CN218612108U

CN218612108U - Vacuum brazing equipment for sealing and welding MEMS (micro-electromechanical systems) device

Info

Publication number: CN218612108U
Application number: CN202221885365.3U
Authority: CN
Inventors: 刘磊; 刘洋
Original assignee: Beijing Xinyi Technology Co ltd
Current assignee: Beijing Xinyi Technology Co ltd
Priority date: 2022-07-20
Filing date: 2022-07-20
Publication date: 2023-03-14
Anticipated expiration: 2032-07-20

Abstract

The application relates to vacuum brazing equipment for sealing and welding an MEMS device, which comprises a brazing furnace, a workbench, a molecular pump and a mechanical pump; the brazing furnace is arranged on the table top of the workbench; the molecular pump is arranged below the brazing furnace, and an air inlet of the molecular pump is communicated with the bottom of the brazing furnace through a communicating pipe; the air outlet of the molecular pump is communicated with the mechanical pump through a vacuum butterfly valve, a three-way pipe fitting and a first vacuum pipe in sequence; the mechanical pump is arranged below the table top of the workbench and is communicated with the brazing furnace sequentially through the first vacuum tube, the three-way pipe fitting, the second vacuum tube and the pre-suction valve, and the filter is arranged between the first vacuum tube and the mechanical pump and is suitable for filtering fine particles generated by the MEMS device in the sealing and welding process. Through the mode that sets up the vacuum butterfly valve between mechanical pump and molecular pump, ensure that the gas through molecular pump suction is discharged by the mechanical pump, when providing better vacuum environment for the MEMS device, the device is whole more simple and convenient. And the air inlet at the upper end of the mechanical pump is provided with a filter, so that fine particles in the brazing process can be effectively filtered, and the aim of ensuring higher vacuum degree of the sealed and welded MEMS device is fulfilled.

Description

Vacuum brazing equipment for sealing and welding MEMS (micro-electromechanical systems) device

Technical Field

The application relates to the field of vacuum brazing, in particular to vacuum brazing equipment for sealing and welding MEMS devices.

Background

With the development of MEMS (Micro-Electro-Mechanical systems), the packaging requirement for the MEMS device is higher and higher, wherein vacuum brazing is widely applied to the packaging of the MEMS device as a packaging process. The vacuum environment can reduce the air damping of the MEMS device, and is one of the most effective measures for improving the quality factor of the device and the sensitivity of an output signal. Specifically, the MEMS device is heated in a vacuum state, and sealing welding is performed by using a mold, so that the inside of a finished product is in a vacuum state.

The traditional vacuum packaging equipment has a complex device structure, and the vacuum degree of the sealed and welded MEMS device is low.

SUMMERY OF THE UTILITY MODEL

In view of this, the present application provides a vacuum brazing apparatus for sealing and welding a MEMS device, which can effectively enhance the vacuum degree of the sealed and welded MEMS device.

According to one aspect of the application, a vacuum brazing device for sealing and welding a MEMS device is provided, and comprises a workbench, a brazing furnace, a molecular pump and a mechanical pump;

the brazing furnace is arranged on the table top of the workbench;

the molecular pump is arranged below the brazing furnace, and an air inlet of the molecular pump is communicated with the bottom of the brazing furnace through a communicating pipe; the air outlet of the molecular pump is communicated with the mechanical pump sequentially through a vacuum butterfly valve, a three-way pipe fitting and a first vacuum pipe;

the mechanical pump is arranged below the table top of the workbench and is communicated with the brazing furnace through the first vacuum tube, the three-way pipe fitting, the second vacuum tube and the pre-pumping valve in sequence, and a filter is arranged between the first vacuum tube and the mechanical pump and is suitable for filtering fine particles generated in the sealing welding process of the MEMS device.

In a possible implementation manner, the device further comprises a gate valve;

the gate valve is arranged at the air inlet of the molecular pump.

In a possible implementation manner, the communicating pipe is made of stainless steel, and a vacuum measuring meter is inserted into the bottom of the communicating pipe;

the vacuum gauge is adapted to measure the vacuum inside the brazing furnace.

