JPH11354924A - Manufacture of multilayer ceramic substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method, in which a multifunction, high density and high precision of a multilayer ceramic substrate are possible. SOLUTION: In the device, there is prepared a raw composite molding 1g which has a plurality of ceramic green sheets 2g to 8g stacked containing a ceramic insulation material and wiring conductors 13 to 18, and in which spaces 29, 34 are provided therein, and molding blocks 10g, 11g containing a raw ceramic functional material to be passive parts are fitted into the spaces 29, 34, and the composite molding 1g is pinched between sheet-like supports 48, 49 which contain raw ceramics which are not burnt at the burning temperature of the composite molding body 1g, while a burning process is performed, thereby to attain a burnt lamination. A difference in the coefficients of thermal expansion between the sheet-like supports 48, 49 and the lamination is set to 2.5×10<-6> degK<-1> , and in a temperature decreasing process after burring, by utilizing a stress which works with the difference in the coefficients of thermal expansion, the sheet-like supports 48, 49 are stripped and removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a multilayer ceramic substrate, and more particularly to a method of manufacturing a multilayer ceramic substrate which is advantageously applied to manufacture of a multilayer ceramic substrate incorporating passive components such as capacitors and inductors. It relates to a manufacturing method.

[0002]

2. Description of the Related Art In order to make a multi-layer circuit board represented by a multi-layer ceramic board multifunctional, high-density, and high-performance, such a multi-layer circuit board incorporates high-precision passive components. It is effective to provide wiring at high density.

[0003] A multilayer circuit board incorporating such passive components is conventionally manufactured by the following various methods.

[0004] The first is a so-called thick film method, in which a dielectric paste or the like is printed on a substrate green sheet by a thick film forming technique, each green sheet is laminated, pressed, and then fired to obtain a multilayer ceramic. This is a method in which a capacitor or the like is partially built in the substrate. However, this method has the following problems. Since there is relatively large variation in paste film thickness and misregistration of printing, variation in characteristics such as the capacitance of the capacitor is also relatively large. Since deformation of the paste occurs during the pressing and baking processes,
This also causes variations in characteristics such as capacitance. As printing and lamination are repeated, the flatness of the printed portion becomes worse and it is difficult to increase the number of laminations. Therefore, it is difficult to increase the capacitance of the capacitor.

[0005] The second is to manufacture a multilayer circuit board with a resistor and a capacitor, which is similar to the first method described above.
This is a method of printing a resistor or the like in multiple layers by a thick film forming technique. However, this method also involves the first method described above, such as variations in characteristics due to misregistration of print patterns and variations in film thickness, capacity limitations due to difficulties in increasing the number of layers, and poor flatness. There is almost the same problem.

A third method is disclosed, for example, in Japanese Patent Application Laid-Open No. Sho 59-17232.
As described in Japanese Patent Application Laid-Open Publication No. H10-260, a method of incorporating a dielectric in a multi-layer substrate in a state of a sheet, in this case, a dielectric sheet having the same area as the substrate is sandwiched between substrate sheets for the substrate. After laminating and pressing, firing is performed. As a result, variations in characteristics such as capacitance,
Although the problem of the restriction on increasing the capacity is improved, the following problems are encountered. In order to co-sinter a laminate including a plurality of types of sheets having different compositions, it is necessary to control the shrinkage behavior and the coefficient of thermal expansion in the firing process to be the same, which is a highly difficult technique. Since the dielectric is arranged in layers inside the substrate, the degree of freedom in design is low. Problems such as signal crosstalk are likely to occur.

[0007] As a method for enabling high-density wiring of a multilayer circuit board, the upper and lower surfaces of a substrate laminate comprising a plurality of substrate green sheets that can be fired at a low temperature are shrunk at the firing temperature of the substrate laminate. After pressing the dummy green sheets not to be pressed, they are fired at a relatively low temperature, and the unsintered layer derived from the latter dummy green sheet is peeled and removed after firing (for example, JP-A-4-243978).
Japanese Patent Application Laid-Open No. 5-503498, and Japanese Patent Application Laid-Open No. 5-503498.

In these methods, the direction of the substrate surface, that is, X
Since shrinkage hardly occurs in the −Y direction, the dimensional accuracy of the obtained substrate can be increased. Therefore, there is an advantage that the problem of disconnection is unlikely to occur even if high-density wiring is provided. However, the above-mentioned publication does not give any teaching about a technique for incorporating a passive component in a substrate or for facilitating removal of a dummy green sheet.

[0009] Again, as a fourth method for manufacturing a multilayer circuit board incorporating passive components, for example, Japanese Patent Application Laid-Open No.
No. 92983 discloses a method in which the above-described method of not causing shrinkage of the substrate in the X-Y direction is combined with a method of partially incorporating a capacitor inside a multilayer circuit board in the form of a sheet or a thick film. I have. This method is suitable for manufacturing a multilayer circuit board having a high-density wiring with built-in passive components.

