Runner system and injection mold

Abstract

The utility model provides a kind of pouring system and injection mold, the included angle of the extension direction of first type pouring gate in pouring system and the extension direction of flow channel is less than the included angle of the extension direction of second type pouring gate and the extension direction of flow channel, the cross-sectional area of second type pouring gate on the plane perpendicular to its extension direction is greater than the cross-sectional area of first type pouring gate on the plane perpendicular to its extension direction, realizes plastic package material flow compensation, so that plastic package material is filled in the cavity connected with second type pouring gate in same time is substantially same with the filling amount in the cavity connected with first type pouring gate, effectively solve the problem of plastic package material filling imbalance caused by included angle difference, improve the phenomenon of uneven encapsulation injection, improve the quality of packaging product.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor packaging, and in particular to a gating system and injection mold. Background Technology

[0002] Injection molds for semiconductor packaging are core tools used to mold epoxy molding compounds (EMC) and other molding materials under high temperature and pressure to encapsulate and protect chips and lead frames. Their structure typically consists of an upper mold, lower mold, cavity, gating system, ejection mechanism, and heating / cooling system. During injection molding, preheated EMC is injected into the cavity through the gating system under specific temperature and pressure, and solidifies to form a sealed outer shell. The materials used in injection molds must possess high rigidity, wear resistance, and corrosion resistance, and dimensional stability must be ensured through cryogenic treatment.

[0003] Advanced designs also integrate multi-cavity simultaneous molding. Multi-cavity simultaneous molding technology enables mass production by setting multiple cavities in the same mold, significantly improving efficiency and reducing costs, but it also presents challenges such as technical complexity and quality control. For example, the gating system (such as runner layout) needs to be balanced; unbalanced designs can easily lead to uneven filling, flash, or shrinkage differences.

[0004] like Figure 1 The diagram illustrates an injection molding process using an existing injection mold. The mold includes a cavity 100 and a gating system 110. The semiconductor device to be encapsulated is mounted on a lead frame 120 and located within the cavity 100. The gating system 110 includes a runner 111 and a gating gate, with the gating gate connecting the runner 111 to the cavity 100. The encapsulating material is injected from the runner 111 and then into the cavity 100 through the gating gate.

[0005] The injection mold has a uniform gate size. The flow rate of the molding compound in the gate is related to the angle between the extension direction of the gate and the extension direction of the runner 111. Differences in the angle between these two angles result in hydrodynamic effects. A larger angle between the extension directions of the gate and the runner 111 leads to a lower flow rate of the molding compound in the gate. This results in variations in the filling of molding compound in cavities 100 located in different rows within the same time frame, causing an imbalance in the encapsulation process and affecting the quality of the packaged product. As the angle between the extension directions of the gate and the runner 111 increases, the flow resistance of the molding compound against the gate sidewall increases, leading to a greater deceleration effect from the gate and a smaller acceleration effect from the flow of the molding compound in the runner, thus reducing the flow rate of the molding compound in the gate.

[0006] Specifically, Figure 2 The image shown is a partially enlarged view of an existing injection mold. Figure 3 The image shown is a simulation diagram of injection molding using existing injection molds. Figure 3 The boundary of the medium-sized cavity 100 is marked with a dashed line, such as... Figures 1-3 As shown, two gating gates, gating gate 112 and gating gate 113, are provided on the same side of the runner 111 along the direction of molded material flow. The angle between the extension direction D4 of gating gate 113 and the extension direction D5 of runner 111 is greater than the angle between the extension direction D3 of gating gate 112 and the extension direction D5 of runner 111. Therefore, the flow velocity of the molded material in gating gate 113 is less than that in gating gate 112. Consequently, in the same amount of time, the amount of molded material filling the cavity 100 connected to gating gate 113 is less than the amount filling the cavity 100 connected to gating gate 112, causing an imbalance in the encapsulation injection molding process and affecting the quality of the encapsulated product. The flow directions of the molded material in gating gate 112, gating gate 113, and runner 111 are as follows: Figure 2 As indicated by the middle arrow.

