JP5300527B2 - Multilayer substrate and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce moisture infiltration in a multilayer substrate. <P>SOLUTION: The multilayer substrate is formed by alternately laminating a plurality of first ceramic layers 11 containing first crystallized glass having a first softening point, and a plurality of second ceramic layers 12 containing second crystallized glass having a second softening point higher than the first softening point. A conductor layer 14 and a third ceramic layer 13 containing third crystallized glass having a third softening point higher than the second softening point, are formed between the first ceramic layer 11 and the second ceramic layer 12. Third crystallized glass is contained between a plurality of sintered particles in the second ceramic layer 12. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a multilayer substrate containing a ceramic material and a method for manufacturing the same.

  Conventionally, there has been known a multilayer substrate in which a plurality of ceramic layers made of different materials are laminated for the purpose of improving strength or incorporating an element such as a capacitor. It is known to vary the softening point of crystallized glass contained in multiple ceramic material layers as a technique to suppress the shrinkage in the planar direction when firing preforms containing multiple ceramic material layers made of different materials. ing.

JP 2007-73728 A

  As the difference between the glass softening points increases, the firing path of the solvent-removing component or the binder-removing component is blocked by the insulating layer that has started to soften in the different adjacent insulating layers during firing. The phenomenon that the solvent removal component or the binder removal component remains inside occurs. Due to this residual component, there may be voids in the multilayer substrate. Due to the voids, there is a possibility that moisture in the atmosphere may enter the inside of the multilayer substrate.

  According to one aspect of the present invention, the multilayer substrate includes a plurality of first ceramic layers including a first crystallized glass having a first softening point, and a second crystal having a second softening point higher than the first softening point. A plurality of second ceramic layers containing the vitrified glass are alternately laminated. A conductor layer and a third ceramic layer containing a third crystallized glass having a third softening point higher than the second softening point are formed between the first ceramic layer and the second ceramic layer. A third crystallized glass is contained between the plurality of sintered particles in the second ceramic layer.

According to another aspect of the present invention, a method for manufacturing a multilayer substrate includes a step of firing a ceramic preform. The ceramic preform includes a plurality of first ceramic material layers including a first crystallized glass having a first softening point, and a plurality of second ceramics including a second crystallized glass having a second softening point higher than the first softening point. A multilayer molded body in which two ceramic material layers are alternately laminated. The ceramic preform includes a conductor layer and a third ceramic material layer having a third crystallized glass having a third softening point higher than the second softening point between the first ceramic material layer and the second ceramic material layer. The third crystallized glass is contained between the plurality of sintered particles in the second ceramic layer .

  In the multilayer substrate according to one aspect of the present invention, the third crystallized glass is contained between the plurality of sintered particles in the second ceramic layer, thereby reducing moisture intrusion.

  According to another aspect of the present invention, there is provided a method for manufacturing a multilayer substrate, comprising: firing a ceramic preform having a third ceramic material layer containing a third crystallized glass; Tricrystallized glass flows in and the porosity can be reduced.

It is sectional drawing which has shown the multilayer substrate in embodiment of this invention typically. It is sectional drawing which has shown typically the ceramic preform in the embodiment of this invention. The relationship between the shrinkage start temperature and shrinkage end temperature of ceramic materials A to C is shown.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the multilayer substrate has a structure in which a plurality of first ceramic layers 11 and a plurality of second ceramic layers 12 are alternately stacked. The multilayer substrate has a third ceramic layer 13 and a conductor layer 14 between the first ceramic layer 11 and the second ceramic layer 12.

  The first ceramic layer 11 includes a first crystallized glass having a first softening point. The second ceramic layer 12 includes a second crystallized glass having a second softening point higher than the first softening point. The third ceramic layer 13 includes a third crystallized glass that is higher than the second softening point.

