JPH081871B2 - Method and apparatus for stacking magnetic green sheets - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic green sheet laminating method and apparatus for laminating magnetic green sheets containing magnetic ceramics, in which a conductor forming an inductor is embedded inside a chip-shaped magnetic ceramic body. The present invention relates to a green sheet laminating method and apparatus applicable to the production of the laminated chip inductor.

[0002]

2. Description of the Related Art A method for producing a laminated chip inductor by laminating magnetic green sheets containing magnetic ceramics and embedding conductors inside the green sheets is disclosed in, for example, Japanese Patent Application Laid-Open No. Hei.
It is known from Japanese Patent No. 151403. A general method for manufacturing this type of laminated chip inductor is, for example, the following series of steps.
First, a green sheet made of magnetic powder such as ferrite and an organic binder is formed. Next, through holes are formed at predetermined positions on the green sheet.
Further, an arc-shaped or U-shaped coil pattern is printed on one surface of the green sheet by using a conductive paste. At this time, the position where the coil pattern is printed is selected at a position where one end of the coil pattern and the through hole overlap each other and both are short-circuited. Then, the green sheets are laminated so that the coil patterns are connected between the layers through the through holes, and the green sheets are thermocompression bonded to be integrated. Here, the laminate obtained as a result of the above steps is cut into chips, separated, and then fired. Then, an external electrode is formed on each of the obtained chips to complete the multilayer chip inductor.

On the other hand, an apparatus and method for cutting and stacking green sheets into a predetermined shape are disclosed in, for example, Japanese Patent Publication No. 2-158.
It is known from publication 306. The step of laminating the green sheets will be described in detail. First, a green sheet obtained by mixing an organic binder and the like is placed on a conveyor device and conveyed. Next, this green sheet is cut into a predetermined shape at a predetermined position, and at the same time, it is adsorbed on the lower surface of the laminating head by the action of a vacuum adsorption mechanism, and is transferred to a laminating plate for laminating the cut green sheets in a prescribed order. Retained.

Subsequently, the green sheet held by the laminating head is lowered onto the laminating plate and pressure-bonded (5 to 15 tons) from its upper surface. The pressing is performed here so that the stacked green sheets do not shift when the laminated plates described later are moved. The above operation is repeated to stack a predetermined number of green sheets, and then the obtained green sheet stack is temporarily pressed (20
~ 30 ton), and then pressed again under high pressure to be integrated.

[0005]

However, in the above prior art, when the green sheet is cut into a predetermined shape and then transferred onto the laminated plate, the green sheet is adsorbed and transferred by the vacuum device. , Must be stacked one by one. Then, precise positioning must be performed each time. Therefore, there is a problem that a precise transfer device with high stop positioning accuracy is required, the number of steps is increased, the time required for the increase is increased, and the manufacturing cost of the manufactured multilayer chip inductor is increased. . Further, according to the above-mentioned conventional technique, when the green sheet is adsorbed by the vacuum device, unevenness is formed on the surface thereof, and the laminated surface of the green sheet is not uniform. In addition, when the cut green sheets are placed on the stacking plate and stacked, they are once pressure-bonded to prevent the stacked green sheets from being displaced. And it becomes wide laterally. Therefore, the characteristics of the obtained multilayer chip inductor are deteriorated, and the inductance thereof deviates from a desired value.

Further, since the negative pressure by the vacuum system is used as the source of the force for adsorbing and holding the green sheet by the laminating head, the laminating apparatus itself becomes large,
Further, there is also an inconvenience that the operation cost becomes large. In view of the above-mentioned problems in the prior art, an object of the present invention is to provide a magnetic green sheet laminating method and apparatus capable of laminating cut magnetic green sheets uniformly and accurately with a relatively simple structure. To provide.

