Heated eutectic solder station and soldering method

Abstract

The application discloses a heating eutectic soldering platform and a soldering method, which comprise a support, a bottom plate, a heating soldering platform, a soldering cavity cover plate, a first driving module, a clamping module and a second driving module; the heating soldering platform is provided with a unique suction hole in the center to realize vacuum suction fixation; the clamping module on both sides clamps the substrate under the drive of the second driving module to form a double holding structure of'single suction hole + clamping jaw clamping'; the soldering cavity cover plate movably closes or opens the soldering cavity, small window opening meets the chip in and out, the whole cover plate opening meets the large substrate taking and placing, and the atmosphere protection and the operation convenience are considered; the second driving module adopts a cam cooperating with elastic elements and an elastic floating assembly to realize self-adaptive flexible clamping. The application meets the soldering requirements of micro and larger size substrates, realizes miniaturization and integrated design, effectively inhibits oxidation, and improves the mounting precision and soldering reliability.

Description

Technical Field

[0001] This invention belongs to the technical field of eutectic welding equipment, and in particular relates to a heated eutectic welding station and welding method. Background Technology

[0002] In the field of microelectronic packaging, eutectic bonding is an important chip mounting process, widely used in the packaging and manufacturing of high-reliability products such as optoelectronic devices, high-power LEDs, and RF modules. During eutectic bonding, the substrate is typically fixed on a heated bonding station, and the eutectic solder (such as AuSn, AuGe, etc.) on the chip and substrate is heated to above the eutectic temperature under a protective atmosphere or vacuum atmosphere. This causes the solder to melt and wet the substrate before cooling and solidifying, achieving a reliable interconnection between the chip and the substrate.

[0003] Existing eutectic bonding stations have the following shortcomings in practical applications: Regarding substrate fixation methods, most existing technologies employ vacuum adsorption. For micro-substrates, a single or multiple small-diameter adsorption holes can meet the fixation requirements; however, as the substrate size increases, single vacuum adsorption often results in insecure fixation due to limited adsorption area or substrate warping. This leads to substrate displacement during mounting, severely affecting the positioning accuracy of the chip. To address this issue, some existing technologies attempt to add more adsorption holes to the heating station. However, this disrupts the overall layout of the heating wires within the heating station, causing uneven temperature distribution in the heating area, which in turn affects the eutectic bonding quality and may even increase the chip bonding void ratio.

[0004] Regarding welding atmosphere control, existing eutectic bonding stations typically have an opening on the top cover plate of the welding cavity for the substrate to enter and exit. This opening must be larger than the substrate size. For larger substrates, the opening is correspondingly larger, leading to significant shielding gas leakage during welding. This results in high residual oxygen levels in the welding cavity, which can easily cause oxidation of the solder and the metal layer on the bottom of the chip, affecting welding strength and long-term reliability. Increasing the shielding gas flow rate to improve the atmosphere, however, would lead to gas waste and increased costs.

[0005] Furthermore, existing eutectic bonding stations mostly employ rigid clamping mechanisms, directly applying clamping force to the substrate. Due to the dimensional tolerances of the incoming substrates, rigid clamping can easily lead to edge damage or insufficient clamping force. When it is necessary to clamp substrates of different sizes, it is often necessary to manually adjust the position of the jaws or replace the fixture, resulting in low adjustment efficiency and difficulty in meeting the rapid changeover requirements of multi-variety, small-batch production.

[0006] Finally, in terms of equipment integration, existing chip mounting equipment integrates multiple functional modules with limited layout space, while traditional eutectic bonding stations are often bulky in structure and have large dimensions in the X and Y directions, making it difficult to meet the requirements of miniaturization integration.

[0007] The prior art patent CN112216632B discloses an LD chip eutectic bonding station. By setting a substrate positioning mechanism, the substrate is positioned in the X and Y directions. Although the eutectic bonding station improves the positioning accuracy and stability of the substrate, it still has the problem of unstable welding atmosphere when welding large-sized substrates. In addition, the substrate clamping and positioning is also rigid, which poses a risk of damaging the substrate.

[0008] Therefore, how to reliably fix large-size substrates while ensuring heating uniformity, how to maintain a good welding atmosphere while taking into account the convenience of substrate handling, and how to achieve automatic adjustment and flexible clamping of the clamping mechanism while meeting the requirements of equipment miniaturization are the technical problems that urgently need to be solved in the field of eutectic bonding station technology. Summary of the Invention

[0009] One of the main objectives of this invention is to provide a heated eutectic bonding station that meets the welding needs of micro and larger substrates, enables miniaturized and integrated design, effectively suppresses oxidation, and improves mounting accuracy and welding reliability.

