JPH02155205A - Laminated type electronic part - Google Patents

Abstract

PURPOSE:To remove the nose sections of partition walls, and to expose the leading-out end sections of an internal electrode having excellent conductive performance by projecting and forming the partition walls for mutually isolating grooves in parallel among the grooves shaped in parallel with both end faces of an element assembly and barrel-polishing the element assembly. CONSTITUTION:The element assembly 3 of a chip inductor 1 is formed by integrally baking a plurality of magnetic substance green sheets mutually laminated through an internal electrode 2, and a plurality of grooves 10 orthogonal in the direction of the laminating of the green sheets are shaped in parallel with both end faces of the green sheets. External electrodes 4 continued with the internal electrode 2 are formed at both end sections of the element assembly 3. When the laminated single body is baked integrally and barrel-polished, the nose sections of the partition walls 11 shaped in parallel with both end faces of the single body are removed, and the leading-out end sections 8 of the internal electrode 2 having excellent conductive performance are exposed from the nose sections of the partition walls 11. When the external electrodes 4 are formed at both end sections, the leading-out edges of the internal electrode 2 and the external electrodes 4 are connected for continuity.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a laminated electronic component, and more particularly to the shape of the external @ of the element body and the end face where the pole is formed.

<Prior Art> As an example of this type of multilayer electronic component, a multilayer chip inductor l having a schematic structure as shown in FIG. 4 has been known. This chip inductor 1 includes an element body 3 formed by integrally firing a plurality of magnetic (ferrite) green sheets laminated with internal electrodes 2 interposed therebetween, and each end of the element body 3 has an internal T ! An external electrode 4 that is electrically connected to one pole 2 is formed.

By the way, when manufacturing such chip inductors 1, it is common to manufacture a large number of them at the same time. Therefore, in producing it, first,
As shown in the exploded perspective view of a main part in FIG. 5, a magnetic green sheet 6 has a magnetic green sheet 6 on which a large number of conductive paste layers 5 of a predetermined shape corresponding to the internal electrodes 2 of each chip inductor 1 are printed, and A plurality of magnetic green sheets 7 on which nothing is printed are prepared.

Note that this conductive paste layer 5 is usually formed using a paste of silver, silver palladium, or the like. Then, after laminating a predetermined number of other magnetic green sheets 7 on top and bottom of the magnetic green sheet 6 on which the conductive paste layer 5 is formed, the whole is pressurized in the vertical direction to form a large number of element bodies. This constitutes an integrated laminate that serves as a base material for forming No. 3.

Next, by cutting the integrated laminate along the shape shown by the imaginary line in FIG. The element body 3 is formed by integrally firing each at a predetermined temperature. Furthermore, after performing barrel polishing on the element body 3 thus obtained, external electrodes 4 are formed by baking a conductive paste onto each of both ends of the element body 3. As a result, the leading edge of the internal electrode 2 exposed on each end face of the element body 3 and the external electrode 4 are connected to each other and conductive.

<Problem to be solved by the invention> By the way, the element body 3 of the chip inductor l as described above
When firing the laminated single body that will become The conductive components such as silver and silver palladium at the outer peripheral edge in contact with the outside air, that is, the pull-out edge 9, will evaporate to a depth of several 100 microns, and the conductive performance at the pull-out edge 9 will be greatly degraded. Resulting in.

Therefore, if the external electrode 4 is formed in such a state, good electrical conduction between the extended end 8 of the internal electrode 2 and the external electrode 4 will not be obtained.

Therefore, the above-mentioned barrel polishing is performed in order to remove the deteriorated lead-out edge 9 of the internal electrode 2 and expose the inner lead-out end 8 having good conductivity to the end face of the element body 3. It turns out. However, by ordinary barrel polishing, only the corner (edge) portion 3a of the element body 3 is removed, as shown in an enlarged view in FIG. 6(b).
The drawn end 8 of the internal electrode 2 is only partially exposed from the removed corner 3a. Therefore, in the chip inductor 1 formed by ordinary barrel polishing, the internal electrode 2 and the external electrode 4 are There was an inconvenience in that reliability deteriorated as a result of unstable contact conditions. Note that if barrel polishing is performed on the element body 3 for a long time, it is possible to remove all the lead-out edges 9 of the internal electrodes 2, but in this case, only the corner portions 3a of the element body 3 are removed. This results in an additional problem of poor stability during mounting on a printed wiring board or the like.

The present invention was devised to eliminate such conventional disadvantages, and is capable of ensuring a good contact state between the internal electrode and the external electrode, and improving reliability. The purpose is to supply laminated electronic components.

<Means for Solving the Problems> In order to achieve the above object, the present invention includes an element body formed by integrally firing a plurality of green sheets laminated with internal electrodes interposed therebetween; In a laminated electronic component in which external electrodes that are electrically connected to the internal electrodes are formed at both ends thereof, each end face of the element body, where the lead-out edges of the internal electrodes are exposed, is provided at right angles to the stacking direction of the green sheets. A plurality of grooves are formed in parallel.

Effects> According to the above configuration, partition walls for separating the grooves from each other are formed in parallel and protrude between the grooves formed in parallel on both end faces of the element body. Therefore, when barrel polishing is applied to this element, the tips of each of these partition walls will be removed.
The drawn-out ends of the internal electrodes, which have good conductivity, are exposed from the respective tips of the removed partition walls.