In a possible realization mode, a heating chamber is arranged in the brazing furnace cavity;

a gap is formed between the outer wall of the heating chamber and the inner wall of the brazing furnace, and a gap is also formed between the top of the heating chamber and the lower part of the heating chamber;

a plurality of heaters are distributed on the inner wall of the heating chamber at intervals, and thermocouples are inserted at the top end of the heating chamber.

In a possible implementation manner, a hydraulic rod is further arranged above the table top of the workbench;

the position of the hydraulic rod, which is close to the upper end of the hydraulic rod, is fixedly connected with the top end of the heating chamber, and the hydraulic rod is suitable for controlling the lifting of the position of the heating chamber.

In a possible implementation manner, the system further comprises a control box;

the control box is installed on one side of the workbench, and the control box is respectively electrically connected with the vacuum gauge and the thermocouple.

In a possible implementation manner, an observation window is arranged at the center of the front end of the brazing furnace;

the observation window is suitable for observing the brazing condition in the brazing furnace.

In one possible implementation, the filter is connected with the mechanical pump air inlet through a flange.

In a possible implementation manner, the control box is further electrically connected with a plurality of heaters, and the heaters are nickel-chromium heating wires.

In a possible implementation manner, the furnace body of the brazing furnace is made of stainless steel.

This application is applicable to and encapsulates the processing to MEMS device, needs series connection molecular pump and mechanical pump to bleed in the stove of brazing, consequently controls the two operation of bleeding to the stove inside of brazing through set up the vacuum butterfly valve between molecular pump and mechanical pump mutually supporting. When the vacuum butterfly valve is in a closed state, the mechanical pump is used as a backing pump of the molecular pump, the interior of the brazing furnace is pre-pumped in advance, when the vacuum degree in the brazing furnace is reduced to 10E-0, the molecular pump is started, then the molecular pump is used for further pumping in the high-temperature heating process of the MEMS device, and at the moment, the purpose of exhausting the gas pumped by the molecular pump by the mechanical pump is achieved by opening the vacuum butterfly valve. The working states of the mechanical pump and the molecular pump are flexibly switched through the vacuum butterfly valve, so that the mechanical pump and the molecular pump can be better matched for air exhaust, and the device is integrally simpler and more convenient while the purpose of vacuum brazing is guaranteed. And the filter that sets up in mechanical pump air inlet department can effectively filter the tiny granule that produces to MEMS device heating process, prevents that the pump mouth from blockking up, influences the effect of bleeding. Therefore, the vacuum brazing of the MEMS device is realized, and the vacuum degree of the sealed and welded MEMS device is higher.

Other features and aspects of the present application will become apparent from the following detailed description of exemplary embodiments, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments, features, and aspects of the application and, together with the description, serve to explain the principles of the application.

FIG. 1 is a main structure diagram of a vacuum brazing apparatus for sealing a MEMS device according to an embodiment of the present application;

FIG. 2 illustrates a side view of a vacuum brazing apparatus for MEMS device sealing in accordance with an embodiment of the present application;

fig. 3 shows a schematic structural diagram of a water cooler connected with a vacuum brazing apparatus according to an embodiment of the present application.

Detailed Description

Various exemplary embodiments, features and aspects of the present application will be described in detail below with reference to the accompanying drawings. In the drawings, like reference numbers can indicate functionally identical or similar elements. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

It will be understood, however, that the terms "central," "longitudinal," "lateral," "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in an orientation or positional relationship indicated in the drawings for convenience in describing the present application or for simplicity of description, and do not indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be considered limiting of the present application.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a better understanding of the present application. It will be understood by those skilled in the art that the present application may be practiced without some of these specific details. In some instances, methods, means, elements and circuits that are well known to those skilled in the art have not been described in detail so as not to obscure the present application.

