JPH0845742A - Laminated inductor substrate and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a laminated inductor substrate of a structure, wherein a magnetic material magnetic circuit member for forming the closed magnetic circuit of a coil part is formed on a laminated material integrally with the laminated material and the improvement of the characteristics of a coil and a handling of the coil are facilitated, and a method of manufacturing the laminated inductor substrate. CONSTITUTION:In a laminated inductor substrate of a structure, wherein a coil part L and a circuit part C are internally provided in a laminated material 1 consisting of insulative ceramic layers 1a to 1j, a magnetic material magnetic circuit member 6, through which the magnetic flux of the coil part L passes, is arranged on the laminated material 1 integrally with the laminated material 1. Moreover, a light-curable monomer-containing ceramic slip material is applied and dried on this member 6 to form an applied film, a magnetic material paste is filled in through recessed parts formed in the applied film by selective exposure and developing treatments to the applied film and a magnetic material film is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated inductor substrate in which a coil is provided in a laminated body made of ceramic layers and a method for manufacturing the same.

[0002]

2. Description of the Related Art A conventional laminated inductor substrate has a coil pattern formed between ceramic layers inside a laminated body of insulating ceramic layers or magnetic ceramic layers, and a layer thickness for connecting the coil patterns. A coil constituted by a via-hole conductor passing through the direction was installed. Further, generally, a desired circuit constituted by an internal wiring pattern and a via-hole conductor penetrating in the layer thickness direction for connecting between the internal wiring patterns is provided inside the laminated inductor substrate to improve the utilization efficiency of the laminated body. .

Further, in order to improve the characteristics of the coil formed on the laminated inductor substrate, a core member for securing the magnetic path of the coil has been used. In this case, a through hole is formed in the magnetic path portion of the coil on the unfired laminate substrate, and a firing process is performed to fit core members having a generally E-shaped cross section into the through holes from both main surface sides of the laminate. Was attached to the laminated body.

[0004]

However, when a core member having a generally E-shaped cross section is mounted on the laminated body, the core member projects to the main surface of the laminated body, and the laminated inductor substrate is used as a printed wiring mother board. When mounting, it was difficult to fix it.

Further, since the core member is exposed on the main surface of the laminated body, when the surface wiring pattern is formed on the main surface of the laminated body, the surface wiring pattern is restricted.

The present invention was devised in view of the above problems, and an object thereof is to integrally form a magnetic body magnetic path member for forming a magnetic path of a coil in a laminated body, An object of the present invention is to provide a laminated inductor substrate that has improved coil characteristics and is easy to handle.

Another object of the present invention is to provide a method of manufacturing a laminated inductor substrate which can easily and surely form the above-mentioned magnetic material magnetic path member in a laminated body.

[0008]

According to a first aspect of the present invention, there is provided a laminated inductor substrate having a structure in which a plurality of ceramic layers are laminated, a coil pattern formed between the ceramic layers, and a via hole conductor penetrating the ceramic layers. In a laminated inductor substrate having a coil formed of and, a magnetic body magnetic path member through which a magnetic flux of the coil passes is integrally arranged in the laminated body.

A second invention is a method of manufacturing the above-mentioned laminated inductor substrate, wherein the laminated body is formed on a supporting substrate,
(1) A step of forming a coating film by coating and drying a ceramic slip material containing a photocurable monomer, (2)
Step (3) of forming a penetrating recess at a position to be a via-hole conductor and / or a magnetic body magnetic path member by selectively exposing and developing the coating film (3) Magnetic paste to the penetrating recess to be the magnetic body magnetic path member And forming a magnetic film, (4) filling a conductive paste into the penetrating recesses to be the via-hole conductor to form a conductor, and printing the conductive paste on the coating film, This is a method of manufacturing a laminated inductor substrate, in which each step of forming a conductor film to be a coil pattern is selectively repeated to form an unfired laminated body, and the unfired laminated body is fired.

[0010]

According to the first aspect of the present invention, the coil composed of the coil pattern and the via-hole conductor is arranged in the laminated body formed by laminating the ceramic layers, and the magnetic body magnetic path constituting the magnetic path of the coil. Since the members are arranged, the characteristics of the coil can be improved. Moreover, since the leakage magnetic flux can be reduced, for example, when the internal wiring pattern is arranged in the laminated body, it is possible to prevent the circuit from being adversely affected by the leakage magnetic flux.

Moreover, since the magnetic material magnetic path member is arranged in the laminated body, the magnetic material magnetic path member does not protrude at least from the main surface of the laminated body, which is very suitable for mounting on the printed wiring mother board. It can be installed easily and stably. Further, when the surface wiring pattern is formed on the surface, the degree of freedom of the surface wiring pattern can be improved.

Further, according to the second invention, the coating film to be the ceramic layer is formed of the slip material containing the photo-curable monomer, and becomes the via-hole conductor and the magnetic material magnetic path member for forming the coil. At the position, a through recess is formed by a selective exposure process and a development process, and a conductor serving as a via hole conductor for forming a coil is formed by filling the through recess with a conductive paste. The magnetic member is formed by filling the penetrating recess with the magnetic paste, and the conductor film serving as the coil pattern is formed by printing the conductive paste on the coating film.

That is, the core, which serves as the magnetic path for the magnetic flux of the coil,
It can be formed by a step of laminating a laminated body in which the magnetic material paste is filled in the penetrating recess formed by the selective exposure treatment and development treatment of the coating film. In addition, since the through recesses and the filling of the paste into the through recesses are substantially the same as the essential steps for forming the coil, the number of steps is not extremely increased, and the magnetic flux can be easily and reliably provided in the laminated body. A road member can be formed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The laminated inductor substrate of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view of a laminated inductor substrate of the first invention. It should be noted that, in the embodiment, a laminated inductor substrate will be described in which a circuit portion having an internal wiring pattern, a surface wiring pattern, and a via-hole conductor connecting them is simultaneously arranged in a laminated body.