[0010] The present invention achieves the above objective through the following technical solution: a heating eutectic bonding station, comprising: Support; A base plate is provided on top of the support; A heating welding station is set on the base plate. A welding cavity with a perimeter is set above the heating welding station. An adsorption hole is set at the center of the heating welding station. There is one and only one adsorption hole. A welding cavity cover plate, located above the heating welding station, is used to close or open the welding cavity; The first drive module is used to drive the welding cavity cover plate to move, so that it covers the welding cavity or retracts from the welding cavity. The clamping module is disposed opposite to both sides of the heating welding station and has a pair of clamping plates extending into the welding cavity for clamping the substrate. The second drive module is used to drive the clamping modules to clamp or open with each other.

[0011] Furthermore, the welding cavity cover plate is provided with an opening for the chip and / or substrate to enter and exit the welding cavity. The size of the opening is configured so as not to affect the atmosphere of the welding cavity during the chip welding process.

[0012] Furthermore, the first drive module drives the welding cavity cover plate to move from one side of the heating welding station in the X direction to above the welding cavity, and the second drive module is disposed on the other side of the heating welding station in the X direction; the pair of clamping plates extend into the welding cavity from both sides of the heating welding station in the Y direction.

[0013] Furthermore, a first support plate is provided on the bracket on the X-direction side of the base plate; the first drive module includes: The first driving component is located below the base plate; A pair of first slide rails are mounted on the first support plate; The first connecting plate has its bottom end fixed to the movable end of the first driving member, and its top end passes through the first support plate and connects to the welding cavity cover plate. The end of the welding cavity cover plate away from the welding cavity is slidably mounted on the pair of first slide rails via a first slider; the first support plate is provided with an avoidance slot to allow the first connecting plate to move in the X direction.

[0014] Furthermore, a baffle cover is provided above the base plate; the baffle cover encloses the base plate and the heating welding station set on the base plate, and together with the base plate, forms the welding cavity; the baffle cover has a window that exposes the heating welding station, and the welding cavity cover can close or open the window by horizontal movement.

[0015] Furthermore, the enclosure cover plate is provided with a support guide groove that supports and guides the welding cavity cover plate to move along the Y direction, and the welding cavity cover plate reciprocates within the support guide groove.

[0016] Furthermore, a second support plate is provided on the bracket on the X-direction side of the base plate; the second drive module includes: The second driving component is disposed below the second support plate; A pair of second slide rails are mounted on the second support plate; The cam is located above the second support plate and is driven by the second driving member to rotate around the Z-axis. A pair of second connecting plates are located on both sides of the cam in the Y direction, with one end slidably mounted on the pair of second slide rails via a second slider, and the other end extending to both sides of the heating welding station in the Y direction; a pair of clamping plates are disposed at the ends of the pair of second connecting plates; The first elastic element has its two ends respectively disposed on the pair of second connecting plates, driving the pair of second connecting plates to remain close to each other, thereby driving the pair of clamping plates to remain clamped. Each of the pair of second connecting plates is provided with a cam roller that cooperates with the cam.

[0017] Furthermore, an elastic floating component is provided at the end of the second connecting plate, and one end of the clamping plate is provided at the floating end of the elastic floating component.

[0018] Furthermore, the elastic floating component includes: The mounting base is fixed to the end of the second connecting plate; The third slide rail is disposed on the mounting base and extends along the Y direction; The third connecting plate is slidably mounted on the third slide rail via a third slider. The second elastic element presses the third connecting plate toward the welding cavity; One end of the clamping plate is disposed on the third connecting plate.

[0019] Another object of the present invention is to provide a eutectic welding method based on the heated eutectic welding station as described above, comprising the following steps: The substrate is placed on the heating welding station, and the substrate is vacuum-adsorbed and fixed through the adsorption holes; According to the size of the substrate, the second driving module drives the clamping module so that the pair of clamping plates clamp and fix the substrate from both sides in the Y direction; The welding cavity cover is moved by the first driving module to close the welding cavity; The chip is placed into the corresponding position on the substrate through the opening on the solder cavity cover, and the heating station is activated to perform pulse heating, so that the solder melts and achieves eutectic welding. After welding is completed, the welding cavity cover is opened by the first drive module, and the pair of clamping plates are opened by the second drive module to remove the welded component.

[0020] This invention solves three major technical problems in the prior art by organically combining the substrate fixing method, atmosphere protection mechanism and flexible adaptive clamping: "the contradiction between fixing reliability and heating uniformity", "the contradiction between atmosphere protection and operation convenience", and "the contradiction between clamping rigidity and size adaptability". It realizes a high-precision, high-reliability, high-compatibility, low-oxidation and miniaturized eutectic welding platform.