[0007] Therefore, improving the encapsulation injection balance and enhancing the encapsulation quality of packaged products has become a key technical problem to be solved. Summary of the Invention

[0008] The technical problem to be solved by this utility model is to provide a gating system and injection mold that can improve the encapsulation injection balance and enhance the encapsulation quality of the packaged product.

[0009] To solve the above problems, this utility model provides a casting system, comprising:

[0010] The flow channel has a main extending direction, which is the direction in which the molding compound flows in the flow channel;

[0011] The gating assembly includes:

[0012] A first type of gating gate is disposed on the side wall of the flow channel and communicates with the flow channel. The first type of gating gate has a first extending direction, which is the direction in which the molding compound flows in the first type of gating gate. The first extending direction has a first angle with the main extending direction. The first type of gating gate has a first cross-sectional area on a plane perpendicular to the first extending direction.

[0013] A second type of gating gate is disposed on the side wall of the flow channel and communicates with the flow channel. The second type of gating gate has a second extending direction, which is the direction in which the molding compound flows in the second type of gating gate. The second extending direction has a second angle with the main extending direction. The second type of gating gate has a second cross-sectional area on a plane perpendicular to the second extending direction.

[0014] Wherein, the first included angle is smaller than the second included angle, and the first cross-sectional area is smaller than the second cross-sectional area.

[0015] In one specific embodiment, the first included angle is an acute angle, and the second included angle is a right angle or an obtuse angle.

[0016] In one specific embodiment, the difference between the second cross-sectional area and the first cross-sectional area is positively correlated with the difference between the second included angle and the first included angle.

[0017] In one specific embodiment, the first type of gating gate and the second type of gating gate located on the same side of the flow channel are alternately distributed.

[0018] In one specific embodiment, the first type of pouring gates located on both sides of the flow channel are symmetrically distributed with the central axis of the flow channel as the axis of symmetry.

[0019] In one specific embodiment, the second type of pouring gates located on both sides of the flow channel are symmetrically distributed with the central axis of the flow channel as the axis of symmetry.

[0020] In one specific embodiment, the flow channel further includes multiple buffer sections and a horizontal flow section disposed between the buffer sections. The width of the buffer section is greater than the width of the horizontal flow section, and the first type of pouring gate and the second type of pouring gate are respectively disposed on the sidewall of the buffer section.

[0021] In one specific embodiment, the first type of pouring gate and the second type of pouring gate are respectively located at the top corner of the buffer section.

[0022] In one specific embodiment, the shape of the first type of gating gate is the same as the shape of the second type of gating gate.

[0023] In one specific embodiment, the cross-sectional shape of the first type of gating gate in the plane where the first extension direction is located and the cross-sectional shape of the second type of gating gate in the plane where the second extension direction is located are both rectangular.

[0024] In one specific embodiment, the cross-sectional shape of the first type of gating gate in the plane of the first extension direction and the cross-sectional shape of the second type of gating gate in the plane of the second extension direction are both trapezoidal. In the first extension direction, the size of the connection between the first type of gating gate and the flow channel is the smallest, and in the second extension direction, the size of the connection between the second type of gating gate and the flow channel is the smallest.

[0025] In one specific embodiment, the first extending direction and the second extending direction are symmetrically distributed about the vertical line of the central axis of the flow channel as the axis of symmetry.

[0026] This utility model also provides an injection mold, comprising:

[0027] The aforementioned gating system;

[0028] Multiple cavities are arranged on both sides of the flow channel, and the first type of gating gate and the second type of gating gate are respectively connected to different cavities.

[0029] In one specific embodiment, the two cavities connected to the first type of gating ports located on both sides of the flow channel and symmetrically distributed with the central axis of the flow channel as the axis of symmetry are symmetrically distributed with the central axis of the flow channel as the axis of symmetry.

[0030] In one specific embodiment, the two cavities connected to the second type of gating ports located on both sides of the flow channel and symmetrically distributed with the central axis of the flow channel as the axis of symmetry are symmetrically distributed with the central axis of the flow channel as the axis of symmetry.

[0031] In one specific embodiment, the cavities are arranged on both sides of the horizontal flow section of the flow channel.

