JP2007220997A - Ceramic electronic component and method of manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method or the like of a ceramic electronic component which can manufacture a ceramic electronic component which ensures electrical connection of a mounting substrate to an electrode element and can realize a long life. <P>SOLUTION: In the method of manufacturing a ceramic electronic component 10 by forming a plurality of bump electrodes in a bump electrode formation surface 10a of a ceramic electronic component body 11, a metallic paste 26 comprising Cu is applied by print to a plurality of places in the bump electrode formation surface 10a of the ceramic electronic component body 11. A metallic ball 22 of a uniform size constituted of Cu having a melting point higher than a baking temperature of the metallic paste 26 is mounted on the metallic paste 26 applied to a plurality of places. The metallic paste 26 is subjected to baking treatment at a temperature lower than a melting point of Cu constituting the metallic ball 22, thus obtaining a bump electrode. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a ceramic electronic component having a plurality of bump electrodes and a method for manufacturing the same.

  In recent years, the need for space saving and high integration of mounting substrates has increased, and flip-type electronic components in which a plurality of terminal electrodes are arranged on a plane have been developed.

In these electronic components, the terminal electrode has a bump shape and is referred to as a bump electrode. When such a bump electrode is formed, a method of forming the bump electrode using a solder ball is often used because it is easy to form (for example, see Patent Document 1 below). In the invention described in this publication, an electrode element and a solder ball are aligned, the solder ball is heated to a melting point or higher of the solder, and the solder ball is connected to the electrode element.
Japanese Patent Laid-Open No. 9-270428

  However, since the resistance of the solder is relatively high, it cannot sufficiently cope with the increase in the signal voltage accompanying the increase in the processing speed of the CPU or the like. In addition, when a high-resistance material such as solder is used, the amount of heat generation increases as the voltage or current increases, so there is a concern about melting of the solder in the circuit and the reliability of the CPU due to the increase in the amount of heat generation. For this reason, it is desired to use a low-resistance material such as Ag, Au, or Cu having a lower resistance than solder instead of the solder ball.

  However, all of such low resistance materials have a very high melting point compared to solder. For this reason, when the ball made of the low resistance material is heated to the melting point or higher and melted, the ceramic is damaged when the ceramic electronic component using ceramic is manufactured as the electronic component. For this reason, there exists a possibility that the lifetime of the ceramic electronic component obtained may be shortened. Further, when the ball is heated to its melting point or higher and melted, the height of the ball becomes uneven due to uneven heating, and bump electrodes with uneven height are formed. As a result, when mounting on the mounting board, there is a possibility that a part of the bump electrode cannot be connected to the electrode element of the mounting board.

  The present invention has been made in view of the above circumstances, and is capable of reliably making electrical connection to an electrode element of a mounting substrate, and capable of producing a ceramic electronic component that can achieve a long life. An object of the present invention is to provide a manufacturing method and a ceramic electronic component.

  The present inventors diligently studied to solve the above problems. For example, it was also considered to form a bump electrode by applying a metal paste containing a metal such as Au on the bump electrode forming surface and baking it by a method such as screen printing. However, in this case, it is difficult to form the bump electrode with high precision, especially for electronic parts that require a reduction in the size of the bump electrode due to space saving of the mounting substrate. It becomes difficult. As a result, the present inventors have found that there is a possibility that the bump electrodes of the electronic component cannot be reliably connected to the electrode elements of the mounting substrate. As a result of further earnest research, the present inventors have found that the above-described problems can be solved by the following invention, and have completed the present invention.

That is, the present invention provides a ceramic electronic component manufacturing method for obtaining a ceramic electronic component by forming a plurality of bump electrodes on a bump electrode forming surface of a ceramic electronic component body. A paste applying step of applying a metal paste containing a metal to a plurality of locations by printing, and having a melting point higher than the baking temperature of the metal paste on the bump electrode forming surface on the metal paste applied to a plurality of locations on the bump electrode forming surface A plurality of bump electrodes including a ball mounting step of mounting a metal ball made of a second metal, and a baking processing step of baking a metal paste at a temperature lower than the melting point of the second metal to obtain a bump electrode. The metal balls that make up have uniform dimensions,
The first and second metals are each composed of at least one selected from the group consisting of Au, Ag, Cu, Ni, Sn, Pb, In, Rh, and Pt.

