JP3013115B2 - Method and apparatus for removing and moving plate-like object - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for taking out and moving a plate (for example, a lead frame for an integrated circuit (hereinafter, referred to as IC) device) and an apparatus used for the method.

When assembling an IC device, an IC chip is mounted at a predetermined position on a lead frame, terminals of the IC chip are electrically connected to leads of the lead frame by wire bonding, and then the IC chip and the leads are connected. There is a step of sealing a part with resin.

A lead frame is a thin metal plate having a thickness of several tens to several hundreds of micrometers, and is formed in a state where several pieces (for example, six pieces) are formed in a continuous state, and has an elongated external shape. Supplied as a unit. Therefore, in order to mount an IC chip on a lead frame, it is necessary to take out each one of a large number of stacked lead frames and send it to a mounting step.

The above-described lead frame is taken out and moved by a method as shown in FIGS. In FIG. 19, the lead frame located at the uppermost end of the lead frame W, which is stacked and accommodated in the stocker 2, is taken out by suction with the vacuum pad 12, and the vacuum pad support plate 11 is indicated by a virtual arrow. Then, the suction by the vacuum pad 12 is released, and the lead frame W that has been sucked up to that time is placed on the stage 63. The lead frame W placed on the stage 63 is
It is transported to the next step. This operation is repeated.

In FIG. 20, the uppermost lead frame is sandwiched between a pair of sandwiching members 66, 66 instead of the suction by the vacuum pad 12 in FIG. The sandwiching member 66 has a structure in which a pad 66b (having a paper file shape on the surface) having a large coefficient of friction is adhered to the tip of a handle 66a having sufficient flexibility. Two or more pairs of the holding members 66 are provided in the longitudinal direction of the lead frame.

In addition to the above, the methods shown in FIGS. 21 and 22 are also employed. The bundle of lead frames is set in the stocker 62. The lead frame W is set vertically in FIG. 21 and obliquely in FIG. Then, a lead frame other than the lowermost lead frame is clamped by the clamper 64, and the lowermost lead frame W is sandwiched between the peeling claws 65, 65.
Drop on 63.

As described above, the lead frame W is a thin plate. As shown in FIG. 18, the lead portion 51 around the IC chip mount portion 52 has a plurality of (many) leads inside (I).
C chip mount 52). When a plurality of the leads are overlapped, the leads of the overlapping lead frames may be entangled, which is more likely to be entangled by design or by increasing the number of leads (the number of pins). Therefore, when the lead frame is taken out by the above method, the following inconvenience occurs.

In the method shown in FIGS. 19 and 20, a plurality of sheets (for example,
May be sent to the next step in close contact with each other, and the processing in the next step may not be performed smoothly. In the worst case, the equipment (particularly, the equipment in the resin sealing step, etc.) It can be destroyed. Also, even if the lead frames do not adhere to each other, if the two are entangled with each other, the lower lead frame is carried on the stage 63 in a state of being suspended obliquely, and the lower lead Accidents are likely to occur, such as the frame falling or, in the worst case, colliding with the structure of the device and causing damage. In addition, when the uppermost lead frame is sucked by the vacuum pad, in order to ensure this suction, the overlapping lead frames must be once pressed by the vacuum pad and then sucked. May cause damage.

In the method shown in FIGS. 21 and 22, when the lead frame is entangled, it must be forcibly peeled off.
At this time, this may be deformed depending on the design of the lead frame.

Therefore, it has been considered that thin paper is sandwiched between the lead frames to prevent adhesion and entanglement.
In this method, not only the cost is increased due to the sandwiching of the thin paper, but also it is necessary to take measures to dispose of the thin paper that is no longer necessary when transporting one sheet at a time, which is uneconomical.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to detect a close contact or an entanglement and easily release them even if a plurality of plate members are taken out of contact or a plurality of plate members are entangled. Further, it is an object of the present invention to provide a plate-like body removal moving method and a device which can always reliably remove a plate-like body one by one.

