JP2006012978A - Composite sheet, its manufacturing method, and manufacturing method of laminated parts - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite sheet having a stable conductor film without delamination or defective continuity, and to provide a manufacturing method of the composite sheet and its manufacturing method of laminating parts. <P>SOLUTION: A composite sheet A is constituted such that a conductor 3 of almost the same thickness as that of a photocuring ceramic layer 1 may be embedded in the photocuring ceramic layer 1 containing at least a ceramic material and a photocuring system, in such a way that the conductor 3 may be exposed. When the conductor 3 is exposed by 100 mJ, the total light transmittance is ≤10% characteristically. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a ceramic laminated component used in a mobile communication device or the like, a composite sheet suitable for a laminated substrate, a composite sheet manufacturing method, and a laminated component manufacturing method.

  In recent years, electronic devices are becoming smaller and lighter and more portable, and the circuit blocks used for them are also becoming smaller and more complex, and the density and size of laminated parts such as ceramic multilayer circuit boards are increasing. Is underway.

  On the other hand, a conventional ceramic multilayer substrate is usually manufactured by a manufacturing method called a green sheet method. In this green sheet method, a ceramic green sheet is produced by a doctor blade method or the like using a slurry containing ceramic powder as an insulating layer, and then an NC punch or a mold is placed on the ceramic green sheet at a position to be a via hole conductor. After forming a through hole with a conductor paste and printing a conductor pattern on the inside and the surface using a conductor paste, filling the through hole with a conductor paste to form a via-hole conductor, This is a manufacturing method in which ceramic green sheets are laminated and the laminate is simultaneously fired. (See Patent Document 1).

  Even in this green sheet method, in response to the demand for higher accuracy and higher density, the thickness of the ceramic green sheet layer between conductors, which are insulating layers, is reduced, and the conductors are made finer and further reduced. In order to realize a loss and a low resistance value, it is required to increase the thickness of the conductor.

  In the conventional manufacturing method such as the green sheet method, when the two requirements of the ceramic green sheet layer thickness reduction and the conductor thickness increase are simultaneously satisfied, a conductor is formed as a portion. A step corresponding to the thickness of the conductor inevitably occurs between the unexposed portions. Due to this step, there is a problem that stacking failure (delamination) occurs, and there is a limit to satisfying simultaneously the reduction of the thickness of the ceramic green sheet layer and the increase of the thickness of the conductor.

  In addition, in order to form a vertical conductor such as a via conductor, a drilling process for forming a through hole by punching or the like in the green sheet is indispensable, which is an additional process for the printing process for forming the conductor. It was. When the insulating layer is a thin layer (50 μm or less) by this drilling step, there are problems such as elongation, deformation, and tearing.

  There has been invented a composite sheet that can solve the above-mentioned problems and can simultaneously satisfy the reduction in the thickness of the insulating layer and the increase in the thickness of the conductor. (See Patent Document 2).

  This composite sheet is a composite sheet in which a conductor having a thickness substantially the same as the thickness of the sheet is embedded in a sheet containing a ceramic material and a photocuring system, and the manufacturing method thereof is as follows. Street.

(A) a step of forming a light non-transparent conductive pattern on a surface of a light transmissive carrier film with a conductive paste containing at least a metal powder material and an organic binder; and (b) forming the conductor. Applying a photocuring slurry containing at least a photocurable monomer, a photopolymerization initiator, and a ceramic material on the carrier film to a thickness equal to or greater than the thickness of the conductor portion, and forming a photocurable ceramic layer; (C) irradiating light from the back surface of the carrier film to photo-cure the photo-curing ceramic layer in a region other than the conductor formation; and (d) applying a developer to A step of solubilizing and removing the non-light-cured portion including the surface of the conductor portion to produce a composite sheet composed of the light-cured ceramic layer and the conductor portion. And it is characterized in and.

  If this sheet from which the carrier film has been removed is arbitrarily laminated and the laminated body is fired, a laminated part that satisfies the two requirements of reducing the thickness of the ceramic green sheet layer and increasing the thickness of the conductor can be obtained.

  However, in order to increase the thickness of the conductor, the following problems arise when the conductor paste is formed by simply selecting only a metal powder material such as Au, Ag, or Cu.

  First, due to the difference in thermal expansion coefficient between the ceramic material and the conductor material, a crack is generated at the interface between the two materials or in the vicinity thereof at the end of firing. Usually, the thermal expansion coefficient of ceramics is about 4 to 12 ppm / ° C., and Au, Ag, and Cu are about 20 ppm / ° C. This difference acts as stress at the end of firing and causes cracks.

  Next, due to the difference in firing shrinkage behavior between the ceramic material and the conductor material, peeling occurs at the interface between the two materials in the middle of firing. For example, the melting point of Ag is 950.5 ° C., and those having a particle size of about 1 μm start firing shrinkage from about 400 ° C. In the case of a ceramic material, for example, glass ceramic, since shrinkage generally starts at a temperature of about 600 to 800 ° C., Ag shrinks first, and peeling occurs at the interface with the ceramic. In addition, there may be a problem that the warpage of the substrate becomes large.