[0032] In the gating gate and injection mold provided by this utility model, the angle between the extension direction of the first type of gating gate and the extension direction of the runner is smaller than the angle between the extension direction of the second type of gating gate and the extension direction of the runner. When the gating system is used for molding compound casting, the flow rate of the molding compound in the first type of gating gate is greater than the flow rate in the second type of gating gate. The gating system of this utility model sets the cross-sectional area of ​​the second type of gating gate on the plane perpendicular to its extension direction to be greater than the cross-sectional area of ​​the first type of gating gate on the plane perpendicular to its extension direction. That is, a large flow rate corresponds to a small cross-sectional area, and a small flow rate corresponds to a large cross-sectional area, which realizes molding compound flow compensation. This makes the amount of molding compound filling in the cavity connected to the second type of gating gate in the same time period basically the same as the amount of filling in the cavity connected to the first type of gating gate. This effectively solves the problem of unbalanced molding compound filling caused by the angle difference, improves the phenomenon of unbalanced encapsulation injection molding, and improves the quality of encapsulated products. Furthermore, the gating system provided by the specific embodiments of this utility model can control the injection balance without changing the injection process parameters. The method is simple and easy to implement, and is conducive to widespread application. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this utility model, the accompanying drawings used in the description of the embodiments 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 these drawings without any creative effort.

[0034] Figure 1 The diagram shown is a schematic of injection molding using an existing injection mold;

[0035] Figure 2 The image shown is a partial enlarged view of an existing injection mold;

[0036] Figure 3 The image shown is a simulation diagram of injection molding using existing injection molds;

[0037] Figure 4 The diagram shown is a schematic diagram of a casting system provided in a specific embodiment of this utility model;

[0038] Figure 5 The figure shown is a partially enlarged schematic diagram of the casting system provided in a specific embodiment of this utility model;

[0039] Figure 6 The diagram shown is a partially enlarged schematic diagram of the connection between the gating system and the mold cavity according to a specific embodiment of this utility model;

[0040] Figure 7 The figure shown is a partially enlarged schematic diagram of a casting system provided in another specific embodiment of this utility model;

[0041] Figure 8 The figure shown is a partially enlarged schematic diagram of a casting system provided in another specific embodiment of this utility model;

[0042] Figure 9 The diagram shown is a schematic diagram of an injection mold provided in a specific embodiment of this utility model;

[0043] Figure 10 The diagram shown is a schematic diagram of a molding process using an injection mold provided in a specific embodiment of this utility model. Detailed Implementation

[0044] The specific implementation methods of the gating system and injection mold provided by this utility model will be described in detail below with reference to the accompanying drawings.

[0045] Figure 4 The diagram shown is a schematic diagram of a casting system provided in a specific embodiment of this utility model. Figure 5 The diagram shown is a partially enlarged schematic diagram of a casting system provided in a specific embodiment of this utility model. Figure 6 The diagram shown is a partially enlarged schematic of the connection between the gating system and the mold cavity according to a specific embodiment of this utility model. Please refer to [the diagram]. Figure 4 , Figure 5 and Figure 6 The specific embodiment of this utility model provides a casting system including:

[0046] The flow channel 410 has a main extension direction D3.

[0047] The gating assembly includes:

[0048] A first type of gating gate 421 is disposed on the side wall of the flow channel 410 and communicates with the flow channel 410. The first type of gating gate 421 has a first extending direction D1. The first extending direction D1 and the main extending direction D3 have a first angle α1. The first type of gating gate 421 has a first cross-sectional area S1 on a plane perpendicular to the first extending direction D1.

[0049] The second type of gating gate 422 is disposed on the side wall of the flow channel 410 and communicates with the flow channel 410. The second type of gating gate 422 has a second extending direction D2, and the second extending direction D2 has a second included angle α2 with the main extending direction D3. The second type of gating gate 422 has a second cross-sectional area S2 on a plane perpendicular to the second extending direction D2.

[0050] Wherein, the first included angle α1 is smaller than the second included angle α2, and the first cross-sectional area S1 is smaller than the second cross-sectional area S2.

