JP2009241456A - Dielectric substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a boundary part whose dielectric constant is different from being peeled or broken up and to increase the thickness of a dielectric whose internal dielectric constant is different, in spite of a dielectric substrate a part of which is different in dielectric constant. <P>SOLUTION: A first dielectric substrate 10A includes a first ceramic fired body 12 having a first dielectric constant ε1 and a second ceramic fired body 14 formed around the first ceramic fired body 12 and having a second dielectric constant ε2. The first ceramic fired body 12 and the second ceramic fired body 14 are configured in such a manner that a first ceramic formed body 16 obtained by at least curing a mixture of a thermosetting resin precursor and first ceramic powder and a ceramic formed body 18 obtained by at least curing a slurry obtained by mixing the thermosetting resin precursor, second ceramic powder and a solvent, after the slurry is supplied to cover the first ceramic formed body 16 are fired. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a dielectric substrate having a partially different dielectric constant, and more particularly to a dielectric substrate suitable for use in an electronic component such as a capacitor or a high-frequency circuit using the difference in dielectric constant.

  For example, Patent Documents 1 to 3 have been proposed as electronic parts using dielectric substrates having different dielectric constants.

  In Patent Document 1, a branching circuit is integrally formed in a dielectric substrate, and a portion having a reception side filter and a transmission side filter in the dielectric substrate is made of a high dielectric constant material (for example, dielectric constant εr = 80). An example is disclosed in which a portion having a branching circuit is formed with a low dielectric constant material (for example, dielectric constant εr = 25). According to this Patent Document 1, in addition to the resonator constituting the filter, the lumped constant element constituting the branching circuit can be miniaturized.

  Patent Document 2 discloses a dielectric material having different dielectric constants for an upper ground electrode dielectric substrate, an interstage coupling capacitive dielectric substrate, a resonator dielectric substrate, and an input / output coupling capacitive dielectric substrate, that is, a high relative dielectric constant. And a composite dielectric substrate made of a first dielectric material having a low dielectric constant and a second dielectric material having a low relative dielectric constant. According to Patent Document 2, a low-loss dielectric filter can be provided.

  Patent Document 3 describes the following points. That is, a second multilayer dielectric film made of a dielectric film having a relative dielectric constant and a film thickness different from those of the dielectric film is formed on the first multilayer dielectric film made of a plurality of dielectric films. . An antenna element is formed on the second multilayer dielectric film. A ground conductor of the antenna element is formed between the first multilayer dielectric films. A strip-shaped conductor is formed on the opposite side of the ground conductor from the antenna element. A signal input to the strip-shaped conductor is electromagnetically coupled to the antenna element through a slot formed in the ground conductor to excite the antenna element. According to the cited document 3, a multiband microstrip antenna that can operate satisfactorily with each antenna having an optimum dielectric substrate thickness for a plurality of operating frequencies arbitrarily in a wide frequency range. Can be realized.

JP 2000-223910 A JP 2002-280805 A JP-A-9-51224

  By the way, in the case of configuring dielectric substrates having partially different dielectric constants, for example, a method shown in FIGS. 18A and 18B can be considered.

  That is, as shown in FIG. 18A, the lower conductor pattern 102a is formed by printing on the first green sheet 100 including the first ceramic powder having the first dielectric constant and the resin, and has the second dielectric constant thereon. A second green sheet 104 containing a second ceramic powder and a resin is laminated, and an upper conductor pattern 102b is formed thereon by printing.

  Thereafter, as shown in FIG. 18B, another first green sheet 100 is laminated on the entire surface, and then pressed and baked, so that the dielectric constant differs between the portion sandwiched between the pair of electrodes and the other portion. A dielectric substrate can be obtained.

  However, in this method, as shown in FIG. 19, the laminated film 106 including the lower conductor pattern 102a, the second green sheet 104, and the upper conductor pattern 102b is formed in a convex shape on the first green sheet. When the first green sheet 100 is laminated, no pressure is applied in the vicinity of the periphery of the laminated film 42, and after the lamination, peeling occurs or the end of the laminated film 42 is crushed, and the upper conductor pattern 102b Deteriorate electrical characteristics. In addition, because of these problems, the thickness of the lower conductor pattern 102a, the second green sheet 104, and the upper conductor pattern 102b cannot be increased. Therefore, the adjustment range of the capacitance value of the capacitor composed of a pair of electrodes and a dielectric existing between them. In addition, there is a problem in that there is a limit in reducing the resistance value, and there is a problem in that there is a limit in improving high frequency characteristics when applied to a high frequency circuit.

  Therefore, as shown in FIG. 20, the first green sheet 100, the second green sheet 104, and the first green sheet 100 having the same area are laminated to form a three-layer structure, and the first green sheet 100 and the second green sheet 104 are stacked. It is conceivable that the lower conductor pattern 102a and the upper conductor pattern 102b are interposed between the lower conductor pattern 102a and the upper conductor pattern 102b. Thereby, at least the formation of the convex shape by the second green sheet 104 can be avoided, and the frequency of peeling can be reduced. However, since the thickness of the lower conductor pattern 102a and the upper conductor pattern 102b cannot be increased, the problem that the resistance cannot be reduced remains.

  The present invention has been made in consideration of such problems, and although it is a dielectric substrate having a partially different dielectric constant, there is no peeling or collapse of a boundary portion having a different dielectric constant, and an internal dielectric constant. It is an object of the present invention to provide a dielectric substrate that can increase the thickness of different dielectrics and improve the degree of freedom in structural design and circuit design when used for circuit boards and circuit components.

  Another object of the present invention is to prevent the conductor pattern from peeling or collapsing even though it is a dielectric substrate having a different dielectric constant, and to increase the thickness of the conductor pattern, to reduce the resistance value, It is an object of the present invention to provide a dielectric substrate that can easily improve characteristics and that can improve the degree of freedom in structural design and circuit design when used for a circuit board or circuit component.

  A dielectric substrate according to the present invention includes a first ceramic molded body obtained by curing at least a mixture of a thermosetting resin precursor and a first ceramic powder in a dielectric substrate partially having different dielectric constants, and thermosetting. And a second ceramic molded body obtained by curing a slurry prepared by supplying a slurry in which a functional resin precursor, a second ceramic powder and a solvent are mixed so as to cover at least the first ceramic molded body. It is characterized by being.

