JP2007201143A - Joining intermediate layer and composite laminate electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite laminate electronic component not only capable of surely joining/integrating a varistor element having a varistor layer and an internal electrode with an inductor element having a ferrite layer and an internal conductor via a joining intermediate layer, but also preventing an adverse influence as deterioration in characteristics to the varistor element and the inductor element, wherein the joining intermediate layer itself has high resistivity and high reliability. <P>SOLUTION: The composite laminate electronic component includes the varistor element (10) having the varistor layer and the internal electrode, the inductor element (20) having the ferrite layer and the internal conductor, and the joining intermediate layer (50) interposed for joining both elements. The ferrite layer is made of ferrite. The varistor layer mainly contains ZnO. The joining intermediate layer contains the ferrite and ZnO as dominant components; and contains at least one kind selected from a group including magnesium oxide, calcium oxide, strontium oxide, and barium oxide as an additional ingredient. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a varistor element part having a varistor layer and an internal electrode, a joining intermediate layer interposed for joining blocks of both an inductor element part having a ferrite layer and an internal conductor, and a composite multilayer electronic component using the same In particular, a junction intermediate layer having a high resistivity without adversely affecting the characteristics of the varistor element part and the inductor element part as well as being able to be reliably joined and integrated, and the use thereof (reliability) The present invention relates to a composite multilayer electronic component.

  In computer equipment etc., ferrite chips, capacitor chips, varistors, etc. are incorporated in the input / output part of the circuit board and in the middle of the circuit so that the equipment itself does not generate noise and also does not allow noise to enter the equipment from the outside. Yes.

  However, if many parts such as a multilayer varistor, inductor (ferrite chip), capacitor chip, etc. are added to the circuit board, these parts occupy a large area of the board, resulting in an increase in mounting space. . In addition, an increase in the number of parts causes a problem of cost increase.

  In order to deal with such problems, attempts have been made to make a composite part by integrally sintering each element chip in a state where the element chips are joined to each other, thereby reducing the size of the part and reducing the mounting space.

In particular, as prior arts related to the integration of a varistor and an inductor (ferrite chip), which are difficult to perform integrated sintering, for example, in Japanese Patent Application Laid-Open Nos. 7-22210 and 7-220906, layer peeling is performed. In order to provide a composite functional element in which delamination and cracks are suppressed, in the case where a semiconductor ceramic having varistor characteristics and a magnetic material ceramic are joined and integrally formed, Bi is applied to both the semiconductor ceramic and the magnetic material ceramic. Proposals have been made to add ₂ O ₃ and glass compositions.

However, when Bi ₂ O ₃ or a glass composition is added to a ferrite or varistor, there arises a problem that the magnetic properties of the ferrite or the electrical properties of the varistor are adversely affected. In addition, cracks tend to occur at the bonding interface, and it can be said that it is extremely difficult to obtain a bonding force sufficient for commercialization.

  A method using an intermediate material produced by mixing materials to be joined has also been proposed. For example, as disclosed in JP-A-4-284610, when high resistivity materials such as ferrite and dielectric are mixed, there are few problems with respect to insulation between the two elements. However, as disclosed in Japanese Patent Laid-Open No. 9-283339, when a low resistivity such as varistor (ZnO) of 0.1 (Ω · m) is mixed with ferrite, a high resistivity is ensured as an intermediate material. As a result, a problem arises in the insulation between the two elements.

  Further, although not directly related to the composite multilayer electronic component, Japanese Patent Application Laid-Open No. 6-89803 and Japanese Patent Application Laid-Open No. 2005-51052 include a description related to high resistance treatment on the varistor surface.

JP 7-22210 A Japanese Patent Laid-Open No. 7-220906 JP-A-4-284610 Japanese Patent Laid-Open No. 9-283339 JP-A-6-89803 JP 2005-51052 A

  The present invention has been devised under such circumstances, and its purpose is to block both a varistor element part having a varistor layer and an internal electrode, and an inductor element part having a ferrite layer and an internal conductor. In addition to being able to be bonded and integrated reliably, the junction intermediate layer having a high resistivity without adversely affecting the characteristics of the varistor element portion and the inductor element portion, and excellent reliability using the same It is to provide a composite laminated electronic component.