  According to this manufacturing method, when the metal paste is heated at a temperature lower than the melting point of the metal ball and the metal paste is baked on the bump electrode forming surface, the first metal and the second metal are mutually diffused. Thus, solid solutions (alloys) are formed in the fired body of the metal paste and in the metal balls, respectively. As a result, the metal balls are bonded to the bump electrode forming surface of the ceramic electronic component body, and a plurality of bump electrodes are formed on the bump electrode forming surface. At this time, since the metal balls mounted at the positions of the respective metal pastes are not melted, the metal balls are not substantially deformed and have a uniform dimension even after the baking process of the metal paste. Further, in the ball mounting process, when the metal ball is mounted on the metal paste, the metal paste is softer than the metal ball, so that the portion where the metal ball is mounted in the metal paste is depressed. In this state, the metal paste is fired. For this reason, the thickness of the metal paste is smaller at the mounting location of the metal ball than the thickness of the metal paste before mounting the metal ball. For this reason, the influence of the printing accuracy of the metal paste can be sufficiently reduced. That is, even if the printing accuracy of the metal paste is low, it is possible to reduce the height variation of the bump electrodes. As a result, it is possible to obtain a ceramic electronic component that enables reliable electrical connection of the mounting substrate to the electrode element.

  Furthermore, since the metal ball is heated at a temperature lower than its melting point, damage given to the ceramic electronic component body can be sufficiently reduced, and the life of the resulting ceramic electronic component can be increased.

  In the manufacturing method, the metal ball is preferably manufactured by a wire cut method or a uniform droplet spraying method. In this case, the dimensional accuracy of the metal ball is further improved. For this reason, the height variation of the bump electrode can be further suppressed. Accordingly, it is possible to obtain a ceramic electronic component that enables more reliable electrical connection of the mounting substrate to the electrode element.

  In the above manufacturing method, it is preferable that the metal paste further includes glass frit, and in the baking treatment step, the baking temperature of the metal paste is set to a temperature equal to or higher than the melting point of the glass frit. In this case, the bonding strength of the bump electrode with respect to the bump electrode forming surface increases.

  In the ball mounting step, it is preferable that the metal ball is pressed toward the bump electrode forming surface and brought into contact with the bump electrode forming surface. In this case, the variation in the height of the bump electrode can be more sufficiently reduced regardless of the printing accuracy of the metal paste.

  The present invention also provides a ceramic electronic component comprising a ceramic electronic component body having a bump electrode forming surface and a plurality of bump electrodes formed on the bump electrode forming surface, wherein each of the plurality of bump electrodes is on the bump electrode forming surface. A metal ball including a first metal and a metal ball mounted on the base and including a second metal, and the metal balls constituting the plurality of bump electrodes have uniform dimensions, Each of the second metals is composed of at least one selected from the group consisting of Au, Ag, Cu, Ni, Sn, Pb, In, Rh, and Pt.

  According to this ceramic electronic component, since the electric resistance of the metal ball is low, it is possible to sufficiently cope with the increase in the signal voltage accompanying the increase in the processing speed of the CPU or the like. In addition, even if the amount of heat generation increases as the applied signal voltage becomes higher in frequency, it is possible to sufficiently prevent the bump electrodes from melting due to the increase in the amount of heat generation. For this reason, according to this invention, even if it mounts on a mounting substrate, the circuit in the said mounting substrate can be functioned normally over a long period of time.

  According to the method for manufacturing a ceramic electronic component according to the present invention, it is possible to manufacture a ceramic electronic component that enables reliable electrical connection to the electrode element of the mounting substrate and realizes a long life.

  Moreover, according to the ceramic electronic component according to the present invention, even when mounted on the mounting board, the circuit on the mounting board can function normally over a long period of time.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected about the same or equivalent element, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a schematic partial sectional view showing an embodiment of a ceramic electronic component of the present invention. As shown in FIG. 1, the ceramic electronic component 10 of the present embodiment includes a flat ceramic electronic component main body 11, and a plurality of bump electrodes 20 are provided on one surface of the ceramic electronic component main body 11. Yes. Therefore, hereinafter, one surface of the ceramic electronic component main body 11 will be referred to as a “bump electrode forming surface” 10a. Here, as the ceramic electronic component main body 11, a multilayer ceramic capacitor element having a plurality of through-hole electrodes is used. In this case, each through hole electrode in the ceramic electronic component main body 11 and each bump electrode 20 of the ceramic electronic component 10 are electrically connected.