[0012]

In order to achieve the above object, first of all, the present invention provides a magnetic green sheet laminating method in which a green sheet containing magnetic ceramics is cut into a predetermined shape and a plurality of the green sheets are laminated. Then, the green sheet is cut into a predetermined shape by a cutter attached to the stacking head, and at the same time, the cut magnetic green sheet is held on the holding surface of the stacking head, and this is repeated a plurality of times to make the stacking head of the stacking head. There is provided a magnetic green sheet laminating method, which comprises laminating a plurality of magnetic green sheets cut into the predetermined shape on a holding surface. Second, a green sheet containing magnetic ceramics is provided, which includes a stage movable on a plane, an elevating mechanism attached to the stage, and a laminating head attached to the elevating mechanism and including a cutter. In a magnetic material green sheet laminating apparatus which performs an operation of cutting a plurality of magnetic green sheets and laminating a plurality of magnetic green sheets, magnetic generation means for generating magnetism for adsorbing and holding a plurality of magnetic green sheets is provided below the laminating head. A magnetic material green sheet laminating apparatus is proposed.

[0013]

According to the present invention described above, a magnetic green sheet containing magnetic ceramics is cut into a predetermined shape by a cutter provided on the laminating head, and at the same time, this is provided on a holding portion of the laminating head. By magnetically attracting and holding by the magnetism generating means and repeating this a plurality of times, a plurality of magnetic green sheets cut into a predetermined shape are stacked and held on the holding portion of the stacking head without being displaced. You can do it. For this reason, there is no need to perform accurate positioning and crimping every time stacking, unlike the conventional method.
Instability and non-uniformity of the laminated state due to compression, lateral displacement, etc. can be eliminated, and the magnetic green sheets can be laminated accurately.

[0014]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. First, in FIG.
A schematic configuration of a manufacturing apparatus for a laminated chip inductor is shown, and reference numeral 1 in the drawing denotes a conveyor device, and a magnetic material green sheet 100 is provided on the conveyor belt 11.
Is continuously supplied.

The magnetic green sheet 100 is made of Fe.
Ni-Z containing ₂ O ₃ , ZnO, NiO and CuO as main components
Polyvinyl butyral is used as a binder in n-Cu ferrite powder to form a long ferrite green sheet having a thickness of 100 μm by the doctor blade method. As shown in FIG. 7, the green sheet 100 is cut into a predetermined size to form a rectangular green sheet, and a through hole 101 is further formed at a predetermined position of the green sheet. The coil pattern 102 is formed on the surface by using a conductor paste. Furthermore, magnetic green sheet 1
In addition to the green sheets as described above, the reference numeral 00 indicates a magnetic green sheet not forming the through holes and not having a coil pattern printed thereon, and a cover green sheet 10.
0C is also available. These cover green sheets 100C are to be laminated on both end faces of the above-mentioned magnetic green sheets 100, which will be clarified in the later description.

The magnetic green sheet 100 manufactured as described above is placed on the conveying path of the conveyor device 1 shown in FIG. 2 and laminated using the magnetic green sheet laminating apparatus of the present invention. It is conveyed to the part 2. As shown in FIG. 3, the stacking unit 2 includes a base 20 arranged below the conveyor belt 11 of the conveyor device 1, a stacking head 21 arranged above the base 20, and the stacking head in the vertical direction. An elevating mechanism 22 for elevating and lowering, and a moving stage device 23 attached with the elevating mechanism for moving the stacking head in the X and Y directions are provided. Further, reference numeral 12 in the drawing indicates a belt rail.

On the other hand, as shown in FIG. 1, a urethane rubber frame 201 is attached to the outer periphery of the base 20 of the laminated portion 2 so as to surround it. Further, the laminating head 21 has a cutter blade 211 on the side of the lower end thereof.
Is attached to the base 20 at a position corresponding to the urethane rubber frame 201, and the lower surface thereof serves as a holding portion 212 for the magnetic green sheet. That is,
As shown in FIG. 4, a plurality of electromagnets 213, 213, ... Are arranged on the bottom surface of the laminated head 21 as the holding portion 212. As shown in FIG. 5, the electromagnet 213 is composed of an electromagnetic coil 2132 wound around the core 2131 and a magnetic path member 2133 drawn out in an annular shape from the core 2131.

