KR0122086B1 - Manufacturing method of chip type noise filter - Google Patents

Abstract

A method for manufacturing chip shape noise suppressing filter comprising : the step printing conductor paste in constant zigzag pattern on ferrite green sheet; the step winding said printed green sheet to form a cylinder; the step pressing said cylinder in the shape which automatic surface filling is possible in; and the step cutting said cylinder in chip shape so as to expose the cut face of the conductor pattern formed within said cylinder; is disclosed. Thereby, it is possible to enhance manhour and workability and to reduce the impedance decreasing phenomenon.

Description

Manufacturing method of chip type noise suppression filter

FIG. 1 is a plan view showing a pattern in which a conductor paste is printed in a zigzag manner on a ferrite green sheet according to the present invention.

FIG. 2 is a perspective view showing a state in which the ferrite green sheet of FIG. 1 is wound in a cylindrical shape.

3 is a perspective view of a compactor for crimping the molded body of FIG.

4 is a perspective view of the molded body in the state of being compressed using the compactor of FIG.

FIG. 5 is a perspective view of a filter obtained by cutting the molded body of FIG. 4 into chips.

6 is a perspective view of a chip-shaped filter having an external terminal of FIG.

7 is a view showing a process of manufacturing a laminate of ferrite green sheet by a conventional method,

8 is a perspective view of a chip-shaped filter manufactured by the process of FIG.

9 is a perspective view of a conventional chip filter manufactured by another method.

* Explanation of symbols for the main parts of the drawings

10,71,73: ferrite green sheet, 11,111,112,74,98: conductor pattern,

12: cutting line, 13: groove,

14, compressor, 15,99: external electrode,

20,20l, 202: molded body, 101,102: side,

75: laminated body, 96: rectangular plate ferrite,

97: hole.

The present invention relates to a method of manufacturing a chip-type noise suppression filter, and more particularly, to a method of manufacturing a chip-type noise suppression filter that can be mounted on a printed board for use in eliminating electromagnetic interference in an electronic device.

In order to remove the unwanted electromagnetic waves from the electronic device, the conductor must pass through the ferrite, and the impedance mainly increases in proportion to the length of the conductor passing through the ferrite.

Therefore, in order to manufacture a filter with high impedance using the same material, it is possible to increase the length of the conductor passing through the ferrite.

In order to manufacture a small chip-type filter that can be mounted on a wiring board while satisfying these conditions, the length of the inner conductor can be increased and downsized by manufacturing the conductor in a state in which the conductor rotates.

The conventional method of manufacturing a noise suppression filter in a chip form can be largely divided into the following two types.

One method is according to Japanese Patent Application Laid-Open No. 3-185,703, in which a ferrite paste made by mixing ferrite powder, a binder and a solvent is produced by a tape cast method (hereinafter referred to as ferrite green sheet), and a metal material and A method of printing a conductor paste (hereinafter referred to as a conductor paste) made by mixing a binder and a solvent by screen printing and then laminating a ferrite green sheet thereon (first method).

Another method is described in Japanese Patent Application Laid-Open No. 60-63,906, in which a series circuit is formed by drilling a hole penetrating through a thick ferrite on each plate and passing an inner conductor pattern through the hole (second method).

An example of manufacturing a chip in this manner is shown in FIG. 7 and FIG. In the first method, in Fig. 7, a series of methods are repeated by printing an L-shaped conductor pattern on the ferrite green sheet 71 with the conductor paste 72 and covering the left half with the ferrite green sheet 73. The laminated body 75 of FIG. 2 is produced by laminating to 1 (K) degree continuously.

As a result, molding is completed in a state in which the conductor patterns are connected to each other and the conductor patterns rotate in the magnetic body. Thereafter, the ferrite green sheet laminate 75 is pressed and simultaneously fired, and then electrode terminals are formed at both ends, thereby manufacturing a device in which the inner conductor and the electrode terminals are electrically connected.

In FIG. 9, in FIG. 9, a hole 97 penetrating through the ferrite 96 on each plate is formed, and a conductor paste is inserted into the hole to form an inner conductor pattern so as to be connected through the hole. Then, a conductor pattern 98 connecting the holes is printed so that the conductors formed in the holes are connected to each other to form a series circuit. Next, an insulation resin or the like is coated on both connecting conductor patterns 98 for insulation (the insulation resin is omitted in the drawing), and then an external electrode 99 is formed to manufacture a noise suppression element having a long conductor pattern inside the chip. do.

However, when the chip device is manufactured by the first method using lamination, the length of the inner conductor must be increased to increase the impedance between the electrode terminals, and the number of processes is increased because the number of times of printing and lamination must be increased to increase the length of the inner conductor. In addition, there is a disadvantage of rising production cost accordingly.

In addition, since the inner conductor pattern spirals parallel to the outer electrode terminal as shown in FIG. 8, the inner conductor pattern rotates when the inner conductor pattern increases the number of rotations and the radius of rotation to increase the impedance. Since the cross-sectional area with the terminal is increased, the stray capacitance is increased, resulting in a decrease in impedance characteristics at high frequencies. In addition, care should be taken not to wire the inner conductor pattern since the layered portion on the ferrite sheet 3 should be printed, such as the portion indicated by 74 in FIG. 7 when printing the inner conductor.

