Pin stamping die after chip plastic packaging

Abstract

This invention relates to the field of stamping die technology and discloses a stamping die for the pins of a chip after molding. The die includes a die base with a flat groove at the center of its upper surface. A chip molding component is placed in the flat groove, and the chip molding component includes several sets of symmetrical pins. The upper surface of the die base, located on both sides of the flat groove, has symmetrical stamping grooves acting on the pins. When the pins are straight, they are laid on the top of the stamping grooves. The groove walls of the stamping grooves are provided with a stationary convex corner die and a stationary oblique corner die acting on the pins. In this invention, two sets of inverted L-shaped moving seats on a double-ended lead screw move towards each other. The linear motion of the horizontal stamping die acts on the lower half of the pin, and the horizontal stationary die, in conjunction with the horizontal flat corner die, causes a second stamping bend in the pin. After stamping, the horizontal oblique corner die, in conjunction with the moving convex corner die, forms a lower arc chamfer at the bend. The use of multiple die combinations achieves the purpose of segmented stamping, avoiding uneven or excessive force on the pins.

Description

Technical Field

[0001] This invention relates to the field of stamping die technology, and in particular to a pin stamping die for a chip after plastic encapsulation. Background Technology

[0002] In the semiconductor packaging field, molded chips are created by encapsulating and sealing the bonded chip and lead frame with molding compounds such as epoxy resin to provide mechanical support and environmental protection. The leads of the lead frame remain exposed after molding, serving as the electrical interface between the chip and the external circuit board. To meet the requirements of surface mount technology (SMT) and other processes, the leads exposed in the molded assembly need to be processed, involving deburring, lead separation, and stamping steps, ultimately forming a chip like... Figure 16 The molded part shown has a standard foot type (zigzag type), in which a combination mold is used during the stamping process.

[0003] Existing pin stamping dies have several technical defects. First, current stamping dies are single-section, one-piece designs, forming two bending sections, which can easily cause uneven or excessive force on the pins, leading to pin deformation or breakage. Second, the molding compound lacks effective positioning, making it susceptible to pressure and vibration during stamping. Adding a separate positioning structure would increase the complexity of the entire die and the difficulty of operation. Third, excessively high stamping speeds can easily cause pin misalignment during downward bending or interference between numerous pins. Currently, there are no effective guiding measures to address these defects.

[0004] In summary, considering that existing facilities cannot meet the needs of operation, we propose a pin stamping die for chip molding. Summary of the Invention

[0005] The main objective of this invention is to provide a pin stamping die for chip molding, which can effectively solve the problems in the background art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A die for stamping pins after chip molding includes a die base. A flat groove is formed at the middle of the upper surface of the die base. A chip molding component is placed in the flat groove. The chip molding component includes several sets of symmetrical pins. The number of pins on each side is preferably 3-10 sets. Stamping grooves acting on the pins are symmetrically formed on the upper surface of the die base and on both sides of the flat groove. When the pins are straightened, they are laid on the top of the stamping grooves. A stationary angle mold and a stationary bevel mold acting on the pins are provided on the groove wall of the stamping groove.

[0007] As a preferred embodiment of the pin stamping mold for chip molding according to the present invention, the upper end face of the mold base is symmetrically riveted with side supports, the tops of the two sets of side supports are connected by a horizontal support, the inner side of each set of side supports is fixed with a limit step, two sets of drive shafts are distributed between the two sets of limit steps, the two ends of the drive shaft are respectively connected by a damping bearing seat and a side support, one end of the drive shaft extends out of the side support and is fitted with a reversing gear, the reversing gears on the two sets of drive shafts mesh with each other, and the end of one set of drive shafts away from the reversing gear is connected to a first servo motor through a coupling.

[0008] As a preferred embodiment of the pin stamping die for chip molding according to the present invention, wherein: a stamping gear is sleeved in the middle of each of the two sets of drive shafts, a stamping seat is movably arranged on the outer side of each set of stamping gears, a rack that meshes with the stamping gear is distributed on the inner side of the stamping seat, a track column groove is symmetrically opened at both ends of the stamping seat, an inclined guide column acting on the track column groove is installed on the inner side of the side support, and an upper die acting on the pin is connected to the bottom of each of the two sets of stamping seats, the upper die group includes a movable internal corner die, a movable oblique corner die, a movable external corner die and a horizontal static die.

