JP7234638B2 - electronic components - Google Patents

Description

One aspect of the present invention relates to electronic components.

Patent Literature 1 discloses a ceramic electronic component including a ceramic body and external electrodes. The external electrode includes a metal electrode layer, an insulating resin layer, and a conductive resin layer. The conductive resin layer absorbs the bending of the external electrodes and suppresses the occurrence of cracks due to thermal shock. The insulating resin layer can reduce the proportion of the expensive conductive resin layer in the external electrodes. As a result, the reliability and economy of the ceramic electronic component can be improved.

WO2014/024593

In the ceramic electronic component described above, there is a risk that moisture may enter the insulating resin layer during the plating process. Since the insulating resin layer has a high proportion of the resin component, it easily absorbs moisture. If the reflow process is performed with the insulating resin layer absorbing moisture, separation may occur between the metal electrode layer and the insulating resin layer or between the insulating resin layer and the conductive resin layer.

One aspect of the present invention provides an electronic component capable of suppressing peeling of external electrodes.

An electronic component according to one aspect of the present invention includes a body containing ceramic and an external electrode, wherein the external electrode comprises a sintered metal layer disposed on the body and a an insulating resin layer disposed thereon; and a conductive resin layer disposed on the insulating resin layer, the conductive resin layer covering the insulating resin layer. The distance between the outer edge and the outer edge of the insulating resin layer is 150 μm or more.

In one aspect, the conductive resin layer covers the insulating resin layer, and the distance between the outer edge of the conductive resin layer and the outer edge of the insulating resin layer is 150 μm or more. Therefore, it is possible to prevent moisture from penetrating into the insulating resin layer. As a result, peeling of the external electrodes can be suppressed.

In the above aspect, the element includes a first principal surface which is a mounting surface, a second principal surface facing the first principal surface, an end surface adjacent to the first principal surface and the second principal surface, and the insulating resin layer has a portion arranged on the end surface, and the length of the portion in the facing direction of the first main surface and the second main surface is 20% or more of the length of the end surface in the facing direction may be The adhesion of the insulating resin layer to the sintered metal layer is higher than the adhesion of the conductive resin layer to the sintered metal layer. Therefore, peeling of the external electrodes can be further suppressed.

In the above aspect, the thickness of the insulating resin layer may be 30% or more and 95% or less of the sum of the thickness of the conductive resin layer and the thickness of the insulating resin layer. Since the insulating resin layer has higher elasticity than the conductive resin layer containing a metal component, by setting the thickness of the insulating resin layer to 30% or more, the thermal stress applied to the external electrodes during the reflow process, for example, can be relaxed. can do. This can further suppress peeling of the external electrodes. By setting the thickness of the insulating resin layer to 95% or less, the conductivity of the external electrodes can be ensured.

In the one aspect described above, the insulating resin layer may contain a thermosetting resin, and the glass transition temperature of the thermosetting resin may be 150° C. or higher. In this case, since the heat resistance of the external electrodes is improved, the reliability of the external electrodes is improved.

An aspect of the present invention provides an electronic component capable of suppressing the occurrence of exfoliation in external electrodes.

1 is a perspective view showing an electronic component according to a first embodiment; FIG. FIG. 2 is a side view showing the electronic component of FIG. 1; 2 is a cross-sectional view showing the electronic component of FIG. 1; FIG. FIG. 4 is a cross-sectional view along line IV-IV of FIG. 3; It is sectional drawing which shows the electronic component which concerns on 2nd Embodiment. FIG. 6 is a cross-sectional view along line VI-VI of FIG. 5; It is a perspective view which shows the electronic component which concerns on 3rd Embodiment. FIG. 8 is a cross-sectional view showing the electronic component of FIG. 7; FIG. 9 is a cross-sectional view along line IX-IX of FIG. 8; It is sectional drawing which shows the electronic component which concerns on 4th Embodiment. It is sectional drawing which shows the electronic component which concerns on 5th Embodiment.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and overlapping descriptions are omitted.

[First embodiment]
FIG. 1 is a perspective view showing an electronic component according to the first embodiment. FIG. 2 is a side view showing the electronic component of FIG. 1. FIG. 3 and 4 are cross-sectional views showing the electronic component of FIG. 1. FIG. As shown in FIGS. 1 to 4, an electronic component 1A according to the first embodiment includes an element body 3 containing ceramic and a pair of external electrodes 5. As shown in FIGS. The electronic component 1A is, for example, a laminated ceramic capacitor. The electronic component 1A may be, for example, a piezoelectric element.

The element body 3 has a rectangular parallelepiped shape. The rectangular parallelepiped shape includes a rectangular parallelepiped shape with chamfered corners and edges, and a rectangular parallelepiped shape with rounded corners and edges. The element body 3 has, as outer surfaces, a main surface 3a (first main surface), a main surface 3b (second main surface) facing the main surface 3a, a pair of side surfaces 3c facing each other, and a pair of end faces 3e facing each other. Each main surface 3a, 3b, each side surface 3c, and each end surface 3e have a rectangular shape. The direction in which the pair of main surfaces 3a and 3b face each other is the first direction D1, the direction in which the pair of side faces 3c face each other is the second direction D2, and the direction in which the pair of end faces 3e face each other is the first direction D1. It is the third direction D3.

The first direction D1 is a direction perpendicular to the main surfaces 3a and 3b. The second direction D2 is a direction orthogonal to each side surface 3c. The third direction D3 is a direction orthogonal to each end face 3e. The first direction D1, the second direction D2, and the third direction D3 cross each other (here, orthogonally). The first direction D1 is the height direction of the element body 3 . The second direction D2 is the width direction of the element body 3 . A third direction D3 is the length direction of the element body 3 . In this embodiment, the length of the element 3 (the length in the third direction D3) is the height of the element 3 (the length in the first direction D1) and the width of the element 3 (the second length in direction D2). The length of the element body is, for example, 5.7 mm, the height of the element body 3 is, for example, 2.75 mm, and the width of the element body 3 is, for example, 5.0 mm.

