JPH0655213U - Chip inductor - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a chip inductor with high magnetic flux efficiency. [Structure] As a core that constitutes a chip inductor, an H-shaped core formed by integrally molding extension portions 12a and 12b having a T shape together with the main shaft portion at both ends of the main shaft portion is used. A coil 30 is provided in each of the extensions of the core.
21a for connecting the start and end of the winding of
21b is assembled. Each of these leads is attached to a position on the lower end surface of the extension portion and outside the end edge on the main shaft portion side.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a chip inductor using an H-shaped core.

[0002]

[Prior art]

 As a core for forming the chip inductor, for example, there is a U-shaped core as shown in FIG. FIG. 7 shows a state in which, when manufacturing a chip inductor, the U-shaped core 40 is mounted so as to bridge over a pair of leads 51a and 51b of a component supply plate called a lead frame. Regulation pieces 52a and 52b for regulating the position of the U-shaped core 40 are provided upright on the leads 51a and 51b, respectively. As will be described later, the combination of the leads 51a, 51b and the U-shaped core 40 is actually provided in large numbers at regular intervals between a pair of frames extending parallel to each other in the lead frame. , It is separated from one frame in the coil component manufacturing process, and is also separated from the other frame in the last manufacturing process.

FIG. 8 shows a state in which the coil 60 is wound around the U-shaped core 40. When the winding process of the coil 60 is completed, the starting end of the coil 60 is connected to the lead 51a, for example, and the ending end of the coil 60 is connected to the lead 51b. After that, the whole of the leads 51a and 51b is partially molded with resin, and the parts of the leads 51a and 51b protruding from the molded body are used as a terminal board when mounted on another circuit board. .

[0004]

[Problems to be solved by the device]

 By the way, the magnetic flux distribution in the chip inductor using such a U-shaped core 40 is, as shown by the arrow in FIG. 8, the innermost one of the upper ends of the two legs which are magnetic pole ends, which is the closest in distance. Concentrate on the edge (corner). However, in the U-shaped core, the magnetic flux efficiency is limited because there is only one magnetic flux concentration point. Further, in the U-shaped core, since the magnetic flux concentration points are small as described above, leakage magnetic flux is likely to occur between the outer edge portions (corner portions) at the lower end portions. Moreover, as shown in the drawing, when the leads 51a and 51b extend to the inside while being in contact with both outer edge portions of the U-shaped core 40, since the leads 51a and 51b are conductors, the leakage magnetic flux is increased. This also causes a decrease in magnetic flux efficiency.

In addition, in the U-shaped core 40, when winding the winding, the position of the winding is regulated between the two leg portions facing each other, but on the lower end side of the U-shaped core 40, Since there is nothing to control the position of the winding, the positional deviation (winding disorder) of the winding as shown in FIG. 8 is likely to occur. If there is winding disorder, the stray capacitance generated between the windings of the coil 60 also varies, and as a result, the frequency characteristics of the chip inductor also vary.

In view of the above problems, the main problem of the present invention is to provide a chip inductor having high magnetic flux efficiency.

Another object of the present invention is to provide a chip inductor in which winding winding is not disturbed.

[0008]

[Means for Solving the Problems]

 According to the present invention, an H-shaped core formed by integrally forming a T-shaped extension with the main shaft portion at both ends of the main shaft portion, a coil wound around the main shaft portion, and a winding of the coil. And a pair of terminal plates assembled to the pair of extension portions for connecting the start end and the end of each of the extension portions, each of the pair of terminal plates being the lower end surface of the extension portion and the end on the spindle side. A chip inductor is obtained which is characterized in that it is assembled at a position outside the edge.

The chip inductor is resin-molded while leaving a part of the pair of terminal plates, and the tip portions of a part of the pair of terminal plates protruding from the resin molded body are respectively formed. It is preferable that the resin mold body is bent and extends along the bottom surface of the resin mold body.