  The bump electrode 20 is an external electrode terminal for surface mounting. When the ceramic electronic component 10 is surface-mounted on the mounting substrate 30 shown by a two-dot chain line in FIG. 1, it contacts the electrode terminal 32 of the mounting substrate 30. This is for electrical connection with the electrode terminal 32. Each bump electrode 20 includes a pedestal 24 having a recess and a metal ball 22 provided at the position of the recess of the pedestal 24. More specifically, the metal ball 22 is in contact with the bump electrode forming surface 10a.

  Here, the metal ball 22 has a surface made of a spherical surface. That is, the entire surface of the metal ball 22 is a spherical surface. Further, the metal balls 22 mounted on the plurality of bump electrodes 20 have a uniform dimension, that is, a uniform diameter. The diameter of the metal ball 22 is, for example, 100 μm. Further, the metal ball 22 is made of Cu (second metal).

  The pedestal 24 has a disk shape, for example, and is made of Cu (first metal). The base 24 is formed by a baking process of a metal paste 26 described later. That is, the pedestal 24 is composed of a fired body of the metal paste 26.

  According to the ceramic electronic component 10, since the electric resistance of the metal ball 22 is low, it can sufficiently cope with the increase in the signal voltage accompanying the increase in the processing speed of the CPU or the like. In addition, even if the amount of heat generation increases as the applied signal voltage becomes higher in frequency, melting of the bump electrode 20 due to the increase in the amount of heat generation can be sufficiently prevented. For this reason, even if the ceramic electronic component 10 is mounted on the mounting board, the circuit on the mounting board can function normally over a long period of time.

  Next, a method for manufacturing the ceramic electronic component 10 will be described with reference to FIG.

  FIG. 2 is a diagram showing a series of manufacturing steps of the ceramic electronic component 10. First, a ceramic electronic component body 11 having a bump electrode forming surface 10a is prepared. The ceramic electronic component main body 11 refers to a state in which bump electrodes are not yet formed. On the bump electrode forming surface 10a of the ceramic electronic component body 11, using a known printing method, for example, a screen printing method, a metal paste 26 is applied to a plurality of locations as shown in FIG. ).

  Here, the metal paste 26 contains Cu (first metal). The metal paste 26 usually further contains a resin, a glass frit and a solvent in addition to Cu. As the resin, for example, ethyl cellulose, acrylic resin, or the like is used. As the solvent, an organic solvent is usually used, and the organic solvent is not particularly limited as long as it is a solvent capable of dissolving the resin. For example, it is composed of terpionol, butyl carbitol, or the like.

The glass frit is not particularly limited, but the glass frit may be any glass frit as long as it functions as glass even in such an atmosphere since it is fired in a reducing or neutral atmosphere. For example, silicate glass (SiO ₂ : 20 to 80 wt%, Na ₂ O: 80 to 20 wt%), borosilicate glass (B ₂ O ₃ : 5 to 50 wt%, SiO ₂ : 5 to 70 wt%, PbO: 1 to 1 _{10wt%, K 2 O: 1~15wt} %), alumina silicate glass _{(Al 2 O 3: 1~30wt%} , SiO 2: 10~60wt%, Na 2 O: 5~15wt%, CaO: 1~20wt %, B ₂ O ₃ : 5 to ₃₀ wt%), or one or more glass frit selected from them may be used.
If necessary, CaO: 0.01-50 wt%, SrO: 0.01-70 wt%, BaO: 0.01-50 wt%, MgO: 0.01-5 wt%, ZnO: 0.01-70 wt% %, PbO: 0.01 to 5 wt%, Na ₂ O: 0.01 to 10 wt%, K ₂ O: 0.01 to 10 wt%, MnO ₂ : 0.01 to ₂₀ wt%, etc. What is necessary is just to mix and use so that it may become ratio. These may be added in a total amount of 50 wt% or less.

The average particle size of the glass frit is preferably about 0.01 to 30 μm.
When the average particle size of the glass frit is smaller than the above range, the glass frit is agglomerated and may cause a local sintering effect of Cu as a conductive material. When the average particle size is larger than the above range, the dispersion of the glass frit is deteriorated, the solid solution of the metal is suppressed, and the adhesiveness is lowered.