  In the present invention, the first ceramic molded body may be obtained by molding a paste containing a thermosetting resin precursor and a first ceramic powder into a predetermined shape and then curing the paste. In this case, the first ceramic molded body may be formed by patterning the paste on a substrate and then curing. The second ceramic molded body may be obtained by applying the first ceramic molded body formed on the substrate so as to cover it and then curing it.

  In the present invention, the thermosetting resin precursor contained in the mixture may be a phenol resin or a polyurethane resin precursor. Further, the thermosetting resin precursor contained in the slurry may be a polyurethane resin precursor.

  In the present invention, the second ceramic molded body may be obtained by curing after supplying the slurry so as to cover the first ceramic molded body and the conductor molded body. In this case, the conductor molded body may be formed so as to be in contact with at least the first ceramic molded body. The conductor molded body is formed by patterning a conductor paste containing a thermosetting resin precursor and at least one powder of silver (Ag), gold (Au), or copper (Cu) based metal, and then cured. You may make it become. The thermosetting resin precursor contained in the conductor paste may be a phenol resin.

  As described above, according to the dielectric substrate according to the present invention, the conductor pattern does not peel or collapse even though the dielectric substrate is partially different in dielectric constant, and the thickness of the conductor pattern can be increased. It is possible to easily reduce the resistance value and improve the high frequency characteristics. In addition to the configuration where the dielectric constant is different for the entire specific layer, it can also be configured so that the dielectric constant is partially different, so the degree of freedom of structural design and circuit design when used for circuit boards and circuit components Can be improved.

  Embodiments of a dielectric substrate according to the present invention will be described below with reference to FIGS.

[First Embodiment]
First, as shown in FIG. 1, a dielectric substrate according to the first embodiment (hereinafter referred to as a first dielectric substrate 10A) includes a first ceramic fired body 12 having a first dielectric constant ε1, A second ceramic fired body 14 having a second dielectric constant ε2 formed around the first ceramic fired body 12.

  The first ceramic fired body 12 and the second ceramic fired body 14 are a first ceramic molded body 16 obtained by curing a mixture of at least a thermosetting resin precursor and a first ceramic powder, and a thermosetting resin precursor. And a second ceramic molded body 18 obtained by curing a slurry prepared by supplying a slurry in which the second ceramic powder and the solvent are mixed so as to cover at least the first ceramic molded body 16. .

  As shown in FIG. 2, the first dielectric substrate 10A has three pairs of electrodes (first upper electrode 20a, first lower electrode 20b, second upper electrode 22a, second lower electrode 22b, third upper electrode). By forming the electrode 24a and the third lower electrode 24b), a composite capacitor component 26 in which three capacitors C1 to C3 are formed on one first dielectric substrate 10A is formed.

  That is, the first capacitor C1 by the first upper electrode 20a and the first lower electrode 20b and a dielectric therebetween (second dielectric constant ε2), the second upper electrode 22a and the second lower electrode 22b, and the dielectric (first dielectric) 2nd dielectric constant ε2−first dielectric constant ε1−second dielectric constant ε2), the third capacitor C2, the third upper electrode 24a, the third lower electrode 24b, and the dielectric between them (second dielectric constant ε2). A composite capacitor component 26 having the capacitor C3 is formed. Of course, the first capacitor C1 and the third capacitor C3 may be integrated to surround the second capacitor C2.

  Here, a manufacturing method of the first dielectric substrate 10A will be described with reference to FIGS. 3A to 3C.

  First, as shown in FIG. 3A, a paste 28 containing a thermosetting resin precursor and a first ceramic powder is patterned by a printing method, and then cured (room temperature curing, dry curing, etc.) to form a first ceramic molded body 16. Get.

  Thereafter, as shown in FIG. 3B, the first ceramic molded body 16 is placed in the casting mold 30, and then a gel casting slurry (hereinafter, slurry 32) containing a thermosetting resin precursor, a second ceramic powder, and a solvent. 3) is cast into the casting mold 30 and then cured (room temperature curing, dry curing, etc.), thereby forming the second ceramic molded body 18 including the first ceramic molded body 16 therein as shown in FIG. 3C. Is obtained. The casting mold 30 is not a problem as long as the slurry 32 does not leak even if a part of the structure shown in cross section is opened.

  The thermosetting resin precursor used for the paste 28 is preferably a self-reactive resol type phenol resin.

  The thermosetting resin precursor used for the slurry 32 is preferably a polyurethane resin precursor.

  In the above-described example, the first ceramic molded body 16 is obtained by molding and curing the paste 28. In addition, another casting mold includes a thermosetting resin precursor, the first ceramic powder, and a solvent. After casting the gel casting slurry, the first ceramic molded body 16 may be obtained by curing. In this case, the thermosetting resin precursor is preferably a polyurethane resin precursor.

  Thus, in the first dielectric substrate 10A, since the slurry 32 contains the thermosetting resin precursor, the deformation of the portion around the first ceramic molded body 16 due to drying shrinkage at the time of curing of the slurry 32 is reduced. small. Accordingly, the deformation of the portion around the first ceramic molded body 16 in the second ceramic molded body 18 is also small. In addition, since the paste 28 also contains a thermosetting resin precursor, when the slurry 32 is injected into the casting mold 30 in which the first ceramic molded body 16 is installed, the first ceramic molded body 16 becomes the slurry 32. It is not easily dissolved in the solvent (improved solvent resistance), and the pattern shape does not collapse.

  Accordingly, although the first dielectric substrate 10A has a partly different dielectric constant, the boundary part having a different dielectric constant does not peel or collapse, and the dielectric has a different internal dielectric constant (first ceramic fired body 12). As shown in FIG. 2, the degree of freedom in structural design and circuit design when used for a circuit board or circuit component can be improved.

[Second Embodiment]
Next, a dielectric substrate according to a second embodiment (hereinafter referred to as a second dielectric substrate 10B) will be described with reference to FIGS. 4 to 7B.

  As shown in FIG. 4, the second dielectric substrate 10B has substantially the same structure as the first dielectric substrate 10A described above, but a part of the surface of the first ceramic fired body 12 is the second ceramic fired body. 14 in that it is exposed from one main surface (for example, the lower surface).

