JP2016171236A - Ceramic electronic component and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceramic electronic component in which troubles hardly occur at the time of mounting, and to provide a method of manufacturing the same.SOLUTION: A multilayer ceramic inductor 10, as a ceramic electronic component, includes a ceramic element body 12 having a substantially rectangular parallelepiped shape. A coil 16 is formed inside the ceramic element body 12. External electrodes 24a and 24b are formed on end surfaces 12e and 12f of the ceramic element body 12, respectively. On the surface of the ceramic element body 12, a water-repellent/flux-repellent film 34 having water-repellency and flux-repellency is formed on portions on which the external electrodes 24a and 24b are not formed, that is, main surfaces 12a and 12b and side surfaces. The water-repellent/flux-repellent film 34 contains Sn and an organosilane having a fluoroalkyl group.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a ceramic electronic component and a method for manufacturing the same, and more particularly, to a ceramic body having pores and a plurality of external electrodes formed on the surface of the ceramic body, for example, a multilayer ceramic inductor, multilayer ceramic capacitor, ceramic piezoelectric The present invention relates to a ceramic electronic component such as a component and a manufacturing method thereof.

International Publication No. WO02 / 082480 discloses a ceramic electronic component such as a chip inductor (see Patent Document 1). In the ceramic electronic component disclosed in Patent Document 1, in order to prevent the occurrence of ion migration, a water repellent film is formed in a gap that leads to the outside between two or more electrodes arranged at a predetermined distance. ing. The water repellent film is formed of, for example, a silane coupling agent containing a perfluoroalkyl group. The ceramic electronic component disclosed in Patent Document 1 has pores on the surface and inside of the sintered body of the ceramic electronic component.
International Publication No. 2010/073493 discloses a ceramic electronic component such as a multilayer ceramic inductor (see Patent Document 2). The ceramic electronic component disclosed in Patent Document 2 is a ceramic body that is obtained by subjecting a ceramic body to an oil repellency treatment using an oil repellency treatment agent that contains a polyfluoroether compound as a main component and hydrofluoroether as a solvent. This is a ceramic electronic component in which a flux intrusion prevention film is formed on the surface. The flux intrusion prevention film is formed to prevent the flux from entering the pores of the ceramic body.

International Publication No. 02/082480 International Publication No. 2010/073493

  In recent years, ceramic electronic components have been increasingly required to be improved in reliability. Further, the water-repellent film and the flux infiltration prevention film provided in the conventional ceramic electronic components as disclosed in Patent Documents 1 and 2 are further increased. There is a need for improved flux repellency.

  SUMMARY OF THE INVENTION Therefore, a main object of the present invention is to provide a ceramic electronic component and a method for manufacturing the same, which are less prone to problems during mounting.

The ceramic electronic component according to the present invention is a ceramic electronic component having a ceramic element body having pores and a plurality of external electrodes formed on the surface of the ceramic element element at intervals. A water repellent / flux repellent film having water and flux repellent properties is formed, and the water repellent / flux repellent film is a ceramic electronic component comprising organosilane containing a fluoroalkyl group and Sn.
In the ceramic electronic component according to the present invention, the water repellent / flux repellent film preferably further contains Cl.
In the ceramic electronic component according to the present invention, the water-repellent / flux-repellent film has an Sn concentration ratio of 0.01 to 0.2 and a Cl content of 0.01 with respect to the constituent elements of the ceramic body in XPS analysis. A film containing 0.7 or more and less is preferable.
Furthermore, in the ceramic electronic component according to the present invention, the organosilane is
CF ₃ — (CF ₂ ) _n1 —R—Si (O—R ′) ₃
(Where n1 is an integer of 0 or more, R is a substituent or alkylene group containing Si or O, and R ′ is an alkyl group)
Or a silane coupling agent represented by
_{CF 3 - (CF 2) n2} -CONH- (CH 2) m -Si (O-R '') 3
(Where n2 is an integer of 0 or more, m is an integer of 0 or more, and R ″ is an alkyl group)
It is preferable that it is formed from the amide bond containing silane coupling agent represented by these.
Another ceramic electronic component according to the present invention is a surface of a ceramic body in a ceramic electronic component having a ceramic body having pores and a plurality of external electrodes formed at intervals on the surface of the ceramic body. Water repellent / flux repellent film having water repellency and flux repellency is formed on a portion where a plurality of external electrodes are not formed.
_{CF 3 - (CF 2) n2} -CONH- (CH 2) m -Si (O-R '') 3
(Where n2 is an integer of 0 or more, m is an integer of 0 or more, and R ″ is an alkyl group)
It is formed from the amide coupling containing silane coupling agent represented by these, It is a ceramic electronic component characterized by the above-mentioned.
In the ceramic electronic component according to the present invention and other ceramic electronic components according to the present invention, for example, each of the plurality of external electrodes includes a base electrode formed on the surface of the ceramic body.
In the ceramic electronic component according to the present invention and the other ceramic electronic component according to the present invention, for example, each of the plurality of external electrodes further includes at least one plated film formed on the base electrode.
A method for manufacturing a ceramic electronic component according to the present invention is a method for manufacturing a ceramic electronic component for manufacturing a ceramic electronic component according to the present invention. Forming a plurality of external electrodes spaced apart, and forming a water-repellent / flux-repellent film containing organosilane containing a fluoroalkyl group and Sn on the surface of the ceramic body where the plurality of external electrodes are not formed A method for manufacturing a ceramic electronic component, comprising the step of:
In the method of manufacturing a ceramic electronic component according to the present invention, in the step of forming the water-repellent / flux-repellent film, for example,
CF ₃ — (CF ₂ ) _n1 —R—Si (O—R ′) ₃
(Wherein n1 is an integer of 0 or more, R is a substituent or alkylene group containing Si or O, and R ′ is an alkyl group) and a Sn compound represented by An Sn-containing silane coupling agent solution containing is prepared, and the ceramic body on which the external electrode is formed is immersed in the Sn-containing silane coupling agent solution.
Another method for manufacturing a ceramic electronic component according to the present invention is a method for manufacturing a ceramic electronic component for manufacturing another ceramic electronic component according to the present invention, comprising the steps of preparing a ceramic element, The step of forming a plurality of external electrodes at intervals on the surface, and the portion of the surface of the ceramic body where the plurality of external electrodes are not formed,
_{CF 3 - (CF 2) n2} -CONH- (CH 2) m -Si (O-R '') 3
(Where n2 is an integer of 0 or more, m is an integer of 0 or more, and R ″ is an alkyl group)
A method for producing a ceramic electronic component comprising a step of forming a water-repellent / flux-repellent film from an amide bond-containing silane coupling agent represented by:
In the method for manufacturing a ceramic electronic component according to the present invention and the method for manufacturing another ceramic electronic component according to the present invention, the step of forming the plurality of external electrodes includes the step of forming a plurality of base electrodes at intervals on the surface of the ceramic body. The step of forming the water-repellent / flux-repellent film including the step of forming is preferably performed after the step of forming the plurality of base electrodes.
Furthermore, in the method for manufacturing a ceramic electronic component according to the present invention and the method for manufacturing another ceramic electronic component according to the present invention, the step of forming the plurality of external electrodes includes at least one plated film on each of the plurality of base electrodes. The step of forming the water repellent / flux repellent film is preferably performed before the step of forming the plating film.
In the method for manufacturing a ceramic electronic component according to the present invention and the method for manufacturing another ceramic electronic component according to the present invention, the step of forming the plurality of external electrodes includes at least one plated film on each of the plurality of base electrodes. The step of forming the water repellent / flux repellent film may be performed after the step of forming the plating film.

