JP2985757B2 - Method of assembling feed-through ceramic capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of assembling a feedthrough ceramic capacitor, and more particularly to a method of assembling a feedthrough ceramic capacitor for high frequency bypass.

[0002]

2. Description of the Related Art A feed-through ceramic capacitor used for a high-frequency bypass has a structure as shown in a sectional view of FIG. A part of the outer conductor 6 to be grounded has a threaded threaded portion 12, which penetrates a mounting plate (for example, a sub-chassis containing a high-frequency circuit) 10 having a ground potential and is fastened with a nut 11 to electrically Ground and mechanically secure.

The lead terminal 1 penetrates the center of the external conductor 6, and the multilayer ceramic capacitor element 2 is arranged in a cylindrical shape around the lead terminal 1, and is electrically connected to the lead terminal 1 and the external conductor 6 by solder 3. You. Such a structure minimizes the lead inductance and is therefore most suitable as a bypass capacitor.

In order to mechanically firmly fix the lead terminal 1 and the external conductor 6, an exterior resin 4 is loaded inside the external conductor 6.

[0005]

Conventionally, when the multilayer ceramic capacitor element 2 is soldered with the solder 3, in FIG. 3, the insulating tube 7 is previously connected to the lead terminal 1 in order to keep the lead terminal 1 at the center of the external conductor 6. 1, after completing the soldering between the multilayer ceramic capacitor element 2 and the lead terminal 1 and the external conductor 6, the exterior resin 4 is loaded.

However, since the insulating tube 7 is inserted for center alignment, the gap is narrow, so that the loaded resin does not flow into the inside, and the escape path of the air accumulated in the cavity 8 shown in FIG. Because there is no, existence of cavity 8 (residual)
Is inevitable.

When the gap 8 is present, when another lead is heated to the lead terminal 1 by, for example, soldering at a temperature higher than the melting point of the solder 3, the solder 3 is melted as shown in FIG. 9 caused a short circuit between the lead terminal 1 and the external conductor 6 in some cases.

As one method for preventing such a short circuit accident, a multilayer ceramic capacitor element 2 and a lead terminal 1 are provided.
As the solder 3 used for soldering between the multilayer ceramic capacitor element 2 and the external conductor 6, a high melting point solder may be used. The electrode may be cracked by silver erosion, and this method is not effective at present.

An object of the present invention is to provide a method of assembling a feed-through ceramic capacitor which does not cause a short circuit even when heated, for example, by soldering another lead to a lead terminal.

[0010]

[0011]

According to the present invention, there is provided a method of assembling a feed-through ceramic capacitor, comprising: a lead terminal serving as an internal terminal of a cylindrical ceramic capacitor element; an external terminal of the capacitor element; A step of preparing an external conductor that can surround the lead terminal and has an air hole, a step of inserting the lead terminal into the capacitor element, and a step of inserting an insulating tube into the lead terminal; Performing a soldering process for surrounding the capacitor element and making an electrical connection between the lead terminal and the external conductor and the capacitor element, and removing the insulating tube from the lead terminal; Filling the gap inside the outer conductor with a resin.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The operation of the present invention is as follows.
By providing an air vent hole in the external conductor and removing the insulating tube in the middle of the manufacturing process, the cavity is not generated inside the through-type ceramic capacitor, and the molten solder cannot move (thus, the lead terminal and the external The conductor is not short-circuited).

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view showing the internal structure of an embodiment of a feed-through ceramic capacitor according to the present invention. FIG. 2 is a cross-sectional view for explaining a manufacturing process. Is shown. In addition, the overlapping description of the same parts as in FIGS. 3 and 4 is omitted.

In manufacturing the cylindrical through-type ceramic capacitor shown in FIG. 1, first, as shown in FIG. 2, when the multilayer ceramic capacitor element 2 and an insulating tube (for example, Outer conductor 6
7 having a length protruding 2 mm or more from the center hole 7 is inserted for center alignment, and is inserted into the outer conductor 6 provided with the air hole 5.

The lead terminal 1 is provided with a protrusion 13, and the inserted multilayer ceramic capacitor element 2 comes into contact with the protrusion 13 of the lead terminal 1 and stops. After soldering the inner and outer surfaces of the multilayer ceramic capacitor element 2 to the lead terminals 1 and the external conductors 6 with, for example, solder 3 having a melting point of 220 degrees Celsius, it was confirmed that the lead terminals 1 were fixed. Then, the insulating tube 7 is removed.

Thereafter, as shown in FIG. 1, an appropriate pressure is applied to load the exterior resins 4a and 4b. In this case, the insulating tube 7 as shown in FIG. 3 is no longer present, so that the gap is wide, and the air inside the outer conductor 6 escapes through the air hole 5, so that the exterior resin 4 completely covers the inside of the outer conductor 6. Fill to leave no cavities.

Therefore, even if the solder 3 is melted by heating, for example, by soldering another lead to the lead terminal 1, there is no room for the melted solder to short-circuit the lead terminal 1 and the external conductor 6.

At the stage when the soldering process of the solder 3 is completed, if the lead terminal 1 is not fixed,
a, and after the lead terminal 1 is fixed, the insulating tube 7 is removed. Thereafter, the exterior resin 4b is filled.

[0020]

As described above, according to the present invention, since the inside of the outer conductor can be completely filled with the exterior resin, the lead terminal is heated by, for example, soldering another lead to the inside of the multilayer ceramic capacitor. Even if the solder connecting the element and the lead terminal or the external conductor melts, there is an effect that the molten solder does not cause an accident such as a short circuit between the lead terminal and the external conductor.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a manufacturing process according to an example of the present invention.

FIG. 3 is a sectional view of an example of a conventional feed-through ceramic capacitor.

FIG. 4 is a cross-sectional view illustrating an example of a short circuit accident of a conventional feedthrough ceramic capacitor.

[Description of Signs] 1 Lead terminal 2 Multilayer ceramic capacitor element 3 Solder 4a, 4b Outer resin 5 Air hole 6 Outer conductor 7 Insulating tube 8 Cavity 9 Melted solder 10 Mounting plate 11 Nut 12 Screw part 13 Convex part

Claims (1)

(57) [Claims] 1. A lead terminal serving as an internal terminal of a cylindrical ceramic capacitor element, and an external conductor serving as an external terminal of the capacitor element and capable of surrounding the capacitor element and the lead terminal and having an air hole. A step of preparing; a step of inserting the lead terminal into the capacitor element; and a step of inserting an insulating tube through the lead terminal; and a step of surrounding the capacitor element with the external conductor, the lead terminal, the external conductor, and the capacitor. A step of performing a soldering process for making an electrical connection with an element; a step of pulling out the insulating tube from the lead terminal; and a step of filling a resin in a gap inside the external conductor. A method of assembling a feed-through ceramic capacitor characterized by the following.