JPH09130018A - Wiring substrate and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize low resistance of a wiring conductor which has extremely small deformation such as waving on the insulated substrate surface, excellent size accuracy and excellent mass productivity. SOLUTION: A wiring conductor 3 in the thickness of 50μm or more provided in an insulated base material formed of sintered ceramics is reactively hardened before lamination of the other ceramic green sheet having a predetermined wiring pattern using a conductive paste with a binder mainly composed of a high melting point metal and reactive hardening resin to form a conductive material. The wiring board obtained shows a waving at the surface of the insulated base material 2 of 20μmWCMmax or less when high region cutoff value is 2.5mm and standard length is 25mm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in a semiconductor element housing package in which a semiconductor element is housed and mounted, and in a hybrid integrated circuit device in which various electronic parts such as capacitors and resistors are mounted in addition to the semiconductor element. The present invention relates to a wiring board having a low conduction resistance of a wiring conductor and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, a wiring board used for a package for housing a semiconductor element, a hybrid integrated circuit device or the like generally uses an insulating base made of an electrically insulating ceramic sintered body such as an alumina sintered body. A plurality of wiring conductors made of a refractory metal such as tungsten (W), molybdenum (Mo), manganese (Mn), and the like, from the periphery to the lower surface of the concave portion provided at substantially the center of the substrate, or to the inside and the surface thereof. And a structure in which the wiring conductors are connected by through-hole conductors made of the same high melting point metal provided in the insulating base.

In the wiring board constructed as described above, for example, in a package for housing a semiconductor element, the semiconductor element is adhered and fixed to the bottom surface of the recess of the insulating substrate via an adhesive such as glass, resin, or brazing material. At the same time, each electrode of the semiconductor element is electrically connected to a wiring conductor located around the recess via a bonding wire, and a lid made of metal or ceramics is sealed in the same manner as the adhesive so as to close the recess. The semiconductor device as a final product is obtained by joining the semiconductor elements in a hermetically sealed manner in the recesses of the insulating base by bonding the materials.

In the wiring board, iron-nickel-cobalt (Fe-Ni-) is formed on a part of the wiring conductor provided on the insulating base.
An external lead terminal made of a Co) alloy, an iron-nickel (Fe-Ni) alloy, or the like is attached via a brazing material such as silver brazing, and the external lead terminal is connected to an external electric circuit to form a semiconductor element. Each of the electrodes is electrically connected to an external electric circuit via a wiring conductor, a bonding wire and an external lead terminal.

However, in the conventional wiring board, the electric resistance value of W and Mo forming the wiring conductor and the through-hole conductor is extremely high at 4 to 8 × 10 ⁻⁶ Ω · cm, so that the electric resistance value between the wirings is high. It cannot be applied to a wiring board that is required to be small, and a lower resistance of the wiring conductor has been desired in applications such as various control devices and information communication devices in recent years.

Therefore, in order to reduce the resistance value of the wiring conductor in the wiring board as described above, a wiring space is formed in the insulating base body constituting the wiring board, and the wiring space is filled with the wiring conductor. Have been proposed (Japanese Patent Laid-Open No. Sho 63-63)
-194 gazette).

[0007]

However, in the wiring board, the wiring space is filled with a conductive paste obtained by mixing a high melting point metal powder such as W or Mo with a binder made of a solvent and an organic additive. Therefore, when another ceramic green sheet having a predetermined wiring pattern is laminated, the filling layer has flexibility, so that deformation is likely to occur, and undulation occurs on the surface of the insulating substrate obtained by firing and integration. I was afraid.

As a result, a multi-layer wiring board on which semiconductor elements such as ICs and LSIs, which are becoming higher in frequency and higher in density in recent years, are mounted, are provided with a high-density fine wiring pattern, so that the semiconductor elements can be mounted compactly. The flip chip connection method for directly connecting a semiconductor element to the multilayer wiring board is adopted, and high flatness is required for the multilayer wiring board, but a high-quality wiring board with good flatness is obtained. There was a problem that it was difficult to get well.