In the ceramic electronic component according to the present invention, the water repellent / flux repellent film contains organosilane containing fluoroalkyl group and Sn, so that the reaction between the ceramic body and the silane coupling agent that forms the water repellent / flux repellent film. Can increase the sex. Therefore, a dense water / flux repellent film can be formed on the surface of the ceramic body. Therefore, in the ceramic electronic component according to the present invention, it is possible to prevent moisture and flux from entering the pores of the ceramic body, and to prevent occurrence of ion migration due to moisture and occurrence of mounting failure due to flux. it can. Therefore, in the ceramic electronic component according to the present invention, the reliability of the ceramic electronic component can be improved.
In the ceramic electronic component according to the present invention, when the water-repellent / flux-repellent film further contains Cl, the reactivity between the ceramic body and the silane coupling agent forming organosilane is further increased. Therefore, a dense water-repellent / flux-repellent film can be formed on the surface of the ceramic body. In this case, when the water / flux repellent film contains Sn and Cl, a finer water / flux repellent film can be formed on the surface of the ceramic body. Therefore, when the water-repellent / flux-repellent film contains Sn and Cl, the reliability of the ceramic electronic component can be further improved.
Furthermore, in the ceramic electronic component according to the present invention, when the solution for forming the water-repellent / flux-repellent film contains Sn, the Sn component derived from the Sn compound is deposited on the external electrode when the solution is attached to the external electrode. Adsorbed. And organosilane is hard to adhere on adsorbed Sn. Therefore, the organosilane in the water-repellent / flux-repellent film can easily be selectively attached to the surface of the ceramic body, and can be prevented from attaching to the external electrode. As a result, problems such as non-plating or solder non-wetting on the external electrode can be prevented. Therefore, when the water-repellent / flux-repellent film contains Sn and Cl, the reliability of the ceramic electronic component can be improved also in this respect.
In the ceramic electronic component according to the present invention, in order to form a finer water-repellent / flux-repellent film as described above, in XPS analysis, the water-repellent / flux-repellent film is subjected to an atomic concentration relative to the constituent elements of the ceramic body. The film preferably contains Sn in a ratio of 0.01 to 0.2 and Cl in a range of 0.01 to 0.7.
Moreover, in the ceramic electronic component according to the present invention, in order to form a dense water-repellent / flux-repellent film as described above,
CF ₃ — (CF ₂ ) _n1 —R—Si (O—R ′) ₃
(Where n1 is an integer of 0 or more, R is a substituent or alkylene group containing Si or O, and R ′ is an alkyl group)
Or a silane coupling agent represented by
_{CF 3 - (CF 2) n2} -CONH- (CH 2) m -Si (O-R '') 3
(Where n2 is an integer of 0 or more, m is an integer of 0 or more, and R ″ is an alkyl group)
It is preferable that it is formed from the amide bond containing silane coupling agent represented by these.
In another ceramic electronic component according to the present invention, the water repellent / flux repellent film is formed of an amide bond-containing silane coupling agent having a fluoroalkyl group and an amide bond. Adhesion with the film is increased. Therefore, even in other ceramic electronic components according to the present invention, moisture and flux are prevented from entering the pores of the ceramic body, and ion migration caused by moisture and mounting defects caused by flux are prevented. be able to. Therefore, the reliability of the ceramic electronic component can be improved also in other ceramic electronic components according to the present invention.
In the method for manufacturing a ceramic electronic component according to the present invention and the method for manufacturing another ceramic electronic component according to the present invention, the step of forming the plurality of external electrodes includes the step of forming a plurality of base electrodes at intervals on the surface of the ceramic body. When the water repellent / flux repellent film is formed after the step of forming the plurality of base electrodes, the step of forming the water repellent / flux repellent film is performed on the surface of the ceramic body when forming the water repellent / flux repellent film. Since the base electrode is already formed on the part where the external electrode is formed, the water-repellent / flux-repellent film can be easily formed on the surface of the ceramic body where a plurality of external electrodes are not formed. it can.
Furthermore, in the method for manufacturing a ceramic electronic component according to the present invention and the method for manufacturing another ceramic electronic component according to the present invention, the step of forming the plurality of external electrodes includes at least one plated film on each of the plurality of base electrodes. The step of forming the water-repellent / flux-repellent film is performed before the step of forming the plating film, and is the surface of the ceramic body when forming the plating film and the external electrode. Since the water-repellent / flux-repellent film is already formed in the portion where the film is not formed, it is possible to prevent the plating solution and the cleaning solution from entering the pores of the ceramic body.
In the method for manufacturing a ceramic electronic component according to the present invention and the method for manufacturing another ceramic electronic component according to the present invention, the step of forming the plurality of external electrodes includes at least one plated film on each of the plurality of base electrodes. The step of forming the water-repellent / flux-repellent film is further performed after the step of forming the plated film, and the water-repellent / flux-repellent film is still formed when the plated film is formed. Therefore, the plating film can be easily formed on the base electrode.

