Anti-damage back drilling process for PTFE (Polytetrafluoroethylene) ultra-thin plate

Abstract

The invention relates to the technical field of back drilling processes, in particular to an anti-damage back drilling process for a PTFE (polytetrafluoroethylene) ultra-thin plate, which comprises a workbench, the PTFE ultra-thin plate is placed on the workbench, a spindle box is suspended above the PTFE ultra-thin plate, and a rotating motor for driving a spindle is arranged at the top of the spindle box; a drill bit part used for drilling is arranged at the lower end of the spindle box and comprises a drill bit; a limiting part used for limiting the lowest height of the drill bit part and pressing and fixing the PTFE ultra-thin plate is arranged at the lower end of the spindle box, the limiting part comprises a limiting frame and a fan-shaped pressing piece which inclines towards the drill bit and is connected to the limiting frame in a sliding mode, and a scraping part used for scraping PTFE fibers attached to the drill bit is arranged on the limiting part. By means of the fan-shaped pressing piece and the scraping part, the PTFE ultra-thin plate can be stably pressed during back drilling, the lowest end of the drill bit is limited, external threads of the drill bit are cleaned, and damage prevention of a back drilling hole during back drilling is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of back drilling technology, in particular to an anti-damage back drilling technology for a PTFE ultra-thin plate. Background Art

[0002] Polytetrafluoroethylene (PTFE), also known as Teflon, commonly known as the "King of Plastics", is a high molecular polymer made from tetrafluoroethylene as a monomer. It has excellent heat and cold resistance and can be used for a long time at -180 to 260°C. This material is also resistant to acids and alkalis, and it is almost insoluble in all solvents. At the same time, its friction coefficient is extremely low, so it can be used as a lubricant, and it is an ideal coating for the inner layer of easy-to-clean water pipes; the back drilling process refers to the additional drilling operation from the through holes on the back of the multi-layer PCB board that has been drilled and electroplated to remove a portion of the electroplated metal material on the wall of some through holes. This process is usually used to improve signal integrity and reduce interference in high-speed signal transmission.

[0003] Application number CN113211539B discloses a back drilling tool, a processing method thereof and a method for controlling the depth drilling of a multilayer circuit board. The back drilling tool comprises: a blade portion, the blade portion comprises a blade body and a blade tip arranged at the front end of the blade body, the central axis of the blade body coincides with the central axis of the blade tip, the blade body is in an inverted cone shape with an outer diameter gradually decreasing from front to back, the outer periphery of the blade body is provided with a plurality of spiral chip grooves, the maximum outer diameter of the blade tip is less than or equal to the outer diameter of the front end of the blade body; wherein the groove surface of the chip groove and the outer surface of the blade tip are insulated, and the outer cylindrical surface of the blade body is conductive. The beneficial effects of the present invention are: the back drilling tool has high processing efficiency and high processing yield, and when the back drill is used for deep hole drilling, the depth control accuracy is high and the operation is simple.

[0004] The tool can indeed control the drilling depth by utilizing the properties of the conductive part of the tool when back-drilling ordinary PCB materials (such as epoxy board FR-4). However, in PCBs made of PTFE material, the PTFE material is more viscous, and a multi-blade drill is often required to drill at a high speed when drilling holes in PCBs made of PTFE material. After drilling to a preset depth, the drill needs to remain at that height and continue to rotate and grind the hole wall to ensure the smoothness of the back-drilled hole. The PCB opening method suitable for ordinary materials (such as epoxy board FR-4) is difficult to ensure the smoothness of the hole wall and fix the relatively smooth PTFE material PCB; and the PTFE material is highly viscous, and the fiber filaments of the PTFE drilled by the drill are easily attached to the spiral texture of the drill bit, and the drill bit with attached fiber filaments is more likely to cause burrs or damage to the inner wall of the back-drilled hole during drilling. Summary of the invention

[0005] In order to overcome the defects in the prior art, the purpose of the present invention is to provide a damage-resistant back-drilling process for PTFE ultra-thin plates to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A damage-resistant back drilling process for a PTFE ultra-thin plate comprises the following steps:

[0008] S1. First, the staff needs to place the PTFE ultra-thin plate-style PCB that has been drilled and electroplated horizontally on the workbench, prepare at least two drill bits and install the first drill bit in the drill chuck, and align the drill bit with the hole to be drilled through the matching controller or by moving the PTFE ultra-thin plate;

[0009] S2. Then, the lifting column is controlled to descend through the matching controller, so that the drill bit originally located above the scraping part enters the upper scraping hole and the lower scraping hole. At the same time, the upper scraper and the lower scraper cooperate with the external thread of the drill bit to rotate;

