JP2001267741A - Method of manufacturing multilayer board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a multilayer board which can minimize the thickness dispersion of a lower insulating layer. SOLUTION: This is a manufacturing method compresses a process of manufacturing a protective film molded item 33 10-5 μm in thickness by repeating the process of applying an insulating material containing photosetting resin and an inorganic material on a supporting substrate 1 and drying it once or more times, a process of forming a stacked molded item where a plurality of insulating layer molded items 71a-71f containing photosetting resin and an inorganic material are stacked on the surface of the protective film molded item 33, a process of removing the supporting substrate 31, and a process of baking the stacked molded item where the protective molded item 33 is made.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer substrate, and more particularly to a method for manufacturing a multilayer substrate having a built-in functional element such as a capacitor or a filter.

[0002]

2. Description of the Related Art In general, a multilayer ceramic circuit board is formed by laminating a plurality of insulating layers such as glass-ceramic, and the inside thereof is formed of a high melting point metal material such as tungsten and a low resistance material such as gold, silver and copper. Internal wiring and via hole conductors are formed.

Conventionally, in a multilayer ceramic circuit board, a slip material containing a glass material and a ceramic material to be an insulating layer is formed, a green sheet is produced by a doctor blade method or the like, and then a via hole conductor is formed in the green sheet. A through hole is formed at the position with an NC punch or a mold, and then a conductive paste is printed and filled on a green sheet according to an internal wiring pattern and a via hole conductor, and then a plurality of these green sheets are laminated. A method using a so-called green sheet laminating method, in which a laminated molded body is produced and the laminated molded body is simultaneously fired at a time, has been common.

However, recently, there is an increasing demand for further miniaturization of circuit components accompanying miniaturization of equipment, and a method of reducing the size by incorporating a passive element such as a capacitor or a coil in a substrate has been studied. In the case of the above-described green sheet laminating method, the accuracy of interlayer lamination positioning is poor due to the influence of the deformation such as the alignment during the integration of the green sheets and the elongation of the green sheet, causing the lamination displacement of about 100 μm, and the built-in element Causes characteristic variations.

As a method of manufacturing a multilayer ceramic circuit board for solving the above-mentioned problem of the green sheet multilayer system, Japanese Patent Application Laid-Open No. 7-154073 discloses an insulating layer material made of glass and ceramic on a support substrate, and a photo-curable material. The slip material containing a suitable monomer and an organic binder is thinned and dried to form an insulating layer molded product, and after selectively subjecting the insulating layer molded product to exposure treatment, the developing treatment is performed to form a via-hole conductor. Forming a through-hole for forming, filling the through-hole with a conductive paste and forming a pattern for internal wiring on the insulating layer molded body by repeating the required number of laminations to produce a laminated molded body, Are collectively fired to obtain a substrate.

According to this method, since the lamination method using the photolithography process is adopted with the support substrate as a reference for alignment, the alignment accuracy at the time of lamination is improved, and the variation in the characteristics of the built-in elements is suppressed. Is done. Further, even if holes having various diameters from a small diameter to a large diameter are formed in a sheet having a small thickness per layer, there is no problem in handling properties, and the problem in the green sheet lamination method can be solved.

[0007]

However, in the case of a process by a so-called build-up method in which a process of forming an insulating layer molded body on a support substrate as described above is repeated, a layer formed on the support substrate has That is, the lowermost insulating layer is affected by the surface roughness and the thickness variation of the support substrate, and the thickness variation of this layer is larger than that of the other layers.

That is, when a glass plate having a thickness of about 2 to 3 mm is used as a support substrate and a release film is adhered thereon, the thickness variation of the support substrate including the surface roughness of the release film is about 30 μm. It is. When a slip material is applied on this supporting substrate by a doctor blade method and dried to form an insulating layer molded body, the thickness after drying is reduced to about ２. The thickness variation after (2) is about 15 μm.

When a layer having a thickness of about 100 to 200 μm is required, such a thickness variation is not a problem. However, when a functional element such as a capacitor is required to be built in, a substrate is required. In order to maintain the capacity of the capacitor without increasing the size, a thinner insulating layer (dielectric layer) is required. Specifically, a layer thickness of 50 μm or less, and in some cases, a layer thickness of 20 to 30 μm may be required. If the thickness variation is 15 μm, the variation is about 40% with respect to the layer thickness, and the capacitance variation is large. And does not function as a capacitor.

