An avoidance type partition compression clamp for laser penetration welding cover face package and welding method

Abstract

The present application relates to the technical field of laser welding fixture, and is a kind of fixture and welding method for arc additive multi-dimensional heterogeneous heterogeneous metal composite plate cover packaging laser penetration welding.The fixture comprises a base and the like, a pressing frame is provided with a laser avoiding channel corresponding to the cover packaging welding path, and a clearance notch is formed in the four corner regions;The four-corner rotatable avoiding pressing assembly is locked with the pressing frame by automatic locking member, and pressing force is applied to the cover plate corner and the four corners of the cover plate through the pressing frame during the four-side linear welding stage.The four-side pressing assembly forms relay pressing after pressing the four sides at the end of the four-side linear welding stage, the four-corner rotatable avoiding pressing assembly is unlocked and exits the four-corner closed welding path and the laser head movement path around the rotation fulcrum, so that the laser head can complete continuous packaging welding of four-side linear segment and four-corner closed segment in one clamping state.The present application can continuously maintain the stable fit gap between the thin cover plate and the base, and avoid the interference of the fixture with the laser head movement.

Description

Technical Field

[0001] This invention relates to the field of laser welding fixtures and cover packaging manufacturing technology, and in particular to an obstacle avoidance partition clamping fixture and welding method for laser penetration welding cover packaging. Background Technology

[0002] In applications such as battery encapsulation, metal-ceramic composite plate encapsulation, precision electronic device housing encapsulation, sensor encapsulation, and heterogeneous metal composite plate cover encapsulation, it is usually necessary to cover the substrate with a thin cover plate and form a continuous closed weld along the perimeter of the cover plate to achieve purposes such as fixation, sealing, moisture protection, corrosion protection, and structural protection.

[0003] Laser penetration welding, with its high energy density, narrow heat-affected zone, and fast welding speed, can achieve localized fusion between thin cover plates and the substrate under relatively low heat input conditions. This helps reduce the thermal impact on vulnerable components such as internal batteries, ceramics, and electronic components. Therefore, laser welding is increasingly used in metal cover packaging.

[0004] However, in the peripheral encapsulation welding of thin cover plates, a reliable clamping force must be applied to the cover plate to ensure a stable fit between the cover plate and the substrate near the welding path. If the fit gap is too large, defects such as incomplete fusion, porosity, discontinuous welds, or unstable penetration depth may occur. If the clamping force is too large or the clamping area is not properly arranged, it may cause local indentations on the thin cover plate, damage to internal vulnerable parts, or welding thermal deformation.

[0005] Existing static clamping fixtures typically use clamping plates, screws, or cylinder blocks to clamp the periphery of the cover plate. These fixtures are relatively easy to arrange near the straight sections of the four sides, but in the closed areas at the four corners of rectangular or near-rectangular closed welds, the clamping components, connecting components, or supporting components often interfere with the movement path of the laser head, causing interference between the laser head and the fixture.

[0006] To avoid interference, traditional processes often require reserving fixture spaces before welding. Welding the four sides one by one requires multiple clamping and unclamping operations, which can lead to insufficient clamping of the cover plate in the four corner areas or springback during welding. Furthermore, multiple clamping or interruption of welding reduces path consistency, increases the risk of thermal deformation and sealing defects, and is not conducive to continuous production.

[0007] Therefore, there is an urgent need to provide a fixture and welding method that can simultaneously clamp the straight sections of the four sides, clamp the four corner areas, and avoid the welding path of the four corners in a single clamping state, so that the clamping parts can perform relay clamping at different welding stages, and the locking parts can automatically lock and unlock, thereby ensuring that the fixture and the laser head movement safety path maintain a reliable avoidance relationship. Summary of the Invention

[0008] The purpose of this invention is to provide an obstacle-avoiding partitioned clamping fixture and welding method for laser penetration welding of cover plates, thereby solving the problems of interference between the clamping structure and the four-corner closed welding path, insufficient corner clamping, the need for multiple clamping operations, and the difficulty in stably controlling the bonding gap of thin cover plates in existing laser welding of cover plates. This invention is applicable to peripheral closed welding between thin cover plates and the substrate, and is particularly suitable for cover plate structures containing vulnerable components, heat-sensitive components, or precision functional components.

[0009] To achieve the above objectives, the present invention provides a clearance-type partitioned clamping fixture comprising a base, a workpiece positioning assembly, a cover plate limiting assembly, a clamping frame, a four-sided clamping assembly, four corner-rotatable clearance clamping assemblies, and a control assembly. The base is used to support the substrate and the cover plate, the workpiece positioning assembly is used to position the substrate, and the cover plate limiting assembly is used to restrict the position of the cover plate before clamping.