  Although the shape of the metal paste 26 after apply | coating on the bump electrode formation surface 10a is not specifically limited, Usually, it is disk shape. However, this shape may be a quadrangle or a triangle. Although the thickness of the metal paste 26 after apply | coating on the bump electrode formation surface 10a is not specifically limited, It is preferable that it is a ratio of 10%-50% of the diameter of the metal ball | bowl 22. FIG. If it is less than 10%, the bonding strength between the metal ball 22 and the pedestal 24 tends to decrease, and if it exceeds 50%, the height variation of the bump electrode 20 tends to be larger than that in the above range. is there.

  Next, as shown in FIG. 2B, metal balls 22 are mounted on each metal paste 26 (ball mounting step). Here, as the metal ball 22, a ball whose entire surface is a spherical surface and made of Cu (second metal) is used. This is because, if a part of the surface of the metal ball 22 is, for example, a flat surface, the posture must be taken into consideration when mounting the metal ball 22, and the mounting posture of the metal ball 22 is very inconvenient. This variation is due to the variation in the height of the obtained bump electrode 20. The metal balls 22 have a uniform size, that is, a uniform diameter.

  As a method for mounting the metal ball 22 on the metal paste 26, for example, the method shown in FIG. 3 can be used. In this method, a flat metal mask 40 is used. The metal mask 40 is provided with a plurality of through holes 40 a through which the metal balls 22 can pass so as to correspond to the positions of the metal paste 26. Then, the metal mask 40 is arranged so as to be parallel to the bump electrode forming surface 10 a, a large number of metal balls 22 are placed on the metal mask 40, and the metal balls 22 are placed in the respective through holes 40 a using the squeegee 42. Drop it. Specifically, the metal ball 22 is dropped into each through hole 40a by moving the squeegee 42 in a certain direction on the surface of the metal mask 40.

  Here, each through hole 40 a is preferably the same as the diameter of the metal ball 22. In this case, the metal ball 22 can be reliably mounted at a desired position on the metal paste 26, and the obtained bump electrode 20 and the electrode element 32 of the mounting substrate 30 can be more reliably connected. In this way, the metal ball 22 is mounted at each position of the metal paste 26 corresponding to the through hole 40a.

  When the metal ball 22 is mounted on the metal paste 26 by the method using the metal mask 40 described above, the metal ball 22 dropped into the through hole 40 a is pressed against the other metal ball 22. For this reason, the metal ball 22 dents the metal paste 26 and eventually comes into direct contact with the bump electrode forming surface 10a.

  After mounting the metal balls 22 on the metal paste 26 as described above, the metal paste 26 is heated, and the metal paste 26 is baked on the bump electrode formation surface 10a (baking process step). At this time, the melting point of the metal ball 22 is 1084.5 ° C., and the baking treatment of the metal paste 26 is performed at a temperature lower than the melting point of the metal ball 22. Here, the baking temperature of the metal paste 26 varies depending on the composition of the metal paste 26 and cannot be generally stated, but is usually 700 to 900 ° C. Thereby, the resin in the metal paste 26 is decomposed, the solvent is not evaporated, and the metal and glass frit remain. In this way, the metal paste 26 is baked onto the bump electrode forming surface 10a to form the pedestal 24, and a plurality of bump electrodes 20 composed of the pedestal 24 and the metal balls 22 are formed on the bump electrode forming surface 10a. Thus, the production of the ceramic electronic component 10 is completed.

  According to the above manufacturing method, when the metal paste 26 is heated at a temperature lower than the melting point of the metal balls 22 and the metal paste 26 is baked on the bump electrode forming surface 10a, the metal in the metal paste 26 and The metal constituting the metal ball 22 is interdiffused to form a solid solution (alloy) in the pedestal 24 and the metal ball 22, whereby the metal ball 22 is formed on the bump electrode forming surface 10 a of the ceramic electronic component body 11. The plurality of bump electrodes 20 are formed on the bump electrode forming surface 10a.

At this time, since the metal balls 22 mounted at the positions of the metal pastes 26 are not melted, the metal balls 22 are not substantially deformed and have a uniform dimension even after the metal paste 26 is baked. That is, neither the height of the bump electrode 20 becomes the height H ₁ identical to the metal ball 22 (see FIG. 1).