For example, for a layer thickness of 20 μm, 15 μm
Is a variation of 12.5 to 27.5 μm, the ratio of which is a maximum of 40 μm for a layer thickness of 20 μm.
%.

Therefore, in the lowermost layer and the second and third layers which are affected by the surface roughness and thickness variation of the supporting substrate, the variation in the layer thickness must be considered, and the functional element is built in this layer. It is difficult to perform the operation, and the design when the functional element is incorporated is restricted.

On the other hand, if the thickness variation of the supporting substrate is made to be 10 μm, more preferably 5 μm or less in order to suppress the layer thickness variation, there is a problem that the cost for the processing is greatly increased. .

It is an object of the present invention to provide a method of manufacturing a multilayer substrate capable of minimizing the thickness variation of an underlying insulating layer without reducing the thickness variation of a supporting substrate.

[0014]

According to the method of manufacturing a multilayer substrate of the present invention, a step of applying a slip material containing a photocurable resin and an inorganic material on a supporting substrate and drying the same is repeated at least once to reduce the thickness. A step of producing a protective film molded body having a thickness of 10 to 50 μm and a step of forming a laminated molded body formed by laminating a plurality of insulating layer molded bodies containing a photocurable resin and an inorganic material on the surface of the protective film molded body And a step of removing the support substrate and a step of firing the laminated molded body on which the protective film molded body is formed.

According to such a method, it is possible to increase the thickness accuracy of the first and second insulating layers which are affected by the surface roughness of the supporting substrate in the formation of the build-up multilayer system. Thus, the accuracy of the functional element incorporated in these insulating layers can be improved. In addition, since a high-precision functional element can be incorporated in the first and second insulating layers, the degree of freedom in design is increased. Furthermore, the formation accuracy of the surface shape and the like can be improved as compared with a protective film that is conventionally formed by printing and firing a dielectric paste after firing.

Therefore, it is useful for forming a high-density pattern and improving the characteristics of a high-frequency circuit. Since the functional elements can be built in the first and second layers, the high-frequency module can be reduced in size and function. Since there is no need to reduce the in-plane thickness variation, the cost can be further reduced.

That is, for example, a thickness of 30 μm
For example, the case where the protective film molded body is formed will be described. Since the slip material for forming the protective film molded body contains a photocurable resin, the slip material has a large resin component and is dried by drying.
%, The thickness of the slip material before drying is required to be 60 μm when forming a protective film molded product having a thickness of 30 μm, and as described above, the surface of the support substrate including the surface roughness of the release film is required. Since the thickness variation is about 30 μm, the thickness variation of the slip material before drying is about 30 μm, and is about 15 μm after drying.

The insulating layer molded body corresponding to the first layer is formed on the protective film molded body. At this time, the thickness variation of the underlying protective film molded body is about 15 μm. The thickness variation of the first insulating layer molded body formed thereon is further reduced to about 7.5 μm.

When forming this protective film molded body, if a thin coating film is formed in two or more steps, for example, 30 μm is formed.
When a 10 μm film is formed in three times to obtain a protective film molded article having a thickness of m, the thickness variation of the first molded article is about 15 μm, about 7.5 μm for the second layer, and about 7.5 μm for the third layer. It becomes about 3.8 μm, and the thickness variation of the first-layer insulating layer molded body can be further reduced to about 1.9 μm.

In the prior art, the lowermost conductor protective film of a multilayer substrate is formed by screen-printing a dielectric paste after the completion of the laminated body. In the present invention, however, the conductor protective film is previously formed as a support substrate flattening layer. However, since this can be used as a protective film, the process is simplified, and the positional accuracy is extremely excellent as compared with the screen printing method.

Further, the thickness of the protective film molded product is 10 to 5
Since the thickness is 0 μm, the reliability as a conductor protective film can be maintained, and the film can be formed without requiring much time for drying during film formation.

According to the manufacturing method of the present invention, in the laminated molded body in the vicinity of the protective film molded body, since the thickness variation of the insulating layer molded body is small, the characteristics as designed can be obtained even if the functional element molded body is incorporated.

