JP2011035341A - Method of manufacturing ceramic substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a ceramic substrate provided with desired characteristics efficiently by inhibiting and preventing warpage and deformation of a ceramic molded body (ceramic substrate) in a baking process. <P>SOLUTION: An unbaked composite laminate, wherein a constraining layer containing sinter-resistant ceramic powder, not sintering at the sintering temperature of an unbaked ceramic molded body, as a main component is arranged, is formed at least on one of one principal surface side and another principal surface side of the unbaked ceramic molded body which becomes the ceramic substrate after baking. After baking at the temperature where the ceramic molded body is sintered and the sinter-resistant ceramic powder constituting the constraining layer is not sintered, the ceramic substrate is manufactured through a process wherein the constraining layer is removed. In this case, as the constraining layer (a green sheet for the constraining layer), a constraining layer 11, which has uniform thickness on the whole and has larger constraining force at the peripheral part (a first green sheet 11A for constraining layer constituting it) than the center part (a second green sheet 11D for constraining layer constituting it), is used. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a ceramic substrate, and in particular, is manufactured through a so-called constrained firing process in which a constraining layer is disposed on a ceramic molded body that becomes a ceramic substrate after firing and firing is performed while suppressing shrinkage. The present invention relates to a method for manufacturing a ceramic substrate.

  Among ceramic electronic components, in a multilayer ceramic substrate or the like that requires high planar dimensional accuracy, firing shrinkage in the planar direction in the firing process, variations in the shrinkage, and the like greatly affect product quality.

  Therefore, as a method of firing the ceramic molded body while suppressing shrinkage in such a firing step, it is difficult to sinter alumina or the like that does not substantially sinter at the firing temperature of the ceramic molded body on both main surfaces of the ceramic molded body. A firing method has been proposed in which firing is performed in a state where a constraining layer containing a sinterable material as a main component is formed, so that firing can be performed substantially without causing shrinkage in the planar direction. (See Patent Document 1).

  However, even when this method is used, the ceramic molded body does not shrink at all, and some shrinks in the firing step. And since the shrinkage | contraction in the plane direction of the ceramic molded body used as a ceramic substrate after baking arises toward a center from a peripheral part, absolute shrinkage becomes large in proportion to the distance from a center. Further, since the periphery of the ceramic molded body, particularly in the vicinity of the corner portion, is not entirely surrounded by the constraining layer, the constraining force by the constraining layer may be insufficient. Therefore, warpage or deformation may occur in the peripheral portion of a ceramic molded body such as a ceramic substrate obtained after firing.

  It is also possible to use a constrained layer using a non-sinterable material powder with a small particle size and a large specific surface area as a constraining layer with a large constraining force in order to prevent warpage and deformation. The removal of the constraining layer after firing becomes difficult, and there is a problem that the ceramic molded body is damaged in the constraining layer removing step.

  Also, at least one of the constraining layers (green sheet for constraining layer) disposed on both main surfaces of the ceramic molded body (laminated body) formed by laminating ceramic green sheets (in this example, on the upper surface side of the laminated body) A method of manufacturing a ceramic substrate has been proposed in which a constraining layer having a peripheral portion thicker than a central portion is disposed on the constraining layer) and fired (see Reference 2). .

  In the case of this method, since the constraining layer in which the peripheral part is thicker than the central part is used, the peripheral part of the laminate is surely constrained with a restraining force larger than that of the central part, and the peripheral part of the ceramic substrate It is possible to prevent the occurrence of warping and deformation.

  However, in the case of the method of Patent Document 2, since the peripheral portion is thicker than the central portion, a uniform pressure cannot be applied at the time of crimping, and the laminate is in a state where the central portion is raised, and a desired shape is obtained after firing. In some cases, it becomes impossible to obtain a ceramic substrate having dimensional accuracy and having intended characteristics.

