Vapor chamber laser welding system

Abstract

The utility model discloses a uniform-temperature plate laser welding system which has the advantages that the welding strength of a welded uniform-temperature plate is high, and an upper cover and a lower cover are sealed and are not easy to crack. The vapor chamber laser welding system comprises an upper jig, a lower jig and laser welding equipment, the upper jig detachably covers and presses the lower jig, the lower jig is provided with a positioning part used for positioning an upper cover and a lower cover, and the laser welding equipment is arranged above the upper jig or below the lower jig. And the laser welding equipment adopts an annular light spot laser welding mode to weld peripheral connecting areas of the upper cover and the lower cover which are pressed by the upper jig and the lower jig.

Description

Technical Field

[0001] The utility model relates to the field of temperature balancing plate preparation, in particular to a temperature balancing plate laser welding system. Background Art

[0002] Electronic devices (such as mobile phones) generate heat during operation. If this heat accumulates inside the device over time, it can cause the product to overheat, affecting the user experience and even causing failures. A vapor chamber is a highly efficient thermally conductive component filled with a phase-changeable fluid. This fluid's cyclic phase change allows for rapid heat transfer and uniform temperature distribution. Ultra-thin vapor chambers are lightweight and are now widely used in electronic product cooling.

[0003] In the prior art, the heat spreader consists of an upper cover and a lower cover, which are sealed and welded using solder in a tunnel furnace at a high temperature. However, this method has the following drawbacks: due to the long cycle time in the tunnel furnace, the efficiency is low, the yield is difficult to monitor, and a large number of graphite jigs are required. After being exposed to high temperatures, the hardness of copper materials decreases significantly, the dimensions shrink, and the product consistency is poor. To address this, the prior art has switched to laser welding to weld the upper and lower covers, but this method still has difficulties to overcome. For example, copper has high thermal conductivity, a heat sink, low laser absorption rate, and large fluctuations in absorption rate. These characteristics can lead to defects such as cold welds, spatter, air holes, and poor appearance.

[0004] Therefore, there is an urgent need to provide a heat spreader laser welding system with high welding strength and a seal that is not prone to cracking between the upper cover and the lower cover to overcome the above-mentioned defects. Utility Model Content

[0005] The utility model aims to provide a laser welding system for a temperature homogenizing plate with high welding strength and the upper cover and the lower cover sealed and not prone to cracking.

[0006] To achieve the above objectives, the present invention provides a heat spreader laser welding system, wherein the heat spreader also includes an upper cover and a lower cover. The heat spreader laser welding system comprises an upper jig, a lower jig, and a laser welding device. The upper jig is detachably pressed onto the lower jig. The lower jig has a positioning portion for positioning the upper and lower covers. The laser welding device is located above the upper jig or below the lower jig. The laser welding device uses an annular spot laser welding method to weld the surrounding connection areas of the upper and lower covers pressed together by the upper and lower jigs.

[0007] Preferably, the laser welding equipment can be moved and adjusted at least along the X, Y, and Z axes.

[0008] Preferably, the laser welding equipment includes a CCD visual monitoring device for monitoring welding leakage.

[0009] Preferably, the heat spreader laser welding system of the present invention further includes a robot, which places the lower cover on the positioning portion and stacks the upper cover on the lower cover. The robot also removes the upper fixture and takes out the heat spreader after welding.

[0010] Preferably, the heat spreader laser welding system of the present invention also includes an area evaluation device, which selects a single upper jig or an even number of upper jigs based on the input / scanned / selected area information of the heat spreader, thereby performing single-stage continuous welding, two-stage welding or four-stage welding.

[0011] Preferably, the laser welding equipment emits a ring beam consisting of an outer ring beam and a central beam. The central beam and the outer ring beam are arranged concentrically, and the outer ring beam surrounds the central beam. The laser power and light emission time of the outer ring beam and / or the central beam can be adjusted independently in real time.

[0012] Preferably, the laser power range of the outer ring light beam and / or the laser power range of the central light beam are respectively 150W to 300W.

[0013] Preferably, the speed range of the laser welding equipment is 300 mm / s to 500 mm / s.

[0014] Preferably, a plurality of positioning rods and a plurality of guide rods are installed on the top of the lower fixture, the plurality of positioning rods together surround the positioning portion, and the guide rods are located circumferentially outside the positioning rods.

[0015] Preferably, the lower jig is provided with a lower notch for the annular light beam to pass through, and the upper jig is provided with a contour-profiling limiting area, and the contour-profiling limiting area is provided with an upper notch.