[0051] The angle (first angle α1) between the extension direction (first extension direction D1) of the first type of gating gate 421 and the extension direction (main extension direction D3) of the runner 410 is smaller than the angle (second angle α2) between the extension direction (second extension direction D2) of the second type of gating gate 422 and the extension direction (main extension direction D3) of the runner 410. When the molding compound is cast using the gating system, the flow rate of the molding compound in the first type of gating gate 421 is greater than the flow rate in the second type of gating gate 422. If the first type of gating gate 421 and the second type of gating gate 422 have the same size, the amount of molding compound filled in the cavity 400 connected to the second type of gating gate 422 will be less than the amount filled in the cavity 400 connected to the first type of gating gate 421 at the same time, causing an imbalance in the encapsulation injection molding and affecting the quality of the encapsulated product.

[0052] The gating system provided in this embodiment of the invention has a cross-sectional area (second cross-sectional area S2) of the second type of gating gate 422 on a plane perpendicular to its extension direction, which is larger than the cross-sectional area (first cross-sectional area S1) of the first type of gating gate 421 on the same plane. This achieves molding compound flow compensation, ensuring that the amount of molding compound filling in the cavity 400 connected to the second type of gating gate 422 within the same time period is approximately the same as the amount filling in the cavity 400 connected to the first type of gating gate 421. This effectively solves the problem of unbalanced molding compound filling caused by the difference in angle, improves the phenomenon of unbalanced injection molding, and enhances the quality of the encapsulated product. Furthermore, the gating system provided in this embodiment of the invention can control injection balance without changing the injection molding process parameters. The method is simple and easy to implement, and is suitable for widespread application.

[0053] The flow channel 410 serves as a channel for the flow of molding compound, ensuring that the molten molding compound is efficiently and evenly delivered from the injection molding machine nozzle to the gating assembly and ultimately fills the cavity 400. The main extension direction D3 of the flow channel 410 refers to the direction in which the molding compound flows in the flow channel 410. In some specific embodiments, the main extension direction D3 coincides with the central axis of the flow channel 410.

[0054] The gating gate assembly is disposed on the side wall of the runner 410 and communicates with the runner 410. Molten molding compound is poured into the cavity 400 from the runner 410 through the gating gate assembly. The gating gate assembly includes a first type gating gate 421 and a second type gating gate 422. The first type gating gate 421 and the second type gating gate 422 have different extending directions and different angles with the main extending direction D3 of the runner 410.

[0055] The first type of gating gate 421 has a first extending direction D1, which is the direction in which the molding compound flows within the first type of gating gate 421. This flow direction refers to the direction in which the molding compound flows from the flow channel 410 to the cavity 400 communicating with the first type of gating gate 421. In some embodiments, the first extending direction D1 coincides with the central axis of the first type of gating gate 421. The first extending direction D1 and the main extending direction D3 have a first included angle α1, which, in this embodiment, is an acute angle.

[0056] The second type of gating gate 422 has a second extending direction D2, which is the direction in which the molding compound flows within the second type of gating gate 422. This flow direction refers to the direction in which the molding compound flows from the flow channel 410 to the cavity 400 communicating with the second type of gating gate 422. In some embodiments, the second extending direction D2 coincides with the central axis of the second type of gating gate 422. The second extending direction D2 and the main extending direction D3 form a second included angle α2, which is greater than the first included angle α1. In some embodiments, the second included angle α2 can be an acute angle, a right angle, or an obtuse angle. In this embodiment, the second included angle α2 is an obtuse angle. Figure 7 As shown, it is a partially enlarged schematic diagram of a casting system provided in another specific embodiment of the present invention. In this specific embodiment, the second included angle α2 is greater than the first included angle α1, and the first included angle α1 is an acute angle, while the second included angle α2 is a right angle.

[0057] The first type of gating gate 421 has a first cross-sectional area S1 in a plane perpendicular to the first extension direction D1. The plane perpendicular to the first extension direction D1 refers to a cross-section orthogonal to the first extension direction D1. When the molding compound flows through the first type of gating gate 421, the volumetric flow rate of the molding compound is the product of the flow velocity of the molding compound in the first type of gating gate 421 and the first cross-sectional area S1.