Preferably, the method further includes a step of forming a through-hole by exposing and developing the protective film molded body, and a step of filling the through-hole with a conductive paste to form an external connection conductor. According to such a manufacturing method, a protective film having an external connection electrode that can be connected to an external component is formed simultaneously with the formation of the multilayer substrate without forming a protective film by applying a dielectric paste to the manufactured multilayer substrate. it can.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A multilayer substrate obtained by the method of the present invention will be described with reference to the cross-sectional view of FIG. In this example, a multilayer substrate that is fired at a low temperature and uses gold, silver, and copper conductors as internal wiring conductors will be described. The multilayer substrate includes a lowermost conductor protection film 1, a lowermost conductor 3, an external connection electrode 5 between the lowermost conductor 3 and an external component, insulating layers 7a to 7f, an internal wiring 9, and a via hole conductor 11. Is the surface wiring 13,
A thick resistor film 15 and various electronic components 17 are formed.

That is, the lowermost conductor 3 is formed between the lowermost conductor protection film 1 and the insulating layer 7f, and the external connection electrode 5 for connecting to an external component is formed on the lowermost conductor protection film 1. ing.

The thickness of the insulating layers 7a to 7f is 40 to 150 μm.
m, and between such a plurality of insulating layers 7a to 7f,
Internal wiring 9 is formed. The internal wiring 9 is made of a gold-based, silver-based, or copper-based metal material, for example, a silver-based conductor.
Further, the internal wirings 9 between the different insulating layers 7a to 7f are connected by via-hole conductors 11 penetrating through the thicknesses of the insulating layers 7a to 7f. This via-hole conductor 11 is also used for the internal wiring 9.
Similarly, it is made of a gold-based, silver-based, or copper-based metal material, for example, a silver-based conductor.

On the surface of the multi-layer substrate, a surface wiring 13 connected to the via-hole conductor 11 of the insulating layer 7a is formed. Although not shown, a thick protective film is formed, plated, and various electronic components 17 including an IC are joined by soldering or bonding thin wires.

A pair of internal electrodes 21 is formed on the multilayer substrate so as to sandwich the insulating layer 7f on the protective film 1, and a functional element 23 composed of a capacitor is formed in the multilayer substrate. . The functional element 23 may be not only a capacitor but also a laminated coil, a resonator (strip line), or a resistor. According to the present invention, the first insulating layer 7f on the protective film 1 and / or A functional element can be provided in the second insulating layer 7e. The characteristics of such a functional element greatly change due to thickness variations.

The method for manufacturing the multilayer substrate of the present invention will be described with reference to FIG. First, a slip material to be the protective film 1 and the insulating layers 7a to 7f is manufactured. The slip material includes, as an inorganic material, glass ceramic or ceramic raw material powder, a photocurable resin (photocurable monomer) such as polyoxyethylated trimethylolpropane triacrylate, and an organic binder such as alkyl methacrylate.
It is produced by mixing a plasticizer with an organic solvent, for example, ethyl carbitol acetate, and kneading with a ball mill.
The protective film 1 and the insulating layers 7a to 7f need not be formed of the same material, but may be formed of different materials.

[0030] As the ceramic raw material powder, for example, at least Mg, Ti, a composite oxide containing Ca, a composition formula by a metal element oxide _{(1-x) MgTiO 3 -xCaTiO} 3 as the metal element ( Where x
Represents a weight ratio, and a boron-containing compound is added to B ₂ O ₃ with respect to 100 parts by weight of a main component represented by 0.01 ≦ x ≦ 0.15).
A compound containing 3 to 30 parts by weight in terms of conversion and 1 to 25 parts by weight of an alkali metal-containing compound in terms of alkali metal carbonate is used.

In the above embodiment, a solvent-based slip material is prepared. However, a photocurable monomer having a hydrophilic functional group added thereto, for example, a polyfunctional methacrylate monomer,
An aqueous slip material kneaded with ion-exchanged water using an organic binder, for example, a carboxyl-modified alkyl methacrylate, may be used.

Examples of the glass ceramic raw material powder include glass materials such as SiO ₂ , Al ₂ O ₃ , ZnO, M
A powder composed of 70% by weight of crystallized glass powder containing gO and B ₂ O ₃ as main components and 30% by weight of alumina powder as a ceramic material is also used. The glass ceramic raw material powder is not particularly limited.

