JP4056952B2 - Manufacturing method of multilayer ceramic chip inductor - Google Patents

Description

The present invention relates to a method for manufacturing a multilayer ceramic chip inductor in which a plurality of sheets comprising a magnetic material or an insulator layer and a conductor layer are laminated and a coiled conductor line is formed by firing.

  In recent years, multilayer ceramic chip inductors are widely used in high-density mounting circuits associated with miniaturization and thinning of digital devices such as noise countermeasure components.

  Hereinafter, a conventional method for manufacturing a multilayer ceramic chip inductor will be described.

  A conductor line (conductor paste) of less than one turn is printed on the magnetic green sheet in advance, and each magnetic green sheet printed with the conductor line is laminated and pressure-bonded, and through the through hole provided in the magnetic green sheet. Then, the conductor lines are electrically connected between the upper and lower layers to form a coiled conductor line, and the laminated magnetic green sheet and coiled conductor line are collectively fired.

As prior art document information related to the invention of this application, for example, Patent Document 1 is known.
Japanese Utility Model Publication No. 59-145209

  However, in order to obtain a large impedance (or inductance) in the conventional multilayer ceramic chip inductor, it is necessary to increase the number of turns of the coiled conductor line, and accordingly, the number of multilayers must be increased.

  However, when the number of laminations increases in this way, there is a problem that the number of lamination processes increases and the manufacturing cost increases. Further, there is a problem that the number of conductor connection points between the green sheets increases and the connection reliability also decreases.

  In order to solve these problems, as shown in JP-A-4-93006, a magnetic layer of a magnetic material sheet is used, and a conductor layer of one turn or more is formed in the same plane by a thick film printing technique. A laminate having a relatively large impedance even when the number of layers is small, by laminating them and electrically connecting the adjacent upper and lower conductor layers through through holes previously formed in the magnetic layer. Type ceramic chip inductors have been proposed.

  However, even such a proposal has the following two drawbacks.

  (1) When manufacturing a small multilayer ceramic chip inductor (for example, an outer size of 2.0 mm × 1.25 mm, 1.6 mm × 0.8 mm, etc.) using a thick film conductor printing technique, Considering the manufacturing yield and the like for printing, the practical range is about 1.5 turns or less, and when a multilayer ceramic chip inductor having a larger impedance is manufactured, it is necessary to increase the number of layers.

  (2) In order to increase the number of turns in the same plane, it is necessary to reduce the thickness of the thick film conductor layer. However, if the conductor width is reduced, the conductor resistance increases, so the printed thickness must be increased. There is. However, as the printed conductor width is reduced, the conductor thickness must be reduced in order to maintain the printing resolution (for example, when the printed conductor width is 75 μm, a dry thickness of about 15 μm seems to be the limit).

  Therefore, the method of simply increasing the number of turns of the thick printed conductor as described above is not very practical although the effect of reducing the number of laminated layers is somewhat recognized.

  In addition, in order to reduce the conductor resistance value, in JP-A-3-219605, a concave portion is formed in a green sheet, and a conductive paste is filled in the concave portion to increase the thickness of the thick film conductor. However, it is difficult for a mass production method to form a complicated concave pattern on the green sheet.

  Furthermore, as another example, in Japanese Patent Application Laid-Open No. 60-176208, a metal foil is punched as a coil forming conductor in a laminated component in which a magnetic layer and a conductor having a half turn for forming a coil are alternately stacked. It is disclosed that the conductor resistance value is reduced by using the conductor pattern. However, in response to the recent miniaturization of parts, it is extremely difficult to accurately punch metal foil so that a conductor can be formed on a minute flat surface, and moreover, a complicated coiled pattern that winds more than one turn is formed. It is impossible to do. It is also difficult to arrange a plurality of punched metal foils on the sheet-like magnetic layer with a constant pitch. Further, when metal foils that are vertically adjacent to each other with the sheet-like magnetic layer interposed therebetween are connected at the end of the pattern, poor connection technology may occur.

  As another approach, there is a method of manufacturing a multilayer ceramic capacitor by transferring a metal thin film formed on a film to a ceramic green sheet in Japanese Patent Publication No. 64-42809 and Japanese Patent Laid-Open No. 4-314476. It is disclosed.

  That is, a desired metal layer was obtained by wet plating on a metal thin film having a releasability formed by vapor deposition on a film, and a pattern was formed by removing an excess metal layer formed by etching if necessary. The object is transferred to a transfer object (ceramic green sheet).

  By applying this transfer technique, it is possible to form a coiled conductor line and transfer it to a magnetic green sheet.

  That is, a relatively thin (for example, 10 μm or less) transfer metal thin film formed on a film is etched by a photoresist method to obtain a fine conductor pattern (for example, a conductor width of 40 μm, a line space of 40 μm, etc.). It is also possible to obtain a ceramic multilayer chip type inductor.

  However, with the above transfer technique, it is difficult to obtain a relatively thick (for example, 10 μm or more) transfer metal film with fine pattern accuracy.

  This is because, in the transfer technique using wet plating as described above, the metal layer once formed on almost the entire surface is removed by an etching method, so that the thick metal layer is thick. It becomes difficult to form a fine conductor pattern.

  In addition, since the desired metal pattern remains below the etching resist, it is necessary to remove the etching resist before transferring the metal pattern to the transfer object. However, when removing the etching resist, The metal pattern may peel off together. This phenomenon is more likely to occur as the thickness of the metal layer increases. This is presumed to occur because the thicker the metal layer, the longer the time required for etching, and the metal thin film layer is affected by the etchant.

  Therefore, even if this technique is used, the problem of reducing the conductor resistance value cannot be sufficiently solved.

In order to solve the above-described problems, a method for manufacturing a multilayer ceramic chip inductor according to the present invention has a step of forming an electroformed conductor pattern by electroforming on a conductive base plate, and a green sheet adhesive property. Directly transferring the electroformed conductor pattern to the surface, laminating a plurality of the green sheet and the electroformed conductor pattern alternately, electrically connecting the electroformed conductor patterns, the green sheet, A step of integrally sintering an electroformed conductor pattern, and the transfer step includes a step of forming a green sheet on the surface of the conductive base plate having the electroformed conductor pattern, and a heat release on the green sheet. A step of bonding a sheet, a step of peeling the green sheet having the electroformed conductor pattern and the heat release sheet from the conductive base plate, It is obtained so as to include a step of peeling by heating a heat release sheet.

As described above, according to the method for manufacturing a multilayer ceramic chip inductor of the present invention, the coiled conductor line is formed by using an electroforming (plating) technique. Therefore, the pattern width of several microns or more depends on the resolution of the photoresist. Therefore, it is possible to obtain a coiled conductor line having a larger number of turns than in the case where a conductor is formed by a printing technique in a small chip component area.

