JP2000277376A - Chip electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chip electronic component having such mechanical strength as to endure expanding and contracting stresses of a board caused when thermal shocks are applied and stresses caused by flexures attributed to external forces applied to the board, and requiring no strict dimensional control over components thereof. SOLUTION: A chip electronic component 11 has metallic terminals 14 and 15 jointed to external electrodes 13a and 13b of a chip electronic component element 12. The terminals 14 and 15 have external electrode joints 14a and 15a to be bonded to the electrodes 13a and 13b, terminal tips 14b and 15b to be electrically and mechanically jointed to external components, and bends 14c and 15c provided between the joints 14a and 15a and the tips 14b and 15b, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip-type electronic component, and more particularly to a chip-type electronic component having a structure capable of increasing thermal and mechanical strength when mounted on a substrate.

[0002]

2. Description of the Related Art FIG. 9 is a sectional view showing a state in which a conventional chip-type electronic component is mounted on a substrate. Electrode lands 1a and 1b for mounting chip-type electronic component 2 on circuit board 1
Are formed. The chip-type electronic component 2 has an element main body 2a made of a ceramic sintered body, and external electrodes 2b and 2c formed on both end surfaces of the element main body 2a. The external electrodes 2b and 2c are connected to the electrode lands 1 by solders 3a and 3b.
a, 1b.

The chip-type electronic component 2 can be surface-mounted on the substrate 1 as described above.
Are directly mounted on the substrate 1, causing the following problems.

That is, when a thermal shock is applied due to a sudden change in the ambient temperature or the like, the substrate 1
In some cases, the chip-type electronic component 2 was broken due to expansion and contraction stress in the direction of arrow A. In particular, when an aluminum substrate or the like having excellent thermal conductivity is used as the substrate 1,
Since the above-mentioned stretching stress is large, it has become more problematic.

Further, since the chip-type electronic component 2 is directly mounted on the substrate 1, the substrate 1 is mounted on the substrate 1 or generated by an external force applied to the substrate 1.
The stress caused by the bending is easily applied to the chip-type electronic component 2, and the chip-type electronic component 2 may be broken by the stress.

In order to solve the above-mentioned problems, a structure in which a cylindrical metal cap is attached to a chip-type electronic component element has been proposed. For example, as shown in FIG. 10, a structure in which cylindrical metal caps 5a and 5b are attached to both ends of a chip-type electronic component element 4 having external electrodes 4a and 4b on both end surfaces has been proposed. In this case, the chip-type electronic component element 4 is inserted into the metal caps 5a and 5b, and the metal caps 5a and 5b are connected to the external electrodes 4a and 5b by a solder or a conductive adhesive.
4b.

In the chip type electronic component using the metal caps 5a and 5b, as shown in FIG. 11, the metal caps 5a and 5b are connected to the electrode lands 1a and 1b by solders 3a and 3b.
Thus, mounting on the substrate 1 has been performed.

[0008]

However, in the structure using the metal caps 5a and 5b, the chip-type electronic component element 4 has to be inserted and fixed in the metal caps 5a and 5b in advance. Therefore, the metal caps 5a,
The inner diameter of 5b had to be kept large enough to allow the chip-type electronic component element 4 to be inserted. On the other hand, since the chip-type electronic component element 4 is made of ceramics, it shrinks by firing, but the degree of shrinkage is not constant. Therefore, even if the precision of the metal caps 5a, 5b is increased, the external dimensions of the chip-type electronic component element 4 to be inserted are not constant, so that the chip-type electronic component elements 4 are not inserted into the metal caps 5a, 5b or can be inserted. Even so, the clearance between the chip-type electronic component element 4 and the metal caps 5a and 5b becomes too large, and it may not be possible to firmly join them.

Further, since the chip-type electronic component 2 shown in FIG. 9 and the chip-type electronic component element 4 in FIG. 10 use a single chip-type electronic component, the characteristics obtained with a single component are obtained. However, there is also a problem that, for example, a larger capacitance (for example, in the case of a multilayer capacitor) cannot be obtained.

