JP2005183522A - Multilayer ceramic substrate and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer ceramic substrate which has less lateral burning shrinkage and has a high dimensional accuracy, and to provide a method of manufacturing the multilayer ceramic substrate which can surely suppress the burning shrinkage. <P>SOLUTION: The multilayer ceramic substrate K comprises a substrate body H made by stacking a plurality of ceramic insulation layers z1-z3, and electrodes 2 and 8 which are formed on the front face 1 and the rear face 10 of the substrate body H, with bottoms (2b and 8b) cutting into the ceramic insulation layers z1 and z3 which constitutes the front face 1 and the rear face 10 respectively by a depth d of 2 μm or above. A distance between the tops (2a and 8a) of the electrodes 2 and 8 and the front face 1 of the substrate body H or the rear face 10 is 19 μm or less. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a multilayer ceramic substrate having a small shrinkage and excellent dimensional accuracy, and a method for manufacturing the same.

When a green sheet is fired to obtain a ceramic substrate, various methods have been proposed for producing a ceramic substrate with good dimensional accuracy by suppressing firing shrinkage associated with sintering.
For example, a glass ceramic / green sheet laminate formed by laminating a plurality of glass ceramic / green sheets is laminated on both sides of a glass ceramic / green sheet laminate, and the process of removing the unfired restraint sheet after firing them is performed. A method of manufacturing a substrate has been proposed (see, for example, Patent Document 1).
The glass component contained in the constrained green sheet is fired by increasing the binding force between the glass ceramic green sheet and the constrained green sheet during firing and suppressing the firing shrinkage of the constrained green sheet. A glass ceramic substrate with high dimensional accuracy can be manufactured later.

JP 2001-158670 A (pages 1 to 7, FIG. 1)

However, in the method for manufacturing the glass ceramic substrate, when the constrained green sheet is removed after firing, the binding force of the glass components contained therein is too strong, so that only the constrained green sheet can be removed cleanly. First, there is a problem that the front and back surfaces of the glass ceramic substrate may be damaged.
On the other hand, a ceramic solid layer is laminated on both sides of an unfired ceramic body containing glass, and the unfired ceramic solid layer is removed from the fired ceramic body obtained after firing. A method of manufacturing a ceramic body in which the penetration depth of the glass component from the body into the ceramic solid layer is 50 μm or less has also been proposed (see, for example, Patent Document 2).
However, in the method for producing a ceramic body, since the penetration depth of the glass component from the ceramic body to the ceramic solid layer is as small as 50 μm or less, the binding force of the ceramic solid layer during firing is weak, and firing shrinkage There was a problem that the suppression of the ink may become insufficient.

JP-A-4-243978 (pages 1-13, FIGS. 1-6)

  Furthermore, in the method for manufacturing a ceramic body, as shown in FIG. 18, after the electrodes 26 and 28 made of conductive paste are formed on the surfaces 21 and 23 of the unfired ceramic bodies 20 and 24 containing glass, 23 has a form in which ceramic solid layers 25 and 27 are laminated. In this case, as illustrated in FIG. 19 in which the one-dot chain line portion Y in FIG. 18 is enlarged, the ceramic solid layer 25 is not filled on the surface 21 around the electrode 26 and a gap 29 having a substantially triangular cross section is formed. The For this reason, the restraining force of the ceramic solid layers 25 and 27 at the time of firing becomes weak, and there is a problem that suppression of firing shrinkage in the fired ceramic body may be insufficient.

  The present invention solves the above-mentioned problems in the background art, and provides a multilayer ceramic substrate having a small dimensional shrinkage in the planar direction and a high dimensional accuracy, and a method for producing a multilayer ceramic substrate capable of reliably suppressing the firing shrinkage. Is an issue.

Means for Solving the Problems and Effects of the Invention

In order to solve the above-mentioned problems, the present invention has been conceived in that electrodes formed on the front surface and the back surface of a substrate body in which a plurality of ceramic insulating layers are stacked are inserted into the ceramic insulating layer. .
That is, the multilayer ceramic substrate of the present invention (Claim 1) includes a substrate body in which a plurality of ceramic insulating layers are laminated, and the front and back surfaces formed on the front and back surfaces of the substrate body and having a bottom portion having a depth of 2 μm or more. And an electrode that penetrates into the inside of the ceramic insulating layer.