  In order to solve these two problems, a method of adding a material for matching the sintering behavior of metal powder with ceramics to a conductor material has been invented. (See Patent Document 3).

According to this, the conductive paste includes a glass frit having a yield point of 700 to 845 ° C., which is lower than the sintering start temperature of the ceramic, and an Ag-based conductive powder, and the glass frit has an average particle size. Is 10 μm or less, and the addition amount is 30 to 55% by volume of the Ag-based conductive powder.
Japanese Patent Laid-Open No. 11-066951 Japanese Patent Application No. 2002-339922 Japanese Patent No. 3130914

  However, when such a conductive paste is used, since the glass amount is large and the light transmittance is high, the conductor does not become a light non-transparent film. Hardens and remains as a residue after development.

  This residue causes problems such as delamination and poor conduction during lamination.

  The present invention provides a composite sheet having a stable conductive film free from the above delamination and conduction failure, a method for manufacturing the composite sheet, and a method for manufacturing a laminated part.

  The composite sheet of the present invention is a composite sheet in which a conductor having substantially the same thickness as the thickness of the light-cured ceramic layer is embedded in a light-cured ceramic layer containing at least a ceramic material and a light-curing system. The total light transmittance when the conductor is exposed at 100 mJ is 10% or less.

  The composite sheet of the present invention is a composite sheet in which a conductor having substantially the same thickness as the thickness of the light-cured ceramic layer is embedded in a light-cured ceramic layer containing at least a ceramic material and a light-curing system. The light transmittance in the h-line wavelength region when the conductor is exposed at 100 mJ is 5% or less.

  The composite sheet of the present invention is a composite sheet in which a conductor having substantially the same thickness as the thickness of the light-cured ceramic layer is embedded in a light-cured ceramic layer containing at least a ceramic material and a light-curing system. The light transmittance in the i-line wavelength region when the conductor is exposed at 100 mJ is 5% or less.

  In the composite sheet of the present invention, it is desirable that the photocuring system contains at least a photocurable monomer and a photopolymerization initiator.

  In the composite sheet of the present invention, the conductor preferably contains a metal and a metal oxide or glass.

In the method for producing a composite sheet of the present invention, (a) the total light transmittance when exposed to 100 mJ with a conductor paste containing at least a metal powder material and a metal oxide or glass on the support surface is 10% or less. Forming a predetermined conductor to be
(B) A photocurable slurry containing at least a photocurable monomer, a photopolymerization initiator, and a ceramic material is applied to a thickness greater than the thickness of the conductor on the support on which the conductor is formed. Forming a layer;
(C) irradiating light from the back surface of the support and photocuring the photocurable ceramic layer in a region other than the conductor formation;
(D) providing a developer and solubilizing and removing the non-light-cured portion including the conductor surface of the light-cured ceramic layer to produce a composite sheet composed of the light-cured ceramic layer and the conductor;
It is characterized by comprising.

The method for producing a composite sheet of the present invention comprises: (a) a light transmittance in the h-line wavelength region when exposed to 100 mJ with a conductor paste containing at least a metal powder material and a metal oxide or glass on the support surface. A step of forming a predetermined conductor that is 5% or less;
(B) A photocurable slurry containing at least a photocurable monomer, a photopolymerization initiator, and a ceramic material is applied to a thickness greater than the thickness of the conductor on the support on which the conductor is formed. Forming a layer;
(C) irradiating light from the back surface of the support and photocuring the photocurable ceramic layer in a region other than the conductor formation;
(D) providing a developer and solubilizing and removing the non-light-cured portion including the conductor surface of the light-cured ceramic layer to produce a composite sheet composed of the light-cured ceramic layer and the conductor;
It is characterized by comprising.

The method for producing a composite sheet of the present invention comprises: (a) a light transmittance in an i-line wavelength region when exposed to 100 mJ with a conductor paste containing at least a metal powder material and a metal oxide or glass on the support surface. And (b) a photocuring slurry containing at least a photocurable monomer, a photopolymerization initiator, and a ceramic material on the support on which the conductor is formed, Applying to a thickness equal to or greater than the thickness of the conductor to form a photo-curing ceramic layer;
(C) irradiating light from the back surface of the support and photocuring the photocurable ceramic layer in a region other than the conductor formation;
(D) providing a developer and solubilizing and removing the non-light-cured portion including the conductor surface of the light-cured ceramic layer to produce a composite sheet composed of the light-cured ceramic layer and the conductor;
It is characterized by comprising.

  Moreover, as for the manufacturing method of the composite sheet of this invention, it is desirable that the thickness of the said photocurable ceramic layer and a conductor is 50 micrometers or less.

The method for producing a laminate of the present invention includes (e) a step of laminating the composite sheets produced by the steps (a) to (d) according to claim 6 and forming a laminate having an arbitrary number of layers;
(F) firing the laminate;
It is characterized by comprising.

The manufacturing method of the laminated body of this invention is the process of peeling the composite sheet which consists of a photocurable ceramic layer and a conductor from a support body after the (a)-(d) process of (g) Claim 7.
(H) a step of laminating a plurality of composite sheets produced by the steps (a) to (d) and (g);
(I) firing the laminate;
It is characterized by comprising.

