JP2006237273A - Electronic part and its manufacturing method, and mobile phone and digital tuner using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such a problem that peeling of a conductor layer occurs due to thermal factor of laser processing or the like, by an electronic part which is formed by forming a conductor layer on the surface of a dielectric porcelain composite and laser-processing it to make a winding shape, namely, due to low adhesion strength of the conductor layer to the surface of the dielectric porcelain. <P>SOLUTION: The electronic part has a ratio of 0.02-1 of a maximum peak intensity of X-ray diffraction of a product existing on the surface of the dielectric porcelain composite to that of the dielectric porcelain composite. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention mainly relates to electronic components such as resistors, inductors and capacitors built in multimedia devices such as mobile phones and personal computers.

  In recent years, miniaturization and high functionality of electric and electronic equipment have progressed, and accordingly, resistors, inductors, capacitors, etc. based on ceramic dielectric materials used are also smaller and have higher performance. What you have is in demand.

  In particular, miniaturization of multimedia devices such as mobile phones, electronic notebooks, notebook computers, digital cameras, etc. is striking, but magnetic elements such as transformers and inductors are wound on the surface of dielectric ceramics, or Since the pattern is drawn with a conductive paste, the volume thereof is larger than that of other electronic components, which hinders further downsizing and thinning of multimedia devices.

  In order to solve this problem, research and development of electronic parts that integrate the inductor (L), capacitor (C), and resistor (R) to reduce the size and thickness have been actively conducted and put into practical use. It is being done.

  Very recently, electronic parts have been proposed in which a conductor layer is formed on the entire core surface, which is a dielectric porcelain, and a part of this layer is removed by laser processing to obtain characteristics equivalent to those of magnetic elements with windings and patterns. Therefore, it has become possible to perform mechanical control processing with an ultra-fine laser as if it were wound around an ultra-small dielectric ceramic.

  However, in such a method, it is necessary to form a conductor layer using a method such as plating while having a high adhesion strength on the surface of the dielectric ceramic. In Patent Documents 1 to 3, the adhesion strength of the conductor layer to the porcelain surface has been increased by roughening the surface of the dielectric porcelain by etching in advance.

On the other hand, as described above, the dielectric ceramic composition for electronic components mounted on multimedia devices can be used in, for example, mobile phone communication circuits, LCD display circuits, etc., and can be applied to all frequency bands. Thus, there is a demand for a material having a dielectric constant several times higher than conventionally used alumina or the like. In response to such a requirement, Patent Documents 4 and 5 obtain desired characteristics by mixing barium titanate having a high dielectric constant, calcium titanate and strontium titanate having a low dielectric constant, and adjusting the dielectric constant. Dielectric porcelain compositions have been proposed.
JP-A-8-307119 JP 2001-267101 A JP 2003-212649 A JP 2000-264729 A JP 2004-131304 A

  However, in the methods of Patent Documents 1 to 3, the surface of the porcelain is roughened by etching to coat the conductor layer, so that the adhesion strength of the conductor layer to the porcelain surface is increased, but laser processing after the conductor layer is formed, There has been a problem that the conductor layer is peeled off due to the influence of heat applied during the process of attaching to the electronic device after processing. That is, the reaction product generated by the reaction between the etching solution and the porcelain during the etching performed to roughen the porcelain surface cannot be removed even in the subsequent cleaning, and in the case of severe damage, Since a coating film is formed starting from pores and the like and remains, this impairs the adhesion between the conductor layer and the porcelain and significantly reduces the adhesion strength of the conductor layer. Therefore, when the conductor layer made of a metal having a large thermal expansion expands significantly compared to the porcelain due to the heat applied to the porcelain covered with the conductor layer in the subsequent process, the conductor due to the difference in thermal expansion between the conductor layer and the porcelain. An internal stress is created between the layer and the porcelain surface. When this internal stress exceeds the adhesion strength between the conductor layer and the porcelain, the conductor layer is peeled off.

  In addition, the reaction product is often a low-temperature evaporant that evaporates at an extremely low temperature, and the reaction product evaporates and gasifies due to heat applied during the laser processing and the attachment process to various electronic devices, resulting in volume expansion. Due to this influence, there is a problem that a phenomenon occurs in which a part of the conductor layer is blistered or, in a severe case, the blister part is peeled off.

  Furthermore, as a ceramic dielectric material used as an electronic component, a dielectric ceramic composition having a material composition mainly composed of three components of barium titanate, calcium titanate, and strontium titanate described in Patent Document 4 has been proposed. However, since the amount of barium titanate having a high dielectric constant is too small, an electronic component having a high dielectric constant that can be used as an electronic component for a mobile phone, for example, in a high frequency band of 800 MHz or higher is manufactured. In the dielectric ceramic composition described in Patent Document 5, which has a material composition similar to that of Patent Document 4, since the barium titanate content is large, a high dielectric constant ceramic can be obtained. However, since the Curie point rises and the dielectric constant of porcelain has temperature dependence, characteristics such as dielectric constant change with temperature by several degrees when used as an electronic component. Because even by change, the performance of the electronic device equipped with this is there is a problem that becomes very unstable.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an electronic component that suppresses the amount of product generated on the surface of the dielectric ceramic composition and does not lower the adhesion strength of the conductor layer. It is to be.

