Film feeding mechanism

Abstract

The utility model belongs to the field of semiconductor film pasting, and relates to a film feeding mechanism which comprises a first guide wheel, a driven counterweight mechanism, a driving lifting mechanism and a second guide wheel, film paper passes through the first guide wheel, is wound below the driven counterweight mechanism, then extends to the upper part of the driving lifting mechanism, passes through the lower part of the second guide wheel, and finally passes through the second guide wheel. And the film paper is wound on the film drawing device and extends to the film pasting platform, and the film paper is wound, so that the driving lifting mechanism can drive the driven counterweight mechanism to perform lifting adjustment. After the structure is adopted, the film pasting device has the beneficial effects that in the film pasting process, film paper is kept in a straightened and non-tight state all the time, the internal stress of the film paper is eliminated, the subsequent film pasting action is facilitated, and the subsequent technological process can be ensured not to be influenced.

Description

Technical Field

[0001] The utility model belongs to the technical field of semiconductor lead frame film pasting, and specifically relates to a film feeding mechanism. Background Art

[0002] In traditional semiconductor lead frame film pasting equipment, as Figure 1 shown, the bottom film recovery disk 700 serves as the driving wheel. The yellow film passes through all functional areas such as the heating mechanism 200, the tensioning wheel 300, the film separating mechanism 400, the buffer mechanism 600, the film guiding mechanism 800, and the film cutting mechanism 900, and finally pulls the raw material disk 100 to achieve the supply of the yellow film. In such a structure, there are too many force change points during the supply process of the yellow film, and the forces applied to the yellow film are all hard limits. The holding force applied by the mechanism to the yellow film remains constant, resulting in the yellow film being likely to be pasted onto the lead frame in a state with certain internal stress, which is not conducive to the subsequent process state of the lead frame after film pasting and is also prone to generating bubbles. Therefore, improvement is needed. Summary of the Utility Model

[0003] The purpose of the utility model is to provide a film feeding mechanism to solve the problem that the existing film pasting equipment applies hard limits to the yellow film, and the holding force applied by the mechanism to the yellow film remains constant, resulting in the yellow film being pasted onto the lead frame in a state with certain internal stress.

[0004] To achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A film feeding mechanism, which includes:

[0006] An installation bracket;

[0007] A first reel, the first reel is rotatably arranged on the installation bracket, and the reel is provided with film paper, which is composed of yellow film and bottom film;

[0008] A tensioning assembly, the tensioning assembly is arranged on the installation bracket, and the assembly is located on the right side of the first reel. The tensioning assembly is used for tension adjustment of the film paper;

[0009] A film puller, the film puller is movably arranged on one side of the installation bracket, and the film puller is located on the right side of the tensioning assembly. The film puller is provided with a negative pressure area, and the film paper is adsorbed on the film puller through the negative pressure area. The film puller slides left and right on the film pasting platform to drive the film paper to the film pasting area;

[0010] A second reel, the second reel is rotatably arranged on the installation bracket, the second reel is located on the right side of the first reel and close to the film pasting platform, and the second reel is used for recovering the bottom film.

[0011] In one embodiment, the tensioning assembly includes:

[0012] A first guide wheel rotatably arranged on the mounting bracket and located on one side of the first reel. The first guide wheel supports and guides the film paper.

[0013] A driven counterweight mechanism movably arranged on the mounting bracket and located on the right side of the first guide wheel. The driven counterweight mechanism can move up and down slidably to achieve the movable placement of the paper film at different positions, so as to keep the film paper always in a just-straightened and non-tight state.

[0014] A main lifting mechanism arranged on the mounting bracket and located on the right side of the driven counterweight mechanism. The main lifting mechanism makes corresponding follow-up movements according to the actions of the film pulling device, avoiding the film paper being in an overly tight state during the film feeding process, eliminating its internal stress, and always keeping the film paper straightened and not subjected to excessive tensile force.

