JPH0618140B2 - Manufacturing method of multilayer chip inductor - Google Patents

Description

The present invention relates to a method for manufacturing a laminated chip inductor.

[Prior Art] A multilayer chip inductor is a chip-shaped inductor in which a conductor forming a coil is incorporated in a magnetic material or an insulating ceramics and integrated. The general method of manufacturing this multilayer chip inductor is as follows.

(1) Make a green sheet consisting of magnetic ceramic powder and organic binder.

(2) A through hole is punched at a predetermined position on the green sheet.

(3) A coil pattern is formed on the green sheet with a conductor paste.

(4) The green sheets are laminated so that the coil patterns are connected to each other through the through holes, and they are thermocompression bonded to be integrated.

(5) Cut the laminated body that has been crimped and separate into chips,
Bake.

(6) The external electrodes are baked on the baked chips to obtain products.

FIG. 2 shows the position of the through hole 2 when the coil pattern is 1/2 turn for each layer of the green sheet piece 1 (a).
FIG. 4 is a plan view showing (A), (B), (C), and (D) of (A), (B), and printed patterns of the conductor coil 3.

FIG. 3 is a perspective view showing a simple manufacturing process of a laminated chip inductor using the green sheet shown in FIG. 2, and FIG. 3A is a green sheet piece 1 to be laminated.
FIG. 5A 'shows the respective patterns of the through holes 2 and the conductor coils 3 on the sheet, and the through holes and the printing are formed in the upper three layers and the lower two layers of the laminated green sheet pieces. Not applied.

1B to 1E respectively show a laminated body 4 of green sheets, a chip 5 cut from the laminated body, a fired body 6 of the chip, and a laminated chip inductor provided with an external electrode 7.

FIG. 4 shows the positions (c), (d), (e), (f) of the through holes 2 and the conductor coil 3 when the coil pattern has 3/4 turns for each layer of the green sheet piece 1.
Print patterns (E), (F), (G), (H),
It is a top view which shows (I) and (J).

FIG. 5 is a perspective view showing a simple manufacturing process of a laminated chip inductor using the green sheet shown in FIG. 4, and FIG.
(A ') shows the respective patterns of the through hole 2 and the conductor coil on the sheet, and FIG.
Similar to the figure, the upper 3 layers and the lower 2 of the laminated green sheet piece
The layers are not provided with through holes and printing, and the figures after (b) in FIG. 8 are the same as those in FIG.

[Problems to be Solved by the Invention] However, in the conventional method for manufacturing a laminated chip inductor, when the mold required for punching through holes in the green sheet is 1/2 turn per one green sheet layer. It is necessary to prepare 2 types, and 4 types in the case of 3/4 turns per layer, and these molds with pins implanted lack durability because they are bent or bent, and they are frequently replaced. However, there is a problem that if a plurality of metal molds are not always prepared, productivity will be hindered, and an increase in manufacturing cost due to purchase of a large number of expensive molds cannot be avoided.

Therefore, it is an object of the present invention to provide a method for manufacturing a laminated chip inductor that can reduce the number of molds, which is a factor of increasing the manufacturing cost, by half and contribute to the reduction of the manufacturing cost.

[Means and Actions for Solving the Problem] As a result of research to achieve the above-mentioned object, the inventors have noticed that the positions of the through holes are arranged at equal intervals, and By rotating the green sheet with the through hole pattern of 180 degrees around the appropriate position so that the position of the through hole comes to the position of the other pattern, two kinds of necessary through holes can be obtained with one mold. The inventors have found that a pattern can be obtained and have reached the present invention.

Therefore, according to the present invention, a through hole is formed at a predetermined position of a green sheet containing a magnetic material or an insulating ceramic as a main component, and a conductor coil pattern formed on the green sheet is connected through the through hole. Are laminated, thermocompression-bonded and integrated, then separated into chip shapes, and then baked external electrodes on the fired body. A green sheet piece having two types of through-hole patterns is produced by one mold by rotating the green sheet by 180 degrees with the center of symmetry of two different types of through-hole patterns being formed as the center of rotation. The present invention provides a method for manufacturing a laminated chip inductor characterized by:

In the method of the present invention, the green sheet piece punched in accordance with one through-hole pattern by the punching die, the position of the through-hole to the position of the other pattern by rotating 180 degrees with its center point as the rotation center point. Since it is set so as to come, two kinds of through hole patterns can be obtained with one mold.