Further, when the wiring space is filled with the conductive paste, a screen printing method, a press-fitting method, etc.
Since the thickness of the wiring conductor is thick, it takes a long time to fill it, and during that time, the organic solvent in the conductive paste evaporates and the viscosity changes, resulting in poor filling. It was a factor that reduced the sex.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to improve the deformation of the surface of an insulating substrate even if the wiring substrate has a wiring conductor with a thickness of 50 μm or more inside the insulating substrate. It is an object of the present invention to provide a wiring board and a method for manufacturing the wiring board, in which the resistance of the wiring conductor is extremely small, the dimensional accuracy is good, and the mass production effect is excellent, and the resistance is reduced.

[0011]

The wiring board of the present invention has an insulating substrate made of a ceramic sintered body and a thickness of 50 μm.
A wiring board formed by integrally forming the above wiring conductor, wherein the wiring conductor comprises a refractory metal such as tungsten (W) or molybdenum (Mo) and a binder containing a reactive curable resin as a main component. 1. A conductive material made of a mixture is used, and the waviness on the surface of the insulating substrate is in a high cutoff value.
It is characterized by having a size of 5 mm and a standard length of 25 mm and being 20 μm W _CM max or less.

A plurality of ceramic green sheets having a predetermined wiring pattern are laminated on the ceramic green sheet having a conductive material having a thickness of 50 μm or more,
As a method of manufacturing a wiring substrate integrally fired in a reducing atmosphere or a neutral atmosphere, the conductive material is mainly composed of the refractory metal and the reaction curable resin in a space formed by punching out a ceramic green sheet. After filling with a conductive paste consisting of a binder, it is cured by reaction or formed, or after the conductive paste is formed into a sheet and cured by reaction, the cured sheet is punched into the dimension of the space. Formed by processing and fitting into the space, or by filling the conductive paste in a mold having a shape of the space and reaction curing, and then fitting the cured body into the space. It is characterized by.

In the wiring board of the present invention, the reaction curable resin constituting the conductive material may be any one as long as it can be cured by reaction, but an epoxy compound or a polyfunctional acrylate having an ether bond in the main chain, or It is more preferable to contain an unsaturated polymer, and the polyfunctional acrylate most preferably has an ether bond in the main chain and contains an unsaturated polymer.

Examples of the epoxy compound include glycidyl ether type, glycidyl ester type, glycidyl amine type, alicyclic type and the like.

Further, the content of the epoxy compound is preferably such that the viscosity does not become high in order to maintain the fluidity and moldability of the mixture of the high melting point metal powder, the solvent and the organic additive. It is preferably 1 part by weight or more and 40 parts by weight or less with respect to 100 parts by weight of the melting point metal powder, and most preferably 10 parts by weight or more and 30 parts by weight or less from the viewpoint of easy handling.

Further, as a curing agent for the epoxy compound,
The polyaddition type includes diethylenediamine, hexahydrophthalic anhydride, etc., the catalyst type includes benzyldimethylamine, aromatic sulfonium salts, etc., and the condensation type includes methylol group-containing melamine resin, and the content thereof is high melting point metal powder. The amount is preferably 1 part by weight or more and 40 parts by weight or less with respect to 100 parts by weight of the body, and most preferably 10 parts by weight or more and 30 parts by weight or less.

The polyfunctional acrylate is a compound having two or more acryloyl groups in one molecule, such as ethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, alkyl diacrylate, glycerin. Examples thereof include triacrylate, dipentaerythritol hexaacrylate, trimethylolpropane triacrylate, PO-modified trimethylolpropane triacrylate, and bisphenol A diacrylate.

Among them, polyalkylene glycol diacrylate represented by polyethylene glycol diacrylate or polyisopropylene glycol diacrylate, which has an ether bond in the main chain and has good thermal decomposability, is more preferable.

The content of the polyfunctional acrylate is preferably such that the viscosity does not become high in order to maintain the fluidity and moldability of the mixture of the high melting point metal powder, the solvent and the organic additive. , Refractory metal raw material powder 10
It is more than 5 parts by weight with respect to 0 parts by weight, and in terms of curing, that is, shrinkage of the molded body due to the condensation reaction of the monomer, it is 40
It is more preferable that the amount is not more than 10 parts by weight, and most preferably 8 to 20 parts by weight from the viewpoint of easy handling of the molded product.