[0009] As a preferred embodiment of the pin stamping mold for chip molding described in this invention, the following features: an inner pressure groove is provided at the lower position of the bottom of the track column groove; a corrugated telescopic air tube is movably arranged inside the inner pressure groove; the corrugated telescopic air tube is connected to the end of the inner pressure groove via a positioning connector; a pressure block acting on the corrugated telescopic air tube is fixed at the bottom of the inclined guide column; a connecting thin tube is connected to the outside of the positioning connector; the number of connecting thin tubes is preferably 2-3 sets; a stop airbag is connected to the connecting thin tube outward; an airbag receiving hole acting on the stop airbag is provided on the end face of the stamping seat; the stop airbag is connected to the hole wall of the airbag receiving hole via an airbag positioning sleeve; after the stop airbag is inflated by air, it extends out of the airbag receiving hole and acts on the inner side of the side support.

[0010] As a preferred embodiment of the pin stamping die for chip molding according to the present invention, each drive shaft is fitted with a large gear, which is located inside the gear sleeve. A small gear is meshed at the lower end of the large gear, and the small gear is fitted onto the transmission shaft. The transmission shaft is connected to the inner wall of the clutch driver through a bearing seat. The gear sleeve and the clutch driver are connected vertically. One end of the clutch driver is fixed to a limiting step. A centrifugal disc is installed at the end of the transmission shaft away from the bearing seat. Several sets of centrifugal blocks are movably arranged inside the centrifugal disc, and the number of centrifugal blocks is preferably 3-5 sets.

[0011] As a preferred embodiment of the pin stamping die for chip molding according to the present invention, wherein: a displacement plate is movably disposed directly below the centrifugal disc, the upper end of the displacement plate is provided with a curved extrusion surface that interacts with the centrifugal block, the displacement plate is movably disposed inside a vertical limiting seat connected to the bottom of the clutch driver, a positioning pressure rod is connected to the lower end of the displacement plate, the positioning pressure rod extends downward outside the vertical limiting seat, a limiting partition for the positioning pressure rod to pass through is riveted inside the vertical limiting seat, a return spring is disposed between the limiting partition and the displacement plate and sleeved on the outside of the positioning pressure rod, and a pressure foot is connected to the lower end of the positioning pressure rod by means of a rotary damping bearing, the pressure foot acting on the upper surface of the chip molding component.

[0012] As a preferred embodiment of the pin stamping mold for chip molding described in this invention, a double-ended lead screw is horizontally rotatably arranged in the middle position inside the mold base. Bearing assembly seats are symmetrically installed at both ends of the double-ended lead screw. A connecting gear is sleeved in the middle of the double-ended lead screw. A working gear is meshed at the lower end of the connecting gear. The working gear is sleeved on the output shaft of the second servo motor.

[0013] As a preferred embodiment of the pin stamping die for chip molding according to the present invention, the double-ended lead screw has symmetrically distributed forward and reverse spiral threads. An inverted L-shaped movable seat is movably arranged on both the forward and reverse spiral threads. A lead screw nut sleeve acting on the double-ended lead screw is installed in the middle of the inverted L-shaped movable seat. A semi-circular guide opening is symmetrically opened at the bottom of the inverted L-shaped movable seat. A horizontal guide rod passing through the semi-circular guide opening is fixed between the two sets of bearing assembly seats. A horizontal stamping die and a horizontal concave corner die are provided at the upper end of the inverted L-shaped movable seat. A straight inner slide groove, respectively connected to the stamping groove, is symmetrically opened inside the die base. The straight inner slide groove allows for partial horizontal extension of the inverted L-shaped movable seat.

[0014] As a preferred embodiment of the pin stamping mold for chip molding according to the present invention, the stamping groove is provided with a horizontally rotating flip shaft. The two ends of the flip shaft are connected to the groove wall of the stamping groove by an inner bearing seat, respectively. One end of the flip shaft is connected to a geared motor group. Two sets of flip arms are symmetrically welded on the flip shaft. A guide function shaft is rotatably provided between the ends of the two sets of flip arms. One end of the guide function shaft is connected to a constant speed motor through a coupling. Several sets of guide wheel assemblies acting on the pins are installed on the guide function shaft. The number of guide wheel assemblies is twice the number of pins. A flat keyway is opened in the middle of the guide wheel assembly for the guide function shaft to pass through. Several sets of pre-interference guide strips are evenly distributed near the pin end face of the guide wheel assembly. The number of pre-interference guide strips is preferably 3-6 sets. Each set of pre-interference guide strips is provided with a semi-circular arc surface.

