FPC punching method

Abstract

The application provides a FPC punching method, which comprises a FPC substrate, an upper cover plate, a buffer pad, a lower cover plate and a punching cutter. The lower cover plate is provided with a clamping groove for accommodating the punching cutter. The clamping groove vertically penetrates through two side surfaces of the lower cover plate. One end of the punching cutter is inlaid and fixed in the clamping groove. The other end of the punching cutter protrudes out of the clamping groove. The FPC substrate with a required width is obtained through twice punching. Meanwhile, extrusion deformation in the punching process can be effectively avoided, and the quality of the product is ensured.

Description

Technical Field

[0001] This invention relates to the field of SMT processing technology, and specifically to an FPC punching method. Background Technology

[0002] Flexible printed circuit boards (FPCs) are printed circuits made of flexible insulating substrates. Their bendable and foldable nature allows for flexible layouts to fit various spaces. FPCs significantly reduce the size of electronic products. To achieve narrower bezels, the area around the backlight edge needs to be minimized. Therefore, the overall width of the FPC and the width of its non-light-emitting surface have become critical challenges for narrow-bezel mobile phones. Furthermore, with the miniaturization of electronic components such as LEDs, the corresponding FPC boards for housing LEDs can be made very small, for example, only 5mm wide, or even less than 3mm. Existing small-width FPCs are widely used due to their small size and space-saving design. However, when performing one-piece punching on such small-width FPCs, the narrow width can easily cause warping in the middle during the punching process.

[0003] For example, Chinese patent application number 201810993837.9, published on May 10, 2019, discloses a narrow-edge FPC punching die and punching process, including the following steps: A. Conveying an FPC flexible board with welded LED beads to the upper and lower templates of the punching die, with the LED beads facing the lower template; B. Positioning the FPC flexible board using positioning pins on the lower template; C. Placing the FPC flexible board on the lower template, with the LED beads placed in the clearance groove of the lower template; D. Driving the upper template downwards using a servo motor, causing the punch on the upper template to press against the lower template for punching; E. Resetting the upper template, completing the punching process; F. Unloading the FPC flexible board from the lower template; G. Removing the finished material and placing it in the unloading area.

[0004] This paper describes a method where the LED clearance groove extends from the upper mold plate to the lower mold plate, ensuring the side of the FPC with the soldered LEDs faces downwards. This eliminates the need for clearance between the LEDs and the LEDs during punching, allowing for sufficient cutting space and enabling one-piece cutting of narrow-edge FPCs. However, for narrower FPC substrates, such as… Figure 1 As shown, since one-piece punching is used, that is, after punching, a smaller width FPC substrate is formed. After one-piece punching, the middle part 3' of the FPC substrate 1' is subjected to force and squeezed inward by the two blades 2'. In addition, the two blades 2' have a certain slope, which makes the FPC substrate 1' narrower and deformed by compression, thus causing damage to the FPC substrate 1'. Summary of the Invention

[0005] The purpose of this invention is to provide an FPC punching method that can effectively avoid extrusion deformation during the punching process and ensure product quality.

[0006] To achieve the above objectives, an FPC punching method includes an FPC substrate, an upper cover plate, a buffer pad, a lower cover plate, and a cutting tool. The cutting tool is provided in the lower cover plate and is vertically protruding from the surface of the lower cover plate. It also includes the following steps: (1) A first positioning hole is provided on the outer periphery of the upper cover plate and the lower cover plate, and then the FPC substrate is fixed on the lower cover plate by passing the positioning pin through the second positioning hole on the FPC substrate. (2) Attach a cushioning pad to the surface of the top cover plate; (3) Place the lower cover plate on a horizontal surface, while exposing the back of the FPC substrate on the lower cover plate. Then, place the upper cover plate horizontally on the lower cover plate and press the upper cover plate to make the back of the FPC substrate adhere to the buffer pad. (4) Position the upper cover plate and the lower cover plate by passing the positioning pin through the first positioning hole, and then place the upper cover plate above the lower cover plate and put it into the punching machine, while placing the lower cover plate in a position that matches the punching machine. (5) The FPC substrate is initially punched by the cutting tool through the punching machine; (6) Replace with different bottom cover plates and repeat steps (1)-(4) to punch the FPC substrate again to finally obtain the FPC substrate of the required width.

