JPH1117348A - Wiring board and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wiring board, composed of an insulation base made of an inorg. insulator powder bonded with a thermosetting resin and wiring conductors made of a metal powder bonded with a thermosetting resin and manufacture thereof with has superior moisture resistance and can normally and stably operate the incorporated semiconductor devices for a long time by preventing the water content of the outside air from entering the insulation base between insulation boards. SOLUTION: This wiring board comprises an insulation base 1 composed of insulation boards 1a-1c made of an inorganic powder 60-95 wt.% bonded with a thermosetting resin 5-40 wt.%, wiring conductors 2 which are made of a metallic powder bonded with a thermosetting resin and disposed between the boards 1a-1c, and insulation layer 5 made by depositing a thermosetting resin or inorganic insulator power bonded with a thermosetting resin on the side faces of the base 1. The insulation layer 5 selectively blocks the water content of the outside air from entering so as to normally and stably operate the incorporated semiconductor devices for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring board used for a package for housing a semiconductor element for housing a semiconductor element or a hybrid integrated circuit board.

[0002]

2. Description of the Related Art Conventionally, a wiring board, for example, a wiring board used for a semiconductor element housing package for housing a semiconductor element is made of ceramics such as an aluminum oxide sintered body, and the semiconductor element is housed in the center of the upper surface thereof. And a wiring conductor made of a refractory metal powder such as tungsten or molybdenum which is led out from the periphery to the lower surface of the concave portion of the insulating substrate. Use glass, resin,
Attach and fix via an adhesive such as brazing material and electrically connect each electrode of the semiconductor element to a wiring conductor via an electrical connection means such as a bonding wire.
A lid made of metal, ceramic, or the like is bonded to the upper surface of the insulating base via a sealing material such as glass, resin, or brazing material so as to cover the concave part of the insulating base, and the semiconductor element is hermetically sealed in the concave part of the insulating base. A semiconductor device as a product is obtained by accommodating the semiconductor device. By connecting the portion of the wiring conductor led out to the lower surface of the insulating base to the wiring conductor of the external electric circuit board via an electric connection means such as solder, the semiconductor element to be accommodated is electrically connected to the external electric circuit board. It will be connected.

This conventional wiring board is manufactured by a ceramic green sheet laminating method. Specifically, an appropriate organic binder, a solvent and the like are added to a ceramic raw material powder such as aluminum oxide, silicon oxide, magnesium oxide and calcium oxide. A plurality of ceramic green sheets are obtained by mixing and forming a slurry into a sheet shape by employing a well-known doctor blade method, and thereafter, these ceramic green sheets are subjected to an appropriate punching process. A metal paste to be a wiring conductor is printed and applied in a predetermined pattern, and finally, these ceramic green sheets are stacked up and down in a predetermined order to form a green ceramic molded body and fired at a high temperature of about 1600 ° C. in a reducing atmosphere. Produced by

However, in the conventional wiring board, since ceramics such as an aluminum oxide sintered body constituting the insulating base have a hard and brittle property, the wiring boards are not connected to each other in a transfer process or an automatic line for manufacturing semiconductor devices. If the wiring board and a part of the automatic semiconductor device manufacturing line collide violently, the insulating substrate may be chipped, cracked, cracked, etc., and as a result, the semiconductor element cannot be housed in a gas-tight manner, and the length of the semiconductor element cannot be increased. There was a disadvantage that normal and stable operation could not be achieved over a period of time.

In addition, according to this conventional method for manufacturing a wiring board, when the green ceramic molded body is fired, uneven firing shrinkage occurs in the green ceramic molded body, and the obtained wiring board is deformed such as warpage. This has the disadvantage that the semiconductor element and the wiring conductor are difficult to electrically and reliably connect with each other as a result.

Therefore, the insulating substrate of the wiring substrate is formed by laminating an insulating substrate made of a material obtained by bonding inorganic insulating powder with a thermosetting resin in place of conventional ceramics, and the wiring conductor is made of conventional tungsten or tungsten. There has been proposed a wiring board formed of a material obtained by bonding a metal powder such as copper with a thermosetting resin in place of a metal having a high melting point such as molybdenum.