On the other hand, the unsaturated polymer is a polymer compound having an unsaturated double bond in the molecule, and examples thereof include unsaturated polyester and polydiene polymer compounds.

The unsaturated polyester is defined as a condensate of a polyfunctional acid and a polyfunctional alcohol and has an unsaturated double bond in the molecule. Such a resin is generally a saturated dibasic acid. , A polyhydric alcohol and an unsaturated dibasic acid can be obtained by a known production method, but these raw materials are not particularly limited.

Specifically, orthophthalic acid, isophthalic acid, phthalic anhydride, succinic acid, adipic acid, sebacic acid, endomethylenetetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, tetrahydrophthalic anhydride, chlorendic acid or Saturated dibasic acids such as adducts of maleic acid and piperylene, ethylene glycol,
Diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, hydrogenated bisphenol A or ethylene oxide or propylene oxide adduct of bisphenol A, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol or glycerin. Polyhydric alcohol,
The desired unsaturated polyester is obtained by reacting an unsaturated dibasic acid such as maleic anhydride, fumaric acid or itaconic acid at a temperature of about 160 to 240 ° C.

Further, the content of the unsaturated polymer is preferably 5 parts by weight or more based on 100 parts by weight of the high melting point metal raw material powder, since it is desirable that the unsaturated polymer has sufficient shape retention property upon curing. Further, in order to reduce the viscosity of the mixture and maintain the moldability, it is more preferably 40 parts by weight or less, and most preferably 15 to 30 parts by weight from the viewpoint of easy handling of the molded product.

Further, the solvent of the present invention is not particularly limited as long as it is compatible with the polyfunctional acrylate and the unsaturated polymer, and examples thereof include aromatic compounds such as toluene, xylene, benzene and phthalic acid ester. Solvents, higher alcohols such as hexanol, octanol, decanol, and oxyalcohol, or esters such as acetic acid ester and glyceride can be used.

Above all, the phthalic acid ester, oxyalcohol and the like can be preferably used, and in addition, two or more kinds of the above solvents can be used together in order to slowly volatilize the solvent.

The content of the solvent is preferably such that the viscosity of the mixture is low in the case of casting.
5 parts by weight or more relative to 100 parts by weight of the high-melting-point metal raw material powder, and 50 parts by weight or less are more preferable in order to increase the strength of the molded product and maintain the shape retention, and particularly easy handling of the molded product. From this, 10 to 30 parts by weight is most suitable.

From the standpoint of moldability of the green sheet, the content of the solvent is 100% of the high melting point metal raw material powder.
The amount is more preferably 30 parts by weight or more and 70 parts by weight or less with respect to parts by weight, and particularly preferably 40 to 60 parts by weight from the viewpoint of easy handling of the molded body.

Further, for the polyfunctional acrylate or unsaturated polymer of the present invention, a curing catalyst called a curing reaction accelerator or a polymerization initiator, a dispersant, and other organic additives are used. You can

As the curing catalyst, an organic peroxide or an azo compound can be used. Examples thereof include ketone peroxide, diacyl peroxide, peroxyketal, alkyl perester, hydroperoxide, and the like.
Peroxycarbonate, t-butylperoxy-2-
Examples thereof include organic peroxides such as ethylhexanoate, bis (4-t-butylcyclohexyl) peroxydicarbonate and dicumyl peroxide, and azo compounds such as azobis and isobutyronitrile.

As the dispersant, any surfactant generally used in the preparation of a kneaded mixture of inorganic material powders can be used. In particular, ammonium polyoxyalkyl acrylate, naphthalene sulfonate formalin are used. Condensates, sorbitan esters and the like are preferable, and the content thereof is preferably 0.5 to 2 parts by weight with respect to 100 parts by weight of the high melting point metal raw material powder.

The refractory metal raw material powder may be any of tungsten (W), molybdenum (Mo), rhenium (Re), ruthenium (Ru) and the like.

