JP3728068B2 - Multilayer wiring board - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to, for example, a multilayer wiring board and a package for housing a semiconductor element, and particularly relates to a multilayer wiring board formed by a build-up method.
[0002]
[Prior art]
In recent years, with the widespread use of communication devices, electronic devices that are required to operate at high speed have come to be widely used, and accordingly, printed wiring boards that can operate at high speed have been required. In order to perform such a high-speed operation, it is necessary to increase the wiring density.
[0003]
As one method for achieving such high density, a build-up method is known. In this method, for example, a photosensitive resin is applied to the surface of a double-sided copper-clad glass epoxy substrate on which wiring is formed by means such as etching of a copper foil, and an insulating layer having a via hole is formed by exposure and development. Thereafter, electroless copper plating is applied to the surface, and a via hole conductor and a wiring circuit layer are formed by applying a resist, etching, and removing the resist. Then, by repeating the formation of the insulating layer with the photosensitive resin and the formation of the via-hole conductor and the wiring circuit layer, after miniaturization and multilayering, a through hole is further formed with a drill or the like, and the inside of the hole is formed. In this case, a plating layer is formed to connect the wiring circuit layers between the layers.
[0004]
As the double-sided copper-clad glass epoxy substrate used at this time, a glass woven fabric or nonwoven fabric impregnated with an epoxy resin is most commonly used.
[0005]
On the other hand, as an insulating substrate of a printed wiring board, a substrate in which a nonwoven fabric made of aramid resin is impregnated with a resin has been proposed. When this aramid nonwoven fabric is used, it is easy to perform drilling as compared with the case where a glass woven fabric or the like is used like a glass epoxy substrate. That is, in the conventional glass woven fabric, drilling is performed by a drill, but the drilling method using the drill itself is difficult to form fine holes and is not suitable for increasing the density of wiring. On the other hand, when an aramid nonwoven fabric is used, laser processing becomes easy and fine holes can be formed at high speed. Then, application to the multichip module (MCM) etc. which mounted many semiconductor elements on the insulated substrate consisting of the material containing an aramid resin is examined.
[0006]
[Problems to be solved by the invention]
Due to the excellent applicability to the fine wiring of the insulating substrate using the aramid nonwoven fabric as described above, it is considered to form fine wiring on the surface by the build-up method as described above using this insulating substrate. However, it has not been put into practical use.
[0007]
The reason is that the aramid resin is inherently hygroscopic. The moisture absorption amount of the organic resin of the insulating material used for a normal insulating substrate is 0.1 to 0.2%, whereas the aramid resin has a moisture absorption of 10% or more, 2 to 3%. Further, the aramid resin is less durable against acids and alkalis than a normal resin.
[0008]
As a result, according to the build-up method as described above, various drugs are contacted during the manufacturing process. Developer solution for photosensitive resin, of course, degreasing process with sodium hydroxide as pretreatment of plating process, immersion process in electroless plating bath or electrolytic plating bath, immersion process in electrolytic plating bath, wiring layer etching process Further, there is a water washing step performed between them. For this reason, the insulation substrate is deformed due to moisture absorption, acid, or alteration of the alkali aramid resin itself, and it is impossible to form highly accurate wiring.
[0009]
Accordingly, it is an object of the present invention to provide a multilayer wiring board in which wiring is formed by a build-up method capable of fine wiring, making use of the characteristics of an insulating substrate using an aramid nonwoven fabric that is easy to process via holes and the like. It is what.
[0010]
[Means for Solving the Problems]
As a result of repeated investigations on the above object, the present inventors have formed a highly moisture-resistant insulating layer that does not contain an aramid resin on the surface of an insulating substrate containing an aramid nonwoven fabric. It has been found that even if fine wiring is formed by the build-up method, a high-density build-up multilayer wiring board without any deformation of the board can be obtained.
[0011]
That is, the multilayer wiring board of the present invention has a photosensitive resin on the surface of an insulating substrate in which an insulating core layer containing an aramid resin and an insulating shell layer not containing an aramid resin are formed on the surface of the insulating core layer. An insulating layer and a wiring circuit layer are sequentially laminated, and the insulating shell layer is made of ceramic powder and a thermosetting resin other than an aramid resin. layers, be impregnated with a resin to aramid nonwoven fabric, the insulating substrate to be al and is characterized by comprising the wiring circuit layers and / or via-hole conductor is formed.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
A method for manufacturing the multilayer wiring board of the present invention will be described with reference to FIG.
