JP2005285968A - Capacitor built-in glass ceramic multilayer wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a capacitor built-in glass ceramic multilayer wiring board, having a small capacitance change in a capacitor depending on the temperature. <P>SOLUTION: In the capacitor built-in glass ceramic multilayer wiring board 10, inside of an insulating substrate 11 composed of a glass ceramic sintered body containing glass and a filler, a capacitor 14 is formed which is constituted of a dielectric layer, having barium titanate as the principal component and electrode layers 13a to 13d composed of a sintered body of metal powder. The dielectric layer is comprised of a plurality of dielectric layers 12a to 12c, in which the Curie temperatures are mutually different. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a capacitor built-in glass ceramic multilayer wiring board in which a capacitor portion is built in an insulating layer made of a glass ceramic sintered body.

  Conventionally, in the fields of portable electronic devices and portable information terminals, module boards in which resistors, capacitors, inductors, etc. are mounted on a substrate such as a printed circuit board as passive components are used together with a multilayer wiring board on which semiconductor elements are mounted. Has been.

  However, in recent years, there has been a strong demand for downsizing, compounding, and high performance of components used in such portable electronic devices and portable information terminals, and as a passive component inside a multilayer wiring board on which a semiconductor element is mounted. The flow of integration of components in which electronic circuit elements having corresponding functions are incorporated and semiconductor elements and passive components are mounted at a high density is advancing. Addressing these passive components inside the multilayer wiring board eliminates the need for a space for mounting these passive components on the surface of the multilayer wiring board and increases the degree of freedom in design. You can contribute.

  For example, when forming a glass ceramic multilayer wiring board with a built-in capacitor, a dielectric paste is partially applied to a glass ceramic green sheet for forming an insulating layer to form a dielectric layer, and then a desired conductor pattern The glass ceramic green sheet formed with a glass ceramic green sheet formed with a dielectric layer is laminated, and the dielectric layer and the conductor pattern are fired simultaneously with the glass ceramic green sheet.

  The structure of the capacitor-embedded glass ceramic multilayer wiring board (hereinafter also referred to as a capacitor-embedded substrate) formed as described above includes a capacitor portion 2 disposed between the insulating layers 1 as shown in FIG. The capacitor part 2 is composed of an electrode layer 3 made of a sintered body of Cu, Ag powder and a dielectric layer 4 made of a sintered body of dielectric powder such as barium titanate powder.

Barium titanate has a high dielectric constant and is used as a main material in the field of high dielectric constant ceramic capacitors. Barium titanate has a Curie temperature between 120 ° C. and 130 ° C., and its dielectric constant increases rapidly at the Curie temperature. Therefore, when it is necessary to suppress the change in the electric capacity of the capacitor from a low temperature to a high temperature, an additive (depressor) is widely added to the dielectric composition in order to suppress an increase in the dielectric constant at the Curie temperature. It has been broken.
Tatsuya Ueda, “Low-temperature fired multilayer substrates, high dielectric constant materials for built-in capacitors and their applications,” Fine Ceramics Report, Japan Fine Ceramics Association, 1996, Vol. 14, No. 8, p. 220-222 Nobuo Kamehara and Shinichi Niwa, “CR Composite Substrate”, New Ceramics, 1995, No. 1, p. 39-44

  However, in the conventional configuration of FIG. 2, when the glass ceramic green sheet and the dielectric layer 4 are simultaneously fired through the electrode layer 3, the firing temperature cannot be set higher than the melting point of Cu, Ag powder. Therefore, when a depressor is added to the dielectric composition of the dielectric layer 4, there is a problem that the depressor inhibits the sintering of the dielectric composition and lowers the dielectric constant of the dielectric composition.

  In addition, since the sintering temperature of the glass ceramic green sheet is relatively low, about 900 ° C to 1000 ° C, the reaction between the depressor and the dielectric composition does not proceed sufficiently, and the increase in the dielectric constant at the Curie temperature is sufficiently suppressed. There was a problem that it was impossible to do.

  The present invention has been completed in order to solve the above-described problems, and an object of the present invention is to provide a glass-ceramic multilayer wiring board with a built-in capacitor whose capacitance change is small depending on temperature.