[0015] A second guide wheel rotatably arranged on the mounting bracket and located on the right side of the main lifting mechanism. The second guide wheel supports and guides the film paper.

[0016] In one embodiment, the driven counterweight mechanism includes a counterweight wheel and a sliding component. The counterweight wheel is fixed on the sliding component, and the sliding component is slidably arranged on the mounting bracket. The counterweight wheel moves up and down on the first guide rail according to different states of film feeding.

[0017] In one embodiment, the sliding component includes a first guide rail and a slider. The slider is slidably arranged on the first guide rail, the counterweight wheel is fixed on the first slider, and the first guide rail is arranged on the mounting bracket.

[0018] In one embodiment, the driven counterweight mechanism further includes a position sensor and a counterweight induction bracket. The position sensor is arranged on the mounting bracket, the counterweight induction bracket is arranged on one side of the first slider, and the position sensor cooperates with the counterweight induction bracket.

[0019] In one embodiment, the position sensor is arranged on a second guide rail. The second guide rail is arranged on the mounting bracket and is parallel to the first guide rail. The position sensor can be freely installed on the second guide rail according to different installation requirements.

[0020] In one embodiment, the active lifting mechanism includes a third guide rail, a lifting wheel, and a driving component. A second slider is provided on the third guide rail, the lifting wheel is arranged on the second slider, and the movable end of the driving component is fixedly arranged on the second slider. The film paper is wound around from below the counterweight wheel and then extends above the lifting wheel, and then the film paper passes below the second guide wheel and then extends to the film application platform. Through this winding of the film paper, the lifting wheel can drive the counterweight wheel to perform lifting adjustment.

[0021] In one embodiment, the active lifting mechanism further includes a fourth guide rail, which is parallel to the third guide rail, and the second sliders are respectively slidably arranged on the third guide rail and the fourth guide rail.

[0022] In one embodiment, the first reel includes a rotating shaft, a fixed side plate, and an adjustable side plate. The fixed side plate and the adjustable side plate are arranged opposite to each other. The fixed side plate is fixedly arranged on the rotating shaft, and the adjustable side plate is movably arranged on the rotating shaft. A damper is provided on one side of the rotating shaft close to the fixed side plate. The rotating shaft is rotatably arranged on the mounting bracket. The damper adjusts the required torque holding force according to the film supply state, so that the film paper can be easily pulled on the first reel while always maintaining a stable state.

[0023] The film feeding mechanism of the present utility model has the following beneficial effects specifically reflected in:

[0024] During the film application process, the film paper is always kept in a just-straightened and non-tight state, eliminating the internal stress of the film paper, which is beneficial to the subsequent film application operation and can ensure that the subsequent process is not affected. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic structural diagram of a semiconductor lead frame film application device in the prior art;

[0026] Figure 2 Schematic three-dimensional structural diagram of the film feeding mechanism of the present utility model;

[0027] Figure 3 Schematic structural diagram of the driven counterweight mechanism of the present utility model;

[0028] Figure 4 Schematic structural diagram of the active lifting mechanism of the present utility model;

[0029] Figure 5 Schematic structural diagram of the first reel of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the relevant utility model, rather than limiting the utility model. Additionally, it should be noted that for the convenience of description, only the parts related to the utility model are schematically shown in the drawings.

[0031] As Figure 2 shown, the film feeding mechanism provided by the present application includes:

[0032] a mounting bracket 1, a first reel 2, a tensioning assembly 3, a film pulling device 4, and a second reel 5.

[0033] Specifically, the first reel 2 is rotatably arranged on the mounting bracket 1. A film paper 21 is arranged on the first reel 2. The film paper 21 includes a base film 211 and a yellow film for film sticking (not marked in the figure, and the base film 211 and the yellow film can be separated). Further, the film winding width of the first reel 2 can be adjusted, and the outer adjusting side plate of the first reel 2 is manually adjusted according to the actual width of the film paper 21.