[0015] This invention provides an improved pin stamping die for a chip after molding, which has the following significant improvements and advantages compared to the prior art: The stamping base presses downwards along the inclined guide post. The moving inclined die of the upper die group moves along the stationary inclined die, acting on the pin to cause the pin to bend for the first time. After stamping, the moving internal angle die and the stationary external angle die form an upper arc chamfer at the bend. The two sets of inverted L-shaped moving seats on the double-ended screw move towards each other. The linear motion of the horizontal stamping die acts on the lower half of the pin. In conjunction with the horizontal stationary die, the pin is bent for the second time. After stamping, the horizontal internal angle die and the moving external angle die form a lower arc chamfer at the bend. By using multiple die combinations, the purpose of segmented stamping is achieved, avoiding uneven force or excessive force on the pin, and the degree of automation is high.

[0016] During the relative motion, the pressure block compresses the corrugated telescopic air tube, causing the gas inside the corrugated telescopic air tube to be continuously injected into the stop airbag through the connecting thread. After the stop airbag is inflated, it partially extends out of the airbag storage hole and acts on the inner side of the side support to achieve auxiliary braking, achieve a buffering effect to avoid wear on the transmission components, solve the problems caused by sudden stops and brakes, and improve the guiding effect.

[0017] Powered by the drive shaft, the large gear rotates, while the meshing action causes the small gear to drive the transmission shaft to rotate at high speed. Several sets of centrifugal blocks inside the centrifugal disc perform centrifugal motion and extend out, acting on the curved extrusion surface of the displacement plate. This causes the displacement plate and positioning pressure rod to move downwards. The positioning pressure rod drives the pressure feet to press against the upper surface of the molded part. The four sets of pressure feet act on the four corners of the molded part, preventing vibration of the molded part during stamping and achieving automatic positioning. Furthermore, the pressure feet are flexible and reduce the difficulty of removing the part.

[0018] When the geared motor unit is working, it drives the tilting shaft to rotate slowly, causing the two tilting arms to carry the guide shaft to make a circular motion above the stamping groove. The pin is bent downward by the stamping force of the upper mold group. The tilting arm drives the guide wheel assembly to move towards the bending area, which plays a role in limiting and guiding, and also avoids interference between the pins. At the same time, the constant speed motor is started, which drives the guide shaft to rotate clockwise. Several sets of guide wheel assemblies rotate with it. The pre-interference guide strip acts symmetrically on both sides of the pin, causing it to deform slightly, achieving the purpose of precise pre-bending and significantly improving the effect of limiting and guiding. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of a pin stamping die for a chip after plastic encapsulation, according to the present invention. Figure 2 This is a schematic diagram of the lower end structure of the horizontal support of the present invention; Figure 3This is a schematic diagram of the transmission structure between the two sets of side supports of the present invention; Figure 4 This is a schematic diagram of the specific structure of the drive shaft of the present invention; Figure 5 This is a schematic diagram of the specific structure of the stamping seat of the present invention; Figure 6 This is a schematic diagram of the internal structure of the track column groove of the present invention; Figure 7 This is a schematic diagram of the connection of the stop airbag of the present invention; Figure 8 This is a schematic diagram of the specific structure of the drive shaft of the present invention; Figure 9 This is a schematic diagram of the connection of the positioning pressure rod of the present invention; Figure 10 This is a schematic diagram of the specific structure of the stamping groove of the present invention; Figure 11 This is a schematic diagram of the transmission structure of the double-ended lead screw of the present invention; Figure 12 This is a schematic diagram of the specific structure of the inverted L-shaped movable seat of the present invention; Figure 13 This is a schematic diagram of the installation position of the flip shaft in Embodiment 2 of the present invention; Figure 14 This is a schematic diagram of the connection structure of the flip shaft of the present invention; Figure 15 This is a schematic diagram of the specific structure of the guide wheel assembly of the present invention; Figure 16 This is a schematic diagram of the pin molding structure of the present invention.

