JPH0313729B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laminated inductor, and more particularly to a laminated inductor having overlapped windings.

The present inventors have proposed manufacturing a multilayer inductor by combining a printing process and a firing process. The multilayer inductor of the present invention basically utilizes the above structure, but the conventional multilayer inductor has a higher inductance value with the same volume because insufficient consideration was given to the structure and manufacturing process. This was ultimately insufficient as a highly integrated inductor.

Therefore, an object of the present invention is to provide a multilayer inductor of this type that has a sufficiently improved inductance value without substantially increasing the volume.

The present invention provides a magnetic raw sheet using a powder paste of an electrically insulating magnetic material (ferrite),
Conductors using powder pastes such as Ag, Ag-Pd, and Pb are alternately printed to form a laminate, and at that time, the conductors form a coil of about half a turn on the surface of the magnetic sheet, and these In a laminated inductor obtained by connecting each layer to form a single coil as a whole and then firing the laminated body,
Approximately half a turn of conductor is printed on the surface of each magnetic sheet. Two conductors run in parallel and connect to two corresponding conductors on the adjacent magnetic layer, and these two conductors are the last to be printed. It is characterized by being combined to form a coil approximately twice as long.

According to the method of the present invention, the inductance value of the multilayer inductor is much larger than that of the conventional one, and can be approximately doubled, while the volume does not substantially increase, so the multilayer inductor can be miniaturized, Alternatively, a large inductance value can be provided with the same volume.

The invention will now be explained in detail with reference to examples. The following explanation assumes that the magnetic layer and coil conductor are all laminated by a printing method.
It should be understood that a part of the magnetic layer can also be formed using a superposition method (a method in which pre-formed magnetic raw sheets are placed and stacked). Further, although the embodiment describes the manufacture of a single product, in reality, a large number of inductors are simultaneously printed and laminated.

Reference is made to FIGS. 1-12 which illustrate a method of manufacturing the multilayer inductor of the present invention. These figures clarify the structure of the multilayer inductor of the present invention.
Now, as shown in FIG. 1, first, a rectangular magnetic sheet 1 (the raw sheet mentioned earlier...the same applies hereinafter) is printed on a suitable substrate (not shown). Moving to the process shown in FIG. 2, a conductive paste (the above-mentioned paste...the same applies hereinafter) is printed on the surface of the magnetic layer 1 to form parallel conductors 2 and 3. These conductors have a length of about half a turn to form a coil, and are U-shaped (or may be circular). Further, as shown in FIG. 2, one ends of the conductors 2 and 3 are drawn out to the upper side and the left side (as viewed in the figure), respectively, to form lead-out portions 1S and 2S. Next, as shown in FIG. 3, a magnetic sheet 4 is printed on the left half of the laminate to cover some of the conductors. Next, as shown in Fig. 4, the conductor 2,
3, and print U-shaped parallel conductors 5 and 6 extending onto the magnetic sheet 4. As shown in Figure 5, this time the magnetic sheet 7 is placed on the right half of the laminate.
Then, as shown in FIG. 6, U-shaped parallel conductors 8 and 9 are printed, which are connected to the conductors 5 and 6, respectively, and extend onto the magnetic sheet 7. Furthermore, the seventh
As shown in the figure, the magnetic sheet 10 is printed on the left half of the laminate, and the process proceeds to the step shown in FIG. 8, where the conductor 11 connected to the conductor 8 and the lower side lead-out portion 2F connected thereto are printed. In the process shown in FIG. 9, a magnetic sheet 12 is further printed on the left half of the laminate, and on top of that, the conductor 13 extending from the conductor 9 and the exposed drawer part 1F on the left side of the laminate are printed as shown in FIG. do. Drawer part 1
F is set in a positional relationship that is vertically aligned with the drawer portion 2S shown in FIG. Finally, the magnetic layer 14 is printed on the entire surface as shown in FIG.

The obtained laminate is still in a raw state. This laminate is charged into a firing furnace and fired at a predetermined high temperature and time to obtain an integral fired body. The conductor lead-out portions 1S, 2S, 1F, and 2F are exposed on the side surface of the fired laminate. External terminal 1 connecting 2S and 1F
6. The external terminal 14 connected to 1S and the external terminal 15 connected to 2F are attached by printing or applying the same conductive paste as the conductor or a conductive paste that can be baked at a low temperature and then baking.
It can be seen that by connecting the drawer parts 2S and 1F, a clockwise conductor coil from the drawer part 1S to 1F is formed, and then a clockwise conductor coil from the drawer part 2S to 2F is formed. . in this way,
A feature of the present invention is that two sets of parallel coils are connected in the middle to form one inductor having twice the number of coil turns. FIG. 13 shows a circuit diagram of the completed multilayer inductor shown in FIG. 12.

As shown in FIGS. 12 and 13, the intermediate (1F, 2S) and other ends (1S, 2F) of the two coils are both located on the circumferential surface of the sintered laminate, so the end-start end of the two coils is Coupling is facilitated and connection to external circuits is also facilitated.

As described above, the present invention has an inductance value that is almost twice that of the conventional multilayer inductor, with only slight changes to the structure and manufacturing method of the conventional multilayer inductor, and with almost the same number of steps as the conventional multilayer inductor manufacturing method. It has the advantage of being able to provide an inductor. Therefore, on the contrary, if the same inductance value is sufficient, a laminated inductor can be manufactured with a significantly reduced number of steps compared to the conventional method. It will be apparent to those skilled in the art that many variations are possible within the scope of the invention.

[Brief explanation of the drawing]

1 to 11 are plan views showing each sequential process of the method for manufacturing a multilayer inductor according to the present invention, and FIG.
The figure is a perspective view of the completed multilayer inductor of the present invention, and FIG. 13 is a circuit configuration diagram of the multilayer inductor of FIG. 3. The main parts in the figure are as follows. 1, 4, 7, 10, 12, 14: electrically insulating magnetic sheet, 2, 5, 8, 11: first set of conductors, 3, 6, 9, 13: second set of conductors, 1S ，
2S, 1F, 2F: Drawer section, 14, 15, 16:
External terminal.

Claims (1)

[Claims] 1 A plurality of electrically insulating magnetic sheets and two sets of plurality of coil conductors each having a length of approximately half a turn are connected to each other through the edges of the magnetic sheets. In a sintered laminated inductor in which the conductor is formed into a coil by laminating the magnetic sheets so as to circulate from layer to layer, the conductor is formed as two sets of parallel coils, and the conductor is formed as two parallel sets of coils, and the conductor is formed as two sets of coils in parallel. A multi-terminal inductor having three terminals, wherein a terminal end of the coil is connected to a starting end of the other coil via an external terminal on the periphery of the multi-layer inductor.