[0010]

[Action]

 In the chip inductor according to the present invention, the H-shaped core allows the extension portions to face each other at a plurality of points, which makes it easy to concentrate the magnetic flux at a plurality of points. Further, since the extension portions are opposed to each other at a plurality of points, the position regulation when winding the winding is also performed at a plurality of points, and winding disorder is less likely to occur.

[0011]

【Example】

 FIG. 1 shows a core used in the present invention. The core 10 is formed into a substantially H shape by integrally forming, at both ends of a main shaft portion 11 around which a winding is wound, extension parts 12a and 12b having a substantially T shape together with the main shaft portion 11. Become. The thickness (height) of the main shaft portion 11 and the thickness of the extension portions 12a, 12b are the same, and the outer surface of the extension portions 12a, 12b is a substantially trapezoidal shape whose width becomes narrower as it goes away from the central portion. It has been

The core 10 is mounted so as to bridge between the leads 21a and 21b as in the conventional case. Restricting pieces 22a and 22b for restricting the position of the core 10 are provided upright on the leads 21a and 21b, respectively, at positions where they abut against the outer surface of the core 10. As described above, the leads 21a and 21b are used as terminal plates for connecting the start end and the end of the winding wound around the main shaft portion 11 of the core 10, and are located outside the restriction pieces 22a and 22b. Slots 23a and 23b for facilitating the bending of the leads 21a and 21b are formed at these locations.

As shown in FIG. 2, the main shaft portion 11 of the core 10 has a coil 30 wound in multiple layers. When the coil 30 is wound, the extension portions 12a and 12b face each other at two locations, and the winding positions of the coil 30 are regulated by the inner walls facing each other, so that winding disorder does not occur. There is no. As a result, the frequency characteristics of the chip inductor are stabilized. In addition, since the extension portions 12a and 12b face each other at two locations and the innermost edge portions that are closest in distance are located at two locations, there are two locations where the magnetic flux distribution is concentrated, and the U-shaped core Compared with the case, the magnetic flux efficiency is significantly improved.

In particular, in the present invention, as shown in FIG. 1, the inner ends of the leads 21 a and 21 b which are in contact with the lower end of the core 10 are arranged at the inner end where the magnetic flux is concentrated in the core 10. By locating it outside the portion, the amount of leakage magnetic flux due to the leads 21a and 21b can be reduced.

FIG. 3 shows an example of a lead frame used in manufacturing a chip inductor using the core 10 shown in FIG. The lead frame 20 has frames 20-1 and 20-2 extending in parallel, and a large number of pairs of leads 21a and 21b for mounting a large number of cores 10 are diagonally arranged at a constant pitch. It is made like this. This is to facilitate the winding work for the core 10, which will be described later. After mounting the core 10 on each pair of the leads 21a and 21b in the lead frame 20 by bonding or the like, the frame 20-2 is separated leaving the leads 21b having a predetermined length. As will be described later, the core 10 is mounted on the lower surface side of the leads 21a, 21b in the lead frame 20 in order to facilitate the soldering of the start and end of the winding to the leads 21a, 21b. .

FIG. 4 shows a state after winding work is performed on each core 10 in the lead frame 20 separated from the frame 20-2 by an automatic winding machine (not shown). The winding work is performed in order from the core 10 on the left side in the figure. When the winding work for a certain core 10 is completed, the lead frame 20 is moved by one pitch in the direction of the arrow in the figure without cutting the winding. Then, the winding work for the next core 10 can be performed. When the winding work is performed in this manner, the coils 30 of the cores 10 are connected to each other by the extra wire (crossover wire) 31.

In the next step, for each core 10, the portion of the coil 30 that is to be the starting end of the winding wire is soldered to the lead 21a, and the portion of the coil 30 that is to be the ending end is soldered to the lead 21b. When this is completed, the part of the extra line 31 is cut off. This state is shown in FIG.