[0021] Compared with existing technologies, the beneficial effects of this invention's heating eutectic soldering station and welding method are as follows: By employing a dual-holding structure of "single adsorption hole vacuum adsorption + cam-driven elastic clamping," a movable soldering chamber cover, and an adaptive flexible clamping method using a cam in conjunction with an elastic floating component, this invention solves the technical problems of existing eutectic soldering stations in achieving a balance between the reliability of fixing micro and large-sized substrates, the protection of the welding atmosphere and the convenience of loading and unloading, and the adaptive clamping of substrates of different sizes. It achieves the technical effects of improving mounting accuracy and welding reliability, suppressing welding oxidation, and realizing the miniaturization and integration of the eutectic soldering station while ensuring heating uniformity. Specifically: (1) The substrate is reliably fixed and does not damage the heating uniformity of the eutectic bonding station: By adopting a dual holding structure of "single adsorption hole vacuum adsorption + clamping", it can meet the fixing requirements of micro substrates through a single adsorption hole, and provide auxiliary fixing for large substrates through the clamping module. Under the premise of avoiding increasing the adsorption hole and damaging the heating wire layout, the stability of substrate positioning and mounting accuracy are significantly improved. (2) Balancing atmosphere protection and ease of operation: The welding cavity cover can be moved to close or open by the first drive module. Only a small window is needed for the chip to enter and exit. The cover can be opened as a whole when the large substrate is picked up and put in. This ensures the relative airtightness of the cavity and the maintenance of the protective atmosphere during the welding process, effectively suppressing oxidation, and also meets the convenient operation requirements of large-size substrates. (3) Adaptive flexible clamping and compact structure: The second drive module uses a cam combined with elastic elements and elastic floating components to achieve automatic adjustment and adaptive flexible clamping of substrates of different sizes, avoiding damage to the substrate caused by rigid clamping; at the same time, the spatial layout of each module—the cover plate moves along the X direction, the clamping plate extends along the Y direction, and the drive component is built into the support—effectively reduces the dimensions in the X and Y directions, meeting the requirements of miniaturization and integration. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural diagram of an embodiment of the present invention; Figure 2 This is a side view of the structure according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the left side of the support exploded in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the right side of the support in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the elastic floating component in an embodiment of the present invention; Figure 6 This is a schematic diagram of the mating structure between the base plate and the enclosure cover plate in an embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of the base plate and the heating welding station in an embodiment of the present invention; The numbers in the diagram represent: 100 - Heated eutectic bonding station; 1-Support; 2-Base plate; 21-Welding cavity; 22-First support plate; 221-Avoidance slot; 23-Second support plate; 24-First slider; 25-Bearing groove; 251-Positioning protrusion; 26-Pressure plate; 3-Heating welding station; 31-Adsorption hole; 4-Welding cavity cover plate; 41-Window; 5-First drive module; 51-First drive component; 52-First slide rail; 53-First connecting plate; 54-Protective cover; 6-Clamping module. 61-Clamping plate, 62-Elastic floating component, 621-Mounting base, 622-Third slide rail, 623-Third slider, 624-Third connecting plate, 625-Second elastic element; 7-Second drive module, 71-Second drive element, 72-Second slide rail, 73-Cam, 74-Second connecting plate, 75-First elastic element, 76-Second slider, 77-Cam roller; 8-Enclosure cover plate, 81-Window, 82-Support guide groove. Detailed Implementation

[0023] Example 1: Please refer to Figure 1-7 This embodiment is a heating eutectic soldering station 100, which includes a support 1, a base plate 2 disposed on the top of the support 1, a heating soldering station 3 disposed on the base plate 2, a soldering cavity cover plate 4 located above the heating soldering station 3, a first drive module 5 for driving the soldering cavity cover plate 4 to close or open, a clamping module 6 for clamping the substrate on the heating soldering station 3, and a second drive module 7 for driving the clamping module 6 to clamp and open with each other.

[0024] A welding cavity 21 with four surrounding barriers is provided above the heating welding station 3. The welding cavity cover plate 4 is driven by the first driving module 5 to cover the welding cavity 21 or to be removed from the welding cavity 21. The clamping module 6 is arranged opposite to each other on both sides of the heating welding station 3 and has a pair of clamping plates 61 extending into the welding cavity 21. The welding cavity cover plate 4 is provided with an opening 41 for the chip and / or substrate to enter and exit the welding cavity 21. An adsorption hole 31 is provided at the center of the heating welding station 3. There is one and only one adsorption hole 31.

