JP4151944B2 - Lead frame transfer device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lead frame transport device.
[0002]
[Prior art]
One of the semiconductor manufacturing processes is a process of bonding a semiconductor pellet (hereinafter simply referred to as “pellet”) to a substrate. In this process, a pellet bonding apparatus is used.
[0003]
This apparatus picks up pellets one by one from a plurality of pellets in a grid-like arrangement formed by scribing a wafer and bonds them onto a substrate such as a lead frame. Each time the pellets are bonded, the lead frame is intermittently conveyed at a constant pitch.
[0004]
Here, a conventional lead frame conveying apparatus will be described with reference to FIG. 6 showing a plan view and FIG. 7 showing a side view. The lead frame transport device 100 includes a guide rail 2 that guides the lead frame 1 along its transport direction (right direction in FIG. 6), and a feed pin 3 provided above the lead frame transport surface of the guide rail 2. Have Along the edge of the lead frame 1, a feed hole 1 </ b> B is provided to face the pellet placement portion 1 </ b> A. A plurality of feed pins 3 are provided in the conveying direction of the lead frame 1, and each feed pin 3 is fixedly supported by a transfer shaft 5 located at the rear end of the guide rail via a pin holder 4, and is vertically moved around the transfer shaft 5. It can be swung in an arc shape in the direction. Reference numeral 6 denotes a feed up / down device 6 such as a cylinder for moving the feed pin 3 up and down.
[0005]
A slide guide 8 is fixedly disposed in parallel with the transfer shaft 5, and a connecting plate 7 integrated with the transfer shaft 5 in the transport direction is slidable on the slide guide 8. A screw shaft 9 that is rotatably arranged in parallel with the slide guide 8 is appropriately rotated forward or reverse by a feed motor 10, and the connecting plate 7 is moved to the slide guide 8 by a feed plate 11 that is moved by this rotational movement. Slide along. By this slide, the feed pin 3 moves along the guide rail.
[0006]
Next, an intermittent conveyance operation at a constant pitch of a series of lead frames by the lead frame conveyance device will be described.
[0007]
First, each feed pin 3 is moved downward by the feed lifting device 6, and the feed pin 3 is inserted into a feed hole 1 </ b> B provided in the lead frame 1. Next, by rotation of the feed motor 10, the connecting plate 7 is moved in the transport direction by a distance (one pitch) corresponding to one feed hole 1B. By this operation, the feed pin 3 moves one pitch in the transport direction, and the lead frame 1 is also transported by one pitch. Next, each feed pin 3 is moved up by the feed lifting device 6. By this operation, the feed pin 3 comes out of the feed hole 1B. Finally, the feed motor 10 is reversely rotated to return the feed pin 3 to the original position. Thereafter, this operation is repeated. When the pellet mounting unit 1A is sequentially positioned at the bonding position by the constant pitch conveyance of the lead frame 1, the lead frame 1 is fixed to the guide rail 2 by a clamping mechanism (not shown), and in this state, the pellet mounting unit 1A is placed on the pellet mounting unit 1A. On the other hand, the pellet is bonded.
[0008]
[Problems to be solved by the invention]
Incidentally, in the lead frame transport apparatus 100 used conventionally, a plurality of feed pins 3 are fixedly supported by one transfer shaft 5 via each pin holder 4, so that there are the following problems. It was. That is, in order to engage each feed pin 3 with the feed hole 1B of the lead frame 1, when the shape of the lead frame 1 is changed, the position of the pin holder 4 on the screw shaft 9 is changed to change the arrangement interval and position of the feed pins 3. the Although Kere should not change, when the transfer shaft 5 and guide rail 2 by the heat at the time of heating the lead frame 1 expands longitudinally thermal expansion, all the feed pin 3 to the feed hole 1B to reliably correspond In order to engage, adjustment had to be made after thermal expansion. For this reason, a large number of steps and time are required for rearranging the feed pins 3 due to the change in the shape of the lead frame 1. Further, since the shape of the pin holder 4 is complicated, there is a problem that the price of the parts is high and the price of the device is greatly increased.