[0034] The tensioning assembly 3 is arranged on the mounting bracket 1 and on the right side of the first reel 2. The film paper 21 is sent out from the first reel 2 and wound around the tensioning assembly 3. The film paper 21 is tensioned and adjusted through the tensioning assembly 3 to keep the film paper 21 always in a just-straightened and non-tight state, eliminating the internal stress of the film paper 21.

[0035] The film pulling device 4 is located on the right side of the tensioning assembly 3 and above the film sticking platform 6. The film sticking platform 6 is arranged on one side of the mounting bracket 1. The film pulling device 4 belongs to the prior art, and its structure will not be described in detail here. A negative pressure area is provided on the film pulling device 4. The film paper 21 is adsorbed on the film pulling device 4 through the negative pressure area. The film pulling device 4 is driven by a servo motor (not shown in the figure) and moves to the right to send the film paper 21 to the film sticking position. Through the reciprocating movement of the film pulling device 4 above the film sticking platform 6, the conveying of the film paper 21 and the separation of the base film 211 and the yellow film are realized.

[0036] The second reel 5 is rotatably arranged on the mounting bracket 1, on the right side of the first reel 2, close to the film laminating platform 6, and is driven by a stepping motor 51. The second reel 5 is connected to the movable end of the stepping motor 51 arranged on the mounting bracket 1. The bottom film 211 after the yellow film is pasted is recycled by the rotation of the second reel 5. One end of the bottom film 211 is wound around the film pulling device 4 and then wound on the second reel 5, and makes corresponding follow-up according to the action of the film pulling device 4. When the film pulling device 4 moves to the right to send the film paper 21 to the film laminating position, the second reel 5 rotates forward. When the film pulling device 4 moves to the left, the second reel 5 rotates in reverse to synchronously recycle the bottom film 211 and tear off the bottom film 211 covering the yellow film. The relative speed of the two remains the same, or the recycling speed of the bottom film is slightly slower than the moving speed of the film pulling device 4 to ensure that the bottom film 211 does not exert a force on the yellow film other than tearing the film. Further, the winding width of the second reel 5 can be adjusted, and its principle and structure are the same as those of the first reel 2, so no more details will be described here.

[0037] In one embodiment, as Figure 2 shown, the tensioning assembly 3 includes: a first guide wheel 31, a driven counterweight mechanism 32, a driving lifting mechanism 33, and a second guide wheel 34.

[0038] Specifically, the first guide wheel 31 is rotatably arranged on the mounting bracket 1, and the first guide wheel 31 is located on one side of the first reel 2, and plays a role of supporting and guiding when the film paper 21 is supplied. The roller surface of the first guide wheel 31 is polished to reduce the friction between the film paper 21 and the first guide wheel 31. The rotating shaft of the first guide wheel 21 has no damping, making the film feeding process smoother; the second guide wheel 34 is arranged on the right side of the driving counterweight mechanism 33, close to the film laminating platform 6, and its principle and structure are the same as those of the first guide wheel 31, so no more details will be described here. The driven counterweight mechanism 32 is arranged on the right side of the first guide wheel 31 and can move up and down to realize the movable placement of the paper film 21 at different positions, and is used to keep the film paper 21 always in a just-straightened and non-tight state; the driving lifting mechanism 33 is arranged on the right side of the driven counterweight mechanism 32 and makes corresponding follow-up according to the action of the film pulling device 4, avoiding the film paper 21 being in an over-tight state during the film feeding process, eliminating its internal stress, and always keeping the film paper 21 straightened and not subject to excessive tensile force. Specifically, after the film paper 21 passes through the first guide wheel 31, it is wound under the driven counterweight mechanism 32, then extends above the driving lifting mechanism 33, and then the film paper 21 passes under the second guide wheel 34 and is wound on the film pulling device 4 and extends to the film laminating platform 6. Through this kind of winding of the film paper 21, the driving lifting mechanism 33 can drive the driven counterweight mechanism 32 to perform lifting adjustment.