  Therefore, a large impedance value can be obtained even with a low number of layers.

  The conductor thickness can be submicron to several tens of microns depending on the thickness of the photoresist and plating conditions, or several millimeters depending on the conditions, so the conductor resistance can be easily controlled. By increasing the film thickness, the conductor resistance value can be reduced while the pattern is fine.

  On the other hand, unlike the case where the coil pattern is formed by using only the thick film conductor, a relatively dense film can be obtained before firing. There is no occurrence of lamination.

  Further, unlike the case where the coil pattern is formed with only the metal foil that does not shrink at all, cracks are rarely generated during sintering.

  Further, the reliability of the product characteristics is enhanced by the pattern accuracy of the conductor and the denseness of the conductor.

  As described above, according to the multilayer ceramic chip inductor and the manufacturing method thereof of the present invention, it is possible to obtain an excellent effect that it is possible to simultaneously realize a reduction in the number of layers, an increase in impedance, and a reduction in conductor resistance.

(Embodiment 1)
Embodiment 1 of the present invention will be described below with reference to the drawings.

  FIG. 1 is an exploded perspective view showing the structure of the multilayer ceramic chip inductor according to Embodiment 1 of the present invention.

  In the following drawings, for convenience, only one multilayer ceramic chip inductor is shown. However, in an actual manufacturing process, a plurality of ceramic chip inductors are simultaneously formed on a plane and divided into individual pieces after lamination. .

  In FIG. 1, reference numerals 1, 3 and 6 denote sheet-like magnetic layers. Reference numerals 2 and 5 are wound coil-shaped plated conductors formed by an electroforming method in which a conductor pattern is formed by plating after forming a resist film having a desired pattern and transferred to the sheet-like magnetic layers 1 and 6, respectively. . Reference numeral 4 denotes a through hole for connecting the coiled coiled conductors 2 and 5 to each other.

  A manufacturing method of the multilayer ceramic chip inductor configured as described above will be described below.

  First, a method for producing the coiled coil conductors 2 and 5 for transfer by electroforming will be described with reference to FIG.

  As shown in FIG. 2, an Ag release layer 9 having a thickness of 0.1 μm or less is obtained by performing strike Ag plating as a conductive release treatment layer on the entire surface of the base stainless steel plate 8.

  Here, as the strike Ag plating, a very general alkali cyan Ag plating bath can be used. As an example of the alkali cyan Ag plating bath, the structure of the plating bath is illustrated in Table 1 below.

  In the case of the Ag plating bath of (Table 1), about 0.1 μm of the Ag release layer 9 can be obtained in about 5 to 20 seconds.

  By the way, the Ag release layer 9 has releasability because the Ag film is strike (high speed) plated on the base stainless steel plate 8 having poor adhesion to Ag. This is considered to be because the Ag film cannot be firmly adhered to the base stainless steel plate 8.

  In addition, in order to obtain a more optimal releasability between the Ag release layer 9 and the base stainless steel plate 8, the surface of the base stainless steel plate 8 is adjusted to have a surface roughness (Ra) of about 0.05 μm to about 1 μm ( It is desirable to roughen).

  Acid treatment, blast treatment, or the like can be used as a method for roughening the surface.

  When the surface roughness (Ra) is about 0.05 μm or less, the adhesion between the Ag release layer 9 and the base stainless steel plate 8 becomes insufficient, and the Ag release layer 9 may be peeled off during the subsequent steps. If the surface roughness (Ra) is about 1 μm or more, the adhesion between the Ag release layer 9 and the base stainless steel plate 8 is too good, and the transfer of the Ag release layer 9 to the magnetic layer can be performed well. Or the resolution of the plating resist pattern 11 may decrease.

  On the other hand, the surface of the base stainless steel plate 8 is appropriately roughened to improve the adhesion of the plating resist pattern 11 formed in the next step, and the release of the Ag release layer 9 in the plating resist pattern 11 peeling step. There is also a secondary effect that the mold prevention effect is improved.

  The Ag release layer 9 can also be formed by utilizing a silver mirror reaction.

  Further, as the base metal plate, it is possible to perform a mold release process using a material other than stainless steel so as to have conductivity. The main usable materials and their demolding methods are listed in (Table 2).

  In addition, it is possible to give the same effect by imparting conductivity to a program board or pet film laminated with copper foil in addition to the base metal plate, but the metal plate is more conductive. It is efficient without the need to give.

  In particular, a stainless steel plate is chemically stable and has a chromium-based oxide film on its surface, so that it has good releasability and can be used most easily.

Thus, after the Ag release layer 9 is formed, a dry film resist is laminated on the Ag release layer 9, and after preliminary drying, a width of 70 μm and about 2 in a plane of 2.0 × 1.25 mm ² size. Using a photomask for forming a 5-turn coiled coil conductor, exposure and development are performed to form a plating resist pattern 11 having a thickness T = 55 μm.

  Various photoresists (liquid, paste, dry film) can be used as the photoresist. Regarding the dry film, although the resist thickness is constant and the thickness of the conductor film can be controlled with relatively high accuracy, it is preferably used for forming a pattern having a conductor pattern accuracy width of about 50 μm or more in view of the degree of resist sensitivity.

  In the case of a liquid photoresist, it is possible to obtain a conductor pattern accuracy of several microns width.

  In the case of the most common paste-like photoresist, a conductor pattern having a conductor width of about 40 μm and a thickness of about 30 to 40 μm can be obtained.

In this case, for example, 2.0 × 1.25 mm ² size winding conductor pattern of about 5 turns in the plane of the three-turn about the pattern can be easily formed into 1.6 × 0.8 mm ² size in the plane .

  In addition, depending on the characteristics of each resist, a resist film coating method such as printing, spin coating, roll coating, dipping, or laminating can be selected.

  The exposure is performed with a parallel light UV exposure device, and the conditions such as the exposure time and the amount of light may be matched to the characteristics of various resists.

  Furthermore, development may be performed using a dedicated developer for various resists.

  Further, if necessary, the chemical resistance of the resist film can be improved by performing re-exposure of UV light after development or post-curing.

  Next, after the plating resist pattern 11 is formed, it is immersed in an Ag electroplating bath to form a transfer Ag conductor pattern 10 having a required thickness t. In the present embodiment, it was formed so that t = about 50 μm.

  The most notable point in this process is that a common alkaline Ag plating bath is not used.

  This is because, in the case of an alkaline bath, it functions as a stripping solution for the plating resist film, so that the plating resist pattern 11 formed in the previous process is destroyed.

  Therefore, it is necessary to use a weakly alkaline (neutral) or acidic Ag plating bath. As the weakly alkaline (neutral) plating bath, those shown in (Table 3) can be used.