In the fourth method, when a dielectric portion is formed from a sheet, a dielectric layer having the same area as the substrate is provided, so that the dielectric layer is exposed at the end face of the substrate. For this reason, the dielectric layer needs to be dense so that moisture does not penetrate, but by pressing from the vertical direction of the substrate during firing, the dielectric layer can be sufficiently densified. . However, since the shape of the dielectric layer is restricted, as in the third method using the dielectric sheet as described above, the dielectric is arranged in a layer inside the substrate, so that the degree of freedom in design is low. Problems such as signal crosstalk are likely to occur.

On the other hand, in the fourth method, when forming the dielectric portion with a thick film, a concave portion is provided in the substrate sheet so as to correspond to the region where the dielectric portion is formed, and the dielectric material is formed there. A process of filling the paste may be employed. In this case, among the problems encountered in the above-described first method, the thick film method, the problem of characteristic variation that may be caused by displacement of the thick film, deformation of the dielectric paste when the substrate sheet is pressed, and the like is improved. However, the variation in the thickness of the paste is small, but still remains and is still insufficient. Further, since it is difficult to form the dielectric portion into a laminated structure, there remains a problem that it is difficult to obtain a large capacity.

In the fourth method, since the shrinkage can be considerably reduced in the direction of the substrate, that is, in the X-Y direction, the variation in the shrinkage decreases accordingly, and the dimensional accuracy of the substrate can be relatively increased. There is.

However, the fourth method requires a step of peeling and removing an unsintered layer that does not shrink at the firing temperature of the substrate after firing. If a process such as polishing or homing is required for such peeling, the manufacturing cost is increased. In this connection, for example, Japanese Unexamined Patent Publication No. 9-266363 discloses that, among the unsintered layers,
A method in which the glass component is melted from the substrate surface and adheres to the substrate surface is forcibly left without being peeled off and used as the surface of the substrate, but in this case, a peeling step is also necessary. . Japanese Patent Application Laid-Open No. 5-136572 discloses a method in which an organic resin is filled by impregnating an organic resin into an unsintered layer without peeling and removing the unsintered layer, and the method is used as a surface of a substrate. Although shown, in this case, a step of filling the organic resin is required.

[0014]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned various problems, and an object of the present invention is to provide a multi-layer ceramic substrate capable of realizing multi-functionality, high density and high precision. The aim is to provide a manufacturing method.

[0015]

SUMMARY OF THE INVENTION The present invention is first directed to a method of manufacturing a multilayer ceramic substrate including a laminate having a plurality of laminated ceramic layers made of a ceramic insulating material and wiring conductors. In order to solve the technical problem, a step of preparing a green molded body having a plurality of laminated ceramic green sheets and wiring conductors including a ceramic insulating material, and a step of preparing a green molded body at both ends in the stacking direction of the green molded body A step of disposing a raw sheet-like support containing a ceramic that does not sinter at the firing temperature of the green compact on the main surface, and laminating the green compact in a state sandwiched by the sheet-like supports. And a step of removing the unsintered sheet-like support, and the difference in the coefficient of thermal expansion between the fired sheet-like support and the laminate is provided. It is characterized by being a 2.5 × 10 ^-6 degK ^-1 or more.

In the above-described method for manufacturing a multilayer ceramic substrate, the molded body is preferably fired at a temperature of 1000 ° C. or less.

In addition to the above-described first invention, the present invention provides, as a second and third invention, a laminate having a plurality of laminated ceramic layers made of a ceramic insulating material and a wiring conductor, and a wiring conductor. The present invention is also directed to a method for manufacturing a multilayer ceramic substrate including a passive component embedded in a laminate in a wired state.

According to a second aspect of the present invention, there is provided a method of manufacturing a multilayer ceramic substrate, comprising a plurality of laminated first ceramic green sheets containing a ceramic insulating material and a wiring conductor, and a ceramic interposed between the first ceramic green sheets. A step of preparing a green composite molded body in which a second ceramic green sheet containing a raw ceramic functional material to be a passive component, which is different from the insulating material, is provided; A step of arranging a raw sheet-like support containing a ceramic that does not sinter at the firing temperature of the green composite molded body on each of the main surfaces located therein, and placing the raw composite molded body in a state sandwiched between the sheet-like supports. A step of obtaining a laminated body incorporating passive components by firing, and a step of removing the unsintered sheet-shaped support, The difference of the sheet-like support of the thermal expansion coefficient of the laminate, is characterized in that it is a 2.5 × 10 ^-6 degK ^-1 or more.

Manufacturing of the multilayer ceramic substrate according to the third invention.
The manufacturing method is different from the ceramic insulating material.
Molded block containing raw ceramic functional material to become
Preparing and laminating including ceramic insulating material
With multiple ceramic green sheets and wiring conductors
In this case, a space is provided in advance, and
To prepare a raw composite molded body with a hook
And located at both ends in the laminating direction of the green composite molded body
No sintering at the firing temperature of the green composite compact on each major surface
Placing a raw sheet-like support containing ceramic
And the raw composite molded body is fired while sandwiched between sheet-like supports.
To obtain a laminated body with built-in passive components
And then the step of removing the unsintered sheet-like support
And a fired sheet-like support and laminate
Is 2.5 × 10 ^-6degK^-1that's all
It is characterized by that.

