Movable clamp jaw of a mold unloader

Abstract

The utility model discloses a movable clamp jaw of mould unloading machine, including jaw body, bolted connection axle, compression spring, oilless bushing and mounting plate, the jaw body adopts PEEK material, and the upper portion is provided with bolt mounting hole, and the lower end of bolted connection axle is fixed with bolt mounting hole thread cooperation, the mounting plate is equipped with the slot and oilless bushing installation site, and the oilless bushing is embedded in the installation site, and bolted connection axle is set up through the oilless bushing, the compression spring is set up in the outside of bolted connection axle, and the compression spring pre -compression length is 4.5mm, can be compressed 2mm along bolted connection axle axial direction, the utility model discloses the jaw structure and spring buffer design of up and down activity, effectively avoid the collision risk of jaw and mould, and guarantee the stability of structure through the mechanics optimization simultaneously, and the accurate operation demand of adaptation semiconductor package production.

Description

Technical Field

[0001] This utility model belongs to the field of semiconductor packaging technology, specifically relating to a movable gripper for a mold unloading machine. Background Technology

[0002] In the semiconductor packaging production process, semiconductor molding molds are the core equipment for realizing chip resin packaging. They work in conjunction with unloaders to complete the loading and unloading of packaged products (such as ball grid array packaged products), which is a key link to ensure production continuity.

[0003] In the existing technology, the normal production process needs to follow a fixed action logic: after the semiconductor molding die is opened, the mold frame of the lower mold needs to be lowered by 3mm so that the packaged product can be kept stationary in its original position by relying on the frame ejector pins. Then the Unloader unit moves to the top of the mold to perform the material picking action. At this time, the lower surface of the movable gripper on the Unloader maintains a safe distance of 1mm from the surface of the lower mold to avoid interference.

[0004] However, in practical applications, due to the incomplete development of software functions in semiconductor packaging equipment, an abnormal situation often occurs where the lower mold holder fails to descend the preset 3mm stroke after mold opening. In this case, the unloader unit will still move above the mold according to the established program, causing the moving gripper to directly collide and interfere with the undescended lower mold. This problem not only causes surface scratches on the semiconductor molding die, affecting mold precision and the quality of subsequent packaged products, but in severe cases, it can also cause the moving gripper to break, resulting in equipment downtime, significantly reducing production efficiency and increasing the cost of mold repair and gripper replacement.

[0005] Therefore, in view of the technical defects of existing unloader active grippers that are prone to collision with molds in scenarios where the equipment software functions are not perfect, there is an urgent need for an active gripper structure that can avoid the above-mentioned collision risks and ensure stable production. Summary of the Invention

[0006] The purpose of this invention is to provide a movable gripper for a mold unloading machine to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a movable gripper for a mold unloading machine, comprising a gripper body, a bolt-connected shaft, a compression spring, an oil-free bushing, and a mounting plate;

[0008] The upper part of the gripper body is provided with a bolt mounting hole, and the lower end of the bolt connecting shaft is provided with an external thread that matches the bolt mounting hole. The two are threadedly connected and fixed.

[0009] The mounting plate is provided with a slot and an oil-free bushing mounting position. The oil-free bushing is embedded in the oil-free bushing mounting position, and the bolt connecting shaft passes through the oil-free bushing.

[0010] The gripper body is adapted to be fitted into the slot and can move up and down along the slot, while the slot restricts the rotation of the gripper body.

[0011] The compression spring is sleeved on the outside of the bolt connection shaft. The preload length of the compression spring is 4.5mm, the maximum compression stroke is 2mm, and the spring length after compression is 2.5mm.

[0012] Preferably, the active gripper satisfies the mechanical design formula: G gripper + G connecting shaft + G spring + F spring preload > f1 + f2; where G gripper is the weight of the gripper body, G connecting shaft is the weight of the bolt connecting shaft, G spring is the weight of the compression spring, F spring preload is the preload of the compression spring, f1 is the frictional force between the gripper body and the slot, and f2 is the frictional force between the bolt connecting shaft and the oil-free bushing.

[0013] Preferably, the inner wall of the card slot is plated with hard chrome, the plating thickness is 10-20 μm, and the surface roughness is 1.6G.

[0014] Preferably, the bottom of the gripper body is provided with an anti-slip and wear-resistant layer, which is a tungsten carbide coating with a thickness of 0.3-0.5mm; this increases the friction between the gripper and the product, prevents the product from slipping during the picking process, and enhances the wear resistance of the bottom of the gripper, thus extending the service life of the gripper.