A wiring board composed of an insulating base formed by bonding an inorganic insulating powder with a thermosetting resin and a wiring conductor formed by bonding a metal powder with a thermosetting resin is composed of a thermosetting resin precursor and an inorganic hardening resin. Prepare a precursor sheet in a semi-cured state by mixing with an insulating powder and subject it to appropriate punching, then mix the precursor sheet with a thermosetting resin precursor and a metal powder. The metal paste is printed and applied in a predetermined pattern, and finally, the precursor sheet on which the metal paste is printed is applied at a temperature of about 150 to 300 ° C. and about 4 to 100 k.
It is manufactured by laminating by hot pressing at a pressure of gf / cm ² and thermosetting at a temperature of about 100 to 300 ° C.

According to this wiring board, since the inorganic insulating powder serving as the insulating board and the metal powder serving as the wiring conductor are bonded by a thermosetting resin having excellent toughness, the wiring boards or the wiring board and the semiconductor device are combined. Even if a part of the automatic production line collides violently, chipping, cracking or cracking of the insulating substrate does not occur at all.

According to this method of manufacturing a wiring board, the wiring board is manufactured by thermosetting a thermosetting resin contained in an insulating base and a wiring conductor. Does not occur.

[0010]

However, according to the present invention, there is provided a wiring board comprising an insulating base formed by bonding the inorganic insulating powder with a thermosetting resin and a wiring conductor formed by bonding a metal powder with a thermosetting resin. For example, when laminating the semi-cured precursor sheets by hot pressing, the curing reaction of the thermosetting resin precursor contained in the precursor sheets to be laminated with each other already partially progresses before lamination and the thermosetting resin Since the number of reactive groups in the resin precursor is reduced, the curing reaction between the thermosetting resin precursors between the upper and lower precursor sheets is weakened by that amount, and therefore, each insulating material constituting the insulating base is reduced. The thermosetting resin is not tightly bonded between the boards, and the moisture permeability to this part is high, and the moisture resistance is slightly inferior. If the wiring board is left in the outside atmosphere for a long time, the Through Moisture in the outside air gradually penetrates into the inside of the edge substrate, and the penetrated water causes corrosion of the wiring conductor. As a result, the semiconductor element contained therein can operate normally and stably for a long period of time. There is a problem that it becomes impossible to do.

The present invention has been devised to solve the above-mentioned problems, and has as its object to bond an insulating substrate formed by bonding an inorganic insulating powder with a thermosetting resin and a metal powder with a thermosetting resin. A wiring board comprising: a wiring conductor formed by: preventing moisture in the external atmosphere from invading the inside of the insulating base through the space between the insulating substrates, having excellent moisture resistance, and allowing the semiconductor element to be housed therein to be used for a long time. It is an object of the present invention to provide a wiring board that can be operated normally and stably over a long period of time.

It is another object of the present invention to provide a method of manufacturing a wiring board comprising an insulating base formed by bonding inorganic insulating powder with a thermosetting resin and a wiring conductor formed by bonding metal powder with a thermosetting resin. Accordingly, it is an object of the present invention to provide a manufacturing method capable of obtaining a wiring substrate having excellent moisture resistance and capable of operating a semiconductor element contained therein normally and stably for a long period of time.

[0013]

According to the present invention, there is provided a wiring board comprising:
A metal powder is coated with a thermosetting resin inside an insulating substrate formed by laminating a plurality of insulating substrates formed by bonding 5 to 40% by weight of an inorganic insulating powder with a thermosetting resin of 5 to 40% by weight. A wiring board comprising a plurality of wiring conductors joined by a thermosetting resin, wherein the insulating base is made of a thermosetting resin, or an inorganic insulating powder is joined to the side face of the insulating base by a thermosetting resin. Characterized in that the layer is applied.

Further, in the method for manufacturing a wiring board according to the present invention, there is provided a step of preparing a precursor sheet obtained by mixing a thermosetting resin precursor and an inorganic insulating powder, and adding a thermosetting resin to the precursor sheet. A step of printing a metal paste formed by mixing the precursor and the metal powder in a predetermined pattern; a step of laminating a precursor sheet on which the metal paste is printed and applied; and a step of applying heat to the side surface of the laminated precursor sheet. A step of applying an insulating paste composed of a curable resin precursor or a mixture of a thermosetting resin precursor and an inorganic insulating powder; and a step of thermally curing the precursor sheet, metal paste, and insulating paste And characterized in that:

According to the wiring board of the present invention, since the insulating layer made of a thermosetting resin or the inorganic insulating powder bonded with the thermosetting resin is applied to the side surface of the insulating base, This insulating layer can effectively prevent moisture in the external air from entering the inside of the insulating base through the space between the insulating substrates, so that it has excellent moisture resistance, and the semiconductor element housed therein can be used for a long time. The wiring board can be normally and stably operated.

