JP3969438B2 - Ceramic substrate and method for manufacturing ceramic substrate - Google Patents

Description

  The present invention relates to a ceramic substrate and a method for manufacturing the same, and more particularly to a method for manufacturing a ceramic substrate having stepped portions on both main surfaces and a ceramic substrate manufactured by the manufacturing method.

Some ceramic substrates have a structure having a stepped portion (typically a cavity) on the surface thereof.
As a method of manufacturing such a ceramic substrate, as shown in FIGS. 18A, 18B, and 18C, a second ceramic sheet 52 having an opening 53 is laminated on the first ceramic sheet 51. In the case of manufacturing a ceramic multilayer substrate having a stepped portion (cavity) through the step of forming a laminate 57 by pressure bonding, a plate material 54 (ceramic sheet 56 and ceramic sheet 56 and substantially the same shape as the opening 53) is formed in the opening 53. A ceramic sheet 56) with a release agent 55 is placed so that its surface 54a is slightly higher than the surface of the laminate 57, and then crimped, and then the plate material 54 is removed, whereby a cavity with good dimensional accuracy is obtained. A method of forming 58 has been proposed (Patent Document 1).
However, in this method, not only is it time-consuming to punch out the ceramic sheet, but there is a problem that the press-bonding process of the cavity part before firing is complicated, resulting in an increase in cost, and the influence of waviness in the firing process. Therefore, it is difficult to maintain dimensional accuracy.
Japanese Patent Laid-Open No. 3-169097

  The invention of the present application solves the above-mentioned problems, and it is possible to suppress the occurrence of distortion and cracks by suppressing the difference in absolute shrinkage amount, and has excellent shape accuracy and dimensional accuracy. Another object of the present invention is to provide a highly reliable ceramic substrate and a manufacturing method capable of manufacturing the ceramic substrate without requiring complicated manufacturing processes and manufacturing equipment.

In order to solve the above problems, the ceramic substrate of the present invention (Claim 1) is:
A ceramic substrate in which stepped portions are disposed on both main surfaces of one main surface and the other main surface,
A concave portion is disposed on one main surface, and a convex portion having a gentle shape without corners is disposed in a region corresponding to the concave portion on the other main surface,
(a) The dimension of the substantially flat surface at the top of the convex portion in the direction parallel to the top surface of the ceramic substrate is A1,
(b) A2 is a dimension in a direction parallel to the top surface of the ceramic substrate of the entire convex portion,
(c) The dimension of the substantially flat surface of the bottom of the concave portion in the direction parallel to the lower surface of the ceramic substrate is B1,
(d) The dimension of the entire recess in the direction parallel to the lower surface of the ceramic substrate is B2.
[1] and [2] below:
A1 <B1 [1]
B2 <A2 ...... [2]
It is characterized by satisfying the following conditions.

The ceramic substrate of claim 2 is the structure of the invention of claim 1,
An angle formed by the inclined surface of the convex portion from the upper surface of the ceramic substrate to the substantially flat surface at the top and the upper surface of the ceramic substrate is θA,
An angle formed between the inner wall surface of the concave portion from the lower surface of the ceramic substrate to the substantially flat surface of the bottom portion and the lower surface of the ceramic substrate is θB.
[3] below:
θA <θB …… [3]
It is characterized by satisfying the above conditions.

The ceramic substrate of claim 3 is the structure of the invention of claim 1 or 2,
An angle θA formed by the inclined surface of the convex portion and the upper surface of the ceramic substrate, and an angle θB formed by the inner wall surface of the concave portion and the lower surface of the ceramic substrate, respectively,
0 ° <θB ≦ 90 ° …… [4]
0 ° <θA <90 ° …… [5]
It is characterized by satisfying the above conditions.

Moreover, the method for producing a ceramic substrate of the present invention (Claim 4) is as follows:
A method for producing a ceramic substrate according to any one of claims 1 to 3,
(A) An auxiliary layer made of a material that does not substantially sinter at the firing temperature of the unfired ceramic body is in close contact with at least one major surface of the unfired ceramic body, and has a recess on one of the principal surfaces. Forming an unfired ceramic body with an auxiliary layer having a convex portion having a smooth shape without corners in a region corresponding to the concave portion of the other main surface;
(B) a step of firing the unfired ceramic body with the auxiliary layer at a temperature at which the unfired ceramic body is sintered while the auxiliary layer is provided, and the auxiliary layer is not substantially sintered. It is characterized by having.

  According to a fifth aspect of the present invention, there is provided a method for manufacturing a ceramic substrate according to the fourth aspect of the present invention, wherein the green ceramic body with an auxiliary layer is maintained so that the thickness of the green ceramic body is substantially constant over the entire surface. The auxiliary layer having the concave portion and the convex portion by deforming a predetermined region of the green ceramic body with the auxiliary layer while keeping the green ceramic body and the auxiliary layer in close contact with each other. It is characterized in that an unfired ceramic body is formed.

  According to a sixth aspect of the present invention, there is provided a method for manufacturing a ceramic substrate according to the fourth or fifth aspect of the invention, wherein a mold having a convex portion is aligned with the surface on which the auxiliary layer of the unfired ceramic body with the auxiliary layer is disposed. To form a concave portion having a shape corresponding to the convex portion of the mold on one main surface, and forming a convex portion having a smooth shape without corners corresponding to the concave portion on the other surface. It is characterized by that.

  According to a seventh aspect of the present invention, there is provided a method for manufacturing a ceramic substrate according to the sixth aspect of the invention, wherein the mold having the convex portion is aligned with the surface on which the auxiliary layer of the unfired ceramic body with the auxiliary layer is disposed. By a method using a hydraulic press or a method of pressing through an elastic body, an unfired ceramic body with an auxiliary layer is formed from the side opposite to the surface of the unfired ceramic body with the auxiliary layer combined with the mold having the projections. It is characterized by pressing so as to apply pressure.

  The method for producing a ceramic substrate according to claim 8 is the construction of the invention according to claim 6 or 7, wherein the mold having the convex portion is disposed on the flat plate-like support and the flat plate-like support. And a convex component member made of a material that does not substantially sinter at the firing temperature of the green ceramic body.

  According to a ninth aspect of the present invention, there is provided a method for manufacturing a ceramic substrate according to the eighth aspect of the present invention, wherein the green ceramic body with an auxiliary layer having the concave portion and the convex portion is engaged with the convex component member of the mold. It is characterized by firing in the state.

  According to a tenth aspect of the present invention, there is provided a method for manufacturing a ceramic substrate according to any one of the sixth to ninth aspects, wherein the convex portion has a tapered shape in the mold having the convex portion. Yes.

  The method for manufacturing a ceramic substrate according to claim 11 is the structure according to any one of claims 6 to 10, wherein at least the protrusions are formed of the unfired ceramic body with the auxiliary layer in the mold having the protrusions. It is characterized by being harder and elastic than any of the ceramic body and the auxiliary layer.

  According to a twelfth aspect of the present invention, there is provided a method for manufacturing a ceramic substrate according to any one of the eighth to eleventh aspects, wherein the convex component member is an unsintered ceramic body with an auxiliary layer. It is characterized by being formed through a step of applying a pressure higher than the pressure applied when forming the film.

Moreover, the manufacturing method of the ceramic substrate of Claim 13 is the structure of the invention in any one of Claims 6-12,
Of the unfired ceramic body with an auxiliary layer, a reinforcing material is applied to at least a part of a portion that deforms along the convex portion in the mold having the convex portion.

  According to a fourteenth aspect of the present invention, there is provided a method for manufacturing a ceramic substrate, wherein the non-fired ceramic body is a non-fired ceramic laminate formed by laminating a plurality of ceramic green sheets. In addition, an interlayer connection conductor pattern for connecting the layers of each ceramic green sheet layer and an in-plane conductor pattern provided at the interface of each ceramic green sheet layer are disposed therein. Yes.

  According to a fifteenth aspect of the present invention, there is provided a method for producing a ceramic substrate according to any one of the fourth to fourteenth aspects, wherein the unfired ceramic body with an auxiliary layer to which the auxiliary layer is adhered is laminated with a ceramic green sheet. The auxiliary layer is adhered to the ceramic green sheet laminate formed by pressing together.

  According to a sixteenth aspect of the present invention, there is provided a method for manufacturing a ceramic substrate according to any one of the fourth to fourteenth aspects, wherein one or a plurality of unfired ceramic bodies with an auxiliary layer to which the auxiliary layer is adhered are provided. It is characterized in that an auxiliary layer is brought into close contact with a ceramic green sheet laminated body formed through a step of sequential pressure bonding in which a pressure is applied every time one ceramic green sheet is laminated.

  According to a seventeenth aspect of the present invention, there is provided a method for manufacturing a ceramic substrate according to the sixth aspect of the invention, wherein the convex portion of the mold having the convex portion of the unfired ceramic body with the auxiliary layer to which the auxiliary layer is adhered is provided. A concave portion is formed at a contact position, and the height H of the convex portion is larger than the depth D of the concave portion.

  The method for producing a ceramic substrate according to claim 18 is the structure according to any one of claims 4 to 17, wherein the unfired ceramic body is a collective substrate of unfired ceramic bodies for a plurality of child substrates, It is characterized by comprising a step of dividing the obtained aggregate substrate into sub-substrates after firing.

  According to a nineteenth aspect of the present invention, there is provided a method for manufacturing a ceramic substrate according to any one of the fourth to eighteenth aspects, further comprising a step of mounting a surface mounting component on the fired ceramic substrate.

  In the ceramic substrate of the present invention (Claim 1), a concave portion is arranged on one main surface, and a convex portion having a gentle shape without corners is formed in a region corresponding to the concave portion of the other main surface. (A) The dimension of the substantially flat surface of the top of the convex part in the direction parallel to the upper surface of the ceramic substrate is A1, and (b) The dimension of the entire convex part in the direction parallel to the upper surface of the ceramic substrate. A2 and (c) the dimension of the substantially flat surface of the bottom of the recess in the direction parallel to the lower surface of the ceramic substrate is B1, and (d) the dimension of the entire recess in the direction parallel to the lower surface of the ceramic substrate is B2. In addition, since the conditions of A1 <B1 and the condition of B2 <A2 are satisfied, the contraction direction (in FIG. 5) in the step portion (side wall portion of the cavity) formed in the boundary region between the convex portion and the concave portion of the ceramic substrate. The thickness in the direction indicated by the arrow 5A is the other part of the ceramic substrate. Of becomes approximated thickness to the thickness, prevent the difference in the absolute shrinkage amount increases in the firing step, it is possible to prevent. As a result, there is no defect such as distortion or crack, high shape accuracy and dimensional accuracy, a ceramic substrate having a cavity structure (having a recess on one main surface, in the region corresponding to the recess on the other main surface, It is possible to provide a ceramic substrate having a convex portion having a smooth shape without corners.