  In order to solve such a problem, the present invention provides a varistor element part having a varistor layer and an internal electrode, an inductor element part having a ferrite layer and an internal conductor, and an intervening element for joining both of these element parts. The ferrite layer to be joined is made of ferrite, the varistor layer is mainly composed of ZnO, and the joint intermediate layer is composed mainly of the ferrite and the ZnO. And containing at least one selected from the group consisting of magnesium oxide, calcium oxide, strontium oxide, and barium oxide as an additive component, and the total amount of the additive components in the main component in terms of MgO, CaO, SrO, BaO It is comprised so that 2-10 wt% may be contained with respect to ZnO.

  Moreover, as a preferable aspect of the joining intermediate | middle layer of this invention, the content ratio of the said ferrite and the said ZnO shall be 5: 95-95: 5Vol (volume)%.

  Moreover, as a preferable aspect of the joining intermediate | middle layer of this invention, the thickness shall be 90-400 micrometers.

  The composite multilayer electronic component of the present invention includes a varistor element part having a varistor layer and an internal electrode, an inductor element part having a ferrite layer and an internal conductor, and a junction intermediate interposed between the element parts. The ferrite layer is composed of ferrite, the varistor layer is composed mainly of ZnO, and the joining intermediate layer includes the ferrite and ZnO as the main components, and includes magnesium oxide and calcium oxide. , Strontium oxide, and at least one selected from the group of barium oxide as an additive component, and the total amount of the additive component is 2 with respect to ZnO in the main component in terms of MgO, CaO, SrO, BaO It is comprised so that it may contain -10 wt%.

  As a preferred embodiment of the composite multilayer electronic component of the present invention, the content ratio of the ferrite and ZnO contained as main components in the joining intermediate layer is 5:95 to 95: 5 Vol (volume)%. Configured.

  Moreover, as a preferable aspect of the composite multilayer electronic component of the present invention, the bonding intermediate layer has a multilayer structure of N = 2 to 6 layers, and the layer closer to the inductor element portion has a content ratio of the ferrite. Is set to be high.

  As a preferred embodiment of the composite multilayer electronic component of the present invention, the thickness of the joining intermediate layer is 90 to 400 μm.

  Moreover, as a preferable aspect of the bonding intermediate layer of the present invention, the varistor layer is configured to contain 95 to 98 mol% of ZnO as a main component thereof.

  The present invention relates to a junction intermediate layer for joining both element portions of a varistor element portion having a varistor layer and an internal electrode, an inductor element portion having a ferrite layer and an internal conductor, and a junction via the junction intermediate layer. In the composite multilayer electronic component, the ferrite layer is made of ferrite, the varistor layer is made of ZnO as a main component, and the joining intermediate layer contains the ferrite and the ZnO as main components, At least one selected from the group consisting of magnesium oxide, calcium oxide, strontium oxide, and barium oxide is included as an additive component, and the total amount of the additive component is ZnO in the main component in terms of MgO, CaO, SrO, BaO In contrast, the varistor element portion and the inductor element are configured so as to be contained in an amount of 2 to 10 wt%. DOO be can be reliably bonded and integrated the well, without adversely affecting that characteristic degradation of the varistor device portion and an inductor device portion having a bonding intermediate layer itself itself has high resistivity. Therefore, the composite multilayer electronic component bonded using the bonding intermediate layer is an electronic component having excellent reliability.

  The present invention relates to a junction intermediate layer for joining both element portions of a varistor element portion having a varistor layer and an internal electrode, and an inductor element portion having a ferrite layer and an internal conductor, and both using the junction intermediate layer. The present invention relates to a composite multilayer electronic component to which the element portions are joined.

  The essential part of the present invention is to make it possible to surely join both of the above-mentioned element parts, which have been difficult to join, and the joining intermediate layer itself has high resistivity and reliability. It is in the setting of the specifications of the excellent bonding interlayer.

  Before describing the specification setting of the joining intermediate layer, which is the main part of the present invention, an explanation of the overall configuration of an example of a composite multilayer electronic component will be given with reference to FIGS. Note that the illustrated example is merely for schematically showing a state in which the varistor element portion and the inductor element portion are joined, and a modified component in which a chip capacitor or the like is further added thereto may be used.

  FIG. 1 is a perspective view showing a composite laminated electronic component. FIG. 2 is an exploded perspective view of a laminated body for easy understanding of the laminated structure of the composite laminated electronic component.