[0058] The second type of gating gate 422 has a second cross-sectional area S2 in a plane perpendicular to the second extension direction D2. The plane perpendicular to the second extension direction D2 refers to a cross-section orthogonal to the second extension direction D2. When the molding compound flows through the second type of gating gate 422, the volumetric flow rate of the molding compound is the product of the flow velocity of the molding compound in the second type of gating gate 422 and the second cross-sectional area S2.

[0059] When the gating system provided in this specific embodiment of the present invention is used for molding compound injection, the flow rate of the molding compound in the second type gating port 422 is less than the flow rate in the first type gating port 421. Since the second cross-sectional area S2 is greater than the first cross-sectional area S1, the difference in filling of the molding compound in the cavity caused by the different flow rates of the molding compound can be compensated, and the problem of unbalanced filling of the molding compound caused by the difference in the included angle is effectively solved.

[0060] In one specific embodiment, the difference between the second cross-sectional area S2 and the first cross-sectional area S1 is positively correlated with the difference between the second included angle α2 and the first included angle α1. That is, the larger the difference between the second included angle α2 and the first included angle α1, the larger the difference between the second cross-sectional area S2 and the first cross-sectional area S1, thereby effectively compensating for the difference in filling of the molding compound in the cavity caused by the different flow rates of the molding compound.

[0061] In one specific embodiment, the shape of the first type of gate 421 is the same as the shape of the second type of gate 422, so as to reduce the difference in molding compound filling caused by the shape difference between the first type of gate 421 and the second type of gate 422. For example, both the first type of gate 421 and the second type of gate 422 are cylinders, cuboids, or frustums, etc.

[0062] Specifically, in this specific embodiment, such as Figure 5 As shown, both the first type of gating gate 421 and the second type of gating gate 422 are cylindrical. The length of the first type of gating gate 421 in the first extension direction D1 is equal to the length of the second type of gating gate 422 in the second extension direction D2. The cross-sectional shape of the first type of gating gate 421 in the plane of the first extension direction D1 and the cross-sectional shape of the second type of gating gate 422 in the plane of the second extension direction D2 are both rectangular. The cross-section of the first type of gating gate 421 in the plane perpendicular to the first extension direction D1 is a circle with a first radius, and the cross-section of the second type of gating gate 422 in the plane perpendicular to the second extension direction D2 is a circle with a second radius. The first radius is smaller than the second radius, such that the first cross-sectional area S1 is smaller than the second cross-sectional area S2.

[0063] like Figure 8The diagram shown is a partially enlarged schematic diagram of a casting system provided in another specific embodiment of the present invention. In this specific embodiment, both the first type of casting port 421 and the second type of casting port 422 are frustums of cylinders. The length of the first type of casting port 421 in the first extension direction D1 is equal to the length of the second type of casting port 422 in the second extension direction D2. The cross-sectional shape of the first type of casting port 421 in the plane of the first extension direction D1 and the cross-sectional shape of the second type of casting port 422 in the plane of the second extension direction D2 are both trapezoidal. In the first extension direction D1, the size of the connection between the first type of casting port 421 and the flow channel 410 is the smallest. In the second extension direction D2, the size of the connection between the second type of casting port 422 and the flow channel 410 is the smallest. The first type of gating gate 421 has a circular cross-section with a first radius on a plane perpendicular to the first extension direction D1, and the second type of gating gate 422 has a circular cross-section with a second radius on a plane perpendicular to the second extension direction D2. The minimum first radius is smaller than the minimum second radius, and the maximum first radius is smaller than the maximum second radius, such that the minimum first cross-sectional area S1 is smaller than the minimum second cross-sectional area S2, and the maximum first cross-sectional area S1 is smaller than the maximum second cross-sectional area S2.

[0064] Furthermore, such as Figure 5 As shown, in one specific embodiment, the first extending direction D1 and the second extending direction D2 are symmetrically distributed about the vertical line of the central axis of the flow channel 410. The first extending direction D1 coincides with the central axis of the first type of gate 421, and the second extending direction D2 coincides with the central axis of the second type of gate 422, thus making the central axes of the first type of gate 421 and the second type of gate 422 symmetrically arranged. This symmetrical design further effectively offsets the uneven flow resistance caused by the difference in gate angle through geometric balance, and the symmetrical design also optimizes the space utilization of the injection mold, avoids local stress concentration, and further improves the dimensional stability and reliability of the packaged product. In this specific embodiment, the central axis of the flow channel 410 coincides with the main extending direction D3 of the flow channel 410.