  The ceramic substrate of the present invention (Claim 1) is characterized in that the convex portion formed on the other surface has a gentle shape without corners, and thus, It is possible to suppress or prevent an increase in the positional difference in absolute shrinkage during molding and firing without being governed by the shape of the recess formed in the surface (the shape within the scope of the present invention). It becomes possible. Therefore, the shape of the recess formed on one surface may be, for example, a sharp shape such as a quadrangular pyramid or a cone, or a gentle shape without corners such as the protrusion. You may have.

Further, in the present invention, the substantially flat surface on the top of the convex portion is a concept that means a region from a position where the altitude of the substantially flat surface is the highest to a position where the altitude is 20 μm lower than the position where the altitude is the highest. The dimension A1 of the substantially flat top surface in the direction parallel to the top surface of the ceramic substrate is a concept that means the dimension in the direction parallel to the top surface of the ceramic substrate in this region.
Further, the dimension A2 of the whole convex part in the direction parallel to the top surface of the ceramic substrate is the dimension of the ceramic substrate of the whole convex part when the region having an elevation of 10 μm or more from the top surface of the ceramic substrate is a convex part. It is a concept that means a dimension in a direction parallel to the upper surface.

Further, as in the ceramic substrate of claim 2, in the configuration of the invention of claim 1, the angle formed by the inclined surface of the convex portion and the upper surface of the ceramic substrate is θA, the inner wall surface of the concave portion, and the lower surface of the ceramic substrate When the angle formed by θB is θB, by satisfying the condition of θA <θB, the shrinkage direction (the side wall portion of the cavity) formed in the boundary region between the convex portion and the concave portion of the ceramic substrate (in FIG. 5) The thickness in the direction indicated by the arrow 5A) can be more reliably set to a thickness that approximates the thickness of the other part of the ceramic substrate, and the above-described effects can be obtained more reliably.
In the present invention, in the case of “an angle θA formed between the inclined surface of the convex portion and the upper surface of the ceramic substrate”, the “upper surface” means the main surface of the ceramic substrate on which the convex portion is formed. .
In the present invention, in the case of “an angle θB formed between the inner wall surface of the recess and the lower surface of the ceramic substrate”, the “lower surface” refers to the main surface of the ceramic substrate where the recess is formed.

Further, like the ceramic substrate of claim 3, in the configuration of the invention of claim 1 or 2, the angle θA formed by the inclined surface of the convex portion and the upper surface of the ceramic substrate, the inner wall surface of the concave portion, and the ceramic substrate The angle θB made with the bottom surface is
0 ° <θB ≦ 90 °
0 ° <θA <90 °
When the above condition is satisfied, the thickness of the shrinkage direction (the direction indicated by the arrow 5A in FIG. 5) in the step portion (side wall portion of the cavity) formed in the boundary region between the convex portion and the concave portion of the ceramic substrate is more It is possible to reliably make the thickness close to the thickness of the other part of the ceramic substrate, and it is possible to further secure the effect of the present invention described above.
A more preferable range of θB is a range satisfying the condition of 30 ° ≦ θB ≦ 60 °. By setting θB to 30 to 60 °, it is possible to provide a ceramic substrate having a cavity structure that is more reliably free from defects such as distortion and cracks and has high shape accuracy and dimensional accuracy.

  On the other hand, in the ceramic substrate of the present invention, θB can be 90 °. That is, even when the shape of the concave portion on the lower surface side is such that θB is 90 °, the convex portion on the upper surface side remains in a smooth shape and follows the shape of the concave portion on the lower surface side. Although the gap between the shape of the concave portion on the lower surface side and the convex portion on the upper surface side becomes large, the dimension A1 of the substantially flat surface on the top of the convex portion is small, and the dimension of the entire concave portion in the direction parallel to the lower surface of the ceramic substrate ( When the bottom surface dimension (B2) is increased and the angle θA formed by the inclined surface of the convex portion on the upper surface side and the upper surface of the ceramic substrate is an acute angle, an effect of reducing variations in the thickness of the ceramic substrate occurs. Moreover, in that case, the effect which relieves | moderates that each sheet | seat which comprises the crimping | compression-bonding body of the said convex part and the periphery of a recessed part expands, and a crimping | compression-bonding body produces distortion. As a result, even when the angle θB formed by the inner wall surface of the concave portion on the lower surface side and the lower surface of the ceramic substrate is 90 °, the basic effect of the present invention, that is, the difference in shrinkage amount is increased. It is possible to obtain the effect of suppressing and preventing, and obtaining a ceramic substrate having a cavity structure with no defects such as distortion and cracks and high shape accuracy and dimensional accuracy.

  The method for producing a ceramic substrate according to the present invention (Claim 4) includes: (A) an auxiliary layer made of a material that is not substantially sintered at the firing temperature of the unfired ceramic body on at least one main surface of the unfired ceramic body. Are formed, and an unfired ceramic body with an auxiliary layer is formed having a concave portion on one main surface and a convex portion having a smooth shape without corners in a region corresponding to the concave portion on the other main surface. And (B) a temperature at which the unfired ceramic body is sintered while the auxiliary ceramic layer is provided with the auxiliary layer having the concave and convex portions, and the auxiliary layer is not substantially sintered. Thus, it is possible to efficiently manufacture a ceramic substrate having a concave portion and a convex portion and having a high shape accuracy without requiring a complicated manufacturing step or manufacturing equipment.

  That is, an auxiliary layer made of a material that is not substantially sintered at the firing temperature of the green ceramic body is in close contact with at least one main surface of the green ceramic body, and a concave portion is formed on one main surface. And forming an unfired ceramic body with an auxiliary layer having a convex portion with a smooth shape without corners in a region corresponding to the concave portion of the other main surface (for example, laminating ceramic green sheets) The unfired ceramic body with an auxiliary layer in a state where the auxiliary ceramic is in close contact with the unfired ceramic body is deformed by pressing with a mold to form an unfired ceramic body with an auxiliary layer having concave and convex portions Or by laminating and crimping the auxiliary layer green sheet and ceramic green sheet on the mold by a sequential crimping method, which is performed each time one or a predetermined number of sheets are laminated. To prevent breakage and breakage in the non-fired ceramic body and the internal electrode pattern disposed therein, etc. It is possible to form an unfired ceramic body having a concave portion on one main surface and a convex portion having a smooth shape without corners in a region corresponding to the concave portion on the other main surface. .

Further, the unfired ceramic body with the auxiliary layer having the concave portion and the convex portion is fired at a temperature at which the unfired ceramic body is sintered and the auxiliary layer is not substantially sintered while the auxiliary layer is in close contact. Since the auxiliary layer has a force (restraint force) that suppresses shrinkage and deformation during sintering of the ceramic body, it suppresses and prevents the ceramic body from shrinking and deforming in the firing process, and is not fired. High shape accuracy while maintaining the shape of the ceramic body (a shape having a concave portion on one main surface and a convex portion having a smooth shape without corners in a region corresponding to the concave portion on the other main surface) It becomes possible to obtain a ceramic substrate.
In addition, since the auxiliary layer is disposed on the surface of the unfired ceramic body, even if surface cracks occur in the auxiliary layer of the unfired ceramic body with the auxiliary layer during bending, the unfired ceramic body is affected. Therefore, it is possible to obtain a ceramic substrate having desired characteristics.

  Further, as in the method for manufacturing a ceramic substrate according to claim 5, in the structure of the invention according to claim 4, the unfired ceramic body with the auxiliary layer is maintained so that the thickness of the unfired ceramic body is substantially constant over the entire surface. While maintaining the state where the unfired ceramic body and the auxiliary layer are in close contact with each other, the predetermined region of the unfired ceramic body with the auxiliary layer is deformed to form a recess on one main surface of the unfired ceramic body with the auxiliary layer. When forming and forming a convex part with a smooth shape without corners in a region corresponding to the concave part of the other main surface, the unfired ceramic body and the interior disposed in the interior are more reliably While suppressing or preventing the occurrence of breakage or breakage in the electrode pattern, etc., as described above, there is a concave portion on one main surface, and the region corresponding to the concave portion on the other main surface is smooth without corners. With convex parts , It is possible to form a high shape accuracy unfired ceramic body.

Further, as in the method for manufacturing a ceramic substrate according to claim 6, in the configuration of the invention according to claim 4 or 5, a mold having a convex portion on the surface on which the auxiliary layer of the unfired ceramic body with the auxiliary layer is disposed. When the concave portion having a shape corresponding to the outer shape of the convex portion of the mold is formed on the surface on which the auxiliary layer of the unfired ceramic body with the auxiliary layer is disposed by pressing together, the convex portion of the mold Is in contact with the unfired ceramic body through the auxiliary layer, so that even if the shape of the convex part is sharp to some extent, breakage or breakage of the unfired ceramic body or the internal electrode pattern disposed in the inside is caused. While having suppression and prevention, it has a concave portion on one main surface as described above, and has a convex portion having a gentle shape without corners in a region corresponding to the concave portion on the other main surface, with high shape accuracy. It is possible to form a green ceramic body To become.
In addition, since an auxiliary layer is disposed on the surface of the unfired ceramic body, even if surface cracks occur in the area where the convex portions of the auxiliary layer come into contact during bending, the unfired ceramic body is affected. Therefore, it is possible to obtain a ceramic substrate having desired characteristics.
In addition, since the convex portion of the mold is in close contact with and engaged with the concave portion formed in the unfired ceramic body after pressing, the convex portion of the mold is engaged with the concave portion even if the surface crack of the auxiliary layer occurs during pressing. By firing as it is, the binding force of the unfired ceramic body by the auxiliary layer can be maintained.

