JPH0555067A - Fabrication of multilayer ceramic inductor - Google Patents

Abstract

PURPOSE:To provide fabrication of multilayer ceramic inductor which can cope with ministurizing of multilayer ceramic inductor and in which number of turn of coil can be increased readily without requiring through-hole and without increasing the number of layers of sheet. CONSTITUTION:When a conductor pattern is set based on a desired number of coil turn, a pair of green sheet pieces where the ends 9 of pattern are exposed on the opposite side faces of sheet piece and printed are prepared. A laminate wrapping the green sheet pieces is then produced and another conductor pattern is arranged on the side face of the laminate(where the end 9 of pattern is exposed) and a complete coil 14 is formed of former and latter patterns.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a laminated ceramic inductor which does not require through holes and can increase the number of coil turns without increasing the number of laminated ceramic sheets.

[0002]

2. Description of the Related Art In a multilayer ceramic inductor, a coil-shaped conductor is spirally wound around magnetic ceramics which are superposed by applying a multilayer technique, and its start end and end are connected to different external electrode terminals. And is manufactured in the following manner.

That is, a green sheet obtained by coating a slurry of magnetic ceramics on a base film was prepared, and through-holes were cut at appropriate positions on each of the sheet pieces cut into appropriate sizes. A conductor pattern is printed so as to obtain a desired coil pattern, these are stacked, and an appropriate number of sheet pieces on which the conductor pattern is not printed are stacked on the upper and lower parts of the conductor pattern and pressure-bonded to form a molded body. The formed body is cut into individual elements, separated and baked, and then external electrodes are applied and baked to obtain a product.

[0004]

With the progress of miniaturization of monolithic ceramic inductors, the size has been reduced to, for example, 1.6 × 0.8 mm, and even 1.0 × 0.5 mm is required. Came.

In response to the demand for obtaining the largest possible inductance with such a size, the thickness of the laminated sheets is reduced to increase the number of layers, and the layers are connected by through holes to form a coil. It is common to try to solve it by increasing the number of turns.

However, when the thickness of the sheet is reduced, the handling of the sheet becomes inconvenient, the number of layers must be increased in order to increase the number of turns of the coil, pattern alignment is difficult, and the process is complicated. However, problems such as a decrease in the connection probability of through holes occur.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above problems and provide a method for manufacturing a monolithic ceramic inductor which can easily increase the number of coil turns without increasing the number of laminated sheets.

[0008]

In order to achieve the above-mentioned object, the inventors of the present invention have focused their attention on a method in which through holes are not used to connect conductor patterns to each other, and carry out research, based on a desired number of turns. When setting, make a laminated body including a pair of green sheet pieces printed with the ends of the pattern exposed to both side surfaces of the sheet piece, and place another conductor pattern on the side surface of this laminated body. The inventors have found that the above-mentioned problems can be solved by forming a coil with the above pattern and the latter pattern, and have reached the present invention.

Therefore, the present invention provides a method for manufacturing a monolithic ceramic inductor in which a coil-shaped conductor spirally circulates in a laminated ceramic magnetic body, and its start end and end are connected to different external electrode terminals, respectively. (A) either one of a plurality of stacked green sheet pieces, or (b) a pair of green sheet pieces in which a conductor pattern is set based on a desired number of turns and the end portions of the pattern are exposed to both sides and printed. One sheet piece, (c) a green sheet piece having a predetermined number of stacked sheets, (d) the other green sheet piece of the conductor pattern set in (b) above, and (e) a plurality of stacked green sheet pieces are Sequentially stacking and crimping one after another to form a laminated body, and the obtained laminated body is overturned, and the two surfaces where the end portions of the conductor pattern are exposed are made upper and lower surfaces, respectively. A pair of green sheet pieces on which one of another pair of conductor patterns for completing the spiral coil and the conductor lead-out portion are respectively printed by contacting the end portions of the pattern exposed at Stacking on top and bottom of the body, stacking a plurality of green sheet pieces on the top and bottom, respectively, and then debinding, firing and attaching external electrodes to the crimped body obtained by crimping A ceramic inductor is provided, and further, two separate coils are simultaneously formed by printing another conductor pattern so as to form another coil pattern between the conductors forming each conductor pattern. , Or in a pair of conductor patterns that are stacked on the upper and lower surfaces of the laminate, another pattern formed between the conductors is pulled out from the middle of the pattern. Also such that to form a number of separate turns are included in the method of the present invention.

