Multilayer coating deposition PCB microbit and coating growth method

Abstract

The invention discloses a multilayer coating deposition PCB microbit and a coating growth method, and relates to the field of microbits, the multilayer coating deposition PCB microbit comprises a drill handle and a drill rod, a threaded sleeve is slidably connected in the drill handle, limiting blocks are fixed on the outer side of the threaded sleeve at equal angles, the limiting blocks are slidably connected with the drill handle, and the drill rod is connected with the drill handle. A first spring is installed between the threaded sleeve and the drill handle, the threaded sleeve is in threaded connection with the threaded connector, and a limiting rod is fixed to the upper end of the threaded connector. According to the multi-layer coating deposition PCB micro drill bit and the coating growth method, a combined elastic connecting mechanism is adopted, in the use process of the drill bit, initial contact between the drill rod and a workpiece is flexible contact, the situation that the drill rod is broken due to the fact that the drill rod moves downwards at the too high speed and is stressed too large when the drill rod makes contact with the workpiece is avoided, the service life of the drill rod is effectively prolonged, and the service life of the drill rod is prolonged. And the drill rod can be replaced when being damaged, so that the drill handle can be repeatedly used, and the use cost of the drill bit is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of micro drills, and specifically relates to a multi-layer coating deposition PCB micro drill and a coating growth method. Background Art

[0002] A drill bit with a diameter less than 3.175 mm is usually called a micro drill bit, or simply a micro drill. During actual use, due to its small diameter, in order to ensure the strength of the drill bit, a coating needs to be attached to the surface of the drill bit to change the physical properties of the drill bit and ensure the strength during the use of the drill bit. Existing micro drill bits are generally of an integral structure. During actual use, the initial contact between the drill bit and the workpiece is a rigid contact. During the machining process, when the downward movement speed of the drill bit is too fast, it is extremely easy to cause the drill bit to break, thus affecting the normal machining process. Summary of the Invention

[0003] The purpose of the present invention is to provide a multi-layer coating deposition PCB micro drill and a coating growth method to solve the problems raised in the above background art.

[0004] To achieve the above purpose, the present invention provides the following technical solution: A multi-layer coating deposition PCB micro drill includes a drill shank and a drill rod. A threaded sleeve is slidably connected inside the drill shank. Equal-angle limit blocks are fixedly arranged on the outer side of the threaded sleeve. The limit blocks are slidably connected with the drill shank. A first spring is installed between the threaded sleeve and the drill shank. The threaded sleeve is threadedly connected with a threaded joint. A limit rod is fixedly arranged at the upper end of the threaded joint. The limit rod is nestedly connected with both the threaded sleeve and the drill shank, and the central axes of the limit rod, the threaded sleeve, and the drill shank coincide. A drill rod is fixedly arranged at the lower end of the threaded joint. A coating is arranged on the surface of the drill rod.

[0005] A coating growth method for a multi-layer coating deposition PCB micro drill includes the following steps: S1: Drill bit surface treatment stage: Place the drill bit in an ultrasonic cleaning device, and effectively process the debris and oil on the surface of the drill bit through the ultrasonic cleaning device. S2: Coating growth preparation stage: Install the drill bit in the cavity of a magnetron sputtering machine, install the target, and perform a vacuum pumping operation on the cavity of the magnetron sputtering machine through a vacuum pump until its vacuum degree ≤ 5×10 -4 Pa, and introduce argon with a pressure of 0.1 - 10 Pa into the cavity of the magnetron sputtering machine. S3: Coating growth stage: The magnetron sputtering machine works to enable the atoms on the surface of the target to obtain energy and sputter and adhere to the surface of the drill bit, thereby forming a coating. S4: Cooling stage: After the coating processing of the drill bit is completed, it is necessary to perform water cooling through a water cooling device to eliminate the coating stress and ensure the coating adhesion effect. S5: Repeat the above steps of S2, S3, and S4, and replace the target material in the S2 stage, so that a multi-layer coating structure can be formed on the surface of the drill bit.

