through a mask M4 for forming a second wiring pattern.

After the development, the exposed plating layer is removed by etching. As a result, (4-7) in FIG.
As shown in FIG. 7, an interlayer connection region 58 having a second wiring pattern 57 and a via hole connecting the second wiring pattern and the first wiring pattern on the insulating resin layer 53.
Is formed.

By repeating the above steps, a multilayer wiring board is formed.

[0041]

【Example】

[Example 1] (I) Film (sheet) with fine particle-containing aqueous resin layer 1) Preparation of fine particle dispersion liquid 50 g of calcium carbonate fine particles (average particle diameter: 4.4 µm; Tunex E, manufactured by Shiraishi Industry Co., Ltd.) and ions Exchange water 5
And mixed with a paint shaker for 30 minutes. 2) Preparation of Film with Aqueous Resin Layer Containing Fine Particles On a 75 μm polyester film, a coating solution for forming an aqueous resin layer having the following composition was dispersed for 60 minutes with a paint shaker, applied, and dried at 100 ° C. for 10 minutes. , 5μ
An aqueous resin layer having a thickness of m was formed.

<Composition of Aqueous Resin Layer Forming Coating Solution> Polyvinyl alcohol (10% by weight aqueous solution; 37.5 parts by weight PVA205, manufactured by Kuraray Co., Ltd.) Polyvinylpyrrolidone (10% by weight aqueous solution; 18.8 parts by weight K905) Shin-Etsu Chemical Co., Ltd.) Hydroxymethylcellulose (5% by weight aqueous solution; 75.0 parts by weight TC5E, manufactured by Gokyo Sangyo Co., Ltd.) 59.4 parts by weight of the fine particle dispersion 59.4 parts by weight Surfactant (30% by weight solution; Surflon S131) , 0.65 parts by weight (made by Asahi Glass Co., Ltd.) 40.0 parts by weight ion-exchanged water

(II) Film with an Insulating Resin Layer (Transfer Sheet) A 75 μm polyester film is coated with a photocurable insulating resin layer forming coating solution having the following composition, dried at 100 ° C. for 10 minutes, and dried at 65 μm. An insulating resin layer having a thickness was formed.

<Composition of Coating Solution for Forming Photocurable Insulating Resin Layer> Styrene / maleic acid / butyl acrylate copolymer 50.0 parts by weight (monomer composition ratio: 40/32/28 (mol), weight average molecular weight: (30000% by weight cyclohexanone solution) Photopolymerization initiator (9-phenylacridine, 0.77 parts by weight, manufactured by Nippon Siber Wagner Co.) Polyfunctional monomer (DPHA, 1.0.8 parts by weight Polyfunctional monomer (R712, manufactured by Nippon Kayaku Co., Ltd.) 4.63 parts by weight Surfactant (F176PF, manufactured by Dainippon Ink and Chemicals, Inc.) 53 parts by weight Methyl ethyl ketone 14.7 parts by weight

(III) Preparation of Multilayer Wiring Board 1) Preparation of Transfer Sheet A film (sheet) with a fine particle-containing aqueous resin layer and a film (transfer sheet) with an insulating resin layer were superimposed and attached with a laminator.

2) Preparation of Multilayer Wiring Board The film of the transfer sheet is peeled off, the insulating resin layer of the second transfer sheet is transferred onto the aqueous resin layer, and the aqueous resin layer and the insulating resin layer are provided on the film. A transfer sheet was obtained.
A wiring pattern (first wiring pattern) having a width of 100 μm and a gap of 120 μm was formed on a double-sided copper-clad laminate having a copper layer having a thickness of 18 μm on both sides by a known subtractive method. The sheet was attached with a laminator such that the wiring surface and the insulating resin layer were in contact with each other. Next, on an insulating resin layer (having an aqueous resin layer and a polyethylene terephthalate film on the surface),
Irradiation with ultraviolet light was performed at 200 mJ / cm ^{2 using} a diffusion exposure machine. The polyethylene terephthalate film was peeled off from the aqueous resin layer, and the substrate having the aqueous resin layer and the insulating resin layer was immersed in a 2.5% dilute sulfuric acid aqueous solution at 24 ° C. for 2 minutes to remove the aqueous resin layer. . Next, the substrate was heated at 160 ° C. for 60 minutes to perform a curing treatment.