  In view of the above problems, the present invention provides an electronic component in which a conductor layer is formed on the surface of a dielectric ceramic composition, wherein a product is present at the interface between the dielectric ceramic composition and the conductor layer, and the dielectric in X-ray diffraction is The ratio of the maximum peak intensity of the product to the maximum peak intensity of the body porcelain composition is 0.02-1.

  Here, as the product, when a minute X-ray diffraction analysis is performed on the boundary between the porcelain and the conductor layer in the cross section of the electronic component, the peak of the dielectric porcelain, the peak of the conductor layer (plating layer = copper), the dielectric Oxides (eg, BaO, CaO, etc.) of body porcelain components, fluorides (eg, BaTiF6, CaTiF6, SrTiF6), etc. of dielectric porcelain components are mainly detected. Among them, oxides (eg, BaO) of dielectric porcelain components are detected. , CaO, etc.), fluorides of dielectric ceramic components (for example, BaTiF6, CaTiF6, SrTiF6) and the like.

  The dielectric ceramic composition may be a composite sintered body containing barium titanate, one of calcium titanate, and strontium titanate.

  Furthermore, the composite sintered body is configured as a total of 100 mol% within a range of 20 to 45 mol% barium titanate, 25 to 70 mol% calcium titanate, and 10 to 30 mol% strontium titanate. It is characterized by.

  Further, the product is characterized by comprising at least an oxide or fluoride of a dielectric ceramic component and an average thickness of 0.5 to 10 μm.

  The oxide of the dielectric ceramic component is made of BaO, CaO, SrO, and the fluoride is made of BaTiF6, CaTiF6, SrTiF6.

  Further, the ratio of the maximum peak intensity around 2θ = 28 ° of the product to the maximum peak intensity of the dielectric ceramic composition detected around 2θ = 32 to 33 ° in X-ray diffraction is 0.02 to 1. It is characterized by that.

  Moreover, the peel strength of the conductor layer is 10 MPa or more.

  Further, the electronic component is used for a mobile phone.

  Further, the electronic component is used in a digital tuner.

  Further, the method of manufacturing the electronic component includes a step of mixing a raw material of barium titanate, calcium titanate, and strontium titanate, then forming and firing to form a dielectric ceramic composition, and the dielectric ceramic composition It comprises a step of etching the surface with a hydrofluoric acid solution having a concentration of 15% to 80% or a mixed solution of hydrofluoric acid and nitric acid, and a step of covering the plating layer after etching.

  In an electronic component in which a conductor layer is formed on the surface of a dielectric ceramic composition as in the present invention, a product is present at the interface between the dielectric ceramic composition and the conductor layer, and the dielectric ceramic composition in X-ray diffraction is When the ratio of the highest peak intensity of the product to the highest peak intensity of the product is 0.02 to 1, during the etching process to roughen the surface of the dielectric ceramic in order to increase the adhesion of the conductor layer, The amount of etching solution and porcelain reaction products adhering to and remaining on the dielectric porcelain surface can be reduced, and the conductor layer does not peel off due to the effect of heat during the laser processing of the conductor layer and the subsequent incorporation into various electronic devices. It becomes possible to make a good electronic component.

  Moreover, when the dielectric ceramic composition is composed of a composite sintered body containing barium titanate, one of calcium titanate and strontium titanate, an electronic component having a high dielectric constant can be formed. When used as an electronic component such as a mobile phone, it can be used in any frequency band.

  This is also because BaTiF6, CaTiF6, and SrTiF6 for preventing evaporation of low-temperature evaporates can be formed in the etching process for roughening the surface of the magnetic element.

  Further, the composite sintered body is constituted as a total of 100 mol% within a range of 20 to 45 mol% of barium titanate, 25 to 70 mol% of calcium titanate, and 10 to 30 mol% of strontium titanate. In addition, the range of the content of barium titanate having high dielectric constant characteristics is optimal, so that a high dielectric constant can be obtained, and a composite sintered body in which the temperature dependence of the dielectric constant is suppressed can be obtained.

  The content ratio of each component is such that barium titanate exhibits particularly high dielectric constant characteristics. To increase the dielectric constant, the content ratio of barium titanate should be increased. As a result, the Curie point increases and the dielectric constant has a significant temperature dependence. For this reason, if the material composition has a barium titanate content of more than 45 mol%, when this is applied as an electronic component, the dielectric constant will change even with a slight temperature change. The performance of the device becomes unstable with temperature change, which is not preferable. On the other hand, if the content is less than 20 mol%, a high dielectric constant characteristic cannot be obtained, which is not preferable.

  Further, since the product is made of at least an oxide or fluoride of a dielectric ceramic component, and the average thickness is 0.5 to 10 μm, the product can reduce thermal stress generated between the ceramic and the conductor layer. In addition to being a layer, it is possible to maintain good adhesion between the porcelain and the conductor layer without inhibiting the adhesion between the porcelain and the conductor layer.

  Further, the ratio of the maximum peak intensity around 2θ = 28 ° of the product to the maximum peak intensity of the dielectric ceramic composition detected around 2θ = 32 to 33 ° in X-ray diffraction is set to 0.02 to 1. Thus, in the etching process for roughening the surface of the dielectric ceramic in order to increase the adhesion of the conductor layer, the reaction product of the etching liquid and the ceramic that adheres to and remains on the surface of the dielectric ceramic can be reduced. Thus, the conductor layer does not peel off due to the influence of heat applied during the laser processing step and subsequent steps for incorporation into various electronic devices, and a good electronic component can be obtained.