In the above second and third inventions, the composite molded body is preferably fired at a temperature of 1000 ° C. or less.

In the second or third aspect of the present invention, the second ceramic green sheet or molded block gives, for example, a capacitor or an inductor when sintered. It should be noted that the present invention is not limited to these capacitors and inductors, but may be other functional elements, and is not limited to a single functional element, but may be a composite functional element, for example, an LC composite component combining a capacitor and an inductor. You may.

The above-mentioned second ceramic green sheet or molded block preferably has a laminated structure for forming a multilayer internal conductor.

In this case, the above-mentioned inner conductor is made of Ag, Ag
It is preferable that at least one selected from the group consisting of -Pt alloy, Ag-Pd alloy, Au, and Cu is used as a main component.

Further, the ceramic functional material contained in the second ceramic green sheet or the molded body block is as follows:
It preferably comprises crystallized glass or a mixture of glass and ceramic.

Further, the first, second, and third
In the invention, the ceramic insulating material contains glass or a mixture of glass and ceramic, and the weight ratio of glass / ceramic is preferably selected in the range of 100/0 to 5/95.

In the first, second and third aspects of the present invention, the sheet-like support is made of Al as a ceramic.
₂ O ₃ , MgO, CaO, SiO ₂ , BaO, Zr
It is preferable to include at least one oxide or composite oxide selected from O ₂ and CeO ₂ .

In the first, second and third aspects of the present invention, the wiring conductor comprises at least one selected from the group consisting of Ag, Ag-Pt alloy, Ag-Pd alloy, Au and Cu. It is preferable that

In the first, second and third inventions, in the step of firing the green compact or the step of firing the green composite molded article, the step of uniaxially applying 10
It is preferable to apply a load of not more than kg / cm ² .

In the first, second and third aspects of the present invention, the step of removing the sheet-like support comprises the step of removing the sheet-like support and the laminate by a difference in thermal expansion coefficient in a temperature decreasing process after the firing step. It is preferable that the sheet-like support is peeled off from the laminate using the stress acting between them.

[0030]

FIG. 1 is a sectional view schematically showing a multilayer ceramic substrate 1 according to an embodiment of the present invention. FIG. 2 is an equivalent circuit diagram provided by the multilayer ceramic substrate 1 shown in FIG.

As shown in FIG. 1, a multilayer ceramic substrate 1
Comprises a laminate 9 having a plurality of laminated ceramic layers 2, 3, 4, 5, 6, 7, and 8 made of a ceramic insulating material. A capacitor 10, an inductor 11, and a resistor 12 as passive components are built in the multilayer body 9. Further, the laminate 9 includes wiring conductors 13, 14, 15, 16, 17, and 18 for wiring the capacitor 10, the inductor 11, and the resistor 12, and has external terminal conductors 19a and 19a on the outer surface. 19b. Thus, the multilayer ceramic substrate 1 forms a circuit as shown in FIG.

The multilayer ceramic substrate 1 having the above structure
Is manufactured as follows. FIG. 3 is a cross-sectional view for explaining a method for manufacturing the multilayer ceramic substrate 1 shown in FIG. FIG. 4 is a sectional view for explaining a method for obtaining a part of the elements shown in FIG.

A molded block 1 for a capacitor containing a raw ceramic functional material to be the above-mentioned capacitor 10
A molded body block for inductor 11g containing 0 g and a raw ceramic functional material to be the inductor 11 is prepared.

The molded body block 10g for a capacitor includes a ceramic dielectric material as a ceramic functional material, and has a laminated structure in which a multilayer internal conductor 21 is formed via a raw dielectric sheet 20 containing such a ceramic dielectric material. Have. Terminal electrodes 22 and 23 are formed on opposite end surfaces of the molded block 10g, respectively. As for the internal conductors 21, those connected to one terminal electrode 22 and those connected to the other terminal electrode 23 are alternately arranged, similarly to the internal electrodes of a known multilayer ceramic capacitor.

The molded body block for inductor 11g includes a ceramic magnetic material as a ceramic functional material, and has a laminated structure in which a multilayer internal conductor 25 is formed via a raw magnetic sheet 24 containing such a ceramic magnetic material. Have. Terminal electrodes 26 and 27 are formed on opposite end surfaces of the molded block 11g, respectively. Each of the multilayer inner conductors 25 is, for example, a respective magnetic sheet 24.
And a conductive path extending in a coil shape as a whole while being connected by a through conductor 28 penetrating through.

These molded blocks 10 g and 11 g
Is preferably configured to be sinterable at a temperature of 1000 ° C. or less.

