JP2012134286A - Electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic component in which adhesion of an electronic component base body and an external electrode is enhanced.SOLUTION: An electronic component 10 with an external terminal comprises: a ceramic base body 12 (laminate) being an electronic component base body, external electrodes 14a and 14b formed on the surface of the ceramic base body 12, external terminals 16a and 16b being jointed to the external electrodes 14a and 14b, and a solder 18 for terminal joint which joints the external electrode 14a and the external terminal 16a, and the external electrode 14b and the external terminal 16b. The external electrodes 14a and 14b and the external terminals 16a and 16b are jointed, respectively, via the solder 18 for terminal joint, and glass layers 38a and 38b exist in a part on the surface of the external electrodes 14a and 14b where the solder 18 for terminal joint does not adhere.

Description

  The present invention relates to an electronic component, and more particularly to an electronic component with an external terminal, for example, an electronic component such as a capacitor.

  In general, for example, multilayer ceramic capacitors 1a and 1b with external terminals as shown in FIGS. 8 and 9 are connected to external electrodes 3a and 3b of the laminated ceramic body 2 and external terminals 4a such as lead wires and lead frames. It is formed by joining 4b with solder.

  In these monolithic ceramic capacitors with external terminals, as shown in FIG. 10, Sn plating 6a and 6b is applied to the surface of the external electrodes 3a and 3b of the ceramic element including the internal electrodes 5a and 5b as a base, and Ni is applied to the base. Plating 7a and 7b are applied (see, for example, Patent Document 1).

JP 2000-235932 A

  However, in the electronic component in which plating is performed on the external electrode as described above, there is a problem that if the glass layer segregated on the surface of the external electrode is thick, the plating is difficult to adhere to the external electrode. Therefore, in ceramic electronic parts plated on the external electrode, the segregation of the glass on the surface of the external electrode is reduced by reducing the amount of glass frit in the external electrode so that the plating does not decrease. There is a need to reduce it.

  When the amount of the glass frit is reduced, the segregation of the glass on the surface of the external electrode can be reduced, and plating is easily applied. However, as shown in FIG. 11, pores inside the external electrode increase during sintering, or the glass is absorbed by the ceramic body at the interface between the external electrode and the ceramic body, and the glass near the interface is insufficient. To do. As a result, there is a problem that sufficient bonding cannot be obtained at the interface between the external electrode and the ceramic body, and the adhesion strength between the external electrode and the ceramic body is reduced.

  Further, in the subsequent plating process, the plating solution tends to reach the ceramic body through the pores of the external electrode, and there is a tendency to increase defects such as weakening the interlayer adhesion between the internal electrode and the ceramic body. There arises a problem of lowering the reliability.

  A main object of the present invention is to provide an electronic component having improved adhesion between the electronic component element body and the external electrode.

An electronic component according to the present invention includes an electronic component element body, an external electrode formed on the surface of the electronic component element body, an external terminal having an extended portion that extends in a predetermined direction from the bonded portion, and the external electrode. The external electrode is joined to the joint portion of the external terminal via the solder, and the surface of the external electrode has a portion to which the solder adheres and the solder In the portion where the solder does not adhere to the surface of the external electrode (hereinafter referred to as a non-solder attachment portion), the glass is present and the solder adheres (hereinafter referred to as the solder attachment portion). The electronic component is characterized in that the amount of glass is smaller than that of the portion where the solder does not adhere.
In the electronic component according to the present invention, the external electrode is preferably made of a base metal.
Furthermore, in the electronic component according to the present invention, it is preferable that the glass on the portion where the solder does not adhere on the surface of the external electrode (non-solder attachment portion) has a layer having a metal surface coverage of 90% or more.

According to the electronic component according to the present invention, since the plating layer is not formed on the surface of the external electrode, the amount of the glass frit in the external electrode paste is reduced without being aware of the plating adhesion and the plating resistance. It can be increased to an amount sufficient to suppress adhesion to the body and pores inside the external electrode. Therefore, the adhesion between the electronic component body and the external electrode can be improved. In addition, when the external electrode and the external terminal are joined via solder, glass is present at the non-solder adhesion portion on the surface of the external electrode, so that the oxidation resistance of the external electrode can be optimized. .
Further, in the electronic component according to the present invention, since the base metal is used for the external electrode, the external electrode can be formed at a low cost, and when the internal electrode is a base metal such as Ni, it is easy to be alloyed. Can be easy.
Moreover, in the electronic component according to the present invention, since the glass of the non-solder-attached portion on the surface of the external electrode forms a layer having a metal surface coverage of 90% or more, the oxidation resistance of the external electrode is further improved. Therefore, a highly reliable electronic component can be provided.