[0010] S3, when the drill bit descends, the inclined lever descends at the same time, and contacts the outer inclined surface of the triangular slider to press the triangular slider downward obliquely, so that the triangular slider slides obliquely downward along the lower section of the limit frame;

[0011] S4. Then, the oblique lever forces the fan-shaped pressing piece to slide obliquely downward until the oblique lever moves the triangular slider and the fan-shaped pressing piece presses and fixes the PTFE ultra-thin plate to prevent the PTFE ultra-thin plate from sliding and being damaged during drilling;

[0012] S5, after that, the spring starts to compress, the rotary motor starts and drives the drill bit through the transmission assembly in the spindle box to start rotating and contact the hole to be drilled and continue drilling downward;

[0013] S6, the drill bit drills downward until the spring cannot be compressed, so that the distance between the sub-triangular slider and the triangular block is locked, so that the inclined lever cannot continue to descend, and the height of the drill bit is locked to prevent it from continuing to descend and damaging the hole wall where the electroplated metal needs to be retained;

[0014] S7. After the drill bit drills and polishes the electroplating layer to a target depth, the rotating motor is powered off. When the drill bit stops rotating, the drill bit is controlled to rise. When the drill bit rises, the lower scraper and the upper scraper rotate in coordination with the rising drill bit. The lower end of the lower scraper hole will be close to the external thread of the drill bit and scrape off the PTFE fiber filaments attached to the external thread of the drill bit during drilling.

[0015] S8. If you need to continue back-drilling other electroplated through holes on the same PTFE ultra-thin board, replace the second clean drill bit and repeat the steps S1-S7. After drilling the second drill bit, if you need to continue back-drilling, you can replace the first drill bit after the fiber filaments have been scraped out of the lower scraping hole and continue working;

[0016] S9, repeating the steps of S1-S8 to ensure that the fiber filaments attached to the external thread of the drill bit can be scraped off in time during the back drilling process, so that the drill bit after the fiber filaments are scraped off by the lower scraper hole is always used during the back drilling, thereby reducing the burrs or damage in the hole wall when the PTFE ultra-thin plate is back drilled. When all the holes are drilled, the rotating motor is turned off, the drill bit is raised, and the PTFE ultra-thin plate that has been back drilled is taken out;

[0017] The above steps use the cooperation of the drill head, the limiter and the scraper to complete the back drilling process of the PTFE ultra-thin plate placed on the workbench;

[0018] A PTFE ultra-thin plate is placed on the workbench, a spindle box is suspended above the PTFE ultra-thin plate, and a rotating motor for driving the spindle is fixedly installed on the top of the spindle box by bolts;

[0019] The lower end of the spindle box is slidably plugged with a drill head for lifting and drilling, and the drill head includes a lifting column, a drill chuck rotatably connected to the bottom end of the lifting column, and a drill bit clamped at the bottom end of the drill chuck;

[0020] The lower end of the spindle box is also provided with a limiting part for limiting the minimum height of the drill head and pressing and fixing the PTFE ultra-thin plate, and the limiting part includes a limiting frame fixedly arranged at the lower end of the spindle box, a swivel ring rotatably connected to the outside of the lifting column, a plurality of oblique levers welded obliquely downward to the outside of the swivel ring, a triangular slider slidably connected to the limiting frame obliquely below the drill bit, a sub-triangular slider slidably connected to the bottom of the triangular slider, a spring connected between the triangular slider and the sub-triangular slider, and a fan-shaped pressing sheet fixedly arranged at the bottom of the sub-triangular slider; the triangular slider is located below the oblique lever;

[0021] A scraping part for cleaning the drill bit is provided at the bottom end of the limit frame, and the scraping part includes the same circular track ring fixed at the bottom ends of the inclined sections of all the sliding rods, and a lower scraper and an upper scraper rotatably connected to the circular track ring. A lower scraper hole is opened at the center of the lower scraper, and an upper scraper hole connected to the lower scraper hole is opened at the center of the lower scraper.

[0022] As a further improvement of the present technical solution, the limit frame includes a threaded ring at the upper end and a plurality of sliding rods welded to the lower end of the threaded ring, and the sliding rods are evenly spaced and distributed at the lower end of the threaded ring. The sliding rods include a vertical section at the upper end and an inclined section at the lower end obliquely toward the bottom of the drill bit.

[0023] As a further improvement of the technical solution, a fixing ring is fixedly installed at the lower end of the spindle box by bolts, a thread is provided on the outside of the fixing ring, and the limit frame is fixedly connected to the thread of the lower end of the fixing ring through the threaded ring at its upper end, and the circular track ring, the threaded ring and the drill bit are arranged concentrically.