[0012]

According to the first aspect of the present invention, when a predetermined plate-shaped object is taken out of a plurality of stacked plate-shaped objects and moved,
A step of taking out a plate-like body at a predetermined position from a plate-like body mounting portion on which the plurality of plate-like bodies are placed by a temporary plate-like body holding unit; Detecting the state of the plate-like body taken out by the method, applying a shock to the temporary plate-like body holding means based on the detection result, and moving the temporary plate-like body holding means. Moving the plate-like body held by the temporary plate-like body holding means to a position different from the plate-like body mounting portion.

According to a second aspect of the present invention, there is provided a plate-shaped member mounting portion for mounting a plurality of stacked plate-shaped members, and a predetermined one of the plate-shaped members mounted on the plate-shaped member mounting portion. A temporary plate-like body holding means for taking out and temporarily holding the plate-like body, a detecting means for detecting a state of the plate-like body temporarily held by the temporary plate-like body holding means, An impact applying means for applying an impact to the temporary plate-like body holding means based on the result, and the plate-like body held by the temporary plate-like body holding means at a different position from the plate-like body mounting portion. The present invention relates to a plate-like body removing and moving device having a plate-like body moving means for moving the same. In the present specification, the “impact” includes vibration.

[0014]

Embodiments of the present invention will be described below. FIG. 1 is a schematic perspective view of a main part showing a structure of a lead frame take-out moving device. The stocker 2 is located on the front side of the apparatus 1, the lead frame transfer unit 3 is located on the rear side, and the stage 23 is located on the rear side.

The stocker 2 has side walls 2a, 2a and a bottom plate 2b located therebetween. A screw 2c is rotatably mounted on the lower surface of the bottom plate 2b, and the bottom plate 2b on which a plurality of lead frames W indicated by phantom lines are placed and moved is moved up and down by the rotation of the screw 2c.

The lead frame transfer section 3 is configured as follows.

Supports 4, 4 are erected on both ends of the bottom plate 5,
A shaft 7 is pivotally supported on the columns 4 and 4, and arms 9 and 9 are mounted on the shaft 7.
Has been fixed. A shaft 10 is rotatably mounted on the distal end side of the arms 9, 9 with respect to the arms 9, 9.
The support plate 11 to which the vacuum pads 12 are attached is fixed. The shaft 7 is rotated by a predetermined angle by a rotary actuator 8 driven by compressed air. Each vacuum pad 12 is connected to a solenoid valve 14 via a pipe 13 and a vacuum switch 37. When the piston is inserted into the cylinder, and the vacuum pad 12 sucks the lead frame W, the inside of the cylinder becomes negative pressure and the piston is pulled, and the movement of the piston turns on or off the micro switch, for example.
(In this example, ON).

An air cylinder 15 is fixed to the support plate 11 via a bracket 16, and a weight 17 is fixed to the air cylinder 15. The support plate 11 is always kept horizontal. The horizontal holding mechanism will be described later in detail.

The lead frame W is transferred from the stocker 2 to the stage 23 as follows.

The screw 2c rotates in the state of FIG.
b rises. When the uppermost lead frame of the lead frames W on the bottom plate 2b rises to a predetermined position, the photo sensor 20 detects this. The photo sensor 20 is a reflection type sensor including a visible light emitting diode and a phototransistor light receiving unit. When the photo sensor 20 detects a predetermined position of the uppermost lead frame, the rotation of the screw 2c is stopped and the lifting of the bottom plate 2b is stopped based on the detection result. At this time, the electromagnetic valve 14 is opened, and the vacuum pad 12 is in a state of sucking the atmosphere.

Then, the screw 2c rotates again, and the bottom plate 2b
Rises little by little until the vacuum pad 12 completely sucks the lead frame and the vacuum switch 37 is turned on. Vacuum pad 1 for lead frame
When the vacuum switch 37 is turned on, the rotation of the screw 2c is completely stopped, and the lifting of the bottom plate 2b is stopped again.

Next, the air cylinder 6A supporting the bottom plate 5 is driven, whereby the support plate 11 is slightly raised. At this time, the lead frame number sensor 21 located below the support plate 11 detects whether the number of lead frames adsorbed on the vacuum pad 12 is one or more. That is, the air cylinder 6A serves to raise the detected lead frame to a position where the detection is performed by the sensor 21. At the same time, the lead frame entanglement sensor 22 detects whether the lead frame is entangled. The mechanism of these detections will be described later in detail.

