JP2749709B2 - Press equipment abnormality detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to an abnormality detection device of a press device for detecting whether a movable type with respect to a fixed type is in a normal state.

(Prior Art) For example, in a mold press apparatus for sealing a semiconductor or the like with a resin, a lead frame on which a semiconductor is mounted is arranged in a fixed mold, and a movable mold is moved to contact the fixed mold (mold closed).
At the same time, mold clamping is performed, and resin sealing is performed in this state. By the way, when performing such resin sealing, the movable mold is fixed, for example, when foreign matter is sandwiched between the fixed mold and the movable mold, or when a plurality of lead frames are arranged in an overlapping state. If resin sealing is performed in a state where the resin is not in close contact with the mold, a failure or an accident may occur. In order to prevent this, as described in Japanese Patent Application Laid-Open No. 2-52706, it is possible to use an abnormality detection device that detects the state of close contact between a fixed type and a movable type and determines whether or not it is normal. Is being done.

As shown in FIG. 5, such an abnormality detection device includes a closed type sensor 1 for detecting a contact state between a movable type and a fixed type,
Position detection sensor 2 for detecting the position of the movable mold at that time
And a control unit 3 for drivingly controlling the press device based on signals from these sensors 1 and 2. The control unit 3 is composed of a microcomputer or the like, and its block configuration includes a gate 4, a comparison unit 5, a setting unit 6, and an abnormality treatment unit 7. In the control unit 3, the gate 4 is turned on by the detection signal of the closed sensor 1, and gives the position detection signal of the position detection sensor 2 to the comparison unit 5. The comparison means 5 compares the position detection signal with the set value from the setting means 6 and outputs an abnormality flag to the abnormality treatment means 7 when the comparison result exceeds the normal operation range.

In such a configuration, when the press device is operated, the control unit 3 starts a program according to the flowchart shown in FIG. First, when the movable mold descends and comes in contact with the fixed mold, the closed sensor 1 detects this and the control unit 3 turns on the gate 4 based on the detection signal (step S1). As a result, the position detection signal from the position detection sensor 2 is input to the comparing means 5, and the detected position is compared with the set value given from the setting means, and the comparison result is within a predetermined normal operation range. Sometimes, the determination is "YES" and the program is terminated (step S2), and thereafter, the resin sealing step is performed. If the comparison result exceeds the normal operation range, “NO” is determined in the step S2, an abnormal flag is set in a succeeding step S3, and the program is terminated. In this case, when the abnormality flag is set in step S3, the abnormality treatment means 7 stops the resin sealing operation by stopping the pressing operation or the like. That is,
Due to the stopping operation by such an abnormal treatment unit, for example, when a foreign object is interposed between the movable mold and the fixed mold or when a plurality of lead blems are arranged in an overlapping state, the resin erroneously remains in that state. Sealing is prevented.

(Problems to be solved by the invention) However, as described above (Japanese Unexamined Patent Application Publication No. 2-52706)
In the case of (1), for example, if the expansion deformation due to the temperature rise occurs in the movable type or the fixed type while the pressing operation is continued, the position detected by the position detection sensor 2 gradually shifts. In other words, the comparison result of the comparison means 5 gradually increases, and the control unit 3 may output an abnormal flag in step S2 even though it is operating normally at last.

On the other hand, to avoid the above-mentioned problems,
If the value of the normal operation range in S2 is set large in advance, the following new problem occurs. That is, for example,
If the dimension changes by about 10 microns with a rise in temperature in one press operation, the change in dimension exceeds 100 microns in 10 or more press operations. Therefore, if the normal operation range is set to be as large as about 300 microns, it is possible to sufficiently cope with the problem. However, since the thickness of the lead frame is about 150 microns, such a setting range may make it impossible to detect even if two lead frames are erroneously arranged. If such an abnormal state is overlooked, a mold such as a fixed mold or a movable mold may be damaged, or a device in a later process may be damaged.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object the proper operation of the movable type and the fixed type without unnecessarily increasing the normal operation range even when the detection position changes due to expansion due to temperature rise. It is an object of the present invention to provide an abnormality detecting device for a press device, which can be set to an abnormal state and can reliably detect an abnormal state.