[0010] The clamping frame is positioned above the cover plate and can descend relative to the base with the lifting mechanism to form a basic clamping. The clamping frame is provided with laser clearance channels corresponding to the encapsulation path of the cover to be welded, and the laser clearance channels cover the straight welding sections on all four sides; in the four corner areas, the clamping frame forms clearance notches to accommodate the space required for the laser head to complete corner turning and closing welding.

[0011] The four-sided clamping assembly is arranged along the four sides of the cover plate and includes one or more of the following: strip clamping blocks, dot matrix clamping blocks, independent clamping actuators, elastic compensation components, force sensors or displacement sensors. It is used to apply clamping force to the four straight segments and their adjacent areas after the straight welding stage is completed.

[0012] The four corner-rotatable clearance clamping assemblies are respectively located at the four corners. Each corner-rotatable clearance clamping assembly includes a rotating support, a clamping arm, a corner clamping head, and a rotary actuator, or includes a corner clamping mechanism that can swing, flip, translate, or perform a combination of movements. The four corner-rotatable clearance clamping assemblies are locked to the clamping frame by automatic locking elements, providing clamping force during the straight-line welding stage on all four sides.

[0013] When the four-sided straight welding section is completed or the laser head is about to enter the four-corner closed welding section, the four-sided clamping assembly applies clamping force to the four sides, thus keeping the cover plate in contact with the substrate while the four-corner rotatable clearance clamping assembly retracts. Subsequently, the automatic locking component releases the lock, and the four-corner rotatable clearance clamping assembly rotates to the retraction position, which is located outside the four-corner welding path and outside the laser head movement path.

[0014] The control component is communicatively connected to the four-sided clamping component, the four-corner rotatable avoidance clamping component, the automatic locking component, and the laser welding equipment. The control component controls the welding path, laser head position, clamping force feedback, locking state, and retraction state according to the four-sided straight welding stage, relay clamping stage, four-corner retraction stage, and four-corner closed welding stage.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects: First, the laser clearance channel and four corner clearance notches of the clamping frame provide clear safe passage space for the laser head when welding the four sides and four corners; Second, the four-side clamping components and the four-corner rotatable clearance clamping components work in a partitioned manner to meet the clamping requirements of straight section welding and corner welding in stages; Third, the automatic locking components and the corner rotatable clamping mechanism ensure that the four-corner clamping structure can reliably bear the load when clamping is required and quickly retract when welding is required, avoiding secondary clamping; Fourth, the relay clamping strategy prevents the cover plate from warping or the fitting gap from abruptly changing after the corner clamping components retract; Fifth, it is suitable for thin cover plates and encapsulation structures containing vulnerable parts, which helps to improve weld closure, airtightness, welding consistency, and automated production efficiency. Attached Figure Description

[0016] Figure 1 This is a top view of the avoidance-type partition clamping fixture of the present invention;

[0017] Figure 2 This is a schematic diagram of the structure of the clamping frame, laser avoidance channel, and four corner clearance notches of the present invention;

[0018] Figure 3 This is a partial schematic diagram of the four-corner rotatable clearance clamping assembly of the present invention in a locked and clamped state;

[0019] Figure 4 This is a partial schematic diagram of the four-corner rotatable clearance clamping assembly of the present invention in a retracted state, allowing for closed welding at the four corners;

[0020] Figure 5 This is a schematic diagram of the process flow of the welding method of the present invention.

[0021] Explanation of reference numerals in the attached drawings: 1-Base; 2-Workpiece positioning assembly; 3-Cover plate limiting assembly; 4-Clamping frame; 41-Laser clearance channel; 42-Clamping notch; 5-Four-sided clamping assembly; 51-Strip clamping block; 52-Independent clamping actuator; 6-Four-corner rotatable clearance clamping assembly; 61-Rotating support; 62-Pressure arm; 63-Corner pressure head; 64-Rotary driver; 7-Automatic locking component; 71-Lock seat; 72-Retractable locking pin; 73-Locking status detection component; 8-Workpiece; 81-Base; 82-Cover plate; 9-Laser head; 91-Laser beam; 10-Control assembly; 11-Support pad or support component; 12-Welding path; 121-Four-sided straight welding section; 122-Four-corner closed welding section; 13-Retreat position; 14-Laser head movement safety path. Detailed Implementation

[0022] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be understood that the following embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent substitutions, simple modifications, or combinations made based on the concept of the present invention should fall within the scope of protection of the present invention.