The external connection electrode 5 and the via-hole conductor 1
1. A conductive paste to be the internal wiring 9 and the surface electrode 13 is prepared. Conductive paste, silver powder such as metallic material and low resistance at a low melting point, borosilicate-based low-melting-point glass, for example, B ₂ O ₃ -SiO ₂ -BaO glass, CaO-
B ₂ O ₃ -SiO _{2 glass, CaO-Al 2 O 3 -B} 2 O 3 -
An SiO ₂ glass and an organic binder, for example, ethyl cellulose, are mixed with an organic solvent, for example, 2,2,4-trimethyl-
Mixed with 1,3-pentadiol monoisobutyrate,
It is manufactured by homogenous kneading with three rollers.

The method for manufacturing the multilayer substrate of the present invention is as follows.
As shown in (a), the step of thinning (hereinafter simply referred to as “application”) and drying the slip material on the support substrate 31 to which the release film is adhered is repeated one or more times so that the thickness becomes 10%. A protective film molded body 33 having a thickness of about 50 μm is formed. The step of applying and drying the slip material is desirably repeated at least twice. In FIG. 2A, a 10 μm film is formed by 3
The process was repeated twice to form a protective film molded body 33 of 30 μm.

The thickness of the protective film molded body 33 is 10 to 5
0 μm. The thickness of the protective film molded body 33 is 10 μm
If it is less than m, a thin portion is formed in a part, and it becomes difficult to maintain insulation reliability as a conductor protective film.
If it exceeds m, there is a problem that time is required for drying at the time of film formation. The thickness of the protective film molded body 33 is
From the viewpoint of maintaining the reliability as a conductor protective film, it is desirable to apply and dry the coating twice or more, and the thickness is 20 to
30 μm is desirable.

The coating is performed by a doctor blade method, a roll coating method, a printing method using a screen having a coating area approximately equal to the area of the supporting substrate, or the like. The drying method is performed using a batch-type drying furnace or an inline-type drying furnace, and the drying condition is preferably 120 ° C or lower, more preferably 80 to 100 ° C. This is because when the temperature is increased, only the surface of the formed film is rapidly dried to make it difficult to uniformly dry the entire film, or the monomer contained in the slip material is hardened by heat. Also, rapid drying may cause cracks on the surface,
It is important to avoid sudden heating.

Here, examples of the support substrate 31 include a glass substrate and an organic film. This support substrate 31
Is removed before the firing step.

Next, a through-hole for forming an external connection electrode 5 for connecting to an external component is formed in the protective film molded body 33 formed on the support substrate 31. Although the lower part of the through hole is actually closed by the support substrate 31 or the like, it is called a through hole for convenience. The formation of through-holes
This is performed by a development process.

In the exposure process, for example, as shown in FIG. 2B, a photomask 35 is placed close to or placed on the protective film molded body 33, and a low pressure, a high pressure, an ultra high pressure Irradiation exposure light of a mercury lamp system. As a result, the photocurable monomer causes a photopolymerization reaction in a region other than the through hole. Therefore, only the through-hole portion becomes the melted portion Y that can be removed by the development process. Actually, the exposure accuracy is improved when the photo target 35 is brought into contact with the protective film molded body 33 and exposed. The optimum exposure time is determined by the thickness of the protective film molded body 33, the diameter of the through hole, and the like. Incidentally, the exposure apparatus may be a general one used in so-called photoengraving technology.

In the developing treatment, a weak alkaline aqueous solution such as sodium carbonate or an organic amine is brought into contact with the exposed and solubilized portion Y serving as a through hole by, for example, a spray developing method or a paddle developing method to perform development. Thereafter, by performing washing and drying as necessary, a through hole 37 is formed as shown in FIG.

Next, as shown in FIG. 2D, an external connection conductor 38 serving as an external connection electrode with an external component is formed by filling and drying a conductive paste. Note that the external connection electrodes need not be formed. In this case, the slurry is applied and dried one or more times to form the protective film molded body 33, but may be exposed and cured each time the application is dried.

Thereafter, as shown in FIG. 2E, a wiring pattern 39 corresponding to the lowermost conductor 3 is formed by printing and drying. The filling of the conductive paste and the printing of the wiring pattern are performed by, for example, a screen printing method.

Next, as shown in FIG. 2F, an insulating layer molded body 71f corresponding to the first layer of the multilayer substrate is formed.
This is formed by thinning and drying the slip material in the same manner as when the protective film molded body 33 was formed. next,
As shown in FIGS. 2G and 2H, the insulating layer molded body 71f
Then, a through hole 41 for forming a via hole conductor is formed. This formation is performed by the same exposure and development processing as in the method of forming the through holes 37 in the protective film molded body 33. Next, as shown in FIG. 2I, a conductor member 43 serving as a via-hole conductor is formed by filling and drying a conductive paste, and further, as shown in FIG. Perform formation.