The pair of main surfaces 3a and 3b extend in the second direction D2 so as to connect the pair of side surfaces 3c. The pair of main surfaces 3a, 3a also extend in the third direction D3 so as to connect the pair of end surfaces 3e. The pair of side surfaces 3c extend in the first direction D1 so as to connect the pair of main surfaces 3a and 3b. The pair of side surfaces 3c also extend in the third direction D3 so as to connect the pair of end surfaces 3e. The pair of end surfaces 3e extend in the first direction D1 so as to connect the pair of main surfaces 3a and 3b. The pair of end surfaces 3e also extend in the second direction D2 so as to connect the pair of side surfaces 3c.

Each main surface 3a, 3b is adjacent to each of the pair of side surfaces 3c and the pair of end surfaces 3e. Each side surface 3c is adjacent to each of the pair of main surfaces 3a, 3b and the pair of end surfaces 3e. Each end surface 3e is adjacent to each of the pair of main surfaces 3a, 3b and the pair of side surfaces 3c.

The element body 3 includes a plurality of laminated dielectric layers. The stacking direction of the plurality of dielectric layers matches the direction in which the pair of main surfaces 3a and 3b face each other, that is, the first direction D1. Each dielectric layer is formed from a sintered ceramic green sheet containing, for example, a dielectric material (a dielectric ceramic such as _BaTiO3 , Ba(Ti,Zr) _O3 , or (Ba,Ca) _TiO3 ). It is configured. In the actual element body 3, each dielectric layer is integrated to such an extent that the boundary between each dielectric layer cannot be visually recognized.

The electronic component 1A is solder-mounted on an electronic device (for example, a circuit board or an electronic component). The electronic component 1A may be mounted with a sintered metal or a conductive adhesive. In the electronic component 1A, the main surface 3a is a mounting surface facing the electronic device.

The electronic component 1A, as shown in FIGS. 3 and 4, includes a plurality of internal electrodes 7 and 9 as internal conductors. The internal electrodes 7 and 9 are made of a conductive material that is commonly used as internal electrodes of laminated electric elements. A base metal (such as Ni or Cu) is used as the conductive material. The internal electrodes 7 and 9 are constructed as a sintered body of a conductive paste containing the conductive material. In this embodiment, the internal electrodes 7 and 9 are made of Ni.

The internal electrodes 7 and the internal electrodes 9 are arranged at different positions (layers) in the stacking direction (that is, the first direction D1). That is, the internal electrodes 7 and the internal electrodes 9 are alternately arranged in the element body 3 so as to face each other with a gap in the stacking direction. The internal electrodes 7 and 9 have different polarities. One ends of the internal electrodes 7 and 9 are exposed on the corresponding end surface 3e.

As shown in FIGS. 2 to 5, the pair of external electrodes 5 are arranged on the side of the end face 3e of the element body 3 (the end face 3e and its periphery), that is, at the ends of the element body 3 in the third direction D3. It is The pair of external electrodes 5 are separated from each other. Each external electrode 5 corresponds to an electrode portion 5a arranged on the main surface 3a, an electrode portion 5b arranged on the main surface 3b, and an electrode portion 5c arranged on each side surface 3c. and an electrode portion 5e arranged on the end face 3e. The external electrodes 5 are formed on five surfaces: a pair of main surfaces 3a and 3b, a pair of side surfaces 3c, and one end surface 3e. The electrode portions 5a, 5b, 5c, and 5e adjacent to each other are physically and electrically connected to each other.

The electrode portion 5e covers all of the exposed end portions of the corresponding internal electrodes 7 and 9 on the end surface 3e. The internal electrodes 7 and 9 are directly connected to the corresponding electrode portion 5e. The internal electrodes 7 and 9 are electrically connected to the corresponding external electrodes 5 .

The electrode portion 5c has a region 5c1 and a region 5c2. Region 5c1 is positioned closer to main surface 3b than region 5c2. Region 5c2 is positioned closer to main surface 3a than region 5c1. The electrode portion 5e has a region 5e1 and a region 5e2. Region 5e1 is positioned closer to main surface 3b than region 5e2. Region 5e2 is positioned closer to main surface 3a than region 5e1.

As shown in FIGS. 3 and 4, the external electrode 5 includes a sintered metal layer E1 arranged on the element body 3, an insulating resin layer E2 arranged on the sintered metal layer E1, A conductive resin layer E3 disposed on the insulating resin layer E2, a first plating layer E4 disposed on the conductive resin layer E3, and a second plating disposed on the first plating layer E4. and a layer E5. The second plated layer E5 constitutes the outermost layer of the external electrode 5. As shown in FIG. The external electrode 5 has a five-layer structure.

The sintered metal layer E1 is formed so as to cover five surfaces: a pair of main surfaces 3a and 3b, a pair of side surfaces 3c, and one end surface 3e. The sintered metal layer E1 is included in the electrode portion 5a, the electrode portion 5b, the regions 5c1 and 5c2 of the pair of electrode portions 5c, and the regions 5e1 and 5e2 of the electrode portion 5e. An outer edge E1a of the sintered metal layer E1 is located on the pair of main surfaces 3a, 3b and the pair of side surfaces 3c. The sintered metal layer E1 is also a base metal layer for forming the insulating resin layer E2 or the conductive resin layer E3.

The sintered metal layer E1 contains a metal component and a glass component. The metal component is Cu, for example. The metal component may be Ni. Thus, the sintered metal layer E1 contains a base metal. The sintered metal layer E1 is formed by applying a conductive paste to the surface of the element body 3 and baking it to sinter the metal component. As the conductive paste, for example, a mixture of a metal powder such as Cu or Ni, a glass component, an organic binder, and an organic solvent is used.

The insulating resin layer E2 partially covers the sintered metal layer E1. The insulating resin layer E2 is arranged on four surfaces: the main surface 3a, the pair of side surfaces 3c, and the corresponding end surfaces 3e. The insulating resin layer E2 is included in the electrode portion 5a, the regions 5c1 and 5c2 of the pair of electrode portions 5c, and the regions 5e1 and 5e2 of the electrode portion 5e. An outer edge E2a of the insulating resin layer E2 is located on the main surface 3a, the pair of side surfaces 3c, and the corresponding end surfaces 3e.

