Photoconductive switch device with heat dissipation structure

Abstract

The utility model discloses a photoconductive switch device with a heat dissipation structure, which comprises a photoconductive switch chip, ceramic and a tube shell which are stacked in sequence, electrodes are arranged on the front surface of the photoconductive switch chip, a metal bottom surface is arranged on the back surface of the photoconductive switch chip, the metal bottom surface is attached to the front surface of the ceramic, the back surface of the ceramic is attached to the front surface of the tube shell, and the electrode is arranged on the front surface of the tube shell. The metal bottom surface and the ceramic front surface are connected through eutectic welding or sintering, and the ceramic back surface and the tube shell front surface are connected through eutectic welding or sintering. Passive heat dissipation is achieved based on the structural design of the device and the external high-heat-conductivity ceramic and tube shell, the heat dissipation efficiency is high, damage caused by heat accumulation of the photoconductive switch device is remarkably reduced, the phenomena of cracking of a passivation layer on the surface of the photoconductive switch, melting of electrode connecting positions, medium sputtering and the like are avoided, the heat reliability of the device is improved, and the service life of the device is prolonged. And the method is suitable for various photoconductive switch devices with different sizes and materials.

Description

Technical Field

[0001] The utility model relates to the technical fields of optoelectronics and microwave technology, and particularly relates to an optical switch device with a heat dissipation structure. Background Art

[0002] An optical switch is a semiconductor device whose conductivity varies with the incident light power. By using its ultra-high voltage resistance and ultra-fast response characteristics, an optical microwave device can be designed to generate high-power microwaves under optical pulse triggering and DC bias. There are two main heat sources during the operation of a high-power optical switch device: one is that the energy of the trigger laser pulse not completely absorbed by the optical switch is converted into heat and accumulates; the other is the joule heat generated by the self-resistance of the optical switch device in the conducting state. The former can be solved by homogenizing the light spot and improving the light absorption rate of the device, while there is currently no effective solution for the latter.

[0003] To improve the voltage resistance characteristics of the optical switch and increase the output power, at present, an insulating material with a high dielectric constant is often filled around the optical switch chip. Although this solution can significantly increase the breakdown voltage, the heat generated during the operation of the chip cannot be quickly dissipated, resulting in heat accumulation. Heat accumulation causes the optical switch to be prone to thermal damage, such as the thermal expansion and cracking of the passivation layer on the surface of the optical switch, resulting in surface flashover; the melting and dielectric sputtering at the connection between the external electrode and the optical switch, etc., reducing the device life. Therefore, it is necessary to optimize the structure of the optical switch, reduce the thermal equilibrium temperature of the device, reduce heat accumulation, and improve the device life. Content of the Utility Model

[0004] Object of the Invention: Aiming at the above-mentioned shortcomings, the utility model provides an optical switch device with a heat dissipation structure, which conducts passive heat dissipation through a high-thermal-conductivity ceramic and a tube shell, making up for the drawback of the inability to dissipate heat in the engineering application of the optical switch from the device packaging structure, thereby improving the thermal reliability and life of the device.

[0005] Technical Solution: To solve the above problems, the utility model adopts an optical switch device with a heat dissipation structure, which includes an optical switch chip, a ceramic, and a tube shell stacked in sequence. An electrode is provided on the front surface of the optical switch chip, and a metal bottom surface is provided on the back surface of the optical switch chip. The metal bottom surface is attached to the front surface of the ceramic, and the back surface of the ceramic is attached to the front surface of the tube shell.

[0006] Furthermore, the attachment surface between the metal bottom surface and the front surface of the ceramic is within the range of the front surface of the ceramic; the attachment surface between the back surface of the ceramic and the front surface of the tube shell is within the range of the front surface of the tube shell.

[0007] Furthermore, the metal bottom surface and the front surface of the ceramic are connected by eutectic soldering or sintering, and the back surface of the ceramic and the front surface of the tube shell are connected by eutectic soldering or sintering.