  In addition, by setting the peeling strength of the conductor layer to 10 MPa or more, it is possible to process the dielectric ceramic without covering the conductor layer even when the dielectric ceramic is covered with the conductor layer and this is laser processed to form an electronic component. It is.

  In addition, by mounting the electronic component of the present invention on a mobile phone or a digital tuner, it can be used in any frequency band and can be used in the environment of other countries with different operating frequencies, and the material composition can be adjusted. If the dielectric constant is increased by this, the electronic component can be further downsized.

  In addition, as a method for manufacturing an electronic component of the present invention, a process of mixing raw materials of barium titanate, calcium titanate, and strontium titanate, and thereafter forming and firing to form a dielectric ceramic composition, and the dielectric ceramic By using a step of etching the surface of the composition with a hydrofluoric acid solution having a concentration of 15 to 80% or a mixed solution of hydrofluoric acid and nitric acid, and a step of coating the plating layer after etching, good peeling does not occur during processing. It is possible not only to form a conductor layer having a sufficient peel strength, but also to suppress the generation of reaction products between the etching solution and the porcelain remaining on the surface of the dielectric ceramic by setting the concentration of the etching solution within the above range. The amount of the reaction product that inhibits the adhesion between the conductor layer and the porcelain can be reduced. Therefore, it is possible to prevent peeling of the conductor layer due to internal stress caused by the influence of the thermal expansion difference between the conductor layer and the porcelain due to heat applied in the laser processing or mounting process on the electronic device, and the reaction product is evaporated. Thus, gasification is performed, and an electronic component in which the conductor layer does not peel off due to internal stress generated between the conductor layer and the porcelain surface due to the volume expansion can be obtained.

  As in the present invention, the surface of the dielectric ceramic composition, which is a magnetic element, and the conductor layer are joined via the fluoride of the dielectric ceramic composition component, thereby improving the adhesive strength of the conductor layer. In the etching process to be performed, the low melting point compound or the carbide previously contained formed on the surface of the dielectric ceramic composition is covered with the fluoride, and the molten metal is directly contacted to evaporate and gasify. Therefore, the conductor layer can be more firmly bonded to the surface of the dielectric ceramic composition.

  Hereinafter, the best mode for carrying out the present invention will be described in detail.

  The electronic component of the present invention is an electronic component in which a conductor layer 1 is formed on the surface of a dielectric ceramic composition 3 (hereinafter referred to as porcelain 3), as shown in a partial cross section in FIG. 1, and the dielectric ceramic composition and conductor A product is present at the interface of the layers, and the ratio of the maximum peak intensity of the product to the maximum peak intensity of the dielectric ceramic composition in X-ray diffraction is set to 0.02-1.

  The electronic component having such a configuration is effective when used as an electronic component of a so-called 1005 size or less, for example, 1 mm × 0.5 mm × 0.5 mm, which is mainly used for a mobile phone or the like. For example, when trying to obtain an electronic component that functions as both an inductor (L) and a capacitor (C) by using the ultra-small electronic component such as the 1005 size, the porcelain 3 can be obtained by using winding and printing techniques that have been used conventionally. It is difficult to form a coil by winding a copper wire around the surface, and a technique is used in which the entire surface of the porcelain 3 is covered with the conductor layer 1 and processed into a coil shape by fine laser processing. In the electronic component formed by such a processing method, if the adhesion strength between the porcelain 3 and the conductor layer 1 is not made strong as a whole, the heat applied during the laser processing causes a gap between the conductor layer 1 and the porcelain 3. Internal stress is generated due to the difference in thermal expansion. If this stress exceeds the adhesion strength of the conductor layer 1 to the surface of the porcelain 3, peeling occurs.

  On the other hand, in order to improve the adhesion of the conductor layer 1 to the surface of the porcelain 3 due to the anchor effect, the surface of the porcelain 3 is generally roughened by etching in advance. However, during this etching process, the etching solution and the porcelain 3 react with each other on the surface of the porcelain 3 and the product 2 and the like generated by this reaction adhere to each other. The product 2 cannot be completely removed, and if it is severe, it may remain as a coating starting from the pores on the surface of the porcelain 3. Therefore, if a large amount of the product 2 remains on the surface of the porcelain 3, the product 2 tends to remain in the concave portion of the roughened porcelain 3 surface, and the unevenness on the surface of the porcelain 3 is reduced, so that the expected anchor effect can be obtained. Accordingly, the adhesion of the conductor layer 1 to the surface of the porcelain 3 is significantly reduced. For this reason, the adhesion strength between the conductor layer 1 and the porcelain 3 against the internal stress generated by the thermal expansion difference between the conductor layer 1 and the porcelain 3 due to the heat applied during the laser processing step and the incorporation step into the electronic device described above. If it is less than this, peeling occurs in the conductor layer 1.

