Hot air preheating device and chip laser welding equipment

Abstract

The present invention discloses a hot air preheating device and chip laser welding equipment, which relate to the technical field of semiconductor manufacturing. The hot air preheating device can be applied to chip laser welding equipment, which includes a hot air hood, a fan, a heating component and an air guide plate, wherein a hollow hot air cavity is formed inside the hot air hood, and the hot air hood is also provided with an air inlet and an air outlet both connected to the hot air cavity at intervals, the heating component is arranged in the hot air cavity, and the air guide plate covers the air outlet and penetrates a plurality of evenly distributed air guide ports. The hot air preheating device arranges a heating component in the hot air cavity, and arranges an air guide plate evenly provided with air guide ports at the air outlet, so that the heated air is evenly discharged from the hot air cavity through the air guide ports and evenly flows through the substrate and each chip, thereby improving the preheating uniformity of each part of the substrate and each chip, and avoiding the problem of warping deformation or even cracking of the edge of the substrate due to large local temperature difference.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and in particular to a hot air preheating device and chip laser welding equipment. Background Art

[0002] The common welding method between general SMD components and substrates is reflow soldering. However, reflow soldering has disadvantages such as multiple process steps, large footprint, and high power consumption. Therefore, later Mini-LED chips mostly use laser welding technology to improve the shortcomings of the reflow soldering process.

[0003] Laser welding machine, also known as laser welding machine, laser welding machine, is a machine used for laser welding of materials. Take the processing and production process of Mini-LED circuit boards as an example. In this process, thousands of Mini-LED chips need to be arranged on each substrate. The Mini-LED chips need to be welded to the corresponding substrate through the high-energy laser beam of the laser welding machine as a heat source. However, due to the large temperature difference generated when the laser is irradiated to the surface of the substrate, the problem of stress cracking of the substrate often occurs during the laser welding process due to the large temperature difference. In particular, the current Mini-LED chips are mostly welded on brittle materials such as glass, and this problem is more prominent. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide a hot air preheating device and a chip laser welding device to solve the problem that stress deformation cracking is easily generated in the substrate during the laser welding process.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect, a hot air preheating device is provided, which is applied to a chip laser welding device, comprising:

[0007] A hot air hood, wherein a hollow hot air cavity is formed inside the hot air hood, and the hot air hood is also provided with an air inlet and an air outlet which are both connected to the hot air cavity;

[0008] The fan is configured to draw the air outside the hot air hood into the hot air cavity through the air inlet along the axial direction of the fan, and let the air in the hot air cavity flow along the radial direction of the fan and then be discharged from the hot air hood through the air outlet along the axial direction;

[0009] A heating component is arranged in the hot air cavity and surrounds the outer periphery of the fan (20) in a radial direction;

[0010] An air guide plate is sealed on the air outlet, a plurality of evenly distributed air guide ports are penetrated on the air guide plate, and air guide pipes are respectively arranged on each of the air guide ports of the air guide plate, and each of the air guide pipes is extended in a direction away from the air guide plate;

[0011] A return air hood, wherein a hollow return air cavity is formed inside the return air hood, and a processing inlet and a processing outlet connected to the return air cavity are respectively opened at opposite ends of the return air hood;

[0012] The hot air hood is arranged in the return air cavity, and a hood wall of the hot air hood and a cavity wall of the return air cavity are spaced apart to form a return air channel communicating with the air inlet and the air outlet.

[0013] As an optional implementation, the fan is configured as a centrifugal fan, and the centrifugal fan comprises:

[0014] A driving device, fixed relatively to the hot air hood through its fixing portion;

[0015] A rotating component, disposed in the hot air chamber and connected to an output portion of the driving device;

[0016] The heating components are arranged around the circumference of the rotating component at intervals.

[0017] As an optional implementation, the heating component includes a plurality of groups of heating wires, each group of the heating wires is wound around the periphery of the rotating component; and

[0018] The heating wires of each group are arranged in sequence and spaced apart along the axial direction of the rotating component.

[0019] As an optional implementation, the air inlet and the air outlet are respectively opened on opposite sides of the hot air hood, and the hot air preheating device further includes:

[0020] A wind shield is arranged in the hot air cavity and divides the hot air cavity into an air inlet chamber and an air outlet chamber. The air inlet is connected to the air inlet chamber, and the air outlet is connected to the air outlet chamber. A ventilation gap connecting the air inlet chamber and the air outlet chamber is formed between the outer edge of the wind shield and the cavity wall of the hot air cavity.

[0021] As an optional implementation, the wind shield plate and the wind guide plate are parallel to each other.

[0022] As an optional embodiment, a guide wall is provided on a cavity wall of the air inlet chamber close to the ventilation gap, and the guide wall is inclined from the inside to the outside in a direction close to the corresponding ventilation gap.

[0023] As an optional implementation, the return air hood includes:

[0024] A first cover wall and a second cover wall are arranged opposite to each other, wherein the first cover wall is opposite to the air inlet and is arranged at a distance therefrom, and forms a collecting channel with the hot air cover, and the second cover wall is opposite to the air outlet and is arranged at a distance therefrom, and forms a conveying channel connecting the processing inlet and the processing outlet with the air guide plate; and

[0025] The third cover wall and the fourth cover wall are arranged opposite to each other, and the opposite sides of the third cover wall and the fourth cover wall are respectively connected to the first cover wall and the second cover wall, and the third cover wall and the fourth cover wall are respectively spaced from the opposite sides of the hot air cover to form a connecting channel connecting the conveying channel and the collecting channel.