JP-A-4-243978 JP 2004-146701 A

  The present invention solves the above-described problems, and suppresses and prevents warping and deformation of a ceramic molded body (ceramic substrate) in a firing process in which the ceramic molded body is fired using a constraining layer. A method of manufacturing a ceramic substrate capable of efficiently manufacturing a ceramic substrate having dimensional accuracy and having intended characteristics, and further excellent in removal of the constraining layer after firing, and the ceramic in the constraining layer removal step It aims at providing the manufacturing method of the ceramic substrate which does not damage a molded object.

In order to solve the above problems, a method for producing a ceramic substrate of the present invention comprises:
At least one of the one main surface side and the other main surface side of the unfired ceramic molded body that becomes the ceramic substrate after firing is mainly composed of a hardly sinterable ceramic powder that does not sinter at the sintering temperature of the unfired ceramic molded body. Forming a green composite laminate in which a constraining layer is disposed;
Firing the unfired composite laminate at a temperature at which the ceramic compact is sintered but the hardly sinterable ceramic powder constituting the constraining layer is not sintered;
A step of removing the constraining layer after the step of firing the unfired composite laminate is completed,
As the constraining layer, a constraining layer having a uniform constraining force and having a large constraining force that suppresses shrinkage of the ceramic molded body in the firing step is used.

  In the method for manufacturing a ceramic substrate according to the present invention, the magnitude of the restraining force of the peripheral portion and the central portion of the constraining layer is adjusted by the specific surface area of the hardly sinterable ceramic powder contained in the constraining layer. It is preferable to do.

Further, the specific surface area of the hardly sinterable ceramic powder contained in the peripheral portion of the constraining layer is 6 m ² / g or more, and the specific surface area of the hardly sinterable ceramic powder contained in the central portion of the constraining layer is 3 m. ² / g or less is preferable.

  In addition, an electrode pattern to be a surface electrode after firing is formed on at least a part of a region of the surface of the ceramic molded body that is in contact with the central portion of the constraining layer.

  Moreover, it is preferable that the said constraining layer is formed by combining the sheet | seat for center parts which comprises the said center part, and the sheet | seat for periphery parts which comprises the said periphery part.

  Moreover, it is preferable that the said edge part sheet | seat which comprises the said constraining layer is a frame-shaped sheet | seat comprised so that the said sheet | seat for center parts might fit inside.

In the method for manufacturing a ceramic substrate according to the present invention, a constraining layer having a uniform thickness as a whole and a constraining layer having a constraining force that is larger in the peripheral part than the central part is used as a constraining layer. It is possible to suppress or prevent warping or deformation of the peripheral edge of the ceramic molded body, which is likely to occur. In addition, the central portion of the constraining layer is a region in which the constraining force is smaller than that of the peripheral portion, and the removability after firing is good. Therefore, the fired ceramic molded body is damaged in the step of removing the constraining layer. The characteristics are not impaired.
Therefore, according to the present invention, it is possible to efficiently manufacture a ceramic substrate having high dimensional accuracy and having intended characteristics.

  In addition, by adjusting the size of the restraining force at the peripheral portion and the central portion of the constraining layer according to the size of the specific surface area of the hardly sinterable ceramic powder contained in the constraining layer, the peripheral portion can be easily and reliably formed. It becomes possible to obtain a constraining layer having a constraining force larger than that of the central portion, and the present invention can be made more effective.

Further, the specific surface area of the hardly sinterable ceramic powder contained in the peripheral portion of the constraining layer is 6 m ² / g or more, and the specific surface area of the hardly sinterable ceramic powder contained in the central portion of the constraining layer is 3 m ² / g or less. By doing so, the peripheral portion has a greater restraining force than the central portion, and a constraining layer excellent in removability can be more reliably obtained at the central portion, which is preferable. In other words, by providing this requirement, the problem of suppressing warpage of the ceramic molded body in the firing process and ensuring the removability of the constrained layer after firing, which are in a trade-off relationship, can be solved more efficiently at the same time. Is possible. However, the present invention is not necessarily required to have this requirement. Even if this requirement is not met, the ceramic surface of the ceramic compact is less warped and the constrained layer has a lower surface area than the conventional constrained layer where the specific surface area of the hardly sinterable ceramic powder is the same in the peripheral part and the central part. This is because at least one of the removability is effective.