  Although pH adjustment is performed with ammonia and citric acid, as a result of various experiments, most of the plating resist is peeled off when the pH exceeds 8.5.

  Therefore, it is desirable to set the pH to at least 8.5 or lower.

  As other acidic plating baths, those shown in (Table 4) can be used.

  Since such an Ag plating bath shown in (Table 4) is acidic, peeling of the plating resist was not observed. Furthermore, by adding a surfactant (methylimidazolethiol, furfural, funnel oil, etc.), the Ag gloss was increased and the surface could be further smoothed.

  In this example, a weak alkali (neutral) bath shown in (Table 3) was used. The pH was 7.3.

However, the current density in the plating process was about 1 A / dm ² .

  This is because, since plating is performed at a high speed, if the current density is increased, the Ag conductor pattern 10 is greatly distorted, and the Ag film may be peeled off before the pattern is transferred.

  In this example, it took a plating time of about 260 minutes to obtain the Ag conductor pattern 10 having a thickness of about 50 μm.

  By the way, the Ag release layer 9 is formed by the strike Ag plating bath (alkaline), but the current density is increased only in the first few minutes in the weakly alkaline (neutral) or acidic bath as described above. It is also possible to impart releasability to the Ag film near the interface with the base stainless steel plate 8 by increasing the distortion of the Ag film.

  In this case, it becomes a structure as shown in FIG. 3, and it is not necessary to provide the Ag release layer 9 purposely.

  Next, the plating resist pattern 11 is peeled off to obtain a structure as shown in FIG.

  The plating resist pattern 11 stripping solution may be used exclusively for the plating resist film, but it can be stripped in about 1 minute when immersed in an approximately 5% NaOH solution (solution temperature: about 40 ° C.).

After the peeling of the plating resist pattern 11, the approximately 0.1 μm Ag release layer 9 was soft-etched (etching time was several seconds) using dilute nitric acid (5%), thereby becoming independent as shown in FIG. A coiled Ag conductor pattern 10 is obtained on a base stainless steel plate. This Ag conductor pattern 10 becomes the winding coil-shaped plated conductors 2 and 5 of about 2.5 turns shown in FIG.

  As a soft etchant for the Ag release layer 9, a sulfuric acid bath of chromic anhydride, a hydrochloric acid bath of ferric chloride, or the like can be used in addition to the above-mentioned dilute nitric acid.

  It should be noted that the Ag release layer located under the wound coil-shaped plated conductor pattern is not etched and the wound coil-shaped plated conductor pattern is not peeled off in an etching time of only a few seconds of soft etching.

  Next, a method for forming the sheet-like magnetic layers 1, 3, 6 will be described.

  First, a vehicle obtained by dissolving a resin such as butyral, acrylic, or ethyl cellulose in a low boiling alcohol such as isopropyl alcohol or butanol, or a solvent such as toluene or xylene and a plasticizer such as dibutyl phthalate, and Ni / Zn / Cu ferrite powder ( A paste (slurry) ferrite formed by kneading with an average particle size of 0.5 to 2.0 μm is formed on a pet film by a doctor blade method, and a state in which a little stickiness is left at about 80 to 100 ° C. Until dry.

  The sheet-like magnetic layers 1, 3, 6 are formed so that the sheet-like magnetic layers 1, 6 have a thickness of about 0.3 to 0.5 mm, and the sheet-like magnetic layer 3 is thick. After being formed to have a thickness of about 20 to 100 μm, the through hole 4 of about 0.15 to 0.3 mm square is made to penetrate by punching or the like.

  Next, a transfer process for transferring and laminating the coiled coiled conductors 2 and 5 and the sheet-like magnetic layers 1, 3 and 6 will be described.

  First, the wound coil-shaped plated conductor 2 that has already been formed is pressed and transferred to the sheet-like magnetic layer 1 formed on the pet film (if necessary, it may be pressurized and heated). Alternatively, the sheet-like magnetic layer 1 is once released from the pet film, and the coiled plated conductor 2 wound on the plasticizer surface side (the surface side in contact with the pet film) having the adhesiveness of the sheet-like magnetic layer 1 is used. May be transferred by pressing.

  At this time, the coiled coiled conductor 2 has moderate release properties from the base stainless steel plate 8, while it has moderate adhesiveness to the sheet-like magnetic layer 1, and the coiled plated conductor. 2 is bitten by compression deformation of the sheet-like magnetic layer 1 in the course of the transfer process, so that the wound coil-like plated conductor 2 can be easily formed by peeling the sheet-like magnetic layer 1 from the base stainless steel plate 8. Is transferred to the magnetic layer 1.

  At this time, if the sheet strength of the sheet-like magnetic layer 1 is insufficient, the lack of strength of the sheet-like magnetic layer is compensated by sticking an adhesive sheet on the sheet-like magnetic layer 1. You can also.

  Further, the coiled coiled conductor 5 is transferred to the sheet-like magnetic layer 6 by the same process.

Further, the sheet-like magnetic layer 3 is disposed between the sheet-like magnetic layers 1 and 6 to which the two wound coil-like plated conductors 2 and 5 thus obtained are transferred. Lamination is performed so that the conductors 2 and 5 are connected to each other, and heating (60 to 120 ° C.) and pressurization (20 to 500 kg / cm ² ) complete the connection between the layers.

  However, the electrical connection between the two coiled coiled conductors 2 and 5 is often more ohmic when a thick film conductor is used. Therefore, as shown in FIG. It is preferable that the through-hole 4 of the magnetic layer 3 is preliminarily printed with a printed thick film conductor 7 or is filled with a bump-like plated conductor 7 having substantially the same size as the through-hole 4.

  In the above process, a plurality of conductor patterns are generally formed on one sheet in order to obtain a plurality of multilayer ceramic chip inductors simultaneously in order to improve manufacturing efficiency. Therefore, after cutting the sheet into individual pieces, the sheet is baked at 850 to 950 ° C. for about 1 to 2 hours. Moreover, you may cut | disconnect after sintering.

  Finally, a silver alloy-based extraction electrode is formed so as to be electrically connected to the internal coiled coiled conductor on the opposing outer pieces of the cut pieces, and sintered at about 600 to 850 ° C. As a result, the external electrode 12 shown in FIG. 6 is formed. Further, Ni, solder or the like is plated on the external electrode 12 as necessary.

  Through such a process, a multilayer ceramic chip inductor having an outer shape of 2.0 × 1.25 mm and a thickness of 0.8 mm was obtained. The inner conductor has a two-layer structure of about 2.5 turns of coiled coiled conductors 2 and 5 and has a total of 5 coiled coiled conductor lines. A value of about 700Ω could be obtained.

  Since the thickness of the Ag conductor was about 50 μm, the direct current resistance value was extremely small and could be about 0.12Ω.