When it is detected that one or both of the plurality of lead frames adhered to the vacuum pad 12 and the presence of a lead frame suspended obliquely by entanglement are detected, Based on this detection result, the solenoid valve 19 connected to the air cylinder 15 via the pipe 18 is driven. Then, the air cylinder 15 is driven to give a periodic impact in the horizontal direction to the vacuum pad 12, and the closely or entangled lead frame is shaken off. Thus, only one lead frame is adsorbed and supported by the vacuum pad.

FIG. 7 is an enlarged front view for explaining the driving of the air cylinder 15. The air cylinder 15 reciprocates between an original position shown by a solid line and a position shown by a virtual line during driving. When moving, it collides with the bracket 16 and impacts the vacuum pad 12 of FIG. The cycle of the impact may be about 10 times / second, and the air cylinder 15 is driven by opening and closing the solenoid valve 19. The stroke l of the reciprocating motion of the air cylinder 15 may be about 10 mm. The weight 17 is provided to increase the impact force.

When it is detected that only one lead frame is adsorbed on the vacuum pad 12 and no entanglement occurs, the air cylinder 6B supporting the bottom plate 5 is operated based on the detection result. When driven, the transfer section 3 is raised to the transfer position, the rotary actuator 8 is subsequently driven to rotate the shaft 7 by 180 degrees, and the support plate 11 moves onto the stage 23. Next, the electromagnetic valve 14 is closed to release the suction of the vacuum pad 12, and the released lead frame W is placed on the pair of tables 24, 24 apart from the vacuum pad 12.

Next, the support plate 11 returns to the position shown in FIG. 1 by driving the rotary actuator 8 in the direction opposite to the above. At the same time, the air cylinder 26 is driven to push the plate 25, whereby the lead frame W on the pedestals 24, 24 is sent to the lead frame transport section of the die bonder (not shown) as indicated by the phantom arrow, and the IC chip Is the IC chip mount part of the lead frame (52 in FIG. 18)
And wire bonding is performed in the next step.

FIGS. 2 to 4 are side views of the main parts of the device for explaining the movement of the arm 9 and the support plate 11. FIG.

As shown in FIG. 2, an arm 9 is pivotally supported at the rear end of the column 4 by a shaft 7, and a pulley 28 is fixed to the column 4 via a collar 27 fitted on the shaft 7. A support plate 11 is fixed to a shaft 10 pivotally supported on the distal end side of the arm 9, and a pulley 29 is fixed to the shaft 10. Pulley 28, 29
A toothed belt 31 is hung on the belt, and the toothed belt 31 is not loosened by the tension pulley 30.

When the arm 9 is rotated by driving the rotary actuator 8 shown in FIG.
The pulley 28 does not rotate because it is fixed to the column 4 as shown in FIG. 5, but rotates counterclockwise by the same angle relative to the arm 9 that rotates clockwise.
Accordingly, the pulley 29 engaged with the pulley 28 via the toothed belt 31 also rotates by the same angle counterclockwise relative to the arm 9.

As described above, the pulley 29 rotates by the same angle with respect to the arm 9 in the direction opposite to the rotation direction, and from the state shown in FIG. 2 to the state shown in FIG. The support plate 11 fixed to the pulley 29 via the shaft 7 revolves around the shaft 7 without rotating, and moves above the stage 23 while maintaining the horizontal position.

Next, the above-described lead frame detection will be described with reference to FIGS.

The lead frame number sensor 21 shown in FIG.
Is a kind of magnetic sensor. When a metal such as a lead frame W is inserted into a magnetic flux M generated from the sensor 21, the magnetic flux M is blocked, and the magnetic flux M is increased in proportion to the thickness of the metal. The shielding amount of the magnetic flux M increases. Therefore, when two lead frames W are present in the magnetic flux M, the strength of the magnetic flux M is reduced. When the decrease in the magnetic flux intensity is detected, it can be determined that a plurality of lead frames W exist in the magnetic flux M.

However, if the design or material of the lead frame changes, the degree of the decrease in the magnetic flux intensity differs even for the same sensor. We are taking such measures.

