JP3129261B2 - Method for manufacturing multilayer ceramic substrate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[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. A multilayer circuit board incorporating such passive components has been conventionally manufactured by the following various methods.

The first is a so-called thick film method, in which a dielectric paste or the like is printed on a green sheet for a substrate by a thick film forming technique, and then each green sheet is laminated and pressed.
Then, by firing, a capacitor or the like is partially built in the multilayer ceramic substrate. But,
The method for manufacturing the multilayer circuit board 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.

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

A third method is disclosed in, for example, JP-A-59-17232.
As described in the publication, in a method of incorporating the dielectric in the state of the sheet inside the multilayer substrate, in this case, a dielectric sheet having the same area as the substrate, sandwiched between the substrate sheets and laminated, After pressing, baking is performed. As a result, the problems of variations in characteristics such as capacitance and restrictions on increasing the capacity are improved, but the following problems are encountered. 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.

[0006] As a method for enabling high-density wiring of a multilayer circuit board, shrinking is performed on both upper and lower surfaces of a substrate laminate composed of a plurality of substrate green sheets that can be fired at a low temperature 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, these methods do not incorporate passive components in a substrate. 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 the dielectric portion is formed of 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 portion 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. However, there is a variation in shrinkage to the last, and when higher dimensional accuracy is required, the dimensional accuracy is not sufficient. More specifically, when the green sheet is sintered, the shrinkage rate is usually 2%.
This is about 0%, and the variation in shrinkage is about 0.5% in standard deviation, even if well managed. In contrast, in this method, the shrinkage rate is 0.1%, and the variation is expressed in standard deviation. 0.
It can be reduced to about 05%. However, when a high-density wiring requiring a dimensional accuracy higher than the shrinkage variation is performed, the shrinkage variation is not sufficiently small.

The shrinkage variation generated by the above-described fourth method is mainly caused by the dispersion of pores generated in the dummy green sheet which does not shrink at the sintering temperature of the substrate green sheet. More specifically, in the firing step, the temperature is raised from room temperature, and the organic components in the green sheet are decomposed, vaporized and desorbed, in a so-called degreasing step, each of the substrate green sheet and the dummy green sheet. Cavities, that is, pores, are formed in the portions where the organic components exist, and both the substrate green sheet and the dummy green sheet have a porous structure. When the temperature is further increased and the green sheet for a substrate starts to sinter, the dummy green sheet itself does not shrink at the substrate sintering temperature, but receives a force to shrink in the direction of the substrate surface from the green sheet for the substrate. At this time, since there is a space provided by the pores in the dummy green sheet, the particles in the dummy green sheet slightly move in the above-described contraction direction, and as a result, the dummy green sheet becomes the green sheet for the substrate. With it, it contracts slightly.

If the dummy green sheet is baked in a state where the dummy green sheet is separated from the substrate green sheet, the dummy green sheet does not receive a force in the contracting direction, so that the inside of the dummy green sheet does not receive any force. Particles do not move, and thus their shrinkage is also substantially 0%. As described above, the phenomenon caused by the particles in the dummy green sheet receiving the contracting force from the substrate green sheet is caused by the space provided by the pores generated in the degreasing process, that is, there is room for movement. However, the dispersed state of the pores in the dummy green sheet is slightly varied, so that the amount of movement of the particles also varies, and therefore, the amount of shrinkage of the dummy green sheet varies, and accordingly, the substrate green sheet is The amount of shrinkage will also vary.

[0013]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned various problems, and to incorporate a passive component, increase the number of functions, increase the density, and increase the accuracy. It is an object of the present invention to provide a method of manufacturing a multi-layer ceramic substrate capable of performing the above.