[0023] like Figure 1 As shown, the present invention provides an obstacle avoidance partition clamping fixture for laser penetration welding cover sealing, including a base 1, a workpiece positioning component 2, a cover plate limiting component 3, a clamping frame 4, a four-sided clamping component 5, a four-corner rotatable obstacle avoidance clamping component 6, an automatic locking component 7, and a control component 10.

[0024] The base 1 is a load-bearing platform with high rigidity and flatness, and can be made of cast iron, welded steel plates, granite platforms, or composite support platforms. The upper surface of the base 1 is provided with a positioning area for placing the workpiece 8, and a support pad or support member 11 can be set in the positioning area. For workpieces containing batteries, ceramics, electronic components, or other heat-sensitive functional components, the support pad or support member 11 preferably avoids the weak support area of ​​the internal vulnerable parts and avoids the welding heat-affected zone to reduce the risk of pressure loss and heat-affected zone.

[0025] The workpiece positioning assembly 2 may include a reference positioning pin, an adjustable positioning block, a side-push clamping block, an end-face positioning block, an elastic pusher, or an adsorption positioning unit. The workpiece positioning assembly 2 is used to form a stable X, Y, and Z-axis positioning reference on the base 1 for the substrate 81, and to suppress overall displacement of the substrate 81 during subsequent clamping and welding processes.

[0026] The cover plate limiting assembly 3 is used to pre-position the cover plate 82. The cover plate 82 can be made of stainless steel, aluminum alloy, titanium alloy, nickel-based alloy, copper alloy, or composite metal sheet. The cover plate limiting assembly 3 may include miniature positioning pins, edge limiting blocks, magnetic blocks, adsorption holes, or elastic pressure plates. For cover plates that are thin and prone to warping, the cover plate limiting assembly 3 can establish the planar relative position between the cover plate 82 and the base 81 before the clamping frame 4 descends, preventing the cover plate from slipping during the clamping process.

[0027] like Figure 2 As shown, the clamping frame 4 can be a rectangular frame, a ring frame, or an irregularly shaped frame designed according to the path of the package to be soldered. An opening is formed in the middle of the clamping frame 4 to expose the welding area of ​​the cover plate. A laser avoidance channel 41 is provided along the welding path 12 of the clamping frame 4. The width of the laser avoidance channel 41 can be determined comprehensively based on the diameter of the laser beam 91, the size of the protective gas nozzle, the shape of the ranging module, and the robot path, so that the laser head 9 does not interfere with the clamping frame 4 during movement.

[0028] The clamping frame 4 has clearance notches 42 at its four corners. These clearance notches 42 not only provide space for the laser head 9 to turn within the closed welding sections 122 at the four corners, but also provide space for the rotatable clearance clamping components 6 to retract. The clearance notches 42 can be chamfered, rounded, rectangular, or composite curve openings. When the welding path 12 is a rounded rectangular path, the clearance notches 42 preferably maintain an equidistant profile with the outer side of the closed welding sections 122 at the four corners to obtain a more stable safety margin for laser head movement.

[0029] The four-sided clamping assembly 5 is arranged along the four sides of the cover plate 82. Each side of the four-sided clamping assembly 5 may include one or more strip-shaped clamping blocks 51, or multiple independent clamping actuators 52. The side of the strip-shaped clamping block 51 that contacts the cover plate 82 is preferably machined as a flat clamping surface, and may also be provided with a flexible high-temperature resistant pad, a ceramic heat insulation layer, a copper alloy heat-conducting pressure head, or an anti-splash coating. The independent clamping actuators 52 may be cylinders, electric cylinders, spring clamping units, or servo clamping units.

[0030] The four-sided clamping assembly 5 is positioned at a preset safe distance from the laser avoidance channel 41. This safe distance can be determined based on the dimensions of the laser head 9, the incident angle of the laser beam 91, the diameter of the protective gas nozzle, the spatter range, and the control error. The four-sided clamping assembly 5 provides stable clamping force near the four-sided straight welding section 121, and simultaneously strengthens the clamping of the adjacent corner transition areas before the four corner rotatable avoidance clamping assemblies 6 retract, thereby forming a relay clamping effect.