In FIG. 1, a laminated inductor substrate 10 is shown.
Is mainly composed of, for example, a laminated body 1 of 10 layers of 10 ceramic layers 1a to 1j, and surface wiring including terminal electrodes and connection pads on the main surface of the laminated body 1 as necessary. The pattern 7 and chip-shaped electronic components, lead-type electronic components, electronic components 8 such as IC chips are mounted.

The ceramic layers 1a to 1j are made of alumina, an insulating ceramic containing a glass component added as necessary, and the like, and the coil patterns 2e to 2g (collectively referred to as "collectively". 2 ”), via-hole conductors 3e to 3g (collectively referred to as“ 3 ”) penetrating the layer thicknesses of the ceramic layers 1e to 1g are respectively formed, whereby the coil portion L is internally provided in the laminated body 1. Will be done.

Further, the laminated body 1 is formed with a magnetic body magnetic path member 6 for securing a magnetic path of the coil portion L.
The magnetic body magnetic path member 6 includes a coil central shaft portion 6a that penetrates a substantially central portion of the coil portion L, upper and lower surface portions 6b and 6c that are planarly arranged above and below the coil portion L, and a peripheral portion surrounding the coil portion L. It consists of 6d. For example, the central axis portion 6a and the peripheral portion 6d of the magnetic body magnetic path member 6 are formed so as to penetrate through the ceramic layers 1d to 1g in the thickness direction, and the upper and lower surface portions 6b and 6c correspond to the ceramic layers 1c and 1h. It is formed in the part to be.

Further, each ceramic layer 1a and 1 of the laminated body 1
b, 1b and 1c ... 1i and 1j, internal wiring patterns 4b to 4j (collectively referred to as “4”) are arranged, and the thickness of each ceramic layer 1a to 1j is different. ,
Via hole conductors 5a to 5 for connecting the internal wiring patterns 4b to 4j to each other and between the internal wiring patterns 4 and the internal wiring patterns 4b and 4j to the surface wiring pattern 7.
j (collectively referred to as “5”) is formed. As a result, the wiring conductor of the predetermined circuit portion C including the internal wiring pattern 4 and the via-hole conductor 5 is formed inside the laminated body 1 together with the surface wiring pattern 7.

Further, the predetermined circuit portion C and the coil portion L are connected, for example, one end of the coil pattern 2d constituting the coil L and the internal wiring pattern 4d are connected to each other, and the coil pattern 2g is connected. The via-hole conductor 3h extending from the other end and the internal wiring pattern 4i are connected to each other.

Here, each pattern between the ceramic layers 1e and 1f will be described with reference to FIG. 2. Each pattern on the ceramic layer 1f has a coil portion L and a circuit portion C, and the coil portion L is For example, the coil pattern 2f having 1.5 turns and the magnetic body magnetic path member 6 (the central shaft portion 6a and the peripheral portion 6d) are formed. The central shaft portion 6a and the peripheral portion 6d both penetrate the entire thickness of the ceramic layer 1f and are integrated with the magnetic material magnetic path member 6 of the lower ceramic layers 1e and 1g. Also, the coil pattern 2f
Is connected to the via-hole conductor 3e of the ceramic layer 1e at one end, and the other end is connected to the ceramic layer 1e.
A via-hole conductor 3f is formed to penetrate the thickness of f.

Further, except for the area surrounded by the magnetic body magnetic path member 6, the predetermined internal wiring pattern 4 constituting the circuit portion C is formed.
f is formed. A via hole conductor 5f penetrating the thickness of the ceramic layer 1f is formed at a predetermined position of the internal wiring pattern 4f and is connected to the internal wiring pattern 4e formed between the ceramics 1f and 1e.

As described above, in the coil portion L, the internal wiring pattern 2d of the circuit portion C is connected to one end of the coil pattern 2e arranged in the ceramic layers 1d and 1e, and the other end of the coil pattern 2e is connected. , A via hole conductor 3e penetrating the ceramic layer 1e is connected to one end of a coil pattern 2f arranged in the ceramic layers 1e and 1f, and the other end of the coil pattern 2f is formed by a via hole conductor 3f penetrating the ceramic layer 1f. And 1g are connected to one end of the coil pattern 2g, and the other end of the coil pattern 2g is connected to the internal wiring pattern 4i via the via-hole conductor 3g.

As a result, the coil portion L having a predetermined number of turns is arranged between the internal wiring pattern 4d and the internal wiring pattern 4i.

Here, a characteristic of the present invention is that the magnetic body magnetic path member 6 for ensuring the magnetic path of the coil portion L including the coil pattern 2 and the via-hole conductor 3 is formed in the laminated body 1. That is.

Therefore, the coil portion L can achieve a high inductance, and the characteristics of the coil can be improved.

Further, since the magnetic body magnetic path member 6 does not project on the surface of the laminated body 1, the laminated inductor substrate 10
When mounted on a printed wiring board (not shown), it can be mounted stably and easily. For example, when the surface wiring pattern 7 is formed on the surface of the laminated body 1 or the electronic component 8 is mounted. However, it can be performed very easily, the degree of freedom in designing the surface wiring pattern 7 is improved, and the density can be increased.

Furthermore, when the circuit portion C is incorporated in the laminated body 1, the magnetic flux path member 6 can suppress the magnetic flux leakage, so that unnecessary magnetic flux is not given to the circuit portion C and the circuit operation is prevented. It can also be stabilized.

Further, a magnetic material magnetic path member 6 made of a magnetic material is arranged only in the magnetic path portion of the coil portion L,
Since the entire laminated body 1 can be substantially composed of an insulating ceramic material, a laminated body excellent in insulation characteristics and strength can be formed.