Further, as in the method for manufacturing a ceramic substrate according to claim 7, in the structure of the invention according to claim 6, a mold having a convex portion is combined with the surface on which the auxiliary layer of the unfired ceramic body with the auxiliary layer is disposed, and Pressure applied to the unfired ceramic body with the auxiliary layer from the surface opposite to the surface of the unfired ceramic body with the auxiliary layer combined with the mold having the convex portion by a method using a hydraulic press or a method of pressing through an elastic body. When the pressing is performed such that the convex portion of the mold comes into contact with the unfired ceramic body through the auxiliary layer, the unfired ceramic body with the auxiliary layer is almost from the side opposite to the surface where the molds are combined. Since pressing is performed so that pressure is applied uniformly, even if the shape of the convex portion is sharp to some extent, breakage or breakage occurs in the unfired ceramic body or the internal electrode pattern disposed therein. As described above, the shape accuracy has a concave portion on one main surface and a convex portion having a smooth shape without corners in the region corresponding to the concave portion on the other main surface. It is possible to form an unfired ceramic body having a high height.
In addition, since the auxiliary layer is disposed on the surface of the unfired ceramic body, the surface of the unfired ceramic body is also affected when a surface crack occurs in the auxiliary layer that comes into contact with the convex portion of the mold during bending. There is nothing.

  Moreover, like the manufacturing method of the ceramic substrate of Claim 8, in the structure of Claim 6 or 7, as a type | mold which has a convex part, it was arrange | positioned on the flat support body and the flat support body. By using a mold comprising a convex component composed of a material that does not substantially sinter at the firing temperature of the unfired ceramic body, when the pressing (crimping) is performed, the convex component and the auxiliary layer-attached It becomes possible to integrate the fired ceramic body, and the shape of the surface of the unfired ceramic body with the auxiliary layer after pressing that comes into contact with the die (including the convex component members that make up the die) is flat. It becomes possible to improve shape stability not only in the pressing process but also after the pressing process.

  Further, as in the method for manufacturing a ceramic substrate according to claim 9, in the configuration of the invention according to claim 8, an unfired ceramic body with an auxiliary layer having a concave portion and a convex portion is connected to the concave portion of the mold. When firing in the combined state, the shape of the non-fired ceramic body with an auxiliary layer after pressing, the shape on the surface side in contact with the mold (including the convex portion constituting the mold) is flat, That is, since firing is performed in a state in which shape stability is excellent and deformation is not likely to occur, a ceramic substrate with high dimensional accuracy and shape accuracy can be manufactured.

Further, as in the method for manufacturing a ceramic substrate according to claim 10, in the configuration of any one of claims 6 to 9, when the shape of the convex portion of the mold is a tapered shape, for example, the protruding portion has a rectangular tube shape. Compared to the case of a cylindrical shape, it is possible to reduce the deformation angle of the concave portion, and even when a deep concave portion is formed, the unfired ceramic body and the internal electrode pattern disposed therein It is possible to form an unfired ceramic body having a recess having a desired depth while suppressing or preventing the occurrence of breakage or breakage in the above.
In addition, since the depth of the concave portion can be increased, the degree of freedom of the dimensions of the concave portion and the convex portion can be increased.

Moreover, like the manufacturing method of the ceramic substrate of Claim 11, in the structure of any one of Claims 6-10, the unsintered ceramic body which comprises the unsintered ceramic body with an auxiliary | assistant layer at least as a convex part of a type | mold. It is possible to reliably form a concave portion having a shape corresponding to the shape of the convex portion in the unfired ceramic body by configuring it to be harder than both of the auxiliary layer and elasticity. Can be effective.
In addition, as a method of configuring the convex portion to be harder than both the unfired ceramic body and the auxiliary layer constituting the unfired ceramic body with the auxiliary layer and to have elasticity, for example, the powder constituting the auxiliary layer A green sheet (mold formation) that leaves a portion that should become a convex part by punching a green sheet (green sheet for auxiliary layer) formed into a sheet by blending a binder etc. (other powders can be used) When a green sheet is laminated and pressure-bonded, the green sheet for substrate formation and the green sheet for the auxiliary layer are laminated and pressure-bonded to press and pressure-bond with the same load as when forming the unfired ceramic body with the auxiliary layer. Etc. That is, when pressed with the same load, the mold forming green sheet has a punched portion. Therefore, even if the substrate forming green sheet or the auxiliary layer green sheet is pressed, the unit area The pressure applied to the surface increases, and it is possible to obtain a mold having convex portions that are harder than both the unfired ceramic body and the auxiliary layer and have elasticity.
Note that, even if the green sheet is pressed as it is in the powder state, the convexity is harder than both the ceramic body and the auxiliary layer constituting the unfired ceramic body with the auxiliary layer and has elasticity. It is usually difficult to form the part.

  Moreover, like the manufacturing method of the ceramic substrate of Claim 12, in the structure of the invention in any one of Claims 8-11, the convex-part component which comprises the convex part of a type | mold is an unbaked ceramic body with an auxiliary layer By applying a pressure higher than the pressure applied when forming the non-fired ceramic body with the auxiliary layer, as described with respect to the invention of claim 11 above, the ceramic body and the auxiliary layer constituting the unfired ceramic body with the auxiliary layer are used. It is possible to more securely form a convex component member that is hard and elastic, and the present invention can be more effectively realized.

Further, as in the method for manufacturing a ceramic substrate according to claim 13, in the structure according to any one of claims 6 to 12, the portion of the green ceramic body with an auxiliary layer that deforms along the convex portion of the mold. When a reinforcing material is applied to at least a part, it becomes possible to efficiently prevent the occurrence of defects such as cracks in the unfired ceramic body with an auxiliary layer, and yield a highly reliable ceramic substrate. It becomes possible to manufacture well.
That is, for example, if a deep concave portion (high convex portion) is to be formed, it is necessary to strongly deform the unfired ceramic body with the auxiliary layer, and deep cracks may occur on the surface of the unfired ceramic body with the auxiliary layer. However, if a reinforcing material (for example, glass paste or conductive paste) that is resistant to deformation or cracking is disposed in advance on a portion where cracking is likely to occur (strongly deforming portion), defects are generated. Can be efficiently prevented.
As the reinforcing material, in addition to the materials remaining after firing, such as the glass paste and conductive paste described above, it is possible to use a resin material that disappears when the binder is removed. There are no restrictions.

Moreover, like the manufacturing method of the ceramic substrate of Claim 14, in the structure of any one of Claims 4-13, an unfired ceramic body is formed by laminating a plurality of ceramic green sheets, It has a structure in which an interlayer connection conductor pattern for connecting the layers of each ceramic green sheet layer and an in-plane conductor pattern provided at the interface of each ceramic green sheet layer are disposed (that is, a multilayer Even in the case of a laminate for a ceramic substrate), by applying the method for manufacturing a ceramic substrate according to the present invention, breakage or breakage of an unfired ceramic body or an internal electrode pattern disposed in the ceramic body can be prevented. While suppressing and preventing, as described above, there is a concave portion on one main surface, and the region corresponding to the concave portion on the other main surface has a gentle shape without corners. Having a part, it is possible to form a high shape accuracy unfired ceramic body.
In addition, the unfired ceramic body is sintered while the auxiliary layer is in close contact, and the auxiliary layer is fired at a temperature that does not substantially sinter, thereby suppressing or preventing shrinkage or deformation from occurring in the baking process. Thus, it becomes possible to efficiently manufacture a multilayer ceramic substrate having a high shape accuracy, and the present invention can be further effectively realized.

  Moreover, like the manufacturing method of the ceramic substrate of Claim 15, in the structure of any one of Claims 4-14, the unfired ceramic body with an auxiliary | assistant layer laminates | stacks a ceramic green sheet, and crimps | bonds it collectively. In the case where the auxiliary layer is adhered to the ceramic green sheet laminate formed by the above method, that is, when a multilayer ceramic substrate is manufactured by a batch pressing manufacturing method, the present invention can be suitably used. Thus, it becomes possible to efficiently produce a multilayer ceramic substrate having desired characteristics.

  Moreover, like the manufacturing method of the ceramic substrate of Claim 16, in the structure of any one of Claims 4-14, the unbaked ceramic body with an auxiliary | assistant layer to which the auxiliary | assistant layer was adhere | attached is one sheet or predetermined | prescribed When an auxiliary layer is closely attached to a ceramic green sheet laminate formed through a step of sequential pressure bonding for each time a plurality of ceramic green sheets are stacked, that is, a multilayer ceramic substrate by a method of sequential pressure bonding The present invention can be preferably used for manufacturing a multilayer ceramic substrate having desired characteristics.

  Further, as in the method for manufacturing a ceramic substrate according to claim 17, in the configuration of the invention according to claim 6, a concave portion is formed at a position in contact with the convex portion of the mold of the unfired ceramic body with the auxiliary layer to which the auxiliary layer is adhered. When forming and making the height H of the convex part of the mold larger than the depth D of the concave part, breakage or breakage of the unfired ceramic body or the internal electrode pattern disposed therein It is possible to efficiently manufacture a ceramic substrate having a deep concave portion and a ceramic substrate having concave portions having different depths on both sides while suppressing and preventing the above.

  Further, as in the method for manufacturing a ceramic substrate according to claim 18, in the structure of any one of claims 4 to 17, when the unfired ceramic body is an aggregate substrate of unfired ceramic bodies for a plurality of sub-substrates In addition, after the firing, when the obtained collective substrate is divided into sub-substrates (that is, when a method of taking multiple pieces from the collective substrate is adopted), the collective substrate is divided into a large number of sub-substrates. It becomes possible to obtain well, and it becomes possible to reduce the cost.

  Further, as in the method for manufacturing a ceramic substrate according to claim 19, in the structure of any one of claims 4 to 18, when the surface-mounted component is mounted on the ceramic substrate after firing, In addition, it is possible to efficiently manufacture a small, high-density, highly reliable ceramic substrate in which surface-mounted components are mounted on the stepped portion formed by the presence of the concave and convex portions.

  The features of the present invention will be described in more detail below with reference to examples of the present invention.

  A method for manufacturing a ceramic substrate according to an embodiment (Example 1) of the present invention will be described below.