[0031] like Figure 3As shown, the four-corner rotatable clearance clamping assembly 6 includes a rotating support 61, a pressure arm 62, a corner pressure head 63, and a rotary actuator 64. The rotating support 61 is fixed to the base 1; one end of the pressure arm 62 is connected to the rotating support 61, and the other end is provided with the corner pressure head 63. The corner pressure head 63 is preferably made of a high-temperature resistant, low-adhesion, and low-scratch material, and can be provided with a spherical adaptive contact structure to accommodate local minor warping of the cover plate 82.

[0032] The automatic locking element 7 provides locking constraint when the four-corner rotatable clearance clamping assembly 6 is in the clamping position. The automatic locking element 7 may include a lock seat 71, a retractable locking pin 72, a tapered guide structure, and a locking status detection element 73. The lock seat 71 may be mounted on the clamping frame 4 or the base 1, and the retractable locking pin 72 may be disposed in the pressure arm 62 or the lock seat 71. During locking, the retractable locking pin 72 inserts into the lock seat 71, causing the corner pressure head 63 to apply a stable downward clamping force to the cover plate 82; during unlocking, the retractable locking pin 72 retracts from the lock seat 71, allowing the pressure arm 62 to be driven to the retracted position 13 by the rotary drive 64.

[0033] The locking status detection element 73 can be a proximity switch, limit switch, magnetic induction switch, photoelectric sensor, or encoder. The control component 10 uses the locking status detection element 73 to determine whether the four rotatable corner avoidance clamping components 6 are in the locked, unlocked, or retracted position. When the sensor signal is abnormal, the control component 10 can prevent the laser head 9 from entering the corresponding area to avoid collision between the laser head and the mechanism that has not been retracted.

[0034] like Figure 4 As shown, when the laser head 9 needs to complete the four-corner closed welding section 122, the corresponding four-corner rotatable clearance clamping assembly 6 drives the pressure arm 62 to rotate around the rotating support 61 to the retraction position 13 via the rotary driver 64. The retraction position 13 is located outside the welding path 12 and the laser head movement safety path 14. Depending on the different equipment layout, the retraction action can also be a lateral swing, a linear translation, an oblique lifting followed by rotation, or a combination of the above actions.

[0035] The control component 10 can be a PLC, industrial computer, robot external axis controller, or dedicated motion controller. The control component 10 communicates with the laser welding equipment, robot control system, clamping actuator, locking actuator, and sensors. The control component 10 can receive path segment information from the welding program and automatically switch clamping strategies based on the path segment type.

[0036] The welding method in this embodiment is as follows: Figure 5As shown. First, the base 81 is placed on the base 1 and positioned by the workpiece positioning assembly 2; then the cover plate 82 is placed on the base 81 and pre-positioned by the cover plate limiting assembly 3; then the clamping frame 4 is lowered, and the four-corner rotatable clearance clamping assembly 6 and the four-side clamping assembly 5 apply clamping force to the clamping frame 4 respectively, so that the four corners and four sides of the cover plate 82 obtain uniform clamping force.

[0037] During the four-sided straight welding stage, the laser head 9 moves along the four-sided straight welding section 121, and the laser beam 91 acts on the overlapping or fitting area between the cover plate 82 and the substrate 81 through the laser avoidance channel 41. At this time, the four-corner rotatable avoidance clamping components 6 remain locked and clamped, which are used to provide clamping force to the clamping frame and suppress the warping of the cover plate 82 at the four corners and adjacent areas, ensuring that the weld formation at the end of the straight section is consistent.

[0038] When the laser head 9 completes one or more four-sided straight welding segments 121 and is about to enter the four-corner closed welding segment 122, the control component 10 causes the four-sided pressing component 5 to press the two adjacent sides at the corresponding corners, forming a relay pressing.

[0039] After the relay clamping reaches the preset conditions, the control component 10 drives the automatic locking component 7 to release the lock and drives the four-corner rotatable clearance clamping component 6 to leave the clamping position. Only when the clearance signal is valid, the locking pin exit signal is valid, and the clamping force on all four sides reaches the set range, will the control component 10 allow the laser head 9 to enter the corresponding four-corner closed welding section 122.

[0040] The laser head 9 then completes the four-corner welding along an arc, chamfered line, spline curve, or other preset four-corner closed trajectory, so that the four-corner closed welding segment 122 is reliably connected with the adjacent four-sided straight welding segment 121, forming a complete closed weld. After welding is completed, the four-sided clamping assembly 5 and the clamping frame 4 can continue to be held for a preset time to reduce the warping of the cover plate caused by the cooling and shrinkage of the weld.