  As shown in FIG. 1, the composite multilayer electronic component 100 includes a substantially rectangular parallelepiped laminate 1, and the laminate 1 constitutes a main body of the multilayer electronic component 100. The laminated body 1 has a pair of side surfaces 9a and 9b facing each other, a pair of side surfaces 9c and 9d, and a pair of upper surfaces 9e and bottom surfaces 9f, and these surfaces 9a to 9f have a substantially rectangular parallelepiped shape. Yes. The bottom surface 9f is a surface facing the external substrate when the composite multilayer electronic component 100 is mounted on the external substrate.

  The composite multilayer electronic component 100 includes an input terminal (first terminal electrode) 3 formed on the side surface 9a of the multilayer body 1 and an output terminal (second terminal electrode) 5 formed on the side surface 9b. And a pair of ground terminals (third terminal electrodes) 7 formed on the side surfaces 9c and 9d. The input terminal 3 covers the entire surface of the side surface 9a, and a part thereof is formed so as to wrap around the surfaces 9c to 9f. The output terminal 5 covers the entire surface of the side surface 9b, and a part of the output terminal 5 wraps around the surfaces 9c to 9f. Each ground terminal 7 extends in a strip shape in the stacking direction of the stacked body 1, and further, both end portions thereof are formed to wrap around the upper surface 9 e and the bottom surface 9 f.

  The composite multilayer electronic component 100 according to the present invention includes a varistor element portion 10 and an inductor element portion 20 as constituent members of the multilayer body 1 as shown in FIG.

[Description of Varistor Element Unit 10]
First, the configuration of the varistor element unit 10 will be described. The varistor element section 10 includes a plurality of varistor green sheets A2 and A3 on which hot electrodes B1 and ground electrodes B2 which are so-called internal electrodes and lead-out sections B1a and B2a are formed (four sheets in the first embodiment). ) Varistor green sheets A1 to A4 are laminated. The hot electrode B1 is a varistor electrode for signals, and the ground electrode B2 is a varistor electrode for grounding.

  The actual composite multilayer electronic component 100 is integrated to such an extent that the boundaries between the varistor green sheets A1 to A4 cannot be visually recognized. The varistor green sheets A1 to A4 function as a varistor layer by firing.

The varistor green sheets A1 to A4 are formed, for example, by applying a slurry using a mixed powder of ZnO, Co ₃ O ₄ , Pr ₆ O ₁₁ , CaCO ₃ , and SiO ₂ as a raw material on a film by a doctor blade method. . Due to the composition of the varistor green sheets A1 to A4, voltage non-linearity in which the resistance value changes non-linearly with respect to the applied voltage appears. The thickness of the varistor green sheets A1 to A4 is, for example, about 30 μm. The composition of the varistor green sheets A1 to A4 will be described in detail later.

  The relationship between the varistor green sheet and the electrode will be described in further detail. A hot electrode B1 and a lead-out portion B1a are formed on the surface of the varistor green sheet A2, and the hot electrode B1 has a substantially rectangular shape that is slightly smaller than the varistor green sheet A2. The hot electrode B1 is integrally formed with a lead-out portion B1a at the center of one short side. The lead-out part B1a of the hot electrode B1 has a substantially rectangular shape, is drawn to the edge of the varistor green sheet A2, and its end is exposed at the end face of the varistor green sheet A2. For this reason, the lead-out part B1a of the hot electrode B1 is electrically connected to the input terminal 3.

  A ground electrode B2 and a lead-out portion B2a are formed on the surface of the varistor green sheet A3. The ground electrode B2 has a substantially rectangular shape that is slightly smaller than the varistor green sheet A3. In the ground electrode B2, a pair of lead-out portions B2a are integrally formed at the center of both short sides. The lead-out part B2a of the ground electrode B2 has a substantially rectangular shape, is drawn out to the edge of the varistor green sheet A3, and its end is exposed at the end face of the varistor green sheet A3. For this reason, the lead-out part B2a of the ground electrode B2 is connected to each ground terminal 7 respectively.

  As described above, the varistor green sheets A1 to A4 are laminated, and the varistor V is configured by sandwiching the varistor green sheet A2 between the hot electrode B1 and the ground electrode B2. The hot electrode B1, the ground electrode B2, and the lead-out portions B1a and B2a are formed, for example, by screen-printing a paste mainly composed of Pd on the varistor green sheets A2 and A3. The thicknesses of the hot electrode B1, the ground electrode B2, and the lead-out portions B1a and B2a are set to about 5 μm, for example.