Next, a method of manufacturing such a laminated inductor substrate will be described with reference to FIGS. As a general manufacturing method, a step of (1) applying and drying a ceramic slip material containing a photocurable monomer on a supporting substrate to form a coating film (2) selectively exposing the coating film to light A step of forming through recesses at positions to be via-hole conductors and magnetic body magnetic path members by development processing (3) Filling the through recesses to be the magnetic body magnetic path members with a magnetic paste to form a magnetic film. Step (4) A conductive paste is filled in the penetrating recesses to be the via-hole conductors to form a conductor, and the conductive paste is printed on the coating film to form a conductor film to be a coil pattern and an internal wiring pattern. Step (1) of
Each step (4) is selectively repeated to form an unbaked laminate, and the unbaked laminate is baked.

However, the laminated inductor substrate is the laminated body 1
Since it is common to form the circuit portion C inside and on the surface, a method of manufacturing a laminated inductor substrate including this circuit portion C will be described.

[Supporting Substrate] For example, as shown in FIG. 3, the supporting substrate has a substrate smoothing layer 16 formed on the surface of the substrate 15 such as ceramic, glass, or heat-resistant resin on the side of lamination.

The substrate smoothing layer 16 is formed by coating and drying a slip material obtained by homogeneously kneading a photo-curable monomer, a binder, and a solvent to form a coating film, and then exposing and curing the entire surface of the coating film. To form. The thickness of the substrate smoothing layer 16 is at least thick enough to absorb the irregularities of the supporting substrate 15, for example, 20 μm or more. The smoothing layer 16 absorbs irregularities on the surface of the substrate 15 to flatten the surface of the laminated body 1 and uniformize the thickness of the first-layer coating film on the side in contact with the substrate 15, It is intended to even out the shrinkage during firing in the firing stage.

A heating foam material may be contained in the smooth layer 16 so that the laminate can be easily peeled from the support substrate 15 by, for example, performing a foaming reaction at a drying treatment temperature described later or higher.

Here, the photo-curable monomer has excellent thermal decomposability so that it can be burnt out at a relatively low temperature and in a short-time firing step, and it is exposed by exposure after coating and drying of the slip material. It is necessary to photopolymerize, free radical formation, chain growth addition polymerization are possible, and a monomer having a secondary or tertiary carbon is preferable, for example, butyl acrylate having at least one polymerizable ethylene group. Alkyl acrylates and their corresponding alkyl methacrylates are effective. In addition, polyethylene glycol diacrylates such as tetraethylene glycol diacrylate and methacrylates corresponding to them can be mentioned.

The binder must have good thermal decomposability as well as the photocurable monomer. At the same time, an ethylenically unsaturated compound having a carboxyl group or an alcoholic hydroxyl group, such as an acrylic acid or methacrylic acid polymer, is preferable because it determines the viscosity of the slip.

The photo-curable monomer and the binder are added in a ratio of 1 to 3: 5.

As the solvent, an organic solvent or an aqueous solvent can be used. In the case of an aqueous solvent, the photo-curable monomer and binder need to be water-soluble, and a hydrophilic functional group such as a carboxyl group is added to the monomer and binder. The amount of addition is 2 to 300, preferably 5 to 100, when expressed by acid value.

In the above-mentioned slip material, the photo-curable monomer and binder must be completely decomposed by heat during the firing of the laminate as described above, but especially 600 ° C. or lower, preferably 500 ° C. or lower. Select the material to be decomposed with.

Further, a sensitizer, a photoinitiating material, etc. may be added to the slip material as required. For example, examples of the photoinitiator-based material include benzophenones and acyloin ester compounds.

As a method of applying the slip material, for example,
A doctor blade method (knife coating method), a roll coating method, a printing method and the like can be mentioned. In particular, a doctor blade method or the like is preferable because the surface of the substrate smoothing layer 16 can be easily flattened. The amount of the solvent added is adjusted according to the coating method to adjust the viscosity to a predetermined value.

As a drying method, a batch-type drying furnace or an in-line-type drying furnace is used, and the drying condition is 120 ° C.
The following is desirable. Further, since rapid drying may cause cracks on the surface, it is important to avoid rapid heating.

The exposure treatment is a negative type in which the photocurable monomer contained in the coating film is photopolymerized,
The entire surface of the coating film is exposed to low-pressure, high-pressure, and ultra-high-pressure mercury lamp exposure light. The exposure conditions are such that the exposure light of 10 to ²⁰ mW / cm ² is irradiated for about 5 to 30 seconds. This allows
The coating film causes a photopolymerization reaction of a photocurable monomer,
It will be photo-cured.

Even if the smooth layer 16 is attached to the laminate, it will be burned out by the firing process.

[Ceramic Coating Film] The ceramic coating film is formed by coating a ceramic slip material on the support substrate or the coating film formed in the steps up to that point and drying.

The ceramic slip material is formed by homogeneously kneading a ceramic powder, a glass frit, a photocurable monomer, a binder and a solvent, if necessary.

Examples of the ceramic powder include insulating ceramic materials such as cristobalite, quartz, corundum (α-alumina), mullite and cordierite. The average particle size thereof is 1.0 to 6.0 μm, preferably 1.5 to 4 0.0μ
What is crushed to m is used.

The ceramic materials may be used as a mixture of two or more kinds. In particular, the use of corundum is advantageous in terms of cost.

The glass frit is a glass frit as long as it crystallizes cordierite, mullite, anorthite, sergian, spinel, garnite, willemite, dolomite, petalite or a derivative thereof or a spinel structure crystal phase by firing treatment. Well, for example, B ₂ O
Examples thereof include glass frits containing ₃ , SiO ₂ , Al ₂ O ₃ , ZnO and alkaline earth oxides. Such a glass frit has a wide vitrification range and a yield point of 600 to
This is because the temperature is around 800 ° C., so that it is suitable for low-temperature firing at about 850 to 1050 ° C., and the sintering behavior with the conductor film to be the internal wiring pattern 2 is similar. The average particle size of the glass frit is 1.0 to 6.0 μm, preferably 1.5 to 3.5 μm.