  When the electrode pattern that becomes the surface electrode after firing is formed on at least a part of the area of the surface of the ceramic molded body that becomes the ceramic substrate after firing and in contact with the central portion of the constraining layer, the surface electrode comes into contact The central part of the constraining layer is a region having a restraining force smaller than that of the peripheral part and easy to remove. Therefore, the surface electrode is less likely to be damaged in the step of removing the constraining layer after firing, and has good characteristics. A ceramic substrate can be efficiently manufactured.

  Moreover, by forming the central portion sheet constituting the central portion of the constraining layer and the peripheral portion sheet constituting the peripheral portion as separate bodies, and combining them, the peripheral portion is easier and more reliable than the central portion. A constraining layer having a large constraining force in the firing step can be obtained.

There are no particular restrictions on the number, specific shape, combination mode, etc. of the central sheet constituting the central part and the peripheral sheet constituting the peripheral part. Appropriate shapes and combinations can be determined in consideration of the structure and shape of the body, firing conditions, characteristics required for the product, and the like.
Specifically, for example, the central sheet is a single rectangular sheet, a sheet divided into a plurality of sheets, or the peripheral sheet is formed of four sides surrounding the rectangular central sheet 4 It is possible to form two strips or two L-shaped pieces.

In particular, the peripheral sheet is a frame-shaped sheet configured such that the central sheet fits inside thereof, so that the peripheral part is more constrained in the firing process than the central part. A large constraining layer can be obtained.
In the case of configuring a constraining layer provided with a frame-shaped sheet, a plurality of frame-shaped sheets can be used. That is, the central sheet is configured to include a first frame-like sheet that fits inside and a second frame-like sheet that fits outside the first frame-like sheet, or further fits outside. A configuration including a third frame-like sheet is also possible, and the number is not particularly limited.

It is a top view which shows the structure of the constrained layer (green sheet for constrained layers) used in manufacturing the ceramic substrate (multilayer ceramic substrate) in the Example (Example 1) of this invention. It is sectional drawing which shows the structure of the unbaking composite laminated body produced in Example 1 of this invention. (a), (b) is a figure which shows the modification of the constrained layer used for the manufacturing method of the ceramic substrate of this invention. It is a figure which shows the other modification of the constrained layer used for the manufacturing method of the ceramic substrate of this invention.

  Hereinafter, the present invention will be described in more detail with reference to embodiments of the present invention.

[Production of green sheet for substrates]
A glass powder obtained by mixing each powder of SiO ₂ , CaO, Al ₂ O ₃ and B ₂ O ₃ was mixed with an alumina powder.

  To this mixed powder, an acrylic organic binder and a solvent (toluene and ethanol) are added, mixed, and thoroughly kneaded in a ball mill, and then uniformly dispersed, and then defoamed under reduced pressure. To obtain a slurry.

  This slurry was formed into a sheet on a carrier film by a casting method using a doctor blade to produce a glass ceramic green sheet having a thickness of 0.20 mm.

  And after drying this glass ceramic green sheet, it cut | disconnected the whole carrier film so that a plane dimension might be a magnitude | size of 150 mm (square).

  Then, an Ag conductor paste is formed on the cut green sheet (glass ceramic green sheet) by a screen printing method to constitute a ceramic layer of the multilayer ceramic substrate having the conductor pattern 21 (see FIG. 2). A substrate green sheet 20 (see FIG. 2) was prepared. If necessary, via hole through holes for interlayer connection are formed in the substrate green sheet 20 and conductors are filled into the via hole through holes.

[Preparation of green sheet for constraining layer]
In Example 1, as shown in FIG. 1, as a constraining layer green sheet, by combining a central portion sheet 11 </ b> D constituting the central portion and a peripheral portion sheet 11 </ b> A constituting the peripheral portion, Difference in restraining force that suppresses shrinkage of a ceramic molded body (laminated body that becomes a ceramic multilayer substrate after firing) in the firing step at the peripheral portion and the central portion at a uniform thickness A constraining layer (constraint layer green sheet) 11 having a constraining force with a peripheral portion larger than that of the central portion was produced. A method for producing the constraining layer will be described below.