FIG. 1 shows an example of an embodiment of the present invention. As shown in the plan view of FIG. 2B, four corners are surrounded by a die contact 9 and a through hole of FIG. The center 8 of the green sheet piece 1 in which the through-hole pattern 2a according to the hole pattern (a) is punched is found at the intersection of the diagonal lines of the sheet piece, and the center is rotated by 180 degrees with the center as the center of rotation. In the plan view of (1), the relative positions of the through hole pattern 2a indicated by a white circle and the through hole pattern 2b indicated by a black circle (the through hole pattern (b) in FIG. 2) are shown.

Similarly, in the plan view of FIG. 3C and the side view of FIG. 3A, the center 8 of the green sheet piece 1 attached to the metal frame 10 is provided with a positioning hole 11 provided in the metal frame 10. The same effect can be obtained by rotating the metal frame 180 degrees around it.

Further, FIG. 4 (4) shows two types of through-hole patterns 2c (through-hole pattern (c) in FIG. 4) and 2d (obtained by rotating 180 degrees about the center 8 of the green sheet piece as a rotation center point). The relative position with respect to the through-hole pattern (e) in FIG. 4 is shown. Similarly, in FIG. 5 (5), the through-hole patterns 2e (through-hole pattern (d) in FIG. 4) and 2f are shown. The relative position with respect to the through hole pattern (f) in FIG. 4 is shown.

Hereinafter, the present invention will be further described with reference to examples.

[Example 1] N containing Fe ₂ O ₃ , ZnO, NiO, and CuO as main components
A polyvinyl butyral resin was used as a binder in the powder of i-Zn-Cu ferrite, and a long green sheet having a thickness of 100 μm was formed by the doctor blade method. This was cut into a predetermined size to obtain a rectangular green sheet piece.

Set this square green sheet piece in the punching die,
A through hole was drilled at a predetermined position, that is, in accordance with the through hole pattern (a) shown in FIG. Next, as shown in FIG. 1 (2), the center 8 of the green sheet piece whose four corners are surrounded by the mold contact 9 is found at the intersection of the diagonal lines of the sheet piece, and this center 8 is the center of rotation. The position of the through hole is changed to another pattern by rotating 180 degrees as shown in FIG. 2, that is, the through hole pattern (b) shown in FIG.
A through hole pattern according to

Next, a conductor paste is printed on the green sheet piece having the through hole pattern of (a) above to obtain the green sheet pieces (A) and (C) shown in FIG. 2, and the through hole pattern of (b) above is formed. Conductive paste is printed on the green sheet piece having the same to obtain the green sheet piece shown in FIG. 2B, and further, the conductive paste is printed on the green sheet piece not having through holes, and the green shown in FIG. In addition to obtaining the sheet piece, a green sheet piece in which the conductor paste was not printed and the through hole pattern was not formed was prepared.

Then, these green sheet pieces are laminated as shown in FIG. 3 (a), thermocompression-bonded at a temperature of 100 ° C. and a pressure of 300 Kg / cm ² to form a laminated body as shown in FIG. 3 (b), and then cut. The chips were cut into individual chips.

This was fired at 900 ° C. for 1 hour to obtain a chip-shaped sintered body. Further, an external electrode containing Ag as a main component was applied to this sintered body and baked at 800 ° C. to obtain a laminated chip inductor.

Example 2 After obtaining a rectangular green sheet piece 1 in the same manner as in Example 1, the green sheet piece 1 is attached to a metal frame 10 as shown in FIG. The position of the positioning pin 12 of the mold was set so that the position of the center of symmetry of the positioning hole coincided with the position of the center of symmetry between the through hole pattern 2a of (a) and the through hole pattern 2b of (b). . By rotating the green sheet piece 1 stretched on the metal frame 10 thus obtained by 180 degrees for each metal frame, two types of through-hole patterns (a) and (b) were obtained.

Then printing the conductor paste in the same manner as in Example 1,
Through-holes were punched by the respective molds based on the positioning holes 11, and the laminated chip inductor was obtained in the same manner as in Example 1 below.

