JP3822714B2 - CR composite electronic component and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a CR composite electronic component in which a resistance or impedance element is added to a multilayer capacitor having a nonmagnetic ceramic dielectric layer.
[0002]
[Prior art]
Currently, switching power supplies and DC-DC converters are used in many power supplies of electronic devices. There is a power supply bypass capacitor as a capacitor used for these power supplies. As the power supply bypass capacitor, a low-capacity multilayer ceramic capacitor and an electrolytic capacitor such as high-capacity aluminum or tantalum have been used according to the power supply capacity, switching frequency, and circuit parameters such as a smoothing coil used together. By the way, the electrolytic capacitor can easily obtain a large capacity, and has an excellent surface as a bypass capacitor for power supply (smoothing), but it is large, inferior in low-temperature characteristics, may cause a short circuit accident, and has an internal impedance. Therefore, there is a problem that loss due to equivalent series resistance (ESR) is steadily generated, heat is generated, and frequency characteristics are poor and smoothness is deteriorated. In recent years, due to technological innovation, the capacitance of multilayer ceramic capacitors is approaching the capacitance of electrolytic capacitors as the dielectric and internal electrodes of multilayer ceramic capacitors are made thinner and the technology for layering advances. For this reason, various attempts have been made to replace electrolytic capacitors with multilayer ceramic capacitors.
[0003]
In a capacitor for bypassing a power supply, ripple noise is important as a factor showing a smoothing action. The degree to which the ripple noise is suppressed is determined by the equivalent series resistance (ESR) of the capacitor. Here, if the ripple voltage is ΔVr, the current flowing through the choke coil is Δi, and the equivalent series resistance is ESR,
ΔVr = Δi × ESR
It can be seen that the ripple voltage is suppressed by lowering the ESR. Therefore, in the power supply bypass circuit, it is preferable to use a capacitor having a low ESR, and attempts have been made to use a multilayer ceramic capacitor having a low ESR for the power supply circuit.
[0004]
However, in a secondary circuit such as a DC-DC converter having a feedback circuit or a switching power supply, the ESR of the smoothing circuit greatly affects the phase characteristics of the feedback loop, and may cause a problem particularly when the ESR becomes extremely low. . That is, when a multilayer ceramic capacitor having a low ESR is used as the smoothing capacitor, the secondary side smoothing circuit is equivalently composed of only the L and C components, and the phase components existing in the circuit are ± 90 ° and 0 It becomes only °, and it oscillates easily with no phase margin. A similar phenomenon appears as an oscillation phenomenon when the load fluctuates even in a power supply circuit using a three-terminal regulator.
[0005]
For this reason, various so-called CR composite electronic components in which a resistance component is added to the multilayer ceramic capacitor have been proposed. For example, Japanese Patent Application Laid-Open No. 8-45784 describes a composite electronic component in which an end portion of a multilayer ceramic capacitor is made into a semiconductor using a carbide and a reducing agent. However, the manufacturing method is such that the external electrode paste is applied to the multilayer ceramic capacitor element body, temporarily calcined in a reducing atmosphere, carbonized to leave the binder, and further baked at 700 to 750 ° C. The carbide is made to act as a reducing agent to make a semiconductor. The resistance value is controlled by the amount of reducing agent. However, in this method, the process of making a semiconductor is complicated, and if the process of forming the terminal electrode is included, heat treatment is required three times, the productivity is lowered, and the energy cost is increased. Moreover, since the resistance value is controlled by the amount of reducing agent, it is difficult to obtain the desired value accurately, circuit design becomes difficult, and there are many variations between products, resulting in mass production. Yield is also bad.
[0006]
Also, for example, as described in JP-A-59-225509, a resistor paste such as ruthenium oxide is further laminated on a multilayer ceramic capacitor, and this is simultaneously fired to obtain a resistor. It has been. However, in this case, when the terminal electrode is provided as it is, the equivalent circuit becomes a parallel circuit of C / R or (LC) / R, and a series circuit cannot be obtained. Further, in order to obtain a series circuit, the shape of the terminal electrode becomes complicated, and the manufacturing process becomes complicated.