On the other hand, when the thickness of the wiring conductor is less than 50 μm, the sheet resistance value becomes as large as about 2 to 3 mΩ / sq, and the resistance of the wiring conductor cannot be reduced. Therefore, the thickness thereof is 50 μm. As described above, from the viewpoint of the sheet resistance value of the wiring conductor and the design of the wiring board, the applicable range is up to about 1 mm.

The waviness of the surface of the insulating substrate is 20 μm at a high cutoff value of 2.5 mm and a reference length of 25 mm.
If mW _CM max is exceeded, in addition to the above-mentioned connection failure by the flip-chip connection method, the coating thickness varies when the wiring pattern is printed, and as a result, the resistance value of the wiring conductor greatly changes. Swell is 20 μm W _CM m
ax or less is required, more preferably 10 μm W _CM m
It is ax or less.

As the reaction curing method in the above-mentioned manufacturing method, in addition to heat curing, UV curing or X-ray curing method can be used. The heat curing method is suitable for a product having a complicated shape, and UV curing or X-ray curing is possible. The curing method is suitable for a product having a thin wall thickness, and is most suitable when the wiring conductor has a thickness of about 50 to 100 μm.

The mold for casting the conductive paste may be made of any material as long as it can be released from the mold after the reaction curing, but it is preferably made of various rubbers or whose surface is coated with silicon or Teflon. To fill the mold or the space with the conductive paste, it can be poured with an injector such as a dispenser.

On the other hand, the green sheet formed of the conductive paste can be punched out in the same manner as the ceramic green sheet even if it is cured.

Further, since all of the above-mentioned cured products have sufficient strength, the weight and shape can be easily controlled, and they can be easily moved by a vacuum chuck or the like, and they are extremely easy to handle, and their productivity is high. Is significantly improved.

[0038]

According to the wiring board and the method of manufacturing the same of the present invention,
Since the wiring conductor was formed by using a conductive material made of a mixture of a refractory metal such as tungsten (W) and molybdenum (Mo) and a binder whose main component is a reaction curable resin, the wiring space was filled. Since the conductive material has an appropriate hardness, no deformation occurs even if another ceramic green sheet having a predetermined wiring pattern is laminated, and the surface of the insulating substrate after firing and integration becomes flat.

Further, as a method of manufacturing a wiring board having a wiring conductor having a thickness of 50 μm or more, a conductive material for forming the wiring conductor is preliminarily filled with a refractory metal and a reaction curable resin in the wiring space. It is formed by filling a conductive paste composed of a binder as a main component and then reacting and curing it, or after molding the conductive paste on a sheet and reacting and curing the cured sheet, the cured sheet is formed into the dimension and shape of the space. Punched into, and fitted into the space, or
Alternatively, the conductive paste is filled in a space-shaped forming die, and the mixture is reacted and cured, and then the cured formed body is fitted into the wiring space to form the other ceramic green sheets. At the stage, the conductive material retains an appropriate hardness, no deformation occurs at the conductive material corresponding portion, and no undulation occurs on the surface of the fired substrate after firing and integration.

Further, in the present invention, by using a curable resin such as a polyfunctional acrylate, the viscosity of the mixture can be lowered and the space for wiring or the details of the molding die can be easily filled. It is not necessary to inject into a molding die under high pressure, and a molded product having a good appearance without defects such as flow marks can be obtained by reaction curing.

Further, the mixture is mixed with the solvent in a state of 3
In order to be dimensionally crosslinked and cured, the solvent with a low thermal decomposition temperature during degreasing, before the thermal decomposition of the crosslinked organic binder,
Since it volatilizes while causing uneven slipping out in advance, when the cured organic binder is thermally decomposed, it will be dispersed through the numerous pores formed by the solvent being removed first, and degreasing will be performed. Will end easily.

By providing a desolvation drying step before the degreasing step, the degreasing can be easily completed as described above.

[0043]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a wiring board of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an embodiment in which the wiring board of the present invention is applied to a multilayer wiring board used in a hybrid integrated circuit device or the like in which various electronic components such as capacitors and resistors are mounted in addition to semiconductor elements. FIG.