  In the multilayer substrate, the third crystallized glass contained in the third ceramic layer 13 flows out between the plurality of sintered particles in the second ceramic layer. Thus, the multilayer substrate is reduced with respect to the absorption of moisture in the atmosphere. Specifically, the multilayer substrate is reduced with respect to moisture absorption in the second ceramic layer 12 in contact with the conductor layer 14.

  The manufacturing method of a multilayer substrate has the process of baking a ceramic preform. As shown in FIG. 2, the ceramic preform includes a first ceramic material layer 21, a second ceramic material layer 22, and a third ceramic material layer 23 having different shrinkage start temperatures. The ceramic preform further includes a conductor layer 24. In the ceramic preform of FIG. 2, the shrinkage start temperature of the ceramic material layer has a relationship of first ceramic material layer 21 <second ceramic material layer 22 <third ceramic material layer 23. The third ceramic material layer 23 is formed in the vicinity of the conductor layer 24 and is partially provided over the entire area of the upper surface of the first ceramic material layer 21. The third crystallized glass contained in the third ceramic material layer 23 flows into voids generated when the second ceramic material layer 22 is sintered. Therefore, the void ratio in the second ceramic layer 12 on the multilayer substrate is reduced. In particular, since the third ceramic material layer 23 is provided in the vicinity of the conductor layer 23, the multilayer substrate is reduced with respect to the influence of moisture on the conductor layer 14.

The outline of the firing shrinkage behavior of the ceramics forming these three types of ceramic material layers 21 to 23 will be described based on the firing shrinkage curve of FIG. FIG. 2 is a shrinkage curve during heating of ceramics having different firing shrinkage behavior, where the horizontal axis represents temperature and the vertical axis represents the shrinkage rate. According to this shrinkage curve, the three ceramic materials A to C having different firing shrinkage temperatures have firing shrinkage start temperatures S _A , S _B , S _C (S _A <S _B <S _C ), and firing shrink end temperatures, respectively. E _A , E _B , E _C (E _A <E _B <E _C ). When applied to the ceramic preform of FIG. 2, the ceramic material layers 21 to 23 correspond to the ceramic materials A to C. The firing shrinkage rate in the main surface direction of the preform formed by laminating the ceramic material layers 21 and 22 is preferably 5% or less. It is possible to suppress warpage or deformation of the multilayer substrate, increase dimensional accuracy, and improve yield. In particular, 3% or less is more desirable. The smaller the difference in thermal expansion coefficient of the ceramic material layers 21 to 23 is, the more preferable it is because warpage during and after firing is suppressed, and the difference in thermal expansion coefficient is particularly preferably 2 × 10 ⁻⁶ / ° C. or less.

Among the ceramic material layers constituting the ceramic preform, the crystallized glass contained in the ceramic material layer 21 is SiO ₂ : 10 to 40% by mass, MgO: 35 to 60% by mass, B ₂ O ₃ : 10 to 30%. 0 to 30% by mass and at least one selected from the group consisting of CaO, Al ₂ O ₃ , SrO, ZnO, TiO ₂ , Na ₂ O, BaO, SnO ₂ , P ₂ O ₃ , ZrO ₂ and Li ₂ O Contains mass%. In particular, components other than SiO ₂ , MgO and B ₂ O ₃ are CaO: 0-10 mass%, Al ₂ O ₃ : 0-20 mass%, SrO: 0-5 mass%, ZnO: 0-30 mass%. , TiO ₂ : 0 to 10% by mass, Na ₂ O: 0 to 3% by mass, BaO: 0 to 30% by mass, SnO ₂ : 0 to 4% by mass, P ₂ O ₅ : 0 to 3% by mass, ZrO ₂ : 0 to 1% by mass, Li ₂ O: 0 to 5% by mass.

