JPS59145557A - Semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a semiconductor device, which has a high-frequency characteristic suitable for a horizontal deflecting circuit, etc., and causes little leakage current in the reverse direction and by which conductive noises and avalanche noises can be removed, by a method wherein silicon pellets, whose P-N junctions are reversely faced to plural sheets of silicon pellets set in the same rectification direction on the cathode side, are serially connected. CONSTITUTION:Silicon pellets 27, each having a zener characteristic, are arranged in the reverse direction on the cathode side of plural sheets of silicon pellets 22a, 22b...22n, each having a P-N junction in the normal direction toward the cathode side from the anode side, and the pellets 27 are laminatedly adhered with a wax material in between a pair of electrodes 24a and 24b through the intermediaries of silicon spacers 23a and 23b. Then, the pellets 27 are coated with glass 25, which is used as an insulating material, and are welded with leads 26a and 26b for outside connection. On each silicon pellet has been diffused platinum, for example, as a lifetime killer for obtaining the prescribed high- frequency characteristic.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a semiconductor device, and in particular, silicon pellets having a plurality of pn junctions between a pair of electrodes are laminated and bonded using a brazing material, and the periphery is molded with an insulating material. The present invention relates to a semiconductor device.

[Prior art]

This type of semiconductor device is often used in horizontal deflection circuits of television receivers and high voltage rectifiers in other high voltage generators.

FIG. 1 shows the structure of semiconductor device #1 using glass as a mold insulating material. A plurality of silicon pellets 2a, 2b, having a pn junction and having the same rectification direction.
・2n and a silicon spacer 3a without a pn junction,
Tungsten or molybdenum electrodes 4a are placed on both ends of 3b.
, 4b are laminated and bonded using a brazing material (not shown),
Its periphery is molded with glass 5, which is an insulating material, from one electrode 4a to the other electrode 4b. External leads 6a, 6b are welded to the electrodes 4a, 4b for electrical and mechanical connection. The glass 5 serves to stabilize the pn junction ends exposed on the side peripheral surfaces of each silicon pellet 2a, 2b, . . . , 2n, and also serves as a package for protection from external stress.

When semiconductor device #1 having the structure shown in FIG. 1 is used in a horizontal deflection circuit of a television receiver, a high frequency operation of 15.75 KHz is required, so each silicon pellet (2a, 2b, . . . ) having a pn junction is required. Gold, platinum, and other heavy metals are diffused into 2n as a lifetime killer. It has been confirmed that for some types of lifetime killers, the forward recovery time and reverse recovery time are 500 ns or less and 1QQns or less, respectively, depending on their diffusion temperature and time. Since the forward recovery time is shortened, the back electromotive force c = -Ld is the product of the current rise rate di/dt during forward recovery and the inductive impedance L of the circuit.
i/dt is generated as noise, propagates to the tuner circuit of the television receiver, is amplified, and adversely affects the image quality of the television receiver (hereinafter, this noise is referred to as conduction noise).

Further, in principle, the semiconductor device 1 has a pn junction diode unit rectifier 11a, as shown in FIG.

11b-1in is the lead wire 12a, 12b-...12
This is equivalent to being connected in series via n-1.

In this semiconductor device which operates at a 1% frequency of 15.75 KHz, each unit rectifier 11a.

An unbalance occurs in the voltages shared between 11b...lln. An example of the unbalanced state is shown in FIG. Therefore, the first
Silicon pellets 2a, 2b with pn junctions shown in the figure...
・The voltage shared by each 2n is also large on the anode side,
It shows a tendency to become smaller on the cathode side. When a voltage higher than the reverse voltage unique to the pellet is applied to a silicon pellet with a pn junction placed on the anode side, the silicon pellet reaches the avalanche breakdown region and locally generates microplasma as noise. do. When used in the horizontal deflection circuit of a television receiver, this noise is also propagated to the tuner circuit and has a negative effect on the image quality of the television receiver (hereinafter this noise will be referred to as avalanche noise).

In order to solve these two problems of conduction noise and avalanche noise, for example, a silicon pellet with a large amount of gold-diffused pn junctions and a silicon pellet with platinum-diffused pn junctions are appropriately combined to form the entire semiconductor device. Attempts were made to reduce conduction noise by increasing the forward recovery time. However, a problem arises in that the reverse leakage current increases and the loss-of-function temperature is lowered. An attempt was made to solve the latter problem by, for example, laminating several sheets of silicon pereno, which increased the reverse withstand voltage, on the anode side.
Avalanche noise caused by microplasma continues to occur, and the inability to coordinate process conditions and the complexity of the manufacturing process have caused problems.

[Purpose of the invention]

Therefore, an object of the present invention is to provide a semiconductor device suitable for use in horizontal deflection circuits of television receivers, etc., which has high frequency characteristics, has low reverse leakage current, and can eliminate both conduction noise and avalanche noise. It's about doing.

[Summary of the invention]

A feature of the present invention that achieves the above object is that a plurality of silicon pellets having the same rectification direction and a plurality of silicon pellets having pn junctions in opposite directions are connected in series on the cathode side.