For this reason, first, as the ceramic functional material contained in the dielectric sheet 20 and the magnetic sheet 24, that is, the ceramic dielectric and the ceramic magnetic substance, for example, crystallized glass or a mixture of glass and ceramic is advantageous. Used for More specifically, as the dielectric sheet 20, a ceramic slurry obtained by mixing a powder obtained by mixing a small amount of borosilicate glass with barium titanate and an organic vehicle was formed into a sheet by a doctor blade method. Can be used. On the other hand, as the magnetic sheet 24, a sheet obtained by mixing a ceramic slurry obtained by mixing a powder obtained by mixing a small amount of borosilicate glass with nickel zinc ferrite and an organic vehicle by a doctor blade method is used. Can be.

The conductors for forming the internal conductor 21, the terminal electrodes 22 and 23, the internal conductor 25, the terminal electrodes 26 and 27, and the through conductor 28 include, for example, Ag, Ag-Pt alloy, Ag-Pd A conductive paste containing at least one selected from the group consisting of alloys, Au, and Cu as a main component is advantageously used.

The internal conductors 21 and 25 can be formed by applying the above-mentioned conductive paste in a predetermined pattern on each of the dielectric sheet 20 and the magnetic sheet 24 by screen printing.

As described above, a predetermined number of dielectric sheets 20 on which the internal conductors 21 are formed and a predetermined number of magnetic sheets 24 on which the internal conductors 25 are formed are laminated to obtain the molded body blocks 10g and 11g. Then, it is preferable to perform a pressure bonding step. In this pressure bonding step, for example, a pressure of 200 kg / cm ² is applied by a hydraulic press.

On the other hand, ceramic green sheets 2g, 3g, 4g, 5g, 6g, 7g and 8 containing a ceramic insulating material to be each of the above-mentioned ceramic layers 2 to 8
g is prepared. 2g of these ceramic green sheets
The ceramic insulating material contained in ８8 g is different from the ceramic functional material contained in the molded block 10 g or 11 g described above.

These ceramic green sheets 2 g to 8
g, for providing the molded body block for capacitor 10g and the molded body block for inductor 11g, respectively, and for the resistor 12 and the wiring conductors 13 to 13 described above.
Processing and treatment for providing the external terminal conductors 18a and 19b and the external terminal conductors 19a and 19b are performed in advance.

More specifically, a series of through holes 30, 31, 32, and 33 which should be spaces 29 for housing the molded body block 10 g for capacitors, and a space 34 for housing the molded body block 11 g for inductors.
Series of through holes 35, 36, 37 and 38
, Respectively, ceramic green sheets 4g, 5g,
6g and 7g are provided in advance.

A series of through holes 39, 40, 41, 42, 43, and 44 for providing the wiring conductors 13 are respectively provided with the ceramic green sheets 2g, 3g, 4g,
It is provided in advance in 5g, 6g and 7g. Further, through holes 45 for providing the wiring conductors 15 are provided in advance in the ceramic green sheet 3g. In addition, a series of through holes 46 and 47 for providing the wiring conductor 18 are provided in advance on the ceramic green sheets 2g and 3g, respectively. And these through holes 39 to 47
Inside, a conductive paste to be the wiring conductors 13, 15, and 18 is applied.

The ceramic green sheet 2g is provided with conductive paste to be the external terminal conductors 19a and 19b by screen printing or the like so as to be connected to the conductive paste in the through holes 39 and 46, respectively. Is done.

The ceramic green sheet 3g is provided with conductive pastes to be the wiring conductors 16 and 17 by screen printing or the like so as to be connected to the conductive pastes in the through holes 45 and 47, respectively. You. In addition, a thick film resistor that becomes the resistor 12 is provided so as to connect between the conductive pastes that become the wiring conductors 16 and 17. As the resistor paste for forming the thick film resistor, for example, a mixture of a powder obtained by mixing a small amount of borosilicate glass with lutetium oxide and an organic vehicle is advantageously used.

The ceramic green sheet 8g is connected to the conductive paste in the through-hole 44 when the conductive paste to be the wiring conductor 14 is laminated with the ceramic green sheets 2g to 8g. And 34 so as to be exposed toward the inside, that is, the terminal electrodes 23 and 27 of the molded body blocks 10g and 11g.
Is provided by screen printing or the like so as to be connected to.

The conductive paste for providing the wiring conductors 13 to 18 and the external terminal conductors 19a and 19b includes Ag, Ag-Pt alloy, Ag-Pd alloy,
Those having at least one selected from the group consisting of u and Cu as a main component are advantageously used.

2 g of such a ceramic green sheet
As the ceramic insulating material contained in ８8 g, a material that can be fired at a temperature of 1000 ° C. or lower is preferably used, and for example, glass or a mixture of glass and ceramic is used. In this case, the weight ratio of glass / ceramic is selected in the range of 100/0 to 5/95. If the weight ratio of glass / ceramic is smaller than 5/95, the sinterable temperature is higher than 1000 ° C. When the firing temperature increases, the above-described wiring conductor 1
It is not preferable because the selection range of materials such as 3 to 18 becomes narrow.

More specifically, as ceramic green sheets 2 g to 8 g, ceramic slurries obtained by mixing borosilicate glass powder, alumina powder and an organic vehicle were formed into sheets by a doctor blade method. Can be used. The ceramic green sheets 2 g to 8 g of such a material system are 800 to 10 g.
It can be fired at a relatively low temperature of about 00 ° C.

