JP6195479B2 - Multilayer ceramic substrate and manufacturing method thereof - Google Patents

Description

  The present invention relates to a multilayer ceramic substrate and a manufacturing method thereof.

  In the process of manufacturing a multilayer ceramic substrate, a plurality of green sheets that are the basis of an insulating layer made of an insulating ceramic are printed with a conductor paste that is the basis of a conductor pattern, and then the plurality of green sheets are laminated and fired. . A multilayer ceramic substrate may be warped during firing due to the difference in firing shrinkage between the insulating layer and the conductor pattern and the bias of the conductor pattern. The firing shrinkage ratio is the ratio of the size that shrinks during firing to the size before firing.

  In Patent Documents 1 and 2, in order to suppress warping during firing, on the surface of the insulating layer, outside the conductor pattern constituting the circuit to be realized by the multilayer ceramic substrate, the conductor pattern constituting the circuit is It is described that different dummy patterns are provided. In Patent Document 3, in order to suppress warping caused by forming a plating layer on the back surface of a multilayer ceramic substrate, the average of ceramics is generated so that warping during firing occurs in a direction opposite to warpage due to the plating layer. An insulating layer having a relatively large particle size, a conductor pattern that occupies 50% or more of the surface of the insulating layer, and a dummy pattern along the outer periphery of the conductor pattern may be disposed closer to the surface of the multilayer ceramic substrate. Have been described.

Japanese Patent Laid-Open No. 9-260844 JP 2006-108529 A JP 2008-270751 A

  In the multilayer ceramic substrate of Patent Documents 1 to 3, the shape and arrangement of the dummy pattern is limited depending on the conductor pattern that forms the circuit to be realized by the multilayer ceramic substrate, so that warping during firing may not be sufficiently suppressed. There was a problem that there was. This problem becomes more prominent when the multilayer ceramic substrate is miniaturized, densified and thinned.

  The present invention has been made to solve the above-described problems, and can be realized as the following forms.

(1) According to one aspect of the present invention, a multilayer ceramic substrate is provided. The multilayer ceramic substrate is made of an insulating ceramic and includes a plurality of laminated insulating layers; at least one first layer of the plurality of insulating layers; and the plurality of insulating layers among outer surfaces of the plurality of insulating layers. At least one wiring layer which is provided on at least one of the outer surfaces facing the stacking direction and has conductivity, and forms wiring; and has at least one wiring layer having conductivity; And at least one through conductor that is electrically connected and penetrates at least one of the insulating layers. The multilayer ceramic substrate is further formed by firing a material having a firing shrinkage ratio higher than that of the wiring layer, and the first interlayer in which the wiring layer is provided among the layers in the plurality of insulating layers. Are provided between different second layers and include a dummy layer electrically insulated from the wiring layer and the through conductor; the dummy layer bisects the multilayer ceramic substrate based on the thickness in the stacking direction. Of the two regions, the region exists in the region where the total volume of the wiring layer in each region is smaller. According to this embodiment, warpage during firing in the multilayer ceramic substrate can be effectively suppressed by the dummy layer.

(2) In the multilayer ceramic substrate described above, the area of the dummy layer viewed from the stacking direction may be larger than the area of each of the plurality of wiring layers viewed from the stacking direction. According to this embodiment, warping during firing in the multilayer ceramic substrate can be more effectively suppressed by the dummy layer having a larger area than the wiring layer.

(3) In the above-mentioned multilayer ceramic substrate, the second interlayer provided with the dummy layer is all the outer surface facing the stacking direction in the region on the side where the dummy layer is present. It may exist in a position closer than the first layer. According to this form, the warp at the time of firing in the multilayer ceramic substrate can be more effectively suppressed by the dummy layer present at a position closer to the outer surface as compared with the first interlayer.

(4) In the multilayer ceramic substrate described above, the dummy layer may be at least one of a conductor and a dielectric. According to this embodiment, a dummy layer can be realized using at least one of a conductor and a dielectric.

  The present invention can be realized in various forms other than the multilayer ceramic substrate. For example, it can be realized in the form of a device including a multilayer ceramic substrate, a method for manufacturing a multilayer ceramic substrate, and the like.