[0026] In a second aspect, a chip laser welding device is provided, comprising:

[0027] The hot air preheating device as described in the first aspect;

[0028] A processing platform, used for placing a substrate, the processing platform being movably disposed on a side of the air guide plate away from the hot air chamber;

[0029] The laser generating device is arranged on a side of the hot air hood away from the processing platform, and the laser generating device is configured to emit laser light to the surface of the substrate.

[0030] The beneficial effects of the present invention are as follows: the hot air preheating device, on the basis of restricting the air flow direction through the hot air cover, sets a heating component in the hot air chamber, so that the air can fully contact the heating component in the hot air chamber and be evenly heated, thereby improving the air heating efficiency and heating uniformity. During the laser welding of the chip, the heated air can preheat the substrate and the chip mounted on the substrate through the air outlet, so that the substrate is close to the welding temperature before the welding operation, avoiding the problem of deformation or even cracking of the substrate due to thermal expansion and contraction;

[0031] By arranging an air guide plate with air guide ports evenly distributed at the air outlet, the heated air can be evenly discharged from the hot air cavity through the air guide ports and evenly flow through the substrate and each chip, thereby improving the preheating uniformity of each part of the substrate and each chip, and effectively increasing the contact area between the heated air and the substrate and each chip, improving the preheating efficiency of the product, and avoiding the problem of deformation or even cracking of the edge of the substrate due to large local temperature difference;

[0032] In addition, preheating the substrate and each chip can also achieve the effect of solder paste infiltration, which improves the welding effect of the chip on the substrate and reduces the power of the laser generator to a certain extent, thereby reducing the energy consumption of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention is further described in detail below based on the accompanying drawings and embodiments.

[0034] Figure 1 This is one of the schematic diagrams of the structure of the chip laser welding equipment according to an embodiment of the present invention;

[0035] Figure 2 This is the second schematic diagram of the chip laser welding equipment according to an embodiment of the present invention;

[0036] Figure 3 An exploded view of the hot air preheating device according to an embodiment of the present invention;

[0037] Figure 4 for Figure 2 AA direction cross-sectional view;

[0038] Figure 5 for Figure 4 A magnified view of part A;

[0039] Figure 6 for Figure 2 BB direction cross-sectional view;

[0040] Figure 7 It is a schematic diagram of the structure of the conveying mechanism described in an embodiment of the present invention.

[0041] In the figure: 10, hot air hood; 11, hot air cavity; 12, air inlet; 13, air outlet; 14, wind shield; 141, air inlet chamber; 142, air outlet chamber; 1421, guide wall; 143, ventilation gap; 20, fan; 21, driving device; 211, fixing part; 212, output part; 22, rotating part; 30, heating component; 40, air guide plate; 41, air guide port; 42, air guide duct; 50, return air hood; 51, return air cavity; 511, collecting channel; 512, conveying channel; 513, connecting channel; 52, processing entrance; 53, processing exit; 54, first hood wall; 55, second hood wall; 56, third hood wall; 57, fourth hood wall; 58, baffle; 59, window; 60, conveying mechanism; 61, first station; 62, second station; 70, laser generating device. DETAILED DESCRIPTION

[0042] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention are further described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0043] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" 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, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0045] Laser welding technology is a microelectronic packaging technology that uses a high-energy-density laser beam as a heat source. By directly irradiating the welding area, the welding material is quickly heated to a molten or sintered state, thereby achieving a firm connection between the chip component and the substrate.

[0046] Laser welding technology has the characteristics of high precision, high speed and high reliability. At the same time, the contactless welding method also avoids mechanical stress damage to the chip components and meets the miniaturization and lightweight requirements of the chip component packaging.

[0047] The laser welding technology briefly introduced above is generally implemented through chip laser welding equipment. The chip laser welding equipment generates a high-energy-density laser beam through a laser generating device. The laser beam is focused through optical elements such as lenses or reflectors to form a small light spot and irradiate the surface of the workpiece to be welded. Taking the processing and production process of Mini-LED circuit boards as an example, when the light spot is irradiated to the surface of the substrate carrying the chip, the laser energy is absorbed by the surface of the substrate and converted into heat energy, so that the metal material is quickly heated to a molten state, and then under the continuous action of the laser beam, the molten metal diffuses and mixes, and finally cools and solidifies to form a welded joint. However, it can be seen from the background technology that due to the large temperature difference generated when the laser beam is irradiated to the surface of the substrate, the problem of stress cracking of the substrate is often caused by excessive temperature difference during the laser welding process. In particular, the current Mini-LED chips are mostly welded on brittle materials such as glass, and this problem is more prominent.

[0048] In view of this, the present embodiment provides a hot air preheating device, which can be applied to chip laser welding equipment. The hot air preheating device heats the air, thereby uniformly heating the substrate and the chip mounted on the substrate in the application of the chip laser welding equipment, thereby solving the problem of stress deformation and cracking of the substrate during the laser welding process, improving the welding yield rate while also improving the operating efficiency of the equipment.

[0049] Please refer to the attached Figure 1-Figure 6 , the hot air preheating device comprises:

[0050] The hot air hood 10 is a semi-enclosed hood structure with a hollow hot air cavity 11 formed therein. The hot air hood 10 is also provided with an air inlet 12 and an air outlet 13 both connected to the hot air cavity 11 at intervals. An air flow channel for gas to flow from the air inlet 12 to the air outlet 13 is defined between the air inlet 12 and the air outlet 13 in the hot air cavity 11. In the application of the chip laser welding equipment, the hot air cavity 11 limits the air flow path through the air flow channel, so that the air entering the hot air cavity 11 from the air inlet 12 can be fully and evenly heated in the hot air cavity 11, and discharged from the hot air hood 10 from the air outlet 13 after heating, thereby realizing preheating treatment of the substrate and the chip.