  Also in this case, as shown in FIG. 5, three pairs of electrodes (first upper electrode 20a, first lower electrode 20b, second upper electrode 22a, second lower electrode 22b, third electrode) are formed on the second dielectric substrate 10B. By forming the upper electrode 24a and the third lower electrode 24b), a composite capacitor component 26 in which three capacitors C1 to C3 are formed on one second dielectric substrate 10B is formed.

  That is, the first capacitor C1 by the first upper electrode 20a and the first lower electrode 20b and a dielectric therebetween (second dielectric constant ε2), the second upper electrode 22a and the second lower electrode 22b, and the dielectric (first dielectric) A second capacitor C2 having a second dielectric constant ε2-a first dielectric constant ε1), and a third capacitor C3 having a third upper electrode 24a, a third lower electrode 24b, and a dielectric (second dielectric constant ε2) therebetween. The capacitor component 26 is configured.

  Here, a manufacturing method of the second dielectric substrate 10B will be described with reference to FIGS. 6A to 7B.

  First, as shown in FIG. 6A, the paste 28 is patterned on the film 34 by a printing method and then cured to form the first ceramic molded body 16 on the film 34. The film 34 is PET (polyethylene terephthalate) whose surface is coated with a silicone release agent. In order to suppress the shrinkage and distortion during the heat curing of the paste 28, it is preferable to subject the film 34 to an annealing treatment for 10 minutes or more at a temperature of 150 ° C. in advance.

  Thereafter, as shown in FIG. 6B, the film 34 is placed in the casting mold 30, and the slurry 32 is cast into the casting mold 30 and then cured. Thereby, as shown in FIG. 6C, a second ceramic molded body 18 including the first ceramic molded body 16 is obtained. In this case, as shown in FIG. 7A, since the second ceramic molded body 18 is placed on the film 34, the second ceramic molded body 18 is replaced with the first ceramic molded body as shown in FIG. 7B. 16 is released from the film 34 and then fired, whereby a part of the first ceramic fired body 12 is exposed from one main surface of the second ceramic fired body 14 as shown in FIG. A dielectric substrate 10B is obtained.

  Thus, in the second dielectric substrate 10B as well, since the slurry 32 contains the thermosetting resin precursor, deformation of the portion around the first ceramic molded body 16 due to drying shrinkage at the time of curing of the slurry 32 is reduced. small. Accordingly, the deformation of the portion around the first ceramic molded body 16 in the second ceramic molded body 18 is also small, and one main surface of the second ceramic molded body 18 (one main surface of the first ceramic molded body 16 is exposed). The smoothness of the surface is also good. As shown in FIG. 8, this is also advantageous when a plurality of second ceramic molded bodies 18 including the first ceramic molded body 16 are laminated to form a ceramic laminated body 21, and adjacent second ceramic molded bodies 18. And the adjacent first ceramic molded body 16 and the second ceramic molded body 18 are in close contact with each other, and no peeling occurs between them.

[Third Embodiment]
Next, a dielectric substrate according to a third embodiment (hereinafter referred to as a third dielectric substrate 10C) will be described with reference to FIGS. 9 to 11B.

  As shown in FIG. 9, the third dielectric substrate 10C has substantially the same configuration as the second dielectric substrate 10B described above, but the first conductor pattern 36a and the second conductor pattern 36b are at least a first ceramic fired. It differs in that it is formed so as to contact the body 12.

  Specifically, the first ceramic fired body 12 is formed on the first conductor pattern 36a, and the second conductor pattern 36b is formed on the first ceramic fired body 12. The first conductor pattern 36a and the first ceramic The second ceramic fired body 14 is formed so as to include the multilayer body 37 of the fired body 12 and the second conductor pattern 36b.

  Here, a manufacturing method of the third dielectric substrate 10C will be described with reference to FIGS. 10A to 11B.

  First, as shown in FIG. 10A, the first conductor paste 38 a is patterned on the film 34 by a printing method and then cured to form the first conductor molded body 40 a on the film 34. Thereafter, the paste 28 is patterned on the first conductor molded body 40a by a printing method, and then cured to form the first ceramic molded body 16. Thereafter, the second conductor paste 38b is patterned on the first ceramic molded body 16 by a printing method and then cured to form the second conductor molded body 40b. At this stage, a laminated film 42 is formed on the film 34 by the first conductor molded body 40a, the first ceramic molded body 16 and the second conductor molded body 40b.

  Thereafter, as shown in FIG. 10B, the film 34 is placed in the casting mold 30, and the slurry 32 is cast into the casting mold 30 and then cured. Thereby, as shown in FIG. 10C, the second ceramic molded body 18 including the laminated film 42 is obtained. In this case, as shown in FIG. 11A, since the second ceramic molded body 18 is placed on the film 34, the second ceramic molded body 18 is filmed together with the laminated film 42 as shown in FIG. 11B. As shown in FIG. 9, the laminate 37 is wrapped with the second ceramic fired body 14, and a part of the surface of the laminate 37 is the second ceramic fired body. The third dielectric substrate 10 </ b> C exposed from one main surface of 14 is obtained.

  As described above, in the third dielectric substrate 10 </ b> C, since the slurry 32 includes the thermosetting resin precursor, deformation of the portion around the laminated film 42 due to drying shrinkage when the slurry 32 is cured is small. Accordingly, the deformation of the portion around the laminated film 42 in the second ceramic molded body 18 is also small, and the smoothness of one main surface of the second ceramic molded body 18 (the surface on which one main surface of the laminated film 42 is exposed). Will also be good. In addition to the first ceramic molded body 16, the first conductive paste 38 a and the second conductive paste 38 b also contain the thermosetting resin precursor, so that the slurry 32 is contained in the casting mold 30 in which the laminated film 42 is installed. The first conductor molded body 40a and the second conductor molded body 40b are not easily dissolved in the solvent of the slurry 32 (improvement of solvent resistance), and the pattern shape does not collapse.