FIG. 1 is a main structure diagram of a vacuum brazing apparatus for sealing a MEMS device according to an embodiment of the present application; fig. 2 shows a side view of a vacuum brazing apparatus for MEMS device sealing according to an embodiment of the present application. As shown in fig. 1 and 2, the vacuum brazing equipment for sealing and welding the MEMS device comprises a brazing furnace and a workbench; the brazing furnace 100 is arranged on the table top of the workbench 200; the molecular pump 110 is arranged below the brazing furnace 100, the air inlet of the molecular pump 110 is communicated with the bottom of the brazing furnace 100 through a communicating pipe 180, and the air outlet of the molecular pump 110 is communicated with the mechanical pump 120 sequentially through a vacuum butterfly valve 130, a three-way pipe 133 and a first vacuum pipe 131; the mechanical pump 120 is arranged below the table top of the workbench 200 and is communicated with the brazing furnace 100 sequentially through a first vacuum tube 131, a three-way pipe 133, a second vacuum tube 132 and a pre-suction valve 150, a filter 140 is arranged between the first vacuum tube 131 and the mechanical pump 120, and the filter 140 is suitable for filtering fine particles generated in the sealing and welding process of the MEMS device.

Here, it should be noted that, in the process of performing air suction on the MEMS device, the vacuum butterfly valve 130 needs to be closed first, and the interior of the brazing furnace 100 needs to be air-sucked only by the mechanical pump 120, and it should be noted that, the pre-suction valve 150 is provided at the rear end of the brazing furnace 100, and the first vacuum tube 131, the tee tube 133, and the second vacuum tube 132 are provided between the brazing furnace and the mechanical pump 120, and before performing heat brazing on the MEMS module, the pre-suction valve 150 is opened first, the interior of the brazing furnace 100 is pre-sucked by the mechanical pump 120, and the process of opening the pre-suction valve 150 needs to be performed slowly, and the process of pre-suction needs to be performed for more than 40 min. When the vacuum degree is reduced to 1E-0, pre-pumping is completed, the molecular pump is opened after the pre-pumping valve 150 is closed, and air is pumped in the heating process of the MEMS device through the molecular pump 110 so as to carry out formal brazing. Specifically, in the process, the vacuum butterfly valve 130 needs to be opened, so that the gas generated in the heating sealing process of the MEMS device can be pumped out through the molecular pump 110, and the gas is exhausted by using the mechanical pump 120 in a matching manner. Because the improvement of the vacuum degree of the MEMS device is difficult to realize only by a molecular pump, the vacuum butterfly valve 130 is arranged between the molecular pump 110 and the mechanical pump 120, the mutual matching work of the molecular pump 110 and the mechanical pump 120 can be effectively ensured, the integral arrangement of the device is simpler and more convenient while the vacuum brazing purpose of the MEMS module can be realized, and the production and maintenance cost of the device is lower. The molecular pump 110 used in this embodiment is a turbine magnetic suspension type molecular pump, which obtains ultra-high vacuum by carrying gas molecules with blades rotating at high speed.

It should be particularly noted that a filter 140 is further disposed at the air inlet at the upper end of the mechanical pump 120, and the filter 140 is used to filter out fine particles generated by sealing and welding at a high temperature during the vacuum brazing process, so as to prevent the mechanical pump 120 from being blocked, provide a good vacuum environment for the MEMS device, and ensure that the vacuum degree inside the brazing furnace is less than 10 ^-5 -10 ^-9 Pa, so that the vacuum degree of the sealed and welded MEMS device is higher.

It should be further noted that the joint between the brazing furnace 100 and the workbench 200 is sealed by a sealing ring, so as to ensure the overall air tightness inside the brazing furnace and further achieve the purpose of vacuum brazing.

In one possible implementation, a gate valve 160 is further included; wherein the gate valve 160 is disposed at the air inlet of the molecular pump 110.

Here, the gate valve 160 is provided to control the process of evacuating the entire interior of the brazing furnace 100 by the molecular pump 110. After the mechanical pump 120 finishes pre-pumping, the pre-pumping valve 150 is closed, the vacuum butterfly valve 130 is opened, and meanwhile, the gate valve 160 is also required to be completely opened, so that the molecular pump 110 continuously pumps air in the heating process, and the vacuum degree in the furnace is guaranteed.