  The glass-ceramic multilayer wiring board with a built-in capacitor according to the present invention includes a dielectric layer mainly composed of barium titanate and a sintered body of metal powder in an insulating base made of a glass-ceramic sintered body containing glass and filler. A capacitor-embedded glass-ceramic multilayer wiring board in which a capacitor portion composed of an electrode layer is formed, wherein the dielectric layer is composed of a plurality of dielectric layer portions having different Curie temperatures.

  The capacitor-embedded glass ceramic multilayer wiring board of the present invention is preferably characterized in that a dielectric diffusion prevention layer and a metallization diffusion prevention layer are sequentially laminated on the upper and lower surfaces of the capacitor portion.

Moreover, in the glass-ceramic multilayer wiring board with a built-in capacitor according to the present invention, preferably, the capacitor portion is a first ferroelectric powder containing 95 to 100 parts by mass of barium titanate powder and 5 parts by mass or less of strontium titanate powder. , B ₂ O ₃ , SiO ₂ , CaO, BaO and ZnO, and a sintered body obtained by adding 2 to 10 parts by mass of CuO powder to 100 parts by mass of the first ferroelectric powder. B ₂ O ₃ , SiO ₂ , CaO, B ₂ O ₃ , SiO ₂ , CaO, _second dielectric powder containing 85 to 90 parts by mass of barium titanate powder and 10 to 15 parts by mass of strontium titanate powder. A sintered body in which 2 to 10 parts by mass of a glass powder containing BaO and ZnO and a CuO powder are added to 100 parts by mass of the second ferroelectric powder, respectively. Of a dielectric layer portion, the third ferroelectric powder comprising barium powder 65-80 parts by weight titanate and strontium titanate powder 20 to 35 parts by _{weight, B 2 O 3, SiO 2} , CaO, BaO and It comprises a third dielectric layer portion made of a sintered body obtained by adding 2 to 10 parts by mass of glass powder containing ZnO and CuO powder to 100 parts by mass of the third ferroelectric powder. And

  According to the glass-ceramic multilayer wiring board with a built-in capacitor of the present invention, the dielectric layer mainly composed of barium titanate constituting the capacitor portion is composed of a plurality of dielectric layer portions having different Curie temperatures. The capacitance change with respect to each other is complemented and equalized by each dielectric layer portion having a plurality of Curie temperatures, so that compared to the case where the dielectric layer is made of a single dielectric material, The amount of change in capacity can be kept small. As a result, a capacitor-embedded substrate having a capacitor portion with a small capacitance change rate with respect to temperature can be obtained.

  For example, when the dielectric layer of the capacitor portion is formed of a single dielectric material having a Curie temperature at 125 ° C., the capacitance change of the capacitor portion in the temperature range of −40 ° C. to 120 ° C. with respect to room temperature (25 ° C.) The dielectric layer is formed from two types of dielectric layer portions adjusted so that the dielectric layer of the capacitor portion has a Curie temperature of 80 ° C. and 15 ° C. In this case, the capacitance change of the capacitor portion in the temperature range of −40 ° C. to 125 ° C. with respect to room temperature can be −10% to 15%.

  In the capacitor-embedded substrate of the present invention, preferably, when the dielectric diffusion prevention layer and the metallization diffusion prevention layer are sequentially laminated on the upper and lower surfaces of the capacitor portion, the insulator layer and the dielectric that are generated at the time of simultaneous firing The interdiffusion phenomenon between the layers can be replaced with the interdiffusion phenomenon between the insulating layer and the dielectric diffusion prevention layer. Therefore, the dielectric component (glass component) of the dielectric layer of the capacitor part flows out to the insulating layer and the electrode layer, resulting in insufficient sintering of the dielectric layer, or the glass component of the insulating layer is contained in the dielectric layer. It is possible to prevent the glass component of the dielectric layer from entering due to intrusion. As a result, it is possible to greatly suppress the capacitance drop of the capacitor portion formed in the capacitor built-in substrate and the variation in the capacitance value.

  Further, by interposing the metallized diffusion prevention layer between the dielectric diffusion prevention layer and the insulating layer composed of the glass ceramic sintered body, an excessive amount of dielectric component (glass component) between the dielectric diffusion prevention layer and the insulation layer is present. Interdiffusion can be suppressed. As a result, voids generated in the dielectric diffusion prevention layer and the insulating layer are eliminated, and the residual stress due to the difference in thermal expansion coefficient between the dielectric diffusion prevention layer and the insulation layer is alleviated. It is possible to prevent the occurrence of cracks in the insulating layer and to provide a highly reliable capacitor built-in substrate.