According to this, since the bottoms of the electrodes respectively formed on the front and back surfaces of the substrate body have entered the inside of the ceramic insulating layer, firing shrinkage along the plane (XY) direction of the substrate body is suppressed. Has been. Therefore, since the dimensional accuracy and the flatness are excellent, the reliability of the electrical characteristics of the electrode and the wiring layer and via conductor that are connected to the electrode is improved.
If the penetration depth at the bottom of the electrode is less than 2 μm, the distance between the top of the electrode and the front or back surface of the laminate described later becomes excessive, and a gap is easily formed in the composite laminate described later, which causes firing shrinkage. This range is excluded because it is difficult to suppress the above.

The present invention also includes a multilayer ceramic substrate (Claim 2) in which the distance between the top of the electrode and the front or back surface of the substrate main body is 19 μm or less.
According to this, since the electrodes are formed on the front and back surfaces of the substrate body at a distance (height) of 19 μm or less, the levels (heights) of a large number of electrodes located on the front and back surfaces are It is uniform. Therefore, it is easy to mount an electronic component such as an IC chip on the front surface, and the multilayer ceramic substrate itself can be easily mounted on a mother board or the like via a large number of electrodes on the back surface.
When the distance exceeds 19 μm, a gap is easily formed in the composite laminate described later, and it becomes difficult to suppress firing shrinkage.

  On the other hand, the method for producing a multilayer ceramic substrate according to the present invention (Claim 3) comprises an electrode comprising a conductive paste containing metal powder on the surface of the green sheet as the front and back surfaces of the substrate body after firing among the plurality of green sheets Forming a laminated body by laminating the plurality of green sheets, and forming a laminated body on the front and back surfaces of the laminated body. Laminating a firing shrinkage-suppressing green sheet having a firing temperature higher than the firing temperature to form a composite laminate, firing the composite laminate at the firing temperature of the green sheet, and firing the composite laminate And removing the unsintered green sheet for suppressing firing shrinkage.

According to this, the electrodes formed on the front and back surfaces of the laminate are in a state of entering the inside of the green sheet. As a result, it becomes difficult to form a gap between the laminate and the firing shrinkage suppression green sheet, and the contact area between the front and back surfaces of the laminate and the firing shrinkage suppression green sheet is improved. improves. Therefore, since firing shrinkage in the planar direction (XY direction) of the substrate body during firing can be suppressed as much as possible, it is possible to reliably provide a multilayer ceramic substrate with excellent dimensional accuracy.
The step of allowing the bottom of the electrode made of conductive paste to enter the green sheet is performed either before or after the step of forming a laminate by laminating and laminating a plurality of green sheets. Also good.

According to the present invention, in the step of causing the bottom of the electrode made of the conductive paste to enter the inside of the green sheet, the bottom of the electrode enters the surface of the green sheet at a depth of 2 μm or more. Also included is a method for manufacturing a multilayer ceramic substrate, wherein the distance between the top of the electrode and the surface of the green sheet is 27 μm or less (Claim 4).
According to this, the electrodes formed on the front and back surfaces of the laminate or the green sheet penetrate into the green sheet and are formed at a distance (height) of 27 μm or less from the front and back surfaces of the green sheet. The Therefore, when the firing shrinkage-suppressing green sheets are laminated on the front and back surfaces of the laminate, it is possible to more surely prevent a gap from being formed around the electrode, thereby suppressing firing shrinkage.
When the depth is less than 2 μm and the distance exceeds 27 μm, the distance between the top of the electrode and the front or back surface of the laminate becomes excessive, a gap is formed in the composite laminate, and firing shrinkage occurs. This range was excluded because it could not be suppressed.

In the following, the best mode for carrying out the present invention will be described.
FIG. 1 shows a cross section of a green sheet s used in the method for manufacturing a multilayer ceramic substrate of the present invention (first method). The green sheet s is obtained by forming a ceramic slurry obtained by mixing glass powder, alumina powder, binder resin, and the like into a sheet having a thickness of about 150 μm by a doctor blade method.
As shown in FIG. 2, three green sheets s1, s2, and s3 that are the same as the green sheet s are prepared and punched by a press. As a result, as shown on the right side of FIG. 2, a through hole h having an inner diameter of about 150 μm penetrating between the front surfaces 1, 5, 9 and the rear surfaces 3, 7, 10 of the green sheets s1, s2, s3 is formed at a predetermined position. A plurality are formed.

