Semiconductor lead welding equipment capable of automatically adjusting pay-off rate

Abstract

The utility model discloses a semiconductor lead welding device capable of automatically adjusting pay-off rate, which belongs to the technical field of semiconductor packaging and comprises a fixing mechanism, a welding head, a lead induction mechanism and a pay-off mechanism, the fixing mechanism is composed of an operation table and a support frame, the welding head is arranged on one side of the top of the operation table, and the lead induction mechanism is positioned above the welding head; the lead induction mechanism comprises a hollow movable sleeve, a first guide pulley is arranged above the top of the movable sleeve, the first guide pulley is movably connected with a movable rod extending into the movable sleeve, and a hollow floating ball is arranged at the bottom of the movable rod. A first sensing element and a second sensing element are sequentially arranged in the movable sleeve from top to bottom; the pay-off mechanism is located on one side of the lead induction mechanism and composed of a driving motor and a pay-off shaft rod. According to the utility model, the pay-off rate can be matched with the lead consumption rate in the lead welding process, and the tension of the lead can be kept stable.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor packaging, and particularly relates to a semiconductor lead welding device with an automatically adjustable wire pay-off rate. Background Art

[0002] During the semiconductor packaging process, leads are usually used to connect various pins, lead frames, and chips inside the package to achieve electrical conduction. Currently, some semiconductors can achieve lead welding through automated equipment. During the lead welding process, the lead coil is rotated by an automatic wire pay-off mechanism to gradually pay off the lead for automatic wire pay-off. However, as the lead in the lead coil is consumed, the amount of lead paid off at the same rotation rate will become less and less, which may lead to too low a wire pay-off rate of the lead, causing the lead to be tightened to a straight state or even broken. If the wire pay-off rate of the lead is too high, it may cause the lead to sag and be hooked by other movable structures, which may also lead to the lead being broken. Therefore, it is necessary to maintain a stable tension of the lead during the welding process to avoid the lead being broken and ensure the smooth progress of the welding process.

[0003] Chinese Patent No. CN114473280A discloses a chip packaging wire bonding device, which is used for wire bonding of semiconductor chips to be packaged. During the welding process, the lead is paid off from the lead bobbin, and a multi-group of wire clamping and positioning wheels distributed longitudinally and transversely can clamp and push the lead from multiple angles to keep the lead in a vertical state. During the lead pushing process, the rotation of the wire clamping and positioning wheels generates a pulling force on the lead to pull the lead out of the bobbin, causing the tension of the lead to change. And when the lead is pulled out, the bobbin will rotate. Even after the wire clamping and positioning wheels pause pushing the lead, the bobbin will still continue to rotate under the action of inertia, thus paying off too much lead. The excess lead may sag and be hooked by other moving structures, affecting the normal progress of the wire bonding process. Therefore, there is still room for improvement in the above chip packaging wire bonding device. Summary of the Utility Model

[0004] In view of the technical defects in the background art, the utility model provides a semiconductor lead welding device with an automatically adjustable wire pay-off rate, which solves the above technical problems and meets the actual requirements. The specific technical solutions are as follows:

[0005] A semiconductor lead welding device with an automatically adjustable wire pay-off rate includes a fixing mechanism, a welding head, a lead sensing mechanism, and a wire pay-off mechanism. The fixing mechanism consists of an operating table at the bottom and a support frame extending upward from the top of the operating table. The welding head is arranged on one side of the top of the operating table, and the lead sensing mechanism is located above the welding head.

[0006] The lead induction mechanism includes the following structure: a movable sleeve that is hollow inside and fixedly connected to the support frame. Above the top of the movable sleeve, there is a first guiding pulley. The first guiding pulley is movably connected by a shaft rod at the shaft end to a movable rod extending into the movable sleeve. At the bottom of the movable rod, there is a hollow float. Inside the movable sleeve, a first sensing element and a second sensing element are sequentially arranged from top to bottom.

[0007] The wire paying-off mechanism is located on one side of the lead induction mechanism. The wire paying-off mechanism includes a driving motor fixedly connected to the support frame and a wire paying-off shaft rod arranged at the output end of the driving motor.