[0051] The presence of the hot air hood 10 also blocks the contact between the air in the hot air chamber 11 and the air outside the hot air hood 10 to the greatest extent, reduces the contact between the internal and external air, avoids the problem of low heating uniformity caused by excessive heat exchange efficiency of the air inside and outside the hot air hood 10, and keeps the air inside the hot air chamber 11 warm, ensuring that the air in the hot air chamber 11 has sufficient heating efficiency, and ensuring that the air discharged from the hot air hood 10 from the air outlet 13 is within the preheating temperature range that meets the requirements of the laser welding process.

[0052] The fan 20 is used to draw the external air of the hot air hood 10 into the hot air chamber 11 along the axial direction of the fan 20 through the air inlet 12, and let the air entering the hot air chamber 11 change direction to flow along the radial direction of the fan 20, and change the flow direction to the axial direction after heating, and finally smoothly discharge the hot air hood 10 from the air outlet 13.

[0053] In this embodiment, the cooperation between the fan 20 and the hot air hood 10 is not specifically limited here, as long as it can meet the functional requirements of allowing air to enter from the air inlet 12 and be discharged from the air outlet 13. In addition, this embodiment does not have strict restrictions on the type of the fan 20, and the fan 20 can be, but is not limited to, the following:

[0054] In the centrifugal fan 20 , the airflow enters the rotating component 22 of the fan 20 axially and then mainly flows radially.

[0055] In the axial flow fan 20 , after the airflow axially enters the rotating component 22 of the fan 20 , it flows along the direction tending to the rotation axis of the rotating component 22 .

[0056] The diagonal flow fan 20 (mixed flow fan 20) has an air flow direction between the centrifugal flow and the axial flow, and tends to flow along a conical surface.

[0057] In the cross-flow fan 20 , the airflow tends to flow in a transverse direction in the rotating component 22 of the fan 20 .

[0058] It should also be noted that the structure of the airflow channel formed by the hot air hood 10 may be, but is not limited to, determined by the type of the fan 20 and the internal structure of the hot air chamber 11, and this embodiment does not impose any requirements or limitations on this.

[0059] The heating component 30 is arranged in the hot air chamber 11 and surrounds the outer periphery of the fan 20 in the radial direction, and is used for exchanging heat with the air in the hot air chamber 11. Specifically, the heating component 30 can heat the air in the hot air chamber 11 to a predetermined temperature by consuming energy such as electricity or gas to meet the preheating requirements of the substrate and the chip. The heating component 30 can be an electric heating element (such as a resistance wire, an electric heating tube, etc.), a gas heater, etc.

[0060] It can be understood that, since the flow direction of the air when entering the hot air chamber 11 through the air inlet 12 is the axial direction of the fan 20, it will be disturbed by the fan 20 after entering the hot air chamber 11 and changed from the axial flow direction to the radial flow direction, and after heating, the flow direction will be changed again to return to the axial direction so as to be discharged from the air outlet 13. Therefore, the time the air stays in the hot air chamber 11 will be extended, so that the air can be fully exchanged with the heating component 30. At the same time, the heating component 30 is also adapted to the flow direction of the air in the hot air chamber 11, and is radially arranged around the fan 20, so that the air disturbed and changed direction by the fan 20 can pass through the heating component 30 and exchange heat with it, thereby effectively improving the heat exchange efficiency between the air and the heating component 30, making the air temperature more stable, and making the temperature of the heated air blown out from the hot air chamber 11 meet the preheating requirements.

[0061] For example, the axial direction and radial direction described in this embodiment can be understood as two mutually perpendicular directions on the same vertical plane. Figure 5 When the “axial direction” indicated by the arrow in the figure is the up-down direction, the radial direction in this embodiment may be the “radial direction” indicated by the arrow in the figure, which is the left-right direction in the figure.

[0062] It should be understood that in order to ensure that the air in the hot air chamber 11 can be evenly heated, the heating component 30 should be arranged in the air flow channel defined by the hot air hood 10 so that the air flowing from the air inlet 12 to the air outlet 13 can pass through the heating component 30 and exchange heat with it.

[0063] Exemplarily, the heating component 30 can heat the air in the following manners, but is not limited to:

[0064] Resistance heating uses electric current to pass through a resistance wire to generate heat, thereby heating the air;

[0065] Electromagnetic induction heating uses the principle of electromagnetic induction to generate eddy currents in the conductor, which in turn generates heat to heat the air;

[0066] Infrared radiation heating uses infrared radiation from infrared radiation sources (such as infrared lamps, infrared heaters, etc.) to directly irradiate the air, causing air molecules to absorb radiation energy and heat up;

[0067] Hot air furnace heating heats the air by burning fuel (such as coal, oil, gas, etc.) to produce high-temperature flue gas or flame.

[0068] Please continue to refer to the attached Figure 3-Figure 6 In this embodiment, the hot air preheating device also includes an air guide plate 40, which covers the air outlet 13 so that the air guide plate 40 completely blocks the air outlet 13. In one embodiment, the edge of the air guide plate 40 is airtightly matched with the edge of the air outlet 13 to prevent air from flowing between the air guide plate 40 and the hot air chamber 11. In this way, when external air enters the hot air chamber 11 from the air inlet 12 under the action of the fan 20 and flows toward the air outlet 13, the air in the hot air chamber 11 will be completely blocked by the air guide plate 40.