It is explanatory drawing which shows the cross section of a multilayer ceramic substrate typically. It is explanatory drawing which shows the cross section cut | disconnected in the position in which the dummy layer in a multilayer ceramic substrate exists. It is process drawing which shows the manufacturing method of a multilayer ceramic substrate. It is a table | surface which shows the result of the evaluation test which evaluates the curvature at the time of baking.

A. Embodiment A-1. Configuration of Multilayer Ceramic Substrate FIG. 1 is an explanatory diagram schematically showing a cross section of a multilayer ceramic substrate 10. The multilayer ceramic substrate 10 is formed with at least a part of a circuit that realizes a predetermined function. In the present embodiment, the multilayer ceramic substrate 10 is formed with a circuit constituting a surface acoustic wave (SAW) diplexer. The multilayer ceramic substrate 10 includes a plurality of insulating layers 200, a plurality of wiring layers 400, a plurality of through conductors 500, and a dummy layer 600.

  FIG. 1 shows XYZ axes orthogonal to each other. Of the XYZ axes in FIG. 1, the X axis is an axis from the left side of FIG. 1 toward the right side of the page, the + X axis direction is a direction toward the right side of the page, and the −X axis direction is a direction toward the left side of the page. It is. Of the XYZ axes in FIG. 1, the Y axis is an axis from the front of the paper to the back of the paper in FIG. 1, the + Y axis direction is a direction toward the back of the paper, and the −Y axis direction is a direction toward the front of the paper. It is. Among the XYZ axes in FIG. 1, the Z axis is an axis that goes from the bottom of FIG. 1 to the top of the paper, the + Z axis direction is a direction that goes on the paper, and the −Z axis direction is a direction that goes down the paper. It is.

The plurality of insulating layers 200 in the multilayer ceramic substrate 10 are made of an insulating ceramic. In this embodiment, the insulating layer 200 is formed by firing a material obtained by mixing a borosilicate glass powder and an alumina (Al ₂ O ₃ ) powder in a mass ratio of 50:50, and constitutes the insulating layer 200. The ceramic is mainly composed of borosilicate glass and alumina. Borosilicate glass is mainly composed of silicon dioxide (SiO ₂ ), alumina (Al ₂ O ₃ ), and boron oxide (B ₂ O ₃ ).

  The plurality of insulating layers 200 are sintered bodies that are sintered in a stacked state. In the present embodiment, the stacking direction in which the plurality of insulating layers 200 are stacked is the Z-axis direction along the Z-axis. In the present embodiment, the insulating layer 200 is a layer extending in a rectangular shape along the X axis and the Y axis.

  In the present embodiment, the plurality of insulating layers 200 are six layers, and sequentially in the + Z-axis direction, the insulating layer 201, the insulating layer 202, the insulating layer 203, the insulating layer 204, the insulating layer 205, An insulating layer 206. In the description of the present embodiment, the reference numeral “200” is used when collectively referring to the insulating layers of the multilayer ceramic substrate 10, and the reference numerals “201 to 206” are used when the insulating layers of the multilayer ceramic substrate 10 are individually indicated. To do.

  The insulating layer 201 has a surface 310 facing the −Z axis direction. The surface 310 of the insulating layer 201 is an outer surface facing the −Z-axis direction among the outer surfaces of the plurality of insulating layers 200.

  The insulating layer 206 has a surface 330 facing the + Z-axis direction. The surface 330 of the insulating layer 206 is an outer surface facing the + Z-axis direction among the outer surfaces of the plurality of insulating layers 200.

  A plurality of layers 320 are formed between the insulating layers 200 in the plurality of insulating layers 200. In the present embodiment, the plurality of layers 320 includes five layers 321, 322, 323, 324, and 325. In the description of the present embodiment, the symbol “320” is used when referring to the layers of the multilayer ceramic substrate 10, and the symbols “321 to 325” are used when indicating the layers of the multilayer ceramic substrate 10 individually.

  Between the insulating layer 201 and the insulating layer 202, an interlayer 321 that is a first interlayer provided with the wiring layer 400 is formed. Between the insulating layer 202 and the insulating layer 203, an interlayer 322 that is a first interlayer provided with the wiring layer 400 is formed. Between the insulating layer 203 and the insulating layer 204, an interlayer 323 which is a first interlayer provided with the wiring layer 400 is formed. An interlayer 324 that is a first interlayer provided with the wiring layer 400 is formed between the insulating layer 204 and the insulating layer 205. Between the insulating layer 205 and the insulating layer 206, an interlayer 325 which is a second interlayer provided with the dummy layer 600 is formed.

