Multi-injection automatic packaging mold

Abstract

The utility model discloses a kind of multi-injection automatic packaging mould, it is related to packaging mould technical field, including the upper die and lower die that can be made similar or apart action, the upper die and lower die are oppositely arranged, and the similar end of two is respectively recessed with upper die cavity, lower die cavity, to when the upper die and lower die present die mode, upper die cavity and lower die cavity jointly enclose and form at least the injection cavity of two groups of lead frame that can be placed;Push plate for being close to or away from lower die cavity is movably arranged at the lower die, and at least two groups of injection plastic barrels are provided on push plate, and the end of each group of injection plastic barrel towards lower die cavity is at least communicated with two groups of injection head, and injection head can be movably extended into lower die cavity, to realize the communication of injection head and injection cavity.The utility model makes the injection cavity formed by upper die and lower die can at least supply two groups of lead frame placement, and is equipped with the injection design of corresponding requirement, solve the problem that existing injection efficiency is low, difficult to synchronize to multiple lead frame injection processing.

Description

Technical Field

[0001] This utility model relates to the field of packaging mold technology, specifically to a multi-injection automatic packaging mold. Background Technology

[0002] A packaging mold is a specialized molding equipment used in semiconductor packaging processes. Its function is to encapsulate the lead frame, which has been soldered onto the chip, with insulating packaging materials such as epoxy resin molding compound through injection molding, compression, etc., thereby forming a dense outer protective layer to effectively prevent impurities in the air from corroding the chip circuit.

[0003] A search revealed a patent document with authorization announcement number CN222927420U, which discloses a whole-board packaging mold for packaging a PCB board with a chip array soldered on it. The whole-board packaging mold includes an upper mold assembly and a lower mold assembly. The upper mold assembly includes an upper mold, and the lower mold assembly includes a lower mold. The upper mold and the lower mold are detachably connected and have a receiving space and a drainage channel. The receiving space is used to receive the PCB board.

[0004] The aforementioned packaging mold directly encapsulates the entire PCB board containing the chip array using a single-board packaging mold, resulting in mold miniaturization. The mold is also detachable, allowing for core replacement and compatibility with various types and models of cores, thus reducing manufacturing costs. However, due to its mold closing action and injection runner layout, this mold structure can only complete the one-time packaging of one entire board product per mold closing cycle. It cannot process multiple independent products in parallel during the same mold closing process, lacks the continuous molding capability of multi-cavity molds, has a long packaging cycle time, and its overall packaging efficiency needs further improvement. Utility Model Content

[0005] The purpose of this invention is to solve the problems in the prior art by proposing a multi-injection automatic packaging mold. By enabling the injection cavity formed by the upper and lower molds to accommodate at least two sets of lead frames and equipping it with the required injection design, this invention solves the problems of low injection efficiency and difficulty in simultaneously injection molding multiple sets of lead frames.

[0006] To solve the above problems, this utility model provides the following technical solution: An automatic packaging mold for multi-injection molding includes an upper mold and a lower mold that can move close together or separate from each other. The upper mold and the lower mold are arranged opposite each other, and the close ends of the two are respectively provided with an upper mold cavity and a lower mold cavity, so that when the upper mold and the lower mold are in a closed state, the upper mold cavity and the lower mold cavity together form an injection cavity that can hold at least two sets of lead frames. The lower mold is movably provided with a push plate for moving closer to or away from the lower mold cavity, and the push plate is provided with at least two sets of injection molding cylinders. Each set of injection molding cylinders is connected to at least two sets of injection heads at one end facing the lower mold cavity, and the injection heads can be movably extended into the lower mold cavity to realize the connection between the injection head and the injection cavity.

[0007] As a further embodiment of this utility model: the injection molding cylinder is configured as four groups, and every two groups of injection molding cylinders work together to form a lead frame located in the injection molding cavity. Each group of injection molding cylinders has four injection heads connected to one end facing the lower mold cavity.

[0008] As a further embodiment of this utility model: the lower mold is provided with a drive source for driving the push plate to move. The drive source includes four sets of racks respectively fixedly arranged around the push plate. The lower mold is provided with four sets of gears that rotate in a corresponding manner, and each set of gears meshes with each set of racks for transmission.