[0065] The gating system includes multiple first-type gating ports 421 and multiple second-type gating ports 422 to achieve multi-cavity injection molding.

[0066] In one specific implementation, such as Figure 4As shown, the first type of gate 421 and the second type of gate 422, located on the same side of the flow channel 410, are alternately distributed. This spatial staggered arrangement effectively improves the compactness of the injection mold structure and maximizes the utilization of the lateral space of the injection mold.

[0067] In one specific implementation, such as Figure 5 As shown, the first type of gating gate 421 located on both sides of the flow channel 410 is symmetrically distributed with the central axis of the flow channel 410 as the axis of symmetry, and the second type of gating gate 422 located on both sides of the flow channel 410 is symmetrically distributed with the central axis of the flow channel 410 as the axis of symmetry.

[0068] The symmetrical design ensures that the path length, turning angle, and flow resistance of the molding compound flowing from the runner 410 to the cavities 400 on both sides of the runner 410 are completely consistent. This eliminates uneven filling caused by process differences, effectively reducing defects such as warpage, shrinkage marks, or weld lines in the molded parts. The geometric symmetry significantly optimizes the flow balance of the molding compound. Furthermore, the symmetrical design balances the stress distribution on the injection mold, avoiding overflow or mold wear caused by unilateral loading, while improving space utilization and making the mold structure more compact, especially suitable for multi-cavity, high-precision molding scenarios. This symmetrical layout not only conforms to the balance principle of gating system design but also stabilizes the dimensional accuracy and mechanical properties of the molded parts through unified pressure transmission and cooling rate control, thus improving the quality of the packaged products.

[0069] In one specific implementation, such as Figure 4 As shown, the flow channel 410 further includes multiple buffer sections 411 and horizontal flow sections 412 disposed between the buffer sections 411. The width of the buffer sections 411 is greater than the width of the horizontal flow sections 412. The first type of gating gate 421 and the second type of gating gate 422 are respectively disposed on the sidewalls of the buffer sections 411. The flow channel 410 adopts a structure with alternating buffer sections 411 and horizontal flow sections 412, wherein the width of the buffer sections 411 is greater than that of the horizontal flow sections 412, forming a periodically changing flow channel cross-section. The buffer sections 411 (with greater width) accumulate molding compound and slow down the flow rate, while the horizontal flow sections 412 (with narrower width) maintain stable flow, thereby dynamically adjusting the pressure and flow rate distribution of the molding compound. The first type of gate 421 and the second type of gate 422 are respectively located on the sidewall of the buffer section 411. The material storage characteristics of the buffer section 411 compensate for pressure loss during multi-cavity filling, further improving filling uniformity. Simultaneously, the molding compound accumulated in the buffer section 411 effectively buffers injection pressure changes, reducing flash or internal stress caused by excessive instantaneous pressure, while also reducing the risk of cold material entering the cavity and improving product surface quality. The runner 410, through alternating wide and narrow runners, addresses the uneven cooling problem, comprehensively improving molding efficiency and product yield.

[0070] In one specific embodiment, the first type of gating gate 421 and the second type of gating gate 422 are respectively located at the top corner of the buffer section 411. The geometric constraint of the top corner can effectively reduce the impact of the molding compound and avoid the spraying phenomenon caused by the molding compound directly rushing into the cavity 400, making the flow front more stable. In addition, the top corner layout is compact, which can maximize the use of the lateral space of the buffer section 411.

[0071] The gating system provided by this utility model achieves molded material flow compensation by setting the cross-sectional areas of the first type gating port 421 and the second type gating port 422. This ensures that the amount of molded material filling in the cavity 400 connected to the second type gating port 422 within the same time period is basically the same as the amount filling in the cavity 400 connected to the first type gating port 421. This effectively solves the problem of unbalanced molded material filling caused by the difference in the included angle, improves the phenomenon of unbalanced encapsulation injection molding, and improves the quality of the encapsulated product.

