A chip encapsulation machine

Abstract

This utility model relates to a chip encapsulation machine, which includes a frame, an upper injection mold, a lower injection mold, a timer, a first drive mechanism, and a second drive mechanism. When the lower injection mold rises to a first position, it closes relative to the upper injection mold to form a cavity between them. When the lower injection mold descends to a second position, it opens relative to the upper injection mold. The lower injection mold is equipped with a barrel communicating with the cavity and an injection rod piston disposed within the barrel. The second drive mechanism drives the injection rod piston to move along the centerline of the barrel to a third position to extrude epoxy resin from the barrel into the cavity under a first pressure. The second drive mechanism also drives the injection rod piston to move along the centerline of the barrel to a fourth position to extrude epoxy resin from the barrel into the cavity under a second pressure. The third pressure is less than the fourth pressure. This utility model can effectively reduce the bending amplitude of the connecting wires inside the chip, thereby improving product quality.

Description

Technical Field

[0001] This utility model relates to the field of chip encapsulation technology, and in particular to a chip encapsulation machine. Background Technology

[0002] Chip molding is a crucial step in semiconductor application technology. Molding encapsulates bare chip dies and connecting wires in plastic material through flow encapsulation, isolating them from the external environment and thus protecting and securing the chip.

[0003] Existing chip encapsulation machines include a frame and an injection mold. The injection mold has an upper injection mold and a lower injection mold, which can be closed or opened relative to each other. When the upper and lower injection molds are closed, a cavity is formed between them to accommodate the chip to be encapsulated. The chip encapsulation machine also includes a barrel communicating with the cavity and an injection rod piston disposed within the barrel; the injection rod piston moves along the centerline of the barrel to extrude molten epoxy resin into the cavity at a set pressure.

[0004] When epoxy resin melts, it flows in the mold cavity in a fluid form. The material itself has viscosity, which may cause the connecting wires on the chip to be molded to be bent during the flow process. Especially when the connecting wires inside the chip are relatively dense and the injection pressure required by the process is high, the degree of bending of the wires may exceed the quality requirements, resulting in product scrap. Utility Model Content

[0005] In view of this, the present invention provides a chip encapsulation machine, the main technical problem to be solved is: how to reduce the bending of the connecting wires on the chip during the encapsulation process.

[0006] To achieve the above objectives, this utility model mainly provides the following technical solutions:

[0007] An embodiment of this utility model provides a chip molding machine, which includes a frame, an upper injection mold, a lower injection mold, a timer, a first drive mechanism, and a second drive mechanism; the upper injection mold is fixed on the frame, and the lower injection mold is movably mounted on the frame via a lifting platform;

[0008] The first driving mechanism is used to drive the lifting platform to move, so that the lifting platform drives the lower injection mold to rise to a first position or fall to a second position; wherein, when the lower injection mold rises to the first position, it closes relative to the upper injection mold to form a cavity for accommodating the chip to be molded between the upper injection mold and the lower injection mold; when the lower injection mold falls to the second position, it opens relative to the upper injection mold.

[0009] The lower injection mold is provided with a barrel communicating with the cavity and an injection rod piston disposed within the barrel; the second driving mechanism is used to drive the injection rod piston to move along the centerline of the barrel to a third position, so as to squeeze the epoxy resin in the barrel into the cavity with a first pressure; the second driving mechanism is also used to drive the injection rod piston to move along the centerline of the barrel to a fourth position, so as to squeeze the epoxy resin in the barrel into the cavity with a second pressure; wherein, the third pressure is less than the fourth pressure;

[0010] The timer is used to time the dwell time of the injection rod piston in the third position.

[0011] In some embodiments, the second drive mechanism includes a first motor, which drives the injection rod piston to move along the centerline of the barrel to the third position and the fourth position via the first motor.

[0012] The chip encapsulation machine also includes a controller, which is connected to both the timer and the first motor.

[0013] In some embodiments, the lifting platform is provided with an injection lifting seat, and the injection rod piston is disposed on the injection lifting seat so as to move along the center line of the barrel to the third position and the fourth position under the drive of the injection lifting seat;

[0014] The second drive mechanism includes a first lead screw and nut structure and a second lead screw and nut structure. The lead screw of the first lead screw and nut structure is fixed at one end of the injection lifting seat, and the lead screw of the second lead screw and nut structure is fixed at the other end of the injection lifting seat.

