CN216671978U

CN216671978U - Ceramic tube shell for improving radio frequency signal transmission performance

Info

Publication number: CN216671978U
Application number: CN202123059184.3U
Authority: CN
Inventors: 李天娇; 李玮; 郑欣; 李军; 何峰; 高海光; 徐佳丽; 高迪; 杜文凯
Original assignee: Hebei Zhongchi Electronic Technology Co ltd
Current assignee: Hebei Zhongchi Electronic Technology Co ltd
Priority date: 2021-12-07
Filing date: 2021-12-07
Publication date: 2022-06-03
Anticipated expiration: 2031-12-07

Abstract

The utility model provides a ceramic tube shell for improving the transmission performance of radio-frequency signals, which belongs to the technical field of photoelectric communication and comprises a shell, a ceramic insulator and a plurality of first welding pads, wherein an installation opening is formed in the side part of the shell, the ceramic insulator is inserted and packaged in the installation opening of the shell in a matched manner, the outer end of the ceramic insulator is arranged outside the shell, the inner end of the ceramic insulator is arranged inside the shell, the plurality of first welding pads are uniformly distributed at the upper end of the ceramic insulator in parallel, a groove is dug between every two adjacent first welding pads on the ceramic insulator, the groove can reduce the dielectric constant between every two adjacent first welding pads, and further the impedance of a radio-frequency transmission line and the transmission performance of the radio-frequency signals are improved. The ceramic tube shell for improving the transmission performance of the radio frequency signals, provided by the utility model, has the technical effects of reducing the dielectric constant between two adjacent first bonding pads and further improving the impedance of a radio frequency transmission line and the transmission performance of the radio frequency signals.

Description

Ceramic tube shell for improving radio frequency signal transmission performance

Technical Field

The utility model belongs to the technical field of photoelectric communication, and particularly relates to a ceramic tube shell for improving the transmission performance of radio frequency signals.

Background

The ceramic tube shell has an absolute position in the field of electronic device packaging, and is widely applied to the field of photoelectric communication packaging. The ceramic insulator is the most important component in the ceramic tube shell, and for the ceramic tube shell with high speed and high bandwidth requirements, the wiring of the radio frequency layer on the ceramic insulator is particularly critical and is the core area of the whole ceramic tube shell. As people demand more and more communication and demand more and more information capacity, communication systems must be developed to high frequency band. Therefore, the electronic packaging field has higher transmission speed requirements on the ceramic tube shell, and the radio frequency performance of the circuit on the ceramic insulator needs to be improved. And based on the existing ceramic wiring rule and process capability, the improvement of the radio frequency performance of the ceramic insulator is limited.

The design of the ceramic package is mainly to reduce the width of the bonding pad, increase the spacing between the bonding pads, and the like to improve the impedance. Especially for a differential 100 ohm ceramic package, to meet the requirement of 100 ohm impedance, the line of the bonding pad is required to be very thin, so that the difficulty of the welding process is very high when the package is used at a later stage, and the reliability of welding is reduced. In addition, the use mode of the ceramic insulator pad position is mostly welding a Flexible Printed Circuit (FPC), which inevitably reduces the impedance of the ceramic insulator pad position. The best design is therefore a design compensation for the impedance of the ceramic insulator pad, i.e. a design value greater than 100 ohms. In this case, there is no obvious way to change the width and pitch of the pad lines, and a new ceramic package needs to be developed to solve the problem.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a ceramic tube shell for improving the transmission performance of radio frequency signals, and aims to solve the technical problem of low impedance of a radio frequency transmission line on a ceramic insulator of the ceramic tube shell.

In order to achieve the purpose, the utility model adopts the technical scheme that: the ceramic tube shell comprises a shell, a ceramic insulator and a plurality of first bonding pads, wherein the side part of the shell is provided with a mounting port; the ceramic insulator is inserted and packaged in the shell mounting port in a matched manner, the inner end of the ceramic insulator is arranged on the inner side of the shell, and the outer end of the ceramic insulator is arranged on the outer side of the shell; the first bonding pads are uniformly distributed at the upper end of the ceramic insulator in parallel and are positioned outside the shell; a groove is formed between every two adjacent first bonding pads on the ceramic insulator, so that the dielectric constant between every two adjacent first bonding pads is reduced, and the impedance of a radio frequency transmission line is improved.

In a possible implementation manner, a GND layer is arranged inside the ceramic insulator, and the bottom of the groove is located above the GND layer.

In a possible implementation manner, the bottom in the groove is covered with an insulating layer for preventing the GND layer from conducting electricity into the groove.