[0007]
Japanese Patent No. 2578264 describes a CR composite component in which a metal oxide film is provided on the surface of an external electrode to obtain a desired equivalent series resistance. However, the CR composite part described in the embodiment of the publication discloses a metal oxide film formed by heat-treating a nickel terminal electrode, and the thickness of the metal oxide film is adjusted by barrel polishing. It is done by adjusting. For this reason, it is difficult to obtain a desired resistance value, and the adjustment of the resistance value is complicated and inferior in mass productivity. Further, a nickel layer is further provided on the formed metal oxide film by electroless plating. However, in this method, it is necessary to provide a mask so that plating does not adhere to portions other than the terminal portion, and the manufacturing process increases. Further, the adhesion between the nickel plating and the metal oxide film which is attached is poor, and when a lead wire is provided on the nickel plating, the lead wire is easily peeled off.
[0008]
Although there is a method of connecting a resistor in series with the smoothing capacitor, the cost is high and it is not practical.
[0009]
[Problems to be solved by the invention]
The object of the present invention is that no special firing conditions are required, firing can be performed under the same conditions as ordinary multilayer ceramic capacitors, the manufacturing process is simple, the production cost is low, and CR or (L / C) R. It is an object of the present invention to provide a CR composite electronic component in which a series circuit can be easily obtained, the resistance value can be easily controlled, and the lead wire has a strong adhesive strength and a method for manufacturing the CR composite electronic component.
[0010]
[Means for Solving the Problems]
The above object is achieved by the following configurations (1) to (10).
(1) Dielectric layers and internal electrodes are laminated alternately,
The internal electrode and the first electrode layer formed at the end of the CR composite electronic component are connected,
A second electrode layer and a third electrode layer on at least one terminal side of the first electrode layer;
The internal electrode layer is connected to the outside through the first to third electrode layers,
A CR composite electronic component in which the second electrode layer contains nickel and phosphorus.
(2) The CR composite electronic component according to (1), wherein the second electrode layer contains 0.01 to 15 wt% of phosphorus in terms of P.
(3) The CR according to (1) or (2) above, further containing 0.01 to 10 wt% in total of one or more of B, Si, V, Fe, Co, Zn, Mo, Sn, Te and W as subcomponents Composite electronic components.
(4) The CR composite electronic component according to any one of (1) to (3), wherein the first electrode layer includes copper, nickel, or an alloy thereof.
(5) The CR electronic composite component according to any one of (1) to (4), wherein the third electrode layer includes tin or a tin-lead alloy.
(6) The CR composite electronic component according to any one of (1) to (5), wherein the resistance value is adjusted by adjusting a shortest separation distance between the first terminal electrode and the third terminal electrode.
(7) The CR composite electronic component according to any one of (1) to (6), wherein the equivalent circuit includes a CR or (LC) R series circuit.
(8) The CR composite electronic component according to any one of (1) to (7), wherein the internal electrode contains nickel.
(9) Forming a green chip by alternately laminating dielectric layers and internal electrode layers,
This is fired into a chip body,
After forming the first terminal electrode on the chip body in a reducing atmosphere,
Forming a second terminal electrode on at least one of the first terminal electrodes by electroless plating;
Furthermore, the manufacturing method of CR composite electronic component which forms a 3rd terminal electrode in a 2nd terminal electrode.
(10) The method for producing a CR composite electronic component according to (9), wherein the internal electrode layer contains nickel.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
In the CR composite electronic component of the present invention, dielectric layers and internal electrodes are alternately laminated, and the internal electrode and the first electrode layer formed at the end of the CR composite electronic component are connected, A second electrode layer and a third electrode layer are provided on at least one terminal side of the first electrode layer, and the internal electrode layer is connected to the outside through the first to third electrode layers. The second electrode layer is an alloy of nickel and phosphorus. By forming the second electrode layer from an alloy obtained by adding phosphorus to nickel, a resistance layer having a relatively high resistance value is formed on the terminal electrode, and a CR composite electronic component in which an equivalent circuit is a series connection of C and R; can do.