[0024] As a further improvement of the technical solution, the oblique levers are arranged in groups of two, and each group is correspondingly clamped on both sides of the sliding rod. The limit frame 30 is located between a pair of oblique levers 32 and extends vertically.

[0025] As a further improvement of the present technical solution, the triangular slider includes a triangular block in the shape of a right-angled triangle, the bottom surface of the triangular block is a hypotenuse corresponding surface and is provided with a triangular groove for sliding the sub-triangular slider, and a concave block in the shape of a concave letter is fixed by bolts on the top of the right-angle surface of the triangular block close to the drill bit side, and the concave block is slidably sleeved on the inclined section of the sliding rod.

[0026] As a further improvement of the technical solution, the triangular slider is always located below the oblique lever, the right-angled surface of the triangular block fixing the concave block, the inclined section of the sliding rod and the corresponding plurality of springs below are all parallel to each other, and another right-angled surface of the triangular block is parallel to the oblique lever; all the springs are distributed in a matrix between the triangular slider and the sub-triangular slider; the bottom end of the inclined section of the sliding rod is T-shaped, and when the triangular slider slides obliquely downward along the sliding rod to the bottom end, the T-shaped bottom end of the sliding rod contacts the concave block.

[0027] As a further improvement of the technical solution, each group of the oblique levers are parallel to each other and have connecting strips fixedly connected at their outer ends by bolts, and a lifting rope for lifting the fan-shaped pressing sheet is fixedly connected between the connecting strip and the fan-shaped pressing sheet.

[0028] As a further improvement of the present technical solution, the triangular groove and the sub-triangular slider are both in the shape of a right-angled triangle, and the triangular groove is provided with an inclined sliding groove at both edges of the right-angled surface of the inner groove of the drill bit close to the drill bit, and the sub-triangular slider is provided with an inclined sliding strip at both edges of the right-angled surface of the drill bit close to the drill bit, and the inclined sliding strip is slidably connected to the corresponding inclined sliding groove.

[0029] As a further improvement of the technical solution, the fan-shaped pressing plate is provided with a docking triangular groove for facilitating the vertical installation of a plurality of the springs. The docking triangular groove 370 is connected to the outer right-angle surface of the sub-triangular slider and is in the same plane.

[0030] As a further improvement of the technical solution, the drill bit is a three-blade leaf-shaped bit that is rotationally symmetrical about its axis, and the lower scraper hole and the upper scraper hole are both spiral shapes for cooperating in scraping the outer wall of the drill bit; an annular groove is provided on the inner arc wall of the circular track ring, and a number of rollers are horizontally connected to the outer circular edges of the upper scraper and the lower scraper, and all of the rollers are slidably connected in the annular groove.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The damage-proof back-drilling process of the PTFE ultra-thin plate is provided with a sliding rod, a rotating ring, an oblique lever, a triangular slider, a sub-triangular slider, a spring, and a fan-shaped pressing piece. When the lifting column drives the drill bit to descend to drill a hole in the PTFE ultra-thin plate, the fan-shaped pressing piece can be obliquely pushed downward by the oblique lever to the bottom of the drill bit to stably press the PTFE ultra-thin plate, and the fan-shaped pressing piece can be closely attached to the back-drilling hole to more fully fix the position of the PTFE ultra-thin plate PCB. When drilling after pressing, the spring can be contracted, thereby continuing to lower the height of the drill bit without damaging the PTFE ultra-thin plate. When the drill bit is lowered to the lowest point, the spring cannot be compressed, and the drill bit can be maintained to rotate continuously at this height, so that the hole is more easily smooth and undamaged. When rising, the oblique lever can drive the fan-shaped pressing pieces to rise and move away from each other for easy removal or adjustment of the position of the PTFE ultra-thin plate.

[0033] 2. The damage-proof back-drilling process of the PTFE ultra-thin plate is provided with a circular rail ring, a lower scraper, a lower scraper hole, an upper scraper and an upper scraper hole. When the drill bit descends, the drill bit is matched with the drill bit external thread sleeve to be connected to the outside of the drill bit. When the drill bit rises, the PTFE fiber filaments attached to the external thread when the drill bit is drilling are scraped off. Through the annular slide groove and roller, when the drill bit is drilling, the lower scraper and the upper scraper can rotate coaxially with it without hindering the rotation of the drill bit, so that the last used drill bit can be cleaned when the drill bit is replaced, ensuring that the drill bit without PTFE fiber filaments attached is always used, thereby ensuring that the back-drilled hole is smooth and damage-free. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings described herein are only for explanation purposes and are not intended to limit the scope of the present invention in any way. In addition, the shapes and proportional dimensions of the various components in the figures are only schematic, used to help understand the present invention, and are not specifically limited to the shapes and proportional dimensions of the various components of the present invention. Those skilled in the art can select various possible shapes and proportional dimensions to implement the present invention according to the teachings of the present invention.