  The plurality of wiring layers 400 in the multilayer ceramic substrate 10 have conductivity and form wiring. In the present embodiment, the wiring layer 400 is formed by firing a conductive paste prepared from silver (Ag) powder having an average particle diameter of 5 μm (micrometer), and the wiring layer 400 is mainly composed of silver. In the present embodiment, the wiring layer 400 is a layer extending along the X axis and the Y axis.

  The plurality of wiring layers 400 are provided on at least one of the surface 310, the plurality of layers 321 to 324, and the surface 330. In the present embodiment, the plurality of wiring layers 400 are provided on the surface 310 and the plurality of layers 320. In the present embodiment, the plurality of wiring layers 400 include a wiring layer 410, a wiring layer 421, a wiring layer 422, a wiring layer 423, and a wiring layer 424. In the description of the present embodiment, the symbol “400” is used when generically referring to the wiring layers of the multilayer ceramic substrate 10, and the symbol “410, 421 to 424” when the wiring layers of the multilayer ceramic substrate 10 are individually indicated. Is used.

  The wiring layer 410 is provided on the surface 310 of the insulating layer 201. The wiring layer 421 is provided in an interlayer 321 between the insulating layer 201 and the insulating layer 202. The wiring layer 422 is provided in the interlayer 322 between the insulating layer 202 and the insulating layer 203. The wiring layer 423 is provided in an interlayer 323 between the insulating layer 203 and the insulating layer 204. The wiring layer 424 is provided in an interlayer 324 between the insulating layer 204 and the insulating layer 205.

  The plurality of through conductors 500 in the multilayer ceramic substrate 10 have conductivity, and form a wiring together with the wiring layer 400. The through conductor 500 is electrically connected to at least one wiring layer 400 and penetrates at least one insulating layer 200. In the present embodiment, the through conductor 500 has a columnar shape extending along the Z axis. In the present embodiment, the through conductor 500 is formed by firing a conductor paste made of silver powder having an average particle diameter of 5 μm, like the wiring layer 400, and the material of the through conductor 500 is mainly composed of silver.

  FIG. 2 is an explanatory diagram showing a cross section cut at a position where the dummy layer 600 exists in the multilayer ceramic substrate 10. The cross section of FIG. 2 is a cross section of the multilayer ceramic substrate 10 as viewed from the arrow F2-F2 in FIG. The XYZ axes in FIG. 2 correspond to the XYZ axes in FIG.

  The dummy layer 600 of the multilayer ceramic substrate 10 is formed by firing a material having a firing shrinkage rate higher than that of the wiring layer 400. In the present embodiment, the dummy layer 600 is a conductor mainly composed of silver, and is a conductor paste prepared from silver powder (for example, average particle diameter of 2 μm) whose average particle diameter is smaller than the silver powder of the wiring layer 400. Is fired. In another embodiment, the dummy layer 600 is a dielectric paste containing a higher proportion of borosilicate glass than the insulating layer 200 (for example, a dielectric having a mass ratio of borosilicate glass to alumina of 60:40). A dielectric material obtained by firing a paste) may be used.

  The dummy layer 600 is provided in a second layer different from the first layer in which the wiring layer 400 is provided among the plurality of layers 320. In this embodiment, the dummy layer 600 is provided in an interlayer 325 different from the interlayers 321, 322, 323, and 324 in which the wiring layer 400 is provided. In the present embodiment, the dummy layer 600 is a layer that extends along the X axis and the Y axis. In the present embodiment, the outer shape of the dummy layer 600 is a rectangular shape that is slightly smaller than the insulating layer 200.

  In the present embodiment, the area of the dummy layer 600 viewed from the stacking direction (Z-axis direction) is larger than the area of each wiring layer 400 viewed from the stacking direction (Z-axis direction). In the present embodiment, the thicknesses (lengths along the Z-axis) of each wiring layer 400 and dummy layer 600 are the same, and are about 10 μm.

  The dummy layer 600 is an area having a smaller total volume of the wiring layer 400 in each of the two areas 110 and 120 obtained by dividing the multilayer ceramic substrate 10 into two equal parts based on the thickness in the stacking direction (Z-axis direction). Exists. The region 110 is a region located on the surface 310 side (−Z axis direction side) of the multilayer ceramic substrate 10, and the region 120 is a region located on the surface 330 side (+ Z axis direction side) of the multilayer ceramic substrate 10. . In the present embodiment, the dummy layer 600 exists in the region 120 in which the total volume of the wiring layer 400 is smaller than the region 110.