Further, according to the method of manufacturing a wiring board of the present invention, a side face of a laminated precursor sheet is formed of a thermosetting resin precursor or a mixture of a thermosetting resin precursor and an inorganic insulating powder. After the application of the insulating paste, the precursor sheet, the metal paste, and the insulating paste are thermally cured, so that the side surfaces of the insulating substrate can be covered with a dense insulating layer in which the bonding of the thermosetting resin is dense. In addition, it is possible to obtain a wiring board which is excellent in moisture resistance and can normally and stably operate a semiconductor element housed therein for a long period of time.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an example of an embodiment in which the wiring board of the present invention is applied to a semiconductor element housing package for housing a semiconductor element. Reference numeral 1 denotes an insulating base, and 2 denotes a wiring conductor.

The insulating substrate 1 is made of an inorganic insulating powder such as silicon oxide, aluminum oxide, aluminum nitride, silicon carbide, barium titanate, zeolite, etc.
Three insulating substrates 1a, 1b, and 1c made of a material bonded by a thermosetting resin such as a polyimide resin, a bismaleimide resin, and a thermosetting polyphenylene ether resin are laminated, and a stepped shape is formed at the center of the upper surface thereof. The semiconductor device 3 has a concave portion A, and the semiconductor element 3 is fixed to the bottom surface of the concave portion A with an adhesive such as a resin.

The inorganic insulating powder contained in the insulating substrates 1a, 1b, 1c has a particle size of about 0.1 to 100 μm, and the coefficient of thermal expansion of the insulating substrates 1a, 1b, 1c is determined by the thermal expansion coefficient of the semiconductor element 3. In addition to the function of making the coefficient close to the coefficient, the function of imparting good thermal conductivity, water resistance, or a predetermined relative dielectric constant to the insulating substrates 1a, 1b, and 1c is performed.

On the other hand, the thermosetting resin contained in the insulating substrates 1a, 1b, and 1c functions to bind the inorganic insulating powder to each other and hold the insulating base 1 in a predetermined shape.

Since the insulating substrates 1a, 1b, and 1c are formed by bonding inorganic insulating powder with a thermosetting resin having excellent toughness, the insulating substrate 1 may be chipped, cracked, or cracked when the wiring substrates collide with each other. Does not occur.

When the content of the inorganic insulating powder contained in the insulating substrates 1a, 1b, and 1c is less than 60% by weight, the thermal expansion coefficient of the insulating base 1 becomes lower than that of the semiconductor element 3. Coefficient, the heat generated when the semiconductor element 3 operates is reduced by the semiconductor element 3 and the insulating base 1.
When applied to the semiconductor element 3, a large thermal stress is generated due to a difference in thermal expansion coefficient between the two, so that the semiconductor element 3 tends to be peeled or cracked from the insulating base 1, and the inorganic insulating powder If the content exceeds 95% by weight, it tends to be difficult to firmly bond the inorganic insulating powder with a thermosetting resin. Therefore, the insulating substrates 1a, 1b and 1c are specified so that the content of the inorganic insulating powder contained therein is in the range of 60 to 95% by weight.

The insulating base 1 penetrates from the upper surface of the insulating substrate 1b around the recess A to the lower surface of the insulating substrate 1c by passing through the insulating substrates 1b and 1c. For example, copper, silver, gold, and the surface are covered with silver. A large number of wiring conductors 2 are provided in which the obtained metal powder such as copper is bonded by a thermosetting resin such as an epoxy resin.

The wiring conductor 2 serves to electrically connect the semiconductor element 3 housed therein to an external electric circuit. And a portion extending to the lower surface of the insulating base 1 is electrically connected to an external electric circuit board.