[0035] Figure 1 It is one of the overall structural schematic diagrams of the present invention;

[0036] Figure 2 This is the second schematic diagram of the overall structure of the present invention;

[0037] Figure 3 For the present invention Figure 1 Schematic diagram of the local structure at A in the middle;

[0038] Figure 4 It is one of the partial structural schematic diagrams of the present invention;

[0039] Figure 5 This is the second schematic diagram of the partial structure of the present invention;

[0040] Figure 6 This is the third schematic diagram of the partial structure of the present invention;

[0041] Figure 7 This is the fourth schematic diagram of the partial structure of the present invention;

[0042] Figure 8 This is the fifth partial structural diagram of the present invention;

[0043] Fig. 9 For the present invention Figure 6 A schematic diagram of the structure from the right;

[0044] Fig.10 It is a schematic diagram of the structure of the circular track ring in the present invention;

[0045] Fig.11 It is a schematic diagram of the partial explosion structure of the present invention;

[0046] Fig.12 It is a structural schematic diagram of the drill bit in the present invention;

[0047] The meaning of each number in the figure is:

[0048] 1. Workbench; 10. PTFE ultra-thin plate; 11. Spindle box; 12. Rotating motor; 13. Fixed ring;

[0049] 2. Drill head; 20. Lifting column; 21. Drill chuck; 22. Drill bit;

[0050] 3. Limiting part; 30. Limiting frame; 301. Threaded ring; 302. Sliding rod; 31. Swivel; 32. Oblique lever; 321. Connecting strip; 33. Suspension rope; 34. Triangular slider; 340. Triangular block; 3401. Triangular groove; 3402. Oblique slide groove; 341. Concave block; 35. Sub-triangular slider; 350. Oblique slide strip; 36. Spring; 37. Fan-shaped pressing piece; 370. Docking triangular groove;

[0051] 4. Scraping part; 40. Circular track ring; 401. Annular slide groove; 41. Lower scraper; 410. Lower scraper hole; 42. Upper scraper; 420. Upper scraper hole; 43. Roller. DETAILED DESCRIPTION

[0052] The details of the present invention can be more clearly understood by combining the accompanying drawings with the description of the specific embodiments of the present invention. However, the specific embodiments of the present invention described herein are only used for the purpose of explaining the present invention and cannot be understood as limiting the present invention in any way. Under the guidance of the present invention, technicians can conceive of any possible variations based on the present invention, which should be regarded as falling within the scope of the present invention. The terms "installation" and "connection" should be understood in a broad sense, which can be directly connected or indirectly connected through an intermediate medium.

[0053] The terms "central axis", "vertical", "horizontal", "front", "back", "up", "down", "left", "right", "top", "bottom", "inside", "outside" and the like used herein to indicate positions or positional relationships are based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the equipment or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, in the description of the present invention, the meaning of "several" is two or more, unless otherwise clearly and specifically defined.

[0054] See also Figure 1-Figure 12 As shown, the present invention provides a damage-resistant back drilling process for a PTFE ultra-thin plate, comprising the following steps:

[0055] S1. First, the staff needs to place the PTFE ultra-thin plate-style PCB that has been drilled and electroplated horizontally on the workbench 1, prepare at least two drill bits 22 and install the first drill bit 22 in the drill chuck 21, and align the drill bit 22 with the hole to be drilled through the matching controller or by moving the PTFE ultra-thin plate;

[0056] S2, then, the lifting column 20 is controlled to descend by the matching controller, so that the drill bit 22 originally located above the scraping part 4 enters the upper scraping hole 420 and the lower scraping hole 410, and at the same time, the upper scraper 42 and the lower scraper 41 are rotated in coordination with the external thread of the drill bit 22;

[0057] S3, when the drill bit 22 descends, the inclined lever 32 descends at the same time, and contacts the outer inclined surface of the triangular slider 34 to press the triangular slider 34 downward obliquely, so that the triangular slider 34 slides obliquely downward along the lower section of the limit frame 30;

[0058] S4, then, the oblique lever 32 forces the fan-shaped pressing sheet 37 to slide obliquely downward until the oblique lever 32 moves the triangular slider 34 and the fan-shaped pressing sheet 37 presses and fixes the PTFE ultra-thin plate to prevent the PTFE ultra-thin plate from sliding and being damaged during drilling;

[0059] S5, after that, the spring 36 starts to compress, the rotary motor 12 starts to drive the drill bit 22 through the transmission assembly in the spindle box 11 to start rotating and contact the hole to be drilled and continue to drill downward;

