JP3230932B2 - Multilayer electronic components - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer electronic component, such as a multilayer chip inductor and a multilayer capacitor, which has an improved connection structure between internal electrodes and external electrodes.

[0002]

2. Description of the Related Art Conventionally, this kind of multilayer chip inductor,
For example, chip beads shown in FIGS. 11 to 14 are known.

When manufacturing the chip beads, first, as shown in FIG. 11, a magnetic green sheet 1a,
1b and 1c are prepared, a conductive paste is applied to one of the magnetic green sheets 1b, and a large number of patterns of the internal electrodes 2 are printed. Next, the printed magnetic green sheets 1b and the protective magnetic green sheets 1a and 1c sandwiching the printed magnetic green sheets 1b are laminated and fixed as indicated by solid arrows. Thereafter, the laminate is cut so that the magnetic green sheet 1b is separated along the dashed line in FIG.
Thus, the chip bead element body 3 as shown in FIGS. 12 and 13 is formed.

[0004] The chip bead element body 3 thus formed
Then, an external electrode 4 connected to the end of the internal electrode 2 (lead electrode portion 2a) is formed on the outside of the chip bead body 3 as shown in FIG. Finally, solder plating is performed on the outside of the external electrodes 4 to produce chip beads.

[0005]

When the chip beads are manufactured as described above, the paste-like internal electrode 2 is dried and fired before the external electrode 4 is applied. As a result, the electrode area of the extraction electrode portion 2a is reduced, or the extraction electrode portion 2a is pulled into the chip bead body 3 as shown in FIG.

[0006] Even when the external electrode 4 is applied in such a state, a gap 5 is formed between the extraction electrode portion 2a and the external electrode 4 as shown in FIG. In addition, the connection reliability between the internal electrode 2 and the external electrode 4 is required to be particularly high when a large current is used. However, the conventional chip beads cannot satisfy the demand, and the chip beads cannot be used. It was unsuitable for manufacturing high-current specifications.

For this reason, conventionally, in order to increase the connection area of the extraction electrode portion 2a in the thickness direction,
A structure in which the extraction electrode portion 2a is formed thicker than usual, or a conductive paste is applied to the extraction electrode portion 2a a plurality of times, and further, the extraction electrode portion 2a is laminated with a plurality of conductive members. Was adopted.

However, when the extraction electrode portion 2a is formed to be thicker than usual, the entire internal electrode 2 including the extraction electrode portion 2a cannot be formed by one screen printing or the like, and the conductive paste is applied a plurality of times. In such a structure, a mask screen for printing the entire internal electrode 2 and a mask screen for printing only the lead-out electrode portion 2a must be prepared separately, which increases the manufacturing cost. Had. Further, in the structure in which a conductive member is laminated on the extraction electrode portion 2a, a conductive member corresponding to the extraction electrode portion 2a must be prepared in advance and laminated, and the manufacturing process becomes complicated. Had.

An object of the present invention is to provide a laminated electronic component which can easily and surely connect an internal electrode and an external electrode and has high connection reliability in view of the above-mentioned conventional problems.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a laminate comprising a plurality of layers each having at least one internal electrode formed thereon, and a laminate formed on the outer surface of the laminate and having the outer surface. In a multilayer electronic component having an external electrode connected to an end of the internal electrode exposed to the outside, a connection portion between the internal electrode and the external electrode in a layer where the internal electrode is formed is filled with a conductive paste. Through hole
Are formed together with the internal electrodes,
The hole extends in the thickness direction of the layer and is formed on the outer surface of the laminate.
The cross section cut in the thickness direction is exposed and the internal
It is characterized by being connected to a pole and an external electrode .

[0011]

According to the present invention, the external electrode is connected to the end of the internal electrode and the through hole connected to the internal electrode, respectively, and the connection area of the through hole is larger than the conventional connection area.

In addition, when the connection area is increased, it is only necessary to form a through hole, so that the connection area can be easily expanded.

[0013]

1 to 9 show one embodiment of a laminated electronic component according to the present invention. FIG. 1 is a perspective view showing a lamination process of a magnetic green sheet. 2 is a perspective view of the chip bead body, FIG. 3 is a cross-sectional view taken along line AA of FIG. 2, FIG. 4 is a cross-sectional view of the chip bead, FIG. 5 is a plan view of the internal electrodes and through holes, and FIG. 7 (a) and 7 (b) are cross-sectional views comparing the connection portion of the internal electrode and the through hole with the conventional example.
(A) and (b) are diagrams showing a bending test and a test result of a chip bead, FIG. 8 is a conventional cross-sectional view showing a peeling state of an external electrode by a bending test, and FIG. FIG. 3 is a cross-sectional view of the embodiment shown. The same components as those of the conventional example are denoted by the same reference numerals.