The metal powder contained in the wiring conductor 2 acts to impart conductivity to the wiring conductor 2, and if the content in the wiring conductor 2 is less than 70% by weight, the conductivity of the wiring conductor 2 tends to deteriorate. And the content in the wiring conductor 2 is
If it exceeds 95% by weight, it tends to be difficult to firmly bond the metal powder with a thermosetting resin. Therefore, the content of the metal powder contained in the wiring conductor 2 in the wiring conductor 2 is preferably in the range of 70 to 95% by weight.

If the average particle size of the metal powder contained in the wiring conductor 2 is less than 0.5 μm, the contact resistance between the metal powders increases and the electric resistance of the wiring conductor 2 tends to be high. Yes, and if it exceeds 50 μm, the insulating substrate 1
The wiring conductor 2 having a predetermined pattern is generally required to be 50 to
It tends to be difficult to form a line width of 200 μm.

Therefore, the metal powder contained in the wiring conductor 2 preferably has an average particle size of 0.5 to 50 μm.

The thermosetting resin contained in the wiring conductor 2 functions to bond the metal powders to each other in contact with each other and to adhere the wiring conductor 2 to the insulating base 1. It is made of epoxy resin such as epoxy resin, novolak type epoxy resin and glycidyl ester type epoxy resin, and thermosetting resin such as phenol resin, polyimide resin, bismaleimide resin and thermosetting polyphenylene ether resin.

The thermosetting resin contained in the wiring conductor 2 is as follows:
If the content in the wiring conductor 2 is less than 5% by weight, the metal powders cannot be firmly bonded to each other, it is difficult to firmly adhere the wiring conductor 2 to the insulating base 1, and the content in the wiring conductor 2 is 30% by weight. %, It is difficult to bring the metal powders into sufficient contact with each other, and the electrical resistance of the wiring conductor 2 tends to increase. Accordingly, the content of the thermosetting resin contained in the wiring conductor 2 in the wiring conductor 2 is preferably in the range of 5 to 30% by weight.

The exposed surface of the wiring conductor 2 is made of a metal, such as nickel or gold, having excellent corrosion resistance and excellent bonding property with the bonding wire 4 or the like by plating method.
When the wiring conductor 2 is adhered to a thickness of μm, it is possible to effectively prevent the wiring conductor 2 from being oxidized and corroded, and to easily and firmly connect the wiring conductor 2 to the bonding wire 4 and the wiring conductor of the external electric circuit board. Can be performed. Therefore, the wiring conductor 2 is preferably coated with a metal having excellent corrosion resistance, such as nickel or gold, and excellent connectivity with the bonding wire 4 or the like to a thickness of 1 to 20 μm on the exposed surface by plating. preferable.

The insulating substrate 1 has an insulating layer 5 formed on the side surface thereof, which is made of a thermosetting resin or which is formed by bonding an inorganic insulating powder with a thermosetting resin.

When the insulating layer 5 is made of, for example, an inorganic insulating powder bonded with a thermosetting resin, the inorganic insulating powder such as silicon oxide, aluminum oxide, aluminum nitride, silicon carbide, barium titanate, zeolite, etc. Each of the insulating substrates 1a, 1b, and 1c, which is formed by bonding with a thermosetting resin such as a resin, a polyimide resin, a bismaleimide resin, and a thermosetting polyphenylene ether resin and covers the side surface of the insulating base 1, is vertically stacked. It acts to prevent moisture in the outside air from entering the inside of the insulating substrate from a short distance.

The insulating substrate 1 has an insulating layer 5 formed by bonding an inorganic insulating powder with a thermosetting resin to the side surface thereof. The moisture in the external atmosphere is reduced by the layer 5 to each of the insulating substrates 1a.
Infiltration into the inside of the insulating base 1 from between 1b and 1c is effectively prevented, and as a result, the semiconductor element 3 housed therein can be operated normally and stably for a long period of time.

If the thickness of the insulating layer 5 is less than 5 μm, it tends to be difficult to sufficiently prevent moisture in the external atmosphere from entering the inside of the insulating substrate 1. Preferably, it is usually 5
The thickness may be set to 50 μm.

When the content of the inorganic insulating powder contained in the insulating layer 5 exceeds 95% by weight, the insulating substrate 1
It tends to be difficult to firmly cover the side surface with the insulating layer 5. Therefore, it is preferable that the content of the inorganic insulating powder contained in the insulating layer 5 is 95% by weight or less.