In one possible implementation, the insulating layer is a porcelain paste.

In a possible implementation manner, the groove is long and the length direction of the groove is along the length direction of the first pad.

In a possible implementation mode, the casing includes wall body, light window support and bottom plate, the wall body with the bottom plate constitutes jointly and has cavity and upper end and have the open-ended cuboid structure that communicates the cavity, installing port on the casing locates the cuboid broadside side on the wall body.

In a possible implementation manner, the wall body is made of ceramic or kovar alloy.

In a possible implementation manner, a structural beam is arranged at the upper end of the ceramic insulator, and after the ceramic insulator is packaged in the shell mounting port, the structural beam is suitable for abutting against the shell to limit the ceramic insulator.

In a possible implementation manner, the first pad is located on one side of the structural beam, and a second pad which is located on the other side of the structural beam and is in conductive connection with the first pad is further arranged at the upper end of the ceramic insulator.

In a possible implementation manner, a side portion of the housing opposite to the mounting opening is provided with a mounting hole, and the mounting hole is used for mounting the optical window bracket.

The ceramic tube shell for improving the transmission performance of the radio frequency signal has the beneficial effects that: compared with the prior art, the ceramic tube shell for improving the transmission performance of the radio frequency signal comprises a shell, a ceramic insulator and a plurality of first bonding pads, wherein the ceramic insulator is spliced and packaged in a shell mounting port and welded in the mounting port, the outer end of the ceramic insulator is positioned outside the shell, the inner end of the ceramic insulator is positioned inside the shell, the first bonding pads are positioned on the ceramic insulator and positioned outside the shell and can be connected with other components, the groove is arranged between two adjacent first bonding pads, the dielectric constant between the two adjacent first bonding pads can be reduced by the groove, the impedance of the radio frequency transmission line is improved, the technical problem of low impedance of the radio frequency transmission line on the ceramic tube shell ceramic insulator is solved, and the ceramic tube shell ceramic insulator is provided with the groove, the dielectric constant between two adjacent first bonding pads can be reduced, and the technical effects of the impedance of the radio frequency transmission line and the transmission performance of radio frequency signals are further improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a ceramic package for improving transmission performance of radio frequency signals according to an embodiment of the present invention;

fig. 2 is a schematic view of a ceramic insulator slotting structure of a ceramic package for improving radio frequency signal transmission performance according to an embodiment of the present invention;

fig. 3 is a cross-sectional view of a groove of a ceramic insulator of a ceramic package according to an embodiment of the present invention, for improving the transmission performance of radio frequency signals;

fig. 4 is a simulation model of the rf signal transmission performance of the ceramic package according to the embodiment of the present invention, for improving the rf signal transmission performance;

fig. 5 is a block diagram of a simulation and preparation process of a ceramic package for improving the transmission performance of radio frequency signals according to an embodiment of the present invention.

Description of reference numerals:

1. a housing; 11. a wall body; 12. a base plate; 2. a ceramic insulator; 3. a first pad; 4. an installation port; 5. a groove; 6. a GND layer; 7. an insulating layer; 8. a structural beam; 9. a second pad; 10. mounting holes; 110. a light window support.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the utility model.

Referring to fig. 1 to 4, a ceramic package for improving the transmission performance of rf signals according to the present invention will be described. The ceramic tube shell for improving the transmission performance of radio frequency signals comprises a shell 1, a ceramic insulator 2 and a plurality of first bonding pads 3, wherein a mounting port 4 is formed in the side part of the shell 1; the ceramic insulator 2 is inserted and packaged in the mounting opening 4 of the shell 1 in a matched manner, the inner end of the ceramic insulator 2 is arranged on the inner side of the shell 1, and the outer end of the ceramic insulator 2 is arranged on the outer side of the shell 1; the first pads 3 are uniformly distributed at the upper end of the ceramic insulator 2 in parallel and are positioned outside the shell 1; a groove 5 is formed between every two adjacent first welding discs 3 on the ceramic insulator 2, and the groove 5 is used for reducing the dielectric constant between every two adjacent first welding discs 3 and improving the impedance of the radio frequency transmission line.

