JP2001313468A - Wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wiring board wherein misregistration of viahole conductor and a wiring circuit layer can be restrained by restraining deformation due to viscous flow of insulating layers. SOLUTION: In this wiring board, the wiring circuit layer is formed on a surface and/or the inside of an insulating board which is formed by laminating a plurality of the insulating layers, and the viahole conductor is formed inside the insulating board. Insulating layers composed of mixture of amorphous inorganic filler and thermosetting resin are used for the insulating board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring circuit layer on the surface and / or inside of an insulating substrate formed by laminating a plurality of insulating layers made of a mixture of an inorganic filler and a thermosetting resin.
The present invention relates to a wiring board having a via-hole conductor.

[0002]

2. Description of the Related Art In recent years, with the demand for higher performance and miniaturization of electronic equipment, there has been a demand for a wiring board which is compatible with higher density and higher functionality of circuit components. As such a wiring board, for example, one disclosed in Japanese Patent Application Laid-Open No. H11-220262 is known. In this publication, a wiring board is configured by laminating a plurality of insulating layers made of a mixture containing an inorganic filler and a thermosetting resin, and a via hole conductor and a wiring circuit layer are formed in the wiring board. ing.

[0003] Such a wiring board is manufactured by laminating a plurality of uncured insulating sheets made of an inorganic filler of spherical particles having good dispersibility and a thermosetting resin, and pressing the laminated body while heating. I have. In such a high-density mounting wiring board, wiring dimensions and circuit positional accuracy are important after the board is manufactured.

[0004]

However, conventionally,
Since the wiring substrate was produced by pressing a laminated body obtained by laminating a plurality of uncured insulating sheets while heating, if the shape of the inorganic filler is spherical particles, in the heating and pressing step at the time of substrate production Due to the large deformation of the insulating layer in the horizontal direction due to the viscous flow of the resin, the finer wiring, the via hole conductors formed at high density, the wiring circuit layer and the built-in electric components are greatly displaced, In addition, there has been a problem that electrical connection failure between the via hole conductor and the wiring circuit layer or the electric element is likely to occur.

For example, a wiring circuit layer formed on the surface of an insulating substrate is displaced, which makes it difficult to mount a semiconductor chip or circuit components to be mounted after the substrate is manufactured, and a product cannot be manufactured stably. There was a problem.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a wiring board capable of suppressing deformation of an insulating layer due to viscous flow and suppressing displacement of a via-hole conductor and a wiring circuit layer.

[0007]

A wiring board according to the present invention is obtained by forming a wiring circuit layer on the surface and / or inside of an insulating substrate formed by laminating a plurality of insulating layers, and forming a via hole conductor inside the insulating substrate. In the wiring board, the insulating layer is made of a mixture of an amorphous inorganic filler and a thermosetting resin.

According to such a configuration, since the inorganic filler mixed in the thermosetting resin has an irregular shape, the movement of the inorganic filler accompanying the viscous flow of the thermosetting resin can be suppressed. In the heating and pressurizing step, the deformation of the insulating layer in the lateral direction can be suppressed, whereby the displacement of the via-hole conductor and the wiring circuit layer can be suppressed, and the connection reliability can be improved.

In the above-mentioned wiring board, the insulating layer contains 30-60% by volume of an inorganic filler and 70-40% by volume of a thermosetting resin.
Is desirable. Thereby, the amount of deformation of the insulating layer can be further suppressed, and the strength of the substrate can be improved.

In the above-mentioned wiring board, it is desirable that the amorphous inorganic filler is at least one selected from SiO ₂ , Al ₂ O ₃ and BaTiO ₃ . When SiO ₂ is used as the inorganic filler, the relative dielectric constant of the insulating layer can be reduced. Also, as an inorganic filler,
When BaTiO ₃ is used, the relative dielectric constant of the insulating layer can be increased.

In the wiring board of the present invention, the inorganic filler B
It is preferable that the ET specific surface area is 1.5 m ² / g or less. When the specific surface area is 1.5 m ² / g or less, the shape of the inorganic filler can be kept square and irregular, and the fluidity of the inorganic filler in the insulating layer can be suppressed.

