JPH08126986A - Switching chuck device - Google Patents

Abstract

PURPOSE: To provide a switching chuck device which can detect the opening and closing condition of a chuck securely, and can release a nonconformity owing to an error detection. CONSTITUTION: This switching chuck 1 is provided with a pair of chuck claws 4 to grasp a lead frame for semiconductor sealing, and a driving cylinder 6 to drive to open and close the chuck claws 4, and a chuck detecting sensor 11 turning ON and OFF interlocking with the opening and closing operation of the chuck claws 4 is also provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an opening / closing chuck device used for supplying a lead frame for semiconductor resin encapsulation to a molding die of a molding device.

[0002]

2. Description of the Related Art In a resin encapsulation process of a semiconductor device, a lead frame having elements mounted thereon, which has been supplied from a wire bonding process before that, is supplied to a molding die for resin encapsulation, where a semiconductor is formed by thermosetting resin. The element is sealed with resin. At that time, an open / close chuck device that supplies a lead frame on which elements are mounted to a molding die is used.

This type of opening / closing chuck device is provided with a pair of chuck claws for holding the lead frame and a drive cylinder for driving the pair of chuck claws to open / close. In the actual operation, the chuck claw held in the open state is lowered to the frame position, and the driving cylinder is driven from this state to close the chuck claw, whereby the side edge of the lead frame is gripped by the chuck claw. Next, the lead frame thus picked up is conveyed to the frame supply position of the molding die, and the drive cylinder is driven again there to open the chuck claws to supply the lead frame to the molding die.

[0004]

However, since the opening / closing chuck device of this kind is not provided with means for detecting the opened / closed state of the chuck, mechanical problems such as insufficient air pressure in the drive cylinder and malfunction of the chuck claws are caused. Due to some troubles, the chuck claws could fall down in the closed state. Therefore, the lead frame is deformed due to the collision (positional interference) between the chuck claw and the lead frame, which causes various inconveniences such as damage to the semiconductor element mounted on the lead frame and disconnection of the wire. Further, generally, a means for detecting the chuck open / closed state based on the stroke amount of the drive cylinder is also known, but in this case not only the detection position setting accuracy is not sufficiently obtained, but also when adopting it. It is necessary to secure a sufficient stroke amount of the drive cylinder, and it is difficult to adopt the chuck structure used in the resin sealing process due to space restrictions and the like. In addition, even if it could be adopted, it is a method that indirectly detects the chuck open / closed state from the stroke amount of the drive cylinder, so even if the drive cylinder operates normally, it is possible to open / close it reliably due to malfunction of the chuck claw. Otherwise, the chuck open / closed state may be erroneously detected (erroneously recognized), resulting in the same problem as described above.

The present invention has been made to solve the above problems, and an object thereof is to provide an opening / closing chuck device capable of surely detecting the opened / closed state of the chuck and eliminating the trouble caused by erroneous detection. Especially.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and a pair of chuck claws for holding a lead frame for semiconductor resin encapsulation, and a pair of these chuck claws. An open / close chuck device including a drive unit for opening / closing is provided with a chuck detection sensor which is turned on / off in association with an opening / closing operation of a pair of chuck claws.

[0007]

In the opening / closing chuck device of the present invention, the on / off state of the chuck detection sensor is switched in conjunction with the opening / closing operation of the chuck claw, so that the opening / closing state of the chuck is directly changed depending on whether the chuck detection sensor is on or off. You will be able to detect.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of an opening / closing chuck apparatus according to the present invention. In the opening / closing chuck device 1 shown in FIG. 1, a pair of chuck claws 4 are rotatably attached to a chuck body 2 via pivots 3. Each of the chuck claws 4 has, for example, an L-shaped cross section as shown in the drawing, and each of the base end portions 4a.
Is urged toward the drive cylinder 6 by a return spring (for example, a compression coil spring) 5 incorporated in the chuck body 2. The drive cylinder 6 is connected to the upper end of the chuck body 2, and presses the base end 4 a of the chuck claw 4 against the biasing force of the return spring 5 by the air pressure supplied through the air tube 7. Further, the air tube 7 is a control valve (for example, a solenoid valve) 9 for opening and closing the chuck.
And a compression pump 10 serving as an air supply source via a control valve 9.