[0012]
That is, a second electrode layer of a nickel-phosphorus alloy layer having a predetermined resistance value is interposed between the first electrode layer and the third electrode layer, which are conductors, so that the capacitor is easily connected in series. It is possible to provide a CR composite part having a resistance component. The composition ratio of nickel and phosphorus in the second electrode layer is preferably in the range of 0.01 to 15 wt%, more preferably 8 to 15 wt%, especially 10 to 15 wt% in terms of phosphorus. If the amount of phosphorus added is too small, it will be difficult to obtain the desired resistance, and if the amount of phosphorus added exceeds 15 wt%, it will be difficult to form a solid solution with nickel.
[0013]
Further, it preferably contains at least one of B, Si, V, Fe, Co, Zn, Mo, Sn, Te and W as subcomponents in a total amount of 0.01 to 10 wt%, more preferably 0.1 to 5 wt%. It may be. By adding these elements, the resistance value becomes larger than that of the nickel-phosphorus alloy. The mixing ratio when using two or more of these elements is arbitrary.
[0014]
The second electrode layer may be provided on either one of the electrodes or on both. In addition, the resistance value in the second electrode layer is proportional to the shortest distance between the first electrode layer and the third electrode layer via the second electrode layer, that is, the minimum thickness of the second electrode layer. In addition, when the 2nd electrode layer is provided in both electrodes, the resistance value becomes the sum total of the resistance value of the 2nd electrode layer in each electrode. The resistance value of the second electrode layer may be appropriately adjusted to a necessary resistance value depending on the circuit to be used, the capacitance of the capacitor, etc., and is not particularly limited. However, the equivalent series resistance (ESR) is preferably It is about 1 m to 2Ω, more preferably about 10 to 100 mΩ.
[0015]
Examples of the method for forming the second electrode layer include wet plating, vapor deposition, thermal spraying, sputtering, and the like, but wet plating, particularly electroless plating is preferable. The use of electroless plating is preferable because the film thickness of the second electrode layer, that is, the resistance value can be easily controlled by the time of immersion in the plating bath. The formed second electrode layer has good adhesion to the first electrode layer and the third electrode layer, and when a lead wire is provided on the third electrode layer, a strong adhesive strength can be obtained. . As the electroless plating bath, a hypophosphite system is preferable,
Nickel sulfate 10-30 g / liter
Lactic acid 15-35g / liter
Propionic acid 1-5g / liter
Sodium hypophosphite 10-35 g / liter
The composition of the range of this is preferable, and 3-5 are preferable for pH. The time to be immersed in the electroless plating bath layer varies depending on the required film thickness of the second electrode layer and the like, but usually ranges from 0.1 to 1 hour, particularly from 0.2 to 0.5 hour. preferable. The temperature of the plating bath is usually about 80 to 95 ° C.
[0016]
The constituent material of the first electrode layer is not particularly limited, but a low resistivity metal is preferable, and examples thereof include copper, nickel, and alloys thereof, preferably copper, nickel, and alloys thereof. It is. The first electrode layer is made of copper, nickel, or an alloy thereof, and the second electrode layer is formed by electroless plating, so that the second electrode layer is formed only on the first electrode layer without providing a special mask. An electrode layer is preferably formed. The thickness of the first electrode layer is not particularly limited, but is preferably in the range of 10 to 100 μm, particularly 20 to 70 μm.
[0017]
In order to provide the first electrode layer, a paste obtained by kneading the metal and the organic vehicle may be used. The electrode layer paste usually contains a glass frit, an organic binder, and a solvent for adjusting electric conductivity in addition to the metal material. The content of the metal material in the electrode layer paste is preferably in the range of about 50 to 80 wt%, more preferably about 65 to 75 wt%.
[0018]
The organic binder is not particularly limited, and may be appropriately selected from those generally used as a binder for ceramic materials. Examples of such an organic binder include ethyl cellulose, acrylic resin, butyral resin, and examples of the solvent include terpineol, terpineol, butyl carbitol, kerosene, and the like. The contents of the organic binder and the solvent in the paste are not particularly limited, and may be usually used amounts, for example, about 1 to 5 wt% of the organic binder and about 10 to 50 wt% of the solvent.