[0014]

SUMMARY OF THE INVENTION The present invention provides a laminate having a plurality of laminated ceramic layers made of a ceramic insulating material and a wiring conductor, and a passive component incorporated in the laminate while being wired by the wiring conductor. In order to solve the above-mentioned technical problem, a step of preparing a molded body block containing a raw ceramic functional material to be a passive component, comprising: A raw composite comprising a plurality of laminated ceramic green sheets and wiring conductors containing a ceramic insulating material different from the contained ceramic functional material, a space provided beforehand, and a molded block fitted into the space. A step of preparing a laminate, and forming a raw composite on each of the main surfaces located at both ends in the laminating direction of the prepared raw composite laminate. A step of arranging a raw sheet-like support containing a ceramic that is not sintered at the firing temperature of the laminate and a metal that can be oxidized in the firing step; And a step of removing the unsintered sheet-like support.

In the firing step included in the above-described manufacturing method, preferably, the composite laminate is fired at a temperature of 1000 ° C. or less. As described above, the composite laminate is 1000
When firing at a temperature of not more than ℃, the sheet-shaped support may be configured to contain, for example, alumina or zirconia as a ceramic.

Similarly, when the composite laminate is fired at a temperature of 1000 ° C. or less, the sheet-like support is composed of Sc, Ti, V, Cr, Mn, Fe, Co, Ni,
It preferably contains at least one selected from the group consisting of Cu, Zn, Si, Al, Mo and W, and more preferably, the weight ratio of metal / ceramic contained in the sheet-like support is 0.1 / 99.9 to 10.0 / 90.
It is selected within the range of 0.

As described above, the metal contained in the sheet-like support may be in the form of a powder, or when the sheet-like support contains an organic vehicle, the metal contained in the organic vehicle may be in the form of a powder. It may be in the state of an organic metal contained as a chain. In the firing step of the green composite laminate, it is preferable to apply a load of 10 kg / cm ² or less by placing a plate-shaped weight on the sheet-like support positioned above.

The passive components advantageously applied in the present invention are, for example, capacitors or inductors. Therefore, when the passive component is a capacitor or an inductor, a molded block that is to be a capacitor or an inductor when sintered is prepared. Note that the passive components incorporated in the multilayer ceramic substrate obtained by the manufacturing method according to the present invention are not limited to simple substances such as capacitors and inductors, and composites of these simple substances, for example, capacitors and inductors are combined. It may be an LC composite part or the like.

As the molded block, a molded block having a laminated structure for forming a multilayer internal conductor is advantageously applied. Further, the ceramic functional material contained in the molded body block preferably contains crystallized glass or a mixture of glass and ceramic. The ceramic insulating material contained in the ceramic green sheet included in the composite laminate includes glass or a mixture of glass and ceramic, and the weight ratio of glass / ceramic is selected from the range of 100/0 to 5/95. Preferably.

The wiring conductor or the inner conductor is made of Ag,
It is preferable that at least one selected from the group consisting of an Ag-Pt alloy, an Ag-Pd alloy, and Au is a main component.

[0021]

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, the multilayer ceramic substrate 1 includes 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. The laminated body 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 an external terminal conductor 19 on the outer surface.
a and 19b. Thus, the multilayer ceramic substrate 1 forms a circuit as shown in FIG.

The multilayer ceramic substrate 1 having such a configuration
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 capacitor block 10g including a raw ceramic functional material to be the above-described capacitor 10 and an inductor molded block 11g including a raw ceramic functional material to be the inductor 11 are 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 multilayered internal conductor 21 is formed via a raw dielectric sheet 20 including 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 multilayer 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 10g and 11g
Is preferably configured to be sinterable at a temperature of 1000 ° C. or less. Therefore, first, as the ceramic functional material contained in the dielectric sheet 20 and the magnetic material sheet 24, that is, the ceramic dielectric and the ceramic magnetic material, for example, crystallized glass or a mixture of glass and ceramic is advantageously used. . 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 forming 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 into a sheet by a doctor blade method is used. Can be.

The conductor 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 is, for example, Ag, Ag-Pt alloy, Ag-Pd Alloy, and A
A conductive paste containing at least one selected from the group consisting of u 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 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, the wiring conductors 13 to
Processing and treatment for providing the external terminal conductors 18a and 19b are provided in advance. More specifically, a series of through holes 30, 31, 3, which serve as spaces 29 for accommodating the molded body block 10 g for a capacitor.
2 and 33, and molded block 1 for inductor
A series of through-holes 35, 36, 37, and 38 which are to be spaces 34 for accommodating 1 g are previously provided in the ceramic green sheets 4g, 5g, 6g, and 7g, respectively.