  Further, when the multilayer ceramic chip inductor according to the present example was cut and observed, no gaps in particular were observed at the interface between the Ag conductor and the magnetic layer.

  This is because the wound coil-shaped plated conductor formed by the electroforming method according to the present invention is relatively small in shrinkage due to firing, unlike the case of being formed of a thick film conductor having a shrinkage rate of 40 to 60% by firing. (5-10%) Therefore, it is considered that the magnetic body (sintering shrinkage rate: 5-20%) was densely sintered around the Ag conductor.

  In addition, when the coiled coiled conductor is a metal foil, the metal foil is denser than the plating film, so that it thermally expands and hardly contracts. Although cracks may occur due to differences, in the case of a wound coil-shaped plated conductor formed by the electroforming method according to this embodiment, cracks are rarely generated.

(Embodiment 2)
Embodiment 2 of the present invention will be described below with reference to the drawings.

  FIG. 7 is an exploded perspective view showing the structure of the multilayer ceramic chip inductor according to the second embodiment of the present invention.

  In FIG. 7, 13 and 18 are sheet-like magnetic layers, and 15 is a sheet-like magnetic layer in which through holes 16 are formed. Reference numeral 14 denotes a wound coiled plating conductor for transfer formed by electroforming, and reference numeral 17 denotes a thick film conductor printed on a sheet-like magnetic layer in which a through hole 16 is formed. The winding coiled conductor 14 for transfer formed by electroforming and the printed thick film conductor 17 are connected to each other through a through hole 16.

  A manufacturing method of the multilayer ceramic chip inductor configured as described above will be described below.

  First, the winding coil-shaped plated conductor 14 for transfer can be produced by the same electroforming method as in the first embodiment.

In this example, a pattern of about 3.5 turns was obtained with a pattern rule having a width of about 40 μm and a thickness of 35 μm in a 1.6 × 0.8 mm ² size plane.

  The resist used is a high-sensitivity paste resist that can be printed.

  Next, a method for forming the sheet-like magnetic layers 13, 15, and 18 will be described.

  A vehicle in which a resin such as butyral, acrylic, or ethyl cellulose is dissolved in a high boiling point solvent such as terpineol and a plasticizer such as dibutyl phthalate, and Ni / Zn / Cu ferrite powder (average particle size: 0.5 to 2.0 μm) The paste-like ferrite formed by kneading is formed on a pet film by printing using a metal mask. Thereafter, drying is performed at about 80 to 100 ° C. (printing and drying are repeated several times if necessary) to obtain sheet-like magnetic layers 13 and 18 formed to have a thickness of about 0.3 to 0.5 mm.

  Alternatively, in addition to the above method, the sheet-like magnetic layers 13 and 18 can be obtained by laminating several sheet-like magnetic layers printed and dried to about 50 to 100 μm.

  In addition, about the sheet-like magnetic body layer 15, the pattern which has the through-hole 16 is formed on a PET film by screen printing, and it adjusts so that thickness may be set to about 40-100 micrometers.

First, the wound coil-shaped plated conductor 14 already formed is pressed and transferred to the sheet-like magnetic layer 13 formed on the pet film. The pressurizing condition is preferably selected from the range of 20 to 100 kg / cm ² , and the heating condition is selected from the range of 60 to 120 ° C.

  At this time, the wound coil-shaped plated conductor 14 has moderate releasability from the base stainless steel plate and moderately sticky to the sheet-like magnetic layer 13. Further, since the wound coil-shaped plated conductor 14 has a relatively narrow pattern width of 40 μm, it has an effect of slightly biting into the sheet-like magnetic body layer 13, so that the wound coil-shaped plated conductor 14 is easily formed into the sheet-like magnetic body layer 13. Is transcribed.

  In addition, it can also transfer by pressing the coiled coil-shaped plating conductor 14 to the plasticizer surface side of the sheet-like magnetic body layer 13 like Example 1. FIG.

  Subsequently, the thick film conductor 17 is printed on the sheet-like magnetic body layer 15 having the through holes 16.

  Furthermore, the sheet-like magnetic body layer 13 to which the wound coil-like plated conductor 14 thus obtained is transferred and the sheet-like magnetic body layer 15 on which the thick film conductor 17 is printed are overlapped, and the wound coil-like shape is passed through the through hole 16. The plated conductor 14 and the thick film conductor 17 are laminated so as to be connected to each other, and the sheet-like magnetic body layer 18 is further laminated thereon, and heated and pressurized to form an integral laminated body.

  In the above process, a plurality of conductor patterns are formed on one sheet in order to obtain a plurality of multilayer ceramic chip inductors simultaneously in order to improve manufacturing efficiency. Therefore, after cutting the sheet into individual pieces, the sheet is baked at 850 to 950 ° C. for about 1 to 2 hours.

  The external electrode shown in FIG. 6 is formed by forming a take-out electrode so as to be connected to the internal coiled coiled conductor at both opposite ends of the last cut piece and sintering at about 600 to 850 ° C. The electrode 12 is formed. Further, Ni, solder or the like is plated on the external electrode 12 as necessary.

Through such a process, a multilayer ceramic chip inductor having an outer diameter of 1.6 × 0.8 mm ² and a thickness of 0.8 mm was obtained. The inner conductor has a two-layer structure of a straight thick film conductor 17 connected to the winding coil-shaped plated conductor 14 of about 3.5 turns through a through hole, and the winding of a total of 3.5 turns Since it has a coil-shaped plated conductor line, the impedance at 100 MHz could be obtained as about 300Ω.

  The direct current resistance value could be about 0.19Ω because the Ag conductor thickness was about 35 μm.

  In this embodiment, only the two winding coil-shaped plating conductors 14 for transfer and the thick film conductor 17 are included. However, if necessary, a plurality of winding coil-shaped plating conductors 14 for transfer and a plurality of winding coil-shaped plating conductors 14 are provided. The thick film conductors 17 may be alternately connected.

  Further, as in this embodiment, the combination of the thick film conductor and the wound coil-shaped plated conductor further increases the connection reliability compared to the case where the wound coil-shaped plated conductors are connected to each other.

  This is presumed to be because the thick film conductor is easily deformed at the time of lamination and is sintered in a state where the adhesiveness with the coiled coiled conductor is increased.

(Embodiment 3)
Embodiment 3 of the present invention will be described below with reference to the drawings.

  FIG. 8 is an exploded perspective view showing the multilayer ceramic chip inductor structure according to the third embodiment of the present invention.

  In FIG. 8, 19 and 24 are sheet-like magnetic layers, and 21 is a sheet-like magnetic layer having through holes 22. Reference numerals 20 and 23 denote winding coil conductors for transfer formed by electroforming. Reference numeral 25 denotes a thick film conductor printed so as to fill the through hole 22 formed in the sheet-like magnetic layer 21. The winding coiled conductors 20 and 23 for transfer formed by electroforming and the printed thick film conductor 25 are connected to each other through the through hole 22.

