Radio frequency coaxial device with air-tight sealing structure

Abstract

The utility model belongs to the technical field of radio frequency coaxial device air-tight sealing, and mainly relates to a radio frequency coaxial device with an air-tight sealing structure, which comprises a coaxial shell, two glass insulators are symmetrically arranged on two opposite sides of the coaxial shell, and the coaxial shell and the two glass insulators are integrally formed; an installation cavity used for installing a chip is arranged in the coaxial shell, and the outer side of the coaxial shell is sleeved with a sleeve so as to seal the installation cavity. According to the radio frequency coaxial device, the glass insulator and the coaxial shell are integrally sintered, so that local gold plating is avoided, the process difficulty and cost are reduced, the welding frequency is reduced, and the possibility of leakage of the radio frequency coaxial device is reduced.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the air-tight sealing technical field of radio frequency coaxial device, and mainly relates to an air-tight sealing structure's radio frequency coaxial device. BACKGROUND

[0002] In the radio frequency system, the radio frequency coaxial device is mainly used to transmit radio frequency signals, and is used in aerospace, submarine and other harsh environments. In order to ensure the reliability of the product in the extreme environment, the product needs to be air-tight sealed, and the product is effectively isolated from the external environment, so that the environmental adaptability of the product is improved.

[0003] The radio frequency coaxial device with the air-tight sealing structure is tin soldered with a glass insulator and other functional parts at two ends of the coaxial shell respectively, and then the cover plate is fixed on the coaxial shell by laser welding, so that the air-tight sealing function is realized. However, this structure has the following defects:

[0004] 1. The coaxial shell needs to be tin soldered and laser welded at the same time, so the local gold plating process needs to be used for the electroplating of the tin soldering part of the coaxial shell, and the volume of the device is small, so the electroplating is difficult and the cost is high, and because two kinds of welding are needed, the risk of leakage is large;

[0005] 2. The glass insulator and the coaxial shell are tin soldered at the same time, and after welding, the welding part needs to be air-tight sealed, and in order to ensure the good installation of the chip, the parallelism between the inner conductor bonding surface and the cavity bottom surface needs to be ensured, which is difficult to realize and has a low yield;

[0006] 3. Because the product has a small size, when the cover plate and the coaxial shell are laser welded, the air-tight sealing is difficult to guarantee, and the yield is low;

[0007] 4. The product structure is complex, and the process is difficult to realize. INVENTION CONTENTS

[0008] The utility model provides a kind of air-tight sealing structure's radio frequency coaxial device to solve the problem that air-tight sealing of radio frequency coaxial device in prior art is difficult to guarantee, is prone to leakage.

[0009] To solve the above problems, the utility model adopts the following technical scheme:

[0010] A kind of air-tight sealing structure's radio frequency coaxial device, including coaxial shell, two glass insulators are symmetrically arranged on the opposite sides of the coaxial shell, and the coaxial shell and the two glass insulators are integrally formed.

[0011] The coaxial shell has a mounting cavity for mounting a chip inside, and a sleeve is sleeved on the outer side of the coaxial shell to seal the mounting cavity.

[0012] The glass insulator and the coaxial shell are integrally sintered, local gold plating is avoided, the process difficulty and cost are reduced, and the welding times are reduced, so that the leakage of the radio frequency coaxial device is reduced.

[0013] Further, each glass insulator has an inner conductor, each inner conductor extends into the mounting cavity, a bonding surface is arranged on the inner conductor extending into the mounting cavity, the bonding surface is parallel to the cavity bottom of the mounting cavity, and the inner conductor is used for electrically connecting the chip in the mounting cavity.

[0014] The glass insulator and the coaxial shell are integrally sintered, the bonding surface is obtained by milling after sintering is completed, and the parallelism of the bonding surface and the cavity bottom is ensured.

[0015] Further, the coaxial shell is provided with a ring-shaped protrusion, one end of the sleeve sleeved on the coaxial shell abuts against the ring-shaped protrusion to position the sleeve.

[0016] When the one end of the sleeve contacts the ring-shaped protrusion, it is indicated that the sleeve is sleeved in place, and then the sleeve can be fixed.