  Further, when the metal ball 22 is mounted on the metal paste 26, the metal paste 26 is softer than the metal ball 22, so that the portion where the metal ball 22 is mounted in the metal paste 26 is recessed. In particular, when the metal ball 22 is mounted on the metal paste 26 using the metal mask 40, the metal ball 22 is dropped into the through hole of the metal mask 40 and then pressed by another metal ball, and eventually the bump electrode is formed. Contact the surface 10a. In other words, the thickness of the metal paste 26 is zero at the place where the metal ball 22 is mounted. In this state, the metal paste 26 is fired. For this reason, it is not necessary to consider the influence of the printing accuracy of the metal paste 26. That is, even if the printing accuracy of the metal paste 26 is low, it is possible to reduce the height variation between the plurality of bump electrodes 20 (that is, between the bump electrodes 20A and 20B). As a result, the ceramic electronic component 10 that enables reliable electrical connection of the mounting substrate 30 to the electrode element 32 can be manufactured.

  Furthermore, since the metal ball 22 is heated at a temperature lower than its melting point, the damage given to the ceramic electronic component body 11 can be sufficiently reduced, and the life of the resulting ceramic electronic component 10 can be increased.

  Furthermore, the metal constituting the metal ball 22 and the metal contained in the metal paste 26 are both Cu, and metal diffusion is likely to occur at the interface between the metal ball 22 and the metal paste 26 (that is, the pedestal 24). Yes. As described above, when the metal contained in the metal ball 22 and the metal contained in the metal paste 26 are matched to cause metal diffusion, the bond strength between the metal ball 22 and the base 24 can be enhanced.

  The baking temperature of the metal paste 26 on the bump electrode forming surface 10a is preferably equal to or higher than the melting point of the glass frit in the metal paste 26. In this case, there is an advantage that the bonding strength of the obtained bump electrode 20 to the bump electrode forming surface 10a can be increased as compared with the case where the baking temperature is lower than the melting point of the glass frit. Although the melting point of the glass frit differs depending on the type of glass constituting the glass frit, it cannot be generally stated. For example, when the main component of the glass frit is composed of barium oxide, it is about 500 ° C.

  Next, a second embodiment of the ceramic electronic component according to the present invention will be described with reference to FIG. FIG. 4 is a partial schematic cross-sectional view showing a second embodiment of the ceramic electronic component according to the present invention.

  As shown in FIG. 4, the ceramic electronic component 10A of the present embodiment is different from the ceramic electronic component 10 in terms of the configuration of the bump electrodes. That is, in the bump electrode 21 of the ceramic electronic component 10A, the disk-shaped pedestal 24 is interposed between the metal ball 22 and the bump electrode forming surface 10a, and the metal ball 22 and the bump electrode forming surface 10a are in contact with each other. Not.

  The ceramic electronic component 10A can be manufactured by the same manufacturing method as the ceramic electronic component 10 described above.

  Whether or not the metal ball 22 is in contact with the bump electrode forming surface 10a or the degree of the distance between the metal ball 22 and the bump electrode forming surface 10a depends on the viscosity of the metal paste 26 and the thickness of the metal mask 40. The number of metal balls 22 placed on the metal mask 40 can be adjusted.

Also in this ceramic electronic component 10A, the deformation of the metal ball 22 does not substantially occur during the baking process of the metal paste 26, and the height dimension of the metal ball 22 (that is, the diameter of the metal ball 22) before and after the baking process. ) H ₁ does not change substantially. Therefore, of the height H of the bump electrode 21, the height H ₁ of the metal ball 22 is uniform with the bump electrode 21.

Further, when the metal ball 22 is mounted on the metal paste 26, the metal paste 26 is softer than the metal ball 22, so that the portion where the metal ball 22 is mounted in the metal paste 26 is recessed. In this state, the metal paste 26 is fired. For this reason, the thickness of the metal paste 26 is smaller at the mounting location of the metal balls 22 than the thickness of the metal paste 26 before mounting the metal balls. For this reason, the influence of the printing accuracy of the metal paste 26 can be sufficiently reduced. That is, the thickness (thickness corresponding to the height of the bottom of the recess in the pedestal 24) of the metal paste 26 applied to the electrode forming surface 10a even H ₂ is not uniform, thoroughly height variation of the bump electrode 20 It can be made smaller. That is, also in the ceramic electronic component 10A manufactured by this manufacturing method, the height variation between the plurality of bump electrodes 21 formed on the bump electrode formation surface 10a (that is, between the bump electrodes 21A and the bump electrodes 21B). Can be made sufficiently small. As a result, it is possible to manufacture the ceramic electronic component 10 </ b> A that can reliably connect the mounting substrate 30 to the electrode element 32. However, when the metal ball 22 is in direct contact with the bump electrode formation surface 10a, the height variation between the bump electrodes can be reduced more effectively.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible. For example, the ceramic electronic component body 11 is not limited to a multilayer ceramic capacitor element, and may be, for example, an inductor element, a varistor element, or the like.