  First, two types of alumina powders having different average particle diameters are prepared, and polyvinyl butyral as an organic binder and toluene and ethanol as solvents are added to each alumina powder, mixed, and sufficiently kneaded in a ball mill. After uniformly dispersing, defoaming treatment was performed under reduced pressure to obtain a slurry.

  This slurry was formed into a sheet on a carrier film by a casting method using a doctor blade, thereby obtaining a green sheet having a thickness of 0.10 mm.

  Then, after drying the green sheet, the carrier film is cut so that the planar dimension is 150 mm □, and the thickness is 0.10 mm for the constraining layer green sheet, that is, two types having different average particle diameters A first constraining layer green sheet 1A and a second constraining layer green sheet 1D were produced using the alumina powder.

Table 1 shows the characteristics (average particle diameter and specific surface area) of the hardly sinterable ceramic powder obtained by degreasing the first and second constraining layer green sheets 1A and 1D at 500 ° C. for 4 hours. .
The specific surface area of the hardly sinterable ceramic powder is a value measured by a gas adsorption method (BET method).
The average particle size of the hardly sinterable ceramic powder is a value measured by a laser diffraction particle size distribution measuring device.

  In addition, regarding the constrained layer (green sheet for constrained layer) in the present invention, the specific surface area and average particle diameter of the hardly sinterable ceramic powder mean values of the specific surface area and average particle diameter thus measured.

  Next, while leaving the carrier film as it is, the peripheral portion of the first constraining layer green sheet 1 </ b> A is left with a width of 27.5 mm, and the inner portion is cut out to form the peripheral portion including the first constraining layer green sheet 1 </ b> A. A sheet (frame-shaped sheet) 11A was obtained (see FIG. 1).

  Further, by leaving the carrier film as it is, leaving the 95 mm square portion of the second constraining layer green sheet 1D and cutting the peripheral portion with a width of 27.5 mm from the second constraining layer green sheet 1D. A rectangular central sheet 11D was obtained (see FIG. 1).

  And after inserting and pressing the center part sheet | seat 11D inside the peripheral part sheet | seat 11A, the carrier film of one side is peeled off, and a non-sinterable ceramic powder (alumina powder) is made into a peripheral part and a center part. Unlike the specific surface area and the average particle diameter, the constrained layer 11 having a larger specific surface area and a smaller average particle diameter was obtained in the non-sinterable ceramic powder in which the peripheral part was contained more than the central part (see FIG. 1).

  The constraining layer 11 is a constraining layer having a uniform constraining force and a large constraining force that suppresses the shrinkage of the ceramic molded body in the firing step from the central portion of the peripheral portion. It is a constrained layer.

  Further, for comparison, contrary to the constraining layer of Sample 1, the second constraining layer green sheet 1D having a small specific surface area and a large average particle diameter as the peripheral sheet is small. As the sheet for the central part, the first constraining layer green sheet 1A having a large specific surface area of the hardly sinterable ceramic powder and a small average particle diameter is used, and the peripheral part is more restraining than the central part. A small constraining layer of Comparative Example 1 (Sample 2 in Table 2) was prepared.

  Further, for comparison, Comparative Example 2 using the first constraining layer green sheet 1A having a greater restraining force than the second constraining layer green sheet 1D for both the peripheral portion sheet and the central portion sheet. A constraining layer (Sample 3 in Table 2) was prepared.

  For comparison, Comparative Example 3 in which the second constraining layer green sheet 1D having a restraining force smaller than that of the first constraining layer green sheet 1A is used for both the peripheral portion sheet and the central portion sheet. A constraining layer (Sample 4 in Table 2) was prepared.

[Production of multilayer ceramic substrate]
An unfired composite laminate 30 as shown in FIG. 2 was produced by the following procedure using the substrate green sheet 20 and the constraining layer (constraint layer green sheet) 11 produced as described above.