[0008] Further, for the eutectic soldering or sintering, a welding material with a thermal conductivity > 100 W / m·K and a melting point > 300 °C after curing is used.

[0009] Further, the package includes a bottom plate, a surrounding frame disposed on the front edge of the bottom plate, and a heat dissipation structure disposed on the back side of the bottom plate. The heat dissipation structure includes a plurality of bumps evenly distributed; the optical switch chip and the ceramic are located inside the surrounding frame, and the back side of the ceramic is attached to the front side of the bottom plate.

[0010] Further, the optical switch chip includes an insulating substrate, an optical semiconductor grown on the insulating substrate, the electrodes are disposed on the optical semiconductor, and the metal bottom surface is attached to the bottom surface of the insulating substrate.

[0011] Further, the optical switch chip is made of GaAs, GaN, SiC or Ga2O3 materials.

[0012] Further, the ceramic is made of an insulating material with a thermal conductivity > 100 W / m·K.

[0013] Further, the surrounding frame is made of a Kovar alloy material, and the bottom plate and the heat dissipation structure are made of a tungsten copper alloy material with a thermal conductivity ≥ 170 W / m·K.

[0014] Beneficial effects: Compared with the prior art, the remarkable advantage of the present utility model is the passive heat dissipation achieved based on the device's own structure design and the external high-thermal-conductivity ceramic and package. The heat dissipation efficiency is high, significantly reducing the damage caused by the heat accumulation of the optical switch device, avoiding phenomena such as cracking of the passivation layer on the surface of the optical switch, melting at the electrode connection, and dielectric sputtering, improving the thermal reliability and lifespan of the device, and being applicable to optical switch devices of various different sizes and materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic diagram of the overall structure of the optical switch device of the present utility model;

[0016] Figure 2 is a schematic diagram of the structure of the optical switch chip of the present utility model;

[0017] Figure 3 is a schematic diagram of the structure of the package of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] As Figure 1 shown, an optical switch device with a heat dissipation structure in this embodiment includes an optical switch chip 1, a ceramic 2, and a package 3 stacked in sequence. As Figure 2As shown in the figure, the photoconductive switch chip 1 includes an electrode 101, a photoconductive semiconductor 102, an insulating substrate 103, and a metal bottom surface 104. The insulating substrate 103 is made of an insulating material with high thermal conductivity. The photoconductive semiconductor 102 is epitaxially formed on the front surface of the insulating substrate 103 to enable the carriers to migrate along the surface, avoiding bulk conduction or forming an inter-stage capacitance that affects the output performance on both sides of the device. The electrode 101 is disposed on the photoconductive semiconductor 102, and the metal bottom surface 104 is attached to the bottom surface of the insulating substrate 103.

[0019] As Figure 3 As shown in the figure, the package 3 includes a bottom plate 302, a surrounding frame 301 disposed on the front edge of the bottom plate 302, and a heat dissipation structure 303 disposed on the back surface of the bottom plate 302. The heat dissipation structure 303 includes a plurality of bumps distributed at equal intervals. The heat dissipation structure 303 improves the heat dissipation efficiency by increasing the surface area in contact with the air. The photoconductive switch chip 1 and the ceramic 2 are located inside the surrounding frame 301. The front surface of the ceramic 2 is attached to the metal bottom surface 104 and connected by eutectic soldering or sintering. The back surface of the ceramic 2 is attached to the front surface of the bottom plate 302 and connected by eutectic soldering or sintering. The bonding surface between the metal bottom surface 104 and the front surface of the ceramic 2 is within the range of the front surface of the ceramic 2; the bonding surface between the back surface of the ceramic 2 and the front surface of the package 3 is within the range of the front surface of the bottom plate 302, so that the contact heat dissipation area between the bonding surfaces reaches the maximum.