[0009]
In view of the above problems, it is an object of the present invention to provide a lead frame transport apparatus that eliminates the above-mentioned problems.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that a guide rail for guiding the lead frame and a plurality of feed pins provided on the lead frame feed surface by the guide rail are appropriately spaced in the longitudinal direction of the guide rail. The feed up / down means for moving the feed pins up and down to engage with the feed holes of the lead frame, the feed means for reciprocating these feed pins in the horizontal direction along the guide rail, and the feed up / down means And a control means for controlling the feeding means, each lead pin is connected by a belt-like member to move along the guide rail, and the belt-like member is wound around a cylindrical body. The slide means is provided so that each feed pin can be moved by the feed means through the belt-like member. Characterized in that arranged in each feed pin of the ax.
[0011]
Further, in the invention according to claim 2, the cylindrical body is arranged for each feed pin, the cylindrical body around which the belt-like member is wound is rotatable, an arc-shaped elongated hole is provided in the cylindrical body, and the elongated hole is provided. Fit the rotation restricting pin to the rotation restricting pin, and contact the end of the long hole of the cylindrical body with this rotation restricting pin so that the spring acts from the cylindrical body in the direction opposite to the feeding direction of the strip member. It has an overload detector which is stretched and biased in the rotational direction by its elastic force and detects the overload by detecting the extension of the spring.
[0012]
According to a third aspect of the present invention, the overload detector includes a load unit that urges the cylindrical body in the rotational direction by the elastic force of the spring, a sensor that detects that the cylindrical body is rotated due to the extension of the spring. The detecting means for detecting by the light shielding plate is arranged so that the elastic force of the spring of the load means and the position of the sensor of the detecting means and the light shielding plate are the same even if the position of the feed pin is moved in the horizontal direction. It is characterized by that.
[0013]
The present invention has the following effects. By arranging the sliding means for each feed pin, the shape change of the pin holder due to the change of the shape of the lead frame is simplified, so that the price of the parts can be reduced, that is, the device price can be reduced. Further, the positioning pins can be easily rearranged and can be adjusted in a short time.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, although one embodiment of the present invention is described based on a drawing, it cannot be overemphasized that the present invention is not limited to this.
[0015]
FIG. 1 is a plan view showing a schematic configuration of a lead frame transport apparatus to which the present invention is applied, FIG. 2 is a side view of a feed pin portion in FIG. 1, and FIG. FIG. 4 is a plan view of an overload detector to which the present invention is applied, and FIG. 5 is a side view of FIG.
[0016]
A lead frame conveying apparatus according to the present embodiment will be described with reference to FIGS. In the following description, an example applied to a lead frame conveying device of a pellet bonding apparatus will be described.
[0017]
First, the configuration of the lead frame transfer device will be described with reference to FIGS. 1 and 2.
[0018]
The lead frame transport device includes a guide rail 12, a feed pin 13, a feed pin vertical unit 14, a feed pin vertical drive device 15, a feed drive device 16, and a control device 17.
[0019]
In the drawing, a lead frame 1 is formed in a strip shape having an appropriate length, and the lead frame 1 has an end in the longitudinal direction at a pitch interval of a pellet placing portion 1A for placing a number of pellets along the longitudinal direction. hole 1B feeding the parts are formed Ru Empire.
[0020]
Guide rail 12 is integrally attached to the base plate (not shown), a transfer rail that guides the lead frame 1. Grooves are formed in the transport rail along the longitudinal direction, and the lead frame is transported in the longitudinal direction using the groove as a guide. Further, a heater (not shown) is built in the guide rail.
[0021]
The feed pin 13 is disposed above the lead frame feed surface by the guide rail, and a pellet placing portion for placing a large number of pellets along the longitudinal end portion of the lead frame formed in a strip shape having an appropriate length. The lead frame is transferred by being fitted into and engaged with a feed hole formed at the end portion in the longitudinal direction at intervals of the pitch. The feed pins are arranged at appropriate intervals in the longitudinal direction so that one feed pin is fitted and engaged with the lead frame.