[0017] Further, the coaxial shell is provided with two tin solder layers arranged at intervals, the two tin solder layers are arranged in a circumferential direction of the coaxial shell, and the sleeve is fixed to the coaxial shell through the tin solder layers.

[0018] Further, the coaxial shell is provided with two ring-shaped grooves arranged at intervals, and the tin solder layers are arranged in the corresponding ring-shaped grooves.

[0019] Further, the sleeve is provided with a gold plating layer on the inner side, and the gold plating layer contacts the coaxial shell.

[0020] The gold plating layer enables the sleeve to be better soldered with the coaxial shell.

[0021] Further, the coaxial shell is made of Kovar alloy.

[0022] The Kovar alloy is an iron-nickel-cobalt alloy, has a similar linear expansion coefficient to the glass insulator in the range of 20-450 DEG C, can maintain dimensional stability when the temperature changes, effectively prevents component deformation, cracking and other problems caused by thermal expansion and contraction, and improves the reliability and stability of the equipment; the oxidation film of the Kovar alloy is dense and can be well infiltrated by glass. BRIEF DESCRIPTION OF DRAWINGS

[0023] The above and other objects, features, and advantages of the present invention will become readily understood by reading the following detailed description of exemplary embodiments with reference to the accompanying drawings. In the drawings, several embodiments of the present invention are shown by way of example and not limitation, and like or corresponding reference numerals denote like or corresponding parts, wherein:

[0024] Figure 1 This is a front view of the present invention;

[0025] Figure 2 This is an internal view of the present invention.

[0026] Explanation of reference numerals in the attached figures:

[0027] 1. Coaxial housing; 2. Glass insulator; 3. Mounting cavity; 4. Sleeve; 5. Solder layer; 6. Inner conductor; 7. Chip; 8. Annular protrusion; 9. Bonding surface. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Those skilled in the art should understand that the embodiments described below are only some, not all, of the embodiments disclosed. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0029] The following describes various non-limiting embodiments of this utility model. Any number of elements in the accompanying drawings is for illustrative purposes only and not for limitation, and any naming is for distinction only and has no limiting meaning. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0030] like Figure 1 , Figure 2 As shown, a hermetically sealed radio frequency coaxial device includes a coaxial housing 1. Two symmetrically arranged glass insulators 2 are provided on opposite sides of the coaxial housing 1. The coaxial housing 1 and the two glass insulators 2 are integrally formed by sintering, thus avoiding welding and reducing the risk of leakage from welding points. The coaxial housing 1 has a mounting cavity 3 for mounting a chip 7, and a sleeve 4 is fitted onto the outside of the coaxial housing 1 to seal the mounting cavity 3. By integrally sintering the glass insulators 2 with the coaxial housing 1, localized gold plating is avoided, reducing process difficulty and cost, while also reducing the number of welding operations, thereby reducing the possibility of leakage in the radio frequency coaxial device.

[0031] In the embodiment, each glass insulator 2 has an inner conductor 6 capable of conducting electricity, each inner conductor 6 extends into the mounting cavity 3, and a bonding surface 9 is arranged on the inner conductor 6 extending into the mounting cavity 3, the bonding surface 9 is a flat surface, the bonding surface 9 is parallel to the cavity bottom of the mounting cavity 3, the inner conductor 6 is used for electrically connecting the chip 7 in the mounting cavity 3, and the inner conductor 6 is also electrically connected with external equipment. In the embodiment, the electrical connection between the inner conductor 6 and the chip 7 is realized by welding between the bonding surface 9 and the chip 7. Because the glass insulator 2 is integrally sintered with the coaxial shell 1, the bonding surface 9 is obtained by milling after sintering is completed, and the parallelism of the bonding surface 9 and the cavity bottom is ensured.

[0032] The coaxial shell 1 is provided with a ring-shaped protrusion 8 on one side, one end of the sleeve 4 sleeved on the coaxial shell 1 abuts against the ring-shaped protrusion 8 to stop and position the sleeve 4, and the ring-shaped protrusion 8 is located outside the solder layer 5, that is, when the sleeve 4 abuts against the ring-shaped protrusion 8, the sleeve 4 can be located outside the two solder layers 5 at the same time. In use, when the one end of the sleeve 4 is in contact with the ring-shaped protrusion 8, it indicates that the sleeve 4 is sleeved in place, and then the sleeve 4 can be fixed.