(1) First, a plurality of ceramic green sheets for ceramic substrates (hereinafter referred to as “substrate green sheets”) containing a ceramic material are prepared. The procedure is as follows.
CaO: 10 to 55 wt%, SiO _2: 45 to 70 wt%, Al ₂ O _3: 0~30 wt%, 0-10 wt% impurities, and B ₂ O _3: 5 to 20% by weight outer percentage The mixture containing the mixture was melted at 1450 ° C. to be vitrified, then rapidly cooled in water, and pulverized to obtain CaO—SiO ₂ —Al ₂ O ₃ —B ₂ O ₃ having an average particle size of 3.0 to 3.5 μm. A system glass powder is prepared.
In Example 1, CaO—SiO ₂ —Al ₂ O ₃ —B ₂ O ₃ glass was used, but other glass sintered at 800 to 1000 ° C. may be used.

  Then, the glass powder: 50 to 65% by weight (preferably 60% by weight) and the alumina powder having impurities of 0 to 10% by weight: 50 to 35% by weight (preferably 40% by weight) are mixed to obtain a ceramic powder. Make it. Then, a solvent (for example, toluene, xylene, water-based), a binder (for example, acrylic, butyral-based resin) and a plasticizer (for example, dioctyl phthalate (DOP), dibutyl phthalate (DBP), etc.) A slurry having a viscosity of 2000 to 40000 cps is prepared by kneading and dispersing into a green sheet having a thickness of 0.01 to 0.4 mm, for example, using a normal casting method (for example, a doctor blade method). A green sheet for a substrate constituting the portion).

  In addition, when manufacturing this board | substrate green sheet, a composition ratio and an additive are adjusted, and it is set as a moderately soft property rather than the following green sheet 2 for auxiliary layers (for constraining layers). At the time of molding, it is possible to improve the followability to the mold 30 and increase the processing accuracy, and it is possible to suppress and prevent the occurrence of cracks, chips, etc. in the green sheet for substrates.

  (2) Then, the substrate green sheet 1 (FIG. 1) produced in the above step (1) is cut into a predetermined size by using a punching die or a punching machine, and an interlayer connection via hole 33 (FIG. 1). Form.

(3) The via hole conductor 34 is formed by filling the via hole 33 of the plurality of substrate green sheets processed in the step (2) with a conductive paste. Further, by printing a conductor paste on the substrate green sheet 1, a predetermined wiring pattern that becomes the surface conductor 31, the inner layer conductor 32, and the like is formed.
As the conductor paste used at this time, a conductor paste containing Ag, Ag-Pd, Ag-Pt, Cu powder or the like as a conductive component is used. If necessary, it is also possible to print a resistance paste or a glass paste together with the conductor paste or instead of the conductor paste.

(4) Also, a plurality of auxiliary layer (constraint layer) green sheets 2 (FIG. 1) including ceramics that are not sintered at the firing temperature of the substrate green sheet 1 are produced.
The auxiliary layer (constraint layer) green sheet 2 can be obtained, for example, by preparing a slurry by dispersing alumina powder in an organic vehicle and molding the slurry into a sheet by a casting method. Since the sintering temperature of the green sheet 2 for the auxiliary layer (for the constraining layer) thus obtained is 1500 to 1600 ° C., the temperature at which the green sheet 1 for the substrate is sintered (for example, 800 to 1000 ° C.) Then, the substrate green sheet 1 is baked in a state in which the auxiliary layer (constraint layer) green sheet 2 is bonded without sintering, thereby suppressing the shrinkage in the planar direction of the substrate green sheet 1. It becomes possible to tie.
The physical properties of the auxiliary layer (constraint layer) green sheet 2 are adjusted so as to be harder than the substrate green sheet 1 so that the green ceramic body 10 can be processed without being damaged during pressing. Use what you did.

  (5) A green sheet (mold forming green) used for forming a mold, in which the auxiliary layer (constraint layer) green sheet 2 produced in the step (4) is punched into a predetermined shape. The main surface of the sheet 3 (FIG. 1) is pressure-bonded to the fixed surface (flat plate) 4 (FIG. 1) with a high pressure to produce a press (deformation) die 30 (FIG. 1).

  In Example 1, the same green sheet 2 as that for the auxiliary layer (for the constraining layer) 2 was punched into a predetermined shape so that the side surface is slanted, and the mold forming green sheet 3 was attached to the flat plate 4. As a result, a mold 30 (see FIG. 1) including a convex portion 22 having a tapered shape with a taper (hems spread) and a concave portion 21 having a taper shape with a taper (hems narrowed) was produced.

The punched portion of the mold forming green sheet 3 becomes a recess (die) 21 of the press die 30, and the remaining portion without being punched becomes a convex component, and this convex component is fixed. It is pressure-bonded to the surface (flat plate) 4 to form a convex portion (mold) 22 of the mold 30. Since the convex portion 22 of this mold 30 is a part of the green sheet and has a certain degree of elasticity, the desired shape can be achieved while suppressing damage to the laminate (unfired ceramic body with auxiliary layer) 11. A step portion 15 (FIGS. 2 and 3) having the shape can be formed.
In addition, as the flat plate 4 used for producing the mold 30, it is preferable to use a material made of a material (resin or metal) having an appropriate hardness. It is also possible to use a flat plate made of a composite material obtained by combining a plurality of types of materials.

  (6) Then, as shown in FIG. 1, on both main surfaces (up and down) of a substrate ceramic green sheet laminate (unfired ceramic body) 10 in which a plurality of substrate green sheets 1 are laminated, A plurality of green sheets 2 (for constraining layers) are laminated to form the auxiliary layer 20, and a laminated body (unfired ceramic body with auxiliary layer) 11 (FIG. 1) is formed. In Example 1, the thickness of the lower auxiliary layer is made thinner than the thickness of the upper auxiliary layer.

(7) Next, as shown in FIG. 2, a pressing (deformation) die 30 is attached to the unfired ceramic body 11 with an auxiliary layer, vacuum packed using the flexible film 6, and subjected to an isostatic press. The green ceramic body 11 with the auxiliary layer is pressed by pressing the isotropic ceramic body 11 with the auxiliary layer isotropically applied from the main surface not in contact with the mold 30 through the water 7. Deform.
Note that the pressing method is not limited to the hydrostatic pressing method, and as shown in FIG. 3, pressing is performed by a flat pressing die 8 through an elastic body 7a (for example, silicon rubber), and an unfired auxiliary layer is provided. It is also possible to deform the ceramic body 11 (to form the stepped portion 15).

  In this pressing step, the water 7 or the elastic body 7a is deformed so as to conform to the concavo-convex shape of the main surface of the unfired ceramic body 11 with the auxiliary layer that is not in contact with the mold 30, and therefore the unfired ceramic body 11 with the auxiliary layer. Is deformed smoothly by the pressure from the water 7 or the elastic body 7a, and the main surface side of the unfired ceramic body 11 with the auxiliary layer in contact with the mold 30 enters the inside of the recess 21 of the mold 30, Reach the top surface.

As a result, the unfired ceramic body 11 with the auxiliary layer is sufficiently deformed, and on the surface facing the mold 30,
1) a concave portion 15 (15a) having a corner whose side surface is sharply inclined;
2) A convex portion 115 (115a) having a sharply inclined side surface formed between the concave portions 15 (15a) having a sharply inclined side surface, and a surface not contacting the mold 30 ,
3) the convex part 115 (115b) having a gentle shape without corners;
4) It is possible to form a pressure-bonding body 13 including a pair of concave portions 15 (15b) having a smooth shape with no corners formed between convex portions 115 (115b) having a smooth shape without corners ( (See FIGS. 3 and 5).

The pressing of the unfired ceramic body 11 with the auxiliary layer by the mold 30 is performed at a pressure of 100 to 2000 kg / cm ² , preferably 1000 to 2000 kg / cm ² , and a temperature of 30 to 100 ° C., preferably 50 to 80 ° C. To implement.

At this time, the green sheet for mold formation (the punched auxiliary layer (constraint layer) green sheet) 3 constituting the press mold 30 is previously press-bonded to the flat plate 4 with a high pressure. Thus, while having a certain degree of elasticity, it has sufficient hardness to deform the unfired ceramic body 11 with the auxiliary layer.
In addition, since the green sheet for substrate 1 constituting the main part of the unfired ceramic body 11 with the auxiliary layer is softer than the green sheet 3 for forming the mold constituting the press mold 30, the unfired ceramic body 10 can be easily and easily formed. It can be reliably deformed.

  (8) Next, the flat plate 4 used as the fixing surface is peeled off from the deformed pressure-bonded body (unfired ceramic body 11 with the auxiliary layer including the mold 30) 13, and the auxiliary layer 20 and the protrusions 22 are left unattached. Firing is performed at a temperature at which the fired ceramic body 10 is sintered, for example, 1000 ° C. or less, preferably 800 to 1000 ° C., to obtain a sintered substrate (ceramic substrate) 14 having auxiliary layers 20 on both main surfaces.

  Note that when a conductive paste using a base metal powder such as Cu powder as the conductive component is used, it is necessary to fire in a reducing atmosphere to prevent oxidation, but Ag, Ag-Pd, Ag-Pt, etc. When a conductive paste containing noble metal powder as a conductive component is used, it can be fired in the air.

(9) Then, by removing the unsintered auxiliary layer 20 from the surface of the sintered substrate (ceramic substrate) 14, the recesses 15 (15 a, 15 b) are formed on the front and back main surfaces as shown in FIG. 4. To obtain a sintered substrate (ceramic substrate) 14.
As a method for removing the auxiliary layer 20, either a physical processing method such as ultrasonic cleaning or a method of spraying alumina abrasive grains, or a chemical processing method such as etching may be used. It is also possible to use a combination of a chemical treatment method and a chemical treatment method.

  In the configuration of the sintered substrate (ceramic substrate) 14 manufactured as described above, the convex portion 22 of the mold 30 used in the pressing process has a tapered shape, and thus the laminate ( The angle at which the unfired ceramic body 11 with the auxiliary layer 11 is bent can be reduced, and even when the deep recess 15 (15a) is formed in the multilayer body 11, it is ensured that the multilayer body 11 is cracked. It becomes possible to suppress and prevent, and it becomes possible to manufacture a highly reliable ceramic substrate with a high yield.

  Further, FIG. 5 is a diagram in which the ceramic substrate 14 of FIG. 4 manufactured by the method for manufacturing a ceramic electronic component of Example 1 is divided, and one concave portion is provided on one main surface and one convex surface is formed on the other main surface. FIG. 6A is a perspective view showing the shape of the upper surface side of the ceramic substrate shown in FIG. 5, and FIG. 6B is a perspective view showing the lower surface side thereof. .

