JPS59213119A - Manufacture of chip coil - Google Patents

Abstract

PURPOSE:To obtain the chip coil of high quality factor at low cost by a method wherein a continued grooved layer forming part is laminated successively on the edge part of a laminated body, then a continued grooves are formed by performing a sintering, and a conductive part which is continued in coillike shape is formed by pressure-filling a fused low melting point metal into the grooves. CONSTITUTION:After the first groove forming part 5 has been formed on the first laminated body 1, and the second laminated body 2 which is smaller than the first laminated body 1 is stacked on the first laminated body 1 in such a manner that the edge part of the first groove forming part 5 will appear. Then, the second groove forming part 6 is formed using paste on the second laminated body 2 continuously from the edge part of the first groove forming part 5. Subsequently, the third laminated body 3 is stacked on the second laminated body 2 in such a manner that the edge part of the second groove forming part 6 will appear, and the third groove forming part 7 is formed on the third laminated body 3 in such a manner that the part 7 will be continued from the edge part of the second groove forming part 6. When the laminated bodies 1-4 stacked as above are placed in a sintering furnace and sintered at the prescribed high temperature, a coillike groove is formed on the laminated bodies 1-4. A fused low melting point metal is filled in the groove from the exposed parts 8 and 9.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a chip coil.

2. Description of the Related Art In recent years, along with the development of semiconductor devices, there has been an increase in the use of coils as chips due to the demand for smaller size and higher integration of electronic devices and electronic circuits. This chip coil is roughly divided into wire-wound type and laminated type. Wire-wound chip coils have good Q characteristics, but are difficult to handle because the windings are exposed.

In order to solve this problem, there are products on the market that are entirely molded with resin, but the cost is significantly higher. On the other hand, a paste consisting of a laminated chip coil material and an Ag. Electrode paste consisting of 75 Pd etc. was alternately applied. Q75 is produced by printing and sintering the electrode material, but the electrode material has a high specific resistance, resulting in poor Q75 quality, and the use of precious metals increases costs.

The purpose of the present invention is to solve the above-mentioned technical problems and
E. It is an object of the present invention to provide a method for manufacturing a chip coil with high cost and low cost.

Embodiments of the present invention will be described in detail below with reference to the drawings. FIGS. 1(a) to 1(g) are plan views for explaining the manufacturing process of an embodiment of the present invention, and FIG. 2 is a sectional view of a completed chip coil. In the present invention, first, laminates 1 to 4 of insulating magnetic raw sheets are prepared. In the first laminate 1, a first gap layer forming portion 5 is formed by a combustible material such as carbon, which is decomposed or expelled during firing, or a paste consisting of a combustible material and magnetic powder (see FIG. 1).
As shown in b), it is formed by screen printing or the like. This first void layer forming portion 5 is formed in the first laminate 1
exposed at the bottom edge of and extending to the top. The portion 8 exposed at the lower edge becomes one terminal as described later. After forming the first void layer forming part 5 on the first laminate 1, as shown in FIG. The laminates 2 are placed and stacked so that the end of the first void layer forming portion 5 is exposed. Next, as shown in FIG. 1(d), a second void layer forming section 6 is formed on the second laminate 2 by using the above-mentioned paste continuously from the end of the first void layer forming section 5. Form. Then the first
As shown in FIG. 1(θ), the third laminate 3 is placed and laminated on the second laminate 2 so that the end of the second void layer forming part 6 appears, and ), the third void layer forming portion 7 is formed in the third laminate 3 so as to be continuous from the end of the second void layer forming portion 6. This third void layer forming portion 7 is exposed at the upper edge of the third laminate 3, and this exposed portion 9 becomes the other terminal as described later.