[Description of Inductor Element 20]
Next, one configuration example of the inductor element unit 20 will be described. The inductor element portion 20 includes a plurality (seven in this first embodiment) of inductor element portions having a ferrite layer and an inner conductor, and inductor green sheets A6 to A11 including conductor patterns B3 to B13 which are inner conductors. Inductor green sheets (ferrite layers) A5 to A12 are laminated.

  The actual composite multilayer electronic component 100 is integrated to such an extent that the boundary between the inductor green sheets A5 to A12 cannot be visually recognized. The inductor green sheets A5 to A12 function as an insulating layer when fired.

  The inductor green sheets A5 to A12 are insulators having electrical insulation.

  The inductor green sheets A5 to A12 in the present invention are formed by applying a slurry of non-magnetic or magnetic ferrite as a raw material on a film by a doctor blade method. The thickness of the inductor green sheets A5 to A12 is, for example, about 20 μm.

  On the surface of the inductor green sheet A6, the conductor patterns B3 and B8 are juxtaposed in the longitudinal direction of the inductor green sheet A6 with a predetermined interval therebetween. The conductor patterns B3 and B8 are electrically insulated from each other. Each of the conductor patterns B3 and B8 corresponds to approximately 1/2 turn of coil formation, and is formed in an approximately L shape. Derived portions B3a and B8a are integrally formed at one end of each conductor pattern B3 and B8. The lead-out portions B3a and B8a of the conductor patterns B3 and B8 are respectively drawn out to the edge of the inductor green sheet A6, and the respective end portions are exposed at the end face of the inductor green sheet A6. For this reason, the lead-out part B3a is electrically connected to the input terminal 3, and the lead-out part B8a is electrically connected to the output terminal 5.

  The other end of each conductor pattern B3, B8 is electrically connected to through-hole electrodes C1, C6 formed through the inductor green sheet A6 in the thickness direction. Therefore, each conductor pattern B3, B8 is electrically connected to one end of each corresponding conductor pattern B4, B9 via the through-hole electrodes C1, C6 in a state where the multilayer body 1 is laminated.

  On the surface of the inductor green sheet A7, the conductor patterns B4 and B9 are juxtaposed in the longitudinal direction of the inductor green sheet A7 with a predetermined distance therebetween. The conductor patterns B4 and B9 are electrically insulated from each other. Each of the conductor patterns B4 and B9 corresponds to approximately ¾ turn of coil formation, and is formed in a substantially U shape.

  One end of each conductor pattern B4, B9 includes a region electrically connected to each through-hole electrode C1, C6 in a state where the multilayer body 1 is laminated. The other end of each conductor pattern B4, B9 is electrically connected to each through-hole electrode C2, C7 formed through the inductor green sheet A7 in the thickness direction. Therefore, each conductor pattern B4, B9 is electrically connected to one end of each corresponding conductor pattern B5, B10 via each through-hole electrode C2, C7 in a state where the multilayer body 1 is laminated.

  On the surface of the inductor green sheet A8, the conductor patterns B5 and B10 are juxtaposed in the longitudinal direction of the inductor green sheet A8 with a predetermined distance therebetween. The conductor patterns B5 and B10 are electrically insulated from each other. Each of the conductor patterns B5 and B10 corresponds to approximately 3/4 turns of coil formation, and is formed in a substantially C shape. One end of each of the conductor patterns B5 and B10 includes a region electrically connected to each of the through-hole electrodes C2 and C7 in a state where the multilayer body 1 is laminated. The other end of each conductor pattern B5, B10 is electrically connected to each through-hole electrode C3, C8 formed through the inductor green sheet A8 in the thickness direction. Therefore, each conductor pattern B5, B10 is electrically connected to one end of each corresponding conductor pattern B6, B11 via each through-hole electrode C3, C8 in a state where the multilayer body 1 is laminated.

  On the surface of the inductor green sheet A9, the conductor patterns B6 and B11 are juxtaposed in the longitudinal direction of the inductor green sheet A9 with a predetermined distance therebetween. The conductor patterns B6 and B11 are electrically insulated from each other. Each of the conductor patterns B6 and B11 corresponds to approximately 3/4 turns of coil formation, and is formed in a substantially U shape. One end of each of the conductor patterns B6 and B11 includes a region electrically connected to each of the through-hole electrodes C3 and C8 in a state where the multilayer body 1 is laminated. The other end of each conductor pattern B6, B11 is electrically connected to each through-hole electrode C4, C9 formed through the inductor green sheet A9 in the thickness direction. Therefore, each conductor pattern B6, B11 is electrically connected to one end of each corresponding conductor pattern B7, B12 via each through-hole electrode C4, C9 in a state where the multilayer body 1 is laminated.

