JPH0314023Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an improvement of a multilayer bead chip inductor.

[Conventional technology]

Conventionally, in the manufacturing process of this type of inductor, as shown in FIGS. 5 and 6, first, a ferrite sheet 01 on which a conductor 02 is printed and a ferrite sheet 03 on which no conductor is printed are laminated, and then the ferrite sheet 03 is laminated. By firing, the ferrite sheets 01 and 03 are integrated to obtain a bead chip element 04. Next, by providing external electrodes 05, 05 at both ends of this element 04, a bead chip inductor as shown in FIG. 7 is completed.

[Problem that the invention attempts to solve]

In the inductor with the above configuration, the ferrite sheet 01 of the printed conductor 02,
Diffusion and evaporation into 03 occur, and the Q value decreases due to an increase in DC resistance, which is a major cause of impairing quality stability.

This invention attempts to solve the above-mentioned conventional drawbacks by improving the laminated structure of ferrite sheets.

[Means to solve the problem]

Therefore, in the present invention, a ferrite sheet on which a main conductor is printed is sandwiched between a pair of ferrite sheets on which a dummy conductor, which is insulated and separated at the center, is printed, and then fired.

[Effect]

According to the above structure, during firing, the diffusion and evaporation of the dummy conductor, which is the outer layer relative to the central main conductor, occur simultaneously, increasing the conductor atmosphere concentration around the main conductor, and suppressing the diffusion and evaporation of the main conductor. become.

〔Example〕

The manufacturing process of the multilayer bead chip inductor according to the present invention will be explained in order with reference to FIGS. 1 to 4.

This inductor is made by laminating and firing seven ferrite sheets. A main conductor 2 is printed in an H-shape on the central ferrite sheet 1, and a pair of dummy conductors 3, 3 are printed on the upper and lower sides of the central ferrite sheet 1, and the center of the H-shape is insulated and separated. Ferrite sheets 4 and 4 are arranged, and two ferrite sheets 5 and 6 each having no conductor printed above and below these are arranged,
These ferrite sheets 1, 4, 5, and 6 groups are
As shown in the figure, a bead chip element 7 is formed by laminating and firing, and then external electrodes 8, 8 are connected to both ends of the element 7 and to both ends of the main conductor 2.
is provided.

In the example, each ferrite sheet had the same thickness, resulting in a seven-layer structure, but the ferrite sheets 5, 5 and 6, 6 were each made into a single sheet with twice the thickness. , overall 5
It is also possible to have a layered structure, and furthermore, a ferrite sheet 4,
It is also possible to make the ferrite sheets 5, 5 into one sheet together with the ferrite sheets 5, 5 into one sheet, resulting in a four-layer structure as a whole. On the other hand, by reducing the sheet thickness,
It is also possible to increase the number of laminated ferrite sheets 5, 5 and 6, 6 and to concentrate the main conductors 2 and dummy conductors 3, 3 in the center.

[Effect of idea]

As explained above, in this invention, by introducing a dummy conductor, most of the conductor diffusion and evaporation during firing is carried out by this dummy conductor, thereby suppressing the diffusion and evaporation of the main conductor and ensuring stable quality. It is now possible to obtain a multilayer bead chip inductor.

Moreover, the dummy conductor itself is pre-insulated and separated at the center so that it does not conduct to the external electrodes at both ends.
There is no fear that the inductance value will decrease due to an increase in the total cross-sectional area of the equivalent conductor, which would occur if insulation is not separated, and it is possible to achieve the desired performance using only the main conductor.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing the composition of the multilayer bead chip inductor according to the present invention, Fig. 2 is a perspective view of the laminated state, Fig. 3 is a vertical side view thereof, and Fig. 4 is the finished product. FIG. Fig. 5 is an exploded perspective view of the conventional product, Fig. 6 is a perspective view of the stacked state, and Fig. 7 is an exploded perspective view of the conventional product.
The figure is an external view of the finished product. 1... Ferrite sheet, 2... Main conductor, 3...
Dummy conductor, 4...ferrite sheet.

Claims (1)

[Scope of utility model registration request] A laminated bead chip in which a ferrite sheet 1 with a main conductor 2 printed on its surface is sandwiched between a pair of ferrite sheets 4, 4, each printed with a dummy conductor 3, which is insulated and separated at the center, and fired. Ductor.