  The metal constituting the metal ball 22 is not limited to Cu, but may be Au, Ag, Ni, Sn, Pb, In, Rh, Pt, or an alloy thereof. However, from the viewpoint of widening the selection range of the baking temperature of the metal paste, a material having a melting point as high as possible, for example, Rh is preferable. Furthermore, the metal contained in the metal paste is not limited to Cu, but may be Au, Ag, Ni, Sn, Pb, In, Rh, Pt, or an alloy thereof. However, among these, those with as low resistance as possible, for example, Ag are preferable.

  Hereinafter, although the content of the present invention will be described more specifically with reference to examples and comparative examples, the present invention is not limited to the following examples.

Example 1
First, Cu balls were prepared as metal balls. The Cu balls were manufactured by a uniform droplet spraying method (UDS method) and had a diameter of 100 μm (tolerance <± 5 μm).

  On the other hand, Cu paste was prepared as a metal paste. The Cu paste was composed of Cu particles, ethyl cellulose, terpineol, and glass frit, and the respective compositions were 80% by mass, 8% by mass, 7% by mass, and 5% by mass. On the other hand, a flat laminated ceramic capacitor element in which no bump electrode was formed was prepared as a ceramic electronic component body. As the multilayer ceramic capacitor element, one having dimensions of 10 mm in length, 10 mm in width, and 1 mm in thickness and having a structure in which both end faces of a plurality of through-hole electrodes are exposed was used.

  And the surface where the end surface of the through-hole electrode of the multilayer ceramic capacitor element was exposed was used as a bump electrode forming surface, and the metal paste was applied thereon by screen printing. Specifically, screen printing is performed using mesh # 200 and a plate making with an emulsion thickness of 20 μm under the conditions of a speed of 100 mm / s, a printing pressure of 1 kPa, and a gap of 0.5 mm. The metal paste has a diameter of 0.1 mm and a thickness of It apply | coated so that it might become 20 micrometers.

  Subsequently, the metal balls prepared as described above were mounted. Specifically, metal balls were mounted at the positions of the metal pastes as follows. That is, first, a flat metal mask having a thickness of 100 μm in which through holes having a diameter of 150 μm were arranged at a pitch of 400 μm was prepared. And this metal mask was arrange | positioned in parallel with respect to the multilayer ceramic capacitor element, and it aligned so that each through-hole might oppose each metal paste. A large number of metal balls were placed on the surface of the metal mask, a flat squeegee was placed on the metal mask and moved in a certain direction, and the metal balls were dropped into each through hole. In this way, the metal ball was passed through each through hole, and the metal ball was mounted on each metal paste. At this time, the metal ball was brought into contact with the bump electrode formation surface.

  Next, the metal paste was dried at 150 ° C. for only 5 minutes, and then heated in a nitrogen atmosphere at 800 ° C. for 60 minutes to perform baking treatment of the metal paste on the bump electrode formation surface. In this way, a plurality of bump electrodes were formed on the bump electrode forming surface to obtain a multilayer ceramic capacitor as a ceramic electronic component.

(Comparative Example 1)
A multilayer ceramic capacitor as a ceramic electronic component was obtained in the same manner as in Example 1 except that the bump electrode was formed using only the metal paste instead of forming the bump electrode using the metal paste and the metal ball. At this time, the bump electrode is formed by screen-printing under conditions of a speed of 100 mm / s, a printing pressure of 1 kPa, and a gap of 1 mm using a mesh # 250 and a plate making with an emulsion thickness of 10 μm, and baking the metal paste went.

For each of the multilayer ceramic capacitors of Example 1 and Comparative Example 1, the height of the bump electrode was measured using a laser microscope (λ = 440 μm). The results are shown in the graph of FIG. For Example 1, 50 bump electrodes were measured, and for Comparative Example 1, 161 bump electrodes were measured. Here, the vertical axis of the graph of FIG. 5 indicates the variation rate, the horizontal axis indicates the measurement number (the number corresponding to the measured bump electrode), the symbol “●” indicates the data according to Example 1, and the symbol “□”. "Indicates data according to Comparative Example 1. Table 1 summarizes the maximum value, the minimum value, the average value, and the standard deviation of “height”, “variation amount”, and “variation rate” for each of Example 1 and Comparative Example 1. The “variation amount” is the variation amount with respect to the average value of the bump height, and the maximum variation amount is the absolute value of the difference between the average value of the height and the maximum value, and the average value of the height. The absolute value of the larger of the absolute values of the difference between the minimum value and the minimum value. The “variation rate” is a value obtained by dividing the variation amount by the average value of the heights.