In the capacitor-embedded substrate of the present invention, preferably, the capacitor portion is formed by adding B ₂ O to the first ferroelectric powder obtained by adding 95 to 100 parts by mass of barium titanate powder and 5 parts by mass or less of strontium titanate powder. ₃ , a sintered body obtained by adding 2 to 10 parts by mass of glass powder containing Cu ₂ , CaO, BaO and ZnO and CuO powder to 100 parts by mass of the first ferroelectric powder, and barium titanate powder 85 A second ferroelectric powder containing ~ 90 parts by mass and 10-15 parts by mass of strontium titanate powder is strongly strengthened with glass powder and CuO powder containing B ₂ O ₃ , SiO ₂ , CaO, BaO and ZnO, respectively. Sintered body added with 2 to 10 parts by mass with respect to 100 parts by mass of dielectric powder, 65 to 80 parts by mass of barium titanate powder and strontium titanate powder Against third ferroelectric powder _{B 2 O 3, SiO 2,} CaO, respectively ferroelectric powder 100 parts by weight of glass powder and CuO powder and the containing BaO and ZnO containing a 20 to 35 parts by weight When the dielectric material is composed of three different dielectric materials with 2 to 10 parts by mass added, each dielectric material has a Curie temperature of 100 ° C to 125 ° C, 60 ° C to 85 ° C, and 10 ° C to 45 ° C, respectively. Therefore, a substrate with a built-in capacitor having a high dielectric constant and a small amount of change in dielectric constant due to a temperature change can be obtained in a wide practical temperature range of −40 ° C. to 120 ° C.

  The capacitor built-in substrate of the present invention will be described in detail below. FIG. 1 is a sectional view showing an example of an embodiment of a substrate with a built-in capacitor according to the present invention. A capacitor-embedded substrate 10 according to the present invention includes a pair of insulating base 11 formed by laminating a plurality of insulating layers 11a, 11b, and 11c, dielectric layer portions 12a, 12b, and 12c, and metallized layers disposed above and below them. Capacitor portion 14 composed of electrode layers 13a to 13d, through conductors 15a to 15d, and wiring layers 16a and 16b.

The insulating layers 11a to 11c in the ceramic wiring substrate 10 of the present invention are made of a sintered body of a glass component and ceramic powder (ceramic filler). Examples of the glass component include SiO ₂ —B ₂ O ₃ system, SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ system, SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ —MO system (where M is Ca, Sr, Mg, Ba or Zn), SiO ₂ —Al ₂ O ₃ —M ¹ O—M ² O system (where M ¹ and M ² are the same or different, and Ca, Sr, Mg , Ba or Zn), SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ —M ¹ O—M ² O system (where M ¹ and M ² are the same as above), SiO ₂ —B ₂ O ₃ —M ³ ₂ O system (where M ³ represents Li, Na or K), SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ —M ³ ₂ O system (where M ³ is the same as above) Pb glass, Bi glass and the like.

Examples of the ceramic powder include Al ₂ O ₃ , SiO ₂ , composite oxide of ZrO ₂ and alkaline earth metal oxide, composite oxide of TiO ₂ and alkaline earth metal oxide, Al ₂ O _3. And composite oxides containing at least one selected from SiO ₂ (for example, spinel, mullite, cordierite) and the like.

  A green sheet, which is a green sheet before firing of the insulating layers 11a to 11c, is made by adding and mixing glass powder and ceramic powder, an organic binder, an organic solvent, a plasticizer, and the like into a slurry. Molding is performed by adopting the method or calendar roll method.

  As the organic binder added to and mixed with the glass powder and the ceramic powder, those conventionally used for ceramic green sheets can be used. For example, acrylic (acrylic acid, methacrylic acid or ester homopolymers thereof) Or a copolymer, specifically, an acrylic ester copolymer, a methacrylic ester copolymer, an acrylic ester-methacrylic ester copolymer, etc.), polyvinyl butyral, polyvinyl alcohol, acrylic-styrene, polypropylene Examples include carbonate-based and cellulose-based homopolymers or copolymers.