  Therefore, although it is the third dielectric substrate 10C having a partly different dielectric constant, there is no peeling or collapse of the boundary part having a different dielectric constant, and the thickness of the dielectric having a different inner dielectric constant can be increased. The first conductor pattern 36a and the second conductor pattern 36b are not peeled off or collapsed, and the thickness of the first conductor pattern 36a and the second conductor pattern 36b can be increased to easily reduce the resistance value and improve the high-frequency characteristics. Can be planned. That is, also in the 3rd dielectric substrate 10C, the freedom degree of the structure design and circuit design at the time of using for a circuit board or a circuit component can be improved.

[Fourth Embodiment]
Next, a dielectric substrate according to a fourth embodiment (hereinafter referred to as a fourth dielectric substrate 10D) will be described with reference to FIGS.

  As shown in FIG. 12, the fourth dielectric substrate 10D has substantially the same configuration as the third dielectric substrate 10C described above, but the laminate 37 has the first conductor pattern 36a to the third conductor pattern 36c. It differs in that it has a multilayer structure.

  Specifically, the lower first ceramic fired body 12a is formed on the first conductor pattern 36a, the second conductor pattern 36b is formed on the lower first ceramic fired body 12a, and the second conductor pattern 36b is formed on the second conductor pattern 36b. An upper first ceramic fired body 12b is formed, and a third conductor pattern 36c is formed on the upper first ceramic fired body 12b. These first conductor pattern 36a, lower first ceramic fired body 12a, and second conductor pattern 36b. The second ceramic fired body 14 is formed so as to include a multilayered structure 37 composed of the upper first ceramic fired body 12b and the third conductor pattern 36c.

  Here, a method of manufacturing the fourth dielectric substrate 10D will be described with reference to FIGS. 13A to 14B.

  First, as shown in FIG. 13A, the first conductor paste 38 a is patterned on the film 34 by a printing method and then cured to form the first conductor molded body 40 a on the film 34. Then, after pattern-forming the 1st paste 28a on the 1st conductor molded object 40a by the printing method, it hardens | cures and the lower 1st ceramic molded object 16a is formed. Thereafter, the second conductor paste 38b is patterned on the lower first ceramic molded body 16a by a printing method and then cured to form the second conductor molded body 40b. Thereafter, the second paste 28b is patterned on the second conductor molded body 40b by a printing method and then cured to form the upper first ceramic molded body 16b. Thereafter, the third conductor paste 38c is patterned on the upper first ceramic molded body 16b by a printing method and then cured to form the third conductor molded body 40c. At this stage, the laminated film 42 is formed on the film 34 by the first conductor molded body 40a, the lower first ceramic molded body 16a, the second conductor molded body 40b, the upper first ceramic molded body 16b, and the third conductor molded body 40c. Is done.

  Thereafter, as shown in FIG. 13B, the film 34 is placed in the casting mold 30, and the slurry 32 is cast into the casting mold 30 and then cured. As a result, as shown in FIG. 13C, the second ceramic molded body 18 including the laminated film 42 is obtained. In this case, as shown in FIG. 14A, since the second ceramic molded body 18 is placed on the film 34, the second ceramic molded body 18 is filmed together with the laminated film 42 as shown in FIG. 14B. As shown in FIG. 12, the laminate 37 is wrapped with the second ceramic fired body 14 and part of the surface of the laminate 37 is the second ceramic fired body. 14, the fourth dielectric substrate 10 </ b> D exposed from one main surface is obtained.

  As described above, also in the fourth dielectric substrate 10D, the boundary portions having different dielectric constants do not peel off or collapse, the thickness of the dielectric having different internal dielectric constants can be increased, and the first conductor patterns 36a to 36d The third conductor pattern 36c is not peeled off or collapsed, and the thickness of the first conductor pattern 36a to the third conductor pattern 36c can be increased, so that the resistance value can be easily reduced and the high frequency characteristics can be easily improved. Note that the dielectric constant of the upper first ceramic fired body 12b may be a third dielectric constant ε3 different from the first dielectric constant ε1 and the second dielectric constant ε2.

  Here, the preferable aspect of each structural member with the manufacturing method (1st manufacturing method) using the casting mold 30 is demonstrated.

[First Conductive Paste 38a to Third Conductive Paste 38c: First Manufacturing Method]
As the first conductor paste 38a to the third conductor paste 38c, those containing an uncured material such as epoxy and phenol as a binder are preferable, but those containing a resol type phenol resin are particularly preferable. As for the metal powder, a simple substance or alloy of metal such as Ag, Pd, Au, Pt, Cu, Ni, Rh, or an intermetallic compound can be used. The oxygen partial pressure, temperature, and firing shrinkage temperature characteristics during firing are selected as appropriate. The firing shrinkage temperature characteristic is appropriately controlled not only by the metal powder composition but also by the particle size, specific surface area, and aggregation degree of the metal powder. As for the binder content in the first conductor paste 38a to the third conductor paste 38c, for example, in the case of Ag powder, a range of 1% to 10% of the weight of the metal powder is used. Considering the printability at the time, the range of 3 to 6% is preferable.

  As described above, the first conductor paste 38a to the third conductor paste 38c are heat-cured after printing. However, the curing conditions differ depending on the type of the curing agent, for example, the resol type used in the first embodiment. In the case of a phenol resin, it is cured at 120 ° C. for 10 to 60 minutes.

  A film 34 (in this case, a PET film) on which the first conductor molded body 40a to the third conductor molded body 40c are formed by the first conductor paste 38a to the third conductor paste 38c is installed in the casting mold 30. When installed in the casting mold 30, in order to suppress waviness of the PET film, it is adsorbed by means of vacuum adsorption, gluing, electrostatic adsorption or the like on a mold plate having a desired parallelism and flatness.

[Casting Die 30 (Mold): First Manufacturing Method]
The template uses a plate member corresponding to the suction means. For example, in the case of vacuum adsorption, regardless of the material such as metal, ceramic, resin, etc., use a porous plate or a plate with a large number of holes for adsorption. It is preferable to use a plate made of a material that does not change in quality even when the paste is wiped off, etc., and in the case of electrostatic adsorption, a plate made of a material that is easily electrostatically adsorbed with PET is preferably used.

  The casting mold 30 has a path through which the slurry 32 circulates, and a film 34 having a laminated film 42 formed between the mold plates so that the slurry 32 after casting and hardening has a plate shape with a desired thickness. It is preferable to install.