  On the surface of the inductor green sheet A10, the conductor patterns B7 and B12 are juxtaposed in the longitudinal direction of the inductor green sheet A10 with a predetermined interval therebetween. The conductor patterns B7 and B12 are electrically insulated from each other. Each of the conductor patterns B7 and B12 corresponds to approximately 1/2 turn of coil formation, and is formed in a substantially C shape. One end of each of the conductor patterns B7 and B12 includes a region electrically connected to each of the through-hole electrodes C4 and C9 in a state where the multilayer body 1 is laminated. The other end of each conductor pattern B7, B12 is electrically connected to each through-hole electrode C5, C10 formed through the inductor green sheet A10 in the thickness direction. For this reason, each conductor pattern B7, B12 is each electrically connected with each edge part of the corresponding conductor pattern B13 via each through-hole electrode C5, C10 in the state which the laminated body 1 was laminated | stacked.

  As described above, the inductor green sheets A5 to A11 are laminated, and the conductor patterns B3 to B7 are electrically connected to each other through the through-hole electrodes C1 to C4, thereby forming one coil. Will be. Moreover, another coil is comprised by each conductor pattern B8-B12 being mutually electrically connected via each through-hole electrode C6-C9.

  On the surface of the inductor green sheet A11, a conductor pattern B13 extends in the longitudinal direction of the inductor green sheet A11 and is formed in a substantially I shape. The positions corresponding to both ends of the conductor pattern B13 include regions that are electrically connected to the through-hole electrodes C5 and C10 in a state where the multilayer body 1 is laminated. Thereby, two coils are electrically connected in series.

  The conductor patterns B3 to B13 and the through-hole electrodes C1 to C11 are formed, for example, by screen-printing a paste mainly containing Pd on the inductor green sheets A6 to A11. The thickness of the conductor patterns B3 to B13 is, for example, about 14 μm.

[ Explanation of bonding interlayer ]
Between the varistor element portion 10 and the inductor element portion 20, a bonding intermediate layer 50 for bonding these element portions is interposed.

  The junction intermediate layer 50 can be composed of one layer as the simplest form, but is preferably a laminate structure (N = 2 to 6 layers, more preferably N = 3 to 5 layers) in FIG. The case of N = 3 is illustrated). In the case of a multilayer having a number N of 2 or more, each layer is set so as to satisfy the claims of the present invention.

  Although there is no particular limitation on the upper limit of N, the number of composition components of the bonding film that must be prepared increases as N increases.

  The bonding intermediate layer 50 includes ferrite and ZnO as main components and at least one selected from the group of magnesium oxide, calcium oxide, strontium oxide, and barium oxide as additive components. And the total amount of the said addition component is 2-10 wt% with respect to ZnO which is a main component, Preferably, 3-5 wt% is contained.

  If this value is less than 2 wt%, there is a tendency that a desired high resistivity cannot be obtained, and if this value exceeds 10 wt%, the thermal expansion coefficient of the intermediate material increases. There is a tendency that the difference in coefficient of thermal expansion with the varistor part becomes too large.

  In addition, when calculating | requiring the total content (wt%) of an addition component, magnesium oxide is converted by MgO, calcium oxide is converted by CaO, strontium oxide is converted by SrO, and barium oxide is converted by BaO.

  The content ratio of ferrite and ZnO contained as main components in the joining intermediate layer is 5:95 to 95: 5 Vol (volume)%, preferably 15:85 to 85:15 Vol (volume)%, more preferably. 25:75 to 75:25 Vol (volume)%.

  The bonding intermediate layer 50 in the present invention can be composed of one layer. However, as described above, the bonding intermediate layer 50 can be formed by laminating the first to Nth bonding films having different compositions. Desirable (in the example of FIG. 2, three bonding layers A20 to A22 are illustrated). Moreover, it is desirable to set the linear expansion coefficient at the bonding interface as described below for the N-layer bonding film constituting the bonding intermediate layer 50 in the present invention.