When the chip is manufactured by the second method using the through hole, there is a limit in reducing the diameter of the through hole. Therefore, when the chip size is reduced, only the number of the through holes is reduced. Therefore, if the chip size is reduced, the length of the internal conductor pattern may also be reduced, thereby making it impossible to manufacture devices with high impedance. That is, there is a limit in miniaturizing the chip size, and even in miniaturization of the chip size, there is a limit in increasing the impedance size in a small size chip. In addition, a demanding process of forming an inner conductor by inserting a conductor paste into a through hole (reference 97 of FIG. 9) is required, and a conductor wire connecting the holes (reference 98 of FIG. 9) is exposed. In order to insulate, a cumbersome process of coating with insulating resin is added, which contributes to cost increase.

Accordingly, the present invention is to solve the disadvantages of the conventional method as described above, the present invention uses a method of laminating the ferrite green sheet as in the first method or inserting the conductor paste in the through hole as in the second method. After printing the conductor paste on the ferrite green sheet in a zigzag pattern, the printed ferrite green sheet is rolled round, and the pressed molding in the form of a chip capable of surface mounting is cut in units of chips, and the inside exposed to both ends Since a chip element is made by connecting an electrode terminal in series with a conductor pattern, an object of the present invention is to provide a method of manufacturing a chip type noise suppression filter which can reduce the number of manufacturing steps of a chip type filter and reduce the difficulty of the step.

Another object of the present invention is to achieve a state in which the inner conductor is in a spiral motion in a direction perpendicular to the electrode terminal, it is possible to reduce the generation of stray capacitance due to the increase in the cross-sectional area between the electrode terminal and the inner conductor compared to the prior art at It is to provide a method of manufacturing a chip-type noise suppression filter that can reduce the impedance reduction phenomenon.

Still another object of the present invention is to provide a method of manufacturing a chip-type noise suppression filter, which can greatly reduce the risk of wiring, since the inner conductor is continuously printed.

Another object of the present invention is to provide a method of manufacturing a chip-type noise suppression filter that can increase the impedance characteristics of the chip because it can reduce the size of the chip by adjusting the thickness and the number of windings of the ferrite green sheet.

Hereinafter, the present invention will be described in detail.

The present invention comprises the steps of printing a conductive paste in a regular zigzag pattern on a ferrite green sheet; Rolling the printed green sheet roundly to form a cylindrical shaped body; Pressing the molded body into a shape in which magnetic surface mounting is possible; And a chip-shaped noise suppression filter which is cut into chips so that the conductor pattern formed inside the molded body is exposed on the cut surface.

The printing of the conductor paste on the ferrite green sheet according to the present invention is successively repeated in successive parallel patterns adjacent to one side of the ferrite green sheet and inclined patterns so that the extension lines meet each other on the other side. Print.

According to the present invention, the cylindrical molded body is formed by winding the side adjacent to the discontinuously parallel printed pattern to be parallel to the axis of the cylindrical molded body, and the cutting of the molded body pressed to a form capable of automatic surface mounting is The printing is carried out in a direction perpendicular to the discontinuously parallel printing pattern.

When described in more detail based on the accompanying drawings of the present invention as follows.

1 is a plan view showing a pattern in which the conductor paste is printed in a zigzag manner on a ferrite green sheet according to the present invention.

According to the present invention, reference numeral 1- in the accompanying drawings, Figure 1, is a ferrite green sheet, which is produced by a conventional tape cast method. At this time, the material of the ferrite green sheet to be used is generally Mn-Zn-based, Ni-Cu-Zn-based ferrite or the like.

According to the present invention, the conductive paste is printed on the ferrite green sheet 10 in a regular zigzag pattern by screen printing. That is, as shown in FIG. 1, the printed pattern of the conductor paste is formed with respect to the discontinuously parallel conductor pattern l11 and the other side 102 adjacent to one side 101 of the ferrite green sheet 10. The inclined conductor pattern 112 is repeated in succession so that their extension lines meet each other.

Here, the parallel conductor pattern 111 is formed on the cut surface when the ferrite green sheet 10 is cut along the cutting line 12 indicated by a dashed line in FIG. 1 after being rolled round as shown in FIG. 2. The inclined conductor pattern 112 is exposed and connected to the step electrode, and the ferrite green sheet 10 is rolled round as shown in FIG. 2 and then cut along a cutting line l2 indicated by a dashed line in FIG. 1. As shown in FIG. 5, the inner conductor pattern 11 is formed in a spiral shape.

According to the present invention, since the inner conductor pattern 11 progresses in a spiral while forming a modified direction with respect to both cutting sections, the phenomenon in which the inner conductor pattern 11 overlaps can be prevented.