[0007] The above configuration, by providing a second positioning hole on the FPC substrate and a first positioning hole on both the upper and lower cover plates, allows the FPC substrate to be fixed to the lower cover plate via positioning pins. Simultaneously, positioning posts passing through the first positioning holes secure the upper and lower cover plates. Furthermore, a buffer pad is provided on the surface of the upper cover plate to prevent damage to the FPC substrate during punching. Additionally, pressing the upper cover plate after horizontally placing it on the lower cover plate improves the adhesion between the FPC substrate and the upper cover plate. After placing the lower cover plate in a position compatible with the punching machine, the punching machine processes the FPC substrate... The FPC substrate is punched once by a stamping tool to form the first contour. Then, the lower cover plate is replaced, and the stamping tool on the replaced lower cover plate corresponds to the second contour. The FPC substrate is punched a second time to form the second contour. This allows for the cutting of a large contour first and then a smaller contour on the large contour, thus avoiding the simultaneous punching of two contours. The gap between the two contours is also small, preventing compression. This allows the tool to cut the FPC substrate to the required width through two punching operations. It also effectively avoids the deformation caused by compression of the FPC substrate during the punching process, ensuring product quality.

[0008] Furthermore, the cutting tool includes a connecting part and a cutting part. One end of the connecting part is fixedly connected to one end of the cutting part. One side of the cutting part is inclined to the end face of the cutting part, and the other side of the cutting part is perpendicular to the end face of the cutting part. Step (5) also includes punching the upper cover plate with a punching machine, so that the upper cover plate presses the FPC substrate vertically downward, so that the cutting tool protruding from the slot performs preliminary punching on the FPC substrate. During the preliminary punching, one side of the cutting part of the punching tool corresponds to the waste area on the substrate that is not in the first contour area. Step (6) also includes repeating steps (1)-(4) after changing different lower cover plates, and punching the FPC substrate again. During the punching, one side of the cutting part of the punching tool corresponds to the waste area on the first contour area that is not in the second contour area, and finally the FPC substrate with the required width is obtained.

[0009] With the above settings, when the tool punches the FPC substrate, it can vertically cut the non-waste area of ​​the FPC substrate, while using the bevel to cut the waste area. Since the beveled edge generates an outward impact force on the waste area during the punching process, it is easier for extrusion to occur. However, with the corresponding settings for the waste area, even if extrusion occurs, the non-waste area can be easily affected by removing the waste area, thereby further avoiding the extrusion of the FPC substrate during the punching process and preventing deformation of the FPC substrate.

[0010] Furthermore, the lower cover plate is provided with a slot, which extends vertically through both sides of the lower cover plate. One end of the tool is welded and fixed inside the slot, and the other end of the tool protrudes from the slot and is vertically set on the surface of the lower cover plate.

[0011] The above settings facilitate the fixing of the cutting tool in the slot, ensuring it remains perpendicular to the FPC substrate during punching.

[0012] Furthermore, the slot in the lower cover plate is misaligned with the first positioning hole.

[0013] The above settings prevent the card slot from overlapping with the first positioning hole, which would prevent the FPC substrate from being positioned correctly.

[0014] Furthermore, the lower cover plate is provided with positioning pins.

[0015] With the above settings, the FPC substrate can be easily fixed in the top cover without the need for additional positioning pins.

[0016] Furthermore, step (1) also includes using a suction pen to pick up the FPC substrate and then flipping it so that the adhesive surface of the FPC substrate is attached to the top cover plate.

[0017] The above settings facilitate the cutting of the FPC substrate by the cutting tool and result in a better cutting effect.

[0018] Furthermore, step (5) also includes adjusting the parameters of the punching machine, including setting the pressing position, buffer position and termination position according to preset pressing position parameters, buffer position parameters and termination position parameters.

[0019] The above settings prevent the cutting tool from failing to fully cut the FPC substrate after stamping, thus avoiding poor FPC substrate stamping.

[0020] Furthermore, the positioning pins are correspondingly set with the second positioning holes, and the first positioning holes are located at the diagonal corners of the upper and lower cover plates, with a total of four first positioning holes.

[0021] The above settings, through the positioning of the positioning pin and the first positioning hole, facilitate the alignment of the positioning pin and the first positioning hole. At the same time, the positioning of the first positioning hole at a diagonal position ensures a reliable and stable connection between the upper cover plate and the lower cover plate.

[0022] Furthermore, the positioning pin is located inside the first positioning hole.

[0023] The above settings allow the PFC substrate to be fixed on the inner side of the upper and lower cover plates. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the existing technology structure.

[0025] Figure 2 This is a schematic diagram of the structure of the lower cover plate, buffer pad, FPC substrate and cutting tool in this invention.

[0026] Figure 3 This is a top view of the lower cover plate in this invention.

[0027] Figure 4 This is a cross-sectional view of the cutting tool in the punching state in this invention.

[0028] Figure 5 This is a schematic diagram of the FPC substrate after one punching in this invention.

[0029] Figure 6 This is a schematic diagram of the FPC substrate after secondary punching in this invention.

[0030] Figure 7 This is a flowchart of the process of the present invention.

[0031] Figure 8 This is a structural diagram of a punched substrate according to another embodiment of the present invention.