Further, 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. Further, the conductive paste to be the wiring conductors 16 and 17 is applied to the ceramic green sheet 3g by screen printing or the like so as to be connected to the conductive paste in the through holes 45 and 47, respectively. 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 ruthenium oxide and an organic vehicle is advantageously used.

In the ceramic green sheet 8g, a conductive paste to be the wiring conductor 14 is connected to the conductive paste in the through hole 44 when the ceramic green sheets 2g to 8g are laminated, and the space 29 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.

As the conductive paste for providing the wiring conductors 13 to 18 and the external terminal conductors 19a and 19b, at least one selected from the group consisting of Ag, Ag-Pt alloy, Ag-Pd alloy, and Au is used. What is a main component is used advantageously. As the ceramic insulating material contained in the ceramic green sheets 2g to 8g, a material that can be fired at a temperature of 1000 ° C. or less is preferably used, and for example, glass or a mixture of glass and ceramic is used. In this case, the glass / ceramic weight ratio is between 100/0 and 5/9.
5 is selected. 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,
This is not preferable because the selection range of the materials for the wiring conductors 13 to 18 described above 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 laminate 1 g which becomes the multilayer ceramic substrate 1 when fired is as follows. Manufactured. First, ceramic green sheet 4g-7g,
As shown in FIG. 4, they are stacked in advance. Next, space 29
And 34 are fitted with molded body blocks 10g and 11g, respectively. At this time, the terminal electrodes 22, 2
3, 26 and 27 are exposed from the openings in each of the spaces 29 or. Then, for example, 500 kg / c
A pressing process using a hydraulic press of m ² is performed, and 4 g to 7 g of the ceramic green sheets are pressed. Thereby, the adhesion between the ceramic green sheets 4 g to 7 g is enhanced, and the molded body blocks 10 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, respectively, are laminated, whereby 1 g of a green composite laminate is obtained. In the state of the composite laminate 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-hole 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, raw sheet supports 48 and 49 are further provided which contain ceramics which do not sinter at the firing temperature of 1 g of the green composite laminate and metals which can be oxidized in the firing step. As described above, if both the molded body blocks 10 g and 11 g and the ceramic green sheets 2 g to 8 g can be fired at a temperature of 1000 ° C. or less, a raw composite laminate 1 g obtained by combining these can be fired at a temperature of 1000 ° C. or less. Since it can be fired, the material of the sheet-like supports 48 and 49 may be any material that does not sinter at 1000 ° C. As the sheet-like supports 48 and 49, for example, those obtained by forming a ceramic slurry obtained by mixing a ceramic powder such as alumina or zirconia, a metal powder, and an organic vehicle into a sheet by a doctor blade or the like are advantageously used. Can be

The metal contained in the sheet-like supports 48 and 49 may be contained in the form of metal powder as described above, or may be in the form of an organic metal contained as a side chain in the resin in the organic vehicle. . The metal contained in the sheet-like supports 48 and 49 is Sc, Ti,
V, Cr, Mn, Fe, Co, Ni, Cu, Zn, S
It is preferable to include at least one selected from the group consisting of i, Al, Mo and W, and the weight ratio of metal / ceramic contained in the sheet-like supports 48 and 49 is 0.1 / 99.9. More preferably, it is selected in the range of 10.0 / 90.0.

Such sheet-like supports 48 and 49
Is contained in the baking process in air.
Oxidizes below 00 ° C and expands. This fills the pores that may be generated in the sheet supports 48 and 49 during the degreasing process, and closes the space where the ceramic particles in the sheet supports 48 and 49 can move. as a result,
The sheet-like supports 48 and 49 do not substantially shrink even if a force is applied in the shrinking direction, because the ceramic particles contained therein cannot move.