As described above, the ferrite green sheet 10 on which the conductor pattern 11 is printed is wound round in the direction (X direction) indicated by the arrow in FIG. 1 to form a cylindrical molded body 20 as shown in FIG.

In particular, the molded body 20 wound as described above has a side surface 101 of the ferrite green sheet 10 adjacent to the discontinuous parallel conductor pattern 111 and the axis of the cylindrical molded body 20. It is preferable to wind them in parallel.

According to the present invention, it is preferable that the cylindrical molded body 20 is press-molded in a form capable of automatic surface mounting. For example, in order to form a rectangular shape that can be surface-mounted at the same time as the pressing object, Likewise, a presser 14 having a plurality of square grooves 13 is used. That is, when the molded body 20 is inserted into the square groove 13 of the presser 14 and pressed, the molded body 20 is formed in a rectangular bar shape as shown in FIG.

However, the use of the presser 14 having the square groove 13 as an example has been described here, but molding into any form that can be surface mounted may be possible depending on the shape of the groove formed in the presser.

Next, a plurality of chips 202 as shown in FIG. 5 are manufactured by cutting the molded body 201 formed in the shape of a square bar, for example. At this time, the cut portion is cut along the cut line 12 indicated by a dashed line in FIG. 1 of the accompanying drawings. In particular, the cutting line 12 is preferably passed in a direction perpendicular to the conductor pattern 111 parallel to one side 101 of the ferrite green sheet 10.

Referring to FIG. 5, the inner conductor pattern 11 of the chip 202 is exposed at both ends, so that the inner conductor pattern 11 forms a vertical direction at the beginning of both ends, and toward the inside. It can be seen that the spiral form.

According to the present invention, after the molded body 202 is co-fired, the external terminal 15 is formed on both ends of the exposed surface of the inner conductor pattern 11 as shown in FIG. The chip | tip filter for noise suppression with which the pattern was electrically connected is manufactured.

In the case of producing a chip-shaped filter according to the present invention, Japanese Patent Laid-Open No. 3-185,703 for repeating the above-described lamination and printing, and Japanese Patent Laid-Open No. 60-63,906 for drilling through-holes and generating an inner conductor therebetween. Compared to the number of processes is reduced, there is an advantage that can reduce the difficulty of the process.

In the case of manufacturing the chip-shaped filter according to the present invention, since the inner conductor is in a spiral motion in a direction perpendicular to the electrode terminal, when manufactured by the method of Japanese Patent Laid-Open No. 3-185,703, the gap between both electrode terminals and the inner conductor is reduced. Increasing cross-sectional area can reduce the disadvantage of floating capacity. Therefore, there is an advantage that can reduce the impedance reduction phenomenon at high frequencies.

In addition, since the inner conductor is continuously printed, as in Japanese Laid-Open Patent Publication No. 3-185,703, the risk of wiring can be greatly reduced, especially in the case of the method according to Japanese Patent Laid-Open No. 60-63,906. As the size of the chip decreases, the length of the inner conductor also decreases, thereby reducing the impedance characteristic. However, the method according to the present invention reduces the chip size by controlling the thickness of the ferrite green sheet and the number of windings. Can be increased.

The present invention will be described based on the following examples, and the present invention is not limited to the following examples.

Examples 1 to 3 (Comparative Example 1)

Ni-Cu-Zn-based ferrite powder was prepared and mixed with a conventional binder and a solvent to prepare a ferrite paste. The ferrite green sheet was made by the tape cast method. At this time, the thickness of the ferrite green sheet was 50 μm.

Ag-Pb-based conductor paste was screen printed on the manufactured ferrite green sheet to form an inner conductor pattern as shown in FIG. Then, the ferrite green sheet on which the conductor pattern was printed was wound round as shown in FIG. 2, and then placed in a compactor having a square groove as shown in FIG. After cutting the molded body pressed into a square and baked at 1000 ℃ to form an external electrode terminal by a tip coating method.

Table 1 compares the impedance characteristic values (Examples 1 to 3) according to the three sizes of the chips manufactured by the above process and the impedance characteristic values (comparative example 1) of the chips manufactured by the conventional method. It was found that the impedance characteristic is better than that by the conventional method.

TABLE 1

Claims (4)

A method of manufacturing a chip noise suppression filter, the method comprising: printing a conductor paste on a ferrite green sheet in a constant zigzag pattern; Rolling the printed green sheet roundly to form a cylindrical shaped body; Pressing the molded body into a form capable of automatic surface mounting; And cutting the conductor pattern formed inside the molded body into chips so as to be exposed on the cut surface. The method of claim 1, wherein the printing step is characterized in that the continuous discontinuous parallel pattern for one side of the ferrite green sheet and the inclined pattern is repeatedly repeated so that the extension lines meet each other on the other side. How to. The method according to claim 1, wherein the forming of the cylindrical shaped body is wound such that a side adjacent to the discontinuously parallel printed pattern is parallel to a circular axis. The method of claim 1 or 2, wherein the cutting step comprises cutting in a direction perpendicular to the discontinuously parallel pattern.