[0016] Compared with the existing technology, the utility model uses the annular spot laser emitted by the laser welding equipment to weld the surrounding connection areas of the upper cover and the lower cover. The annular spot can effectively expand the keyhole opening, improve the stability of the welding process, and at the same time expand the molten pool area, reduce the solidification speed of the molten pool, facilitate the escape of pores, reduce the porosity of the weld, and make the upper cover and the lower cover quickly sealed, thereby improving the structural strength of the product, avoiding the reduction of hardness of the copper material after being exposed to high temperature, and improving production timeliness. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a processing schematic diagram of the temperature homogenizing plate laser welding system of the present invention.

[0018] Figure 2 The utility model is a processing flow chart of the temperature homogenizing plate laser welding system.

[0019] Figure 3 For areas between 500 and 2000 mm 2 A three-dimensional diagram of the upper and lower fixtures used for the temperature distribution plate.

[0020] Figure 4 For areas between 2000 and 5000 mm 2 A three-dimensional diagram of the upper and lower fixtures used for the temperature distribution plate.

[0021] Figure 5 For areas between 5000 and 6000 mm 2 A three-dimensional diagram of the upper and lower fixtures used for the temperature distribution plate.

[0022] Figure 6 It is a top view of the temperature homogenizing plate obtained after the upper cover and the lower cover are welded using the temperature homogenizing plate laser welding system of the present invention.

[0023] Figure 7 It is a structural diagram of a ring beam composed of a central beam and an outer ring beam.

[0024] Figure 8 This is a microscopic enlarged image of the connection area around the upper cover and the lower cover after welding.

[0025] Figure 9 This is a test report on the laser edge sealing tensile strength of a heat spreader processed using the heat spreader laser welding system of the present invention.

[0026] Figure 10 This is a brazing tensile strength test report obtained using a conventional brazing method to produce a heat spreader. DETAILED DESCRIPTION

[0027] In order to explain the technical content and structural features of the present invention in detail, the following is a further description in conjunction with the embodiments and the accompanying drawings.

[0028] like Figure 1 and Figure 2 As shown, the present invention provides a heat spreader laser welding system 100, wherein the heat spreader 01 includes an upper cover 02, a lower cover 03, and a capillary structure. The capillary structure is provided on the lower cover 03, and this structure is well known to those skilled in the art, so it will not be described here in detail.

[0029] like Figures 1 to 5 As shown, the heat spreader laser welding system 100 of the present invention is mainly used to laser weld the surrounding connection areas of the upper cover 02 and the lower cover 03, thereby sealing the edges of the upper cover 02 and the lower cover 03 to form a heat spreader with a sealed cavity, and the capillary structure is in the sealed cavity.

[0030] The heat spreader laser welding system 100 of the present invention includes an upper jig 10, a lower jig 20 and a laser welding device 30. The upper jig 10 can be detachably pressed on the lower jig 20. The lower jig 20 has a positioning portion 21 for positioning the upper cover 02 and the lower cover 03. In the embodiment provided by the present invention, the laser welding device 30 is arranged below the lower jig 20, but is not limited to this. According to actual needs, the laser welding device 30 can be arranged above the upper jig 10. Among them, the laser welding device 30 adopts an annular spot laser welding method to weld the surrounding connection areas of the upper cover 02 and the lower cover 03 pressed by the upper jig 10 and the lower jig 20 to seal the edges of the upper cover 02 and the lower cover 03, and form a heat spreader with a sealed cavity.

[0031] The present invention uses the annular spot laser emitted by the laser welding equipment 30 to weld the surrounding connection areas of the upper cover 02 and the lower cover 03. The annular spot can effectively expand the keyhole opening, improve the stability of the welding process, and at the same time expand the molten pool area, reduce the solidification speed of the molten pool, which is conducive to the escape of pores and reduce the porosity of the weld, so that the upper cover 02 and the lower cover 03 are quickly sealed, thereby improving the structural strength of the product, avoiding the reduction in hardness of the copper material after being exposed to high temperature, and improving production timeliness.