[0069] Based on the above, the air guide plate 40 is further penetrated by a plurality of evenly distributed air guide ports 41, so that the air blocked by the air guide plate 40 can be discharged from the hot air hood 10 through the air guide ports 41, and in order to ensure that the wind pressure of each air guide port 41 tends to be consistent and the exhaust is uniform, the total area of ​​the air inlet 12 should be set to be larger than the total area of ​​the plurality of air guide ports 41, so that the maximum air intake volume of the hot air cavity 11 can be greater than the maximum air outlet volume, so that when the hot air cavity 11 is filled with air, a positive pressure is formed compared to the external environment, thereby achieving a uniform air outlet effect.

[0070] Hot air preheating device is used in chip laser welding equipment, such as Figure 4-Figure 6As shown, the processing platform for conveying the substrate is arranged on the lower side of the hot air hood 10 (the side of the air guide plate 40 away from the hot air chamber 11), and under the conveying of the conveying mechanism 60, it can move along the bottom of the hot air hood 10, and convey the conveyed substrate from the first station 61 related to the previous process step to the second station 62 related to the next process step. During this conveying process, the substrate (carrying the chip) passes under the hot air hood 10, and the air outside the hot air hood 10 enters the hot air chamber 11 from the air inlet 12 under the action of the fan 20, and exchanges heat with the heating component 30 in the process of flowing to the direction of the air outlet 13, so that the air in the hot air chamber 11 reaches the range required for preheating. Finally, the heated air is discharged from the hot air hood 10 from each air guide port 41 under the action of the air guide plate 40. The heated air discharged from the hot air hood 10 can evenly contact and exchange heat with the substrate passing through the lower side of the hot air hood 10 and each chip mounted on the substrate, and finally complete the preheating of the substrate and the chip.

[0071] The above-mentioned implementation method realizes preheating and wetting of the solder paste on the substrate. At the same time, the hardness of the substrate after heating is lower than its hardness at room temperature. Therefore, when the substrate is preheated, it is also more conducive to sticking to the processing platform, thereby improving the deformation and warping problem on the processing platform.

[0072] In addition, preheating the substrate and chip through a hot air preheating device can make the substrate temperature closer to the temperature during laser welding, avoiding the problem of stress deformation cracking caused by excessive instantaneous temperature difference due to rapid heating of the substrate during laser welding. Even if the substrate is further heated during the subsequent welding process, since the substrate has been heated to a higher temperature, the problem of deformation cracking during welding is avoided.

[0073] It is also worth mentioning that preheating the substrate and each chip can also achieve the effect of solder paste infiltration, which improves the welding effect of the chip on the substrate and reduces the power of the laser generating device 70 to a certain extent, thereby reducing the energy consumption of the equipment.

[0074] In one embodiment, in order to ensure that the substrate is heated uniformly as a whole, in the application of the chip laser welding equipment, the size of the air guide plate 40 should be adaptively set according to the size of the substrate to be welded. Generally, the size of the air guide plate 40 should be set as large as possible to be larger than the substrate size. At least, the size of the air guide plate 40 in the width direction should be set larger than the width of the substrate to ensure that the heated air discharged from the air guide ports 41 evenly distributed thereon can flow through every part of the surface of the substrate to achieve an overall uniform heating effect.

[0075] Please continue to refer to the attached Figure 3-Figure 6Taking the fan 20 as a centrifugal fan 20 as an example, the centrifugal fan 20 mainly includes a driving device 21 as a power source and a rotating component 22 for accelerating the air in the hot air chamber 11 and pushing it outward.

[0076] Specifically, the driving device 21 is usually an electric motor, which provides power to rotate the rotating component 22. The electric motor can generally be an AC motor or a DC motor. The selection should be reasonably matched according to the power requirements and usage environment of the fan 20 to ensure the efficiency and reliability of the fan 20.

[0077] The driving device 21 is relatively fixed to the hot air hood 10 through its fixing part 211 (such as the housing of the motor), so that the output part 212 of the driving device 21 (such as the rotating shaft of the motor) can rotate relative to the hot air hood 10. The rotating component 22 is connected to the output part 212 of the driving device 21, and is at least partially disposed in the hot air chamber 11. Whether the rotating component 22 is partially disposed in the hot air chamber 11 or entirely disposed in the hot air chamber 11 depends on the design requirements of the centrifugal fan 20 and the actual connection structure between the driving device 21 and the rotating component 22, so as to ensure that the rotating component 22 can rotate under the action of the driving device 21, and accelerate and transport the air in the hot air chamber 11 during the rotation process, so that the air can flow rapidly in the hot air chamber 11 along the radial direction of the output part 212.

[0078] It should be understood that, in some embodiments, in order to facilitate the connection between the driving device 21 and the rotating component 22, the output portion 212 of the driving device 21 can be configured to be at least partially (depending on whether the fixed portion 211 of the driving device 21 is entirely disposed outside the hot air chamber 11 or inside the hot air chamber 11) located inside the hot air chamber 11, so that the rotating component 22 can be located as a whole inside the hot air chamber 11 to achieve connection with the driving device 21; or in other embodiments, the output portion 212 of the driving device 21 can also be externally disposed outside the hot air chamber 11, so that the portion of the driving device 21 located outside the hot air hood 10 is connected directly or indirectly (such as through belts, gears, etc.).