The crystallized glass contained in the ceramic material layer 22 includes SiO ₂ : 15 to 45% by mass, MgO: 30 to 55% by mass, B ₂ O ₃ : 7 to 27% by mass, CaO, Al ₂ O ₃ , SrO, _{ZnO, TiO 2, Na 2 O} , BaO, at least one selected from _{SnO 2, P 2 O 3,} ZrO 2 and Li ₂ O groups containing 0-27 wt%. In particular, components other than SiO ₂ , MgO and B ₂ O ₃ are CaO: 0-10% by mass, Al ₂ O ₃ : 0-20% by mass, SrO: 0-5% by mass, ZnO: 0-27% by mass. , TiO ₂ : 0 to 10% by mass, Na ₂ O: 0 to 3% by mass, BaO: 0 to 27% by mass, SnO ₂ : 0 to 4% by mass, P ₂ O ₅ : 0 to 3% by mass, ZrO ₂ : 0 to 1% by mass, Li ₂ O: 0 to 5% by mass.

The crystallized glass contained in the ceramic material layer 23 includes SiO ₂ : 20 to 50% by mass, MgO: 3 to 25% by mass, B ₂ O ₃ , CaO, Al ₂ O ₃ , SrO, ZnO, TiO ₂ and Na. Contains 0 to 55% by mass of at least one selected from the group consisting of ₂ O, BaO, SnO ₂ , P ₂ O ₃ , ZrO ₂ and Li ₂ O In particular, components other than SiO ₂ and MgO are B ₂ O ₃ : 0 to 20% by mass, CaO 0 to 10% by mass, Al ₂ O ₃ : 0 to 20% by mass, SrO 0 to 5% by mass, ZnO. : 0-30 wt%, TiO _2: 0 wt%, Na ₂ O: 0~3 wt%, BaO: 0 to 30 wt%, SnO _2: 0 to 4 wt%, P ₂ O _5: 0~ 3 wt%, ZrO _2: 0 to 1 wt%, Li ₂ O: there is a composition in the range of 0 to 5 wt%.

  The glass composition contained in the ceramic material layers 21 to 23 is the above composition because the final firing shrinkage ratio is set while providing the shrinkage start temperature difference of these insulating layers and making the firing temperature range different. This is because the values are the same.

By increasing the amount of MgO and B ₂ O _{3 in} the glass composition contained in the ceramic material layer, the softening point of the crystallized glass can be lowered, and the firing start temperature can be lowered. By increasing the amount of ₂ , the softening point of the crystallized glass can be increased, thereby increasing the firing start temperature.

  According to the combination of the crystallized glass and the ceramic filler, the binding force between the ceramic material layers 21 to 23 is increased, the firing shrinkage rate in the planar direction can be reduced to 5% or less, and the adhesion between the insulating layers. Becomes stronger, warping, peeling and delamination can be prevented, and the dimensional accuracy of the substrate can be improved.

In addition to the glass, the ceramic material layer may contain a ceramic filler. Examples of the ceramic filler used include Al ₂ O ₃ , SiO ₂ , MgTiO ₃ , CaZrO ₃ , CaTiO ₃ , Mg ₂ SiO ₄ , and BaTi. One or more selected from ₄ O ₉ , ZrTiO ₄ , SrTiO ₃ , BaTiO ₃ , TiO ₂ , ZrO ₂ , La ₂ Ti ₂ O ₇ , and Nd ₂ Ti ₂ O ₇ can be mentioned. In particular, as the ceramic filler, Al ₂ O ₃ is suitably used for high strength and reasons, and when the ceramic powder other than the above is mixed and fired, the thermal properties of the glass change by reacting with the glass, As a result, the firing shrinkage behavior is changed, and the restraining force in the planar direction (xy direction) during firing is weakened.

  The amount of the ceramic filler contained in the ceramic material layers 21 to 23 is 10 to 70% by mass and the amount of crystallized glass is 30 to 90% by mass, because the sinterability of the insulating layer deteriorates outside this range. It is. In particular, from the viewpoint of further improving the sinterability, the crystallized glass component is preferably 60% by mass or more, while the ceramic filler is preferably 40% by mass or less.

  These crystallized glass powders and ceramic fillers are mixed to prepare three kinds of ceramic materials with different firing shrinkage behavior, and these three kinds of ceramic materials, organic binder, organic solvent, and plasticizer as needed are mixed. A ceramic slurry is prepared.