1 to 11 are views for explaining the method of the present invention. Although the drawings show the case of making one chip, in the actual manufacturing process, many chips are formed at the same time. It is made by. That is, it is general to prepare a stencil in which a plurality of patterns of one chip are arranged and use the stencil to form a plurality of inductors. A description will be given below with reference to the drawings.

(1) A plurality of ceramic green sheet pieces 1 are stacked (see FIG. 2). (2) Sheet pieces 2 and 3 in which the patterns A and B are printed on another ceramic green sheet piece are prepared. The number of internal conductors to be printed is determined in consideration of the number of turns of the coil in the pattern to be printed, and (A) and (B) of FIG.
It is for forming 3.5 turns (see Figure 3). (3) Sheet piece 1 on which pattern A is printed is sheet piece 1
(See Fig. 4). (4) Further stack a predetermined number of unprinted green sheet pieces 4 (see FIG. 5). (5) The green sheet piece 3 on which the pattern B is printed is superposed on the sheet piece 4 (see FIG. 6). (6) A plurality of unprinted ceramic green sheet pieces 5 are stacked on the sheet piece 3, and pressure bonding is performed at this stage to form a laminated body 6 (see FIG. 7). (7) FIG. 8 is a view showing a state in which the laminated body 6 of FIG. 7 is rolled over, and the end portions of the respective patterns of the sheet pieces 2 and 3 on which the patterns A and B are printed are exposed on the upper surface. (See Figure 8). (8) Sheet pieces 7 and 8 in which patterns C and D are printed on another ceramic green sheet piece are prepared (see FIG. 9).
8), the sheet piece 7 having the pattern C printed on the upper surface which is the main surface of FIG. 8, the sheet piece 8 having the pattern D printed on the lower surface which is the other main surface, and the conductors of the patterns A and B of FIG. Align and stack so that the ends of are connected to form a coil. The sheet pieces 7 are turned over and overlapped, and the ends (conductor lead-out portions) 9 of the coil conductors are exposed on the end faces (see FIG. 10). (9) A plurality of green sheet pieces 10 that are not printed on the upper and lower surfaces are stacked (see FIG. 11) and pressure-bonded to complete the stacking. (10) The above laminated body is debindered and fired to apply the external electrode 11 to the end surface of the coil conductor where the terminal 9 is exposed,
FIG. 1 is a transparent perspective view showing the chip which has been baked and completed. In this figure, the main surface (upper surface) of FIG. 11 is shown in the front and the front surface is shown as the lower surface. 14 is a completed coil.

[0012]

12 to 14 are views for explaining a method for manufacturing a chip having an increased number of coils without increasing the number of sheets for pattern printing, and thus the number of sheets for a laminated body in the method of the present invention. And will be described below.

In the method described with reference to FIGS.
The sheet pieces 2 and 3 on which the patterns A and B are printed and the sheet pieces 7 and 8 on which the patterns C and D are printed are shown in FIGS. 12 (A ′), (B ′) and FIG.
(C ') and (D'), the sheet pieces 12, 13 and 1 changed to patterns A ', B'and C', D '.
7 and 18 are produced respectively. That is, another pattern shown by a dotted line is added to each of the conductor patterns of FIGS. 3 and 9, and another coil pattern is printed while being shifted by one pitch so as to advance by two pitches per turn (FIG. 12 and 13).