The composition ratio of the above-mentioned ceramic material and glass material is such that when firing at a relatively low temperature of 850 to 1050 ° C., the ceramic material is 10 to 60 wt%, preferably 30 to 50 wt%. Is 90-40
wt%, preferably 70 to 50 wt%.

The photocurable monomer is used for the substrate smoothing layer 16
The materials used for can be used. This is to make the exposure conditions substantially the same. The photocurable monomer is added in a predetermined amount so that the portion other than the exposed portion can be easily removed by the developing treatment after the exposure treatment. For example, 5 to 15w for solid components (ceramic material and glass material)
It is t% or less. It is also necessary to give importance to the wettability with the solid content as the binder, and the material used for the substrate smoothing layer 16 can be used. 25 wt% based on solid content
The following are preferred.

As the solvent, an organic solvent or an aqueous solvent can be used. In the case of an aqueous solvent, the photo-curable monomer and binder need to be water-soluble, and a hydrophilic functional group such as a carboxyl group is added to the monomer and binder. The added amount is 2 to 300, preferably 5 to 100 when expressed in terms of acid value.

When the addition amount is small, the solubility in water and the dispersibility of the powder of the fixed component are poor, and when the addition amount is large, the thermal decomposability is poor. Therefore, the addition amount is the solubility and dispersibility in water, Considering the thermal decomposability, it is appropriately added within the above range.

Further, a sensitizer, a photo-initiating material and the like may be added to the slip material, if necessary. For example, examples of the photoinitiator-based material include benzophenones and acyloin ester compounds.

As a coating method for coating such a ceramic slip material, as described above, for example, a doctor blade method (knife coating method), a roll coating method, a printing method and the like can be mentioned. In particular, a doctor blade method or the like, which makes it easy to flatten the surface of the coating film, is suitable.

As a drying method, a batch type drying oven or an in-line type drying oven is used, and the drying condition is 120 ° C.
The following is desirable. Further, rapid drying may cause cracks on the surface of the coating film, so it is important to avoid rapid heating.

[Through Penetration Recesses That Become Via-Hole Conductor and Magnetic Magnetic Path Member] The penetrating recesses are, for example, formed on the support substrate 15 and the coating film formed over the entire surface of the coating film located below.
Penetrating recesses are formed at the positions to be the via-hole conductors 3 and 5 and the magnetic body magnetic path member 6. Specifically, it is formed by selective exposure processing and development processing.

As shown in FIG. 4 (a), the selective exposure process is carried out, for example, on the coating film 10f which is baked to form the ceramic layer 1f, and the via hole conductors 3 and 5 and the magnetic material magnetic path member 6 are formed. The photo target 45 having a shape that blocks the exposure only at the positions where the through recesses 30, 50, 60 are formed.
Placed or placed close to each other, as shown in FIG.
As shown in, the exposure light X is irradiated through the photo target 45. The exposure conditions are such that low-pressure, high-pressure, and ultra-high-pressure mercury lamp-based exposure light is applied at, for example, 10 to 20 mW / cm ² for about 5 to 30 seconds.

As a result, the coating film 1 irradiated with the exposure light
Portions 30 ', 5 that will become 0f through recesses 30, 50, 60
The portions other than 0 ′ and 60 ′ cause a photopolymerization reaction of the photocurable monomer, and the coating film 10f is selectively photocured.

The developing treatment is performed by using a developing solution to form the coating film 10
This is a process of removing a portion which is not photo-cured in f.
Specifically, as shown in FIG. 4C, the phototarget 45 is removed from the coating film 10f, and a developing solvent such as organic chlorocene, 1,1,1-trichloroethane, or an alkaline water solvent is removed. Is sprayed, brought into contact with, or dipped by, for example, a spray developing method or a paddle developing method. Then, if necessary, washing and drying are performed. As a result, only the unexposed portion of the coating film 10f is removed, and the via-hole conductors 3 and 5 and the magnetic body magnetic path member 6 are removed.
Through recesses 30, 50, 60 are formed.

The shape of the penetrating recesses 30, 50, 60 formed by the above-described selective exposure processing / development processing is substantially determined by the pattern accuracy of the photo target 45. Moreover, this exposure processing / development processing is
It is used for wiring processing of semiconductor chips,
Very fine and highly accurate processing becomes possible. That is,
This means that the shapes of the via-hole conductors 3 and 5 and the magnetic body magnetic path member 6 can be increased depending on the amount of current and the amount of magnetic flux flowing therethrough, which means that loss due to conductor resistance is reduced. Further, since the formation positions of the through recesses 30, 50, 60 are also determined by the alignment accuracy of the photo target 45, this also enables highly accurate processing. That is, it means that the connection reliability of the via-hole conductors 3 and 5 is improved and the lamination reliability of the magnetic body magnetic path member 6 is improved.

[Magnetic Material Portion as Magnetic Body Magnetic Path Member] The magnetic body film 61 serving as the magnetic body magnetic path member 6 includes the central shaft portion 6a, the upper and lower surface portions 6b and 6c, and the peripheral portion 6d) formed on the coating film. Through recess 60 (through recess serving as the magnetic flux path member 6)
Then, the magnetic paste is selectively filled and dried.

The magnetic paste is a powder of a magnetic ceramic material such as Ni-Zn ferrite and Mn-Zn ferrite (which is called ceramic in a broad sense), if necessary, a glass frit, a binder, a solvent, and optionally a light. It is formed by homogeneously kneading a curable monomer, and has an average particle size of magnetic ceramic powder of 1.0 to 6.0 μm.
m, preferably 1.5 to 4.0 μm. Also,
Although the glass frit should be omitted in terms of characteristics, it may be contained in a predetermined amount in order to approximate the sintering behavior to that of a coating film or the like.