The insulating resin layer E2 covers the sintered metal layer E1 in the electrode portion 5a, the region 5c2 of the electrode portion 5c, and the region 5e2 of the electrode portion 5e. The sintered metal layer E1 is exposed from the insulating resin layer E2 in the electrode portion 5b, the region 5c1 of the electrode portion 5c, and the region 5e1 of the electrode portion 5e. The insulating resin layer E2 covers the outer edge E1a of the sintered metal layer E1 on the main surface 3a and the side surfaces 3c. The insulating resin layer E2 is in contact with part of the main surface 3a and part of each side surface 3c. The insulating resin layer E2 is not in contact with the main surface 3b and the end surface 3e.

In this embodiment, the insulating resin layer E2 covers the outer edge E1a and extends outside the outer edge E1a in the regions 5c2 of the electrode portions 5a and 5c. The outer edge E2a is positioned outside the outer edge E1a in the region 5c2 of the electrode portion 5a and the electrode portion 5c and extends along the outer edge E1a. In the region 5c2 of the electrode portion 5a and the electrode portion 5c, the distance by which the insulating resin layer E2 spreads outside the outer edge E1a is, for example, 50 μm or more and 500 μm or less. The insulating resin layer E2 does not cover the outer edge E1a of the electrode portion 5b, the region 5c1 of the electrode portion 5c, and the electrode portion 5e as a whole.

The insulating resin layer E2 contains, for example, a thermosetting resin. The glass transition temperature (Tg) of thermosetting resin is, for example, 150° C. or higher. Thermosetting resins are, for example, phenolic resins, acrylic resins, silicone resins, epoxy resins, or polyimide resins. The insulating resin layer E2 may contain an ultraviolet curable resin, a thermoplastic resin, or the like. The insulating resin layer E2 does not contain filler. The insulating resin layer E2 is formed by curing an insulating resin applied on the sintered metal layer E1 of the electrode portion 5a, the region 5c2 of the electrode portion 5c, and the region 5e2 of the electrode portion 5e. As the insulating resin, for example, a mixture of a thermosetting resin, an organic binder, and an organic solvent is used.

The conductive resin layer E3 covers the entire insulating resin layer E2. The insulating resin layer E2 is not exposed from the conductive resin layer E3. The conductive resin layer E3 is arranged on four surfaces: the main surface 3a, the pair of side surfaces 3c, and the corresponding end surface 3e. The conductive resin layer E3 is included in the electrode portion 5a, the region 5c2 of the pair of electrode portions 5c, and the region 5e2 of the electrode portion 5e. The conductive resin layer E3 covers the entire circumference of the outer edge E2a of the insulating resin layer E2 and extends outside the outer edge E2a. The outer edge E3a of the conductive resin layer E3 is positioned outside the outer edge E2a. The outer edge E3a is located on the main surface 3a, the pair of side surfaces 3c, and the corresponding end surface 3e.

The conductive resin layer E3 covers the sintered metal layer E1 of the electrode portion 5a, the region 5c2 of the electrode portion 5c, and the region 5e2 of the electrode portion 5e via the insulating resin layer E2. The sintered metal layer E1 of the electrode portion 5b, the region 5c1 of the electrode portion 5c, and the region 5e1 of the electrode portion 5e are exposed from the conductive resin layer E3. The conductive resin layer E3 covers the outer edge E1a of the sintered metal layer E1 on the main surface 3a and the side surfaces 3c via the insulating resin layer E2. The conductive resin layer E3 is in contact with part of the main surface 3a and part of each side surface 3c. The conductive resin layer E3 is in contact with part of the sintered metal layer E1 at the end face 3e.

The conductive resin layer E3 contains a metal component and a resin component. Metal components are Ag and Cu, for example. The resin component is, for example, a thermosetting resin. Thermosetting resins are, for example, phenolic resins, acrylic resins, silicone resins, epoxy resins, or polyimide resins. The resin component may be an ultraviolet curable resin or a resin such as a thermoplastic resin. The resin component may be the same as or different from the resin contained in the insulating resin layer E2.

The conductive resin layer E3 is a conductive resin applied to the entire insulating resin layer E2, a portion of the main surface 3a, a portion of the pair of side surfaces 3c, and a portion of the sintered metal layer E1 on the end surface 3e. It is formed by curing. As the conductive resin, for example, a mixture of conductive particles, a thermosetting resin, an organic binder, and an organic solvent is used. As the conductive particles, for example, Ag powder, Cu powder, or coated particles are used. A coated particle has, for example, a resin particle and a metal layer such as Ag or Cu that coats the surface of the resin particle.

The first plating layer E4 is formed on the sintered metal layer E1 and the conductive resin layer E3 by plating. The first plating layer E4 is included in the electrode portion 5a, the electrode portion 5b, the regions 5c1 and 5c2 of the pair of electrode portions 5c, and the regions 5e1 and 5e2 of the electrode portion 5e. In this embodiment, the first plating layer E4 is a Ni plating layer formed by Ni plating on the sintered metal layer E1 and the conductive resin layer E3. The first plating layer E4 may be a Sn plating layer, a Cu plating layer, or an Au plating layer. Thus, the first plating layer E4 contains Ni, Sn, Cu, or Au.

The second plating layer E5 is formed on the first plating layer E4 by plating. The second plating layer E5 is included in the electrode portion 5a, the electrode portion 5b, the regions 5c1 and 5c2 of the pair of electrode portions 5c, and the regions 5e1 and 5e2 of the electrode portion 5e. In this embodiment, the second plating layer E5 is a Sn plating layer formed by Sn plating on the first plating layer E4. The second plating layer E5 may be a Cu plating layer, a Pd plating layer, or an Au plating layer. Thus, the second plating layer E5 contains Sn, Cu, Pd or Au. The first plating layer E4 and the second plating layer E5 are formed on the conductive resin layer E3 and the sintered metal layer E1 on the region 5c1 of the electrode portion 5b and the electrode portion 5c, and the region 5e1 of the electrode portion 5e. It constitutes the plating layer. That is, in the present embodiment, the plating layer formed on the conductive resin layer E3 and the sintered metal layer E1 of the electrode portion 5b, the region 5c1 of the electrode portion 5c, and the region 5e1 of the electrode portion 5e has a two-layer structure. have.