  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 schematic perspective view which shows an example of the external appearance of the electronic component with an external terminal concerning this invention. FIG. 2 is an illustrative sectional view showing a section taken along line AA of the electronic component with external terminals shown in FIG. 1 according to the present invention. It is the figure which showed the method of removing the glass layer formed in the external electrode in the electronic component with an external terminal concerning this invention. It is BB sectional drawing of an example of a plate-shaped lead frame as an external terminal of the electronic component with an external terminal concerning this invention. It is front sectional drawing which shows the other example of the electronic component with an external terminal concerning this invention. It is front sectional drawing which shows the further another example of the electronic component with an external terminal concerning this invention. It is sectional drawing of an example of the extension part at the time of using a round cross-section lead wire as an external terminal of the electronic component with an external terminal concerning this invention, (a) is one layer of a metal layer in the lead wire of a round cross section. (B) shows the case where a metal layer is made into two layers. It is front sectional drawing which shows an example of the conventional electronic component with an external terminal. It is front sectional drawing which shows the other example of the conventional electronic component with an external terminal. It is a cross-sectional view solution figure of the ceramic element which shows an example of the conventional electronic component with an external terminal. It is the elements on larger scale of the ceramic element of FIG. 10 which shows an example of the conventional electronic component with an external terminal.

  An embodiment of a ceramic electronic component according to the present invention will be described. FIG. 1 is a schematic perspective view showing an example of the appearance of a ceramic electronic component constituted by a ceramic element body that is an electronic component element body and external electrodes, and FIG. 2 is an A of the ceramic electronic component shown in FIG. The cross-section solution figure which shows the cross section in the -A line | wire is shown.

  The electronic component with external terminals 10 according to this embodiment includes a ceramic body 12 (laminated body) that is an electronic component body, external electrodes 14a and 14b formed on the surface of the ceramic body 12, and external electrodes 14a and 14a. External terminals 16a and 16b to be connected to 14b, and terminal bonding solder 18 for connecting the external electrodes 14a and 14b and the external terminals 16a and 16b, respectively.

  The ceramic body 12 used in the electronic component 10 with external terminals according to this embodiment is composed of a plurality of laminated ceramic layers 20a and 20b. The ceramic body 12 is formed in a rectangular parallelepiped shape, and the first main surface 22a and the second main surface 22b extending along the length direction and the width direction, and the first main surface extending along the length direction and the height direction. It has the side surface 24a and the 2nd side surface 24b, and the 1st end surface 26a and the 2nd end surface 26b which extend along the width direction and a height direction. The ceramic body 12 preferably has rounded corners 30 and ridges 32.

As a material of the ceramic layers 20a and 20b, for example, a dielectric ceramic made of a main component such as BaTiO ₃ , CaTiO ₃ , SrTiO ₃ , CaZrO ₃ can be used. Moreover, you may use what added subcomponents, such as a Mn compound, Mg compound, Si compound, Co compound, Ni compound, rare earth compound, to these main components. In addition, piezoelectric ceramics such as PZT ceramics, semiconductor ceramics such as spinel ceramics, and the like can also be used.

  The ceramic body 12 according to this embodiment functions as a capacitor because a dielectric ceramic is used.

  The ceramic body 12 has a plurality of internal electrodes 28a and 28b so as to be sandwiched between the plurality of ceramic layers 20a and 20b. For example, Ni, Cu, Ag, Pd, an Ag—Pd alloy, Au, or the like can be used as the material of the internal electrodes 28a and 28b. The thickness of the internal electrodes 28a and 28b after firing is preferably 0.3 to 2.0 μm. In addition, the thickness of the fired ceramic layers 20a and 20b is preferably 0.5 to 10 μm.