The exposed region of the insulating resin layer where via holes were to be formed was irradiated with excimer laser light to remove the resin layer in that region, and via holes were formed in the insulating resin layer. Electroless plating was formed on the substrate having the insulating resin layer with via holes by the following process using the following processing agent. I) The substrate was immersed in a pretreatment agent (PC236, manufactured by Meltex) at 25 ° C. for 2 minutes, and then washed with pure water for 2 minutes. II) The above substrate was immersed in a catalyst imparting agent (Activator 444, manufactured by Meltex Corporation) at 25 ° C. for 6 minutes, and then washed with pure water for 2 minutes. III) Activation agent (PA491, manufactured by Meltex Corporation)
Then, the substrate was immersed at 25 ° C. for 10 minutes, and then washed with pure water for 2 minutes. IV) Electroless plating solution (CU390, manufactured by Meltex Corporation)
Then, the substrate was immersed in the condition of 25 ° C. and pH 12.8 for 20 minutes, and then washed with pure water for 5 minutes. V) Dried at 100 ° C. for 15 minutes. As a result, an electroless copper plating film having a thickness of 0.3 μm was formed on the insulating resin layer.

Subsequently, the film was immersed in a degreasing agent (PC455) manufactured by Meltex Co., Ltd. at 25 ° C. for 30 seconds, washed with water for 2 minutes, and then subjected to electrolytic copper plating. The electrolytic copper plating solution is
Copper sulfate 75 g / L, sulfuric acid 190 g / L, chlorine ion about 5
0 ppm and Covertex PCM manufactured by Meltex
It has a composition of 5 mL / L.
Plating was performed under the conditions of 100 cm ² and 40 minutes. As a result, about 20 μm of copper was deposited (see (2-5) in FIG. 2). Next, the obtained substrate having the plating layer was placed in an oven and left at 170 ° C. for 60 minutes to perform an annealing treatment. Using a dry film photoresist, imagewise exposure and development followed by exposed plating layer (copper)
Was performed to form a second wiring pattern and an interlayer connection region (see (2-6) in FIG. 3). When a wiring pattern and an interlayer connection region were formed on the obtained insulating resin layer and subjected to a soldering heat test at 260 ° C. for 20 seconds, the wiring and the like did not peel off or swell. In addition, a grid test at 5 mm intervals according to JIS-K5400 also gave a score of 10 points, indicating that the adhesion between the wiring pattern and the insulating resin layer was good. Furthermore, the substrate is 100 mm
The sheet was cut to a width and subjected to a 90 ° peel test using a Tensilon tensile tester to measure the peel strength.
g / cm or more.

Further, a transfer sheet was laminated thereon again to form a third-layer wiring pattern in the same manner as described above, but no problem occurred in the solder heat resistance test. Also,
A grid test at 5 mm intervals according to JIS K5400 also gave a score of 10 points, indicating that the adhesion between the wiring pattern and the insulating resin layer was good.

Example 2 (I) Film with Fine Particle-Containing Aqueous Resin Layer (Transfer Sheet) 1) Preparation of Fine Particle Dispersion Calcium Carbonate Fine Particles (Average Particle Diameter: 4.4 μm; Tunex E, manufactured by Shiraishi Industry Co., Ltd.) ) 50g and ion exchange water 5
And mixed with a paint shaker for 30 minutes. 2) Preparation of Film with Aqueous Resin Layer Containing Fine Particles A coating solution for forming an aqueous resin layer having the following composition was dispersed on a 75 μm polyester film using a paint shaker for 60 minutes, applied, and dried at 100 ° C for 10 minutes. And 5
An aqueous resin layer having a thickness of μm was formed.

<Composition of Aqueous Resin Layer Forming Coating Solution> Polyvinyl alcohol (10% by weight aqueous solution; 37.5 parts by weight PVA205, manufactured by Kuraray Co., Ltd.) Polyvinylpyrrolidone (10% by weight aqueous solution; 18.8 parts by weight K90) Shin-Etsu Chemical Co., Ltd.) Hydroxymethylcellulose (5% by weight aqueous solution; 75.0 parts by weight TC5E, manufactured by Gokyo Sangyo Co., Ltd.) 59.4 parts by weight of the fine particle dispersion 59.4 parts by weight Surfactant (30% by weight solution; Surflon S131) , 0.65 parts by weight (made by Asahi Glass Co., Ltd.) 40.0 parts by weight of ion-exchanged water

(II) Film with an Insulating Resin Layer (Transfer Sheet) A 75 μm polyester film is coated with a photocurable insulating resin layer forming coating solution having the following composition,
After drying for 5 minutes, a photosensitive insulating resin layer having a thickness of 65 μm was formed.