It is an object of the present invention to be able to withstand the expansion and contraction stress of a substrate caused by a thermal shock applied after mounting and the stress caused by the deflection of the substrate generated at the time of mounting the substrate or by an external force applied to the substrate, and to allow the components to be mounted. An object of the present invention is to provide a chip-type electronic component that does not require a high degree of dimensional accuracy control.

[0011]

According to a broad aspect of the present invention, at least one chip-type ceramic electronic component having a ceramic sintered body and external electrodes formed on both end faces of the ceramic sintered body. An element, a metal terminal bonded to the external electrode, and a conductive bonding material made of resin and conductive powder, wherein the metal terminal is bonded to the external electrode, and the metal terminal faces the external electrode. A flat-plate-bonded external electrode joint portion arranged so as to be disposed, a terminal tip portion arranged at a position distant from the external electrode joint portion and electrically connected to the outside, and the external electrode A connecting portion and a terminal end portion, and a bent portion provided on the opposite side to the substrate when mounted on the substrate, wherein the external electrode bonding portion in the form of a plate is formed of the conductive bonding material. Makes contact with the external electrode Characterized in that it is wood,
It is a chip type electronic component.

[0012]

According to the present invention, the metal terminal is joined to the external electrode of the chip-type electronic component element, and the metal terminal is used to electrically connect the external electrode joint to the external electrode and the outside. And a bent portion between the terminal end portion. Therefore, since the bent portion of the metal terminal has a spring property, when the terminal tip moves by an external force, the stress due to the movement of the terminal tip is absorbed by the bent portion, and the stress applied to the external electrode joint is reduced. Transmission can be reduced.

When mounting on a board, the terminal end of the terminal is electrically and mechanically joined to an electrode land or the like on the board by soldering or the like. In this case, even if the substrate is bent by a thermal shock or by an external force applied to the substrate during mounting or on the substrate, the stress from the substrate is received by the bent portion of the metal terminal. Therefore, even when the chip-type electronic component element is made of ceramics, the chip-type electronic component element itself hardly breaks.

That is, the present invention is characterized in that the chip-type electronic component element is protected by using the metal terminal having the above-mentioned bent portion so as to withstand the stress from the substrate.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be clarified by describing embodiments with reference to the drawings.

FIG. 1 is a sectional view showing a state in which a chip-type electronic component according to a first example which is a premise of the present invention is mounted on a substrate. The chip-type electronic component 11 has a chip-type electronic component element 12 for forming a multilayer capacitor. The chip-type electronic component element 12 has a structure in which a plurality of internal electrodes (not shown) are arranged so as to overlap with each other via a ceramic layer in a ceramic sintered body made of dielectric ceramics. External electrodes 13a and 13b are formed so as to cover both end surfaces of the ceramic sintered body.

In the chip-type electronic component 11, metal terminals 14 and 15 are joined to the external electrodes 13a and 13b, respectively. Details of the structure of the metal terminals 14 and 15 will be described with reference to FIG.

The metal terminal 14 is formed by bending a metal plate.
Terminal tip portion 14b, bent portion 14c, and pair of grip portions 14
d and 14e.

The external electrode joint 14a is connected to the external electrode 13a.
This is equivalent to a portion electrically and mechanically connected to the motor, and is configured as a flat plate-shaped portion having a certain area as shown in the figure. The terminal tip 14b is also configured to have a certain area in order to form a portion that is electrically and mechanically connected to an electrode land on the substrate as described later. On the other hand, a bent portion 14c provided between the terminal tip portion 14b and the external electrode joining portion 14a
Is provided to impart a spring property to a part of the metal terminal 14, extends outward from the lower end of the external electrode joint 14a, and is bent so as to face upward again at the distal end side. Have been.

The terminal grips 14d and 14e extend from the side edge of the external electrode joint 14a to the side opposite to the terminal tip 14b, that is, to the chip-type electronic component element side. The terminal holding portions 14d and 14e are formed to have an outwardly curved shape as shown in the drawing, so that the chip-type electronic component element 12 can be held with a spring property.

Returning to FIG. 1, the metal terminal 15 is configured similarly to the metal terminal 14. Therefore, the corresponding parts are given the same reference numerals, and the description thereof will be omitted.