Example 3 After obtaining a rectangular green sheet piece 1 in the same manner as in Example 1, as shown in FIG. 1 (4), as shown in FIG. 4 (C).
4 so that the center of symmetry between the through-hole pattern of FIG. 4 and the through-hole pattern of (e) coincides with the center of the outer shape of the green sheet piece 1, that is, the center point 8, and as shown in FIG. 1 (5). Each of the two punching molds was adjusted so that the center of symmetry of the through hole pattern of (d) and the center of symmetry of the through hole pattern of (f) coincide with the center of the outer shape of the green sheet piece 1.

By this method, two kinds of through-hole patterns can be obtained by using two molds. By rotating this mold 180 degrees, (c), (d), (e) shown in FIG.
(F) Green sheet pieces having four types of through-hole patterns were obtained.

Next, a conductor paste was printed on the green sheet piece having the through hole pattern (c) above to obtain a green sheet piece having the conductor coil print pattern (E) shown in FIG. Similarly, those having the print pattern (F) using the through hole pattern of the above (d), those having the print patterns (G) and (I) using the through hole pattern of the above (e), the above ( The printed sheet (H) having the printed pattern (H) was obtained by using the through-hole pattern of 1), and the green sheet piece having the printed pattern (J) was obtained by using the green sheet pieces having no through holes.

Next, these green sheet pieces were laminated as shown in FIG. 5 (a), and a laminated chip inductor was manufactured in the same manner as in Example 1 below.

[Effects of the Invention] As described above, by manufacturing a laminated inductor according to the method of the present invention, it is possible to halve the number of punching dies that conventionally required a plurality, and to reduce expensive dies. And has the effect of enabling cost reduction.

[Brief description of drawings]

FIG. 1 is a view for explaining a method of punching a through-hole pattern adopted in each embodiment of the manufacturing method of the present invention, in which (1), (4) and (5) are all shown. A plan view showing the relative positions of two types of through-hole patterns obtained by rotating the green sheet piece 180 degrees about the center of rotation. In the figure (2), the four corners are surrounded by a die abutment. FIG. 3A is a plan view showing a case where the center of the green sheet piece is obtained, and FIG. 3C is a plan view and a side view showing a case where the center of the green sheet piece attached to the metal frame is obtained. Fig. 2 shows that the coil pattern is for each green sheet layer
Through hole patterns (a) and (b) for 1/2 turn and conductor coil print pattern (A),
It is a top view which shows (B), (C), (D). FIG. 3 is a perspective view showing a simple manufacturing process of a laminated chip inductor using a green sheet having each pattern shown in FIG. Fig. 4 shows that the coil pattern is for each green sheet layer
Through hole pattern (C) for 3/4 turn,
It is a top view which shows (d), (e), (f) and conductor coil printing patterns (E), (F), (G), (H), (I), (J). FIG. 5 is a perspective view showing a simple manufacturing process of a laminated chip inductor using a green sheet having each pattern shown in FIG. Explanation of code 1 …… Green sheet piece 2 …… Through hole 2a …… Through hole pattern (a) (white circle) 2b …… Through hole pattern (b) (black circle) 2c …… Through hole pattern (c) (white circle) 2d ... Through-hole pattern (e) (black circle) 2e ... Through-hole pattern (d) (white circle) 2f ... Through-hole pattern (f) (black circle) 3 ... Conductor coil 4 ... Laminated body 5 ... Chip 6 …… Burning body 7 …… External electrode 8 …… Center point of green sheet piece 9 …… Attach pin receiving die 10 …… Metal frame 11 …… Positioning hole 12 …… Positioning pin

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Takahashi 6-16-20 Ueno, Taito-ku, Tokyo Within Taiyo Denki Co., Ltd. (56) References JP-A-62-118505 (JP, A) JP-A-SHO 57-26499 (JP, A)

Claims (1)

[Claims] 1. A green sheet having a magnetic sheet or an insulating ceramics as a main component and having a through hole formed at a predetermined position of the green sheet, so that a conductor coil pattern formed on the green sheet is connected through the through hole. In a method of manufacturing a laminated chip inductor, which comprises stacking, thermocompression-bonding and integrating them, separating them into chip shapes, and then baking external electrodes to a baked body, which is formed on the green sheet by a punching die. By rotating the green sheet 180 degrees with the center of symmetry of the two different through-hole patterns being different as the center of rotation, it is possible to produce a green sheet piece having two kinds of through-hole patterns with one mold. A method of manufacturing a characteristic multilayer chip inductor.