  The internal electrode 28a has a facing part 34a and a lead part 36a. The facing part 34a faces the internal electrode 28b. The lead portion 36a is drawn from the facing portion 34a to the first end surface 26a of the ceramic body 12. The end portion of the lead portion 36a of the internal electrode 28a is formed so as to extend to the first end face 26a of the ceramic body 12 and be exposed.

  Similarly to the internal electrode 28a, the internal electrode 28b has a facing portion 34b facing the internal electrode 28a and a lead portion 36b drawn from the facing portion 34b to the second end face 26b of the ceramic body 12. The end portion of the lead portion 36b of the internal electrode 28b is formed so as to extend to the second end face 26b of the ceramic body 12 and be exposed.

  The external electrode 14a is electrically connected to the internal electrode 28a on the first end surface 26a of the ceramic body 12 so as to cover the first end surface 26a and the internal electrode 28a. Similarly, the external electrode 14b is electrically connected to the internal electrode 28b on the second end surface 26b of the ceramic body 12 so as to cover the second end surface 26b and the internal electrode 28b.

  For example, Cu, Ni, Ag, Pd, Ag-Pd alloy, Au, or the like can be used as the material of the external electrodes 14a and 14b. Among these, for example, it is preferable to use a base metal such as Cu or Ni. The thickness of the external electrodes 14a and 14b is preferably 10 to 80 μm.

  The external electrode 14a is electrically connected to the external terminal 16a via a terminal bonding solder 18, and a glass layer 38a is formed in a non-solder attachment portion where the terminal bonding solder 18 does not adhere in the external electrode 14a. Yes. At this time, it is preferable that the surface of the external electrode 14a other than the portion to which the external terminal 16a is connected is substantially covered with the glass layer 38a. On the end face (joint face) of the external electrode 14a, a solder attachment portion 40a is formed by mechanically removing the glass layer 38a by sandblasting or the like at a portion to which the external terminal 16a is connected.

  Further, the external electrode 14b is electrically connected to the external terminal 16b via the terminal bonding solder 18, and the glass layer 38b is also formed on the non-solder attachment portion where the terminal bonding solder 18 does not adhere in the external electrode 14b. Is formed. At this time, it is preferable that the surface of the external electrode 14b other than the portion to which the external terminal 16b is connected is substantially covered with the glass layer 38b. On the end face (joint face) of the external electrode 14b, the solder connection portion 40b is also formed by mechanically removing the glass layer 38b by sandblasting or the like in the portion to which the external terminal 16b is connected.

The glass layers 38a and 38b preferably have a thickness of 0.1 to 5 μm.
As for the kind of glass, B-Si type glass is mentioned, for example. More specifically, B-Si-Bi system, B-Si-alkali metal system, B-Si alkali metal- (Ti, Zr) system, B-Si-alkaline earth metal system, B-Si-alkali metal- Alkaline earth metal, B—Si—Zn—alkali metal, B—Si—Zn—alkaline earth metal, and the like can be given. The amount of glass is preferably 40 to 60% by volume of the total solid content of the external electrode.

  The glass layers 38a and 38b have very poor solder wettability, and as such, the terminal joining solder 18 is repelled and the external terminals cannot be joined. Therefore, as described above, the glass layers 38a and 38b are mechanically removed by sandblasting or the like as shown in FIG. 3 at a part of the end faces of the external electrodes 14a and 14b. When the glass layers 38a and 38b are removed by sand blasting, the glass layers 38a and 38b are not cut with angular abrasive grains such as alumina or zirconia, but with spherical glass beads. By doing so, damage to the metal (for example, Cu) used for the external electrodes 14a and 14b can be reduced.

Note that the glass layers 38a and 38b may be formed continuously in the external electrodes 14a and 14b as long as they are in the range excluding the solder adhesion portions 40a and 40b, or a portion that is not formed in a small island shape. It may be scattered. Therefore, it is not always necessary to cover the entire exposed surfaces of the external electrodes 14a and 14b. If the terminal bonding solder 18 is not repelled, the terminal bonding solder 18 is partially applied to the external electrode 14a formed on the first main surface 22a and the external electrode 14b formed on the second main surface 22b. There are problems such as appearance and cracks due to stress concentration. In order to ensure the oxidation resistance of the external electrodes 14a and 14b, the glass coverage on the metal surfaces of the external electrodes 14a and 14b is desirably 90% or more.
As described above, the plating layer is not formed on the external electrodes 14a and 14b in the electronic component 10 with external terminals according to the present embodiment.