The sensor 21 outputs the magnetic flux intensity as an analog signal as a voltage or a current, and the control circuit finely controls the change of the analog signal. The control circuit has a function (auto-zero function) of forcibly shifting the analog input value to zero with one touch.

Therefore, only one lead frame is sucked,
While supported, the control circuit shifts the analog input signal to zero. When a plurality of lead frames are closely attached to each other and sucked and supported by the vacuum pad, the input analog signal is not always zero, so
Regardless of the design and material of the lead frame, it is possible to reliably detect the lead frame.

The entanglement sensor 22 shown in FIG. 6 has a light emitting diode 22A and a phototransistor 22B opposed to each other on both sides at a position slightly below the lead frame W adsorbed on the vacuum pad 12. .

In a normal state where no entanglement occurs, the light L from the light emitting diode 22A is
The light enters B and an output “1” is output. On the other hand, if there is an oblique lead frame W that is entangled and indicated by a virtual line, the light L is blocked by this and the phototransistor 22B
Stops receiving the light L. Thus, the presence or absence of occurrence of entanglement is detected.

The control for driving the air cylinder 15 or stopping or not driving the air cylinder 15 and the driving control of the rotary actuator 8 based on the detection by the sensors 21 and 22 will be schematically described with reference to the block diagram of FIG. .

Sensor 21 and phototransistor 22B
Are output to the impact control circuit 33, and the output from the impact control circuit 33 is input to the solenoid valve 19 . The other outputs of the sensor 21 and the phototransistor 22B are input to an arm rotation control circuit 34,
The output from the arm rotation control circuit 34 is input to a solenoid valve 35. The solenoid valve 35 is connected to the rotary actuator 8 via a pipe 26.

When one or both of the sensor 21 detects a plurality of lead frames and the sensor 22 detects the entanglement of the lead frame, an impact control circuit
The output of 33 drives the solenoid valve 19, which drives the air cylinder 15 to shake off the extra lead frame as described above. At this time, the arm rotation control circuit keeps the solenoid valve closed.

When the sensor 21 detects only one lead frame and the sensor 22 detects that no entanglement has occurred in the lead frame, the shock control circuit 33 controls the solenoid valve.
19 is closed or kept closed, and the arm rotation control circuit 34
Opens the solenoid valve 35 to drive the rotary actuator 8. Thereby, the support plate 11 moves as described above.

The above-described movement and its control are shown in flowcharts in FIGS. FIG. 9 shows the operation from the start of operation of the apparatus to the transfer of the first lead frame, and FIG. 10 shows the subsequent continuous operation. 9 and 10, “ON”,
“OFF” means detection of abnormality and normality in the case of a sensor, “opening and closing” or “repetition of opening and closing and closing” in the case of an electromagnetic valve, and “driving, "No drive". In these figures, L / F represents a lead frame (W in FIGS. 1 to 6), and V / S represents a vacuum switch (37 in FIG. 1).

FIG. 12 is an enlarged partial sectional view taken along the line XII--XII of FIG. 18, and FIG. 11 is an enlarged partial perspective view of FIG. In addition, FIG.
FIG. 12 shows a state in which two lead frames overlap and are displaced (ie, before impact is applied). In FIG. 12, the thickness of the lead frame is exaggerated.

IC chip mounting part 52 of support pin 54
The connection 53 is inclined downward toward the IC chip mount 52, and the IC chip mount 52 is slightly lower than the leads 51 and the support pins 54 and is recessed. The above inclined portion 53 is called an offset portion.

Since a large number of the leads 51 are arranged with a slight gap therebetween, a difference in the plane direction between the upper and lower lead frames which are in contact with each other at the time of operations such as packing, transportation, loading into a stocker, etc. As shown in an enlarged manner, the upper and lower lead frames W, W may be displaced. Then, the offset portion 53 of the upper lead frame and the lead 51 of the lower lead frame come into contact at the point P, and the upper and lower lead frames are entangled, making it difficult for them to separate. However, according to this example, the periodic impact by the air cylinder 15 described above
The upper and lower lead frames are easily separated.