  The film 34 may be a PET film, a metal plate / ceramic plate coated with a release agent, a Teflon (registered trademark) resin plate, or the like.

  Then, a slurry 32 containing a reaction-curing resin is poured into the casting mold 30 and cured.

[Slurry 32: First production method]
Depending on the application, the slurry 32 includes oxide ceramics such as alumina, stabilized zirconia, various piezoelectric ceramic materials, various dielectric ceramic materials, nitride ceramics such as silicon nitride and aluminum nitride, and carbides such as silicon carbide and tungsten carbide. The ceramic powder containing a ceramic powder or a glass component as a binder is composed of an inorganic component and, for example, a dispersant and an organic compound that induces a chemical reaction between the gelling agent or the gelling agent.

  The slurry 32 contains an organic dispersion medium and a gelling agent in addition to the inorganic component powder, and may contain a dispersant and a catalyst for adjusting viscosity and solidification reaction. The organic dispersion medium may or may not have a reactive functional group. However, the organic dispersion medium particularly preferably has a reactive functional group.

  The following can be illustrated as an organic dispersion medium which has a reactive functional group.

  That is, the organic dispersion medium having a reactive functional group is a liquid substance that can chemically bond with the gelling agent and solidify the slurry 32, and a liquid substance that can form a highly fluid slurry 32 that can be easily cast. Two things need to be satisfied.

  In order to chemically bond with the gelling agent and solidify the slurry 32, a reactive functional group, that is, a functional group capable of forming a chemical bond with the gelling agent such as a hydroxyl group, a carboxyl group, or an amino group is included in the molecule. It is necessary to have. The dispersion medium need only have at least one reactive functional group, but in order to obtain a more solidified state, it is preferable to use an organic dispersion medium having two or more reactive functional groups. Examples of liquid substances having two or more reactive functional groups include polyhydric alcohols and polybasic acids. In addition, the reactive functional group in a molecule | numerator does not necessarily need to be the same kind of functional group, and a different functional group may be sufficient as it. Moreover, there may be many reactive functional groups like polyglycerol.

  On the other hand, in order to form a highly fluid slurry 32 that is easy to cast, it is preferable to use a liquid material having a viscosity as low as possible, and in particular, a material having a viscosity at 20 ° C. of 20 cps or less. Is preferred. Since the polyhydric alcohol and polybasic acid described above may have high viscosity due to the formation of hydrogen bonds, even if the slurry 32 can be solidified, it may not be preferable as a reactive dispersion medium. Therefore, it is preferable to use esters having two or more ester groups such as polybasic acid esters and acid esters of polyhydric alcohols as the organic dispersion medium. In addition, it is effective to use polyhydric alcohol or polybasic acid for strength reinforcement as long as the amount of the slurry 32 is not so thick. This is because esters are relatively stable, but can be sufficiently reacted with a highly reactive gelling agent and have a low viscosity, so the above two conditions are satisfied. In particular, an ester having a total carbon number of 20 or less can be suitably used as a reactive dispersion medium because of its low viscosity.

  Specific examples of the organic dispersion medium having a reactive functional group that may be contained in the slurry 32 include ester-based nonions, alcohol ethylene oxide, amine condensates, nonionic special amide compounds, modified polyester compounds, carboxyls. Examples thereof include a group-containing polymer, a maleic polyanion, a polycarboxylic acid ester, a multi-chain polymer nonionic system, a phosphoric acid ester, a sorbitan fatty acid ester, an alkylbenzenesulfonic acid Na, and a maleic acid compound. Examples of the non-reactive dispersion medium include hydrocarbon, ether, toluene and the like.

[Gelling agent: first production method]
The gelling agent contained in the slurry 32 reacts with the reactive functional group contained in the dispersion medium to cause a solidification reaction, and the following can be exemplified.

  That is, it is preferable that the viscosity of the gelling agent at 20 ° C. is 3000 cps or less. Specifically, it is preferable to solidify the slurry 32 by chemically bonding an organic dispersion medium having two or more ester groups and a gelling agent having an isocyanate group and / or an isothiocyanate group.

  Specifically, the reactive gelling agent is a substance that can chemically bond with the dispersion medium and solidify the slurry 32. Accordingly, the gelling agent only needs to have a reactive functional group capable of chemically reacting with the dispersion medium in the molecule. For example, a prepolymer (three-dimensionally cross-linked by adding a monomer, oligomer, or cross-linking agent) For example, any of polyvinyl alcohol, an epoxy resin, a phenol resin, etc. may be sufficient.

  However, as the reactive gelling agent, from the viewpoint of ensuring the fluidity of the slurry 32, it is preferable to use a material having a low viscosity, specifically, a material having a viscosity at 20 ° C. of 3000 cps or less.

  In general, since prepolymers and polymers having a large average molecular weight have high viscosity, in this example, monomers or oligomers having a molecular weight smaller than these, specifically, an average molecular weight (according to GPC method) of 2000 or less are used. It is preferable. Here, “viscosity” means the viscosity of the gelling agent itself (viscosity when the gelling agent is 100%), and a commercially available gelling agent diluted solution (for example, an aqueous solution of the gelling agent). It does not mean the viscosity of.

  The reactive functional group of the gelling agent is preferably selected as appropriate in consideration of the reactivity with the reactive dispersion medium. For example, when an ester having a relatively low reactivity is used as the reactive dispersion medium, a highly reactive isocyanate group (—N═C═O) and / or an isothiocyanate group (—N═C═S). It is preferred to select a gelling agent having

  Isocyanates are generally reacted with diols and diamines. However, diols are often highly viscous as described above, and diamines are too reactive so that the slurry 32 is cast before casting. May solidify.

  Also from such a viewpoint, it is preferable to solidify the slurry 32 by a reaction between a reactive dispersion medium composed of an ester and a gelling agent having an isocyanate group and / or an isothiocyanate group. In order to obtain it, it is preferable to solidify the slurry 32 by a reaction between a reactive dispersion medium having two or more ester groups and a gelling agent having an isocyanate group and / or an isothiocyanate group. In addition, it is effective to use diols and diamines for reinforcing the strength as long as the amount does not greatly increase the viscosity of the slurry 32.