[0008] As a further technical solution of the present invention, there are two second guiding pulleys between the first guiding pulley and the wire paying-off shaft rod. There is a gap allowing the lead to pass between the two second guiding pulleys. Both of the second guiding pulleys are movably connected to the support frame by shaft rods at the shaft ends.

[0009] As a further technical solution of the present invention, a limiting groove is wound around the radial surface of the first guiding pulley.

[0010] As a further technical solution of the present invention, a third guiding pulley is arranged on the side of the lead induction mechanism away from the wire paying-off mechanism. The third guiding pulley is movably connected to the movable sleeve by a shaft rod at the shaft end.

[0011] As a further technical solution of the present invention, a welding nozzle is arranged at the bottom of the welding head, and a lead hole penetrating through to the bottom of the welding nozzle is arranged at the top of the welding head.

[0012] As a further technical solution of the present invention, a displacement mechanism is arranged on the top of the operating table. The displacement mechanism includes the following structure: a first guide rail fixedly connected to the operating table and extending horizontally. A first slider is mounted on the top of the first guide rail. A second guide rail extending longitudinally is arranged on the top of the first slider. A second slider is mounted on the top of the second guide rail. The welding head is fixedly connected to the second slider.

[0013] As a further technical solution of the present invention, a dust-proof cover is hinged to the top of the support frame, and the dust-proof cover is sleeved outside the wire paying-off shaft rod.

[0014] The beneficial effects of the present invention are as follows:

[0015] During the lead welding process of the present utility model, the length of the lead between the lead reel and the welding head will change and be accompanied by a change in tension. The change in the tension of the lead will cause the first guiding pulley and the floating ball to reciprocate vertically. The first sensing element and the second sensing element sense the position of the floating ball to judge the change in the tension of the lead, so as to adjust the rate at which the wire feeding mechanism releases the lead to match the lead consumption rate, and can maintain the stability of the lead tension, keep the length of the lead between the lead reel and the welding head within a suitable range, avoid the lead being broken due to being too short or the lead being hooked by other movable structures and broken due to being too long and sagging, and ensure the continuous and stable progress of the lead welding process. Description of the Drawings

[0016] Figure 1 is a schematic structural diagram of a semiconductor lead welding device for automatically adjusting the wire feeding rate.

[0017] Figure 2 is a cross-sectional view of the lead sensing mechanism of a semiconductor lead welding device for automatically adjusting the wire feeding rate.

[0018] Figure 3 is a schematic structural diagram of another angle of a semiconductor lead welding device for automatically adjusting the wire feeding rate.

[0019] Wherein: fixing mechanism 1, operating table 11, support frame 12, welding head 2, welding nozzle 21, lead hole 22, lead sensing mechanism 3, movable sleeve 31, first guiding pulley 32, limiting groove 321, movable rod 33, floating ball 34, first sensing element 35, second sensing element 36, wire feeding mechanism 4, driving motor 41, wire feeding shaft rod 42, second guiding pulley 5, third guiding pulley 6, displacement mechanism 7, first guide rail 71, first slider 72, second guide rail 73, second slider 74, dust cover 8. Detailed Embodiment

[0020] The following combines the drawings with related embodiments to illustrate the embodiments of the present utility model. The embodiments of the present utility model are not limited to the following embodiments, and the related necessary components involved in the present utility model should be regarded as well-known technologies in the technical field, which can be known and mastered by those skilled in the technical field.

[0021] Such as Figures 1-3As shown in the figure, a semiconductor lead welding device with an automatically adjustable wire feeding rate includes a fixing mechanism 1, a welding head 2, a lead induction mechanism 3, and a wire feeding mechanism 4. The fixing mechanism 1 consists of an operating table 11 at the bottom and a support frame 12 extending upward from the top of the operating table 11. The welding head 2 is arranged on one side of the top of the operating table 11. A welding nozzle 21 is provided at the bottom of the welding head 2, and a lead hole 22 penetrating to the bottom of the welding nozzle 21 is provided at the top of the welding head 2. The lead induction mechanism 3 is located above the welding head 2. The lead induction mechanism 3 includes the following structure: a movable sleeve 31 with a hollow interior and fixedly connected to the support frame 12. Above the top of the movable sleeve 31, there is a first guiding pulley 32. The first guiding pulley 32 is movably connected by a shaft rod at the shaft end to a movable rod 33 extending into the movable sleeve 31. A hollow float 34 is provided at the bottom of the movable rod 33. Inside the movable sleeve 31, a first sensing element 35 and a second sensing element 36 are arranged in sequence from top to bottom. The wire feeding mechanism 4 is located on one side of the lead induction mechanism 3. The wire feeding mechanism 4 includes a driving motor 41 fixedly connected to the support frame 12 and a wire feeding shaft rod 42 arranged at the output end of the driving motor 41.

