JPH0445229Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The present invention relates to a low-inductance type SH capacitor.

(Prior art) Capacitors for snubber circuits in semiconductor devices, which are used in snubber circuits that have seen remarkable development in recent years, are
Absorbs surge voltage such as SCR and GTO.
It is used in parallel with the SCR and GTO elements to protect the GTO, and must absorb steep pulses at high speed, and the residual inductance of the capacitor greatly affects its function.

Therefore, reducing the residual inductance in the capacitor for the snubber circuit eliminates the risk of destroying the SCR or GTO due to the back electromotive force generated by the residual inductance, and is essential for fully demonstrating the function of the snubber circuit. extremely important.

Generally, the inductance of the capacitor element itself, which has a non-inductive structure, is not so large, but for example, in a 7.4 μF metallized plastic film capacitor, as shown in FIG. In the case of a capacitor with a general structure with lead wires 23 and 24 drawn out, the inductance value is
It showed a high value of 0.253μH, and could not be used as a capacitor for snubber circuits. Therefore, as shown in FIG.
7 into the winding core hole 28 of the capacitor element 25.
It is possible to reduce the inductance by passing it through, but the inductance value is also 0.191μH.
There is also a limit to the degree of reduction, and there is also the problem that it is limited to hollow capacitor elements. Further, as shown in FIG. 8, the lead wires 31 and 32 drawn out from the electrode lead-out portions 30 formed on both end faces of the capacitor element 29 are placed as close to the sides of the capacitor element 29 as possible, and are placed near the center in the length direction of the element 29. It is possible to reduce the inductance by connecting it to an external terminal (not shown), but the inductance value in this case is 0.206 μH, which is not much different from the structure shown in Figure 7 and is sufficient. I couldn't say that. Therefore, as shown in FIG. 9, two capacitor elements 34 and 35 are formed on the same axis with a separator 33 in between, and the elements 34 and 35 are arranged in a series structure, thereby increasing the inductance value.
A significant inductance reduction of 0.075μH can be achieved.

However, since it has a series structure, it is not suitable for low voltages, and in order to obtain the same capacity, four times as much capacity is required, resulting in a large size. In FIG. 9, 36 is an electrode lead-out portion, 37 is a connection wire, and 38 is a lead wire.

(Problems to be solved by the invention) As described above, the capacitors shown in Figures 7 and 8 cannot be expected to significantly reduce inductance, and are unsuitable as capacitors for snubber circuits. In terms of inductance characteristics, the capacitor shown has a sufficient function as a capacitor for a snubber circuit, but it is not suitable for low voltage applications and has the problem of significantly increasing the size of the element. There was a problem in using this as it is as a capacitor for a snubber circuit.

The purpose of the present invention is to eliminate the drawbacks of the above-mentioned structures and to provide an SH capacitor that can significantly reduce inductance and is optimal for use in snubber circuits.

[Structure of the invention] (Means for solving the problem) The SH capacitor of the invention has one end attached to the outer periphery of a wound capacitive layer in which a pair of metallized dielectrics are wound as a capacitor element structure. An insulating separator part is formed with a protrusion aligned with the end face and the other end protrudes, and a vapor-deposited conductor is wound around the outer periphery of the separator part to form a vapor-deposited lead electrode layer, and the end face of the wound capacitor layer and the end face of the insulating separator part are formed. A first metallicon electrode is formed by connecting the end face of the wound capacitive layer and the end face of the vapor-deposited extraction electrode layer on one end face of the capacitor element, which is aligned, and the wound capacitive layer and the vapor-deposited film are formed on the other end face of the capacitor element, which is the protrusion of the insulating separator portion. The present invention is characterized in that a second metallicon electrode and a third metallicon electrode are formed by separating the lead electrode layer, and lead wires are drawn out from the second metallicon electrode and the third metallicon electrode.

(Function) According to the SH capacitor having the above configuration, the vapor-deposited lead electrode layer is formed in a tightly wound state around the outer periphery of the wound capacitor part as the capacitor element structure, and the pair of lead wire attachments are connected to the wound capacitor layer. A second methacholine electrode and a third methacholine electrode formed by separating the vapor-deposited extraction electrode layer
Since it is a metallicon electrode, the current flowing through the vapor-deposited extraction electrode layer and the wound capacitor layer always flows in opposite directions, so that the induction is canceled out.

(Example) An example of the present invention will be described below with reference to the drawings. That is, as shown in FIG. 2, a pair of metallized dielectrics made of metallized plastic film or metallized paper are laminated and wound a desired number of times to form a wound capacitive layer 1. Next, as shown in FIG. 3, an insulating separator portion 2 is formed by winding, for example, insulating paper or plastic film one or more times around the outer periphery of the wound capacitive layer 1. In this case, a protruding portion 3 is formed such that one end of the insulating separator portion 2 is aligned with one end surface of the wound capacitive layer 1 and the other end projects from the other end surface of the wound capacitive layer 1. As shown in FIGS. 4 and 5, a vapor-deposited conductor 4 made by vapor-depositing metal powder such as zinc, aluminium, or copper on both sides of an insulating paper or plastic film is wound around the outer periphery of the insulating separator portion 2. A vapor-deposited lead electrode layer 5 is formed to constitute a capacitor element 6.