[0022]
The feed pin vertical unit 14 is disposed at a predetermined interval along the longitudinal direction of the guide rail at the rear end of the guide rail. That is, as shown in FIG. 2, a horizontal slide guide 20 that moves in the horizontal direction is attached to the horizontal block 19 via the spacer 18 at the rear end of the guide rail for each feed pin. In addition, a vertical slide guide 22 that moves in the vertical direction via a horizontal base 21 is attached to the horizontal slide guide. An upper and lower base 23 is attached to the upper and lower slide guides, and is formed in an approximately L shape so as to be positioned from the rear end to the front end of the guide rail so that a pin holder 24 for attaching a feed pin is attached to the tip. Further, a connecting plate 26 is formed on the horizontal base so as to be connected to a timing belt 25 that can move in the horizontal direction. Further, a cam follower 28 that follows the plate cam 27 for vertical driving is pivotally supported at the lower part of the vertical base, and the cam follower is brought into contact with the plate cam by the elastic force of a spring 29 stretched between the vertical base and the horizontal base. Yes.
[0023]
In the feed pin vertical drive device 15, a horizontal slide guide 20A is disposed at the rear end of the guide rail via a spacer 18A and a horizontal block 19A in the same manner as the feed vertical unit. The horizontal slide guides are all fixed by the slide plate 30 so as to move integrally, and the plate cams are fixed to the slide plates at respective positions so as to contact the cam followers pivotally supported by the upper and lower bases. The slide plate is fixed to a timing belt 32 wound around pulleys 31A and 31B rotatably supported by a fixing bracket 33. A servo motor 34 for feed pin up / down drive is incorporated in one pulley 31A, and between the two pulleys. Are connected by a timing belt.
[0024]
The feed driving device 16 is wound around and fixed to a timing belt 25 wound around pulleys 35A and 35B rotatably supported on a pulley 36 that does not rotate on the connecting plate of the horizontal base, and is fed to one pulley 35A for feed driving. A servo motor 37 is incorporated, and both pulleys are connected by a timing belt. Also,
The controller 17 controls the feed pin vertical drive servomotor and the feed drive servomotor to control the vertical movement and horizontal movement of the feed pin.
[0025]
Further, as shown in FIG. 2, sensors 26 </ b> A are fixedly supported on the connecting plates 26 provided for the respective feed pins 13, while the feed pins 13 are connected to the corresponding upper and lower bases 23. The dogs 23A that block the sensor 26A when inserted into the feed hole 1B are fixedly supported. As will be described later, when the feed pin 13 is lowered by the plate cam 27, if the feed pin 13 is not inserted into the corresponding feed hole 1B, the sensor 26A corresponding to the feed pin 13 not inserted. Is not obstructed by the dog 23A, in the control device 17, all the feed pins 13 are normally inserted into the corresponding feed holes 1B based on the signals from the sensors 26A, or which feed pins 13 are normal. It is possible to determine whether it has been inserted into the display device, and display it on a display device (not shown).
[0026]
Furthermore, this lead frame transport device has a clamp device (not shown) for clamping the lead frame on the guide rail after positioning at the bonding position.
[0027]
Next, an intermittent transfer operation at a constant pitch of a series of lead frames composed of the feed pin up-and-down operation and the feed pin horizontal movement operation of the lead frame conveying apparatus described above will be described with reference to FIG.
[0028]
The feed pin is raised and stands by at the retracted position ((1) in the figure). First, when the servo motor 34 of the feed pin vertical drive device 15 rotates forward by a predetermined amount, the timing belt 32 wound around the pulleys 31A and 31B is rotated, and the slide plate 30 fixed to the timing belt advances. To do. A plate cam 27 for feeding pins up and down is attached to the slide plate for each feeding pin. That is, when the plate cam advances, the cam follower 28 pivotally supported by the upper and lower bases that are in contact with the plate cam is operated at a timing corresponding to the inclined shape of the cam provided on the plate cam. The cam follower is always urged downward by the elastic force of a spring stretched between the upper and lower bases. A vertical slide guide is built in the vertical base so that it can move freely. For this reason, the cam follower descends following the plate cam by descending the inclined shape of the cam ((2) in the figure). That is, the pin holder incorporated in the upper and lower bases and the feed pin incorporated at the tip thereof are lowered. This means that the feed pin is fitted and engaged with the feed hole of the lead frame.
[0029]
Next, when the servo motor 37 of the feed driving device 16 is rotated forward by a predetermined amount, the timing belt 25 wound around the pulleys 35A and 35B is rotated, and the connecting plate 26 fixed to the timing belt advances. The connecting plate is a protruding portion from the horizontal base 21, and the horizontal base is fixed to the horizontal slide guide 20 for each feed pin. The horizontal slide guide can move freely in the horizontal direction, and is fixed to the timing belt via a connecting plate of a protruding portion of the horizontal base incorporated in the horizontal slide guide. In addition, a vertical slide guide is incorporated in the horizontal base, and a feed pin is incorporated in the vertical slide base via the vertical base. That is, the feed pin moves forward along the longitudinal direction of the guide rail. At this time, the servo motor for driving the feed pin up and down also simultaneously rotates forward by a predetermined amount, and the timing belt wound around the pulley is rotated around a distance equal to the horizontal movement amount by the servo motor of the feed drive device. Move the plate cam of the slide plate fixed to the belt. That is, the cam follower pivotally supported by the upper and lower bases moves while being located at the bottom dead center of the plate cam ((3) in the figure). Therefore, the feed pin moves while being lowered. This means that the lead frame is moved while being engaged with the feed hole of the lead frame, that is, the lead frame is conveyed by one pitch.
[0030]
Next, the servo motor of the feed pin vertical drive device rotates reverse by a predetermined amount, rotates the timing belt wound around the pulley, and the slide plate fixed to the timing belt moves backward. A plate cam for moving the feed pin up and down is attached to this slide plate for each feed pin. When the plate cam moves backward, it contacts the plate cam at a timing corresponding to the inclined shape of the plate cam provided on the plate cam. The cam follower is pivotally supported by the upper and lower bases. The cam follower is always urged downward by the elastic force of a spring stretched between the upper and lower bases. Since the vertical slide guide is built in the vertical base, it can move freely up and down. For this reason, the cam follower is forced up by the cam and moves up (indicated by (4) in the figure). That is, the pin holder incorporated in the upper and lower bases and the feed pin incorporated at the tip thereof are raised. This means that the feed pin is pulled out from the feed hole of the lead frame.
[0031]
Next, the servo motor of the feed driving device rotates reverse by a predetermined amount, so that the timing belt wound around the pulley is rotated, and the connecting plate fixed to the timing belt moves backward. This connecting plate is a protruding portion from the horizontal base, and since this horizontal base is fixed to the horizontal slide guide for each feed pin, this horizontal slide guide can move freely in the horizontal direction, and the horizontal slide It is fixed to the timing belt through a protruding portion of a horizontal base incorporated in the guide. In addition, a vertical slide guide is incorporated in the horizontal base, and a feed pin is incorporated in the vertical slide base via the vertical base. That is, the feed pin moves backward. At this time, the servo motor for driving the feed pin up and down also rotates in the reverse direction by a predetermined amount at the same time, and moves the distance plate cam equal to the horizontal movement amount by the feed drive motor. That is, the cam follower pivotally supported on the upper and lower bases moves while being located at the top dead center of the plate cam ((5) in the figure). Therefore, the feed pin moves in a state where it is raised. This is to retract the feed pin to its original position. By repeating this series of operations, the lead frame is intermittently transferred at a constant pitch. The lead frame intermittently transferred at a constant pitch is positioned at a bonding position, pressed by a clamper (not shown), fixed, and then pellets are bonded.
[0032]
In the above embodiment, the conveyance of the feed pin in the horizontal direction has been described with the content that the horizontal base connecting plate incorporated in the horizontal slide guide of the feed pin vertical drive device is fixed to the timing belt of the feed drive device. An overload detector may be provided.
[0033]
The overload detector will be described with reference to FIGS. The overload detector 40 mainly includes a pulley 41, a load device 42, and a detection device 43.
[0034]
The pulley 41 is wound around the timing belt 25 of the feed driving device 16 so as to be rotatable, and an arcuate slot 44 concentric with the rotation center of the pulley is formed in the vicinity of the outer periphery. A pin 45 for restricting rotation is fitted into the elongated hole, the end of the elongated hole is brought into contact with the rotation restricting pin, and the pulley is biased by the elastic force of the spring 46 in the rotational direction. Further, the pulley is provided with a light shielding plate 47 for detecting overload and a spring post 48 necessary for biasing the pulley by the elastic force of the spring.
[0035]
The load device 42 feeds the end of the long hole 44 formed in the pulley 41 by the elastic force of the spring 46 and the pin 45 for restricting the rotation of the pulley, and the elastic force acts in the direction opposite to the direction in which the timing belt 25 of the pin drive device advances. Thus, the spring post provided on the pulley and the spring post 50 provided on the position adjusting plate 49 are stretched. The elastic force of the spring can be appropriately selected as required, and the end of the long hole provided in the pulley even when the slide unit 51 is moved by the timing belt of the feed driving device. It has an elastic force that can be brought into contact with the rotation control pin. However, when the lead frame conveying force acting on the feed pin is increased from that during the steady transfer, the spring 46 is extended and deformed.
[0036]
The detection device 43 is provided with the detection sensor 52 on the position adjustment plate 49, and the position where the light shielding plate 47 provided on the pulley turns off the detection sensor is set as the initial position.
[0037]
In the configuration as described above, the lead frame is transferred along the guide rail by engaging the feed pin with the feed hole of the lead frame by the feed pin vertical drive device, and the pulley 31A by the servo motor of the feed drive device. This is done by rotating and advancing the timing belt. At this time, at the time of steady transfer that moves smoothly along the guide rail of the lead frame, the feed pin, that is, the horizontal slide guide 20 urges the feed regulating pin to the end of the long hole provided in the pulley under the action of the spring. Thus, it moves forward at a speed equal to that of the timing belt of the feed driving device without the extension deformation of the spring. In other words, the light emitted from the light projecting unit 53 of the detection sensor is blocked by the light shielding plate and does not reach the light receiving unit 54 during the steady transfer.
[0038]
On the other hand, when the lead frame is overloaded, the lead frame is restricted from moving forward along the guide rail. This also restricts the advance of the feed pin engaged with the feed hole of the lead frame. As a result, the timing belt of the transport device moves forward and the feed pin is stopped, that is, the spring is extended and deformed, so that the pulley is rotated. Further, the light shielding plate provided on the pulley also rotates. If the light shielding plate rotates, it moves away from the detection sensor, and the light constantly irradiated from the detection sensor light projecting unit reaches the light receiving unit. Here, a signal is transmitted from the detection sensor to the control device, and based on this, the control device immediately stops the rotation of the servo motor for driving the feed, thereby stopping the advance of the feed pin and engaging with the feed pin. An overload acting on the lead frame can be prevented beforehand.
[0039]
In this overload detector, since the detection sensor and the spring post for tensioning the spring are attached to the position adjustment plate, the position adjustment plate is rotated along the rotation center of the pulley and the feed pin is moved. The elastic force of the spring acting on the overload detector is always constant regardless of whether it is moved forward or backward. The positional relationship between the detection sensor and the light shielding plate is also the same. For this reason, even if the position of the feed pin is adjusted, the force acting on the overload detector always remains constant, and overload detection can be performed without adjusting the position of the detection sensor.
[0040]
As mentioned above, although the embodiment taking the lead frame as an example has been described, the present invention is applicable to the transfer of strip-shaped thin plates other than the lead frame. In addition, although the embodiment has been described with reference to the die bonder lead frame transport device used in the pellet bonding process, the present invention can also be applied to other transport devices such as flip chip bonders.
