JPS62241310A - Laminated chip inductor - Google Patents

Abstract

PURPOSE:To increase contact area between an internal conductor and external electrodes and improve reliability through their stable connecting condition by forming the electrode leadout part of internal conductor which is larger than the width of main body and thereby making larger the area exposed from the chip body. CONSTITUTION:An insulated chip body 10 consisting of ceramic is formed in almost square parallelopiped and an internal conductor 20 in the straight belt shape is buried within the chip 10. An almost T-shaped electrode leadout parts 21, 22 is formed at both ends of internal conductor 20. The side surfaces of the electrode leadout portions 21, 22 are respectively exposed at both end surfaces in the longitudinal direction of chip 10. Here, the longitudinal direction of electrode leadout portions 21, 22 is parallel with the width direction of end surface of chip 10. The both ends in the longitudinal direction of chip 10 and its periphery are covered, for example, with a pair of external electrodes 30, 31 consisting of silver paste. The external electrodes 30, 31 are electrically connected with the electrode leadout portions 21, 22.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a multilayer chip inductor that is improved so that the contact area between an electrode lead-out portion of an internal conductor and an external electrode is increased.

(Prior Art) An example of a conventional multilayer chip inductor is shown in FIG. 4 and will be described. The multilayer chip inductor shown in the figure has a chip body 11 made of ceramic or the like having a rectangular parallelepiped shape. A linear strip-shaped internal conductor 2 embedded in the inner conductor 2, and an electrode extraction portion 2 of this internal conductor 2.
The external electrode 3.4 is electrically connected to the terminals a and 2b and coated on both end surfaces of the chip body 1 and the periphery thereof.

This multilayer chip inductor has, for example, an inner conductor 2
Another ferrite raw sheet is laminated on top of the printed ferrite raw sheet, and this is fired to form a chip body l, and external electrodes 3 and 4 are formed by baking silver paste or the like on both ends of this chip body l. It is manufactured by methods such as forming.

In addition to the linear band-shaped internal conductor 2, there is also a coil formed by forming the internal conductor 2 into a spiral shape, as disclosed in JP-A-55-91103, for example. There are some.

(Problems to be Solved by the Invention) In such a conventional multilayer chip inductor, the main body portion of the internal conductor 2 and the electrode extraction portion 2a.

2b has a uniform width. Therefore, if the width of the internal conductor 2 is smaller than that of the depth body,
t[g Since the contact area of the external electrodes 3 and 4 to the exposed portions of the extraction portions 2a and 2b is small, the connection state tends to become unstable.

If the connection state is unstable in this way, there is a risk of an increase in DC resistance or a disconnection, which will lead to a decrease in the reliability of the product.

The present invention has been made in view of the above circumstances, and it is possible to increase the contact area between the internal conductor and the external electrode, stabilize the connection state between the two, and improve the reliability. The purpose is to provide a multilayer chip inductor that can

(Means for Solving the Problems) The multilayer chip inductor according to the present invention has a configuration in which the electrode lead-out portion of the internal conductor is larger than the width of the main body, and the exposed area from the chip main body is large. I made it.

(Function) Since the exposed area of the electrode extraction portion of the internal conductor is large, the contact area with the external electrode increases.

(Example) Hereinafter, each example of the present invention will be described with reference to the drawings.

Example 1 In the multilayer chip inductor shown in FIG.
is an insulating chip body made of ceramic, for example. The chip body IO is formed into a substantially rectangular parallelepiped shape.

A linear strip-shaped internal conductor 20 is buried inside the chip body IO. T-shaped electrode extraction portions 21 and 22 are formed at both ends of the internal conductor 20. The side surfaces of the electrode extraction portions 21 and 22 are exposed at both longitudinal end surfaces of the chip body IO, respectively. In this embodiment, the length direction of the electrode extraction portions 21.22 is parallel to the width direction of the end surface of the chip body IO.

A pair of external electrodes 3 made of, for example, silver paste are provided at both lengthwise ends of the chip body 10 and around the edges.
0.31 is coated. The external electrode 30.31 is electrically connected to the electrode extraction portion 21.22 of the internal conductor 20.

Example 2 - The multilayer chip inductor shown in FIG. 2 differs from Example 1 in that the electrode lead-out portions 21a and 22a of the internal conductor 20 have the same width as the end face of the chip body 10. For this reason, the depth body I
It is exposed on both sides of O, and from this point also the external electrode 30
．． 31 is larger than that in the first embodiment.

In the multilayer chip inductor shown in FIG. 3, the electrode lead-out portions 21a and 22b have the same width as the end face of the chip body 10 as in the second embodiment, and also have folding parts that wrap around both sides of the chip body 10. This embodiment differs from the second embodiment in that it includes curved pieces 23b and 24b. This has the effect of increasing the contact area with the external electrodes 30, 31 even more than in the second embodiment.

Note that the present invention provides the electrode extraction portions 21, 22, 21a, 2 of the internal conductor 20 shown in each of Examples 1.2 and 3.
2a, 21b, and 22b, and it goes without saying that the inner conductor 20 may be in a shape other than a straight line, for example, in a spiral shape.

(Effects of the Invention) In the present invention, since the electrode extraction portion of the internal conductor is largely exposed from the chip body, the contact area with the external TL pole is increased compared to the conventional case.

As a result, in the present invention, the contact state between both the electrode extraction part and the external electrode is stabilized, so that DC resistance does not increase unnecessarily, and there is no risk of wire breakage, resulting in improved reliability. This effect is achieved.

[Brief explanation of drawings]

1 to 3 relate to each embodiment of the present invention, FIG. 1 is a perspective view of Embodiment 1, FIG. 2 is a perspective view of Embodiment 2, and FIG.
The figure is a perspective view of Example 3. FIG. 4 is a perspective view of a conventional example. IO is the chip body, 20 is the internal conductor, 21, 22.21
a, 22a, 21b, 22b are electrode extraction parts, 30.31
is an external electrode.

Claims (1)

[Claims] (1) A chip body, an internal conductor buried inside the chip body and having electrode lead-out portions at both ends exposed at both ends of the chip body, and an internal conductor covered at both ends of the chip body and the periphery thereof. A multilayer chip inductor comprising a pair of external electrodes electrically connected to an electrode lead-out part of the inner conductor, wherein the electrode lead-out part of the internal conductor is wider than the main body part, and the electrode lead-out part is wider than the main body part. A multilayer chip inductor characterized by being largely exposed from the chip body.