JP2003218160A - Insulating film and multilayer wiring board using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulating film made of an organic material and a multilayer wiring board using the same, failing to satisfy all of high-density wiring, insulation reliability, conduction reliability, and high-frequency transmission characteristics. SOLUTION: The insulating film 3 has a porosity of 3 to 3.
It is characterized in that a coating layer 2 made of a polyphenylene ether-based organic substance is provided on the upper and lower surfaces of a liquid crystal polymer layer 1 of 40% by volume. An insulating film 3 excellent in insulation, conduction reliability, and high-frequency transmission characteristics can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating film used in various kinds of electronic equipment such as AV equipment, home electric appliances, communication equipment, computers and peripheral equipment thereof, and a multilayer wiring board using the same, and particularly to a liquid crystal polymer. The present invention relates to an insulating film used in part and a multilayer wiring board using the same.

[0002]

2. Description of the Related Art Conventionally, a multilayer wiring board for forming a hybrid integrated circuit in which a large number of active components such as semiconductor elements and passive components such as capacitance elements and resistance elements are mounted to form a predetermined electronic circuit is usually Formed by stacking a number of wiring boards, each having a plurality of wiring conductors formed inside the through hole and on the surface of the insulating layer by forming through holes in the insulating film made of glass cloth impregnated with epoxy resin by a drill. ing.

In general, current electronic devices are required to be small, thin, lightweight, high-performance, high-performance, high-quality and highly reliable, as represented by mobile communication devices. Electronic components such as hybrid integrated circuits mounted on
There is a demand for higher densities, and in order to meet such demands for higher densities, the multilayer wiring boards that compose electronic components are also made finer in wiring conductors and thinner in insulating layers.
The miniaturization of through holes has become necessary. For this reason, in recent years, in order to miniaturize the through holes, laser machining, which enables finer machining than drilling, has come to be used.

However, the insulating film formed by impregnating glass cloth with an epoxy resin has a limit in miniaturizing the through holes because it is difficult to drill the glass cloth with a laser, and the glass cloth of There is a problem that it is difficult to form a through hole having a uniform hole diameter due to the uneven thickness.

In order to solve these problems, an insulating film formed by impregnating a non-woven fabric made of aramid resin fiber with an epoxy resin or an insulating film formed by coating a polyimide film with an epoxy adhesive is used as an insulating layer. The multilayer wiring board used for is proposed.

However, an insulating film using an aramid non-woven fabric or a polyimide film has a high hygroscopic property, and when solder reflow is performed in a moisture-absorbed state, moisture absorbed by the solder reflow is vaporized to generate a gas, and the insulating layers are separated. There was a problem such as peeling.

In order to solve such a problem, it has been studied to use a liquid crystal polymer as a material for an insulating layer of a multilayer wiring board. The layer made of liquid crystal polymer is composed of rigid molecules and also has a structure in which the molecules are regularly arranged to some extent, and the intermolecular force is strong.
Shows high heat resistance, high elastic modulus, high dimensional stability and low moisture absorption,
It is characterized in that it does not require the use of a reinforcing material such as glass cloth and is excellent in fine workability. Further, even in a high frequency region, it has a characteristic that it has a low dielectric constant and a low dielectric loss tangent and is excellent in high frequency characteristics.

Utilizing the characteristics of such a liquid crystal polymer,
JP-A-8-97565 discloses that a circuit layer contains a first liquid crystal polymer, and an adhesive layer containing a second liquid crystal polymer having a melting point lower than that of the first liquid crystal polymer is inserted between the circuit layers. Has been proposed, and in JP-A-2000-269616, there is proposed a high-frequency circuit board formed by adhering a thermoplastic liquid crystal polymer film and a metal foil with an epoxy adhesive. Has been done.

[0009]

SUMMARY OF THE INVENTION
The multilayer printed circuit board proposed in 8-97565 is
When an adhesive layer containing a liquid crystal polymer is inserted between circuit layers and they are bonded by thermocompression bonding, the liquid crystal polymer molecules are rigid and molecules are regularly oriented to some extent to strengthen the intermolecular force. Of the liquid crystal polymer of the circuit layer and the liquid crystal polymer of the adhesive layer can be entangled with only a small part of the molecules, resulting in poor adhesion and peeling between layers in a high temperature bias test, resulting in insulation failure. There was a problem that it would occur. Also, when the conductor foil of the circuit layer and the liquid crystal polymer are bonded by heat fusion, the liquid crystal polymer molecules are difficult to move and therefore cannot enter the minute recesses on the conductor foil surface, resulting in sufficient anchoring effect. However, the adhesiveness between the conductor foil and the liquid crystal polymer deteriorates, and there is a problem that the conductor foil peels off between the two under high temperature and high humidity and the conductor foil is broken.

In the high frequency circuit board proposed in Japanese Patent Laid-Open No. 2000-269616, since the dielectric constant of the epoxy adhesive is greatly different from the dielectric constant of the liquid crystal polymer, a slight thickness caused by pressurization during lamination is required. Due to the variation, there is a problem that the transmission characteristic is deteriorated in a high frequency region, particularly in a frequency region of 100 MHz or more.

The present invention has been devised in view of the above problems of the prior art, and an object thereof is to provide an insulating film excellent in insulation, conduction reliability, and high frequency transmission characteristics, and a multilayer wiring board using the same. It is in providing.

[0012]

The insulating film of the present invention comprises a liquid crystal polymer layer having a porosity of 3 to 40% by volume and a coating layer made of a polyphenylene ether organic material formed on the upper and lower surfaces of the liquid crystal polymer layer. To do.

Further, the insulating film of the present invention is characterized in that, in the above constitution, the liquid crystal polymer layer has a dielectric constant of 2.1 to 3.5.

Further, the insulating film of the present invention has the above-mentioned constitution, in which the upper and lower surfaces of the liquid crystal polymer layer have a contact angle with triallyl isocyanurate of 3 to 50 ° and a surface energy of 45 to 70 mJ / m ^2. It is characterized by being.

Further, the insulating film of the present invention has the above-mentioned constitution, and the center line surface roughness R of the upper and lower surfaces of the liquid crystal polymer layer
a is 0.05 to 5 μm.

Furthermore, the insulating film of the present invention is characterized in that, in the above constitution, the polyphenylene ether organic substance is a thermosetting polyphenylene ether.

