High-efficiency and high-strength wire leading method for high-temperature MEMS device

Abstract

The invention belongs to the technical field of MEMS lead packaging, and relates to a high-efficiency and high-strength lead method for a high-temperature MEMS device, which comprises the following steps of: S1, coating a layer of conductive paste on a lead area of the high-temperature MEMS device with a prepared sensitive layer and to be subjected to lead, and sintering and curing; and S2, pressing and welding a wire into the sintered and cured conductive slurry to serve as a lead. According to the method, the high temperature resistance of the MEMS device is remarkably improved through an innovative strategy of firstly leading wires and then integrally packaging, the advantages of welding and slurry sintering are combined, and the strength and reliability of the leading wires are enhanced through accurate silver slurry printing and sintering processes and accurate pressure welding of pressure welding equipment; the lead method not only ensures the stability and reliability of the device in a severe environment, but also improves the electrical performance of the device, and provides powerful support for wide application of the high-temperature MEMS device.

Description

Technical Field

[0001] The invention belongs to the technical field of MEMS lead packaging and relates to a high-efficiency and high-strength lead method for a high-temperature MEMS device. Background Art

[0002] With the rapid advancement of science and technology and the continuous development of industry, MEMS devices, as miniaturized products integrating mechanical, electronic and sensor technologies, have shown great application potential in various sensors and actuators. Due to their miniaturization, low power consumption and high integration, MEMS devices have been widely used in aerospace, automotive electronics, biomedicine and other fields. However, in high-temperature application scenarios, the stable operation and long-term reliability of MEMS devices have become technical problems that need to be solved urgently.

[0003] Lead packaging is a key link in the communication between MEMS devices and external circuits. Its performance is directly related to the functional realization and life of the entire system. Under high temperature conditions, lead packaging needs to withstand multiple tests such as thermal stress and thermal expansion, which places increasingly stringent requirements on packaging technology. Although traditional lead packaging technologies, such as wire bonding and metal solder sintering, can meet the needs of certain application scenarios to a certain extent, these technologies have obvious shortcomings in high temperature environments. Specifically, traditional wire bonding technology mainly relies on mechanical crimping between metal wires and chip pads. Its high temperature resistance is limited, the lead strength is low, and it is easy to break or fall off at high temperatures, thus affecting the stability of the entire system. Although metal solder sintering technology can achieve a stronger connection, its production process is complex, production efficiency is limited, and solder accumulation is prone to creep at high temperatures, resulting in reduced connection reliability. In addition, as MEMS devices develop towards smaller sizes and higher integration, traditional packaging technology has been difficult to meet its requirements for fine dimensions such as lead spacing and lead height.

[0004] In summary, for MEMS devices working in high-temperature environments, developing an innovative high-efficiency and high-strength lead method for high-temperature MEMS devices is not only of great significance for improving the stability and reliability of MEMS devices, but also the key to promoting the further development and application of MEMS technology. Summary of the invention

[0005] In view of this, an object of the present invention is to provide a high-efficiency and high-strength lead method for a high-temperature MEMS device, so as to solve the shortcomings of the existing lead method.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A high-efficiency and high-strength lead method for a high-temperature MEMS device comprises the following steps:

[0008] S1. Coating a layer of conductive paste on the lead area of ​​the high-temperature MEMS device where the sensitive layer is prepared and to be wired and sintering and curing;

[0009] S2. Then the wire is pressed and welded into the sintered and solidified conductive paste to serve as a lead.

[0010] Further, it also includes step S3;

[0011] S3. An insulating protective film layer is provided on the high-temperature MEMS device as a high-temperature protective layer, and the high-temperature protective layer covers the sensitive layer, the conductive paste and the wire.

[0012] Furthermore, in step S1, the high-temperature MEMS device with a prepared sensitive layer and to be wired is arranged on a wafer, and the wafer has a plurality of high-temperature MEMS devices with a prepared sensitive layer and to be wired, and the high-temperature MEMS devices are arranged in an array on the wafer;

[0013] Before coating the conductive paste, the wafer is firstly fixed in a limited position.

[0014] Furthermore, in step S1, after the conductive paste is sintered and solidified, the wafer is firstly diced into a single row, so as to diced the high temperature MEMS devices on the wafer into a single row of high temperature MEMS devices, so as to facilitate step S3.

[0015] Further, in step S3, the high temperature protection layer covers the entire surface of the single row of high temperature MEMS devices to cover a plurality of high temperature MEMS devices at one time;

[0016] After the high temperature protection layer covers the entire surface of the single-row high temperature MEMS device, the single-row high temperature MEMS device is divided into adhered units, and finally the pieces are split to form a plurality of high temperature MEMS devices that have completed lead packaging.