[0060] S6, the drill bit 22 drills downward until the spring 36 cannot be compressed, so that the distance between the sub-triangular slider 35 and the triangular slider 34 is locked, so that the inclined lever 32 cannot continue to descend, and the height of the drill bit 22 is locked to prevent it from continuing to descend and damaging the hole wall where the electroplated metal needs to be retained;

[0061] S7, when the drill bit 22 drills and polishes the electroplating layer of a target depth, the rotating motor 12 is powered off, and when the drill bit 22 stops rotating, the drill bit 22 is controlled to rise. When the drill bit 22 rises, the lower scraper 41 and the upper scraper 42 rotate in coordination with the rising drill bit 22, and the lower end of the lower scraper hole 410 will be close to the external thread of the drill bit 22 and scrape off the PTFE fiber filaments attached to the external thread of the drill bit 22 during drilling;

[0062] S8, if it is necessary to continue back-drilling other electroplated through holes on the same PTFE ultra-thin board, replace the second clean drill bit 22 and repeat the steps S1-S7. After drilling the second drill bit 22, if it is necessary to continue back-drilling, the first drill bit 22 after the fiber filaments have been scraped out by the lower scraping hole 410 can be replaced to continue working;

[0063] S9, repeating the steps S1-S8 to ensure that the fiber filaments attached to the external threads of the drill bit 22 can be scraped off in time during the back drilling process, so that the drill bit 22 after the fiber filaments are scraped off by the lower scraper hole 410 is always used during the back drilling, thereby reducing the burrs or damage in the hole wall when the PTFE ultra-thin plate is back drilled. When all the holes are drilled, the rotating motor 12 is turned off, the drill bit 22 is raised, and the PTFE ultra-thin plate that has been back drilled is taken out;

[0064] In the above steps, the drill head 2, the stopper 3 and the scraper 4 cooperate to complete the back drilling process of the PTFE ultra-thin plate 10 placed on the workbench 1;

[0065] A PTFE ultra-thin plate 10 is placed on the workbench 1, a spindle box 11 is suspended above the PTFE ultra-thin plate 10, and a rotating motor 12 for driving the spindle is fixedly installed on the top of the spindle box 11 by bolts;

[0066] The lower end of the spindle box 11 is slidably plugged with a drill head 2 for lifting and drilling, and the drill head 2 includes a lifting column 20, a drill chuck 21 rotatably connected to the bottom end of the lifting column 20, and a drill bit 22 clamped at the bottom end of the drill chuck 21;

[0067] The lower end of the spindle box 11 is also provided with a limiting part 3 for limiting the minimum height of the drill head 2 and pressing and fixing the PTFE ultra-thin plate 10. The limiting part 3 includes a limiting frame 30 fixedly arranged at the lower end of the spindle box 11, a rotating ring 31 rotatably connected to the outside of the lifting column 20, a plurality of oblique levers 32 welded obliquely downward to the outside of the rotating ring 31, a triangular slider 34 slidably connected to the limiting frame 30 below the oblique drill bit 22, a sub-triangular slider 35 slidably connected to the bottom of the triangular slider 34, a spring 36 connected between the triangular slider 34 and the sub-triangular slider 35, and a fan-shaped pressing piece 37 fixedly arranged at the bottom of the sub-triangular slider 35; the triangular slider 34 is located below the oblique lever 32;

[0068] A scraping part 4 for cleaning the drill bit 22 is provided at the bottom end of the limiting frame 30, and the scraping part 4 includes the same circular track ring 40 fixed at the bottom end of the inclined section of all sliding rods 302, a lower scraper 41 and an upper scraper 42 rotatably connected to the circular track ring 40, a lower scraper hole 410 is opened at the center of the lower scraper 41, and an upper scraper hole 420 connected to the lower scraper hole 410 is opened at the center of the lower scraper 41.

[0069] Specifically, the limit frame 30 includes a threaded ring 301 at the upper end and a plurality of sliding rods 302 welded to the lower end of the threaded ring 301 , and the sliding rods 302 are evenly spaced and distributed at the lower end of the threaded ring 301 . The sliding rods 302 include an upper vertical section and a lower inclined section obliquely disposed below the drill bit 22 .

[0070] Preferably, a fixing ring 13 is fixedly installed at the lower end of the spindle box 11 by bolts, and a thread is provided on the outside of the fixing ring 13. The limit frame 30 is fixedly connected to the lower end of the fixing ring 13 by a threaded ring 301 at its upper end, and the circular track ring 40, the threaded ring 301 and the drill bit 22 are arranged cocentrically.