  That is, the difference in linear expansion coefficient between the ferrite layer forming the main part of the so-called substrate of the inductor element 20 and the first bonding film in contact with the ferrite layer is within 1 (ppm / K) (particularly preferably 0). .6 (ppm / K) or less, and the difference in linear expansion coefficient between adjacent bonding films constituting the other N-1 bonding interfaces is within 2 (ppm / K) (particularly preferable). Is within 1 (ppm / K)), and the difference in linear expansion coefficient between the varistor layer forming the main part of the base of the varistor element portion 10 and the Nth bonding film in contact therewith is 2 (ppm / It is desirable that the composition be within a range of K) (particularly, preferably within 1 (ppm / K)). When the difference in the desired linear expansion coefficient defined in this way cannot be obtained, the junction intermediate layer 50 is thinned, and the inductor element portion 20 and the varistor element portion 10 are securely joined without cracking. This tends to make it difficult to integrate.

  For this reason, when the junction intermediate layer is composed of two or more laminated structures, the layer closer to the inductor element portion may be set so that the content of ferrite as a main component is higher. desirable. In other words, it is desirable that the layer closer to the varistor element portion is set to have a higher content of ZnO as the main component.

  Further, it is desirable that the thickness of the joining intermediate layer is as thin as possible in order to make the composite integrated sintered product compact, and the thickness is 90 to 400 μm, preferably 120 to 270 μm.

[ Description of the composition of the ferrite layer of the inductor element ]
The ferrite layer of the inductor element portion of the present invention is made of, for example, Ni—Zn magnetic ferrite or nonmagnetic Zn ferrite.

The Ni-Zn-based magnetic ferrite, for example, 40 to 50 mol% in terms of iron oxide Fe ₂ O _3, 10 to 50 mol% of nickel oxide in terms of NiO, zinc oxide 1 to 35 mole% calculated as ZnO What is contained is illustrated. Such a Ni—Zn-based ferrite may have a composition in which a part of Zn or Fe is substituted with at least one of Cu, Mg, and Mn. Furthermore, as an additive component, SiO ₂ , CaCO ₃ , ZrO ₂ , SnO ₂ , TiO ₂ , MoO ₃ , Bi ₂ O ₃ , WO ₃ , CoO and the like may be contained in an amount of about 1 wt%.

Examples of the nonmagnetic Zn-based ferrite include those in which iron oxide is contained in an amount of 40 to 50 mol% in terms of Fe ₂ O ₃ and zinc oxide is contained in a remaining mol% in terms of ZnO. Such a non-magnetic Zn-based ferrite may have a composition in which a part of Zn or Fe is substituted with at least one of Ni, Mg, Mn, and Cu. In this case, the substitution of Ni, Mg, Mn and Cu is usually within 10 mol%. Furthermore, as an additive component, SiO ₂ , CaCO ₃ , ZrO ₂ , SnO ₂ , TiO ₂ , MoO ₃ , Bi ₂ O ₃ , WO ₃ , CoO and the like may be contained in an amount of about 1 wt%.

[ Description of the composition of the varistor layer of the varistor element ]
The varistor layer contains 95 mol% or more, particularly 95 to 98 mol%, of ZnO as the main component. Furthermore, Co, Pr, etc. are contained as subcomponents.

  Next, a method for manufacturing the composite multilayer electronic component 100 shown in FIGS. 1 and 2 will be described. First, varistor green sheets A1 to A4, inductor green sheets A5 to A12, and bonding film green sheets A20 to A22 as bonding intermediate layers are prepared.

  Next, through holes are formed by laser processing or the like at predetermined positions of the inductor green sheets A6 to A11, that is, positions where the through hole electrodes C1 to C10 are to be formed.

  Next, the hot electrode B1, the ground electrode B2, and the lead-out portions B1a and B2a are formed on the varistor green sheets A2 and A3, respectively. Conductor patterns B3 to B13 and lead-out portions B3a and B8a are formed on the inductor green sheets A6 to A11, respectively. Further, the through-hole electrodes C1 to C10 are formed.

  Next, the varistor green sheets A1 to A4, the inductor green sheets A5 to A12, and the bonding film green sheets A20 to A22 as bonding intermediate layers are laminated in the order shown in FIG. Then, after cutting into chips, firing is performed at a predetermined temperature (for example, 1100 to 1200 ° C.).

  Thereby, it integrates to such an extent that the boundary between each green sheet cannot be visually recognized, and the laminated body 1 will be formed.