A laminated body is formed from the above-mentioned pattern-printed sheet piece and non-printed sheet piece, and a sheet piece on which another pattern is printed is superposed on the side surface of the laminated body where the conductor pattern is exposed, and pressure-bonded. Furthermore, debinding, firing, attachment of external electrodes and the like are exactly the same as in the case of FIGS.

As described above, in the inductor manufactured by the method of the present invention, the conductor pattern is provided by shifting the pitch of the coil if necessary, so that the increase in the number of coils does not increase the number of conductor pattern printed sheets. It is easy, and if it is pulled out from the middle of the pattern, a specific number of turns can be set independently, and it can be used as a transformer.

[0016]

Embodiments FIGS. 15 to 19 are views for explaining one embodiment of the present invention, showing eight cases in which a large number of chips are manufactured at the same time. Hereinafter, description will be given with reference to these drawings.

(1) A total of four green sheet pieces 2 having the same conductor pattern A printed at two locations and two green sheet pieces 3 having the pattern B printed at two locations are formed (see FIG. 15). ). (2) As shown below, as in the case of one chip, they are stacked in order from the bottom and pressure-bonded to form a laminated body 6 (see FIG. 16). Unprinted sheet strip 1 consisting of several sheets 1 Sheet strip 2 with pattern A printed 2 Unprinted sheet strip 4 consisting of several sheets 1 Sheet with pattern B printed in 2 spots Piece 3 Unprinted sheet piece 1 consisting of several sheets 1 Sheet of pattern A printed on 2 places 2 Sheet piece 2 consisting of several sheets of unprinted sheet 4 1 Pattern B printed on 2 places Unprinted sheet piece 5 consisting of several sheets (3) Laminated body 6 is cut along a cutting line 19 indicated by XX ', and
A set of laminated bodies is formed, and this is rolled over to change the direction so that the surface where the end portions of the respective patterns are exposed faces up (FIG. 17).
reference). (4) Sheet piece 7 in which four patterns C are printed on another sheet piece and sheet piece 8 in which pattern D is printed
2 pieces are made for each cut laminated body (Fig. 1
8). (5) One set of the above-mentioned cut laminated bodies are superposed in order from the bottom as follows. Unprinted sheet piece 10 consisting of several sheets 1 Sheet piece printed with pattern C 7 Laminated body 6 1 Sheet piece printed with pattern D 8 Unprinted sheet piece consisting of several sheets 10 Here, the sheet pieces 7 and 8 on which the patterns C and D are printed are turned over so that the internal conductors exposed on the surface of the laminated body 6 and the internal conductors of the sheet pieces 7 and 8 come into contact with each other and are superposed and pressure-bonded. .. Therefore, the end 9 of the coil conductor is shown exposed on the end face. (6) Further, the above-mentioned crimping body is cut along the YY 'cutting line 20 and
The Z ′ cutting line 21 cuts into four chips. Since there are two sets of crimp bodies, a total of eight chips are manufactured. (7) Firing of the above chips, attachment of external electrodes, etc. are completed products according to conventional methods.

[0018]

As described above, according to the manufacturing method of the present invention, through holes are not used to connect the conductor patterns printed on the sheet pieces to form the coils, and different conductor patterns are provided on both side surfaces of the laminate. Since the coils are arranged to form the coil, it is possible to easily increase the number of coil turns by increasing the number of printed conductors of each conductor pattern with respect to the desired number of coil turns. By printing another pattern between the conductor and the conductor, it is possible to easily increase the number of coils, and thus it is possible to easily provide a miniaturized inductor.

[Brief description of drawings]

FIG. 1 is a transparent perspective view of a chip-shaped inductor manufactured by a method of the present invention.

FIG. 2 is a perspective view of a sheet piece on which a pattern is not printed.

FIG. 3 is a perspective view of a sheet piece on which a pattern A and a pattern B are printed, respectively.

FIG. 4 is a perspective view showing a sheet piece on which a pattern A superimposed on FIG. 2 is printed.