Further, in the above-mentioned wiring board, at least one kind of thermosetting resin selected from a polyphenylene ether-based resin, an epoxy-based resin and a cyanate-based resin is preferably used. This is because these resins are excellent in heat resistance and electrical insulation.

In the above-mentioned wiring board, by incorporating an electric element, for example, a capacitor element, in the wiring board, the distance between the semiconductor element mounted on the surface of the wiring board and the electric element and the wiring length of the wiring board can be shortened. Therefore, the inductance between them can be reduced, the responsiveness of the capacitor element as a decoupling capacitor is improved, and the electric signal noise generated from the wiring board can be effectively reduced. Can be deformed in the lateral direction, the connection between the electric element and the via-hole conductor can be reliably performed, and an increase in inductance can be suppressed.

In the above wiring board, the insulating substrate has a first insulating layer formed of a mixture of a thermosetting resin and an amorphous inorganic filler, and a second insulating layer formed by impregnating a fibrous body with the thermosetting resin.
The first insulating layer has an electric element built therein, and the second insulating layer is disposed on the outermost surface of the insulating substrate. Of the strength due to the insulating layer can be suppressed by the high-strength second insulating layer. Since the second insulating layer exists on the outermost surface, the flatness of the wiring board surface is improved, and the semiconductor element and the like are flip-chip mounted. In this case, it is possible to obtain a wiring board that can be sufficiently applied. In addition, by incorporating, for example, a capacitor element as an electric element, electric signal noise generated from the wiring board can be effectively reduced as described above. Further, as described above, since the displacement of the electric element can be prevented, the connection between the via hole conductor and the electric element can be reliably performed. For example, after the thermal shock test using a capacitor element as the electric element, Can be suppressed from increasing.

Further, by adjusting the kind and amount of the inorganic filler contained in the first insulating layer, which is composed of an amorphous inorganic filler and a thermosetting resin, the thermal expansion coefficient and the Young's modulus of the first insulating layer are adjusted. Can be adjusted, the difference in thermal expansion between the electric element and the first insulating layer can be reduced, the stress generated in the built-in electric element can be reduced, and the connection reliability can be improved. Thereby, the displacement of the electric element can be further suppressed.

In the above-mentioned wiring board, it is desirable that a resin adhesive containing spherical SiO ₂ and epoxy resin is interposed at the interface between the built-in electric element and the insulating layer. With the resin adhesive, the electric element can be bonded and fixed inside the substrate, and the inorganic filler is formed into spherical particles, so that the viscous flow of the thermosetting resin at the interface between the surface of the electric element and the insulating layer is reduced. Accordingly, wetting of the resin adhesive can be improved, and the adhesive effect can be enhanced.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 (Structure of Wiring Board) One embodiment of the wiring board of the present invention will be described in detail with reference to the schematic sectional view of FIG. The wiring board A of the present invention is configured by forming wiring circuit layers 9a and 9b on both surfaces of an insulating substrate 7 formed by laminating three insulating layers 1, 3, and 5. A wiring circuit layer 9 is provided between the insulating layers 1 and 3 and between the insulating layers 1 and 5.
c is formed, and via-hole conductors 11 are formed in the insulating layers 1, 3, and 5 in the thickness direction.

The via-hole conductor 11 electrically connects the wiring circuit layers 9a and 9b on the surface of the insulating substrate 7 and the wiring circuit layer 9c inside the insulating substrate 7, or connects the wiring circuit layers on both surfaces of the insulating substrate 7 to each other. 9a and 9b are electrically connected.

In the insulating layer 1, a cavity 13 is formed, in which an electric element 15 composed of two capacitor elements is accommodated and buried.

Via electrodes 11 are connected to the external electrodes of these electric elements 15, and are electrically connected to the wiring circuit layers 9 a and 9 b on the surface of the insulating substrate 7. The electric element 15 is bonded to the insulating layers 3 and 5 on the upper and lower surfaces of the cavity 13 with a resin adhesive 17.