  In this embodiment, the interlayer 325 provided with the dummy layer 600 has all the layers 321, 322, 323, and 324 provided with the wiring layer 400 with respect to the surface 330 in the region 120 on the side where the dummy layer 600 exists. It exists in a closer position.

  The dummy layer 600 is electrically insulated from the wiring layer 400 and the through conductor 500. An opening 650 is formed in the dummy layer 600 according to the position of the through conductor 500 that penetrates the insulating layer 206. In the present embodiment, the through conductor 500 penetrating the insulating layer 206 reaches the surface 330 on the + Z-axis direction side and penetrates the insulating layer 205 on the −Z-axis direction side.

A-2. Manufacturing Method of Multilayer Ceramic Substrate FIG. 3 is a process diagram showing a manufacturing method of the multilayer ceramic substrate 10. When manufacturing the multilayer ceramic substrate 10, the manufacturer produces a green sheet that is the basis of the insulating layer 200 (process P110). The green sheet is formed by mixing a raw material powder of insulating ceramic with a binder (binder), a plasticizer, a solvent, and the like to form a thin plate (sheet). In the present embodiment, the raw material of the green sheet includes borosilicate glass powder and alumina powder. The raw material borosilicate glass mainly contains silicon dioxide (SiO ₂ ), alumina (Al ₂ O ₃ ), and boron oxide (B ₂ O ₃ ). In this embodiment, the raw material borosilicate glass has an average particle size of about 4 μm. In this embodiment, the raw material alumina powder has an average particle size of 3 μm and a specific surface area of 1.0 m ² / g.

  In this embodiment, the manufacturer weighs the raw material borosilicate glass and alumina powder so that the mass ratio is 50:50 and the total amount is 1 kg, and then these raw materials are placed in an alumina container (pot). Put in. Thereafter, the manufacturer added 120 g of acrylic resin as a binder, an appropriate amount of methyl ethyl ketone (MEK) as a solvent, and an appropriate amount of dioctyl phthalate (DOP) as a plasticizer to the raw materials in the pot. Thereafter, the manufacturer obtains a ceramic slurry by mixing the raw materials in the pot for 5 hours. Then, a manufacturer produces a green sheet from a ceramic slurry by a doctor blade method. In this embodiment, there are three types of thickness of the green sheet, 0.05 mm, 0.10 mm, and 15 mm, and the manufacturer uses the thickness of the green sheet depending on the insulating layer 200.

  After producing the green sheet (process P110), the manufacturer applies a conductive paste that is the basis of the wiring layer 400 and the through conductor 500 to the green sheet (process P122). The conductor paste used for the wiring layer 400 and the through conductor 500 is a mixture of a conductive material powder and a binder, a plasticizer, a solvent, and the like. In this embodiment, the raw material of the conductor paste used for the wiring layer 400 and the through conductor 500 includes silver (Ag) powder. In this embodiment, the raw material silver powder used for the wiring layer 400 and the through conductor 500 has an average particle diameter of 5 μm.

  In producing the conductor paste for the wiring layer 400, in the present embodiment, the manufacturer adds a glass having a softening point of 760 ° C. to the silver powder as a raw material so that the volume is 5% by volume with respect to the inorganic component in the conductor paste. Add. Thereafter, the manufacturer adds ethyl cellulose as a binder and terpineol as a solvent to the raw material. Thereafter, the manufacturer obtains a conductor paste for the wiring layer 400 by kneading this raw material using a three-roll mill. In the present embodiment, the manufacturer applies the conductive paste for the wiring layer 400 to the surface of the green sheet in accordance with the pattern of the wiring layer 400 by screen printing.

  In producing the conductor paste for the through conductor 500, in this embodiment, the manufacturer adds ethyl cellulose as a binder and terpineol as a solvent to the silver powder as a raw material. Thereafter, the manufacturer obtains a conductor paste for the through conductor 500 by kneading this raw material using a three-roll mill. In this embodiment, the manufacturer forms a via hole (through hole) in the green sheet by punching in accordance with the position of the through conductor 500, and then fills the via hole with a conductor for the through conductor 500 by hole filling printing. Fill with paste.