[0009] As a further embodiment of this utility model: the upper mold is provided with an upper sprue extending into its upper mold cavity, and the lower mold is provided with a lower sprue extending into its lower mold cavity. Both the upper sprue and the lower sprue have grooves at one end in their respective mold cavities, so that when the upper mold and the lower mold are in the closed state, the ends of the upper sprue and the lower sprue in their respective mold cavities are in a mating state, blocking the direct channel between the injection head and the injection cavity. In this mating state, the grooves of the upper sprue and the lower sprue together form a sprue for indirectly connecting the injection head and the injection cavity.

[0010] As a further embodiment of this utility model: the end of the groove near the injection head is defined as the front end, and the end away from the injection head is defined as the rear end. Along the flow direction of the injection fluid, the depth of the groove bottom gradually decreases from its front end to its rear end.

[0011] As a further embodiment of this utility model: the upper pouring head is detachably installed at the upper mold, and the lower pouring head is detachably connected at the lower mold.

[0012] As a further embodiment of this utility model: a first movable plate is movably provided at the upper mold for moving closer to or away from the upper mold cavity. A core-pulling rod with one end extending into the upper mold cavity is fixedly provided on the first movable plate, so that when the core-pulling rod moves closer to the upper mold cavity with the first movable plate, one end of the core-pulling rod extends into the upper mold cavity and abuts against the lead wire frame.

[0013] As a further embodiment of this utility model: a second movable plate is movably provided at the upper mold for moving closer to or away from the upper mold cavity. An upper demolding rod with one end extending into the upper mold cavity is fixedly provided on the second movable plate, so that when the upper demolding rod moves closer to the upper mold cavity with the second movable plate, one end of the upper demolding rod extends into the upper mold cavity and applies a peeling action to the finished product.

[0014] As a further embodiment of this utility model: a lower demolding rod is movably provided at the lower mold, one end of which can extend into the lower mold cavity, so as to apply a peeling action to the finished product when the lower demolding rod extends into the lower mold cavity.

[0015] As a further embodiment of this utility model: the lower mold is provided with a number of positioning pins extending into the lower mold cavity.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The mold cavity design of the upper and lower molds can simultaneously accommodate injection cavities for at least two sets of lead frames, enabling multi-station parallel production and improving output efficiency per unit time. Simultaneously, the added pusher plate structure allows the injection barrel and injection head to be positioned closer to or further away from the lower mold cavity. This layout of a single barrel with multiple injection heads provides the structural basis for subsequent high-flow, multi-point balanced injection molding, solving the problems of low efficiency and difficulty in simultaneously processing multiple lead frames in traditional single-head injection molding.

[0017] 2. By limiting the interaction of two sets of barrels to a single lead frame, a dual-path independent material supply system for each workpiece is formed. This effectively shortens the flow path of the injection fluid, reduces injection pressure loss, and thus improves the stress distribution inside the package. Simultaneously, four injection heads are connected to one end of each barrel facing the lower mold cavity, allowing a single frame to receive high-speed injection at four points simultaneously. This not only increases the filling speed but also ensures uniform spreading of the injection fluid within the cavity.

[0018] 3. By adopting a drive method in which four sets of racks are distributed around the push plate and mesh with corresponding gears, compared with the traditional single-point hydraulic cylinder or pneumatic cylinder drive, this circumferential rack and pinion layout can ensure that the push plate is subjected to completely balanced force during lifting and lowering, eliminating tilting or jamming caused by uneven load, thereby ensuring that multiple injection heads can enter and exit the lower mold cavity simultaneously and accurately.

[0019] 4. By connecting the upper and lower sprues during mold closing, an indirect transition gate is established between the injection head and the injection cavity. This is equivalent to adding a buffer chamber at the front end of the high-pressure injection fluid jet, which can mitigate the high-speed, high-pressure injection fluid ejected from the injection head and prevent it from directly eroding the fine connecting lines on the lead frame or causing frame displacement. At the same time, the method of forming a closed flow channel and blocking the direct channel also avoids the risks of flash and leakage that are prone to occur in traditional direct injection molding, thus improving the quality stability of the encapsulation molding.