[0020] In the diagram: 1. Mold base; 2. Flat slot; 3. Chip molding compound; 4. Pin; 5. Stamping slot; 6. Static external corner mold; 7. Static oblique angle mold; 10. Side support; 11. Horizontal support; 12. Limiting step; 13. Drive shaft; 14. Damping bearing seat; 15. Reversing gear; 16. First servo motor; 17. Stamping gear; 18. Angled guide post; 19. Pressure block; 20. Stamping seat; 21. Rack; 22. Upper mold; 23. Moving internal corner mold; 24. Moving oblique angle mold; 25. Moving external corner mold; 26. Horizontal static mold; 27. 30. Track column groove; 31. Inner pressure groove; 32. Corrugated telescopic air tube; 33. Positioning joint; 34. Connecting thin tube; 35. Airbag positioning sleeve; 36. Stop airbag; 47. Airbag storage hole; 48. Gear sleeve; 49. Clutch actuator; 40. Vertical limit seat; 41. Large gear; 42. Small gear; 43. Drive shaft; 44. Bearing seat; 45. Centrifuge disc; 46. Centrifuge block; 57. Displacement plate; 58. Curved extrusion surface; 59. Positioning pressure rod; 50. Limiting partition; 51. Return spring; 52. Pressure foot; 53. Rotary damping bearing; 60. Double-ended lead screw; 61. Bearing assembly seat; 62. Connecting gear; 63. Working gear; 64. Second servo motor; 65. Forward spiral pattern; 66. Reverse spiral pattern; 67. Horizontal guide rod; 70. Inverted L-shaped moving seat; 71. Lead screw nut sleeve; 72. Semi-circular guide opening; 73. Horizontal stamping die; 74. Horizontal internal corner die; 75. Straight inner slide groove; 80. Tilting shaft; 81. Inner bearing seat; 82. Gear motor assembly; 83. Tilting arm; 90. Guide function shaft; 91. Uniform speed motor; 92. Guide wheel assembly; 93. Flat keyway; 94. Pre-interference guide bar; 95. Semi-circular arc surface. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0022] like Figures 1-12 As shown, this embodiment provides a pin stamping mold for chip molding, including a mold base 1. A flat groove 2 is provided at the middle position of the upper end surface of the mold base 1. A chip molding component 3 is placed in the flat groove 2. The two are of the same size. The chip molding component 3 includes several sets of symmetrical pins 4. A stamping groove 5 acting on the pins 4 is symmetrically provided on the upper end surface of the mold base 1 and on both sides of the flat groove 2. When the pins 4 are straightened, they are laid on the top of the stamping groove 5 and fit perfectly with the top of the groove.

[0023] The stamping groove 5 has a stationary angle mold 6 and a stationary bevel mold 7 on its groove wall, which act on the pin 4. The stationary angle mold 6 and the stationary bevel mold 7 are smoothly connected, and the stationary angle mold 6 is flush with the top of the stamping groove 5. Figures 1-3 , Figure 10 As shown.

[0024] Furthermore, the upper end face of the mold base 1 is symmetrically riveted with side supports 10. The tops of the two sets of side supports 10 are connected by horizontal supports 11 for reinforcement. The inner surface of each set of side supports 10 is fixed with a limiting step 12, and two sets of drive shafts 13 are distributed between the two sets of limiting steps 12. Figure 2 and Figure 3 As shown.

[0025] Specifically, the two ends of the drive shaft 13 are connected by a damping bearing housing 14 and a side support 10, respectively. One end of the drive shaft 13 extends out of the side support 10 and is fitted with a reversing gear 15. The reversing gears 15 on the two sets of drive shafts 13 mesh with each other. The end of one set of drive shafts 13 away from the reversing gear 15 is connected to a first servo motor 16 via a coupling. Figures 2-4 As shown.

[0026] In this configuration, a stamping gear 17 is sleeved in the middle of each of the two sets of drive shafts 13. A stamping seat 20 is movably mounted on the outer side of each set of stamping gears 17. Racks 21 meshing with the stamping gears 17 are distributed on the inner surface of the stamping seat 20. Track grooves 27 are symmetrically formed at both ends of the stamping seat 20. An inclined guide post 18 acting on the track groove 27 is mounted on the inner surface of the side support 10. The two components are shaped to fit together. The cross-sectional shape and inclination of the inclined guide post 18 are designed according to actual requirements, such as... Figures 2-5 As shown.

[0027] The bottom of each of the two sets of stamping bases 20 is connected to an upper die 22 that acts on the pin 4. The upper die set 22 includes a movable internal corner die 23, a movable oblique corner die 24, a movable external corner die 25, and a horizontal static die 26, which are connected sequentially from top to bottom, as follows: Figure 5 and Figure 6 As shown.

[0028] In this embodiment, an inner pressure groove 30 is formed at the lower part of the bottom of the track column groove 27. A corrugated telescopic air pipe 31 is movably arranged inside the inner pressure groove 30. The corrugated telescopic air pipe 31 has telescopic and reset properties. The corrugated telescopic air pipe 31 is connected to the end of the inner pressure groove 30 via a positioning joint 32. A pressure block 19 acting on the corrugated telescopic air pipe 31 is fixed at the bottom of the inclined guide column 18. The pressure block 19 slides within the inner pressure groove 30, limiting its movement. Figure 3 and Figure 6 As shown.