A region 5c2 of the electrode portion 5a, the electrode portion 5c, and a region 5e2 of the electrode portion 5e are composed of a sintered metal layer E1, an insulating resin layer E2, a conductive resin layer E3, a first plating layer E4, and a second plating layer E5. have. That is, the electrode portion 5a, the region 5c2 of the electrode portion 5c, and the region 5e2 of the electrode portion 5e have a five-layer structure. The electrode portion 5b, the region 5c1 of the electrode portion 5c, and the region 5e1 of the electrode portion 5e have a sintered metal layer E1, a first plating layer E4, and a second plating layer E5. That is, the electrode portion 5b, the region 5c1 of the electrode portion 5c, and the region 5e1 of the electrode portion 5e have a three-layer structure.

The sintered metal layer E1 of each of the electrode portions 5a, 5b, 5c, 5e is integrally formed. The insulating resin layer E2 of each electrode portion 5a, 5c, 5e is integrally formed. The conductive resin layer E3 of each electrode portion 5a, 5c, 5e is integrally formed. The first plated layer E4 of each electrode portion 5a, 5b, 5c, 5e is integrally formed. The second plated layer E5 of each electrode portion 5a, 5b, 5c, 5e is integrally formed.

A distance L1 between the outer edge E3a of the conductive resin layer E3 and the outer edge E2a of the insulating resin layer E2 is 150 μm or more. The distance L1 is the distance by which the conductive resin layer E3 spreads outside the outer edge E2a. A distance L1 is the distance between the outer edge E3a and the outer edge E2a in the cross-sectional view of the external electrode 5 . In this embodiment, the distance L1 is the distance L1a, the distance L1c, or the distance L1e. The distance L1a is the distance L1 on the main surface 3a. The distance L1c is the distance L1 on the side surface 3c. The distance L1e is the distance L1 on the end face 3e.

The distance L1a is the distance from the outer edge E2a to the outer edge E3a along the main surface 3a in the cross section of the external electrode 5 . The distance L1c is the distance from the outer edge E2a to the outer edge E3a along the side surface 3c in the cross section of the external electrode 5 . The distance L1e is the distance from the outer edge E2a to the outer edge E3a along the surface of the sintered metal layer E1 of the electrode portion 5e in the cross section of the external electrode 5 .

The distance L1 can be measured, for example, as follows. First, a cross-sectional view of the external electrode 5 is obtained. When measuring the distance L1a and the distance L1e, a cross-sectional view of the external electrode 5 cut along a plane orthogonal to the second direction D2 is acquired. The cross-sectional view at this time can be, for example, a plane orthogonal to the second direction D2 and positioned equidistant from the pair of side surfaces 3c. When measuring the distance L1c, for example, a cross-sectional view when the external electrode 5 is cut along a plane orthogonal to the extending direction of the outer edge of the external electrode 5 (that is, the outer edge of the second plating layer E5) on the side surface 3c is obtained. do. When the outer edge of the external electrode 5 is curved, a cross-sectional view obtained by cutting the external electrode 5 along a plane perpendicular to the tangent to the outer edge of the external electrode 5 may be obtained. Also, for example, a cross-sectional view of the external electrode 5 cut along a plane including a ridgeline portion between the principal surface 3a and one end surface 3e and a ridgeline portion between the principal surface 3b and the other end surface 3e is shown. may be obtained.

The distance L1a, the distance L1c, and the distance L1e are measured by image analysis of the obtained cross-sectional view. The distance L1a, the distance L1c, and the distance L1e can be, for example, minimum values of a plurality of measurement results in a plurality of cross-sectional views.

The sum of the thickness t1 of the insulating resin layer E2 and the thickness t2 of the conductive resin layer E3 is, for example, 50 μm or more and 200 μm or less. The thickness t1 and the thickness t2 are measured, for example, by image-analyzing a cross-sectional view of the external electrode 5 . The thickness t1 and the thickness t2 can be, for example, the thickness of the insulating resin layer E2 and the thickness of the conductive resin layer E3 at the center of the portion of the end surface 3e where the region 5e2 of the electrode portion 5e is provided.

The thickness t1 of the insulating resin layer E2 is 30% or more and 95% or less of the sum of the thickness t1 of the insulating resin layer E2 and the thickness t2 of the conductive resin layer E3. The thickness t1 is, for example, 15 μm or more and 190 μm or less. The thickness t2 is, for example, 10 μm or more and 185 μm or less.

The length L2 of the insulating resin layer E2 of the electrode portion 5e in the first direction D1 is 20% or more of the length L3 of the end surface 3e in the first direction D1. The length L3 is the maximum length in the first direction D1 from the main surface 3a to the upper end of the external electrode 5 (that is, the outer surface of the electrode portion 5b) from the reference surface. The length L3 is equal to the length obtained by adding the thickness of the electrode portion 5b to the distance in the first direction D1 between the principal surfaces 3a and 3b. The insulating resin layer E2 of the electrode portion 5e is a portion of the insulating resin layer E2 that is arranged on the end surface 3e. The length L2 is the maximum length in the first direction D1 from the main surface 3a to the outer edge E2a located on the end surface 3e. The outer edge E2a positioned on the end surface 3e is the outer edge E2a overlapping the element body 3 when viewed from the third direction D3.

The length L2 and the length L3 are measured, for example, by image analysis of a cross-sectional view including the electrode portion 5e and the end surface 3e. The cross section can be, for example, a plane orthogonal to the second direction D2 and positioned equidistant from the pair of side surfaces 3c. The length L2 and the length L3 can be, for example, minimum values of multiple measurement results in multiple cross-sectional views. Length L2 may be 95% or less of length L3. In this case, L1 of 150 μm or more can be ensured for almost any chip size. This can suppress peeling of the external electrodes 5 in the reflow process.