Further, when the lead frame is sucked by the vacuum pad, the two lead frames may come into close contact with each other, for example, at one end in the longitudinal direction, and the lower lead frame may be suspended obliquely. However, according to the present embodiment, this can be easily solved as described above. The same problem as described above may occur even with a flat lead frame having no offset portion, but this problem is also solved according to the present embodiment in the same manner as described above.

With the mechanism described above, even if a plurality of lead frames come into close contact with each other and are attracted to the vacuum pad, or if an extra lead frame is suspended obliquely due to entanglement, the sensors 21 and 22 can be used. Thus, these abnormal states are detected, and the undesired lead frame is reliably separated from one desired lead frame to be attracted by the impact of the driving of the air cylinder 15. Also, since the above detection and driving are performed automatically,
Continuous operation is possible without stopping the operation of the device,
High productivity can be maintained.

Next, a description will be given of the result of an experiment on the vibration state of the lead frame W caused by the operation of the air cylinder 15.

The experiment was performed as shown in FIG. In the vicinity of the suction position of the vacuum pad 12 of the lead frame W, two portions in the longitudinal direction and the width direction are bent upward, and the X direction in the horizontal direction, the Y direction, and the vertical direction facing the vacuum pad 12 from below. The amplitude and cycle of the vibration of the lead frame W were measured in three Z directions. The device used for the measurement was an ultra-precision non-contact displacement meter OPTO manufactured by San Techno.
This is an oscilloscope equipped with a METRIC (optical displacement meter) and a memory function. 2565R was used for the probe part and OM-10II was used for the amplifier part. PH in the figure is a probe head.

FIGS. 14, 15 and 16 show waveforms of the oscilloscope in the X, Y and Z directions, respectively. The amplitude is greatest in the X direction, which is parallel to the operating direction of the air cylinder 15,
It is similar in the Y direction and the Z direction orthogonal to this direction.

When the apparatus shown in FIG. 1 was operated continuously for 7 days (24 hours × 7), it was found that MTBA (average period of operation stop of the apparatus caused by close contact and entanglement of the lead frame) and damage caused by entanglement of the lead frame were caused. The defective rate was as shown in the table below. The table includes, for comparison, FIG. 19 and FIG.
Similar results using the conventional apparatus shown in FIG. 22 are also shown.

[0052] It should be noted that the same result as in the table was obtained by using the apparatus of this example for almost one year.

FIG. 17 is a schematic perspective view of a main part of a device according to another example, similar to FIG. Note that parts common to FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. The device 41 is configured to move the stage 23 from the stocker 2 side of the support plate 11.
The movement to the side is based on vertical movement and horizontal movement, not on rotational movement. That is, the support plate 11 is
The vertical drive unit 48 of the transfer unit 43
, A horizontal movement by the horizontal drive unit 49 following this, and a descent by the next vertical drive unit 48.
These drives are all performed by an air cylinder (not shown). The movement of the support plate 11 from the stage 23 side to the stocker 2 side is performed in the reverse procedure. Other than that, there is no difference from the apparatus of FIG.

Although the embodiment of the present invention has been described above, various modifications can be made to the above embodiment based on the technical idea of the present invention. For example, as the various sensors, non-contact appropriate types of sensors different from the above-described example may be used.
The impact is given by air cylinder, electromagnetic piston,
Any suitable means such as an electromagnetic vibrator and an eccentric cam may be used, and the impact direction may be a horizontal direction or a vertical direction. The support of the lead frame may be performed by an appropriate method other than the suction. Driving of each drive unit may be performed by an appropriate mechanism such as a link mechanism in addition to the air cylinder. Also, depending on how the lead frame is entangled, the impact cycle,
The direction and the like can be made variable. Further, the superposed direction of the supplied lead frames may be a horizontal direction or any other direction in addition to the vertical direction. The plate to be taken out may be a lead frame or any other plate having a possibility of close contact or entanglement.

