JPS637612A - Manufacture of chip type lc filter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a chip-type LC filter,
In particular, the soldering between the inner electrode and the center conductor of the cylindrical capacitor relates to improvements in the method.

[Conventional technology]

As an example of a chip-type LC filter that can be surface mounted on a substrate, a structure as shown in FIG. 1 can be considered.

That is, the chip-type LC filter 2 of this example is of a so-called T-shape, and a cylindrical capacitor 6 having an inner electrode 62 and an outer electrode 63 on the inner and outer peripheral surfaces of a cylindrical dielectric 61 is connected to a center conductor (center lead). wire) 4, and a cylindrical magnetic core (e.g. ferrite bead) 8a on both sides.
, 8b to both ends of the center conductor 4.
The inner electrode 62 of the capacitor 6 and the center conductor 4 are electrically connected to each other by solder 12. In this specification, a product before soldering between the inner electrode 62 and the center conductor 4 is completed is referred to as a "semi-finished product."

[Problem that the invention seeks to solve]

However, when manufacturing the LC filter 2 as described above, it is necessary to ensure continuity between the inner electrode 62 and the center conductor 4 of the capacitor 6, which has the magnetic cores 8a and 8b on both sides. The problem is that it is difficult. This is because the parts are in close contact with each other, so simply immersing the semi-finished product described above in molten solder makes it difficult for solder to enter the above-mentioned locations.

Therefore, the present invention has developed a chip-type LC that can ensure continuity between the inner electrode and the center conductor of the capacitor as described above.
The purpose of the present invention is to provide a method for manufacturing a filter.

[Means for solving problems]

The manufacturing method of the present invention includes passing a cylindrical capacitor having electrodes on the inner and outer peripheral surfaces and a cylindrical magnetic core through a central conductor.
Using a semi-finished product with terminals connected to the center conductor arranged at both ends of the center conductor, a chip type LC can be created by soldering between the inner electrode of the capacitor and the center conductor.
A method for manufacturing a filter includes a first step of placing a plurality of semi-finished products in a container containing molten solder and reducing the pressure inside the container, and then immersing the semi-finished products in molten solder to reduce the pressure inside the container. It is characterized by comprising a second step of pressurizing the product, and a third step of pulling the product out of the molten solder and cooling it.

[Effect]

The first step removes air trapped in gaps within the semifinished product. In the second step, the molten solder is forcibly pressed between the inner electrode and the center conductor of the semi-finished capacitor. Then, after going through the third process, the chip shape L is made to ensure continuity between the inner electrode of the capacitor and the center conductor.
A C filter is obtained.

〔Example〕

FIG. 2 is a schematic diagram showing an example of an apparatus used to carry out the present invention. 14 is a sealable container in which solder can be melted to produce molten solder 15. Inside this container 14, a container 20 that can hold a plurality of semi-finished products described above can be stored, and this container 20 can be moved up and down in the direction of arrow A via a shaft 18. For example, it is possible to rotate at a high speed as shown by arrow B. Preferably, the container 20 has a shape such as a mesh corner so that the molten solder 15 can easily enter therein and the semi-finished products inside cannot easily come out. The inside of the container 14 can be depressurized by the vacuum pump 22 and can be pressurized by high-pressure gas (for example, nitrogen gas) from the gas source 24.

An example of the steps for manufacturing the chip-type LC filter 2 using the above-mentioned semi-finished products using such an apparatus will be listed in order as follows.

■ Melt the solder in the container 14 to create molten solder 15.

■ For example, a plurality of preheated semi-finished products are placed in the container 20 and placed in the space of the container 14, and the container 14 is sealed;
The pressure inside the container 14 is reduced by the vacuum pump 22. As a result, air trapped in the gaps within each semi-finished product is removed, and subsequent press-fitting of molten solder 15 becomes easy and reliable.

■ As shown by the broken line in the figure, place the container 20 into the molten solder 15.
The semi-finished product therein is immersed in the molten solder 15.

(2) A high-pressure gas, preferably nitrogen gas, is introduced into the container 14 from the gas source 24 to pressurize the inside.

The reason for using nitrogen gas is that it is preferable to prevent oxidation of the molten solder 15. As a result, the molten solder 15 is forced into the gap in each semi-finished product, and the inner electrode 62 of the capacitor 6 and the center conductor 4 are electrically connected by the solder.

(2) Lift the container 20 above the molten solder 15 and preferably rotate the container 20 by the motor 16 to shake off excess solder. This is done because it is preferable to prevent soldering between semi-finished products and to improve the appearance. However, the solder (12) that establishes conduction between the inner electrode 62 of the capacitor 6 and the center conductor 4 is not blown away due to the wettability of the solder.

■ Wait until the semi-finished product in the container 20 is cooled to a temperature lower than the melting point of the solder. As a result, soldering between the inner electrode 62 of the capacitor 6 and the center conductor 4 is completed, and the chip-type LC filter 2 as described above is obtained.

(2) Return the inside of the container 14 to atmospheric pressure and take out the completed chip-type LC filter 2 from there.

Therefore, according to the manufacturing method described above, since solder is forcibly inserted between the inner electrode 62 of the capacitor 6 and the center conductor 4 for soldering, reliable conduction can be obtained between the two.

Therefore, a chip-type LC filter 2 with high reliability etc. can be obtained.

Moreover, since a large amount of processing can be performed at one time, productivity is also good.

Incidentally, such a manufacturing method is applicable to the above-mentioned so-called T-shaped L.
In addition to manufacturing C filter 2, we also manufacture other types of LC.
Filters, such as the so-called L-shaped LC filter that has a magnetic core only on one side of the capacitor, as described above,
Of course, the present invention can also be applied to the production of a so-called π-type LC filter having capacitors on both sides of a magnetic core as described above.

〔Effect of the invention〕

As described above, according to the present invention, conduction can be ensured between the inner electrode of the capacitor and the center conductor. Therefore, a chip-type LC filter with high reliability etc. can be obtained. Moreover, since a large amount of processing can be performed at one time, productivity is also good.

[Brief explanation of the drawing]

Figure 1 shows the chip shape L to be manufactured by this invention.
An example of a C filter is shown, in which (A) is a perspective view thereof, (B) is a sectional view thereof, and (C) is an equivalent circuit diagram thereof. FIG. 2 is a schematic diagram showing an example of an apparatus used to carry out the present invention. 2... Chip type LC filter, 4... Center conductor, 6
... Capacitor, 62 ... Inner electrode, 8a, 8b.
... Magnetic core, 14... Container, 15... Molten solder.

Claims (1)

[Claims] (1) Using a semi-finished product in which a cylindrical capacitor with electrodes on the inner and outer peripheral surfaces and a cylindrical magnetic core are passed through a center conductor, and terminals connected to the center conductor are placed at both ends of the center conductor, In the method of manufacturing a chip-type LC filter by soldering between the inner electrode and the center conductor of the capacitor, a plurality of semi-finished products are placed in a space in a container containing molten solder, and the pressure inside the container is reduced. The method is characterized by comprising the first step, the second step of immersing the semi-finished product into molten solder and pressurizing the inside of the container, and the third step of pulling the second half product out of the molten solder and cooling it. A method for manufacturing a chip-type LC filter.