In FIG. 1, a plurality of wiring conductors 3 having a thickness of 50 μm or more are integrally formed inside an insulating substrate 2, and each wiring conductor 3 is a through-hole conductor 4 provided in the insulating substrate 2. Is a wiring board electrically connected via
For example, an electronic component 5 such as a semiconductor element, a capacitor, or a resistor is mounted on the upper surface of the insulating substrate 2, and each electronic component 5
The electrode terminals are electrically connected to each other through the through-hole conductors 4 and the like to form a predetermined electric circuit.

In the wiring board of the present invention, when the wiring conductor is formed, the curable resin which is the main component of the binder of the conductive material is used.
When heat-curing at 0 to 150 ° C., resins such as epoxy, unsaturated polyester, phenol, urea, melamine, and polyurethane can be mentioned.
Epoxy acrylate, urethane acrylate and the like are preferable.

Further, for example, 1 to 50 parts by weight of the above-mentioned curable resin and 100 parts by weight of high melting point metal powder such as tungsten (W) or molybdenum (Mo) and acrylic, butyral, or cellulose-based organic material. 0.5 to 3 system additives
An electrically conductive paste is prepared by adding 0 part by weight, an organic solvent such as aromatics such as phthalester or higher alcohols such as hexatol in the range of 1 to 70 parts by weight.

At this time, the conductive paste most suitable for various processes such as a filling process, a sheet molding process, a cast molding process, a printing process, etc., by combining various kinds of the organic additives and the organic solvent and their addition amounts. Can be prepared.

The conductive paste can be reactively hardened by a known hardening means, and another ceramic green sheet having a predetermined wiring pattern formed as a conductive material filling the wiring space is laminated and reduced. It is produced by firing and integration in a neutral atmosphere or a neutral atmosphere.

[0049]

【Example】

(Example 1) As an insulating substrate made of an alumina sintered body, a slurry was prepared by adding and mixing a known organic binder, a plasticizer, and a solvent to raw material powders of Al ₂ O ₃ , SiO ₂ , MgO, CaO and the like. The thickness of the slurry is about 3 by a well-known tape molding technique such as a doctor blade method or a calendar roll method.
After a ceramic green sheet having a thickness of 00 μm was formed, a punching process was performed in advance on predetermined positions of the ceramic green sheet to form a space portion for intra-layer wiring and a through hole.

Next, the binder compositions shown in Tables 1 and 2 were added to and mixed with molybdenum (Mo) powder having a particle size of 0.5 to 10 μm, and then 1% by weight of a defoaming agent was added to the mixture, followed by vacuum degassing. A conductive paste was prepared by bubbling.

[0051]

[Table 1]

[0052]

[Table 2]

The conductive paste thus obtained was poured directly into the wiring space and then cured by heating to produce a ceramic green sheet having a conductive material with a thickness of 300 μm in the wiring space.

Thereafter, two ceramic green sheets each having a thickness of 300 μm are laminated on the upper and lower surfaces thereof, respectively, in a reducing atmosphere composed of a mixed gas of hydrogen (H ₂ ) and nitrogen (N ₂ ), or with an argon ( By firing at a temperature of about 1600 ° C. in a neutral atmosphere such as Ar) gas,
A wiring board for evaluation consisting of five layers containing wiring conductors having a thickness of about 250 μm was prepared.

As a comparative example, a wiring substrate made of the same five-layer laminate as described above, which was fired and integrated using a binder containing ethyl cellulose and butyral as an organic additive without using a curable resin was used.

Using the thus obtained wiring board for evaluation, a stylus method is used by using a surface roughness meter so as to cross the relevant portion surface of the insulating substrate containing the wiring conductor having a thickness of 50 μm or more. The surface waviness was measured under the conditions of a high cutoff value of 2.5 mm and a reference length of 25 mm, and the comparative example was 56 μmW _CM max, whereas all of Examples 1 to 3 were 12 μmW _CM max. It was extremely small as below.