As for the filling method, since the penetrating recess 60 is filled, it can be carried out by a selective screen printing method or an injection method using a dispenser. Further, after the photo-curable monomer is contained in the magnetic paste and the magnetic coating film is formed on the entire surface of the coating film including all the through recesses 30, 50 and 60 by the doctor blade method or the like, the magnetic magnetic path member is formed. It is also possible that only the magnetic material coating film filled in the penetrating recesses 60 to be 6 is photo-cured by the above-described selective exposure method, and the other portions of the magnetic material coating film are removed by the development process.

[Conductor to be via-hole conductor] The conductors to be the via-hole conductors 3 and 5 are the through recesses 3 formed in the coating film.
It is formed by selectively filling conductive paste in conductive pastes 0 and 50 (through concave portions that become via-hole conductors).

The conductive paste is Ag-based (Ag simple substance, A
Conductive material powder such as Ag alloy such as g-Pd), Cu-based (Cu simple substance, Cu alloy), for example, silver-based powder, low melting point glass component, binder, solvent, and optionally a photocurable monomer. It is formed by homogeneously kneading and. As for the filling method, since the penetrating recesses 30 and 50 are filled, it can be performed by a selective screen printing method or an injection method using a dispenser. When the filling is performed by the selective screen printing method, it is desirable that the filling is performed at the same time as the conductor film to be the internal wiring pattern 4 and the coil pattern 2 described below.

[Conductor Film to be Coil Pattern and Internal Wiring Pattern] Coil Pattern 2 and Internal Wiring Pattern 4
The conductor film to be formed is formed on the ceramic coating film in a predetermined pattern by using the above-mentioned conductive paste. At this time, a conductor which becomes the via-hole conductor 3 may be simultaneously formed.

As a forming method, a screen capable of printing a predetermined shape is used for screen printing. Further, it is desirable that the above-mentioned conductive paste contains a photocurable monomer. This is to perform photo-curing under the above-mentioned exposure conditions after forming the conductor film to be the coil pattern 2 and the internal wiring pattern 4 having a predetermined shape. In this way, the surface of the conductor film is coated with the ceramic slip material. A coating film is formed, a through recess is further formed, and the coil pattern 2 and the internal wiring pattern 4 exposed from the through recess are formed.
This is because even if the conductor film to be exposed is exposed, it will not be attacked by the developing solution.

As another forming method, a photo-curable monomer is contained in a conductive paste, and a conductor coating film is formed by coating or printing on the entire surface of the coating film or a rough shape including a predetermined pattern. After that, the conductor film may be photo-cured so as to have a predetermined shape by a selective exposure process, and the unnecessary conductor film may be removed by a development process. According to this, the coil pattern 2 and the internal wiring pattern 4 can be finely processed, and erosion by the developing solution used in the above-mentioned post-process does not occur at all.

Next, the entire process of forming the laminated inductor substrate will be described with reference to the process diagram of FIG. 5 and the schematic sectional views in the main processes of FIGS. 6 to 27.

[Preparation Step] First, as the step of FIG. 5A, the support substrate 15 on which the smooth layer 16 is formed, the ceramic slip material, the magnetic paste, and the conductive paste are prepared.

[Laminating Step] (Circuit Part C Only) Next, as the step of FIG.
As shown in FIG. 6, a coating film 10j to be the ceramic layer 1j is formed on the smoothing layer 16 of the support substrate 15.

Next, as a step of FIG. 5C, as shown in FIG. 7, a penetrating recess 50 to be the via-hole conductor 5g is formed in the coating film 10j.

Then, in the step of FIG. 5D, as shown in FIG. 8, the through hole 50 of the coating film 10j is filled with the conductor 51 to be the via-hole conductor 5j, and the coating film 10j is formed on the coating film 10j. A conductor film 40 to be the internal wiring pattern 4j between the ceramic layers 1i and 1j is formed.

Next, the steps of (b) to (d) of FIG. 5 are repeated to form a coating film 10i on the coating film 10j, and a conductor which becomes a via-hole conductor 5i in the thickness direction of the coating film 10i. 51 is formed, and the conductor film 40 to be the internal wiring pattern 4i is formed.

Next, as a step of FIG. 5E, as shown in FIG. 9, a coating film 10h is formed on the coating film 10i.

(Circuit portion C and coil portion L are provided in parallel) Next, as the step of FIG. 5F, as shown in FIG.
The via-hole conductor 5 and the magnetic body magnetic path member 6 are formed on the coating film 10h.
Through recesses 50 and 60 are formed.

Next, as a step of FIG.
As shown in FIG.
Then, the magnetic paste is selectively printed or applied (including selective exposure and development) to form the magnetic film 61.

Next, as a step of FIG.
As shown in, while filling the through recess 50 which becomes the via-hole conductor 5 with the conductor 51 which becomes the via-hole conductor 5,
On the coating film 10h, the conductor film 40 to be the internal wiring pattern 4h between the ceramic layers 1h and 1i is formed.

Next, as a step of (i) of FIG.
As shown in, a coating film g is formed on the coating film 10h.

Next, as a step of FIG.
As shown in FIG.
5. Penetrating recesses 30, 50, 60 which become the magnetic body magnetic path member 6
To form.

Next, as a step of FIG.
As shown in FIG.
Then, the magnetic paste is selectively printed or applied (including selective exposure and development) to form the magnetic film 61.

Next, as a step of (l) of FIG.
As shown in FIG.
0 and 50 are filled with the conductors to be the via-hole conductors 3 and 5, and the ceramic layers 1i and 1g are formed on the coating film 10g.
Conductor films 20 and 40 that will become the coil pattern 2g between them and the internal wiring pattern 4g are formed.