Here, the calculation method of the glass coverage is as follows.
First, cut the electronic component along the main surface at about 1/2 the height direction of the electronic component, observe the state of the external electrodes (4 locations) on the side surface with SEM, and externally from the end surface of the ceramic body The length L1 of the glass layer formed to the tip of the electrode and the length L2 of the external electrodes 14a and 14b from the end face of the ceramic body to the tip of the external electrode are measured. Thereafter, in the following mathematical formula 1, the coverage (%) of each of the external electrodes 14a and 14b by the glass layer is obtained.

[Equation 1]
Coverage (%) = (total length L1 / external electrode length L2) × 100

  Next, the electronic component is cut along the side surface at about 1/2 of the width direction of the electronic component, and the state of the external electrodes (four locations) on the side surface is observed with an SEM. The length L1 of the glass layer formed up to the tip of the electrode and the length L2 of the external electrodes 14a, 14b from the end face of the ceramic body to the tip of the external electrode are measured. Thereafter, in the following Equation 2, the coverage (%) of each of the external electrodes 14a and 14b by the glass layer is obtained.

[Equation 2]
Coverage (%) = (total length L1 / external electrode length L2) × 100

  From the above measurement results, the average value of the coverage (%) at 8 locations is obtained, and the average value is taken as the coverage.

  The external terminals 16a and 16b are provided for mounting the electronic component with external terminals 10 on a substrate. For example, plate-like lead frames are used for the external terminals 16a and 16b. The external terminals 16a and 16b are formed in a substantially L shape. The external terminal 16a includes a joint portion 42a that is joined to the external electrode 14a and an extension portion 44a that is mounted on a mounting board (not shown). The external terminal 16b includes a joint portion 42b that is joined to the external electrode 14b and an extension portion 44b that is mounted on a mounting board (not shown).

The external terminals 16 a and 16 b have a base material 46 and a metal layer 48 formed on the surface of the base material 46. As a material of the base material 46 of the external terminals 16a and 16b, for example, Cu, Ni, Ag, Fe, or an alloy containing at least one of them can be used.
The material of the metal layer 48 is preferably made of, for example, Ni, Cu, Cr, Ag, Au, Sn, or an alloy containing at least one of these metals as a main component. An example of the metal layer 48 is a plating layer.

The metal layer 48 may be formed of one layer of the first metal layer 48a formed on the surface of the base material 46, and the second metal layer 48b is formed on the first metal layer 48a. It may be. When only one metal layer 48 is formed, the material of the first metal layer 48a is mainly a metal with good solder wettability, for example, Au, Ag, Sn, or one or more of these metals. It is preferable to consist of an alloy contained as a component. When two metal layers 48 are formed, the material of the first metal layer 48a is a metal having poor solder wettability, for example, Ni, Cu, Cr, or one or more of these metals as a main component. The material of the second metal layer 48b preferably includes a metal having good solder wettability, such as Au, Ag, Sn, or one or more of these metals as a main component. It preferably consists of an alloy. Further, regardless of whether the metal layer 48 is formed of one layer or two layers, Sn is most preferable as the metal material constituting the outermost metal layer 48. Specifically, for example, Sn-based lead-free plating such as Sn-3.5Cu alloy.
As such external terminals 16a and 16b, for example, a round lead wire or a plate-like lead frame can be used.

  FIG. 4 is a cross-sectional view taken along the line BB of an example when the external terminal 16a is a plate-like lead frame. FIG. 4 is a cross-sectional view of the extension 44a of the external terminal 16a. The case where the external terminals 16a and 16b are lead wires having a round cross section will be described later.