[0015] Both the first and second lead screw nut structures have rotatable nut seats mounted on the lifting platform. A first synchronous pulley is fixed to the nut seat of the first lead screw nut structure, and a second synchronous pulley is fixed to the nut seat of the second lead screw nut structure. The first and second synchronous pulleys are connected by a synchronous belt drive. The first motor drives the first synchronous pulley to rotate, thereby causing the nut seat of the first lead screw nut structure to rotate. The first synchronous pulley drives the second synchronous pulley to rotate via the synchronous belt, causing the second synchronous pulley to drive the nut seat of the second lead screw nut structure to rotate.

[0016] In some embodiments, the second drive mechanism further includes an idler wheel and a transmission gear meshing with the idler wheel. The timing belt passes around the idler wheel. The first motor drives the transmission gear to rotate, causing the transmission gear to drive the idler wheel to rotate. When the idler wheel is driven to rotate, it drives the first timing pulley to rotate via the timing belt.

[0017] In some embodiments, the first drive mechanism includes a second motor, a third lead screw and nut structure, and a connecting rod structure. The connecting rod structure includes a first connecting rod, a second connecting rod, and a third connecting rod. One end of the first connecting rod is rotatably mounted on the frame, and the other end of the first connecting rod is hinged to one end of the second connecting rod. The other end of the second connecting rod is hinged to the lifting platform.

[0018] The lead screw of the third lead screw nut structure is rotatably mounted on the frame. One end of the third connecting rod is hinged to the nut seat of the third lead screw nut structure, and the other end of the third connecting rod is hinged to the middle of the first connecting rod. The second motor is used to drive the lead screw of the third lead screw nut structure to rotate, thereby driving the nut seat of the third lead screw nut structure to rise and fall, so that the third connecting rod drives the first connecting rod to rotate. When the first connecting rod is driven to rotate, it drives the injection mold to rise to the first position or fall to the second position through the second connecting rod.

[0019] In some embodiments, there are two connecting rod structures, which are symmetrically arranged at both ends of the lower side of the lifting platform.

[0020] By employing the above technical solution, the chip encapsulation machine of this utility model has at least the following beneficial effects:

[0021] The second driving mechanism of this invention drives the injection rod piston to perform segmented movements. Initially, a lower pressure (first pressure) is used to inject epoxy resin into the cavity, filling it completely. Then, a higher final pressure (second pressure) is used to compact the epoxy resin filling the cavity. This process reduces the impact of the epoxy resin on the connecting wires on the chip due to the lower initial injection pressure, thus reducing wire bending. After a preset time, the epoxy resin has partially cured. The final pressure then compacts the epoxy resin filling the cavity. The partially cured epoxy resin provides protection, further reducing the impact of the later, higher injection pressure on the connecting wires. This effectively reduces the bending of the connecting wires within the chip while meeting process requirements, thereby improving product quality.

[0022] The above description is only an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a chip encapsulation machine provided in one embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram showing the connection between the lifting seat and the injection rod piston;

[0026] Figure 3 This is a schematic diagram illustrating the connection between the third lead screw nut structure and the connecting rod structure.

[0027] Reference numerals: 1. Frame; 2. Upper injection mold; 3. Lower injection mold; 4. Lifting platform; 5. Lifting seat; 6. Injection rod piston; 8. First lead screw and nut structure; 9. Second lead screw and nut structure; 10. Third lead screw and nut structure; 11. Connecting rod structure; 81. Lead screw of the first lead screw and nut structure; 82. First synchronous pulley; 91. Lead screw of the second lead screw and nut structure; 92. Second synchronous pulley; 101. Lead screw of the third lead screw and nut structure; 102. Nut seat of the third lead screw and nut structure; 111. First connecting rod; 112. Second connecting rod; 113. Third connecting rod. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0030] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0031] like Figure 1-3 As shown in the figure, one embodiment of the present invention provides a chip encapsulation machine, which includes a frame 1, an upper injection mold 2, a lower injection mold 3, a timer, a first drive mechanism, and a second drive mechanism. The upper injection mold 2 is fixed on the frame 1, and the lower injection mold 3 is vertically and flexibly mounted on the frame 1 via a lifting platform 4.

[0032] The first drive mechanism drives the lifting platform 4 to move, causing the lower injection mold 3 to rise to a first position or fall to a second position. When the lower injection mold 3 rises to the first position, it closes relative to the upper injection mold 2, forming a cavity between the upper and lower injection molds to accommodate the chip to be molded. The chip to be molded may also be referred to as a lead frame in some contexts. When the lower injection mold 3 falls to the second position, it opens relative to the upper injection mold 2 to facilitate demolding of the molded chip.