[0079] It should be noted that the rotating component 22 described in this embodiment can be set as an impeller of the fan 20, and the impeller of the fan 20 is composed of multiple curved blades. Alternatively, the rotating component 22 can be set as a wind wheel, which is generally a cylindrical structure with a central opening, and a plurality of openings arranged at equal intervals are opened on the cylinder wall to form a plurality of fan blades on the wind wheel, so that the wind wheel can inhale air through its opposite ends during the rotation process, and the air can be discharged from each opening under the action of the fan blades, so as to achieve radial blowing.

[0080] In this embodiment, by setting the fan 20 as a centrifugal fan 20, the air flow direction in the hot air chamber 11 can be effectively constrained, so as to avoid the situation in which the air in the hot air chamber 11 is blown directly from the air inlet 12 to the air outlet 13 in some embodiments, and to extend the air flow channel from the air inlet 12 to the air outlet 13 to a certain extent, so that the air in the hot air chamber 11 can fully exchange heat with the heating component 30, thereby improving the heating efficiency and uniformity of the air, and finally making the substrate and each chip heated more evenly, reducing the possibility of local uneven heating of the substrate during the preheating process.

[0081] On the basis of the above, the heating component 30 is arranged at intervals around the circumference of the rotating component 22, and is specifically arranged around the rotation axis of the rotating component 22 and is arranged at intervals from the rotating component 22, so that the radial airflow generated by the rotating component 22 during the rotation process can pass through the heating component as much as possible, thereby achieving the purpose of improving the air heat exchange efficiency.

[0082] It should be noted that in the embodiment where the total area of ​​the above-mentioned air guide port 41 is smaller than the air inlet port 12, and a positive pressure is formed in the hot air chamber 11 compared to the external environment of the hot air hood 10 during the operation of the fan 20, since the exhaust efficiency of the air guide port 41 is not as high as the air inlet efficiency of the air inlet port 12, the heated air cannot be uniformly and quickly discharged from the hot air hood 10. Therefore, while part of the heated air is discharged from the hot air hood 10 through the air guide ports 41 to preheat the substrate and the chip, another part of the heated air is still in the hot air chamber 11 and circulates in the hot air chamber 11 under the action of the rotating component 22. During this period, the air still in the hot air chamber 11 can be re-inhaled by the rotating component 22 and blown out along the radial direction of the rotating component 22, and heated and insulated with the heating component 30 for a second or even more times, thereby ensuring the uniformity of air heating and keeping the air within the temperature range required for preheating, thereby improving the preheating effect of the substrate and the chip.

[0083] Based on the above implementation method, please refer to the attached Figure 3-Figure 6 The heating component 30 includes a plurality of groups of heating wires, each group of heating wires is wound around the circumference of the rotating component 22, and each group of heating wires wound around the circumference of the rotating component 22 can be set as a structure with multiple sections connected, or a structure with multiple sections spaced apart from each other, and this embodiment does not make strict limitations on this.

[0084] Each group of heating wires is arranged in sequence along the axial direction of the rotating part 22 at intervals, thereby increasing the contact surface between the heating component 30 and the air, and providing corresponding space for the flow of air between any two adjacent heating wires, ensuring that the air can flow normally in the hot air chamber 11 and be discharged from the air guide port 41, or circulate normally. The mutually spaced heating wire layout allows the hot air to flow more easily in the gap, reducing the accumulation and obstruction of the hot air on the surface of the heating wire, thereby improving the air circulation of the entire heating component 30 area, helping to evenly dissipate heat in multiple directions, avoiding local overheating or uneven temperature problems, improving its safety performance, and making the heated air temperature more uniform.

[0085] In addition, since air can pass through the gaps between the heating wires more easily, heat can be absorbed and carried away by the air more effectively, thereby improving the utilization efficiency of thermal energy. Under the same heating effect, due to the improvement in the utilization efficiency of thermal energy, the consumption of electricity or other energy can be reduced, achieving the purpose of energy saving.

[0086] In the above-mentioned embodiment using the centrifugal fan 20, please refer to the attached Figure 3-Figure 6 In order to avoid the situation where the air is blown directly from the air inlet 12 to the air outlet 13 as much as possible, the air inlet 12 and the air outlet 13 are respectively opened on opposite sides of the hot air hood 10, and the connecting line between the air inlet 12 and the air outlet 13 is set at an angle (for example, 90°) to the rotation axis of the rotating component 22, so that the air entering the hot air chamber 11 from the air inlet 12 can be blown in a direction staggered from the air outlet 13 under the action of the rotating component 22, and then flow to the direction of the air outlet 13 after heat exchange with the heating component 30, thereby extending the residence time of the air in the hot air chamber 11.

[0087] On the basis of the above-mentioned limitation of the air flow channel by the type of fan 20 and the arrangement of the air inlet 12 and the air outlet 13, the hot air preheating device further includes a wind shield 14, which is arranged in the hot air chamber 11 and divides the hot air chamber 11 into an air inlet chamber 141 and an air outlet chamber 142, the air inlet 12 is connected to the air inlet chamber 141, and the air outlet 13 is connected to the air outlet chamber 142. In this example, the fan 20 is arranged on a side of the hot air hood 10 where an air inlet chamber 141 is formed, so that the fan 20 can suck external air into the air inlet chamber 141 through the air inlet 12, and under the action of the wind shield 14, the air flows in a radial direction and passes through the heating component 30, thereby improving the heating efficiency and uniformity. Specifically, a ventilation gap 143 connecting the air inlet chamber 141 and the air outlet chamber 142 is formed between the outer edge of the wind shield 14 and the cavity wall of the hot air cavity 11, and the heating component 30 can be arranged on one side of the ventilation gap 143 or in the ventilation gap 143, ensuring that the air can fully contact the heating component 30 under the constraints of the wind shield 14 and the fan 20, thereby ensuring the heating effect.