[0019]
Furthermore, the electrode layer paste may contain various dispersants as necessary. The total content of these is preferably 1 wt% or less. The method for providing the electrode layer paste on the dielectric chip is not particularly limited, but can be easily provided by, for example, a dipping method, a screen printing method, preferably a dipping method.
[0020]
The third electrode layer is provided on the first or second electrode layer. The third electrode layer improves solder wettability at the time of attaching the lead wire, reliably connects the second electrode layer and the lead wire, and covers the second electrode layer with a conductor. Therefore, the resistance value provided by the second electrode layer becomes stable. As a constituent material of the third electrode layer, a material having low resistivity and good solder wettability is preferable, and tin or tin-lead alloy solder is preferable. These may be provided in one layer or in two or more layers, and particularly preferably those provided with tin-lead alloy solder. The method for forming the third electrode layer is not particularly limited, but can be easily provided by a conventionally known wet plating method. The thickness of the third electrode layer is preferably about 1 to 10 μm.
[0021]
<Dielectric layer>
The dielectric material constituting the dielectric layer is not particularly limited, and various dielectric materials may be used. For example, titanium oxide-based, titanic acid-based composite oxide, or a mixture thereof may be used. Preferred titanium oxide systems include NiO, CuO, and Mn as required. _Three O _Four , Al ₂ O _Three , MgO, SiO ₂ TiO containing about 0.001 to 30 wt% in total ₂ As the titanate-based composite oxide, barium titanate BaTiO _Three Etc. The atomic ratio of Ba / Ti is preferably about 0.95 to 1.20, and BaTiO _Three Includes MgO, CaO, Mn _Three O _Four , Y ₂ O _Three , V ₂ O _Five , ZnO, ZrO ₂ , Nb ₂ O _Five , Cr ₂ O _Three , Fe ₂ O _Three , P ₂ O _Five , SrO, Na ₂ O, K ₂ O etc. may be contained about 0.001 to 30 wt% in total. In addition, (BaCa) SiO for adjusting the firing temperature and the linear expansion coefficient _Three Glass such as glass may be contained.
[0022]
The thickness per layer of the dielectric layer is not particularly limited, but is usually about 5 to 20 μm. Moreover, the number of laminated dielectric layers is usually about 2 to 300.
[0023]
<Internal electrode layer>
The conductive material contained in the internal electrode layer is not particularly limited, but it is preferable to use a material having a reduction resistance as the dielectric layer constituent material because an inexpensive base metal can be used. As the base metal used as the conductive material, Ni or Ni alloy is preferable. The Ni alloy is preferably an alloy of Ni and one or more elements selected from Mn, Cr, Co, Al, etc., and the Ni content in the alloy is preferably 95 wt% or more.
[0024]
In addition, in Ni or Ni alloy, various trace components, such as P, may be contained by about 0.1 wt% or less.
[0025]
The thickness of the internal electrode layer may be appropriately determined according to the application, etc., but it is usually preferably about 0.5 to 5 μm, particularly about 0.5 to 2.5 μm.
[0026]
Next, a method for manufacturing the CR composite electronic component of the present invention will be described.
[0027]
The CR composite electronic component of the present invention can be manufactured by producing a green chip by a normal printing method or a sheet method using a paste, printing or transferring a resistor paste on at least one end of the chip, and simultaneously firing it.
[0028]
<Dielectric layer paste>
The dielectric layer paste is manufactured by kneading a dielectric material and an organic vehicle.
[0029]
As the dielectric material, a powder corresponding to the composition of the dielectric layer is used. The method for producing the dielectric material is not particularly limited. For example, when barium titanate is used as the titanate-based composite oxide, BaTiO synthesized by a hydrothermal synthesis method or the like. _Three In addition, a method of mixing the subcomponent raw materials can be used. BaCO _Three And TiO ₂ A dry synthesis method may be used in which a mixture of the raw material and the auxiliary component raw material is calcined to cause a solid phase reaction, or a hydrothermal synthesis method may be used. Alternatively, a mixture of a precipitate obtained by a coprecipitation method, a sol-gel method, an alkali hydrolysis method, a precipitation mixing method, and the like and a subcomponent raw material may be calcined and synthesized. In addition, at least 1 sort (s), such as an oxide and various compounds which become an oxide by baking, for example, carbonate, an oxalate, nitrate, a hydroxide, an organic metal compound, etc., can be used for a subcomponent raw material.