  According to the present invention, it is possible to obtain a ceramic electronic component with improved reliability that is unlikely to cause problems during mounting.

  The above-described object, other objects, features, and advantages of the present invention will become more apparent from the following description of embodiments for carrying out the invention with reference to the drawings.

It is a perspective view which shows an example of the multilayer ceramic inductor as a ceramic electronic component concerning this invention. 2 is a cross-sectional view of the multilayer ceramic inductor shown in FIG. 1 taken along line II-II in FIG. It is a disassembled perspective view which shows typically the principal part structure of the multilayer ceramic inductor shown in FIG. FIG. 2 is a partially enlarged schematic view showing an example of pores and discontinuous water / flux resistant films of the ceramic body of the multilayer ceramic inductor shown in FIG. 1. It is a figure which shows the structural formula of an example of the silane coupling agent used for the water repellent / flux repellent film of the multilayer ceramic inductor shown in FIG. It is a figure which shows the structural formula of an example of the amide bond containing silane coupling agent used for the water repellent / flux repellent film of the multilayer ceramic inductor shown in FIG.

  FIG. 1 is a perspective view showing an example of a multilayer ceramic inductor as a ceramic electronic component according to the present invention. FIG. 2 is a cross-sectional view of the multilayer ceramic inductor shown in FIG. FIG. 3 is an exploded perspective view schematically showing a main configuration of the multilayer ceramic inductor shown in FIG. FIG. 4 is a partially enlarged schematic view showing an example of pores and discontinuous water / flux resistant film of the ceramic body of the multilayer ceramic inductor shown in FIG. 1.

  A multilayer ceramic inductor 10 shown in FIG. 1 includes a substantially rectangular parallelepiped ceramic body 12 made of ferrite, for example. As shown in FIG. 1, the ceramic body 12 may include a plurality of ferrite layers 14. These ferrite layers 14 are integrally sintered in a laminated state. The ceramic body 12 has pores on the surface and inside (for example, see FIG. 4). The ceramic body 12 includes a first main surface 12a and a second main surface 12b facing each other, a first side surface 12c and a second side surface 12d facing each other, and a first end surface 12e facing each other. And a second end face 12f. The first side surface 12c and the second side surface 12d are connected to the first main surface 12a and the second main surface 12b, respectively. The first end surface 12e and the second end surface 12f are connected to the first main surface 12a, the second main surface 12b, the first side surface 12c, and the second side surface 12d, respectively. The ceramic body 12 has rounded corners and ridges. The ceramic body 12 may be formed in other shapes.

  Inside the ceramic element body 12 is a coil 16. The coil 16 is made of, for example, Cu or Ag. The coil 16 includes a patterned conductor 18. These patterned conductors 18 are formed on each ferrite layer 14. The patterned conductors 18 are connected in a coil shape by via holes 20 formed in the ferrite layer 14. One end of the coil 16 is led out to the first end face 12e of the ceramic body 12 as a first lead electrode 22a. The other end of the coil 16 is led out to the second end face 12f of the ceramic body 12 as the second lead electrode 22b. The coil 16 may be a conducting wire wound in a coil shape.

On the first and second end faces 12e, 12f side of the ceramic body 12, first and second external electrodes 24a, 24b are formed, respectively.
The first external electrode 24a is formed from the first end face 12e of the ceramic body 12 to the first and second main faces 12a, 12b and the first and second side faces 12c, 12d. In this case, the first external electrode 24 a is electrically connected to the first extraction electrode 22 a of the coil 16.
The second external electrode 24b is formed from the second end face 12f of the ceramic body 12 to the first and second main faces 12a, 12b and the first and second side faces 12c, 12d. In this case, the second external electrode 24 b is electrically connected to the second extraction electrode 22 b of the coil 16.

The external electrode 24a includes a base electrode 26a and a plating film 28a in this order from the ceramic body 12 side.
The base electrode 26a is made of a conductor such as Ag or an Ag alloy. The base electrode 26a is formed on the surface of the ceramic body 12, that is, on the first end face 12e. In this case, the base electrode 26a is electrically connected to the first extraction electrode 22a.
The plating film 28a has a two-layer structure including the Ni plating film 30a and the Sn plating film 32a. The Ni plating film 30a is formed on the base electrode 26a. The Sn plating film 32a is formed on the Ni plating film 30a.

Similarly to the external electrode 24a, the external electrode 24b includes a base electrode 26b and a plating film 28b in this order from the ceramic body 12 side.
The base electrode 26b is made of a conductor such as Ag or an Ag alloy. The base electrode 26b is formed on the surface of the ceramic body 12, that is, on the second end face 12f and the like. In this case, the base electrode 26b is electrically connected to the second extraction electrode 22b.
The plating film 28b has a two-layer structure including the Ni plating film 30b and the Sn plating film 32b. The Ni plating film 30b is formed on the base electrode 26b. The Sn plating film 32b is formed on the Ni plating film 30b.

  On the surface of the ceramic body 12, the portions where the external electrodes 24a, 24b are not formed, that is, the main surfaces 12a, 12b and the side surfaces 12c, 12d between the external electrodes 24a, 24b have water repellency and flux repellency. A water / flux repellent film 34 is formed. The water repellent / flux repellent film 34 is for preventing moisture and flux from entering the pores of the ceramic body 12 from the outside.

The water repellent / flux repellent film 34 includes, for example, organosilane containing a fluoroalkyl group and Sn. The water repellent / flux repellent film 34 preferably further contains Cl. Further, the water-repellent / flux-repellent film 34 contained Sn in the range of 0.01 to 0.2 and Cl in the range of 0.01 to 0.7 in terms of the atomic concentration ratio with respect to the constituent elements of the ceramic body 12 in XPS analysis. A membrane is preferred.
Alternatively, the water / flux repellent film 34 is formed from an amide bond-containing silane coupling agent.