In one possible implementation, the communicating tube 180 is made of stainless steel, and a vacuum gauge 183 is provided at the bottom thereof; the vacuum gauge 183 is adapted to measure the vacuum inside the brazing furnace.

Here, it should be noted that the brazing furnace 100 and the molecular pump 110 are communicated with each other by providing a stainless steel communication pipe, and a vacuum gauge 183 is inserted into the lower end of the communication pipe 180, so as to monitor the specific vacuum degree inside the brazing furnace in real time, specifically, the resistance vacuum gauge 181 and the ionization vacuum gauge 182 are used for monitoring.

In one possible implementation, a heating chamber 195 is provided in the brazing furnace 100 cavity; a gap is formed between the outer wall of the heating chamber 195 and the inner wall of the brazing furnace 100, and a gap is also formed between the top of the heating chamber 195 and the lower part thereof; a plurality of heaters 194 are disposed at intervals on the inner wall of the heating chamber 195, and a thermocouple 193 is inserted into the top end of the heating chamber 195.

Here, it should be noted that a plurality of heaters 194 are disposed inside a heating chamber 195 disposed inside the brazing furnace to provide a heat source for the whole brazing process, and the specific temperature can be adjusted according to actual needs. Wherein the outer wall of brazing furnace 100 is provided with cooling water inlet 191 and cooling water outlet 192 respectively, and is concrete, and cold water inlet 191 sets up at cold water outlet 192 lower extreme, all is applicable to and connects the water-cooled generator, lets in the cooling water and carries out cooling treatment to equipment, prevents brazing furnace 100 casing deformation, ensures the gas tightness of equipment from this. Meanwhile, as shown in fig. 3, the top end of the heating chamber 195 is also connected to a water cooler 400 through a cold water pipe, and the water cooler 400 has a water temperature of 20 ℃ for cooling after heating. It should be noted that the working state of the water cooling machine needs to be concerned at any time during the preheating process, and the heating needs to be stopped in time when the water temperature is abnormal.

In a possible implementation manner, a hydraulic rod 190 is further disposed above the table top of the workbench 200; the hydraulic rod 190 is fixedly connected to the top end of the heating chamber 195 near the upper end thereof, and the hydraulic rod 190 is adapted to control the elevation of the heating chamber 195.

Here, the cover plate side of the heating chamber 195 is fixedly connected to a position near the top end of the hydraulic rod, and the heating chamber is controlled to be raised and lowered by the operation of the operation handle of the hydraulic rod 190. Because the top apron area of heating chamber is greater than its lower extreme barrel area, and apron size and brazing stove top opening phase-match, so adopt between heating chamber 195 apron and brazing stove 100 top to have the sealing washer to seal, the holistic gas tightness of guarantee equipment that can be better, it describes to need to explain, it still is provided with breather valve 170 to deviate from hydraulic stem one side at brazing stove 100, be used for adjusting the inside atmospheric pressure of brazing stove, specifically for after sealing, through slowly opening breather valve 170, it is full of gas in the guarantee brazing stove 100 to bleed repeatedly many times, make inside and outside atmospheric pressure unanimous, the realization is with the purpose of taking out in the brazing stove 100 of sealing material from this.

It should be noted that the thermocouple 193 is inserted at the top end of the heating chamber 195 to detect the internal temperature thereof.

In one possible implementation, the system further comprises a control box 300; the control box 300 is installed at one side of the table 200, and the control box 300 is electrically connected to the vacuum gauge 183 and the thermocouple 193, respectively.

Here, it should be noted that the control box 300 is electrically connected to the vacuum gauge 183 and the thermocouple 193, the thermocouple 193 transmits the acquired internal temperature to the control box 300, and the control box 300 controls the heater 194 according to the current temperature, thereby accurately controlling the internal temperature of the brazing furnace in real time. Meanwhile, the control box 300 is also provided with a display, and the brazing temperature is displayed more visually by the display, so that the temperature is conveniently controlled.