[0088] In one embodiment, the wind shield 14 and the air guide plate 40 are configured as two parallel plates to each other, so that the cavity walls on both sides of the air outlet chamber 142 are arranged in parallel, so that the structure of the air outlet chamber 142 is more regular, ensuring that the air can flow and distribute evenly between the wind shield 14 and the air guide plate 40, so that the air is discharged from each air guide port 41 in a tendency to be evenly discharged, so that during the preheating process, the air flow speed at each point on the substrate and each chip is basically the same, so that the preheating uniformity is stronger.

[0089] Based on the above-mentioned embodiment in which a wind shield 14 is provided in the hot air chamber 11, as an optional embodiment, a guide wall 1421 is provided on the cavity wall of the air inlet chamber 141 on the side close to the ventilation gap 143, and the guide wall 1421 is inclined from the inside to the outside in a direction close to the corresponding ventilation gap 143.

[0090] According to the above-provided embodiment, during the operation of the hot air preheating device, under the action of the fan 20, the external air of the hot air hood 10 enters the air inlet chamber 141 through the air inlet 12, and flows toward the ventilation gap 143 along the radial direction of the rotating component 22 under the further action of the rotating component 22. In this example, because the air inlet chamber 141 and the air outlet chamber 142 are arranged up and down, the air flow channel defined between the two is a bent structure, so that the air flow will inevitably collide with the hood wall of the hot air hood 10 before entering the ventilation gap 143. Therefore, a guide wall 1421 is provided on the cavity wall of the air inlet chamber 141 near the ventilation gap 143, which can allow the air flow to collide with the guide wall 1421 while better guiding the air flow toward the gap direction, so that the air flow can finally be discharged from the hot air hood 10 from the air guide port 41.

[0091] Of course, it can be understood from the above embodiment that, since the hot air chamber 11 is in a positive pressure state during the operation of the fan 20, the airflow acted upon by the rotating component 22 cannot all flow into the air outlet chamber 142 through the ventilation gap 143, and a part of the airflow will still be in the air inlet chamber 141, and this part of the airflow will continue to circulate in the air inlet chamber 141, thereby achieving the effect of uniform heating and heat preservation.

[0092] According to any of the above implementations, please refer to the attached Figure 3-Figure 6 In one embodiment, the hot air preheating device also includes a return air hood 50, which is used to improve the hot air utilization rate of the hot air preheating device, thereby improving the preheating effect of the device while reducing the energy consumption of the heating component 30.

[0093] Specifically, a hollow return air chamber 51 is formed inside the return air hood 50, and a processing inlet 52 and a processing outlet 53 connected to the return air chamber 51 are respectively provided at the opposite ends of the return air hood 50. In the application scenario of the chip laser welding equipment, the processing inlet 52 is used to transport the processing platform from the outside of the hot air preheating device to the return air chamber 51 (below the air guide plate 40), and the processing outlet 53 is used to transport the processing platform out of the return air chamber 51, so as to ensure the smooth progress of the laser welding process of the chip and the substrate.

[0094] For ease of understanding, in this embodiment, the space connecting the processing inlet 52 and the processing outlet 53 in the return air chamber 51 is defined as a conveying channel 512 .

[0095] The hot air hood 10 is arranged in the return air chamber 51 and is located above the conveying channel 512. In order to alleviate the heat loss of the heated air blown out from the air guide port 41 at the processing inlet 52 and the processing outlet 53, the return air hood 50 is located above the processing inlet 52 and the processing outlet 53 and is respectively provided with baffles 58 for blocking the opposite ends of the hot air hood 10, so as to restrict the size of the processing inlet 52 and the processing outlet 53 to avoid the opposite ends of the hot air hood 10 being directly exposed to the outside of the return air hood 50 through the processing inlet 52 and the processing outlet 53.

[0096] For further information, please refer to the attached Figure 6The hood wall of the hot air hood 10 and the cavity wall of the return air cavity 51 are separated to form a return air channel connecting the air inlet 12 and the air outlet 13. In the above-mentioned embodiment in which the delivery channel 512 is defined, the delivery channel 512 serves as a part of the return air channel. The air blown out from the air guide port 41 still retains a part of the heat after heat exchange with the substrate and the chip. This part of the air can pass through the return air channel and re-enter the hot air cavity 11 through the air inlet 12 for reheating, so that the heat in this part of the air can be reused, thereby improving the air heating efficiency while reducing the burden on the heating component 30.

[0097] At the same time, the return air hood 50 partially wraps the hot air hood 10, which can alleviate the heat loss of the hot air hood 10 and keep it warm. On the basis of ensuring that the temperature of the heated air can meet the preheating requirements, the power consumption of the heating component 30 is reduced. In addition, in the application of chip laser welding equipment, the substrate and the chip can complete preheating (and laser welding) in the conveying channel 512 defined by the hot air hood 10, which can maximize the heating effect of the substrate and the chip and reduce the heat loss rate of the heated air, so that the substrate and the chip can be fully preheated, and the substrate and the chip can be kept within a temperature range of composite requirements from preheating to laser welding, thereby improving the subsequent laser welding effect.