  After producing the green sheet (process P110), the manufacturer applies the paste that is the source of the dummy layer 600 to the green sheet (process P124). The material used for the dummy layer 600 has a higher baking shrinkage rate than the material used for the wiring layer 400. In this embodiment, the manufacturer applies paste for the dummy layer 600 to the surface of the green sheet in accordance with the pattern of the dummy layer 600 by screen printing.

  In this embodiment, the paste used for the dummy layer 600 is a conductive paste in which a conductive material powder is mixed with a binder, a plasticizer, a solvent, and the like. In the present embodiment, the raw material of the conductor paste used for the dummy layer 600 includes silver (Ag) powder. The raw material silver powder used for the dummy layer 600 is a powder having an average particle size smaller than that of the raw material silver powder used for the wiring layer 400, and in this embodiment, the average particle size is 2 μm. In producing the conductor paste for the dummy layer 600, in this embodiment, the manufacturer adds a glass having a softening point of 760 ° C. to the silver powder as a raw material so as to be 5% by volume with respect to the inorganic component in the conductor paste. Add. Thereafter, the manufacturer adds ethyl cellulose as a binder and terpineol as a solvent to the raw material. Thereafter, the manufacturer obtains a conductive paste for the dummy layer 600 by kneading this raw material using a three-roll mill.

  In another embodiment, the paste used for the dummy layer 600 in the step of applying the paste that is the source of the dummy layer 600 to the green sheet (step P124) is a dielectric material powder, a binder, a plasticizer, and a solvent. A dielectric paste in which these are mixed may be used. The raw material of the dielectric paste used for the dummy layer 600 may be a raw material similar to the raw material of the green sheet, that is, a raw material containing borosilicate glass and alumina powder. When producing the dielectric paste for the dummy layer 600, the manufacturer uses, for example, a raw material borosilicate glass and alumina powder so that the proportion of the borosilicate glass is larger than that of the green sheet material. After weighing to a mass ratio of 60:40, ethyl cellulose as a binder and terpineol as a solvent are added to these raw materials. Thereafter, the manufacturer obtains a dielectric paste for the dummy layer 600 by kneading this raw material using a three-roll mill.

  In the present embodiment, the manufacturer performs the step of applying the conductor paste for the wiring layer 400 and the through conductor 500 (step P122) before the step of applying the paste for the dummy layer 600 (step P124). In another embodiment, the manufacturer performs the process of applying the conductor paste for the wiring layer 400 and the through conductor 500 (process P122) after the process of applying the paste for the dummy layer 600 (process P124). Or may be carried out simultaneously.

  After applying each paste (processes P122 and P124), the manufacturer divides the multilayer ceramic substrate 10 into two equal parts based on the thickness in the stacking direction (Z-axis direction). A plurality of green sheets corresponding to each of the plurality of insulating layers 200 are stacked so that the dummy layer 600 is disposed in a region having a smaller total volume of the wiring layer 400 (region 120 in the present embodiment), Thereafter, adjacent green sheets are joined by thermocompression bonding (process P130). Thereby, the manufacturer obtains a green sheet laminate in which a plurality of green sheets are laminated.

  After producing a green sheet laminated body (process P130), a manufacturer shape | molds a green sheet laminated body in the shape suitable for baking of a post process (process P140). In the present embodiment, the manufacturer forms the green sheet laminate by cutting.

  After forming the green sheet laminate (process P140), the manufacturer degreases the green sheet laminate (process P150). In this embodiment, the manufacturer degreases the green sheet laminate by exposing the green sheet laminate to air at 250 ° C. for 10 hours.

  After degreasing the green sheet laminate (process P150), the manufacturer fires the green sheet laminate (process P160). In the present embodiment, the manufacturer fires the green sheet laminate by exposing the green sheet laminate in a reducing gas at 850 ° C. for 30 minutes. As a result, the manufacturer obtains a sintered body obtained by sintering the green sheet laminate.

  After producing the sintered body (process P160), the manufacturer forms the sintered body (process P170). In the present embodiment, the manufacturer forms the sintered body by polishing cutting. In another embodiment, the manufacturer may perform plating on at least a part of the wiring layer 400 and the through conductor 500 exposed on the surface of the sintered body. Through these steps, the multilayer ceramic substrate 10 is completed.