[0017] Further, in step S3, the high temperature protection layer covers the entire surface of the wafer to cover a plurality of high temperature MEMS devices at one time;

[0018] After the high temperature protection layer covers the entire surface of the wafer, the wafer is divided into adhered units, and finally the wafer is split into a plurality of high temperature MEMS devices with completed lead packaging.

[0019] Furthermore, the conductive paste is one or more of gold-based, silver-based, nickel-based, tungsten-based or platinum-based.

[0020] Furthermore, the material of the wire is one or more of nickel and its alloys, tungsten and its alloys, or platinum and its alloys.

[0021] A high-efficiency and high-strength lead method for a high-temperature MEMS device comprises the following steps:

[0022] S12. In the lead area of ​​the high-temperature MEMS device where the sensitive layer is prepared and to be wired, a wire is welded into the lead area to serve as a lead;

[0023] S22. Then, a layer of conductive paste is coated on the lead area of ​​the high-temperature MEMS device and sintered and solidified.

[0024] Further, it also includes step S32;

[0025] S32. Arrange an insulating protective film layer as a high-temperature protective layer on the high-temperature MEMS device, and the high-temperature protective layer covers the sensitive layer, the conductive paste and the wire.

[0026] The beneficial effects of the present invention are:

[0027] The present invention provides a high-efficiency and high-strength lead method for high-temperature MEMS devices. First, the high-temperature resistance of MEMS devices is significantly improved through an innovative strategy of first lead and then overall packaging. This strategy not only ensures the stable operation of the device in a high-temperature environment, but also simplifies the operation steps by optimizing the production process, thereby improving production efficiency. Compared with the prior art, the present invention has achieved significant improvements in both high-temperature resistance and production efficiency.

[0028] Secondly, the present invention combines the advantages of welding and paste sintering, and enhances the strength and reliability of the lead through precise silver paste printing and sintering processes, as well as precise pressure welding of pressure welding equipment. This lead method not only ensures the stability and reliability of the device in harsh environments, but also improves the electrical performance of the device, providing strong support for the widespread application of high-temperature MEMS devices.

[0029] Finally, the lead method of the present invention is easy to realize automated production. Through the application of automated equipment such as mechanical grippers, fixing fixtures, wire feeding equipment, and pressure welding equipment, efficient and mass production of high-temperature MEMS devices is realized. This not only reduces production costs, but also improves production efficiency, provides a new and efficient solution for the manufacture of high-temperature MEMS devices, and has significant practical value and economic benefits. At the same time, the innovation and practicality of this method also provide a strong impetus for the further development of high-temperature MEMS devices.

[0030] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0032] Figure 1 It is a schematic diagram of fixing the wafer in the embodiment;

[0033] Figure 2 This is a schematic diagram of printing silver paste on a wafer in the embodiment;

[0034] Figure 3 This is a schematic diagram of sintering printed silver paste on a wafer in the embodiment;

[0035] Figure 4 A schematic diagram of dicing a wafer into a single row of high-temperature MEMS devices in an embodiment;

[0036] Figure 5 A schematic diagram of pressure welding leads of a high-temperature MEMS device in an embodiment;

[0037] Figure 6 A schematic diagram of providing a high temperature protection layer for a high temperature MEMS device in an embodiment;

[0038] Figure 7 A schematic diagram of dicing a single-row high-temperature MEMS device into individual MEMS devices in an embodiment;

[0039] Figure 8 It is a schematic diagram of the structure of a high-temperature MEMS device that has completed lead packaging in an embodiment.

[0040] Figure numerals: 1-fixing fixture; 2-wafer; 3-high temperature MEMS device; 4-silver paste printing template; 5-silver paste; 6-single row high temperature MEMS device; 7-laser processing equipment; 8-pressure welding equipment; 9-wire; 10-high temperature protective layer; 11-high temperature MEMS device with completed lead packaging; 12-sensitive area; 13-substrate. DETAILED DESCRIPTION

[0041] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0042] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0043] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0044] See also Figures 1 to 8 , which is an efficient and high-strength lead method for high-temperature MEMS devices. First, the wafer 2 with a functional layer prepared and to be led is taken out. A plurality of high-temperature MEMS devices 3 are arranged on the wafer 2, wherein the body of the high-temperature MEMS device 3 is a high-temperature resistant MEMS product. The material of the substrate 13 in the high-temperature MEMS device 3 is alumina ceramic, and the material of the sensitive area 12 is nickel alloy.