[0039] Further, as Figure 3As shown, the driven counterweight mechanism 32 includes a counterweight wheel 322 and a sliding member. The sliding member includes a first guide rail 321 and a first slider 323. The counterweight wheel 322 is slidably arranged on the first guide rail 321 through the first slider 323. The film paper 21 is wound around from below the counterweight wheel 322. In order to more accurately position the counterweight wheel 322, a position sensor is provided on one side of the first guide rail 321. The position sensor includes a first sensor 324, a second sensor 325, and a third sensor 326. The first sensor 324 and the third sensor 326 are at the same horizontal position at the upper and lower ends of the first guide rail 321 respectively, and the second sensor 325 is at the same horizontal position in the middle of the first guide rail 321. A counterweight induction bracket 327 is provided on one side of the first slider 323. The counterweight wheel 322 moves between the first sensor 324 and the third sensor 326 according to different states of film feeding, and its initial position is confirmed by the second sensor 325. Specifically, when the first reel 2 is stuck or the damping is too large to pull, the counterweight wheel 322 slides upward, and the counterweight induction bracket 327 touches the first sensor 324, and the film feeding action stops; when the film paper 21 is used up, the counterweight wheel 322 slides downward, and the counterweight induction bracket 327 touches the third sensor 326, and the film feeding action stops; the position of the counterweight wheel 322 is judged by the counterweight sensor 327 sliding downward or upward to touch the second sensor 325. The active lifting mechanism 33 makes a choice on whether to perform lifting adjustment according to the positioning and feedback of the position of the counterweight wheel 322 by the second sensor 325.

[0040] Preferably, a second guide rail 328 is provided on the mounting bracket 1, parallel to the first guide rail 321, and the position sensor can be freely mounted on the second guide rail 328 according to different installation requirements.

[0041] Furthermore, as Figure 4 shown, the active lifting mechanism 33 includes a third guide rail 331, a lifting wheel 332, and a driving member. The driving member is a cylinder 334. The third guide rail 331 is parallel to the first guide rail 321. The lifting wheel 332 is slidably arranged on the third guide rail 331 through a second slider 333. One end of the push rod of the cylinder 334 is connected to the second slider 333. Preferably, a fourth guide rail 335 is also arranged in parallel on one side of the third guide rail 331. The lifting wheel 332 is slidably arranged on the third guide rail 331 and the fourth guide rail 335 through the second slider 333. By providing two third guide rails 331, the second slider 333 can run stably, and the wear of the second slider 333 caused by the weight of the components can be reduced. Preferably, as Figure 2As shown in the figure, in order to reduce the volume of the device and achieve a reasonable layout, a slotted opening 336 is provided on the mounting bracket 1. The lifting wheel 332 passes through the slotted opening 336 and is connected to the second slider 333, so that the guide rail and the cylinder 334 are arranged on the other side of the mounting bracket 1. In this embodiment, the lifting and lowering of the lifting wheel 332 is driven by the telescopic movement of the push rod of the cylinder 334. Optionally, the adjustment method of the cylinder 334 can be replaced by a screw rod slider mechanism or a synchronous belt and synchronous pulley structure. It can be understood that in this embodiment, only the lifting and lowering movement of the second slider 333 needs to be realized, and the driving method of the second slider 333 is not limited by this application.

[0042] In one embodiment, as Figure 5 shown, a rotatable shaft is provided on the mounting bracket 1. A fixed side plate 22 and an adjustable side plate 23 are provided on the shaft. The distance between the adjustable side plate 23 and the fixed side plate 22 is set according to the actual situation by film papers 21 of different size specifications. A damper 24 is arranged on one side of the shaft close to the fixed side plate 22. The model of the damper 24 can be MK10 of the Tsunamoto Group. The damper 24 is mainly used for torque adjustment of the first reel 2. According to the film supply state, the required torque holding force is adjusted so that a certain torque needs to be exceeded when the film paper 21 is detached from the first reel 2, thereby ensuring that the film paper 21 always remains in a straightened state during the film feeding process. At the same time, it can also prevent the film paper 21 from detaching from the first reel 2 excessively and maintain the stability of the film feeding state.