Next, the steps (i) to (l) of FIG. 5 are repeated to form the coating film 10f on the coating film 10g, and further, the via-hole conductor 3f, in the thickness direction of the coating film 10f.
Coil pattern 2 is formed by forming conductors 31 and 51 to be 5f.
f, the conductor films 20 and 40 to be the internal wiring patterns 4f are formed, the coating film 10e is further formed, and the conductors 31 and 51 to be the via hole conductors 3e and 5e are further formed in the thickness direction of the coating film 10e, The conductor films 20 and 40 to be the coil pattern 2e and the internal wiring pattern 4e are formed, and further, the coating film 10d is further formed, and the coating film 1 is further formed.
The conductors 31 and 51 to be the via-hole conductors 3d and 5d are formed in the thickness direction of 0d, and the conductor films 20 and 40 to be the coil pattern 2d and the internal wiring pattern 4d are formed. This state is shown in FIG.

Next, as a step of FIG.
As shown in, the coating film c is formed on the coating film 10d.

Next, as a step (n) of FIG.
As shown in FIG.
Through penetrating recesses 50 and 60 to be the magnetic body magnetic path member 6 are formed.

Next, as a step (o) in FIG.
As shown in FIG.
Then, the magnetic paste is selectively printed or applied (including selective exposure and development) to form the magnetic film 61.

Next, as a step of (p) of FIG.
As shown in FIG. 5, the through-hole recess 50 serving as the via-hole conductor 5 is filled with the conductor serving as the via-hole conductor 5, and the conductor film 40 serving as the internal wiring pattern 4c between the ceramic layers 1b and 1c is formed on the coating film 10c. Form.

(Circuit portion C only) Next, as a step (q) in FIG. 5, a coating film b is formed on the coating film 10c as shown in FIG.

Next, as a step of (r) of FIG.
As shown in FIG. 5, the through-hole recess 50 to be the via-hole conductor 5b is formed in the coating film 10b.

Next, as a step (s) of FIG.
As shown in FIG.
Is filled with a conductor to be the via-hole conductor 5, and a conductor film 40 to be the internal wiring pattern 4b between the ceramic layers 1a and 1b is formed on the coating film 10b.

Next, the steps of (q) to (s) of FIG. 5 are repeated to form the coating film 1a on the coating film 10b and form the through recess 50 to be the via-hole conductor 5a. Fill the conductor.

With the above, the laminating step is completed, and as shown in FIG. 25, the unfired laminated body 1 including the smoothing layer 16 is achieved on the supporting substrate 15.

[Peeling Step] Next, FIG. 5B to FIG. 5S
The laminated body formed on the support substrate 15 in the step of is processed from the support substrate 15 to the substrate smoothing layer 16 in the step of (t) of FIG.
Containing ceramic coating films 10a to 10j, the conductor film 20 serving as the coil pattern 2, the conductor film 40 serving as the internal wiring pattern 4, and the conductors 31, 5 serving as the via-hole conductors 3 and 5.
1. The laminated body made of the magnetic film 61 which becomes the magnetic flux path member 6 is peeled off.

As described above, the peeling interface serves as an interface between the supporting substrate 15 and the substrate smoothing layer 16, and the substrate smoothing layer 16 exists on the laminate side. Therefore, peeling is mechanically
For example, even if the support substrate 15 is curved or the cutter blade is slid on the peeling interface in a planar manner, the laminate itself is not adversely affected (cracks due to peeling, etc.) and can be stably peeled.

Prior to the peeling process, individual laminated inductor substrates can be extracted on the main surface of the laminated body.
You may form a dividing groove.

[Firing Step] Next, as a step of FIG. 5 (u), as shown in FIG. 26, the substrate smoothing layer 16, the ceramic coating films 10a to 10j, the conductor film 20 serving as the coil pattern 2, and the internal wiring pattern 4 are formed. Then, the laminated body including the conductor film 40, the conductors 31 and 51 to be the via-hole conductors 3 and 5, and the magnetic film 61 to be the magnetic body magnetic path member 6 is fired.

Specifically, the firing process includes a binder removal process and a sintering process. In particular, the conductor films 20 and 40 and the conductor 3 are
The firing atmosphere differs depending on the material such as 1 and 51, and further, the sintering peak temperature varies depending on the sintering behavior of the material such as the ceramic coating films 10a to 10j, the conductor films 20 and 40, and the conductors 31 and 51. .

For example, in the binder removal process, the ceramic coating films 10a to 10j, the magnetic film 61, the conductor films 20 and 4 are used.
0, to remove the organic components contained in the conductors 31 and 51, and to burn off the substrate smoothing layer 16, for example, in a temperature range of 600 ° C. or lower.

[0100] Further, in the sintering process, the ceramic coating film 10
a to 10j, a glass component is interposed around the ceramic powder of the magnetic film 61 to give a predetermined strength to the laminated body,
The metal powder of the conductor films 20, 40 and the conductors 31, 51 is grown to reduce the resistance, and the peak temperature is 850.
It is performed in a temperature range reaching to 1050 ° C.

The firing atmosphere is an atmospheric (oxidizing) atmosphere or a neutral atmosphere when Ag or Au is used as the metal material of the conductive paste, and a reducing atmosphere when Cu is used. Or it is performed in a neutral atmosphere.

As a result, the ceramic coating films 10a-1
0j is the ceramic layers 1a to 1j, the conductor film 20 is the coil pattern 2, the conductor film 40 is the internal wiring pattern 4, and the conductors 31 and 51 are the via-hole conductors 3, respectively.
5, the magnetic film 61 becomes the magnetic flux path member 6.

[Surface Treatment Step] Next, as a step (u) of FIG. 5, as shown in FIG. 27, surface treatment is performed on both main surfaces of the large-sized laminate substrate that has been subjected to the firing treatment.

For example, the surface wiring pattern 7 is formed on both main surfaces of the large-sized laminated substrate by printing, drying, and baking of a copper-based conductive paste so as to be connected to the via-hole conductors 3 formed in the ceramic layer 1a. To do. Here, the copper-based surface wiring pattern 7 is joined to the via-hole conductor 5a of the silver-based conductor, but the surface wiring pattern 7 is burned at a low temperature in consideration of the eutectic temperature of silver and copper ( 600 ~
It is important to use a Cu-based conductive paste for 780 ° C.) in a reducing atmosphere or a neutral atmosphere. Then, if necessary, a thick film resistance film, a protective film, or the like is formed, and various electronic components 8 are mounted.