[0055]

According to the present invention, the state (for example, the presence or absence of contact or entanglement) of the plate-like body taken out and held by the temporary plate-like body holding means is detected, and based on the detection result, the temporary plate-like body is detected. Since the impact is applied to the body holding means, the plate-like body held by the temporary plate-like body holding means is released by the above-described impact even if, for example, tight contact or entanglement occurs. Is done. Therefore, only a predetermined plate-like body is held by the temporary plate-like body holding means. As a result, the removal and subsequent movement of the plate-like body are constantly and stably performed in a normal state, and there is no risk of damaging the plate-like body and a device in a subsequent process. In addition, the above-described detection and impact application can be performed automatically, and stoppage of the device is prevented, thereby ensuring high productivity.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a main part of a lead frame take-out moving device according to an embodiment.

FIG. 2 is a side view of a main part of the device.

FIG. 3 is a side view of a main part showing a process of moving the support plate.

FIG. 4 is a main part side view showing a state after the movement of the support plate.

FIG. 5 is a schematic side view for explaining a detection mechanism of a lead frame number detection sensor.

FIG. 6 is a schematic front view for explaining a detection mechanism of a sensor that detects entanglement of the lead frame.

FIG. 7 is a front view for explaining the operation of the impact applying air cylinder.

FIG. 8 is a block diagram for explaining control of each operation based on a detection result of each sensor.

FIG. 9 is a flowchart showing the movement of each part from the start of operation of the apparatus to the first lead frame transfer and its control.

FIG. 10 is a flowchart showing the movement of each unit and its control during continuous operation of the device.

FIG. 11 is an enlarged partial perspective view showing a state in which two lead frames overlap with each other with a positional shift (a state before impact is applied).

12 is an enlarged partial sectional view of the lead frame in the state of FIG. 11 (an enlarged partial sectional view taken along line XII-XII of FIG. 18).

FIG. 13 is a perspective view of a main part showing a procedure of lead frame vibration measurement.

14 is a vibration waveform in the X direction of FIG.

FIG. 15 shows a vibration waveform in the Y direction.

FIG. 16 shows a vibration waveform in the Z direction.

FIG. 17 is a schematic perspective view of a main part of a lead frame removing / moving apparatus according to another embodiment, similar to FIG.

FIG. 18 is a plan view of a lead frame.

FIG. 19 is a schematic front view of a main part of a conventional lead frame take-out moving device.

FIG. 20 is a schematic front view of a main part of another conventional lead frame take-out moving device.

FIG. 21 is a schematic front view of a main part of a lead frame removing / moving apparatus according to still another conventional example.

FIG. 22 is a schematic front view of a main part of a lead frame take-out moving device according to still another conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1, 41 Lead frame removal moving apparatus 2 Lead frame stocker 3, 43 Transfer part 6A, 6B, 15, 26, 37 Air cylinder 7, 10 axis 8 Rotary actuator 9 Arm 11 Support plate 12 Vacuum pad 14, 19, 35 Electromagnetic Valves 20, 21, 22 Sensor 22A Light emitting diode 22B Phototransistor 33 Impact control circuit 34 Arm rotation control circuit 37 Vacuum switch 48 Vertical drive unit 49 Horizontal drive unit 51 Lead 52 IC chip mount unit 53 Offset unit 54 Support pin PH Probe head W Lead frame

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/50

Claims (2)

(57) [Claims] When a predetermined plate-shaped body is taken out of a plurality of stacked plate-shaped bodies and moved, a predetermined plate-shaped body mounting part for mounting the plurality of plate-shaped bodies is used. Taking out the plate-like body at the left position by the temporary plate-like body holding means, detecting the state of the plate-like body taken out by the temporary plate-like body holding means, and based on the detection result. Applying a shock to the temporary plate-like body holding means, and moving the temporary plate-like body holding means so that the plate-like body held by the temporary plate-like body holding means is moved to the plate-like body. Moving the plate-shaped body to a position different from the mounting portion. 2. A plate-like body mounting section for mounting a plurality of stacked plate-like bodies, and a predetermined plate-like body among the plate-like bodies mounted on the plate-like body mounting section. Temporary plate-like body holding means for taking out and temporarily holding, detecting means for detecting the state of the plate-like body temporarily held by the temporary plate-like body holding means, and based on the detection result. Impact applying means for applying an impact to the temporary plate holding means, and a plate for moving the plate held by the temporary plate holding to a different position from the plate mounting portion A plate-shaped object removing / moving device having a shape-object moving means.