A conductive silver paste stirring mixing structure suitable for N-type devices

Abstract

The utility model relates to the field of stirring device structure, especially suitable for N type device's conductive silver paste stirring mixing structure, including jar body, the jar body bottom is equipped with feed inlet and discharge gate, the jar body top is provided with vacuum pump, the jar body inside is equipped with stirring device, the stirring device includes drive motor and with drive motor output shaft connection's stirring axle, the stirring axle fixedly connected with spiral stirring vane, the spiral stirring vane is from below to above in turn is equipped with stirring part one, stirring part two and stirring part three, the screw pitch of stirring part one is greater than stirring part three, the screw pitch of stirring part three is greater than stirring part two, the spiral stirring vane is equipped with tip portion, the curvature radius of tip portion is less than 0.05mm. The conductive silver paste stirring mixing structure of the application can effectively remove the micro-bubble in high viscosity conductive silver paste.

Description

Technical Field

[0001] This utility model relates to the field of stirring device structure, and in particular to a conductive silver paste stirring and mixing structure suitable for N-type devices. Background Technology

[0002] In the fabrication of N-type semiconductor devices, devices based on N-type semiconductor materials place extremely stringent requirements on the performance of electrode materials. As a key material for forming electrodes, the electrical properties, contact resistance, and density of the metallization layer of conductive silver paste directly affect the final efficiency and long-term reliability of the device. Therefore, specialized conductive silver pastes for N-type devices must meet stringent standards such as high uniformity, extremely low contact resistance, high conductivity, and absence of bubble inclusions.

[0003] To meet the aforementioned performance requirements, the mixing process during silver paste preparation is crucial. It is essential to achieve highly uniform dispersion of multiple components, including fillers, the glass phase, and the organic carrier, and to completely eliminate microbubbles within the paste. However, silver pastes specifically designed for N-type devices typically have higher solids content and viscosity. This characteristic results in poor rheology and strong cohesion during mixing, making it difficult for traditional mixing equipment to achieve effective, uniform mixing across the entire surface. Furthermore, air bubbles trapped within the high-viscosity paste are difficult to escape, and the broad shear force distribution at the blade tips of existing mixers fails to effectively generate directional removal forces targeting microbubbles, further hindering the expulsion of microbubbles from the high-density silver paste. Utility Model Content

[0004] To address the problems mentioned above, this invention provides a conductive silver paste stirring and mixing structure suitable for N-type devices, which can effectively remove microbubbles from high-viscosity conductive silver paste.

[0005] The solution adopted by this utility model to solve its technical problem is: a conductive silver paste stirring and mixing structure suitable for N-type devices, including a tank, an inlet and an outlet at the bottom of the tank, a vacuum pump at the top of the tank, and a stirring device inside the tank. The stirring device includes a drive motor and a stirring shaft connected to the output shaft of the drive motor. The stirring shaft is fixedly connected with a spiral stirring blade. The spiral stirring blade is provided with stirring part one, stirring part two and stirring part three from bottom to top. The pitch of stirring part one is greater than that of stirring part three, and the pitch of stirring part three is greater than that of stirring part two. The spiral stirring blade is provided with a tip, and the radius of curvature of the tip is less than 0.05 mm.

[0006] Furthermore, the tip is needle-shaped.

[0007] Furthermore, the tip of one side wall of the stirring section is inclined at 10-15° relative to the horizontal surface and the top surface.

[0008] Furthermore, the pointed ends of the two side walls of the stirring section are inclined at 10-15° relative to the horizontal surface and the bottom surface.

[0009] Furthermore, a reinforcing plate is provided between the spiral stirring blade and the stirring shaft, and the reinforcing plate has through holes.

[0010] Furthermore, the bottom of the reinforcing plate is provided with reinforcing ribs.

[0011] In summary, the beneficial effects of this utility model are as follows: The spiral stirring blade of this application is a variable pitch spiral stirring blade. The large pitch structure of the stirring section one provides a strong axial pushing force, quickly conveying the high-density slurry deposited at the bottom of the tank upwards, ensuring that all materials in the entire tank can participate in the circulation; the small pitch structure of the stirring section two has a stronger shearing frequency and shearing force at the same rotation speed, which can effectively disperse silver powder agglomerates, break larger bubbles, and evenly disperse solid particles such as silver powder and glass powder into the organic carrier; the medium pitch structure of the stirring section three can smoothly convey the rising material to the top area of ​​the tank, facilitating vacuum degassing. Moreover, when the high-viscosity silver slurry flows through the tip of the spiral stirring blade, it is forcibly divided, squeezed, and stretched, increasing the flow rate and forming a local low-pressure zone. This causes bubbles to move from the previous high-pressure zone into the low-pressure zone, then rapidly expand and become unstable, thus rupturing. In the subsequent vacuum environment, they are more easily dissolved or escaped.

[0012] The above description is merely an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this utility model more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0013] Figure 1 This is the front view of this embodiment;

[0014] Figure 2 This is a cross-sectional view of this embodiment;

[0015] Figure 3 This is a schematic diagram of the structure of this embodiment.

[0016] In the diagram: 1. Tank body; 2. Inlet; 3. Outlet; 4. Vacuum pump; 5. Drive motor; 6. Stirring shaft; 7. Spiral stirring blade; 71. Stirring section one; 72. Stirring section two; 73. Stirring section three; 8. Tip; 9. Reinforcing plate; 91. Reinforcing rib. Detailed Implementation

[0017] To make the content of this utility model easier to understand, the present utility model will be further described below with reference to specific embodiments and accompanying drawings.

[0018] It should be noted that the terms "center," "upper," "lower," "front," "rear," "left," "right," "inner," and "outer" used herein to indicate the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Unless otherwise stated, "a plurality of" means two or more.

[0019] Unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0020] like Figures 1 to 3 As shown, a conductive silver paste mixing structure suitable for N-type devices includes a tank 1, with an inlet 2 and an outlet 3 at the bottom of the tank 1, a vacuum pump 4 sealed to the top flange of the tank 1, and a stirring device inside the tank 1. The stirring device includes a drive motor 5 and a stirring shaft 6 connected to the output shaft of the drive motor 5, with a spiral stirring blade 7 fixedly connected to the stirring shaft 6.

[0021] Optionally, a bottom valve, such as a disc valve or a ball valve, can be connected to the discharge port 3.

[0022] like Figure 1 As shown, the top of the tank 1 is provided with a nitrogen inlet, and the tank 1 is provided with a jacket. The jacket is provided with an inlet and an outlet on both sides. Through the inlet and outlet, heat transfer oil or coolant can be introduced into the jacket to control the process temperature during the stirring process.

[0023] like Figure 2 As shown, in this embodiment, the spiral stirring blades 7 are arranged from bottom to top as stirring section one 71, stirring section two 72, and stirring section three 73. The pitch of stirring section one 71 is greater than that of stirring section three 73, and the pitch of stirring section three 73 is greater than that of stirring section two 72. Through the above design, stirring section one 71 has the largest pitch, which can provide a strong axial pumping capacity. It can quickly lift the heavy silver powder, glass powder, and other raw materials that have settled at the bottom of the tank to the top in the initial stage of stirring, so as to achieve preliminary macroscopic mixing and transportation and prevent bottom sedimentation. Stirring section two 72 has the smallest pitch, which can increase the contact frequency and action path between the spiral stirring blades 7 and the materials, forming a strong squeezing and shearing action, thereby breaking up silver powder agglomerates, strongly shearing organic carriers, and fully dispersing additives.

[0024] The spiral stirring blade 7 has a pointed tip 8 on its top surface and sidewalls. The pointed tip 8 is needle-shaped with a radius of curvature of less than 0.05 mm. During high-speed rotation, the pointed tip 8 can generate local shear stress and velocity gradient, effectively breaking up micro-nano agglomerates, soft agglomerates, and microbubbles formed during the stirring process, thereby improving the dispersion and degassing effect of the slurry. The pointed tip 8 can be formed by electrical discharge machining or laser ablation.

[0025] The pointed portion 8 on the side wall of the stirring section 71 is inclined at 10-15° relative to the horizontal surface towards the top surface. When the stirring blades rotate, the pointed portion towards the top surface exerts an upward force on the adhered material at the moment of scraping, so that it is captured by the main body of the spiral blades and conveyed upward. In conjunction with the upward conveying function of the stirring section 71, the axial circulation capability of the entire stirring device is enhanced.

[0026] The tip 8 at the side wall of the second mixing section 72 is inclined at 10-15° relative to the horizontal surface to the bottom surface, which enhances the downward pumping and forms convection with the mainstream slurry conveyed from the top upward, further improving the uniform dispersion of the slurry.

[0027] like Figure 3 As shown, a reinforcing plate 9 is provided between the spiral stirring blade 7 and the stirring shaft 6. The reinforcing plate 9 has through holes and reinforcing ribs 91 at its bottom. Through the above design, the force borne by the spiral stirring blade 7 is transmitted more evenly to the stirring shaft 6 through the entire plane of the reinforcing plate 9, which enhances the blade's resistance to torsion and bending. The through holes can reduce the weight and rotational inertia of the entire stirring device, reduce the load on the stirring shaft 6, and generate more localized, small-scale eddies, thereby improving the slurry mixing efficiency.

[0028] The embodiments described above are merely preferred embodiments of this utility model and should not be construed as limiting the scope of protection of this utility model. Any non-substantial changes and modifications made by those skilled in the art based on this utility model shall fall within the scope of protection of this utility model.

Claims

1. A conductive silver paste mixing structure suitable for N-type devices, comprising a tank body (1), characterized in that, The tank (1) has an inlet (2) and an outlet (3) at the bottom. The tank (1) has a vacuum pump (4) at the top. The tank (1) has a stirring device inside. The stirring device includes a drive motor (5) and a stirring shaft (6) connected to the output shaft of the drive motor (5). The stirring shaft (6) is fixedly connected with a spiral stirring blade (7). The spiral stirring blade (7) is provided with stirring part one (71), stirring part two (72) and stirring part three (73) from bottom to top. The pitch of stirring part one (71) is greater than that of stirring part three (73), and the pitch of stirring part three (73) is greater than that of stirring part two (72). The spiral stirring blade (7) is provided with a tip (8), and the radius of curvature of the tip (8) is less than 0.05 mm.

2. The conductive silver paste mixing structure for N-type device according to claim 1, wherein, The tip (8) is needle-shaped.

3. The conductive silver paste mixing structure for N-type device according to claim 1, wherein, The tip (8) of the stirring part (71) is inclined at 10-15° relative to the horizontal surface to the top surface.

4. The conductive silver paste mixing structure for N-type device according to claim 1, wherein, The tip (8) of the stirring section 2 (72) is inclined at 10-15° relative to the horizontal surface and the bottom surface.

5. The conductive silver paste mixing structure for N-type device according to claim 1, wherein, A reinforcing plate (9) is provided between the spiral stirring blade (7) and the stirring shaft (6), and the reinforcing plate (9) is provided with through holes.

6. The conductive silver paste mixing structure for N-type device according to claim 5, wherein, The bottom of the reinforcing plate (9) is provided with reinforcing ribs (91).

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