Next, as shown in the left and center of FIG. 2, the via conductors v are filled by filling the plurality of through holes h with a conductive paste containing Ag powder using a metal mask and a squeegee (not shown). Form individually.
Further, as shown in FIG. 3, the conductive paste similar to the above is printed on the front surfaces 1, 5, 9 of the green sheets s 1, s 2, s 3 and the back surface 10 of the green sheet s 3 to obtain a thickness of about The electrodes 2 and 8 or the wiring layers 4 and 6 having a predetermined pattern made of the conductive paste of 15 μm are formed (step of forming electrodes).
Next, as shown in FIG. 4, the green sheets s1, s2, and s3 on which the via conductors v, the electrodes 2 and 8, and the wiring layers 4 and 6 are formed are laminated in the thickness direction and thermocompression bonded. A laminated body S having a structure is formed (step of forming a laminated body).

Next, as shown in FIG. 5, the stacked body S is placed on the surface of the metal plate 12. The metal plate 12 incorporates heating means such as a heater (not shown), is fixed to the upper end of the piston rod 13 of a hydraulic cylinder (not shown), and can be moved up and down. The metal plate 12 may be a surface plate (not shown) without the hydraulic cylinder and the piston rod 13, and the laminate S may be placed and fixed thereon.
Further, as shown in FIG. 5, a vertically movable metal plate 14 facing the metal plate 12 is disposed above the stacked body S placed on the surface of the metal plate 12. This metal plate 14 is fixed to the lower end of a piston rod 15 of a hydraulic cylinder (not shown).

In this state, as shown by the arrows in FIG. 5, the piston rods 13 and 15 are extended, and the metal plates 12 and 14 are moved up and down so as to approach each other. 1 and the electrodes 2 and 8 formed on the back surface 10 stop the metal plates 12 and 14 at a position where the entire electrodes have entered the green sheets s1 and s3. Then, as indicated by the dashed arrows in FIG. 6, the piston rods 13 and 15 are retracted, and the metal plates 12 and 14 are lowered or raised so as to be separated from each other.
A process of allowing the electrodes 2 and 8 to enter the green sheets s1 and s3 from the front surface 1 and the back surface (front surface) 10 will be described in detail with reference to FIGS.
As illustrated in the electrode 2 of FIG. 7, the electrode 2 that has received the pressure (about 5 MPa) indicated by the arrows along the thickness direction of the green sheets s1 to s3 by the metal plates 12 and 14 is as shown in FIG. In order to be embedded in the green sheet s1 once.

Thereafter, when the pressure on the metal plates 12 and 14 is released, the restoring force due to the elasticity of the green sheets s1 and s3 itself acts in the thickness direction, so that the electrode 2 has a surface 1 of the green sheet s1 as shown in FIG. The majority of the thickness rises above. At this time, as shown in FIG. 8, the bottom 2b of the electrode 2 enters (cuts in) at a depth d of 2 μm or more from the surface 1 of the green sheet s1, and the top 2a of the electrode 2 and the surface 1 of the green sheet s1 The pressure is set so that the distance (height) t is 27 μm or less.
The electrode 8 on the back surface 10 of the green sheet s3 also exhibits the same behavior as that of the electrode 2, and the bottom portion 8b penetrates from the back surface 10 of the green sheet s3 with a depth d of 2 μm or more, and the top portion 8a of the electrode 8 and the green The distance t from the back surface 10 of the sheet s3 is also 27 μm or less. Further, the levels at the top portions 2a and 8a of the multiple electrodes 2 and 8 formed on the front surface 1 and the back surface 10 are also uniform.

Next, as shown in FIG. 9, firing shrinkage-suppressing green sheets y <b> 1 and y <b> 2 are laminated on the front surface 1 and the back surface 10 of the laminate S, and thermocompression-bonded to form a composite laminate FS. At this time, the electrodes 2 and 8 have small bottoms (2b and 8b) that enter the green sheets s1 and s3 and project from the front surface 1 and the back surface 10, so that the electrodes 2 and 8 The gaps as described above are not formed between the surroundings and the firing shrinkage-suppressing green sheets y1 and y2, or can be suppressed to extremely small gaps.
The fired shrinkage-suppressing green sheets y1 and y2 are mainly made of alumina and do not contain glass, and are thicker than the green sheets s1 to s3.