The chip bead body according to the present embodiment is also manufactured in the same manner as the conventional example. As shown in FIG. 1, three magnetic green sheets 1a, 1b and 1c are arranged as shown by solid arrows. The laminated body is cut and fixed so that the magnetic green sheet 1b on which the internal electrodes 2 are printed is separated along the dashed line in FIG. 1 to form a chip bead body 6 as shown in FIG. I do.

The features of this embodiment are as follows.
In the magnetic green sheet 1b on which the internal electrode 2 is printed, a through hole 7 is formed in a lead electrode portion 2a which is an end of the internal electrode 2.

That is, the through hole 7 is formed in a cylindrical shape in the thickness direction of the magnetic green sheet 1b.
As shown in FIG. 5, the cut line of the stacked body is arranged to pass through the center of the through hole 7. As a result, as shown in FIGS. 2 and 3, a connection portion to the external electrode 4 is exposed on the side surface of the chip bead element body 6. Since this connection portion is composed of the extraction electrode portion 2a and the through hole 7, the connection area thereof is wider than that of the related art as shown in FIG.

The rate of increase of the connection area is shown in FIGS.
A description will be given based on (a) and (b). Here, in the present embodiment (FIG. 6)
In both (a)) and the conventional example ((b) of FIG. 6), the width of the lead electrode portion 2a is 0.92 mm, the thickness is 0.02 mm, and the connection area is 0.0184 mm ² ( 0.92mm × 0.02m
m). On the other hand, the diameter of the through hole 7 of this embodiment is
0.25mm, thickness is 0.06mm.
Has a connection area of 0.015 mm ² (0.25 mm × 0.06 mm). Therefore, expansion ratio of the connection area of the present embodiment for conventional connection area about ^{1.82 [(0.0184mm 2 + 0.015mm 2} ) /0.0184mm 2]
Double. The dashed line indicates the cutting line.

As described above, since the chip bead according to the present embodiment has a larger connection area with the external electrode 4 due to the through hole 7, the internal electrode 2 shrinks in the chip bead manufacturing process and the chip bead body 6 side , The connection area of the through hole 7 can cover the connection area, and the connection reliability between the internal electrode 2 and the external electrode 4 is improved.

In order to confirm such connection reliability, a bending test shown in FIG. 7A was performed. The chip beads of the present example and the conventional chip beads were
Each chip bead was soldered to a substrate, and the mechanical and electrical destruction of each chip bead due to the deflection of the substrate was counted. As a result, as shown in FIG. 7B, the chip beads of the present example cause mechanical and electrical destruction only when the deflection amount is 12 mm or more, whereas the conventional chip beads have The amount of deflection is less than 12 mm,
About five mechanical and electrical destructions have occurred. Therefore, it can be understood from the deflection test that the chip beads according to the present example have excellent connection reliability.

The mechanical and electrical destruction by the bending test will be described with reference to FIGS. 8A and 8B and FIGS. As shown in FIG. 8 (a), after the conventional chip beads are fixed to the substrate 8 with solder 9, as shown in FIG. 8 (b), when pressure is Further, a force is applied to the external electrode 4 in the direction of the solid arrow. As a result, the external electrode 4 is peeled off from the chip bead body 6,
The external electrode 4 is separated from the extraction electrode portion 2a. This delamination causes mechanical and electrical destruction.

On the other hand, as shown in FIG. 9 (a), after the chip beads of this embodiment are fixed to the substrate 8 with solder 9, pressure is also applied in the direction of a white arrow as shown in FIG. 9 (b). Is applied, a force is also applied in the direction of the solid arrow, and the external electrode 4 may peel off from the chip bead body 6. However, the inner electrode 2, the through hole 7, and the outer electrode 4
Are made of a common material mainly composed of Ag or the like, so that their connection strength is high. Therefore, when the contact area of the lead-out electrode portion 2a with the through-hole 7 is large as in this embodiment, the mechanical strength is high. Can be understood, and the destruction is unlikely to occur.