[0071] Preferably, the diagonal levers 32 are arranged in groups of two, and each group is clamped on both sides of the sliding rod 302 . The limit frame 30 is located between a pair of diagonal levers 32 and extends vertically, so that the diagonal levers 32 can rise freely with the lifting column 20 without being blocked by the limit frame 30 .

[0072] Specifically, the triangular slider 34 includes a triangular block 340 in the shape of a right-angled triangle. The bottom surface of the triangular block 340 is a hypotenuse corresponding surface and is provided with a triangular groove 3401 for sliding the sub-triangular slider 35. The top of the right-angle surface of the triangular block 340 close to the drill bit 22 is fixed with a concave block 341 in the shape of a concave letter by bolts. The concave block 341 is slidably sleeved on the inclined section of the sliding rod 302.

[0073] Preferably, the triangular slider 34 is always located below the oblique lever 32, the right-angled surface of the triangular block 340 fixing the recessed block 341, the inclined section of the sliding rod 302 and the corresponding plurality of springs 36 below are all parallel to each other, and another right-angled surface of the triangular block 340 is parallel to the oblique lever 32; all the springs 36 are distributed in a matrix between the triangular slider 34 and the sub-triangular slider 35, so as to slide evenly under force; the bottom end of the inclined section of the sliding rod 302 is T-shaped, and when the triangular slider 34 slides obliquely downward along the sliding rod 302 to the bottom end, the T-shaped bottom end of the sliding rod 302 contacts the recessed block 341, thereby ensuring that the triangular slider 34 will not contact the drill bit 22 even when it slides to the lowest point.

[0074] Preferably, each group of inclined levers 32 are parallel to each other and have connecting strips 321 fixedly connected at their outer ends by bolts, and a suspension rope 33 for lifting the fan-shaped pressing sheet 37 is fixedly connected between the connecting strip 321 and the fan-shaped pressing sheet 37, so that when the drill bit leaves the PTFE ultra-thin plate 10 and rises, the suspension rope 33 can drive the fan-shaped pressing sheet 37 to rise and move away from each other to facilitate taking or adjusting the position of the PTFE ultra-thin plate 10.

[0075] Preferably, the triangular groove 3401 and the sub-triangular slider 35 are both in the shape of a right-angled triangle, and the triangular groove 3401 is provided with an inclined sliding groove 3402 on both edges of the right-angled surface of the inner groove close to the drill bit 22, and the sub-triangular slider 35 is provided with an inclined sliding bar 350 on both edges of the right-angled surface close to the drill bit, and the inclined sliding bar 350 is slidably connected to the corresponding inclined sliding groove 3402, thereby stabilizing the sliding direction of the sub-triangular slider 35 and the maximum sliding stroke of the sub-triangular slider 35 in cooperation with the spring 36.

[0076] Specifically, the fan-shaped pressing piece 37 is provided with a docking triangular groove 370 for facilitating the vertical installation of a plurality of springs 36 . The docking triangular groove 370 is in contact with the outer right-angle surface of the sub-triangular slider 35 and is located in the same plane, so as to evenly place a plurality of springs 36 .

[0077] Furthermore, the drill bit 22 is a three-blade leaf-shaped blade that is rotationally symmetrical about its axis. The lower scraper hole 410 and the upper scraper hole 420 are both spirally shaped for cooperating in scraping the outer wall of the drill bit 22, so as to fully contact and scrape off the PTFE fiber filaments attached to the outer thread of the drill bit 22; an annular groove 401 is opened on the inner arc wall of the circular track ring 40, and a plurality of rollers 43 are horizontally connected to the outer circular edges of the upper scraper blade 42 and the lower scraper blade 41 for rotation, and all the rollers 43 are slidably connected in the annular groove 401, so as not to affect the rotation of the drill bit 22 and will not damage the scraping part 4 itself.

[0078] Furthermore, it should be noted that the components such as the spindle box 11, the rotating motor 12 and the matching controller involved in the present invention are all universal standard parts or components known to technical personnel in this field, and their structures and principles are all known to technical personnel through technical manuals or through conventional experimental methods. In the idle space of this device, all the above-mentioned electrical components, which refer to power elements, electrical components, and compatible controllers and power supplies, are connected through wires. The specific connection means should refer to the working principle of the present invention. The electrical connection is completed between each electrical component in a sequential working order, and the detailed connection means are all well-known technologies in the field.