<Composition of Photocurable Insulating Resin Layer Forming Coating Solution> Styrene / maleic acid / butyl acrylate copolymer 50.0 parts by weight (monomer composition ratio: 40/32/28 (mol), weight average molecular weight: about (30000% by weight cyclohexanone solution) Photopolymerization initiator (9-phenylacridine, 0.77 parts by weight, manufactured by Nippon Shibelwagne) Multifunctional monomer (DPHA, Japan) 10.8 parts by weight Polyfunctional monomer (R712, manufactured by Nippon Kayaku Co., Ltd.) 4.63 parts by weight Surfactant (F176PF, manufactured by Dainippon Ink and Chemicals, Inc.) 2.53 Parts by weight Methyl ethyl ketone 14.7 parts by weight

(III) Preparation of Multilayer Wiring Board A wiring pattern (first wiring pattern) having a width of 100 μm and a gap of 120 μm was formed on a double-sided copper-clad laminate having a copper layer having a thickness of 18 μm on both sides by a known subtractive method. A photosensitive transfer sheet having the above-mentioned insulating resin layer was attached on the wiring by a laminator so that the wiring surface and the insulating resin layer were in contact with each other, and the support was peeled off. Next, the transfer sheet having the aqueous resin layer was superimposed on the copper-clad laminate so that the photosensitive insulating resin layer and the aqueous resin layer on the first wiring pattern were in contact with each other, and were attached with a laminator. Next, ultraviolet light was applied to the insulating resin layer (having an aqueous resin layer and a polyethylene terephthalate film on the surface) at 200 mJ / cm ² by a diffusion exposure machine.
Irradiation was performed under the following conditions. The polyethylene terephthalate film is peeled off from the aqueous resin layer, and the substrate having the aqueous resin layer and the insulating resin layer is placed in a 2.5% dilute sulfuric acid aqueous solution.
The aqueous resin layer was removed by immersion at 4 ° C. for 2 minutes. Next, the substrate was heated at 160 ° C. for 60 minutes to perform a curing treatment.

The exposed region of the insulating resin layer where via holes were to be formed was irradiated with excimer laser light to remove the resin layer in that region and form via holes in the insulating resin layer. The substrate having the insulating resin layer with via holes was subjected to electroless plating in the same manner as in Example 1.

Subsequently, a plating layer was formed in the same manner as in Example 1. Next, an annealing treatment was performed in the same manner as in Example 1.
Then, development was performed after imagewise exposure in the same manner as in Example 1, followed by etching to form a second wiring pattern and an interlayer connection region (see (4-7) in FIG. 5).
When a wiring pattern and an interlayer connection region were formed on the obtained insulating resin layer and subjected to a soldering heat test at 260 ° C. for 20 seconds, the wiring and the like did not peel off or swell. In addition, a grid test at 5 mm intervals according to JIS-K5400 also gave a score of 10 points, indicating that the adhesion between the wiring pattern and the insulating resin layer was good. In addition, the substrate
It was cut to a width of 00 mm, and 9 was cut using a Tensilon tensile tester.
When a 0 degree peel test was performed to measure the peel strength,
It was 0.7 kg / cm or more.

Further, a third-layer wiring pattern was formed thereon in the same manner as described above, but no problem occurred in the solder heat resistance test. In addition, a grid test at 5 mm intervals according to JIS K5400 gave a score of 10 points, indicating that the adhesion between the wiring pattern and the insulating resin layer was good. Furthermore,

[0058]

According to the present invention, the transfer sheet of the present invention is laminated on an insulating base material having a wiring pattern formed thereon, and after removing the aqueous resin layer containing fine particles, the surface of the insulating resin layer is irradiated with a laser beam to form irregularities and via holes. Can be easily formed, and therefore the resin surface is polished by honing or the like, and the surface is roughened without using a processing solution that is not environmentally unfavorable, such as potassium permanganate or chromic acid. And the adhesive strength to metal plating can be significantly improved. Thus, according to the present invention,
The manufacturing process of the multilayer wiring board by the build-up method can be greatly simplified.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a photosensitive transfer sheet of the present invention and a method for producing the same.

FIG. 2 is a schematic cross-sectional view for explaining an image forming method and a method for manufacturing a multilayer wiring board of the present invention.

FIG. 3 is a schematic cross-sectional view for explaining the method for manufacturing a multilayer wiring board (a step following FIG. 2) according to the present invention;

FIG. 4 is a schematic cross-sectional view for explaining another example of the image forming method and the method for manufacturing a multilayer wiring board of the present invention.

FIG. 5 is a schematic cross-sectional view for explaining the method for manufacturing a multilayer wiring board of the present invention (a step following FIG. 4).