[0022] The utility model is used for the lead welding process in the semiconductor chip packaging process. All components in the lead welding device are controlled to operate through a servo system. The lead coil is fixed on the wire feeding shaft rod 42. When the driving motor 41 operates, the wire feeding shaft rod 42 and the lead coil rotate simultaneously to release the lead from the lead coil. The lead is released and extends downward into the lead hole 22 after passing around the top of the first guiding pulley 32, thus completing the installation of the lead. The welding head 2 is preferably a ball welding type welding head. Below the welding head 2, there is a conveying device for conveying the lead frame and a fixing fixture for fixing the lead frame and the chip. When the lead frame is conveyed below the welding head 2, the lead is pushed from the top of the lead hole 22 to the bottom through the transmission structure inside the welding head 2. The linear motor inside the welding head 2 drives the welding nozzle 21 to reciprocate in the vertical direction. At the same time, the welding head 2 is moved horizontally through the displacement mechanism 7, so that the welding nozzle 21 moves between the welding points matching the lead frame and the chip. Electrical connection is achieved by welding between the set welding points through the lead. After the lead frame and the chip are welded and fixed, the displacement mechanism 7 drives the welding head 2 to reset, and the conveying device conveys the next set of lead frame and chip to be welded below the welding head 2 for lead welding.

[0023] In the lead wire induction mechanism 3 of the present utility model, the extending direction of the axis line of rotation of the first guiding pulley 32 is the same as the extending direction of the wire pay-off shaft rod 42. The movable sleeve 31 is filled with pure water. The first induction element 35 and the second induction element 36 are both infrared sensors. When the lead wire induction mechanism 3 is in the reset state, the buoyancy generated by the pure water on the floating ball 34 makes it located at the inner top of the movable sleeve 31. The movable rod 33 extends upward from the top of the movable sleeve 31 so that the first guiding pulley 32 is at the highest point, and the floating ball is not within the range of the first induction element 35 and the second induction element 36. When the length of the lead wire between the lead wire reel and the welding head 2 shortens, the tension of the lead wire will increase, and the pressure exerted by the lead wire on the first guiding pulley 32 increases. The first guiding pulley 32 and the floating ball 34 will gradually move downward. When the length of the lead wire between the lead wire reel and the welding head 2 increases, the tension of the lead wire will decrease, and the pressure exerted by the lead wire on the first guiding pulley 32 decreases. Under the action of the buoyancy of the pure water, the first guiding pulley 32 and the floating ball 34 will gradually move upward.

[0024] After adopting the above structure, it should be noted that during the lead wire welding process, the lead wire will be gradually consumed, resulting in the shortening of the length of the lead wire between the lead wire reel and the welding head 2. At this time, the tension of the lead wire increases and the pressure exerted by the lead wire on the first guiding pulley 32 increases. As the lead wire length shortens, the first guiding pulley 32 will gradually move downward. When the floating ball 34 enters the range of the first induction element 35 and is sensed, it means that the lead wire is gradually shortening, and the driving motor 41 needs to be operated to start paying out the lead wire. If the floating ball 34 enters the range of the second induction element 36 and is sensed, it means that the pay-off rate of the pay-off mechanism 4 is lower than the consumption rate of the lead wire, and the pay-off rate of the pay-off mechanism 4 needs to be increased until the floating ball 34 is not within the sensing range of the second induction element 36. If the floating ball 34 leaves the sensing range of the first induction element 35, it means that the pay-off rate of the pay-off mechanism 4 is too high, and the pay-off rate of the pay-off mechanism 4 needs to be decreased until the floating ball 34 re-enters the sensing range of the first induction element 35. By controlling the pay-off rate of the pay-off mechanism 4, the floating ball is maintained within the sensing range of the first induction element 35, so as to achieve the matching of the pay-off rate and the consumption rate of the lead wire, and the tension of the lead wire can be maintained stable, so that the length of the lead wire between the lead wire reel and the welding head 2 is kept within a suitable range, avoiding the lead wire being pulled off due to being too short or being hooked by other movable structures and pulled off due to being too long and sagging, ensuring the continuous and stable progress of the lead wire welding process.