As described above, in the electronic component 1A, the external electrodes 5 have the insulating resin layers E2. Since the insulating resin layer E2 has a high proportion of the resin component, it easily absorbs moisture. In the electronic component 1A, the conductive resin layer E3 covers the entire insulating resin layer E2, and the distance L1 (distance L1a , distance L1c, and distance L1e) are 150 μm or more. Therefore, for example, in the process of forming the first plated layer E4 and the second plated layer E5, it is possible to prevent moisture from entering the insulating resin layer E2. Thereby, for example, peeling of the external electrodes 5 in the reflow process can be suppressed.

The length L2 of the insulating resin layer E2 of the electrode portion 5e in the first direction D1 is 20% or more of the length L3 of the end face 3e in the first direction D1. The adhesion of the insulating resin layer E2 to the sintered metal layer E1 is higher than the adhesion of the conductive resin layer E3 to the sintered metal layer E1. Therefore, peeling of the external electrodes 5 in the reflow process can be further suppressed.

The thickness t1 of the insulating resin layer E2 is 30% or more and 95% or less of the sum of the thickness t2 of the conductive resin layer E3 and the thickness t1 of the insulating resin layer E2. The insulating resin layer E2 containing no metal component has higher elasticity than the conductive resin layer E3 containing a metal component. Therefore, by setting the thickness t1 of the insulating resin layer E2 to 30% or more, the thermal stress applied to the external electrodes 5 in the reflow process can be relaxed. This can further suppress peeling of the external electrodes 5 in the reflow process. By setting the thickness t1 of the insulating resin layer E2 to 95% or less, the conductivity of the external electrodes 5 can be ensured.

The insulating resin layer E2 contains a thermosetting resin, and the glass transition temperature of the thermosetting resin is 150° C. or higher. Therefore, since the heat resistance of the external electrodes 5 is improved, the reliability of the reflow process is improved.

[Second embodiment]
FIG. 5 is a cross-sectional view showing an electronic component according to the second embodiment. FIG. 6 is a cross-sectional view along line VI-VI of FIG. As shown in FIGS. 5 and 6, in the electronic component 1B according to the second embodiment, the insulating resin layer E2 does not cover the outer edge E1a in the regions 5c2 of the electrode portions 5a and 5c. It differs from the electronic component 1A (see FIG. 1) according to the first embodiment in that it is positioned inside E1a. That is, in the electronic component 1B, the entire insulating resin layer E2 is positioned inside the outer edge E1a of the sintered metal layer E1.

The outer edge E2a extends along the outer edge E1a in the region 5c2 of the electrode portion 5a and the electrode portion 5c. In the regions 5c2 of the electrode portions 5a and 5c, the distance by which the sintered metal layer E1 spreads outside the outer edge E2a is, for example, 50 μm or more and 300 μm or less.

In the present embodiment, the distance L1a is the distance from the outer edge E2a to the outer edge E3a along the surface of the sintered metal layer E1 of the electrode portion 5a and the main surface 3a in the cross section of the external electrode 5. The distance L1c is the distance from the outer edge E2a to the outer edge E3a along the surface and the side surface 3c of the sintered metal layer E1 of the electrode portion 5c in the cross section of the external electrode 5 .

Also in the electronic component 1B, the conductive resin layer E3 covers the entire insulating resin layer E2, and the distance L1 (the distance L1a, the distance L1c, and the distance L1e) is 150 μm or more. Therefore, like the electronic component 1A, the peeling of the external electrodes 5 can be suppressed. Length L2 is 20% or more of length L3. Therefore, in the electronic component 1B, like the electronic component 1A, it is possible to further suppress peeling of the external electrodes 5 during the reflow process. The thickness t1 is 30% or more and 95% or less of the sum of the thickness t2 and the thickness t1. Therefore, the electrical conductivity of the external electrodes 5 can be ensured while enhancing the effect of alleviating the thermal stress on the external electrodes 5 . The insulating resin layer E2 contains a thermosetting resin, and the glass transition temperature of the thermosetting resin is 150° C. or higher. Therefore, since the heat resistance of the external electrodes 5 is improved, the reliability of the reflow process is improved.

[Third Embodiment]
FIG. 7 is a perspective view showing an electronic component according to the third embodiment. 8 is a cross-sectional view showing the electronic component of FIG. 7. FIG. 9 is a cross-sectional view along line IX-IX of FIG. 8. FIG. As shown in FIGS. 7 to 9, the electronic component 1C according to the third embodiment is different from the second embodiment in that the insulating resin layer E2 covers the entire sintered metal layer E1 except for the outer edge portion. 1B (see FIG. 5). In the electronic component 1C, the insulating resin layer E2 and the conductive resin layer E3 are also arranged on the main surface 3b. Moreover, the insulating resin layer E2 and the conductive resin layer E3 cover the entire corresponding end faces 3e. That is, the insulating resin layer E2 and the conductive resin layer E3 are included not only in the electrode portion 5b but also in the entire electrode portion 5e. The electrode portion 5c includes an insulating resin layer E2 and a conductive resin layer E3 over the entire first direction D1.

An outer edge E2a of the insulating resin layer E2 is located on the main surface 3a, the main surface 3b, and the pair of side surfaces 3c, and is not located on the end surface 3e. Therefore, the distance L1 is the distance L1a, the distance L1b, or the distance L1c. The distance L1b is the distance L1 on the main surface 3b. The distance L1b can be measured similarly to the distance L1a. That is, the distance L1b is the distance from the outer edge E2a to the outer edge E3a along the surface of the sintered metal layer E1 of the electrode portion 5b and the main surface 3b in a cross section perpendicular to the second direction D2.

In this embodiment, the distance L1c is the distance from the outer edge E2a to the outer edge E3a along the surface and the side surface 3c of the sintered metal layer E1 of the electrode portion 5c in the cross section orthogonal to the first direction D1. The insulating resin layer E2 covers the entire corresponding end surface 3e. Therefore, length L2 is equal to length L3.