When the above-mentioned metal is not contained, the sheet-like support slightly shrinks due to the pores generated in the degreasing process, and the dispersion of the pores varies slightly. , The contraction amount varies. On the other hand, when an appropriate amount of metal is included as in this embodiment, even if there is a slight variation in the dispersibility of the pores, the pores are filled with the oxide of the metal. As a result, the shrinkage of the sheet-like supports 48 and 49 is eliminated, and the variation is accordingly eliminated.

In order to fill the pores with a metal oxide, it is effective to selectively position the metal at a location where a resin as an organic substance causing pores is present. In view of this point, it can be said that it is more preferable to include such a metal as a side chain of the organic metal in the resin contained in the organic vehicle functioning as a binder in the sheet-like supports 48 and 49.

As described above, the weight ratio of metal / ceramic contained in the sheet supports 48 and 49 is preferably selected from the range of 0.1 / 99.9 to 10.0 / 90.0. The reason is that if the amount of metal is less than this range,
It becomes difficult for the metal oxide to sufficiently fill the pores. On the other hand, when the amount of the metal is larger than this range, the oxidative expansion of the metal exceeds the volume of the pores, and the porousness of the sheet-like supports 48 and 49 becomes large. This is because the structure is broken.

The raw sheet-like supports 48 and 49 are arranged on the main surfaces located at both ends in the stacking direction of the raw composite laminate 1g, that is, on the upper and lower main surfaces.
Then, the raw composite laminate 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, the raw composite laminate 1 g is fired at a temperature of 900 ° C. in an atmosphere containing oxygen, for example, in the air, while being sandwiched between the raw sheet-like supports 48 and 49. In this firing step, it is preferable to apply a load of 10 kg / cm ² or less by placing a plate-shaped weight (not shown) on the sheet-like support 48 located above. Due to this load, 1 g of the composite laminate is fired in the firing step.
However, undesired deformation such as slight warping can be avoided. Since this effect, even load exceed 10 kg / cm ^2, which is substantially the same as the case of 10 kg / cm ^2,
Loads exceeding 10 kg / cm ² are unnecessary.

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

Even after such a firing step, since the sheet supports 48 and 49 are not sintered, they can be easily peeled and removed, and after cooling, the sheet supports 48 and 49 can be removed. Is removed, whereby a desired multilayer ceramic substrate 1 can be taken out. The above-mentioned sheet supports 48 and 49 do not substantially shrink in the firing step. As described above, the metal contained in the sheet-like supports 48 and 49 is oxidized and expanded in the firing step, so that pores that can be generated in the degreasing process are filled, and the ceramic in the sheet-like supports 48 and 49 is filled. This is because the room where the particles can move is closed. Therefore, these sheet-like supports 48
X-Y during firing of 1 g of the composite laminate sandwiched between and 49
Shrinkage in the main surface direction of the ceramic green sheets 2g to 8g 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, capacitor 1
It has been confirmed that 0, the inductor 11 and the resistor 12 each exhibit characteristics as designed.

As described above, since shrinkage in the X and Y directions is suppressed, when firing the composite laminate 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.

As described above, the present invention has been described in relation to the illustrated embodiment. However, within the scope of the present invention,
Various modifications are possible. For example, the circuit design employed in the illustrated multilayer ceramic substrate 1 is only a typical example that allows an easier understanding of the present invention, and the present invention is also applicable to a multilayer ceramic substrate having various circuit designs. Can be equally applied.

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-described embodiment, the molded body blocks 10g and 11g
The spaces 29 and 34 for fitting the through holes 3 through holes 3 provided in the ceramic green sheets 4 g to 7 g, respectively.
Although formed by 0-33 and 35-38, 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.

[0050]

As described above, according to the method for manufacturing a multilayer ceramic substrate according to the present invention, the passive component incorporated in the multilayer body having the plurality of ceramic layers and the wiring conductors provided on the multilayer ceramic substrate includes: Since the molded block containing the raw ceramic functional material embedded in the structure is constituted by being sintered together with the firing of the laminate, the characteristics of the passive component itself are substantially at the stage of obtaining the molded block. The properties inherently determined and latent in the compact block will be substantially maintained after sintering. Therefore, if the molded block is manufactured properly, the characteristics of the passive components built into the multilayer ceramic substrate will be as designed, and therefore, the multilayer ceramic substrate as a whole must be supplied with stable quality. Will be able to From this,
It is possible to easily realize a multi-layer ceramic substrate with multi-functionality, higher density, higher precision, and higher performance.