[0006] Preferably, the water cooling device includes a water cooling box. A first water pump is installed at the front end on the right side of the water cooling box, and the first water pump is connected to a first water inlet pipe. And the first water inlet pipe is connected to a cooling water tank through a conduit. A first water outlet pipe is installed at the front end on the left side of the first water inlet pipe, and a control valve is installed on the first water outlet pipe. And the first water outlet pipe is connected to the cooling water tank through a conduit. A temperature sensor is installed on the inner wall of the water cooling box, and an annular frame is fixed at the lower end inside the water cooling box. Through the above structure, the circulation of cooling water can be realized, thus providing a basic guarantee for the cooling of the drill bit.

[0007] Preferably, a water temperature regulating mechanism is installed in the water cooling box. The water temperature regulating mechanism includes a second water pump and a second water outlet pipe. The second water pump is fixed on the water cooling box, and the second water pump is connected to a second water inlet pipe fixed on the water cooling box. At the same time, the second water pump is connected to the cooling water tank through a conduit. The second water outlet pipe is fixed on the water cooling box, and the second water outlet pipe is connected to the cooling water tank through a conduit. And a cross bar is arranged in the second water outlet pipe. At the same time, the cross bar is slidably connected to the second water inlet pipe. One end of the cross bar is fixed with a first sealing plug slidably connected in the second water inlet pipe, and one end of the cross bar is fixed with a second sealing plug slidably connected in the second water outlet pipe. And a second spring is fixed between the second sealing plug and the second water outlet pipe. Through the above structure, when the water temperature in the water cooling box is too high, the flow of water in the water cooling box can be accelerated, so as to quickly reduce the water temperature, and further ensure the cooling effect of the drill bit.

[0008] Preferably, a motor is fixed on the lower end surface of the water cooling box, and an installation sleeve is fixed at the output end of the motor. And the installation sleeve is connected to a rotating frame, and at the same time, the rotating frame is connected to a fixing frame. Through the above structure, a basic acting force can be provided for the rotation of the rotating frame, so as to facilitate the rotation of the drill bit, ensure the full contact between the drill bit and the cooling water, and further ensure the cooling effect of the drill bit.

[0009] Preferably, the fixing frame includes a fixing ring. The fixing ring is arranged in the water cooling box, and adjacent two fixing rings are fixed to each other through vertical rods. And a positioning rod is fixed on the lower end surface of the lowermost fixing ring. At the same time, the positioning rod is nested with the opening on the annular frame to realize positioning. Through the nested positioning between the positioning rod and the annular frame, the stability of the installation of the fixing frame can be ensured.

[0010] Preferably, convex tooth blocks are fixed on the inner side of the fixing ring, and a handle is fixed on the uppermost fixing ring. The fixing frame can be disassembled and assembled conveniently through the handle.

[0011] Preferably, the rotating frame includes a fixing rod, on which a mounting plate is fixed, and the mounting plate and the fixing ring are distributed in a one-to-one correspondence, and a ball shaft is fixed at equal angles on the outside of the mounting plate, and the ball shaft is nested in a groove on the fixing ring for sliding. When the mounting plate rotates, the sliding action between the ball shaft and the fixing ring can ensure the stability of the rotation of the mounting plate.

[0012] Preferably, the bearing on the mounting plate is connected to a gear, and the gear is engaged with the convex tooth block to realize transmission, and a clamping block is fixed on the lower end face of the lowermost mounting plate, and the clamping block is nested with the mounting sleeve to realize positioning. Through the meshing transmission effect between the gear and the convex tooth block, a basic force can be provided for the self-rotation of the gear.

[0013] Preferably, a circular ring is fixed on the gear, and the center of the circular ring is not on the same vertical line as the center of the gear, and a positioning ring is provided on the inner side of the circular ring. At the same time, a third spring is fixed between the positioning ring and the circular ring. When the gear rotates, the circular ring can be driven to rotate eccentrically. With the action of the third spring, the positioning ring can produce eccentric vibration, thereby realizing the vibration of the drill bit and further eliminating the stress of the surface coating of the drill bit.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This multi-layer coated PCB micro drill bit uses a modular elastic connection mechanism. This ensures flexible initial contact between the drill rod and the workpiece during use, preventing the drill rod from moving down too quickly and causing excessive force and breakage when in contact with the workpiece. This effectively extends the service life of the drill rod. It also allows for replacement of the drill rod if damaged, making the drill shank reusable and effectively reducing the cost of the drill bit. 2. In the coating growth method for a multi-layer coating deposition PCB micro drill bit, after the coating production is completed, when the drill bit is water-cooled, the rotating water-cooling structure can make the drill bit fully contact with the cooling water, thereby achieving a one-time elimination of the coating stress. Combined with the eccentric vibration mechanism, the drill bit can generate eccentric vibration during the drill bit water cooling process, and the eccentric vibration of the drill bit can further achieve the elimination of the coating stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the exploded three-dimensional structure of the drill bit of the present invention; Figure 2 This is a schematic diagram of a partial cross-sectional three-dimensional structure of the drill bit of the present invention; Figure 3 This is a schematic diagram of the front three-dimensional structure of the water cooling box of the present invention; Figure 4 This is a schematic side view of the three-dimensional structure of the water cooling box of the present invention; Figure 5This is a front - view sectional three - dimensional structure schematic diagram of the water - cooled box of the present invention; Figure 6 This is a front - view sectional three - dimensional structure schematic diagram of the water temperature regulating mechanism of the present invention; Figure 7 This is a disassembled state structure schematic diagram of the positioning ring and the fixing frame of the present invention; Figure 8 This is a front - view three - dimensional structure schematic diagram of the fixing frame of the present invention; Figure 9 This is a front - view three - dimensional structure schematic diagram of the rotating frame of the present invention; Figure 10 This is a partial - sectional three - dimensional structure schematic diagram of the rotating frame and the fixing frame of the present invention; Figure 11 This is a sectional three - dimensional structure schematic diagram of the circular ring of the present invention.

[0016] In the figure: 1. Drill handle; 2. Threaded sleeve; 3. Limit block; 4. First spring; 5. Threaded joint; 6. Limit rod; 7. Drill rod; 8. Water - cooled box; 801. First water pump; 802. First water inlet pipe; 803. First water outlet pipe; 804. Control valve; 805. Temperature sensor; 806. Ring - shaped frame; 9. Water temperature regulating mechanism; 901. Second water pump; 902. Second water inlet pipe; 903. Second water outlet pipe; 904. Cross bar; 905. First sealing plug; 906. Second sealing plug; 907. Second spring; 10. Motor; 11. Mounting sleeve; 12. Fixing frame; 1201. Fixed ring; 1202. Vertical rod; 1203. Positioning rod; 1204. Convex tooth block; 1205. Handle; 13. Rotating frame; 1301. Fixed rod; 1302. Mounting disc; 1303. Ball shaft; 1304. Gear; 1305. Circular ring; 1306. Positioning ring; 1307. Third spring; 1308. Block. Detailed implementation manners

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0018] Please refer to Figures 1 - 11, the present invention provides a technical solution: a PCB micro drill with multi-layer coating deposition, including a drill shank 1 and a drill rod 7. A threaded sleeve 2 is slidably connected inside the drill shank 1. Limiting blocks 3 are fixedly arranged at equal angles on the outer side of the threaded sleeve 2. The limiting blocks 3 are slidably connected with the drill shank 1. A first spring 4 is installed between the threaded sleeve 2 and the drill shank 1. The threaded sleeve 2 is threadedly connected with a threaded joint 5. A limiting rod 6 is fixedly arranged at the upper end of the threaded joint 5. The limiting rod 6 is nestedly connected with both the threaded sleeve 2 and the drill shank 1, and the central axes of the limiting rod 6, the threaded sleeve 2, and the drill shank 1 coincide. The lower end of the threaded joint 5 is fixedly provided with a drill rod 7, and a coating is arranged on the surface of the drill rod 7.

[0019] When using this PCB micro drill with multi-layer coating deposition, as Figures 1 - 2 shown, first, the threaded joint 5 and the threaded sleeve 2 are assembled through threaded connection, and then the drill shank 1 is installed on the drilling machine. When drilling the workpiece, the drilling machine drives the drill shank 1 and the drill rod 7 to move downward. When the drill rod 7 contacts the workpiece, at this time, the drill rod 7 drives the threaded joint 5 and the threaded sleeve 2 to move upward under force. With the sliding effect between the limiting blocks 3 and the slots on the drill shank 1, the stability of the movement of the threaded joint 5 and the threaded sleeve 2 can be ensured. At this time, the drill rod 7 and the workpiece are in flexible contact until the limiting blocks 3 contact the upper ends of the slots on the drill shank 1 to achieve positioning. At this time, the drill rod 7 and the workpiece are in rigid contact for normal drilling. According to the above principle, the initial contact between the drill rod 7 and the workpiece can be made flexible contact, effectively avoiding the problem of breakage caused by the too fast downward movement speed of the drill rod 7 when contacting the workpiece, thereby effectively prolonging the service life of the drill rod 7. And when the drill rod 7 is damaged, by separating the threaded joint 5 and the threaded sleeve 2, the replacement of the drill rod 7 can be realized, so that the drill shank 1 and the threaded sleeve 2 can be reused, reducing the use cost of the drill bit; A method for coating growth of a PCB micro drill with multi-layer coating deposition includes the following steps: S1: Bit surface treatment stage: Place the bit in an ultrasonic cleaning device, and effectively treat the debris and oil stains on the surface of the bit through the ultrasonic cleaning device; S2: Coating growth preparation stage: Install the bit in the cavity of a magnetron sputtering machine, install the target, and perform a vacuum pumping operation on the cavity of the magnetron sputtering machine through a vacuum pump until its vacuum degree ≤ 5×10 -4 Pa, and introduce argon with a pressure of 0.1 - 10 Pa into the cavity of the magnetron sputtering machine; S3: Coating growth stage: The magnetron sputtering machine works to enable the atoms on the surface of the target to obtain energy and sputter and adhere to the surface of the bit, thereby forming a coating; S4: Cooling stage: After the coating processing of the bit is completed, it is necessary to perform water cooling through a water cooling device to eliminate the coating stress and ensure the coating adhesion effect; S5: Repeat the above steps S2, S3 and S4, and replace the target material in the S2 stage, so that a multi-layer coating structure can be formed on the surface of the drill bit.

[0020] The water cooling device includes a water cooling box 8, a first water pump 801 is installed at the front end of the right side of the water cooling box 8, and the first water pump 801 is connected to the first water inlet pipe 802, and the first water inlet pipe 802 is connected to the cooling water tank through a conduit, a first water outlet pipe 803 is installed at the front end of the left side of the first water inlet pipe 802, and a control valve 804 is installed on the first water outlet pipe 803, and the first water outlet pipe 803 is connected to the cooling water tank through a conduit, a temperature sensor 805 is installed on the inner wall of the water cooling box 8, and a temperature sensor 805 is fixed on the lower end of the inner side of the water cooling box 8. The annular frame 806; the motor 10 is fixed to the lower end surface of the water-cooling box 8, and the output end of the motor 10 is fixed with a mounting sleeve 11, and the mounting sleeve 11 is connected to the rotating frame 13, and the rotating frame 13 is connected to the fixed frame 12; the fixed frame 12 includes a fixing ring 1201, the fixing ring 1201 is arranged in the water-cooling box 8, and the two adjacent fixing rings 1201 are fixed to each other by a vertical rod 1202, and the lower end surface of the lowermost fixing ring 1201 is fixed with a positioning rod 1203, and the positioning rod 1203 is connected to the annular frame 80 6 is nested to achieve positioning; a convex tooth block 1204 is fixed on the inner side of the fixing ring 1201, and a handle 1205 is fixed on the uppermost fixing ring 1201; the rotating frame 13 includes a fixing rod 1301, a mounting plate 1302 is fixed on the fixing rod 1301, and the mounting plate 1302 and the fixing ring 1201 are distributed one-to-one, and a ball shaft 1303 is fixed at an equal angle on the outer side of the mounting plate 1302, and the ball shaft 1303 is nested in the groove on the fixing ring 1201 for sliding; the bearing connection on the mounting plate 1302 A gear 1304 is connected, and the gear 1304 meshes with the convex tooth block 1204 to achieve transmission, and a clamping block 1308 is fixed to the lower end surface of the lowermost mounting plate 1302, and the clamping block 1308 is nested with the mounting sleeve 11 to achieve positioning. A ring 1305 is fixed to the gear 1304, and the center of the ring 1305 is not on the same vertical line as the center of the gear 1304. A positioning ring 1306 is provided inside the ring 1305, and a third spring 1307 is fixed between the positioning ring 1306 and the ring 1305. After the drill bit coating is completed, the drill bit is water-cooled to eliminate stress. Figures 3 - 11As shown, first, the drill bit is nested with the positioning ring 1306 to realize the installation of the drill bit. After the drill bit is installed, by starting the first water pump 801, the cooling water in the cooling water tank enters the water cooling box 8 through the first water inlet pipe 802. At this time, the control valve 804 is in a closed state, realizing the water storage function in the water cooling box 8. The temperature sensor 805 can be used to monitor the temperature of the cooling water in the water cooling box 8. After the water storage is completed, the control valve 804 is opened so that the cooling water in the water cooling box 8 can flow back into the cooling water tank. At this time, the cooling water inlet and outlet are in a balanced state, ensuring the liquid level of the cooling water in the water cooling box 8. The drill bit is then installed into the water cooling box 8 through the carrying handle 1205. The positioning of the rotating frame 13 can be achieved by nesting the clamping block 1308 with the installation sleeve 11. The installation and positioning of the fixed frame 12 can be achieved by nesting the positioning rod 1203 with the opening on the annular frame 806, thereby completing the installation. The motor 10 is then started to drive the installation sleeve 11 to rotate. The fixing rod 1301, the mounting plate 1302, the gear 1304, the ring 1305, the positioning ring 1306 and the drill bit are driven to revolve. The rotation can make the drill bit fully contact with the cooling water, which can not only quickly cool the drill bit, but also achieve a primary stress elimination effect on the drill bit coating. When the gear 1304, the ring 1305, the positioning ring 1306 and the drill bit revolve, the meshing transmission effect between the gear 1304 and the convex tooth block 1204 causes the ring 1305, the positioning ring 1306 and the drill bit to rotate synchronously. Since the center of the ring 1305 is not in the same vertical line as the center of the gear 1304, the ring 1305, the positioning ring 1306 and the drill bit rotate eccentrically, and the elastic effect of the third spring 1307 can make the positioning ring 1306 and the drill bit generate eccentric vibration. Through the vibration of the drill bit, the stress of the drill bit coating can be secondary eliminated, thereby ensuring the production quality of the drill bit coating. A water temperature regulating mechanism 9 is installed in the water cooling box 8, and the water temperature regulating mechanism 9 includes a second water pump 901 and a second water outlet pipe 903, and the second water pump 901 is fixed on the water cooling box 8, and the second water pump 901 is connected to the second water inlet pipe 902 fixed on the water cooling box 8, and the second water pump 901 is connected to the cooling water tank through a conduit, the second water outlet pipe 903 is fixed on the water cooling box 8, and the second water outlet pipe 903 is connected to the cooling water tank through a conduit, and a cross bar 904 is provided in the second water outlet pipe 903, and the cross bar 904 and the second water inlet pipe 902 are slidably connected, one end of the cross bar 904 is fixed with a first sealing plug 905 slidably connected to the second water inlet pipe 902, and one end of the cross bar 904 is fixed with a second sealing plug 906 slidably connected to the second water outlet pipe 903, and a second spring 907 is fixed between the second sealing plug 906 and the second water outlet pipe 903; During the water cooling process of the drill bit, Figures 3 - 11As shown, when the temperature sensor 805 detects that the water temperature in the water cooling tank 8 is too high, the second water pump 901 starts at this time, sending the cooling water in the cooling water tank into the second water inlet pipe 902. Under the action of water pressure, the first sealing plug 905 moves in the second water inlet pipe 902. At this time, the cross bar 904 and the second sealing plug 906 move synchronously under force. When the first sealing plug 905 releases the seal of the second water inlet pipe 902, the second sealing plug 906 just releases the seal of the second water outlet pipe 903, thus forming a second cooling water circulation channel. At this time, the cooling water inflow and the cooling water outflow in the water cooling tank 8 increase synchronously, thereby effectively accelerating the replacement of the heated cooling water in the water cooling tank 8, enabling the temperature of the cooling water in the water cooling tank 8 to be quickly reduced, and then effectively ensuring the cooling effect of the drill bit.