The open / close chuck device 1 of this embodiment is provided with a chuck detection sensor 11 which is turned on / off in conjunction with the opening / closing operation of the pair of chuck claws 4. The chuck detection sensor 11 is shown in the drawing, for example. It is attached near one side (left side in the drawing) of the chuck claw 4 by a bracket member or the like. Chuck detection sensor 11
Is composed of, for example, an optical sensor (photointerrupter) in which a light emitting portion and a light receiving portion are arranged to face each other with a predetermined gap. In this sensor structure, the sensor light emitted from the light emitting portion is received by the light receiving portion. In that state, the output signal is turned on, the sensor light emitted from the light emitting portion is blocked, and the output signal is turned off when the light does not reach the light receiving portion.
A detection dog 12 is attached to one of the chuck claws 4 (on the left side in the drawing) in correspondence with its movable range and the attachment position of the chuck detection sensor 11. When the chuck is opened and closed, the detection dog 12 detects the chuck. By advancing to the detection position P (between the light emitting portion and the light receiving portion) of the sensor 11, the on / off state of the chuck detection sensor 11 is switched.

FIG. 2 is a functional block diagram of the chuck operation control system. In FIG. 2, the sequencer 20 is, for example, C
The CPU of the sequencer 20 has a timer function together with a PU (central processing unit) and various memories.
A plurality (4 in the figure) via the input interface circuit
The individual chuck detection sensors 11a to 11d and a timer setting input unit 21 for manually setting a setting allowable range of detection timings (described later) of the sensors are connected. Further, the error output unit 22 and the interlock circuit 23 are connected to the CPU of the sequencer 20 via the output interface circuit. Interlock circuit 2
3 operates under a certain condition, in this case, when an abnormality occurs in the chuck open / closed state, and when an abnormality occurs in the chuck open / closed state, the lowering operation of the chuck is forcibly stopped and an error output is output. The error information is output from the unit 22.

Here, the "sensor detection timing" means
This is the timing at which the chuck open / close state is actually checked via the individual chuck detection sensors 11a to 11d, and this timing is appropriately set according to the operating speed of the chuck claw 4 accompanying the operation of the drive cylinder 6. For example, when the drive cylinder 6 is operated with the control valve 9 in the ON state or the OFF state, and the time required until the chuck is completely opened or closed by this is T,
When the timer set value of the detection timing starting from the ON / OFF switching timing of the control valve 9 is set earlier than the time T, the operation is performed while the chuck is not completely opened, that is, the chuck claw 4 is moving. Since the check is performed, false detection occurs. On the other hand, when the timer setting value of the detection timing starting from the ON / OFF switching timing of the control valve 9 is set to be extremely later than the T time, the time required for the operation check becomes long, The operating rate is significantly reduced. Therefore, in the present embodiment, the setting allowable range of the detection timing is stored and set as data in the memory of the sequencer 20 in advance, and the detection timing set by the timer setting input unit 21 is set in the operation flow described later. The detection timing is optimized depending on whether the value is within the above setting allowable range.

Next, the operation procedure of the opening / closing chuck device having the above-mentioned structure will be described with reference to the time chart of FIG. 3 and the flowchart of FIG. First, in the flowchart shown in FIG. 4, in step S1, the entire system including the opening / closing chuck device 1 is activated, and each system component is brought into an initial state, that is, an operable state. Next, in step S2, it is determined whether or not the start switch for starting the operation is in the ON state, and when the operator turns on the start switch, step S2 is performed.
Go to 3.