[0072] This utility model also provides an injection mold in a specific embodiment. For example... Figures 1-10 As shown, where, Figure 9 The diagram shown is a schematic diagram of an injection mold provided in a specific embodiment of this utility model. Figure 10 The diagram shows a molding process using an injection mold provided by a specific embodiment of the present invention. The injection mold includes the aforementioned gating system and multiple cavities 400. The multiple cavities 400 are arranged on both sides of the runner 410. The first type of gating port 421 and the second type of gating port 422 are respectively connected to different cavities 400.

[0073] The angle between the extension direction of the first type of gating gate 421 and the extension direction of the flow channel 410 is smaller than the angle between the extension direction of the second type of gating gate 422 and the extension direction of the flow channel 410. Furthermore, the cross-sectional area of ​​the second type of gating gate 422 on the plane perpendicular to its extension direction is larger than the cross-sectional area of ​​the first type of gating gate 421 on the plane perpendicular to its extension direction. This achieves molded material flow compensation, ensuring that the amount of molded material filling in the cavity 400 connected to the second type of gating gate 422 within the same time period is basically the same as the amount filling in the cavity 400 connected to the first type of gating gate 421. This effectively solves the problem of unbalanced molded material filling caused by the angle difference, improves the phenomenon of unbalanced encapsulation injection molding, and enhances the quality of encapsulated products.

[0074] The cavity 400 is an empty cavity. The semiconductor device to be encapsulated (not shown in the figure) is placed on the lead frame 500 and located in the cavity 400. Molten encapsulating material is injected from the flow channel 410 and injected into the cavity 400 through the first type of gating port 421 or the second type of gating port 422.

[0075] In one specific embodiment, two cavities 400 connected to the first type of gating ports 421 located on both sides of the flow channel 410 and symmetrically distributed with the central axis of the flow channel 410 as the axis of symmetry are also symmetrically distributed with the central axis of the flow channel 410 as the axis of symmetry. Similarly, two cavities 400 connected to the second type of gating ports 422 located on both sides of the flow channel 410 and symmetrically distributed with the central axis of the flow channel 410 as the axis of symmetry are also symmetrically distributed with the central axis of the flow channel 410 as the axis of symmetry. This symmetrical design balances the force distribution of the injection mold, avoiding overflow or mold wear caused by unilateral loading, while also improving space utilization and making the injection mold structure more compact. It is particularly suitable for multi-cavity, high-precision molding scenarios. Furthermore, by controlling the pressure transmission and cooling rate uniformly, it stabilizes the dimensional accuracy and mechanical properties of the molded parts, which is beneficial for improving the quality of the packaged products.

[0076] In one specific embodiment, the cavities 400 are arranged on both sides of the horizontal flow section 412 of the flow channel 410. The width of the horizontal flow section 412 is smaller than the width of the buffer section 411. By arranging the cavities 400 on both sides of the horizontal flow section 412 of the flow channel 410, the space utilization rate can be further improved, making the injection mold structure more compact.

[0077] The gating system and injection mold provided by this utility model are configured with the cross-sectional area of ​​the gating gate according to the extension direction of the gating gate, thereby realizing the compensation of the molding compound flow rate. This ensures that the amount of molding compound filling in the cavity connected to the second type of gating gate in the same time period is basically the same as the amount filling in the cavity connected to the first type of gating gate. This effectively solves the problem of uneven filling of molding compound caused by the difference in the included angle, improves the phenomenon of uneven encapsulation injection molding, and improves the quality of the encapsulated product.

[0078] It should be noted that the terms "comprising" and "having," and their variations, used in this utility model document are intended to cover non-exclusive inclusion. The terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence, unless explicitly indicated by the context; it should be understood that such use of data can be interchanged where appropriate. The term "one or more" depends at least in part on the context and can be used to describe features, structures, or characteristics in a singular sense, or in a plural sense to describe combinations of features, structures, or characteristics. The term "based on" can be understood as not necessarily intended to express an exclusive set of factors, but can instead, also at least in part on the context, allow for the presence of other factors that are not necessarily explicitly described. Furthermore, embodiments and features in embodiments of this utility model can be combined with each other without conflict. In addition, descriptions of well-known components and technologies have been omitted in the above description to avoid unnecessarily obscuring the concepts of this utility model. In the various embodiments described above, each embodiment focuses on the differences from other embodiments; similar / identical parts between embodiments can be referred to mutually.