Further, when the sheet resistance was measured, it was desirable that the variation was ± 0.2 for the comparative example with respect to 1 mΩ / sq, and within ± 0.03 for each of the examples 1 to 3. It was

Furthermore, a high-temperature storage test in which the wiring board for evaluation was held at a temperature of 150 ° C. for 2000 hours was performed, the wiring board was treated with a penetrant flaw detection liquid, and visually inspected with a microscope.
The presence or absence of cracks in the wiring board was confirmed, but no cracks were found, and it was confirmed that there was no difference from the conventional product.

Example 2 A ceramic green sheet molded in the same manner as in Example 1 and a conductive paste having the composition shown in Table 3 were used to form a sheet, which was then heat cured.
The punched hardened sheet was fitted into the wiring space to produce a ceramic green sheet having a conductive material with a thickness of 300 μm. The types of binders are shown in Table 2.

[0060]

[Table 3]

Thereafter, in the same manner as in Example 1, the thickness is about 25.
A wiring board for evaluation consisting of 5 layers having a wiring conductor of 0 μm therein was prepared. In addition, the comparative example is the same as the example 1.

[0062] Thus obtained using the wiring board for evaluation, it was determined the surface waviness in the same manner as in the evaluation method of Example 1, with respect to 56μmW _CM max of Comparative Example, Example 1
In each of Example 2 and Example 2, the value was 13 μmW _CM max or less, which was extremely small.

The variation in sheet resistance is 1 mΩ / s.
For q, ± 0.2 for the comparative example was within ± 0.05 for both Example 1 and Example 2.

Further, no crack was found on the wiring board in the high temperature storage test.

(Example 3) A ceramic green sheet molded in the same manner as in Example 1 and a conductive paste having the composition shown in Table 4 were used, and the conductive paste was cast into a mold having the same shape as the wiring space. Then, it was heated and hardened, and the hardened body was fitted into the space for wiring to prepare a ceramic green sheet having a conductive material having a thickness of 300 μm. The types of binders are shown in Table 2.

[0066]

[Table 4]

Thereafter, in the same manner as in Example 1, the thickness is about 25.
A wiring board for evaluation consisting of 5 layers having a wiring conductor of 0 μm therein was prepared. In addition, the comparative example is the same as the example 1.

Using the wiring board for evaluation thus obtained, the surface waviness was determined in the same manner as in the evaluation method of Example 1. As a result, in comparison with the comparative example of 56 μmW _CM max,
All of Examples 3 to 8 were the smallest with 8 μmW _CM max or less.

The variation in sheet resistance is also 1 mΩ / s.
In contrast to q of ± 0.2 in Comparative Example, all of Examples 1 to 3 were within ± 0.01, which was extremely good.

Further, in the high temperature storage test, no cracks were found on the wiring board, and it was confirmed that the wiring board was comparable to the conventional product.

The present invention is not limited to the above-mentioned embodiments, but various modifications can be made without departing from the gist of the present invention.

For example, in the above-described embodiment, an example in which the wiring board of the present invention is applied to a multilayer wiring board on which various electronic parts used in a hybrid integrated circuit device are mounted has been described. FIG. 11 is a cross-sectional view of an essential part showing another example of the same multilayer wiring board, which is the wiring board 1 in which the wiring conductors 3 having a thickness of 50 μm or more are exposed on the surface of the insulating base 2;
Is the wiring conductor 3 on the surface of the insulating substrate 2 and the through-hole conductor 4
Is connected to the wiring conductor 3 inside the insulating substrate 2.

Further, FIG. 3 is a cross-sectional view of a main part showing another example when applied to a semiconductor element housing package for housing a semiconductor element.

In FIG. 3, reference numeral 1 denotes a wiring board which constitutes a package for housing a semiconductor element in which a wiring conductor 3 having a thickness of 50 μm or more is integrally formed in an insulating base 2.
A recess 7 is formed at the center of the upper surface of the recess to form a space for housing the semiconductor element 6, and the wiring conductor 3 is drawn from the periphery of the recess 7 to the lower surface via the through-hole conductor 4.
The electrodes of the semiconductor element 6 are electrically connected to the periphery of the recess 7 via the bonding wires 8, and the external lead terminals 9 for connecting to an external electric circuit are electrically connected to the portion led out to the lower surface of the insulating base 2. Are electrically connected to each other so that the electrodes of the semiconductor element 6 are electrically connected to the external lead terminals 9. Finally, a lid 10 made of metal, ceramics or the like is provided above the recess 7. The semiconductor element 6 is hermetically housed in the recess 7 of the insulating base 2 by being bonded via a sealing material so as to close the recess 7.