[0025] In summary, during the lead welding process of the present utility model, the length of the lead between the lead reel and the welding head 2 changes and is accompanied by a change in tension. The change in the tension of the lead causes the first guide pulley 32 and the floating ball 34 to reciprocate vertically. The first sensing element 35 and the second sensing element 36 sense the position of the floating ball to judge the change in the tension of the lead, so as to adjust the release rate of the lead by the wire release mechanism 4 to match the lead consumption rate, and can maintain the stability of the lead tension, keep the length of the lead between the lead reel and the welding head 2 within a suitable range, avoid the lead being broken due to being too short or the lead being hooked by other movable structures and broken due to being too long and sagging, and ensure that the lead welding process proceeds continuously and stably.

[0026] As Figure 1 , 3 shown, as one of the preferred embodiments of the present utility model, two second guide pulleys 5 are provided between the first guide pulley 32 and the wire release shaft rod 42. A gap allowing the lead to pass through is provided between the two second guide pulleys 5. Both second guide pulleys 5 are movably connected to the support frame 12 through the shaft rods at the shaft ends; the extending direction of the axis of rotation of the second guide pulley 5 is perpendicular to the extending direction of the axis of rotation of the first guide pulley 32. The gap between the two second guide pulleys 5 faces the center of the first guide pulley 32. The lead first passes through the gap between the two second guide pulleys 5 and then winds around the top of the first guide pulley 32. The two second guide pulleys 5 are used to adjust the direction of the lead and make the lead always located at the center of the first guide pulley 32, avoiding the lead from detaching from the first guide pulley 32.

[0027] As Figure 2 shown, as one of the preferred embodiments of the present utility model, a limiting groove 321 is wound around the radial surface of the first guide pulley 32; the limiting groove 321 of the present utility model can limit the lead wound around the surface of the first guide pulley 32, and avoid the lead from detaching from the first guide pulley 32 by embedding the lead into the limiting groove 321, ensuring that the lead welding process proceeds continuously and stably.

[0028] As Figure 1 , 3 shown, as one of the preferred embodiments of the present utility model, a third guide pulley 6 is provided on the side of the lead sensing mechanism 3 away from the wire release mechanism 4. The third guide pulley 6 is movably connected to the movable sleeve 31 through the shaft rod at the shaft end; the third guide pulley 6 is used to adjust the angle of the lead when it leaves the lead sensing mechanism 3, avoiding the lead from contacting the movable sleeve 31 and affecting the smoothness of the lead pushing.

[0029] As Figure 1 , 3As shown, as one of the preferred embodiments of the present utility model, a displacement mechanism 7 is provided at the top of the operating table 11. The displacement mechanism 7 includes the following structure: a first guide rail 71 fixedly connected to the operating table 11 and extending horizontally. A first slider 72 is mounted on the top of the first guide rail 71. A second guide rail 73 extending longitudinally is provided on the top of the first slider 72. A second slider 74 is mounted on the top of the second guide rail 73. The welding head 2 is fixedly connected to the second slider 74. The displacement mechanism 7 is used to move the welding head 2 so that the welding nozzle 21 moves between the welding points to achieve lead welding. The first slider 72 moves horizontally along the first guide rail 71, so that the second guide rail 73 and the welding head 2 can move horizontally synchronously. The second slider 74 moves longitudinally along the second guide rail 73 so that the welding head 2 can move longitudinally synchronously. Thus, the welding head 2 can move freely in a horizontal plane, cooperating with the reciprocating movement of the welding nozzle 21 in the vertical direction, so that the welding nozzle 21 can connect two welding points through the lead.

