JPH0121611B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a laminated inductor, and particularly to a laminated inductor with a small internal capacitance. 2. Description of the Related Art Laminated inductors manufactured by a thick film method such as a printing method, a thin film method such as a vapor deposition method, or a sputtering method are well known. Multilayer inductors made by the printing method are made by pasting electrically insulating powders such as non-magnetic ceramics and magnetic ferrites, and
Metal powder such as silver-palladium is made into a paste,
An insulating layer is formed by printing a thin film of insulating paste, and a conductor of approximately half a turn is formed by printing metal powder paste in a line on that surface. An insulator layer is printed, and a second conductor for approximately half a turn is printed on it to connect to the exposed end of the conductor, and the same process is repeated a predetermined number of times to overlap vertically in the insulator. In this method, a coiled conductor pattern is formed while rotating, and the thus obtained laminate is fired to form an integrated sintered laminate. Further, the vapor deposition method is a method in which an insulator and a conductor are alternately vapor-deposited in the same steps as above. In any case, in the laminated inductor described above, the conductor layers do not face each other over a large area, as is the case when forming a spiral pattern of conductors on the same plane and connecting one end to the spiral conductor of the next layer. It has the characteristic that the internal capacitance of the inductor is small. However, unlike conventional round conductors, printed or vapor-deposited conductors are formed in wide layers, so even if there is just one turn in each layer, there is still a considerable gap between vertically overlapping turns of the conductor. A capacitance is formed. For example, as shown in Figure 9, if the inductance value is L (μH) and the capacitance formed between each turn of the conductor is △C (pF), the self-resonant frequency is

[Formula] becomes. Therefore, if ΔC is large, it is not suitable for use at high frequencies. It is therefore an object of the present invention to provide a laminated inductor that does not have the above-mentioned drawbacks. The present invention is characterized in that in a laminated inductor, at least adjacent conductor turns are arranged in a staggered relationship to minimize overlapping portions and thereby minimize internal capacitance. As a result, a laminated inductor using a thin layered conductor can be used in a form close to a pure inductor. Embodiments of the present invention will be described in detail below with reference to the drawings. In the following example, magnetic ferrite powder is used for the insulator, metal powder is used for the conductor, and the printing method is used. Since these are well known, their explanation will be omitted, and only the parts necessary for understanding the present invention will be explained. Note that it is clear that the present invention can also be realized by thin film forming methods such as vapor deposition and sputtering. 1 to 7 are process diagrams showing a laminated inductor and its manufacturing method according to an embodiment of the present invention. As shown in FIG. 1, an electrically insulating magnetic layer 1
is prepared by printing, and the linear conductor 2 is printed on its surface. The lead-out end T ₁ of the conductor 2 is drawn out to the lower side of the magnetic body 1 . Moving on to the process shown in Figure 2, conductor 2
The magnetic layer 3 is printed so that one end of the conductor 2 is exposed, and the conductor 4 connected to the exposed end of the conductor 2 is printed in an L-shape. Next, as shown in FIG. 3, a magnetic layer 5 is printed on the upper half of the laminate so that one end of the conductor 4 is exposed, and then an L-shaped conductor 6 is printed to connect to the exposed end of the conductor 4. do. In this case, it is important that the conductor 6 crosses the lower conductor 2 and then extends parallel to it without overlapping it. This reduces the capacitance between the conductors. In the process shown in FIG. 4, a magnetic layer 7 is printed with one end of the conductor 6 exposed, and then a conductor 8 parallel to the lower conductor 4 is printed in an L shape to extend the conductor 6. As shown in FIG. 5, a magnetic layer 9 is now printed on the upper part of the stack (as seen in the figure), and an L-shaped conductor 10 is also printed so as to be connected to one end of the conductor 8. In this case as well, the conductor 10 extends above and parallel to the lower conductor 6. Note that it is desirable that the conductors 2 and 10 do not overlap, but since the insulating magnetic materials 3, 5, 7, and 9 are interposed between them, the coupling capacitance is very small even if they are in an overlapping position. So there is no problem. One end of the conductor 10 is drawn out to the upper side of the laminate to form a drawn-out end _T2 . Finally, as shown in FIG. 6, a magnetic material 11 is printed on the surface of the laminate to complete the lamination. The obtained laminate is placed in a firing furnace and fired at a high temperature to form a sintered body having an integral structure. The pull-out end exposed on the top and bottom sides of the sintered body as shown in Figure 7
External terminals T ₁ ′ and T ₂ ′ connected to T ₁ and T ₂ are formed by, for example, applying a conductive paste and baking at a low temperature to complete the multilayer inductor of the present invention. FIG. 8 is a perspective view thereof. Note that the number of laminated layers can be changed arbitrarily, and it is also possible to replace a part of the magnetic layer with a non-magnetic ceramic material. For example, to change to an open magnetic path multilayer inductor, only the part surrounded by the conductor should be made of magnetic material, and the other parts should be made of ceramic material such as Al ₂ O ₃ or TiO ₂ . As is clear from the above explanation, the external terminal
The conductor path starting from T ₁ ' and ending at T ₂ ' forms a winding with a circumferential pattern in which at least no overlap occurs between adjacent turns. Therefore, the possibility that capacitive coupling will occur between the conductor layers forming adjacent turns with the magnetic material interposed between the turns of the winding wire is greatly reduced. Furthermore, since the laminated inductor of the present invention can be manufactured by combining several printed patterns, it is possible to provide an inductor with good characteristics without losing any of the advantages of the laminated inductor, such as simplified processes.

[Brief explanation of drawings]

Figures 1 to 7 are plan views showing the sequential manufacturing process and structure of the laminated inductor of the present invention, Figure 8 is a perspective view of the completed laminated inductor, and Figure 9 is a conceptual diagram explaining the internal capacitance of the coil. It is. The main parts in the figure are as follows. 1, 3, 5, 7, 9, 11: magnetic layer, 2,
4, 6, 8, 10: Linear conductor.

Claims (1)

[Scope of Claims] 1. An alternately laminated body of a plurality of insulator layers and a plurality of conductor layers, wherein the conductor layers are connected via the edges of the insulator layers so that there is no interlayer connection between the insulator layers. In a laminated inductor in which the conductor layers are connected at their ends to form a winding that goes around from layer to layer, the conductor layers form a coil of about half a turn in each layer, and the edges to which the conductor layers are connected The insulating layers having substantially the same shape are formed, and the edge portions are formed alternately at two opposing locations of the laminate, and at least most of the vertically adjacent portions of the winding wire are formed in substantially the same shape. A laminated inductor characterized by being staggered in the direction of the layer planes. 2. The multilayer inductor according to claim 1, wherein the insulating layer is made of magnetic ferrite.