[0043] During use, after the film paper 21 is correctly installed in the mechanism, the entire lead frame film pasting unit performs action initialization (the origin of each functional mechanism is restored). At this time, the weight induction bracket 327 of the weight wheel 322 is located between the first sensor 324 and the second sensor 325. If the weight wheel 322 is not within this range, the unit cannot be initialized. At the same time, the lifting wheel 332 is in the raised position, that is, the push rod of the cylinder 334 is in the retracted state. The film puller 4 is at the film cutting position of the film pasting platform 6, and the adsorption state is turned on. The film paper 21 is adsorbed and fixed, and the second reel 5 is in a stationary state.

[0044] After the film pasting unit starts automatic operation, first, the film puller 4 drives the film paper 21 to move to the right to the end point of film feeding on the film pasting platform 6 through the adsorption force in the negative pressure area. During this process, the lifting wheel 332 moves downward synchronously, that is, the push rod of the cylinder 334 starts to extend from the retracted state. At this time, the weight wheel 322 starts to move downward synchronously with the movement of the lifting wheel 332 due to the action of gravity. When the film puller 4 sends the film paper 21 to the set position, the push rod of the cylinder 334 just finishes extending at this time, and the lifting wheel 332 reaches the lowest state. At the same time, the position of the weight wheel 322 also drops to completion, and its specific position is located between the second sensor 325 and the third sensor 326. During the process, the second reel 5 has no film winding action, that is, the stepping motor 51 does not rotate.

[0045] After the film feeding is completed, the film paper 21 is adsorbed on the film pasting platform 6, the vacuum area of the film pulling device 4 breaks the vacuum, and then the film pulling device 4 starts to move leftward. At the same time, the second reel 5 synchronously winds the film, tearing off the base film 211 covering the yellow film. The relative speed of the two remains consistent, or the speed of the base film recovery is slightly slower than the moving speed of the film pulling device 4 to ensure that the base film does not exert a force other than film tearing on the yellow film. When tearing the base film, in order to reserve the length of the film paper required for the next film pasting, the push rod of the air cylinder 334 contracts synchronously and completes the action synchronously with the film pulling device 4. After the film pulling device 4 reaches the film cutting position on the film pasting platform 6, the yellow film is cut by a cutting knife (not marked in the figure). At this time, the push rod of the air cylinder 334 will perform another telescopic action, the purpose of which is to lift the position of the counterweight wheel 322 to between the first sensor 324 and the second sensor 325.

[0046] After the film pulling device 4 retracts to the initial position, the air cylinder 334 will choose whether to act according to the position of the induction bracket 327 of the counterweight wheel 322. That is, when the position of the counterweight wheel 322 is between the first sensor 324 and the second sensor 325, the air cylinder 334 has no corresponding action. When the counterweight wheel 322 is between the third sensor 326 and the second sensor 325, the push rod of the air cylinder 334 completes a telescopic action so that the counterweight wheel 322 is always above the second sensor 325 before the next film feeding. Thus, an action of film feeding and base film recovery is completed.

[0047] In the above process, the force on the film paper 21 is always only the film paper tension generated by the weight of the counterweight wheel 322, and this tension is just the minimum force that can pull the first reel 2 in cooperation with the damper 23, so that during the entire film feeding process, the film paper 21 will not generate internal stress due to excessive tension, ensuring that the subsequent process is not affected. At the same time, due to the existence of the weight of the counterweight wheel 322, during the film feeding process, the film paper 21 is in a straightened state throughout, which is beneficial to the subsequent film pasting action.