[0033] The aforementioned injection mold 3 is equipped with a barrel communicating with the cavity and an injection rod piston 6 disposed within the barrel. A second drive mechanism drives the injection rod piston 6 to move along the centerline of the barrel to a third position, thereby extruding epoxy resin from the barrel into the cavity under a first pressure. The second drive mechanism also drives the injection rod piston 6 to move along the centerline of the barrel to a fourth position, thereby extruding epoxy resin from the barrel into the cavity under a second pressure. The third pressure is less than the fourth pressure. The aforementioned timer is used to time the dwell time of the injection rod piston 6 at the third position.

[0034] In the above example, when encapsulating the chip, the chip to be encapsulated is first placed into the cavity, and epoxy resin is placed into the barrel. Then, the first drive mechanism drives the lifting platform 4 to move, so that the lifting platform 4 drives the lower injection mold 3 to rise to the first position, so that the lower injection mold 3 and the upper injection mold 2 can close. Then, the second drive mechanism first drives the injection rod piston 6 to move along the center line of the barrel to the aforementioned third position, so as to squeeze the epoxy resin in the barrel into the cavity with the first pressure. The timer counts the dwell time of the injection rod piston 6 in the third position. After a preset time, the second drive mechanism drives the injection rod piston 6 to move along the center line of the barrel to the aforementioned fourth position, so as to squeeze the epoxy resin in the barrel into the cavity with the second pressure.

[0035] The aforementioned second driving mechanism drives the injection rod piston 6 in segmented motion. Initially, a lower pressure (first pressure) is used to fill the cavity with epoxy resin. Then, a higher final pressure (second pressure) is used to compact the epoxy resin filling the cavity. This process reduces the impact of the epoxy resin on the connecting wires on the chip due to the lower initial injection pressure, thus reducing wire bending. After a preset time, the epoxy resin has partially cured. The final pressure then compacts the epoxy resin filling the cavity. The partially cured epoxy resin provides protection, reducing the impact of the later, higher injection pressure on the connecting wires. This effectively reduces the bending of the connecting wires within the chip while meeting process requirements, thereby improving product quality.

[0036] It should be noted that the aforementioned injection rod piston 6 may also be referred to as an injection rod in some contexts. The aforementioned barrel is equipped with a heating device to heat the epoxy resin inside, causing the epoxy resin to melt.

[0037] In some embodiments, the aforementioned second drive mechanism includes a first motor, which drives the injection rod piston 6 to move along the centerline of the barrel to the aforementioned third and fourth positions. The chip encapsulation machine also includes a controller, which is connected to both the timer and the first motor.

[0038] In the example above, the controller first controls the first motor to drive the injection rod piston 6 to move along the centerline of the barrel to the aforementioned third position, so as to extrude the epoxy resin in the barrel into the cavity with a first pressure. Then, the controller controls the first motor to stop running, so that the injection rod piston 6 stays at the third position. The timer counts the time the injection rod piston 6 stays at the third position. After the preset time is reached, the timer sends a signal to the controller. The controller controls the first motor to drive the piston to move along the centerline of the barrel to the aforementioned fourth position according to the timer signal, so as to extrude the epoxy resin in the barrel into the cavity with a second pressure.

[0039] The controller, timer, and first motor work together to automatically control the movement of the injection rod piston 6, thus saving manpower and improving control efficiency.

[0040] In some implementations, such as Figure 2 As shown, the aforementioned lifting platform 4 can be equipped with an injection lifting seat 5, and the aforementioned injection rod piston 6 is mounted on the injection lifting seat 5. Driven by the injection lifting seat 5, the injection rod piston 6 moves along the centerline of the barrel to the aforementioned third and fourth positions. The second drive mechanism includes a first lead screw and nut structure 8 and a second lead screw and nut structure 9. The lead screw 81 of the first lead screw and nut structure is fixed to one end of the injection lifting seat 5, and the lead screw 91 of the second lead screw and nut structure is fixed to the other end of the injection lifting seat 5. The nut seats of both the first lead screw and nut structure 8 and the second lead screw and nut structure 9 are rotatably mounted on the lifting platform 4. A first synchronous pulley 82 is fixed to the nut seat of the first lead screw and nut structure 8, and the centerline of the first synchronous pulley 82 coincides with the centerline of the lead screw 81 of the first lead screw and nut structure. A second synchronous pulley 92 is fixed to the nut seat of the second lead screw and nut structure 9, and the centerline of the second synchronous pulley 92 coincides with the centerline of the lead screw 91 of the second lead screw and nut structure. The first synchronous pulley 82 and the second synchronous pulley 92 are connected by a synchronous belt drive. The aforementioned first motor is used to drive the first synchronous pulley 82 to rotate, thereby causing the nut seat of the first lead screw nut structure 8 to rotate. The first synchronous pulley 82 drives the second synchronous pulley 92 to rotate via the synchronous belt, so that the second synchronous pulley 92 causes the nut seat of the second lead screw nut structure 9 to rotate.