[0041] In this embodiment, the cover plate 82 has a thickness of 0.05 mm to 3 mm, and the unit length clamping force applied by the four-sided clamping assembly 5 is set according to the cover plate material, thickness, welding power, and welding speed; the corner clamping force of the four-corner rotatable clearance clamping assembly 6 does not exceed the safety threshold that may cause damage to internal vulnerable parts. The control assembly 10 can correct the output of each clamping point in real time based on the force sensor signal.

[0042] The four-corner rotatable clearance clamping assembly 6 can return to the clamping position after welding at one corner, or remain in the retracted state until all welding is completed. For continuous circumferential welding processes, the control assembly 10 can perform a cycle of "relay clamping - unlocking - retraction - welding - holding" corner by corner according to the path position of the laser head 9; for segmented welding processes, the control assembly 10 can simultaneously retract two or four corner mechanisms.

[0043] This invention is not limited to rectangular cover plates. For cover packages with polygonal, rounded rectangular, oblong, or partially irregular boundaries, as long as the welding path contains a closed area requiring phased avoidance by the clamping components, the partitioned clamping, relay clamping, and avoidance welding concepts of this invention can be adopted. The shape of the clamping frame 4, the outline of the laser avoidance channel 41, and the number and arrangement of the four rotatable avoidance clamping components 6 can all be adjusted according to the actual welding path.

[0044] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, any improvements, substitutions, or combinations made to the shape and dimensions of the components, the driving method, the sensor type, the control logic, the material selection, and the arrangement without departing from the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A clearance-type partition clamping fixture for laser penetration welding of cover plate encapsulation, characterized in that, include: The base is used to support the substrate to be welded and the cover plate covering the substrate; The workpiece positioning assembly, mounted on the base, is used for planar positioning and height reference positioning of the base. A cover plate limiting assembly is provided on the base and the clamping frame to limit the planar position of the cover plate relative to the base and to pre-position the cover plate. The clamping frame is positioned above the cover plate and can be raised and lowered relative to the base. The clamping frame has a laser clearance channel corresponding to the cover plate sealing welding path and clearance notches are formed at the four corners for the laser head to pass through. The four-sided clamping assembly is arranged along the four sides of the clamping frame to apply clamping force to the straight sections of the four sides of the cover plate and to form a relay clamping force on the cover plate after the four-sided straight welding stage is completed. The four-corner rotatable clearance clamping components are respectively set at the four corners of the clamping frame. They are used to apply clamping force to the corners of the clamping frame and the cover plate during the straight welding stage and rotate out of the four-corner welding path and the laser head movement path during the four-corner closed welding stage. An automatic locking component, in conjunction with a four-corner rotatable clearance clamping assembly and a clamping frame, is used to automatically lock and unlock the four-corner rotatable clearance clamping assembly; In the four-sided straight welding stage, the four-corner rotatable clearance clamping components are in a locked and clamped state. After the four-sided clamping components form a relay clamping force on the clamping frame and cover plate, the automatic locking component is released, and the four-corner rotatable clearance clamping components rotate to the retraction position, so that the workpiece can complete the laser edge sealing welding of the four-sided straight welding section and the four-corner closed welding section in one clamping state.

2. The clearance-type partition clamping fixture according to claim 1, characterized in that, The laser avoidance channel includes four straight channel segments corresponding to the four-sided straight welding segments and corner connecting areas corresponding to the four-corner closed welding segments. The clearance gap is located on the outer side of the intersection of two adjacent straight channel segments. The width of the clearance gap is greater than the combined safe width of the laser head, protective gas nozzle, ranging sensor and coaxial monitoring module, and a preset safe distance is maintained between the laser avoidance channel and the four-sided clamping components.

3. The clearance-type partition clamping fixture according to claim 1, characterized in that, The four-corner rotatable avoidance clamping assembly includes a rotating support, a pressure arm, corner pressure heads, and a rotary driver; one end of the pressure arm is hinged or pivotally connected to the rotating support, and the other end is provided with a corner pressure head; the rotary driver is used to drive the pressure arm to switch between a clamping position and a retracting position; the rotation angle of the pressure arm when switching from the clamping position to the retracting position is 45° to 135°, and the corner pressure head is located outside the laser avoidance channel and outside the laser head movement safety path in the retracting position.