Here, a method for calculating an atomic concentration ratio using analysis using X-ray photoelectron spectroscopy (hereinafter also referred to as XPS analysis) will be described.
The atomic concentration ratio can be obtained using the following equation.
Atomic concentration ratio = (atomic concentration of target element in flux repellent film) / (constituent atomic concentration of constituent elements of ceramic body)
The atomic concentration can be measured by XPS analysis.
The constituent atoms of the ceramic body indicate transition metal elements in the ceramic. Does not contain oxygen. For example, when Cu—Ni—Zn-based ferrite is used as the raw material of the element body, the constituent elements are Fe, Cu, Ni, and Zn. The measurement conditions for XPS analysis are as follows.
Measurement conditions VersaProbe manufactured by ULVAC-PHI is used as an X-ray photoelectron spectrometer. In this case, the measurement region is a region having a diameter of 100 μm and an analysis depth of several nm. The X-ray source is AlKα radiation. The total number of surveys is 10. The survey energy range is 0-1200 eV.

Organosilane contained in the water / flux repellent film 34 is:
CF ₃ — (CF ₂ ) _n1 —R—Si (O—R ′) ₃
(Where n1 is an integer of 0 or more, R is a substituent or alkylene group containing Si or O, and R ′ is an alkyl group)
It is preferable that it is formed from the silane coupling agent represented by these.
For example, n1 may be an integer from 0 to 7. R ′ may be a methyl group or an ethyl group.

The silane coupling agent used in the present invention includes at least one alkoxy group that is a reactive group. The silane coupling agent has one or more perfluoroalkyl groups.
Specifically, as the silane coupling agent, for example, the silane coupling agent shown in FIG.
CF ₃ (CF ₂ ) ₅ (CH ₂ ) ₂ Si (OCH ₃ ) ₃
Or
CF ₃ (CF ₂ ) ₃ (CH ₂ ) ₂ Si (OCH ₃ ) ₃ ,
CF ₃ (CF ₂ ) ₃ (CH ₂ ) ₂ Si (OC ₂ H ₅ ) ₃ ,
CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (OCH ₃ ) ₃ ,
CF ₃ CH ₂ O (CH ₂ ) ₁₅ Si (OCH ₃ ) ₃ ,
CF ₃ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₁₅ Si (OCH ₃ ) ₃ ,
CF ₃ (CF ₂ ) ₃ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₉ Si (OCH ₃ ) ₃ ,
CF ₃ COO (CH ₂ ) ₁₅ Si (OCH ₃ ) ₃ ,
CF ₃ (CF ₂ ) ₅ (CH ₂ ) ₂ Si (OC ₂ H ₅ ) ₃ ,
CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₉ Si (OC ₂ H ₅ ) ₃ ,
CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₆ Si (OC ₂ H ₅ ) ₃ ,
CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (OC ₂ H ₅ ) ₃ ,
CF ₃ CH ₂ O (CH ₂ ) ₁₅ Si (OC ₂ H ₅ ) ₃ ,
CF ₃ COO (CH ₂ ) ₁₅ Si (OC ₂ H ₅ ) ₃ ,
CF ₃ (CF ₂ ) ₄ CONH (CH ₂ ) ₃ Si (OCH ₃ ) ₃ ,
CF ₃ (CF ₂ ) ₇ CONH (CH ₂ ) ₃ Si (OCH ₃ ) ₃ ,
CF ₃ (CF ₂ ) ₅ CONH (CH ₂ ) ₃ Si (OC ₂ H ₅ ) ₃ , or
CF ₃ (CF ₂ ) ₇ CONH (CH ₂ ) ₃ Si (OC ₂ H ₅ ) ₃
Can be used.

In addition, the water repellent / flux repellent film 34 is, for example,
_{CF 3 - (CF 2) n2} -CONH- (CH 2) m -Si (O-R '') 3
(Where n2 is an integer of 0 or more, m is an integer of 0 or more, and R ″ is an alkyl group)
It is formed from the amide containing silane coupling agent represented by these.
n2 may be an integer of 0 or more and 7 or less. m may be an integer from 0 to 7. R ″ may be a methyl group or an ethyl group.
Specifically, the amide-containing silane coupling agent is, for example, a silane coupling agent shown in FIG.
CF ₃ (CF ₂ ) ₄ CONH (CH ₂ ) ₃ Si (OCH ₃ ) ₃
Or
CF ₃ (CF ₂ ) ₇ CONH (CH ₂ ) ₃ Si (OCH ₃ ) ₃ ,
CF ₃ (CF ₂ ) ₅ CONH (CH ₂ ) ₃ Si (OC ₂ H ₅ ) ₃ , or
CF ₃ (CF ₂ ) ₇ CONH (CH ₂ ) ₃ Si (OC ₂ H ₅ ) ₃
Can be used.

  Next, an example of a method for manufacturing the multilayer ceramic inductor 10 will be described.

First, the process for preparing the ceramic body will be described.
For example, fermented oxide (Fe ₂ O ₃ ), zinc oxide (ZnO), nickel oxide (NiO), and copper oxide (CuO) are weighed at a predetermined ratio and charged into a ball mill as raw materials. To obtain a mixture.
The powder obtained by drying and pulverizing this mixture is calcined at 700 ° C. for 1 hour to obtain a calcined powder. This calcined powder is wet pulverized for a predetermined time with a ball mill, and then dried and crushed to obtain a ferrite powder.

A binder resin, a plasticizer, a wetting agent, and a dispersing agent are added to the ferrite powder, mixed for a predetermined time with a ball mill, and then defoamed under reduced pressure to obtain a slurry.
The slurry is applied onto a peelable film using a lip coater or a multi coater and dried to obtain a long ferrite green sheet having a desired film thickness.

The long ferrite green sheet is cut into a predetermined size, and a via hole is formed by a method such as laser processing to obtain a ferrite sheet having a via hole at a predetermined position.
On this ferrite sheet, a conductor paste mainly composed of Ag or an Ag alloy is applied in a predetermined pattern by a method such as screen printing, and is heated and dried to obtain an electrode-formed ferrite sheet provided with a coil conductor. obtain.