  As an organic solvent used in a slurry for forming a green sheet, the organic solvent, glass powder, ceramic powder, and an organic binder are kneaded to obtain a slurry having a viscosity suitable for green sheet forming, for example, carbonization. Examples thereof include hydrogen, ethers, esters, ketones, alcohols and the like.

  A through hole is formed in the green sheet produced as described above by mechanical processing such as die processing, laser processing, micro drilling, punching, or the like as necessary. This through hole is filled with a paste for penetrating conductor obtained by adding an appropriate organic binder and solvent to a metal powder such as Ag, Cu, Ag-Pt, Ag-Pd, and glass powder, and then mixed with the screen through printing. A conductor 17 is formed.

  In addition, a paste for wiring conductor in which a metal powder such as Ag, Cu, Ag-Pt, or Ag-Pd and a glass powder is mixed with a suitable organic binder and solvent is applied to the surface of these green sheets by screen printing or the like. The wiring layers 16a and 16b may be formed.

  The electrode layers 13a to 13d are made of a metal powder such as Ag, Cu, Ag-Pt, Ag-Pd, or the like, or a glass powder or an organic binder or solvent suitable for the green sheet or the dielectric layer portions 12a to 12c. The electrode paste to which is added and mixed can be applied and formed by a screen printing method or the like. The amount of glass added to the electrode layers 13a to 13d is preferably 10 parts by mass or less. Thereby, electrode layer 13a-13d can be made into a precise | minute metal sintered compact. As a result, mutual diffusion between the dielectric layers 12a to 12c and the insulating layer 11 can be reduced.

  The dielectric layer portions 12a to 12c are dielectric pastes obtained by adding glass powder, an appropriate organic binder, and a solvent to a ferroelectric powder obtained by adding appropriate amounts of barium titanate powder and strontium titanate powder on the electrode layers 13a to 13d. Can be applied by screen printing or the like. The dielectric layer portions 12a to 12c are formed by laminating a plurality of dielectric materials mainly composed of barium titanate adjusted to have different Curie temperatures in the thickness direction of the substrate 10 with a built-in capacitor. .

The dielectric layer is composed of B ₂ O ₃ , SiO ₂ , CaO, BaO and a first ferroelectric powder obtained by adding 95 to 100 parts by mass of barium titanate powder and 5 parts by mass or less of strontium titanate powder. A first dielectric layer portion 12a made of a sintered body obtained by adding 2 to 10 parts by mass of glass powder containing ZnO and CuO powder to 100 parts by mass of the first ferroelectric powder, and barium titanate powder; A second ferroelectric powder obtained by adding 85 to 90 parts by mass and 10 to 15 parts by mass of strontium titanate powder, and glass powder and CuO powder containing B ₂ O ₃ , SiO ₂ , CaO, BaO and ZnO. Each of the second dielectric layer portion 12b made of a sintered body added with 2 to 10 parts by mass with respect to 100 parts by mass of the second ferroelectric powder, 65 to 80 parts by mass of barium titanate powder, _B and phosphate strontium powder third ferroelectric powder obtained by adding 20 to 35 parts by mass _{2 O 3, SiO 2, CaO} , third intensity of each glass powder and CuO powder and the containing BaO and ZnO It is preferable to comprise the third dielectric layer portion 12c made of the sintered body 3 added with 2 to 10 parts by mass with respect to 100 parts by mass of the dielectric powder.

  Since the first dielectric layer portions 12a to 12c have Curie temperatures of 100 ° C. to 125 ° C., 60 ° C. to 85 ° C., and 10 ° C. to 45 ° C., respectively, the dielectric constant in a wide temperature range of −40 ° C. to 120 ° C. Therefore, the capacitor-embedded substrate 10 having a high capacitance and a small change in capacitance due to temperature can be obtained.

  In addition, a dielectric diffusion prevention layer and a metallization diffusion prevention layer may be provided on the upper and lower surfaces of the capacitor portion 14 in order. By providing the dielectric diffusion preventing layer and the metallized diffusion preventing layer, the interdiffusion between the dielectric layer and the insulating layer 11 can be more preferably suppressed, and the dielectric layer can be a dense sintered body.