[0025] The heating welding station 3 is internally equipped with a pulse heating wire (not shown in the figure) and at least one thermocouple sensing element. The pulse heating wire is evenly distributed in a U-shape or ring around the adsorption hole 31. The pulse heating wire is electrically connected to an external pulse heating power supply, and the thermocouple sensing element is signal-connected to a temperature controller to achieve pulse heating curve control for rapid heating, constant temperature, and cooling, ensuring temperature uniformity within the welding cavity 21. The adsorption hole 31 penetrates the heating welding station 3 and is connected to an external vacuum generator.

[0026] Chip mounting involves precisely attaching chips onto a substrate. Different products require substrates of varying sizes. For micro-substrates, a single vacuum suction hole is used for fixation. However, as the substrate size increases, relying solely on suction to fix its position can lead to instability and substandard mounting accuracy. Existing technologies sometimes involve creating more vacuum suction holes on the heating station, but this affects the heating wire layout and can disrupt the uniformity of the heating zone, impacting the substrate. Therefore, to address this issue, this embodiment adds a clamping module 6. A second driving module 7 drives the clamping module 6 to clamp and fix slightly larger substrates. Combined with the single suction hole 31 on the heating station 3, this forms a dual-fixation method of "single suction hole + gripper clamping" to secure the substrate, meeting the positional fixation requirements for both micro-substrates and larger substrates.

[0027] In addition, the substrate needs to enter and exit the soldering cavity before and after placement. To facilitate this, existing technologies typically include an inlet / outlet on the top cover of the soldering cavity. This inlet / outlet must be larger than the substrate size to allow for smooth passage. For micro-substrate placement, a small inlet / outlet on the cover is acceptable and won't significantly affect the soldering atmosphere. However, for slightly larger substrates, the inlet / outlet size needs to be correspondingly enlarged. Larger inlet / outlet designs can lead to a poor atmosphere in the soldering cavity during chip placement, resulting in severe soldering oxidation and affecting product quality. To meet the chip mounting requirements of micro-substrates and larger substrates and solve the aforementioned technical problems, this embodiment includes a first driving module 5 that switches the solder cavity cover 4 between a closed and open state. When a larger substrate needs to enter or exit the soldering cavity 21, the first driving module 5 opens the solder cavity cover 4 to facilitate substrate placement and removal. During chip mounting, the solder cavity cover 4 remains closed to ensure the relative sealing of the soldering cavity 21, thereby protecting the atmospheric environment of the soldering cavity 21, effectively suppressing oxidation reactions, and improving thermal stability. The size of the opening 41 on the solder cavity cover 4 is configured so as not to affect the atmospheric environment of the soldering cavity 21 during chip soldering.

[0028] In addition, to achieve the best anti-oxidation welding effect, at least one protective gas inlet (not labeled in the figure) is provided on the support 1 or the base plate 2. The protective gas inlet is connected to the welding cavity 21 and is used to introduce nitrogen, argon, or a mixture of formic acid gas into the welding cavity 21 before and during welding. When the welding cavity cover plate 4 is closed, the welding cavity 21 forms a relatively sealed cavity, maintaining a very small gap with the outside only through the window 41. After the protective gas is introduced, a positive pressure protective atmosphere can be formed in the cavity, further suppressing the oxidation reaction during the eutectic welding process. For the mounting of larger substrates, since the welding cavity cover plate 4 can be fully opened for substrate loading and unloading, there is no need to open a large window on the cover plate. This ensures the ease of operation of large substrates and avoids the problem of excessively rapid leakage of protective gas and difficulty in maintaining the atmosphere caused by a large window.

[0029] Because existing chip mounting equipment typically integrates a chip feeding module, a substrate feeding module, a chip transfer and position correction module, a lower camera imaging module, and a soldering and mounting module, and these multiple modules need to be arranged on the same workbench, in order to reduce the overall area occupied by the chip mounting equipment, the layout of these modules is generally quite compact. Therefore, the layout space for the soldering and mounting module is relatively limited, which in turn requires the eutectic bonding station to be miniaturized.

[0030] To meet the miniaturized structural design requirements of the eutectic bonding station, the overall structural layout of the eutectic bonding station in this embodiment has been optimized. Specifically: In this embodiment, the first driving module 5 drives the welding cavity cover plate 4 to move from one side of the heating welding station 3 in the X direction to above the welding cavity 21, and the second driving module 7 is disposed on the other side of the heating welding station 3 in the X direction; the pair of clamping plates 61 extend into the welding cavity 21 from both sides of the heating welding station 3 in the Y direction. Through the above layout design, the overall size of the eutectic welding station in the X and Y directions can be effectively reduced, thereby reducing the space occupied by the eutectic welding station.