External electrode 13 of chip-type electronic component element 12
External electrode joints 14a and 15a of the metal terminals 14 and 15 are joined to the metal terminals 14a and 13b by joining materials 16a and 16b. As the bonding materials 16a and 16b, a known conductive bonding material such as a conductive adhesive can be used.

The chip-type electronic component 11 includes the above-described metal terminal 1.
It is mounted and fixed on the substrate 1 by using 4 and 15. That is, the electrode lands 1a formed on the substrate 1,
1b, the terminal end portions 14b of the metal terminals 14 and 15,
15b are joined by the solders 3a and 3b, and the chip-type electronic component 11 is mounted on the substrate 1. In the state after mounting, for example, thermal shock is applied, and an arrow A
It is assumed that a stretching stress occurs in the direction. In this case, due to the stress, the terminal end portions 14b, 15 of the metal terminals 14, 15 are formed.
b is moved in the direction of arrow A. However, since the bent portions 14c and 15c are provided on the metal terminals 14 and 15, the stress is absorbed by the bent portions 14c and 15c, and the transmission of the stress to the external electrode joint portions 14a and 15a is effective. Can be reduced.

Accordingly, cracking of the ceramic sintered body in the chip-type electronic component element 11 can be effectively prevented, and the metal terminals 14, 15 and the chip-type electronic component 1
1 and the joints between the metal terminals 14, 15 and the electrode lands 1a, 1b can also be effectively prevented from being destroyed.

Also, the metal terminals 14 and 15 are
Since d, 14e, 15d, and 15e (not shown) are configured, even when an external force is applied in the paper surface-back direction in FIG. 1, such external force is applied to the grip portions 14d, 14e, and 14e.
It is received at 15d and 15e. Therefore, the chip-type ceramic electronic component 11 can be effectively protected against external force generated in the paper surface-back direction.

Further, as the joining materials 16a and 16b,
A conductive adhesive having a certain degree of elasticity, for example, a compound obtained by compounding a conductive powder such as a carbon powder or a metal powder with a silicon resin is used. By using such an elastic conductive adhesive as the bonding materials 16a and 16b,
The stress that could not be absorbed by the bent portions 14c, 15c can be further attenuated by the elasticity of the joining materials 16a, 16b.

FIG. 3 is a sectional view showing a state in which the chip type electronic component of the second example as a premise of the present invention is mounted on a substrate. In the chip-type electronic component 21, three chip-type electronic component elements (the internal structure is omitted) 22, 23, and 24 are used. The chip-type electronic component elements 22 to 24 have external electrodes 25a, 25b, 26a, 26, respectively, so as to cover both end surfaces of the ceramic sintered bodies 22a, 23a, 24a.
(The external electrode is not shown for the electronic component element 23).

The chip type electronic component elements 22 to 24 are
They are joined and integrated by metal terminals 27 and 28. The structure of the metal terminal 27 will be described with reference to FIG.
As shown in FIGS. 4A and 4B, the metal terminal 27 includes an external electrode bonding portion 27a, a terminal tip portion 27b, and a bent portion 27c.
And a pair of gripping portions 27d and 27e. Since the details of these parts are the same as those of the metal terminal 14 shown in FIG. 2, the detailed description is omitted. However, the metal terminal 27
Now, the above-mentioned three chip-type electronic component elements 22 to 24
Are integrated with each other, the dimension in the vertical direction when mounted on the substrate is longer than that of the metal terminal 14.

The other metal terminal 28 has the same configuration as that of the metal terminal 27. Therefore, corresponding portions are denoted by corresponding reference numerals. Returning to FIG.
In the example, the metal terminals 27 are connected to the external electrodes 25a and 26a of the chip-type electronic component elements 22 to 24 by the bonding material 29a.
Electrically and mechanically. Similarly, for the metal terminal 28, the external electrode 2
5b and 26b are mechanically and electrically connected.
As in the case of the first embodiment, a conductive bonding material made of resin and metal powder can be used as the bonding materials 29a and 29b.

The chip-type electronic component 21 can be mounted on the substrate 1 by bonding the terminal tips 27b and 28b to the electrode lands 1a and 1b of the substrate 1 by the solders 3a and 3b. In this case, the bent portions 27c, 28c
Due to the resiliency of the substrate, the stress caused by the deformation of the substrate can be effectively absorbed, so that the destruction of the chip-type electronic component element and the destruction of the joint can be prevented as in the case of the first example. .