Each of these insulating layers 1, 3, 5 has a thickness of about 50 to 150 μm per layer, and is appropriately laminated to a predetermined thickness in accordance with the size of the electric element 15 such as a built-in capacitor element. Is formed.

The electric element 15 built in the insulating layer 1
It is preferable to provide an electrode at the end because it can be directly connected to the via-hole conductor 11 in the wiring board. In particular, a multilayer capacitor is preferable because of its small size.

The electric element 1 built in the insulating substrate 7
5 is, for example, as shown in FIG.
8a and 18b and a plurality of dielectric layers 19, which are alternately laminated, and are composed of external electrodes 21b and 21c provided at both ends of the electric element main body 21a, respectively. The internal electrode 17a is electrically connected to the positive external electrode 21b, and the negative internal electrode 17b is electrically connected to the negative external electrode 21c.

A semiconductor element 18 is connected to the wiring circuit layer 9a on the upper surface of the insulating substrate 7 by solder 20 on the upper surface of the wiring substrate A thus configured.

Although the present invention has been described with respect to an example in which the electric element 9 is built in the insulating substrate 4, the electric element 9 may not be built. In addition, although a capacitor is used as an electric element, an inductor other than the capacitor, an LC component, or the like may be incorporated.

(Insulating Layer Material) In the present invention, the insulating substrate 7 of the wiring board A is composed of insulating layers 1, 3, and 5 made of a composite of a thermosetting resin and an inorganic filler. As the inorganic filler, an amorphous inorganic filler is used. Examples of amorphous inorganic fillers include, for example, SiO ₂ , A
l ₂ O _3, at least one selected from the group of BaTiO ₃ can be suitably used. As an inorganic filler, S
When iO ₂ is used, the relative dielectric constant of the insulating layer can be reduced. Further, when Al ₂ O ₃ is used as the inorganic filler, the thermal conductivity of the wiring board can be increased. When BaTiO ₃ is used as the inorganic filler, the relative dielectric constant of the insulating layer can be increased. In particular, in order to perform high-speed transmission for the purpose of miniaturization and high performance of electronic devices, it is desirable to use SiO ₂ having a low dielectric constant.

The amorphous inorganic filler has a square shape and a non-spherical shape as shown in FIG. 3A prepared by crushing a massive melt. On the other hand, as shown in FIG. 3B, a conventionally used inorganic filler has a spherical shape and a spherical shape close to a true sphere.

These amorphous inorganic fillers are suitably in the range of 30 to 60% by volume based on the total amount. Among them, regarding the material properties such as fluidity of the insulating layer, substrate strength, water absorption, etc.
The amorphous inorganic filler contained in the insulating layers 1, 3, and 5 contains 4
The optimum amount is 0 to 50% by volume and the thermosetting resin is 60 to 50% by volume.

The insulating layers 1, 3, and 5 made of an amorphous inorganic filler and a thermosetting resin can easily change the thermal expansion coefficient of the insulating layers 1, 3, and 5 depending on the type and amount of the filler. Therefore, the thermal expansion coefficient can be easily matched with the built-in electric element, and the difference in thermal expansion between the built-in electric element 15 and the insulating layer 1 in the insulating layer 1 is set to 7 × 10 ⁻⁶ / ° C. or less. Thereby, the electrical and mechanical connection reliability between the electric element 15 and the wiring board A can be improved.

The specific surface area of the amorphous inorganic filler is 1.5
It is desirably not more than m ² / g. Further, when the maximum length of the irregular shaped particles is defined as the particle size, the average particle size is 0.
It is desirable to be within the range of 5 to 30 μm, particularly 5 to 15 μm. By leaving such an angular irregular shape, the movement of particles can be suppressed. On the other hand, when the specific surface area is larger than 1.5 m ² / g, the particle diameter is reduced, and the shape of the inorganic filler changes from a square amorphous shape to a rounded shape, so that the inorganic filler easily flows, and the insulating layer is deformed. Easy to grow. In particular, the specific surface area of the inorganic filler is 1.2 to 1.5 m ² / g from the viewpoint that the slurry viscosity can be stabilized and the deformation of the cured material insulating layer can be suppressed.
Is desirable.