Further, the multilayer wiring board of the present invention is formed by laminating a plurality of the above-mentioned insulating films in which wiring conductors made of metal foil are provided on at least one of the upper and lower surfaces.
It is characterized in that the wiring conductors located above and below the insulating film are electrically connected to each other via a through conductor formed in the insulating film.

According to the insulating film of the present invention, since the coating layer made of polyphenylene ether organic material is formed on the upper and lower surfaces of the liquid crystal polymer layer having the porosity of 3 to 40% by volume, the upper and lower surfaces of the liquid crystal polymer layer are formed. The liquid crystal polymer layer is satisfactorily impregnated with the coating layer made of a polyphenylene ether organic substance, and the liquid crystal polymer layer and the coating layer can be a firmly adhered insulating film having a sufficient anchoring effect. Further, even when the insulating film is multilayered, the polyphenylene ether-based organic molecule is not as rigid as the liquid crystal polymer molecule, and the ordered orientation is not shown, so the molecule is relatively easy to move and the adhesion between the insulating films is improved. As a result, in a high temperature bias test, there is no possibility of peeling between the insulating films or between the liquid crystal polymer layer and the coating layer to cause insulation failure. Further, even when the wiring conductor is arranged on the surface of the insulating film, the polyphenylene ether-based organic molecule can enter the fine recesses on the surface of the wiring conductor and exhibit a sufficient anchoring effect, resulting in close contact between the insulating film and the wiring conductor. As a result, there is no possibility that the wiring conductor will break due to peeling between the two under high temperature and high humidity. In addition, since the frequency behavior of the dielectric constant of the coating layer made of polyphenylene ether-based organic material and the liquid crystal polymer layer are almost the same, even if a slight thickness variation occurs in the coating layer due to pressure when bonding the wiring conductor, It is possible to obtain an insulating film excellent in high-frequency transmission characteristics without causing deterioration in transmission characteristics in a region.

Further, according to the insulating film of the present invention, in the above structure, since the dielectric constant of the insulating film is 2.1 to 3.5, a plurality of insulating films having wiring conductors on the surface are laminated to form a multilayer wiring board. Even if you make
It is possible to obtain an insulating film excellent in high-frequency transmission characteristics without causing deterioration in transmission characteristics in a high-frequency region.

Further, according to the insulating film of the present invention, in the above constitution, the contact angle of the liquid crystal polymer layer with triallyl isocyanurate is 3 to 50 °, and the surface energy of the liquid crystal polymer layer is 45 to 70 mJ / m. ^Because it was ² ,
An insulating film in which the activated molecular layer on the surface of the liquid crystal polymer layer, which is relatively easily moved by heat, and the coating layer made of a polyphenylene ether-based organic substance are entwined and entangled well, and the liquid crystal polymer layer and the coating layer are more firmly adhered to each other. Can be

Further, according to the insulating film of the present invention, in the above-mentioned constitution, since the center line surface roughness Ra of the upper and lower surfaces of the liquid crystal polymer layer is 0.05 to 5 μm, the upper and lower surfaces of the liquid crystal polymer layer are polyphenylene ether type. The coating layer made of an organic substance has a good anchoring effect and good adhesiveness, and an insulating film in which the liquid crystal polymer layer and the coating layer are more firmly adhered can be obtained.

Further, according to the insulating film of the present invention,
In the above configuration, since the polyphenylene ether-based organic material is a thermosetting polyphenylene ether, the thermosetting polyphenylene ether is excellent in heat resistance and dimensional stability, as a result, excellent in temperature cycle reliability, and the wiring conductor It is possible to obtain an insulating film having good positional accuracy when bonding.

Further, according to the multi-layer wiring board of the present invention, since the multi-layer wiring board is formed by using the above-mentioned insulating film, the multi-layer wiring board is excellent in moisture resistance, continuity reliability and high frequency transmission characteristics. You can

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an insulating film of the present invention and a multilayer wiring board using the same will be described in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view showing an example of an embodiment of an insulating film of the present invention, and FIG. 2 is a semiconductor device on a multilayer wiring board of the present invention formed by using the insulating film of FIG. FIG. 3 is a cross-sectional view showing an example of an embodiment of a hybrid integrated circuit in which electronic components such as the above are mounted. Furthermore, FIG.
FIG. 3 is an enlarged sectional view of an essential part of a wiring conductor of the multilayer wiring board shown in FIG. 2 in a width direction. In these figures, 1 is a liquid crystal polymer layer, 2 is a coating layer made of a polyphenylene ether organic material, and these mainly constitute the insulating film 3 of the present invention. Further, 4 is a wiring conductor, 5 is a penetrating conductor, 7 is an electronic component such as a semiconductor element, and the multilayer wiring board 6 of the present invention is mainly composed of the insulating film 3, the wiring conductor 4, and the penetrating conductor 5. In addition, the multilayer wiring board 6 of this example is shown as being formed by laminating four layers of the insulating films 3.

The insulating film 3 includes the liquid crystal polymer layer 1 and
A coating layer 2 made of a polyphenylene ether-based organic material is formed on the upper and lower surfaces thereof, and when a multilayer wiring board 6 is formed using this, it is mounted on the wiring conductor 4 or the multilayer wiring board 6. It has a function as a support for the electronic component 7.

Here, the liquid crystal polymer means a polymer exhibiting liquid crystallinity or a polymer having optical birefringence in a molten state or a solution state,
Generally, a lyotropic liquid crystal polymer that exhibits liquid crystallinity in a solution state, a thermotropic liquid crystal polymer that exhibits liquid crystallinity when melted, or type 1 or type 2 that is classified by heat distortion temperature
The liquid crystal polymer includes all three types of liquid crystal polymers, and the liquid crystal polymer used in the present invention has a temperature of 230 to 420 ° C., particularly from the viewpoint of temperature cycle reliability, solder heat resistance, and workability.
Those having a melting point at a temperature of 270 to 380 ° C. are preferable. Further, the polyphenylene ether-based organic material means a polyphenylene ether resin, a resin in which various functional groups are bonded to polyphenylene ether, or a derivative / polymer thereof.

The liquid crystal polymer layer 1 is 3-40% by volume.
It has a porosity of, which is important in the present invention.