Further, the insulating layer 5 comprises insulating substrates 1a, 1b,
When the insulating substrate 1 and the insulating layer 5 are formed of the same material as the material forming 1c, the insulating substrate 1 and the insulating layer 5 can be firmly bonded to each other, so that the side surface of the insulating substrate 1 can be firmly covered. Therefore, it is preferable that the insulating layer 5 is formed of the same material as the material forming the insulating substrates 1a, 1b, and 1c.

Thus, according to the wiring board of the present invention, the semiconductor element 3 is bonded and fixed to the bottom surface of the concave portion A of the insulating base 1 and each electrode of the semiconductor element 3 is electrically connected to the wiring conductor 2 via the bonding wire 4. Connect and finally insulating base 1
The lid 6 is joined to the upper surface of the semiconductor device via a sealing material to form a semiconductor device as a product.

Next, a method of manufacturing a wiring board according to the present invention will be described.

First, as shown in FIG. 2A, three semi-cured precursor sheets 11a, 11b, and 11c formed by bonding inorganic insulating powder with a thermosetting resin precursor are prepared.

For example, when the inorganic insulating powder is made of silicon oxide and the thermosetting resin is made of epoxy resin, the precursor sheets 11a, 11b and 11c are formed by adding bisphenol to silicon oxide powder having a particle size of about 0.1 to 100 μm. A type epoxy resin
A paste obtained by adding and mixing epoxy resins such as novolak type epoxy resins and glycidyl ester type epoxy resins and curing agents such as amine type curing agents, imidazole type curing agents, and acid anhydride type curing agents. It is manufactured by forming into a sheet by using a sheet forming technique such as a method and heating and semi-curing the sheet at a temperature of about 25 to 100 ° C. for 1 to 60 minutes.

Next, as shown in FIG. 2 (b), two precursor sheets 11a, 11b, 11c of the precursor sheets 11a, 11b, 11c are used.
b, openings A1 and A2 to be the concave portions A, and through holes B1 and B2 as passages for routing the wiring conductor 2 in the two precursor sheets 11b and 11c, respectively.

The openings A1, A2 and the through holes B1, B2 formed in the precursor sheets 11a, 11b, 11c are formed by subjecting the precursor sheets 11a, 11b, 11c to a conventionally well-known punching method. It is formed by drilling a hole of a predetermined shape in each of 11b and 11c.

Next, as shown in FIG. 2C, wiring conductors are formed in the upper surface of the precursor sheet 11b, the upper and lower surfaces of the precursor sheet 11c, and the through holes B1 and B2 formed in the precursor sheets 11b and 11c. The second metal paste 12 is printed and applied in a predetermined pattern by employing a conventionally known screen printing method and filling method.

The metal paste 12 serving as the wiring conductor 2 may be, for example, a powder of copper having a particle size of about 0.1 to 20 μm, an epoxy resin such as a bisphenol A type epoxy resin, a novolak type epoxy resin, a glycidyl ester type epoxy resin, or the like. A paste obtained by adding and mixing a curing agent such as an amine curing agent, an imidazole curing agent, and an acid anhydride curing agent is used.

Next, as shown in FIG. 2D, the precursor sheets 11a, 11b and 11c are stacked one on top of the other and hot pressed at a temperature of about 150 to 300 ° C. and a pressure of about 4 to 100 kgf / cm ^2. And laminated, the laminated precursor sheet 11
a. Insulating paste 13 which becomes insulating layer 5 on side surfaces of 11b and 11c
Is applied by printing using a conventionally known screen printing method.

The insulating paste 13 that becomes the insulating layer 5 is
From a thermosetting resin precursor, or a mixture of a thermosetting resin precursor and an inorganic insulating powder, for example, a mixture of a thermosetting resin precursor and an inorganic insulating powder, Of epoxy resin such as bisphenol A type epoxy resin, novolak type epoxy resin, glycidyl ester type epoxy resin and amine type curing agent, imidazole type curing agent, acid anhydride type curing agent etc. It is manufactured by adding and mixing a curing agent and the like.

In this case, the laminated precursor sheets 11a
Since the thermosetting resin precursor in the insulating paste 13 applied to the side surfaces of 11b and 11c has not been hardened, a large amount of reactive groups are present in the thermosetting resin precursor.