[0013]
FIG. 1 illustrates a method for manufacturing a multilayer wiring board based on a build-up method. According to FIG. 1, first, at least a wiring circuit layer 2 is formed on an insulating substrate 1 as shown in FIG. The wiring circuit layer 2 is obtained by 1) attaching a metal foil such as copper to the entire surface of the insulating substrate 1 with an adhesive, or forming a metal layer on the entire surface of the insulating substrate 1 by plating or the like, and then forming a resist for a circuit pattern. A method of etching away unnecessary portions of metal with an acid or the like, 2) a method of sticking a previously punched metal foil to the insulating substrate 1, 3) a method of screen printing a conductor paste on the surface of the insulating substrate 1 and 4) A method in which plating, metal foil is formed on a film, glass, or metal plate, a wiring circuit layer is formed by etching, and transferred onto the insulating substrate 1 while being pressed is employed. In general, the method 1) is employed.
[0014]
Subsequently, as shown in FIG. 1B, an insulating layer 3 made of a photosensitive resin is formed on the surface of the insulating substrate 1 on which the wiring circuit layer 2 is formed, and an insulating layer of a portion 4 for forming a via hole is formed. Remove by exposure and development. Thus, a fine via hole can be obtained by forming a via hole in the exposure and development steps.
[0015]
In forming the insulating layer 3, a method of applying a photosensitive resin by a curtain coating method or a spin coating method is preferably employed because it can be easily formed with a uniform thickness. As the resin for forming the insulating layer, a well-known photosensitive resin is used. For example, photosensitive polyimide resin, epoxy resin, epoxy acrylate resin, polyester resin, urethane acrylate resin, bismaleide triazine (BT) resin, etc. The thickness of the insulating layer 3 used is preferably 40 to 100 μm.
[0016]
Next, as shown in FIG. 1C, after a metal layer is formed on the insulating layer 3 by a thin film forming method such as electroless plating, electrolytic plating, vapor deposition, sputtering, ion plating, etc. The wiring circuit layer 6 and the via-hole conductor 5 are formed by etching the metal layer. Note that the formation of the wiring circuit layer and the via-hole conductor by etching may be performed by either the subtractive method or the additive method. This metal layer is preferably formed of a low resistance metal such as copper, silver, gold, aluminum, nickel or an alloy containing them.
[0017]
Next, as shown in FIG. 1 (d), an insulating layer 7 made of a photosensitive resin is formed on the entire surface of the wiring circuit layer 6 and the via hole conductor 5, and further exposed and developed to form the via hole via hole portion 8. Remove by exposure and development. The formation of the via hole portion 8 may be the same as the method used in the step of FIG. Further, a through hole 9 for a through hole is formed.
[0018]
Then, as shown in FIG. 1 (e), a metal layer is formed on the entire surface by the same method as in FIG. 1 (c), and then the via layer conductor 10, the wiring circuit layer 11 and the through layer are etched by etching the metal layer. A hole conductor 12 is formed. In this case, it is desirable that the through-hole conductor 12 has a hole diameter as small as possible so that the wiring circuit layers 6 and 11 and the via-hole conductors 5 and 10 do not hinder high-density wiring formation.
[0019]
At this time, for example, the wiring circuit layer 13 of the power supply layer may be formed by forming a metal layer on the surface opposite to the side on which the wiring circuit layer 11 is formed and etching at the same time.
[0020]
Then, a solder resist 14 is provided to protect the wiring circuit layer 11, the power supply wiring circuit layer 13, and the like, thereby completing the multilayer wiring board.
[0021]
According to the present invention, in the multilayer wiring board formed by the build-up method described above, the insulating substrate 1 includes an insulating core layer 15 containing an aramid resin and an insulating core layer 15 as shown in FIG. An insulating substrate having an insulating shell layer 16 that does not contain an aramid resin on the surface is used. Further, as shown in FIG. 2B, a wiring circuit layer, a via hole conductor, and the like may be formed in the insulating substrate 1.