[Constitution of the Invention] (Means for Solving the Problems) The abnormality detecting device for a press device of the present invention is directed to a press device comprising a fixed die and a movable die capable of moving toward and away from the fixed die. State detecting means for detecting a state in which the movable mold is in contact with the fixed mold, position detecting means for detecting the position of the movable mold in the contacted state, and comparing a position detected by the position detecting means with a set value. Comparing means, abnormal treatment means for performing an abnormal measure when the comparison result by the comparing means exceeds the normal operation area, and detection position by the position detection means when the comparison result by the comparison means is within the normal operation area And a setting value changing means for changing and setting the setting value of the comparing means based on the above.

(Operation) According to the abnormality detection device for a press device of the present invention, when the movable die descends and comes into contact with the fixed die during the press operation,
The state detecting means detects this, and the position detecting means detects the position of the movable mold at this time. Then, the comparing means compares the detected position from the position detecting means with the set value, and determines whether or not the comparison result is within the normal operation area. When the result of the judgment by the judging means exceeds the normal operation range, the abnormal action means performs the abnormal action to prevent the pressing operation from being performed as it is. The set value changing means changes and sets a new set value based on the position detected by the position detecting means when the result of the judgment by the judging means is within the normal operation area. Accordingly, in the state where the press operation is operating normally, even if the movable type and the fixed type expand due to a temperature rise or the like and the detection position of the movable type by the position detecting means shifts, the normal state is responded to the shift. Since the position is reset, the error can be set without including the error due to the temperature change in the normal operation region. That is, the degree of adhesion of the movable mold to the fixed mold can be set more strictly, and malfunction can be reliably prevented.

(Embodiment) Hereinafter, a first embodiment in which the present invention is applied to an abnormality detecting device of a semiconductor mold press device will be described with reference to FIGS. 1 and 2. FIG.

First, the target press device moves the movable mold to contact the fixed mold (close the mold) and perform mold clamping.
In this state, a series of pressing operations, such as injecting and molding a resin, are performed to seal the lead frame on which the semiconductor arranged therein is mounted with the resin. In this case, when the movable mold comes into contact with the fixed mold, the closed type sensor 11 as a state detecting means detects this and outputs a detection signal. At this time, the position sensor 12, which is a position detecting means, detects the position of the movable type and outputs a detection signal. The control unit 13 including a microcomputer controls the press device based on these signals, and includes a gate 14, a comparing unit 15, a set value changing unit 16,
It comprises a setting means 17 and an abnormality treatment means 18. Gate
The switch 14 is turned on when a detection signal is supplied from the closed sensor 11, and in this state, a position detection signal from the position sensor 12 is supplied to the comparing means 15. The comparing means 15 is a position sensor
The position detection signal from 12 is compared with the set value from the setting means 17 to calculate the difference, and a signal is output to the set value changing means 16 or the abnormality treatment means 18 based on the comparison result. ing. In this case, as described later, these components perform their functions based on a program stored in the control unit 13 in advance.

Next, the operation of the present embodiment will be described with reference to the flowchart of FIG.

First, when the press operation is started and the movable mold moves to a position where the movable mold comes into contact with the fixed mold, the closed mold sensor 11 detects this and sends a detection signal to the control unit 13. On the other hand, in this state, the position detection sensor 12 detects the position of the movable die and outputs a position detection signal. When receiving the detection signal from the closed sensor 11, the control unit 13 turns on the gate 14 in response to the signal (Step P1), and inputs the position detection signal from the position detection sensor 12. Subsequently, the input position detection signal is compared in the comparing means 15 with the set value given from the setting means 17, and the difference is calculated (step P2). When the comparison result is within the normal operating range (for example, 100 microns), "YE
S ”, and proceeds to Step P3. Change value setting means 16
In step P3, the change position is set by giving the detection position now given from the position detection sensor 12 as a new set value to the setting means 17, and then the program ends.
That is, this completes the die setting of the press operation, and thereafter, the resin sealing is performed as described above. On the other hand, if "NO" is determined in the step P2, that is, if the comparison result is beyond the normal operation range, the process proceeds to a step P4, where an abnormal flag is set and the program ends. When the abnormality flag is set, an abnormality treatment such as stopping the press operation by the abnormality treatment means 18 is performed to prevent the press operation from being performed in an abnormal state.

Hereinafter, in the state of normal operation, the above steps
Repeat P1 to P3 to close the mold, close the mold (resin sealing),
Press operation such as mold opening is continued,
The fixed type and the movable type gradually expand as the temperature gradually increases. Accordingly, the position detected by the position detection sensor 12 also changes each time, but when the operation is normal, the set value is changed based on the detection position in step P3 as described above, so that the next press operation is performed. In the step P2 in, the actual deviation can be read quite accurately. In other words, the set value of the normal operation range can be set quite strictly because the error component caused by the temperature rise only needs to include the error generated in one cycle. The difference between the heights can be reliably detected.