Using the molded body blocks 10 g and 11 g and the ceramic green sheets 2 g to 8 g obtained as described above, a raw composite molded body 1 g which becomes the multilayer ceramic substrate 1 when fired is as follows. Manufactured.

First, ceramic green sheets 4g-7g
g is previously laminated as shown in FIG. Then, in the spaces 29 and 34, respectively, the molded body blocks 10g
And 11g are fitted. At this time, the terminal electrode 2
2, 23, 26 and 27 are exposed from the openings in each of the spaces 29 or 34. Then, for example, 500k
A pressing step using a g / cm ² hydraulic press is performed, and 4 g to 7 g of the ceramic green sheets are pressed. Thereby, the ceramic green sheets 4g to 7g
g and the molded article block 1
0 g and 11 g are brought into close contact with the inner peripheral surfaces of the spaces 29 and 34, respectively.

Next, 2 g of ceramic green sheets are placed above and below the above-mentioned ceramic green sheets 4 g to 7 g.
And 3 g and 8 g are respectively laminated, whereby 1 g of a green composite molded body is obtained. In the state of the composite molded body 1g, the conductive paste in the through holes 39 to 44 forms a series of wiring conductors 13 and is connected to the wiring conductor 14, and the conductive paste in the through holes 45 is The conductive paste in the through holes 46 and 47 connected to the terminal electrodes 22 of the molded block 10g forms a series of wiring conductors 18 and forms the molded block 1
1 g is connected to the terminal electrode 26. The terminal electrodes 23 and 27 of the molded blocks 10g and 11g are connected to the wiring conductor 14.

In this embodiment, sheet supports 48 and 49 made of raw ceramic which are not sintered at the firing temperature of 1 g of the green composite molded body are further prepared. As described above, the molded body blocks 10 g and 11 g and the ceramic green sheets 2 g to 8 g were both 1000 ° C.
If it can be fired at the following temperature, it means that 1 g of a raw composite molded article obtained by combining these can be fired at a temperature of 1000 ° C. or less. Any material that does not sinter at ℃ may be used. The sheet supports 48 and 49 are, for example,
Al ₂ O ₃ , MgO, CaO, SiO ₂ , BaO, Zr
Advantageously, a ceramic slurry obtained by mixing a ceramic powder containing at least one oxide or a composite oxide selected from O ₂ and CeO ₂ with an organic vehicle is formed into a sheet by a doctor blade or the like. Can be obtained.

The above-mentioned sheet-like supports 48 and 49 are
As will be described later, after firing, the laminate 9 is removed by peeling from the laminate 9 for the multilayer ceramic substrate 1. It is effective to provide a difference in the coefficient of thermal expansion between.

In this embodiment, the sheet-like supports 48 and 49 are made porous in the firing step, and the glass contained in 1 g of the composite molded body penetrates into such a porous structure and becomes dense. However, in the temperature drop process after firing, in the temperature range below the strain point of the glass,
A stress due to a difference in the coefficient of thermal expansion acts between the fired laminate 9 and the porous sheet-like supports 48 and 49. If this difference in the coefficient of thermal expansion is set to 2.5 × 10 ⁻⁶ degK ⁻¹ or more on average from the strain point of the glass to room temperature, the stress caused by the difference in the coefficient of thermal expansion will cause the sheet to become porous. Experiments have shown that the sheet supports 48 and 49 can be advantageously broken and the sheet supports 48 and 49 can be spontaneously released from the laminate 9.

The sheet supports 48 and 4 as described above
As shown in FIG. 3, 9 is disposed on each main surface located at both ends in the stacking direction of the raw composite molded product 1g, that is, on the upper and lower main surfaces. Then, the raw composite molded body 1g is pressed together with the sheet-like supports 48 and 49. For this pressure bonding, for example, a hydraulic press with a pressure of 1000 kg / cm ² is applied.

Next, 1 g of the green composite molded body is fired at a temperature of 900 ° C., for example, in the air while being sandwiched between the sheet-like supports 48 and 49. In this firing step, for example, a plate-shaped weight is placed on the sheet-like support 48 located above, and the weight is set to 10 kg / cm ² or 10 k.
It is preferable to apply a load of g / cm ² or less uniaxially. This load can advantageously prevent the laminate 9 or the multilayer ceramic substrate 1 from being undesirably deformed such as warping in the firing step. In addition,
Such effects, even under a load in excess of 10 kg / cm ^2, are substantially the same as the case of the load of 10 kg / cm ^2, a load in excess of 10 kg / cm ² is unnecessary.

By this firing, a molded body block 10 g
And 11 g are fired to form a sintered capacitor 10 and an inductor 11, respectively, and ceramic green sheets 2 g to 8 g are fired to form a laminated body 9 having a plurality of sintered ceramic layers 2 to 8. Therefore, the multilayer ceramic substrate 1 in a sintered state as a whole is obtained.

