CN2710170Y - Surge absorber - Google Patents

Abstract

The utility model discloses a surge absorber, which comprises a glass tube shell, in which two electrodes and a chip are sealed and arranged, the chip is clamped between the two electrodes, the electrodes are connected with lead wires, and the glass tube shell There is a gas chamber filled with gas inside, and the feature is that the chip is composed of symmetrical multi-layer semiconductor layers and insulator layers. Its structure is set as: insulator layer—N+ semiconductor layer—N type semiconductor layer—N+ semiconductor layer—insulator layer, insulator The layer is in contact with the electrode, which has the advantages of fast response speed, low impact breakdown voltage, no photosensitive effect, small size, high insulation resistance, etc., and also has a symmetrical chip structure, which can ensure the DC shock in two directions of the surge absorber. The breakdown voltage is basically symmetrical, and the N+ semiconductor layer of this structure can make the DC breakdown voltage of the surge absorber more stable, and this surge absorber is manufactured with conventional semiconductor technology and silicon materials, and the manufacturing cost is greatly reduced.

Description

A surge absorber

technical field

The utility model relates to a gas discharge device, in particular to a surge absorber.

Background technique

The surge absorber is an overvoltage protection device that plays the role of lightning protection and high-voltage static electricity protection in electronic circuits. Most of the existing surge absorbers made of semiconductors are silicon mesas with a certain height etched on semiconductor silicon wafers in conventional processes, and a layer of insulators are grown on the mesas to obtain discharge micro-gap. After slicing, use The glass tube filled with inert gas seals the silicon wafer with the upper and lower electrodes. The defect of this surge absorber is due to the asymmetry of the microgap structure, one side of the microgap is an electrode with an uncontrollable surface, resulting in asymmetrical DC breakdown voltages in two directions, often with a voltage difference of more than 30 volts, and The DC breakdown voltage is also unstable.

Contents of the invention

The technical problem to be solved by the utility model is to provide a surge absorber aiming at the above-mentioned current state of the art, which has the characteristics that the DC breakdown voltage in two directions is basically symmetrical, and at the same time the DC breakdown voltage is more stable; the manufacturing cost is low .

The technical scheme adopted by the utility model to solve the above-mentioned technical problems is: a surge absorber, which includes a glass shell, and the glass shell is sealed with two electrodes and a chip, and the chip is clamped In the middle of the two electrodes, the electrodes are connected with lead wires, a gas chamber filled with gas is arranged in the glass shell, and the chip is composed of symmetrical multi-layer semiconductor layers and insulator layers. The structure is set as: insulator layer-N+semiconductor layer-N-type semiconductor layer-N+semiconductor layer-insulator layer, the insulator layer is in contact with the electrode.

The gas chamber can be filled with pure or mixed inert gas or non-inert gas.

The chip can be in the shape of a cube.

Compared with the prior art, the utility model has the advantages of fast response speed, low impact breakdown voltage, no photosensitive effect, small volume and high insulation resistance of common surge absorbers. The symmetrical chip structure can ensure that the DC breakdown voltage in the two directions of the surge absorber is basically symmetrical, and the voltage difference is less than 20V; at the same time, the N+ semiconductor layer of this structure can make the DC breakdown voltage of the surge absorber more stable; its Strong surge resistance ability, can withstand the impact of 1500A, 8/20ms and 4000V, 10/700ms electric pulse, and the inherent capacitance is less than 1pF. This surge absorber is manufactured with conventional semiconductor technology and silicon materials, which can greatly reduce the manufacturing cost of the surge absorber; the structure of the utility model is non-mesa, and there is no early discharge along the mesa, so it is better than the mesa structure. More stable DC breakdown voltage; the utility model does not have a thin metal layer at the edge of the micro-gap, so that metal sputtering is not easy to occur during discharge, and the insulation resistance of the surge absorber is greater and the service life is longer.

The utility model can adjust the DC breakdown voltage between 80V and 1500V by changing the width of the micro-gap, the gas composition and pressure charged; it can be widely used in the fields of displays, antenna circuits, sensors and data lines, communication systems, networks, etc. .