In the above case, the normal operation range is set to 100 microns for practical use, but the error due to one thermal expansion is 10%.
Since it is less than a micron, it can theoretically be strictly detected up to about 10 microns.

FIG. 3 shows a second embodiment of the present invention. What is different from the first embodiment is a method of changing a set value in a program. In the present embodiment, the program is a program in which step P5 is added between step P1 and step P2.

That is, when the comparison result in the comparison means 15 is within the normal operation range, the setting value changing means 16 changes and sets, for example, the average value of the past three detection positions as the setting value. A buffer area for storing the detection position is provided in the control unit 13, and the initial value is stored here,
The detection positions are sequentially stored. The detected position data stored in the buffer area is
An average value based on the data of the times is calculated, and the average value is set as a set value. If the comparison result is within the normal operation range, the detection position just given is stored in the buffer area as arithmetic data of the average value in the following step P3 '. By setting in this way, the same operation and effect as those of the first embodiment can be obtained, and furthermore, even if there is some variation in the detection positions, a value that is not greatly deviated can be prevented from being set.

FIG. 4 shows a third embodiment of the present invention, which differs from the first embodiment in the way of changing the set values in the program. That is, in the first embodiment, whether or not the comparison result is within the normal operation range is determined in step P2. However, in this embodiment, in addition to this, the value that can be set and changed is set in two steps. It is determined in steps P6 and P7 whether the values exceed the first and second changeable values, respectively.

That is, in the case of the present embodiment, after determining “YES” in Step P2, in Step P6, it is determined whether or not the value of the detected position is a value that can be changed with respect to the set value just compared. Or to compare. In other words, a large deviation of the set value is prevented by excluding a case where the set value is within the normal operation range but the change amount of the set value is abnormally large. If "YES" is determined in the step P6, in a succeeding step P7, it is determined whether or not the value of the detected position is abnormally large as compared with the first set value.
In other words, when the set values are changed one after another, even if the comparison with the previous time is normal, it is prevented that the difference from the initial set value becomes abnormally large when viewed cumulatively. .

According to the third embodiment, in addition to the same functions and effects as those of the first embodiment, an effect that an abnormal change of the set value can be prevented can be obtained.

In each of the above embodiments, the case where the present invention is applied to a semiconductor mold press apparatus has been described. However, the present invention is not limited to this, and can be applied to all press apparatuses that perform a press operation using a movable mold and a fixed mold.

[Effects of the Invention] As described above, according to the abnormality detection device for a press device of the present invention, when the detection position of the movable mold is within the normal operation range, the next press operation is performed using the value of the detection position. When the fixed type and the movable type expand due to a rise in temperature, the position detected by the position detecting means changes each time and the normal operation is performed. Since the set value is changed on the basis of the detected position during the operation, the actual deviation can be read quite accurately in the next press operation. In other words, the set value of the normal operation range does not need to include a large error component due to temperature rise, and can be set quite strictly. Therefore, for example, a difference in thickness of one workpiece can be reliably detected. Thus, an excellent effect that malfunction can be prevented can be achieved.

[Brief description of the drawings]

FIGS. 1 and 2 show a first embodiment of the present invention.
FIG. 2 is a block diagram conceptually showing a main part, FIG. 2 is a flowchart of an abnormality detection program, and FIGS. 3 and 4 show second and third embodiments of the present invention, respectively. FIG. 5 and FIG. 6 are diagrams corresponding to FIG. 1 and FIG. 2 showing a conventional example. In the drawing, 11 is a closed type sensor (state detection means), 12 is a position detection sensor (position detection means), 13 is a control unit, 14 is a gate,
15 is comparison means, 16 is set value change means, 17 is setting means, 18
Is an abnormality treatment means.

Claims (1)

(57) [Claims] 1. A press device comprising a fixed die and a movable die movable toward and away from the fixed die, a state detecting means for detecting a state in which the movable die is in contact with the fixed die, and Position detecting means for detecting the position of the movable die, a comparing means for comparing a position detected by the position detecting means with a set value, and performing an abnormal action when the comparison result by the comparing means exceeds a normal operation area. Abnormality treatment means;
A press apparatus comprising: a set value changing unit configured to change and set a set value of the comparing unit based on a position detected by the position detecting unit when a result of the comparison by the comparing unit is within the normal operation area. Detection device.