Flow adjusting device suitable for vacuum negative pressure

Abstract

The flow adjusting device comprises a valve seat, flow guiding connectors and a valve rod, a horizontal channel and a vertical channel which are crossed with each other are arranged in the valve seat, the flow guiding connectors are arranged on the two sides of the horizontal channel, the valve rod is connected with the interior of the vertical channel in a sealed mode and can move up and down or rotate, and the valve rod is connected with the valve seat in a sealed mode. The valve rod further comprises a plurality of valve element adjusting holes which are formed at intervals, the valve element adjusting holes penetrate through the valve rod, and any number of valve element adjusting holes are controlled to be located on a circulation path of the horizontal channel by controlling the valve rod to move to different positions. According to the utility model, the flow of vacuum negative pressure can be adjusted as required, gas in a mold cavity can be completely extracted, a plastic package material can be subjected to injection production and multi-point synchronous adsorption of a lead frame in a certain vacuum environment, the lead frame is ensured to be reliably and flatly adsorbed, and the packaging efficiency, performance and reliability of a product are greatly improved; meanwhile, the device is low in manufacturing cost, long in service life and good in using effect.

Description

Technical Field

[0001] The utility model relates to the technical field of vacuuming, in particular to a flow regulating device suitable for vacuum negative pressure. Background Art

[0002] With the increasingly rapid development of semiconductor packaging equipment and the rapid development of artificial intelligence, mobile communications and new energy, the requirements for power module chip packaging technology are becoming increasingly higher. Packaging has also changed from simple to complex forms. Some special chips have special requirements during the packaging process.

[0003] Traditional packaging equipment uses a robotic arm to move the semiconductor chip lead frame and epoxy resin to the mold cavity and insert. The mold heats up, and the injection mechanism melts the epoxy resin into a liquid form, squeezing it into the mold cavity. After a period of time, the epoxy resin solidifies, completing the package.

[0004] The mold utilizes sealing rings of varying sizes and types to construct the mold frame encapsulation into a sealed container. Vacuum holes are then introduced to evacuate the mold frame, reducing air bubbles and ensuring packaging quality. Currently, the vacuum system within the mold relies solely on vent holes and slots built into the mold inserts. After the mold is formed, an ejection mechanism, such as an ejector pin, is required to eject the chip from the mold. These ejection components require a certain clearance between them and the molded components.

[0005] Although the setting of these exhaust mechanisms in the mold can effectively solve the problem of residual gas in the mold cavity, for large and complex chip products, due to their intricate internal structural characteristics, the mold cavity is also extremely complex and changeable. Traditional valves used for vacuum negative pressure flow regulation are expensive, and the accuracy and effect of flow regulation are poor. Various molding quality problems are prone to occur during packaging production, so the quality of the product after being packaged from the mold is very unstable. Utility Model Content

[0006] The purpose of the utility model is to solve the shortcomings of the existing technology and propose a flow regulating device suitable for vacuum negative pressure, which can adjust the flow rate of vacuum negative pressure, ensure that the gas in the mold cavity is completely extracted, and ensure that the chip and the outside world are packaged in a completely vacuum state, thereby greatly improving the product packaging efficiency, performance and reliability.

[0007] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0008] A flow regulating device suitable for vacuum negative pressure includes a valve seat, two guide joints and a valve stem. The valve seat is provided with a horizontal channel and a vertical channel that intersect with each other. The guide joints are arranged on both sides of the horizontal channel. The valve stem is sealed and connected to the inside of the vertical channel and can move up and down or rotate. The valve stem also includes a plurality of valve core adjustment holes arranged at intervals. The valve core adjustment holes pass through the valve stem. By controlling the valve stem to move to different positions, any number of valve core adjustment holes can be controlled to be located on the flow path of the horizontal channel.

[0009] Preferably, the first flow guide joint is connected to the vacuum equipment, and the second flow guide joint is connected to the vacuumed mold.

[0010] Preferably, the vacuum negative pressure flow regulating device further comprises a sealing sleeve, which connects the valve stem and the valve seat to control the valve seat and the upper end of the valve stem to be in a sealed connection state.

[0011] Preferably, the sealing sleeve comprises an inner tube and an outer tube, a reset element is provided between the inner tube and the outer tube, the inner tube and the outer tube are sealed and movably connected, and the inner tube is fixedly connected to the valve stem.

[0012] Preferably, the reset element is a spring.

[0013] Preferably, the reset element is a damping element.

[0014] Preferably, a handle is fixedly provided on the upper end of the valve stem, and the handle is arranged crosswise with the valve stem.

[0015] Preferably, the valve core adjustment holes are arranged in the same direction.