This electrode-formed ferrite sheet is laminated so that coil conductors are connected to each other to form a coil, thereby forming a laminate, and ferrite green sheets not coated with a conductive paste are placed on the upper and lower sides of the laminate to form an unfired laminate. Get the body.
In addition, when the electrode-formed ferrite sheet provided with the coil conductor is laminated, the coil conductor is interlayer-connected in a coil shape through the above-described via hole, and a coil is formed inside the unfired laminated body.

Then, this unfired laminated body is pressure-bonded, for example, at 45 ° C. and a pressure of 1.0 t / cm ² to obtain a laminated pressure-bonded body. And this laminated press-bonded body is cut into a predetermined size by a method such as dicing with a dicer or cutting with a press cutting blade to obtain an unfired ceramic body.

Next, the unfired ceramic body is debindered under predetermined conditions and then fired. The binder removal is performed, for example, under conditions of heating at 500 ° C. for 2 hours in a low oxygen atmosphere. Further, the firing is performed, for example, under the conditions of firing at 870 ° C. for 150 minutes in an Air atmosphere. As a result, the ceramic body 12 (see FIGS. 1, 2, and 3) is formed. The ceramic body 12 includes a plurality of ferrite layers 14. These ferrite layers 14 are integrally sintered in a laminated state. A coil 16 is formed inside the ceramic body 12. The coil 16 includes each patterned conductor 18. Each patterned conductor 18 is formed on each ferrite layer 14. Further, each patterned conductor 18 is connected in a coil shape by a via hole 20.
1 and 2 show the multilayer ceramic inductor 10 in which the external electrodes 24a and 24b are formed on the end faces 12e and 12f of the ceramic body 12. FIG.

Next, a process for forming the external electrode will be described.
First, an electrode material paste for forming an external electrode is applied to the end faces 12e and 12f of the ceramic body 12 from which the lead electrodes 22a and 22b of the coil 16 are exposed, and dried at 120 ° C. for 10 minutes, for example. By baking the electrode material paste at 15 ° C. for 15 minutes, the base electrodes 26a and 26b of the external electrodes 24a and 24b are formed.

Next, a process of forming a water / repellent film is described.
First, a silane coupling agent solution is prepared. The silane coupling agent solution may be a Sn-containing silane coupling agent solution or an amide bond-containing silane coupling agent solution.
The Sn-containing silane coupling agent solution can be prepared by mixing a silane coupling agent having a fluoroalkyl group, an Sn compound, and a solvent as necessary. The silane coupling agent is, for example,
CF ₃ (CF ₂ ) ₅ (CH ₂ ) ₂ Si (OCH ₃ ) ₃
Or
CF ₃ (CF ₂ ) ₃ (CH ₂ ) ₂ Si (OCH ₃ ) ₃ ,
CF ₃ (CF ₂ ) ₃ (CH ₂ ) ₂ Si (OC ₂ H ₅ ) ₃ ,
CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (OCH ₃ ) ₃ ,
CF ₃ CH ₂ O (CH ₂ ) ₁₅ Si (OCH ₃ ) ₃ ,
CF ₃ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₁₅ Si (OCH ₃ ) ₃ ,
CF ₃ (CF ₂ ) ₃ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₉ Si (OCH ₃ ) ₃ ,
CF ₃ COO (CH ₂ ) ₁₅ Si (OCH ₃ ) ₃ ,
CF ₃ (CF ₂ ) ₅ (CH ₂ ) ₂ Si (OC ₂ H ₅ ) ₃ ,
CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₉ Si (OC ₂ H ₅ ) ₃ ,
CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₆ Si (OC ₂ H ₅ ) ₃ ,
CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (OC ₂ H ₅ ) ₃ ,
CF ₃ CH ₂ O (CH ₂ ) ₁₅ Si (OC ₂ H ₅ ) ₃ , or
CF ₃ COO (CH ₂ ) ₁₅ Si (OC ₂ H ₅ ) ₃
Can be used.
The silane coupling agent used to prepare the Sn-containing silane coupling agent solution may be an amide bond-containing silane coupling agent described later.
The solvent can be, for example, methanol, ethanol, or isopropanol. Sn compounds include SnCl ₂ , SnCl ₄ , dibutyltin diacetate, bis (acetoxydibutyltin) oxide, bis (lauroxydibutyltin) oxide, dibutyltin bisacetylacetonate, dibutyltin bismaleic acid monobutyl ester, dioctyl bismaleic acid monobutyl ester It may be. Of these, SnCl ₂ is preferred as the Sn compound. The concentration of the silane coupling agent in the Sn-containing silane coupling agent solution may be, for example, 0.1 volume% or more and 5 volume% or less. Further, the concentration of Sn in the Sn-containing silane coupling agent solution may be, for example, 0.01 g / L or more and 1.0 g / L or less.
The amide bond-containing silane coupling agent solution can be prepared by mixing an amide bond-containing silane coupling agent containing a fluoroalkyl group and an amide group with a solvent. As the amide bond-containing silane coupling agent, for example,
CF ₃ (CF ₂ ) ₄ CONH (CH ₂ ) ₃ Si (OCH ₃ ) ₃ ,
CF ₃ (CF ₂ ) ₇ CONH (CH ₂ ) ₃ Si (OCH ₃ ) ₃ ,
CF ₃ (CF ₂ ) ₅ CONH (CH ₂ ) ₃ Si (OC ₂ H ₅ ) ₃ , or
CF ₃ (CF ₂ ) ₇ CONH (CH ₂ ) ₃ Si (OC ₂ H ₅ ) ₃
Can be used.
And the ceramic body which formed the external electrode is made to adhere to the silane coupling agent solution prepared in this way. The method for attaching the silane coupling agent solution to the ceramic body may be dipping, coating, spin coating or spraying. Thereafter, by heating the ceramic body to which the silane coupling agent solution is attached, a water-repellent / flux-repellent film can be formed on the ceramic body. The heating temperature may be 60 ° C. or higher and 150 ° C. or lower. The heating time may be 60 minutes or more and 120 minutes or less.

  The water repellent / flux repellent film refers to a film formed on the surface of a ceramic body formed through a process of forming a water repellent / flux repellent film. The water repellent / flux repellent film may be discontinuous. For example, as shown in FIG. 4, the protrusions may be formed adjacent to each other. Even in such a water-repellent / flux-repellent film, the protrusion prevents the entry of moisture and flux into the pores of the ceramic body, and the occurrence of ion migration due to moisture and the mounting failure caused by the flux Occurrence can be suppressed.