Further, after inserting the composite laminate FS into a firing furnace (not shown), the green sheets s1 to s3 are heated to a firing temperature (about 850 ° C.) and fired for about 2 hours (baking step). At the same time, a part of the glass components in the green sheets s <b> 1 to s <b> 3 in the laminate S slightly permeates the firing shrinkage-suppressing green sheets y <b> 1 and y <b> 2 through the front surface 1 and the back surface 10 with firing.
At this time, since the firing shrinkage-suppressing green sheets y1 and y2 do not have the above-described gaps around the electrodes 2 and 8 or are formed with very small gaps, the laminates are interposed via the front surface 1 and the back surface 10 of the laminate S. Firing shrinkage along the plane direction of S is strongly suppressed.
After firing, the green sheets s1 to s3 of the composite laminate FS become ceramic insulating layers (z1 to z3), and unfired firing shrinkage suppression green sheets y1 and y2 are formed on the front surface 1 and the back surface 10 of the laminate S. Remaining. The fired shrinkage-suppressing green sheets y1 and y2 contain almost no glass component and have not been fired.

Then, the firing shrinkage-suppressing green sheets y1 and y2 are removed from the front surface 1 and the back surface 10 of the ceramic insulating layer (z1, z3) (removal step). At this time, since the fired shrinkage-suppressing green sheets y1 and y2 contain almost no glass component and have not been fired, they can be easily removed by physical peeling or thermal shock.
As a result, as shown in FIG. 10, a multilayer ceramic substrate including a fired substrate body H, electrodes 2 and 8, and wiring layers 4 and 6 in which fired ceramic insulating layers z1 to z3 are integrally laminated. K can be obtained. In such a multilayer ceramic substrate K, the penetration depth (d) of the electrodes 2 and 8 into the front surface 1 and back surface 10 of the substrate body H is 2 μm or more, and the distance between the electrodes 2 and 8 and the front surface 1 and back surface 10 is as follows. (t, height) is 19 μm or less.

11 and 12 show a manufacturing method (second method) in a different process order.
Similarly to the above, the green sheet s1 in which the via conductors v and the electrodes 2 are formed is placed alone on the surface of the surface plate 16 incorporating a heater or the like, as shown in FIG. Above the green sheet s1, a metal plate 14 fixed to the lower end of the piston rod 15 that can be raised and lowered is disposed, and the metal plate 14 is lowered as indicated by an arrow in FIG.
As shown by the solid line arrow in FIG. 12, the lowered metal plate 14 stops at a position where almost the entire electrode 2 has entered the green sheet s1, and then, as shown by the broken line arrow in FIG. As the piston rod 15 moves backward, it rises (returns).

As a result, as shown in FIG. 13, the electrode 2 is in a state in which the bottom (2b) enters the inside of the surface 1 of the green sheet s1 with a depth (d) of 2 μm or more.
Further, the green sheet s3 in which the electrode 8 is formed on the back surface 10 can also enter the bottom portion (8b) from the back surface 10 to the inside with a depth (d) of 2 μm or more through the above steps.
After the above steps, three layers of the green sheets s1, s3 into which the electrodes 2 and 8 have entered and the green sheet s2 are laminated to form the laminate S, and further, the composite laminate FS is formed. The multilayer ceramic substrate K similar to the above can also be obtained by performing the firing step and the firing shrinkage-suppressing green sheets y1 and y2.

According to the above manufacturing method (first method, second method), the bottom portions (2b, 8b) of the electrodes 2, 8 formed on the front surface 1 and the back surface 10 of the laminate S are formed on the green sheets s1, s3. The surface 1 and the back surface 10 of the green sheet s1 are inserted at a depth of 2 μm or more, and the distance between the tops (2a, 8a) of the electrodes 2 and 8 and the surface 1 and the back surface 10 of the green sheets s1 and s3 is 27 μm or less. As a result, it becomes difficult to form a gap between the firing shrinkage suppression green sheets y1 and y2, and the contact area between the front and back surfaces 10 and the firing shrinkage suppression green sheets y1 and y2 of the laminate S is improved. The restraining force at the time increases significantly. Therefore, firing shrinkage in the planar direction (XY direction) of the substrate body H after firing can be suppressed as much as possible, and the multilayer ceramic substrate K having excellent dimensional accuracy can be reliably provided.
Further, since the obtained multilayer ceramic substrate K is formed by the above-described manufacturing method, the ceramic insulating layers z1 to z3 that form the substrate body H are less baked and shrunk, and thus have excellent dimensional accuracy and flatness. . Therefore, the reliability of the electrical characteristics related to the wiring layers 4 and 6, the via conductors v and the electrodes 2 and 8 that are possessed is improved. In addition, since the levels of the numerous electrodes 2 and 8 formed on the front surface 1 and the back surface 10 of the substrate body H are uniform, the mounting of the IC chip and the connection with the mother board are facilitated.