[0098] Please refer to the attached Figure 6 As a specific structural form of the return air cover 50, the return air cover 50 includes:

[0099] The first cover wall 54 and the second cover wall 55 are arranged opposite to each other, the first cover wall 54 is arranged opposite to the air inlet 12 and spaced apart, and forms a collecting channel 511 with the hot air hood 10, and the second cover wall 55 is arranged opposite to the air outlet 13 and spaced apart, and forms a conveying channel 512 connecting the processing inlet 52 and the processing outlet 53 with the air guide plate 40. Specifically, in the embodiment in which the air inlet 12 and the air outlet 13 are respectively opened on the upper side and the lower side of the hot air hood 10, the first cover wall 54 is specifically located on the upper side of the return air hood 50, and the second cover wall 55 is located on the lower side of the return air hood 50, and the interval between the second cover wall 55 and the air guide plate 40 forms the above-mentioned conveying channel 512 for the processing platform to pass through.

[0100] In addition, the third cover wall 56 and the fourth cover wall 57 are arranged opposite to each other, and the third cover wall 56 and the fourth cover wall 57 respectively serve as the opposite side walls of the return air hood 50, and the opposite sides of the third cover wall 56 and the fourth cover wall 57 are respectively connected to the first cover wall 54 and the second cover wall 55, so that the first cover wall 54, the third cover wall 56, the second cover wall 55 and the fourth cover wall 57 are connected in sequence and surround the return air chamber 51 through the processing inlet 52 and the processing outlet 53 at both ends. The third cover wall 56 and the fourth cover wall 57 are respectively spaced from the opposite sides of the hot air hood 10 to form a connecting channel 513 connecting the conveying channel 512 and the collecting channel 511, and the conveying channel 512, the connecting channel 513 and the collecting channel 511 are connected in sequence to form the above-mentioned return air channel.

[0101] In one embodiment, the hot air hood 10 is provided with heat insulation plates on the first hood wall 54, the second hood wall 55, the third hood wall 56 and the fourth hood wall 57 to ensure that the return air hood 50 has good heat insulation and heat preservation functions. At the same time, the fixing part 211 of the driving device 21 of the fan 20 can be arranged on the heat insulation plate installed on the first hood wall 54, so that the fixing part 211 of the driving device 21 is relatively fixed to the hot air hood 10, thereby achieving the purpose of reducing the influence of the heated air on the fan 20.

[0102] Please refer to the attached Figure 4-Figure 6 In one embodiment, in order to alleviate the diffusion of the airflow discharged from the air guide port 41 from the processing inlet 52 and the processing outlet 53 in the conveying channel 512, so as to improve the heat exchange efficiency when the airflow flows through the substrate surface and each chip, the air guide plate 40 is provided with an air guide duct 42 on each air guide port 41, and each air guide duct 42 is extended in a direction away from the air guide plate 40, that is, the air guide duct 42 extends toward the bottom of the conveying channel 512, so as to be as close as possible to the substrate and the chip placed on the surface of the processing platform when the processing platform is under the guide plate, thereby correctly guiding the airflow to the surface of the substrate and the chip, so that the heated air still has a channel that can maintain its airflow directionality and stability when it is discharged from the air guide port 41, so that the heated air diffuses when it is as close to the product surface as possible, thereby reducing heat loss and ensuring that more heated air can contact the substrate and the chip.

[0103] Please refer to the attached Figure 1-Figure 7This embodiment also provides a chip laser welding device. Based on the hot air preheating device described in any of the above embodiments, the chip laser welding device also includes a processing platform for mounting a substrate. The processing platform can be movably arranged on the side of the air guide plate 40 away from the hot air chamber 11 through a conveying mechanism 60. The conveying mechanism 60 passes through the above-mentioned conveying channel 512 so that it can drive the processing platform to reciprocate between its two ends, and convey the unwelded substrate from one end thereof to the bottom of the air guide plate 40 through the processing inlet 52, and after preheating and laser welding, it is conveyed from the processing outlet 53 to the other end thereof for subsequent process steps.

[0104] Continuing with the above embodiment, the chip laser welding equipment also includes a laser generating device 70, which is arranged on the side of the hot air hood 10 away from the processing platform, and the laser generating device 70 is configured to be able to emit laser light to the surface of the substrate. Specifically, taking the first end of the conveying mechanism 60 as the first station 61 and the other end as the second station 62 as an example, during the preheating and laser welding of the substrate and the chip, the conveying mechanism 60 transports the processing platform from the first station 61 to the second station 62, and the laser generating device 70 is located on the side of the hot air hood 10 away from the first station 61 (i.e., close to the second station 62), so that the substrate and the chip are preheated by the hot air hood 10 (the hot air blown out by the air guide plate 40 on it), and then laser welding is performed by the laser generating device 70.

[0105] In one embodiment, in the implementation scheme where the hot air preheating device includes a return air hood 50, in order to improve its thermal insulation performance, the length dimension of the return air hood 50 is set to be greater than the length dimension of the hot air hood 10. In this way, in order to allow the chip to quickly perform the laser welding step after preheating, the laser generating device 70 is located above the return air hood 50, and the return air hood 50 is provided with a window 59 corresponding to the laser generating device 70. A dustproof mirror is provided on the window 59 to ensure that the laser spot can be irradiated on the substrate and the chip passing through the window 59 through the dustproof mirror, thereby ensuring the smooth progress of the laser welding process and avoiding dust from falling from the window 59 to the substrate and the chip.