Next, in step S3, the detection timing (T1, T1 input through the timer setting input section 21 is input.
It is determined whether T2) is within the setting allowable range of the detection timing set in the memory of the sequencer 20 in advance. Here, if the input detection timing is out of the allowable range, the process proceeds to step S4, where error information indicating that the input setting timing is inappropriate is output to stop the system. Proceed to S5. In step S5, the open / closed state of the chuck claw 4 is confirmed based on the output signal of the chuck detection sensor 11. Here, under the normal operable state, the chuck claw 4 is kept in the closed state, that is, the chuck detection sensor 11 is kept in the ON state. Therefore, if the sensor output is in the OFF state, the process proceeds to step S6. Then, error information is output to the effect that the sensor output is abnormal, and the system is stopped.
If the sensor output is in the ON state, the process proceeds to step S7, where production of the system is started.

Succeedingly, in a step S8, a valve opening / closing signal (a) is raised to drive the chuck opening / closing control valve 9 as shown in FIG. Thereby, the compression pump 1
Since the compressed air generated at 0 is supplied to the drive cylinder 6 through the air tube 7, the substrate portion 4a of the chuck claw 4 is pressed against the urging force of the return spring 5, and the chuck claw 4 is opened. Start. Then, the predetermined time t1
When (Fig. 3) has elapsed, the chuck claw 4 is completely opened, and the output signal (b) of the chuck detection sensor 11 is turned off (Low level) due to the advance of the detection dog 12. On the other hand, step S9 following step S8
Then, the timer incorporated in the sequencer 20 starts the counting operation, and in step S10, it is repeatedly determined whether or not the count value of the timer has reached the set value T1 of the detection timing.

Thereafter, as shown in FIG. 3, when the time T1 elapses after the valve opening / closing signal (a) rises, the detection timing signal (c) for checking the chuck opening operation is output, and at the same time, the chuck detection signal 11 is output. The open / closed state of the chuck claw 4 is confirmed based on the output signal (b) of (step S11). At this time, the chuck detection sensor 1
When the output signal (b) of 1 is in the ON state, that is, when the chuck claw 4 is not opened even though the control valve 9 is opened and the drive cylinder 6 is operated,
Since it is assumed that the chuck claw 4 has malfunctioned due to some mechanical trouble, the process proceeds to step S12, at which the error information indicating that the chuck opening / closing operation is abnormal is output and the system is stopped.

On the other hand, when it is determined in step S11 that the output signal (b) of the chuck detection sensor 11 is in the off state (Low level), the chuck claw 4 is opened / closed by opening / closing the control valve 9 in step S8. Is assumed to have been normally opened and closed, so that step S13 is performed as it is.
Proceed to. In step S13, the opening / closing chuck device 1 drives the preheat table 1 by driving an elevating unit (not shown).
3 (Fig. 1). Next, in step S14,
As shown in FIG. 3, the valve opening / closing signal (a) is lowered to drive the chuck opening / closing control valve 9. This allows
The supply of compressed air to the drive cylinder 6 is cut off, the substrate portion 4a of the chuck claw 4 is pushed back by the urging force of the return spring 5, and the chuck claw 4 starts the closing operation. Then, when the predetermined time t2 (FIG. 3) elapses, the chuck claw 4 is completely closed, and the detection dog 12 is separated from the detection position P of the sensor, and the output signal of the chuck detection sensor 11 (b). Is turned on (Hi level). further,
In step S15 following step S14, the timer incorporated in the sequencer 20 starts counting operation,
Further, in step S16, it is repeatedly determined whether or not the count value of the timer has reached the set value T2 of the detection timing.

Thereafter, as shown in FIG. 3, when the time T2 elapses after the valve opening / closing signal (a) rises, the detection timing signal (d) for checking the chuck closing operation is output, and at the same time, the chuck detection signal 11 is output. The open / closed state of the chuck claw 4 is confirmed based on the output signal (b) of step S17). At this time, the chuck detection sensor 1
When the output signal (b) of 1 is in the OFF state, that is, when the chuck claw 4 does not close even though the control valve 9 is closed and the drive cylinder 6 is returned to the initial state, the same as above. Since it is assumed that the chuck claw 4 has malfunctioned due to some mechanical trouble, the process proceeds to step S18, at which error information indicating that the chuck opening / closing operation is abnormal is output and the system is stopped.