The insulating layer molded body 71 corresponding to the first layer
By repeating the step of forming f a desired number of times, the unfired multilayer substrate having the protective film molded body 33 formed thereon is completed. After that, the support substrate 31 is removed, and the shape is adjusted by pressing or the like as needed, or a slit for division is formed.

Finally, firing is performed. The firing step includes a binder removal step and a firing step.
° C), the organic components of the insulating layer molded product, the protective film molded product, the external connection conductor, the internal wiring pattern, and the conductor component of the via-hole conductor are eliminated. Then, the internal wiring patterns, via hole conductors, and external connection conductors are fired all together.

[0046]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Materials) First, a protective film 1 and insulating layers 7a to 7
A slip material serving as f is produced. Solvent slip material
Glass materials SiO ₂ , Al ₂ O ₃ , ZnO, Mg
70% by weight of crystallized glass powder containing O and B ₂ O ₃ as main components
A glass-ceramic powder composed of a glass material and 30% by weight of an alumina powder as a ceramic material; a polyoxyethylated trimethylolpropane triacrylate as a photocurable monomer; an alkyl methacrylate as an organic binder; And mixed with ethyl carbitol acetate as above, and kneaded with a ball mill for about 48 hours.

Also, a conductive paste to be the lower layer conductor 3, the external connection electrode 5 between the lower layer conductor 3 and an external component, the internal wiring 9, and the via hole conductor 11 is prepared. The conductive paste is composed of silver powder, which is a metal material having a low melting point and low resistance, and B powder.
₂ O ₃ —SiO ₂ —BaO glass, ethyl cellulose as an organic binder, and 2,2,4-trimethyl-1,3-pentadiol monoisobutyrate as an organic solvent are mixed and uniformly kneaded with a three-roll mill. It was produced.
(Step) The above-mentioned slip material is applied and dried on the release film of the support substrate 31 to which the release film is attached, and a protective film molded body 33 to be the protective film 1 of the lowermost conductor is formed. Was formed. Specifically, as shown in FIG. 2A, first, the step of applying and drying the above-mentioned slip material on the supporting substrate 31 by the doctor blade method is performed by the number of times shown in Table 1, and the results are shown in Table 1. Protective film molded body 3 having the thickness shown in FIG.
3 was formed. Here, as the support substrate 31, a substrate obtained by attaching a releasable PET film to a glass plate is used.
Removed before firing step. Drying condition after application is 80 ° C
For 10 minutes.

Next, a through hole 37 is formed in the protective film molded body 33.
Was done. The formation of the through hole 37 is performed by an exposure process, a development process,
The cleaning and drying were performed. Specifically, exposure processing
Is formed on the protective film molded body 33 as shown in FIG.
A photo in which the area where the through hole 37 is formed is shielded from light
The mask 35 is placed and an ultra-high pressure mercury lamp (10 mW / cm
^Two) Was used as a light source for exposure. In addition, 30 μm
The protective film molded body 33 of the order is an ultra-high pressure mercury lamp (10 mW /
cm2) for about 3 to 5 seconds to perform exposure.
it can.

The developing process is performed in the molten portion Y of the protective film molded body 33.
Was spray-developed using a triethanolamine aqueous solution as a developing solution, and a through-hole 37 was formed in the protective film molded body 33 as shown in FIG. Thereafter, unnecessary debris and the like generated by development of the protective film molded body 33 were completely removed by washing and drying processes.

Next, as shown in FIG. 2D, the above-mentioned conductive paste was filled in the through holes 37 formed in the above-mentioned steps, and dried. The external connection conductor 38 with the external component was formed by printing using a screen capable of printing only at the portion corresponding to the through hole 37, and then dried at 80 ° C. for 15 minutes.

Next, as shown in FIG. 2E, a lowermost conductor pattern 39 to be the lowermost conductor 3 was formed. It is formed by screen printing, and this is
Dried in minutes.

Next, as shown in FIG. 2 (f), the above-mentioned slip material is applied and dried on the protective film molded body 33 including the lowermost conductive pattern 39 by a doctor blade method.
An insulating layer molded body 71f constituting the lowermost insulating layer 7f in FIG. 1 was formed. Drying condition after application is 80 ℃ 3
The insulating layer molded body 71 that has been dried for 0 minutes, and has been thinned and dried.
The average thickness of f was 100 μm. The thickness variation of the insulating layer molded body 71f was measured using a contact type film thickness measuring instrument, and is shown in Table 1.