The method for producing a laminate of the present invention includes (j) a step of producing a first composite sheet on the first support by the steps (a) to (d) according to claim 8;
(K) Steps for producing a second composite sheet on the second support through the steps (a) to (d);
(L) laminating the second composite sheet on the surface of the first composite sheet;
(M) peeling the second support from the second composite sheet;
(N) If necessary, a step of forming a laminate having an arbitrary number of layers by a composite sheet by repeating the steps (k) to (m).
(K) firing the laminate;
It is characterized by comprising.

  Moreover, as for the manufacturing method of the laminated body of this invention, it is desirable that the thickness of the said photocurable ceramic layer and a conductor is 50 micrometers or less.

  According to the composite sheet of the present invention, it is important that the total light transmittance of the conductor is 10% or less. By setting the total light transmittance of the conductor to 10% or less, when the photocurable ceramic layer is cured and developed, the degree of exposure of the metal portion of the conductor exposed from the composite sheet is greatly improved. In other words, if the total light transmittance exceeds 10%, the photocured ceramic layer residue to be removed remains on the conductor surface. Setting it to 10% or less leads to greatly improving the connection reliability between the conductors when the composite sheet is laminated.

  Moreover, according to the composite sheet of the present invention, it is important that the light transmittance in the h-line wavelength region of the conductor is 5% or less. As a photo-curing system for curing the photo-curing ceramic layer, it is desirable to use a system with a long wavelength and high sensitivity so as to cope with a thick one. In that case, if the h-line transmittance of the conductor is 5% or less, the photocured ceramic layer residue is small, and the degree of exposure of the metal portion of the conductor is greatly improved.

  Further, according to the composite sheet of the present invention, it is important that the light transmittance in the i-line wavelength region of the conductor is 5% or less. One of the most commonly used light sources for exposure is an ultra-high pressure mercury lamp, which is characterized by high i-line intensity. Accordingly, as a photocuring system for curing the photocuring ceramic layer, a photocuring material that generates radicals by i-line is used. Therefore, if the i-line transmittance of the conductor is 5% or less, the photocuring ceramic layer remains. The exposure of the metal part of the conductor is greatly improved.

  Moreover, it is preferable that the photocuring system used for the composite sheet of the present invention contains at least a photocurable monomer and a photopolymerization initiator. As a result, a difference in developer solubility between the exposed portion and the non-exposed portion is likely to occur in a short time, and the productivity is improved.

  Moreover, it is preferable that the conductor used for the composite sheet of this invention consists of a metal and a metal oxide, or glass. In particular, it is preferable to use a kind of gold, silver, copper, or an alloy thereof as a conductive material that controls conductivity. Since these metals have high conductivity, the conductor resistance value can be kept low. However, the melting points of the respective metals are 1063 ° C., 961 ° C., and 1083 ° C., which are comparatively low materials used for ceramics. Or it is preferable to add glass. Glass is particularly preferred because it easily controls the coefficient of thermal expansion and softening fluidity.

In the composite sheet of the present invention, (a) a light transmittance when exposed to 100 mJ with a conductive paste containing at least a metal powder material and a metal oxide or glass on the support surface is a predetermined value or less. A step of forming a conductor; and (b) a photocuring slurry containing at least a photocurable monomer, a photopolymerization initiator, and a ceramic material on the support on which the conductor is formed. (C) a step of irradiating light from the back surface of the support and photocuring the photocurable ceramic layer in a region other than the conductor formation; ) A composite solution composed of a photocurable ceramic layer and a conductor is prepared by applying a developer and solubilizing and removing the non-photocured portion including the conductor surface of the photocurable ceramic layer. And the extent,
It can implement | achieve by using the manufacturing method of the composite sheet characterized by comprising. By this manufacturing method, since a thick conductor and a thin ceramic layer are provided and the thicknesses of both are substantially the same, it can be suitably used to easily produce a flat laminated component.

  Further, according to the method for producing a composite sheet of the present invention, the above-described composite sheet can be easily and accurately produced at a low cost.

  In addition, according to the method for manufacturing a laminated part of the present invention, since all conductors are formed as conductors on a flat surface, and there is little residue on the surface of the conductor, the conventional via hole is poorly filled with paste. Occurrence of poor conduction due to the accumulation of conductors can be prevented.

  In addition, since via processing is unnecessary, alignment at the time of via embedding becomes unnecessary, and the process is greatly shortened. Moreover, in forming the photosensitive ceramic green sheet, according to the present invention, the printed conductor itself can be used as a mask, and can be formed by front coating of the photosensitive ceramic green sheet and front exposure from the back surface of the support. Therefore, a composite sheet composed of a photosensitive ceramic green sheet and a conductor can be easily produced at low cost. In addition, since the formation of such a composite sheet can be formed in parallel on each support in accordance with the number of layers, the composite sheets having the required number of layers are prepared and then collectively. By firing after lamination, the process can be greatly simplified, and automation is also facilitated.