Also in the electronic component 1C, the conductive resin layer E3 covers the entire insulating resin layer E2, and the distance L1 (the distance L1a, the distance L1b, and the distance L1c) is 150 μm or more. Therefore, like the electronic component 1A, the peeling of the external electrodes 5 can be suppressed. Length L2 is 20% or more of length L3. Therefore, in the electronic component 1C, like the electronic component 1A, it is possible to further suppress peeling of the external electrodes 5 during the reflow process. The thickness t1 is 30% or more and 95% or less of the sum of the thickness t2 and the thickness t1. Therefore, the conductivity of the external electrodes 5 can be ensured while increasing the effect of alleviating the stress on the external electrodes 5 . The insulating resin layer E2 contains a thermosetting resin, and the glass transition temperature of the thermosetting resin is 150° C. or higher. Therefore, since the heat resistance of the external electrodes 5 is improved, the reliability of the reflow process is improved.

[Fourth Embodiment]
FIG. 10 is a cross-sectional view showing an electronic component according to the fourth embodiment. FIG. 10 shows a cross-sectional view taken along a plane orthogonal to the second direction D2. A cross-sectional view taken along a plane orthogonal to the first direction D1 so as to include the region 5e2 of the electrode portion 5e and the region 5c2 of the electrode portion 5c is omitted because it is the same as FIG.

As shown in FIG. 10, the electronic component 1D according to the fourth embodiment is different from the electronic component 1A according to the first embodiment (see FIG. 1) in that the conductive resin layer E3 is also arranged on the main surface 3b. ). In addition, in the electronic component 1D, the conductive resin layer E3 covers the side surface 3c over the entire first direction D1 and also covers the entire corresponding end surface 3e. That is, the conductive resin layer E3 is included not only in the electrode portion 5b, but also in the entire electrode portion 5c and the entire electrode portion 5e. The electrode portion 5b, the region 5e1 of the electrode portion 5e, and the region 5c1 of the electrode portion 5c have a four-layer structure including a sintered metal layer E1, a conductive resin layer E3, a first plating layer E4, and a second plating layer E5. ing.

An outer edge E3a of the conductive resin layer E3 is located on the main surface 3a, the main surface 3b, and the pair of side surfaces 3c, and is not located on the end surface 3e. Therefore, the distance L1 is the distance L1a, the distance L1eb, or the distance L1c. The distance L1eb is the distance L1 between the end surface 3e and the main surface 3b. The distance L1eb is the distance from the outer edge E2a to the outer edge E3a along the surface and main surface 3b of the sintered metal layer E1 of the electrode portion 5e and the electrode portion 5b in a cross section perpendicular to the second direction D2. Like the distance L1e, the distance L1eb is measured, for example, by obtaining a cross-sectional view of the external electrode 5 cut along a plane perpendicular to the second direction and performing image analysis on the obtained cross-sectional view. The distance L1eb can be, for example, the minimum value of multiple measurement results in multiple cross-sectional views.

Also in the electronic component 1D, the conductive resin layer E3 covers the entire insulating resin layer E2, and the distance L1 (distance L1a, distance L1eb, and distance L1c) are 150 μm or more. Therefore, like the electronic component 1A, the peeling of the external electrodes 5 can be suppressed. Length L2 is 20% or more of length L3. Therefore, in the electronic component 1D, like the electronic component 1A, it is possible to further suppress peeling of the external electrodes 5 during the reflow process. The thickness t1 is 30% or more and 95% or less of the sum of the thickness t2 and the thickness t1. Therefore, the conductivity of the external electrodes 5 can be ensured while increasing the effect of alleviating the stress on the external electrodes 5 . The insulating resin layer E2 contains a thermosetting resin, and the glass transition temperature of the thermosetting resin is 150° C. or higher. Therefore, since the heat resistance of the external electrodes 5 is improved, the reliability of the reflow process is improved.

[Fifth embodiment]
FIG. 11 is a cross-sectional view showing an electronic component according to the fifth embodiment. FIG. 11 shows a cross-sectional view taken along a plane orthogonal to the second direction D2. A cross-sectional view taken along a plane orthogonal to the first direction D1 so as to include the region 5e2 of the electrode portion 5e and the region 5c2 of the electrode portion 5c is omitted because it is the same as FIG.

As shown in FIG. 11, in the electronic component 1E according to the fifth embodiment, the insulating resin layer E2 does not cover the outer edge E1a in the region 5c2 of the electrode portion 5a and the electrode portion 5c. This is different from the electronic component 1D (see FIG. 10) according to the fourth embodiment in that it is positioned at That is, in the electronic component 1D, the entire insulating resin layer E2 is positioned inside the outer edge E1a of the sintered metal layer E1.

The outer edge E2a extends along the outer edge E1a in the region 5c2 of the electrode portion 5a and the electrode portion 5c. In the regions 5c2 of the electrode portions 5a and 5c, the distance by which the sintered metal layer E1 spreads outside the outer edge E2a is, for example, 50 μm or more and 300 μm or less.

Also in the electronic component 1E, the conductive resin layer E3 covers the entire insulating resin layer E2, and the distance L1 (distance L1a, distance L1eb, and distance L1c) are 150 μm or more. Therefore, like the electronic component 1A, the peeling of the external electrodes 5 can be suppressed. Length L2 is 20% or more of length L3. Therefore, in the electronic component 1E, like the electronic component 1A, it is possible to further suppress peeling of the external electrodes 5 during the reflow process. The thickness t1 is 30% or more and 95% or less of the sum of the thickness t2 and the thickness t1. Therefore, the electrical conductivity of the external electrodes 5 can be ensured while enhancing the effect of alleviating the thermal stress on the external electrodes 5 . The insulating resin layer E2 contains a thermosetting resin, and the glass transition temperature of the thermosetting resin is 150° C. or higher. Therefore, since the heat resistance of the external electrodes 5 is improved, the reliability of the reflow process is improved.

The present invention is not necessarily limited to the above-described embodiments, and various modifications are possible without departing from the scope of the invention.

Each external electrode 5 may be arranged only on the main surface 3a. That is, the external electrode 5 may have only the electrode portion 5a and may not have the electrode portion 5b, the electrode portion 5e, and the pair of electrode portions 5c.