[0031] In a preferred further miniaturization scheme, the ratio of the length of the support 1 in the X direction to the length of the heating station 3 in the X direction is no greater than 1.6:1, and the ratio of the length of the support 1 in the Y direction to the length of the heating station 3 in the Y direction is no greater than 1.8:1. This ensures that the ratio of the overall projected area of ​​the eutectic station 100 to the area of ​​the heating area is controlled within a reasonable range while meeting the functions of clamping, cover plate driving, and atmosphere protection, making it easy to integrate into a compact mounting device.

[0032] A first support plate 22 and a second support plate 23 are fixedly installed on the support 1 on both sides of the base plate 2 in the X direction. The first support plate 22 is used as the mounting base for some components in the first drive module 5, and the second support plate 23 is used as the mounting base for the second drive module 7.

[0033] The first drive module 5 includes a first drive component 51, a pair of first slide rails 52, and a first connecting plate 53. The first drive component 51 is located below the base plate 2. The pair of first slide rails 52 are mounted on the first connecting plate 53. The end of the welding cavity cover plate 4 away from the welding cavity 21 is slidably mounted on the pair of first slide rails 52 via a first slider 24. The bottom end of the first connecting plate 53 is fixed to the movable end of the first drive component 51, and the top end passes upward through the first support plate 22 and connects to the welding cavity cover plate 4. The first support plate 22 has an avoidance slot 221 to allow the first connecting plate 53 to move in the X direction. The first drive component 51 drives the first connecting plate 53 to move in the X direction, thereby driving the welding cavity cover plate 4 to move in the X direction, realizing the switching between the closed and open states.

[0034] To protect the service life and guiding reliability of the first drive module 5, the first drive module 5 also includes a protective cover 54 that covers the pair of first slide rails 52.

[0035] In this embodiment, the first drive module 5 is a cylinder, and the welding cavity cover plate 4 switches between the open and closed positions. The cylinder can meet the action requirements, which reduces costs and saves space.

[0036] A retaining cover plate 8 is provided above the base plate 2; the retaining cover plate 8 encloses the base plate 2 and the heating welding station 3 set on the base plate 2, forming a welding cavity 21 together with the base plate 2. The retaining cover plate 8 has a window 81 that exposes the heating welding station 3, and the welding cavity cover plate 4 can close or open the window 81 by horizontal movement.

[0037] To ensure the stability of the welding cavity cover plate 4, a support guide groove 82 is provided on the enclosure cover plate 8 to support and guide the welding cavity cover plate 4 to move along the Y direction. The welding cavity cover plate 4 reciprocates within the support guide groove 82.

[0038] In some embodiments, the opening size of the window 41 is only for the chip to pass through. Therefore, the solder cavity cover 4 is detachably mounted on the first connecting plate 53, and the solder cavity cover 4 can be flexibly replaced according to different chip sizes. The size of the opening 41 on the solder cavity cover 4 can be flexibly designed to meet the needs of various chip sizes.

[0039] In some other embodiments, the opening size of window 41 is such that, in addition to allowing the chip to pass through, it can also allow a small substrate to pass through.

[0040] The second drive module 7 includes a second drive member 71, a pair of second slide rails 72, a cam 73, a pair of second connecting plates 74, and a first elastic member 75. The second drive member 71 is disposed below the second support plate 23, and the pair of second slide rails 72 are disposed on the second support plate 23; the cam 73 is located above the second support plate 23 and is driven by the second drive member 71 to rotate around the Z-axis; the pair of second connecting plates 74 are located on both sides of the cam 73 in the Y direction, with one end slidably disposed on the pair of second slide rails 72 via a second slider 76, and the other end extending to both sides of the heating welding station 3 in the Y direction; the pair of clamping plates 61 are disposed at the ends of the pair of second connecting plates 74; the two ends of the first elastic member 75 are respectively disposed on the pair of second connecting plates 74 to drive the pair of second connecting plates 74 to keep them close to each other, thereby driving the pair of clamping plates 61 to keep them in a clamping state; each of the pair of second connecting plates 74 is provided with a cam roller 77 that cooperates with the cam 73. When the substrate needs to be clamped, under the elastic pulling action of the first elastic member 75, the two second connecting plates 74, together with the clamping plates 61 located at the ends of the second connecting plates 74, are driven to move closer to each other, clamping the Y-direction sides of the substrate; when it is necessary to remove the clamping action on the substrate, the second driving member 71 drives the cam 73 to rotate, and under the transmission action of the cam 73 and the cam roller 77, the two second connecting plates 74 are driven to move away from each other, thereby switching the two clamping plates 61 to the open state, which facilitates the removal and placement of the substrate.