Here, specific examples of the present invention will be described together with comparative examples.
First, in order to obtain the green sheets s1 to s3, glass powder used for this was prepared. SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ , CaO, and ZnO powders were mixed to prepare a glass raw material powder. The obtained raw material powder was heated and dissolved, and then poured into water, quenched and granulated to obtain a glass frit. The glass frit was further pulverized in a ball mill to obtain glass powder having an average particle size of 3 μm.
Next, the glass powder and an alumina powder having an average particle diameter of 3 μm and a specific surface area of 1.0 m ² / g are weighed so as to have a weight ratio of 1: 1 and a total weight of 1 kg. I put it in. In such a pot, an acrylic resin as a binder: 120 g and an amount of a solvent (MEK) and a plasticizer (DOP: 2-ethylhexyl phthalate) necessary to obtain a required slurry viscosity and sheet strength are charged. And ceramic slurry was obtained by mixing for 5 hours. Using this ceramic slurry, 14 sets of green sheets s1 to s3 each having a length and width of 50 mm and a thickness of 0.15 mm were obtained by a doctor blade method.

On the other hand, using the same alumina powder as described above, 14 sets of fired shrinkage-suppressing green sheets y1 and y2 each having a length and width of 50 mm and a thickness of 0.30 mm were obtained by the same method as described above.
Further, as illustrated in FIGS. 14 and 15, the front and back surfaces 10 of the green sheets s 1 and s 3 of each group are 5 mm in length and width and the thickness is as shown in Table 1 for each group. The electrodes 2 and 8 changed to 5 were formed by screen printing so that there were 5 vertical and horizontal electrodes at intervals of 5 mm. The via conductors v and the wiring layers 4 and 6 are not formed on the green sheets s1 to s3.

Seven sets of green sheets s1 to s3 are laminated and thermocompression-bonded by the same method as the first method to obtain seven sets of laminates S, and then the pressing pressure is applied between the metal plates 12 and 14. As shown in Table 1, the bottom portions (2b, 8b) of the electrodes 2, 8 were inserted into the front surface 1 and the back surface 10 of the green sheets s1, s3 at different depths (d).
At the same time, as shown in Table 1, the distances (t) between the tops (2a, 8a) of the electrodes 2, 8 and the front surface 1 and the back surface 10 of the green sheets s1, s3 were also changed for each group. Seven sets of composite laminates FS were obtained by individually laminating and crimping the firing shrinkage-suppressing green sheets y1 and y2 on the front surface 1 and the back surface 10 of the seven sets of laminates S.
After seven sets of the composite laminate FS were fired at 850 ° C. × 2 hours, the unfired fired shrinkage-suppressing green sheets y1 and y2 were removed. As a result, as illustrated in FIG. 16 and FIG. 17 in which the one-dot chain line portion X is enlarged, the bottom portions 2b and 8b of the electrodes 2 and 8 enter the ceramic insulating layer z1 at a depth d, and Seven sets of multilayer ceramic substrates (K) were obtained in which the distance between the tops 2a, 8a and the surface 1 of the ceramic insulating layer z1 was t.

Further, in the same method as the second method, the remaining seven sets of green sheets s1, s3 are individually pressed between the metal plates 12, 14, and the bottom portions 2b, 8b of the electrodes 2, 8 are placed on the green sheets s1, s3. As shown in Table 1, the front surface 1 and the back surface 10 were inserted at different depths d. At the same time, as shown in Table 1, the distance t between the tops 2a, 8a of the electrodes 2, 8 and the front surface 1 and the back surface 10 of the green sheets s1, s3 was also changed for each group. Thereafter, the green sheets s2 were sandwiched between the green sheets s1 and s3 and thermocompression bonded to obtain seven sets of laminates S.
Seven sets of composite laminates FS were obtained by individually laminating and pressure-bonding the firing shrinkage-suppressing green sheets y1 and y2 on the front surface 1 and the back surface 10 of the seven sets of laminates S. After firing these 7 sets of composite laminate FS at 850 ° C. × 2 hours, the unfired shrinkage-suppressing green sheets y1 and y2 are removed, so that another 7 sets of multilayer ceramics similar to FIGS. A substrate (K) was obtained.
The firing shrinkage in the plane direction (XY direction) of the substrate body H in the total 14 sets of multilayer ceramic substrates (K) was measured and shown in Table 1.