[0029] The positioning connector 32 is externally connected to two sets of connecting thin tubes 33. Each connecting thin tube 33 extends outward and connects to a stop airbag 35. The stop airbag 35 has deformation recovery capability and is made of wear-resistant material. The end face of the stamping seat 20 has an airbag receiving hole 36 for receiving the stop airbag 35. In its natural state, the stop airbag 35 does not extend out of the airbag receiving hole 36. The stop airbag 35 is connected to the hole wall of the airbag receiving hole 36 via an airbag positioning sleeve 34. After the stop airbag 35 is inflated, it extends out of the airbag receiving hole 36 and acts on the inner side of the side support 10. After losing its restraint, it retracts back into its original position. Figure 6 and Figure 7 As shown.

[0030] Furthermore, each drive shaft 13 is fitted with a large gear 43, which is located inside the gear sleeve 40. A small gear 44 meshes with the lower end of the large gear 43 and is fitted onto the drive shaft 45. Figure 4 and Figure 8 As shown.

[0031] The drive shaft 45 is connected to the inner wall of the clutch actuator 41 via the bearing housing 46. The gear sleeve 40 is connected vertically to the clutch actuator 41. One end of the clutch actuator 41 is fixed to the limiting step 12. A centrifugal disc 47 is installed at the end of the drive shaft 45 away from the bearing housing 46. Several sets of centrifugal blocks 48 are movably arranged outward inside the centrifugal disc 47, adopting a conventional centrifugal structure, such as... Figure 4 , Figure 8 and Figure 9 As shown.

[0032] Furthermore, a displacement plate 50 is movably disposed directly below the centrifugal disc 47. The upper end of the displacement plate 50 has a curved pressing surface 51 that interacts with the centrifugal blocks 48. The width of the curved pressing surface 51 is much larger than the distance between adjacent centrifugal blocks 48. The displacement plate 50 is movably disposed inside the vertical limiting seat 42 connected to the bottom of the clutch actuator 41. The lower end of the displacement plate 50 is connected to a positioning pressure rod 52. Figure 8 and Figure 9 As shown.

[0033] Specifically, the positioning pressure rod 52 extends downward beyond the vertical limiting seat 42. A limiting partition 53, through which the positioning pressure rod 52 passes, is riveted inside the vertical limiting seat 42. The limiting partition 53 serves as a limiting and guiding element. A return spring 54, sleeved on the outside of the positioning pressure rod 52, is provided between the limiting partition 53 and the displacement plate 50. The return spring 54 maintains the contact force between the curved extrusion surface 51 and the centrifugal block 48. The lower end of the positioning pressure rod 52 is connected to a pressure foot 55 via a rotary damping bearing 56. The rotary damping bearing 56 provides a certain damping force to prevent rotation. The pressure foot 55 partially acts on the upper surface of the chip encapsulation component 3, such as... Figure 3 , Figure 8 and Figure 9 As shown.

[0034] Furthermore, a double-ended lead screw 60 is horizontally rotatably mounted at the center of the mold base 1. Bearing assembly seats 61 are symmetrically mounted at both ends of the double-ended lead screw 60. A connecting gear 62 is sleeved in the middle of the double-ended lead screw 60, and a working gear 63 is meshed at the lower end of the connecting gear 62. The working gear 63 is sleeved on the output shaft of the second servo motor 64. Figure 10 As shown.

[0035] The double-ended lead screw 60 has symmetrically distributed forward spiral threads 65 and reverse spiral threads 66. Both the forward spiral threads 65 and reverse spiral threads 66 are movably mounted with inverted L-shaped movable seats 70. A lead screw nut sleeve 71 (containing a helical nut) is installed in the middle of the inverted L-shaped movable seat 70, acting on the double-ended lead screw 60. The bottom of the inverted L-shaped movable seat 70 has symmetrically opened semi-circular guide openings 72. A horizontal guide rod 67 passing through the semi-circular guide opening 72 is fixed between the two sets of bearing assembly seats 61. The relative movement of the two guide rods serves a guiding function. Figure 11 and Figure 12 As shown.

[0036] In this embodiment, the upper end of the inverted L-shaped movable seat 70 is provided with a horizontal stamping die 73 and a horizontal internal corner die 74. The interior of the die base 1 is symmetrically provided with straight inner sliding grooves 75, each communicating with the stamping groove 5. These straight inner sliding grooves 75 allow partial horizontal extension of the inverted L-shaped movable seat 70, serving as a limiting and guiding function. Figure 12 As shown.