  A manufacturing method of the multilayer ceramic chip inductor configured as described above will be described below.

  First, the method for producing the winding coiled conductors 20 and 23 for transfer by electroforming can be performed by the same electroforming method as in the first embodiment.

In this embodiment, the winding coiled plating conductor 20 for transfer has a pattern rule of about 40 μm width and 35 μm thickness in a 1.6 × 0.8 mm ² size plane, and about 3.5 turns for transfer. A pattern of about 2.5 turns was obtained as the wound coiled plated conductor 23.

  The resist used is a high-sensitivity paste resist that can be printed.

  Next, a method for forming the sheet-like magnetic layers 19, 21, and 24 will be described.

A vehicle in which a resin such as butyral, acrylic, or ethyl cellulose is dissolved in a high boiling point solvent such as terpineol and a plasticizer such as dibutyl phthalate, and Ni / Zn / Cu ferrite powder (average particle size: 0.5 to 2.0 μm ) The paste-like ferrite formed by kneading the above is formed on a pet film by printing using a metal mask, dried at about 80 to 100 ° C. until a little stickiness is left, and has a thickness of 0.3 to 0.00. The sheet-like magnetic layers 19 and 24 formed to have a thickness of about 5 mm are obtained. The sheet-like magnetic layer 21 is adjusted so that a pattern having through holes 22 is formed on the pet film by screen printing, and the thickness is about 40 to 100 μm.

  Further, the thick film conductor 25 is printed so that the through hole 22 is filled with the thick film conductor.

  Next, the coiled coiled conductor 20 for transfer that has already been formed is pressed and transferred to the sheet-like magnetic layer 19 formed on the pet film (pressurized and heated as necessary).

  Similarly, the winding coil-shaped plated conductor 23 for transfer is also transferred to the sheet-like magnetic layer 24.

  At this time, it may be transferred to the sheet-like magnetic layer 21 instead of the sheet-like magnetic layer 24.

  Further, a sheet-like magnetic material having a through-hole 22 between the sheet-like magnetic material layer 19 to which the wound coil-shaped plated conductor 20 is transferred and the sheet-like magnetic material layer 24 to which the wound coil-shaped plated conductor 23 is transferred. The body layer 21 is arranged, laminated so that the winding coil-shaped plating conductors 20 and 23 for transfer are connected to each other through the thick film conductor 25 filled in the through hole 22, and heated and pressurized, and integrally laminated. Let it be the body.

  In the above process, a plurality of conductor patterns are generally formed on one sheet in order to obtain a plurality of multilayer ceramic chip inductors simultaneously in order to improve manufacturing efficiency. Therefore, the sheet is cut into individual pieces, and then fired at 850 to 1000 ° C. for about 1 to 2 hours.

  Finally, an extraction electrode is formed at both opposite ends of the cut piece so as to be connected to the inner coiled coiled conductor, and sintered at about 600 to 850 ° C. The electrode 12 is formed. Further, Ni, solder or the like is plated on the external electrode 12 as necessary.

Through such a process, a multilayer ceramic chip inductor having an outer diameter of 1.6 × 0.8 mm ² and a thickness of 0.8 mm was obtained. The inner conductor has a two-layer structure of a coiled coiled conductor 20 having a conductor width of about 40 μm and a length of about 3.5 turns, and a coiled coiled conductor 23 of about 2.5 turns connected through a through hole. Thus, since the coiled plated conductor line has a total of 6 turns, an impedance of about 1000Ω can be obtained at 100 MHz.

  The direct current resistance value could be about 0.32Ω because the thickness of the coiled coiled conductor was about 35 μm.

(Embodiment 4)
Embodiment 4 of the present invention will be described below with reference to the drawings.

  FIG. 9 is an exploded perspective view showing the structure of the multilayer ceramic chip inductor according to the fourth embodiment of the present invention.

  In FIG. 9, 26 and 31 are sheet-like magnetic layers, 28 is a sheet-like magnetic layer having a through-hole 29, and 27 and 30 are winding coil-like plated conductors for transfer formed by electroforming.

  The wound coiled plating conductors 27 and 30 for transfer formed by electroforming are connected to each other through a through hole 29.

  Since the manufacturing method of the multilayer ceramic chip inductor configured as described above is the same as that of the first embodiment, the description thereof is omitted.

According to this example, a multilayer ceramic chip inductor having an outer shape of 2.0 × 1.25 mm ² and a thickness of 0.8 mm was obtained. The internal conductor has a two-layer structure of a coiled coiled conductor 30 having a conductor width of about 40 μm and a coiled coiled conductor 27 having a winding of about 5.5 turns and a winding coiled conductor 30 of about 2.5 turns connected through a through hole 29. Therefore, the impedance at 100 MHz can be obtained about 1400Ω.

  The DC resistance value could be about 0.47Ω because the wound coiled plating conductor thickness was about 35 μm.

(Embodiment 5)
Embodiment 5 of the present invention will be described below with reference to the drawings.

  Since the multilayer ceramic chip inductor in this example has the same structure as that of the second embodiment, it will be described with reference to FIG.

  In FIG. 7, 13 and 18 are sheet-like magnetic layers, 15 is a sheet-like magnetic layer having a through-hole 16, 14 is a coiled coil conductor for transfer formed by electroforming, and 17 is a through-hole 16. A thick coil conductor printed on a sheet-like magnetic material layer having a transfer, and a wound coiled plating conductor for transfer 14 formed by electroforming and a printed thick film conductor 17 through a through hole 16. Connect to each other.

  A manufacturing method of the multilayer ceramic chip inductor configured as described above will be described below.

First, in the same manner as in the second embodiment, a coiled coil plating for transferring a pattern of about 3.5 turns with a pattern rule of width about 40 μm and thickness 35 μm in a 1.6 × 0.8 mm ² size plane. A conductor 14 was obtained.

  Next, a method for forming the sheet-like magnetic layer 13 will be described with reference to FIG.

A vehicle in which a resin such as butyral, acrylic, or ethyl cellulose is dissolved in a high boiling point solvent such as terpineol and a plasticizer such as dibutyl phthalate, and Ni / Zn / Cu ferrite powder (average particle size: 0.5 to 2.0 μm ) The paste-like ferrite formed by kneading is printed on the base stainless steel plate 32 on which the Ag conductor pattern 34 is formed using a metal mask and dried at about 80 to 100 ° C. (If necessary, repeated printing and drying are performed. The sheet-like magnetic layer 33 is formed so as to have a thickness of about 0.3 to 0.5 mm.