[0041] The design of the second connecting plate 74 and the first elastic element 75 achieves primary elastic clamping, avoiding damage to the substrate caused by rigid clamping. In conjunction with the positional layout of other components of the second drive module 7 and the transmission design of the cam 73 and cam roller 77, on the one hand, the distance between the two clamping plates 61 can be flexibly adjusted by the cam 73, thus making it suitable for clamping substrates of various sizes. On the other hand, the cam drive can also drive the two clamping plates 61 to open, meeting the clamping opening power requirements. In addition, the above positional layout, while meeting the above functional requirements, does not significantly increase the overall space occupied by the eutectic bonding station, achieving a miniaturized design.

[0042] For mass production of substrate chip mounting, the incoming substrates will inevitably have some dimensional errors. To avoid excessive force when clamping the substrate with the clamping plate 61, an elastic floating component 62 is provided at the end of the second connecting plate 74, and one end of the clamping plate 61 is located at the floating end of the elastic floating component 62. The elastic floating component 62 includes a mounting base 621 fixed to the end of the second connecting plate 74, a third slide rail 622 disposed on the mounting base 621 and extending along the Y direction, a third connecting plate 624 slidably disposed on the third slide rail 622 via a third slider 623, and a second elastic member 625 pressing the third connecting plate 624 toward the welding cavity 21. When clamping substrates of different sizes, the second drive unit 71 drives the cam 73 to rotate to a set angle, so that the clamping distance between the two clamping plates 61 can be matched with the substrate of the corresponding size. When the substrate size changes, the clamping distance can be automatically adjusted by rotating the angle of the cam 73 to meet the clamping requirements of substrates of different sizes. Regarding the issue of substrate size error, if there is an error in the substrate size when the clamping plate 61 clamps the substrate, the error can be eliminated by the elastic floating component 62 to achieve adaptive clamping of the substrate. This meets the precise clamping requirements of all substrates of the same specification with size errors, effectively avoids the problem of rigid clamping that may crush the substrate or the substrate clamping not being secure, and greatly improves the uniformity of force and the reliability of the substrate clamping.

[0043] When the eutectic bonding station 100 is used in conjunction with an external placement head or nozzle (not shown in the figure) for chip mounting, the placement head picks up the chip, moves it above the substrate through the opening 41, and then lowers it to bring the chip into contact with the solder on the substrate. To achieve good eutectic bonding quality, the placement head applies a set placement pressure during the bonding process, ranging from 0.5N to 5N (determined according to the chip size and solder type). In some preferred embodiments, a pressure sensor (not shown in the figure) is integrated into the placement head. The pressure sensor is connected to the control system signal. When the detected real-time pressure reaches a set threshold, the control system initiates a pulse heating program, maintaining a constant pressure while the solder melts, thereby ensuring sufficient wetting between the molten solder and the chip and substrate, reducing void ratio.

[0044] After the eutectic soldering station 100 completes pulse heating to melt the solder, it can enter the cooling stage. Cooling methods include natural cooling, air cooling, or water-assisted cooling. In a preferred embodiment, the heating soldering station 3 also has a cooling channel (not shown in the figure) inside, which is connected to an external cooling medium source. After welding, compressed air or cooling water is introduced for rapid cooling, accelerating the solidification of the eutectic solder, reducing excessive growth of intermetallic compounds, and improving welding strength. Simultaneously, shielding gas continues to be introduced during the cooling stage until the temperature of the welding cavity 21 drops below the set temperature to prevent oxidation during the high-temperature cooling process.

[0045] In some embodiments, to enable quick installation and removal of the heating soldering station 3, a supporting groove 25 for supporting the heating soldering station 3 is provided on the base plate 2. The heating soldering station 3 has a rectangular block structure, and the supporting groove 25 is designed to conform to the shape of the heating soldering station 3. Positioning protrusions 251 are provided on the inner wall surface of the supporting groove 25 to position the heating soldering station 3 around its perimeter. The horizontal position of the heating soldering station 3 is locked and fixed in the supporting groove 25 by the interference fit between the positioning protrusions 251 and the outer surface of the heating soldering station 3. To fix the position of the heating soldering station 3 in the vertical direction, a pressure plate 26 is provided on the upper perimeter of the supporting groove 25 to press the heating soldering station 3 downward. The supporting groove 25, the positioning protrusions 251 on the inner wall surface, and the pressure plate 26 enable quick installation and removal of the heating soldering station 3, making it suitable for quick replacement of heating soldering stations with different adsorption hole sizes.