[0030]
The average particle size of the dielectric material may be determined according to the average crystal particle size of the target dielectric layer, but usually a powder having an average particle size of about 0.3 to 1.0 μm is used.
[0031]
The organic vehicle is obtained by dissolving a binder in an organic solvent. The binder used for the organic vehicle is not particularly limited, and may be appropriately selected from various ordinary binders such as ethyl cellulose. Further, the organic solvent to be used is not particularly limited, and may be appropriately selected from various organic solvents such as terpineol, butyl carbitol, acetone, toluene, and the like, depending on a method to be used such as a printing method or a sheet method.
[0032]
<Internal electrode layer paste>
The internal electrode layer paste is prepared by kneading the above-described various conductive metals and alloys, or various oxides, organometallic compounds, resinates, and the like that become the above-described conductive material after firing and the above-described organic vehicle.
[0033]
<Paste for terminal electrode>
The terminal electrode paste may be prepared in the same manner as the above internal electrode layer paste.
[0034]
<Organic vehicle content>
There is no restriction | limiting in particular in content of the organic vehicle in each above-mentioned paste, For example, what is necessary is just about 1-5 weight% of binders, for example, about 10-50 weight% of binders. Each paste may contain an additive selected from various dispersants, plasticizers, dielectrics, insulators and the like as necessary. The total content of these is preferably 10% by weight or less.
[0035]
<Green chip production>
When using the printing method, the dielectric layer paste and the internal electrode layer paste are laminated and printed on a substrate such as PET. At this time, lamination is performed so that one of the end portions of the internal electrode paste is alternately exposed to the outside from the end portions of the dielectric layer paste. Thereafter, it is cut into a predetermined shape to form a chip, and peeled from the substrate to obtain a green chip.
[0036]
When the sheet method is used, a dielectric layer paste is used to form a green sheet, and the internal electrode layer paste is formed on the green sheet, and the end portions of the internal electrode paste are alternately formed on the dielectric layer paste. Laminates are printed so as to be exposed from one end, and cut into a predetermined shape to obtain a green chip.
[0037]
<Binder removal process>
The conditions of the binder removal treatment performed before firing may be normal, but when a base metal such as Ni or Ni alloy is used as the conductive material of the internal electrode layer, it is particularly preferably performed under the following conditions.
Temperature increase rate: 5 to 300 ° C./hour, especially 10 to 100 ° C./hour
Holding temperature: 200-400 ° C, especially 250-300 ° C
Temperature holding time: 0.5 to 24 hours, especially 5 to 20 hours
Atmosphere: in the air
[0038]
<Baking process>
The atmosphere at the time of firing the green chip may be appropriately determined according to the type of conductive material in the internal electrode layer paste, but when a base metal such as Ni or Ni alloy is used as the conductive material, the firing atmosphere is N ₂ As the main component and H ₂ H obtained by water vapor pressure at 1-10%, 10-35 ° C ₂ What mixed O gas is preferable. The oxygen partial pressure is 10 ^-8 -10 ^-12 It is preferable to set it to atmospheric pressure. When the oxygen partial pressure is less than the above range, the conductive material of the internal electrode layer may be abnormally sintered and may be interrupted. Further, when the oxygen partial pressure exceeds the above range, the internal electrode layer tends to be oxidized.
[0039]
The holding temperature during firing is preferably 1100 to 1400 ° C, particularly preferably 1200 to 1300 ° C. If the holding temperature is less than the above range, the densification is insufficient, and if it exceeds the above range, the internal electrodes are likely to be interrupted. The temperature holding time during firing is preferably 0.5 to 8 hours, particularly 1 to 3 hours.