The thermosetting resin contained in the insulating layer 1 is preferably at least one selected from the group consisting of polyphenylene ether (APPE) resins, epoxy resins and cyanate resins. APPE resin has low relative permittivity, low dielectric loss, low water absorption,
Because of the high glass transition point and high heat resistance,
Particularly preferred. Further, the mixture may contain a dispersant or a coupling agent to improve the wettability with the filler.

The viscosity of the mixture of the amorphous inorganic filler forming the uncured insulating layer and the thermosetting resin is 100
At 200C, it is preferably 200 Pa.s or more. This is because the viscous flow is suppressed when the substrate is cured, and the substrate is unlikely to be deformed by heating and pressing. In particular, in view of the deformation resistance of the insulating layer and the lamination adhesion, 100 ° C.
Is desirably 200 to 1000 Pa · s.

The resin adhesive for adhering and fixing the built-in electric element is made of a mixture of a spherical SiO ₂ filler and an epoxy resin. In order to improve the fluidity of the bonding interface, the average particle diameter of the SiO ₂ filler is increased. Is 0.5 to 3.5 μ
It is preferably a spherical particle having a particle size of m.

(Preparation method) For forming an insulating layer, an uncured insulating sheet made of a mixed material of a thermosetting resin such as a polyphenylene ether resin or an epoxy resin and an amorphous inorganic filler such as silica or alumina is used. Make it.

Then, as shown in FIGS. 4A and 4C, via holes 27 are formed in the insulating sheets 29 and 30 to be the insulating layers 3 and 5 by a carbon dioxide laser or punching. Next, as shown in FIG. 4B, a cavity 25 containing the electric element 15 and a via hole 27 are formed in the insulating sheet 23 serving as the insulating layer 1.

Next, as shown in FIG.
The via holes 27 of 3, 29, and 31 are filled with a conductive paste containing a conductive powder such as a Cu powder to form a via hole conductor 33.

Thereafter, the insulating sheets 23, 29, 31
The conductor layer 35 is formed on the surface of the substrate. These conductor layers 35
For example, a metal foil such as a copper foil or an Al foil is
After being transferred to the surfaces of 3, 29, and 31, the resist is applied, exposed, developed, etched, and removed.
There is a method of forming a conductor layer having a predetermined pattern, or a method of previously transferring the conductor layer to the surface of the insulating sheet on the surface of the resin film. Among them, the latter method is preferable in that the insulating sheet is not exposed to an etchant or the like and the insulating sheet is not deteriorated.

Then, the cavity 25 of the insulating sheet 23
After installing the electric element 15 in the inside, and applying a resin adhesive 17 containing a spherical inorganic filler to both surfaces of the electric element 15,
Above and below the insulating sheet 23, the insulating sheets 29, 3
By laminating 1 and pre-heating the laminate at a temperature lower than the temperature at which the thermosetting resin in the insulating sheet cures, and curing the resin adhesive 17 applied to the electric element 15, The adhesion at the interface between the built-in electric element and the insulating layer is strengthened, and the deformation of the substrate in the subsequent curing process can be suppressed. Thereafter, the wiring substrate is cured by applying heat and pressure at a temperature at which the thermosetting resin is cured.

As described above, since the via-hole conductor and the wiring circuit layer are formed on the uncured insulating sheet made of the mixed material of the inorganic filler and the thermosetting resin, and then laminated to form the wiring board, the high-density wiring is achieved. Can be manufactured. Further, by using an amorphous inorganic filler as the inorganic filler in the insulating layer, the movement of the inorganic filler during curing can be suppressed, so that a wiring board having excellent dimensional stability can be manufactured.

Form 2 An insulating layer (prepreg) in which a fibrous body is impregnated with a thermosetting resin.
In the case where is used for the outermost surface of the wiring board, a description will be given based on FIG. 5 showing a schematic sectional view. The structure of the second embodiment is the same as the structure of the first embodiment except for the type of the insulating material.