  Next, the thermally releasable sheet 35 is adhered from the upper layer of the sheet-like magnetic layer 33 (may be heated or pressurized as necessary), and together with the thermally releasable sheet 35, the Ag conductor pattern 34 and the sheet-like magnetic material are adhered. The body layer 33 is released from the base stainless steel plate 32 at the same time.

  In this manner, a green sheet in which the wound coil-shaped plated conductor 14 is formed on the sheet-like magnetic layer 13 can be obtained.

  Further, if necessary, an Ag release layer 9 as shown in FIG. 2 is provided on the base stainless steel plate 32 on which the Ag conductor pattern 34 is formed before the sheet-like magnetic layer 33 is printed. You can also.

  With such an Ag release layer, the release property between the sheet-like magnetic layer 33 and the base stainless steel plate 32 can be improved. The Ag release layer can be formed by dip-coating a liquid fluorine-based coupling agent (perfluorodecyltriethoxysilane or the like) and drying at about 200 ° C. The thickness of the release layer is preferably about 0.1 μm.

  On the other hand, the sheet-like magnetic material layer 15 is formed in a pattern having through holes 16 on a pet film by screen printing. The thickness is adjusted to be about 40 to 100 μm, and this sheet is laminated on the coiled coiled conductor 14.

It is preferable that the pressurizing condition at the time of lamination is selected from the range of 20 to 500 kg / cm ² and the heating condition of 80 to 120 ° C.

  In this embodiment, the wound coil-shaped plated conductor 14 bites into the sheet-like magnetic body layer 13 and has less irregularities, so that the sheet-like magnetic body layer 15 is easily transferred onto the sheet-like magnetic body layer 13. The

  Next, a thick film conductor 17 is printed on the sheet-like magnetic layer 15 so as to be connected to the coiled coiled conductor 14 through the through hole 16.

  Further, a sheet-like magnetic material layer 18 is laminated on the upper portion, and heated and pressurized to form an integral laminated body. In this case, the sheet-like magnetic layer 18 may be directly printed and laminated.

  The remaining steps (green sheet cutting, firing, end face electrode formation, etc.) are exactly the same as in the second embodiment.

  The electrical characteristics of the multilayer ceramic chip inductor in this example are also equivalent to those of the second embodiment.

(Embodiment 6)
Embodiment 6 of the present invention will be described below with reference to the drawings.

  This example has the same structure as the second and fifth embodiments, and will be described with reference to FIGS.

  In FIG. 7, 13 and 18 are sheet-like magnetic layers, and 15 is a sheet-like magnetic layer having through holes 16. 14 is a coiled coil conductor for transfer formed by electroforming, and 17 is a thick film conductor printed on a sheet-like magnetic layer having a through-hole 16. The winding coiled conductor 14 for transfer formed by electroforming and the printed thick film conductor 17 are connected to each other through a through hole 16.

  In the manufacturing method of the multilayer ceramic chip inductor configured as described above, a process of transferring the winding coiled plating conductor 14 for transfer to the sheet-like magnetic layer 13 will be described below with reference to FIG.

Similar to the second embodiment, an Ag conductor pattern 38 having a pattern rule of a width of about 40 μm and a thickness of 35 μm in a 1.6 × 0.8 mm ² size plane (about a winding coil shape for transfer) (Same as the plated conductor 14) was obtained on the base stainless steel plate 36. A conductive Ag release layer (strike Ag plating layer) 37 is formed between the Ag conductor pattern 38 and the base stainless steel plate 36 (FIG. 11A).

  Next, by foaming by heating from the upper part of the Ag conductor pattern 38, a foam sheet 39 having heat release properties from the base stainless steel plate 36 is attached (if necessary, heating and pressurization may be applied) (FIG. 11 (b )).

  Since the foam sheet 39 has a strong adhesive force, when the foam sheet 39 is peeled off from the base stainless steel plate 36, the Ag conductor pattern 38 and the Ag release layer 37 are transferred to the foam sheet 39 (FIG. 11C).

  The upper part of the Ag release layer 37 on the Ag conductor pattern 38 in which the sheet-like magnetic layer 40 (thickness 50 μm to 500 μm) formed in advance on a PET film or the like by a technique such as printing is transferred onto the foam sheet 39. Laminate to. In this case, the sheet-like magnetic layer 40 is laminated so that the plasticizer surface side is in contact with the Ag release layer 37, and the lamination is continued until the total thickness of the sheet-like magnetic layer 40 is about 0.3 to 0.5 mm. Repeat (FIG. 11 (d)).

  Of course, if necessary, pressurization and heating may be performed under suitable conditions during lamination.

  Next, by heating the integral body composed of the sheet-like magnetic layer 40, the Ag conductor pattern 38, the Ag release layer 37, and the foam sheet 39 at about 120 ° C. for 10 minutes, the foam sheet 39 is foam-released, A sheet-like magnetic body layer 40 (corresponding to the sheet-like magnetic body layer 13 of FIG. 7) integrated with the Ag conductor pattern 38 (corresponding to the wound coil-like plated conductor 14 of FIG. 7) can be obtained (FIG. 11 (FIG. 11)). e)).

  Next, as shown in FIG. 7, a sheet-like magnetic body layer 15 having a through-hole 16 is formed on the wound coil-like plated conductor 14 by using a lamination or printing technique, and the through-hole is further formed on the sheet-like magnetic body layer 15. A thick film conductor 17 is laminated or printed so as to be connected to the coiled coiled conductor 14 via 16.

  Further, a sheet-like magnetic material layer 18 is laminated on the upper portion, and heated and pressurized to form an integral laminated body. In this case, the sheet-like magnetic layer 18 may also be directly printed and laminated.

  The remaining steps (green sheet cutting, firing, end face electrode formation, etc.) are exactly the same as in Example 2.

  The electrical characteristics of the multilayer ceramic chip inductor in this example were also equivalent to those of the second embodiment.

  In this embodiment, meandering coiled plating conductors are used, but coils may be formed by combining linear conductor patterns.

(Embodiment 7)
Hereinafter, Embodiment 7 will be described with reference to the drawings as an application example of the present invention.

  FIG. 12 is an exploded perspective view showing the structure of the multilayer ceramic chip inductor according to the seventh embodiment of the present invention.

  In FIG. 12, 41 and 43 are sheet-like magnetic layers, and 42 is a meandering coiled plating conductor for transfer formed by electroforming.

  The meandering coiled plating conductor 42 for transfer formed by electroforming is arranged so as to be drawn out to both ends of the chip of the multilayer ceramic chip inductor.

  The manufacturing method of the multilayer ceramic chip inductor configured as described above is the same as that of the first embodiment, and therefore will be omitted.