Then, on the base electrodes 26a and 26b of the external electrodes 24a and 24b, plating films 26a and 26b having a two-layer structure in which the lower layer is the Ni plating films 30a and 30b and the upper layer is the Sn plating films 32a and 32b are formed.
Thereby, the multilayer ceramic inductor 10 shown in FIG. 1 is obtained.

  In this multilayer ceramic inductor 10, the reactivity of the silane coupling agent can be increased by including the Sn compound in the silane coupling agent solution for forming the water / flux repellent film 34. Therefore, a dense water-repellent / flux-repellent film 34 can be formed on the surface of the ceramic body 12 (main surfaces 12a, 12b and side surfaces 12c, 12d). Therefore, in this case, it is possible to prevent moisture and flux from entering the pores of the ceramic body 12, and to prevent occurrence of ion migration due to moisture and occurrence of mounting defects due to flux. Therefore, in this case, the reliability of the multilayer ceramic inductor can be improved.

  Further, in the multilayer ceramic inductor 10, when the water / flux repellent film 34 further contains Cl, the reactivity between the ceramic body 12 and the silane coupling agent that forms organosilane is further increased. Therefore, a dense water / repellent film 34 can be formed on the surface of the ceramic body 12.

  Furthermore, in this multilayer ceramic inductor 10, when the solution for forming the water-repellent / flux-repellent film 34 contains an Sn compound, when this solution is attached to the external electrodes 24a and 24b, the Sn component derived from the Sn compound is present. It is adsorbed on the external electrodes 24a and 24b (base electrodes 26a and 26b). And organosilane is hard to adhere on the adsorbed Sn component. Therefore, the organosilane in the water-repellent / flux-repellent film 34 is likely to be selectively attached to the surface of the ceramic body 12, thereby preventing the organosilane from adhering to the external electrodes 24 a and 24 b (underlying electrodes 26 a and 26 b). it can. As a result, problems such as non-plating and solder non-wetting can be prevented on the external electrodes 24a and 24b (base electrodes 26a and 26b). Therefore, when the water / flux repellent film 34 contains Sn and Cl, the reliability of the multilayer ceramic inductor can also be improved in this respect.

  In this multilayer ceramic inductor 10, in order to form a finer water-repellent / flux-repellent film 34 as described above, the water-repellent / flux-repellent film 34 has an atomic concentration relative to the constituent elements of the ceramic body in XPS analysis. The film preferably contains Sn in a ratio of 0.01 to 0.2 and Cl in a range of 0.01 to 0.7.

In addition, in order to form a dense water repellent / flux repellent film in the multilayer ceramic inductor 10 as described above,
CF ₃ — (CF ₂ ) _n1 —R—Si (O—R ′) ₃
(Where n1 is an integer of 0 or more, R is a substituent or alkylene group containing Si or O, and R ′ is an alkyl group)
Or a silane coupling agent represented by
_{CF 3 - (CF 2) n2} -CONH- (CH 2) m -Si (O-R '') 3
(Where n2 is an integer of 0 or more, m is an integer of 0 or more, and R ″ is an alkyl group)
It is preferable that it is formed from the amide bond containing silane coupling agent represented by these.

  In this multilayer ceramic inductor 10, when the water repellent / flux repellent film 34 is formed of an amide bond-containing silane coupling agent having a fluoroalkyl group and an amide bond, the ceramic body 12 and the water repellent / flux repellent film 34. Adhesion with is increased. Therefore, in this case, it is possible to prevent moisture and flux from entering the pores of the ceramic body 12, and to prevent occurrence of ion migration due to moisture and occurrence of mounting defects due to flux. Therefore, in this case, the reliability of the multilayer ceramic inductor can be improved.

  In the above-described manufacturing method of the multilayer ceramic inductor, the step of forming the water-repellent / flux-repellent film 34 is performed after the step of forming the base electrodes 26a, 26b of the external electrodes 24a, 24b. When forming 34, base electrodes 26 a and 26 b are already formed on the surface of the ceramic body 12 where the external electrodes 24 a and 24 b are formed. Therefore, the water / flux repellent film 34 can be easily formed on the surface of the ceramic body 12 where the external electrodes 24a and 24b are not formed.

  Furthermore, in the above-described method for manufacturing a multilayer ceramic inductor, the step of forming the water-repellent / flux-repellent film 34 is performed before the step of forming the plating films 28a and 28b. Further, a water repellent / flux repellent film 34 has already been formed on the surface of the ceramic body 12 where the external electrodes 24a and 24b are not formed. Therefore, it is possible to prevent the plating solution or the cleaning solution from entering the pores of the ceramic body 12.

  In the method for manufacturing a multilayer ceramic inductor described above, when the step of forming the water-repellent / flux-repellent film 34 is performed after the step of forming the plating films 28a and 28b, when the plating films 28a and 28b are formed. The water repellent / flux repellent film 34 has not yet been formed. Therefore, the plating films 28a and 28b can be easily formed on the base electrodes 26a and 26b.

(Experimental example)
In the experimental example, first, the multilayer ceramic inductors of Example 1, Example 2, and Comparative Example were each manufactured as a sample by the same method as the above-described manufacturing method of the multilayer ceramic inductor. Specifically, a 1005 size (1.0 mm × 0.5 mm × 0.5 mm) multilayer ceramic inductor was prepared. The ferrite layer of the ceramic body is made of Ni—Cu—Zn ferrite. The coil is made of Ag. The base electrode of the external electrode is made of Ag. A plating film is not formed on this inductor.