[0045] The high-efficiency and high-strength lead method specifically comprises the following steps:

[0046] Wafer 2 is arranged as a whole on the fixing fixture 1 to limit and fix wafer 2. The fixing fixture 1 is designed with process grooves matching the wafer 2 dicing grooves and vacuum adsorption holes and other structures. A mechanical gripper is used to adsorb and grab wafer 2 from the material rack and place it in the specified position of the fixing fixture 1. After wafer 2 is in place, it is limited and fastened by vacuum adsorption. To ensure the adsorption effect, the vacuum adsorption holes in the uncovered area of ​​wafer 2 are closed, and the mechanical gripper releases wafer 2 and resets to complete the loading and fixing process;

[0047] A layer of silver paste printing template 4 is attached to wafer 2, and a layer of silver paste 5 with a thickness of 50 to 100 μm is printed on the lead electrode area of ​​each high-temperature MEMS device 3 on wafer 2 using a screen printing device. The silver paste 5 needs to evenly and completely cover the lead electrode area; after the silver paste printing is completed, wafer 2 is moved to a high-temperature furnace by moving a fixing fixture 1 to sinter the silver paste. The sintering temperature is 150° C. and the sintering time is 1 hour.

[0048] After the silver paste is sintered, a cutting path is designed according to the size of the high-temperature MEMS device 3 to form a scribe groove, and a laser processing device 7 is used to scribe the wafer 2 along the scribe groove into a single row of high-temperature MEMS devices 6;

[0049] The laser power of the laser processing equipment 7 is set to 500 W, the laser frequency is 200 Hz, the purge gas is compressed air, the gas pressure is 5 bar, and the cutting speed is set to 20 mm / s.

[0050] A nickel-based alloy compensation wire 9 with a diameter of 0.127 mm, which is consistent with the lead area electrode of the high-temperature MEMS device 3, is placed in the wire feeding device, and the wire feeding device is set to automatically extend a 5 mm length of the wire 9, and is pressure-welded in the sintered silver paste on each lead electrode area on the single-row high-temperature MEMS device through the pressure welding device 8, and then the wire feeding device cuts the wire 9;

[0051] The single-row high-temperature MEMS device with completed leads is provided with an insulating protective film layer as a high-temperature protective layer 10 for in-situ packaging protection, and a high-temperature protective layer 11 is provided by electron beam evaporation coating. The material for protecting the high-temperature protective layer 11 is aluminum oxide, and the thickness is set to 5 μm to increase the high-temperature resistance of the MEMS device;

[0052] Set the parameters of the electron beam evaporation coating equipment to 20% electron beam output power, set the coating starting vacuum to 3*e-5Torr, set the coating temperature to 150℃, and set the coating rate Set the oxygen flow rate to 50sccm and the aluminum oxide coating thickness to

[0053] The single-row high-temperature MEMS device 6 that has completed lead packaging is diced by laser cutting. The cutting path is designed according to the size of the MEMS device, and wafer 2 is cut along the edge of the high-temperature MEMS device 11 that has completed lead packaging. The laser power is set to 500W, the laser frequency is 200Hz, the purge gas is compressed air, the gas pressure is 5bar, and the cutting speed is set to 20mm / s. The single-row high-temperature MEMS device is divided into adhered units, and finally the slices form multiple complete high-temperature MEMS devices 11 that have completed lead packaging.

[0054] Key References Figure 8 , which is a structural schematic diagram of a high-temperature MEMS device 11 with completed lead packaging, includes a substrate 13 and a sensitive area 12 arranged on the substrate 13, a silver paste 5 is provided at the lead electrode area in the sensitive area 12, and a wire 9 is press-welded on the silver paste 5, and a high-temperature protective layer covering the sensitive area 12, the silver paste 5 and the wire 9 is also provided on the substrate 13.

[0055] In other embodiments, the material of the substrate 13 can be selected from any one of high temperature resistant materials such as aluminum oxide, magnesium oxide, zirconium oxide, silicon carbide, silicon nitride, boron nitride, silicate, glass, etc.; the material of the sensitive area 12 can be selected from metals such as nickel and its alloys, tungsten and its alloys, platinum and its alloys, and oxides such as indium tin oxide (ITO) and zinc oxide (ZnO), and any one of doped conductive oxide solid solution high temperature resistant materials; the fixing fixture 1 can be used to fix wafer 2 by different fastening methods such as pneumatic, hydraulic, bolt screwing, spring pressing, vacuum adsorption, magnetic adsorption, etc.