[0022]
As the insulating core layer 15 containing the aramid resin in the insulating substrate 1, it is desirable that the aramid resin is contained in the insulating core layer in a proportion of 30 to 70% by volume. In particular, the aramid resin is a nonwoven fabric or a woven fabric. It is desirable to contain as. In the case of using an aramid nonwoven fabric or a woven fabric, the insulating layer is formed by impregnating the nonwoven fabric or the woven fabric with an organic resin.
[0023]
Examples of the organic resin impregnated in the insulating core layer at this time include resins such as PPE (polyphenylene ether), BT resin (bismaleimide triazine), epoxy resin, polyimide resin, fluorine resin, phenol resin, and polyamide bismaleimide. Desirably, it is particularly desirable that the raw material is a thermosetting resin that is liquid at room temperature.
[0024]
The insulating shell layer 16 that does not include aramid resins, that make up an insulating material composed of an organic resin and an inorganic filler other than aramid resin. When the aramid resin is contained in the insulating shell layer 16, as described above, the insulating substrate expands during the process of forming the insulating layer and the wiring circuit layer by the build-up method due to the high hygroscopicity of the aramid resin itself. This is because adverse effects such as deformation occur.
[0025]
Examples of organic resins other than the aramid resin constituting the insulating shell layer 16 include PPE (polyphenylene ether) resin, BT (bismaleimide triazine) resin, epoxy resin, imide resin, fluorine resin, phenol resin, polyamino bismaleimide, and the like. Resin is desirable. Further, this insulating layer, by incorporating an inorganic filler, arbitrary desirable to approximate the thermal expansion properties of the insulating core layer 15. As the inorganic filler used at this time, SiO ₂ , Al ₂ O ₃ , AlN, and the like are suitable, and the filler has an average spherical particle size of 20 μm or less, particularly 10 μm or less, and most preferably a spherical powder having an average particle size of 7 μm or less. Is used. This inorganic filler is mixed in a ratio range of 15:85 to 5:95 in a volume ratio of organic resin: inorganic filler.
[0026]
More specifically, it is desirable that the thermal expansion coefficient of the insulating shell layer 16 from room temperature to 150 ° C. is 30 ppm / ° C. or less, particularly 20 ppm / ° C. or less. If the temperature exceeds 30 ppm / ° C., the thermal expansion coefficient of the aramid resin itself is low, and the thermal expansion coefficient of the insulating core layer 15 is also 10 ppm / ° C. or less. Therefore, the insulating shell layer 16 and the insulating core layer 15 are This is because when the thermal cycle is applied to the laminated insulating substrate 1, a problem such as peeling of the insulating shell layer 16 may occur.
[0027]
Moreover, since the general organic resin contained in the insulating shell layer 16 has a high coefficient of thermal expansion of 50 to 60 ppm / ° C. or more, an inorganic filler having at least a coefficient of thermal expansion of 20 ppm / ° C. or less is used. Appropriate amounts can be blended to control the above thermal expansion characteristics. Therefore, the insulating shell layer 16 includes an organic resin other than an aramid resin, and is formed by a composite of an organic resin and an inorganic filler in some cases. The organic resin, the kind of the inorganic filler used here, and the blending ratio of the organic resin and the inorganic filler are as described above.
[0028]
Since the insulating shell layer 16 and the insulating core layer 15 containing an aramid resin function as a moisture-proof layer, the thickness of the insulating shell layer 16 that does not contain an aramid resin in order to exhibit moisture resistance is 10 to 300 μm, particularly 40 to 100 μm.
[0029]
Furthermore, in order to ensure moisture resistance by the insulating shell layer 16 in the insulating substrate 1, it is desirable that the side surface of the insulating substrate 1 is also covered with the same material as the insulating shell layer 16.
[0030]
In addition, as shown in FIG. 2B, in the case where a wiring circuit layer, a via-hole conductor, or the like is formed in the insulating substrate 1, together with the wiring circuit layer 2 formed on the surface of the insulating substrate 1, the manufacturing method thereof An example will be described with reference to FIG. First, as shown in FIG. 3A, via holes 18 are formed by punching, laser processing, plasma etching, or the like on the insulating sheet 17 containing an aramid resin for forming the insulating core layer 15 of the insulating substrate. . As described above, this insulating sheet 17 is, for example, an aramid woven fabric or non-woven fabric that is impregnated into a woven fabric or non-woven fabric after slurrying an organic resin or a mixture of an organic resin and an inorganic filler into a slurry. It is.