5 is a perspective view showing a plurality of unprinted sheet pieces overlaid on FIG. 4. FIG.

FIG. 6 is a perspective view showing a sheet piece on which a pattern B overlaid on FIG. 5 is printed.

FIG. 7 is a perspective view of a laminated body obtained by stacking a plurality of non-printed sheet pieces on top of FIG. 6 and press-bonding them.

8 is a perspective view showing a state in which the laminated body of FIG. 7 is rolled over.

FIG. 9 is a perspective view of a sheet piece having patterns C and D printed on the upper and lower surfaces of FIG.

10 is a perspective view of a laminated body in which the sheet pieces of FIG. 9 are stacked on the upper and lower surfaces.

FIG. 11 is a perspective view showing a state in which unprinted sheet pieces are stacked on the lower surface of FIG.

FIG. 12 is a perspective view of a sheet piece on which a pattern A ′ and a pattern B ′ are printed, respectively.

FIG. 13 is a perspective view of a sheet piece having patterns C ′ and D ′ printed on the upper and lower surfaces of the laminate.

FIG. 14 is a transparent perspective view of a laminated chip inductor manufactured by using sheet pieces on which patterns A ′, B ′ and C ′, D ′ are printed.

FIG. 15 is a perspective view of a sheet piece on which a pattern is printed, which is used when a large number of chips are produced at the same time.

FIG. 16 is a perspective view of a laminate manufactured using the sheet piece of FIG.

FIG. 17 is a perspective view of the laminated body of FIG. 16 when it is turned over and the surfaces where the end portions of the pattern are exposed are set up and down.

18 is a perspective view of a sheet piece on which patterns C and D are printed, which are overlaid on the upper and lower surfaces of the stack of FIG.

FIG. 19 is a perspective view showing a state in which sheet pieces on which patterns C and D are printed are stacked on the upper and lower surfaces of the laminated body of FIG. 17, and an unprinted sheet piece is further stacked and pressure-bonded thereon. ..

[Explanation of symbols]

 1 Unprinted Sheet Piece 2 Sheet Piece with Pattern A Printed 3 Sheet Piece with Pattern B Printed 4 Predetermined Number of Sheet Pieces 5 Not Printed Sheet Piece 6 Laminate 7 Pattern C Printed The sheet piece 8 printed with the pattern D 9 The terminal of the coil conductor 10 The sheet piece not printed 11 The external electrode 12 The sheet piece 13 printed with the pattern A ′ 13 The sheet piece 14 printed with the pattern B ′ 14 Completed The coil 15 The terminal of the coil A 16 The terminal of the coil B 17 The sheet piece on which the pattern C'is printed 18 The sheet piece on which the pattern D'is printed 19 XX 'cutting line 20 YY' cutting line 21 ZZ 'cutting line

Claims (1)

[Claims] 1. A method for manufacturing a monolithic ceramic inductor in which a coil-shaped conductor spirally circulates in a laminated ceramic magnetic body, and its start end and end are connected to different external electrode terminals, respectively. One sheet of a pair of green sheet pieces in which a conductor pattern is set based on a desired number of turns and printed with the end portions of the pattern exposed to both side surfaces. Piece, (c) Green sheet piece with a predetermined number of layers,
(D) The other green sheet piece among the conductor patterns set in (b) above, and (e) a plurality of stacked green sheet pieces are sequentially stacked in this order and pressed to form a laminated body, and the obtained laminated body is formed. The two surfaces, which are overturned and whose end portions of the conductor pattern are exposed, are respectively defined as an upper surface and a lower surface, and another surface for contacting the pattern end portions exposed on these upper and lower surfaces to complete the spiral coil. Each of the pair of conductor patterns and the conductor lead-out portion are formed, and a plurality of green sheet pieces are further stacked, respectively, and then debonded, fired, and attached with external electrodes to the crimped body obtained by crimping. A method of manufacturing a monolithic ceramic inductor, comprising: