A micro-connection system based on ultrasonic laser coupling mechanism

Abstract

The present invention relates to the field of micro-connection technology, and provides a micro-connection system based on the ultrasonic laser coupling mechanism, comprising: a base, an ultrasonic vibration device, a positioning mechanism, a pressure mechanism and a laser generating device; the ultrasonic vibration device is arranged on the base, and the ultrasonic vibration device includes a vibration part, and the vibration part is provided with a first positioning groove, and the first positioning groove is used to fix the lower substrate of the sample to be connected; the positioning mechanism is arranged on the base, and the positioning mechanism includes a positioning platform, and the positioning platform is provided with a second positioning groove, and the second positioning groove is used to fix the upper cover plate of the sample to be connected. The pressure mechanism includes a pressure block, and the pressure block is used to extend into the second positioning groove to apply pressure to the upper cover plate; the laser generating device includes a laser emitting head, and the laser emitting head is used to emit laser to the area in the second positioning groove or around the second positioning groove. The present invention solves the defects in the prior art that the micro-connection technology using laser as a heat source cannot guarantee the mechanical properties of the micro-connection solder joints and cannot guarantee the airtightness of the package.

Description

Technical Field

[0001] The present invention relates to the field of micro-connection technology, and in particular to a micro-connection system based on an ultrasonic laser coupling mechanism. Background Art

[0002] In recent years, micro-connection technology using laser as heat source has gradually matured, breaking the stereotype that high-energy-density lasers cause thermal damage to IC chips. Due to the high concentration of laser energy, under the condition of reasonable adjustment of process parameters, selective precision heating of the packaging structure can be achieved, and the size of the heat-affected zone can be strictly controlled. It effectively avoids damage to heat-sensitive components caused by heat input during the interconnection process, thereby improving the reliability of the packaging structure. This process is suitable for scenarios with high-precision requirements for material interconnection and component packaging.

[0003] However, due to the instantaneous nature of the laser heat source, the extremely high heating / cooling rate causes the solder joint to cool and solidify within a few seconds after the heating is stopped, which severely restricts the metallurgical reaction. The element diffusion and recrystallization reactions are forced to be interrupted, which is not conducive to the formation of homogeneous and refined intermetallic compound components. The formation and evolution of each intermetallic compound member in the micro-joint solder joint is the decisive factor affecting the strength and performance of the solder joint. The single laser process mechanism makes it impossible to guarantee the mechanical properties of the solder joint and the airtightness of the package. Summary of the invention

[0004] The present invention provides a micro-connection system based on the ultrasonic laser coupling mechanism, which is used to solve the defects in the prior art that the micro-connection technology using laser as a heat source cannot guarantee the mechanical properties of the micro-connection solder joints and cannot ensure the airtightness of the package.

[0005] The invention provides a micro-connection system based on an ultrasonic laser coupling mechanism, comprising a base, an ultrasonic vibration device, a positioning mechanism, a pressure applying mechanism and a laser generating device.

[0006] The ultrasonic vibration device is arranged on the base, and comprises a vibration part, and the vibration part is provided with a first positioning groove, and the first positioning groove is used to fix the lower base of the sample to be connected.

[0007] The positioning mechanism is arranged on the base, and the positioning mechanism comprises a positioning platform, and the positioning platform is provided with a second positioning groove, and the second positioning groove is used to fix the upper cover plate of the sample to be connected.

[0008] The pressure mechanism includes a pressure block, and the pressure block is used to extend into the second positioning groove to apply pressure to the upper cover plate.

[0009] The laser generating device comprises a laser emitting head, and the laser emitting head is used to emit laser into the second positioning groove or the area around the second positioning groove.

[0010] According to the micro-connection system based on the ultrasonic laser coupling mechanism provided by the present invention, the pressure mechanism also includes a pressure plate, the pressure block is connected to the pressure plate, a transmission groove for transmitting laser is provided on the pressure plate, the pressure block is located on the first side of the transmission groove, the laser emission head is arranged on the second side of the transmission groove, and the pressure block is made of a material that can transmit laser.

[0011] According to the micro-connection system based on the ultrasonic laser coupling mechanism provided by the present invention, the pressing block is made of sapphire ceramic.

[0012] According to the micro-connection system based on the ultrasonic laser coupling mechanism provided by the present invention, the pressure-applying mechanism also includes a pressure-regulating component, and the pressure-regulating component includes two pressure-regulating screws and two pressure-regulating nuts. One end of the pressure-regulating screw is connected to the positioning platform, and the two pressure-regulating screws are symmetrically arranged on both sides of the pressure plate, and the pressure-regulating nuts are threadedly matched with the pressure-regulating screws in a one-to-one correspondence.

[0013] According to the micro-connection system based on the ultrasonic laser coupling mechanism provided by the present invention, the pressure-applying mechanism further includes a fixed cover, and the fixed cover is connected to the pressing plate.

[0014] The pressing plate includes a main body and a pressure-applying portion, wherein the pressure-applying portion is connected to the main body, the main body is disposed between the pressing plate and the fixing cover, and the pressure-applying portion extends out of the fixing cover.

[0015] Pressure sensors are symmetrically arranged between the two sides of the main body and the pressure plate.

[0016] According to the micro-connection system based on the ultrasonic laser coupling mechanism provided by the present invention, a third positioning groove is provided on the positioning platform, a laser transmission positioning plate is provided in the third positioning groove, the second positioning groove is provided on the laser transmission positioning plate, and the laser transmission positioning plate is made of a material that can transmit laser.

[0017] According to the micro-connection system based on the ultrasonic laser coupling mechanism provided by the present invention, the laser transmission positioning plate is made of sapphire ceramic.

[0018] According to the micro-connection system based on ultrasonic laser coupling mechanism provided by the present invention, the upper and lower end surfaces of the vibration part are provided with positioning blocks, the first positioning groove is provided on the positioning block, and the positioning block is made of polytetrafluoroethylene material.

[0019] According to the micro-connection system based on the ultrasonic laser coupling mechanism provided by the present invention, the positioning mechanism also includes a support plate, the support plate is arranged on the base, the positioning platform is arranged on the support plate, and the positioning platform is an X / Y / R three-axis displacement platform.

[0020] According to the micro-connection system based on the ultrasonic laser coupling mechanism provided by the present invention, the ultrasonic vibration device also includes an ultrasonic transducer, an ultrasonic vibration head, a first fixing seat, a fixing ring, a second fixing seat, a limiter and a buffer pad.

[0021] The first fixing seat is rigidly connected to the base, a mounting groove is provided on the first fixing seat, the fixing ring is arranged in the mounting groove and forms a limiting slot with the first fixing seat, a limiting flange is formed on the outer wall of the ultrasonic transducer along the circumferential direction, the limiting flange is engaged with the limiting slot, the ultrasonic vibration head is connected to the ultrasonic transducer, and the vibration part is arranged at the end of the ultrasonic vibration head.

[0022] The second fixing seat is arranged on the base, a limiting groove is arranged on the second fixing seat, the limiting member is arranged in the limiting groove, the buffer pad is arranged on the inner wall of the limiting member, and the outer wall of the ultrasonic vibration head flexibly abuts against the buffer pad.

[0023] The micro-connection system based on the ultrasonic laser coupling mechanism provided by the present invention is provided with an ultrasonic vibration device, a positioning mechanism, a pressure mechanism and a laser generating device. When the lower substrate and the upper cover plate of the sample to be connected are connected, the lower substrate is placed in a first positioning groove with the side provided with an airtight packaging material (such as a transient liquid phase micro-connection material, a glass frit, an epoxy resin, etc.) facing upward, and the upper cover plate is placed in a second positioning groove with the side provided with the airtight packaging material facing downward, and pressure is applied to the upper cover plate by a pressing block. At the same time, the ultrasonic vibration device and the laser generating device are operated according to set parameters, and laser and ultrasonic vibrations are applied to the positions of the lower substrate and the upper cover plate, so that a micro-connection structure with good mechanical properties and airtightness is formed between the lower substrate and the upper cover plate, thereby solving the defects in the prior art that the micro-connection technology using laser as a heat source cannot guarantee the mechanical properties of the micro-connection weld and cannot ensure the airtightness of the package.

[0024] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1It is one of the schematic diagrams of a micro-connection system based on the ultrasonic laser coupling mechanism provided in an embodiment of the present invention.

[0027] Figure 2 This is the second schematic diagram of the micro-connection system based on the ultrasonic laser coupling mechanism provided in an embodiment of the present invention.

[0028] Figure 3 It is a schematic diagram of a positioning platform in a micro-connection system based on the ultrasonic laser coupling mechanism provided by an embodiment of the present invention.

[0029] Figure 4 It is one of the schematic diagrams of the pressure-applying mechanism in the micro-connection system based on the ultrasonic laser coupling mechanism provided by the embodiment of the present invention.

[0030] Figure 5 This is the second schematic diagram of the pressure-applying mechanism in the micro-connection system based on the ultrasonic laser coupling mechanism provided in an embodiment of the present invention.

[0031] Figure 6 This is the third schematic diagram of the pressure-applying mechanism in the micro-connection system based on the ultrasonic laser coupling mechanism provided in the embodiment of the present invention.

[0032] Figure 7 It is one of the schematic diagrams of the ultrasonic vibration device in the micro-connection system based on the ultrasonic laser coupling mechanism provided by the embodiment of the present invention.

[0033] Figure 8 This is the second schematic diagram of the ultrasonic vibration device in the micro-connection system based on the ultrasonic laser coupling mechanism provided by the embodiment of the present invention.

[0034] Reference numerals:

[0035] 10. Base; 20. Ultrasonic vibration device; 210. Vibration part; 220. Positioning block; 221. First positioning groove; 230. Ultrasonic transducer; 240. Ultrasonic vibration head; 250. First fixing seat; 260. Fixing ring; 270. Second fixing seat; 280. Limiting member; 290. Buffer pad; 30. Positioning mechanism; 310. Positioning platform; 311. Third positioning groove; 320. Laser transmission positioning sheet; 321. Second positioning groove; 330. Support plate; 40. Pressing mechanism; 410. Pressing block; 411. Main body; 412. Pressing part; 420. Pressing plate; 421. Transmission groove; 430. Pressure regulating screw; 440. Pressure regulating nut; 450. Fixing cover; 460. Pressure sensor. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0038] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0039] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0040] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0041] Combine the following Figures 1 to 8 The present invention describes a micro-connection system based on the ultrasonic laser coupling mechanism.

[0042] It should be noted that the “lower substrate” mentioned below specifically refers to the lower substrate of the sample to be connected, and the “upper cover” mentioned below specifically refers to the upper cover of the sample to be connected.

[0043] See also Figures 1 to 3 As shown, the micro-connection system based on the ultrasonic laser coupling mechanism provided by the embodiment of the present invention includes: a base 10, an ultrasonic vibration device 20, a positioning mechanism 30, a pressure mechanism 40 and a laser generating device (not shown in the figure).

[0044] Among them, the ultrasonic vibration device 20 is arranged on the base 10, and the ultrasonic vibration device 20 includes a vibration part 210, and the vibration part 210 is provided with a first positioning groove 221, and the first positioning groove 221 is used to fix the lower substrate; the positioning mechanism 30 is arranged on the base 10, and the positioning mechanism 30 includes a positioning platform 310, and the positioning platform 310 is provided with a second positioning groove 321, and the second positioning groove 321 is used to fix the upper cover plate; the pressure mechanism 40 includes a pressure block 410, and the pressure block 410 is used to extend into the second positioning groove 321 to apply pressure to the upper cover plate; the laser generating device includes a laser emission head, and the laser emission head is used to emit laser to the second positioning groove 321 or the area around the second positioning groove 321.

[0045] The micro-connection system based on the ultrasonic laser coupling mechanism provided by the present invention is provided with an ultrasonic vibration device 20, a positioning mechanism 30, a pressure mechanism 40 and a laser generating device. When the lower substrate and the upper cover are connected, the lower substrate is placed in the first positioning groove 221, so that the side provided with the airtight packaging material (such as transient liquid phase micro-connection material, glass frit, epoxy resin, etc.) faces upward, and the upper cover is placed in the second positioning groove 321, so that the side provided with the airtight packaging material faces downward, and pressure is applied to the upper cover by the pressing block 410. At the same time, the ultrasonic vibration device 20 and the laser generating device are operated according to the set parameters, and laser and ultrasonic vibrations are applied to the positions of the lower substrate and the upper cover, so that a micro-connection structure with good mechanical properties and airtightness is formed between the lower substrate and the upper cover, thereby solving the defects in the prior art that the micro-connection technology using laser as a heat source cannot guarantee the mechanical properties of the micro-connection solder joints and cannot ensure the airtightness of the package.

[0046] Specifically, the unique acoustic cavitation effect of ultrasound can generate millions of continuously imploding cavitation bubbles inside the solder joint, forming a local environment of high temperature and high pressure, thereby accelerating the diffusion and nucleation of liquid metal, promoting the metallurgical reaction process between metal elements, eliminating grain boundary lines, and forming a uniform and dense interconnection interface. The specific principle is: after the ultrasonic vibration device 20 is started, when the sound pressure exceeds the cavitation threshold, a large number of cavitation bubbles are generated in the molten solder layer, and these bubbles gradually undergo nucleation, expansion and implosion collapse. The diameter of the cavitation bubble can be as small as tens of microns or as large as hundreds of microns, and the gas in the molten interlayer acts as a nucleation point. A cycle of the cavitation bubble is shorter than 50μs, and the temperature at the center of the implosion can reach thousands of K or more, becoming a local hot spot. After the implosion, due to the pressure difference between the inside and outside, the movement of the surrounding liquid is hindered, and a large number of microjets and shock waves are generated, with a speed of up to 1000m / s. The impact and high temperature of the microjets cause the interface of the solid material to be "etched". This material interface etching phenomenon caused by ultrasound is called "acoustic erosion". Acoustic erosion first erodes and breaks the oxide layer on the surface of the parent material, causing it to decompose into the liquid phase. The wettability between the two is poor, and the strong acoustic flow caused by ultrasound causes the liquid phase to stir violently to remove the oxide layer, thereby enhancing the wettability of the liquid phase and the parent material. The shear force generated by ultrasound in liquid metal can promote the diffusion of atoms and the elimination of surface defects, making the bonding interface denser and more uniform, thereby reducing the stress of the interface and the formation of grain boundary lines. At the same time, sound waves will also cause convection inside the liquid metal, making it easier for unstable factors such as impurities to diffuse and be eliminated during the flow process, which is conducive to the formation of uniform grains. The unique acoustic cavitation effect of ultrasound is used to accelerate the metal metallurgical reaction to solve the problem of long-term heating in traditional micro-joining processes, so as to achieve fast and highly reliable interconnection.

[0047] The micro-connection system based on the ultrasonic laser coupling mechanism provided by the present invention combines the unique acoustic cavitation effect of ultrasound with the process advantages of laser selective heat source, and realizes a fast, precise, and highly reliable airtight interconnection process for metal-based interconnection material systems such as transient liquid phase micro-connection materials. It is expected to provide technical solutions for multiple application scenarios such as integrated circuits, aerospace and military industry, and consumer electronics.

[0048] See also Figures 4 to 6 As shown, according to some embodiments of the present invention, the pressure mechanism 40 also includes a pressure plate 420, the pressure block 410 is connected to the pressure plate 420, and a transmission groove 421 for transmitting laser is provided on the pressure plate 420. The pressure block 410 is located on a first side of the transmission groove 421, and the laser emission head is located on a second side of the transmission groove 421. The pressure block 410 is made of a material that can transmit laser.

[0049] It should be noted that the above-mentioned “first side of the transmissive slot 421” specifically refers to Figure 5 The right side of the transmission slot 421, the above-mentioned "second side of the transmission slot 421" specifically refers to Figure 5 The left side of the middle transmission slot 421.

[0050] Specifically, the laser emitted by the laser emitting head can reach the back of the pressing block 410 through the transmission groove 421 . Since the pressing block 410 is made of a material that can transmit laser light, the laser can pass through the pressing block 410 to reach the area inside or around the second positioning groove 321 .

[0051] Since different materials have different transmittances to lasers, the selection of the material of the pressure plate 420 needs to ensure the highest possible transmittance to the laser to heat the components, while having a certain mechanical strength and rigidity to meet the force requirements.

[0052] As an example, the embodiment of the present invention is described by taking a laser generating device with an output ray wavelength of 980nm as an example, based on which, sapphire ceramic is selected as the preparation material of the compact 410. The measurement data of the infrared absorption spectrometer show that the average transmittance of the sapphire ceramic material for the laser with a wavelength of 980nm reaches more than 80%, and it can absorb the laser energy well for interconnection. Subsequently, the absorption rate of the upper cover plate material to the laser energy can be further improved by designing and depositing an optical anti-reflection layer.

[0053] Therefore, as a preferred embodiment, the pressing block 410 is made of sapphire ceramic.

[0054] See also Figures 4 to 6As shown, according to some embodiments of the present invention, the pressure mechanism 40 further includes a pressure regulating assembly, which includes two pressure regulating screws 430 and two pressure regulating nuts 440, one end of the pressure regulating screw 430 is connected to the positioning platform 310, and the two pressure regulating screws 430 are symmetrically arranged on both sides of the pressure plate 420, and the pressure regulating nuts 440 are threadedly matched with the pressure regulating screws 430 in a one-to-one correspondence. By symmetrically arranging the pressure regulating screws 430 and the pressure regulating nuts 440 on both sides of the pressure plate 420, it is possible to apply a clamping force to both sides of the pressure plate 420 by rotating the two pressure regulating nuts 440, and to apply pressure to the upper cover plate located in the second positioning groove 321 through the pressure block 410, so that it can maintain relative stability with the lower base located in the first positioning groove 221 during the micro-connection process. In addition, by controlling the rotation direction and rotation angle of the two pressure regulating nuts 440, it is also possible to control the pressure applied by the pressure block 410 to the upper cover plate.

[0055] Further, see Figures 4 to 6 As shown, according to some embodiments of the present invention, the pressure mechanism 40 further includes a fixed cover 450, which is connected to the pressure plate 420, and the pressure plate 420 includes a main body 411 and a pressure part 412, which is connected to the main body 411, and the main body 411 is arranged between the pressure plate 420 and the fixed cover 450, and the pressure part 412 extends out of the fixed cover 450, and pressure sensors 460 are symmetrically arranged between the two sides of the main body 411 and the pressure plate 420. The fixed cover 450 can fix the main body 411 of the pressure block 410 on the pressure plate 420, and enable the pressure applied by the pressure adjusting nut 440 to the pressure plate 420 to be transmitted to the pressure block 410, and the pressure part 412 extending out of the fixed cover 450 can extend into the second positioning groove 321 to apply pressure to the upper cover. The pressure sensors 460 symmetrically arranged between the two sides of the main body 411 and the pressure plate 420 can detect the pressure applied by the two pressure regulating nuts 440 to prompt the operator. When the pressure values ​​of the two pressure sensors 460 are inconsistent or do not reach the set value, the pressure can be adjusted by rotating the corresponding pressure regulating nuts 440 to make the pressure value reach the preset requirement.

[0056] Specifically, see Figure 6 As shown, the detection end of the pressure sensor 460 abuts against the main body 411 of the pressure block 410, and after the pressure-applying part 412 abuts against the upper cover plate, the upper cover plate has a reaction force on the pressure-applying part 412 (and the main body 411), and the reaction force detected by the pressure sensor 460 is the pressure applied by the pressure-adjusting nut 440. The pressure values ​​of the two pressure sensors 460 can be displayed by a dual-channel display.

[0057] See also Figures 1 to 3As shown, according to some embodiments of the present invention, a third positioning groove 311 is provided on the positioning platform 310, a laser transmission positioning piece 320 is provided in the third positioning groove 311, a second positioning groove 321 is provided on the laser transmission positioning piece 320, and the laser transmission positioning piece 320 is made of a material that can transmit laser. By providing the third positioning groove 311 on the positioning platform 310, and providing the laser transmission positioning piece 320 made of a material that can transmit laser in the third positioning groove 311, the second positioning groove 321 provided on the laser transmission positioning piece 320 can position the upper cover plate to ensure its stable position during the micro-connection process. In addition, if the laser emitted from the laser transmitting head needs to irradiate the area around the second positioning groove 321, the laser transmission positioning piece 320 can transmit the laser, so that the laser reaches the area around the second positioning groove 321 with less energy loss.

[0058] According to some embodiments of the present invention, the laser transmission positioning plate 320 is detachably disposed in the third positioning groove 311 so that laser transmission positioning plates 320 of different specifications can be replaced according to different needs. Second positioning grooves 321 of different sizes are formed on laser transmission positioning plates 320 of different specifications to adapt to the positioning requirements of different upper cover plates.

[0059] Preferably, the laser transmission positioning plate 320 is also made of sapphire ceramics. The specific reasons are as mentioned above and will not be repeated here.

[0060] See also Figure 7 As shown, according to some embodiments of the present invention, the upper and lower end surfaces of the vibration part 210 are provided with positioning blocks 220, the first positioning groove 221 is provided on the positioning block 220, and the positioning block 220 is made of polytetrafluoroethylene material. During micro-connection, the lower substrate is fixed in the first positioning groove 221 of the positioning block 220. The positioning block 220 made of polytetrafluoroethylene material has a lower thermal conductivity at room temperature, which can reduce the heat dissipation of the laser to the rest of the platform structure. And because the upper and lower end surfaces of the vibration part 210 are provided with positioning blocks 220, positioning blocks 220 of different specifications can be set on the upper and lower end surfaces of the vibration part 210 according to needs to adapt to the installation and positioning of lower substrates of different specifications.

[0061] Specifically, the thermal conductivity of the positioning block 220 material directly affects the dissipation rate of the laser energy. If the thermal conductivity of the positioning block 220 is good, the laser energy cannot be accumulated inside the component and is dissipated to the rest of the platform structure through the positioning block 220, which seriously affects the heating effect. In the field of thermodynamics, Fourier's law is used to analyze and predict heat conduction behavior, thereby describing the heat transfer process. Its mathematical expression is: .

[0062] Among them, q is the heat flux density, which represents the amount of heat passing through a unit area per unit time; k is the thermal conductivity of the material, which represents the ability of the material to conduct heat; is the temperature gradient, which represents the rate of change of temperature in space.

[0063] In the experiment, taking indium solder layer material as an example (its melting point is 156°C), positioning blocks 220 made of four materials, namely aluminum alloy (grade 6061), alumina ceramics, zirconia ceramics and polytetrafluoroethylene, were used to observe the melting effect of metal-based interconnection materials.

[0064] Aluminum alloy (grade 6061) has excellent thermal conductivity, and the thermal conductivity coefficient at room temperature is λ 25℃ =166W / (m·K). When a high-energy laser irradiates the sample surface through the pressing block 410 made of sapphire ceramic, the heat is rapidly transferred to adjacent structural parts and dissipated mainly through heat conduction, resulting in the inability to exert the process advantages of the laser heat source.

[0065] Use sapphire ceramic with lower thermal conductivity [λ 25℃ =20-30W / (m·K)], the heat accumulation effect is improved, but there is still a large dissipation.

[0066] Further use of zirconia ceramics with lower thermal conductivity [λ 25℃ =2-3W / (m·K)], the cumulative effect of laser energy is significantly improved. Under the conditions of adjusting the laser output power to 18W and heating for 2 seconds, the indium layer was successfully melted.

[0067] In order to further improve the interconnection efficiency, polytetrafluoroethylene [λ 25℃ =0.25W / (m·K)] is used as the material of the positioning block 220. The experimental results show that under the conditions of a laser output power of 9W and a heating time of 1 second, the melting interconnection of the indium layer is successfully achieved.

[0068] See also Figure 1 and Figure 2 As shown, according to some embodiments of the present invention, the positioning mechanism 30 further includes a support plate 330, the support plate 330 is disposed on the base 10, the positioning platform 310 is disposed on the support plate 330, and the positioning platform 310 is an X / Y / R three-axis displacement platform. By setting the positioning platform 310 as an X / Y / R three-axis displacement platform, the position of the second positioning groove 321 on the positioning platform 310 can be accurately adjusted so that it can face the second positioning groove 321 on the vibration part 210, thereby improving the micro-connection accuracy.

[0069] Specifically, adjusting the X / Y / R three-way knob can drive the positioning stage 310 (second positioning slot 321) to move precisely. The laser diameter used by the laser generating device is usually in the micron level. In order to maximize the use of the high concentration of heat source energy to effectively control the size of the interconnection heat affected zone, whether the heating point of the laser beam is accurate directly determines the scientificity and rationality of the process. To this end, the X / Y / R three-axis displacement platform used in the embodiment of the present invention includes a precision slider and a guide rail structure, in which the graduation value of the adjustment knob is 0.05mm. The positioning stage 310 is linked with the CCD industrial lens carried by the laser interconnection system, and the position of the upper cover plate can be displayed and adjusted in real time with the peripheral display system, so as to complete the precise positioning of the sample. Among them, the display screen can also set multiple sets of cross alignment lines separately to calibrate the moving point of the laser transmitter head.

[0070] See also Figure 7 and Figure 8 As shown, according to some embodiments of the present invention, the ultrasonic vibration device 20 further includes an ultrasonic transducer 230, an ultrasonic vibration head 240, a first fixing seat 250 and a fixing ring 260. The first fixing seat 250 is rigidly connected to the base 10, a mounting groove is provided on the first fixing seat 250, the fixing ring 260 is arranged in the mounting groove and forms a limiting groove with the first fixing seat 250, a limiting flange is formed on the outer wall of the ultrasonic transducer 230 along the circumferential direction, the limiting flange is engaged with the limiting groove, the ultrasonic vibration head 240 is connected to the ultrasonic transducer 230, and the vibration part 210 is arranged at the end of the ultrasonic vibration head 240.

[0071] The ultrasonic transducer 230 is the core component of the ultrasonic vibration device 20, and its function is to convert electrical energy into mechanical vibration (ultrasound). Generally, the ultrasonic transducer 230 is made of piezoelectric material. When voltage is applied, the piezoelectric material will deform, thereby generating ultrasonic vibration. The ultrasonic vibration head 240 is connected to the ultrasonic transducer 230 to transmit the mechanical vibration generated by the ultrasonic transducer 230 to the vibration part 210. The first fixing seat 250 and the fixing ring 260 can effectively fix the ultrasonic transducer 230 to ensure its stability during operation.

[0072] Further, see Figure 7 and Figure 8 As shown, according to some embodiments of the present invention, the ultrasonic vibration device 20 further includes a second fixing seat 270, a stopper 280 and a buffer pad 290. The second fixing seat 270 is disposed on the base 10, a stopper groove is provided on the second fixing seat 270, the stopper 280 is disposed in the stopper groove, the buffer pad 290 is disposed on the inner wall of the stopper 280, and the outer wall of the ultrasonic vibration head 240 flexibly abuts against the buffer pad 290. By providing the second fixing seat 270, the stopper 280 and the buffer pad 290, the ultrasonic vibration head 240 can be supported and protected.

[0073] Specifically, see Figure 1 As shown, according to some embodiments of the present invention, a protective cover for protecting the ultrasonic transducer 230 is further provided on the base 10, the ultrasonic transducer 230 and the first fixing seat 250 are both arranged in the protective cover, the ultrasonic vibration head 240 extends out of the protective cover, and correspondingly the second fixing seat 270 is located outside the protective cover.

[0074] The following is a detailed description of the operation process of the micro-connection system based on the ultrasonic laser coupling mechanism provided by the present invention. Figures 1 to 8 .

[0075] During micro-connection, the sample includes lower substrate and upper cover materials. The lower substrate includes but is not limited to ceramic / metal tube shells of various specifications, and the upper cover can be made of glass, metal or ceramic according to the packaged components and service scenarios.

[0076] In the embodiment of the present invention, the lower substrate is an alumina ceramic tube shell, and the upper cover plate is a silicon optical cover plate as an example to illustrate the micro-connection process flow.

[0077] First, install the corresponding ultrasonic vibration head 240 according to the specifications of the alumina ceramic shell, and install the alumina ceramic shell sample into the first positioning groove 221 of its end surface. Select the corresponding laser transmission positioning piece 320 according to the size of the silicon optical cover plate, and install the silicon optical cover plate sample into the second positioning groove 321 for rough positioning.

[0078] Adjust the X / Y / R three-axis displacement platform to position the second positioning groove 321 directly above the first positioning groove 221 to complete the sample positioning. Then install the pressure mechanism 40, and insert the pressure regulating screws 430 on both sides of the positioning platform 310 into both sides of the pressing plate 420 to position the pressing plate 420. Rotate the pressure regulating nut 440 to make the pressing block 410 generate downward pressure to press the silicon optical cover plate sample, and observe the displayed value of the dual-channel pressure sensor 460 to complete the loading of the interconnection pressure.

[0079] The interconnection parameters of the ultrasonic vibration device 20 and the laser generating device are set according to the setting requirements. The parameter settings of the laser generating device include power, heat source moving speed and laser moving path; the parameter settings of the ultrasonic vibration device 20 include amplitude, vibration time and curing time.