[0031]
The slurry impregnated in the woven fabric or non-woven fabric is prepared by adding a solvent such as toluene, butyl acetate, methyl ethyl ketone, isopropyl alcohol, methanol or the like to the above-described organic resin or composite of organic resin-inorganic filler. It is preferable to consist of a fluid having a viscosity of 1 to 500 poise. In addition, after organic resin impregnation, it heat-processes and makes it semi-cure.
[0032]
On the other hand, as shown in FIG. 3A ′, via holes 20 are formed in the same manner as in FIG. 3A for forming the insulating shell layer 16 on the insulating sheet 19 that does not contain an aramid resin. This insulating sheet 19 is a mixture of an organic resin as described above, or a composition composed of an organic resin and an inorganic filler, by means of a kneader or three rolls, and this is rolled, extruded, injection, After forming into a sheet by the doctor blade method or the like, the organic resin is semi-cured. For semi-curing, if the organic resin is a thermoplastic resin, the mixture mixed under heating is cooled. In the case of a thermosetting resin, the organic resin is heated to a temperature slightly lower than a temperature sufficient for complete solidification. That's fine.
[0033]
Then, as shown in FIGS. 3B and 3B ′, via hole conductors 21 and 22 are formed by filling the via holes 18 and 20 of the insulating sheets 17 and 19 produced as described above with a conductor paste. To do. The conductive paste is a resin powder added with a resin component such as epoxy resin or cellulose and kneaded with a solvent such as butyl acetate. The metal powder blended in the conductive paste includes copper, aluminum, silver, It is desirable to be made of at least one low resistance metal of gold or an alloy containing them. If desired, after filling in the hole, heat treatment can be performed at 60 to 140 ° C. to decompose and volatilize and remove the solvent and resin content in the paste.
[0034]
Next, the wiring circuit layers 23 and 24 are formed on the front and / or back surfaces of the insulating sheet 17 and the insulating sheet 19 on which the via-hole conductors are formed. Generally, as a method for forming a conductor circuit layer, as described above, the methods 1) to 4) described in the case where the wiring circuit layer 2 is formed on the surface of the insulating substrate 1 can be mentioned, but an aramid resin is contained. The insulating sheet 17 needs to be formed by the methods 2), 3) and 4) which do not come into contact with chemicals.
[0035]
And the insulating sheet 17 containing the aramid resin produced as described above, the insulating sheet 19 not containing the aramid resin, and the via-hole conductor 22 'produced by the method shown in FIGS. 3 (a') to (c '). And the insulating sheet 19 ′ having the wiring circuit layer 24 ′, as shown in FIG. 3 (d), are aligned, laminated and pressure-bonded, and heated at a curing temperature of 150 to 300 ° C. to form an organic resin of the insulating layer. The insulating substrate 1 having the insulating core layer 25 and the insulating shell layers 26 and 26 ′, the wiring circuit layers 23, 23 ′, 24, 24 ′ and the via-hole conductors 21, 22, 22 ′ is cured completely. Can be formed.
[0036]
According to this method, the insulating core layer 25 and the insulating shell layers 26 and 26 'of the insulating substrate are both bonded in a semi-cured state and are simultaneously cured, so that the insulating shell layers 26 and 26' It is possible to manufacture a strong insulating substrate that is difficult to peel from the insulating core layer 25 and on which the insulating layer and the wiring circuit layer can be formed by a build-up method.
[0037]
【Example】
Example 1
A slurry containing polyimide resin was impregnated into an aramid nonwoven fabric, and then a prepreg heated at 60 ° C. and semi-cured was produced. The content ratio was set to 50% by volume of polyimide resin and 50% by volume of non-woven fabric of aramid resin. A via hole having a diameter of 0.1 mm is formed in this prepreg with a carbon dioxide laser, and a via hole conductor is formed by filling the hole with a copper paste containing copper powder plated with silver, thereby insulating the insulating core layer. A sheet (A) was produced.
[0038]
On the other hand, 50% by volume of polyimide resin and 50% by volume of silica powder were mixed with varnished resin and powder to produce an insulating sheet by the doctor blade method, and heated at 60 ° C. to be semi-cured. A via hole having a diameter of 0.1 mm is formed in the insulating sheet by punching, and a copper paste containing copper powder plated with silver is filled in the hole to form a via hole conductor. An insulating sheet for an insulating shell layer (B) was produced.