[0075]

According to the wiring board of the present invention, a wiring conductor having a thickness of 50 μm or more provided in an insulating substrate is made of a mixture of a refractory metal and a binder whose main component is a reaction curable resin. Material, and the undulations on the surface of the insulating substrate have a high cutoff value of 2.5 mm and a reference length of 25 mm.
20 μmW _CM max or less, and as a manufacturing method thereof, the conductive material is formed by filling the space for wiring with a conductive paste and then curing by reaction, or by molding the conductive paste into a sheet shape. And then reaction-cured, punched into the dimension of the space and formed by fitting into the space, or after filling the space-shaped mold with the conductive paste and reaction-curing Since the cured molded body is formed by being fitted in the space, the wiring base having a low resistance value in which the deformation of the surface of the insulating substrate is extremely small, the dimensional accuracy is good, and the resistance value is stable at the same time, is formed. It can be firmly attached to the wire, is suitable for the flip-chip connection method, and is extremely excellent in mass production. As a result, the voltage drop of the electric signal transmitted through the wiring conductor is small. Succoth can, is very useful in applications including various types of control devices and information communication devices such as the resistance of the wiring conductors is required.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of essential parts showing an embodiment in which a wiring board of the present invention is applied to a multilayer wiring board on which various electronic components used in a hybrid integrated circuit device are mounted.

FIG. 2 is a cross-sectional view of essential parts showing another embodiment in which the wiring board of the present invention is applied to a multilayer wiring board on which various electronic components used in a hybrid integrated circuit device are mounted.

FIG. 3 is a cross-sectional view of essential parts showing another embodiment in which the wiring board of the present invention is applied to a package for housing a semiconductor element.

[Explanation of symbols]

 1 wiring board 2 insulating substrate 3 wiring conductor

Claims (4)

[Claims] 1. A wiring board in which a wiring conductor having a thickness of 50 μm or more is integrally formed on an insulating substrate made of a ceramic sintered body, wherein the wiring conductor is made of a conductive material containing a reaction curable resin as a main binder. And the waviness of the surface of the insulating substrate has a high cutoff value of 2.5 mm and a reference length of 25 mm.
Wiring board characterized in that it is less than 20 μm W _CM max. 2. A wiring board in which a plurality of ceramic green sheets having a predetermined wiring pattern are laminated on a ceramic green sheet having a conductive material having a thickness of 50 μm or more, and fired and integrated in a reducing atmosphere or a neutral atmosphere. The conductive material is formed by punching a ceramic green sheet into a space portion, filling a conductive paste containing a reactive curable resin as a main binder, and then curing the conductive paste. And a method for manufacturing a wiring board. 3. A wiring board in which a plurality of ceramic green sheets having a predetermined wiring pattern are laminated on a ceramic green sheet having a conductive material having a thickness of 50 μm or more, and fired and integrated in a reducing atmosphere or a neutral atmosphere. The conductive material, in the space portion formed by punching out the ceramic green sheet, after reaction curing a green sheet molded with a conductive paste having a reactive curable resin as a main binder, the space A method for manufacturing a wiring board, characterized in that the wiring board is formed by fitting a hardened sheet punched into the shape of a part. 4. A wiring board in which a plurality of ceramic green sheets having a predetermined wiring pattern are laminated on a ceramic green sheet having a conductive material having a thickness of 50 μm or more, and fired and integrated in a reducing atmosphere or a neutral atmosphere. In the manufacturing method of the conductive material, a space formed by punching out a ceramic green sheet is filled with a conductive paste containing a reactive curable resin as a main binder in a molding die having the shape of the space and is cured by reaction. A method of manufacturing a wiring board, characterized in that the cured body is fitted into the space portion and then formed.