According to the insulating film 3 of the present invention, since the coating layer 2 made of polyphenylene ether organic material is formed on the upper and lower surfaces of the liquid crystal polymer layer 1 having a porosity of 3 to 40% by volume, the liquid crystal polymer layer 1 is formed. The liquid crystal polymer layer 1 is satisfactorily impregnated with the coating layer 2 made of a polyphenylene ether organic compound on the upper and lower surfaces, and the liquid crystal polymer layer 1 and the coating layer 2 form a firmly adhered insulating film 3 having a sufficient anchoring effect. You can

When the porosity of the liquid crystal polymer layer 1 is less than 3% by volume, the polyphenylene ether organic compound molecules constituting the coating layer 2 made of the polyphenylene ether organic compound on the upper and lower surfaces of the liquid crystal polymer layer 1 are liquid crystal polymer layers. 1
It becomes difficult to enter the fine recesses on the surface to exert a sufficient anchoring effect, and as a result, there is a tendency for peeling between the two to easily occur under high temperature and high humidity. When it exceeds 40% by volume, the coefficient of thermal expansion of the liquid crystal polymer layer 1 becomes large, and the coating layer 2 made of polyphenylene ether organic material having a large coefficient of thermal expansion is satisfactorily restrained so that the thermal expansion of the entire insulating film 3 is suppressed. Tends to be difficult to make small,
For example, when the multilayer wiring board 6 is manufactured using the insulating film 3, the thermal expansion coefficient of the insulating film 3 becomes larger than the thermal expansion coefficient of the wiring conductor 4, and the insulating film 3 is caused by the stress generated by the difference in thermal expansion. Cracks tend to occur easily. Therefore, the liquid crystal polymer layer 1
It is important that the porosity of 3 is in the range of 3 to 40% by volume, and particularly in the range of 10 to 30% from the viewpoint of connection reliability when the multilayer wiring board 6 is manufactured and the electronic parts 7 are mounted. It is preferable.

Here, the pores formed in the liquid crystal polymer layer 1 mean substantially spherical bubbles, and the diameter of the bubbles is 0.01.
˜3 μm. The measuring method is, for example, a method that can be quantified by observation with an electron microscope. From the viewpoint of the uniformity of the dielectric constant and the coefficient of thermal expansion of the liquid crystal polymer layer, it is preferable that the distribution of bubbles be uniform.
When the liquid crystal polymer layer 1 is produced by the axial stretching method or the inflation method, it can be set to a desired value by appropriately adjusting the pressure and the temperature rising rate.

Further, the dielectric constant of the liquid crystal polymer layer 1 is in the range of 2.1 to 3.5 from the viewpoint of the insulating film 3 having excellent high frequency transmission characteristics which does not deteriorate the transmission characteristics in the high frequency region. It is preferable.

If the dielectric constant of the liquid crystal polymer layer 1 is less than 2.1, the difference in dielectric constant between the liquid crystal polymer layer 1 and the coating layer 2 made of polyphenylene ether organic material formed on the upper and lower surfaces of the liquid crystal polymer layer 1 becomes large. When transmitting the high frequency signal, the liquid crystal polymer layer 1 and the coating layer 2 have different propagation delay times of the high frequency signal, so that the signal is distorted and the transmission loss tends to increase. Further, when the dielectric constant of the liquid crystal polymer layer 1 exceeds 3.5, the difference in dielectric constant between the liquid crystal polymer layer 1 and the coating layer 2 made of polyphenylene ether organic material formed on the upper and lower surfaces of the liquid crystal polymer layer becomes large, and the insulating film 3 itself Since the dielectric constant increases, the transmission loss tends to increase when transmitting a high frequency signal of 100 MHz or higher. Therefore, the dielectric constant of the liquid crystal polymer layer 1 is preferably in the range of 2.1 to 3.5.

The liquid crystal polymer layer 1 is a light stabilizer such as an antioxidant for improving thermal stability and a light stabilizer such as an ultraviolet absorber for improving light resistance as long as the physical properties of the layer are not impaired. Halogen-based or phosphoric acid-based flame retardants to add flame retardancy, antimony compounds and zinc borate.
Flame retardant aids such as barium metaborate and zirconium oxide,
Lubricants such as higher fatty acids and higher fatty acid esters / higher fatty acid metal salts / fluorocarbon-based surfactants for improving lubricity; aluminum oxide for adjusting the thermal expansion coefficient and / or improving mechanical strength. Silicon oxide, titanium oxide, barium oxide, strontium oxide,
Zirconium oxide, calcium oxide, zeolite, silicon nitride, aluminum nitride, silicon carbide, potassium titanate, barium titanate, strontium titanate, calcium titanate, aluminum borate, barium stannate,
A filler such as barium zirconate or strontium zirconate may be contained.

The shape of the particles of the above-mentioned filler and the like may be substantially spherical, needle-like, flake-like, etc. From the viewpoint of filling properties, substantially spherical shape is preferred. The particle diameter is usually about 0.1 to 15 μm, which is smaller than the thickness of the liquid crystal polymer layer 1.

The liquid crystal polymer layer 1 is subjected to buffing, blasting, brushing, plasma treatment, corona treatment, ultraviolet treatment, chemical treatment, etc. on its surface in order to improve the adhesion with the coating layer 2. It is preferable that the treatment is performed so that the contact angle with triallyl isocyanurate is 3 to 50 ° and the surface energy is 45 to 70 mJ / m ² .

The wettability of the liquid triallyl isocyanurate to the liquid crystal polymer layer 1 is similar to the wettability of the polyphenylene ether to the liquid crystal polymer layer 1,
By making the upper and lower surfaces of the liquid crystal polymer layer 1 have a contact angle with triallyl isocyanurate of 3 to 50 °, the coating layer 2 satisfactorily wets and spreads on the upper and lower surfaces of the liquid crystal polymer layer 1, and the liquid crystal polymer layer 1 and the coating layer. Adhesion with 2 can be made good, and as a result, it is possible to obtain an insulating film 3 which does not peel off between the two even in a high temperature bias test.
When the contact angle with triallyl isocyanurate is smaller than 3 °, the coating layer 2 spreads extremely over the liquid crystal polymer layer 1 and the positional accuracy deteriorates, and a plurality of insulating films 3 are stacked and heated. When applying pressure to make multiple layers,
The wiring conductors 4 formed on the surface of the insulating film 3 and the penetrating conductors 5 formed inside tend to be displaced and easily break. If the angle exceeds 50 °, the liquid crystal polymer layer 1 and the coating layer are subjected to a high temperature bias test. There is a tendency that the adhesiveness with No. 2 decreases and peeling easily occurs between the two. Therefore, the contact angle between the upper and lower surfaces of the liquid crystal polymer layer 1 and triallyl isocyanurate is preferably 3 to 50 °.