  Next, the input terminal 3, the output terminal 5, and the ground terminal 7 are formed on the laminate 1. Thereby, the multilayer electronic component E1 is formed. The input terminal 3, the output terminal 5 and the ground terminal 7 are baked at a predetermined temperature (for example, 600 to 700 ° C.) after transferring the electrode paste mainly composed of silver to the side surfaces 9a to 9d of the laminate 1, respectively. It is formed by applying electroplating. For electroplating, Ni and Sn, Cu and Ni and Sn, Ni and Au, Ni and Pd and Au, Ni and Pb and Ag, Ni and Ag, or the like can be used.

Hereinafter, the present invention will be described in more detail with reference to specific examples of the present invention.
[ Experiment 1 ]

[Preparation of Ni-Zn magnetic ferrite layer forming material for inductor elements]
Weighing was performed so that Fe ₂ O ₃ was 49 mol%, NiO was 36 mol%, and ZnO was 15 mol%. Pure water was added to this weighed product and mixed with a ball mill for 24 hours to form a slurry.

The slurry was filtered, dried and granulated, and calcined at 900 ° C. for 2 hours.
Next, pure water was added to the calcined product and further pulverized.

  Next, the obtained fine powder was filtered and dried, and then dispersed in a solvent together with an organic binder to form a slurry.

  Thereafter, a ferrite sheet having a thickness of 20 μm was produced from this slurry by a doctor blade method.

[Production of varistor layer forming material for varistor element]
Main component ZnO is 97 mol% is, Co ₃ O ₄ is 1 mol%, Pr ₆ O ₁₁ is 1 mol%, so that CaCO ₃ is 0.5 mol%, and SiO ₂ is 0.5 mol% Weighed. This weighed product was dispersed in a solvent together with an organic binder to form a slurry.

  Thereafter, a green sheet for a varistor having a thickness of 30 μm was produced from this slurry by a doctor blade method.

[Preparation of bonding film constituting bonding intermediate layer]
In order to determine the specifications of the bonding intermediate layer, first, an intermediate material test sample for confirming the physical properties of the bonding intermediate layer itself was prepared in the following manner. In other words, the inter-terminal resistance in the composite multilayer electronic component is the same value as the resistivity of the intermediate material with the lowest resistivity among the used intermediate materials (joining intermediate layer), and the amount of ferrite is increased. Therefore, the basic material was an intermediate material of ZnO / ferrite = 75/25 Vol (volume)% with a small amount of ferrite that could be a problem. Then, various samples were prepared by adding the additive components used in the present invention to the basic composition in the amounts shown in Table 1 below (addition amount with respect to ZnO).

  The intermediate material test sample was formed by stacking 30 μm thick sheets to a thickness of about 1 mm, and the sheet size was 10 mm × 5 mm. In such an intermediate material test sample, the internal conductor was not embedded, but only the terminal electrodes were installed at both ends, and the resistance between the terminals of the sample was measured by the capacitance method. The results are shown in Table 1 below.

  Next, as shown in Table 2 below, three types of bonding films (differentiated by C ** etc.) having different blending compositions were prepared in order to produce various bonding intermediate layers (three-layer laminates). That is, the composition constituting the ferrite layer (indicated as “ferrite” in Table 2) and ZnO which is the main component of the varistor layer are blended in three ratios as shown in Table 2. In addition, a predetermined amount of a predetermined additive component was added to prepare three types of bonding film green sheets. The thickness of each bonding film green sheet was 30 μm.

  Using a bonding intermediate layer formed by laminating three bonding films, a bonding experiment of a ferrite layer and a varistor layer was performed.

  That is, 18 ferrite layers having a thickness of 20 μm composed of the above composition, 10 bonding intermediate layers shown in Table 2, and 10 varistor layers having a thickness of 30 μm composed of the above composition were laminated, and a pressure of 100 MPa was applied in the laminating direction. To form a laminate. Next, this laminate was cut into a predetermined size, and then fired at 1150 ° C. for 1 hour to prepare a sintered body sample. The internal electrodes and internal conductors are formed by applying a predetermined conductor paste in advance before forming the laminate, and the external electrodes are applied with the predetermined conductor paste after forming the laminate. Was formed.

  With respect to the composite multilayer electronic component formed in this way, when the insulation resistance between the two terminals was measured by the capacitance method, there was no problem with the insulation between the two elements. In addition, no problem occurred with respect to the bonding between the elements.

[ Experimental example 2 ]
The material for forming the Ni—Zn-based magnetic ferrite layer of the inductor element portion in Experimental Example 1 was changed to the following Zn ferrite.