Also, the holding portions 27 of the metal terminals 27, 28
d, 27e, 28d, 28e (not shown), the chip-type electronic component
~ 24 can be protected.

Moreover, three chip-type electronic component elements 22
To 24, the chip-type electronic component element 22
24, the gripping portions 27d, 27e, 2
8d and 28e.

Since the three chip-type electronic component elements 22 to 24 are stacked, characteristics that cannot be obtained by a single chip-type electronic component element, for example, high capacitance (in the case of a multilayer capacitor) can be realized. Can be. Furthermore, as the three electronic component elements, those having different functions may be used. For example, one of the elements may be a multilayer capacitor, and the other element may be another electronic component element such as an inductor.

Further, four or more chip-type electronic component elements may be stacked and integrated by metal terminals. FIG.
FIG. 2 is a cross-sectional view showing a state in which the chip-type electronic component element according to the embodiment of the present invention is mounted on a substrate. The chip-type electronic component element 31 of the present embodiment is different from the chip-type electronic component element 11 of the first example.
Therefore, the corresponding parts are denoted by the same reference numerals, and description thereof will be omitted. This embodiment is different from the first embodiment in the structure of the metal terminals 34 and 35.

As shown in FIGS. 6A and 6B, in the metal terminal 35, a bent portion 35c between the external electrode joining portion 35a and the terminal end portion 35b is mounted on the substrate. It is provided upward in the state, that is, in the direction opposite to the substrate. The other points are the same as those of the metal terminals 14 and 15 used in the first example.
And holding portions 35d and 35e provided on the ceramic electronic component element side from the side. The other metal terminal 34 is also configured in the same manner as the metal terminal 35.
Description is omitted.

As is apparent from FIG. 5, the bent portions 34c,
35c is located above, that is, at a portion away from the substrate 1, the bent portions 34c, 35c of the solders 3a, 3b
It is possible to reliably prevent adhesion to the surface. Therefore, it is possible to more reliably absorb the external force due to the spring properties of the bent portions 34c and 35c than in the first example.

FIG. 7 is a sectional view showing a state in which a chip-type electronic component element 41 according to another embodiment of the present invention is mounted on a substrate 1. This embodiment corresponds to a modification of the chip-type electronic component of the second example, and differs in the structure of the metal terminals 46 and 47.

As shown in FIGS. 8A and 8B, the metal terminal 47 has a bent portion 47c between the external electrode joint portion 47a and the terminal tip portion 47b. That is, when mounted on the substrate 1,
And is located on the opposite side. Also, the external electrode joint 4
The grips 47d and 47e extend from the side of 7a. The other metal terminal 46 is configured similarly to the metal terminal 47. Therefore, the corresponding parts will be denoted by the corresponding reference numerals.

Also in this embodiment, the metal terminals 46, 47
Thus, the same operation and effect as those of the second example are exhibited, but the bent portions 46c and 47 are similar to the case of the embodiment shown in FIG.
c is located above, the electrode lands 1a, 1b
Bent portion 46 of solder 3a, 3b used for bonding
Adhesion to c and 47c can be reliably prevented. Therefore, the effect of reducing the external force due to the elasticity of the bent portions 46c and 47c can be more reliably exerted.

[0040]

According to the present invention, the metal terminal having the bent portion is joined to a portion of at least one chip-type electronic component element where the external electrode is formed. Therefore,
When the terminal end of the metal terminal is mounted by soldering to an electrode land or the like on the substrate by soldering, even if stress due to deformation of the substrate or the like is applied, the bent portion effectively reduces the stress. be able to.

Therefore, the stress caused by the expansion and contraction of the substrate due to a rapid change in the ambient temperature and the stress caused by the bending of the substrate caused by the external force applied to the substrate at the time of mounting the substrate or by the external force applied to the substrate are caused by the bent portion. Therefore, destruction of the chip-type electronic component element and destruction of the junction between the chip-type electronic component element and the metal terminal or the junction between the metal terminal and the substrate can be effectively prevented.