As shown in FIGS. 5, 6 (a), (b), in this ceramic substrate 14,
(a) The dimension of the substantially flat surface 116b on the top of the convex portion 115 (115b) on the upper surface side in the direction parallel to the upper surface 117b of the ceramic substrate 14 is A1,
(b) The dimension of the entire upper surface side convex portion 115 (115b) in the direction parallel to the upper surface 117b of the ceramic substrate 14 is A2,
(c) The angle formed by the inclined surface 118b of the convex portion 115 (115b) on the upper surface side from the upper surface of the ceramic substrate 14 to the substantially flat surface 116b at the top and the upper surface 117b of the ceramic substrate 14 is θA,
(d) The dimension of the substantially flat surface 116a at the bottom of the recess 15 (15a) on the lower surface side in the direction parallel to the lower surface 117a of the ceramic substrate 14 is B1,
(e) The dimension of the entire recess 15 (15a) on the lower surface side in the direction parallel to the lower surface 117a of the ceramic substrate 14 is B2,
(f) The angle formed between the inner wall surface 118a of the recess 15 (15a) on the lower surface side from the lower surface 117a of the ceramic substrate 14 to the substantially flat surface 116a at the bottom and the lower surface 117a of the ceramic substrate 14 is θB.
In this case, the ceramic substrate 14 (or the press-bonded body 13) manufactured by the method for manufacturing a ceramic electronic component of Example 1 is
A1 <B1 [1]
B2 <A2 ...... [2]
Meet the conditions.

In addition, the ceramic substrate 14 (or the crimped body 13) is
θA <θB …… [3]
Meet the conditions.

Further, the ceramic substrate 14 (or the crimped body 13) is
0 ° <θB ≦ 90 ° …… [4]
0 ° <θA <90 ° …… [5]
It has the conditions of

  By satisfying the above condition [1] (A1 <B1) and condition [2] (B2 <A2), the lower surface side concave portion 15 (15a) and the upper surface side convex portion 115 (115b) of the ceramic substrate 14 are satisfied. Shrinkage direction (direction indicated by arrow 5A in FIG. 5) in the step forming portion 19 (the portion defined by the inclined surface 118b and the inner wall surface 118a) (see FIG. 5, FIG. 6 (a), (b)) The thickness of the cavity becomes a thickness that approximates the thickness of other portions of the ceramic substrate 14, and suppresses or prevents the difference in absolute shrinkage from increasing in the firing process, thereby preventing a cavity structure (recessed portion) free from defects such as distortion and cracks. 15, a structure including a convex portion 115 and the like) can be obtained.

  Further, during sintering of the ceramic substrate, the auxiliary layer 20 (constraint layer green sheet 2) disposed on both main surfaces of the pressure-bonded body 13 does not substantially shrink while maintaining its shape. It is possible to suppress or prevent the peeling at the interface between the (constraint layer green sheet 2) and the pressure-bonding body 13 (ceramic substrate 14), and the pressure-bonding body 13 is substantially in the plane direction. In order to sinter without shrinking and without inhibiting the shrinkage in the thickness direction, the ceramic substrate 14 having a cavity structure (structure having the concave portion 15, the convex portion 115, etc.) with high dimensional accuracy is manufactured. It becomes possible.

  Further, it is not necessary to add a special process for forming the concave portion 15 and the convex portion 115 (forming the cavity) (the cavity can be formed only by the crimping process), and thus a flat surface without a cavity is provided. As compared with the case of manufacturing a simple ceramic substrate, the ceramic substrate 14 having a cavity structure with high dimensional accuracy can be manufactured without increasing the manufacturing cost.

  Further, when the condition [3] (θA <θB) is satisfied, the shrinking direction (in the step forming portion 19 between the concave portion 15 (15a) on the lower surface side and the convex portion 115 (115b) on the upper surface side ( The thickness in the direction indicated by the arrow 5A) can be more reliably approximated to the thickness of other portions of the ceramic substrate 14, and the above-described effects can be obtained more reliably.

Furthermore, when the condition [4] (0 ° <θB ≦ 90 °) and the condition [5] (0 ° <θA <90 °) are satisfied, the recess 15 (15a) on the lower surface side and the upper surface side The thickness of the step forming portion 19 between the convex portions 115 (115b) in the contraction direction (the direction indicated by the arrow 5A) can be more reliably approximated to the thickness of other portions of the ceramic substrate 14. Thus, the above-described effect can be further ensured.
Note that, when the condition of 30 ° ≦ θB ≦ 60 ° is satisfied, the above-described effects can be further ensured.

  In the ceramic substrate of the present invention, the recess 15 (15a) formed on the surface in contact with the mold 30 has a sharp shape and a smooth surface, and a sintered substrate ( The concave portion 15 (15b) formed on the surface of the ceramic substrate 14 that is not in contact with the mold 30 is also smoothly deformed and has a smooth surface without corners. Therefore, according to the present invention, it is possible to reliably manufacture a ceramic substrate with little residual stress, high shape accuracy and dimensional accuracy, and excellent surface smoothness.

  Moreover, FIG. 7 is a figure which shows the modification of the ceramic substrate of this Example. That is, in the present invention, as shown in FIG. 7, a recess having a shape in which the inner wall surface is substantially vertical with the angle θB formed by the inner wall surface 118a of the recess 15a on the lower surface side and the lower surface 117a of the ceramic substrate 14 being 90 °. It is also possible to have a structure with

  As shown in FIG. 7, since the shape of the upper surface side convex portion 115b smoothly follows the shape of the lower surface side concave portion 15a, the deviation between the shapes of the lower surface side concave portion 15a and the upper surface side convex portion 115b is Although the size is large, the dimension A1 of the substantially flat surface 116b at the top is small, and the entire dimension of the recess 15a is large in the direction parallel to the lower surface 117a of the ceramic substrate 14 (bottom dimension) B2. Since the angle θA formed between the inclined surface 118b of the ceramic substrate 14 and the upper surface 117b of the ceramic substrate 14 is an acute angle, the thickness variation of the ceramic substrate 14 is reduced. In this case, the convex portion 115b Each sheet constituting the pressure-bonding body 13 around the recess 15a is stretched and an effect of relaxing the thickness of the pressure-bonding body 3 is obtained. When the angle θB of the lower surface 117a of the ceramic substrate 14 and 90 °, it is possible to obtain the basic actions and effects of the effects obtained from the present invention.

  Further, in the sintered substrate (ceramic substrate) 14 having the structure as shown in FIG. 4, the concave portion can be formed by appropriately selecting the position to be divided and the surface to be used on the mounting side of the two main surfaces. When attention is paid to the shape and direction of 15, it can be used as four types of structures as shown in FIGS. 8 (a), (b), (c), and (d).

That is, as shown in FIGS. 8A and 8B, the concave portion 15 (15a) whose side surface is sharply inclined becomes the upper surface side (FIG. 8A) or the lower surface side (FIG. 8B). 8A and 8B, the concave portion 15 (15b) having a smooth shape without corners is formed on the upper surface side (FIG. 8C) or the lower surface side (see FIG. 8C and FIG. 8D). It is possible to produce a ceramic substrate 14 as shown in FIG.
Further, in FIGS. 8A to 8D, the description has been given focusing on one concave portion (cavity) 15 (15a or 15b), but one sintered substrate (ceramic substrate) 14 has a plurality of concave portions (cavities). 15 may be configured.

  Then, as shown in FIG. 9A, the ceramic substrate 14 is arranged so that the concave portion 15 (15a) whose side surface is sharply inclined faces upward, and a chip-type capacitor and a chip type are formed inside the concave portion 15 (15a). An electronic component 16 such as an inductor or a semiconductor element is mounted, or as shown in FIG. 9B, the electronic component 16 is mounted on a mother board 18 and a concave portion 15 (15a) whose side surface is sharply inclined is formed thereon. For example, the ceramic substrate 14 may be disposed downward to protect the electronic component 16.

  Further, as shown in FIG. 9 (c), the ceramic substrate 14 is arranged so that the concave portion 15 (15b) having a smoothly inclined side surface and facing the upper side faces upward, and inside the concave portion 15 (15b). The electronic component 16 is mounted or the electronic component 16 is mounted on the mother board 18 as shown in FIG. 9 (d), and the concave portion 15 (15b) having a corner with a gently sloping side surface is directed downward. By arranging, the electronic component 16 can be protected.

In addition, in order to mount various electronic components on the sintered substrate (ceramic substrate) 14 with high reliability, a plating film is formed on the surface conductor 31 and the via-hole conductor 34 exposed on the surface. Is desirable.
At this time, it is desirable to use, for example, Ni—Au, Ni—Pd—Au, Ni—Sn or the like as the material of the plating film. In addition, as a formation method of a plating film, it is possible to use either electrolytic plating or electroless plating.

  FIG. 10 is a diagram showing another example of the ceramic substrate that can be manufactured by the method of the first embodiment.

Here, the surface of the ceramic substrate 14 that is in contact with the mold 30 in the crimping process is
1) a concave portion 15 (15a) having a corner whose side surface is sharply inclined;
2) a convex portion 115 (115a) having a sharply inclined side surface formed between the concave portions 15 (15a) having a sharply inclined side surface;
On the surface that does not contact the mold 30 in the crimping process,
3) the convex part 115 (115b) having a gentle shape without corners;
4) A pair of gently concave portions 15 (15b) without corners formed between the convex portions 115 (115b) having smooth shapes without corners, and the electronic component 16 or the semiconductor element. 17 on the surface conductor 31 and the via-hole conductor 34 in which plating films are formed on the surfaces of the concave portions 15 (15a, 15b) and the convex portions 115 (115a, 115b) on both main surfaces of the sintered substrate (ceramic substrate) 14. As a result, the module substrate 114 as a product is formed. As described above, according to the method of the first embodiment, it is possible to obtain an advanced module substrate 114 in which the electronic component 16 and the semiconductor element 17 are efficiently arranged on both main surfaces.

  In the method for manufacturing a ceramic substrate of the present invention, after mounting electronic parts on a sintered substrate (ceramic substrate), resin sealing is performed as necessary, and the product is divided into individual product units. It is possible to apply a so-called multi-cavity method for obtaining a ceramic substrate at the same time, and efficiently manufacture an advanced module substrate 114 in which electronic parts 16 and semiconductor elements 17 are efficiently arranged on both main surfaces. Is possible.