[0040]
<Annealing process>
When firing in a reducing atmosphere, the CR composite electronic component chip body is preferably annealed. Annealing is a process for re-oxidizing the dielectric layer, which can significantly increase the IR accelerated lifetime.
[0041]
The oxygen partial pressure in the annealing atmosphere is 10 ^-6 Above atmospheric pressure, especially 10 ^-Five -10 ^-8 It is preferable to set it to atmospheric pressure. When the oxygen partial pressure is less than the above range, it is difficult to reoxidize the dielectric layer, and when it exceeds the above range, the internal electrode layer tends to be oxidized.
[0042]
The holding temperature at the time of annealing is preferably 1100 ° C. or lower, particularly 500 to 1000 ° C. If the holding temperature is less than the above range, the dielectric layer tends to be insufficiently oxidized and the lifetime tends to be shortened. If the holding temperature exceeds the above range, the internal electrode layer is oxidized and the capacity is reduced. It tends to react with the substrate and shorten its life. Note that the annealing step may be composed of only temperature rise and temperature drop. In this case, the temperature holding time is zero, and the holding temperature is synonymous with the maximum temperature. The temperature holding time is preferably 0 to 20 hours, particularly 2 to 10 hours. For atmosphere gas, humidified N ₂ It is preferable to use gas or the like.
[0043]
In each step of the above binder removal processing, firing and annealing, N ₂ And H ₂ For example, a wetter or the like may be used to wet the gas, O, mixed gas, and the like. In this case, the water temperature is preferably about 5 to 75 ° C.
[0044]
The binder removal process, the firing process, and the annealing process may be performed continuously or independently.
[0045]
When these are performed continuously, after removing the binder, the atmosphere is changed without cooling, and then the temperature is raised to the holding temperature for firing, followed by firing, and then cooled to reach the holding temperature in the annealing step. Sometimes it is preferable to perform annealing by changing the atmosphere.
[0046]
Moreover, when performing these independently, a binder removal process heats up to predetermined | prescribed holding | maintenance temperature, and after holding | maintaining for predetermined time, it falls to room temperature. The binder removal atmosphere at that time is the same as that performed continuously. Further, in the annealing step, the temperature is raised to a predetermined holding temperature, held for a predetermined time, and then lowered to room temperature. The annealing atmosphere at that time is the same as that in the case of continuous operation. Further, the binder removal step and the firing step may be performed continuously, and only the annealing step may be performed independently, or only the binder removal step may be performed independently, and the firing step and the annealing step performed continuously. You may do it.
[0047]
<First electrode layer formation>
The first electrode layer paste is printed or transferred to the chip body obtained as described above and fired to form terminal (external) electrodes. The firing condition of the external electrode paste is, for example, N ₂ And H ₂ In a reducing atmosphere such as a mixed gas, it is preferable to set the temperature at 600 to 800 ° C. for about 10 minutes to 1 hour.
[0048]
<Second electrode layer plating step>
The chip body on which the terminal electrode is formed is immersed in the second electrode layer plating bath to form a nickel-phosphorus alloy layer. In this case, it is not necessary to perform special masking or the like, and the first electrode layer is activated and a nickel-phosphorus alloy layer is formed only in that portion. The film formation conditions such as the film thickness and immersion time of the second electrode layer to be formed are as described above.
[0049]
<Third electrode layer plating step>
Further, the chip body on which the second electrode layer is formed is immersed in a third electrode layer plating bath to form a third electrode layer.
[0050]
A configuration example of the CR composite electronic component of the present invention manufactured as described above is shown in FIG. In FIG. 1, the CR composite electronic component of the present invention has a dielectric layer 2, an internal electrode layer 3, a first electrode layer 4, a second electrode layer 5, and a third electrode layer 6. . The second electrode layer 5 has a resistance value corresponding to the shortest distance from the first electrode layer 4 to the third electrode layer 6, d1 + d2. Here, FIG. 1 shows the case where the second electrode layer is formed on both terminals of the CR composite electronic component. However, the second electrode layer may be formed on only one of the terminals. The distance to the three electrode layers 6 is only one of d1 and d2.