  In addition, when the product 2 uses, for example, hydrofluoric acid that is generally used as an etching solution, the fluoride of the porcelain 3 and the oxide produced when the porcelain 3 undergoes a fluorination reaction are used as the reaction product 2. It remains on the surface of the porcelain 3. Among the products 2, the fluoride of the porcelain 3 generally has a low evaporation temperature and is easily evaporated at a low temperature. For this reason, when the conductor layer 1 is formed by a method such as electroless plating in a state in which the fluoride of the porcelain 3 remains on the surface of the porcelain 3, it takes place in the subsequent laser processing or assembling process into an electronic device. Under the influence of heat, the reaction product 2 evaporates and gasifies, resulting in a significant volume expansion. Due to the volume expansion, an internal stress is generated between the conductor layer 1 and the porcelain 3 in a direction in which the conductor layer 1 is peeled off. When the internal stress exceeds the adhesion strength, the conductor layer 1 partially blows up or peels off.

  In order to prevent such peeling of the conductor layer 1, it is necessary to minimize the generation amount and the residual amount of the product 2 remaining on the surface of the porcelain 3 during the etching process. However, quantification of these products 2 is difficult, and no method for confirming this abundance has been proposed yet.

  The present invention has been made in view of this point. The generated amount and the residual amount of the reaction product 2 between the porcelain 3 and the etching solution existing on the surface of the porcelain 3 are replaced with the peak intensity in the X-ray diffraction. It has been found that if the ratio between the maximum peak intensity of the product 2 and the maximum peak intensity of the porcelain 3 is in the range of 0.02-1, no peeling occurs in the conductor layer 1.

  That is, if the ratio between the peak intensity of the product 2 and the peak intensity of the porcelain 3 is detected at an equivalent level, the surface ratio of the porcelain 3 and the reaction product 2 is equal on the surface after etching. If it is in a state, it is possible to form an electronic component in which the conductor layer 1 does not peel off. When the maximum peak intensity of the porcelain 3 exceeds the maximum peak intensity of the product 2, the presence ratio of the product 2 on the surface of the porcelain 3 is small and the surface is more roughened. The adhesion of the will be improved. On the other hand, when the reaction product 2 becomes extremely small, as described above, it is considered that the surface of the porcelain 3 is roughened and the adhesion between the porcelain 3 and the conductor layer 1 is increased, and this product 2 is good. Also has a function of relieving internal stress generated by a difference in thermal expansion between the porcelain 3 and the conductor layer 1. Thus, the effect of relaxing the internal stress is obtained when the ratio of the maximum peak intensity of the product 2 to the maximum peak intensity of the porcelain 3 in the minute X-ray diffraction of the cross section of the electronic component is in the range of 0.02-1. Yes, if this ratio is less than 0.02 and the presence of the product 2 is minimized, the cooling process after the generation of the conductor layer 1, the subsequent laser processing process, and the heating in the electronic component mounting process There is a high possibility that the conductor layer 1 is peeled off due to an internal stress generated by the difference in thermal expansion between the conductor layer 1 and the porcelain 3.

  The present invention is effective only when a general hydrofluoric acid as an etching solution or a mixture of hydrofluoric acid and another etching solution is used. As the product 2, the fluoride and porcelain of the porcelain 3 are particularly useful. If the ratio is in the range of 0.02 to 1 using the maximum peak intensity in X-ray diffraction of oxides or the like generated when 3 is fluorinated, and the maximum peak intensity of porcelain 3, the surface of porcelain 3 Therefore, it is possible to form a good electronic component without peeling on the conductor layer 1.

  FIG. 2 shows an example of a porcelain 3 surface X-ray diffraction chart of the electronic component of the present invention. As the dielectric ceramic composition 3, for example, a three-component material of barium titanate-calcium titanate-strontium titanate is used. 3 and 4 show X-ray diffraction charts on the surface of the porcelain 3 when this is etched with a hydrofluoric acid solution having a concentration of 50% or more. The vertical axis represents the diffraction peak intensity, and the horizontal axis represents the diffraction angle (2θ). In FIG. 2, only the peak of the porcelain 3 is detected, while in FIGS. 3 and 4 after etching, it can be seen that many other peaks of the reaction product 2 are detected. In FIG. 4, the maximum peak intensity of the product 2 other than the porcelain 3 is larger than the maximum peak intensity of the porcelain 3, and the ratio is about 1.3, which is outside the range of 0.02-1. Become. In such a state of the surface of the porcelain 3, the conductor layer 1 is peeled off as described above due to the influence of heat applied in the processing step when the conductor layer 1 is subsequently formed to form an electronic component and the incorporation into the electronic device. Therefore, it is not preferable. Compared with FIG. 4, the peak intensity of the product 2 is lower on the surface of the post-etched porcelain 3 shown in FIG. 3 than on FIG. 4, and the product 2 is hardly present on the surface of the porcelain 3. The ratio of the highest peak intensity of the product 2 and the highest peak intensity of the porcelain 3 is about 0.09. Therefore, when the conductor layer 1 is formed on the surface of the porcelain 3, the presence of the product 2 that reduces the adhesion strength between the porcelain 3 and the conductor layer 1 is small, and as a stress relaxation layer for relaxing the stress due to the difference in thermal expansion. The product 2 is sufficiently present, and when this is used as an electronic component, the conductor layer 1 does not peel off due to the influence of heat applied during processing and incorporation into an electronic device.