  The thickness of the external terminals 16a and 16b is preferably 0.15 to 0.2 mm, for example. The base material 46 used for the external terminals 16a and 16b of the plate-like lead frame includes, for example, copper-based alloys such as tough pitch copper, brass, phosphor bronze, and beryllium copper, and Fe-Ni alloys and stainless steel. It is preferable to use an iron-based alloy. Further, in the plate-like lead frame, the first metal layer 48a is plated with Ni as a base, and the second metal layer 48b is plated with Sn as a surface layer.

  The terminal joining solder 18 is used to join the external electrode 14a and the joint portion 42a of the external terminal 16a. The terminal joining solder 18 is used to join the external electrode 14b and the joint portion 42b of the external terminal 16b. For the terminal joining solder 18, for example, Sn-Sb-based, Sn-Ag-Cu-based, Sn-Cu-based, Sn-Bi-based lead-free solder can be used. Since the external electrode and the external terminal can be joined with a relatively small amount of solder, there is no problem that the metal in the external electrode is melted into the solder and eroded by the solder.

  In the present embodiment, no plating layer is formed on the external electrodes 14a and 14b. For example, in the electronic component 10 with external terminals, the contacts with the substrate to be mounted are the external terminals 16a and 16b, and the external electrodes 14a and 14b of the electronic component 10 with external terminals need only be able to be joined to the external terminals 16a and 16b. This is because a plating layer is not necessarily required.

  Further, for example, the surface of Cu that appears by removing the glass layers 38a and 38b is easily oxidized even at room temperature. If Cu is oxidized and discolored, the solder 18 for terminal bonding becomes difficult to wet, so it cannot be used as an electronic component for board mounting. However, in the present invention, the external terminals 16a and 16b are bonded. Since the glass layers 38a and 38b are removed immediately before the operation, no particular problem occurs.

Further, in this embodiment, the exterior resin is not formed on the electronic component 10 with external terminals, but the ceramic body 12, the external electrodes 14a and 14b, a part of the external terminals 16a and 16b, and the terminal joining solder 18 are used. In order to protect them, an exterior resin may be formed.
In this case, the exterior resin is formed, for example, by coating a liquid or powdery resin such as silicone or epoxy. Engineering plastics may be molded by injection molding, transfer molding, or the like.

  According to the electronic component 10 with external terminals according to this embodiment, since no plating layer is formed on the surfaces of the external electrodes 14a and 14b, the external electrode paste in the external electrode paste is not conscious of plating adhesion and plating resistance. The amount of the glass frit can be increased to an amount sufficient to suppress the adhesion between the external electrodes 14a and 14b and the ceramic body 12 and the pores inside the external electrodes 14a and 14b. Adhesiveness with the electrodes 14a and 14b can be optimized.

Moreover, according to the electronic component 10 with an external terminal according to this embodiment, deterioration of the interface between the internal electrodes 28a and 28b and the ceramic body 12 due to the plating solution can be prevented by not forming the plating layer.
The plating layer also has a role of increasing the weather resistance of Cu of the external electrodes 14a and 14b and preventing discoloration (darkening) due to oxidation of the surface, but without considering the plating adhesion, the glass of the external electrode paste If the frit is increased to an amount sufficient to suppress the adhesion with the ceramic body 12 and the pores inside the external electrodes 14a and 14b, the glass layer 38a formed on the surface after the sintering of the external electrodes 14a and 14b and 38b can be thickened. The glass layers 38a and 38b can suppress the oxidation of the Cu surface.

  Accordingly, the plating layers are not formed on the external electrodes 14a and 14b, and the glass layers 38a and 38b are removed only at a part of the end surfaces necessary for joining the external electrodes 14a and 14b and the external terminals 16a and 16b. By sealing the external terminals 16a and 16b and the terminal joining solder 18 as necessary, the glass layers 38a and 38b can prevent the external electrodes 14a and 14b from being oxidized. As a result, it is possible to supply a highly reliable electronic component 10 with external terminals that can withstand in-vehicle quality. Moreover, since plating is not used, cost can be suppressed.

  Further, when high-temperature lead-free solder is used as the terminal joining solder 18, there is a problem that cracks occur in the electronic component 10 with external terminals due to stress when the hard lead-free solder is cooled and solidified. This was also a hindrance to the lead-free soldering of the terminal joining solder 18, but according to the electronic component 10 with external terminals according to this embodiment, the glass layers 38a and 38b remain on the surfaces of the external electrodes 14a and 14b. Since the terminal bonding solder 18 does not adhere to the portion, excessive adhesion of the terminal bonding solder 18 is suppressed, and such a problem can be prevented.