  As described above, according to the composite sheet of the present invention and the method for manufacturing a laminated part, a composite sheet having stable light curability is obtained, and a step corresponding to the thickness of the conductor does not occur during lamination. The level difference between the conductor and the light-hardened ceramic layer is small, and there is no problem of delamination or deformation due to excessive pressure, making it easy to reduce the thickness of the photosensitive ceramic green sheet between the conductors and the conductor. Therefore, the reliability of the connection between conductors can be ensured.

For example, as shown in FIG. 1 (a), the composite sheet of the present invention has a conductor 3 having a thickness substantially the same as the thickness of the light-curing ceramic layer 1 on a light-curing ceramic layer 1 containing at least a ceramic material and a light-curing system. Is the composite sheet A embedded so that the conductor 3 is exposed, and the total light transmittance of the conductor 3 when the conductor 3 is exposed to light of an ultrahigh pressure mercury lamp with an illuminance of 30 mW / cm ² under the condition of 100 mJ. Is 10% or less, in particular 5% or less, more preferably 3% or less. Further, it is important that the conductor 3 has an h light transmittance of 5% or less, particularly 3% or less, more preferably 1% or less when exposed to light of an ultra-high pressure mercury lamp with an illuminance of 30 mW / cm ² under a condition of 100 mJ. It is. Further, it is important that the conductor 3 has an i-light transmittance of 5% or less, particularly 3% or less, more preferably 1% or less when exposed at 100 mJ using an ultra-high pressure mercury lamp with an illuminance of 30 mW / cm ² as a light source. It is.

  In order to achieve these, the light transmittance and blending amount of the metal oxide or glass to be blended simultaneously with the metal in the conductor 3 and the thickness of the conductor 3 in addition to the problem at the time of production such as fading of printing. It becomes a problem. If the amount of glass added as shown in Patent Document 3 is 55% by volume, the total light transmittance does not become 10% or less because the light transmittance of the glass is generally high even at a thickness of about 50 μm. The same applies to h-ray light transmittance and i-ray light transmittance.

  Therefore, when the manufacturing method of the present invention is not carried out, photo-cured photosensitive ceramics remain on the conductor 3 and flatness cannot be ensured, and connection reliability is lowered.

  In particular, when the conductor 3 is thin, or when the composite sheet is thin, attention should be paid to other parameters.

  Hereinafter, a method for controlling the total light transmittance, h-ray transmittance, and i-ray transmittance of the conductor 3 will be described in detail.

  The conductor 3 can be formed by, for example, a conductor paste, and the conductor paste has an average particle diameter of about 1 to 5 μm, and an inorganic component obtained by adding a ceramic material to the powder as necessary. Add an organic binder such as ethyl cellulose and acrylic resin, and mix an appropriate solvent such as dibutyl phthalate, α-terpineol, butyl carbitol, 2,2,4-trimethyl-3,3-pentadiol monoisobutyrate, and 3 It is prepared by homogeneously kneading with this roller or ball mill.

  The material, particle size, addition amount, and addition amount of the organic binder of the inorganic component added to the conductor paste greatly affect the total light transmittance, h-ray transmittance, and i-ray transmittance of the conductor 3.

  As a material for the inorganic component, when a light-transmitting glass or a light-transmitting crystal is used, the addition amount is preferably as small as possible and the particle size is preferably small. It is desirable to reduce the organic binder as long as it does not adversely affect the shape retention.

  These effects vary depending on the thickness of the conductor 3, but in any case, it is important to set the total light transmittance, h-ray transmittance, and i-ray transmittance within the scope of the present invention.

Further, the photocurable ceramic layer that is an element constituting the composite sheet of the present invention can use a crystalline inorganic powder or an amorphous inorganic powder. For example, a wiring board using the composite sheet of the present invention can be used. (1) A ceramic material whose main component is Al ₂ O ₃ , AlN, Si ₃ N ₄ and SiC and whose firing temperature is 1100 ° C. or higher, (2) at least SiO ₂ and BaO, CaO, SrO A ceramic material fired at 1100 ° C. or less, particularly 1050 ° C. or less, comprising a mixture of metal oxides containing alkaline earth metal oxides such as MgO, (3) glass powder, or glass powder and ceramic filler powder At least one selected from the group of low-temperature sinterable ceramic materials made of a mixture and fired at 1100 ° C. or lower, particularly 1050 ° C. or lower is selected It is.

As the mixture of (2) and the glass composition of (3) used, SiO ₂ —BaO—Al ₂ O ₃ system, SiO ₂ —B ₂ O ₃ system, SiO ₂ —B ₂ O ₃ —Al ₂ O Examples thereof include ₃ systems, SiO ₁ l ₂ O ₃ -alkali metal oxide systems, and compositions in which alkali metal oxides, ZnO, PbO, Pb, ZrO ₂ , TiO _{2 and the} like are blended with these systems. Examples of the ceramic filler in (3) include at least one selected from the group consisting of Al ₂ O ₃ , SiO ₂ , forsterite, cordierite, mullite, AlN, Si ₃ N ₄ , SiC, MgTiO ₃ , and CaTiO _3. The glass is preferably mixed at a rate of 20 to 80% by mass with respect to the glass. Since the average particle size of the raw material affects the sinterability of the ceramic material, the average particle size is preferably 0.5 to 8 μm, more preferably 1 to 5 μm.

  Examples of the photosensitive resin include a monomer imparted photosensitivity and a photopolymerization initiator. As the monomer imparted with photosensitivity, it is desirable that the monomer has excellent thermal decomposability in order to cope with a baking process at a low temperature for a short time. In addition, the photosensitized monomer needs to be photopolymerized by exposure after application and drying of the slurry material, and can form free radicals and chain-growth addition polymerization, and has secondary or tertiary carbon. Monomers are preferred, and examples thereof include alkyl acrylates such as butyl acrylate having at least one polymerizable ethylene group, and alkyl methacrylates corresponding thereto. In addition, polyethylene glycol diacrylates such as tetraethylene glycol diacrylate and methacrylates corresponding thereto are also effective. Examples of the photopolymerization initiator include benzophenones and acyloin ester compounds.

  Also, the organic binder is desired to have good thermal decomposability like the photosensitized monomer, and at the same time, it determines the viscosity of the slurry, so it is necessary to consider the wettability with the solid content. It is. According to the present invention, an ethylenically unsaturated compound having a carboxyl group and an alcoholic hydroxyl group such as an acrylic acid or methacrylic acid polymer is preferred.

  Examples of the organic solvent include at least one selected from the group consisting of ethyl carbitol acetate, butyl cellosolve, 3 methoxybutyl acetate, toluene, and IPA.

  In the present invention, the content of each component is 5 to 20 parts by mass of a photosensitized monomer and a photopolymerization initiator, 10 to 30 parts by mass of an organic binder, and a plasticizer per 100 parts by mass of the ceramic powder. The proportions of 1 to 5 parts by mass and 50 to 100 parts by mass of the organic solvent are appropriate.

  The photo-curing ceramic layer of the present invention is obtained by mixing, for example, a monomer imparted with photosensitivity, a photopolymerization initiator, an organic binder, and a plasticizer in an organic solvent in the proportion described above. The slurry prepared by kneading with a ball mill can be made into a sheet by a conventionally known doctor blade method or the like.

  More specifically, the thickness of each of the photocurable ceramic layer 1 and the conductor 3 is formed by a thin layer of 10 to 50 μm, particularly 15 to 40 μm, and further 15 to 30 μm. 3 is 20% or less of the thickness of the conductor 3, particularly 10% or less, more preferably 5% or less, or the difference in thickness is 5 μm or less, further 3 μm or less. The step with the photo-curing ceramic layer 1 due to the thickness is substantially suppressed.

  Further, by removing the support from such a composite sheet A, a composite sheet A is obtained alone, and a laminated body obtained by laminating a plurality of sheets is fired to produce a laminated component 5 as shown in FIG. can do.

  In such a multilayer component 5, the wiring layer 3a obtained by firing the conductor 3 forms a planar circuit by extending the ceramic layer 1a obtained by firing the photosensitive ceramic green sheet 1 in the planar direction. ing. Further, the via conductor 3b is formed by partially stacking the wiring layer 3a in the thickness direction.

  In such a multilayer component 5, the ceramic layer 1a and the wiring layer 3a are formed to have substantially the same thickness, so that the multilayer component 5 with significantly less unevenness is obtained. Moreover, in such a laminated component 5, since the wiring layer 3a can be formed much thicker than before, the electrical resistance of the wiring layer 3a can be significantly reduced. Moreover, since the thickness of the ceramic layer 1a is also thin, the laminated component 5 can also be reduced in size. Such a multilayer component 5 is suitably used as a wiring board on which an electrical component 6 such as a semiconductor element or a multilayer capacitor is mounted on the surface.

  And it becomes the laminated component 5 excellent in the connection reliability between the conductors 3 especially by controlling the characteristic of the conductor 3 in the range of this invention.

  Below, the manufacturing method of the composite sheet A of this invention and the laminated component 5 is demonstrated.

  According to the present invention, first, a conductor 3 containing at least a metal powder and an organic binder is formed so as to penetrate through the photocurable ceramic layer 1 in a part of the photocurable ceramic layer 1 containing at least a ceramic material. A composite sheet A is prepared.

  The conductor paste that becomes the conductor 3 is added to an organic component such as ethyl cellulose or an acrylic resin with respect to an inorganic component in which a ceramic material is added to the powder of the conductor material having an average particle size of about 1 to 5 μm as necessary. Furthermore, a suitable solvent such as dibutyl phthalate, α-terpineol, butyl carbitol, 2,2,4-trimethyl-3,3-pentadiol monoisobutyrate is mixed and homogeneously kneaded with a three roller or ball mill. Prepared.

  The photosensitive slurry to be the photo-curing ceramic layer 1 is preferably a ball mill in which a monomer imparting photosensitivity to a ceramic powder, a photopolymerization initiator, an organic binder, and a plasticizer are mixed in an organic solvent. Knead and prepare. The details are the same as described above for the method for producing the photo-curing ceramic layer.

  Next, the composite sheet A is formed by the following steps using the photosensitive slurry and the conductive paste.

  First, in the present invention, as shown in FIG. 2A, the conductor 3 is formed by printing the conductor paste on a predetermined light-transmitting support 7 by a screen printing method or the like. To do.

At this time, the total light transmittance of the conductor 3 is 10% or less, particularly 5% or less, more preferably 5% or less when the conductor 3 is exposed to light of an ultrahigh pressure mercury lamp with an illuminance of 30 mW / cm ² under the condition of 100 mJ. It is important to. Further, it is important that the conductor 3 has an h light transmittance of 5% or less, particularly 3% or less, and more preferably 1% or less when exposed at 100 mJ using an ultra-high pressure mercury lamp with an illuminance of 30 mW / cm ² as a light source. is there. Further, it is important that the conductor 3 has an i-light transmittance of 5% or less, particularly 3% or less, more preferably 1% or less when exposed to light of an ultra-high pressure mercury lamp with an illuminance of 30 mW / cm ² under a condition of 100 mJ. It is.

  Next, as shown in FIG. 2 (b), the photosensitive slurry is applied to the entire surface of the conductor 3 by a doctor blade method, for example, by a doctor blade method, and is applied to the entire surface with a predetermined thickness. 1 is formed.

Then, as shown in FIG. 2C, exposure is performed from the back surface of the support 7 using, for example, an ultrahigh pressure mercury lamp as a light source. By this exposure, the photo-curing ceramic layer 1 in a region other than the formation of the conductor 3 is photo-cured. In this exposure process, the photo-curing ceramic layer 1 is subjected to a photopolymerization reaction from the back surface to a certain thickness depending on the amount of light irradiated in the photo-curing ceramic layer 1 in a region other than the conductor 3 formation, thereby forming an insolubilized portion. Since the conductor 3 does not pass ultraviolet light, the photo-curing ceramic layer 1 formed on the conductor 3 becomes a solubilized portion where the photo-polymerization reaction of the photo-curable monomer does not occur. The exposure amount at this time is preferably adjusted so that the thickness of the insolubilized portion is substantially the same as the thickness of the conductor 3. The specific exposure amount is desirably 30 mJ to 150 mJ using an ultra-high pressure mercury lamp (illuminance 30 mW / cm ² ) as a light source.

  Thereafter, the entire photocurable ceramic layer 1 is developed. The development treatment is to remove the solubilized portion of the photosensitive ceramic green sheet 1 with a developer, and specifically, for example, spray development using a triethanolamine aqueous solution, sodium carbonate, sodium hydroxide or the like as the developer, Wash and dry. By this treatment, as shown in FIG. 2D, a composite sheet A in which the conductor 3 and the light-curing ceramic layer 1 are integrated with substantially the same thickness is formed on the support 7.

  In addition, this composite sheet A can obtain the composite sheet A single-piece | unit by peeling the composite sheet A from the support body 7. FIG.

  Next, a method for producing a laminated part using this composite sheet A will be described below. First, according to FIGS. 2 (a) to (d), the photocurable ceramic layer 1 and a predetermined layer are formed on the support 7. A plurality of composite sheets with a support on which pattern conductors 3 are formed are prepared, and the support 7 is removed to prepare a plurality of composite sheets A1 to A14.

  And as shown to Fig.3 (a), the laminated body 8 is formed by superimposing and crimping | bonding together the composite sheet of these composite sheets A1-A14, aligning. In addition, it is desirable to perform the pressure bonding while applying a temperature higher than the glass transition point of the organic binder contained in the composite sheet A.

  In addition, when laminating all at once, the support 7 may be peeled off and laminated, but considering the handling of the lowermost surface and the uppermost surface at the time of pressure bonding, only the lowermost surface and the uppermost surface are separated from the support 7. The laminated body 8 can also be formed as shown in FIG.3 (b) by peeling the support body 7 after laminating | stacking and crimping | bonding, without peeling.

  Then, by firing the laminated body 8 at a predetermined temperature, it is possible to form the laminated component 5 in which a three-dimensional circuit is formed by the conductor 3. In the firing, the produced laminate 8 is removed in the binder process, the organic binder and the monomer imparted photosensitivity contained in the molded body are lost, and in an inert atmosphere such as nitrogen in the firing process. Alternatively, the ceramic material and the conductor material used are fired at a temperature at which the ceramic material and the conductor material can be sufficiently fired in the atmosphere, and are densified to a relative density of 95% or more.

  Further, as necessary, the surface treatment is further performed by printing / baking a thick film resistance film or a thick film protective film on the surface of the laminated component 5, plating, and further joining the electrical component 6 including the IC chip. A ceramic circuit board can be fabricated.

  The conductor 3 on the surface may be printed and dried on the surface of the fired laminated body and baked in a predetermined atmosphere.

  Further, the surface of the conductor 3 and the terminal electrode formed on the surface of the ceramic multilayer circuit board as the multilayer component 5 has a plating layer of 1 to 3 μm such as nickel and gold in order to improve the wettability with the solder. You may form by thickness.

  First, with respect to 100 parts by volume of Ag powder, barium borosilicate glass powder having a particle size shown in Table 1 is added at a ratio shown in Table 1, and further, 1 part by mass of ethyl cellulose, and 2.2.4. 12 parts by weight of trimethyl 3,3-pentadiol monoisobutyrate was added and mixed with a three roll mill to prepare a conductor paste.