[0021] It should be noted that in this text, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article or device.

[0022] In this article, specific examples are used to elaborate on the principle and implementation mode of the present invention. The description of the above examples is only used to help understand the method of the present invention and its core idea. The above is only the preferred implementation mode of the present invention. It should be pointed out that due to the limited nature of written expression and objectively existing infinite specific structures, for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements, embellishments or changes can be made, or the above technical features can be combined in an appropriate manner; these improvements, embellishments, changes or combinations, or directly applying the concept and technical solution of the invention to other occasions without improvement, should all be regarded as the protection scope of the present invention.

Claims

1. A PCB micro drill bit for multi-layer coating deposition, comprising a drill shank (1) and a drill rod (7), characterized in that: A threaded sleeve (2) is slidably connected inside the drill shank (1). A plurality of limiting blocks (3) are fixedly arranged on the outer side of the threaded sleeve (2) at equal angles. The limiting blocks (3) are slidably connected with the drill shank (1). A first spring (4) is installed between the threaded sleeve (2) and the drill shank (1). The threaded sleeve (2) is threadedly connected with a threaded joint (5). A limiting rod (6) is fixedly arranged at the upper end of the threaded joint (5). The limiting rod (6) is nestedly connected with both the threaded sleeve (2) and the drill shank (1), and the central axes of the limiting rod (6), the threaded sleeve (2), and the drill shank (1) coincide. A drill rod (7) is fixedly arranged at the lower end of the threaded joint (5). A coating is arranged on the surface of the drill rod (7).

2. A method for coating growth of a multi-layer coated PCB micro drill, which is applied to prepare a multi-layer coated PCB micro drill described in claim 1, characterized in that, It includes the following steps: S1: Bit surface treatment stage: Place the bit in an ultrasonic cleaning device, and effectively process the debris and oil stains on the surface of the bit through the ultrasonic cleaning device; S2: Coating growth preparation stage: Install the drill bit in the magnetron sputtering machine cavity, install the target, and evacuate the magnetron sputtering machine cavity through a vacuum pump until its vacuum degree ≤ 5×10 -4 Pa, and introduce argon gas with a pressure of 0.1 - 10 Pa into the magnetron sputtering machine cavity; S3: Coating growth stage: The magnetron sputtering machine works to enable the atoms on the surface of the target to obtain energy and sputter and adhere to the surface of the bit, thereby forming a coating; S4: Cooling stage: After the coating of the bit is processed, it needs to be water-cooled through a water-cooling device to eliminate the coating stress and ensure the coating adhesion effect; S5: Repeat the above steps S2, S3, and S4, and replace the target in the S2 stage, so as to form a multi-layer coating structure on the surface of the bit.