A-3. Evaluation Test FIG. 4 is a table showing the results of an evaluation test for evaluating warpage during firing. In the evaluation test of FIG. 4, the tester produced a plurality of multilayer ceramic substrates 10 having different configurations of the dummy layer 600 as samples, and evaluated the warpage amount during firing of these samples.

The configuration of the sample 1 is the same as that of the above-described embodiment except that the shape viewed from the Z-axis direction is a square of 100 mm × 100 mm. The dummy layer 600 of the sample 1 is a conductor. The manufacturing method of the sample 1 is the same as the manufacturing method of the above-described embodiment. In Sample 1, the raw material of the dummy layer 600 is silver powder having an average particle diameter of 2 μm, and the firing shrinkage rate of the dummy layer 600 is 15.5%. In Sample 1, the raw material of the wiring layer 400 is silver powder having an average particle diameter of 5 μm, and the firing shrinkage rate of the wiring layer 400 is 13.8%. In the sample 1, the area of the dummy layer 600 viewed from the Z-axis direction is 70 mm ² , and the maximum area of each wiring layer 400 viewed from the Z-axis direction is 50 mm ² . In sample 1, the thickness of the dummy layer 600 is equivalent to that of each wiring layer 400.

Sample 2 is the same as Sample 1 except that the size of the dummy layer 600 is different. In sample 2, the area of dummy layer 600 viewed from the Z-axis direction is 60 mm ² .

  Sample 3 is the same as Sample 1, except that the firing shrinkage rate of the dummy layer 600 is different. In Sample 3, the raw material of the dummy layer 600 is silver powder having an average particle diameter of 3 μm, and the firing shrinkage rate of the dummy layer 600 is 14.9%.

  Sample 4 is the same as Sample 1 except that the dummy layer 600 is a dielectric. In sample 4, the raw material of dummy layer 600 is a mixture of borosilicate glass having an average particle diameter of 4 μm and alumina powder having an average particle diameter of 3 μm, and the mass ratio thereof is 60:40. In sample 4, the firing shrinkage rate of the dummy layer 600 is 14.5%.

  Sample 5 is the same as Sample 1 except that the dummy layer 600 is not provided.

Sample 6 is the same as Sample 1 except that the size of the dummy layer 600 is different. In sample 6, the area of dummy layer 600 viewed from the Z-axis direction is 50 mm ² .

  In the evaluation test of FIG. 4, the tester measured the amount of warpage generated during firing in each sample after preparing each sample. The amount of warpage is the magnitude of warpage generated in the Z-axis direction in each sample that is 100 mm × 100 mm square as viewed from the Z-axis direction. Since the amount of warpage required for mounting the multilayer ceramic substrate 10 is 200 μm or less, the tester evaluates a sample having a warpage amount of 200 μm or less as “good”, and a sample whose warpage amount exceeds 200 μm. Rated “impossible”.

  According to the result of the evaluation test in FIG. 4, it can be seen from the comparison between the samples 1 to 4 and 6 and the sample 5 that the amount of warpage can be suppressed by providing the dummy layer 600. Further, from comparison between Samples 1 and 2 and Sample 6, it can be seen that the warpage amount can be further suppressed by making the area of the dummy layer 600 larger than the area of any wiring layer 400. Further, from comparison between the sample 1 and the sample 2, it can be seen that the warpage amount can be further suppressed by increasing the area of the dummy layer 600 viewed from the Z-axis direction. Further, from comparison between Sample 1, Sample 3, and Sample 4, it can be seen that the amount of warpage can be further suppressed by increasing the firing shrinkage rate of the dummy layer 600. From comparison between Samples 1 to 3 and Sample 4, it can be seen that the amount of warpage can be suppressed regardless of whether the dummy layer 600 is a conductor or a dielectric.

A-4. Effect According to the embodiment described above, warpage during firing in the multilayer ceramic substrate 10 can be effectively suppressed by the dummy layer 600. Further, since the area of the dummy layer 600 viewed from the stacking direction is larger than the area of each wiring layer 400 viewed from the stacking direction, the warp during firing in the multilayer ceramic substrate 10 is more effectively caused by the area of the dummy layer 600. Can be suppressed. Further, the interlayer 325 provided with the dummy layer 600 is present at a position closer to all the layers 321 to 324 provided with the wiring layer 400 with respect to the surface 330 in the region 120 on the side where the dummy layer 600 exists. Therefore, warpage during firing in the multilayer ceramic substrate 10 can be more effectively suppressed by the position of the dummy layer 600.