Description of drawings

Fig. 1 is the structural representation of the utility model surge absorber;

Fig. 2 is a schematic diagram of the chip structure of the surge absorber of the present invention.

Detailed ways

The utility model is described in further detail below in conjunction with the accompanying drawings.

As shown in Fig. 1 and Fig. 2, a kind of surge absorber is provided with a glass shell 1, and a semiconductor silicon chip 3 arranged between electrodes 4a, 4b is arranged in the glass shell 1, and the semiconductor silicon chip 3 and The end surfaces of the electrodes 4a, 4b are in contact with each other and sealed by the glass shell 1. There is a gas chamber 2 filled with pure or mixed inert or non-inert gas inside the glass shell 1, and the lead wires 5a, 5b are respectively connected to the electrodes 4a, 4b. Connected, semiconductor silicon chip 3 is made of insulator layer 33a, N+ semiconductor layer 32a, N-type semiconductor layer 31, N+ semiconductor layer 32b and insulator layer 33b, and is cut into cuboid, N+, N-type semiconductor layer is made of semiconductor silicon material The insulator layer 3 is made of glass, the sum of the thicknesses of the insulator layers 33a and 33b is the micro-gap width of the double micro-gap, and the insulator layers 33a and 33b are in contact with the electrodes 4a and 4b respectively.

The invention can be directly connected in parallel to high-frequency or low-frequency circuits that need overvoltage protection, and can also be used in conjunction with other overvoltage protection devices or circuits. When working, the voltage applied to the electrodes 4a and 4b two ends will generate a non-uniform strong electric field near the insulator layers 33a and 33b of the semiconductor chip 3. The initial electrons are generated, and under the action of the electric field, the initial electrons collide with the gas molecules, and generate electrons and positive ions, which starts the microgap discharge along the surface of the chip. Weak initial discharge current is to flow to electrode 4b (or 4a) by electrode 4a (or 4b) by the semiconductor layer 31,32a, 32b of semiconductor chip 3 and the ionized gas on insulator layer 33a, 33b surface, along with the discharge current increase, a larger voltage drop is produced on the semiconductor layers 31, 32a, 32b, which makes the gas ionization region near the micro-gap continuously expand, and finally covers the surface of the entire semiconductor chip 3, so that the discharge current directly passes through the gas ionization region from One electrode flows to another electrode, and the current flowing through the semiconductor chip 3 only accounts for a very small proportion, thereby ensuring that the semiconductor chip 3 will not be burned due to the excessive current flowing; when the discharge current increases further (~ 100mA), the above-mentioned glow discharge will become an arc discharge, and at this time the voltage at both ends of the surge absorber will also be clamped to a very low level (~30V), so as to achieve the function of overvoltage protection; due to the surge absorber The symmetry of the device structure and the structure of the semiconductor chip 3 makes the DC breakdown voltage in two directions of the surge absorber basically equal; at the same time, the N+ semiconductors 32a and 33b of this structure can stabilize the DC breakdown voltage of the surge absorber.

The insulator layers 33a and 33b in the above embodiments can also be made of materials such as ceramics.

Claims (4)

1, a kind of surge absorber, comprise a glass shell, sealing is provided with two electrodes and a chip in the described glass shell, described chip gripper is held in the middle of described two electrodes, be connected with lead-in wire on the described electrode, be provided with gassiness gas compartment in the described glass shell, it is characterized in that described chip is made of the multi-lager semiconductor layer and the insulator layer of symmetry, its structure is set to: insulator layer-N+ semiconductor layer-n type semiconductor layer-N+ semiconductor layer-insulator layer, described insulator layer contacts with described electrode.

2, a kind of surge absorber as claimed in claim 1 is characterized in that being full of in the described gas compartment inert gas pure or that mix.

3, a kind of surge absorber as claimed in claim 1 is characterized in that being full of in the described gas compartment non-inert gas pure or that mix.

4, a kind of surge absorber as claimed in claim 1 is characterized in that described chip is square.

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