  In producing the unfired composite laminate 30, first, six layers of green sheets for substrates (glass ceramic green sheets) 20 having a conductor pattern formed as described above are laminated in a predetermined order, and then laminated. A body (sheet laminate for substrate) 22 was produced. In addition, each green sheet 20 for substrates was peeled off from the carrier film and laminated sequentially.

  Then, a constraining layer (constraint layer green sheet) 11 (FIG. 1) peeled off from the carrier film is laminated on both main surfaces of the substrate sheet laminate 22 and pressed in the laminating direction, whereby the plane dimension is 150 mm. An unfired laminate before cutting having a size of □ was prepared.

  Next, the unfired laminate before cutting is cut parallel to each edge at a position of 52.5 mm from the center, the planar shape is square, and the length of one side is 105 mm (that is, 105 mm □) unfired composite laminate 30 (FIG. 2) was produced.

  As shown in FIG. 2, the unfired composite laminate 30 includes a laminate (substrate sheet laminate) 22 formed by laminating a plurality of ceramic green sheets (substrate green sheets) 20 provided with conductor patterns 21. It has a structure in which constraining layers (constraint layer green sheets) 11 are disposed on one main surface side and the other main surface side.

  Then, the unfired composite laminate 30 is fired at a temperature at which the substrate sheet laminate 22 is sintered but the constraining layer (constraint layer green sheet) 11 is not sintered, in this example, 800 to 1050 ° C. did.

And the ceramic board | substrate (multilayer ceramic board | substrate) was obtained by removing the constrained layer which remained on the both main surfaces from the composite laminated body after sintering. In addition, this multilayer ceramic substrate is a multilayer ceramic substrate manufactured using the constraining layer provided with the requirements of this invention of the sample 1 of Table 2.
Moreover, the multilayer ceramic substrate for a comparison was produced with the same method using the constraining layer of said samples 2-4 (constraint layer of Comparative Examples 1-3).

[Characteristic evaluation]
The warpage amount of the produced multilayer ceramic substrate (samples 1 to 4) and the removability (removal rate) of the constraining layer after completion of the firing step were examined by the method described below.

(1) Warpage amount First, the thickness of the central portion of the multilayer ceramic substrate was measured with calipers or the like.
Then, a glass plate of 200 mm □ size and a glass plate of 200 mm × 40 mm size were prepared, a metal plate having a known thickness was sandwiched between the two glass plates, and fixed with a crocodile clip to produce a gap gauge. Then, each sample (multilayer ceramic substrate) was passed through the gap gauge, and whether or not it completely passed was examined to evaluate the warpage. For example, when a 0.500 mm thick multilayer substrate passes through a 0.700 mm gap and does not pass through a 0.690 mm gap, the warpage is considered to be 0.190 mm to 0.200 mm. The warp amount was 0.200 mm on the larger side.

(2) Removability of constrained layer After firing, the sintered body provided with the constrained layer is put into an ultrasonic cleaning tank containing water, washed for 1 minute at an output of 200 W, and then the removal rate of the constrained layer is examined. The removal property of the constraining layer was evaluated.
The removal rate of the constrained layer was calculated by the following formula.
Removal rate (%) = {(weight reduced by washing) / (total constrained layer weight)} × 100
However, the total constrained layer weight is a value determined by the following formula.
Total constrained layer weight = (substrate weight after firing + constrained layer weight)-(substrate weight after all constrained layer removal)

  Table 2 shows the amount of warpage and the removal rate measured as described above.

  As shown in Table 2, in the case of the sample 1 using the constraining layer having the requirements of the present invention in which the peripheral part has a constraining force larger than that of the central part, firing is performed while ensuring the removability of the constraining layer after firing. The amount of warpage of the subsequent multilayer ceramic substrate could be kept small.