According to this example, a multilayer ceramic chip inductor having an outer shape of 2.0 × 1.25 mm ² and a thickness of 0.8 mm was obtained. The internal conductor has a conductor width of about 50 μm, and a meandering coiled plated conductor penetrates the longitudinal direction of the magnetic layer, and an impedance at 100 MHz of about 120Ω can be obtained.

  The direct current resistance value was about 0.08Ω when the meandering coiled plating conductor 42 had a thickness of about 35 μm.

  In this embodiment, a meandering coiled plating conductor is used, but a linear plating conductor pattern can also be used.

  In the above seven embodiments, Ag is used as each winding or meandering coiled plating conductor for transfer, but Au, Pt can be used unless considering price, specific resistance, and oxidation resistance. , Pd, Cu, Ni, etc., and alloys thereof can also be used as appropriate.

  In addition, all the laminated bodies are listed only as examples made of Ni / Zn / Cu-based magnetic materials, but other magnetic materials such as Ni / Zn-based materials, Mn / Zn-based materials and various low dielectric constant insulating materials are used. Needless to say, it is also possible to form a multilayer ceramic chip inductor having air-core coil characteristics.

(Comparative example)
Next, comparative examples for the above-described embodiments will be described with reference to the drawings.

  FIG. 14 is a perspective view showing a method of manufacturing the multilayer ceramic chip inductor in the comparative example.

  In FIG. 14, reference numerals 101 and 111 denote sheet-like magnetic layers, and reference numerals 102, 104, 106, 108, and 110 denote thick film conductor layers for forming a winding coil-like plated conductor having about a half turn.

  Reference numerals 103, 105, 107, and 109 denote sheet-like magnetic layers that serve as insulating layers for laminating the above-mentioned half-turn thick film conductor, and the conductor is exposed only at the edge of the half-turn conductor layer. Arranged and stacked as described above.

  A manufacturing method of the multilayer ceramic chip inductor configured as described above will be described below.

  First, as shown in FIG. 14A, a ferrite paste is printed in a rectangular shape to obtain a sheet 101. Next, the conductive paste is printed about 1/2 turn on the sheet 101 to form the conductor line 102 (FIG. 14B).

  Further, a sheet 103 is formed by printing a ferrite paste so as to hide a part of the conductor line 102 (FIG. 14C).

  Then, an Ag conductive paste is printed so as to be connected to the end of the conductor line 102, thereby forming a thick film conductor layer 104 of about ½ turn (FIG. 14 (d)).

  Similarly, as shown in FIGS. 14E to 14K, printing and lamination are performed and high-temperature sintering is performed to obtain a ceramic laminated body having a wound coil-shaped plated conductor line having a total of 2.5 turns.

  In this comparative example, a conductor pattern was obtained with a pattern rule having a width of about 150 μm and a print dry thickness of 12 μm in a 1.6 × 0.8 mm size plane.

  Since the inner conductor has a 2.5-turn coiled coil conductor, an impedance at 100 MHz could be obtained at about 150Ω.

  The direct current resistance value was about 0.16Ω, with the wound coiled plated conductor thickness after sintering being about 8 μm.

  In this comparative example, although the total number of layers is 11 layers, the wound coil-shaped plated conductor can obtain only 2.5 turns. Therefore, the impedance is small for the number of layers, and the conductor resistance value is also an impedance value. Big against.

  Further, the process is complicated and the connection reliability between the conductor layers is poor.

  By the way, also in this comparative example, each thick film conductor layer can be formed by transferring the plating conductor pattern by the electroforming method in this embodiment, and the conductor resistance value can be lowered. Effects such as an increase in impedance value cannot be expected.

(Embodiment 8)
Embodiment 8 of the present invention will be described below with reference to the drawings.

  FIG. 15 is an exploded perspective view showing the structure of the multilayer ceramic chip inductor according to the eighth embodiment of the present invention.

  In FIG. 15, 201 and 206 are sheet-like magnetic layers, 203 is a sheet-like magnetic layer in which a through hole 207 is formed in a substantially central portion, and 202 and 205 are winding windings formed in a meandering manner by electroforming. A coil-shaped plated conductor 204 is a bump-shaped plated conductor formed by electroforming in the through-hole 207 of the sheet-like magnetic layer 203, and is a wound coil-shaped plated conductor 202 for transfer formed by electroforming. 205 is electrically connected via a bump-like plated conductor 204 transferred to the through hole 207.

A method for manufacturing the multilayer ceramic chip inductor configured as described above will be described below. First, a method for producing the wound coil-shaped plated conductors 202 and 205 for transfer by electroforming and the bump-shaped plated conductor 204 connecting the wound coil-shaped plated conductors 202 and 205 will be described with reference to FIG. As shown in FIG. 16A, a liquid resist is screen-printed on the base stainless steel plate 210 and dried at about 100 ° C. to obtain a resist film 211 of about 25 μm. Next, the resist film 211 is exposed to parallel light under predetermined conditions, and immediately developed using a sodium carbonate aqueous solution. Next, after development, the plate is thoroughly washed with water, further immersed in 0.5 to 1 mm in a 5% solution of H ₂ SO ₄ , acid-treated, and neutral type strike silver plating made by Daiwa Kasei Co. A release layer 212 is obtained. The strike silver plating time is about 1 minute (current density 0.3 A / dm ² ) and the plating film thickness is about 0.1 μm.

Next, a commercially available Ag plating solution containing no cyanide (Yamato Kasei) is used, the pH is about 1.0, an acid bath, and a current density of 1 A / dm ² and a plating condition of about 20 minutes, a thickness of about 20 μm. The Ag plating film 213 is prepared.

  In addition, the silver plating solution containing no cyanide used in this example has no toxicity at all, and it is possible to improve work safety and simplify the processing of the drainage, and to improve work efficiency and reduce manufacturing costs. is there.

  Next, as shown in FIG. 16B, the resist film 211 was peeled off by being immersed in a NaOH 5% solution. By the above method, the diameter of the through-hole 207 of the coiled plated conductors 202 and 205 having a width of 35 μm, space of 25 μm, thickness of 20 μm, and equivalent to about 2.5 turns and the sheet-like magnetic layer 203 is 0.18 size. The through-hole filling bump-like Ag plating pattern 204 is provided.

  Next, a method for forming the sheet-like magnetic layers 201, 203, 206 will be described.

  First, high-temperature calcined powder of Ni / Zn / Cu ferrite (800 to 1100 ° C.), a resin such as butyral, acrylic and ethyl cellulose, a low-boiling solvent such as toluene and xylene, a plasticizer such as dibutyl phthalate, and a small amount of additives A slurry obtained by pot-mixing is formed into a film with a doctor blade device to obtain green sheets of about 100 μm and 40 μm.

  Further, four green sheets of about 100 μm are laminated to obtain green sheets 201 and 206 of about 400 μm. On the other hand, a green sheet 203 in which a through-hole having a diameter of 0.1 is formed on a 40 μm green sheet using a puncher (a device that mechanically drills holes using a mold pin) is produced.