[0037] In this embodiment, the chip molding compound 3 is first placed into the flat slot 2, with the dimensions matching, and several sets of horizontal pins 4 are placed against the top of the stamping slot 5. The first servo motor 16 is started, driving one set of drive shafts 13 to rotate. Through the meshing of the reversing gear 15, the other set of drive shafts 13 rotates synchronously in the opposite direction. The stamping gears 17 on the two sets of drive shafts 13 rotate accordingly. Through the meshing with the rack 21, the stamping seat 20 is pressed obliquely downward along the inclined guide post 18. The moving oblique angle mold 24 of the upper mold group 22 moves along the stationary oblique angle mold 7, acting on the pins 4, causing the pins 4 to undergo the first stamping bend. After stamping, the moving internal angle mold 23 cooperates with the stationary external angle mold 6 to form an upper arc chamfer at the bend.

[0038] Then, the second servo motor 64 is started, and the working gear 63 rotates. Through meshing with the connecting gear 62, the double-ended lead screw 60 rotates. The two sets of inverted L-shaped moving seats 70 on the double-ended lead screw 60 move towards each other (the lead screw nut sleeve 71 and the forward spiral thread 65 and the reverse spiral thread 66 act in opposite directions respectively). The inverted L-shaped moving seats 70 move along the straight inner slide groove 75 and extend into the stamping groove 5. The horizontal stamping die 73 acts linearly on the lower half of the pin 4. With the help of the horizontal flat die 26, the pin 4 undergoes a second stamping bend. The horizontal inner corner die 74 of the stamping section, in conjunction with the moving outer corner die 25, forms a lower arc chamfer at the bend, and finally forms a shape like... Figure 16 The shape of pin 4 shown enables automatic pin stamping.

[0039] When the stamping seat 20 presses downwards along the inclined guide post 18 and enters the tail section to prepare for parking, the pressure block 19 enters from the lower end of the inner pressure groove 30. During the relative movement, the pressure block 19 compresses the corrugated telescopic air tube 31, so that the gas inside the corrugated telescopic air tube 31 is continuously injected into the stop airbag 35 through the connecting thin tube 33. After the stop airbag 35 is inflated, it partially extends out of the airbag storage hole 36 and acts on the inner side of the side support 10 to achieve auxiliary braking and achieve a buffering effect to avoid wear of the transmission components.

[0040] When the two sets of drive shafts 13 rotate, the large gear 43 on the drive shaft 13 rotates accordingly. At the same time, through meshing, the small gear 44 drives the transmission shaft 45 to rotate at high speed, causing the clutch driver 41 to work. Several sets of centrifugal blocks 48 in the centrifugal disc 47 perform centrifugal motion and extend out, acting on the curved pressing surface 51 of the displacement plate 50, causing the displacement plate 50 and the positioning pressure rod 52 to move downward (the return spring 54 is compressed). The positioning pressure rod 52 drives the pressure foot 55 to press on the upper end surface of the chip molded part 3. The four sets of pressure feet 55 act on the four corners of the chip molded part 3 respectively to prevent the chip molded part 3 from vibrating during stamping. When the drive shaft 13 stops rotating, the centrifugal blocks 48 on the clutch driver 41 return inward. The return spring 54 uses the return elastic force to drive the positioning pressure rod 52 to return upward. The pressure foot 55 leaves the upper end surface of the chip molded part 3. After the pressure foot 55 rotates around the rotation damping bearing 56, the chip molded part 3 can be removed. Example 2

[0041] Based on Embodiment 1, when pin 4 bends for the first time, due to the lack of limiting during the stamping process, excessively fast stamping speed can easily cause the lower half to deviate from the predetermined position and direction, and also cause mutual interference between pins. To solve the above technical problems, a rotating shaft 80 is provided for horizontal rotation of the stamping groove 5. The two ends of the rotating shaft 80 are connected to the groove wall of the stamping groove 5 by the inner bearing seat 81, respectively. Figures 13-15 As shown.

[0042] Specifically, one end of the tilting shaft 80 is connected outward to a geared motor assembly 82, which includes a drive motor and a reducer. Two sets of tilting arms 83 are symmetrically welded onto the tilting shaft 80. A guide shaft 90 is rotatably connected between the ends of the two sets of tilting arms 83. One end of the guide shaft 90 is connected to a constant speed motor 91 via a coupling. Figure 13 and Figure 14 As shown.