[0020] 5. By limiting the depth of the groove bottom to gradually decrease from the front end to the rear end, a gradual change in the runner cross-section is achieved. As the injection fluid flows from the deeper front end to the shallower rear end, the runner volume continuously shrinks, which can apply stable back pressure and acceleration to the injection fluid. At the same time, by limiting the upper and lower sprues to be detachable, the ease of mold maintenance and economy are improved.

[0021] 6. By setting a core-pulling rod that can extend into the upper mold cavity, active clamping and positioning of the lead frame is achieved during the injection molding process. During the mold closing and injection molding process, the core-pulling rod abuts against the suspended area of ​​the lead frame, which can overcome the buoyancy and impact force generated by the injection fluid on the frame during high-speed and high-pressure injection, thereby ensuring that the suspended area does not shift or lift up during the injection molding process. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings.

[0023] Figure 1 This is a cross-sectional structural schematic diagram of the present invention; Figure 2 yes Figure 1 Enlarged structural diagram at point A; Figure 3 This is a schematic diagram of the cross-sectional structure of the upper mold in this utility model; Figure 4 This is a schematic diagram of the cross-sectional structure of the lower mold in this utility model; Figure 5 yes Figure 4 Enlarged structural diagram at point B; Figure 6 This is a top view of the lower mold structure in this utility model; Figure 7 This is a schematic diagram of the three-dimensional structure of the bottom gating head in this utility model. Figure 1 ; Figure 8 This is a schematic diagram of the three-dimensional structure of the bottom gating head in this utility model. Figure 2 ; Figure 9 This is a front view schematic diagram of the upper and lower gating heads in the present invention in a docked state.

[0024] In the diagram: 1. Upper mold; 101. Upper mold cavity; 2. Lower mold; 201. Lower mold cavity; 3. Injection cavity; 4. Ejector plate; 5. Injection tube; 6. Rack; 7. Gear; 8. Upper sprue; 9. Lower sprue; 10. Groove; 11. Sprue; 12. First moving plate; 13. Core pull rod; 14. Second moving plate; 15. Upper ejector rod; 16. Lower ejector rod; 17. Positioning pin; a. Lead wire frame; b. Finished product; c. Branch structure. Detailed Implementation

[0025] 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 skilled in the art without creative effort are within the protection scope of the present utility model.

[0026] As described in the background section, existing packaging molds, due to their structural design, can only complete the one-time packaging of one product per mold closing cycle. They cannot process multiple independent products in parallel during the same mold closing process and lack the continuous molding capability of multi-cavity molds. Based on this, this application proposes the following solution: like Figures 1-5 As shown, this application proposes a multi-injection automatic packaging mold, including an upper mold 1 and a lower mold 2. The upper mold 1 and the lower mold 2 are arranged opposite each other and are respectively set on their respective mold closing equipment (such as an injection molding machine). The two can perform close or separate actions to realize mold closing and mold opening actions. The upper mold 1 has an upper mold cavity 101 at the end facing the lower mold 2, and the lower mold 2 has a lower mold cavity 201 at the end facing the upper mold 1. When the upper mold 1 and the lower mold 2 are closed, the upper mold cavity 101 and the lower mold cavity 201 together form a set of injection cavity 3. The injection cavity 3 can accommodate at least two sets of lead frames a, realizing the injection of at least two sets of lead frames a.

[0027] For the design of this injection cavity 3, which can accommodate at least two sets of lead frames a, the injection cavity 3 formed by the closing of the upper mold cavity 101 and the lower mold cavity 201 can be divided into at least two injection areas. At least two sets of lead frames a correspond one-to-one with at least two injection areas, and at least two sets of lead frames a can be placed in at least two injection areas respectively. Taking two sets of lead frames a as an example, the injection cavity 3 is divided into two identical injection areas. Correspondingly, the upper mold cavity 101 and the lower mold cavity 201 are also divided into two half-areas. In the mold-closed state, one half-area of ​​the upper mold cavity 101 and one half-area of ​​the lower mold cavity 201 together constitute one injection area. Thus, both the upper mold cavity 101 and the lower mold cavity 201 have two half-areas, forming two injection areas when the mold is closed.