In the present invention, the wiring board B is made of an insulating layer 37.
The wiring circuit layer 4 is formed on both surfaces of an insulating substrate 43 formed by laminating insulating layers 39 and 41 made of prepreg on the upper and lower sides thereof.
5a and 45b are formed. Further, between the insulating layer 37 and the insulating layer 39 and between the insulating layer 37 and the insulating layer 4.
1, a wiring circuit layer 45c is formed, and a via-hole conductor 47 is formed in the insulating layers 37, 39, 41 in the thickness direction.

The via-hole conductor 47 electrically connects the wiring circuit layers 45 a and 45 b on the surface of the insulating substrate 43 to the wiring circuit layer 45 c inside the insulating substrate 43,
3, the wiring circuit layers 45a and 45b on both surfaces are electrically connected.

A cavity 47 is formed in the insulating layer 37, in which the electric element 15 composed of a capacitor element is housed and buried.

These electric elements 15 are connected to via-hole conductors 47, and are connected to wiring circuit layers 45 on the surface of insulating substrate 43.
a, 45b. Electric element 15
Are bonded to the insulating layers 39 and 41 on the upper and lower surfaces of the cavity 47 by the resin adhesive 17.

In this embodiment, the insulating layer 37 is made of a mixture of an amorphous inorganic filler and a thermosetting resin, and the insulating layers 39 and 41 are made of a prepreg in which a fibrous body is impregnated with a thermosetting resin. ing.

The thickness of each of the insulating layers 39 and 41 is preferably about 100 μm or less, and the fibrous body is preferably 40 to 60% by volume and the thermosetting resin is preferably 60 to 40% by volume. .

As the fibrous body, glass and / or aramid fiber is used. The fiber diameter is 10μ.
m or less is desirable for increasing the strength. Also,
The fibrous body may be uniformly dispersed, but is desirably made of a woven or nonwoven fabric in order to increase the rigidity of the substrate.

Although an example in which the insulating layers 39 and 41 are laminated one layer above and below the insulating layer 37 has been described, a plurality of layers may be laminated. Further, the prepreg insulating layer may be formed only on one surface of the insulating layer 37.

Such a wiring board is composed of insulating layers 39 and 41
Can be produced by the same manufacturing method as in the first embodiment, except that prepreg is used.

The wiring board constructed as described above uses an insulating material made of a mixture of an amorphous inorganic filler and a thermosetting resin as the insulating layer 37, so that the insulating layer 37 flows during manufacturing. Since the deformation of the insulating layer 37 can be suppressed, and the insulating layer made of prepreg is used for the surface layer, the strength of the substrate is improved, and the fibrous body in the prepreg moves via-hole conductors and electric elements inside the substrate. Can be further suppressed.

[0051]

EXAMPLES Example 1 A sample for property evaluation and a wiring board shown in FIG. 1 were prepared based on the composition of a resin component shown in Table 1 and an inorganic filler having a shape, a component and a specific surface area shown in the table. Was prepared.

For example, an allylated polyphenylene ether resin (APPE) and an amorphous inorganic filler are dissolved in a toluene solvent heated to 80 ° C., a dispersant is added as an additive, and the mixture is mixed for 30 minutes by a mixing stirrer. Do
A slurry was prepared.

The stirring mixer used has two stirring blades facing each other, and is a type that rotates and revolves in a mixing vessel, and can mix a relatively high-viscosity slurry and uniformly disperse the slurry. A slurry is obtained. An uncured insulating sheet having a thickness of 120 μm was produced from the slurry thus prepared by a doctor blade method using a PET film as a release film.

Next, the uncured insulating sheet was peeled from the release film, cut into small pieces, packed in a molding die, and pressed at a molding pressure of 100 kg / cm ² to form a sheet having a diameter of 10 mm and a thickness of 10 mm. A 5 mm disk-shaped press-formed body was obtained.
This molded product is used as a flow tester (manufactured by Shimadzu Corporation).
Was used to measure the viscosity at a temperature of 100 ° C. and a shear rate of 100 s ⁻¹ .