Furthermore, from the configuration of the first embodiment, the following specific effects can be obtained.
1) Since the surface of the unfired ceramic body 11 with the auxiliary layer on the side opposite to the surface where the mold 30 is combined is gently deformed, the concave portion 15 (15a) having a sharp shape is formed on the surface in contact with the mold 30. Even when it is formed, the depression 15 (15a) having the intended shape is formed without suppressing the unsintered ceramic body 10 from being broken by suppressing a large stress on the contact surface with the mold 30. It becomes possible.

  2) Further, the convex portion 22 of the mold 30 is formed by using the same auxiliary layer (for constraining layer) green sheet 2 as the surface of the laminated body (unfired ceramic body with auxiliary layer) 11, and has elasticity. Therefore, the processing to the laminated body (unfired ceramic body with auxiliary layer) 11 becomes soft, and the laminated body (unfired ceramic body with auxiliary layer) 11 particularly in the portion corresponding to the edge portion of the convex portion 22. It can suppress that a crack generate | occur | produces.

  3) In the case of Example 1 as well, cracks may occur on the surface of the laminate (non-fired ceramic body with auxiliary layer) 11 during pressing, but the cracks are caused by the laminate (unfired with auxiliary layer). Since the ceramic body 11 stays on the auxiliary layer (constraint layer) green sheet 2 on the surface and does not reach the unfired ceramic body 10 inside, it is possible to finally obtain a highly reliable ceramic substrate 14. Become.

  4) When the laminate (unfired ceramic body with an auxiliary layer) 11 is pressed, even if a surface crack occurs in the auxiliary layer 20 in contact with the convex portion 22 of the mold 30, the mold 30 is on the cracked surface. Because of the close contact, the binding force during firing is not impaired.

  5) Further, the convex portion 22 of the pressing (deforming) mold 30 is the same auxiliary layer (constraint layer) green sheet 2 as the auxiliary layer 20 disposed on the surface of the unfired ceramic body 11 with the auxiliary layer. Therefore, when pressing (crimping), it can be integrated with the unfired ceramic body 11 with an auxiliary layer, and a deformed crimped body (unfired ceramic body with an auxiliary layer including the mold 30) 11) Since one main surface of 13 can be made flat, the laminated body (unfired ceramic body with auxiliary layer) 11 is securely held by the flat plate 4, and the laminated body (unfired ceramic with auxiliary layer) It is possible to improve the shape stability of the body 11 at the time of degreasing and firing, and it is possible to reliably manufacture a sintered substrate (ceramic substrate) 14 with high processing accuracy and small dimensional strain. .

FIG. 11 is a diagram showing one step in the method of manufacturing the ceramic substrate of this example (Example 2).
In FIG. 11, the same reference numerals as those in FIGS. 1 and 2 indicate the same or corresponding parts.

  In this Example 2, as a die for pressing (deformation), a process of forming concave portions 21 and convex portions 22 of a predetermined shape on a flat plate 4 made of a material having moderate hardness (resin in this Example 2). A mold 30 produced by directly applying is used. Other configurations are the same as those of the first embodiment.

Note that the mold 30 is not limited to the resin as described above, and a mold having a concave portion and a convex portion provided on a metal flat plate can also be used.
Then, using a mold 30 as shown in FIG. 11, as in the case of Example 1, a laminate in which auxiliary layers 20 are disposed on both sides of the unfired ceramic body 10 (unfired ceramic body with an auxiliary layer) ) 11 is pressed by a method of hydrostatic pressure pressing (or pressure bonding through an elastic body) to form a pressure-bonded body 13 having a predetermined shape, and a ceramic substrate is manufactured.

  When the mold 30 using the flat plate (resin plate) 4 made of a resin material that is moderately hard and elastic as in the second embodiment is used, the following effects can be obtained.

  1) Since the surface of the unfired ceramic body 11 with the auxiliary layer that is opposite to the surface on which the mold 30 is combined can be gently deformed (a gentle recess 15 (15b) is formed on the back surface), Even when the inner wall surface 118a is formed with the concave portion 15 (15a) having a sharp shape inclined at a predetermined angle, the contact surface with the mold 30 is prevented from being subjected to a large stress on the contact surface. Thus, the recess 15 (15a) having the intended shape can be formed without causing the unfired ceramic body 10 to break (an effect corresponding to the effect (1) of the first embodiment). As the recess 15 (15a), it is also possible to form a recess having a sharp shape with the side wall being nearly vertical.

  2) Further, since the convex portion 22 of the mold 30 is made of a resin that is moderately hard and elastic, the processing to the laminated body (unfired ceramic body with auxiliary layer) 11 becomes soft, particularly the convex portion. It is possible to suppress the occurrence of cracks in the laminated body (unfired ceramic body with an auxiliary layer) 11 in a portion corresponding to the edge portion of 22 (an effect corresponding to a part of the effect of 2 of Example 1). . In addition, since the bottom surface of the concave portion 21 of the mold 30 (that is, the flat plate body constituting the mold 30) has elasticity, when the laminate 11 is pressed and deformed, the bottom surface of the concave portion 21 is deformed and rises downward, Damage due to deformation of the laminate 11 can be reduced.

  3) Even when a crack occurs on the surface of the laminate (unfired ceramic body with an auxiliary layer) 11 during pressing, the crack remains in the green sheet 2 for the auxiliary layer (for the constraining layer) on the surface of the laminate 11, Since the inner unfired ceramic body 10 is not reached, a highly reliable ceramic substrate 14 can be finally obtained (an effect equivalent to the effect 3 of Example 1)).

  4) Since the mold 30 can be used repeatedly, the manufacturing cost can be reduced. Further, since the flat plate surface also has elasticity, when the laminated body 11 is deformed and pressure-bonded, it rises from the bottom surface, and damage due to deformation of the laminated body 11 can be reduced.

Further, when the mold 30 is used using a flat plate (metal plate) 4 made of a hard and non-elastic metal material, among the effects 1) to 4) when the mold 30 made of the above resin is used, The effects 1), 3) and 4) can be obtained.
In addition, when the metal mold 30 is used, not only can it be used repeatedly, but since the metal is hard and has excellent workability for smoothing the surface, the processing surface can be made flatter. It becomes possible, and it becomes possible to perform highly accurate molding.

  However, when the metal mold 30 is used, since the convex portion 22 is hard and does not have elasticity, the effect 2) as obtained when the mold has elasticity cannot be obtained.

  Further, when the mold 30 made of resin or metal is used, the material of the mold 30 is different from the material of the laminate, so that the laminate (unfired ceramic body with an auxiliary layer) 11 is simultaneously used. Since it is necessary to peel off the mold 30 from the deformed pressure-bonded body (unfired ceramic body 11 with an auxiliary layer including the mold 30) 13 that cannot be fired, the surface on which the molds are aligned is flattened. However, the auxiliary layer (green sheet for constraining layer) is the surface of the laminate, although the effect as in 4) of Example 1 cannot be obtained in terms of restraining force during firing. Therefore, it is possible to obtain a ceramic substrate with higher shape accuracy and dimensional accuracy than in the case of the conventional manufacturing method.

FIG. 12 is a diagram showing one step in a method of manufacturing a ceramic substrate according to still another embodiment (Example 3) of the present invention.
In FIG. 12, the same reference numerals as those in FIGS. 1 and 2 denote the same or corresponding parts.

  In this Example 3, as in the case of the mold 30 of Example 1, the green sheet 3 for mold formation obtained by punching the same sheet as the green sheet 2 for the auxiliary layer (for constraining layer) into a predetermined shape is used as the flat plate 4. A green sheet 2 for an auxiliary layer (for constraining layer) containing a ceramic that does not sinter at the firing temperature of the green sheet for a substrate, and a green sheet for a substrate that becomes a ceramic substrate. 1 and a predetermined number of green sheets 2 for constraining layers are laminated and pressure-bonded, and a pressure-bonded body having auxiliary layers 20 on both upper and lower surfaces of the unfired ceramic body 10 and having concave and convex portions of a desired shape. 13 is formed.

  That is, in Example 3, the green sheets 2 for the auxiliary layer (constraint layer), the green sheet 1 for the substrate serving as the ceramic substrate, and the green sheet 2 for the constrained layer are laminated in a predetermined number. Each time one sheet is laminated, it is pressed from the upper surface by pressing with a flat plate-shaped pressing die 8 through an elastic body (for example, silicon rubber) 7a, and this is repeated to form the pressing body 13. .

Incidentally, the pressing pressure is preferably in the range of 100 to 2,000 kg / cm ^2, further preferably in a range of 1000~2000kg / cm ^2. Moreover, it is preferable to make the temperature at the time of press into the range of 30-100 degreeC, and also it is preferable to set it as the range of 50-80 degreeC.

  Also in the case of the method of the third embodiment, as in the case of the first embodiment, a concave portion 15 (15a) having a sharp shape in which the inner wall surface 118a is inclined at a predetermined angle is formed on the surface facing the mold 30. A pressure-bonded body 13 as shown in FIG. 12 having a recess 15 (15b) whose side wall is gently inclined on the surface that is formed and not in contact with the mold 30 can be obtained. As the recess 15 (15a), it is also possible to form a recess having a sharp shape with the side wall being nearly vertical.

  Further, in the method of manufacturing the ceramic substrate of the third embodiment, since the auxiliary layer (constraint layer) green sheet 2 and the substrate green sheet 1 are laminated, the pressure bonding is performed. Each time the elastic body 7a is deformed so as to follow the concave and convex shape of the mold 30, each green sheet is sufficiently inserted into the concave portion 21 of the mold 20 to form the crimped body 13 having a desired shape. it can.

  According to the method of Example 3, each green sheet is laminated and pressure-bonded one by one inside the concave portion 21 of the deformation die 30, so that the green sheet gradually extends and the concave portion of the die 30 is 21 is selectively filled, and the depth of the recess 15 (15b) formed on the surface opposite to the surface facing the mold 30 becomes shallower as the number of stacked layers (the number of crimps) increases. .

  And the recessed part 15 (15b) formed in the surface on the opposite side to the surface which opposes the type | mold 30 as shown in FIG. 13 by baking the crimping | compression-bonding body 13 crimped | bonded to the shape as shown in FIG. A ceramic substrate 14 having a shallow depth is obtained.