Then, one Embodiment of the manufacturing method of the electronic component 10 with an external terminal concerning this invention is described.
First, a ceramic green sheet, a conductive paste for internal electrodes, and a conductive paste for external electrodes are prepared. The ceramic green sheet and various conductive pastes include a binder resin and a solvent, and a known binder resin or organic solvent can be used. The conductive paste for external electrodes contains a glass component.

  Then, the internal electrode conductive paste is printed in a predetermined pattern on the ceramic green sheet by, for example, screen printing, and the internal electrode pattern is formed on the ceramic green sheet. Then, a predetermined number of ceramic green sheets for the outer layer on which the internal electrode pattern is not printed are stacked, then a ceramic green sheet on which the internal electrode pattern is printed is sequentially stacked, and the internal electrode pattern is printed thereon. A mother laminate is produced by laminating a predetermined number of ceramic green sheets for outer layers that are not formed. This mother laminated body is pressure-bonded in the lamination direction by means such as an isostatic press.

Thereafter, the raw mother laminate is cut into a predetermined size, and the raw laminate is cut out. At this time, the corners and ridges of the laminate may be rounded by barrel polishing or the like.
Subsequently, the cut raw laminate is fired to produce a ceramic body that is a laminate. The firing temperature depends on the ceramic material and the internal electrode material, but is preferably 900 to 1300 ° C.
Then, a conductive paste for external electrodes is applied to both ends of the ceramic body and baked to form external electrodes. The baking temperature is preferably 700 to 900 ° C.

Then, the external terminal attachment process in the manufacturing method of the electronic component with an external terminal concerning this invention is demonstrated.
First, the glass layer on the surface is removed by sandblasting or the like at the joint portion of the external terminal and the end face portion of the external electrode connected via the solder for terminal joining. For removal of the glass layer by sandblasting, for example, spherical glass beads are preferably used. And an external terminal is attached to the external electrode of the ceramic body which is an electronic component body using the solder for terminal joining. Subsequently, if necessary, the exterior resin so as to cover all of the ceramic body, the external electrode, the external terminal part in contact with the external electrode, and the processed part that is a concavely processed part of the external terminal Is given.

  Next, another embodiment of the electronic component with external terminals which is an electronic component according to the present invention will be described. FIG. 5 shows a cross-sectional view of an example of an electronic component with external terminals according to this embodiment.

  As shown in FIG. 5, the electronic component 110 with external terminals according to this embodiment is a stacked ceramic formed by stacking a plurality of ceramic bodies 12 having the same structure as the ceramic body 12 that is an electronic component body. Element body 112, external electrodes 114a and 114b formed on the surface of stacked ceramic body 112, external terminals 116a and 116b joined to external electrodes 114a and 114b, external electrodes 114a and 114b, and external terminals 116a and 116b And a terminal joining solder 18 for joining together.

  Also in the electronic component with external terminal 110 of this embodiment, the external electrode 114a is electrically connected to the external terminal 116a via the terminal bonding solder 18, and the terminal bonding solder 18 adheres to the external electrode 114a. A glass layer 138a is formed on the non-solder attachment portion. On the end face (joint face) of the external electrode 114a, a solder attachment portion 140a is formed by mechanically removing the glass layer 138a by sandblasting or the like at a portion to which the external terminal 116a is connected.

  The external electrode 114b is electrically connected to the external terminal 116b via the terminal bonding solder 18, and a glass layer 138b is formed in a non-solder attachment portion where the terminal bonding solder 18 does not adhere in the external electrode 114b. Has been. On the end face (joint face) of the external electrode 114b, a solder attachment portion 140b is formed by mechanically removing the glass layer 138b by sandblasting or the like at a portion to which the external terminal 116b is connected.

A plate-like lead frame is used for the external terminals 116a and 116b. The external terminals 116a and 116b are formed in a substantially L shape. The external terminal 116a includes a joint 142a that is joined to the external electrode 114a and an extension 144a that is mounted on a mounting board (not shown). The external terminal 116b includes a joint 142b that is joined to the external electrode 114b and an extension 144b that is mounted on a mounting board (not shown).
The external terminals 116a and 116b are made of the same material as the external terminals 16a and 16b of the electronic component with external terminals 10 shown in FIG.