[0051]
The CR composite electronic component of the present invention is provided with a lead wire as necessary, and is mounted on a printed circuit board by soldering or the like, and is used for various electronic devices such as a power supply device.
[0052]
【Example】
Next, an Example is shown and this invention is demonstrated more concretely.
[0053]
<Example 1>
BaCO as the main raw material for the dielectric layer _Three (Average particle size: 2.0 μm) and TiO ₂ (Average particle diameter: 2.0 μm) was prepared. The atomic ratio Ba / Ti is 1.00. In addition to this, BaTiO _Three As an additive to MnCO _Three 0.2 wt%, MgCO _Three 0.2wt%, Y ₂ O _Three 2.1 wt%, (BaCa) SiO _Three 2.2 wt% was prepared. Each raw material powder was mixed with an underwater ball mill and dried. The obtained mixed powder was calcined at 1250 ° C. for 2 hours. The calcined portion was pulverized with an underwater ball mill and dried. To the obtained calcined powder, an acrylic resin as an organic binder and methylene chloride and acetone as an organic solvent were added and further mixed to obtain a dielectric slurry. The obtained dielectric slurry was made into a dielectric green sheet using a doctor blade method.
[0054]
Prepare base metal Ni powder (average particle size: 0.8 μm) as internal electrode material, add ethyl cellulose as organic binder and terpineol as organic solvent, knead using 3 rolls, paste for internal electrode It was. Also, ZnO (average particle size: 0.5 μm) is prepared as a resistor paste raw material, and SiO 2 is used as a glass frit. ₂ 42wt%, B ₂ O _Three 17wt%, Al ₂ O _Three 6 wt%, CaO 10 wt%, ZnO 3 wt%, BaO 22 wt%, ethyl cellulose as an organic binder, and terpineol as an organic solvent were added and kneaded using three rolls to obtain a resistor paste.
[0055]
In order to obtain a predetermined thickness, several green sheets were laminated, and printed thereon by screen printing so that the ends of the internal electrode paste were alternately exposed from the ends of the dielectric layer paste. A predetermined number of green sheets are laminated, and finally, a predetermined number of green sheets on which no internal electrodes are printed are laminated, thermocompression-bonded, and the chip shape is 3.2 × 1.6 × 1 in length × width × thickness after firing. Cut to 0.0 mm to obtain a green chip.
[0056]
The obtained green chip was left to dry in the air at 80 ° C. for 30 minutes. Then humidified N ₂ + H ₂ (H ₂ 3%) N in a reducing atmosphere, kept at 1300 ° C. for 3 hours, calcined, and further humidified ₂ Oxygen partial pressure 10 ^-7 The chip body was obtained by holding at 1000 ° C. for 2 hours in an atmosphere of atmospheric pressure. A Cu terminal electrode paste was applied to the end of the obtained chip body, and N ₂ + H ₂ (H ₂ 4%) Holding at 770 ° C. for 10 minutes in a reducing atmosphere and firing to form a terminal electrode.
[0057]
Next, a second electrode layer made of a nickel-phosphorus alloy (P = 12 wt%) was immersed in an electrolytic bath having the following composition for 0.5 hour to form both electrodes of 5 μm.
Nickel sulfate 25g / liter
Lactic acid 30g / liter
Propionic acid 2.6g / liter
Sodium hypophosphite 25g / liter
[0058]
At this time, the pH was 4.5 and the temperature was 90 ° C. Furthermore, 3 μm of tin-lead alloy plating was formed to obtain a CR composite electronic component. The capacitance of the obtained sample was 1 μF.
[0059]
Similarly, samples containing no phosphorus in the second electrode layer were prepared, and the frequency-impedance characteristics of each sample were measured. The obtained results are shown in FIG.
[0060]
As can be seen from the figure, the use of an alloy of nickel and phosphorus for the second electrode layer increases the impedance and increases the equivalent series resistance.