[0106] It can be understood that in some embodiments, the processing platform can also be directly understood as the conveying mechanism 60, so that the substrate can be directly conveyed through the conveying mechanism 60, and the conveying mechanism 60 located below the substrate can be set as a hollow structure so that the heated air can simultaneously heat the two opposite sides of the substrate in the conveying channel 512.

[0107] In summary, the chip laser welding equipment effectively reduces the instantaneous temperature difference between the substrate and the chip during the laser welding operation by adopting the hot air preheating device provided by the above-mentioned embodiment, avoids excessive instantaneous temperature difference of the substrate, and causes problems such as cracking and warping caused by stress concentration. At the same time, it also ensures uniform preheating of the substrate and each chip, so that the welding effect of each chip on the substrate is consistent, thereby improving the effect of the finished product.

[0108] In the description herein, it should be understood that the terms "upper", "lower", "left", "right", etc., and other directions or positional relationships are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0109] In the description of this specification, the description with reference to the terms "an embodiment", "example", 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 present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0110] In addition, it should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0111] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without paying creative labor, and these methods will fall within the scope of protection of the present invention.

Claims

1. A hot air preheating device, applied to chip laser welding equipment, characterized in that: include: A hot air hood (10) having a hollow hot air cavity (11) formed therein, the hot air hood (10) also being provided with an air inlet (12) and an air outlet (13) both connected to the hot air cavity (11) at intervals; The fan (20) is configured to draw the air outside the hot air hood (10) into the hot air cavity (11) along the axial direction through the air inlet (12), and to allow the air in the hot air cavity (11) to flow along the radial direction and then be discharged from the hot air hood (10) along the axial direction through the air outlet (13); A heating component (30) is disposed in the hot air chamber (11) and surrounds the outer periphery of the fan (20) in a radial direction; An air guide plate (40) is sealed on the air outlet (13), a plurality of evenly distributed air guide ports (41) are passed through the air guide plate (40), and an air guide pipe (42) is respectively arranged on each of the air guide ports (41) of the air guide plate (40), and each of the air guide pipes (42) is extended in a direction away from the air guide plate (40); A return air cover (50) is formed with a hollow return air cavity (51) therein, and two opposite ends of the return air cover (50) are respectively provided with a processing inlet (52) and a processing outlet (53) connected to the return air cavity (51); The hot air hood (10) is arranged in the return air cavity (51), and the hood wall of the hot air hood (10) and the cavity wall of the return air cavity (51) are spaced apart to form a return air channel connecting the air inlet (12) and the air outlet (13).

2. The hot air preheating device according to claim 1, characterized in that: The fan (20) is configured as a centrifugal fan (20), and the centrifugal fan (20) comprises: A driving device (21) is relatively fixed to the hot air hood (10) via a fixing portion (211); A rotating component (22) is disposed in the hot air chamber (11) and connected to an output portion (212) of the driving device (21); The heating components (30) are arranged at intervals around the circumference of the rotating component (22).

3. The hot air preheating device according to claim 2, characterized in that: The heating component (30) comprises a plurality of groups of heating wires, each group of the heating wires being wound around the periphery of the rotating component (22); and Each group of heating wires is arranged in sequence at intervals along the axial direction of the rotating component (22).

4. The hot air preheating device according to claim 2, characterized in that: The air inlet (12) and the air outlet (13) are respectively arranged on opposite sides of the hot air hood (10), and the hot air preheating device further comprises: A wind shield (14) is arranged on the hot air cavity (11) and divides the hot air cavity (11) into an air inlet chamber (141) and an air outlet chamber (142); the air inlet (12) is connected to the air inlet chamber (141), and the air outlet (13) is connected to the air outlet chamber (142); a ventilation gap (143) connecting the air inlet chamber (141) and the air outlet chamber (142) is formed between the outer edge of the wind shield (14) and the cavity wall of the hot air cavity (11).

5. The hot air preheating device according to claim 4, characterized in that: The wind shield (14) and the wind guide plate (40) are parallel to each other.

6. The hot air preheating device according to claim 4, characterized in that: A guide wall (1421) is provided on a side wall of the air inlet chamber (141) close to the ventilation gap (143), and the guide wall (1421) is inclined from the inside to the outside in a direction close to the corresponding ventilation gap (143).

7. The hot air preheating device according to claim 1, characterized in that: The return air cover (50) comprises: a first cover wall (54) and a second cover wall (55) arranged opposite to each other, wherein the first cover wall (54) is arranged opposite to the air inlet (12) and is spaced apart from each other, and forms a collecting channel (511) with the hot air cover (10), and the second cover wall (55) is arranged opposite to the air outlet (13) and is spaced apart from each other, and forms a conveying channel (512) communicating with the processing inlet (52) and the processing outlet (53) with the air guide plate (40); and A third cover wall (56) and a fourth cover wall (57) are arranged opposite to each other, and opposite sides of the third cover wall (56) and the fourth cover wall (57) are respectively connected to the first cover wall (54) and the second cover wall (55), and the third cover wall (56) and the fourth cover wall (57) are respectively spaced apart from opposite sides of the hot air cover (10) to form a connecting channel (513) connecting the conveying channel (512) and the collecting channel (511).

8. A chip laser welding device, characterized in that: include: The hot air preheating device according to any one of claims 1 to 7; A processing platform, used for placing a substrate, the processing platform being movably arranged on a side of the air guide plate (40) facing away from the hot air chamber (11); A laser generating device (70) is arranged on a side of the hot air hood (10) away from the processing platform, and the laser generating device (70) is configured to emit laser light onto a surface of a substrate.

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