[0041] In the above example, when the nut seats of both the first lead screw nut structure 8 and the second lead screw nut structure 9 are driven to rotate, they can drive their respective lead screws to rise and fall synchronously, so that the lead screws drive the injection lifting seat 5 to rise and fall synchronously. Then, the injection lifting seat 5 drives the injection rod piston 6 to move along the center line of the barrel to the aforementioned third and fourth positions, thereby realizing the function of the aforementioned second drive mechanism.

[0042] To achieve the aforementioned purpose of the first motor driving the first synchronous pulley 82 to rotate, in some embodiments, the aforementioned second drive mechanism further includes an idler pulley and a transmission gear meshing with the idler pulley. The aforementioned synchronous belt passes around the idler pulley, and the first motor drives the transmission gear to rotate, causing the transmission gear to drive the idler pulley to rotate. When the idler pulley is driven to rotate, it drives the first synchronous pulley 82 to rotate via the synchronous belt, thereby achieving the aforementioned purpose of the first motor driving the first synchronous pulley 82 to rotate.

[0043] To achieve the purpose of driving the lifting platform 4 to move using the aforementioned first drive mechanism, in some embodiments, such as... Figure 3As shown, the aforementioned first drive mechanism may include a second motor, a third lead screw and nut structure 10, and a connecting rod structure 11. The connecting rod structure 11 includes a first connecting rod 111, a second connecting rod 112, and a third connecting rod 113. One end of the first connecting rod 111 is rotatably mounted on the frame 1, and the other end of the first connecting rod 111 is hinged to one end of the second connecting rod 112. The other end of the second connecting rod 112 is hinged to the lifting platform 4.

[0044] The aforementioned lead screw 101 of the third lead screw nut structure is rotatably mounted on the frame 1. One end of the third connecting rod 113 is hinged to the nut seat 102 of the third lead screw nut structure, and the other end of the third connecting rod 113 is hinged to the middle of the first connecting rod 111. The second motor is used to drive the lead screw 101 of the third lead screw nut structure to rotate, thereby driving the nut seat 102 of the third lead screw nut structure to rise and fall, causing the third connecting rod 113 to drive the first connecting rod 111 to rotate. When driven to rotate, the first connecting rod 111 is used to drive the injection mold 3 to rise to the aforementioned first position or fall to the aforementioned second position via the second connecting rod 112.

[0045] In the above example, the first connecting rod 111, the second connecting rod 112, and the lifting platform 4 form a crank-slider mechanism. The first connecting rod 111 constitutes the crank of the crank-slider mechanism, and the lifting platform 4 constitutes the slider of the crank-slider mechanism. When the nut seat 102 of the third lead screw and nut structure rises, it drives the first connecting rod 111 to rotate forward through the third connecting rod 113, causing the first connecting rod 111 to drive the injection mold 3 to rise to the aforementioned first position through the second connecting rod 112. When the nut seat 102 of the third lead screw and nut structure falls, it drives the first connecting rod 111 to rotate in reverse through the third connecting rod 113, causing the first connecting rod 111 to drive the injection mold 3 to fall to the aforementioned second position through the second connecting rod 112. The cooperation of the second motor, the third lead screw and nut structure 10, and the connecting rod structure 11 enables the aforementioned first drive mechanism to drive the lifting platform 4 to move up and down.

[0046] In some implementations, such as Figure 3 As shown, there can be two connecting rod structures 11, which are symmetrically arranged at both ends of the lower side of the lifting platform 4, thereby improving the stability of the lifting movement of the lifting platform 4.