[0032] Figure 9 This is a partial cross-sectional view of the lower cover plate in this invention. Detailed Implementation The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation details.

[0033] like Figure 2-6 and Figure 9 As shown, this embodiment of the invention provides an FPC punching method, including an FPC substrate 1, a lower cover plate 6, a buffer pad 4, an upper cover plate 3, and a cutting tool 2. In one embodiment, the lower cover plate 6 has a slot 8 for accommodating the cutting tool 2, the slot 8 perpendicularly penetrating both sides of the lower cover plate 6, one end of the cutting tool 2 being welded and fixed in the slot 8, and the other end of the cutting tool 2 protruding from the slot 8 and perpendicularly disposed on the surface of the lower cover plate 6. In another embodiment, the cutting tool 2 is integrally formed with the lower cover plate 6 and the cutting tool 2 protrudes perpendicularly from the surface of the lower cover plate 6, thus enabling... When the FPC substrate 1 is punched with the cutter 2, it is ensured that the cutter 2 is perpendicular to the FPC substrate 1. The cutter 2 includes a connecting part 21 and a cutting part 22. One end of the connecting part 21 is fixedly connected to one end of the cutting part 22. The other end of the cutting part 22 cuts the FPC substrate 1 perpendicularly during punching. One side of the cutting part 22 is inclined to the end face 23 of the cutting part 22, and the other side of the cutting part 22 is perpendicular to the end face 23 of the cutting part 22. This enables the FPC substrate 1 to be cut perpendicularly, while avoiding the FPC substrate 1 from being squeezed and deformed.

[0034] In this embodiment, the FPC substrate 1 is provided with four second positioning holes 9, and the lower cover plate 6 is provided with four positioning pins 10 for fixing the FPC substrate 1 to the lower cover plate 6. The positioning pins 10 are arranged corresponding to the second positioning holes 9. Four first positioning holes 7 are respectively processed at two opposite corners in the lower cover plate 6 and the upper cover plate 3. The number of first positioning holes 7 is four, and the positioning pins 10 on the upper cover plate are located on the inner side of the first positioning holes 7 forming a ring.

[0035] like Figure 7 As shown, the FPC punching method includes the following specific steps: (1) Four first positioning holes 7 are processed at opposite corners of the lower cover plate 6 and the upper cover plate 3 respectively. Then, the FPC substrate 1 is picked up by suction pen. Then, the FPC substrate 1 is flipped so that the second positioning hole on the FPC substrate is aligned with the positioning pin 10 on the upper cover plate. At the same time, the FPC substrate 1 is fixed on the lower cover plate 6 by passing through the four second positioning holes 9 on the FPC substrate 1 with four positioning pins 10, so that the adhesive surface 60 of the FPC substrate 1 is attached to the lower cover plate 6. (2) Attach the buffer pad 4 to the surface of the upper cover plate 3. In this embodiment, the buffer pad 4 is set as a sponge pad or silver dragon sheet or other pads with buffering function.

[0036] (3) Place the lower cover plate 6 on a horizontal surface, and expose the back side 5 of the FPC substrate 1 on the lower cover plate 6. Then, place the upper cover plate 3 horizontally on the lower cover plate 6 and gently press the lower cover plate 6 so that the back side 5 of the FPC substrate 1 is in contact with the buffer pad 4. In this embodiment, no LED components are placed on the back side of the FPC substrate 1, but it has a functional area.

[0037] (4) The lower cover plate 6 and the upper cover plate 3 are positioned by passing through the four first positioning holes 7 through the positioning pins (not shown in the figure). The upper cover plate 3 can move towards the lower cover plate 6 under the guidance of the positioning pins, so that the upper cover plate 3 is above the lower cover plate 6 and is placed into the punching machine, while the lower cover plate 6 is placed in a position that matches the punching machine. (5) Adjust the parameters of the punching machine, including the pressing position, buffer position and termination position. In this embodiment, the pressing position is set to 185.0 mm, the buffer position is set to 185.3 mm, and the termination position is set to a range of 185.58~186.18 mm. Then, the punching machine is started to punch the lower cover plate, so that the lower cover plate presses the FPC substrate vertically downward, so that the tool protruding from the slot performs preliminary punching on the FPC substrate to form the first contour 12. During the preliminary punching, one side of the cutting part of the punching tool corresponds to the waste area of ​​the non-first contour area on the substrate. The FPC substrate 1 includes the waste area 120 of the first contour, the first contour 12 and the second contour 11, and the waste area 110 of the second contour. In this embodiment, the first contour 12 is punched into a circle. (6) Replace with a different lower cover plate 6. The punching tool on the lower cover plate 6 is set to correspond to the second contour 11. Repeat steps (1)-(4) to punch the FPC substrate 1 again to form the second contour 11. During punching, one side of the cutting part of the punching tool corresponds to the waste area 110 of the non-second contour area on the first contour area. The area of ​​the first contour is larger than the area of ​​the second contour. In this embodiment, the second contour 11 is punched into a circle, and the diameter of the second contour 11 is smaller than the diameter of the first contour 12. Finally, a circular FPC substrate 1 with a width of 3mm is obtained.