[0043] The guide shaft 90 is equipped with several sets of guide wheel assemblies 92 that act on the pin 4, symmetrically distributed on both sides of the pin 4. A flat keyway 93 is provided in the middle of each guide wheel assembly 92 for the guide shaft 90 to pass through. Several sets of pre-interference guide strips 94 are evenly distributed on the end face of the guide wheel assembly 92 near the pin 4. The pre-interference guide strips 94 slightly protrude from the end face of the pin 4. Each set of pre-interference guide strips 94 has a semi-circular arc surface 95, all facing the clockwise direction. The semi-circular arc surface 95 guides and acts on the pin 4, such as... Figure 14 and Figure 15 As shown.

[0044] In this embodiment, when the upper mold assembly 22 approaches the pin 4 during the stamping process, the reduction motor assembly 82 is activated, driving the flipping shaft 80 to rotate slowly. This causes the two sets of flipping arms 83, carrying the guide shaft 90, to perform circular motion above the stamping groove 5 until several sets of guide wheel assemblies 92 contact the pin 4. The pin 4 is bent downward by the stamping force of the upper mold assembly 22. The flipping arms 83 drive the guide wheel assemblies 92 to move towards the bending area, playing a limiting and guiding role. At the same time, the uniform speed motor 91 is activated, driving the guide shaft 90 to rotate clockwise. Several sets of guide wheel assemblies 92 rotate with it. The pre-interference guide strip 94 acts symmetrically on both sides of the pin 4, causing it to deform slightly, achieving the purpose of precise pre-bending. As the pin 4 bends further downward, the guide wheel assemblies 92 separate from the pin 4. The flipping arms 83 drive the guide shaft 90 to move to the side away from the inverted L-shaped moving seat 70, avoiding interference with the subsequent horizontal stamping process of the mold assembly.

[0045] All structural components disclosed in the embodiments need to be adjusted in size and shape according to the actual installation environment, and are not limited to the styles disclosed in the drawings. Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

[0046] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

Claims

1. A pin stamping die for a chip after molding, comprising a die base (1), characterized in that: A flat groove (2) is provided at the middle position of the upper end face of the mold base (1). A chip molding compound (3) is placed in the flat groove (2). The chip molding compound (3) includes several sets of symmetrical pins (4). A stamping groove (5) acting on the pins (4) is symmetrically provided on the upper end face of the mold base (1) and on both sides of the flat groove (2). When the pins (4) are straightened, they are laid on the top of the stamping groove (5). A static positive angle mold (6) and a static oblique angle mold (7) acting on the pins (4) are provided on the groove wall of the stamping groove (5). A double-ended lead screw (60) is horizontally rotatably mounted in the middle of the mold base (1). Bearing assembly seats (61) are symmetrically mounted at both ends of the double-ended lead screw (60). A connecting gear (62) is sleeved in the middle of the double-ended lead screw (60). A working gear (63) is meshed at the lower end of the connecting gear (62). The working gear (63) is sleeved on the output shaft of the second servo motor (64). A forward spiral pattern (65) and a reverse spiral pattern (66) are symmetrically distributed on the double-ended lead screw (60). An inverted L-shaped movable seat (70) is movably mounted on both the forward spiral pattern (65) and the reverse spiral pattern (66). The inverted L-shaped movable seat (70) is equipped with a screw nut sleeve (71) that acts on the double-ended screw (60) in the middle. The bottom of the inverted L-shaped movable seat (70) is symmetrically provided with a semi-circular guide opening (72). A horizontal guide rod (67) passing through the semi-circular guide opening (72) is fixed between the two sets of bearing assembly seats (61). The upper end of the inverted L-shaped movable seat (70) is provided with a horizontal stamping die (73) and a horizontal inside corner die (74). The mold base (1) is symmetrically provided with straight inner slide grooves (75) that are connected to the stamping groove (5). The straight inner slide grooves (75) allow the inverted L-shaped movable seat (70) to extend horizontally in a partial manner.

2. The pin stamping die for a chip after plastic encapsulation according to claim 1, characterized in that: The upper end of the mold base (1) is symmetrically riveted with side supports (10). The tops of the two sets of side supports (10) are connected by a horizontal support (11). The inner side of each set of side supports (10) is fixed with a limiting step (12). Two sets of drive shafts (13) are distributed between the two sets of limiting steps (12). The two ends of the drive shafts (13) are connected to the side supports (10) by a damping bearing seat (14) respectively. One end of the drive shaft (13) extends out of the side support (10) and is fitted with a reversing gear (15). The reversing gears (15) on the two sets of drive shafts (13) mesh with each other. The end of one set of drive shafts (13) away from the reversing gear (15) is connected to a first servo motor (16) through a coupling.