Compared with the prior art, the ceramic tube shell for improving the transmission performance of the radio frequency signal comprises a shell 1, a ceramic insulator 2 and a plurality of first welding pads 3, wherein the side part of the shell 1 is provided with a mounting port 4, the ceramic insulator 2 is inserted and packaged into the mounting port 4 of the shell 1 in a matching way, the ceramic insulator 2 is inserted and packaged into the mounting port 4 of the shell 1 and is arranged on the mounting port 4 in a riding way, the outer end of the ceramic insulator is arranged outside the shell 1, the inner end of the ceramic insulator is arranged inside the shell 1, the first welding pads 3 are arranged on the ceramic insulator 2 and outside the shell 1 and can be connected with other components, a groove 5 is arranged between two adjacent first welding pads 3, the groove 5 is used for reducing the dielectric constant between the two adjacent first welding pads 3, the impedance of a radio frequency transmission line of the tube shell is improved, and the technical problem of low impedance of the radio frequency transmission line on the ceramic insulator 2 is solved, the groove 5 is formed to reduce the dielectric constant between two adjacent first bonding pads 3, and further improve the technical effects of the impedance of the radio frequency transmission line and the transmission performance of radio frequency signals.

The grooves 5, above or below, may also be referred to as cavities or air chambers.

In actual use, the impedance at the position of the first pad 3 on the ceramic insulator 2 is pulled down, so that the impedance amount (value) is increased in advance, and the function of compensating for the subsequent impedance can be performed. Through the result that computer numerical simulation software (three-dimensional) emulation obtained, reasonable design recess 5's size or distance between the first pad 3 can help promoting the impedance, be convenient for later stage reasonable operation and processing ceramic insulator 2.

In this embodiment, the groove 5 is formed between two adjacent first pads 3, and the groove 5 reduces the dielectric constant between the first pads 3, so as to improve the transmission impedance of the radio frequency signal of the ceramic insulator 2, theoretically, the larger the size (including the length, the width, and the depth) of the groove 5 is, the larger the impedance improvement is, but the size of the groove 5 cannot be too large, that is, the size cannot exceed the area between two adjacent first pads 3. Recess 5 usually adopts square punch or oval punch to process, so recess 5's shape is unanimous with the punch shape, can go on one by one through the superimposed mode in the punch operation process, if recess 5's length is 2mm, punch length is 0.9mm, then need let the punch superpose many times and rush into and just can accomplish the processing on the recess 5 length direction, and recess 5's the depth direction is once rush out and make, the processing on the width direction of recess 5, generally choose for use the punch unanimous with recess 5 width, once rush out and make, then do not need many times to superpose the processing.

For the size of the groove 5 machined by the present invention, the distance between the edge of the groove 5 and the first pad 3 may be 0.04mm, which is desirable for machining production accuracy. The impedance mentioned in the present embodiment, the amount of which is generated by computer numerical simulation, can be reduced by reducing the size of some of the grooves 5 or by appropriately reducing the distance between two adjacent first pads 3 if, in practical cases, the amount of impedance does not need to be increased too much.

In order not to affect the normal use of the GND layer 6, in some embodiments, referring to fig. 3, the ceramic insulator 2 is provided with the GND layer 6 inside, and the bottom of the groove 5 is located above the GND layer 6. When the groove 5 is machined, the layer of the groove 5 does not need to be machined, the single-layer material is positioned together after being punched, and the thickness of the single-layer material has certain requirements. That is, after the depth of the groove 5 is determined, the depth of the groove 5 is divided into a plurality of single layers to be punched, and then the single layers are stacked together to form the total depth. Generally, the bottom of the groove 5 is not in contact with the GND layer 6, i.e. they are not connected to each other, and also has an insulating effect. The bottom of the recess 5 is above the GND plane 6, which means that the two may or may not be in contact, when in contact an insulation treatment is to be performed.

In order to increase the insulating effect of the GND layer 6 on the groove 5, in some embodiments, referring to fig. 3, the bottom of the groove 5 is covered with an insulating layer 7 for preventing the GND layer 6 from conducting electricity into the groove 5. By coating one or more layers (the thickness of the layer can be controlled according to actual conditions) of the insulating layer 7 in the groove 5, the insulating layer 7 can play a good insulating role once the groove 5 is communicated with the GND layer 6, and the GND layer 6 is prevented from being guided into the groove 5.

In some embodiments, referring to fig. 3, the insulating layer 7 is formed of a slurry. The magma is the slurry liquid of generally used among the prior art, and its itself is insulating, easy preparation, and use cost is low, after covering it in recess 5 inside, just can play good insulating effect, avoids appearing and the risk of other local short circuits.

In order to make the size or specification of the groove 5 as large as possible so as to maximize the impedance of the ceramic insulator rf transmission line, in some embodiments, please refer to fig. 1 to 2, the groove 5 is a long bar shape, and the length direction is along the length direction of the first pad 3. Therefore, the first bonding pad 3 is strip-shaped, the groove 5 is also arranged to be strip-shaped, and the shapes of the first bonding pad and the groove are consistent, so that the radio frequency signal transmission performance can be improved to the maximum extent.