[0028] When the lead frame a needs to be placed, the upper mold 1 and the lower mold 2 are in an open state. The lead frame a is placed in a designated position in the lower mold cavity 201 before the mold is closed, so that the lead frame a is placed in the corresponding injection area. In order to ensure that the position of the lead frame a in the lower mold cavity 201 is stable, this application provides a number of positioning pins 17 with one end extending into the lower mold cavity 201 at the lower mold 2.

[0029] Based on the above-mentioned design of an injection cavity 3 that can accommodate at least two sets of lead frames a, taking the setting of two injection areas as an example, this application has a push plate 4 movably set at the lower mold 2. The push plate 4 can move closer to or away from the lower mold cavity 201. An injection molding cylinder 5 is set on the push plate 4. At least two sets of injection molding cylinders 5 are set, that is, each injection area corresponds to at least one set of injection molding cylinders 5. In this embodiment, a total of four sets of injection molding cylinders 5 are set (two sets for each injection area). At least two sets of injection heads are connected to one end of the injection molding cylinder 5 facing the lower mold cavity 201. Under the movement of the push plate 4, the injection head can be driven to insert into the lower mold cavity 201. In the mold closed state, that is, the injection head is connected to one of the injection areas. Through this injection molding cylinder 5 and the injection head, the injection fluid can be injected into the injection area to realize the encapsulation of the lead frame a.

[0030] It should be noted that the installation method and feeding mode of the injection molding cylinder 5 are conventional technical means in the existing technology, and will not be elaborated here in order to avoid cumbersome writing.

[0031] like Figure 6 As shown, 'b' represents the packaged finished product 'b', which has the same shape as the lead frame 'a'. As can be seen from the figure, the lead frame 'a' has four sets of branch structures 'c' on both sides, which can serve as injection points. Therefore, in this embodiment, for the same injection area, two sets of injection molding cylinders 5 are set, each corresponding to one of the branch structures 'c' on both sides of the lead frame 'a'. Each set of injection molding cylinders 5 has four injection heads connected to one end facing the lower mold cavity 201, corresponding to four sets of branch structures 'c' on each side. Each of the four injection heads corresponds one-to-one with one of the four injection points. In the case of two injection areas in this application, a total of four sets of injection molding cylinders 5 and sixteen sets of injection heads are set.

[0032] In order to realize the movement of the push plate 4 at the lower mold 2, this application provides a drive source at the lower mold 2 to drive the push plate 4 to move. The drive source can be any kind of drive component in the prior art. This application provides a drive design: the drive source includes four sets of racks 6 respectively fixedly arranged around the push plate 4, and four sets of gears 7 are correspondingly rotatably arranged at the lower mold 2, and each set of gears 7 meshes with each set of racks 6 for transmission; during operation, the four sets of gears 7 are driven synchronously to realize the synchronous upward or downward movement of the four sets of racks 6, thereby driving the push plate 4 to move smoothly upward or downward.

[0033] Furthermore, to facilitate the control of the injection fluid injected into the injection area by the injection head, this application provides an upper sprue 8 extending into its upper mold cavity 101 at the upper mold 1, and a lower sprue 9 extending into its lower mold cavity 201 at the lower mold 2. Both the upper sprue 8 and the lower sprue 9 have grooves 10 at their respective ends within their mold cavities. When the upper mold 1 and the lower mold 2 close together, the end of the upper sprue 8 extending into the injection cavity (i.e., the injection area 3) and the end of the lower sprue 9 extending into the injection cavity 3 are in a vertically aligned position. This alignment can be achieved by... Figure 2 To illustrate, in this state, the docking of the two can block the direct passage between the injection head and the injection cavity (i.e., the injection area) 3. At the same time, the grooves 10 on both together form a set of material ports 11. The material ports 11 are used to indirectly connect the aforementioned blocked injection head and the injection cavity (i.e., the injection area) 3. That is, the injection fluid injected by the injection head enters the injection cavity (i.e., the injection area) 3 through the material ports 11 to complete the encapsulation.