Further, according to the present invention, since the passive components are completely embedded in the laminate, a multilayer ceramic substrate having high environmental resistance such as moisture resistance can be obtained. Further, according to the present invention, since the passive components can be arranged three-dimensionally in the multilayer ceramic substrate, the degree of freedom in design can be increased, and problems such as signal crosstalk can be advantageously avoided.

Further, according to the present invention, a molded block containing a raw ceramic functional material to be a passive component to be incorporated is prepared, and a raw composite laminate in which the raw molded block is embedded is fired. This eliminates the need to strictly control the shrinkage behavior during firing, compared to firing with embedded passive components that have been fired in advance, and the range of choices of materials that can be used in ceramic green sheets to be laminated. Can be expanded.

Further, according to the present invention, in the green composite laminate, a space for fitting a molded body block to be a passive component is provided in advance, so that the flatness of the obtained multilayer ceramic substrate is improved. It can be maintained well. Therefore, undesired deformation and disconnection of the wiring conductor can be made less likely to occur, so that high-density wiring can be performed with high dimensional accuracy while preventing variations in characteristics. It is possible to increase the number of stacked ceramic layers without any problem, and as a result, it is easy to improve the performance of the multilayer ceramic substrate.

Further, according to the present invention, on each main surface located at both ends in the laminating direction of the green composite laminate, the ceramic which does not sinter at the firing temperature of the green composite laminate and can be oxidized in the firing step. Since the raw composite laminate is fired while arranging the raw sheet-like support containing the metal, the metal contained in the sheet-like support is oxidized and expanded in the firing step, so that in the degreasing process, This advantageously fills the pores that may occur and closes the space for movement of the ceramic particles in the sheet-like support, so that the sheet-like support does not undergo substantial shrinkage during the firing step, so that these The shrinkage in the XY direction during firing of the composite laminate sandwiched between the sheet-like supports is suppressed. Therefore, the dimensional accuracy of the multilayer ceramic substrate can be further increased, and even if fine and high-density wiring is provided, problems such as disconnection can be further reduced. Also,
As described above, since the shrinkage in the XY directions is suppressed, when the composite laminate is fired to simultaneously fire the molded body block and the ceramic green sheet, each shrinkage of the molded body and the ceramic green sheet is reduced. It is easier to match the behavior to one another, so that the choice of the respective materials for the compact and the ceramic green sheet can be further expanded.

In the present invention, as the metal contained in the sheet-like support, Sc, Ti, V, Cr, Mn, Fe,
A material containing at least one selected from the group consisting of Co, Ni, Cu, Zn, Si, Al, Mo and W is used, and the weight ratio of metal / ceramic is 0.1 / 9.
When selected within the range of 9.9 to 10.0 / 90.0, the metal is oxidized at a firing temperature of 1000 ° C. or less, and it is more likely that the oxide of this metal will fill the pores with the proper and sufficient amount. It will be easier.

In the present invention, when the metal contained in the sheet-like support is included as a side chain of the organic metal in the resin contained in the organic vehicle functioning as a binder for the sheet-like support, Since the metal can be selectively located at the portion where the resin causing the pores is present, it is more effective to fill the pores with the metal oxide.

In the present invention, when the firing step is performed, a load of 10 kg / cm ² or less is applied by placing a plate-shaped weight on a sheet-like support positioned above. Thereby, it can be advantageously prevented that the composite laminate is undesirably deformed in the firing step, such as slightly warping.

In the present invention, if the molded body block to be a passive component 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 molded body block contains crystallized glass, or a mixture of glass and ceramic, or the ceramic insulating material contained in the ceramic green sheet provided in the composite laminate is 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, at a relatively low temperature of, for example, 1000 ° C. Can be fired. Therefore, Ag, Ag-Pt alloy, Ag-P
An alloy mainly containing at least one selected from the group consisting of d alloy and Au can be used without any problem. Further, as the ceramic contained in the above-mentioned sheet-shaped support, alumina or zirconia which is relatively easily available and is chemically stable can be used.