  Moreover, the photosensitive slurry used as a photocurable ceramic layer is 100 mass parts of ceramic raw material powder, the monomer (polyoxyethylated trimethylol propane triacrylate) (8 mass parts) which provided photosensitivity, and an organic binder (alkyl methacrylate). 25 parts by mass, 3 parts by mass of a plasticizer, and 70 parts by mass of an organic solvent (ethyl carbitol acetate) were mixed and kneaded by a ball mill.

Note that the ceramic raw material _powder, SiO 2 _-45% by weight, _{B 2} O 3 -12 _wt%, Al ₂ O 3 -25 wt%, MgO-8 wt%, CaO-4% by weight, of ZnO-6 wt% A mixed powder of glass powder-75% by mass and Al ₂ O ₃ powder-25% by mass was used.

  Next, a conductor paste was printed on a support made of PET (polyethylene terephthalate) by a screen printing method or the like to form a plurality of conductors having a minimum wiring width of 100 μm and a thickness of 25 μm.

  Next, the photosensitive slurry is applied and dried on the conductor by a doctor blade method so that the photosensitive slurry is thicker than the conductor before drying, and the thickness after drying in a place where no conductor exists. A photosensitive ceramic green sheet was formed so as to be 27 μm.

Next, the entire surface was exposed at 100 mJ using an ultrahigh pressure mercury lamp (illuminance 30 mW / cm ² ) as a light source from the back side of the support to the back side of the light-hardening ceramic layer. Thereafter, spray development was performed for 30 seconds using a triethanolamine aqueous solution having a dilution concentration of 2.5% as a developer. Thereafter, the film was washed at 70 ° C. after pure water washing after development.

  Thus, the completed composite sheet was removed by development processing so that the thickness of the melted portion on the conductor and the thickness of the light-hardened ceramic layer was equal to the thickness of the conductor, and the conductor was exposed. A composite sheet in which the conductor having a thickness and the photo-cured ceramic layer having the thickness shown in Table 1 were integrated could be produced.

  Similarly, 14-layer composite sheets each having conductors for internal conductors, surface conductors and via conductors were prepared on the respective supports.

  From the composite sheet produced as described above, each PET film was peeled off, and lamination was performed while positioning in order. Thereafter, using a press machine, pressing was performed at a pressing pressure of 40 MPa and a temperature of 60 ° C. for 2 minutes to press-bond the laminate.

Thereafter, when the conductor was Ag or Ag—Pd, the binder was removed in the atmosphere at 300 ° C. for 2 hours, and then fired in the atmosphere at 900 ° C. for 1 hour to prepare a multilayer ceramic circuit board as a multilayer component. In the case where the conductor was Cu, the binder removal treatment was performed at 700 ° C. for 1 hour in an N ₂ atmosphere, and then the ceramic multilayer circuit board was fabricated by firing at 900 ° C. for 1 hour in N ₂ . A circuit for continuity test was formed on this evaluation board.

(Composite sheet appearance evaluation, thickness variation accuracy evaluation)
About the produced composite sheet, the number of evaluation was 50, and the appearance (breaking, voids, etc.) of the light-curing ceramic layer was inspected with a microscope (× 20), and each part of the light-curing ceramic layer of each sheet was 5 points. The thickness variation was evaluated by measuring using a non-contact laser thickness measuring instrument and subtracting the thickness of the support.

(Continuity evaluation)
Continuity was confirmed for the evaluation board. The number of evaluations was 50, and the yield was calculated.

(Cross section SEM)
About the produced evaluation board | substrate, the cross-section was observed using the scanning electron microscope (SEM) about the presence or absence of the delamination generate | occur | produced by the relationship of ceramic layer thickness and wiring layer thickness.

(Light transmittance of conductor)
The light transmittance of the conductor was measured as follows. Using a UV illuminance meter (UIS-101 made by Ushio Electric Co., Ltd.) equipped with an all-ray, h-line and i-line receiver, the illuminance with and without the support is measured, and the light from the value to the conductor is measured. The transmittance was calculated (total light, h-line, i-line). In the measurement, the distance between the light source and the conductor was 360 cm, and the distance between the support and the light receiver was 0.01 cm. The results are shown in Table 1.

In addition, about the sample in which h line | wire and i line | wire are not described, it tested using the filter which does not let h line | wire and i line | wire pass, respectively.

  The total light transmittance of a conductor that is outside the scope of the present invention exceeds 10%, the light transmittance in the h-line wavelength region exceeds 5%, or the light transmittance in the i-line wavelength region exceeds 5%. Sample No. In 1, 9, and 17, the photosensitive ceramic layer on the conductor was hardened and was not removed, and thus a conduction failure between the conductors occurred.

  On the other hand, sample no. In 2-8, 10-16, and 18-24, the thickness dispersion | variation and the conduction defect were improved significantly compared with the comparative example.