[0079] Finally, it should be noted that the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A damage-resistant back drilling process for an ultra-thin PTFE plate, comprising a workbench (1), comprising the following steps: S1. First, the staff needs to place the PCB in the form of a PTFE ultra-thin plate that has been drilled and electroplated horizontally on a workbench (1), prepare at least two drill bits (22) and install the first drill bit (22) in a drill chuck (21), and align the drill bit (22) with the hole to be drilled through a matching controller or by moving the PTFE ultra-thin plate; The invention is characterized in that: S2, then, the lifting column (20) is controlled to descend by a matching controller, so that the drill bit (22) originally located above the scraping part (4) enters the upper scraping hole (420) and the lower scraping hole (410), and at the same time, the upper scraper (42) and the lower scraper (41) are rotated in coordination with the external thread of the drill bit (22); S3, when the drill bit (22) descends, the inclined lever (32) descends at the same time, and contacts the outer inclined surface of the triangular slider (34) to press the triangular slider (34) obliquely downward, so that the triangular slider (34) slides obliquely downward along the lower section of the limiting frame (30); S4, then, the oblique lever (32) forces the fan-shaped pressing sheet (37) to slide obliquely downward until the oblique lever (32) moves the triangular slider (34) and the fan-shaped pressing sheet (37) presses and fixes the PTFE ultra-thin plate, thereby preventing the PTFE ultra-thin plate from sliding and being damaged during drilling; S5, after that, the spring (36) starts to compress, the rotary motor (12) starts and drives the drill bit (22) through the transmission assembly in the spindle box (11) to start rotating and contact the hole to be drilled and continue drilling downward; S6, the drill bit (22) drills downward until the spring (36) cannot be compressed, so that the distance between the sub-triangular slider (35) and the triangular slider (34) is locked, so that the inclined lever (32) cannot continue to descend, and the height of the drill bit (22) is locked to prevent it from continuing to descend and damaging the hole wall where the electroplated metal needs to be retained; S7, when the drill bit (22) drills and polishes the electroplating layer to a target depth, the rotating motor (12) is powered off, and when the drill bit (22) stops rotating, the drill bit (22) is controlled to rise, and when the drill bit (22) rises, the lower scraper (41) and the upper scraper (42) rotate in coordination with the rising drill bit (22), and the lower end of the lower scraper hole (410) is closely attached to the external thread of the drill bit (22) and scrapes off the PTFE fiber filaments attached to the external thread of the drill bit (22) during drilling; S8, if it is necessary to continue back-drilling other electroplated through holes on the same PTFE ultra-thin board, replace the second clean drill bit (22) and repeat the steps S1-S7. After the second drill bit (22) is drilled, if it is necessary to continue back-drilling, the first drill bit (22) after the fiber filaments have been scraped off by the lower scraper hole (410) can be replaced to continue working; S9, repeating steps S1-S8 to ensure that during the back drilling process, the fiber filaments attached to the external thread of the drill bit (22) can be scraped off in time, so that during the back drilling, the drill bit (22) after the fiber filaments are scraped off by the lower scraping hole (410) is always used, thereby reducing the burrs or damage in the hole wall when the PTFE ultra-thin plate is back drilled. When all the holes are drilled, the rotating motor (12) is turned off, the drill bit (22) is raised, and the PTFE ultra-thin plate that has been back drilled is taken out; In the above steps, the drill head (2), the stopper (3) and the scraper (4) cooperate to complete the back drilling process of the PTFE ultra-thin plate (10) placed on the workbench (1); A PTFE ultra-thin plate (10) is placed on the workbench (1), a spindle box (11) is suspended above the PTFE ultra-thin plate (10), and a rotating motor (12) for driving the spindle is fixedly installed on the top of the spindle box (11) by bolts; A drill head (2) for lifting and drilling holes is slidably inserted at the lower end of the spindle box (11), and the drill head (2) comprises a lifting column (20), a drill chuck (21) rotatably connected to the bottom end of the lifting column (20), and a drill bit (22) clamped at the bottom end of the drill chuck (21); The lower end of the spindle box (11) is also provided with a limiting part (3) for limiting the minimum height of the drill head (2) and pressing and fixing the PTFE ultra-thin plate (10), the limiting part (3) includes a limiting frame (30) fixedly arranged at the lower end of the spindle box (11), a rotating ring (31) rotatably connected to the outside of the lifting column (20), a plurality of oblique levers (32) welded obliquely downward to the outside of the rotating ring (31), a triangular slider (34) slidably connected to the limiting frame (30) obliquely below the drill head (22), a sub-triangular slider (35) slidably connected to the bottom of the triangular slider (34), a spring (36) connected between the triangular slider (34) and the sub-triangular slider (35), and a fan-shaped pressing sheet (37) fixedly arranged at the bottom of the sub-triangular slider (35); the triangular slider (34) is located below the oblique lever (32); A scraping portion (4) for cleaning the drill bit (22) is provided at the bottom end of the limiting frame (30), and the scraping portion (4) includes a same circular track ring (40) fixed at the bottom end of the inclined section of all the sliding rods (302), a lower scraper (41) and an upper scraper (42) rotatably connected to the circular track ring (40), a lower scraper hole (410) is provided at the center of the lower scraper (41), and an upper scraper hole (420) connected to the lower scraper hole (410) is provided at the center of the lower scraper (41).