  Examples of the gelling agent having an isocyanate group and / or an isothiocyanate group include MDI (4,4′-diphenylmethane diisocyanate) -based isocyanate (resin), HDI (hexamethylene diisocyanate) -based isocyanate ( Resin), TDI (tolylene diisocyanate) based isocyanate (resin), IPDI (isophorone diisocyanate) based isocyanate (resin), isothiocyanate (resin) and the like.

  In consideration of chemical characteristics such as compatibility with the reactive dispersion medium, it is preferable to introduce another functional group into the basic chemical structure described above. For example, when making it react with the reactive dispersion medium which consists of ester, it is preferable to introduce a hydrophilic functional group from the point which improves the compatibility with ester and improves the homogeneity at the time of mixing.

  The gelling agent molecule may contain a reactive functional group other than an isocyanate group or an isothiocyanate group, or an isocyanate group and an isothiocyanate group may be mixed. Furthermore, a large number of reactive functional groups may be present, such as polyisocyanate.

  In addition to the components described above, various additives such as an antifoaming agent, a surfactant, a sintering aid, a catalyst, a plasticizer, and a property improver may be added to the slurry 32.

  The slurry 32 described above can be produced as follows.

  (A) An inorganic powder is dispersed in a dispersion medium to form a slurry 32, and then a gelling agent is added.

  (B) The slurry 32 is produced by simultaneously adding and dispersing the inorganic powder and the gelling agent in the dispersion medium.

  Considering workability at the time of casting and coating, the viscosity of the slurry 32 at 20 ° C. is preferably 30000 cps or less, and more preferably 20000 cps or less. The viscosity of the slurry 32 depends not only on the viscosity of the reactive dispersion medium and the gelling agent described above, but also on the type of powder, the amount of the dispersant, and the concentration of the slurry 32 (powder volume% with respect to the total volume of the slurry 32). Can be adjusted.

  However, the concentration of the slurry 32 is usually preferably 25 to 75% by volume, and more preferably 35 to 75% by volume in consideration of reducing cracks due to drying shrinkage. It has a dispersion medium, a dispersant, a reaction cured product, and a reaction catalyst as organic components. Among these, for example, it is solidified by a chemical reaction between the dispersion medium and the gelling agent or the gelling agent.

  In the above-described example, the first dielectric substrate 10A to the fourth dielectric substrate 10D are manufactured using the casting mold 30. In addition, the first dielectric substrate 10A to the fourth dielectric are applied by applying the slurry 32. The body substrate 10D can also be manufactured.

  As an example, a method of manufacturing the third dielectric substrate 10C by applying the slurry 32 will be described with reference to FIGS. 15A to 17B.

  First, as shown in FIG. 15A, the first conductor paste 38 a is patterned on the base 64 by a printing method and then cured to form the first conductor molded body 40 a on the base 64. Thereafter, the paste 28 is patterned on the first conductor molded body 40a by a printing method, and then cured to form the first ceramic molded body 16. Thereafter, the second conductor paste 38b is patterned on the first ceramic molded body 16 by a printing method and then cured to form the second conductor molded body 40b. At this stage, the laminated film 42 of the first conductor molded body 40a, the first ceramic molded body 16 and the second conductor molded body 40b is formed on the base body 64. In addition, the base | substrate 64 can use PET (polyethylene terephthalate) by which the silicone release agent was coated on the surface similarly to the film 34 mentioned above.

  Thereafter, as shown in FIG. 15B, the slurry 32 in which the thermosetting resin precursor, the second ceramic powder, and the solvent are mixed is applied onto the substrate 64 so as to cover the laminated film 42. Examples of the application method include a dispenser method, a method shown in FIGS. 16A and 16B, a spin coating method, and the like. In the method shown in FIGS. 16A and 16B, a base 64 (base 64 on which the laminated film 42 is formed) is installed between the pair of guide plates 66a and 66b, and then the slurry 32 is coated with the laminated film 42. Then, after applying onto the base body 64, the blade-like jig 68 is slid (slid) on the upper surfaces of the pair of guide plates 66a and 66b to remove excess slurry 32. By adjusting the height of the pair of guide plates 66a and 66b, the thickness of the slurry 32 can be easily adjusted.

  Thereafter, as shown in FIG. 17A, the slurry 32 applied on the base 64 is cured, and further, as shown in FIG. 17B, the base 64 is peeled off and removed, whereby the second ceramic including the laminated film 42 is obtained. A molded body 18 is obtained. Also in this case, the smoothness of one main surface of the second ceramic molded body 18 (the surface on which one main surface of the laminated film 42 is exposed) is good.

  Then, by firing the second ceramic molded body 18 including the multilayer film 42, as shown in FIG. 9, a part of the surface of the multilayer body 37 is exposed from one main surface of the second ceramic fired body 14. A three-dielectric substrate 10C is obtained.

  Here, the preferable aspect of each structural member in the manufacturing method (2nd manufacturing method) using the application | coating method is demonstrated.

[First Conductive Paste 38a to Third Conductive Paste 38c: Second Manufacturing Method]
Since it is the same as the 1st manufacturing method, the overlapping description is omitted, but the 1st conductor paste 38a-the 3rd conductor paste 38c in the 2nd manufacturing method are resin, silver (Ag), gold (Au), copper ( Cu) based metal containing at least one kind of powder. The resin used for the first conductor paste 38a to the third conductor paste 38c is preferably a thermosetting resin precursor. In this case, the thermosetting resin precursor is preferably a self-reactive resol type phenol resin.

  As described above, the first conductor paste 38a to the third conductor paste 38c are heat-cured after printing. However, the curing conditions differ depending on the type of the curing agent, and for example, the resol type phenol used in the second manufacturing method. In the case of a resin, it can be cured at a temperature of 80 to 150 ° C. for a time of 10 to 60 minutes.

[Slurry 32: Second production method]
Since it is the same as the first manufacturing method, overlapping description is omitted, but the ceramic powder contained in the slurry 32 in the second manufacturing method is alumina, stabilized zirconia, various piezoelectric ceramic materials, various dielectrics depending on the application. It includes oxide ceramics such as ceramic materials, nitride ceramics such as silicon nitride and aluminum nitride, carbide ceramic powders such as silicon carbide and tungsten carbide, and glass components as binders.