Example 1
In Example 1, a silane coupling agent solution containing a silane coupling agent containing a fluoroalkyl group and an alkylene group, SnCl ₂ and isopropanol was prepared as a silane coupling agent solution. In the silane coupling agent solution, the concentration of the silane coupling agent was 1% by volume, and the concentration of Sn was 0.14 g / L. Specifically, the silane coupling agent is
CF ₃ (CF ₂ ) ₅ (CH ₂ ) ₂ Si (OCH ₃ ) ₃
Was used.
And the prepared silane coupling agent solution was put into the container, and this ceramic body was immersed in it for about 5 minutes. The immersed ceramic body was heat-treated at 100 ° C. for about 90 minutes to react with the silane coupling agent to form a water-repellent / flux-repellent film containing organosilane, Sn and Cl.
For this inductor, the fluorine atom concentration on the base electrode and the fluorine atom concentration on the ceramic body were measured by XPS analysis. The ratio of the fluorine atom concentration on the base electrode to the fluorine atom concentration on the ceramic body was 0.50. Thereby, it was found that the water-repellent / flux-repellent film was selectively formed on the surface of the ceramic body rather than on the base electrode.

(Example 2)
In Example 2, a silane coupling agent solution prepared by diluting an amide bond-containing silane coupling agent containing a fluoroalkyl group and an amide group with isopropyl alcohol was prepared as a silane coupling agent solution. This amide bond-containing silane coupling agent is
CF ₃ (CF ₂ ) ₄ CONH (CH ₂ ) ₃ Si (OCH ₃ ) ₃
Was used. Then, using this silane coupling agent, a water repellent / flux repellent film was formed on the multilayer ceramic inductor in the same manner as in Example 1.

(Comparative example)
In the comparative example, a silane coupling agent solution prepared by diluting a silane coupling agent containing a fluoroalkyl group and an alkylene group with isopropyl alcohol was prepared as a silane coupling agent solution. This silane coupling agent
CF ₃ (CF ₂ ) ₅ (CH ₂ ) ₂ Si (OCH ₃ ) ₃
Was used.
Then, using this silane coupling agent solution, a flux repellent film was formed in the same manner as in Example 1. In the comparative example, when the fluorine atom concentration on the base electrode and the fluorine atom concentration on the ceramic body were measured by XPS analysis, the ratio of the fluorine atom concentration on the base electrode to the fluorine atom concentration on the ceramic base was 0. 93.

  Furthermore, in Example 1, Example 2, and the comparative example, the ceramic body 12 on which the coil 16, the base electrodes 26a and 26b, and the water-repellent / flux-repellent film 34 are formed is subjected to a barrel at 60 ° C. for 60 minutes. Electrolytic Ni plating with a Watt bath composition was performed, washed with water, and dried at 65 ° C. for 30 minutes to form Ni plating films 30a and 30b on the base electrodes 26a and 26b. In this experimental example, the ceramic body 12 thus formed with the coil 16, the base electrodes 26a and 26b, and the Ni plating films 30a and 30b was used as a sample.

  For each sample of Example 1, Example 2 and Comparative Example, between the base electrodes 26a and 26b before and after the formation of the Ni plating films 30a and 30b (between the Ni plating films 30a and 30b after the formation of the Ni plating films 30a and 30b) The impedance of was measured. Table 1 shows the rate of change in impedance before and after the formation of the Ni plating films 30a and 30b of each sample. The impedance measurement is to measure the absolute value | Z | of the impedance using a measurement RF impedance / material analyzer (Agilent Technologies E4991A) for a sample fixed using the lower electrode SMD test fixture (Agilent Technologies 16197A). It went by.

If the water-repellent / flux-repellent treatment is insufficient, the plating solution penetrates into the ceramic body 12 and the impedance changes.
The denser the water-repellent / flux-repellent film 34 is, the more the infiltration of the plating solution can be prevented, and the impedance change rate becomes smaller.
From the results shown in Table 1, in Example 1 and Example 2, the rate of change in impedance is smaller than in the comparative example, and the effect of preventing the infiltration of the plating solution by the water-repellent / flux-repellent film 34 is great. This effect becomes higher as the number of water repellent / flux repellent treatments is increased.

  In addition, in the samples of Example 1 and Example 2, the impedance change rate was small and the flux repellency was good even when mounted with solder.

Moreover, the soldering reliability evaluation (non-aggregation evaluation) was performed on the samples of Examples 1 and 2 and the comparative example. The soldering reliability was evaluated by the following method. First, an FR4 grade glass epoxy substrate was prepared. The glass epoxy substrate has a copper foil on the surface. This copper foil was patterned to form two lands each having a length of 400 μm and a width of 500 μm on the substrate. The two lands were formed so as to be spaced apart by 300 μm in the length direction. Then, a solder resist was formed on the glass epoxy substrate so as to surround the two lands with an interval of 50 μm. The glass epoxy substrate on which the land and the solder resist were formed was immersed in GLICOAT-SMD (F2) manufactured by Shikoku Kasei Kogyo Co., Ltd. at 40 ° C. for 60 seconds, washed with water, and dried at 60 ° C. for 10 minutes. Solder paste (manufactured by Senju Metal Industry Co., Ltd., trade name: S70G) was applied to each of the lands so that the thickness was 80 μm. The sample was shifted by 150 μm in the length direction (left and right direction in FIG. 2) from the center of the two lands, and mounted on the applied paste so as to straddle the two lands. And the glass epoxy board | substrate with which the sample was mounted was reflowed on condition of the following.
(Reflow conditions)
Reflow furnace: Product number TNR25-435PH (manufactured by Tamura Corporation)
Conveyor speed: 0.75m / min
Blower speed: 2500rpm
Peak temperature: 230 ° C

The sample after reflow is observed with a microscope (trade name: bDSZ-44PF, manufactured by Carton Optics Co., Ltd.), and there are 60 or more 50 to 50 μm solder non-aggregates per chip. Judged as non-aggregated. It is considered that the solder non-aggregation occurs because the solder is not melted due to the flux being absorbed by the ceramic body.
100 samples of Examples 1 and 2 and Comparative Example were evaluated, and the occurrence rate of non-aggregation was evaluated. The results are shown in Table 2.

  As can be seen from Table 2, compared to the comparative example, Examples 1 and 2 had a lower incidence of samples judged to be non-aggregated, and the electronic parts obtained by the present invention were found to have high reliability.

  In the multilayer ceramic inductor 10 shown in FIG. 1 described above, the external electrodes 24a and 24b are respectively composed of the base electrodes 26a and 26b and the two-layered plating films 28a and 28b. Or a base electrode and a plating film having a single layer structure or a plating film having a multilayer structure of three or more layers.