Returning to FIG. 3 again, a laminating plate 24 is arranged adjacent to the laminating head 21. As shown in FIG. 6, this laminated plate 24 has a plurality of magnets 241, 241 ...
The poles are arranged alternately. Further, in FIG. 2, a pressing device 3 for pressing and press-bonding the laminated magnetic material green sheets on the conveyance destination side of the laminated portion 2 is further provided on the conveyance destination side. A cutting device 4 for cutting and dividing the green sheet into chips and a firing furnace 5 for firing the cut and divided chip-shaped magnetic material laminated green sheets are provided.

The operation of the laminated chip inductor manufacturing apparatus described above will be described in detail below with reference to FIG. First, in (a) of FIG. 1, the magnetic green sheet 100 for a laminated chip inductor obtained as described above is conveyed onto the conveyor belt 11 of the conveyor device 1 to be the base of the laminating unit 2. Located on 20. At this time, the belt rails 12, 12 supporting the conveyor belt 11 are lowered, and the magnetic green sheet 100 is fixed on the base 20. Therefore, as shown in FIG. 1B, the stacking head 21 disposed above the base is lowered to move the magnetic green sheet 100 into a predetermined shape and size (for example, 15 × in this embodiment). 15 cm square)
At the same time, the magnetic green sheet 100 cut into a predetermined shape is sucked and held by the holding portion 212 on the lower surface of the stacking head 21. That is, at this time, the plurality of electromagnets 213, 213 ... (See FIG. 5) arranged on the plane of the holding portion 212 of the stacking head are energized to generate lines of magnetic force. These magnetic lines of force pass through the magnetic green sheet 100, and magnetically magnetic green sheet 1
00 is held in close contact with the flat surface of the holding portion 212. In addition,
At this time, the magnetic green sheet initially supplied by the conveyor belt 11 is the cover green sheet 100C.

After that, the laminated head 11 holds the magnetic green sheet cut into a predetermined shape in its holding portion 21.
It rises and returns to the original position while it is adsorbed and held on 2.
At the same time, the above-mentioned belt rails 12 and 12 are also raised, and the remaining magnetic green sheet 100 having a predetermined shape cut.
Is lifted from the base 20 and moved to the side to be removed. Then, the next magnetic green sheet 100 is transferred and supplied onto the conveyor belt 11, fixed on the base 20 and cut into a predetermined shape in the same manner as described above.
At the same time, the magnetic green sheet 100 cut into the predetermined shape is further stacked on the magnetic green sheet 100 that has been sucked and held by the holding portion 212 of the stacking head 21 in the previous operation. That is, by repeating the above operation a predetermined number of times, a predetermined number of magnetic green sheets 1 are held in the holding portion 212 of the stacking head 21.
00 is automatically and automatically laminated at a correct position.

The laminated magnetic green sheets 100 laminated in a predetermined number as described above are then placed on the laminated plate 22 arranged adjacent to the laminated head 21 in the laminated portion 2 (see FIG. See 3). That is,
After the stacking head 21 is lifted by the lifting mechanism 22,
It is moved to the position of the laminated plate 24 by the moving stage device 23 in the X and Y directions, and is lowered and placed on the surface of the laminated plate 24. At the same time, the laminating head 21
Reduces or interrupts the current supplied to the electromagnets 213, 213 ... Of the holding part 212. On the other hand, since the plurality of magnets 241, 241 ... Are provided on the surface of the laminated plate 24, the laminated green sheet 100 made of a magnetic material is reliably placed on the laminated plate 24.