Further, in the liquid crystal polymer layer 1, the molecular layer whose surface is activated and which is relatively easily moved by heat and the coating layer 2 are entwined and entangled well, and the adhesion between the two is further strengthened. From the surface energy of 45-70m
It is preferably J / m ² . Surface energy is 45m
When it is less than J / m ² , the molecular layer on the surface of the liquid crystal polymer layer 1 is not sufficiently activated, and it tends to be difficult to entangle and bond well with the coating layer 2, and more than 70 mJ / m ² . The surface of the liquid crystal polymer layer 1 becomes very reactive and reacts with oxygen in the air to form a weak oxide on the surface. As a result, the liquid crystal polymer layer 1 and the coating layer 2 are formed.
There is a tendency that the adhesiveness to and decreases, and peeling easily occurs between the two. Therefore, the surface energy of the liquid crystal polymer layer 1
It is preferably 45 to 70 mJ / m ² .

Further, the liquid crystal polymer layer 1 preferably has a center line surface roughness Ra of the surface of 0.05 to 5 μm. According to the insulating film 3 of the present invention, since the centerline surface roughness Ra of the upper and lower surfaces of the liquid crystal polymer layer 1 is set to 0.05 to 5 μm, the upper and lower surfaces of the liquid crystal polymer layer 1 have a good anchoring effect with the coating layer 2. The adhesiveness is improved, and the liquid crystal polymer layer 1 and the coating layer 2 can be more firmly adhered.

The center line surface roughness Ra is preferably 0.05 μm or more from the viewpoint of preventing separation of the liquid crystal polymer layer 1 and the coating layer 2 during solder reflow, and the coating layer 2 on the surface. The thickness is preferably 5 μm or less from the viewpoint of preventing the entrapment of air when forming the film. Therefore, the liquid crystal polymer layer 1 preferably has a center line surface roughness Ra of the surface of 0.05 to 5 μm.

Next, the coating layer 2 has a function of an adhesive when the wiring conductor 4 which will be described later is adhered and formed, and the insulating film 3 is used when the multilayer wiring board 6 is formed by using the insulating film 3. It plays the role of an adhesive when laminating each other.

The coating layer 2 contains 30 to 90% by volume of a polyphenylene ether resin or its derivative, or a polyphenylene ether type organic substance such as a polymer alloy of these, and particularly the thermal cycle reliability and the adhesion of the wiring conductor 4 to each other. From the viewpoint of positional accuracy in this case, it is preferable to contain a thermosetting polyphenylene ether such as allyl-modified polyphenylene ether.

When the content of the polyphenylene ether organic substance is less than 30% by volume, the kneading property with the filler described below tends to be lowered, and when it exceeds 90% by volume, the surface of the liquid crystal polymer layer 1 is deteriorated. When forming the coating layer 2 on
The thickness variation of the coating layer 2 tends to increase. Therefore, the content of polyphenylene ether-based organic matter,
A range of 30 to 90% by volume is preferable.

From the viewpoint of improving the adhesiveness with the liquid crystal polymer layer 1 and the adhesiveness with the wiring conductor 4 and the through conductor 5 described later, the coating layer 2 has two functional groups capable of undergoing a polymerization reaction. It is preferable to contain an additive such as a polyfunctional monomer or a polyfunctional polymer having the above, and for example, it is preferable to contain triallyl isocyanurate, triallyl cyanurate, or a polymer thereof.

Further, the coating layer 2 comprises a rubber component for adjusting the elastic modulus and an antioxidant for improving the thermal stability,
Light stabilizers such as UV absorbers to improve light resistance, halogen-based or phosphoric acid-based flame retardants to add flame retardancy, antimony compounds, zinc borate, barium metaborate, and zirconium oxide. Flame retardant aids such as, lubricants such as higher fatty acids and higher fatty acid esters to improve lubricity, higher fatty acid metal salts and fluorocarbon surfactants,
Aluminum oxide, silicon oxide, titanium oxide, barium oxide, strontium oxide, zirconium oxide, calcium oxide, zeolite, silicon nitride, aluminum nitride, silicon carbide, potassium titanate for adjusting thermal expansion coefficient and improving mechanical strength・ Filling materials such as barium titanate, strontium titanate, calcium titanate, aluminum borate, barium stannate, barium zirconate, strontium zirconate, etc., or improving their bondability and mechanical properties. A coupling agent such as a silane coupling agent or a titanate coupling agent for increasing the mechanical strength may be contained.

Particularly, when the insulating film 3 is laminated and pressed to form the multilayer wiring board 6, the fluidity of the coating layer 2 is suppressed, and the displacement of the through conductor 5 and the variation in the thickness of the coating layer 2 are prevented. From the viewpoint, the coating layer 2 is used as a filler.
It is preferable to contain the inorganic insulating powder in a volume% or more.
In addition, the adhesive interface with the liquid crystal polymer layer 1 and the wiring conductor 4
The content of the filler is preferably 70% by volume or less from the viewpoint of preventing peeling during solder reflow at the adhesive interface with. Therefore, it is preferable that the coating layer 2 made of a polyphenylene ether-based organic material contains 10 to 70% by volume of the filler.

The shape of the above-mentioned filling material is substantially spherical.
There are needle-like shapes and flake-like shapes, and a substantially spherical shape is preferable from the viewpoint of filling properties. The particle size is about 0.1 to 15 μm, which is smaller than the thickness of the coating layer 2.

Such an insulating film 3 is obtained by adding a thermosetting polyphenylene ether resin and a solvent, a plasticizer, a dispersant, etc. to an inorganic insulating powder such as silicon oxide having a particle size of about 0.1 to 15 μm. The paste was surface-treated by plasma treatment so that the contact angle with triallyl isocyanurate was 3 to 50 ° and the surface energy was 45 to 70 mJ / m ² , the melting point was 230 to 420 ° C., and the porosity was After forming the coating layer 2 on the upper and lower surfaces of the liquid crystal polymer layer 1 of 3 to 40% by volume by using a conventionally known sheet molding method such as a doctor blade method, or by immersing the liquid crystal polymer layer 1 in the above paste. Liquid crystal polymer layer 1 by pulling up vertically
It is manufactured by forming the coating layer 2 on the surface of and heating and drying the coating layer 2 at a temperature of 60 to 100 ° C. for 5 minutes to 3 hours.