[0079] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A casting system, characterized in that, include: The flow channel has a main extending direction; The gating assembly includes: A first type of gating gate is disposed on the sidewall of the flow channel and communicates with the flow channel. The first type of gating gate has a first extending direction, which forms a first angle with the main extending direction. The first type of gating gate has [specific features] on a plane perpendicular to the first extending direction. First cross-sectional area; A second type of gating gate is disposed on the sidewall of the flow channel and communicates with the flow channel. The second type of gating gate has a second extending direction, which forms a second angle with the main extending direction. The second type of gating gate has [specific features] on a plane perpendicular to the second extending direction. Second cross-sectional area; Wherein, the first included angle is smaller than the second included angle, and the first cross-sectional area is smaller than the second cross-sectional area.

2. The casting system according to claim 1, characterized in that, The first included angle is an acute angle, and the second included angle is a right angle or an obtuse angle.

3. The casting system according to claim 1, characterized in that, The difference between the second cross-sectional area and the first cross-sectional area is positively correlated with the difference between the second included angle and the first included angle.

4. The casting system according to claim 1, characterized in that, The first type of gating gate and the second type of gating gate are alternately distributed on the same side of the flow channel.

5. The casting system according to claim 1, characterized in that, The first type of pouring gates located on both sides of the flow channel are symmetrically distributed with the central axis of the flow channel as the axis of symmetry.

6. The casting system according to claim 1, characterized in that, The second type of pouring gates located on both sides of the flow channel are symmetrically distributed with the central axis of the flow channel as the axis of symmetry.

7. The gating system according to claim 1, characterized in that, The first extension direction and the second extension direction are symmetrically distributed about the vertical line of the central axis of the flow channel.

8. The gating system according to claim 1, characterized in that, The flow channel also includes multiple buffer sections and a horizontal flow section disposed between the buffer sections. The width of the buffer section is greater than the width of the horizontal flow section. The first type of pouring gate and the second type of pouring gate are respectively disposed on the side wall of the buffer section.

9. The gating system according to claim 8, characterized in that, The first type of gating gate and the second type of gating gate are respectively located at the top corner of the buffer section.

10. The casting system according to claim 1, characterized in that, The shape of the first type of gating gate is the same as that of the second type of gating gate.

11. The casting system according to claim 1, characterized in that, The cross-sectional shape of the first type of gating gate in the plane of the first extension direction and the cross-sectional shape of the second type of gating gate in the plane of the second extension direction are both rectangular.

12. The casting system according to claim 1, characterized in that, The cross-sectional shape of the first type of gating gate in the plane of the first extension direction and the cross-sectional shape of the second type of gating gate in the plane of the second extension direction are both trapezoidal. In the first extension direction, the size of the connection between the first type of gating gate and the flow channel is the smallest, and in the second extension direction, the size of the connection between the second type of gating gate and the flow channel is the smallest.

13. An injection mold, characterized in that, include: The gating system as described in any one of claims 1 to 12; Multiple cavities are arranged on both sides of the flow channel, and the first type of gating gate and the second type of gating gate are respectively connected to different cavities.

14. The injection mold according to claim 13, characterized in that, The two cavities connected to the first type of gating gates located on both sides of the flow channel and symmetrically distributed with the central axis of the flow channel as the axis of symmetry are symmetrically distributed with the central axis of the flow channel as the axis of symmetry.

15. The injection mold according to claim 13, characterized in that, The two cavities connected to the second type of gating ports located on both sides of the flow channel and symmetrically distributed with the central axis of the flow channel as the axis of symmetry are symmetrically distributed with the central axis of the flow channel as the axis of symmetry.

16. The injection mold according to claim 13, characterized in that, The cavities are arranged on both sides of the horizontal flow section of the flow channel.

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