(A), (c) is a schematic sectional drawing of the composite sheet of this invention, (b), (d) is a schematic sectional drawing of the laminated component of this invention. It is process drawing for demonstrating the preparation methods of the composite sheet of this invention. It is process drawing for demonstrating the method of producing the laminated component of this invention.

Explanation of symbols

A ... Composite sheet 1 ... Photo-curing ceramic layer 1a ... Ceramic layer 2 ... Support 3 ... Conductor 3a ... Wiring layer 3b ... Via conductor 5 ... Multilayer component 6 ... Electric components 7 ... Laminates

Claims (13)

A composite sheet in which a conductor having a thickness substantially the same as the thickness of the light-curing ceramic layer is embedded in a light-curing ceramic layer containing at least a ceramic material and a light-curing system, and the conductor is exposed, A composite sheet having a total light transmittance of 10% or less when exposed at 100 mJ. A composite sheet in which a conductor having a thickness substantially the same as the thickness of the light-curing ceramic layer is embedded in a light-curing ceramic layer containing at least a ceramic material and a light-curing system, and the conductor is exposed, A composite sheet having a light transmittance of 5% or less in an h-line wavelength region when exposed at 100 mJ. A composite sheet in which a conductor having a thickness substantially the same as the thickness of the light-curing ceramic layer is embedded in a light-curing ceramic layer containing at least a ceramic material and a light-curing system, and the conductor is exposed, A composite sheet having a light transmittance of 5% or less in an i-line wavelength region when exposed at 100 mJ. The composite sheet according to claim 1, wherein the photocuring system contains at least a photocurable monomer and a photopolymerization initiator. The composite sheet according to claim 1, wherein the conductor contains a metal and a metal oxide or glass. (A) forming a predetermined conductor having a total light transmittance of 10% or less when exposed to 100 mJ on a support surface with a conductor paste containing at least a metal powder material and a metal oxide or glass; ,
(B) A photocurable slurry containing at least a photocurable monomer, a photopolymerization initiator, and a ceramic material is applied to a thickness greater than the thickness of the conductor on the support on which the conductor is formed. Forming a layer;
(C) irradiating light from the back surface of the support and photocuring the photocurable ceramic layer in a region other than the conductor formation;
(D) providing a developer and solubilizing and removing the non-light-cured portion including the conductor surface of the light-cured ceramic layer to produce a composite sheet composed of the light-cured ceramic layer and the conductor;
A method for producing a composite sheet, comprising: (A) A predetermined conductor having a light transmittance of 5% or less in the h-line wavelength region when exposed at 100 mJ on the support surface with a conductor paste containing at least a metal powder material and a metal oxide or glass. Forming, and
(B) A photocurable slurry containing at least a photocurable monomer, a photopolymerization initiator, and a ceramic material is applied to a thickness greater than the thickness of the conductor on the support on which the conductor is formed. Forming a layer;
(C) irradiating light from the back surface of the support and photocuring the photocurable ceramic layer in a region other than the conductor formation;
(D) providing a developer and solubilizing and removing the non-light-cured portion including the conductor surface of the light-cured ceramic layer to produce a composite sheet composed of the light-cured ceramic layer and the conductor;
A method for producing a composite sheet, comprising: (A) A predetermined conductor having a light transmittance in an i-line wavelength region of 5% or less when exposed at 100 mJ on a support surface containing a conductive paste containing at least a metal powder material and a metal oxide or glass. And (b) applying a photocurable slurry containing at least a photocurable monomer, a photopolymerization initiator, and a ceramic material to a thickness greater than or equal to the thickness of the conductor on the support on which the conductor is formed. Forming a photo-curing ceramic layer,
(C) irradiating light from the back surface of the support and photocuring the photocurable ceramic layer in a region other than the conductor formation;
(D) providing a developer and solubilizing and removing the non-light-cured portion including the conductor surface of the light-cured ceramic layer to produce a composite sheet composed of the light-cured ceramic layer and the conductor;
A method for producing a composite sheet, comprising: The method for producing a composite sheet according to any one of claims 6 to 8, wherein the photocurable ceramic layer and the conductor have a thickness of 50 µm or less. (E) a step of laminating the composite sheets produced by the steps (a) to (d) according to claim 6 to form a laminate having an arbitrary number of layers;
(F) firing the laminate;
A method for producing a laminated part, comprising: (G) After the steps (a) to (d) according to claim 7, a step of peeling a composite sheet composed of a photocurable ceramic layer and a conductor from the support;
(H) a step of laminating a plurality of composite sheets produced by the steps (a) to (d) and (g);
(I) firing the laminate;
A method for producing a laminated part, comprising: (J) A step of producing a first composite sheet on the first support by the steps (a) to (d) according to claim 8;
(K) Steps for producing a second composite sheet on the second support through the steps (a) to (d);
(L) laminating the second composite sheet on the surface of the first composite sheet;
(M) peeling the second support from the second composite sheet;
(N) If necessary, a step of forming a laminate having an arbitrary number of layers by a composite sheet by repeating the steps (k) to (m).
(K) firing the laminate;
A method for producing a laminated part, comprising: 13. The method of manufacturing a laminated part according to claim 10, wherein the thickness of the photo-curing ceramic layer and the conductor is 50 [mu] m or less.

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