[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 laminate 2g-8g Ceramic green sheet 10g Capacitor block 11g Inductor block 48,49 Sheet support

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI C04B 35/64 C04B 35/65 35/65 H01L 21/48 H01L 21/48 H05K 1/16 H05K 1/16 1/18 1 / 18 C04B 35/64 G J (56) References JP-A-9-92983 (JP, A) U.S. Pat. No. 5,618,882 (US, A) EP 581294 (EP, A2) (58) Fields investigated (Int) .Cl. ⁷ , DB name) H05K 3/46 C04B 35/64 C04B 35/65 H01L 21/48 H05K 1/16 H05K 1/18

Claims (13)

(57) [Claims] 1. 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 molded body block including a raw ceramic functional material to be the passive component is provided. Prepared, comprising a plurality of laminated ceramic green sheets containing the ceramic insulating material different from the ceramic functional material and the wiring conductor, a space was previously provided inside, and the molded body block was fitted into the space. Preparing a green composite laminate, on each of the main surfaces located at both ends in the laminating direction of the green composite laminate, a ceramic that does not sinter at the firing temperature of the green composite laminate and is oxidized in a firing step A raw sheet-like support containing a metal to be obtained is arranged, and the green composite laminate is sandwiched between the sheet-like supports to form an atmosphere containing oxygen. A method for manufacturing a multilayer ceramic substrate, comprising: firing in the air; and removing the unsintered sheet-like support. 2. The method of claim 1, wherein the composite laminate is fired at a temperature of 1000 ° C. or less. 3. The method for manufacturing a multilayer ceramic substrate according to claim 2, wherein said sheet-shaped support includes alumina or zirconia as said ceramic. 4. The sheet-like support according to claim 1, wherein the metal includes Sc, Ti, V, Cr, Mn, Fe, Co, Ni,
4. The method for manufacturing a multilayer ceramic substrate according to claim 2, wherein the method includes at least one selected from the group consisting of Cu, Zn, Si, Al, Mo, and W. 5. 5. The method according to claim 4, wherein the weight ratio of the metal / the ceramic contained in the sheet-shaped support is selected from a range of 0.1 / 99.9 to 10.0 / 90.0. Of manufacturing a multilayer ceramic substrate. 6. The method for manufacturing a multilayer ceramic substrate according to claim 4, wherein the metal contained in the sheet-shaped support is in a powder state. 7. The sheet-shaped support further includes an organic vehicle containing a resin, and the metal included in the sheet-shaped support is in an organic metal state included as a side chain in the resin. Item 6. The method for producing a multilayer ceramic substrate according to item 4 or 5. 8. In the firing step of the green composite laminate, a load of 10 kg / cm ² or less is applied by placing a plate-like weight on the sheet-like support positioned above. 8. The method for producing a multilayer ceramic substrate according to any one of items 7. 9. The method for manufacturing a multilayer ceramic substrate according to claim 1, wherein a molded body block that becomes a capacitor or an inductor when sintered is prepared. 10. The method for manufacturing a multilayer ceramic substrate according to claim 1, wherein said molded body block has a laminated structure for forming a multilayer internal conductor. 11. The method for manufacturing a multilayer ceramic substrate according to claim 2, wherein the ceramic functional material contained in the molded body block includes crystallized glass or a mixture of glass and ceramic. 12. The ceramic insulating material included in the ceramic green sheet provided in the composite laminate includes glass or a mixture of glass and ceramic, and a weight ratio of glass / ceramic is 100/0 to 5/9.
The method for producing a multilayer ceramic substrate according to any one of claims 2 to 11, wherein the method is selected from the range of (5). 13. The wiring conductor or the inner conductor,
Ag, Ag-Pt alloy, Ag-Pd alloy, and at least one selected from the group consisting of Au as a main component,
A method for manufacturing a multilayer ceramic substrate according to claim 2.