[0030] As Figure 1 , 3 As shown, as one of the preferred embodiments of the present utility model, a dust-proof cover 8 is hinged to the top of the support frame 12. The dust-proof cover 8 is sleeved outside the wire-releasing shaft rod 42. The dust-proof cover 8 is preferably made of transparent plastic. The dust-proof cover 8 sleeved outside the lead coil can avoid the accumulation of dust, thus avoiding problems such as semiconductor short circuit caused by dust on the surface of the lead. The dust-proof cover 8 can be turned up upward through the hinge hinged to the support frame 12, so as to install or replace the lead coil.

[0031] The above are only the preferred embodiments of the present utility model. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present utility model, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present utility model.

Claims

1. A semiconductor wire bonding device capable of automatically adjusting a wire release rate, comprising a fixing mechanism (1), a welding head (2), a wire sensing mechanism (3), and a wire release mechanism (4), characterized in that: The fixing mechanism (1) is composed of an operating table (11) at the bottom and a support frame (12) extending upward from the top of the operating table (11); the welding head (2) is arranged on one side of the top of the operating table (11); and the lead sensing mechanism (3) is located above the welding head (2); The lead sensing mechanism (3) comprises the following structure: a movable sleeve (31) which is hollow inside and fixedly connected to the support frame (12); a first guide pulley (32) is provided above the top of the movable sleeve (31); the first guide pulley (32) is movably connected to a movable rod (33) extending into the movable sleeve (31) via an axial rod at an axial end; a floating ball (34) which is hollow inside is provided at the bottom of the movable rod (33); and a first sensing element (35) and a second sensing element (36) are provided in sequence from top to bottom inside the movable sleeve (31); The wire-releasing mechanism (4) is located on one side of the wire-leading induction mechanism (3), and comprises a driving motor (41) fixedly connected to the support frame (12) and a wire-releasing shaft (42) provided at the output end of the driving motor (41).

2. The semiconductor wire bonding equipment for automatically adjusting the wire pay-off rate according to claim 1, characterized in that: Two second guide pulleys (5) are provided between the first guide pulley (32) and the wire-releasing shaft (42), a gap allowing the wire to pass through is provided between the two second guide pulleys (5), and the two second guide pulleys (5) are movably connected to the support frame (12) via the shaft at the shaft end.

3. The semiconductor wire bonding equipment with automatic adjustment of wire pay-off rate according to claim 1, characterized in that: A limiting groove (321) is arranged around the radial surface of the first guide pulley (32).

4. The semiconductor wire bonding equipment with automatic adjustment of wire pay-off rate according to claim 1, characterized in that: A third guide pulley (6) is provided on the side of the lead-wire sensing mechanism (3) away from the wire-releasing mechanism (4), and the third guide pulley (6) is movably connected to the movable sleeve (31) via a shaft rod at the end of the shaft.

5. The semiconductor wire bonding equipment capable of automatically adjusting the wire pay-off rate according to claim 1, characterized in that: A welding nozzle (21) is provided at the bottom of the welding head (2), and a lead hole (22) penetrating to the bottom of the welding nozzle (21) is provided at the top of the welding head (2).

6. The semiconductor wire bonding equipment capable of automatically adjusting the wire pay-off rate according to claim 1, characterized in that: A displacement mechanism (7) is provided on the top of the operating table (11), and the displacement mechanism (7) comprises the following structures: a first guide rail (71) fixedly connected to the operating table (11) and extending transversely, a first slider (72) being mounted on the top of the first guide rail (71), a second guide rail (73) extending longitudinally being mounted on the top of the first slider (72), a second slider (74) being mounted on the top of the second guide rail (73), and the welding head (2) being fixedly connected to the second slider (74).

7. The semiconductor wire bonding equipment capable of automatically adjusting the wire pay-off rate according to claim 1, characterized in that: A dust cover (8) is hingedly connected to the top of the support frame (12), and the dust cover (8) is sleeved on the outside of the pay-off shaft (42).

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