[0034] like Figures 7-9 As shown, this application designs the upper gating head 8 and the lower gating head 9 as follows: (Still using...) Figure 2 From the perspective shown, the upper sprue 8 and lower sprue 9, located on the left and in a docking position, block the left injection head (not shown in the figure) from the injection cavity 3. This corresponding perspective can be seen from... Figure 9 To represent, Figure 9 The arrows in the diagram indicate the flow direction of the injection fluid. The end of the upper grommet 8 or lower grommet 9 closest to the injection head is defined as the front end, and the end furthest from the injection head is defined as the rear end. From the perspective of the injection fluid flow direction, the depth of the groove bottom 10 gradually decreases from its front end to its rear end. Figure 9 From this perspective, the sprue 11 formed by the two sets of grooves 10 appears to be "narrowed" when viewed in the direction of the arrow. The injection fluid first passes through the large diameter end of the sprue 11 and then flows into the injection cavity 3 from the small diameter end.

[0035] When the upper sprue 8 and lower sprue 9 wear out after prolonged use, in order to facilitate quick replacement, this application makes the upper sprue 8 detachably installed at the upper mold 1 and the lower sprue 9 detachably connected at the lower mold 2.

[0036] Furthermore, when the encapsulated lead frame 'a' is a three-dimensional structure (such as steps or bulges) rather than a simple planar thin plate, it often has several sets of suspended pins and / or heat sinks over a large area. These pins and / or heat sinks resemble cantilever beams. During injection molding, the impact force of the injection fluid will generate upward buoyancy and lateral shear force on the suspended areas, causing the pins and / or heat sinks to warp or sway. If the pins and / or heat sinks are warped, it can lead to minor issues like injection fluid overflowing into the bottom of the pins and / or heat sinks, forming burrs, or more serious issues like exposed pins and / or heat sinks (material shortage) and rendering them unusable.

[0037] Based on this, this application has a first movable plate 12 movably provided at the upper mold 1 for moving closer to or away from the upper mold cavity 101. A core-pulling rod 13 with one end extending into the upper mold cavity 101 is fixedly provided on the first movable plate 12. When the core-pulling rod 13 moves closer to the upper mold cavity 101 with the first movable plate 12, one end of the core-pulling rod 13 extends into the upper mold cavity 101 and abuts against the corresponding suspended surface of the lead frame a, thereby providing stable support force to the suspended area during the injection molding process to counteract the upward buoyancy and shear force generated by the injection fluid, effectively preventing injection molding defects such as warping of the leads and / or heat sinks.

[0038] like Figures 1-2 As shown, after injection molding, to facilitate the separation of the finished product b from the upper mold cavity 101 and the lower mold cavity 201, a second movable plate 14 is movably provided at the upper mold 1 to move closer to or further away from the upper mold cavity 101. An upper ejector rod 15, one end of which extends into the upper mold cavity 101, is fixedly provided on the second movable plate 14. When the upper ejector rod 15 moves closer to the upper mold cavity 101 with the second movable plate 14, one end of the upper ejector rod 15 extends into the upper mold cavity 101 and applies a peeling action to the finished product b. On the other hand, a lower ejector rod 16, one end of which extends into the lower mold cavity 201, is movably provided at the lower mold 2. When the lower ejector rod 16 extends into the lower mold cavity 201, it applies a peeling action to the finished product b.

[0039] It should be noted that a reset spring connected to the first moving plate 12 and / or the second moving plate 14 can also be provided at the upper mold 1 to reset the corresponding moving plate. At the same time, by providing core-pulling limit posts of appropriate height at the upper mold 1, the consistency of the downward depth of multiple sets of core-pulling rods 13 can be ensured.