[0046] This embodiment also provides a eutectic welding method based on a eutectic welding station 100, which includes the following steps: Step S1: The substrate is placed in and vacuum adsorbed through the adsorption hole 31, while the second drive module 7 drives the clamping plate 61 to clamp the substrate. Step S2: The first drive module 5 drives the welding cavity cover plate 4 to close; Step S3: Introduce protective gas into the welding cavity 21 and continue for 2s to 10s to replace the atmosphere; Step S4: The external mounting head places the chip onto the corresponding position on the substrate through the window 41 and applies the set mounting pressure; Step S5: Start pulse heating to raise the solder temperature above the eutectic temperature (e.g., 280℃~310℃ for AuSn eutectic solder), and hold for 0.5s~3s; Step S6: Stop heating or start cooling to allow the solder to cool down and solidify quickly; Step S7: Stop the protective gas, the first drive module 5 opens the welding chamber cover plate 4, the second drive module 7 drives the clamping plate 61 to open, the suction hole 31 disconnects the vacuum, and the welded component is taken out.

[0047] This embodiment of a heating eutectic bonding station 100 differs substantially from existing technologies in terms of substrate fixing method, atmosphere protection mechanism, flexible adaptive clamping method, and miniaturized integration. It solves problems in existing technologies such as unreliable fixing of large-size substrates, contradiction between atmosphere protection and operational convenience, and easy damage to the substrate by rigid clamping, and has significant technological progress.

[0048] In this embodiment, the substrate fixing method (single adsorption hole + clamping module), the atmosphere protection mechanism (movable welding cavity cover plate + small opening), and the flexible adaptive clamping method (cam drive + elastic floating component) are not independent technical features, but rather mutually supportive and work collaboratively around the core goal of "improving eutectic welding quality, efficiency, and equipment compatibility." Specifically: (1) Flexible adaptive clamping provides a reliable means of execution for the "single adsorption hole + clamping" fixing method. Under the premise of using only one adsorption hole, for large-sized substrates or substrates with warping / tolerance, flexible clamping can automatically adapt to the actual size and position of the substrate, avoiding damage or inaccurate positioning caused by rigid clamping, thereby ensuring the reliability of the dual-fixation structure; the substrate fixing method of "single adsorption hole + clamping module" can stably fix large-sized and tolerance substrates with flexible adaptive clamping, expanding the compatibility range of the equipment; in addition, flexible adaptive clamping and vacuum adsorption together constitute a "soft fixation" system, so that the substrate does not shift or warp during the welding process.

[0049] (2) Reliable substrate fixation creates the operational prerequisite for atmosphere protection of “small window + movable cover plate”. Because the substrate is fixed firmly and accurately, there is no need to repeatedly adjust the position of the substrate during the soldering process. Therefore, the soldering cavity cover plate can be kept closed, and chip mounting can be completed only through the small window, thereby maximizing the cavity airtightness, reducing protective gas leakage, and inhibiting oxidation.

[0050] (3) The good atmosphere protection, in turn, improves the stability of flexible clamping and vacuum adsorption. Under the low oxygen and positive pressure protective atmosphere, the substrate and solder are not easily oxidized, the surface condition is stable, and the action boundary of clamping force and adsorption force is more consistent, which further ensures the repeatability and positioning accuracy of flexible clamping and vacuum adsorption.

[0051] For those skilled in the art, various modifications and improvements can be made without departing from the inventive concept of this invention, and these all fall within the protection scope of this invention.

Claims

1. A heating eutectic bonding station, characterized in that, include: Support (1); The base plate (2) is disposed on top of the support (1); A heating welding station (3) is set on the base plate (2). A welding cavity (21) with a perimeter is provided above the heating welding station (3). An adsorption hole (31) is provided at the center of the heating welding station (3). There is only one adsorption hole (31). The welding cavity cover plate (4) is located above the heating welding station (3) and is used to close or open the welding cavity (21). The first drive module (5) is used to drive the welding cavity cover plate (4) to move so that it covers the welding cavity (21) or is removed from the welding cavity (21); The clamping module (6) is disposed opposite to both sides of the heating welding station (3) and has a pair of clamping plates (61) extending into the welding cavity (21) for clamping the substrate; The second drive module (7) is used to drive the clamping modules (6) to clamp or open with each other.