Thereafter, the large-sized laminate substrate is divided into laminates having a predetermined shape along the dividing grooves formed before firing. As a result, the laminated inductor substrate having the structure shown in FIG. 1 is completed.

According to the above manufacturing method, the coil pattern 2 and the via-hole conductor 3 which will be the coil portion L are formed simultaneously with the internal wiring pattern 4 and the via-hole conductor 5, and the coil portion L and the circuit are provided inside the laminated body 1. The portion C can be easily formed, and the coil portion L
The magnetic body magnetic path member 6 through which the magnetic flux generated in 1 passes can also be formed in the laminating process and can be installed inside the laminated body 1 to easily form the coil portion L having improved characteristics by the magnetic body magnetic path member 6. It is possible to easily form a laminated inductor substrate that can be connected to the internal wiring pattern 4 or the like that constitutes the circuit portion C, is densely wired, and is wholly compact.

Since the shape of the via-hole conductors 3 and 5 is controlled by the pattern of the photo target 45 used for the selective exposure process applied to the ceramic coating films 10e to 10g, it can be an arbitrary shape. Therefore, the shape can be arbitrarily set according to the current flowing through the via-hole conductors 3 and 5, and the coil portion L and the circuit portion C with a small conductor loss can be formed. Further, since the formation positions of the via hole conductors 3 and 5 are determined only by the position control of the photo target 45, the connection reliability of the coil pattern 2 and the internal wiring pattern 4 that are connected to each other via the via hole conductors 3 and 5 is also high. Greatly improved.

In the magnetic body magnetic path member 6, the through-hole recess 60 formed by the selective exposure treatment / development treatment of the ceramic coating films 10c to 10h is formed by filling the magnetic body paste. In forming the magnetic path member 6, for example, it is easy to arbitrarily set the shape without distinguishing the upper and lower members, the peripheral member, the central member, and the like. Moreover, the ceramic coating films 10c-1
Since it is integrally fired with 0 h, it is firmly integrated in the laminated body 1, and thus the through hole formed in the unfired substrate (the shape of the through hole is changed by sintering is changed as in the conventional case. ), There is no need to insert it, and its formation is greatly improved.

Further, in the ceramic coating films 10a to 10j, the ceramic coating films 10a to 1j are formed on the entire surface of the support substrate 15 and the lower ceramic coating films 10b to 10j by a doctor blade method or the like.
Since 0j is formed, the surfaces of the applied coating films 10a to 10j are always uniform, and the control of the thickness thereof is extremely easy. This is because the coil pattern 2 formed on the coating films 10a to 10j, the conductor films 20 and 40 that will become the internal wiring patterns 4, the surface wiring pattern 7, the thick film resistor film, and the electronic parts after firing are formed. The mounting is stable, and even if the number of stacked layers increases, no stacking distortion occurs. In addition, since the thickness of each of the coating films 10a to 10 is uniform, when the exposure process is performed, the exposure process can be stably performed under uniform conditions.

In the manufacturing process described above, the surface wiring pattern 7 was formed in the step (v) of FIG. 5, but the surface wiring pattern 7 is formed by forming a conductor film on the surface of the unfired laminated body and laminating it. The body may be fired at the same time. Further, only the surface wiring pattern 7 on the one main surface side may be formed at the beginning of the laminating process. When the conductor film to be the surface wiring pattern 7 is dried in this way, the surface of the conductor tends to be dented, but the dented surface is on the inner side of the laminated body, and the surface of the surface wiring pattern 7 and the laminated body 1 are The surface can be made uniform. Therefore, when the thick film resistor film is formed, step disconnection does not occur at a portion connected to the surface wiring pattern 7, and the electronic component 8 can be stably mounted. When a bonding thin wire is applied, it can be formed in an area necessary for wire bonding.

Further, the formation of the dividing groove and the dividing treatment performed along the dividing groove can be arbitrarily performed in the surface structure of each laminated inductor substrate.

In the above-mentioned embodiment, a laminated body composed of 10 ceramic layers is taken as an example, but the number of laminated layers can be arbitrarily changed depending on the shape of the coil portion L and the configuration of the circuit portion C. . Further, although the magnetic body magnetic path member 6 is not exposed in the laminated body 1, it may be exposed from the magnetic body magnetic path member 6 if the high density of the surface wiring pattern 7 is not required. . Furthermore, in the laminated body 1,
Although only 10 coil portions L are formed, a plurality of coil portions L may be formed and the magnetic body magnetic path member 6 may be formed in each of them. Alternatively, a plurality of coil portions L may be formed and a common coil portion L may be formed. The magnetic body magnetic path member 6 may be formed to be a transformer component.

Further, in the embodiment, the laminated inductor substrate in which the circuit portion C is arranged is used, but the laminated inductor substrate in which the circuit portion C is omitted and only the coil component L is formed may be used.

[0114]

As described above, according to the present invention, the coil composed of the coil pattern and the via-hole conductor is arranged in the laminated body formed by laminating the ceramic layers, and the closed magnetic circuit of the coil is constituted. Since the magnetic body magnetic path member is arranged, the characteristics of the coil can be improved. Moreover, since the leakage flux can be reduced,
For example, when arranging the internal wiring pattern in the stack,
It is also possible to prevent the adverse effect on the circuit due to the leakage magnetic flux.

However, since the magnetic material magnetic path member is arranged in the laminated body, the magnetic material magnetic path member does not protrude at least from the main surface of the laminated body, which is very difficult when mounted on the printed wiring mother board. It can be installed easily and stably.