Next, five insulating sheets each having a thickness of 120 μm were stacked and laminated.
After heating and pressurizing under the condition of 10 kg / cm ² for 10 minutes, subsequently, by heating and pressing at 220 ° C. and a temperature and pressure of 40 kg / cm ² for 60 minutes, a thickness of 600 μm is obtained.
Thus, plate-shaped insulators to be m insulating layers 1, 3, 5, and 23 were obtained. Next, the cured plate-shaped insulator was processed into predetermined dimensions, and the linear thermal expansion coefficient, substrate strength, and water absorption were measured. The linear thermal expansion coefficient is determined by measuring the substrate size to 10 × 3 × 0.5 (m
m) in a temperature range from normal temperature to 250 ° C., using a thermomechanical analysis (TMA) apparatus (manufactured by Seiko Co., Ltd.). The board strength is determined by setting the board size to 40 × 30 × 0.5 (m
m) at room temperature, and measured by three-point bending using an autograph at a fulcrum span of 45 mm.

The water absorption was determined by measuring the substrate size to 30 × 30 × 0.5.
(Mm), which was left for 24 hours in water at a room temperature of 23 ° C., which is a normal measurement condition of an organic substrate, and evaluated from a change in weight before and after that. The relative permittivity is obtained by measuring the substrate size to 60 × 60 × 0.
5 (mm), with an area of 50 mmφ on both surfaces of the substrate,
A silver paste was coated, and a frequency of 1 MHz was measured using a capacitance meter (manufactured by Hewlett-Packard Company).
At an input signal level of 1.0 Vrms, the capacitance was measured, and the relative permittivity was calculated. The results are shown in Table 2.

As shown in Table 2, the insulating substrate prepared by the above method can increase the viscosity of the insulator compared to the spherical filler when the amorphous filler is used as the inorganic filler. Even if the content is low or low,
It was found to exhibit high viscosity. Also, if it is irregular,
Even when Al ₂ O ₃ and BaTiO ₃ were used, the viscosity could be increased. And the coefficient of thermal expansion, substrate strength,
The water absorption and the relative permittivity showed the same characteristics as those of the insulating substrate made of the spherical inorganic filler.

Next, a wiring board as shown in FIG. 1 was manufactured as follows. First, varnished resin and powder were mixed with the APPE resin so that the amorphous silica powder had a predetermined ratio, and an insulating sheet having a thickness of 120 μm was prepared by a doctor blade method. A via hole (diameter 0.
1 mm), and the via holes are filled with a conductive paste containing a conductive powder such as Cu powder to form via-hole conductors, thereby forming insulating sheets 29 and 31 to be the insulating layers 3 and 5 in FIG. did.

Next, the insulating sheet 23 having the same sample thickness as the insulating sheets 29 and 31 was trepanned by a carbon dioxide gas laser, and was slightly larger than the size of the capacitor to be housed. A via hole (diameter: 0.1 mm) is also formed by a carbon dioxide laser and a through hole for a cavity of 0.5 mm, and the via hole is filled with a conductive paste containing a conductive powder such as Cu powder to form a via hole conductor. Was formed, and an insulating sheet 23 to be the insulating layer 1 in FIG. 1 was produced.

Next, as a wiring circuit layer, first, an adhesive was applied to the surface of a transfer sheet made of polyethylene terephthalate (PET) resin to have a thickness of 12 μm and a surface roughness of 0.1 μm.
An 8 μm copper foil was adhered to one surface. Then, after applying a dry film resist, performing exposure and development, using a spray type etching apparatus using a ferric chloride solution, the non-pattern portion is removed by etching, and a wiring circuit layer made of copper foil is formed. Was formed on the transfer sheet.

Then, on the surface of the insulating sheets 29 and 31 including the via-hole conductor, the wiring circuit layer side of the transfer sheet is
After pressure bonding at 0 ° C. and 20 kg / cm ² , the transfer sheet was peeled off, and the wiring circuit layers were transferred to the insulating sheets 29 and 31.