  In addition, since the other structure is the same as that of the embodiment in the electronic component 10 with an external terminal, description is abbreviate | omitted in order to avoid duplication. Further, in FIG. 5, the parts denoted by the same reference numerals as those in FIGS. 1 and 2 indicate the same or corresponding parts as those in FIGS. 1 and 2.

  Next, still another embodiment of the electronic component with external terminals which is the electronic component according to the present invention will be described. FIG. 6 shows a cross-sectional view of an example of an electronic component with external terminals according to this embodiment.

  The electronic component with external terminals 210 according to this embodiment includes a ceramic body 12 (laminated body) that is an electronic component body, external electrodes 214a and 214b formed on the surface of the ceramic body 12, and external electrodes 214a and 214a. External terminals 216a and 216b (lead wires) joined to 214b, terminal joining solder 18 for joining the external electrodes 214a and 214b and the external terminals 216a and 216b, the ceramic body 12, and the external electrodes 214a and 214b In addition, the external resin 216a and 216b and a part of the external bonding resin 250 for insulatingly covering the terminal joining solder 18 are formed.

  Also in the electronic component with external terminals 210 of this embodiment, the external electrode 214a is electrically connected to the external terminal 216a via the terminal bonding solder 18, and the terminal bonding solder 18 adheres to the external electrode 214a. A glass layer 238a is formed on the non-solder-attached portion. On the end surface (joint surface) of the external electrode 214a, the solder connection portion 240a is formed by mechanically removing the glass layer 238a by sandblasting or the like at the portion to which the external terminal 216a is connected.

  In addition, the external electrode 214b is electrically connected to the external terminal 216b via the terminal bonding solder 18, and the glass layer 238b is also formed on the non-solder adhesion portion where the terminal bonding solder 18 does not adhere in the external electrode 214b. Is formed. On the end surface (joint surface) of the external electrode 214b, the solder connection portion 240b is also formed by mechanically removing the glass layer 238b by sandblasting or the like in the portion to which the external terminal 216b is connected.

  In the present embodiment, for example, lead wires having a round cross section are used for the external terminals 216a and 216b.

  The external terminal 216a includes a joint portion 242a and an extension portion 244a. The joint portion 242a is joined to the solder attachment portion 240a of the external electrode 214a formed on the ceramic body 12 by the terminal joining solder 18. The extension portion 244a is connected to the joint portion 242a and is formed to extend in a direction away from the ceramic body 12.

  The external terminal 216b is configured by a joint portion 242b and an extension portion 244b. Further, the joint portion 242b is joined to the solder attachment portion 240b of the external electrode 214b formed on the ceramic body 12 by the terminal joining solder 18. The extension part 244b is connected to the joint part 242b and is formed to extend in a direction away from the ceramic body 12.

  FIG. 7 shows a cross-sectional view of an example of the external terminals 216a and 216b. FIG. 7A shows a case where the metal layer 248 is one layer on the lead wire having a round cross section, and FIG. 7B shows a case where the metal layer 248 is two layers.

  When using lead wires having a round cross section as the external terminals 216a and 216b, the diameter is preferably 0.48 to 0.78 mm, for example. Further, as the base material 246 used for the external terminals 216a and 216b of the lead wire having a round cross section, for example, a copper wire such as tough pitch copper or a copper coated steel wire called a CP wire is mainly used. In any case, when the lead-free terminal joining solder 18 is designated, the surface layer is made of Sn-based alloy as the metal layer 248. 7B, when two metal layers 248 are formed, Cu is used for the first metal layer 248a, and an Sn-based alloy is used for the second metal layer 248b. Is used.

  The exterior resin 250 is formed by covering the ceramic body 12, the external electrodes 214a and 214b, a part of the external terminals 216a and 216b, and the terminal joining solder 18 together to form an exterior resin to protect them. .