In the case of the sheet-like supports 48 and 49, as described above, during the temperature decreasing process after firing,
In a temperature range equal to or lower than the strain point of the glass, a coefficient of thermal expansion of 2.5 × 10 ⁻⁶ degK ⁻¹ or more between the laminated body 9 after firing and the porous sheet-like supports 48 and 49 is obtained. A stress due to the difference acts, and the porous sheet-like supports 48 and 49 are advantageously broken by the stress, and the sheet-like supports 48 and 49 can be spontaneously peeled off from the laminate 9. Therefore, a desired multilayer ceramic substrate 1 can be easily and efficiently taken out.

The above-mentioned sheet supports 48 and 49 are
No substantial shrinkage occurs in the firing step. Therefore, shrinkage in the X-Y direction, that is, in the main surface direction of the ceramic green sheets 2g to 8g during firing of the composite molded body 1g sandwiched between the sheet-like supports 48 and 49 can be advantageously suppressed. Therefore, the dimensional accuracy of the multilayer ceramic substrate 1 can be further increased, and even if fine and high-density wiring is provided using the wiring conductors 13 to 18, for example, a problem such as disconnection can be made less likely to occur. According to experiments, it has been confirmed that the capacitor 10, the inductor 11, and the resistor 12 each exhibit characteristics as designed.

Further, as described above, since shrinkage in the XY directions is suppressed, when firing the composite molded body 1 g and simultaneously firing the molded body blocks 10 g and 11 g and the ceramic green sheets 2 g to 8 g, It is easier to make the respective shrinkage behaviors of the molded body blocks 10 g and 11 g and the ceramic green sheets 2 g to 8 g coincide with each other.
0g and 11g and ceramic green sheet 2
g to 8 g of each material can be further expanded.

Although the present invention has been described with reference to the illustrated embodiment, other than the above, within the scope of the present invention,
Various modifications are possible.

For example, the illustrated multilayer ceramic substrate 1
Is merely a typical example that allows easier understanding of the present invention, and the present invention can be equally applied to a multilayer ceramic substrate having various circuit designs.

The molded block is not limited to a single capacitor or inductor, but may be, for example, a molded block of an LC composite component.

In the above embodiment, the spaces 29 and 34 for fitting the molded body blocks 10g and 11g are formed by the through holes 30 to 33 and 35 to 38 provided in the ceramic green sheets 4g to 7g, respectively. However, depending on the size and shape of the molded body block, a space for fitting the molded body block may be formed by a concave portion provided in a specific ceramic green sheet.

In the illustrated method for manufacturing the multilayer ceramic substrate 1, the passive component 10 built in the laminate 9 is
And 11 are provided by molded blocks 10g and 11g, respectively, comprising raw ceramic functional material,
These molded body blocks 10g and 11g were respectively fitted in the spaces 29 and 34 previously provided in the raw composite molded body 1g, but instead or additionally, the passive component is made of ceramic insulating material. It may be provided by a second ceramic green sheet comprising a ceramic functional material, different from the ceramic insulating material, arranged between a plurality of stacked first ceramic green sheets comprising the material.

Further, the present invention can be advantageously applied to a method of manufacturing a multilayer ceramic substrate including a laminate in which only the wiring conductors are formed without particularly incorporating the passive components as described above. .

[0069]

As described above, according to the present invention, the sintering temperature of the green molded product or the composite molded product is set on each of the main surfaces located at both ends in the laminating direction of the green molded product or the composite molded product. Since the green molded body or the composite molded body is fired while the sheet-shaped support made of raw ceramic that is not sintered is fired, the sheet-shaped support does not substantially shrink in the firing step. The shrinkage in the X-Y direction during firing of the molded article or composite molded article sandwiched between these sheet-shaped supports is suppressed. Therefore, the dimensional accuracy of the multilayer ceramic substrate can be increased, and even if fine and high-density wiring is provided, problems such as disconnection can be suppressed.

According to the present invention, the difference in the coefficient of thermal expansion between the fired sheet-like support and the laminate is 2.5 × 10
^{Since it is -6} degK ^-1 or more, the stress due to the difference in the thermal expansion coefficient advantageously acts on the separation of the sheet-like support, and the sheet-like support can be easily removed.

When the sheet-like support is removed as described above, a temperature reduction process after firing is used, and in this temperature-falling process, the stress due to the difference in the coefficient of thermal expansion between the sheet-like support and the laminate is used to act. If the support is peeled from the laminate, the sheet-like support can be efficiently removed.

When the present invention is applied to a method of manufacturing a multilayer ceramic substrate having a passive component incorporated in a laminate, a passive ceramic green sheet including a ceramic insulating material constituting the laminate is provided separately. The component is provided with a second ceramic green sheet or green body block containing the raw ceramic functional material. According to the present invention, when firing a composite green body containing these second ceramic green sheets or green body blocks, Since the shrinkage in the XY directions is suppressed as described above,
It is easier to make the respective shrinkage behaviors of the ceramic green sheet or the molded body block and the first ceramic green sheet coincide with each other. Therefore, the second ceramic green sheet or molded block and the first
The range of selection of each material with the ceramic green sheet can be expanded.