[0056] The silver paste 5 can be replaced by one or more conductive pastes such as gold-based, silver-based, nickel-based, tungsten-based, platinum-based and other high-temperature resistant pastes, and the coating of the conductive material can be selected by dispensing or screen printing.

[0057] The wafer 2 may be cut by physical cutting or laser cutting; the high temperature protection layer 11 may be formed by magnetron sputtering, electron beam evaporation, atomic layer deposition or screen printing, and its material may be one or more high temperature resistant materials such as aluminum oxide, magnesium oxide, zirconium oxide, silicon carbide, silicon nitride, boron nitride, silicate, glass, etc.; the wire may be made of one or more wires such as nickel and its alloys, tungsten and its alloys, platinum and its alloys.

[0058] In another embodiment, if the film layer in the lead electrode region of the high-temperature MEMS device is relatively thick, a wire may be directly welded into the lead region of the high-temperature MEMS device by pressure welding to serve as a lead, and then coated with a conductive material and sintered to solidify.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A high-efficiency and high-strength lead method for high-temperature MEMS devices, characterized in that: The following steps are involved: S1. Coating a layer of conductive paste on the lead area of ​​the high-temperature MEMS device where the sensitive layer is prepared and to be wired and sintering and curing; S2. Then the wire is pressed and welded into the sintered and solidified conductive paste to serve as a lead.

2. The high-efficiency and high-strength lead method for high-temperature MEMS devices according to claim 1, characterized in that: Also includes step S3; S3. An insulating protective film layer is provided on the high-temperature MEMS device as a high-temperature protective layer, and the high-temperature protective layer covers the sensitive layer, the conductive paste and the wire.

3. The high-efficiency and high-strength lead method for high-temperature MEMS devices according to claim 2, characterized in that: In step S1, the high-temperature MEMS device with a prepared sensitive layer and to be wired is arranged on a wafer, and the wafer has a plurality of high-temperature MEMS devices with a prepared sensitive layer and to be wired, and the high-temperature MEMS devices are arranged in an array on the wafer; Before coating the conductive paste, the wafer is firstly fixed in a limited position.

4. The high-efficiency and high-strength lead method for high-temperature MEMS devices according to claim 3, characterized in that: In step S1, after the conductive paste is sintered and solidified, the wafer is firstly diced into single rows, so as to diced the high temperature MEMS devices on the wafer into single rows of high temperature MEMS devices, so as to facilitate step S3.

5. The high-efficiency and high-strength lead method for high-temperature MEMS devices according to claim 4, characterized in that: In step S3, the high temperature protection layer covers the entire surface of the single row of high temperature MEMS devices to cover a plurality of high temperature MEMS devices at one time; After the high temperature protection layer covers the entire surface of the single-row high temperature MEMS device, the single-row high temperature MEMS device is divided into adhered units, and finally the pieces are split to form a plurality of high temperature MEMS devices that have completed lead packaging.

6. The high-efficiency and high-strength lead method for high-temperature MEMS devices according to claim 3, characterized in that: In step S3, the high temperature protection layer covers the entire surface of the wafer to cover multiple high temperature MEMS devices at one time; After the high temperature protection layer covers the entire surface of the wafer, the wafer is divided into adhered units, and finally the wafer is split into a plurality of high temperature MEMS devices with completed lead packaging.

7. The high-efficiency and high-strength lead method for high-temperature MEMS devices according to claim 1, characterized in that: The conductive paste is one or more of gold-based, silver-based, nickel-based, tungsten-based or platinum-based.

8. The high-efficiency and high-strength lead method for high-temperature MEMS devices according to claim 1, characterized in that: The material of the wire is one or more of nickel and its alloys, tungsten and its alloys, or platinum and its alloys.

9. A high-efficiency and high-strength lead method for high-temperature MEMS devices, characterized in that: The following steps are involved: S12. In the lead area of ​​the high-temperature MEMS device where the sensitive layer is prepared and to be wired, a wire is welded into the lead area to serve as a lead; S22. Then, a layer of conductive paste is coated on the lead area of ​​the high-temperature MEMS device and sintered and solidified.

10. The high-efficiency and high-strength lead method for high-temperature MEMS devices according to claim 9, characterized in that: Also includes step S32; S32. An insulating protective film layer is provided on the high-temperature MEMS device as a high-temperature protective layer, and the high-temperature protective layer covers the sensitive layer, the conductive paste and the wire.

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