Further, to examine the point of the electrical breakdown,
Even when mechanical destruction occurs as shown in FIG. 9B, the internal electrode 2 and the external electrode 4 are electrically connected to each other due to the large connection area, so that electrical destruction is unlikely to occur. Can understand.

Further, when forming the internal electrode 2 and the through hole 7, a hole for a through hole is formed in the magnetic green sheet 1b, and a conductive paste is applied so that the extraction electrode portion 2a corresponds to the hole. All you need is this
The internal electrode 2 and the through hole 7 are formed at a time, and the connection area to the external electrode 4 can be easily enlarged.

FIGS. 10 (a), (b), (c) and (d) show another example of the chip bead body according to the present embodiment. Of FIG.
(a) shows a chip bead body 6a in which through-holes 7a are formed at both ends of a lead electrode portion 2a. By forming the through-holes 7a at two locations in this manner, the connection area to the external electrode 4 is further increased.

FIG. 10B shows a chip bead body 6b in which the width of the extraction electrode portion 2a is reduced in order to improve the electrical characteristics of the internal electrode 2. In such a case, since the connection area of the extraction electrode portion 2a becomes very small, the through hole 7b is indispensable for connection with the external electrode 4.

FIGS. 10 (c) and 10 (d) show chip bead bodies 6c and 6d in which internal electrodes are formed in two upper and lower layers, of which FIG. A through hole 7c for integrally connecting the electrode portion 2a is shown in FIG.
0 (d) shows a through hole 7d for separately connecting the upper and lower extraction electrode portions 2a. As described above, even when the internal electrodes are formed in multiple layers, the connection area can be arbitrarily increased by the through holes 7c and 7d.

In the above embodiment, in the multilayer electronic component,
Although the chip beads, which are multilayer chip inductors, have been described, it goes without saying that the present invention can be applied to all multilayer electronic components such as multilayer capacitors as long as they have internal electrodes and external electrodes connected to them.

[0028]

As described above, according to the present invention,
The end of the internal electrode and the through-hole connected to the internal electrode are connected to the external electrode, respectively, and the connection area of the through-hole is larger than the conventional connection area, thereby connecting the internal electrode to the external electrode. Reliability can be improved. In addition, when the connection area is increased, it is only necessary to form a through-hole, so that the connection area can be easily increased.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a step of laminating a magnetic green sheet according to the present invention.

FIG. 2 is a perspective view of a chip bead body according to the present invention.

FIG. 3 is a sectional view taken along the line AA of FIG. 2;

FIG. 4 is a cross-sectional view of a chip bead body on which external electrodes according to the present invention are formed.

FIG. 5 is a plan view of an internal electrode and a through hole according to the present invention.

FIG. 6 is a cross-sectional view comparing a connection portion of an internal electrode and a through hole according to the present invention with a conventional example.

FIG. 7 is a diagram showing a bending test and test results of chip beads.

FIG. 8 is a conventional cross-sectional view showing a peeled state of an external electrode by a bending test.

FIG. 9 is a cross-sectional view of the present example showing a state of peeling of the external electrode by a deflection test.

FIG. 10 is a perspective view showing another example of the chip bead body according to the present invention.

FIG. 11 is a perspective view showing a conventional magnetic green sheet laminating process.

FIG. 12 is a perspective view of a conventional chip bead element body.

FIG. 13 is a sectional view taken along the line AA of FIG. 12;

FIG. 14 is a cross-sectional view of a conventional chip bead body on which external electrodes are formed.

[Explanation of symbols]

2 ... internal electrode, 2 a ... lead electrode part, 4 ... external electrode,
6, 6a, 6b, 6c, 6d: chip bead body, 7,
7a, 7b, 7c, 7d ... through holes.

Claims (1)

(57) [Claims] 1. A laminate formed by laminating a plurality of layers having at least one internal electrode formed thereon, and an external electrode formed on an outer surface of the laminate and connected to an end of the internal electrode exposed on the outer surface. In the multilayer electronic component having: a connection portion between the internal electrode and the external electrode in the layer on which the internal electrode is formed, a portion filled with conductive paste.
A through hole is formed integrally with the internal electrode, and the through hole extends in the thickness direction of the layer and is
The cross section cut in the thickness direction is exposed on the outer surface of the layer body, and
A multilayer electronic component connected to the internal electrode and the external electrode