  The average thickness of the product is preferably in the range of 0.5 to 10 μm. If the thickness is 0.5 μm or less, it does not function as a stress relaxation layer. This is because the surface irregularities are blocked and the adhesion due to the anchor effect with the conductor layer is hindered. The thickness of the product is obtained by calculating the average thickness of the products deposited in the concave portions of the ceramic 3 cross section at 10 places, and calculating the average value at the 10 places.

  In addition, the reason why the three-component material of barium titanate-calcium titanate-strontium titanate is used is that the electronic component of the present invention is mainly used for multimedia equipment such as a mobile phone and a digital tuner. To make it usable in a band, the dielectric constant is adjusted by adding one or more of calcium titanate and strontium titanate having low dielectric constant characteristics to barium titanate having high dielectric constant characteristics. This is because a higher dielectric constant characteristic can be obtained than conventional ceramics such as alumina and ferrite. Therefore, the dielectric ceramic composition 3 is preferably made of a composite sintered body containing barium titanate, one of calcium titanate and strontium titanate.

  The frequency band is required to be usable in a region of 800 MHz or higher. In order to obtain a dielectric that can resonate with a radio wave having a frequency of 800 MHz or higher in such a region, the product size Is constant, the electronic component must have a high dielectric constant and a desired resonance frequency.

  Further, as shown in FIG. 5, the dielectric ceramic composition 3 of the present invention has a composition in the range of 20 to 45 mol% barium titanate, 25 to 70 mol% calcium titanate, and 10 to 30 mol% strontium titanate. It is good to be composed of.

  The content ratio of each component is such that barium titanate exhibits particularly high dielectric constant characteristics. To increase the dielectric constant, the content ratio of barium titanate should be increased. As a result, the Curie point increases and the dielectric constant has a significant temperature dependence. For this reason, if the material composition has a barium titanate content of more than 45 mol%, when this is applied as an electronic component, the dielectric constant will change even with a slight temperature change. The performance of the device becomes unstable with temperature change, which is not preferable. On the other hand, if the content is less than 20 mol%, a high dielectric constant characteristic cannot be obtained, which is not preferable.

  The calcium titanate and strontium titanate are added to adjust the dielectric constant and lower the Curie point so that the temperature dependence of the dielectric constant is minimized. However, the present inventors have found that there is an appropriate content for these two materials. That is, with respect to calcium titanate, an addition amount of less than 25 mol% is not preferable because the proportion of barium titanate increases and the temperature dependence of the dielectric constant increases. On the other hand, if it exceeds 70 mol%, the dielectric constant is lowered, which is not preferable. Further, when the content of strontium titanate is less than 10 mol%, the ratio of barium titanate increases, and although a high dielectric constant can be obtained, its temperature dependency increases, which is not preferable. Moreover, when the addition amount is more than 30 mol%, the temperature at which the strontium titanate component is slightly dissolved in barium titanate to change from tetragonal to cubic is lowered, and the Curie point is also shifted to the low temperature side. Therefore, it is not preferable because the temperature dependency increases at a lower temperature.

  Further, in the three-component material of barium titanate-calcium titanate-strontium titanate, when etching is performed with hydrofluoric acid or a mixed solution of hydrofluoric acid and another etching solution, mainly BaTiO 3 is easily etched. Accordingly, the product 2 such as BaO and BaTiOF 6 produced by etching BaTiO 3 remains on the surface of the porcelain 3. Thus, in the X-ray diffraction chart of the surface of the porcelain 3 mainly etched with BaTiO 3, the maximum peak intensity of the product 2 is around 2θ = 28 ° around 2θ = 32 to 33 ° as shown in FIGS. The highest peak intensity of porcelain 3 exists.

  In the present invention, the ratio of the maximum peak intensity in the vicinity of 2θ = 28 ° of the product to the maximum peak intensity of the dielectric ceramic composition detected in the vicinity of 2θ = 32 to 33 ° in the X-ray diffraction is 0.02 to 0.02. More preferably, it is 1. As a result, the adhesion strength of the conductor layer 1 formed on the porcelain surface to the porcelain 3 is improved particularly when an electronic component is constructed using the three-component material of barium titanate-calcium titanate-strontium titanate as the porcelain 3. There is an effect that the residual amount of the product 2 generated by etching BaTiO3, which becomes a factor of decreasing, on the surface of the porcelain 3 is reduced.

  Examples of the product 2 include BaTiF6, CaTiF6, and SrTiF6 as fluorides, and BaO, CaO, and SrO that are simultaneously generated when the BaTiF6 and the like are generated as oxides.

  Further, as described above, the residual amount of the product 2 using X-ray diffraction can be confirmed by checking that the spot diameter is 2 at the boundary between the conductor layer 1 and the dielectric ceramic in the cross section of the electronic component after the conductor layer 1 is formed. The measurement can be performed by using a commercially available micro X-ray diffractometer of 10 μm and analyzing the X-ray diffraction chart. The cross section is more preferably measured by processing the surface roughness to 1 μm or less in order to irradiate minute X-rays.

  Further, the electronic component of the present invention has a characteristic that the peel strength of the conductor layer 1 is 10 MPa or more. The peel strength is measured by applying a load resistance of 10 gf or more with a scratch tester generally used for confirming the adhesion of the film. When this measured value is less than 10 MPa, the conductor layer When the porcelain and the conductor layer 1 expand due to heat generation during the processing step 1 or the incorporation into the electronic device, the conductor layer 1 peels off due to the internal stress generated between the conductor layer 1 and the porcelain due to the thermal expansion difference. This is not preferable.