  Further, according to the method for manufacturing the ceramic substrate of the third embodiment, the same effects as those in the method for manufacturing the ceramic substrate of the first embodiment can be obtained in other respects. Further, the structure of the ceramic substrate manufacturing method of the third embodiment is the same as that of the above-described second embodiment (a structure in which a mold 30 (see FIG. 11) made of a resin or metal having appropriate hardness is used). In this case, the same effects as those in the method of manufacturing the ceramic substrate of the second embodiment can be obtained.

Further, in the above example, the pressure bonding is performed through the elastic body 7a, but it is also possible to perform the pressure bonding by a hydrostatic press method.
Moreover, it is also possible to comprise so that the crimping | compression-bonding body 13 deform | transformed by crimping | bonding via the elastic body 7a may further be crimped | bonded by the method of an isostatic press. At this time, in the deformed crimping body 13, the main surface on which the step portion (recessed portion) 15 (15b) is formed is sandwiched between elastic bodies (for example, silicone rubber) that are easily deformed so that isotropic pressure is applied. It is preferable to pressure-bond with.

FIG. 14 shows the configuration of a mold used in a method for manufacturing a ceramic substrate according to still another embodiment (Example 4) of the present invention and a green ceramic body with an auxiliary layer before pressing formed into a corresponding shape. FIG. 15 is a diagram showing a state where an unfired ceramic body with an auxiliary layer is pressed. 14 and 15, the same reference numerals as those in FIGS. 1 and 2 indicate the same or corresponding parts.
The fourth embodiment is the same as the first embodiment except for the configuration described below.

  In this Example 4, first, as in Example 1, the green sheet 3 for mold formation obtained by punching the same sheet as the auxiliary layer (constraint layer) green sheet 2 into a predetermined shape is attached to the flat plate 4. A mold 30 (see FIG. 14) provided with the concave portion 21 and the convex portion 22 is prepared.

  Then, as a laminate (unfired ceramic body with an auxiliary layer) 11, after laminating a predetermined number of green sheets 2 for auxiliary layers (for constraining layers) not punched and green sheets 1 for substrates not punched, By laminating the punched green sheet for substrate 1a and the punched auxiliary layer (for constraining layer) green sheet 2a, auxiliary layers 20 are disposed on both sides of the unfired ceramic body 10, and Then, a laminated body (unfired ceramic body with an auxiliary layer) 11 (see FIG. 14) in which the concave portions 11a are formed at positions facing the convex portions 22 of the mold 30 is produced.

  The depth D of the concave portion 11a of the laminate (unfired ceramic body with auxiliary layer) 11 is such that the bottom of the concave portion 11a is pressed (crimped) by the convex portion 22 of the mold 30, and a step portion (concave portion) having a predetermined shape. 15 (15a) is formed so as to be shallower than the height H of the convex portion (mold) 22 of the mold 30.

  Then, as shown in FIG. 15, the laminated body (unfired ceramic body with auxiliary layer) 11 so that the convex portion 22 of the mold 30 and the concave portion 11 a of the laminated body (unfired ceramic body with auxiliary layer) 11 face each other. The mold 30 is put together and pressed by a method of hydrostatic pressure pressing (or pressure bonding via an elastic body). As a result, a step portion (recessed portion) 15 (15a) having a deep and sharp shape is formed on the surface facing the mold 30, and the side wall is gently formed on the surface that is not in contact with the mold 30. It is possible to obtain the pressure-bonded body 13 that is inclined and has a stepped portion (recessed portion) 15 (15b) that is shallower than the recessed portion 15 (15a) formed on the surface in contact with the mold 30.

  In particular, in the configuration of the fourth embodiment, a layered body (unfired ceramic body with an auxiliary layer) 11 is previously formed in a region where the recess 15 (15a) is to be formed in the finally produced ceramic substrate. Since the concave portion 11a is formed, the thickness of the portion having the deep and sharp shape and the concave portion 15 (15a) (the bottom portion of the concave portion 15a) is formed by pressing the mold 30 together. Accordingly, it is possible to reliably form the step portion (recessed portion) 15 (15a) having a small thickness.

  Further, since the concave portion 11a is formed in the laminated body (unfired ceramic body with an auxiliary layer) 11 in advance, the deep concave portion 15 (15a) is formed by pressing using the mold 30. In this case, the thickness of the portion (the bottom of the recess 15a) having a deep and sharp shape and having the recess 15 (15a) formed without causing breakage of the unfired ceramic body 10 can be obtained. It becomes possible to manufacture the press-bonded body 13 including the thin step portion (recessed portion) 15 (15a) with a high yield.

  In addition, according to the method for manufacturing a ceramic substrate of Example 4, the same effects as those of the method for manufacturing the ceramic substrate of Example 1 can be obtained in other respects. Furthermore, the structure of the ceramic substrate of Example 4 can also be applied to the structure of the manufacturing method of the ceramic substrate of Examples 2 and 3 described above, in which case the ceramic of Examples 2 and 3 described above is used. The same effects as those of the substrate manufacturing method can be obtained.

FIG. 16 shows the structure of a die used in a method for manufacturing a ceramic substrate according to yet another example (Example 5) of the present invention and a green ceramic body with an auxiliary layer before pressing formed into a corresponding shape. FIG. 17 is a diagram showing a state where an unfired ceramic body with an auxiliary layer is pressed.
16 and 17, the same reference numerals as those in FIGS. 1 and 2 indicate the same or corresponding parts.
The fifth embodiment is the same as the first embodiment except for the configuration described below.

  In Example 5, as in Example 1, first, a green sheet 3 for mold formation obtained by punching the same sheet as the auxiliary layer (constraint layer) green sheet 2 into a predetermined shape is attached to the flat plate 4. A mold 30 (see FIG. 16) provided with the concave portion 21 and the convex portion 22 is prepared.

  Further, as a laminate (unfired ceramic body with an auxiliary layer) 11, a green sheet 1 for a substrate and a green sheet 2 for an auxiliary layer (for a constraining layer) are laminated in a predetermined order in a predetermined number of times, thereby forming an unfired ceramic body 10. The laminated body 11 (refer FIG. 16) by which the auxiliary | assistant layer 20 was arrange | positioned is prepared.

  In Example 5, the convexity of the mold 30 on the surface of the auxiliary layer 20 on the side facing the mold 30 and the surface of the unfired ceramic body 10 of the laminate (unfired ceramic body with an auxiliary layer) 11. A material (for example, a glass paste or a metal conductor paste) that is resistant to deformation and cracking of the laminate 11 in a position facing the edge portion of the portion 22 and its vicinity region, that is, a region that is bent during pressing (pressing). And reinforcing layers 9a and 9b made of an organic buffer or the like.

  The reinforcing layers 9a and 9b are formed by a method such as screen printing of a reinforcing layer paste for forming the reinforcing layers 9a and 9b on the auxiliary layer (constraint layer) green sheet 2 and the substrate green sheet 1. It forms by apply | coating so that it may become a predetermined shape. As the reinforcing layer paste, for example, the same paste as that used for the surface conductor 31, the inner layer conductor 32, the via-hole conductor 34, etc. can be used, or a different paste can be used. .

  Then, as shown in FIG. 17, the die 30 is combined with the laminated body (unfired ceramic body with an auxiliary layer) 11, and hydrostatic pressure pressing (or pressure bonding through an elastic body) is performed to form the pressure bonding body 13. . As a result, a stepped portion (recessed portion) 15 (15a) having a sharp shape is formed on the surface facing the mold 30, and a stepped portion with a gently sloping side wall (on the surface not in contact with the mold 30 ( The pressure-bonded body 13 in which the concave portion 15 (15b) is formed can be obtained.

  And in the structure of this Example 5, in the process of a press (deformation), the deformation | transformation or crack of the laminated body 11 is previously carried out in the part which is bent and deform | transformed greatly of the laminated body (unfired ceramic body with an auxiliary layer) 11. Since the reinforcing layers 9a and 9b made of a material strong against the above are disposed, the surface conductor and the inner layer conductor are broken and the unfired ceramic body 10 is formed even when the crimped body 13 having a large step portion is formed. It is possible to suppress or prevent the occurrence of defects such as cracks in the ceramic green sheet.

  In addition, according to the method for manufacturing a ceramic substrate of Example 5, the same effects as those of the method for manufacturing a ceramic substrate of Example 1 can be obtained in other respects. Furthermore, the structure of the ceramic substrate of Example 5 can also be applied to the structure of Examples 2 to 4 described above, in which case the method of manufacturing the ceramic substrate of Examples 2 to 4 described above is used. The same effect can be obtained.

  In the above examples, the laminate was pressed and molded with the auxiliary layer (constraint layer) green sheet. However, the ceramic substrate of the present invention is an auxiliary layer (constraint layer) green sheet. Can also be produced by molding using an upper mold and a lower mold, and in this case as well, the difference in absolute shrinkage is suppressed due to structural features. A ceramic substrate having a cavity structure free from defects such as distortion and cracks can be manufactured.

According to the invention of the present application, it is possible to suppress an increase in the difference in absolute shrinkage, to suppress or prevent the occurrence of distortion, cracks, etc., and to have excellent shape accuracy and dimensional accuracy, and a highly reliable ceramic substrate. Can be provided, and the ceramic substrate can be manufactured without requiring complicated manufacturing processes and manufacturing equipment.
Therefore, the present invention can be widely applied to fields such as a ceramic substrate used for various applications and a module substrate on which various electronic components are mounted on the ceramic substrate.