[0020] The photoconductive switch chip 1 can be made of materials such as GaAs, GaN, SiC, or Ga2O3. The ceramic 2 can also be other insulating materials with high thermal conductivity (> 100 W / m·K), such as ceramics that meet the above requirements, such as aluminum nitride. The surrounding frame 301 is made of a kovar alloy material, and the bottom plate 302 and the heat dissipation structure 303 can be made of a tungsten copper alloy material with a thermal conductivity ≥ 170 W / m·K. The eutectic soldering or sintering uses a welding material with a thermal conductivity > 100 W / m·K and a melting point > 300 °C after curing to prevent the material from failing during use. Materials that meet the above requirements, such as nano silver (thermal conductivity 398.2 W / m·K, melting point 960.5 °C), can be used.

[0021] The passive heat dissipation of the present utility model is realized based on the device's own structure design and external high-thermal-conductivity ceramics and packages. It has high heat dissipation efficiency, significantly reduces the damage caused by heat accumulation of the photoconductive switch device, avoids phenomena such as cracking of the surface passivation layer of the photoconductive switch, melting of the electrode connection, and dielectric sputtering, improves the thermal reliability and lifespan of the device, and is applicable to photoconductive switch devices of various different sizes and materials.

Claims

1. A photoconductive switch device with a heat dissipation structure, characterized in that, It includes a photoconductive switch chip (1), a ceramic (2), and a package (3) stacked in sequence. An electrode (101) is provided on the front surface of the photoconductive switch chip (1), and a metal bottom surface (104) is provided on the back surface of the photoconductive switch chip (1). The metal bottom surface (104) is attached to the front surface of the ceramic (2), and the back surface of the ceramic (2) is attached to the front surface of the package (3).

2. The optical waveguide switch device with a heat dissipation structure according to claim 1, characterized in that, The bonding surface between the metal bottom surface (104) and the front surface of the ceramic (2) is within the range of the front surface of the ceramic (2); the bonding surface between the back surface of the ceramic (2) and the front surface of the package (3) is within the range of the front surface of the package (3).

3. The optical switch device with a heat dissipation structure according to claim 1, characterized in that, The metal bottom surface (104) and the front surface of the ceramic (2) are connected by eutectic soldering or sintering, and the back surface of the ceramic (2) and the front surface of the package (3) are connected by eutectic soldering or sintering.

4. The optical switch device with a heat dissipation structure according to claim 3, characterized in that, The eutectic soldering or sintering uses a welding material with a thermal conductivity > 100 W / m·K and a melting point > 300 °C after curing.

5. The optical switch device with a heat dissipation structure according to claim 1, characterized in that, The package (3) includes a bottom plate (302), a surrounding frame (301) arranged on the front edge of the bottom plate (302), and a heat dissipation structure (303) arranged on the back surface of the bottom plate (302). The heat dissipation structure (303) includes a number of equally spaced bumps; the photoconductive switch chip (1) and the ceramic (2) are located inside the surrounding frame (301), and the back surface of the ceramic (2) is attached to the front surface of the bottom plate (302).

6. The optical switch device with a heat dissipation structure according to claim 1, wherein The photoconductive switch chip (1) includes an insulating substrate (103) and a photoconductive semiconductor (102) grown on the insulating substrate (103). The electrode (101) is arranged on the photoconductive semiconductor (102), and the metal bottom surface (104) is attached to the bottom surface of the insulating substrate (103).

7. The optical switch device with a heat dissipation structure according to claim 1, characterized in that, The photoconductive switch chip (1) is made of GaAs, GaN, SiC, or Ga2O3 materials.

8. The optical waveguide switch device with a heat dissipation structure according to claim 1, wherein The ceramic (2) is made of an insulating material with a thermal conductivity > 100 W / m·K.

9. The optical switch device with a heat dissipation structure according to claim 5, characterized in that, The surrounding frame (301) is made of kovar alloy material, and the bottom plate (302) and the heat dissipation structure (303) are made of tungsten copper alloy material with a thermal conductivity ≥ 170 W / m·K.

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