[0032] The test was conducted using the heat spreader laser welding system 100 of the present invention (the resulting report is referred to as the laser edge sealing tensile strength test report, see Figure 9 ) and the traditional brazing method (the resulting report is called the brazing tensile strength test report, see Figure 10 ) A comparison revealed that the tensile strength of the weld zone of the heat spreader 01 achieved using the heat spreader laser welding system 100 of the present invention was greater than that achieved using traditional brazing. This demonstrates that the weld zone of the heat spreader 01 achieved using annular laser spot welding is stronger and more reliable, and the upper and lower covers 02 and 03 are less susceptible to cracking and deformation after sealing. Field testing has shown that, under the same operating conditions, the heat spreader laser welding system 100 of the present invention can effectively improve the weld seal yield rate, reaching 98%. It also significantly shortens production cycles, with each weld requiring only approximately 10 to 20 seconds to complete.

[0033] Figure 8 This is a microscopic enlarged image of the connection area of ​​the upper cover 02 and the lower cover 03 after welding. The dotted line demarcates the area where the weld point is located. The overall penetration depth is 0.232mm, while the thickness of the upper cover 02 is 0.2mm, and the thickness of the lower cover 03 is 0.1mm. The penetration ratio is: (0.232-0.1) / 0.2=65.5%. It can be seen that the penetration ratio of the product after welding reaches 60% to 70%, achieving deep penetration welding and improving welding quality.

[0034] Preferably, the laser welding equipment 30 can be moved and adjusted along at least the X, Y, and Z axes. The laser welding equipment 30 can fuse and weld the surrounding connection areas between the upper cover 02 and the lower cover 03 except the liquid injection port by moving and adjusting along the X, Y, and Z axes to form a laser weld.

[0035] The laser welding equipment 30 is driven by a three-axis platform, allowing translational adjustments along the X, Y, and Z axes to quickly and accurately weld the surrounding connection areas. Alternatively, a multi-axis drive, such as a six-axis platform, can be used to drive the movement, depending on actual needs. Preferably, the laser welding equipment 30 operates at a speed range of 300 mm / s to 500 mm / s, ensuring rapid movement and high production efficiency. Furthermore, to promptly detect defective welds, the laser welding equipment 30 includes a CCD visual monitoring device (not shown) for detecting weld leaks.

[0036] To improve the system's automation, the heat spreader laser welding system 100 of the present invention also includes a robot (not shown). The robot places the lower cover 03 on the positioning portion 21 and stacks the upper cover 02 on the lower cover 03. The robot also removes the upper fixture 10 and removes the welded heat spreader 01. The robot enables automated loading and unloading, achieving automated processing, improving processing efficiency, and reducing workload.

[0037] The vapor chamber laser welding system 100 of the present invention also includes an area assessment device (not shown). Based on the input, scanned, or selected vapor chamber area information, the area assessment device selects a single upper fixture 10 or an even number of upper fixtures 10 to perform single-stage continuous welding, two-stage welding, or four-stage welding. The area information of the vapor chamber 01 represents the size of the vapor chamber 01, and different areas require different welding methods.

[0038] The area information of the vapor chamber 01 can be input directly by typing, scanned by scanning a barcode or QR code containing the area information, or directly selected from the laser welding device 30. Different welding methods are required for vapor chambers 01 of varying areas. The area evaluation device can utilize a device with logic and processing capabilities, such as a central processing unit (CPU).

[0039] The present invention can be used for areas ranging from 500 to 2000 mm 2 Specifically, for the area of ​​500 to 2000 mm 2 The uniform temperature plate 01 adopts single-stage continuous welding, for the area of ​​2000 ~ 5000mm 2 The temperature plate 01 adopts two-stage welding, which is suitable for the area of ​​5000~6000mm2 The heat spreader 01 is welded in 4 sections. This is mainly due to the consideration of welding quality and operability.

[0040] like Figure 1 、 Figure 2 and Figure 3 As shown, for example, for an area of ​​500 to 2000 mm 2 Considering the relatively small area of ​​the temperature equalizing plate 01, single-stage continuous welding is adopted, and a single upper jig 10 can be used at this time. During welding, the lower cover 03 is placed on the lower jig 20, and the upper cover 02 is placed on the lower cover 03. The upper jig 10 and the lower jig 20 are pressed together to press the edges of the upper cover 02 and the lower cover 03. The speed of the laser welding equipment 30 is controlled to be 300-500mm / s, and the laser power is controlled to be 150-300w, and welding is started. After the welding is completed, the laser welding equipment 30 is controlled to move away, the upper jig 10 is moved up, and the product is taken out. In this case, the laser welding equipment 30 continuously moves around the product (except for the liquid injection port) for welding.