  Furthermore, each green sheet used as insulating layer 11a, 11b, 11c is thermocompression-bonded by the pressure of 3-20 MPa and the temperature of 50-80 degreeC, and a laminated body is produced.

  Thereafter, for example, when the metal powder such as the wiring layers 16a and 16b is Ag powder, the temperature is 900 to 1000 ° C. in the atmosphere, and when the metal powder such as the wiring layers 16a and 16b is Cu powder, the atmosphere is a nitrogen atmosphere. By firing the laminate, the capacitor built-in substrate 10 of the present invention is obtained.

  In addition, when the laminate is fired, a constrained green sheet made of an inorganic component that does not substantially shrink and shrink at the temperature at which the green sheet sinters, such as alumina, is laminated on both sides of the laminate and fired. Sintering between the green sheet and a dielectric paste coating layer, which is a dielectric layer mainly composed of barium titanate, because the sheet restrains shrinkage during firing in the main surface direction of the laminate. Warpage or the like of the capacitor built-in substrate 10 due to the difference in shrinkage behavior can be suppressed.

  Furthermore, the wiring layers 16a and 16b located on the surface of the capacitor-embedded substrate 10 are made of nickel, copper for improving solder wettability when mounting electronic components on the surface and preventing corrosion of the wiring layers 16a and 16b. A plating layer of gold or the like may be applied.

  In the above embodiment, the dielectric layer portions 12a to 12c made of a plurality of dielectric materials mainly composed of barium titanate adjusted to have different Curie temperatures are provided in the thickness direction of the capacitor built-in substrate 10. However, the present invention is not limited to this embodiment. For example, the dielectric layer portions 12a to 12c are formed side by side in the plane direction, or the dielectric layer portion. 12a may be surrounded by the dielectric layer portion 12b, and the dielectric layer portion 12c may be surrounded by the dielectric layer portion 12b.

  Examples of the substrate with built-in capacitor according to the present invention will be described below.

In order to obtain a green sheet serving as an insulator layer of a substrate with a built-in capacitor, 50 parts by mass of SiO ₂ —CaO—MgO-based glass powder as glass and 50 parts by mass of Al ₂ O ₃ powder as ceramic filler are mixed. To 100 parts by mass of inorganic powder composed of powder and ceramic filler, 12 parts by mass of an acrylic resin as an organic binder, 6 parts by mass of a phthalic acid plasticizer and 30 parts by mass of toluene as a solvent were added and mixed by a ball mill method to obtain a slurry. Using this slurry, a glass ceramic green sheet having a thickness of 200 μm was formed by a doctor blade method.

In addition, in order to obtain a green sheet to be a first dielectric layer portion of the capacitor built-in substrate, B ₂ O ₃ , SiO ₂ , CaO, 12 parts by mass of an acrylic resin as an organic binder is added to 100 parts by mass of the first inorganic powder obtained by adding 5 parts by mass of glass powder containing BaO and ZnO and CuO powder to 100 parts by mass of the first ferroelectric powder. Then, 6 parts by mass of a phthalic acid plasticizer and 30 parts by mass of toluene as a solvent were added and mixed by a ball mill method to prepare a first slurry. Using the first slurry, a first green sheet having a thickness of 30 μm was formed by a doctor blade method.

Further, in order to obtain a green sheet serving as the second dielectric layer portion, 87.5 parts by mass of barium titanate powder and 12.5 parts by mass of strontium titanate powder were added to the second ferroelectric powder. _To 100 parts by mass of the second inorganic powder obtained by adding 5 parts by mass of glass powder containing ₂ O ₃ , SiO ₂ , CaO, BaO and ZnO and CuO powder to 100 parts by mass of the second ferroelectric powder, 12 parts by mass of an acrylic resin as an organic binder, 6 parts by mass of a phthalic acid plasticizer, and 30 parts by mass of toluene as a solvent were added and mixed by a ball mill method to prepare a second slurry. Using the second slurry, a second green sheet having a thickness of 30 μm was formed by a doctor blade method.