  Using this ceramic slurry, tape molding is performed by a doctor blade method or the like, and the ceramic green sheet is cut into a predetermined size to form a ceramic material layer 21 compact and a ceramic material layer 22 compact. The slurry of the ceramic material layer 23 is prepared into a slurry that can be formed by a screen printing method. A through-hole is formed in the ceramic green sheet by punching or the like, and the through-hole is filled with a conductor paste, or a surface conductor layer or an internal conductor layer is formed by screen printing or the like using the conductor paste. A predetermined pattern of the ceramic material layer 23 is deposited and formed by a screen printing method or the like between the wirings of the formed body of the ceramic material layer 21 and the inner conductor layer of the formed body of the ceramic material layer 22. The ceramic green sheets thus obtained are laminated according to a predetermined lamination order to form a laminated molded body, and then fired.

  Due to firing, the ceramic material layer 21 in which the sintering is almost completed suppresses firing shrinkage in the planar direction (xy direction) and fires and shrinks in the longitudinal direction (Z direction). The ceramic material layer 23 supplies an amorphous glass component to the void generating part in the ceramic material layer 22 to reduce the void ratio around the inner conductor layer.

  Both the ceramic material layer 21 and the ceramic material layer 22 are restrained from firing shrinkage in the plane direction (xy direction), fired and shrunk in the longitudinal direction (Z direction), and have high dimensional accuracy and a void ratio around the inner conductor layer. A reduced substrate can be manufactured.

  From the viewpoint of reducing the firing shrinkage, the overall volume shrinkage is desirably 95% or more. The shrinkage start temperature difference of the ceramic material layers 21 to 23 is desirably 10 ° C. or higher, particularly 20 ° C. or higher.

  This is because the shrinkage restraining effect increases as the temperature range in which the ceramics are fired and shrunk together decreases.

  The shrinkage start temperature is the temperature at which each ceramic material layer is fired and shrunk by 0.1%, and the firing shrinkage end temperature is the temperature at which firing shrinkage has progressed 99% of the final fired volume shrinkage rate. A plurality of insulating layers formed of materials having different firing shrinkage behaviors, firing shrinkage start temperatures, and firing shrinkage end temperatures are laminated, and their dielectric constants may be the same or different depending on the purpose. The three types of ceramics having different behaviors may differ not only in the difference in firing shrinkage behavior but also in other characteristics such as different dielectric constants, different strengths, and different dielectric losses depending on purposes.

11 First ceramic layer 12 Second ceramic layer 13 Third ceramic layer 14 Conductor layer

Claims (4)

Alternately, a plurality of first ceramic layers including a first crystallized glass having a first softening point and a plurality of second ceramic layers including a second crystallized glass having a second softening point higher than the first softening point. A multi-layer substrate laminated to
A conductor layer and a third ceramic layer containing a third crystallized glass having a third softening point higher than the second softening point are formed between the first ceramic layer and the second ceramic layer. ,
The multilayer substrate, wherein the third crystallized glass is contained between a plurality of sintered particles in the second ceramic layer.   The multilayer substrate according to claim 1, wherein the third ceramic layer is separated from the conductor layer. A method for producing a multilayer substrate comprising a step of firing a ceramic preform,
The ceramic preform is
A plurality of first ceramic material layers including a first crystallized glass having a first softening point; a plurality of second ceramic material layers including a second crystallized glass having a second softening point higher than the first softening point; Is a multilayer molded body in which the layers are alternately laminated,
A conductor layer and a third ceramic material layer including a third crystallized glass having a third softening point higher than the second softening point are provided between the first ceramic material layer and the second ceramic material layer. It is and,
The method for producing a multilayer substrate , wherein the third crystallized glass is contained between a plurality of sintered particles in the second ceramic layer .   4. The method for manufacturing a multilayer substrate according to claim 3, wherein the third ceramic material layer is separated from the conductor layer.

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