  The thermosetting resin precursor contained in the slurry 32 includes a gelling agent having an isocyanate group or an isothiocyanate group and a polymer having a hydroxyl group.

  Among the application methods described above, when the slurry 32 is applied onto the substrate 64 by the dispenser method or the method shown in FIGS. 16A and 16B, the viscosity of the slurry 32 is preferably relatively high. The viscosity of the slurry 32 may be the same as that of the first manufacturing method. However, if the slurry 32 has a low viscosity, the shape retaining property after coating is low, and thickness variation due to flow tends to occur. Therefore, the viscosity of the slurry 32 is preferably 200 cps to 2000 cps.

  Therefore, the viscosity of the slurry 32 can be increased by using a resin having a large molecular weight as the polymer having a hydroxyl group. As an example, since the butyral resin has a large molecular weight, it is suitable for increasing the viscosity of the slurry 32. Of course, since the viscosity of the slurry 32 can be controlled by the molecular weight of the polymer, the resin used as the polymer may be appropriately selected according to the coating method.

  The above-mentioned butyral resin is generally a polyvinyl acetal resin, but since OH groups derived from the raw material polyvinyl alcohol resin remain in the resin, this OH group reacts with the isocyanate group or isothiocyanate group of the gelling agent. It is considered a thing.

  In particular, when a butyral resin is added in excess of the amount necessary for the reaction with an isocyanate group or an isothiocyanate group, the butyral resin remaining after the reaction acts as a thermoplastic resin, which is a drawback of the thermosetting resin. The characteristic that the adhesiveness is deteriorated can be improved. As a result, for example, as shown in FIG. 8, when a plurality of second ceramic molded bodies 18 are laminated to form a ceramic laminated body 21, the adhesiveness of each second ceramic molded body 18 is improved. Inconvenience that the second ceramic molded body 18 is peeled off during the process can be avoided, and the yield of the dielectric substrate by the ceramic laminate 21 of the plurality of second ceramic molded bodies 18 can be improved.

  In addition, as the polymer having a hydroxyl group, an ethyl cellulose resin, a polyethylene glycol resin, or a polyether resin can be preferably used.

  Next, the problems of the conventional dielectric substrate using a thermoplastic resin precursor as the resin contained in the slurry, and the first dielectric substrate 10A to the fourth dielectric substrate 10D (hereinafter collectively referred to as the present embodiment). To solve the problem. The first conductor paste 38a to the third conductor paste 38c are collectively referred to as a conductor paste 38, and the first conductor molded body 40a to the third conductor molded body 40c are collectively referred to as a conductor molded body 40.

  Conventionally, gaps and cracks are generated at the interface with the conductor molded body during drying shrinkage of the slurry containing the thermoplastic resin, or the green sheet becomes uneven.

  On the other hand, in the present embodiment, the above-mentioned problem is caused by including a thermosetting resin precursor in the slurry 32, curing the thermosetting resin precursor during drying to generate a three-dimensional network structure, and reducing shrinkage. Is solved.

  In this case, it is desirable to select a solvent having a low vapor pressure at a temperature at which the thermosetting resin precursor is cured as the solvent used for the slurry 32, and to reduce shrinkage due to solvent drying during thermosetting. When a resin that cures at room temperature is used, operations and equipment are particularly simplified.

  Polyurethane resin has advantages such as easy control of elasticity after curing and also enables a flexible molded body. Considering the handling in the subsequent process, a hard molded body may not be suitable, and the thermosetting resin is generally hard because it has a three-dimensional network structure, but the polyurethane resin can also be a flexible molded body, In particular, a tape-shaped molded body is desirable because flexibility is often required. Further, a thermoplastic resin may be included for controlling the slurry properties.

  Conventionally, when a paste or a conductive paste containing a thermoplastic resin is applied to a slurry, the paste is dissolved in the solvent of the slurry and the pattern shape is lost.

  On the other hand, in the present embodiment, since the thermosetting resin precursor is included in the paste 28 or the conductive paste 38, the solvent resistance is improved and the pattern shape is not broken.

  Since the thermosetting resin precursor has a three-dimensional network structure after curing and does not return to its original state, it does not have re-solubility in a solvent after curing, and generally has higher solvent resistance than a thermoplastic resin.

  Among thermosetting resin precursors, phenol resin, epoxy resin, and polyester resin are preferable because they can control the molecular weight of the prepolymer before curing and can control the paste properties. In addition, you may make it include a thermoplastic resin with a thermosetting resin for control of paste property.

  In particular, epoxy resins and phenol resins do not require a curing agent and are of a type that cures only by heating and are suitable for efficient use of the conductive paste 38. That is, other thermosetting resin precursors that require the addition of a curing agent need to be mixed with the curing agent before printing the paste 28 or the conductive paste 38, but cannot be stored when mixed. Therefore, when the paste 28 or the conductor paste 38 is printed by a printing method that needs to collect and store the paste 28 or the conductor paste 38 remaining after printing, a thermosetting epoxy resin that does not need to be mixed with a curing agent, A thermosetting phenol resin is preferred.

  Conventionally, a ceramic molded body using a thermoplastic resin as a binder is likely to have a density variation of the ceramic molded body. Therefore, the dimensional variation of the fired ceramic sintered body is large, and the embedded conductor molded body is fired. Variations in dimensions also increase.

  On the other hand, in the present embodiment, by using the thermosetting resin precursor as a binder to obtain the second ceramic molded body 18 in which the first ceramic molded body 16 and the conductor molded body 40 are embedded, the firing variation is reduced. can do.

  For example, the size after firing of the second ceramic molded body 18 is mainly determined by the raw density of the second ceramic molded body 18 excluding the first ceramic molded body 16 and the conductor molded body 40. This is because the structure of the second ceramic fired body 14 has very few voids, whereas the portion of the second ceramic molded body 18 has many voids, so the amount of the voids determines the amount of shrinkage during firing. It is.

  A slurry containing a conventional thermoplastic resin as a binder obtains a ceramic molded body by drying the solvent. However, the coating ratio (ratio of the slurry volume and the molded body volume after molding) during drying is large. The work ratio causes variation in the density of the compact.