Further, according to the second aspect of the invention, the magnetic body magnetic path member, which serves as a closed magnetic circuit circuit for the magnetic flux of the coil, has a magnetic body inside the through recess formed by selective exposure and development of the coating film. It can be formed in the lamination process of filling the paste, and since this through recess is an indispensable process for forming the via-hole conductor, it does not increase the number of processes extremely and is easy and reliable. Can be formed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a laminated inductor substrate of the present invention.

FIG. 2 is a schematic plan view for explaining a pattern between predetermined ceramic layers in the laminated inductor substrate of the present invention.

FIG. 3 is a schematic cross-sectional view of a supporting substrate used in the method for manufacturing a laminated inductor substrate of the present invention.

4A to 4C are views for explaining selective exposure processing / development processing used in the method for manufacturing a laminated inductor substrate according to the present invention.

FIG. 5 is a process drawing for explaining the manufacturing method of the laminated inductor substrate of the present invention.

FIG. 6 is a cross-sectional view in the main surface process of the method for manufacturing a laminated inductor substrate according to the present invention.

FIG. 7 is a cross-sectional view in the main surface process of the method for manufacturing a laminated inductor substrate according to the present invention.

FIG. 8 is a cross-sectional view in the main surface process of the method for manufacturing a laminated inductor substrate according to the present invention.

FIG. 9 is a cross-sectional view in the main surface process of the method for manufacturing a laminated inductor substrate according to the present invention.

FIG. 10 is a cross-sectional view in the main surface process of the method for manufacturing a laminated inductor substrate according to the present invention.

FIG. 11 is a cross-sectional view in the main surface step of the method for manufacturing a laminated inductor substrate according to the present invention.

FIG. 12 is a cross-sectional view in the main surface process of the method for manufacturing a laminated inductor substrate according to the present invention.

FIG. 13 is a cross-sectional view in the main surface process of the method for manufacturing a laminated inductor substrate according to the present invention.

FIG. 14 is a cross-sectional view in the main surface process of the method for manufacturing a laminated inductor substrate according to the present invention.

FIG. 15 is a cross-sectional view in the main surface step of the method for manufacturing the laminated inductor substrate of the present invention.

FIG. 16 is a cross-sectional view in the main surface process of the method for manufacturing a laminated inductor substrate according to the present invention.

FIG. 17 is a cross-sectional view in the main surface process of the method for manufacturing a laminated inductor substrate according to the present invention.

FIG. 18 is a cross-sectional view in the main surface step of the method for manufacturing the laminated inductor substrate of the present invention.

FIG. 19 is a cross-sectional view in the main surface step of the method for manufacturing the laminated inductor substrate of the present invention.

FIG. 20 is a cross-sectional view in the main surface step of the method for manufacturing the laminated inductor substrate of the present invention.

FIG. 21 is a cross-sectional view in the main surface step of the method for manufacturing the laminated inductor substrate of the present invention.

FIG. 22 is a cross-sectional view in the main surface process of the method for manufacturing a laminated inductor substrate according to the present invention.

FIG. 23 is a cross-sectional view in the main surface step of the method for manufacturing the laminated inductor substrate of the present invention.

FIG. 24 is a cross-sectional view in the main surface step of the method for manufacturing the laminated inductor substrate of the present invention.

FIG. 25 is a cross-sectional view in the main surface step of the method for manufacturing a laminated inductor substrate according to the present invention.

FIG. 26 is a cross-sectional view in the main surface step of the method for manufacturing the laminated inductor substrate of the present invention.

FIG. 27 is a cross-sectional view in the main surface step of the method for manufacturing the laminated inductor substrate of the present invention.

[Explanation of symbols]

 10 ... Multilayer inductor substrate 1 ... Multilayer body 1a to 1j ... Ceramic layer 10a to 10j ... Insulating film 2, 2e to 2g ... Coil pattern 3, 3e. 3g ... Via hole conductor 4, 4b to 4j ... Internal wiring pattern 5, 5a to 5j ... Via hole conductor 6 ... Magnetic material magnetic path member 7 ...・ ・ Surface wiring pattern ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Electronic parts 15 ・ ・ ・ ・ ・ ・ Support substrate 20 ・ ・ ・ ・ ・ ・ Coil pattern conductor film 30 ・ ・ ・ ・ ・ ・.... Through-hole recesses serving as via-hole conductors 31 ... Conductors serving as via-hole conductors 40 ... Conductor films serving as internal wiring patterns 50. Penetrating recessed part 51 ... Conductor 6 serving as a via hole conductor ........ magnetic film serving as a through-recess 61 ........ magnetic path member comprising a magnetic path member

Claims (2)

[Claims] 1. A laminated inductor substrate comprising a laminated body formed by laminating a plurality of ceramic layers, and a coil comprising a coil pattern formed between the ceramic layers and a via-hole conductor penetrating the ceramic layers. In the laminated inductor substrate, a magnetic flux path member through which the magnetic flux of the coil passes is integrally arranged. 2. A coil formed by a coil pattern formed between the ceramic layers and a via hole conductor penetrating the ceramic layers, and a magnetic body through which a magnetic flux of the coil passes, in a laminated body formed by laminating a plurality of ceramic layers. A method for manufacturing a laminated inductor substrate in which magnetic path members are integrally arranged, wherein the laminated body selectively repeats the following steps (1) to (4) on a supporting substrate, A method for manufacturing a laminated inductor substrate, comprising forming an unfired laminated body and subjecting the unfired laminated body to a firing treatment. (1) A step of forming a coating film by coating and drying a ceramic slip material containing a photocurable monomer (2) A via-hole conductor and / or a magnetic path of magnetic material by selectively exposing and developing the coating film Step of forming a through recess at a position to be a member (3) Filling the through recess to be the magnetic flux path member with a magnetic paste to form a magnetic film (4) Forming a through recess to be the via hole conductor A step of filling a conductive paste to form a conductor and printing the conductive paste on the coating film to form a conductor film to be a coil pattern.