[0015] The technical effects and advantages of this utility model are as follows:

[0016] 1. Collision risk avoidance: Through the design of compression spring and vertically movable gripper structure, when the mold frame does not descend as preset, the gripper can be compressed upward by 2mm due to the resistance of the lower mold, so as to achieve buffer avoidance and effectively avoid direct collision between the gripper and the mold, protect the mold precision and the integrity of the gripper structure, and reduce equipment downtime and maintenance costs.

[0017] 2. High structural stability: The gripper rotation is restricted by the slot, and the friction of the movement is reduced by the oil-free bushing. At the same time, the optimized design based on mechanical formulas ensures that the gripper can stably reset in the free state, ensuring the accuracy and reliability of the material handling operation.

[0018] 3. Upgraded wear resistance and extended service life: The 10-20μm thick hard chrome plating (surface roughness 1.6G) on the inner wall of the slot reduces friction and wear between the gripper body and the slot. The 0.3-0.5mm thick tungsten carbide anti-slip and wear-resistant layer on the bottom of the gripper body not only improves the friction with the product (preventing the material from slipping) but also enhances the wear resistance of the bottom.

[0019] 4. Excellent adaptability and environmental friendliness: The gripper body is made of PEEK material, which has excellent wear resistance and insulation properties, making it suitable for the clean working environment of semiconductor packaging; the oil-free bushing requires no additional lubrication, avoiding the risk of grease contamination of semiconductor products. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this utility model;

[0021] Figure 2 This is a side view of the present invention (without mounting plate).

[0022] In the diagram: gripper body-1, bolt connecting shaft-2, compression spring-3, oil-free bushing-4, mounting plate-5, bolt mounting hole-11, slot-51. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] like Figure 1 - Figure 2 This invention illustrates a specific embodiment of a movable gripper for a mold unloading machine: it includes a gripper body 1, a bolt-connected shaft 2, a compression spring 3, an oil-free bushing 4, a mounting plate 5, and bolt mounting holes 11;

[0025] The model selection and functions of each component are as follows:

[0026] Gripper body 1: Made of PEEK material in one piece, it has excellent wear resistance and insulation properties, making it suitable for the clean working environment of semiconductor packaging. The upper part of gripper body 1 has bolt mounting holes 11 along the vertical direction, and the inner wall of the bolt mounting holes 11 is machined with internal threads. After sandblasting, the bottom of gripper body 1 is coated with a 0.4mm thick tungsten carbide anti-slip and wear-resistant layer. This coating is prepared by plasma spraying process, has high bonding strength, and can effectively improve the friction when the gripper contacts the ball grid array packaged product, preventing the product from slipping during the picking process. At the same time, it enhances the wear resistance of the bottom of the gripper and extends its service life.

[0027] Bolt connecting shaft 2: Made of stainless steel, its lower end is provided with an external thread that matches the bolt mounting hole 11. The bolt connecting shaft 2 and the gripper body 1 are detachably fixed through the threaded connection, which is convenient for later maintenance and replacement. The shaft diameter of the bolt connecting shaft 2 is matched with the inner diameter of the oil-free bushing 4 to ensure coaxiality during the movement.

[0028] Compression spring 3: A cylindrical compression spring of model WF6-5 is selected, with a compression length of 2.3mm. In this device, the preload length is set to 4.5mm, the maximum compression stroke is 2mm, and the spring length after compression is 2.5mm, which meets the requirements for spring elastic deformation and can provide stable preload and buffer force.

[0029] Oil-free bushing 4: A self-lubricating oil-free bushing of model K5B0403 is used and is embedded in the oil-free bushing mounting position of the mounting plate 5. The outer ring of the oil-free bushing 4 is fixed with the mounting plate 5 by interference fit, and the inner ring is slidably fitted with the bolt connecting shaft 2. This can effectively reduce the friction when the bolt connecting shaft 2 moves up and down, improve the smoothness of movement, and at the same time avoid the contamination of semiconductor products by lubricating grease.

[0030] Mounting plate 5: Made of aluminum alloy, it has a rectangular slot 51 and a circular oil-free bushing mounting position integrally formed on it; the cross-sectional dimensions of the slot 51 are matched with the outer dimensions of the gripper body 1 to ensure that the gripper body 1 can move up and down along the slot 51, while restricting the rotation of the gripper body 1 around the bolt connection shaft 2 to ensure material picking accuracy.