[Explanation of symbols]

 11, 41 Support 12, 42 Aqueous resin layer 12p, 42p Fine particles 13, 53 Insulating resin layer 14 Support 21, 51 Insulating substrate 22, 52 First wiring pattern 23, 54 Via hole 24, 55 Plating layer 25, 56 Interlayer connection part 26, 57 Second wiring pattern 27, 58 Interlayer connection part area M2, M4 Mask PR, PR2 Photoresist

Claims (6)

[Claims] 1. A sheet comprising fine particles having an average particle diameter of 1 to 10 μm, on which an aqueous resin layer having fine irregularities formed on the surface is provided on a support, A photosensitive sheet provided on the body,
A transfer sheet in which the aqueous resin layer and the insulating resin layer are overlaid in contact with each other. 2. A sheet comprising fine particles having an average particle size of 1 to 10 μm and having fine irregularities formed on the surface by the fine particles is provided on a sheet of the support, on which the aqueous resin layer is formed. And a transfer sheet on which an insulating resin layer is laminated. 3. The following step: the average particle diameter is 1 to 10 μm
A transfer sheet comprising an insulating resin layer laminated on the aqueous resin layer of a sheet in which an aqueous resin layer having fine irregularities formed on the surface by the fine particles is provided on a support. A step of superposing the first wiring pattern and the insulating resin layer on the insulating substrate on which the first wiring pattern is formed so as to be in contact with the first wiring pattern, and applying pressure by heating and pressing. After the support is peeled off, Contacting the aqueous resin layer with an aqueous liquid to remove the resin layer; irradiating the insulating resin layer with a laser beam to remove the insulating resin layer in the irradiated area; Forming an insulating resin layer having an exposed hole and having fine irregularities on the surface, forming a plating layer on the surface of the insulating resin layer and the hole, and forming a photoresist layer on the plating layer. Formed, imagewise exposed and developed After the step of forming a second wiring pattern exposed plating layer is removed by etching, a method for manufacturing a multilayer wiring board comprising a. 4. The following step: the average particle diameter is 1 to 10 μm
A transfer sheet comprising an insulating resin layer laminated on the aqueous resin layer of a sheet in which an aqueous resin layer having fine irregularities formed on the surface by the fine particles is provided on a support. A step of superposing the first wiring pattern and the insulating resin layer on the insulating substrate on which the first wiring pattern is formed so as to be in contact with the first wiring pattern, and applying pressure by heating and pressing. After the support is peeled off, Contacting the aqueous resin layer with an aqueous liquid to remove the resin layer; and irradiating the insulating resin layer with a laser beam in an imagewise manner to remove the insulating resin layer in the irradiated area, thereby forming a wiring pattern. Forming an insulating resin image having fine irregularities on the surface thereof on an insulating substrate having the same. 5. The following step: a step of providing an insulating resin layer on the first wiring pattern on the insulating substrate on which the first wiring pattern is formed, containing fine particles having an average particle diameter of 1 to 10 μm. Then, a transfer sheet having an aqueous resin layer having fine irregularities formed on the surface by the fine particles provided on a support is superposed on the insulating substrate so that the aqueous resin layer and the insulating resin layer are in contact with each other. Heating and pressurizing by pressing, removing the support, and then contacting the aqueous resin layer with an aqueous liquid to remove the resin layer; irradiating the insulating resin layer with a laser beam; Removing the insulating resin layer in the irradiation area to form an insulating resin layer having holes through which the first wiring pattern is exposed and having fine irregularities on the surface; the insulating resin layer and the holes Forming a plating layer on the surface of the Layers forming a photoresist layer, imagewise exposure, after developing, the step of forming a second wiring pattern exposed plating layer is removed by etching, a method for manufacturing a multilayer wiring board comprising a. 6. The following step: a step of providing a photosensitive insulating resin layer on the first wiring pattern on the insulating substrate on which the first wiring pattern is formed, wherein fine particles having an average particle diameter of 1 to 10 μm are formed. Containing, a sheet having an aqueous resin layer having fine irregularities formed on the surface by the fine particles provided on a support, on the insulating substrate, such that the aqueous resin layer and the photosensitive insulating resin layer come into contact with each other. A step of applying pressure by heating and pressing; a step of removing the resin layer by contacting an aqueous liquid with the aqueous resin layer after peeling off the support; and a step of applying a laser beam to the insulating resin layer. Forming an insulating resin image having fine irregularities on the surface on an insulating substrate having a wiring pattern by irradiating the resin in an imagewise manner and removing the insulating resin layer in the irradiated area.