As for the chip inductor component on the left side in FIG. 5, the start end of the winding of the coil 30 is soldered to the position Pa of the lead 21a, and the end of the winding of the coil 30 is connected to the position Pb of the lead 21b. Soldered and connected. At the time of soldering, the core 10 is on the lower surface side of the leads 21a and 21b in the figure, and there is no protrusion on the upper surface side of the leads 21a and 21b. There is nothing to do, and the soldering work can be easily performed. Then, a resin mold is applied to each coil component. The resin molding is performed so that parts of the leads 21a and 21b, strictly speaking, parts outside the elongated holes 23a and 23b are exposed from the molded body. After that, each chip inductor component is separated from the lead frame 20 leaving the lead 21a having a predetermined length.

FIG. 6 shows a chip inductor component which is resin-molded and separated from the lead frame 20. The leads 21a and 21b protruding from the mold body 1 are bent 90 degrees at the elongated holes 23a and 23b (23a is not shown), and further bent at 90 degrees at the portion corresponding to the lower end portion of the mold body 1. As a result, the tips of the leads 21 a and 21 b are arranged along the lower end surface of the molded body 1. These tips are used as terminals for soldering connection when mounting the chip inductor on a circuit board or the like. In FIG. 6, for convenience, the chip inductor component in the molded body 1 is also shown by a solid line.

As described above, in the present invention, the H-shaped core having the T-shaped extension portions at both ends of the main shaft portion is used. The DC magnetic resistance R _DC is lower than that, and the magnetic flux efficiency is improved. This means that the same inductance L can be obtained with a smaller number of turns than in the case of the U-shaped core. Therefore, when the number of turns is the same, a high inductance value can be obtained, and Q as an inductor can be increased.

The H-shaped core is not limited to the shape shown in FIG. 1, but for example, a collar-shaped, for example, a square extension is integrally formed at both ends of the main shaft portion 11 to form a T-shaped core. However, in this case, the magnetic flux distribution is concentrated at four points, and the magnetic flux efficiency is further improved.

[0022]

[Effect of device]

 As described above, according to the present invention, by using the H-shaped core, the magnetic flux efficiency can be increased, and thus the inductances L and Q can be increased, and at the same time, winding disorder can be prevented during winding work. Therefore, it is possible to provide a chip inductor with stable frequency characteristics.

[Brief description of drawings]

FIG. 1 is a view partially showing a state in which a core used in the present invention is mounted on a lead of a lead frame.

FIG. 2 is a diagram for explaining a distribution state of magnetic flux in the case where a winding is applied to the core shown in FIG.

FIG. 3 is a view showing a state in which a core used in the present invention is mounted on a lead frame.

FIG. 4 is a diagram for explaining a process of winding a winding on the core shown in FIG.

FIG. 5 is a diagram for explaining a process of transitioning from the winding process shown in FIG. 4 and performing processing of a winding start end and a winding end.

FIG. 6 is a diagram showing a resin-molded chip inductor component obtained in the process shown in FIG.

FIG. 7 partially shows a conventional U-shaped core mounted on a lead frame.

FIG. 8 is a diagram for explaining the distribution state of magnetic flux in the case where the core shown in FIG. 7 is wound.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Molded body 10 H-shaped core 11 Main shaft part 12a, 12b Extension part 20 Lead frame 21a, 21b Lead 22a, 22b Control piece 30 Coil

Claims (2)

[Scope of utility model registration request] 1. An H-shaped core formed by integrally forming a T-shaped extension with the main shaft portion at both ends of the main shaft portion, a coil wound around the main shaft portion, and a winding of the coil. A pair of terminal plates assembled to the pair of extension parts for connecting a start end and a terminal end, each of the pair of terminal plates being a lower end surface of the extension part and an edge of the spindle part side. Is a chip inductor characterized in that it is also mounted on the outer side. 2. The coil component according to claim 1 is resin-molded while leaving a part of the pair of terminal plates, and a part of a tip portion of the pair of terminal plates protruding from the resin-molded body. The chip inductors are characterized in that each of them is bent and extends along the bottom surface of the resin mold body.