  The green sheets 201 and 206 thus obtained are hot-pressed on the wound coil-shaped plated conductors 202 and 205, respectively, and the green sheets 201 and 206 are separated from the base stainless steel plate to thereby form the wound coil-shaped plated conductor. The sheet-like magnetic layers 201 and 206 to which the above are transferred are obtained. Similarly, the bump-shaped Ag plating pattern 204 is transferred after aligning the green sheet 203 having through-holes having a diameter of 0.1 to obtain the sheet-shaped magnetic layer 203 to which the bump-shaped Ag plating pattern is transferred. .

At this time, the thermal transfer conditions are 100 ° C., 70 kg / cm ² , and 5 sec. As shown in FIG. 17A, the transfer is performed so that the plated conductor bites into each green sheet.

  The thus obtained sheet-like magnetic layers 201, 203, and 206 are sequentially stacked so that they are electrically connected and aligned so as to be formed as one coil. Baking at ˜920 ° C. to obtain a laminate having an outer size of 1.6 × 0.8 and a thickness of about 0.8.

  In general, ferrite powders are sintered at 700 to 800 ° C. and fine ferrite powder (0.2 to 1.0 μm) is used to increase the sintering density, and shrinkage is about 15 to 20% in the sintering process. Although it is usual to make it carry out, in this Example, 800-1100 degreeC high temperature calcined powder (1-3 micrometers) was used, and sintering shrinkage was suppressed to about 2-10%. This is because the Ag-plated conductor shrinks only slightly during the sintering process, so that the shrinkage is matched as much as possible to reduce the internal strain after sintering.

  However, generally, when the calcination temperature of the powder is raised, the shrinkage rate is lowered, but the magnetic properties are deteriorated. Therefore, it is important to add an additive that minimizes the deterioration of the magnetic properties.

  As a result of research, it is effective to add a small amount of organic lead compound such as lead octylate (0.1 to 1.0% of ferrite) as an additive to suppress deterioration of magnetic properties while maintaining the shrinkage rate. I found it.

  This is because the organic lead compound is very well dispersed in the ferrite slurry, so that the atomic atomic metal Pb or atomic PbO thermally decomposed during the firing process efficiently and effectively dissolves in the ferrite powder grain boundary. It is thought to improve.

  On the other hand, powders such as PbO have a high specific gravity, so that they are easily separated from ferrite in the slurry and have poor dispersibility. Furthermore, the ferrite powder reactivity is also inferior to a substance (atomic metal lead or atomic PbO) produced by thermal decomposition of an organic lead compound. Therefore, the addition of oxide powder such as PbO is not very effective.

  It is also effective to introduce non-shrinkable ferrite instead of high temperature fuel.

This is to prepare a powder obtained by preliminarily reducing the portion Fe ₂ O ₃ that becomes Fe ₂ O _{3 of} Ni · Zn · Cu ferrite and calcining it separately, and adding metal Fe powder and unreacted NiO, ZnO, CuO separately. In addition, the sintering shrinkage is eliminated by adjusting the ratio of the metal Fe powder oxidized and expanded with Fe ₂ O ₃ and the so-called general sintering shrinkage ratio during the sintering process. Specific examples are described in (Table 5).

  As shown in Table 5, it is easy to produce chip beads using low-shrinkage ferrite powder or non-shrinkage ferrite powder.

  Further, as a final process, chip deburring, external electrode formation, and external electrode plating (Ni, solder) are performed to complete chip beads. In addition, since an electrical property changes a little with materials to be used, it shows in (Table 6). The sintering temperature is 910 ° C., and the data when kept for 1 hour is shown.

The multilayer ceramic chip inductor manufacturing method according to the present invention can obtain a large impedance value even with a small number of multilayers, and can be applied to applications such as high-density mounting circuits accompanying the downsizing and thinning of digital devices such as noise countermeasure components. it can.

1 is an exploded perspective view showing the structure of a multilayer ceramic chip inductor according to a first embodiment of the present invention. Explanatory drawing which shows the manufacturing process of the multilayer ceramic chip inductor in the same 1st Example. Explanatory drawing which shows the manufacturing process of the multilayer ceramic chip inductor in the same Example Explanatory drawing which shows the manufacturing process of the multilayer ceramic chip inductor in the same Example Explanatory drawing which shows the manufacturing process of the multilayer ceramic chip inductor in the same Example External perspective view of multilayer ceramic chip inductor in each example Exploded perspective view showing the structure of the multilayer ceramic chip inductor in the second, fifth and sixth embodiments Exploded perspective view showing the structure of the multilayer ceramic chip inductor in the third embodiment Exploded perspective view showing the structure of the multilayer ceramic chip inductor in the fourth embodiment Explanatory drawing which shows the manufacturing process of the multilayer ceramic chip inductor in the same 5th Example. Explanatory drawing which shows the manufacturing process of the multilayer ceramic chip inductor in the same 6th Example. Exploded perspective view showing the structure of the multilayer ceramic chip inductor in the seventh embodiment The fragmentary perspective view which shows another example of the structure of the multilayer ceramic chip inductor in 1st Example of this invention Explanatory drawing which shows the manufacturing process of the multilayer ceramic chip inductor as a comparative example with respect to the respective embodiments Exploded perspective view showing the structure of the multilayer ceramic chip inductor in the eighth embodiment Diagram explaining the process Diagram explaining the process

Explanation of symbols

1, 3, 6, 13, 15, 18, 19, 21, 24, 26, 28, 31, 33, 40, 41, 43 Sheet-like magnetic layers 2, 5, 14, 20, 23, 27, 30 Coiled plated conductor 4, 16 Through hole 8, 32, 36 Base stainless steel plate 9, 37 Ag release layer 10, 34, 38 Ag conductor pattern 11 Plating resist pattern 12 External electrode 17, 25 Thick film conductor 39 Foam sheet 42 Serpentine coiled conductor

Claims (1)

A step of forming an electroformed conductor pattern by electroforming on a conductive base plate, and the electroformed conductor pattern is directly transferred to the adhesive surface of the green sheet; and the green sheet and the electroformed conductor A plurality of patterns alternately stacked, and a step of electrically connecting the electroformed conductor patterns, and a step of integrally sintering the green sheet and the electroformed conductor pattern, and the transfer step includes the conductive step Forming a green sheet on the surface of the conductive base plate having the electroformed conductor pattern, adhering a heat release sheet on the green sheet, the green sheet having the electroformed conductor pattern, and the heat release A laminated ceramic chip inductor comprising: a step of peeling a mold sheet from the conductive base plate; and a step of peeling the thermal release sheet by heating. Method of manufacturing data.

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