  Next, details of the method for manufacturing an electronic component of the present invention will be described using an example in which a ternary material of barium titanate, calcium titanate, and strontium titanate is used.

  First, commercially available primary raw materials of barium titanate, calcium titanate, and strontium titanate having a particle diameter of 0.5 to 10 μm are obtained. These are obtained by barium titanate 20 to 40 mol%, calcium titanate 35 to 70 mol%. , Mixed with an appropriate amount of binder and water within the range of 10-25% strontium titanate, and pulverized and mixed using a mixing pulverizer such as a ball mill or a bead mill to produce a slurry. After discharging the slurry, A secondary raw material having good powder flowability is produced by granulating with a spray granulator such as a spray dryer. And after shape | molding the said secondary raw material to a predetermined shape with the shaping | molding pressure of 0.5-2 t / cm <2> by methods, such as powder press molding, and obtaining the green compact of 2.7-3.2 g / cm <3>, It is fired at a temperature of 1200 to 1500 ° C. in the air atmosphere to obtain a dielectric ceramic composition 3 comprising three components of barium titanate, calcium titanate and strontium titanate used for the electronic component of the present invention.

  Thereafter, the surface of the dielectric ceramic composition 3 is etched in order to increase the adhesion strength between the conductor layer 1 and the ceramic. As the etching method, chemical etching with an etching solution is performed. As the etching solution, in the present invention, it is particularly preferable to add water to a hydrofluoric acid solution having a concentration of 15% to 80% or a mixed solution of hydrofluoric acid and nitric acid.

  Here, hydrofluoric acid or a mixed solution of hydrofluoric acid and nitric acid is used as the etching solution in order to roughen the surface of the dielectric ceramic composition 3 with barium titanate, calcium titanate, titanic acid on the surface. This is because any of the strontium crystals can be reacted with hydrofluoric acid or a mixed solution of hydrofluoric acid and nitric acid, and then the crystals floating on the porcelain surface by the reaction can be removed by washing. The reason why the concentration of the hydrofluoric acid or hydrofluoric acid / nitric acid mixed solution in the etching solution is in the above range is that if the concentration is made lower than 15%, the effect of the etching solution is insufficient and a sufficient etching effect cannot be obtained. This is because if the content is higher than%, the production cost is affected. More preferably, it is good to set it as 30 to 70% of range. In some cases, the etching of the hydrofluoric acid solution and the mixed solution of hydrofluoric acid and nitric acid is less likely to proceed at a higher concentration than at a lower concentration. In the present invention, the same phenomenon was confirmed when the surface of the dielectric ceramic composition 3 was etched using a high-concentration hydrofluoric acid or a mixed solution of hydrofluoric acid and nitric acid. It is not.

  Then, the conductor layer 1 is formed on the surface of the dielectric ceramic composition 3 after the etching. The conductor layer 1 can be formed by electroplating, electroless plating, painting, spraying, etc., but it is preferable to use the electroless plating method from the viewpoint of accuracy and cost after the formation of the conductor layer 1. They are formed using a commercially available electroless plating apparatus. As the material of the conductor layer 1 (plating), nickel, zinc, tin, chromium, solder, cobalt, palladium, copper, silver, gold, etc., or alloys thereof can be applied. Especially, the price, thermal conductivity, and porcelain are applicable. In consideration of characteristics such as no need to raise to a high temperature, it is preferable to use copper plating. After the formation of the conductor, the surface of the conductor layer 1 can be processed by polishing the surface of the conductor layer 1 by blasting, buffing, barrel polishing or the like, if necessary.

  The shape of the dielectric ceramic composition 3 may be any shape, but laser processing is difficult with a hollow shape, and it is preferable to use a solid body. Furthermore, in order to eliminate the resistance of the electrode part, it is also possible to use one having only the thickness of the electrode part increased.

  The electronic component of the present invention manufactured as described above does not peel off the conductor layer 1 formed on the surface of the dielectric ceramic composition 3 and has a very high dielectric constant characteristic. It can be installed in multimedia devices such as mobile phones used in the frequency band, and electronic devices equipped with the electronic parts of the present invention have stable radio wave reception characteristics and exhibit excellent performance over a long period of time. It becomes possible to do.

  Next, an example of an electronic device equipped with the electronic component of the present invention will be described.

  The electronic component of the present invention can be mounted on, for example, a mobile phone 10 as shown in FIG. The cellular phone 10 has different frequency bands used by telephone companies and countries around the world, and must be able to handle a wide frequency band from 800 to 2000 MHz. On the other hand, when the electronic component of the present invention is mounted, the same shape as that of the conventional electronic component has a very high dielectric constant and low temperature dependence of the dielectric constant. The resonance frequency can be made to correspond to radio waves in the frequency band, and can be favorably applied as an electronic component for mobile phones.

  Furthermore, since the electronic component of the present invention has a high dielectric constant and a low temperature dependency of the dielectric constant compared to a conventional electronic component having a low dielectric constant, a digital tuner used for sanitary broadcasting, BS broadcasting, etc. It can also be used as an electronic component for a digital tuner that can be used in a frequency band of 500 to 600 MHz.

  As mentioned above, although the electronic component and its manufacturing method of the present invention have been described, it goes without saying that the present invention can be applied to various improvements and modifications as long as they do not depart from the gist of the present invention.