Further, according to the present invention, when a multilayer ceramic substrate incorporating a passive component is manufactured as described above, the passive component is obtained by being sintered together with the laminate, and thus the passive component itself has The properties are substantially determined during the green phase, and the properties latent at this green phase will be substantially maintained after sintering. Therefore, it is easy to make the characteristics of the passive components incorporated in the multilayer ceramic substrate as designed, and therefore, it is possible to supply the multilayer ceramic substrate as a whole with a stable quality. From this, it is possible to easily manufacture a multi-layer ceramic substrate with multi-functionality, higher density, higher precision, and higher performance.

In the present invention, if the passive component is provided by a molded block embedded in the laminate, the passive component is completely embedded in the laminate. Thus, a multilayer ceramic substrate having high environmental resistance such as moisture resistance can be obtained.

In the present invention, as described above,
When the passive component is provided by the molded block, the passive component can be easily arranged three-dimensionally in the multilayer ceramic substrate, so that the degree of freedom in design is increased and the problem such as signal crosstalk is advantageous. Can be avoided.

In the present invention, when the passive component is provided by the molded body block, the green composite molded body in which the green molded block is embedded is fired. Compared with the case where firing is performed in an embedded state, it is not necessary to strictly control the shrinkage behavior at the time of firing, and the range of selection of materials that can be used for ceramic green sheets to be a laminate can be expanded.

In the present invention, when the passive component is provided by the molded body block, since the space for fitting the molded body block is provided in advance, the flatness of the obtained multilayer ceramic substrate is maintained well. can do. Therefore, also in this respect, since undesired deformation and disconnection of the wiring conductor can be made less likely to occur, high-density wiring with high dimensional accuracy can be performed while preventing variation in characteristics, Further, the number of stacked ceramic layers provided on the multilayer ceramic substrate can be increased without any problem, and as a result, the performance of the multilayer ceramic substrate can be easily improved.

In the present invention, the passive component is the second component.
When given by the ceramic green sheet or the molded body block, a capacitor or an inductor can be easily constituted by such a second ceramic green sheet or molded body block.

Further, when the second ceramic green sheet or the molded block has a laminated structure forming a multilayer internal conductor, for example, when the passive component is a capacitor, a high capacity can be obtained. When the passive component is an inductor, high inductance can be obtained.

In the present invention, the ceramic functional material contained in the second ceramic green sheet or the molded body block contains crystallized glass or a mixture of glass and ceramic, or a molded body or a composite molded body that becomes a laminate. The ceramic insulating material contained in the ceramic green sheet provided in the body includes glass or a mixture of glass and ceramic, and the weight ratio of glass / ceramic is selected in the range of 100/0 to 5/95. In this case, sintering can be performed at a relatively low temperature, for example, 1000 ° C.

Therefore, Ag, Ag-Pt alloy, Ag-Pd alloy, Au, N
Those containing at least one selected from the group consisting of i and Cu as a main component can be used without any problem.
As the ceramic for the above-mentioned sheet-like support, Al ₂ O ₃ , which is relatively easily available and chemically stable,
At least one oxide or composite oxide selected from MgO, CaO, SiO ₂ , BaO, ZrO ₂ , and CeO ₂ can be used.

Further, in the firing step included in the present invention, by uniaxially applying a load of 10 kg / cm ² or less to the sheet-like support, the obtained multilayer ceramic substrate warps in the firing step. Such undesirable deformation can be advantageously avoided.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing a multilayer ceramic substrate 1 according to an embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram provided by the multilayer ceramic substrate 1 shown in FIG.

FIG. 3 is a view for explaining a method for manufacturing the multilayer ceramic substrate 1 shown in FIG. 1, and illustrates ceramic green sheets 2g to 2g to be prepared for manufacturing the multilayer ceramic substrate 1;
It is sectional drawing which shows 8g, 10 g and 11 g of molded object blocks, and sheet-shaped support bodies 48 and 49.

FIG. 4 shows ceramic green sheets 4g to 4g shown in FIG.
FIG. 7 is a cross-sectional view showing 7 g and molded blocks 10 g and 11 g separated from each other.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Multilayer ceramic substrate 2-8 Ceramic layer 9 Laminated body 10 Capacitor 11 Inductor 12 Resistance 13-18 Wiring conductor 19a, 19b External terminal conductor 20 Dielectric sheet 21, 25 Internal conductor 22, 23, 26, 27 Terminal electrode 24 Magnetic body Sheet 29,34 Space 30-33,35-47 Through-hole 1g Raw composite molded body 2g-8g Ceramic green sheet 10g Capacitor molded block 11g Inductor molded block 48,49 Sheet support

Claims (14)