The thickness of the insulating film 3 is preferably 10 to 200 μm from the viewpoint of ensuring insulation reliability, and from the viewpoint of ensuring high heat resistance, low hygroscopicity and high dimensional stability. It is preferable that the thickness of the liquid crystal polymer layer 1 be within the range of 40 to 90% of the thickness of the insulating film 3.

Next, the multilayer wiring board 6 of the present invention is formed by laminating a plurality of insulating films 3 each having a wiring conductor 4 made of a metal foil disposed on at least one of the upper and lower surfaces thereof.
Wiring conductors 4 located above and below with the insulating film 3 interposed therebetween
It is formed by electrically connecting the gaps through the penetrating conductors 5 formed on the insulating film 3.

The wiring conductor 4 has a thickness of 2 to 30 μm and is made of a metal foil having good conductivity such as copper or gold. The electronic component 7 mounted on the multilayer wiring board 6 is connected to an external electric circuit (not shown). It has a function of electrically connecting.

Such a wiring conductor 4 is made up of the insulating film 3
From the viewpoint of preventing voids from being generated around the wiring conductor 4 when a plurality of layers are laminated, as shown in the enlarged cross-sectional view of the main part of FIG. 3, the coating layer 2 includes at least the surface of the wiring conductor 4 and the coating layer. It is preferable that the second surface and the second surface are buried so as to be flat. When the wiring conductor 4 is embedded in the coating layer 2, the porosity of the coating layer 2 in the dry state is 3 to 40% by volume.
If so, the coating layer 2 around the wiring conductor 4 can be flattened without causing resin swelling, and the air trapped between the wiring conductor 4 and the coating layer 2 can be easily discharged to prevent entrapment of air bubbles. can do. When the porosity in the dry state exceeds 40% by volume, pores remain in the coating layer 2 after pressurizing and heating and curing a plurality of laminated insulating films 3, and the pores adsorb moisture in the air. Therefore, it is preferable that the porosity of the coating layer 2 in the dry state is in the range of 3 to 40% by volume because the insulating property may be deteriorated.

The porosity of the coating layer 2 in the dry state is appropriately adjusted by adjusting the drying conditions such as the drying temperature and the heating rate when the coating layer 2 is applied on the surface of the liquid crystal polymer layer 1 and dried. By doing so, a desired value can be obtained.

Further, the cross-sectional shape in the width direction of the wiring conductor 4 arranged on the insulating film 3 is a trapezoidal shape in which the length of the bottom side on the insulating film 3 side is shorter than the length of the opposite bottom side, and the insulating film is formed. The angle between the bottom side and the side on the 3 side is
It is preferably set to 95 to 150 °. The cross-sectional shape of the wiring conductor 4 disposed on the insulating film 3 in the width direction is a trapezoid whose base length on the insulating film 3 side is shorter than the length of the opposing base, and By setting the angle formed by the sides with 95 to 150 °, the wiring conductor 4
When the wiring conductor 4 is embedded in the coating layer 2, the wiring conductor 4 can be easily embedded in the coating layer 2 so that the surface of the coating layer 2 after the wiring conductor 4 is embedded can be made substantially flat. It is possible to obtain the multilayer wiring board 6 that does not bite into and deteriorate the insulation. From the viewpoint of embedding air bubbles without biting, it is preferable that the angle formed by the bottom side and the side side of the insulating film 3 side be 95 ° or more.
From the viewpoint of miniaturization, it is preferable that the angle be 150 ° or less.

In addition, the thickness x (μm) of the coating layer 2 located between the short bases of the wiring conductors 4 and the liquid crystal polymer layer 1 between the insulating film 3 is between the upper and lower liquid crystal polymer layers 1. Is T (μm), and the thickness of the wiring conductor 4 is t
(Μm), 3 μm ≦ 0.5T−t ≦ x ≦ 0.5T
≦ 35 μm (however, 8 μm ≦ T ≦ 70 μm, 1 μm ≦ t ≦
32 μm) is preferable.

The distance between the liquid crystal polymer layers 1 is T (μm),
Assuming that the thickness of the wiring conductor 4 is t (μm), the thickness x (μ of the coating layer 2 made of polyphenylene ether organic material between the bottom of the wiring conductor 4 and the liquid crystal polymer layer 1 is short.
m) is 3 μm ≦ 0.5T−t ≦ x ≦ 0.5T ≦ 35 μm, the distance between the short bottom of the wiring conductor 4 and the liquid crystal polymer layer 1 and the long bottom of the wiring conductor 4 are adjacent to each other. It is possible to reduce the difference in distance between the liquid crystal polymer layers 1 to be less than t (μm), and it is possible to prevent warpage of the multilayer wiring board 6 caused by a large difference in the thickness of the coating layer 2. Therefore, the thickness x of the coating layer 2, which is located between the trapezoidal upper bottom surface of the wiring conductor 4 and the liquid crystal polymer layer 1,
(Μm), the distance between the liquid crystal polymer layers 1 is T (μm),
When the thickness of the wiring conductor 4 is t (μm), 3 μm ≦
It is preferable that 0.5T−t ≦ x ≦ 0.5T ≦ 35 μm.

The wiring conductor 4 as described above is formed by the insulating film 3
It is formed by depositing a metal foil made of, for example, copper, which is patterned by a subtractive method using a known photoresist, on the precursor sheet to be formed by a transfer method or the like. First, a metal foil transfer film is prepared by adhering a metal foil made of copper on a film serving as a support through an adhesive, and then a metal foil on the film is subjected to a subtractive method using a known photoresist. Is used to etch in a pattern. At this time, the side surface on the surface side of the pattern is more likely to be etched because the side surface on the surface side is in contact with the etching solution for a longer time than the side surface on the film side, and the cross-sectional shape in the width direction of the pattern can be trapezoidal. In addition,
The trapezoidal shape allows the angle between the short base and the side to be adjusted to 95 ~ by adjusting the concentration of the etching solution and the etching time.
It can be trapezoidal at 150 °. Then, this metal foil transfer film is laminated on a precursor sheet which becomes the insulating film 3, and hot pressed for 10 minutes to 1 hour under the conditions of a temperature of 100 to 200 ° C. and a pressure of 0.5 to 10 MPa, and then becomes a support. By removing the film by peeling and transferring the metal foil onto the surface of the precursor sheet which becomes the insulating film 3, the wiring conductor 4 having the trapezoidal upper bottom side embedded in the coating layer 2 can be formed.