[0041]
【The invention's effect】
As described above, according to the lead frame conveying apparatus according to the present invention, since the slide means is provided for each feed pin, the change of the shape of the pin holder due to the change of the shape of the lead frame is simplified. It can be reduced, that is, the device price can be reduced. Further, the positioning pins can be easily rearranged and can be adjusted in a short time. In addition, since an overload detector is provided for each feed pin, the apparatus immediately stops when the lead frame is overloaded. For this reason, since a large force does not act on the feed pin at the time of overload, the feed pin is hardly damaged. In addition, since the spring post of the spring stretched over the overload detector and the detection sensor are arranged on the position adjustment plate, the length of the spring can be adjusted even if the position of the feed pin is adjusted in the longitudinal direction using the position adjustment plate. Since the elastic force is the same, the force at which the overload is activated can be made the same. Further, since the detection sensor and the light shielding plate move in the same manner, it is not necessary to adjust the light shielding plate.
[0042]
[Brief description of the drawings]
FIG. 1 is a plan view showing a schematic configuration of a lead frame transport apparatus to which the present invention is applied.
FIG. 2 is a side view of a feed pin portion in FIG.
FIG. 3 is an operation explanatory view of a feed pin up / down operation and a horizontal operation to which the present invention is applied.
FIG. 4 is a plan view of an overload detector adapted to the present invention.
FIG. 5 is a side view of FIG. 4;
FIG. 6 is a plan view showing a schematic configuration of a conventional lead frame transport apparatus.
7 is a side view of the feed pin portion in FIG. 6. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Lead frame 1A Pellet mounting part 1B Feed hole 2 Guide rail 3 Feed pin 4 Pin holder 5 Transfer shaft 6 Feed up-and-down apparatus 7 Connecting plate 8 Slide guide 9 Screw shaft 10 Feed motor 11 Feed plate 12 Guide rail 13 Feed pin 14 Feed pin Vertical unit 15 Feed pin vertical drive device 16 Feed drive device 17 Control device 18 Spacer 18A Spacer 19 Horizontal block 19A Horizontal block 20 Horizontal slide guide 20A Horizontal slide guide 21 Horizontal base 22 Vertical slide guide 23 Vertical base 23A Dog 24 Pin holder 25 Timing belt 26 connecting plate 26A sensor 27 plate cam 28 cam follower 29 spring 30 slide plate 31A pulley 31B pulley 32 timing belt 33 fixing bracket 34 servo motor 35A pulley 35B pulley 36 37 servomotor 40 Overload detector 41 pulley 42 load device 43 detector 44 slot 45 pin 46 spring 47 shielding plate 48 spring post 49 position adjustment plate 50 the spring posts 51 slide unit 52 sensor 53 light emitting portion 54 receiving portion

Claims (3)

A guide rail that guides the lead frame and a plurality of feed pins provided on the lead frame feed surface by the guide rail are arranged at appropriate intervals in the longitudinal direction of the guide rail, and these feed pins are moved up and down to move the lead frame. Lead frame conveying apparatus having feed up / down means engaged with the feed hole, feed means for reciprocating these feed pins in the horizontal direction along the guide rail, and control means for controlling the feed up / down means and the feed means In order to move each feed pin along the guide rail with a belt-like member, the belt-like member is wound around a cylindrical body, and each feed pin is fed by the feeding means via the belt-like member. A slide means is provided so as to be movable, and the slide means is arranged for each feed pin. Frame transport apparatus. The cylindrical body is arranged for each feed pin, the cylindrical body around which the belt-shaped member is wound is rotatable, an arc-shaped elongated hole is provided in the cylindrical body, and a rotation regulating pin is fitted into the elongated hole. The end of the long hole of the cylindrical body is brought into contact with this rotation restricting pin, and a spring is stretched from the cylindrical body so that an elastic force acts in the direction opposite to the feeding direction of the belt-shaped member. 2. The lead frame conveying device according to claim 1, further comprising an overload detector which is urged to detect overload by detecting the extension of the spring. The overload detector comprises a load means for urging the cylinder body in the rotational direction by the elastic force of the spring, and a detection means for detecting that the spring is extended and deformed and the cylinder body is rotated by a sensor and a light shielding plate. , claim 2, characterized in that the position of the sensor and the light shielding plate of the elastic force detecting means of the spring of said load means is arranged so as to have the same be moved along the position of the feed pin horizontally The lead frame conveying apparatus as described.

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