  Examples of the present invention will be described below.

Example 1
An electronic component of the present invention in which the dielectric ceramic composition 3 was coated with the conductor layer 1 was formed, and a test for evaluating the adhesion of the conductor layer 1 to the ceramic 3 was performed.

  First, commercially available primary raw materials of barium titanate, calcium titanate, and strontium titanate are purchased, put into a ball mill together with a binder and water, and then mixed and ground for 6 hours or more. Thereafter, the slurry was discharged from a ball mill, and the slurry was granulated with a spray granulator such as a spray dryer to produce a secondary material. And the said secondary raw material is shape | molded by the raw density of 2.7-3.2 g / cm3 using a press molding machine, a molded object is produced, and this is baked at the temperature of 1200-1500 degreeC in air | atmosphere. Porcelain 3 was obtained.

  Next, in order to form the conductor layer 1 on the surface of the porcelain 3, first, a mixed solution of hydrofluoric acid and nitric acid in which the concentration of the surface of the porcelain 3 is shaken to 10%, 12%, 15%, 30%, 50%, 80%. The surface of the porcelain 3 is roughened by etching at a ratio of hydrofluoric acid: nitric acid = 2: 1. Etching was performed by immersing the porcelain 3 in the etching solution bath for 5 to 20 minutes.

  Then, the surface of the porcelain 3 after the etching is subjected to copper plating by a general plating method, so that a sample No. 0603 size of 0.6 mm × 0.3 mm × 0.3 mm size is obtained. 1 to 9 electronic components were obtained. In addition, each sample is produced with n number of 10 or more.

  Sample No. For 1 to 8 electronic parts, one of n = 10 is subjected to resin embedding so that it can be divided into two in the vertical direction with respect to the surface of the porcelain 3 provided with a plating layer, and it is mirror-finished. After the two-divided size was washed, the boundary portion between the conductor layer 1 and the porcelain 3 was analyzed with a micro X-ray diffractometer (spot diameter of 5 to 20 μm). From the X-ray diffraction chart, the product 2 and The ratio of the highest peak intensity of porcelain 3 is taken as the X-ray diffraction peak intensity ratio, and it is evaluated as ○ when it is within the range of the present invention, 0.02-1, and as x otherwise. Yes.

  Moreover, about 5 in remaining n number, the scratch test was implemented on the conditions of the load of 10 kgf using the commercially available scratch test machine, and the average value of the peeling strength was measured. After the peel test, the conductor layer 1 is further processed using a commercially available laser processing machine, and the conductor layer 1 can be satisfactorily processed. Was evaluated as x.

The results are shown in Table 1.

  From Table 1, the sample Nos. 10 and 12% whose etching solution concentrations are lower than 15% are shown. As for 1 and 2, in the micro X-ray diffraction chart, the maximum peak intensity of the reaction product 2 between the etchant and the porcelain is higher than the maximum peak intensity of the dielectric porcelain. Since the ratio of the maximum peak intensity of 3 was larger than 1, it was confirmed in the subsequent scratch test that the peel strength of the plating layer was low due to the influence of the product 2 and was outside the range of the present invention.

  It was also confirmed that the lower the concentration of the etchant, the more the dielectric ceramic surface was etched. This is considered to be related to the dissociation concentration of hydrofluoric acid contained in the etching solution. Therefore, the sample No. with a low concentration of the etching solution is used. With regard to 1 and 2, since many products 2 remained on the porcelain surface, it is considered that the adhesion strength of the copper plating to the porcelain surface was lowered.

  Furthermore, the sample No. 2 having the highest etching solution concentration of 92% was obtained. Regarding No. 9, since the porcelain surface is hardly etched and the product 2 is hardly formed, the X-ray diffraction peak intensity ratio is smaller than 0.02. For this reason, when the conductor layer 1 is formed on the porcelain 3, the product 2 as a stress relaxation layer that relieves the stress generated by the difference in thermal expansion between the two is hardly formed. The conductor layer was peeled off by laser processing.

  In comparison with this, Sample No. About 3-8, there were few reaction products 2 of the etching liquid and porcelain component which remain | survived on the ceramic surface, and peeling strength was as favorable as 10 Mpa or more. In addition, the sample No. in which the concentration of the etching solution is higher than 80%. Samples Nos. 7 and 8 were prepared by etching with an etching solution having a concentration of 50% or 80% to roughen the surface of the porcelain. Compared with 5 and 6, the peel strength of the copper plating layer as the conductor layer 1 tended to decrease. As described above, as described above, the dissociation concentration of hydrofluoric acid is related, and it is considered that the surface is not easily roughened by etching because the dissociation is difficult when the hydrofluoric acid concentration is high.

  Further, using the etching solution having a ratio of hydrofluoric acid and nitric acid of 1: 1 and 1: 2 in the etching solution, the surface of the dielectric ceramic was roughened in the same manner as described above, and a sample in which a copper plating layer was formed was produced. . As a result, the surface of the porcelain can be roughened, and the same effect can be exerted with respect to the peel strength of the copper plating layer. It was confirmed that this was undesirable.