[0061]
<Example 2>
A CR composite electronic component was fabricated in the same manner as in Example 1, except that the outer shape was 3225 and the thickness of the second electrode layer was 5 μm. The capacity of the obtained CR composite electronic component was measured and found to be 10 μF. The impedance measured at 6 MHz was 20 mΩ. When this CR composite electronic component is used as a bypass capacitor of a DC-DC converter and the switching frequency is changed from 100 kHz to 40 MHz, it operates normally without causing a voltage fluctuation phenomenon of the input voltage due to oscillation or the like. Was confirmed.
[0062]
<Example 3>
In Example 1, except that a sample in which 3 wt% each of B, Si, V, Fe, Co, Zn, Mo, Sn, Te, and W were added as subcomponents to the second electrode layer was used. When a CR composite electronic component was fabricated in the same manner as described above, almost the same result was obtained.
[0063]
<Example 4>
Samples obtained in the same manner as in Example 1 and nickel as the first electrode layer, which were oxidized by heat treatment, and further subjected to nickel plating were prepared 100 samples each. A lead wire was connected to each sample, and an adhesive strength test of the lead wire was performed under the following conditions.
[0064]
That is, both ends of the lead wire were fixed up and down, one end of the lead was pulled upward, and the strength value of the sample from which the lead wire was peeled was examined.
[0065]
As a result, the number of samples in the comparative example was 100/100, and the number of samples according to the present invention was 0/100. Furthermore, the strength of 2 kg or more was obtained in all the samples, and it was found that the samples of the present invention were excellent in the adhesion of lead wires.
[0066]
【The invention's effect】
As described above, according to the present invention, no special firing conditions are required, firing can be performed under the same conditions as those of a normal multilayer ceramic capacitor, the manufacturing process is simple, the production cost is low, and CR or (L / C) It is possible to provide a CR composite electronic component in which an R series circuit is easily obtained, the resistance value is easily controlled, and the lead wire has a strong adhesive strength, and a method for manufacturing the CR composite electronic component.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a basic configuration of a CR composite electronic component of the present invention, in which a second electrode layer is formed on both terminal electrodes.
FIG. 2 is a graph showing frequency-impedance characteristics of a sample using an alloy of nickel and phosphorus for a second electrode layer and a sample containing only nickel.
[Explanation of symbols]
2 Dielectric layer
3 Internal electrodes
4 First electrode layer
5 Second electrode layer
6 Third electrode layer

Claims (8)

Dielectric layers and internal electrodes are stacked alternately,
The internal electrode and the first electrode layer formed at the end of the CR composite electronic component are connected,
A second electrode layer and a third electrode layer on at least one terminal side of the first electrode layer;
The internal electrode layer is connected to the outside through the first to third electrode layers,
The second electrode layer is formed by electroless plating;
The second electrode layer contains nickel and phosphorus, and phosphorus is contained in an amount of 8 to 15 wt % in terms of P ;
A CR composite electronic component that controls a DC equivalent resistance of the second electrode layer in a range of 10 to 100 mΩ by changing a thickness of the second electrode layer . The CR composite electronic component according to claim 1 , further comprising 0.01 to 10 wt% in total of at least one of B, Si, V, Fe, Co, Zn, Mo, Sn, Te and W as subcomponents. It said first electrode layer is copper or nickel, or CR composite electronic component according to claim 1 or 2 with these alloys. The third electrode layer tin or tin - either CR electronic composite component according to claim 1 to 3 with a lead alloy. Either CR composite electronic component according to claim 1-4 equivalent circuit comprises a CR or (LC) R series circuit. Either CR composite electronic component of claim 1 to 5 in which the internal electrodes containing nickel. A method for producing the CR composite electronic component according to claim 1,
A green chip is formed by alternately laminating dielectric layers and internal electrode layers,
This is fired into a chip body,
After forming the first electrode layer on the chip body in a reducing atmosphere,
Forming the second electrode layer on at least one of the first electrode layers by electroless plating so that the DC equivalent resistance is in the range of 10 to 100 mΩ ;
Furthermore, the manufacturing method of CR composite electronic component which forms a said 3rd electrode layer in a said 2nd electrode layer . The method for producing a CR composite electronic component according to claim 7 , wherein the internal electrode layer contains nickel.

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