The thickness x (μm) of the coating layer 2 between the liquid crystal polymer layers 1 opposed to the short base of the wiring conductor 4 is small.
Can be set to a desired range by adjusting the pressure of the hot press at the time of transferring the metal foil. Further, in order to improve the adhesion with the coating layer 2, the surface of the wiring conductor 4 is preferably roughened by a treatment such as buffing, blasting, brushing, or chemical treatment.

The insulating film 3 has a diameter of 20 to 15
The through conductor 5 having a thickness of about 0 μm is formed. Through conductor 5
Are the wiring conductors 4 located above and below with the insulating film 3 in between.
Has a function of electrically connecting to each other. After a through hole is formed by performing a drilling process on the insulating film 3 with a laser, a conductive paste made of copper, silver, gold, solder or the like is conventionally provided in the through hole. It is formed by embedding by a known screen printing method.

According to the multilayer wiring board 6 of the present invention, since the insulating film 3 has the coating layers 2 made of polyphenylene ether organic material on the upper and lower surfaces of the liquid crystal polymer layer 1, the liquid crystal polymer layer 1 has a high quality. It has heat resistance, high elastic modulus, high dimensional stability, and low hygroscopicity, and it is possible to configure the insulating film 3 without using a reinforcing material such as glass cloth. As a result, laser drilling is easy. Therefore, fine and uniform through holes can be formed.

In such a multilayer wiring board 6, a through conductor 5 is formed at a desired position of a precursor sheet to be the insulating film 3 manufactured by the above-mentioned method, and then a patterned metal foil of copper, for example, is formed. , The temperature is 100-200 ℃ and the pressure is 0.
Transfer by hot pressing for 10 minutes to 1 hour under the condition of 5 to 10 MPa, stacking these, and finally hot pressing under the condition of temperature of 150 to 300 ° C and pressure of 0.5 to 10 MPa for 30 minutes to 24 hours. It is manufactured by being completely cured.

According to the multilayer wiring board 6 of the present invention, a plurality of insulating films 3 each having a coating layer 2 made of a polyphenylene ether organic substance formed on the upper and lower surfaces of the liquid crystal polymer layer 1 are laminated. Polyphenylene ether-based organic molecules are not as rigid as liquid-crystal polymer-based organic molecules, and because they do not show regular orientation, the molecules move relatively easily, so they enter the minute recesses on the surface of the wiring conductor 4 and exert a sufficient anchoring effect. You can
As a result, the adhesion between the insulating film 3 and the wiring conductor 4 is improved, and peeling between the two does not occur under high temperature and high humidity. Further, since the frequency behavior of the permittivity of the coating layer 2 made of a polyphenylene ether-based organic material and the liquid crystal polymer layer 1 are substantially equal to each other, a slight thickness variation occurs in the coating layer 2 due to the pressure applied when the wiring conductor 4 is bonded. Even in this case, it is possible to obtain the multilayer wiring board 6 excellent in the high frequency transmission characteristics without causing the deterioration of the transmission characteristics in the high frequency region. Furthermore, when the insulating film 3 is multilayered, since the polyphenylene ether-based organic molecule is easily moved, the polyphenylene ether-based organic molecule is easily entangled with each other, and the adhesion between the coating layers 2 is increased,
As a result, even under the high temperature bias test, the insulating films 3 are not peeled from each other to cause insulation failure.

Thus, according to the multilayer wiring board 6 of the present invention, the semiconductor element is connected to the connection pad 8 formed of a part of the wiring conductor 4 formed on the upper surface of the multilayer wiring board 6 having the above-mentioned structure, through the conductor bump 8 such as solder. And the like electronic components 7 are electrically connected, and at the same time, a conductor bump 9 such as solder is attached to the connection pad 8 formed of a part of the wiring conductor 4 formed on the lower surface of the multilayer wiring board 6.
By forming the above, it is possible to obtain a hybrid integrated circuit having a high wiring density and an excellent insulating property.

The multilayer wiring board 6 of the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the scope of the present invention. Then, the multilayer wiring board 6 is manufactured by laminating the four layers of the insulating films 3, but the multilayer wiring board 6 may be manufactured by laminating the insulating films 3 of two layers, three layers, or five layers or more. Further, on the upper and lower surfaces of the multilayer wiring board 6 of the present invention, a build-up layer or a solder resist layer 10 made of an insulating layer containing one, two, or three or more layers of organic resin as a main component, or the multilayer wiring board 6 is provided. To electronic parts 7
After mounting, the underfill material 11 may be formed between the multilayer wiring board 6 and the electronic component 6.

[0065]

EXAMPLES Next, the following samples were manufactured and evaluated for the insulating film of the present invention and a multilayer wiring board using the same.

Example 1 First, spherical fused silica having an average particle size of 0.6 μm was added to a thermosetting polyphenylene ether resin so that the content thereof was 40% by volume, and toluene was further added as a solvent, and an organic resin was further added. A catalyst for accelerating the curing of the above was added and mixed for 1 hour to prepare a varnish.
Next, a liquid crystal polymer layer having various porosities, a thickness of 45 μm, and a dielectric constant of 2.8 was prepared, and the surface thereof was subjected to a voltage of 27 kV and an atmosphere of O ₂ by using a vacuum plasma device. CF ₄ (gas flow rate is 80 cm ³ / min each)
Plasma treatment under conditions of 15 minutes × 2 times on one side, the contact angle with triallyl isocyanurate is 35 °, the surface energy is 60 mJ / m ² , and the centerline surface roughness Ra is 0.14.
The varnish is applied to the upper surface of the liquid crystal polymer layer by the doctor blade method to give a thickness of about 15 μm.
m thermosetting polyphenylene ether coating layer was formed. Then, a thermosetting polyphenylene ether coating layer was similarly formed on the lower surface of the liquid crystal polymer layer to produce an insulating film.

Further, UV-YA is applied to this insulating film.
A through hole having a diameter of 50 μm was formed by a G laser, and a conductor paste containing copper powder and an organic binder was embedded in the through hole by screen printing to form a through conductor.

