JP2568553Y2 - Semiconductor device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly to an improvement in a structure for taking out electrodes of a semiconductor device.

[0002]

2. Description of the Related Art FIGS. 7 and 8 show a control electrode structure of a conventional semiconductor device, wherein 1 is a cathode electrode and 2 is a cathode electrode.
A gate electrode 3 serving as a control electrode formed on the outer periphery of the electrode 1, a ring-shaped lead frame 3 for supplying a gate signal to the gate electrode 2, 4 a tail of the lead frame, 5 an insulator, 6 Is a spring, and 7 is a heat buffer plate.

When a thyristor, which is a current-driven semiconductor switch, is turned on, as shown in FIG. 9, when an ON signal is input to a single gate, a region 8 that is energized over the entire surface of the element is expanded with time. In other words, it takes time for the energized area to increase. Therefore, when the anode is turned on at a steep anode current increase rate, the loss due to the turn-on is concentrated when the energized area is small, and the power loss density increases. The power loss turns into heat, but at a certain temperature, it causes thermal destruction. In order to alleviate this power concentration, a center gate thyristor having a gate formed at the center and a ring gate thyristor having a gate formed in a ring surrounding a cathode have been developed.

The ring gate type thyristor has a case structure as shown in FIG. 8, and the gate electrode 2 is taken out of the case using a lead frame 3. The lead frame 2 has a donut-shaped ring and a tail 4 for taking out a gate. In this structure, when the turn-on is performed at an anode current increase rate exceeding 10 ⁸ A / sec, the lead frame 3
Since the conduction region 8a of the cathode 1 starts from the periphery of the tail portion 4, the electrode density increases and thermal destruction occurs.

In order to alleviate this thermal destruction, it is conceivable to provide two gate (base) outlets and arrange them so that the elements are at the same diagonal distance.

However, when the area of the element is increased or a higher di / dt resistance and a higher peak current are required, the conduction area increases from both ends on the diagonal line. It is assumed that only the cathode located at a distance r from the gate outlet when the flowing current reaches a peak value is turned on. In this case, the element conducts an area of about 2/3 little in all the cathode area πr ² at the peak current value ^{(2/3) r 2 {(2π} -3 × (3 1/2) / 2}.

For this reason, in order to increase the cathode area, it is conceivable to turn on using the same main circuit as described above with the cathode radius being 2r. Even in this case, it can be assumed that the cathode located at a distance r from the gate outlet at the time of the peak current is turned on, so that the conduction area hardly changes. That is, even if the cathode area is increased four times, the power is concentrated on about 1/5 to 1/6 of the area, and the anode current increase rate and the peak current cannot be obtained as much as the increase in the cathode area.

In view of the above-mentioned problems, a semiconductor device having a control electrode portion for supplying a control signal to a semiconductor element having at least two junction regions by alternately arranging semiconductor layers having different polarities is provided. A lead frame provided along the outer peripheral portion of the semiconductor element, and electrode terminal portions disposed on the lead frame at equal intervals in the circumferential direction;
The control electrode portion is formed by a plurality of connection frames connecting two adjacent ones of the electrode terminal portions, and a bridging frame bridging these connection frames, and the anode current rise rate di / dt is determined. A semiconductor device (hereinafter, referred to as a semiconductor device A) that can improve any of the peak currents flowing at this time, increase the area of the element, and efficiently utilize the element can be considered.

However, in order to make di / dt steep and allow current to flow through the element at a high speed, it is necessary to make a gate (base) current sufficiently flow at the beginning of the turn-on time.

That is, in order to obtain a high di / dt, it is necessary to supply a gate (base) current steeply.

Therefore, the element having a small area does not have the problem of the gate current increase rate di _G / dt, but the larger the area, the longer the path through which the gate current flows, and the di _G / dt required by the inductance. Can not be obtained.

That is, the distance from the lead frame gate (base) outlet to the tail of the lead frame is about twice as long. In addition, the path of the semiconductor device A is tripled. For this reason, a device having a large element area cannot supply a gate (base) current sufficiently in the early stage of the turn-on time, and the di / dt cannot be increased as the area increases.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a control electrode portion which is electrically connected to a control layer of a semiconductor device and is provided along an outer peripheral portion of the semiconductor device. An object of the present invention is to provide a semiconductor device having excellent turn-on characteristics and high reliability by supplying a control current in a non-inductive state.

[0014]

According to the present invention, there is provided a semiconductor device comprising at least an anode layer, a cathode layer or an emitter layer and a gate layer by alternately arranging semiconductor layers having different polarities. In a semiconductor device provided with a control electrode portion for supplying a control signal to an element, the semiconductor device is provided along an outer peripheral portion of a cathode electrode of the semiconductor element.
The ignition current to the cathode electrode of the semiconductor device.
The control electrode portion is formed by a lead frame for flowing, and a plurality of electrode terminals arranged in the frame at equal intervals in the circumferential direction or symmetrically with respect to the center of the cathode, and each of the electrode terminals of the control electrode portion is respectively formed. In addition to connecting equal-length lead wires, the cathode layer or the emitter layer is connected to other lead wires so as to be equal in length to the lead wires connected to the respective electrode terminals and to be non-inductive. Features.

[0015]

The cathode region or the emitter region conducts simultaneously and with the same area from the point of symmetry, and the control signal is supplied so as to be non-inductive with other current signals, whereby the control current rise rate and the anode current rise rate are increased. And turn-on characteristics are improved.

[0016]

EXAMPLES be described with reference to FIGS. 1 to 5 an embodiment of the present invention below.