It is a figure which shows the structure of the laminated body (unfired ceramic body with an auxiliary | assistant layer) formed in the Example (Example 1) of this invention, and a deformation | transformation type | mold. In the Example (Example 1) of this invention, it is a figure which shows the state which is pressing the laminated body (unfired ceramic body with an auxiliary | assistant layer) by the method of the isostatic pressing using a type | mold. It is a figure which shows the modification of the press method of the laminated body (unfired ceramic body with an auxiliary | assistant layer) in the manufacturing method of the ceramic substrate of the Example (Example 1) of this invention. It is a figure which shows the sintered substrate (ceramic substrate) provided with the level | step-difference part (recessed part) in both the main surfaces of the front and back manufactured by the manufacturing method of the ceramic substrate concerning the Example (Example 1) of this invention. FIG. 4 is a cross-sectional view showing a ceramic substrate obtained by dividing the ceramic substrate of Example 1 of the present invention (the ceramic substrate of FIG. 4), having one concave portion on one main surface and one convex portion on the other main surface. is there. (a) is a perspective view which shows the shape of the upper surface side of the ceramic substrate shown in FIG. 5, (b) is a perspective view which shows the shape of the lower surface side. It is sectional drawing which shows the modification of the ceramic substrate of Example 1 of this invention. (a), (b), (c), (d) is a figure which shows the variation of the structure of the ceramic substrate manufactured by the manufacturing method of the ceramic substrate concerning the Example (Example 1) of this invention. (a), (b), (c), (d) is a figure which shows the usage condition of the ceramic substrate manufactured by the manufacturing method of the ceramic substrate concerning the Example (Example 1) of this invention. It is a figure which shows the module board | substrate which mounted many electronic components on the ceramic substrate manufactured by the method of the Example (Example 1) of this invention. It is a figure which shows 1 process of the manufacturing method of the ceramic substrate concerning other Example (Example 2) of this invention. It is a figure which shows 1 process of the manufacturing method of the ceramic substrate concerning further another Example (Example 3) of this invention. 6 is a diagram showing a ceramic substrate manufactured by the method of Example 3. FIG. The figure used in the manufacturing method of the ceramic substrate concerning further another Example (Example 4) of this invention and the figure which shows the structure of the unbaking ceramic body with the auxiliary layer before the press shape | molded by the shape corresponding to it. is there. In Example 4 of this invention, it is a figure which shows the state which is pressing the unbaking ceramic body with an auxiliary | assistant layer. The figure used in the manufacturing method of the ceramic substrate concerning further another Example (Example 5) of this invention and the figure which shows the structure of the unbaking ceramic body with the auxiliary layer before the press shape | molded by the shape corresponding to it. is there. In Example 5 of this invention, it is a figure which shows the state which is pressing the unbaking ceramic body with an auxiliary | assistant layer. (a), (b), (c) is a figure which shows the manufacturing method of the conventional ceramic substrate which has a level | step-difference part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate green sheet 1a Punched substrate green sheet 2 Auxiliary layer (constraint layer) green sheet 2a Punched auxiliary layer green sheet 3 (3a, 3b) Mold forming green sheet 4 Fixed surface ( Flat plate)
6 Flexible film 7 Water 7a Elastic body 8 Flat die for crimping 9a, 9b Reinforcement layer 10 Ceramic green sheet laminate for substrate (unfired ceramic body)
11 Laminated body (unfired ceramic body with auxiliary layer)
11a Concave part 13 Pressure bonding body 14 Sintered substrate (ceramic substrate)
15 (15a, 15b) Stepped portion (recess, cavity)
DESCRIPTION OF SYMBOLS 16 Electronic component 17 Semiconductor element 18 Mother board 19 Level | step difference formation part 20 Auxiliary layer 21 Type | mold recessed part 22 Type | mold convex part 30 Type | mold 31 Surface conductor 32 Inner layer conductor 33 Via hole 34 Via hole conductor 114 Module board 115 (115a) Lower surface convex part 115 (115b) Upper surface convex portion 116a Lower flat surface substantially flat surface 116b Lower upper surface convex surface 116b Upper upper surface substantially flat surface 117a Ceramic substrate lower surface 117b Ceramic substrate upper surface 118a Inner wall 118b Inclined surface D Recessed portion Depth H Height of convex part A1 Dimension of a substantially flat surface at the top of the convex part on the upper surface side in a direction parallel to the upper surface of the ceramic substrate A2 Direction of the entire convex part on the upper surface side in parallel with the upper surface of the ceramic substrate Dimensions B1 Dimensions in the direction parallel to the bottom surface of the ceramic substrate of the substantially flat surface of the bottom of the recess on the bottom surface side B2 Bottom Dimension of the whole concave portion in the direction parallel to the lower surface of the ceramic substrate θA Angle formed by the inclined surface from the upper surface of the ceramic substrate to the substantially flat surface of the convex portion on the upper surface side and the upper surface of the ceramic substrate θB Angle formed by the inner wall surface of the recess on the lower surface side from the lower surface of the ceramic substrate to the substantially flat surface of the bottom and the lower surface of the ceramic substrate

Claims (19)

A ceramic substrate in which stepped portions are disposed on both main surfaces of one main surface and the other main surface,
A concave portion is disposed on one main surface, and a convex portion having a gentle shape without corners is disposed in a region corresponding to the concave portion on the other main surface,
(a) The dimension of the substantially flat surface at the top of the convex portion in the direction parallel to the top surface of the ceramic substrate is A1,
(b) A2 is a dimension in a direction parallel to the top surface of the ceramic substrate of the entire convex portion,
(c) The dimension of the substantially flat surface of the bottom of the concave portion in the direction parallel to the lower surface of the ceramic substrate is B1,
(d) The dimension of the entire recess in the direction parallel to the lower surface of the ceramic substrate is B2.
[1] and [2] below:
A1 <B1 [1]
B2 <A2 ...... [2]
A ceramic substrate characterized by satisfying the following conditions. An angle formed by the inclined surface of the convex portion from the upper surface of the ceramic substrate to the substantially flat surface at the top and the upper surface of the ceramic substrate is θA,
An angle formed between the inner wall surface of the concave portion from the lower surface of the ceramic substrate to the substantially flat surface of the bottom portion and the lower surface of the ceramic substrate is θB.
[3] below:
θA <θB …… [3]
The ceramic substrate according to claim 1, wherein the condition is satisfied. The angle θA formed by the inclined surface of the convex portion and the upper surface of the ceramic substrate, and the angle θB formed by the inner wall surface of the concave portion and the lower surface of the ceramic substrate are respectively [4] and [5]:
0 ° <θB ≦ 90 ° …… [4]
0 ° <θA <90 ° …… [5]
The ceramic substrate according to claim 1, wherein the condition is satisfied. A method for producing a ceramic substrate according to any one of claims 1 to 3,
(A) An auxiliary layer made of a material that does not substantially sinter at the firing temperature of the unfired ceramic body is in close contact with at least one major surface of the unfired ceramic body, and has a recess on one of the principal surfaces. Forming an unfired ceramic body with an auxiliary layer having a convex portion having a smooth shape without corners in a region corresponding to the concave portion of the other main surface;
(B) a step of firing the unfired ceramic body with the auxiliary layer at a temperature at which the unfired ceramic body is sintered while the auxiliary layer is provided, and the auxiliary layer is not substantially sintered. A method for producing a ceramic substrate, comprising:   While maintaining the unfired ceramic body with the auxiliary layer so that the thickness of the unfired ceramic body is substantially constant over the entire surface, the unfired ceramic body and the auxiliary layer are kept in close contact with each other, The ceramic substrate according to claim 4, wherein the unfired ceramic body with the auxiliary layer having the concave portion and the convex portion is formed by deforming a predetermined region of the unfired ceramic body with the auxiliary layer. Production method.   By pressing a mold having a convex portion on the surface on which the auxiliary layer of the unfired ceramic body with the auxiliary layer is disposed and pressing, a concave portion having a shape corresponding to the convex portion of the mold is formed on one main surface. 6. The method for manufacturing a ceramic substrate according to claim 4, wherein a convex portion having a smooth shape without corners corresponding to the concave portion is formed on the other surface.   The mold having the convex portion is aligned with the surface of the unfired ceramic body with the auxiliary layer, and the uncoated ceramic body with the auxiliary layer is formed by a method of isostatic pressing or pressing through an elastic body. The ceramic substrate according to claim 6, wherein pressing is performed so that pressure is applied to the unfired ceramic body with an auxiliary layer from the surface opposite to the surface of the fired ceramic body having the molds having the projections. Production method.   The mold having the convex part includes a flat plate-like support member and a convex component member made of a material that is disposed on the flat plate-like support member and does not sinter substantially at the firing temperature of the unfired ceramic body. The method for producing a ceramic substrate according to claim 6, wherein the method is provided.   The method for producing a ceramic substrate according to claim 8, wherein the unfired ceramic body with an auxiliary layer having the concave portion and the convex portion is fired in a state in which the convex constituent members of the mold are engaged. .   The method for manufacturing a ceramic substrate according to any one of claims 6 to 9, wherein in the mold having the convex portion, the convex portion has a tapered shape.   In the mold having the convex portion, at least the convex portion is harder than both the unfired ceramic body and the auxiliary layer constituting the unfired ceramic body with the auxiliary layer, and has elasticity. The manufacturing method of the ceramic substrate in any one of Claims 6-10.   In the mold having the convex portion, the convex component member is formed through a step of applying a pressure higher than the pressure applied when forming the unfired ceramic body with the auxiliary layer. The manufacturing method of the ceramic substrate in any one of Claims 8-11.   The reinforcing material is provided to at least a part of a portion of the green ceramic body with an auxiliary layer that deforms along the convex portion in the mold having the convex portion. The manufacturing method of the ceramic substrate in any one of -12.   The unsintered ceramic body is an unsintered ceramic laminate formed by laminating a plurality of ceramic green sheets, and an interlayer connection conductor pattern for connecting the layers of each ceramic green sheet layer and each ceramic therein The method for manufacturing a ceramic substrate according to any one of claims 4 to 13, wherein an in-plane conductor pattern provided at an interface of the green sheet layer is disposed.   The unfired ceramic body with an auxiliary layer to which the auxiliary layer is adhered is a ceramic green sheet laminated body formed by laminating ceramic green sheets and pressing them together. The method for producing a ceramic substrate according to claim 4, wherein:   The green ceramic body with an auxiliary layer to which the auxiliary layer is adhered is applied to a ceramic green sheet laminate formed through a step of sequential pressing for pressing each time one or a predetermined number of ceramic green sheets are stacked. The method for producing a ceramic substrate according to any one of claims 4 to 14, wherein the auxiliary layer is adhered.   A concave portion is formed at a position in contact with the convex portion of the mold having the convex portion of the unfired ceramic body with the auxiliary layer to which the auxiliary layer is adhered, and the value of the height H of the convex portion is The method for manufacturing a ceramic substrate according to claim 6, wherein the depth is larger than the value of the depth D of the recess.   5. The unfired ceramic body is an aggregate substrate of unfired ceramic bodies for a plurality of sub-substrates, and includes a step of dividing the obtained aggregate substrate into sub-substrates after the firing. The manufacturing method of the ceramic substrate in any one of -17.   The method for manufacturing a ceramic substrate according to any one of claims 4 to 18, further comprising a step of mounting a surface mounting component on the fired ceramic substrate.

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