[0047] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A chip encapsulation machine, characterized in that, It includes a frame (1), an upper injection mold (2), a lower injection mold (3), a timer, a first drive mechanism, and a second drive mechanism; the upper injection mold (2) is fixed on the frame (1), and the lower injection mold (3) is movably mounted on the frame (1) via a lifting platform (4); The first driving mechanism is used to drive the lifting platform (4) to move, so that the lifting platform (4) drives the lower injection mold (3) to rise to a first position or fall to a second position; wherein, when the lower injection mold (3) rises to the first position, it closes relative to the upper injection mold (2) to form a cavity for accommodating the chip to be molded between the upper injection mold (2) and the lower injection mold (3); when the lower injection mold (3) falls to the second position, it opens relative to the upper injection mold (2); The lower injection mold (3) is provided with a barrel communicating with the cavity and an injection rod piston (6) disposed in the barrel; the second driving mechanism is used to drive the injection rod piston (6) to move along the center line of the barrel to a third position, so as to squeeze the epoxy resin in the barrel into the cavity with a first pressure; the second driving mechanism is also used to drive the injection rod piston (6) to move along the center line of the barrel to a fourth position, so as to squeeze the epoxy resin in the barrel into the cavity with a second pressure; wherein, the third pressure is less than the fourth pressure; The timer is used to time the dwell time of the injection rod piston (6) in the third position.

2. The chip encapsulation machine as described in claim 1, characterized in that, The second drive mechanism includes a first motor, which drives the injection rod piston (6) to move along the center line of the barrel to the third position and the fourth position via the first motor. The chip encapsulation machine also includes a controller, which is connected to both the timer and the first motor.

3. The chip encapsulation machine as described in claim 2, characterized in that, The lifting platform (4) is provided with an injection lifting seat (5), and the injection rod piston (6) is arranged on the injection lifting seat (5) so that it can move along the center line of the barrel to the third position and the fourth position under the drive of the injection lifting seat (5). The second drive mechanism includes a first lead screw nut structure (8) and a second lead screw nut structure (9). The lead screw (81) of the first lead screw nut structure is fixed at one end of the injection lifting seat (5), and the lead screw (91) of the second lead screw nut structure is fixed at the other end of the injection lifting seat (5). Both the first lead screw nut structure (8) and the second lead screw nut structure (9) have their nut seats rotatably mounted on the lifting platform (4); a first synchronous pulley (82) is fixed on the nut seat of the first lead screw nut structure (8), and a second synchronous pulley (92) is fixed on the nut seat of the second lead screw nut structure (9). The first synchronous pulley (82) and the second synchronous pulley (92) are connected by a synchronous belt drive; the first motor is used to drive the first synchronous pulley (82) to rotate, thereby causing the nut seat of the first lead screw nut structure (8) to rotate; and the first synchronous pulley (82) drives the second synchronous pulley (92) to rotate through the synchronous belt, so that the second synchronous pulley (92) drives the nut seat of the second lead screw nut structure (9) to rotate.

4. The chip encapsulation machine as described in claim 3, characterized in that, The second drive mechanism also includes an idler wheel and a transmission gear meshing with the idler wheel. The synchronous belt passes around the idler wheel. The first motor is used to drive the transmission gear to rotate, so that the transmission gear drives the idler wheel to rotate. When the idler wheel is driven to rotate, it drives the first synchronous pulley (82) to rotate through the synchronous belt.

5. The chip encapsulation machine as described in any one of claims 1-4, characterized in that, The first drive mechanism includes a second motor, a third lead screw and nut structure (10) and a connecting rod structure (11). The connecting rod structure (11) includes a first connecting rod (111), a second connecting rod (112) and a third connecting rod (113). One end of the first connecting rod (111) is rotatably mounted on the frame (1). The other end of the first connecting rod (111) is hinged to one end of the second connecting rod (112). The other end of the second connecting rod (112) is hinged to the lifting platform (4). The lead screw (101) of the third lead screw nut structure is rotatably mounted on the frame (1). One end of the third connecting rod (113) is hinged to the nut seat (102) of the third lead screw nut structure, and the other end of the third connecting rod (113) is hinged to the middle of the first connecting rod (111). The second motor is used to drive the lead screw (101) of the third lead screw nut structure to rotate, so as to drive the nut seat (102) of the third lead screw nut structure to rise and fall, so that the third connecting rod (113) drives the first connecting rod (111) to rotate. When the first connecting rod (111) is driven to rotate, it drives the injection mold (3) to rise to the first position or fall to the second position through the second connecting rod (112).

6. The chip encapsulation machine as described in claim 5, characterized in that, The number of the connecting rod structure (11) is two, and they are symmetrically arranged at both ends of the lower side of the lifting platform (4).

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