Next, as shown in FIG. 1, metal spraying is applied to one end surface of the capacitor element 6 where the end surface of the wound capacitive layer 1 and the end surface of the insulating separator section 2 are aligned.
A first metallicon electrode 7 is formed by connecting one end surface of the vapor-deposited extraction electrode layer 5 to the first metallicon electrode 7. On the other hand, the capacitor element 6 with the insulating separator part 2 protruding from the end face is separated from the wound capacitive layer 1 and the vapor-deposited lead electrode layer 5 by the protruding part 3 of the insulating separator part 2 on the other end face and connected to the end face of the wound capacitive layer 1. A third metallicon electrode 9 is formed which is connected to the second metallicon electrode 8 and the end face of the vapor-deposited lead electrode layer 5, and a lead wire 10 is attached to the second metallicon electrode 8 and the third metallicon electrode 9. .

According to the SH capacitor constructed as described above, the capacitor element 6 is constructed of the vapor-deposited lead electrode layer 5 which is wound and tightly attached to the wound capacitor layer 1 through the insulating separator portion 2 formed on the outer periphery of the wound capacitor layer 1. One end surface of the wound capacitance layer 1 and the vapor deposition lead electrode layer 5 are commonly connected by the first metalincon electrode 7, and the other end surface of the wound capacitance layer 1 and the vapor deposition lead electrode layer 5 is connected to the protrusion 3 of the insulating separator section 2. Separated by and wound capacitive layer 1
A second metallicon electrode 8 and a third metallicon electrode 9 are formed independently on the other end surface of the vapor-deposited extraction electrode layer 5, and the second metallicon electrode 8 and the third metallicon electrode 9 are independent of each other.
Since the lead wires 10 attached to the metallicon electrodes 9 are used as opposing poles, the current flowing through the wound capacitor layer 1 and the current flowing through the vapor-deposited lead electrode layer 5 always flow in opposite directions, so that the induction cancels out. This can significantly reduce residual inductance. Also the 9th
Since the capacitor layer does not have a series structure as in the conventional example shown in the figure, the size of the capacitor element itself is not so large, and it can be applied to low voltages.

The residual inductance of the metallized plastic film capacitor constructed according to the present invention having the same capacity as that described in the prior art, that is, 7.4 μF, was measured to be 0.072 μH, indicating excellent low inductance characteristics. The insulating separator in the sample was a polyethylene terephthalate film wrapped twice, and the metal extraction electrode layer was 10 μm thick.
A vapor-deposited conductor made of double-sided vapor-deposited insulating paper with Zn metal vapor-deposited on both sides of the insulating paper was used, and the vapor-deposited conductor was wound 30 times.

In the above embodiments, the vapor-deposited conductor 4 constituting the vapor-deposited lead electrode layer 5 was exemplified using insulating paper or plastic film with metal vapor-deposited on both sides. The same effect can be obtained even if a vapor-deposited material is used.

Further, although the above embodiment has been explained using one capacitor element as an example, even if a plurality of capacitor elements are used as necessary, the wiring work can be facilitated by using the capacitor element having the structure according to the present invention. Needless to say, this can cancel out the induction and is effective in reducing residual inductance.

[Effects of the invention] According to the invention, it is possible to obtain an SH capacitor of high practical value, which is suitable for use in snubber circuits and can significantly reduce residual inductance.

[Brief explanation of drawings]

Figures 1 to 5 relate to one embodiment of the present invention, with Figure 1 being a front cross-sectional view showing an SH capacitor, and Figures 2 to 5.
Figure 5 shows the manufacturing process of the SH capacitor shown in Figure 1, and Figure 2 is a perspective view showing the wound capacitor layer.
Fig. 3 is a perspective view showing a state in which an insulating separator portion is formed around the outer periphery of the wound capacitor layer, Fig. 4 is a perspective view of the evaporation conductor being wound in the middle of winding around the periphery of the insulating separator portion, and Fig. 5 is a perspective view of the evaporation drawer. A front sectional view showing a capacitor element after electrode layer formation, and FIGS. 6 to 9 are front sectional views showing respective SH capacitors according to conventional reference examples. 1...Wound capacitive layer, 2...Insulating separator part,
3... Projection portion, 4... Vapor deposited conductor, 5... Vapor deposited extraction electrode layer, 6... Capacitor element, 7... First metallicon electrode, 8... Second metallicon electrode, 9...
Third metallicon electrode, 10... lead wire.

Claims (1)

[Claims for Utility Model Registration] (1) A wound capacitive layer formed by laminating and winding a pair of metallized dielectrics, with one end aligned with one end surface of the capacitive layer on the outer periphery of the capacitive layer, and the other end of the capacitive layer. A capacitor element consisting of an insulating separator part formed with a protrusion protruding from the other end face, a vapor deposited lead electrode layer formed by winding a vapor deposited conductor around the outer periphery of the separator part, and an end face of the wound capacitor layer of the element and an insulating separator part. A first metallicon electrode is formed by connecting the end face of the wound capacitor layer and the end face of the vapor-deposited extraction electrode layer to one end face whose end faces are aligned, and a protrusion is formed on the other end face of the capacitor element, which becomes the protrusion of the insulating separator portion. A second metallicon electrode formed by separating and connected to the end face of the wound capacitor layer, a third metallicon electrode formed by connecting to the end face of the vapor-deposited extraction electrode layer, and a third metallicon electrode and the second metallicon electrode An SH capacitor characterized by having an attached lead wire. (2) The SH capacitor according to claim (1) of the utility model registration, characterized in that the vapor-deposited conductor is made of insulating paper or plastic film with metal vapor-deposited on one or both sides.