  In addition, since the other structure is the same as that of the embodiment in the electronic component 10 with an external terminal, description is abbreviate | omitted in order to avoid duplication. Further, in FIG. 6, the same reference numerals as those in FIGS. 1 and 2 indicate the same or corresponding parts as those in FIGS. 1 and 2.

  According to the electronic component with an external terminal according to the present invention, since the plating layer is not formed on the surface of the external electrode, the amount of the glass frit in the external electrode paste can be reduced without considering the plating adhesion and the plating resistance. Adhesion with the body The amount can be increased to an amount sufficient to suppress pores inside the external electrode. Therefore, the adhesion between the ceramic body and the external electrode can be improved.

  Moreover, according to the electronic component with an external terminal according to the present invention, when the external electrode and the external terminal are joined through the terminal joining solder, the glass layer is formed at the non-solder attachment portion where the solder does not adhere to the surface of the external electrode. Therefore, the oxidation resistance of the external electrode can be optimized.

  Furthermore, according to the electronic component with external terminals according to the present invention, since the base metal is used for the external electrode, the external electrode can be formed at a low cost, and in addition, it is easy to alloy when the internal electrode is a base metal such as Ni. Therefore, the connection with the internal electrode can be facilitated.

  Further, in the electronic component with external terminals according to the present invention, the glass layer of the non-solder-adhered portion where the solder does not adhere on the surface of the external electrode forms a continuous layer, so that the oxidation resistance of the external electrode is further improved. As a result, a highly reliable electronic component with an external terminal can be provided.

  In the embodiment according to the present invention, the ceramic body which is the electronic component body is a ceramic body composed of a plurality of ceramic layers, but is not limited to this. It may be formed. Therefore, in this case, the internal electrode may not be formed inside the ceramic body.

  In the embodiment according to the present invention, the external terminal has the base material and the metal layer. However, the present invention is not limited to this, and the external terminal may be composed only of the base material.

  Furthermore, since the ceramic body in the embodiment according to the present invention uses a dielectric ceramic, it functions as a capacitor. However, the ceramic body is not limited to this, and when a piezoelectric ceramic is used, it functions as a piezoelectric component. When a semiconductor ceramic is used, it functions as a thermistor, and when a magnetic ceramic is used, it functions as an inductor. When functioning as an inductor, the internal electrode is a coiled conductor.

DESCRIPTION OF SYMBOLS 10,110 Electronic component with an external terminal 12 Ceramic body 14a, 14b, 114a, 114b External electrode 16a, 16b, 116a, 116b External terminal 18 Solder for terminal joining 20a, 20b Ceramic layer 22a First main surface 22b Second main surface 24a 1st side surface 24b 2nd side surface 26a 1st end surface 26b 2nd end surface 28a, 28b Internal electrode 30 Corner | angular part 32 Ridge part 34a, 34b Opposing part 36a, 36b Lead part 38a, 38b, 138a, 138b Glass layer 40a, 40b, 140a, 140b Solder attachment portion 42a, 42b, 142a, 142b Joint portion 44a, 44b, 144a, 144b Extension portion 46, 246 Base material 48 Metal layer 48a First metal layer 50b Second metal layer 112 Stacked ceramic body 210 Electronic components with external terminals 2 4a, 214b external electrodes 216a, 216b external terminals 238a, 238b glass layer 240a, 240b solder attachment 242a, 242b joints 244a, 244b extended portion 248 metal layer 248a first metal layer 248b second metal layer 250 outer resin

Claims (3)

An electronic component body,
An external electrode formed on the surface of the electronic component body;
An external terminal having a joint and an extension extending in a predetermined direction from the joint; and
Solder for joining the external electrode and the joint;
An electronic component comprising:
The external electrode is joined to the joint portion of the external terminal via the solder, and the surface of the external electrode has a portion to which the solder adheres and a portion to which the solder does not adhere. ,
An electronic component, wherein glass is present in a portion where the solder does not adhere on the surface of the external electrode, and the amount of glass in the portion where the solder adheres is less than the portion where the solder does not adhere.   The electronic component according to claim 1, wherein the external electrode is made of a base metal.   3. The electronic component according to claim 1, wherein the glass on a portion of the surface of the external electrode to which the solder does not adhere forms a layer having a metal surface coverage of 90% or more. .

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