[0041] like Figure 1 、 Figure 2 and Figure 4 As shown, for areas between 2000 and 5000 mm 2 Considering the relatively large area of ​​the temperature plate 01, a two-stage welding method is adopted. After welding one section, the other section is welded. When welding, place the lower cover 03 on the lower fixture 20, place the upper cover 02 on the lower cover 03, and then press the upper fixture 10 onto the lower fixture 20. At this time, the upper fixture 10 and the lower fixture 20 jointly press the upper cover 02 and the lower cover 03 half of the edge ( Figure 4 The K part is delineated by the dotted line in the middle), and the speed of the laser welding equipment 30 is controlled at 300-500 mm / s, and the laser power is 150-300w, and welding begins. After welding is completed, the upper fixture 10 automatically moves upward, and then the upper fixture 10 presses the lower fixture 20. At this time, the upper fixture 10 and the lower fixture 20 jointly press the other half of the edge of the upper cover 02 and the lower cover 03 ( Figure 4 After the welding is completed, the laser welding equipment 30 is controlled to move away, the upper fixture 10 is moved up, and the product is taken out. In this case, the laser welding equipment 30 first completes half of the product, and then completes the other half of the product. In this case, two upper fixtures 10 (such as Figure 4 The upper jig 10 can be pressed sequentially using the M and N jigs, for example, first using the M jig and then the N jig. Alternatively, a single upper jig 10 can be used, with half of the upper jig 10 pressed for half-circle welding, and then the other half of the upper jig 10 pressed for the other half-circle welding.

[0042] like Figure 1 、 Figure 2 and Figure 5 As shown, for areas between 5000 and 6000 mm 2 Considering the larger area of ​​the uniform temperature plate 01, a 4-stage welding method is used, with 1 / 4 of the edge welded each time. During welding, place the lower cover 03 on the lower jig 20, place the upper cover 02 on the lower cover 03, and then press the upper jig 10 onto the lower jig 20. At this time, the upper jig 10 and the lower jig 20 jointly press the 1 / 4 edge (including corners) of the upper cover 02 and the lower cover 03. Control the speed of the laser welding equipment 30 at 300-500mm / s and the laser power at 150-300w to start welding. After welding is completed, the upper jig 10 automatically moves upward, and then the upper jig 10 presses the lower jig 20. At this time, the upper jig 10 and the lower jig 20 jointly press the other 1 / 4 edge (including corners) of the upper cover 02 and the lower cover 03, and weld at the same speed and power. And so on, please refer to Figure 5 , the laser welding of the four edges can be performed in sequence: the upper left (section A), the lower left (section B), the upper right (section C), and the lower right (section D). After welding is completed, the laser welding equipment 30 is controlled to move away, the upper fixture 10 is moved upward, and the product is removed.

[0043] In this case, the laser welding equipment 30 passes through 1 / 4 of the product (including corners) each time, and after passing through 4 times, all welding can be completed. In this case, 4 upper jigs 10 (such as Figure 1 The E, F, G, and H jigs are used in the order indicated by the arrows for pressing. Alternatively, a single upper jig 10 can be used, and 1 / 4 of the structure of the upper jig 10 is pressed to perform 1 / 4 of the welding. After 4 times, the entire welding process can be completed.

[0044] like Figure 7 As shown, laser welding equipment 30 emits an annular beam 33 composed of an outer ring beam 31 and a central beam 32. Central beam 32 is arranged concentrically with outer ring beam 31, and outer ring beam 31 surrounds central beam 32. The laser power and emission time of outer ring beam 31 and central beam 32 can be independently adjusted in real time, increasing the flexibility and possibilities of laser welding.

[0045] Outer beam 31 is a high-power-density fiber laser, responsible for heating the base material and expanding the keyhole opening. Center beam 32, also high-power-density, is used to penetrate the metal and achieve deep-penetration welding. Preferably, the laser powers of outer beam 31 and center beam 32 are 150W to 300W, respectively. Preferably, the welding light type of outer beam 31 and center beam 32 is blue light, but this is not limited to this.

[0046] like Figure 3 、 Figure 4 and Figure 5As shown, the top of the lower jig 20 is mounted with multiple positioning rods 22 and multiple guide rods 23. The multiple positioning rods 22 collectively enclose the positioning portion 21, and the guide rods 23 are located circumferentially outside the positioning rods 22. The positioning rods 22 define the placement area for the upper cover 02 and the lower cover 03, preventing them from shifting and thus positioning them. The guide rods 23 serve as a guide and positioning mechanism, aligning the upper jig 10 with the lower jig 20 for press-fitting.