Thereafter, the laminated green sheet 100 placed on the laminated plate 24 is thermocompression-bonded by the pressing device 3 at a temperature of 100 ° C. and a pressure of 300 kg / cm ² , for example, and is then cut. After being cut and divided into chips by 4, the baking furnace 5 for example 900 ° C
It is baked at the temperature of. Further, a conductive paste containing Ag or the like as a main component was applied to both end faces of this chip-shaped fired body, and this was baked at a temperature of, for example, 800 ° C. to form external electrodes, thereby completing a multilayer chip inductor. In the above embodiment, an electromagnet is used as the magnetic generator provided on the plane of the holding portion 212 of the laminating head 21, but the present invention is not limited to this, and for example, a permanent magnet is used, and then the adsorbed laminated green sheet is used. It suffices if the magnetic attraction force can be turned on and off arbitrarily by sending compressed air or the like into the gap at the time of leaving. In addition, the laminated plate 24
The upper magnet can also be an electromagnet.

[0023]

As is clear from the above description, according to the magnetic green sheet laminating method and apparatus of the present invention, magnetic force is utilized instead of the conventional vacuum suction means, so that it is relatively simple. With the configuration and the operation, it becomes possible to stack the cut magnetic green sheets at uniform and accurate positions.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part of a laminating apparatus for explaining a magnetic green sheet laminating method according to the present invention.

FIG. 2 is a schematic configuration diagram illustrating an outline of a multilayer chip inductor manufacturing apparatus that employs the magnetic green sheet stacking apparatus of FIG.

FIG. 3 is a side view showing an overall structure of a laminated portion of a laminated chip inductor manufacturing apparatus adopting the magnetic green sheet laminating apparatus of FIG.

FIG. 4 is a bottom view showing the bottom structure of the laminated head shown in FIG. 1;

5 is a partially enlarged cross-sectional view showing a detailed structure of an electromagnet provided on the bottom surface of the laminated head shown in FIG.

6 is a top view showing a structure of a laminated surface of the laminated plate shown in FIG.

FIG. 7 is a developed perspective view showing details of a magnetic green sheet laminated by the laminated chip inductor manufacturing apparatus.

[Explanation of symbols]

 1 Conveyor Device 11 Belt Conveyor 2 Laminating Unit 20 Base 21 Laminating Head 211 Cutter Blade 212 Holding Unit 213 Electromagnet 22 Elevating Device 23 Moving Stage Device 24 Laminating Plate 241 Magnet 3 Pressing Device 4 Cutting Device 5 Baking Furnace 100 Magnetic Green Sheet 101 Through hole 102 coil pattern

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Masami Shimakata, 6-16-20 Ueno, Taito-ku, Tokyo Within Taiyo Denki Co., Ltd. (72) Kenichi Hoshi, 6-16-20 Ueno, Taito-ku, Tokyo Within Taiyo Denki Co., Ltd. (56) Reference JP-A-61-102719 (JP, A)

Claims (3)

[Claims] 1. A magnetic green sheet laminating method for cutting a green sheet containing magnetic ceramics into a predetermined shape and laminating a plurality of the green sheets, wherein the green sheets are formed into a predetermined shape by a cutter attached to a laminating head. Simultaneously with cutting into a shape, the cut magnetic green sheets are held on the holding surface of the stacking head, and this is repeated a plurality of times, and a plurality of magnetic green sheets cut into the predetermined shape are held on the holding surface of the stacking head. A method for laminating magnetic green sheets, which comprises laminating. 2. A green sheet containing a magnetic ceramics, comprising a stage movable on a plane, an elevating mechanism attached to the stage, and a laminating head attached to the elevating mechanism and having a cutter. In a magnetic material green sheet laminating apparatus which performs an operation of cutting a predetermined shape and laminating a plurality of layers, a magnetic generation unit for generating a magnetism for adsorbing and holding a plurality of magnetic green sheets is provided below the laminating head. A magnetic material green sheet laminating apparatus characterized by being provided. 3. The laminating apparatus according to claim 2, wherein magnetic poles having different polarities are arranged at a constant distance on the surface of the laminating head.