  However, when the thermosetting resin precursor is used as the binder of the slurry 32 as in the present embodiment, the coating ratio can be reduced because the resin is cured while containing the solvent, and the raw density can be reduced. Variation can be reduced. As a result, the dimensional variation after firing is reduced, and the dimensional variation of the embedded first ceramic molded body 16 and conductor molded body 40 can be reduced.

  In addition, the dielectric substrate according to the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

It is sectional drawing which shows a 1st dielectric substrate. It is sectional drawing which shows the example which comprised the composite capacitor | condenser component using the 1st dielectric substrate. FIG. 3A is a cross-sectional view showing a state in which a first ceramic molded body is formed from paste, and FIG. 3B is a cross-sectional view showing a state in which slurry is injected into the casting mold after the first ceramic molded body is installed in the casting mold. FIG. 3C is a cross-sectional view showing a state in which the slurry injected into the casting mold is cured to form a second ceramic molded body. It is sectional drawing which shows a 2nd dielectric substrate. It is sectional drawing which shows the example which comprised the composite capacitor | condenser component using the 2nd dielectric substrate. FIG. 6A is a cross-sectional view showing a state in which a first ceramic molded body is formed on the film by a paste, and FIG. 6B is a cross-sectional view showing a state in which slurry is injected into the casting mold after the film is installed in the casting mold. FIG. 6C is a cross-sectional view showing a state in which the slurry injected into the casting mold is cured to form a second ceramic molded body. 7A is a cross-sectional view showing a state in which the second ceramic molded body is released from the casting mold together with the film, and FIG. 7B is a cross-sectional view showing a state in which the second ceramic molded body is released from the film together with the first ceramic molded body. It is. It is sectional drawing which shows a ceramic laminated body. It is sectional drawing which shows a 3rd dielectric substrate. 10A is a cross-sectional view showing a state in which a laminated film is formed on the film, and FIG. 10B is a cross-sectional view showing a state in which slurry is injected into the casting mold after the film is placed in the casting mold. FIG. 3 is a cross-sectional view showing a state in which a slurry injected into a casting mold is cured to form a second ceramic molded body. FIG. 11A is a cross-sectional view showing a state where the second ceramic molded body is released from the casting mold together with the film, and FIG. 11B is a cross-sectional view showing a state where the second ceramic molded body is released from the film together with the laminated film. It is sectional drawing which shows a 4th dielectric substrate. 13A is a cross-sectional view showing a state in which a laminated film is formed on the film, and FIG. 13B is a cross-sectional view showing a state in which slurry is injected into the casting mold after the film is installed in the casting mold. FIG. 3 is a cross-sectional view showing a state in which a slurry injected into a casting mold is cured to form a second ceramic molded body. 14A is a cross-sectional view showing a state in which the second ceramic molded body is released from the casting mold together with the film, and FIG. 14B is a cross-sectional view showing a state in which the second ceramic molded body is released from the film together with the laminated film. FIG. 15A is a cross-sectional view showing a state in which a laminated film is formed on a substrate, and FIG. 15B is a cross-sectional view showing a state in which slurry is applied on the substrate so as to cover the laminated film. FIG. 16A is a perspective view showing an example of a method for applying slurry on a substrate, and FIG. 16B is a side view thereof. FIG. 17A is a cross-sectional view showing a state in which the slurry applied on the base is cured, and FIG. 17B is a cross-sectional view showing a state in which the base is peeled to form a second ceramic molded body. 18A is a cross-sectional view showing a state in which a laminated film is formed on the first green sheet, and FIG. 18B is a cross-sectional view showing a state in which another first green sheet is laminated. It is explanatory drawing which shows the state which peeled around the laminated film. It is sectional drawing which shows the state which made the green sheet of the same area the 3 layer structure.

Explanation of symbols

10A to 10D: 1st dielectric substrate to 4th dielectric substrate 12 ... 1st ceramic fired body 14 ... 2nd ceramic fired body 16 ... 1st ceramic molded body 18 ... 2nd ceramic molded body 21 ... Ceramic laminated body 28 ... Paste 30 ... Casting mold 32 ... Slurry 34 ... Film 36a ... First conductor pattern 36b ... Second conductor pattern 37 ... Laminated body 38a ... First conductor paste 38b ... Second conductor paste 40a ... First conductor molded body 40b ... Second Conductor compact 42 ... laminated film 64 ... substrate

Claims (10)

For dielectric substrates with different dielectric constants,
At least a first ceramic molded body obtained by curing a mixture of at least a thermosetting resin precursor and a first ceramic powder, and a slurry in which a thermosetting resin precursor, a second ceramic powder and a solvent are mixed, A dielectric substrate comprising: a second ceramic molded body obtained by curing after being supplied so as to cover the first ceramic molded body. The dielectric substrate according to claim 1,
The first ceramic molded body is obtained by molding a paste containing a thermosetting resin precursor and a first ceramic powder into a predetermined shape and then curing the paste. The dielectric substrate according to claim 2, wherein
The first ceramic molded body is obtained by patterning the paste on a substrate and then curing the paste. The dielectric substrate according to claim 3, wherein
The dielectric substrate according to claim 1, wherein the second ceramic molded body is obtained by applying the first ceramic molded body formed on the substrate so as to cover it and then curing it. The dielectric substrate according to any one of claims 1 to 4,
The dielectric substrate, wherein the thermosetting resin precursor contained in the mixture is a phenol resin or a polyurethane resin precursor. In the dielectric substrate according to any one of claims 1 to 5,
The dielectric substrate, wherein the thermosetting resin precursor contained in the slurry is a polyurethane resin precursor. The dielectric substrate according to any one of claims 1 to 6,
The second ceramic molded body is obtained by curing after supplying the slurry so as to cover the first ceramic molded body and the conductor molded body. The dielectric substrate according to claim 7, wherein
The dielectric substrate, wherein the conductor molded body is formed so as to be in contact with at least the first ceramic molded body. The dielectric substrate according to claim 7 or 8,
The conductor molded body is formed by patterning a conductor paste containing a thermosetting resin precursor and at least one powder of silver (Ag), gold (Au), or copper (Cu) based metal, and then cured. A dielectric substrate characterized by comprising: The dielectric substrate according to claim 9, wherein
The dielectric substrate, wherein the thermosetting resin precursor contained in the conductor paste is a phenol resin.

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