[0047] like Figures 1 to 5 As shown, the lower fixture 20 has a lower notch 24 for the annular beam 33 to pass through. The annular beam passes through the lower notch 24 to weld the surrounding connection area between the upper cover 02 and the lower cover 03. The upper fixture 10 has a contoured stopper 11, which has an upper notch 12. The shape and position of the upper notch 12 correspond to the shape and position of the lower notch 24. It is understood that the upper notch 12 can also be used to weld the surrounding connection area between the upper cover 02 and the lower cover 03.

[0048] The following briefly describes the working process of the heat spreader laser welding system 100 of the present invention: input / scan / select the area information of the heat spreader 01, and the area evaluation device selects a single upper fixture 10 or an even number of upper fixtures 10 based on the input / scan / selected area information of the heat spreader, thereby performing single-stage continuous welding, two-stage welding or four-stage welding. For areas between 500 and 2000 mm 2 Single-stage continuous welding of the uniform temperature plate 01 is performed for an area of ​​2000 to 5000 mm 2 The temperature plate 01 adopts two-stage welding, which is suitable for the area of ​​5000~6000mm 2 The heat spreader 01 is welded using a four-stage process. The following describes the use of single-stage continuous welding as an example. The lower cover 03 is placed on the lower jig 20, the upper cover 02 is stacked on the lower cover 03, and the upper jig 10 is pressed against the lower jig 20. The upper jig 10 and the lower jig 20 jointly press the edges of the upper cover 02 and the lower cover 03. The laser welding equipment 30 uses an annular spot laser welding method to weld the connection area around the upper cover 02 and the lower cover 03, sealing the edges of the upper cover 02 and the lower cover 03. After welding is completed, remove the upper jig 10 and then remove the welded heat spreader 01.

[0049] The above disclosure is only a preferred embodiment of the present invention and cannot be used to limit the scope of the rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention are all within the scope covered by the present invention.

Claims

1. A heat spreader laser welding system, wherein the heat spreader further comprises an upper cover and a lower cover, characterized in that: The invention comprises an upper jig, a lower jig and a laser welding device. The upper jig can be detachably pressed on the lower jig. The lower jig has a positioning portion for positioning the upper cover and the lower cover. The laser welding device is arranged above the upper jig or below the lower jig. The laser welding device uses an annular spot laser welding method to weld the surrounding connection areas of the upper cover and the lower cover pressed by the upper jig and the lower jig.

2. The heat sink laser welding system according to claim 1, characterized in that: The laser welding equipment can be moved and adjusted at least along the X, Y and Z axes.

3. The heat sink laser welding system according to claim 1, characterized in that: The laser welding equipment includes a CCD visual monitoring device for monitoring welding leakage.

4. The vapor chamber laser welding system according to claim 1, characterized in that: The invention also includes a robot, which places the lower cover on the positioning portion and stacks the upper cover on the lower cover. The robot also removes the upper fixture and takes out the welded temperature equalizing plate.

5. The heat sink laser welding system according to claim 1, characterized in that: It also includes an area evaluation device, which selects a single upper fixture or an even number of upper fixtures based on the area information of the input / scanned / selected temperature equalizing plate, so as to perform single-stage continuous welding, two-stage welding or four-stage welding.

6. The vapor chamber laser welding system according to claim 1, characterized in that: The laser welding equipment emits a ring beam consisting of an outer ring beam and a central beam. The central beam is arranged concentrically with the outer ring beam, and the outer ring beam surrounds the central beam. The laser power and light emission time of the outer ring beam and / or the central beam can be adjusted independently in real time.

7. The heat sink laser welding system according to claim 6, characterized in that: The laser power range of the outer ring light beam and / or the laser power range of the central light beam are respectively 150W to 300W.

8. The vapor chamber laser welding system according to claim 1, characterized in that: The speed range of the laser welding equipment is 300 mm / s to 500 mm / s.

9. The vapor chamber laser welding system according to claim 1, characterized in that: A plurality of positioning rods and a plurality of guide rods are installed on the top of the lower fixture. The plurality of positioning rods together surround the positioning portion, and the guide rods are located on the circumferential outside of the positioning rods.

10. The heat sink laser welding system according to claim 6, characterized in that: The lower fixture is provided with a lower notch for the annular light beam to pass through, and the upper fixture is provided with a contour limiting area, and the contour limiting area is provided with an upper notch.

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