[0016] Preferably, the valve core adjustment holes are arranged circumferentially around a predetermined axis.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] Through the above structural design, the position of the valve stem is controlled by lifting to open and close the equipment, and the number of valve core adjustment holes in the horizontal channel is controlled by rotating the valve stem to adjust the gas circulation rate. The above structural design can open and close the equipment, and can also adjust the flow rate of the vacuum negative pressure as needed, so that the maximum vacuum force on the vacuum mold reaches -90kgPa, ensuring that the gas in the mold cavity is completely evacuated, so that the plastic packaging material can be injected under a certain high vacuum environment, and the lead frame is adsorbed synchronously at multiple points to ensure reliable and flat adsorption of the lead frame, greatly improving the product packaging efficiency, performance and reliability. At the same time, the device has low cost, high adjustment accuracy, long service life and good use effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1It is a schematic diagram of the three-dimensional structure of the utility model.

[0020] Figure 2 It is a side structural schematic diagram of the present utility model.

[0021] Figure 3 This is a schematic diagram of the AA-section structure of the present invention.

[0022] Figure 4 For this utility model Figure 3 Schematic diagram of the enlarged structure at point B.

[0023] Figure 5 This is a schematic diagram of the utility model in use.

[0024] In the figure: 100, valve seat; 110, horizontal channel; 120, vertical channel; 200, guide joint; 300, sealing sleeve; 310, inner tube; 320, outer tube; 400, reset element; 500, valve stem; 510, valve core adjustment hole; 520, handle; 600, vacuum mold frame. DETAILED DESCRIPTION

[0025] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of specific embodiments of the present invention is provided in conjunction with the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without violating the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0026] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly attached to the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0027] Packaged chips QFN, DFN, DIP, LGA, MSOP8, OMP, QFNC, these high-end chips used in different occasions have very high packaging requirements. It is necessary to ensure that the chip and the outside world are in a completely vacuum state before the epoxy resin is cured. In the vacuum forming state, the product has no filling defects and is reliably sealed. The maximum vacuum force on the vacuum mold must reach -90kgPa.

[0028] The utility model is mainly used for semiconductor packaging chips in the vacuum forming state. The product has no filling defects. The speed and flow of vacuum suction can be adjusted to achieve reliable sealing, ensure multi-point synchronous adsorption of lead frames, and ensure reliable and flat adsorption of lead frames.

[0029] This set of components is mainly used to design a vacuum circuit under the molding insert, and to adjust the single-sided gap between the valve air groove adjustment core and the vacuum air hole to 0.2mm. When the mold is packaged, the lead frame is first adsorbed to make the lead frame and the molding insert fit tightly to ensure that the lead frame is flat.

[0030] In order to solve the problems raised in the background technology, Figure 1 -Attached Figure 5 A flow regulating device suitable for vacuum negative pressure includes a valve seat 100, a guide joint 200 and a valve stem 500. The valve seat 100 is provided with a cavity to form a horizontal channel 110 for the flow of vacuum medium and a vertical channel 120 for the movement of the valve stem 500. The valve stem 500 here can move up and down and rotate in the vertical channel 120; the left and right ends of the valve seat 100 are connected to the guide joints 200, the first guide joint 200 is connected to the vacuum equipment, and the second guide joint 200 is connected to the mold to be vacuumed. The horizontal channel 110 runs through the guide joint 200, and the gas is discharged through the horizontal channel 110 during the vacuuming process.

[0031] The valve stem 500 is inserted into the vertical channel 120 and abuts against the inside of the valve seat 100; when the valve stem 500 is inserted into the bottom of the valve seat 100, the horizontal channel 110 is blocked by the valve stem 500 and gas cannot flow, then the vacuum extraction stops. When the valve stem 500 is lifted to the upper end of the horizontal channel 110, the vacuum extraction starts and the rate is maximum.

[0032] Here, the valve stem 500 and the valve seat 100 are closed and connected by a sealing sleeve 300. The sealing sleeve 300 includes an inner cylinder 310 and an outer cylinder 320. The inner cylinder 310 and the outer cylinder 320 are sealed and movable, and a reset element 400 is provided in the middle. The inner cylinder 310 is fixedly connected to the valve stem 500. Under normal circumstances, the reset element 400 is in a first state, the bottom of the valve stem 500 is against the bottom of the valve seat 100, and the device is in a closed state. Pressing the valve stem 500 puts the reset element 400 in a second state, driving the valve stem 500 to move upward, and the device is in an open state.

[0033] Those skilled in the art can control the reset element 400 and the valve stem 500 to be in different opening and closing control states according to the adjustment requirements of different systems to achieve a special open or closed state.

[0034] The above-mentioned reset element 400 can be selected as a common spring or other elastic components with elastic function.

[0035] In order to further achieve precise regulation of the flow rate of vacuum negative pressure, an adjustment handle 520 is provided at the upper end of the valve stem 500, and a plurality of relative valve core adjustment holes 510 are provided near the bottom end of the valve stem 500. The valve core adjustment holes 510 pass through the valve stem 500 to allow gas to flow out.