[Implementation sequence of the invention]

FIG. 4 shows a semiconductor device 21 according to an embodiment of the present invention, which includes a plurality of silicon pellets 22a, 2 having a pn junction in the forward direction from the anode side to the cathode side.
A silicon pellet 27 having Zener characteristics is arranged in the opposite direction on the cathode side of 2b...22n, and a silicon spacer 23a.

A pair of electrodes 24a and 24b are laminated and bonded with a brazing material via 23b. The structure is such that one electrode 2'4a to the other electrode 24b is covered with glass 25 as an insulating material. Leads 26a and 26b for external connection are welded to the electrodes 24a and 24b.

For example, platinum is diffused into each of the silicon pellets 22a, 22b, . . . , 22n as a lifetime killer in order to obtain predetermined high frequency characteristics.

That is, since the silicon pellets in which different types of lifetime killers are diffused are not appropriately combined, the reverse leakage current is small.

The electrode 24a side is the anode side, and the polarization 24b side is the cathode side. FIG. 5 shows an equivalent circuit of the semiconductor device 21 shown in FIG.

22b...22n1 Silicon pellets 27 having Zener characteristics are each /r31a, 31b, 31n.

33, and lead wires 32a, 32b...
32n is shown connected.

Each silicon pellet 22a, 22b...22n (fifth
In the figure, conduction noise and avalanche noise generated in silicon pellets 27 (5th
In the figure, it is suppressed by the operating resistance of the silicon pellet 27 given by the reverse VI characteristic of 33), and does not appear as a noise level on the cathode side electrode 24b or lead wire 26b. Therefore, when such a semiconductor device is used in a television receiver, both types of noise will not be propagated to the tuner circuit18.

FIG. 6 shows a conduction noise voltage 41 and an avalanche noise voltage 42a when the conventional semiconductor device 1 shown in FIG. 1 is used in a high-sensitivity television receiver.

42b is shown as the secondary voltage waveform 44 of the flyback transformer on the video signal 43 when there is no signal and in phase with the video signal 43.
This was observed along with In this figure, a semiconductor device 1
It is shown that two types of noise 41, 42a and 42b generated from the video signal propagate to the tuner circuit, are amplified by the tuner circuit, and are superimposed on the video signal.

Conduction noise 41 and avalanche noise 42a.

When 42b is superimposed on the video signal 43, adverse effects such as shaking or bending of the screen of the television receiver appear.

FIG. 7 shows the secondary output voltage 54 of the flyback transformer and the video signal voltage 53 when there is no signal when the semiconductor device 21 according to the present invention is used in a television receiver.

In this figure, it can be seen that no conduction noise voltage or avalanche noise voltage is superimposed on the video signal 53.

That is, it was confirmed that as an effect of the silicon diode 27 inserted in the semiconductor device #21, two types of noise voltages, conduction noise and avalanche noise, were suppressed and their propagation to the tuner circuit became extremely small.

Although one silicon pellet 27 is used in the above embodiment, a plurality of silicon pellets may be used to obtain predetermined characteristics as a whole.

In addition, the silicon spacer was used to match the thermal expansion coefficients of the insulating glass and the laminated adhesive.
The presence or absence of silicon spacers is not important to the invention.

〔Effect of the invention〕

As explained above, according to the present invention, it has high frequency characteristics,
It is possible to obtain a semiconductor device that has a small reverse leakage current and can suppress both conduction noise and avalanche noise.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a conventional semiconductor device, Fig. 2 is an equivalent circuit diagram of the semiconductor device shown in Fig. 1, and Fig. 3 is a voltage distribution when a reverse voltage is applied to the semiconductor device shown in Fig. 1. 4 is a longitudinal sectional view showing an embodiment of the present invention, FIG. 5 is an equivalent circuit diagram of the semiconductor device shown in FIG. 4, and FIGS. 6 and 7 are respectively similar to FIG. 1. FIG. 5 is a diagram showing waveforms of a video signal voltage and a secondary output voltage of a flyback transformer when the semiconductor device shown in FIG. 4 is used in a television receiver. 21-...Semiconductor device, 22a, 22b-22n. 27... Silicon pellet, 23a, 23b... Noricon spacer, 24a, 24b... Electrode, 25...
・Ga 27 fig. 2 fig. f 3 fig. completed Note)ul)
Hl'1zrL/-dotsu 5 Saito Off 5gυ No6v

Claims (1)

[Claims] 1. A silicon pellet having a plurality of pn junctions between a pair of electrodes with the direction from the anode side to the cathode side as the forward direction, and a pn junction opposite to each silicon pellet on the cathode side. A semiconductor device characterized in that oriented silicon pellets are laminated and bonded with a brazing material. 2. The semiconductor device according to item 1 above, wherein the same type of lifetime killer is diffused into the plurality of silicon pellets in the forward direction. 3. The semiconductor device according to item 1 above, characterized in that one or more silicon pellets with pn junctions inverted are arranged.