Moreover, since the metal terminals are not shaped so as to insert chip-type electronic component elements, even if the chip-type electronic component elements have dimensional variations, the metal terminals can be reliably inserted. Terminals can be joined. Therefore, when the conventional cylindrical metal cap is used, strict control of the dimensional accuracy is required, whereas in the present invention, such strict control of the dimensional accuracy is not required.

In the case of mounting on a substrate by a reflow soldering method, since the above-mentioned metal terminal is a portion to be joined to the solder, even if the external electrode is made of Ag or the like, the metal terminal is not used. By using a metal material that is not easily eroded by solder, solder erosion can be reliably prevented.

Further, when soldering with a soldering iron, the chip-type electronic component element and the tip do not come into direct contact with each other. It can also be prevented.

Further, since two or more chip-type electronic component elements can be stacked and integrated using the metal terminal, in this case, the mounting area can be increased without increasing the mounting area.
Characteristics that cannot be obtained with a single chip-type electronic component element, for example, large capacitance can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a state in which a chip-type electronic component of a first example is mounted on a substrate.

FIGS. 2A and 2B are a perspective view and a plan view, respectively, showing a metal terminal used in the first example.

FIG. 3 is a sectional view showing a state in which the chip-type electronic component of the second example is mounted on a substrate.

FIGS. 4A and 4B are a perspective view and a plan view, respectively, showing a metal terminal used in a second example.

FIG. 5 is a sectional view showing a state in which the chip-type electronic component of the embodiment is mounted on a substrate.

FIGS. 6A and 6B are a perspective view and a plan view, respectively, showing a metal terminal used in the embodiment.

FIG. 7 is a sectional view showing a state in which a chip-type electronic component of another embodiment is mounted on a substrate.

FIGS. 8A and 8B are a perspective view and a plan view, respectively, showing a metal terminal used in another embodiment.

FIG. 9 is a sectional view showing a state in which a conventional chip-type electronic component is mounted on a substrate.

FIG. 10 is a perspective view showing a step of joining a cylindrical metal cap to a conventional chip-type electronic component element.

FIG. 11 is a sectional view showing a state in which a conventional chip-type electronic component to which a cylindrical metal cap is bonded is mounted on a substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Chip-type electronic component 12 ... Chip-type electronic component element 13a, 13b ... External electrode 14, 15 ... Metal terminal 14a, 15a ... External electrode joining part 14b, 14b ... Terminal tip part 14c, 15c ... Bending part 14d, 14e, 15d, 15e: gripping portion 21: chip-type electronic component 22-24: chip-type electronic component element 25a, 25b, 26a, 26b: external electrode 27, 28: metal terminal 27a, 28a: external electrode joint 27b, 28b: terminal Tip portions 27c, 28c: bent portions 27d, 27e, 28d, 28e: gripping portions 31: chip-type electronic components 32: chip-type electronic component elements 33a, 33b: external electrodes 34, 35: metal terminals 34a, 35a: external electrode bonding Portions 34d, 34e, 35d, 35e: Holding portions 34b, 35b: Terminal end portions 34c, 35c: Bending portions 41 Chip-type electronic components 42, 43 ... Chip-type electronic component elements 44a, 44b, 45a, 45b ... External electrodes 46, 47 ... Metal terminals 46a, 47a ... External electrode joints 46b, 47b ... Terminal tip portions 46c, 47c ... Bending portions 46d, 46e, 47d, 47e ... gripping part

Claims (1)

[Claims] At least one chip-type ceramic electronic component element having a ceramic sintered body, and external electrodes formed on both end surfaces of the ceramic sintered body, and a metal terminal joined to the external electrode And a conductive bonding material comprising a resin and conductive powder, wherein the metal terminal is bonded to an external electrode, and wherein the metal terminal is arranged so as to face the external electrode. And, disposed at a position away from the external electrode junction, and a terminal tip for electrically connecting to the outside, connecting the external electrode junction and the terminal tip, and the substrate A bent portion provided on a side opposite to the substrate in a mounted state, wherein the flat plate-shaped external electrode bonding portion is planarly bonded to the external electrode by the conductive bonding material. Chip-type electronic components.