[Claims] 1. A method for manufacturing a multilayer ceramic substrate, comprising a laminated body having a plurality of laminated ceramic layers made of a ceramic insulating material and a wiring conductor, wherein the plurality of laminated ceramics containing the ceramic insulating material are provided. A green molded body having a green sheet and the wiring conductor is prepared, and on each main surface located at both ends in the laminating direction of the green molded body, a ceramic that is not sintered at a firing temperature of the green molded body is provided. The laminated body is obtained by arranging a raw sheet-like support including the sheet-shaped support, and baking the green compact in a state sandwiched between the sheet-shaped supports, and then removing the unsintered sheet-shaped support. to provided with a respective process, the difference in the thermal expansion coefficient of the sheet support after firing and said laminate is a 2.5 × 10 ^-6 degK ^-1 or more, the multilayer Serra Click substrate manufacturing method of. 2. The method according to claim 1, wherein the molded body is fired at a temperature of 1000 ° C. or less. 3. A laminate having a plurality of laminated ceramic layers and a wiring conductor made of a ceramic insulating material;
A method of manufacturing a multilayer ceramic substrate, comprising: a passive component embedded in the laminate in a state of being wired by the wiring conductor, wherein a plurality of the stacked first ceramic green sheets including the ceramic insulating material are provided. And the wiring conductor, and between the first ceramic green sheets,
A green composite molded body is provided, on which a second ceramic green sheet containing a raw ceramic functional material to be the passive component, which is different from the ceramic insulating material, is provided. On each of the main surfaces located at both ends, a raw sheet-like support containing a ceramic that does not sinter at the firing temperature of the green composite molded body is arranged, and the raw composite is sandwiched between the sheet-like supports. Obtaining a laminate including the passive component by firing a molded body; and removing the unsintered sheet-like support. A method for manufacturing a multilayer ceramic substrate, wherein a difference in thermal expansion coefficient between the multilayer ceramic substrate and the laminate is 2.5 × 10 ⁻⁶ degK ⁻¹ or more. 4. A laminate having a plurality of laminated ceramic layers and a wiring conductor made of a ceramic insulating material;
A method of manufacturing a multilayer ceramic substrate, comprising: a passive component embedded in the laminate in a state wired by the wiring conductor, wherein the raw ceramic to be the passive component is different from the ceramic insulating material. A molded body block including a functional material is prepared. The ceramic body includes a plurality of laminated ceramic green sheets including the ceramic insulating material and the wiring conductor. A space is provided in advance, and the molded body block is fitted into the space. A raw composite molded body was prepared, and on each of the main surfaces located at both ends in the laminating direction of the green composite molded body, a raw composite including a ceramic that did not sinter at the firing temperature of the green composite molded body was prepared. Disposing a sheet-shaped support, firing the green composite molded body in a state sandwiched by the sheet-shaped support, and incorporating the passive component therein; Obtaining a layered body, and then removing the unsintered sheet-shaped support. Each of the steps is provided. The difference in the coefficient of thermal expansion between the fired sheet-shaped support and the laminate is 2.5 × 10 ⁻⁶ degK ⁻¹ or more, a method for manufacturing a multilayer ceramic substrate. 5. The method according to claim 3, wherein the composite molded body is fired at a temperature of 1000 ° C. or less. 6. The method for manufacturing a multilayer ceramic substrate according to claim 5, wherein said second ceramic green sheet or said molded body block provides a capacitor or an inductor when sintered. 7. The method for manufacturing a multilayer ceramic substrate according to claim 6, wherein said second ceramic green sheet or said molded body block has a laminated structure forming a multilayer internal conductor. 8. The multilayer ceramic according to claim 7, wherein the inner conductor has at least one selected from the group consisting of Ag, Ag-Pt alloy, Ag-Pd alloy, Au, and Cu as a main component. Substrate manufacturing method. 9. The method for manufacturing a multilayer ceramic substrate according to claim 5, wherein the ceramic functional material includes crystallized glass or a mixture of glass and ceramic. 10. The ceramic insulating material is glass,
Or containing a mixture of glass and ceramic,
The method for manufacturing a multilayer ceramic substrate according to claim 2, wherein the weight ratio of the ceramic is selected within a range of 100/0 to 5/95. 11. The sheet-like support is made of ceramics such as Al ₂ O ₃ , MgO, CaO, SiO ₂ , Ba.
The method for producing a multilayer ceramic substrate according to claim 2, wherein the method comprises at least one oxide or composite oxide selected from O, ZrO ₂ , and CeO ₂ . 12. The wiring conductor according to claim 2, wherein the wiring conductor has at least one selected from the group consisting of Ag, Ag-Pt alloy, Ag-Pd alloy, Au, and Cu as a main component. A method for manufacturing the multilayer ceramic substrate according to any one of the above. 13. The method according to claim 1, wherein in the step of firing the green compact or the step of firing the green composite molded article, a load of 10 kg / cm ² or less is uniaxially applied to the sheet-like support. 13. The method for manufacturing a multilayer ceramic substrate according to any one of 12. 14. The step of removing the sheet-like support utilizes a stress acting between the sheet-like support and the laminate due to a difference in the coefficient of thermal expansion in a temperature lowering process after the baking step. The method for manufacturing a multilayer ceramic substrate according to any one of claims 1 to 13, further comprising a step of peeling the sheet-like support from the laminate.