[0038] like Figure 8 As shown, in another embodiment, it can also be used to punch other shapes of FPC substrates, such as punching a corner of a square to form a trapezoid.

[0039] The working principle of this invention is as follows: By providing a second positioning hole 9 on the FPC substrate 1, and simultaneously providing a first positioning hole on the upper and lower cover plates, the FPC substrate is fixed to the lower cover plate by positioning pins, while the upper and lower cover plates are positioned by positioning posts passing through the first positioning holes; in addition, a buffer pad is provided on the surface of the upper cover plate to prevent damage to the FPC substrate during the punching process; after the upper cover plate is horizontally placed on the lower cover plate and pressed, the FPC substrate and the upper cover plate are better bonded; after the lower cover plate is placed in a position that matches the punching machine, the punching machine punches the FPC substrate... The FPC substrate is stamped to form a first contour. Then, the lower cover plate is replaced, and the stamping tool on the new lower cover plate corresponds to the second contour, which is then used to perform a second stamping to form the second contour. This process cuts a large contour first and then cuts a smaller contour on top of the large contour, thus avoiding the simultaneous stamping of two contours. The gap between the two contours is also small, preventing compression. This allows the tool to cut the FPC substrate to the required width through two stamping operations, while also effectively avoiding deformation caused by compression during the stamping process, ensuring product quality.

Claims

1. A method for punching FPCs, comprising an FPC substrate, an upper cover plate, a buffer pad, a lower cover plate, and a cutting tool, characterized in that: The lower cover plate is provided with a cutting tool, which is vertically protruding from the surface of the lower cover plate. The cutting tool includes a connecting part and a cutting part. One end of the connecting part is fixedly connected to one end of the cutting part. One side of the cutting part is inclined to the end face of the cutting part, and the other side of the cutting part is perpendicular to the end face of the cutting part. The cross-section of the end face of the cutting part is a plane. The lower cover plate has a slot that runs vertically through both sides of the lower cover plate. One end of the tool is welded and fixed inside the slot, and the other end of the tool protrudes from the slot and is set vertically on the surface of the lower cover plate. It also includes the following steps: (1) A first positioning hole is provided on the outer periphery of both the upper cover plate and the lower cover plate. A positioning pin is provided on the lower cover plate. The FPC substrate is then fixed on the lower cover plate by passing the positioning pin through the second positioning hole on the FPC substrate. (2) Attach a cushioning pad to the surface of the top cover plate; (3) Place the lower cover plate on a horizontal surface, while exposing the back of the FPC substrate on the lower cover plate. Then, place the upper cover plate horizontally on the lower cover plate and press the upper cover plate to make the back of the FPC substrate adhere to the buffer pad. (4) Position the upper cover plate and the lower cover plate by passing the positioning pin through the first positioning hole, and then place the upper cover plate above the lower cover plate and put it into the punching machine, while placing the lower cover plate in a position that matches the punching machine. (5) The punching machine presses the FPC substrate to make the tool perform preliminary punching; the punching machine presses the upper cover plate to make the upper cover plate press the FPC substrate vertically downward, so that the tool with the protruding slot performs preliminary punching on the FPC substrate, and the tool performs preliminary punching on the FPC substrate to form the first contour. During the preliminary punching, one side of the cutting part of the tool corresponds to the waste area of ​​the non-first contour area on the substrate. (6) Replace different bottom cover plates and repeat steps (1)-(4) to punch the FPC substrate again to form the second contour. During punching, one side of the cutting part of the tool corresponds to the waste area of ​​the non-second contour area on the first contour area, and finally obtain the FPC substrate of the required width.

2. The FPC punching method according to claim 1, characterized in that: The slot in the lower cover plate is misaligned with the first positioning hole.

3. The FPC punching method according to claim 1, characterized in that: Step (1) further includes using a suction pen to pick up the FPC substrate and then flipping it so that the adhesive surface of the FPC substrate is attached to the lower cover plate.

4. The FPC punching method according to claim 1, characterized in that: Step (5) also includes adjusting the parameters of the punching machine, including setting the pressing position, buffer position and termination position according to the preset pressing position parameters, buffer position parameters and termination position parameters.

5. The FPC punching method according to claim 1, characterized in that: The positioning pins are set in correspondence with the second positioning holes. The first positioning holes are located at the diagonal corners of the upper and lower cover plates, and there are four first positioning holes.

6. The FPC punching method according to claim 5, characterized in that: The positioning pin is located inside the first positioning hole.

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