In one possible implementation manner, a viewing window 172 is arranged at the center of the front end of the brazing furnace 100; the observation window 172 is adapted to observe the brazing conditions inside the brazing furnace 100.

Here, it should be noted that, the observation window 172 is disposed at the center of the front end of the brazing furnace 100, so that the specific brazing situation inside the brazing furnace 100 can be observed more intuitively, and the upper die and the lower die can be attached to each other.

In one possible implementation, the filter 140 is flanged to the inlet of the mechanical pump 120.

It should be noted that, the filter 140 is connected to the mechanical pump 120 and the first vacuum tube 131 by flanges, and the filter element inside the filter 140 is a detachable filter element assembly, which is easy to clean and replace and can better ensure the pumping speed and the pumping effect.

In one possible implementation, the control box 300 is further electrically connected to a plurality of heaters 194, and the heaters 194 are nichrome wires.

Here, it should be noted that the plurality of heaters 194 provides better temperature conditions for vacuum brazing of the MEMS device. Meanwhile, the heater is connected with the control box, and when the temperature collected by the thermocouple is transmitted to the control box, the control box 300 controls the heaters 194 according to the collected temperature, so that the heating temperature is adjusted, and the accurate control of the heating temperature is facilitated.

In one possible implementation, the brazing furnace 100 is made of stainless steel.

Here, considering the adaptability of the equipment to gas, stainless steel is used as the material of the furnace body of the brazing furnace 100, and stainless steel is used for the heating chamber, which is further advantageous for ensuring the airtightness of the apparatus.

Having described embodiments of the present application, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen in order to best explain the principles of the embodiments, the practical application, or improvements made to the technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A vacuum brazing device for sealing and welding MEMS devices is characterized by comprising a workbench, a brazing furnace, a molecular pump and a mechanical pump;

the brazing furnace is arranged on the table top of the workbench;

the mechanical pump is arranged below the table top of the workbench and is communicated with the brazing furnace through the first vacuum pipe, the three-way pipe fitting, the second vacuum pipe and the pre-pumping valve in sequence; and a filter is arranged between the first vacuum tube and the mechanical pump and is suitable for filtering fine particles generated in the sealing and welding process of the MEMS device.

2. The vacuum brazing apparatus for sealing a MEMS device according to claim 1, further comprising a gate valve;

the gate valve is arranged at the air inlet of the molecular pump.

3. The vacuum brazing apparatus for sealing and welding a MEMS device according to claim 1, wherein the communicating tube is made of stainless steel, and a vacuum gauge is inserted into the bottom of the communicating tube;

the vacuum gauge is adapted to measure the vacuum inside the brazing furnace.

4. The vacuum brazing apparatus for sealing and welding a MEMS device according to claim 3, wherein a heating chamber is arranged in the brazing furnace chamber;

a plurality of heaters are distributed on the inner wall of the heating chamber at intervals, and thermocouples are inserted into the top of the heating chamber.

5. The vacuum brazing apparatus for sealing and welding a MEMS device according to claim 4, wherein a hydraulic rod is further arranged above the table top of the workbench;

the position of the hydraulic rod, which is close to the upper end of the hydraulic rod, is fixedly connected with the top of the heating chamber, and the hydraulic rod is suitable for controlling the lifting of the position of the heating chamber.

6. The vacuum brazing apparatus for sealing a MEMS device according to claim 4, further comprising a control box;

7. The vacuum brazing apparatus for sealing a MEMS device according to claim 1, wherein an observation window is provided at a center position of a front end of the brazing furnace;

8. The vacuum brazing apparatus for sealing a MEMS device according to claim 1, wherein the filter is flanged to the mechanical pump inlet.

9. The vacuum brazing apparatus for sealing a MEMS device according to claim 6, wherein said control box is further electrically connected to a plurality of said heaters, said heaters being nichrome wire.

10. The vacuum brazing apparatus for sealing and welding the MEMS device according to any one of claims 1 to 9, wherein the furnace body of the brazing furnace is made of stainless steel.