[0033] In the embodiment, the coaxial shell 1 is provided with two spaced-apart solder layers 5, the solder layers 5 are annular on the coaxial shell 1, and the two solder layers 5 are circumferentially arranged around the coaxial shell 1. The sleeve 4 is fixed to the coaxial shell 1 through the solder layers 5, that is, the sleeve 4 is fixed to the coaxial shell 1 through soldering to seal the mounting cavity 3.

[0034] The coaxial shell 1 is provided with two spaced-apart annular grooves, each annular groove is circumferentially arranged around the coaxial shell 1, and the two solder layers 5 are arranged in the corresponding annular grooves.

[0035] The inside of the sleeve 4 is provided with a gold plating layer, and the gold plating layer is in contact with the coaxial shell 1. The gold plating layer enables the sleeve 4 to be better soldered with the coaxial shell 1.

[0036] In the embodiment, the material of the coaxial shell 1 is Kovar alloy. Kovar alloy, also known as 4J29 alloy or Kovar alloy, is a kind of iron-nickel-cobalt constant expansion sealing alloy.

[0037] The chemical composition of the Kovar alloy mainly consists of iron, nickel and cobalt, among which the content of nickel is about 28.5%-29.5%, the content of cobalt is about 16.8%-17.8%, and the balance is iron. In addition, it also contains a small amount of carbon, manganese, silicon, phosphorus, sulfur and other elements, the density is about 8.36 g / cm³, and the melting point is about 1449℃.

[0038] In the range of 20-450℃, the Kovar alloy has a similar linear expansion coefficient to the glass insulator 2, can maintain dimensional stability when the temperature changes, effectively prevents the deformation, cracking and other problems of the components caused by thermal expansion and contraction, and improves the reliability and stability of the equipment. At the same time, the Kovar alloy has high strength and hardness, and also has good toughness and tensile strength, and can withstand large impact and vibration. The Kovar alloy is easy to process and manufacture, and can be formed and processed by various methods such as forging, hot rolling, cold rolling, cold drawing, cold forging and welding, and can meet the manufacturing requirements of parts of different shapes and sizes.

[0039] The Kovar alloy has good corrosion resistance to water and some chemicals, and performs well in acidic and alkaline environments, and can operate stably for a long time in various harsh environments.

[0040] At the same time, the Curie point of the Kovar alloy is high, about 435℃, has good low-temperature organizational stability, and does not interact with mercury, in addition, the oxidation film of the Kovar alloy is dense and can be well infiltrated by glass.

Claims

1. A radio frequency coaxial device of gas tight construction, characterised in that, The coaxial shell is integrally formed with the two glass insulators. The coaxial shell has a mounting cavity for mounting a chip, and a sleeve is sleeved on the outer side of the coaxial shell to seal the mounting cavity.

2. A radio frequency coaxial device of gas tight construction according to claim 1, characterised in that, Each glass insulator has an inner conductor, and each inner conductor extends into the mounting cavity and is provided with a bonding surface parallel to the cavity bottom of the mounting cavity, and the inner conductor is used for electrically connecting the chip in the mounting cavity.

3. A radio frequency coaxial device of gas tight construction according to claim 2, characterised in that, One side of the coaxial shell is provided with an annular protrusion, and one end of the sleeve sleeved on the coaxial shell abuts against the annular protrusion to position the sleeve.

4. A radio frequency coaxial device of gas tight construction according to claim 3, characterised in that, The coaxial shell is provided with two spaced tin solder layers, and the two tin solder layers are arranged circumferentially around the coaxial shell, and the sleeve is fixed on the coaxial shell through the tin solder layers.

5. A radio frequency coaxial device of gas tight construction according to claim 4, characterised in that, The coaxial shell is provided with two spaced annular grooves, and the tin solder layers are arranged in the corresponding annular grooves.

6. A radio frequency coaxial device of gas tight construction according to claim 5, characterised in that, The inner side of the sleeve is provided with a gold plating layer, and the gold plating layer is in contact with the coaxial shell.

7. A gas-tight radio frequency coaxial device according to any one of claims 1 to 6, characterized in that The coaxial shell is made of Kovar alloy.

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