Thereafter, the laminate 4 is placed and laminated. The laminates 1 to 4 placed and stacked in this manner are placed in the first void layer forming portion 5.
The exposed portion 8 continues in a coiled manner to reach the exposed portion 9 of the third void layer forming portion 7 . Although FIG. 1 shows an example in which the laminates 1 to 4 are prepared one by one, in other embodiments, the laminates 1 to 4 may be prepared by cutting a large number of printed sheets. Good too. Alternatively, the laminates 1 to 4 and the void layer forming portions 5 to 7 may be sequentially formed by a printing method.

Next, the laminated bodies 1 to 4 placed and stacked are placed in a firing furnace and fired at a predetermined high temperature to form an integral sintered body. The first to third void layer forming parts 5 to 70 paste are decomposed or expelled during firing as described above, so by firing, the first to third void layer forming parts 5 to 7 have no voids. Thus, a continuous coil-shaped void layer is formed in the laminates 1 to 4.

Next, this sintered body is immersed in a melting tank of a low melting point metal such as Pb, Sn, or an alloy thereof, and is subjected to Calorie pressure, so that the molten low melting point metal is first introduced into the void layer.
The exposed portion 8 of the third laminate 1 or the exposed portion 9 of the third laminate 3 is filled.

Thereafter, it is taken out of the melting tank and allowed to cool naturally, thereby forming a continuous conductive part in a coil shape as shown in FIG. As described above, in the method for manufacturing a chip coil according to the present invention, since a continuous conductive portion is formed in a coil shape using a low melting point metal, a chip coil with a high Q can be obtained at low cost. One terminal of this continuous conductive portion is the exposed portion 8 of the first laminate 1, and the other terminal is the exposed portion 9 of the third laminate.

After a coil-shaped continuous conductive part is formed in this way, as shown in FIG. A chip coil is manufactured. As another embodiment of the present invention, the external terminals 10° 11 may be formed by baking before being immersed in a melting bath of a low melting point metal, and the external terminals 10° 11 may be porous. .

In the above-mentioned embodiment, four laminates were laminated, but in the present invention, the number of laminates may be a predetermined number necessary to form a desired coil-shaped conductive part.

Further, as shown in FIG. 3, the end of the first void layer forming part 5 formed on the first laminate 1 and the end of the second void layer forming part 6 of the second laminate 2 The portions may be connected at the middle of the upper side of the first laminate 1. Although not shown in the drawings, other void layer forming portions may be connected in the same manner.

As described above, according to the present invention, continuous void layer forming portions are sequentially formed in the end portions of the laminate, and then the continuous void layer is formed by firing, and the void layer has a low melting state. Since a continuous conductive portion is formed in a coil shape by press-fitting and filling the melting point metal, it is possible to obtain a chip coil with a high Q value at low cost.

[Brief explanation of drawings]

FIGS. 1(a) to (g) are plan views for explaining the manufacturing process of one embodiment of the present invention, FIG. 2 is a sectional view of a completed chip coil, and FIG. 3 is another embodiment of the present invention. FIG. 3 is a plan view of an example. 1-4...Laminated body, 5-7...Void layer forming part, 10°1
1...External terminal. Applicant: Murata Manufacturing Co., Ltd. Agent: Kazuhide Okada, patent attorney

Claims (1)

[Claims] (1) Prepare a plurality of insulating laminates, form a first void layer forming portion that becomes a void layer by firing in the first laminate, and form a second void layer on the first laminate. The laminate is placed in the first
The second laminate is placed and laminated so that the end of the void layer forming part of the second laminate is exposed, a second void layer forming part is formed in the second laminate so as to be continuous from the end, and the second laminate is placed on the second laminate. The third laminate is placed and stacked so that the end of the second void layer forming section is exposed, and a third void layer forming section is placed so as to be continuous from the end of the second void layer forming section. A predetermined number of laminates are sequentially stacked in this manner so that the void forming portion continues in a coil shape at the end thereof, and the stacked laminate is fired. See above, No. 1. Second. A method for producing a chip coil, characterized in that the third void layer forming portion is formed as a void layer, and the void layer is filled with a molten low melting point metal to form a continuous conductive portion in a coil shape. .