On the other hand, when it is determined in step S17 that the output signal (b) of the chuck detection sensor 11 is in the on state (Hi level), the chuck claw 4 is opened and closed by opening and closing the control valve 9 in step S14. Is normally closed, and it is assumed that the element mounted lead frame 14 (FIG. 1) set on the preheat table 13 is securely gripped by the chuck claws 4, and thus the process directly proceeds to step S19. In step S19, the lead frame 14 gripped by the chuck claws 4 is transferred from the preheat table 13 to the molding die, where the semiconductor device 15 (FIG. 1) is resin-sealed by a molding device (not shown). . At this point, if there is no lead frame 14 to be processed next, the operator turns on the stop switch.

Finally, in step S20, the on / off state of the stop switch is confirmed, and if the stop switch is in the off (OFF) state, the next lead frame 1
In order to pick up No. 4, the process returns to step S7 and the same operation as described above is repeated. If the stop switch is in the ON state, the process directly proceeds to step S21 to stop the system and exit the series of processes.

Thus, the opening / closing chuck device 1 of this embodiment
In the state where the chuck claw 4 is opened by the drive of the drive cylinder 6, the detection dog 12 advances to the detection position P of the chuck detection sensor 11 to turn off the sensor signal, and conversely by the urging force of the return spring 5. Chuck claw 4
When is closed, the detection dog 12 is separated from the detection position P of the chuck detection sensor 11 and the sensor signal is turned on. Therefore, when the chuck claw 4 is opened and closed, the open / closed state of the chuck claw 4 can be directly detected depending on whether the output signal of the chuck detection sensor 11 is in the on state or the off state. Further, in the present embodiment, the chuck detection sensor 11 is operated after a predetermined time (T1, T2) corresponding to the operating speed of the chuck claw 4 has elapsed from the switching timing of the valve opening / closing signal (a), that is, the drive timing of the drive cylinder 6.
Since the detection timing is set, it is possible to reliably detect the chuck open / closed state by the chuck detection sensor 11 when the chuck claw 4 is completely opened or closed.

Although an optical sensor (photointerrupter) is used as the chuck detection sensor 11 in the configuration of the above embodiment, the present invention is not limited to this, and various modifications such as a fiber sensor and a proximity sensor are possible. Examples are possible. In addition, the detection timing (T1, T
Sequencer 20 can also be used as a timer to count 2)
I adopted an internal timer softly incorporated into
In addition to this, a separate external timer may be connected to the sequencer 20.

[0022]

As described above, according to the present invention,
Since the open / closed state of the chuck can be directly detected based on the output signal of the chuck detection sensor that turns on / off in synchronization with the opening / closing operation of the chuck claw, for example, when a chuck claw malfunction occurs due to mechanical trouble. Even if there is, it is possible to reliably detect the chuck open / close state without erroneous detection as in the conventional case. As a result, it is possible to reliably prevent deformation of the lead frame due to erroneous detection of the chuck opening / closing operation, damage to the semiconductor element due to this, and further wire cutting, and to greatly improve the reliability of the opening / closing chuck device. It becomes possible. Also,
By eliminating erroneous detection of the chuck opening / closing operation and various inconveniences associated therewith, the mean failure interval can be extended and the tact time can be shortened at the same time, leading to an increase in the operating rate in the molding process.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an opening / closing chuck apparatus according to the present invention.

FIG. 2 is a functional block diagram of a chuck operation control system.

FIG. 3 is a time chart showing a chuck operation in the example.

FIG. 4 is a flowchart showing a chucking operation in the embodiment.

[Explanation of symbols]

 1 Open / close chuck device 4 Chuck claw 11 Chuck detection sensor 12 Detection dog

Claims (2)

[Claims] 1. An opening / closing chuck device comprising a pair of chuck claws for holding a lead frame for semiconductor resin encapsulation, and a drive means for driving the pair of chuck claws to open and close. An opening / closing chuck device comprising a chuck detection sensor that is turned on / off in association with opening / closing operation. 2. The opening / closing chuck according to claim 1, wherein the detection timing of the chuck detection sensor is set after a predetermined time corresponding to the operation speed of the chuck claw has been set with the drive timing of the drive means as a starting point. apparatus.