Further, in order to obtain a green sheet serving as a third dielectric layer portion, a third ferroelectric powder containing 70 parts by mass of barium titanate powder and 30 parts by mass of strontium titanate powder is added to B ₂ O ₃ , A glass powder containing SiO ₂ , CaO, BaO and ZnO and a CuO powder are added as acrylic binder as an organic binder to 100 parts by mass of the third inorganic powder obtained by adding 5 parts by mass to 100 parts by mass of the third ferroelectric powder. 12 parts by mass of a resin, 6 parts by mass of a phthalic acid plasticizer and 30 parts by mass of toluene as a solvent were added and mixed by a ball mill method to obtain a third slurry. A third green sheet having a thickness of 30 μm was formed by the doctor blade method using the third slurry.

  A paste for metallization diffusion prevention layer was applied to a glass ceramic green sheet to be an insulating layer by a screen printing method and dried at 70 ° C. for 30 minutes to form a pattern of the paste for metallization diffusion prevention layer. In addition, said paste for metallization diffusion prevention layers consists of a mixture of Ag powder and glass powder, and when Ag powder and glass powder are 100 mass parts, to this, 12 mass parts of acrylic resins and α- 6 parts by mass of terpineol was added, and the mixture was thoroughly mixed with a stirring deaerator.

  Further, the dielectric diffusion prevention layer paste was applied on the metallized diffusion prevention layer paste layer by a screen printing method and dried at 70 ° C. for 30 minutes to form a dielectric baking diffusion prevention layer paste pattern. The dielectric diffusion preventing layer paste is composed of a mixture of barium titanate powder and glass powder. When the barium titanate powder and glass powder are 100 parts by mass, 12 parts by mass of acrylic resin and α as an organic solvent are added thereto. -Terpineol 8 parts by mass was added, and after sufficiently mixing with a stirring defoamer, a mixture kneaded sufficiently with three rolls was used.

  Next, a through hole is formed at a predetermined position in a glass ceramic green sheet on which a pattern of the paste layer for the metallized diffusion prevention layer and the paste layer for the dielectric diffusion prevention layer is formed using a punching machine, and screen printing is performed on the through hole. The paste for through conductors was filled by this method. As a paste for penetrating conductors, 10 parts by mass of glass powder is added to 100 parts by mass of Ag powder (average particle size 3 μm), and a predetermined amount of acrylic resin and terpineol are added as binder components. A well-mixed one was used.

  Next, through holes were formed at predetermined positions in the first to third green sheets using a punching machine, and the through-conductor paste was filled into the through holes by a screen printing method. Furthermore, the electrode layer paste was applied on the first to third green sheets by a screen printing method and dried at 70 ° C. for 30 minutes to form a pattern of the electrode layer paste layer. As the electrode layer paste, the same paste as the metallized diffusion preventing layer paste was used.

  Furthermore, the green sheet laminated body which laminated | stacked the 1st-3rd green sheet in which the pattern of the paste layer for electrode layers was formed was formed. At this time, a green sheet laminate in which three layers of the second green sheets were laminated was referred to as a green sheet laminate A, and a green sheet laminate in which the first to third green sheets were laminated was referred to as a green sheet laminate B.

Next, the green sheet laminates A and B to be the capacitor parts are each cut to a predetermined size (3 mm square), and these are set on the dielectric diffusion prevention layer on the glass ceramic green sheet to be the insulating layer, A vacuum was applied at a pressure of 5 MPa and a temperature of 50 ° C. to obtain a glass ceramic green sheet in which the green sheet laminates A and B to be the capacitor part were partially laminated. Further, in order to absorb the thickness caused by partially laminating the green sheet laminates A and B that become the capacitor portions, the same as the glass ceramic green sheet so as to cover the green sheet laminates A and B that become the capacitor portions. A glass ceramic paste made of a material and serving as an insulating layer after sintering was applied by screen printing. In this glass ceramic paste, 50 parts by mass of SiO ₂ —CaO—MgO-based glass powder as glass and 50 parts by mass of Al ₂ O ₃ powder as ceramic filler are mixed, and acrylic resin 12 as an organic binder is added to 100 parts by mass of this inorganic powder. A mass part and 8 parts by mass of α-terpineol as an organic solvent were added, and the mixture was sufficiently mixed with a stirring defoamer and then sufficiently kneaded with three rolls.