Finally, an insulating paste 13 is applied to this side.
Is heated at a temperature of about 100 to 300 ° C. to form precursor sheets 11a, 11b, 11c.
By completely thermosetting b.11c, metal paste 12, and insulating paste 13, the wiring board as shown in FIG. 1 is completed.

In this case, the thermosetting resin precursors in the insulating paste 13 in which a large amount of reactive groups are present, and the thermosetting resin precursors and the thermosetting resin precursors of the precursor sheets 11a, 11b, 11c Reacts densely, the side surfaces of the insulating base 1 can be covered with the insulating layer 5 in which the bonding of the thermosetting resin is dense, and a wiring board having excellent moisture resistance can be provided.

In this case, the precursor sheets 11a, 11b
11c, the metal paste 12 and the insulating paste 13 hardly shrink during thermosetting, and therefore, there is no deformation or dimensional variation in the obtained wiring board. Can be connected accurately.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention. For example, in the above-described embodiment, Although the case where the wiring board of the present invention is applied to a semiconductor element housing package for housing a semiconductor element has been described as an example, this may be applied to a wiring board used for a hybrid integrated circuit board or the like.

In the above embodiment, the wiring board is formed by laminating three insulating substrates. However, the wiring board is formed by laminating two or four or more insulating substrates. It may be formed.

Further, in the above embodiment, the wiring conductor is formed by bonding metal powder with a thermosetting resin, but the wiring conductor is formed by bonding the metal powder to a low melting point metal such as solder and a thermosetting resin. It may be formed by bonding with a resin. In this case, an appropriate amount of a low-melting metal such as solder is contained in the metal paste to be the wiring conductor, and is contained in the metal paste before or at the same time as the heat curing of the metal paste to be the wiring conductor. A method of bonding the metal powder with the low melting point metal by melting the low melting point metal can be adopted.

[0055]

According to the wiring board of the present invention, the insulating layer made of a thermosetting resin or the inorganic insulating powder bonded with the thermosetting resin is applied to the side surface of the insulating base. Therefore, the insulating layer can effectively prevent moisture in the external atmosphere from entering the inside of the insulating base through the space between the insulating substrates, and as a result, the semiconductor element contained therein can be normally maintained for a long time. And it can be operated stably.

Further, according to the method of manufacturing a wiring board of the present invention, a side face of a laminated precursor sheet is formed of a thermosetting resin precursor or a mixture of a thermosetting resin precursor and an inorganic insulating powder. After the application of the insulating paste, the precursor sheet, the metal paste, and the insulating paste are thermally cured, so that the side surfaces of the insulating substrate can be covered with a dense insulating layer in which the bonding of the thermosetting resin is dense. A wiring board having excellent moisture resistance can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of an embodiment in which a wiring board of the present invention is applied to a package for housing a semiconductor element.

FIGS. 2A to 2D are cross-sectional views for explaining steps of a method for manufacturing a wiring board according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insulating base 1a-1c ... Insulating substrate 2 ... Wiring conductor 3 ... Semiconductor element 5 ... ..Insulating layers 11a-11c ... Precursor sheet 12 ... Metal paste 13 ... Insulating paste

Claims (2)

[Claims] 1. An insulating substrate formed by laminating a plurality of insulating substrates each formed by bonding 60 to 95% by weight of an inorganic insulating powder with 5 to 40% by weight of a thermosetting resin has a metal inside. What is claimed is: 1. A wiring board comprising a plurality of wiring conductors formed by bonding powders with a thermosetting resin, wherein said insulating substrate comprises a thermosetting resin on a side surface thereof, or said inorganic insulating powder comprises a thermosetting resin. A wiring board, wherein an insulating layer formed by bonding is bonded. 2. A step of preparing a precursor sheet obtained by mixing a thermosetting resin precursor and an inorganic insulating powder; and mixing the thermosetting resin precursor and a metal powder in the precursor sheet. Printing the metal paste in a predetermined pattern, laminating a precursor sheet on which the metal paste is printed and coated, and comprising a thermosetting resin precursor on the side surface of the laminated precursor sheet, or A wiring board, comprising: a step of applying an insulating paste formed by mixing a curable resin precursor and an inorganic insulating powder; and a step of thermally curing the precursor sheet, the metal paste, and the insulating paste. Manufacturing method.