Next, the insulating sheet 23 formed with the through hole for the cavity and the via hole conductor was laminated so as to overlap the through hole for the cavity, and a multilayer ceramic capacitor was temporarily installed in the cavity.

Then, an epoxy resin adhesive containing spherical silica was applied to both surfaces of the capacitor element. On the front and back surfaces of the insulating sheet 23, insulating sheets 29 and 31 having a conductor layer and via-hole conductors produced through the above steps were temporarily laminated.

Then, the laminate was placed in a vacuum hot press apparatus, and the pressure was 10 kg / cm ² , and the temperature was raised at a rate of 7 ° C./m.
in. When the temperature reached 100 ° C., holding was performed for 30 minutes to fix the capacitor element to the insulating layer.
Then, at the same heating rate and at a pressure of 40 kg / cm ² ,
The temperature was raised to 20 ° C., heated at a maximum temperature of 220 ° C. for 1 hour, and completely cured to produce a wiring board with a built-in electric element. Then, for the manufactured electric element built-in wiring board,
The following considerations were made.

The surface of the manufactured wiring board with a built-in electric element
The dimensions of the wiring pattern are distributed using an electronic three-dimensional measuring machine.
Measure the distance between the lines, compare with the design dimension value, and
Calculated. In addition, using an impedance analyzer
At a frequency of 1.0 MHz to 1.8 MHz,
Measure the frequency characteristics of the impedance, and at the same time at 1MHz
Is measured, and f₀= 1 /
(2π (L / C)^1/2) (Where f ₀: Resonance frequency (H
z), C: capacitance (F), L: inductance
(H)), the inductance is calculated from the resonance frequency.
It was calculated (L (room temperature)). Note that this measurement
(L (TS
After)) and before the test. The conditions of the thermal shock test were as follows:
Temperature range of -55 to 125 ° C, when held at the highest and lowest temperatures
The interval was 5 minutes each.

[0066]

[Table 1]

[0067]

[Table 2]

As is evident from the results of Tables 1 and 2, in the wiring board manufactured according to the present invention, the filler used for the insulating layer formed by mixing with the thermosetting resin is the same as the amorphous filler and the thermosetting resin. Nos. 1 to 8 and 13 to 25 using an insulating layer made of a mixture with a reactive resin, the increase in the amount of amorphous inorganic filler and the increase in water absorption were observed, In addition, the deformation of the insulating layer and the via-hole conductor could be suppressed to 50 μm or less, the change in inductance was small, and the connection reliability could be improved. In particular, when the amount of the amorphous filler used for the insulating layer is set to 40% by volume to 60% by volume, the dimensional change amount of the wiring on the substrate surface can be suppressed, and the built-in capacitor before and after the thermal shock test is evaluated. Was able to reduce the amount of inductance change.

In the case where the electric element is built-in, a resin adhesive is applied in advance to the surface of the built-in electric element to prevent adhesion (sample Nos. 21 to 2).
Compared with 3), the electric component built in the insulating layer was firmly adhered and fixed, and the connection between the via-hole conductor and the connection terminal of the electric component could be reliably performed. Thereby, the amount of change in inductance after the thermal shock test can be reduced. In addition, the sample No. of the comparative example using a spherical inorganic filler as the inorganic filler contained in the insulating sheet. In Nos. 9 to 12, the viscosity of the insulator is lower than in the case where the amorphous inorganic filler is used,
The amount of deformation of the wiring of the wiring board was increased, and the inductance of the wiring board having a built-in capacitor after room temperature and thermal shock tests was increased.

Next, as described in Sample Nos. 24 and 25 in Tables 1 and 2, epoxy resin and cyanate resin were used as the thermosetting resin for the insulating layer.
Under the curing conditions of 40 ° C., 40 kg / cm ² , and 60 minutes, a sample for characteristic evaluation and a wiring board were produced. In these samples, although the relative permittivity was slightly higher, the same results as those in the case of using the APPE resin were obtained with respect to the deformation amount and the inductance of the wiring board.