  As shown in the graph of FIG. 5 and Table 1, the amount of variation, the variation rate, and the standard deviation of Example 1 are sufficiently smaller than those of Comparative Example 1. From this, it can be seen that the height variation of the bump electrode in Example 1 is clearly smaller than the height variation of the bump electrode in Comparative Example 1. That is, based on the results of Example 1 and Comparative Example 1, the method of manufacturing a ceramic electronic component in which the metal paste is applied by printing and the bump electrode is formed using the metal ball forms the bump electrode using only the metal paste. Compared with the method for manufacturing a ceramic electronic component, it was confirmed that the variation in the height of the bump electrode can be sufficiently suppressed and the electrical connection of the mounting substrate to the electrode element can be reliably performed.

  In Example 1, since the metal paste is baked at a temperature lower than the melting point of the metal ball, damage to the multilayer ceramic capacitor element as the ceramic electronic component body can be reduced, and the ceramic electronic component has a long service life. It may be possible to make it possible.

It is a partial schematic sectional drawing which shows one Embodiment of the ceramic electronic component of this invention. FIG. 2 is a process diagram showing a series of processes for manufacturing the ceramic electronic component shown in FIG. 1. It is a figure which shows the process of mounting a metal ball | bowl on a metal paste among the procedures shown in FIG. It is a partial schematic sectional drawing which shows other embodiment of the ceramic electronic component of this invention. 6 is a graph showing a relationship between a measurement number corresponding to each bump electrode according to Example 1 and a variation rate.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10,10A ... Ceramic electronic component, 10a ... Bump electrode formation surface, 20, 20A, 20B, 21, 21A, 22B ... Bump electrode, 22 ... Metal ball, 24 ... Base, 26 ... Metal paste, 30 ... Mounting board.

Claims (5)

In a method for manufacturing a ceramic electronic component in which a ceramic electronic component is obtained by forming a plurality of bump electrodes on a bump electrode forming surface of a ceramic electronic component main body,
A paste application step of applying a metal paste containing a first metal to a plurality of locations by printing on the bump electrode forming surface of the ceramic electronic component body;
A ball mounting step of mounting a metal ball made of a second metal having a melting point higher than the baking temperature of the metal paste on the bump electrode forming surface on the metal paste applied to a plurality of locations on the bump electrode forming surface; ,
Baking process of obtaining the bump electrode by baking the metal paste at a temperature lower than the melting point of the second metal;
Including
The metal balls constituting the plurality of bump electrodes have uniform dimensions;
Each of the first and second metals is composed of at least one selected from the group consisting of Au, Ag, Cu, Ni, Sn, Pb, In, Rh, and Pt;
A method of manufacturing a ceramic electronic component characterized by   The method of manufacturing a ceramic electronic component according to claim 1, wherein the metal ball is manufactured by a wire cutting method or a uniform droplet spraying method.   The method for manufacturing a ceramic electronic component according to claim 1, wherein the metal paste further includes a glass frit, and the baking temperature of the metal paste is set to a temperature equal to or higher than a melting point of the glass frit in the baking process.   The method for manufacturing a ceramic electronic component according to any one of claims 1 to 3, wherein, in the ball mounting step, the metal ball is pressed toward the bump electrode forming surface and brought into contact with the bump electrode forming surface. A ceramic electronic component body having a bump electrode forming surface;
In a ceramic electronic component comprising a plurality of bump electrodes provided on the bump electrode formation surface,
Each of the plurality of bump electrodes is
A pedestal provided on the bump electrode forming surface and including a first metal;
A metal ball mounted on the pedestal and containing a second metal;
Consists of
The metal balls constituting the plurality of bump electrodes have uniform dimensions;
Each of the first and second metals is composed of at least one selected from the group consisting of Au, Ag, Cu, Ni, Sn, Pb, In, Rh, and Pt;
Ceramic electronic parts characterized by

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