On the other hand, in the case of Sample 2 using a constraining layer (green sheet for constraining layer) having a large constraining force in the central part and a constraining force in the peripheral part having a smaller constraining force than the central part, the constraining force in the peripheral part is insufficient and firing It was confirmed that not only the amount of warpage of the subsequent multilayer ceramic substrate was increased, but also that the removal of the constraining layer was poor at the center. In the case of Sample No. 2, the removability of the central part of the constraining layer is poor because the specific surface area of the hardly sinterable ceramic powder contained in the central part of the constraining layer is large, This is due to the increase in the binding force.
In addition, when the removability at the central portion of the constraining layer is insufficient, for example, if the multilayer ceramic substrate to be a product is provided with a surface electrode, the surface electrode may be damaged, This is not preferable because it cannot be sufficiently exposed.

  Further, in the case of the multilayer ceramic substrate of Sample 3 using a constraining layer having a large constraining force at both the peripheral part and the central part, the amount of warpage could be suppressed small, but the removability of the constraining layer was possible in the central part. It was confirmed that it was bad.

  Moreover, in the case of the multilayer ceramic substrate of sample number 4 using a constraining layer having a small constraining force at both the peripheral part and the center part, the removability of the constraining layer after firing was good, but the amount of warpage was large. It was confirmed that it was not preferable.

  Six types of constraining layer green sheets A, B, C, D, E, and F having average particle sizes and specific surface areas as shown in Table 3 were prepared.

  The constraining layer green sheet A in Table 3 is the same as the first constraining layer green sheet 1A prepared in Example 1, and the constraining layer green sheet D in Table 3 is the same as in the above example. 1 is the same as the second constraining layer green sheet 1D produced in step 1.

Then, using these constraining layer green sheets A, B, C, D, E, and F, a peripheral portion sheet and a central portion sheet are produced in the same manner as in Example 1, and these peripheral portions are formed. The constraining layer was produced by combining the sheet for use and the sheet for the center part in the manner shown in Table 4.
In addition, conditions, such as a dimension of the sheet | seat for peripheral parts, and the sheet | seat for center parts, are the same as that of the case of the said Example 1. FIG.

Then, using these constraining layers (green sheets for constraining layers), a multilayer ceramic substrate was produced by the same method as in Example 1, and the removability of the constraining layer after firing was examined, and the resulting multilayer was obtained. The amount of warpage of the ceramic substrate was examined.
The results are also shown in Table 4.

As shown in Table 4, in the case of Samples 15 to 21, it was confirmed that the amount of warpage could be reduced while ensuring good removability of the constraining layer after firing.
In particular, Samples 16, 17, and 19 in which the specific surface area of the hardly sinterable ceramic powder in the peripheral portion is 6 m ² / g or more and the specific surface area of the hardly sinterable ceramic powder in the central sheet is 3 m ² / g or less. 20 and 21, it was confirmed that the amount of warp could be made sufficiently small while ensuring good removability of the constraining layer after firing. Further, in Samples 18 and 22 to 24 that do not have the requirement for the specific surface area, a conventional constraining layer (restraint) in which the specific surface area of the peripheral portion sheet and the central portion sheet is the same as in Samples 11 to 14. Compared with the green sheet for the layer, it was confirmed that either the warpage amount or the removability was good.

  On the other hand, in the samples 11 to 14 using the non-sinterable ceramic powder having the same specific surface area as the non-sinterable ceramic powder of the peripheral portion sheet and the non-sinterable ceramic powder of the central portion sheet, When the specific surface area of the sintered ceramic powder is large (in the case of sample numbers 11 and 12), it is confirmed that the removal rate of the constrained layer is reduced, and when the specific surface area of the hardly sinterable ceramic powder is small (sample) In the case of numbers 13 and 14, it was confirmed that the amount of warpage was large.

  In Examples 1 and 2, a multilayer ceramic substrate is manufactured by disposing and firing a constraining layer (a constraining layer green sheet) on a ceramic molded body (ceramic laminate) to be a single multilayer ceramic substrate. The case has been described by way of example. A constraining layer is disposed on the mother ceramic laminate, firing is performed while suppressing shrinkage, the constraining layer is removed, and then the multilayer ceramic substrate is divided into individual multilayer ceramic substrates. Even in the case of manufacturing the present invention, it is possible to apply the present invention as in the case of the above embodiment, and in this case, the same effect as in the case of the above embodiment can be obtained.