(Example 2) In this example, the insulating layer on the front side and the back side of the wiring substrate was replaced with a prepreg, and an insulating substrate having a thickness of 0.6 mm was prepared. A wiring board was manufactured in the same manner as in Example 1, and the same characteristics as in Example 1 were evaluated. 26-28.

In Table 2, the sample No. As can be seen from 26 to 28, even when the prepreg is used for the surface layer of the wiring board,
The amount of deformation was not different from the case of the insulating layer made of an amorphous inorganic filler, and the substrate strength was greatly improved.

Although an increase in inductance after the thermal shock test was observed, the amount of deformation of the wiring on the wiring board and the inductance before the thermal shock test were equivalent to those using a resin adhesive.

[0074]

As described above, according to the present invention, since the insulating layer is made of a mixture of the amorphous inorganic filler and the thermosetting resin, the deformation of the insulating layer is suppressed during the heating and pressurization during the production of the substrate. As a result, the displacement of the via-hole conductor and the wiring circuit layer can be suppressed, and the connection reliability can be improved. When an electric element is incorporated, a resin adhesive is applied in advance to the surface of the electric part to fix the electric element incorporated in the insulating layer, and the via hole conductor and the electric part are electrically connected to each other. The connection between the connection terminals can be reliably performed.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a wiring board of the present invention.

FIG. 2 is a view for explaining an electric element (capacitor element) used in the present invention, wherein (a) is a perspective view,
(B) is a pattern diagram of a positive electrode internal electrode, and (c) is a pattern diagram of a negative electrode internal electrode.

FIG. 3 is a diagram showing an amorphous inorganic filler of the present invention and a conventional spherical inorganic filler.

FIG. 4 is a process chart for manufacturing the wiring board of the present invention.

FIG. 5 is a cross-sectional view showing another wiring board of the present invention in which an insulating layer composed of an amorphous inorganic filler and a thermosetting resin is sandwiched between prepregs.

[Explanation of symbols]

 A, B Wiring board 7 Insulating board 9a, 9b, 9c Wiring circuit layer 11 Via hole conductor 13 Cavity 15 Electric element 17 Resin adhesive 18 Semiconductor element 37 First insulating layer 39, 41 Second insulating layer

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H05K 1/03 610 H05K 1/03 610L

Claims (9)

[Claims] 1. A wiring board comprising: a wiring circuit layer formed on the surface and / or inside of an insulating substrate formed by laminating a plurality of insulating layers; and a via-hole conductor formed inside the insulating substrate.
The wiring board, wherein the insulating layer is made of a mixture of an amorphous inorganic filler and a thermosetting resin. 2. The method according to claim 1, wherein the insulating layer contains an amorphous inorganic filler in an amount of 30 to 6%.
2. The wiring board according to claim 1, wherein said wiring board contains 0% by volume and 70 to 40% by volume of a thermosetting resin. 3. An amorphous inorganic filler comprising SiO ₂ , Al ₂
The wiring board according to claim 1, wherein the wiring board is at least one selected from O ₃ and BaTiO ₃ . 4. The wiring board according to claim 1, wherein the amorphous inorganic filler has a BET specific surface area of 1.5 m ² / g or less. 5. The thermosetting resin according to claim 1, wherein the thermosetting resin contains at least one selected from a polyphenylene ether resin, an epoxy resin and a cyanate resin.
5. The wiring substrate according to any one of items 4 to 4. 6. The wiring substrate according to claim 1, wherein an electric element is built in the insulating substrate. 7. An insulating substrate comprising: a first insulating layer made of a mixture of a thermosetting resin and an amorphous inorganic filler; and a second insulating layer made by impregnating a fibrous body with a thermosetting resin. 6. An electric element is built in the first insulating layer, and the second insulating layer is disposed on the outermost surface of the insulating substrate. The wiring board as described. 8. The wiring board according to claim 6, wherein the electric element is fixedly adhered with a resin adhesive. 9. The wiring board according to claim 8, wherein the resin adhesive contains a spherical inorganic filler made of SiO ₂ and an epoxy resin.