  Further, although the above-described multilayer ceramic inductor 10 has one coil 16, the present invention can also be applied to other ceramic electronic components such as a common mode choke coil and a filter having two or more coils. In addition to the multilayer ceramic inductor, the present invention can also be applied to other ceramic electronic components such as a multilayer ceramic capacitor having a capacitor element and a piezoelectric component having a piezoelectric element. That is, the ceramic body need not have a coil. For example, a ceramic body may be formed of a dielectric, and a component including the ceramic body and external electrodes may function as a capacitor. At this time, an internal electrode may be provided inside the ceramic body formed of a dielectric.

  The present invention is not limited to a ceramic inductor or a ceramic capacitor having two external electrodes, but can be applied to a common mode choke coil or a filter having three or more external electrodes. That is, the present invention can be applied to a ceramic electronic component having a plurality of external electrodes.

  The ceramic electronic component and the method of manufacturing the same according to the present invention have, in particular, a ceramic body having pores and a plurality of external electrodes formed on the surface of the ceramic body. For example, a multilayer ceramic inductor, a multilayer ceramic capacitor, a ceramic It is suitably used for ceramic electronic parts such as piezoelectric parts and the manufacturing method thereof.

DESCRIPTION OF SYMBOLS 10 Multilayer ceramic inductor 12 Ceramic body 12a, 12b Main surface 12c, 12d Side surface 12e, 12f End surface 14 Ferrite layer 16 Coil 18 Patterned conductor 20 Via hole 22a, 22b Lead-out conductor 24a, 24b External electrode 26a, 26b Base electrode 28a, 28b Plating film 30a, 30b Ni plating film 32a, 32b Sn plating film 34 Water repellent / flux repellent film

Claims (13)

In a ceramic electronic component having a ceramic body having pores and a plurality of external electrodes formed on the surface of the ceramic body at intervals,
A water repellent / flux repellent film having water repellency and flux repellency is formed on the surface of the ceramic body,
The water-repellent / flux-repellent film contains organosilane containing a fluoroalkyl group and Sn.   The ceramic electronic component according to claim 1, wherein the water repellent / flux repellent film further contains Cl.   The water repellent / flux repellent film is a film containing Sn in the range of 0.01 to 0.2 and Cl in the range of 0.01 to 0.7 with respect to the constituent elements of the ceramic body in XPS analysis. The electronic component according to claim 2. The organosilane is
CF ₃ — (CF ₂ ) _n1 —R—Si (O—R ′) ₃
(Where n1 is an integer of 0 or more, R is a substituent or alkylene group containing Si or O, and R ′ is an alkyl group)
Or a silane coupling agent represented by
_{CF 3 - (CF 2) n2} -CONH- (CH 2) m -Si (O-R '') 3
(Where n2 is an integer of 0 or more, m is an integer of 0 or more, and R ″ is an alkyl group)
The ceramic electronic component according to any one of claims 1 to 3, wherein the ceramic electronic component is formed from an amide bond-containing silane coupling agent represented by: In a ceramic electronic component having a ceramic body having pores and a plurality of external electrodes formed on the surface of the ceramic body at intervals,
A water repellent / flux repellent film having water repellency and flux repellency is formed on a portion of the surface of the ceramic body where the plurality of external electrodes are not formed,
The water repellent / flux repellent film is
_{CF 3 - (CF 2) n2} -CONH- (CH 2) m -Si (O-R '') 3
(Where n2 is an integer of 0 or more, m is an integer of 0 or more, and R ″ is an alkyl group)
A ceramic electronic component formed from an amide bond-containing silane coupling agent represented by:   6. The ceramic electronic component according to claim 1, wherein each of the plurality of external electrodes includes a base electrode formed on a surface of the ceramic body.   The ceramic electronic component according to claim 6, wherein each of the plurality of external electrodes further includes at least one layer of a plating film formed on the base electrode. A method of manufacturing a ceramic electronic component for manufacturing the ceramic electronic component according to claim 1,
Preparing the ceramic body,
A step of forming the plurality of external electrodes on the surface of the ceramic body at intervals, and an organosilane containing a fluoroalkyl group on a surface of the ceramic body where the plurality of external electrodes are not formed. A method for producing a ceramic electronic component, comprising the step of forming the water-repellent / flux-repellent film containing Sn. In the step of forming the water repellent / flux repellent film,
CF ₃ — (CF ₂ ) _n1 —R—Si (O—R ′) ₃
(Wherein n1 is an integer of 0 or more, R is a substituent or alkylene group containing Si or O, and R ′ is an alkyl group) and a Sn compound represented by Preparing a Sn-containing silane coupling agent solution containing, and immersing the ceramic body on which the external electrode is formed in the Sn-containing silane coupling agent solution,
A method for manufacturing a ceramic electronic component according to claim 8. A method of manufacturing a ceramic electronic component for manufacturing the ceramic electronic component according to claim 5,
Preparing the ceramic body,
Forming the plurality of external electrodes at intervals on the surface of the ceramic body, and a portion of the surface of the ceramic body where the plurality of external electrodes are not formed,
_{CF 3 - (CF 2) n2} -CONH- (CH 2) m -Si (O-R '') 3
(Where n2 is an integer of 0 or more, m is an integer of 0 or more, and R ″ is an alkyl group)
The manufacturing method of a ceramic electronic component including the process of forming the said water repellent and flux repellent film | membrane from the amide bond containing silane coupling agent represented by these. The step of forming the plurality of external electrodes includes a step of forming a plurality of base electrodes at intervals on the surface of the ceramic body.
11. The method for manufacturing a ceramic electronic component according to claim 8, wherein the step of forming the water-repellent / flux-repellent film is performed after the step of forming the plurality of base electrodes. The step of forming the plurality of external electrodes further includes a step of forming at least one plated film on each of the plurality of base electrodes,
The method for producing a ceramic electronic component according to claim 11, wherein the step of forming the water-repellent / flux-repellent film is performed before the step of forming the plating film. The step of forming the plurality of external electrodes further includes a step of forming at least one plated film on each of the plurality of base electrodes,
The method for producing a ceramic electronic component according to claim 11, wherein the step of forming the water-repellent / flux-repellent film is performed after the step of forming the plating film.