3. A coating growth method for a multi-layer coating deposited PCB micro drill bit according to claim 2, characterized in that: The water-cooling device includes a water-cooling box (8). A first water pump (801) is installed at the front end of the right side of the water-cooling box (8), and the first water pump (801) is connected to a first water inlet pipe (802). The first water inlet pipe (802) is connected to a cooling water tank through a conduit. A first water outlet pipe (803) is installed at the front end of the left side of the first water inlet pipe (802). A control valve (804) is installed on the first water outlet pipe (803), and the first water outlet pipe (803) is connected to the cooling water tank through a conduit. A temperature sensor (805) is installed on the inner wall of the water-cooling box (8), and an annular frame (806) is fixedly arranged at the lower end inside the water-cooling box (8).

4. A method for growing a coating on a multi-layer coated deposition PCB micro drill bit according to claim 3, characterized in that: A water temperature regulating mechanism (9) is installed inside the water cooling box (8). The water temperature regulating mechanism (9) includes a second water pump (901) and a second water outlet pipe (903). The second water pump (901) is fixed on the water cooling box (8), and the second water pump (901) is connected to a second water inlet pipe (902) fixed on the water cooling box (8). At the same time, the second water pump (901) is connected to a cooling water tank through a conduit. The second water outlet pipe (903) is fixed on the water cooling box (8), and the second water outlet pipe (903) is connected to the cooling water tank through a conduit. A cross bar (904) is arranged inside the second water outlet pipe (903), and the cross bar (904) is slidably connected to the second water inlet pipe (902). One end of the cross bar (904) is fixed with a first sealing plug (905) slidably connected inside the second water inlet pipe (902), and one end of the cross bar (904) is fixed with a second sealing plug (906) slidably connected inside the second water outlet pipe (903). A second spring (907) is fixed between the second sealing plug (906) and the second water outlet pipe (903).

5. A method for coating growth of a multi-layer coating deposited PCB micro drill bit according to claim 4, characterized in that: A motor (10) is fixed on the lower end face of the water cooling box (8). The output end of the motor (10) is fixed with a mounting sleeve (11), and the mounting sleeve (11) is connected to a rotating frame (13). At the same time, the rotating frame (13) is connected to a fixing frame (12).

6. A method for coating growth of a multi-layer coating deposited PCB micro drill bit according to claim 5, characterized in that: The fixing frame (12) includes a fixing ring (1201). The fixing ring (1201) is arranged inside the water cooling box (8). Adjacent two fixing rings (1201) are fixed to each other through a vertical rod (1202). The lower end face of the lowermost fixing ring (1201) is fixed with a positioning rod (1203), and the positioning rod (1203) is nested in an opening on the annular frame (806) to achieve positioning.

7. A method for coating growth of a multi-layer coating deposited PCB micro drill bit according to claim 6, characterized in that: Convex tooth blocks (1204) are fixed inside the fixing ring (1201), and a handle (1205) is fixed on the uppermost fixing ring (1201).

8. A method for coating growth of a multi-layer coating deposited PCB micro drill bit according to claim 7, characterized in that: The rotating frame (13) includes a fixing rod (1301). A mounting disc (1302) is fixed on the fixing rod (1301). The mounting discs (1302) and the fixing rings (1201) are distributed in a one-to-one correspondence. Ball shafts (1303) are fixed on the outer side of the mounting disc (1302) at equal angles, and the ball shafts (1303) are nested in grooves on the fixing rings (1201) for sliding.

9. A method for coating growth of a multi-layer coating deposited PCB micro drill according to claim 8, characterized in that: A gear (1304) is connected to the mounting disc (1302) through a bearing. The gear (1304) is engaged with the convex tooth blocks (1204) to achieve transmission. The lower end face of the lowermost mounting disc (1302) is fixed with a clamping block (1308), and the clamping block (1308) is nested with the mounting sleeve (11) to achieve a positioning function.

10. A method for coating growth of a multi-layer coating deposited PCB micro drill bit according to claim 9, characterized in that: A ring (1305) is fixed on the gear (1304). The center of the ring (1305) and the center of the gear (1304) are not on the same vertical line. A positioning ring (1306) is arranged inside the ring (1305). A third spring (1307) is fixed between the positioning ring (1306) and the ring (1305).

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