[0036] When the device is in the open state, move the adjustment handle 520 to control the number of valve core adjustment holes 510 in the horizontal channel 110 to adjust the gas circulation rate. The more valve core adjustment holes 510 there are, the greater the gas circulation rate, and vice versa. The vacuum negative pressure in the mold is ensured by adjusting the gas circulation rate.

[0037] Taking the three valve core adjustment holes 510 in the attached figure as an example, controlling one valve core adjustment hole 510 to be located on the conduction path of the horizontal channel 110 completes the flow rate of one valve core adjustment hole 510 , and the effects of two or three valve core adjustment holes 510 are similar.

[0038] Opening and closing can be achieved by lifting the valve stem 500, and can also be achieved by rotating the valve stem 500; the valve core adjustment holes 510 here can be designed to face the same direction, or can be arranged circumferentially around a predetermined axis, controlling the valve stem 500 to rotate to different angular positions, and controlling different valve core adjustment holes 510 to be located on the flow path of the horizontal channel 110 to achieve the purpose of flow regulation.

[0039] The structural design adopts multiple valve core adjustment holes 510, and a damping element can also be set between the sealing sleeve 300 and the valve stem 500. The control valve stem 500 can be moved to any position to stop without the need for staff or working equipment to adjust and control, which is simple and efficient.

[0040] Workflow: external vacuum pump - through KF16 vacuum bellows - high vacuum valve body - suction mold cavity - stainless steel K vacuum stop valve core adjustment port - reach the set negative pressure - the whole set of steps is completed.

[0041] A vacuum circuit is designed under the molding insert. When the mold is packaged, the lead frame is first adsorbed to make the lead frame and the molding insert fit tightly to ensure that the lead frame is flat.

[0042] In summary, through the above structural design, the position of the valve stem 500 is controlled by lifting to open and close the equipment, and the number of valve core adjustment holes 510 in the horizontal channel 110 is controlled by rotating the valve stem 500 to adjust the rate of gas circulation; through the above structural design, the equipment can be opened and closed, and the flow rate of the vacuum negative pressure can be adjusted as needed, so that the maximum vacuum force on the vacuum mold reaches -90kgPa, ensuring that the gas in the mold cavity is completely extracted, so that the plastic packaging material can be injected under a certain vacuum environment, and the lead frame is adsorbed synchronously at multiple points to ensure that the lead frame is adsorbed reliably and flatly, greatly improving the product packaging efficiency, performance and reliability; at the same time, the device has low cost, long service life and good use effect.

[0043] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the present invention can make equivalent replacements or changes based on the technical solution and utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A flow regulating device suitable for vacuum negative pressure, comprising a valve seat (100), two flow guide joints (200) and a valve stem (500), characterized in that: The valve seat (100) is provided with a horizontal channel (110) and a vertical channel (120) that intersect with each other, and the flow guide joint (200) is provided on both sides of the horizontal channel (110). The valve stem (500) is sealed and connected to the inside of the vertical channel (120) and can move up and down or rotate. The valve stem (500) also includes a plurality of valve core adjustment holes (510) arranged at intervals. The valve core adjustment holes (510) pass through the valve stem (500). By controlling the valve stem (500) to move to different positions, any number of valve core adjustment holes (510) can be controlled to be located on the flow path of the horizontal channel (110).

2. A flow regulating device suitable for vacuum negative pressure according to claim 1, characterized in that: The first flow guide joint (200) is connected to a vacuuming device, and the second flow guide joint (200) is connected to a vacuumed mold.

3. A flow regulating device suitable for vacuum negative pressure according to claim 1, characterized in that: The valve stem (500) and the valve seat (100) are connected to each other to control the valve seat (100) and the upper end of the valve stem (500) to be in a sealed connection state.

4. A flow regulating device suitable for vacuum negative pressure according to claim 3, characterized in that: The sealing sleeve (300) comprises an inner cylinder (310) and an outer cylinder (320), a reset element (400) is provided between the inner cylinder (310) and the outer cylinder (320), the inner cylinder (310) and the outer cylinder (320) are sealed and movably connected, and the inner cylinder (310) is fixedly connected to the valve stem (500).

5. A flow regulating device suitable for vacuum negative pressure according to claim 4, characterized in that: The reset element (400) is a spring.

6. A flow regulating device suitable for vacuum negative pressure according to claim 4, characterized in that: The reset element (400) is a damping element.

7. A flow regulating device suitable for vacuum negative pressure according to claim 1, characterized in that: A handle (520) is fixedly provided on the upper end of the valve stem (500), and the handle (520) and the valve stem (500) are arranged crosswise.

8. A flow regulating device suitable for vacuum negative pressure according to claim 1, characterized in that: The valve core adjustment holes (510) are arranged in the same direction.

9. A flow regulating device suitable for vacuum negative pressure according to claim 1, characterized in that: The valve core adjustment holes (510) are circumferentially arranged around a predetermined axis.

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