FIGS. 1 and 2 show a semiconductor device according to an embodiment of the present invention. A ring-shaped gate, which is a control electrode, is disposed near the outer periphery of a disk-shaped cathode 1. Is electrically connected to a ring-shaped lead frame 3.

The electrode terminal strips (9a, 9b) and (9a, 9b), which are gate outlets, are provided on the lead frame 3 at equal intervals along the circumference thereof or symmetrically with respect to the center of the cathode 1.
c, 9d) are provided. The electrode terminal pieces 9a and 9c are connected by a connection frame 10a, and the electrode terminal pieces 9b
And 9d are connected by a connection frame 10b.

It is desirable that these outlets are arranged at equal intervals. In the above embodiment, since there are four gate outlets, they are arranged every 90 °. The gate electrode terminals 11a and 11b are connected to intermediate points between the gate electrode terminals 11a and 11b.

With this connection, the gate signal input from the gate terminal reaches each gate outlet through the same distance. In the vicinity of the gate outlet, a turn-on region is formed almost simultaneously. Heat is generated by the turn-on loss from the point where it starts to turn on, but this is dispersed,
The withstand capacity is improved.

The gate electrode terminals 11a and 11b are connected to a drive circuit as shown in FIG. FIG. 2 shows a flat type semiconductor device, in which 12 is an anode electrode, 13 is a flat case, 14a and 14b are cathode electrode terminals, 15
Reference numerals a and 15b denote gate leads, 16a and 16b denote cathode leads, and 17 denotes a drive circuit.

As shown in FIG. 2, the gate electrode terminal 11
a and 11b are connected to the drive circuit 17 by the gate lead wires 15a and 15b and are driven simultaneously. At this time,
For each gate electrode terminal 15a, 15b, the cathode electrode terminal 14a, 14b is connected to the cathode coaxial cable 16a,
The drive circuit 17 is wired by 16b to be non-inductive.

With such a structure, the current from the external drive circuit 17, which is the source of the gate current, can be made extremely steep, and the anode current rise rate d can be increased.
i / dt can be flowed.

According to the semiconductor device of the above embodiment, a high gate current increase rate and a high anode current increase rate can be obtained.
That is, when driven in the drive circuit through a single gate terminal from the case as in the semiconductor device of the above (A), becomes a curve L ₁ in FIG. 4, the two using the lead frame shown in FIG. 1 In the case where driving is performed with the gate electrode terminals 11a and 11b passing through and two gate electrode terminals
Gate current rise rate as indicated by a curve L ₂ is more than doubled.

Further, FIG. 5 shows the anode current rise rate according to the above embodiment, FIG. 6 shows the anode current rise rate of the above-mentioned semiconductor device (A), the curve L ₄ of the drawings
As apparent from L _5, if driven by the same main circuit, the current increase rate, according to the present embodiment increased by more than 20%,
It can be seen that the anode current peak value also increased by 10% or more. This indicates that the element is in a state where it is easy to turn on, and it is considered that both the tolerance of the anode current increase rate and the tolerance of the anode current peak value have increased. As described above, the turn-on characteristics can be improved without changing the drive circuit or the element itself.

FIG. 3 shows a semiconductor device according to another embodiment of the present invention. In this embodiment, the ring frame 3 is provided with gate electrode terminals 11a to 11d at equal intervals to form a control electrode portion. I have. In this case, each of the gate electrode terminals 11a to 11d is connected to an external drive circuit by a gate lead wire of the same length and driven simultaneously.
Functions and effects similar to those of the above-described embodiment can be obtained.

[0027]

The present invention is as described above, in which a plurality of control electrode terminals are provided at regular intervals on a lead frame provided on a semiconductor element, and lead wires having the same length are respectively connected to these control electrode terminals. Connected, these leads are non-inductive with other leads supplying cathode signal or emitter signal, etc., so that high control current rise rate and anode current rise rate are obtained, and excellent turn-on characteristics and A highly reliable semiconductor device can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view of a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a front view of the flat semiconductor device to which the present invention is applied.

FIG. 3 is a plan view of a semiconductor device according to another embodiment of the present invention;

FIG. 4 is a gate current waveform diagram of the present invention and a conventional semiconductor device.

FIG. 5 is a waveform diagram of an anode voltage and an anode current of the semiconductor device according to the embodiment of the present invention;

FIG. 6 is a waveform diagram of an anode voltage and an anode current of a conventional semiconductor device.

FIG. 7 is a plan view of a conventional semiconductor device.

FIG. 8 is a partial cross-sectional view of a conventional semiconductor device.

FIG. 9 is an explanatory diagram showing a turn-on state of a conventional semiconductor device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cathode electrode, 3 ... Lead frame, 9a, 9b ...
Electrode terminals, 10a, 10b ... connection frame, 11a-1
1d: gate electrode terminal, 13: flat case, 14a, 1
4b: cathode electrode terminal, 15a, 15b: gate lead wire, 16a, 16b: cathode lead wire, 17 ...
Drive circuit.

Claims (1)

(57) [Scope of request for utility model registration] 1. A semiconductor comprising a semiconductor device having at least an anode layer, a cathode layer or an emitter layer, and a gate electrode layer. In the device, the semiconductor device is provided along an outer peripheral portion of a cathode electrode of the semiconductor element.
The ignition current to the cathode electrode of the semiconductor device.
The control electrode portion is formed by a lead frame for flowing, and a plurality of electrode terminals disposed at equal intervals in the circumferential direction or symmetrically with respect to the center of the cathode on the frame, and each electrode terminal of the control electrode portion is respectively formed. In addition to connecting equal-length lead wires, the cathode layer or the emitter layer is connected to other lead wires so as to be equal in length to the lead wires connected to the respective electrode terminals and to be non-inductive. Characteristic semiconductor device.