Each external electrode 5 may be arranged on two surfaces, the main surface 3a and the corresponding end surface 3e. That is, the external electrode 5 may have one electrode portion 5a and electrode portion 5e and not have the other electrode portion 5a and the pair of electrode portions 5c. The length of the electrode portion 5e in the first direction D1 may be shorter than the length of the end surface 3e in the first direction D1. That is, the electrode portion 5e may be separated from the main surface 3b. The length in the second direction D2 of one of the electrode portions 5a and 5e may be shorter than the length in the second direction D2 of the end surface 3e. That is, the external electrode 5 may be arranged on a part of the main surface 3a in the second direction D2 and a part of the end surface 3e in the second direction D2. The length of the electrode portion 5e in the first direction D1 may be shorter than the length of the end surface 3e in the first direction D1. That is, the external electrode 5 may be spaced apart from the main surface 3b.

Each external electrode 5 may be arranged on three surfaces, ie, a pair of main surfaces 3a and 3b and a corresponding end surface 3e. That is, the external electrode 5 may have the electrode portion 5a, the electrode portion 5b, and the electrode portion 5e, and may not have the pair of electrode portions 5c. The lengths of the electrode portion 5a, the electrode portion 5b, and the electrode portion 5e in the second direction D2 may be shorter than the length of the end surface 3e in the second direction D2. That is, the external electrodes 5 may be arranged on a part of the pair of main surfaces 3a and 3b in the second direction D2 and on a part of the end surface 3e in the second direction D2.

The effects of the electronic component according to the above embodiments will be specifically described using examples and comparative examples.

[Influence of distance L1]
The effect of the distance L1 (see FIG. 3) between the outer edge of the conductive resin layer and the outer edge of the sintered metal layer on the peeling of the external electrodes was evaluated. Samples 1 to 7 were used for this evaluation.

(Sample 1)
As an electronic component according to an example, a sample 1 corresponding to the electronic component according to the first embodiment was prepared. The size (chip size) of the sample 1 is 5.7 mm in length, 5.0 mm in width, and 2.75 mm in height, and the distance L1 (distance L1a, distance Lc and distance L1e) (see FIG. 3) is 150 μm. and The length L2 (see FIG. 3) of the insulating resin layer on the end face was set to 1390 μm, and the length L3 (see FIG. 3) of the end face was set to 2780 μm. That is, the length L2 is 50% of the length L3. The thickness t1 of the insulating resin layer (see FIG. 3) is 15 μm, the thickness t2 of the conductive resin layer (see FIG. 3) is 55 μm, and the sum of the thickness of the insulating resin layer and the thickness of the conductive resin layer (the entire resin layer thickness) was set to 70 μm. The glass transition temperature (Tg) of the thermosetting resin contained in the insulating resin layer was set at 120°C.

(Sample 2)
Sample 2 was prepared in the same manner as Sample 1, except that the distance L1 was 200 μm.

(Sample 3)
As an electronic component according to an example, a sample 3 corresponding to the electronic component according to the second embodiment was prepared. Sample 3 was the same as sample 2 except that the insulating resin layer did not cover the outer edge of the sintered metal layer in the regions 5c2 (see FIGS. 5 and 6) of the electrode portions 5a and 5c. In sample 3, the distance by which the sintered metal layer extends outside the outer edge of the insulating resin layer in the regions 5c2 (see FIGS. 5 and 6) of the electrode portions 5a and 5c was set to 200 μm. In sample 3, the size (chip size), lengths L2 and L3, thicknesses t1 and t2, and the glass transition temperature (Tg) of the thermosetting resin contained in the insulating resin layer were made equal to those of sample 1.

(Sample 4)
As an electronic component according to an example, a sample 4 corresponding to the electronic component according to the third embodiment was prepared. The distance L1 (distance L1a, distance Lb, and distance L1c) (see FIGS. 8 and 9) was set to 150 μm. In sample 4, the insulating resin layer does not cover the outer edge of the sintered metal layer. In sample 4, the distance by which the sintered metal layer spreads outside the outer edge of the insulating resin layer in the electrode portions 5a, 5b, and 5c was set to 200 μm. In sample 4, the size (chip size), lengths L2 and L3, thicknesses t1 and t2, and the glass transition temperature (Tg) of the thermosetting resin contained in the insulating resin layer were made equal to those of sample 1.

(Sample 5)
Sample 5 was prepared in the same manner as Sample 4, except that the distance L1 was 200 μm.

(Sample 6)
As an electronic component according to a comparative example, a sample 6 was prepared in the same manner as the sample 1 except that the distance L1 was set to 0 μm. In sample 6, the outer edge of the conductive resin layer and the outer edge of the insulating resin layer match.

(Sample 7)
As an electronic component according to a comparative example, a sample 7 was prepared in the same manner as the sample 4 except that the distance L1 was set to 100 μm.

100 each of samples 1 to 7 as described above were prepared, and a reflow test was performed at 260°C. Table 1 shows the number of external electrodes peeled off when the reflow test was performed 3 times and when the reflow test was performed 10 times.

As shown in Table 1, in sample 6 with a distance L1 of 0 and sample 7 with a distance L1 of 100 μm, the external electrodes peeled off in 11 or more pieces after three reflow tests and 42 or more pieces after ten reflow tests. There has occurred. On the other hand, in Samples 1 to 5 in which the distance L1 was 150 μm or more, peeling of the external electrodes occurred only in 0 pieces after 3 reflow tests and 5 pieces or less after 10 reflow tests.

[Influence of ratio L2/L3]
The influence of the ratio L2/L3 of the length L2 to the length L3 on peeling of the external electrodes was evaluated. Samples 8-15 were used for this evaluation.

(Sample 8)
As an electronic component according to an example, a sample 8 corresponding to the electronic component according to the fourth embodiment was prepared. In sample 8, the conductive resin layer is also arranged on main surface 3b (see FIG. 10) and covers the entire corresponding end surface. In sample 8, the distance L1a and the distance L1c were 200 μm, the distance L1eb was 3180 μm, the length L2 was 280 μm, the length L3 was 2780 μm, and the ratio L2/L3 was 10%. The size (chip size), thicknesses t1 and t2, and the glass transition temperature (Tg) of the thermosetting resin contained in the insulating resin layer were made the same as those of sample 1.