4. The clearance-type partition clamping fixture according to claim 1, characterized in that, The automatic locking mechanism includes a lock seat, a retractable locking pin, a tapered guide structure, and a locking status detection component. The retractable locking pin is driven by a cylinder, electric cylinder, electromagnet, or servo actuator. In the locked state, it inserts into the lock seat and provides anti-lifting constraint to the four rotatable corner avoidance clamping components. In the unlocked state, it retracts from the lock seat. The locking status detection component is a proximity switch, limit switch, magnetic induction switch, or encoder.

5. The clearance-type partition clamping fixture according to claim 1, characterized in that, The four-sided clamping assembly includes several independent clamping actuators and strip clamping blocks distributed along the straight segments of the four sides. The independent clamping actuators apply adjustable clamping force to the four sides of the cover plate through elastic compensation components, force sensors, and displacement sensors to keep the cover plate in contact with the substrate before and after the four corners can be rotated to avoid the clamping assembly from retracting. The strip clamping block is provided with a high-temperature resistant insulation layer, an anti-spatter layer, and a low-adhesion coating on the side near the welding path.

6. The clearance-type partition clamping fixture according to claim 1, characterized in that, The cover plate limiting assembly includes at least one of a positioning pin, a lateral limiting block, an elastic pushing component, a vacuum adsorption hole, or a magnetic positioning component, used to pre-position the thin cover plate before the clamping frame is pressed down and to suppress the warping of the thin cover plate; the base is provided with a support pad, a conformal support block, and an adjustable support column that are adapted to the shape of the back of the base. The support pad, conformal support block, and adjustable support column are located outside the welding heat-affected zone or on a low heat conduction path to reduce the pressure loss and heat conduction impact on vulnerable parts inside the base.

7. The clearance-type partition clamping fixture according to any one of claims 1 to 6, characterized in that, It also includes a control component, which is communicatively connected to the four-sided clamping component, the four-corner rotatable avoidance clamping component, the automatic locking component, and the laser welding equipment. It is used to perform interlocking control sequentially according to the four-sided straight welding stage, the relay clamping stage, the four-corner retreating stage, and the four-corner closed welding stage. The control component makes interlocking judgments based on the laser head position, welding path, clamping force feedback, locking status feedback, and retreating position feedback. It allows the laser head to enter the corresponding four-corner welding area only when the four-corner rotatable avoidance clamping component at the corresponding corner has retreated to the position and the four-sided clamping component has reached the preset clamping force.

8. A welding method for laser penetration welding of cover plate encapsulation, characterized in that, The welding method using the clearance-type partition clamping fixture according to any one of claims 1 to 7 includes the following steps: (1) Place the substrate on the base, position the substrate using the workpiece positioning assembly, and cover the area of ​​the substrate to be packaged with the cover plate; (2) The cover plate is prepositioned by the cover plate limiting assembly, so that the clamping frame is lowered to the working position, and the four-sided clamping assembly and the four-corner rotatable clearance clamping assembly apply clamping force to the four-sided area and the four-corner area of ​​the cover plate respectively; (3) Make the laser head perform laser penetration welding on the straight welding section on all four sides along the laser avoidance channel. During the welding process, the four corner rotatable avoidance clamping components remain locked and clamped. (4) After the four straight welding sections are completed, the four-sided clamping components are used to clamp the four-sided areas in relay, and the locking of the corresponding four corner rotatable clearance clamping components is released by the automatic locking components. (5) Rotate the four-corner rotatable clearance clamping components to the retraction position, and after confirming that they have left the four-corner welding path and the laser head movement safety path, make the laser head complete the four-corner closed welding; (6) After the weld has cooled, release the clamping of the four-sided clamping assembly and the clamping frame, and take out the packaged workpiece.

9. The welding method according to claim 8, characterized in that, In steps (3) to (5), the control component performs interlocking judgment based on the laser head position, welding path, clamping force feedback, locking status feedback and retreating position feedback; when the four corner rotatable avoidance clamping components of any corner are not retreated to the position, or the four-sided clamping components do not reach the preset clamping force, or the automatic locking component is not in the corresponding unlocking state, the laser head is paused from entering the corresponding four-corner closed welding section.

10. The welding method according to claim 8, characterized in that, The four straight welding sections are completed by continuous welding or segmented continuous welding. The four corner closed welding sections are completed by arc, chamfered broken line or spline curve welding trajectory, and form a closed weld with the adjacent four straight welding sections. The cover plate is a metal sheet with a thickness of 0.05mm to 3mm. The substrate is a solid substrate, or the substrate contains batteries, ceramics, electronic components, sensors, composite material cores and thermal functional components. The cover plate and the substrate are encapsulated in a single clamping state.

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