According to Table 1, all of the multilayer ceramic substrates K of Examples 1 to 10 manufactured by the first method or the second method had a firing shrinkage of 0.23% or less.
On the other hand, the multilayer ceramic substrates of Comparative Examples 1 to 4 manufactured by the first method or the second method had a remarkable firing shrinkage of 1.18% or more. That is, in the multilayer ceramic substrates of Comparative Examples 1 to 4, the depth d into which the electrodes 2 and 8 entered was 2 μm or more, but the tops 2a and 8a of the electrodes 2 and 8 and the surface 1 of the green sheets s1 and s3 The distance t from the back surface 10 was 28 μm or more before firing and 20 μm or more even after firing. As a result, a gap was prominently formed between the periphery of the electrodes 2 and 8 and the firing shrinkage-suppressing green sheets y1 and y2, so that the firing shrinkage rate during firing exceeded 1%.
It can be easily understood that the effects of the invention of the present application are supported by the results of Examples 1 to 10 as described above.

The present invention is not limited to the embodiments and examples described above.
For example, the laminate S and the substrate body H may be formed of only two layers, or four or more green sheets or ceramic insulating layers.
Further, the laminate S or the substrate body H may have a cavity having an upward opening in one or more green sheets or ceramic insulating layers located near the surface 1.
Further, a press driven by an air cylinder, a WIP (hot water isostatic press), or the like may be used for the step of causing the electrodes 2 and 8 to enter the green sheets s1 and s3.
In addition to the Ag powder, the conductive paste may contain W, Mo, Cu powder, or Ag—Cu, Ag—Pd, Ag—Pt, or Cu—W alloy powder.

Sectional drawing which shows the green sheet used for the manufacturing method of this invention. Schematic which shows 1 process in the said manufacturing method. Schematic which shows the process following FIG. Schematic which shows the process following FIG. Schematic which shows the process following FIG. Schematic which shows the process following FIG. The enlarged view which shows the electrode vicinity in the process of FIG. The enlarged view which shows the electrode vicinity after the process of FIG. Schematic which shows the process of following FIG. Schematic which shows the process following FIG. 9, and the obtained multilayer ceramic substrate of this invention. Schematic which shows 1 process in a different manufacturing method. Schematic which shows the process following FIG. Schematic which shows the green sheet with a penetration electrode obtained by the said process. The top view which illustrates the green sheet of an Example or a comparative example. The side view of the said green sheet. Schematic which shows the green sheet of the Example obtained by the said manufacturing method. The enlarged view of the dashed-dotted line part X in FIG. Schematic which shows the manufacturing method of the conventional ceramic body. The enlarged view of the dashed-dotted line part Y in FIG.

Explanation of symbols

1 …………… Surface 2, 8 ……… Electrode (conductive paste)
2a, 8a ... Top 2b, 8b ... Bottom 10 ......... Back side s1 to s3 ... Green sheet S ... ... ... Laminated body d ... ... ... Electrode biting depth t ... ... ... Top of electrode Distance between green sheet and front or back surface of green sheet y1, y2 ... Sintered green sheet FS ………… Composite laminated body H ………… Substrate body z1 to z3… Ceramic insulating layer K ………… Multilayer ceramic substrate

Claims (4)

A substrate body in which a plurality of ceramic insulating layers are laminated;
An electrode that is formed on the front and back surfaces of the substrate body and has a bottom portion that enters the inside of the ceramic insulating layer that forms the front and back surfaces at a depth of 2 μm or more,
A multilayer ceramic substrate characterized by the above. The distance between the top of the electrode and the front or back surface of the substrate body is 19 μm or less.
The multilayer ceramic substrate according to claim 1, wherein: Forming an electrode made of a conductive paste containing metal powder on the surface of the green sheet to be the front and back surfaces of the substrate body after firing among the plurality of green sheets;
A step of allowing the bottom of the electrode to enter the inside of the green sheet;
Laminating the plurality of green sheets to form a laminate;
A step of laminating a firing shrinkage-suppressing green sheet having a firing temperature higher than the firing temperature of the green sheet on the front and back surfaces of the laminate to form a composite laminate,
Firing the composite laminate at the firing temperature of the green sheet;
Removing the unfired firing shrinkage-suppressing green sheet from the composite laminate after firing;
A method for producing a multilayer ceramic substrate, comprising: In the step of allowing the bottom of the electrode made of the conductive paste to enter the inside of the green sheet, the bottom of the electrode enters the surface of the green sheet at a depth of 2 μm or more, and the top of the electrode and the above The distance from the surface of the green sheet is 27 μm or less,
The method for producing a multilayer ceramic substrate according to claim 3.

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