3. The pin stamping die for a chip after plastic encapsulation according to claim 2, characterized in that: Both sets of drive shafts (13) are fitted with stamping gears (17) in the middle. Each set of stamping gears (17) is movably provided with a stamping seat (20) on the outer side. The inner side of the stamping seat (20) is provided with racks (21) that mesh with the stamping gears (17). The two ends of the stamping seat (20) are symmetrically provided with track column grooves (27). The inner side of the side support (10) is provided with inclined guide columns (18) that act on the track column grooves (27). The bottom of both sets of stamping seats (20) is connected with upper molds (22) that act on the pins (4). The upper mold group (22) includes a moving internal corner mold (23), a moving oblique corner mold (24), a moving external corner mold (25), and a horizontal flat mold (26), which are connected in sequence from top to bottom.

4. The pin stamping die for a chip after plastic encapsulation according to claim 3, characterized in that: An inner pressure groove (30) is provided at the lower part of the bottom of the track column groove (27). A corrugated telescopic air pipe (31) is movably arranged inside the inner pressure groove (30). The corrugated telescopic air pipe (31) is connected to the end of the inner pressure groove (30) by a positioning joint (32). A pressure block (19) acting on the corrugated telescopic air pipe (31) is fixed at the bottom of the inclined guide column (18).

5. The pin stamping die for a chip after plastic encapsulation according to claim 4, characterized in that: Two sets of connecting tubes (33) are connected to the outside of the positioning connector (32). The connecting tubes (33) extend outward to connect to the stop airbag (35). The end face of the stamping seat (20) is provided with an airbag storage hole (36) for storing the stop airbag (35). The stop airbag (35) is connected to the hole wall of the airbag positioning sleeve (34) and the airbag storage hole (36). After the stop airbag (35) is inflated, it expands out of the airbag storage hole (36) and acts on the inner side of the side support (10).

6. The pin stamping die for a chip after plastic encapsulation according to claim 2, characterized in that: Each drive shaft (13) is fitted with a large gear (43), which is located inside the gear sleeve (40). The lower end of the large gear (43) is meshed with a small gear (44), which is fitted onto the transmission shaft (45). The transmission shaft (45) is connected to the inner wall of the clutch driver (41) through the bearing seat (46). The gear sleeve (40) and the clutch driver (41) are connected vertically. One end of the clutch driver (41) is fixed to the limiting step (12). A centrifugal disc (47) is installed at the end of the transmission shaft (45) away from the bearing seat (46). Several sets of centrifugal blocks (48) are movably arranged inside the centrifugal disc (47).

7. The pin stamping die for a chip after plastic encapsulation according to claim 6, characterized in that: A displacement plate (50) is movably disposed directly below the centrifugal disc (47). The upper end of the displacement plate (50) is provided with a curved extrusion surface (51) that interacts with the centrifugal block (48). The displacement plate (50) is movably disposed inside a vertical limiting seat (42) connected to the bottom of the clutch driver (41). A positioning pressure rod (52) is connected to the lower end of the displacement plate (50). The positioning pressure rod (52) extends downward beyond the vertical limiting seat (42).

8. The pin stamping die for a chip after plastic encapsulation according to claim 7, characterized in that: The vertical limiting seat (42) is riveted with a limiting partition (53) through which the positioning pressure rod (52) passes. A return spring (54) is sleeved on the outside of the positioning pressure rod (52) between the limiting partition (53) and the displacement plate (50). The lower end of the positioning pressure rod (52) is connected to a pressure foot (55) by a rotary damping bearing (56). The pressure foot (55) acts on the upper surface of the chip encapsulation (3).

9. The pin stamping die for a chip after plastic encapsulation according to claim 1, characterized in that: The stamping groove (5) is provided with a horizontal rotating rotating shaft (80). The two ends of the rotating shaft (80) are connected to the groove wall of the stamping groove (5) by the inner bearing seat (81) respectively. One end of the rotating shaft (80) is connected to the geared motor group (82) outward. Two sets of rotating arms (83) are symmetrically welded on the rotating shaft (80). A guide function shaft (90) is rotatably provided between the ends of the two sets of rotating arms (83). One end of the guide function shaft (90) is connected to a uniform speed motor (91) through a coupling.

10. The pin stamping die for a chip after plastic encapsulation according to claim 9, characterized in that: The guide functional shaft (90) is equipped with several sets of guide wheel assemblies (92) that act on the pin (4). The guide wheel assembly (92) has a flat keyway (93) in the middle for the guide functional shaft (90) to pass through. Several sets of pre-interference guide strips (94) are evenly distributed on one end face of the guide wheel assembly (92) near the pin (4). Each set of pre-interference guide strips (94) is provided with a semi-circular arc surface (95).

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