[0039]
On the other hand, an adhesive was applied to the surface of a transfer sheet made of polyethylene terephthalate (PET) resin to give tackiness, and a copper foil having a thickness of 12 μm and a surface roughness of 0.8 μm was adhered to one surface. Then, after apply | coating a photoresist and performing exposure development, this was immersed in the ferric chloride solution, the non-pattern part was etched away, and the wiring circuit layer was formed. The produced wiring circuit layer is a fine pattern having a line width of 60 μm and a distance between the wirings of 60 μm.
[0040]
Then, the transfer sheet on which the wiring pattern was formed as described above was superimposed on the surface of the insulating core layer insulating sheet (A) and pressed, and only the transfer sheet was peeled off to transfer the wiring circuit layer. . Similarly, the wiring circuit layer was transferred to the surface of the insulating sheet (B) for the insulating shell layer in the same manner as described above.
[0041]
Then, the insulating sheet for insulating core layer (B) is laminated on the upper and lower sides of the three insulating core layer insulating sheets (A) on which the wiring circuit layers are formed as described above, and the pressure is 50 kg / cm ² . Then, it was cured by heating at 200 ° C. for 1 hour to prepare an insulating substrate having a build-up wiring circuit layer and a via-hole conductor. Note that the thickness of the insulating shell layer not containing the aramid resin was 50 μm. The thermal expansion coefficient of this insulating shell layer from room temperature to 150 ° C. was 25 ppm / ° C.
[0042]
Next, an insulating layer and a wiring layer were formed on both surfaces of the insulating substrate by a build-up method. First, a photosensitive epoxy resin having a thickness of 50 μm was applied by spin coating, and then pre-cured by heating at 60 ° C. for 30 minutes to form an insulating layer. Thereafter, a via hole having a diameter of 30 μm was formed in the insulating layer by exposure and development. Next, after forming a copper plating layer having a thickness of 5 μm on the surface of the insulating layer and in the via hole by electroless plating, a photoresist is applied to the plating layer, exposure and development are performed, and then in a ferric chloride solution. The wiring pattern layer and the via hole conductor were formed by removing the non-patterned portion by etching.
[0043]
Then, after forming the insulating layer with the photosensitive resin and forming the wiring circuit layer and the via hole conductor twice, after forming the insulating layer again, the via hole was formed and the diameter was measured with a micro drill. A 0.2 mm through hole was formed, a metal layer was formed on the entire surface by electroless plating in the same manner as described above, and a via hole conductor, a wiring circuit layer, and a through hole conductor were formed by etching the metal layer. . Then, a solder resist made of epoxy resin was formed as a protective layer on the outermost wiring circuit layer, via-hole conductor, and wiring circuit layer.
[0044]
As a result of observing the vicinity of the formation of the wiring circuit layer and via-hole conductor in the cross section of the obtained multilayer wiring board, there was no deformation of the insulating substrate containing the aramid resin, and the wiring circuit layer, via-hole conductor and through-hole conductor The connection was also good, and as a result of conducting a continuity test between each wiring, no disconnection of the wiring was recognized.
[0045]
The obtained multilayer wiring board was left in a high-humidity atmosphere with a humidity of 85% and a temperature of 85 ° C. for 100 hours, but no change occurred. Moreover, as a result of conducting a thermal cycle test from room temperature to 150 ° C., no change was observed after 200 cycles.
[0046]
Comparative Example In Example 1, without forming an insulating shell layer containing no aramid resin, the wiring circuit layer and the via-hole conductor were formed on the insulating substrate, and the aramid nonwoven fabric forming the insulating core layer was impregnated with an epoxy resin. An insulating substrate having a wiring circuit layer and a via-hole conductor was produced in the same manner except that the prepreg was used.
[0047]
Then, an insulating layer, a wiring circuit layer, a via-hole conductor, a through-hole conductor, and a protective layer were formed on the surface of the insulating substrate by a build-up method in the same manner as in Example 1 to produce a wiring substrate.
[0048]
As a result of observing the vicinity of the formation of the wiring circuit layer and via hole conductor in the cross section of the obtained wiring board, deformation due to moisture absorption of the aramid resin was recognized in the insulating substrate, and the wiring circuit layer, via hole conductor and through hole were observed. The conductor connection was also partially broken.