2. The heating eutectic bonding station (100) according to claim 1, characterized in that, The welding cavity cover plate (4) is provided with an opening (41) for the chip and / or substrate to enter and exit the welding cavity (21). The size of the opening (41) is configured so that it does not affect the atmosphere of the welding cavity (21) during the chip welding process.

3. The heating eutectic bonding station (100) according to claim 1, characterized in that, The first driving module (5) drives the welding cavity cover plate (4) to move from one side of the heating welding station (3) in the X direction to above the welding cavity (21), and the second driving module (7) is set on the other side of the heating welding station (3) in the X direction; the pair of clamping plates (61) extend into the welding cavity (21) from both sides of the heating welding station (3) in the Y direction respectively.

4. The heating eutectic bonding station (100) according to claim 1, characterized in that, A first support plate (22) is provided on the support (1) on the X-direction side of the base plate (2); the first drive module (5) includes: The first driving component (51) is located below the base plate (2); A pair of first slide rails (52) are provided on the first support plate (22); The first connecting plate (53) has its bottom end fixed to the movable end of the first driving member (51) and its top end passes through the first support plate (22) and is connected to the welding cavity cover plate (4). The end of the welding cavity cover plate (4) away from the welding cavity (21) is slidably mounted on the pair of first slide rails (52) via the first slider (24); the first support plate (22) is provided with a clearance slot (221) to allow the first connecting plate (53) to move in the X direction.

5. The heating eutectic bonding station (100) according to claim 1, characterized in that, A baffle cover (8) is provided above the base plate (2); the baffle cover (8) encloses the base plate (2) and the heating welding station (3) provided on the base plate (2), and together with the base plate (2) forms the welding cavity (21); the baffle cover (8) has a window (81) that exposes the heating welding station (3), and the welding cavity cover (4) closes or opens the window (81) by horizontal movement.

6. The heated eutectic bonding station (100) according to claim 5, characterized in that, The enclosure cover plate (8) is provided with a support guide groove (82) that supports and guides the welding cavity cover plate (4) to move along the Y direction, and the welding cavity cover plate (4) reciprocates within the support guide groove (82).

7. The heating eutectic bonding station (100) according to claim 1, characterized in that, A second support plate (23) is provided on the support (1) on one side of the base plate (2) in the X direction; the second drive module (7) includes: The second driving component (71) is disposed below the second support plate (23); A pair of second slide rails (72) are provided on the second support plate (23); The cam (73) is located above the second support plate (23) and is driven by the second drive member (71) to rotate around the Z-axis; A pair of second connecting plates (74) are located on both sides of the cam (73) in the Y direction, and one end is slidably mounted on the pair of second slide rails (72) via a second slider (76), and the other end extends to both sides of the heating welding station (3) in the Y direction; the pair of clamping plates (61) are disposed at the ends of the pair of second connecting plates (74); The first elastic element (75) has its two ends respectively disposed on the pair of second connecting plates (74), driving the pair of second connecting plates (74) to remain close to each other, thereby driving the pair of clamping plates (61) to remain clamped. Each of the pair of second connecting plates (74) is provided with a cam roller (77) that cooperates with the cam (73).

8. The heated eutectic bonding station (100) according to claim 7, characterized in that, The end of the second connecting plate (74) is provided with an elastic floating component (62), and one end of the clamping plate (61) is provided at the floating end of the elastic floating component (62).

9. The heated eutectic bonding station (100) according to claim 8, characterized in that, The elastic floating component (62) includes: Mounting base (621) is fixed to the end of the second connecting plate (74); The third slide rail (622) is disposed on the mounting base (621) and extends along the Y direction; The third connecting plate (624) is slidably mounted on the third slide rail (622) via the third slider (623); The second elastic element (625) presses the third connecting plate (624) toward the welding cavity (21); One end of the clamping plate (61) is disposed on the third connecting plate (624).

10. A eutectic welding method based on a heated eutectic welding station according to any one of claims 1 to 9, characterized in that, Includes the following steps: The substrate is placed on the heating station (3), and the substrate is vacuum adsorbed and fixed through the adsorption hole (31); According to the size of the substrate, the second driving module (7) drives the clamping module (6) so that the pair of clamping plates (61) clamp and fix the substrate from both sides in the Y direction; The welding cavity cover plate (4) is moved by the first driving module (5) to close the welding cavity (21). The chip is placed on the corresponding position of the substrate through the opening (41) on the solder cavity cover plate (4), and the heating station (3) is activated to perform pulse heating, so that the solder melts and achieves eutectic welding; After welding is completed, the welding cavity cover plate (4) is opened by the first drive module (5), and the pair of clamping plates (61) are opened by the second drive module (7) to take out the welded component.

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