In a specific implementation, the length of the groove 5 is less than or equal to the length of the first pad 3, the inner end of the groove 5 is flush with the inner end of the first pad 3 or slightly smaller than the inner end of the first pad 3, for example, the inner end of the groove 5 is 0.1mm smaller than the inner end of the first pad 3; the outer end of the groove 5 can be pulled through or run through to the side of the ceramic insulator 2, so that the length of the groove 5 is equal to the length of the first welding pad 3; when the ceramic insulator 2 is not pulled through or penetrated at the side portion, the length of the groove 5 is smaller than the length of the first land 3.

In order to form the ceramic package into the housing 1 suitable for mounting or matching with the electronic device package, in some embodiments, referring to fig. 1, the housing 1 includes a wall 11, an optical window bracket 110 and a bottom plate 12, the wall 11 and the bottom plate 12 together form a rectangular parallelepiped structure having a cavity and an opening at an upper end thereof communicating with the cavity, and the mounting opening 4 on the housing 1 is disposed on the wall 11 at a short side of the rectangular parallelepiped. The light window bracket 110 and the housing 1 are connected by welding, preferably by brazing. In addition, there may be two walls 11 having some cases 1, and one wall 11 is shown in the drawings of the present embodiment.

Specifically, electronic devices may be mounted inside the housing 1, and may also be electrically connected to external devices.

In order to improve the insulation effect of the tube, in some embodiments, referring to fig. 1, the wall 11 is made of ceramic or kovar alloy. The ceramic has various forms, such as alumina ceramic and the like, has high mechanical strength, good insulating function, small high-frequency loss, high electric strength resistance, high temperature resistance, thermal shock resistance and the like, and is suitable for the tube shell of a high-power electron tube; in special cases, various patterns such as aluminum nitride ceramics may be used.

In order to stabilize the front connection between the ceramic insulator 2 and the housing 1, in some embodiments, referring to fig. 1 to 2, a structural beam 8 is disposed at the upper end of the ceramic insulator 2, and after the ceramic insulator 2 is packaged in the mounting opening 4 of the housing 1, the structural beam 8 is adapted to abut against the housing 1 to limit the ceramic insulator 2.

Specifically, the structure beam 8 and the ceramic insulator 2 are of an integrated structure, the structure beam 8 is punched into a required structure through a layer of material, and then multiple layers of the structure beam are positioned together, and when the structure beam 8 is in contact with the shell 1 or the shell 1 at the upper end inside the mounting opening 4, the structure beam can play a role in limiting the ceramic insulator 2.

In some embodiments, referring to fig. 1 to 2, the first bonding pad 3 is located on one side of the structural beam 8, and the upper end of the ceramic insulator 2 is further provided with a second bonding pad 9 located on the other side of the structural beam 8 and electrically connected to the first bonding pad 3. The structural beam 8 is disposed at the upper ends of the first and

second pads

3 and 9, and the first and

second pads

3 and 9 are located on both sides of the structural beam 8.

In order to electrically connect the ceramic package to the external electronic device, in some embodiments, referring to fig. 1, a mounting hole 10 is formed on a side portion of the housing 1 opposite to the mounting opening 4, and the mounting hole 10 is used for mounting the optical window bracket 110. The optical window bracket 110 can be installed through the installation hole 10, generally, the optical window bracket 110 is in a hollow cylindrical shape, the interior of the optical window bracket is used for installing an optical window, the optical window plays a role in transmitting light, transmitting optical signals and the like, and the installation is convenient to operate.

In the utility model, computer software is used for simulation, as shown in fig. 4, the radio frequency performance simulation and the tube shell preparation process are as follows:

according to the impedance requirement of design input and the porcelain structure, the initial line width, the line spacing and the medium thickness of the design are determined by utilizing impedance matching software, and then each layer of radio frequency wiring is drawn in two-dimensional software. And (3) guiding each drawn radio frequency wiring layer into three-dimensional simulation software, performing operations such as stretching, translation, combination, subtraction and the like, and adding a groove (namely, arranging a groove 5) between the two bonding pads to complete the establishment of the ceramic insulator model, as shown in fig. 2.

In combination with the use of the ceramic insulator, an FPC model is added on the outer bonding pad side and is welded together through metal solder; the internal bonding means that a Submount substrate model needs to be established and connection is realized through gold wire bonding. Thus, the modeling of the radio frequency simulation path of the ceramic insulator is completed. As shown in fig. 4.