[0049]
Example 2
In the same manner as in Example 1, a prepreg was prepared by impregnating an aramid non-woven fabric so as to comprise 55% by volume of a polyaminobismaleimide resin and 45% by volume of an aramid non-woven fabric. A via hole having a diameter of 0.1 mm is formed in the prepreg by a carbon dioxide laser, and the hole is filled with a copper paste made of copper powder plated with silver having a particle diameter of about 5 μm, and an insulating sheet for an insulating core layer (A ) Was produced.
[0050]
On the other hand, polyamino bismaleimide resin 50 vol%, such as a silica powder 50% by volume percentage, of the varnish state resin powder were mixed for punching a diameter 0.1mm into a sheet-like insulation layer produced by a doctor blade method via A hole was formed, and a copper paste containing copper powder plated with silver was filled in the hole to form a via-hole conductor to produce an insulating sheet (B) for an insulating shell layer.
[0051]
Thereafter, in the same manner as in Example 1, a wiring circuit layer was formed on each insulating sheet (A) (B) by transfer from the transfer sheet, and then three insulating sheets (A) were formed in the center, and upper and lower insulating shells. Two insulating sheets (B) are laminated on each layer, pressed with a pressure of 50 kg / cm ² , and heated at 200 ° C. for 1 hour to be completely cured to produce an insulating substrate having a wiring circuit layer and a via-hole conductor. did. Note that the thickness of the insulating shell layer not containing the aramid resin was 75 μm. The thermal expansion coefficient of this insulating shell layer from room temperature to 150 ° C. was 20 ppm / ° C.
[0052]
Then, an insulating layer, a wiring circuit layer, a via-hole conductor, a through-hole conductor, and a protective layer were formed on the surface of the insulating substrate by a build-up method in the same manner as in Example 1 to produce a wiring substrate.
[0053]
As a result of observing the vicinity of the formation of the wiring circuit layer and via-hole conductor in the cross section of the obtained multilayer wiring board, there was no deformation of the insulating substrate containing the aramid resin, and the wiring circuit layer, via-hole conductor and through-hole conductor The connection was also good, and as a result of conducting a continuity test between each wiring, no disconnection of the wiring was recognized.
[0054]
The obtained multilayer wiring board was left in a high-humidity atmosphere with a humidity of 85% and a temperature of 85 ° C. for 100 hours, but no change occurred. Moreover, as a result of conducting a thermal cycle test from room temperature to 150 ° C., no change was observed after 200 cycles.
[0055]
【The invention's effect】
As described above in detail, according to the present invention, even when a fine wiring layer is formed by a build-up method on an insulating substrate containing an aramid resin that can be easily processed by a laser or the like, it is manufactured. deformation of the insulating substrate due to the contact of water and various chemicals during the process, it is possible to suppress the occurrence of disconnection or the like of the wiring associated therewith, producing a wiring board having excellent stability and long-term stability during production can do.
[0056]
An object of the present invention is to provide a multilayer wiring board on which accompanying wiring is formed.
[Brief description of the drawings]
FIG. 1 is a process diagram for explaining a manufacturing method of a multilayer wiring board based on a build-up method in the present invention.
2A and 2B are diagrams for explaining the structure of an insulating substrate in the present invention, in which FIG. 2A is an example, and FIG. 2B is a schematic cross-sectional view for explaining another example.
FIG. 3 is a process diagram for manufacturing the insulating substrate of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Insulation board | substrate 2,6,11,13 Wiring circuit layer 3,7 Insulation layer 4,8 Via hole 5,10 Via hole conductor 9 Through hole 12 for through hole Through hole conductor 15 Insulating core layer 16 Insulating shell layer

Claims (3)

An insulating core layer containing an aramid resin, and an insulating substrate layer formed by forming an insulating shell layer not containing an aramid resin on the surface of the insulating core layer, and an insulating layer containing a photosensitive resin and a wiring circuit layer. A multilayer wiring board characterized in that the insulating shell layer is made of a ceramic powder and a thermosetting resin other than an aramid resin . The multilayer wiring board according to claim 1, wherein the insulating core layer is formed by impregnating aramid nonwoven fabric with a resin. The multilayer wiring board according to claim 1, wherein a wiring circuit layer and / or a via hole conductor is formed in the insulating substrate.

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