Then, the transfer supporting film having a thickness of 12 μm and having a copper foil formed in a circuit shape and the insulating film having a penetrating conductor formed thereon were aligned with each other and a vacuum laminating machine was operated at a pressure of 3 MPa for 30 minutes. After pressing for 2 seconds, the transfer support film was peeled off and the wiring conductor was embedded on the insulating film. Finally, four insulating films having this wiring conductor formed thereon were stacked, and heat-treated at a temperature of 200 ° C. for 5 hours under a pressure of 3 MPa to completely cure them to obtain a multilayer wiring board.

As the test board for evaluating the conductivity, there are two upper and lower wiring conductors located inside via the insulating layer of the multilayer wiring board and a through conductor electrically connecting the two. Assuming that a via chain is formed, the reliability of continuity is evaluated by a change rate of 15% in the continuity resistance before the test.
Less than was rated good, and 15% or more was rejected. Table 1 shows the conduction reliability results.

[0070]

[Table 1]

From Table 1, the porosity of the liquid crystal polymer layer is 3
% Multi-layer wiring board (Sample No. 1) and porosity of 40
% Of the multilayer wiring board (Sample No. 6) exceeding 7%, the change rate of the conduction resistance was small at 7% or less even after 168 hours of high temperature and high humidity test, but the change rate of the conduction resistance was large at 19% or more after 312 hours. It was found that the reliability of continuity tends to be slightly inferior.

On the other hand, in Examples (Sample Nos. 2 to 5), which are multilayer wiring boards of the present invention, the rate of change in conduction resistance was as small as 4% or less after 168 hours of high temperature and high humidity test.
Furthermore, it was found that the rate of change in conduction resistance was as small as 13% or less even after 312 hours, which was excellent.

(Example 2) The multilayer wiring board used for Example 2 was used except that the liquid crystal polymer layer was changed to liquid crystal polymer layers having porosities of 5 and 20% by volume and various dielectric constants. The multilayer wiring board for Example 1 was manufactured in the same manner.

As a test board for evaluating the high frequency transmission characteristics, a wiring conductor having a stripline structure is formed inside the multilayer wiring board, and the high frequency transmission characteristics are evaluated.
It was evaluated by measuring the high frequency transmission loss in the frequency range of 100 MHz to 40 GHz. The high-frequency transmission characteristics were judged to be good when the transmission loss was -1.0 dB or more, and bad when it was less than -1.0 dB. Table 2 shows the evaluation results of the high frequency transmission characteristics.

[0075]

[Table 2]

From Table 2, the liquid crystal polymer layer has a dielectric constant of 2.
For multilayer wiring boards of less than 1 (Sample Nos. 7 and 13) and multilayer wiring boards with a dielectric constant of more than 3.5 (Samples Nos. 12 and 18),
Although it is good at 20 GHz, the high-frequency transmission characteristics tend to deteriorate to -1.03 dB or less in the high-frequency region of 40 GHz or higher, while the multilayer wiring board with a dielectric constant of 2.1 to 3.5 (Sample Nos. 8 to 11, No. 14 to 17) is -0.82 dB or more, which is particularly excellent in high frequency transmission characteristics.

Example 3 The multilayer wiring board used for Example 3 had a liquid crystal polymer layer with a porosity of 20% by volume, a dielectric constant of 2.8, and a contact angle with various triallyl isocyanurates on the surface. A multilayer wiring board for Example 1 was manufactured by the same method except that the liquid crystal polymer layer having surface energy was used.

As a test substrate for evaluating insulation, wiring conductors having a wiring width of 50 μm and a wiring interval of 50 μm having a comb-tooth pattern were formed in the multilayer wiring substrate, and the insulation reliability was evaluated by using a sample. Performed a high temperature bias test with an applied voltage of 5.5V under conditions of temperature 130 ° C and relative humidity 85%, measured insulation resistance between wiring conductors after 168 hours, and evaluated by comparing the amount of change before and after the test. did. The insulation reliability was judged to be good when the insulation resistance was 1.0 × 10 ⁸ Ω or higher, and was judged to be bad when it was less than 1.0 × 10 ⁸ Ω. Table 3 shows the evaluation results of insulation reliability.

[0079]

[Table 3]

From Table 3, a multilayer wiring board having a contact angle with the triallyl isocyanurate on the surface of the liquid crystal polymer layer of less than 3 ° (Sample No. 19) and a multilayer wiring board having a contact angle of more than 50 ° (Sample No. 19) were obtained. In 23), although the insulation resistance after 168 hours of high temperature bias test is good, the insulation resistance tends to deteriorate to 9.8 × 10 ⁷ Ω or less after 340 hours, whereas
The multilayer wiring boards (Sample Nos. 20 to 22) having a contact angle of 3 to 50 ° were 4.9 × 10 ⁹ Ω or more even after 340 hours of high temperature bias test, and were excellent in insulation reliability. However, even if the contact angle is 3 to 50 °, the surface energy of the liquid crystal polymer is less than 45 mJ / m ² , and the multilayer wiring board (Sample No. 24) and
With a multilayer wiring board of 70 mJ / m ² or more (Sample No. 27), the insulation resistance after 168 hours of high-temperature bias test is good, but after 340 hours, the insulation resistance tends to deteriorate to 8.5 × 10 ⁷ Ω or less. there were. On the other hand, in a multilayer wiring board (sample Nos. 20-22, 25, 26) having a contact angle of 3 to 50 ° and a surface energy of 45 to 70 mJ / m ² , a high temperature bias test 340
It was 4.9 × 10 ⁹ Ω or more even after the time, and it was found that the insulation reliability was particularly excellent.

Example 4 The multilayer wiring board used for Example 4 had a liquid crystal polymer layer having a porosity of 20% by volume, a dielectric constant of 2.8, and a contact angle with various triallyl isocyanurates of 35. The multilayer wiring board of Example 1 was manufactured in the same manner as in Example 1, except that the liquid crystal polymer layer having a surface temperature of 60 mJ / m ² and a surface having various centerline surface roughness Ra was used.

The adhesion was evaluated by using a multilayer wiring board 26
After dipping in a solder bath at 0 ° C. for 20 seconds and repeating this several times, the adhesiveness was evaluated by observing the appearance of the multilayer wiring board. Table 4 shows the evaluation results of adhesion.