(Samples 9-13)
Samples 9 to 13 were prepared in the same manner as Sample 8, except that the distance L1eb and the length L2 were set to the values shown in Table 2.

(Sample 14)
As an electronic component according to an example, a sample 14 corresponding to the electronic component according to the fifth embodiment was prepared. In sample 14, the entire insulating resin layer is located inside the outer edge of the sintered metal layer. In sample 14, the distance L1a and the distance L1c were 300 μm, the distance L1eb was 2800 μm, the length L2 was 560 μm, the length L3 was 2780 μm, and the ratio L2/L3 was 20%. The size (chip size), thicknesses t1 and t2, and the glass transition temperature (Tg) of the thermosetting resin contained in the insulating resin layer were made the same as those of sample 1.

(Sample 15)
A sample 15 was prepared in the same manner as the sample 14 except that the distance L1eb and the length L2 were set to the values shown in Table 2.

100 each of samples 8 to 15 as described above were prepared, and a reflow test was performed at 260°C. Table 2 shows the number of external electrodes peeled off when the reflow test was performed 3 times and when the reflow test was performed 10 times.

As shown in Table 2, in Samples 9 to 12, 14, and 15 in which the ratio L2/L3 is 20% or more and 95% or less, the external electrodes were not affected by the reflow test 3 times or 10 times. No peeling occurred. On the other hand, in sample 8, which is 10%, peeling of the external electrodes occurred in 3 samples after 10 reflow tests. In Sample 13, which is 100%, peeling of the external electrodes occurred in two of the 10 reflow tests.

[Influence of Thickness Ratio of Insulating Resin Layer]
The ratio of the thickness of the insulating resin layer to the sum of the thickness t2 (see FIG. 3) of the conductive resin layer and the thickness t1 (see FIG. 3) of the insulating resin layer (thickness of the entire resin layer) affects the peeling of the external electrodes. An evaluation was made of the impact. Samples 11, 16-19 were used for this evaluation.

(Samples 16-19)
Samples 16 to 19 were prepared in the same manner as sample 11, except that the thickness t1 of the insulating resin layer and the thickness t2 of the conductive resin layer were changed, and the thickness ratio of the insulating resin layer was set to the value shown in Table 2. .

100 samples 11 and 16 to 19 as described above were prepared, and reflow tests were conducted at 260°C and 300°C. Table 3 shows the number of cases where the external electrodes were peeled off when the reflow test was performed 3 times at 260°C, when the reflow test was performed 10 times at 260°C, and when the reflow test was performed 10 times at 300°C. .

As shown in Table 3, in Samples 16 to 19, in which the thickness ratio of the insulating resin layer was 29% or more and 96% or less, no peeling of the external electrodes occurred in any of the reflow tests. On the other hand, in sample 11, peeling of the external electrodes occurred in 11 samples after 10 reflow tests at 300°C.

[Evaluation of glass transition temperature]
The influence of the glass transition temperature on the peeling of the external electrodes was evaluated. Samples 17, 20-25 were used for this evaluation.

(Samples 20-22)
Samples 20 to 22 were prepared in the same manner as Sample 17, except that a thermosetting resin having a glass transition temperature (Tg) shown in Table 4 was used for the insulating resin layer.

(Sample 23)
A sample 23 was prepared in the same manner as the sample 17 except that the length L2 was 2224 μm and the ratio L2/L3 was 80%.

(Samples 24 and 25)
Samples 24 and 25 were prepared in the same manner as Sample 23, except that a thermosetting resin having a glass transition temperature (Tg) shown in Table 4 was used for the insulating resin layer.

100 each of samples 17 and 20 to 25 as described above were prepared, and reflow tests were conducted at 260°C and 300°C. Table 4 shows the number of cases where the external electrodes were peeled off when the reflow test was performed 3 times at 260°C, when the reflow test was performed 10 times at 260°C, and when the reflow test was performed 10 times at 300°C. .

As shown in Table 4, according to a comparison of the test results of Samples 17 and 20 to 22, the higher the glass transition temperature, the less the number of external electrodes that peeled off after 10 reflow tests at 300°C. have understood. A comparison of the test results of Samples 23 to 25 also revealed that the higher the glass transition temperature, the fewer the number of external electrodes peeled off after 10 reflow tests at 300.degree.

DESCRIPTION OF SYMBOLS 1A, 1B, 1C, 1D, 1E... Electronic component, 3... Element body, 3a... Main surface, 3b... Main surface, 3c... Side surface, 3e... End surface, 5... External electrode, 5a, 5b, 5c, 5e... Electrode Part, E1... Sintered metal layer, E2... Insulating resin layer, E2a... Outer edge, E3... Conductive resin layer, E3a... Outer edge, E4... First plating layer, E5... Second plating layer.

Claims (4)

comprising an element body containing ceramic and an external electrode,
The external electrodes are
a sintered metal layer disposed on the base body;
an insulating resin layer disposed on the sintered metal layer;
a conductive resin layer disposed on the insulating resin layer;
The conductive resin layer covers the entire insulating resin layer,
The electronic component, wherein the distance between the outer edge of the conductive resin layer and the outer edge of the insulating resin layer is 150 μm or more. The base body has a first main surface which is a mounting surface, a second main surface facing the first main surface, and end surfaces adjacent to the first main surface and the second main surface. death,
The insulating resin layer has a portion arranged on the end surface, and the length of the portion in the facing direction of the first main surface and the second main surface is 20 times the length of the end surface in the facing direction. % or more, the electronic component according to claim 1. 3. The electronic component according to claim 1, wherein the thickness of said insulating resin layer is 30% or more and 95% or less of the sum of the thickness of said conductive resin layer and the thickness of said insulating resin layer. The insulating resin layer contains a thermosetting resin,
The electronic component according to any one of claims 1 to 3, wherein the thermosetting resin has a glass transition temperature of 150°C or higher.

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