2. The damage-resistant back drilling process of the PTFE ultra-thin plate according to claim 1, characterized in that: The limiting frame (30) comprises a threaded ring (301) at the upper end and a plurality of sliding rods (302) welded to the lower end of the threaded ring (301), and the sliding rods (302) are distributed at equal intervals at the lower end of the threaded ring (301), and the sliding rods (302) comprise an upper vertical section and a lower inclined section obliquely directed below the drill bit (22).

3. The damage-resistant back drilling process of the PTFE ultra-thin plate according to claim 1, characterized in that: A fixing ring (13) is fixedly installed at the lower end of the main spindle box (11) by bolts. Threads are provided on the outer part of the fixing ring (13). The limiting frame (30) is fixedly connected to the lower end of the fixing ring (13) by a thread ring (301) at its upper end. The circular rail ring (40), the thread ring (301), and the drill bit (22) are concentrically arranged.

4. The damage-resistant back drilling process of the PTFE ultra-thin plate according to claim 1, characterized in that: The inclined push rods (32) are grouped in pairs of two, and each pair is correspondingly clamped on both sides of the sliding rod (302). The limiting frame (30) is located between a pair of inclined push rods (32) and extends vertically.

5. The damage-resistant back drilling process of the PTFE ultra-thin plate according to claim 1, characterized in that: The triangular slider (34) includes a triangular block (340) in the shape of a right triangle. The bottom surface of the triangular block (340) is the hypotenuse corresponding surface and is provided with a triangular groove (3401) for sliding the sub-triangular slider (35). At the top of the right-angle surface on one side of the triangular block (340) close to the drill bit (22), a concave block (341) in the shape of a concave character is fixedly installed by bolts. The concave block (341) is slidably sleeved on the inclined section of the sliding rod (302).

6. The damage-resistant back drilling process of the PTFE ultra-thin plate according to claim 5, characterized in that: The triangular slider (34) is always located below the inclined push rod (32). The right-angle surface of the triangular block (340) fixing the concave block (341), the inclined section of the sliding rod (302), and several corresponding springs (36) below are all parallel to each other. The other right-angle surface of the triangular block (340) is parallel to the inclined push rod (32). All the springs (36) are distributed in a matrix between the triangular slider (34) and the sub-triangular slider (35). The bottom end of the inclined section of the sliding rod (302) is in a T shape. When the triangular slider (34) slides obliquely downward along the sliding rod (302) to the bottom end, the T-shaped bottom end of the sliding rod (302) contacts the concave block (341).

7. The damage-resistant back drilling process of the PTFE ultra-thin plate according to claim 4, characterized in that: Each group of the inclined push rods (32) is parallel to each other, and a connecting bar (321) is fixedly connected between their outer ends by bolts. A lifting rope (33) for lifting the sector pressing piece (37) is fixedly connected between the connecting bar (321) and the sector pressing piece (37).

8. The damage-resistant back-drilling process for PTFE ultra-thin plates according to claim 5, characterized in that: Both the triangular groove (3401) and the sub-triangular slider (35) are in the shape of a right triangle. Oblique sliding grooves (3402) are provided at both edges of the inner groove right-angle surface of the triangular groove (3401) close to the drill bit (22). An oblique sliding strip (350) is provided at both edges of the right-angle surface of the sub-triangular slider (35) close to the drill bit. The oblique sliding strip (350) is slidably connected in the corresponding oblique sliding groove (3402).

9. The damage-resistant back-drilling process for PTFE ultra-thin plates according to claim 5, characterized in that: The sector pressing piece (37) is provided with a butt joint triangular groove (370) for conveniently vertically installing several springs (36). The butt joint triangular groove (370) is butted against the outer right-angle surface of the sub-triangular slider (35) and is in the same plane.

10. The damage-resistant back-drilling process for PTFE ultra-thin plates according to claim 9, characterized in that: The drill bit (22) is a three-blade blade that is rotationally symmetrical about its axis, and the lower scraper hole (410) and the upper scraper hole (420) are both spirally shaped for cooperating in scraping the outer wall of the drill bit (22); an annular groove (401) is provided on the inner arc wall of the circular track ring (40), and a plurality of rollers (43) are horizontally rotatably connected between the outer circular edges of the upper scraper (42) and the lower scraper (41), and all of the rollers (43) are slidably connected in the annular groove (401).

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