[0040] The above description provides a detailed account of one embodiment of the present invention. However, this description is merely a preferred embodiment and should not be construed as limiting the scope of the present invention. All equivalent variations and improvements made within the scope of the claims of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A multi-injection automatic packaging mold, characterized in that, The mold includes an upper mold (1) and a lower mold (2) that can move close together or apart. The upper mold (1) and the lower mold (2) are arranged opposite to each other, and the close ends of the two are respectively provided with an upper mold cavity (101) and a lower mold cavity (201). When the upper mold (1) and the lower mold (2) are in a closed state, the upper mold cavity (101) and the lower mold cavity (201) together form an injection cavity (3) that can hold at least two sets of lead frames (a). The lower mold (2) is movably provided with a push plate (4) for approaching or moving away from the lower mold cavity (201), and the push plate (4) is provided with at least two sets of injection molding cylinders (5). Each set of injection molding cylinders (5) is connected to at least two sets of injection heads at one end facing the lower mold cavity (201), and the injection heads can be movably extended into the lower mold cavity (201) to realize the connection between the injection head and the injection cavity (3).

2. The multi-injection automatic packaging mold according to claim 1, characterized in that, The injection molding cylinder (5) is set in four groups, and each two groups of injection molding cylinders (5) work together to form a lead frame (a) located in the injection cavity (3). Each group of injection molding cylinders (5) is connected to four injection heads at one end facing the lower mold cavity (201).

3. The multi-injection automatic packaging mold according to claim 2, characterized in that, The lower mold (2) is provided with a drive source to drive the push plate (4) to move. The drive source includes four sets of racks (6) fixedly arranged around the push plate (4). The lower mold (2) is provided with four sets of gears (7) that rotate in the same direction. Each set of gears (7) meshes with each set of racks (6) for transmission.

4. The multi-injection automatic packaging mold according to claim 3, characterized in that, The upper mold (1) is provided with an upper sprue (8) extending into its upper mold cavity (101), and the lower mold (2) is provided with a lower sprue (9) extending into its lower mold cavity (201). Both the upper sprue (8) and the lower sprue (9) have grooves (10) at one end in their respective mold cavities. When the upper mold (1) and the lower mold (2) are in the closed state, the upper sprue (8) and the lower sprue (9) are in the docking state and block the direct channel between the injection head and the injection cavity (3). In this docking state, the grooves (10) of the upper sprue (8) and the lower sprue (9) together form a sprue (11) for indirectly connecting the injection head and the injection cavity (3).

5. The multi-injection automatic packaging mold according to claim 4, characterized in that, The end of the groove (10) near the injection head is defined as the front end, and the end away from the injection head is defined as the rear end. Along the flow direction of the injection fluid, the depth of the bottom of the groove (10) gradually decreases from its front end to its rear end.

6. A multi-injection automatic packaging mold according to claim 5, characterized in that, The upper gating head (8) is detachably installed at the upper mold (1), and the lower gating head (9) is detachably connected at the lower mold (2).

7. A multi-injection automatic packaging mold according to claim 6, characterized in that, The upper mold (1) is movably provided with a first movable plate (12) for moving closer to or away from the upper mold cavity (101). A core-pulling rod (13) with one end extending into the upper mold cavity (101) is fixedly provided on the first movable plate (12) so that when the core-pulling rod (13) moves closer to the upper mold cavity (101) with the first movable plate (12), one end of the core-pulling rod (13) extends into the upper mold cavity (101) and abuts against the lead frame (a).

8. A multi-injection automatic packaging mold according to claim 7, characterized in that, The upper mold (1) is movably provided with a second movable plate (14) for moving closer to or away from the upper mold cavity (101). The second movable plate (14) is fixedly provided with an upper demolding rod (15) that can extend into the upper mold cavity (101) at one end. When the upper demolding rod (15) moves closer to the upper mold cavity (101) with the second movable plate (14), one end of the upper demolding rod (15) extends into the upper mold cavity (101) and applies a peeling action to the finished product (b).

9. A multi-injection automatic packaging mold according to claim 8, characterized in that, A lower ejector rod (16) is movably provided at the lower mold (2), with one end extending into the lower mold cavity (201), so as to apply a peeling action to the finished product (b) when the lower ejector rod (16) extends into the lower mold cavity (201).

10. A multi-injection automatic packaging mold according to claim 9, characterized in that, The lower mold (2) is provided with a number of positioning pins (17) with one end extending into the lower mold cavity (201).

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