[0031] Work process:

[0032] Normal material handling state: After the semiconductor molding die is opened, the mold base of the lower die descends 3mm according to the preset stroke. The packaged product is kept stationary in its original position by the frame ejector pins. At this time, under the combined action of its own weight (G gripper), the weight of the bolt connecting shaft (G connecting shaft), the weight of the compression spring (G spring), and the spring preload (F spring preload), the gripper body overcomes the friction between the gripper and the slot (f1) and the friction between the bolt connecting shaft and the oil-free bushing (f2) and stably falls back to the initial position.

[0033] At this time, the lower surface of the gripper body maintains a safe distance of 1mm from the surface of the lower mold. The Unloader unit moves above the mold, the gripper body clamps the product and completes the material handling action. The entire process is interference-free and the precision is controllable.

[0034] Abnormal buffer state: When the equipment software malfunctions and the lower mold frame does not descend by the preset 3mm after the mold opens, the Unloader unit still moves to the top of the mold according to the established program; the lower surface of the gripper body first contacts the lower mold that has not descended, and the lower mold applies upward resistance, pushing the gripper body to slide upward along the slot; the compression spring is further compressed until it reaches the maximum compression stroke of 2mm, and absorbs the impact force of the collision through elastic deformation to achieve buffer avoidance, avoid rigid contact between the gripper and the mold, and protect the structural integrity and precision of both.

[0035] The structural design of this utility model strictly follows the mechanical formula: G gripper + G connecting shaft + G spring + F spring preload > f1 + f2; where G gripper is the weight of gripper body 1, G connecting shaft is the weight of bolt connecting shaft 2, G spring is the weight of compression spring 3, F spring preload is the preload of compression spring 3, f1 is the frictional force between gripper body 1 and guide bushing 6, and f2 is the frictional force between bolt connecting shaft 2 and oil-free bushing 4; through this mechanical design, it is ensured that gripper body 1 can stably fall back to the initial position when there is no resistance from the lower die, thus ensuring the reliability of the material handling operation.

[0036] The applicant further declares that while the above embodiments illustrate the implementation method and apparatus structure of this utility model, this utility model is not limited to the above-described embodiments, meaning that this utility model must rely on the above methods and structures to be implemented. Those skilled in the art should understand that any improvements to this utility model, equivalent substitutions for the selected implementation methods, additions of steps, and selection of specific methods all fall within the protection and disclosure scope of this utility model.

[0037] This utility model is not limited to the above-described embodiments. All methods that use similar structures and methods to achieve the purpose of this utility model are within the protection scope of this utility model.

Claims

1. A movable gripper for a mold unloading machine, characterized in that: Includes gripper body (1), bolt connection shaft (2), compression spring (3), oil-free bushing (4) and mounting plate (5); The upper part of the gripper body (1) is provided with a bolt mounting hole (11), and the lower end of the bolt connecting shaft (2) is provided with an external thread that matches the bolt mounting hole (11). The two are threadedly connected and fixed. The mounting plate (5) is provided with a slot (51) and an oil-free bushing mounting position. The oil-free bushing (4) is embedded in the oil-free bushing mounting position. The bolt connecting shaft (2) passes through the oil-free bushing (4). The gripper body (1) is adapted to be fitted into the slot (51) and can move up and down along the slot (51). The slot (51) restricts the rotation of the gripper body (1). The compression spring (3) is sleeved on the outside of the bolt connection shaft (2). The pre-compression length of the compression spring is 4.5mm, the maximum compression stroke is 2mm, and the spring length after compression is 2.5mm.

2. The movable gripper of a mold unloading machine according to claim 1, characterized in that: The gripper in this activity satisfies the mechanical design formula: G gripper + G connecting shaft + G spring + F spring preload > f1 + f2; where G gripper is the weight of the gripper body, G connecting shaft is the weight of the bolt connecting shaft, G spring is the weight of the compression spring, F spring preload is the preload of the compression spring, f1 is the frictional force between the gripper body and the slot, and f2 is the frictional force between the bolt connecting shaft and the oil-free bushing.

3. The movable gripper of a mold unloading machine according to claim 1, characterized in that: The inner wall of the card slot (51) is plated with hard chrome, with a plating thickness of 10-20 μm and a surface roughness of 1.6G.

4. The movable gripper of a mold unloading machine according to claim 1, characterized in that: The gripper body (1) has an anti-slip and wear-resistant layer at the bottom, which is a tungsten carbide coating with a thickness of 0.3-0.5 mm.

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