[0083]

[Table 4]

From Table 4, it is seen that the center line surface roughness Ra of the liquid crystal polymer layer surface is less than 0.05 μm.
8) and a multilayer wiring board with Ra exceeding 5 μm (Sample No.
In 32), when the immersion in the solder bath was repeated 10 times, there was a tendency that a bulge portion was generated in the multilayer wiring board due to peeling between the liquid crystal polymer layer and the coating layer.
It was found that the multilayer wiring boards having Ra of 0.05 to 5 μm (Samples 29 to 31) did not change the appearance of the multilayer wiring board even after repeated immersion in the solder bath 10 times, and were particularly excellent in adhesion.

[0085]

According to the insulating film of the present invention, a coating layer made of a polyphenylene ether organic material is formed on the upper and lower surfaces of a liquid crystal polymer layer having a porosity of 3 to 40% by volume. The liquid crystal polymer layer is satisfactorily impregnated with a coating layer made of a polyphenylene ether organic compound on the lower surface, and the liquid crystal polymer layer and the coating layer can be a firmly adhered insulating film having a sufficient anchoring effect, Even in a multi-layered structure, the polyphenylene ether-based organic molecule is not as rigid as the liquid crystal polymer molecule, and since it does not show a regular orientation, the molecule is relatively easy to move and the adhesion between insulating films can be improved. As a result, in the high temperature bias test, between the insulating films or between the liquid crystal polymer layer and the coating layer In is not that peeling to insulation failure occurs. Further, even when the wiring conductor is arranged on the surface of the insulating film, the polyphenylene ether-based organic compound molecules can enter the minute recesses on the surface of the wiring conductor and exhibit a sufficient anchoring effect, resulting in close contact between the insulating film and the wiring conductor. As a result, there is no possibility that the wiring conductor will break due to peeling between the two under high temperature and high humidity. Furthermore, since the frequency behavior of the dielectric constant of the coating layer made of polyphenylene ether organic material and the liquid crystal polymer layer are almost the same, even if a slight thickness variation occurs in the coating layer due to the pressure when bonding the wiring conductor, It is possible to obtain an insulating film excellent in high-frequency transmission characteristics without causing deterioration in transmission characteristics in a region.

Further, according to the insulating film of the present invention, in the above structure, since the insulating film has a dielectric constant of 2.1 to 3.5, a plurality of insulating films having wiring conductors on the surface are laminated to form a multilayer wiring board. Even if you make
It is possible to obtain an insulating film excellent in high-frequency transmission characteristics without causing deterioration in transmission characteristics in a high-frequency region.

Further, according to the insulating film of the present invention, in the above constitution, the contact angle of the liquid crystal polymer layer with triallyl isocyanurate is 3 to 50 °, and the surface energy of the liquid crystal polymer layer is 45 to 70 mJ / m 2. ^Because it was ² ,
An insulating film in which the activated molecular layer on the surface of the liquid crystal polymer layer, which is relatively easily moved by heat, and the coating layer made of a polyphenylene ether-based organic substance are entwined and entangled well, and the liquid crystal polymer layer and the coating layer are more firmly adhered to each other. Can be

Further, according to the insulating film of the present invention, in the above structure, the center line surface roughness Ra of the upper and lower surfaces of the liquid crystal polymer layer is set to 0.05 to 5 μm. The coating layer made of an organic substance has a good anchoring effect and good adhesiveness, and an insulating film in which the liquid crystal polymer layer and the coating layer are more firmly adhered can be obtained.

Further, according to the insulating film of the present invention,
In the above configuration, since the polyphenylene ether-based organic material is a thermosetting polyphenylene ether, the thermosetting polyphenylene ether is excellent in heat resistance and dimensional stability, as a result, excellent in temperature cycle reliability, and the wiring conductor It is possible to obtain an insulating film having good positional accuracy when bonding.

Further, according to the multilayer wiring board of the present invention, since the multilayer wiring board is formed by using the above-mentioned insulating film, the multilayer wiring board is excellent in moisture resistance, continuity reliability and high frequency transmission characteristics. You can

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of an embodiment of an insulating film of the present invention.

FIG. 2 is a sectional view showing an example of an embodiment of a hybrid integrated circuit in which a semiconductor element is mounted on a multilayer wiring board of the present invention.

3 is an enlarged cross-sectional view of a main part of the multilayer wiring board shown in FIG. 2 in a width direction of a wiring conductor.

[Explanation of symbols]

1 ... Liquid crystal polymer layer 2 ... coating layer 3 ... Insulation film 4 ... Wiring conductor 5 ... Penetration conductor 6 ... Multi-layer wiring board

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05K 1/03 610 H05K 1/03 630D 630 3/46 N 3/46 T H01L 23/12 NF term ( (Reference) 4F100 AB01D AB01E AB33D AB33E AK01A AK54B AK54C AS00A BA03 BA04 BA05 BA06 BA10B BA10C BA10D BA10E BA11 GB43 JA11A JB04B JC13GGG04 J22AEE CC22AEE CC22AEE AA02A38B15AEE HH26 5F044 MM04 MM06

Claims (6)

[Claims] 1. An insulating film comprising a liquid crystal polymer layer having a porosity of 3 to 40% by volume and a coating layer made of a polyphenylene ether organic material formed on the upper and lower surfaces of the liquid crystal polymer layer. 2. The liquid crystal polymer layer has a dielectric constant of 2.1 to
It is 3.5, The insulating film of Claim 1 characterized by the above-mentioned. 3. The upper and lower surfaces of the liquid crystal polymer layer have a contact angle with triallyl isocyanurate of 3 to 50 °,
The surface energy is 45 to 70 mJ / m ² , and the insulating film according to claim 1 or 2. 4. The insulating film according to claim 1, wherein the upper and lower surfaces of the liquid crystal polymer layer have a centerline surface roughness Ra of 0.05 to 5 μm. 5. The insulating film according to claim 1, wherein the polyphenylene ether-based organic substance is a thermosetting polyphenylene ether. 6. The insulating film according to claim 1, wherein a wiring conductor made of a metal foil is provided on at least one of the upper and lower surfaces, and the insulating film is laminated. A multilayer wiring board, characterized in that the wiring conductors located above and below with a pinch therebetween are electrically connected via a penetrating conductor formed in the insulating film.