B. Other Embodiments The present invention is not limited to the above-described embodiments, examples, and modifications, and can be realized with various configurations without departing from the spirit thereof. For example, the technical features in the embodiments, examples, and modifications corresponding to the technical features in each embodiment described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the above-described effects, replacement or combination can be performed as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

  In another embodiment, the insulating ceramic of the insulating layer 200 is not limited to a ceramic mainly composed of borosilicate glass and alumina, but may be a ceramic mainly composed of borosilicate glass and mullite. Further, a ceramic mainly composed of borosilicate glass and cordierite powder may be used. In other embodiments, the glass component of the insulating layer 200 is not limited to borosilicate glass but may be crystallized glass.

  In another embodiment, the conductive component used for the wiring layer 400, the through conductor 500, and the dummy layer 600 is not limited to silver (Ag), but is silver-palladium alloy (Ag-Pd), silver-platinum alloy (Ag-). It may be at least one of Pt), gold (Au), and copper (Cu).

  In other embodiments, the multilayer ceramic substrate 10 may include a plurality of dummy layers 600 in the plurality of layers 320. In another embodiment, the multilayer ceramic substrate 10 may include an interlayer 320 where the wiring layer 400 and the dummy layer 600 are not provided. In another embodiment, the multilayer ceramic substrate 10 may include an interlayer 320 provided with a wiring layer 400 between the surface 330 and the dummy layer 600.

DESCRIPTION OF SYMBOLS 10 ... Multilayer ceramic substrate 110,120 ... Area | region 200,201,202,203,204,205,206 ... Insulating layer 310 ... Surface 320,321,322,323,324,325 ... Interlayer 330 ... Surface 400,410,421 , 422, 423, 424 ... wiring layer 500 ... penetrating conductor 600 ... dummy layer 650 ... opening

Claims (3)

A plurality of laminated insulating layers made of insulating ceramic;
Provided in at least one of at least one first layer in the plurality of insulating layers and an outer surface facing the stacking direction in which the plurality of insulating layers are stacked among the outer surfaces of the plurality of insulating layers, And at least one wiring layer that forms wiring,
A multilayer ceramic substrate comprising: at least one through conductor having conductivity, electrically connected to at least one wiring layer, and penetrating through at least one insulating layer;
Further, a second interlayer different from the first interlayer in which the wiring layer is provided among the layers in the plurality of insulating layers is formed by firing a material having a firing shrinkage rate higher than that of the wiring layer. Provided with a dummy layer that is a conductor electrically insulated from the wiring layer and the through conductor,
The dummy layer exists in a region where the total volume of the wiring layers in each region is smaller among two regions obtained by dividing the multilayer ceramic substrate into two equal parts based on the thickness in the stacking direction ,
An area of the dummy layer viewed from the stacking direction is larger than an area of each of the plurality of wiring layers viewed from the stacking direction . The second interlayer provided with the dummy layer is present at a position closer to the outer surface facing the stacking direction in the region on the side where the dummy layer is present than all the first interlayers. The multilayer ceramic substrate according to claim 1. A plurality of laminated insulating layers made of insulating ceramic;
Provided in at least one of at least one first layer in the plurality of insulating layers and an outer surface facing the stacking direction in which the plurality of insulating layers are stacked among the outer surfaces of the plurality of insulating layers, Having at least one wiring layer constituting the wiring;
A method for producing a multilayer ceramic substrate, comprising: producing a multilayer ceramic substrate having electrical conductivity, electrically connected to at least one wiring layer, and comprising at least one through conductor penetrating at least one of the insulating layers. There,
Of the two regions obtained by dividing the multilayer ceramic substrate into two equal parts based on the thickness in the stacking direction, the region having the smaller total volume of the wiring layer in each region, the layer among the layers in the plurality of insulating layers A dummy layer, which is a conductor electrically insulated from the wiring layer and the through conductor , is higher than the material of the wiring layer in a second layer different from the first layer in which the wiring layer is provided. Formed by firing a material having a firing shrinkage rate ,
An area of the dummy layer viewed from the stacking direction is larger than an area of each of the plurality of wiring layers viewed from the stacking direction .

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