<Example> Hereinafter, the present invention will be applied to a multilayer chip inductor as a multilayer electronic component, and one example thereof will be described based on the drawings.

FIG. 1 is a partially omitted perspective view showing a schematic structure of the entire multilayer chip inductor, and FIGS. 2(a) and 2(b) are cross-sectional views taken along line 1--2. The overall structure of the chip inductor according to this embodiment is basically the same as that of the conventional example except for the end face shape of the element body, so FIGS. 1 and 2 are different from those in FIGS. 4 to 6. Identical or corresponding parts are given the same reference numerals.

The element body 3 of the chip inductor 1 according to this embodiment is formed by integrally firing a plurality of magnetic green sheets 6.7 (see FIG. 5) that are laminated with each other via the internal electrodes 2. Green sheet 6.7 on each end face
A plurality of grooves 10 are formed in parallel, perpendicular to the a-layer direction. External electrodes 4 that are electrically connected to the internal electrodes 2 are formed at both ends of the element body 3, respectively.

By the way, the element body 3 of the chip inductor 1 according to this embodiment
is also formed by the same procedure as the conventional example described above,
In this embodiment, when cutting out the single laminate that will become the element body 3 from the integrated laminate, a cutter 20 as shown in FIG. 3, that is, a cutter 20 having a so-called zigzag wave-shaped blade 21 is used. The cutter 20 is adapted to cut out both end faces of the single laminate.

Therefore, a plurality of concave grooves 10 each having a shape corresponding to the wavy blade 21 of the cutter 20, for example, a substantially triangular cross-sectional shape, are arranged in parallel with each other on both end faces of the laminated single body cut out using the cutter 20. It will be formed by At the same time as these recesses tJ$10 are formed, the recess grooves 1 formed in parallel on both end faces are
Partition walls 11 having a substantially triangular cross-sectional shape that separate these from each other are formed in parallel in a protruding manner between the two. It goes without saying that the cross-sectional shapes of each of the groove 10 and the partition wall 11 are not limited to the above-mentioned shapes, but can be changed by selecting the shape of the blade 21 of the cutter 20. Further, the side surface of this laminated single body is cut out by a cutter (not shown) having a normal planar blade.

Then, if the laminated single body constructed in this way is integrally fired, as shown in FIG. The conductive components such as silver and silver palladium in 9 are several 10
This results in evaporation over a depth of approximately 0 μm. However, if barrel polishing is applied to this element 3,
As shown in an enlarged view in FIG. 2(b), the tips of the partition walls 11 formed in parallel on both end faces of the partition walls 11 are removed in the same manner as the corner portions 3a in the conventional example. The leading ends 8 of the internal electrodes 2 having good conductivity are drawn from the respective tips of the partition walls 11.
will be exposed. Therefore, if the external electrodes 11i4 are formed by baking a conductive paste on each end of the element 3, the leading edge of the internal electrode 2 exposed on each end face of the element 3 and the external electrode 4 will be connected to each other. This results in conduction.

Although the above description assumes that the multilayer electronic component according to the present invention is the chip inductor 1, the chip inductor 1 is not limited to this, and for example, a plurality of dielectric green sheets may be stacked. - It goes without saying that it is also applicable to chip capacitors formed by firing.

<Effects of the Invention> As explained above, according to the laminated electronic component according to the present invention, the lead-out end of the internal electrode in the element body is formed by integrally firing a plurality of green sheets laminated with internal electrodes interposed in between. A plurality of grooves arranged in parallel along the stacking direction of the green sheets are formed on each end surface where the edges are exposed, so a partition wall protrudes between these grooves to separate them from each other. They will be formed in parallel.

Therefore, if barrel polishing is applied to this element, the tips of each of these partition walls will be removed.
The drawn-out end portions of the internal electrodes having good conductive performance are exposed from the removed tip portions of the partition walls. Therefore, if external electrodes are formed on each end face of this element, the internal electrode and external electrode will come into contact with each other at multiple locations, resulting in good contact between the two. , its reliability can be improved.

Further, according to the present invention, since the contact area between the end face of the element body and the external electric power source is increased compared to the conventional example, there is another advantage that the adhesive strength between the two is increased.

[Brief explanation of the drawing]

1 to 3 relate to embodiments of the present invention, FIG. 1 is a partially omitted perspective view showing the general structure of the entire chip inductor, and FIGS. 2(a) and 2(b) are its ■-■ lines. FIG. 3 is a perspective view of a cutter used for cutting a single laminated body. 4 to 6 relate to a conventional example, and FIG. 4 is a partially omitted perspective view showing a schematic structure of the entire chip inductor;
FIG. 5 is an exploded perspective view of the main parts of the laminate;
J(a) and (b) are cross-sectional views taken along the line Vl-Vl in FIG. 4. In the figure, reference numeral 1 is a chip inductor (multilayer electronic component), 2 is an internal electrode, 3 is an element body, 4 is an external electrode, 6.7 is a green sheet, and 10 is a groove.

Claims (1)

[Claims] (1) A laminated electronic component comprising an element body formed by integrally firing a plurality of green sheets laminated via internal electrodes, and having external electrodes connected to the internal electrodes formed at both ends of the element body. A multilayer electronic component, characterized in that a plurality of concave grooves perpendicular to the stacking direction of the green sheets are formed in parallel on each of both end faces of the element body where the lead edges of the internal electrodes are exposed.