[0048] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0049] For ease of description, spatial relative terms such as "above", "over", "on the upper surface", "upper" etc. can be used here to describe the spatial positional relationship of a device or feature shown in the figure with other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation described in the figure for the device. For example, if the device in the attached drawing is inverted, the device described as "above or over other devices or structures" will then be positioned "below or under other devices or structures". Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the corresponding explanations are made for the spatial relative descriptions used here.

[0050] In addition, it should be noted that the use of words such as "first", "second" etc. to limit components is only for the convenience of distinguishing the corresponding components. Without additional statements, the above words have no special meanings, and thus should not be construed as limiting the protection scope of this application.

[0051] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, terms such as "installed", "provided with", "connected" etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0052] The above are only the preferred embodiments of the present utility model. All equivalent changes and modifications made according to the scope of the patent application of the present utility model shall fall within the scope covered by the present utility model.

Claims

1. A film feeding mechanism, characterized in that: It includes: Mounting bracket; a first reel, the first reel being rotatably disposed on the mounting bracket; A tensioning assembly, the tensioning assembly being arranged on the mounting bracket; And the tensioning assembly is located on the right side of the first reel; A film puller, which is movably arranged on one side of the mounting bracket and is located on the right side of the tensioning assembly; The second reel is rotatably mounted on the mounting bracket and is located on the right side of the first reel.

2. The film feeding mechanism according to claim 1, characterized in that: The tensioning assembly comprises: A first guide wheel, the first guide wheel is rotatably disposed on the mounting bracket, and the first guide wheel is located at one side of the first reel; A driven counterweight mechanism, which is movably disposed on the mounting bracket and is located on the right side of the first guide wheel; An active lifting mechanism, which is disposed on the mounting bracket and is located on the right side of the driven counterweight mechanism; The second guide wheel is rotatably disposed on the mounting bracket and is located on the right side of the active lifting mechanism.

3. The film feeding mechanism according to claim 2, characterized in that: The driven counterweight mechanism comprises a counterweight wheel and a sliding component, the counterweight wheel is fixed on the sliding component, and the sliding component is slidably arranged on the mounting bracket.

4. The film feeding mechanism according to claim 3, characterized in that: The sliding component includes a first guide rail and a first slider, the first slider is slidably arranged on the first guide rail, the counterweight wheel is fixed on the first slider, and the first guide rail is arranged on the mounting bracket.

5. The film feeding mechanism according to claim 4, characterized in that: The driven counterweight mechanism also includes a position sensor and a counterweight sensing bracket. The position sensor is arranged on the mounting bracket. The counterweight sensing bracket is arranged on one side of the sliding component. The position sensor cooperates with the counterweight sensing bracket.

6. The film feeding mechanism according to claim 5, characterized in that: It also includes a second guide rail, the position sensor is arranged on the second guide rail, the second guide rail is arranged on the mounting bracket, and the second guide rail is parallel to the first guide rail.

7. The film feeding mechanism according to claim 2, characterized in that: The active lifting mechanism comprises a third guide rail, a lifting wheel and a driving component. A second slider is slidably arranged on the third guide rail, the lifting wheel is arranged on the second slider, and the movable end of the driving component is fixedly arranged on the second slider.

8. The film feeding mechanism according to claim 7, characterized in that: The active lifting mechanism further includes a fourth guide rail, which is parallel to the third guide rail, and the second slider is slidably disposed on the third guide rail and the fourth guide rail respectively.

9. The film feeding mechanism according to claim 1, characterized in that: The first reel includes a rotating shaft, a fixed side plate and an adjustable side plate, the fixed side plate and the adjustable side plate are arranged opposite to each other, the fixed side plate is fixedly arranged on the rotating shaft, the adjustable side plate is movably arranged on the rotating shaft, a damper is provided on the side of the rotating shaft close to the fixed side plate, and the rotating shaft is rotatably arranged on the mounting bracket.

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