  In the above embodiment, the case where the peripheral sheet is a frame-shaped sheet has been described as an example. However, as shown in FIG. 3A, the peripheral sheet surrounds a square central sheet 41. It is possible to make a structure composed of four strips 42 constituting four sides, or to form two L-shaped pieces 43 surrounding a square central sheet 41 as shown in FIG. 3 (b). is there.

  Further, in the case of configuring a constraining layer including a frame-like sheet (peripheral sheet) into which the central sheet fits, as shown in FIG. 4, the first frame fitted into the outer side of the central sheet 41. It is also possible to adopt a configuration including a sheet-like sheet 44a and a second frame-like sheet 44b fitted on the outside of the first frame-like sheet 44a. It is also possible to adopt a configuration provided with a frame-shaped sheet.

  In the above embodiment, the case where the constraining layers are arranged on both main surface sides of the ceramic molded body has been described as an example. However, for example, a thick constraining layer is disposed only on one main surface side of the ceramic molded body. It can also be configured to be arranged. Thus, there are cases where warping and deformation can be suppressed by disposing the constraining layer only on the one main surface side of the ceramic molded body.

  In addition, as a constituent material of the constraining layer (constraint layer green sheet), there are no special restrictions as long as the constraining force required in the firing process can be exhibited without sintering at the sintering temperature of the substrate sheet laminate. For example, it is also possible to use a material containing a glass component. However, when glass is contained, the removability at the time of removal after the firing step tends to decrease, and therefore it is usually preferable not to contain glass.

  The present invention is not limited to the above embodiments in other respects as well, and relates to the arrangement of the conductors such as the type of material constituting the ceramic substrate, the number of laminated ceramic layers, the internal electrode pattern, etc. Various applications and modifications can be added within the range.

11A Peripheral sheet made of the first constraining layer green sheet 11D Central sheet made of the second constraining layer green sheet 11 Constraining layer (constraint layer green sheet)
20 Green sheet for substrate 21 Conductor pattern 22 Laminate (sheet laminate for substrate)
30 Unfired Composite Laminate 41 Sheet for Central Part 42 Strip Piece 43 L-Shape Piece 44a First Frame Sheet 44b Second Frame Sheet

Claims (6)

At least one of the one main surface side and the other main surface side of the unfired ceramic molded body that becomes the ceramic substrate after firing is mainly composed of a hardly sinterable ceramic powder that does not sinter at the sintering temperature of the unfired ceramic molded body. Forming a green composite laminate in which a constraining layer is disposed;
Firing the unfired composite laminate at a temperature at which the ceramic compact is sintered but the hardly sinterable ceramic powder constituting the constraining layer is not sintered;
A step of removing the constraining layer after the step of firing the unfired composite laminate is completed,
As the constraining layer, a constraining layer having a uniform constraining force and a large constraining force that suppresses shrinkage of the ceramic molded body in the firing step is used, which has a uniform thickness as a whole and a peripheral part that is more central than the central part. Production method.   The size of the restraining force of the peripheral portion and the central portion of the constraining layer is adjusted by the size of the specific surface area of the hardly sinterable ceramic powder contained in the constraining layer. A method for manufacturing a ceramic substrate. The specific surface area of the sintering-resistant ceramic powder contained in the peripheral portion of the constraining layer is 6 m ² / g or more, a specific surface area of the sintering-resistant ceramic powder contained in the central portion of the constraining layer 3m ² / 3. The method for producing a ceramic substrate according to claim 2, wherein g is less than or equal to g.   The electrode pattern which becomes a surface electrode after firing is formed on at least a part of a region of the surface of the ceramic molded body which is in contact with the central portion of the constraining layer. The manufacturing method of the ceramic substrate of description.   The said constraining layer is formed by combining the sheet | seat for center parts which comprises the said center part, and the sheet | seat for periphery parts which comprises the said periphery part. The manufacturing method of the ceramic substrate of description.   6. The method for manufacturing a ceramic substrate according to claim 5, wherein the peripheral portion sheet constituting the constraining layer is a frame-shaped sheet configured such that the central portion sheet fits inside thereof.

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