Corresponding material attributes are respectively given to each part of the model, boundary conditions, ports, sweep frequency parameters and the like are set, and then simulation is started. And adjusting the size of the slot between the bonding pads according to the Time Domain Reflectometry (TDR) result at the bonding pads. And finally obtaining the optimal simulation result. After the simulation result is confirmed, the radio frequency wiring of the ceramic tube shell is determined, and then the drawing design of the production stage of the ceramic tube shell can be carried out.

And manufacturing tool dies such as a punching program, a hole filling bushing, a printing silk screen, a laminated protection plate and the like according to the production drawing file. And then carrying out processes of punching, hole filling, printing, laminating, hot cutting, sintering and the like on the cast alumina green ceramic chip to obtain the fired ceramic piece. The porcelain piece needs to be plated with nickel to have brazing condition.

After the fired porcelain piece is plated with nickel, the fired porcelain piece is welded with metal parts such as a wall body, a bottom plate, a light window bracket and the like into a whole through metal welding flux. Then gold plating is carried out on the tube shell to form a protective film on the surface. And then, adhering and welding the light window in the light window bracket hole. Thus, the whole ceramic envelope is manufactured. As shown in fig. 1. The specific flow can be seen in fig. 5, and the pad indicated in fig. 5 can be understood as the first pad 3.

The slotting among the bonding pads is added when the radio frequency performance of the ceramic tube shell is designed, so that the impedance matching of radio frequency can be better realized, the power of a wave source can be effectively transmitted to a load by a transmission system, and the transmission efficiency, the power capacity and the stability of the system are improved.

The utility model not only has one choice for matching the impedance of the radio frequency design of the ceramic tube shell, but also has simple and convenient method as can be seen from the design and the tube shell preparation process, is beneficial to solving the bottleneck problem of the radio frequency performance design of the ceramic insulator, and simultaneously can not increase the process difficulty and the cost.

The above description is intended to be illustrative of the preferred embodiment of the present invention and should not be taken as limiting the utility model, but rather, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the utility model.

Claims

1. A ceramic package for enhancing rf signal transmission performance, comprising:

a housing having a side portion provided with a mounting port;

the ceramic insulator is inserted into and packaged in the shell mounting port in a matched manner, the inner end of the ceramic insulator is arranged on the inner side of the shell, and the outer end of the ceramic insulator is arranged on the outer side of the shell; and

the first bonding pads are uniformly distributed at the upper end of the ceramic insulator in parallel and are positioned outside the shell;

a groove is formed between every two adjacent first bonding pads on the ceramic insulator, so that the dielectric constant between every two adjacent first bonding pads is reduced, and the impedance of a radio frequency transmission line is improved.

2. The ceramic package for improving transmission performance of radio frequency signals according to claim 1, wherein a GND layer is disposed inside the ceramic insulator, and the bottom of the groove is located above the GND layer.

3. The ceramic package for improving the transmission performance of radio frequency signals according to claim 2, wherein the bottom of the recess is covered with an insulating layer for preventing the GND layer from conducting electricity into the recess.

4. A ceramic package for enhancing rf signal transmission as recited in claim 3, wherein the dielectric layer is a ceramic paste.

5. The ceramic package for improving rf signal transmission performance of claim 1, wherein the recess has a long bar shape and a length direction along the length direction of the first pad.

6. The ceramic package for improving the transmission performance of radio frequency signals according to claim 1, wherein the housing comprises a wall, an optical window bracket and a bottom plate, the wall and the bottom plate together form a rectangular structure having a cavity and an opening at the upper end thereof, the opening is communicated with the cavity, and the mounting hole of the housing is formed in the wall at the short side of the rectangular structure.

7. The ceramic package for improving transmission performance of radio frequency signals according to claim 6, wherein the wall is made of ceramic or kovar alloy.

8. The ceramic package for improving transmission performance of radio frequency signals according to claim 1, wherein a structural beam is disposed at an upper end of the ceramic insulator, and after the ceramic insulator is encapsulated in the housing installation opening, the structural beam is adapted to abut against the housing to limit the ceramic insulator.

9. The ceramic package for improving transmission of radio frequency signals according to claim 8, wherein the first bonding pad is located on one side of the structural beam, and a second bonding pad is further disposed on the upper end of the ceramic insulator and electrically connected to the first bonding pad.

10. The ceramic package for improving transmission performance of rf signals of claim 6, wherein a side of the housing opposite to the mounting opening is provided with a mounting hole, and the mounting hole is used for mounting the optical window bracket.