That, Fe ₂ O ₃ is 49 mol%, ZnO was weighed so that 51 mol%. Other than that, a Zn ferrite layer was prepared in the same manner as in Experimental Example 1, and the same experiment as in Experimental Example 1 was performed. As a result, there was no problem with the insulation between the two elements. In addition, no problem occurred with respect to the bonding between the elements.

[ Experiment 3 ]
The material for forming the Ni—Zn-based magnetic ferrite layer of the inductor element portion in Experimental Example 1 was changed to the following Zn ferrite.

Weighing was performed so that Fe ₂ O ₃ was 48 mol%, ZnO was 51 mol%, and Mn ₂ O ₃ was 1 mol%. Other than that, a Zn ferrite layer was prepared in the same manner as in Experimental Example 1, and the same experiment as in Experimental Example 1 was performed. As a result, there was no problem with the insulation between the two elements. In addition, no problem occurred with respect to the bonding between the elements.

[ Experimental Example 4 ]
Sample No. in Table 2 above. The bonding intermediate layer (3-layer laminate) of II-1 was changed to the bonding intermediate layer of the following 5-layer laminate.

C'11: ferrite 90 mol%, ZnO-10 mol%, MgO-2 wt%
C'12: Ferrite 70 mol%, ZnO-30 mol%, MgO-2wt%
C'13: Ferrite 50 mol%, ZnO-50 mol%, MgO-2wt%
C'14: Ferrite 30 mol%, ZnO-70 mol%, MgO-2wt%
C'15: ferrite 10 mol%, ZnO-90 mol%, MgO-2 wt%

  Other than that, the same experiment as in the experimental example 1 was performed in the same manner as in the experimental example 1. As a result, the sample Nos. Shown in Table 2 above were obtained. It was confirmed that the same experimental results as II-1 were obtained.

  The composite multilayer electronic component of the present invention can be widely used in various electric component industries.

FIG. 1 is a perspective view showing a composite laminated electronic component. FIG. 2 is an exploded perspective view of a laminated body for easy understanding of the laminated structure of the composite laminated electronic component. FIG. 3 is a cross-sectional view for explaining a specific bonding state where the number N of bonding films constituting the bonding intermediate layer is three.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Laminated body 10 ... Varistor element part 20 ... Inductor element part 50 ... Junction intermediate | middle layer 100 ... Composite laminated type electronic component

Claims (8)

A varistor element part having a varistor layer and an internal electrode, an inductor element part having a ferrite layer and an internal conductor, and a joining intermediate layer interposed to join both of these element parts,
The ferrite layer to be joined is made of ferrite,
The varistor layer is mainly composed of ZnO,
The bonding intermediate layer includes the ferrite and the ZnO as main components, and includes at least one selected from the group of magnesium oxide, calcium oxide, strontium oxide, and barium oxide as an additive component,
The joining intermediate layer, wherein the total amount of the additive components is 2 to 10 wt% with respect to ZnO in the main component in terms of MgO, CaO, SrO, and BaO.   The joining intermediate layer according to claim 1 whose content ratio of said ferrite and said ZnO is 5: 95-95: 5Vol (volume)%.   The joining intermediate layer according to claim 1 or 2 whose thickness is 90-400 micrometers. A composite multilayer electronic component having a varistor element portion having a varistor layer and an internal electrode, an inductor element portion having a ferrite layer and an internal conductor, and a joining intermediate layer interposed to join both of the element portions. There,
The ferrite layer is made of ferrite,
The varistor layer is mainly composed of ZnO,
The bonding intermediate layer includes the ferrite and the ZnO as main components, and includes at least one selected from the group of magnesium oxide, calcium oxide, strontium oxide, and barium oxide as an additive component,
A composite multilayer electronic component, wherein the total amount of the additive components is 2 to 10 wt% with respect to ZnO in the main component in terms of MgO, CaO, SrO, and BaO.   5. The composite multilayer electronic component according to claim 4, wherein a content ratio of the ferrite and ZnO contained as main components in the joining intermediate layer is 5:95 to 95: 5 Vol (volume)%.   The said joining intermediate | middle layer consists of a laminated body structure of N = 2-6 layers, and is set so that the content rate of the said ferrite may become high, so that the layer which exists in the position which approaches an inductor element part. 5. A composite multilayer electronic component according to 5.   The composite laminated electronic component according to claim 4, wherein the bonding intermediate layer has a thickness of 90 to 400 μm.   8. The composite multilayer electronic component according to claim 4, wherein the varistor layer contains 95 to 98 mol% of ZnO as a main component thereof. 9.

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