[0080] Finally, the ultrasonic vibration device 20 and the laser generating device operate according to the set parameters, applying laser and ultrasonic vibrations to the location area of ​​the alumina ceramic tube shell and the silicon optical cover plate, so that a micro-connection structure with good mechanical properties and airtightness is formed between the lower substrate and the upper cover plate.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A micro-connection system based on ultrasonic laser coupling mechanism, characterized in that: include: Pedestal; An ultrasonic vibration device, the ultrasonic vibration device is arranged on the base, the ultrasonic vibration device comprises a vibration part, the vibration part is provided with a first positioning groove, and the first positioning groove is used to fix the lower base of the sample to be connected; A positioning mechanism, the positioning mechanism is arranged on the base, the positioning mechanism comprises a positioning platform, the positioning platform is provided with a second positioning groove, and the second positioning groove is used to fix the upper cover plate of the sample to be connected; A pressure mechanism, the pressure mechanism comprising a pressure block, the pressure block is used to extend into the second positioning groove to apply pressure to the upper cover plate; A laser generating device, the laser generating device comprising a laser emitting head, the laser emitting head being used to emit laser light into the second positioning groove or into an area around the second positioning groove; The pressure mechanism further includes a pressure plate, the pressure block is connected to the pressure plate, a transmission groove for transmitting laser light is provided on the pressure plate, the pressure block is located on a first side of the transmission groove, the laser emitting head is located on a second side of the transmission groove, and the pressure block is made of a material that can transmit laser light; The pressure mechanism further includes a pressure regulating assembly, which includes two pressure regulating screws and two pressure regulating nuts. One end of the pressure regulating screw is connected to the positioning platform, and the two pressure regulating screws are symmetrically arranged on both sides of the pressure plate. The pressure regulating nuts are threadedly matched with the pressure regulating screws in a one-to-one correspondence. The positioning platform is provided with a third positioning groove, a laser transmission positioning piece is provided in the third positioning groove, the second positioning groove is provided on the laser transmission positioning piece, and the laser transmission positioning piece is made of a material that can transmit laser.

2. The micro-connection system based on the ultrasonic laser coupling mechanism according to claim 1 is characterized in that: The pressing block is made of sapphire ceramics.

3. The micro-connection system based on the ultrasonic laser coupling mechanism according to claim 1 is characterized in that: The pressure mechanism further comprises a fixed cover, and the fixed cover is connected to the pressure plate; The pressing plate includes a main body and a pressure-applying part, wherein the pressure-applying part is connected to the main body, the main body is arranged between the pressing plate and the fixing cover, and the pressure-applying part extends out of the fixing cover; Pressure sensors are symmetrically arranged between the two sides of the main body and the pressure plate.

4. The micro-connection system based on the ultrasonic laser coupling mechanism according to claim 1 is characterized in that: The laser transmission positioning plate is made of sapphire ceramic.

5. The micro-connection system based on the ultrasonic laser coupling mechanism according to claim 1 is characterized in that: The upper and lower end surfaces of the vibration part are both provided with positioning blocks, the first positioning groove is provided on the positioning blocks, and the positioning blocks are made of polytetrafluoroethylene material.

6. The micro-connection system based on the ultrasonic laser coupling mechanism according to any one of claims 1 to 5, characterized in that: The positioning mechanism further comprises a support plate, wherein the support plate is arranged on the base, and the positioning platform is arranged on the support plate, and the positioning platform is an X / Y / R three-axis displacement platform.

7. The micro-connection system based on the ultrasonic laser coupling mechanism according to any one of claims 1 to 5, characterized in that: The ultrasonic vibration device also includes an ultrasonic transducer, an ultrasonic vibration head, a first fixing seat, a fixing ring, a second fixing seat, a stopper and a buffer pad; The first fixing seat is rigidly connected to the base, a mounting groove is provided on the first fixing seat, the fixing ring is arranged in the mounting groove and forms a limit slot with the first fixing seat, a limit flange is formed on the outer wall of the ultrasonic transducer along the circumferential direction, the limit flange is engaged with the limit slot, the ultrasonic vibration head is connected to the ultrasonic transducer, and the vibration part is arranged at the end of the ultrasonic vibration head; The second fixing seat is arranged on the base, a limiting groove is arranged on the second fixing seat, the limiting member is arranged in the limiting groove, the buffer pad is arranged on the inner wall of the limiting member, and the outer wall of the ultrasonic vibration head flexibly abuts against the buffer pad.

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