(Example 2)
Next, in the same manufacturing method as in Example 1, the sample No. 5 was changed in the composition ratio of barium titanate (BaTiO3), calcium titanate (CaTiO3), and strontium titanate (SrTiO3). The dielectric ceramic composition 3 of 9-27 was produced, and the relative dielectric constant was measured.

  The specific material composition ratio is a point shown in FIG. 7 for each sample, and the relative dielectric constant (εr) of this dielectric ceramic composition 3 at a size of 0.6 mm × 0.3 mm × 0.3 mm is measured. Has been implemented.

The results are shown in Table 2.

  From Table 2, it can be seen that the relative dielectric constant tends to increase as the addition amount of barium titanate and strontium titanate increases. Therefore, sample No. 2 with a small amount of barium titanate added. Nos. 9 to 11 have a low relative dielectric constant, which is not preferable, and 19 and 24 having a small amount of addition of strontium titanate have a large relative dielectric constant because of a large amount of barium titanate. is not.

  In addition, the inventors of the present invention have the sample no. Samples similar to those of 9 to 27 were prepared, and a test for examining the temperature dependence of the change in dielectric constant was performed using this dielectric ceramic. The results are shown in Table 2. The evaluation is x when the dielectric constant at room temperature is 2 times or more, Δ when it is 1.5 times or more and less than 2 times, and ◯ when it is less than 1.5 times.

  As a result, Sample No. with the largest amount of barium titanate added. It was confirmed that Nos. 25 to 27 have a particularly large change amount of the relative dielectric constant depending on the temperature and have a change rate of more than twice the relative dielectric constant at room temperature, which is not suitable for use as an electronic component. Sample No. 2 with a large amount of strontium titanate added. Although it was not as high as barium titanate also about 15 and 20, it was confirmed that the change of a dielectric constant is large and it is not suitable to use as an electronic component. The change in the relative permittivity depends on the change rate of the capacitance used for calculating the relative permittivity.

  As described above, it was confirmed that when the amount of barium titanate or strontium titanate added is excessively increased, the dielectric constant characteristics are improved, but the temperature dependency may be deteriorated.

  In comparison with this, sample No. Especially about 12-14, 16-18, 21-23, the favorable characteristic was shown.

  Next, the above-mentioned sample No. 1 having a high relative dielectric constant and a low temperature dependence of a change in dielectric constant of less than 1.5 times showed good characteristics. After forming a copper plating layer on the surface using the dielectric ceramic of No. 23 in the same manner as in Example 1, the plating layer was processed into a winding shape by laser processing to complete an electronic component. After that, when this was mounted on a mobile phone as a noise filter, it was confirmed that good characteristics were exhibited.

The partial schematic sectional drawing of the electronic component of this invention is shown. The X-ray diffraction chart before the etching of the dielectric ceramic of the present invention is shown. The X-ray diffraction chart after the etching of the dielectric ceramic within the scope of the present invention is shown. The X-ray diffraction chart after the etching of the dielectric ceramic outside the scope of the present invention is shown. It is the figure which showed the composition range of the dielectric ceramic composition used for the electronic component of this invention. It is the schematic which shows the mobile telephone carrying the electronic component of this invention. It is the schematic which shows each composition point of the dielectric material ceramic composition sample which consists of barium titanate, calcium titanate, and strontium titanate used for Example 2 of this invention.

Explanation of symbols

1: Conductor layer 2: Product 3: Porcelain (dielectric porcelain composition)
10: Mobile phone

Claims (10)

In an electronic component in which a conductor layer is formed on the surface of a dielectric ceramic composition, there is a product at the interface between the dielectric ceramic composition and the conductor layer, and the maximum peak intensity of the dielectric ceramic composition in X-ray diffraction The ratio of the maximum peak intensity of the product with respect to is 0.02 to 1, and the electronic component. The electronic component according to claim 1, wherein the dielectric ceramic composition includes at least one of barium titanate, calcium titanate, and strontium titanate. The dielectric ceramic composition is configured as a total of 100 mol% within a range of 20 to 45 mol% barium titanate, 25 to 70 mol% calcium titanate, and 10 to 30 mol% strontium titanate. The electronic component according to claim 1 or 2, characterized in that 4. The electronic component according to claim 1, wherein the product is made of at least an oxide or fluoride of the dielectric ceramic composition and has an average thickness of 0.5 to 10 [mu] m. . 5. The electronic component according to claim 1, wherein the product is made of BaO, CaO, and SrO, and the fluoride is made of BaTiF6, CaTiF6, and SrTiF6. The ratio of the maximum peak intensity of the product detected near 2θ = 28 ° to the maximum peak intensity of the dielectric ceramic composition detected near 2θ = 32 to 33 ° by X-ray diffraction is 0. The electronic component according to claim 1, wherein the electronic component is. The electronic component according to claim 1, wherein the peel strength of the conductor layer is 10 MPa or more. A mobile phone using the electronic component according to claim 1 as an inductor and / or a capacitor. A digital tuner using the electronic component according to claim 1 as an inductor and / or a capacitor. Mixing a raw material composed of barium titanate, calcium titanate, strontium titanate, forming and firing to form a dielectric ceramic composition;
Etching the surface of the dielectric ceramic composition with a hydrofluoric acid solution having a concentration of 15% to 80% or a mixed solution of hydrofluoric acid and nitric acid;
The method of manufacturing an electronic component according to claim 1, further comprising a step of coating the plating layer after etching.

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