Next, through holes 41 were formed in the insulating layer molded body 71f. The formation of the through-hole 41 was performed by the same exposure processing, development processing, washing and drying processing as the through-hole 37.
Note that the insulating layer molded body 71f of about 100 μm can be exposed by irradiating it with an ultra-high pressure mercury lamp (10 mW / cm ² ) for about 5 to 10 seconds. The solubilized portion Y of the insulating layer molded body 71f is removed by spray development using an aqueous solution of triethanolamine as a developing solution, and as shown in FIG. A hole 41 was formed. After that, unnecessary scum and the like generated by development of the insulating layer molded body 71f were completely removed by a washing and drying process to form a through hole 41.

Next, filling of the through-hole 41 with the conductive paste
After drying, the conductor member 43 was formed as shown in FIG. Specifically, the through hole 41 formed in the above-described process is used.
Is filled with the conductive paste described above, dried, and
Only the portion corresponding to No. 1 was filled by printing using a printable screen, and then dried at 80 ° C. for 15 minutes.

Next, screen printing is performed in the same manner as for the lowermost layer conductor, dried at 80 ° C. for 30 minutes, and an internal wiring pattern 45 is formed as shown in FIG. Then, an insulating layer molded body 71f including the internal wiring pattern 45 was formed. The steps of FIGS. 2F to 2J were repeated the required number of times to produce a laminated molded body.

Finally, a conductive film to be the surface wiring 13 is formed by printing and drying. This is because each of the insulating layer molded bodies 71a-
71f, the internal wiring pattern to be the internal wiring 9 and the conductor film to be the surface wiring 13 when the conductive member 43 to be the via hole conductor 11 are to be fired at once.

Next, if necessary, the shape of the laminated molded product was adjusted by pressing, and the support substrate 31 to which the release film was attached was removed. Next, binder removal treatment was performed at 600 ° C., and firing was performed at a peak temperature of 900 ° C. for 30 minutes. As a result, a multilayer substrate as shown in FIG. 1 was obtained in which the internal wiring 9 and the via-hole conductor 11 were formed between the six insulating layers 7a to 7f and the surface wiring 13 was further formed.

As a comparative example, a multilayer substrate in which an insulating layer molded body was directly formed on a supporting substrate without forming a protective film molded body was manufactured, and the thickness variation of the first-layer insulating layer molded body was also measured. It was measured and described in Table 1.

[0059]

[Table 1]

According to Table 1, according to the manufacturing method of the present invention, the thickness variation of the first insulating layer molded body 71f is 7.5 μm.
m, but in the comparative example, the thickness variation was 1
It is 5 μm, which is large. Further, it can be seen that the more the number of coating and drying steps for forming the protective film molded body, the smaller the thickness variation.

[0061]

According to the present invention, it is possible to reduce the thickness variation in the lower insulating layer of the multilayer substrate, and to improve the characteristics, for example, the capacity variation when a capacitor is built in. Therefore, when the element is built in the substrate, the element characteristics can be improved in accuracy, which is useful for improving the characteristics of the high-frequency circuit, and the high-frequency module can be reduced in size and improved in performance.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a multilayer substrate obtained by a manufacturing method of the present invention.

FIG. 2 is a process chart illustrating a method for producing a multilayer substrate of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 31 ... Support substrate 33 ... Protective film molded body 71a-71f ... Insulating layer molded body 37 ... Through-hole 38 ... External connection conductor

Claims (3)

[Claims] A step of applying a slip material containing a photocurable resin and an inorganic material on a supporting substrate and repeating a step of drying at least once to produce a protective film molded body having a thickness of 10 to 50 μm; Forming a laminated molded body formed by laminating a plurality of insulating layer molded bodies containing a photocurable resin and an inorganic material on the surface of the protective film molded body; removing the support substrate; Baking the laminated molded body on which the film molded body has been formed. 2. The method according to claim 1, wherein the functional element molded body is incorporated in the laminated molded body near the protective film molded body. 3. A method comprising: exposing and developing a protective film molded body to form a through hole; and filling the through hole with a conductive paste to form an external connection conductor. The method for producing a multilayer substrate according to claim 1.