  Next, a glass ceramic green sheet in which green sheet laminates A and B to be a capacitor portion are laminated, a measurement pad on the surface, and a metallized diffusion prevention layer pattern that suppresses diffusion above the capacitor portion on the back surface And the glass ceramic green sheet in which the pattern of the dielectric diffusion preventing layer was formed was vacuum-heat-pressed at a pressure of 5 MPa and a temperature of 50 ° C. to produce a green sheet laminate for a capacitor built-in substrate. This green sheet laminate is fired in a firing process consisting of a binder combustion process at 500 ° C. for 3 hours and a ceramic sintering process at 900 ° C. for 1 hour, and an insulating layer comprising a dense glass ceramic sintered body A capacitor built-in substrate having a dielectric layer disposed therein by simultaneous firing was obtained. Here, the substrate with a built-in capacitor in which the sintered body of the green sheet laminate A was incorporated was Sample 1, and the substrate with a capacitor in which the sintered body of the green sheet laminate B was incorporated was Sample 2.

About the obtained board | substrate with a built-in capacitor | condenser, the electric capacity of the capacitor | condenser part (capacitance element) was measured in the temperature range of -40 degreeC-130 degreeC. The capacitance was measured using an impedance measuring instrument (“4294A Precision Impedance Analyzer” manufactured by Agilent Technologies, Inc., measurement accuracy ± 0.08%) under the conditions of a measurement frequency of 1 MHz and a measurement temperature of 25 ° C. The measurement results are shown in Table 1. Table 1 shows the capacity ratio at each temperature with respect to room temperature (25 ° C.).

  From Table 1, it was found that in the temperature range of −40 ° C. to 120 ° C., Sample 2 had a smaller capacity change rate with respect to temperature than Sample 1.

  The present invention is not limited to the above-described embodiments and examples, and various modifications may be made without departing from the scope of the present invention.

It is sectional drawing which shows one example of embodiment of the glass ceramic multilayer wiring board with a built-in capacitor | condenser of this invention. It is sectional drawing which shows one example of the conventional glass ceramic multilayer wiring board with a built-in capacitor | condenser.

Explanation of symbols

10: Glass ceramic multilayer wiring board with built-in capacitor 11: Insulating bases 11a, 11b, 11c: Insulating layers 12a, 12b, 12c: First, second and third dielectric layer portions 13a, 13b, 13c, 13d: Electrode layers 14: Capacitors 15a, 15b, 15c, 15d: Through conductors 16a, 16b: Wiring layer

Claims (3)

A capacitor portion composed of a dielectric layer composed mainly of barium titanate and an electrode layer composed of a sintered body of metal powder is formed inside an insulating base composed of a glass ceramic sintered body containing glass and filler. A glass-ceramic multilayer wiring board with a built-in capacitor, wherein the dielectric layer is composed of a plurality of dielectric layer portions having different Curie temperatures. 2. The glass-ceramic multilayer wiring board with a built-in capacitor according to claim 1, wherein a dielectric diffusion preventing layer and a metallized diffusion preventing layer are sequentially laminated on the upper and lower surfaces of the capacitor part. The capacitor portion includes B ₂ O ₃ , SiO ₂ , CaO, BaO, and ZnO in a first ferroelectric powder that includes 95 to 100 parts by mass of barium titanate powder and 5 parts by mass or less of strontium titanate powder. A first dielectric layer portion made of a sintered body obtained by adding 2 to 10 parts by mass of glass powder and CuO powder to 100 parts by mass of the first ferroelectric powder, and barium titanate powders 85 to 90, respectively. parts by weight of the second ferroelectric powder and a strontium titanate powder 10 to 15 parts by _{weight, B 2 O 3, SiO 2} , CaO, respectively the second and the glass powder and CuO powder containing BaO and ZnO 2 to 10 parts by mass of a second dielectric layer composed of a sintered body added to 100 parts by mass of the ferroelectric powder, 65 to 80 parts by mass of barium titanate powder, and titanium titanate A third ferroelectric powder comprising a lithium powder 20 to 35 parts by _{weight, B 2 O 3, SiO 2} , CaO, each of the third ferroelectric powder glass powder and CuO powder and the containing BaO and ZnO 3. The glass-ceramic multilayer wiring board with a built-in capacitor according to claim 1, further comprising a third dielectric layer portion made of a sintered body added with 2 to 10 parts by mass with respect to 100 parts by mass.

Images