JPH08290437A - Press molding apparatus and method - Google Patents

Abstract

PURPOSE: To provide a press molding apparatus capable of certainly detecting the accurate clamping force of a mold. CONSTITUTION: A voltage applying means 20 applying voltage across two predetermined points P, Q of a tie bar 1 generating strain when molds 5, 6 are clamped to generate a current. and a mold clamping force detection means 10 detecting the mold clamping force between the molds 5, 6 on the basis of the change of the current value generated between two predetermined points P, Q of the tie bar 1 by the voltage applying means 20 caused by the strain at the time of mold clamping are provided. Since the tie bar 1 is utilized in place of a strain gauge, trouble is hard to generate and accurate mold clamping force can be certainly detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press molding apparatus and a press molding method, such as a transfer molding apparatus, for molding a semiconductor resin sealing device by clamping a pair of molds.

[0002]

2. Description of the Related Art FIG. 9 is a block diagram of a conventional transfer molding apparatus for resin-sealing a semiconductor. In the figure, 1 is a tie bar arranged in parallel with each other in the vertical direction, 2 is an upper platen fixed to the upper end of the tie bar 1,
3 is a lower platen fixed to the lower end of the tie bar 1, 4 is a middle platen that can be moved up and down while being guided by the tie bar 1, 5 is fixed to the lower surface of the upper platen 2, and an upper metal having a heater for heating resin therein. A mold, 6 is fixed to the upper surface of the middle platen 4, moves vertically with the middle platen 4, and has a lower mold having a heater for heating the resin inside, and 7 is a middle platen 4.
And the upper and lower molds 5 and 6 are clamped under pressure, and the middle platen 4 is lowered to open the upper and lower molds 5 and 6, and 8 is a link mechanism. A press drive source to be operated, 100 is a strain gauge attached to the tie bar 1.

Next, the operation of this transfer molding apparatus will be described. After setting the lead frame and resin (neither shown) in the lower mold 6, the press drive source 8 is operated to extend the link mechanism 7, and the lower mold 6 is moved up through the middle platen 4. Raise to the die 5 side. Then, after bringing the upper die 5 and the lower die 6 into contact with each other, they are clamped with a high load. Next, advance <br/> softening resin under die within 6, via a plunger (not shown), is injected into the cavity formed by the upper and lower mold 5,6, lead The semiconductor element on the frame is resin-sealed. Then, the resin is heated and cured by the upper and lower molds 5 and 6.
Then, the link mechanism 7 is turned on by the press drive source 8.
The lower mold 6 is lowered through the middle platen 4 and the upper and lower molds 5 and 6 are opened, and then the lead frame and the like are taken out from the lower mold 6 .

In this transfer molding apparatus, since the reaction force of the link mechanism 7 acts on the lower end side of the tie bar 1 via the lower platen 3 during mold clamping, the mold clamping force acts on the tie bar 1 as it is. Therefore, a strain corresponding to the mold clamping force is generated in the tie bar 1, and the mold clamping force is generated from the stress acting on the tie bar 1 via the mold clamping force detection device (not shown) connected to the strain gauge 100. To be detected. That is, in this transfer molding apparatus, the strain gauge 100
While detecting the mold clamping force of the molds 5 and 6 via the link mechanism, the link mechanism 7 applies an appropriate mold clamping force to the upper mold 5 and the lower mold 6.

[0005]

However, in the conventional transfer molding apparatus, since the mold clamping force is detected by using the strain gauge 100 which is liable to be deteriorated or broken and is easily peeled off, an accurate mold clamping force can be obtained. There was a problem that it may not be detected. Therefore, in this transfer molding apparatus, there is a problem that the upper and lower molds 5 and 6, the tie bar 1 and the like are subjected to a mold clamping force exceeding an allowable value, which may cause a damage accident.

The present invention has been made in order to solve the above problems, and it is possible to accurately detect the mold clamping force of a mold and to prevent a damage accident and the like, and a press molding apparatus and a press molding method. The purpose is to provide.

[0007]

According to a first aspect of the present invention, there is provided a press forming apparatus, which comprises a voltage applying means for applying a voltage between two points in an apparatus main body which is distorted when a die is clamped to generate a current. And a mold clamping force detecting unit that detects a mold clamping force of the mold based on a change in a current value generated between the two points by the voltage applying unit due to the strain. .

The press molding apparatus according to claim 2 of the present invention is
In the invention of claim 1, two points in the apparatus main body are defined as a single member insulated from other members.

The press molding apparatus according to claim 3 of the present invention is
In the invention of claim 2, the single member is a tie bar that fixes one of the molds and supports the reaction force of the other mold during mold clamping.

The press molding apparatus according to claim 4 of the present invention is
In the invention of claim 2, the single member is one of a pair of molds heated to a predetermined temperature.

The press molding apparatus according to claim 5 of the present invention is
In the invention of claim 1, one of two points in the apparatus main body is defined on one side of the pair of molds, and the other of the two points is defined on the other side of the pair of molds. is there.

The press molding apparatus according to claim 6 of the present invention is
Between a plurality of points on the apparatus body by the voltage applying means for applying a voltage between two points on the apparatus body to generate a current at a plurality of points on the apparatus body, which is distorted when the mold is clamped. A mold clamping force detecting means for detecting the mold clamping force of the mold at a plurality of points based on the change in the generated current value due to the strain.

The press molding apparatus according to claim 7 of the present invention is
In the invention of claim 6, an abnormality detecting means for detecting an abnormal portion of the apparatus main body is provided by a signal of the mold clamping force from the mold clamping force detecting means.

The press molding apparatus according to claim 8 of the present invention is
A drive control means for driving and controlling a press drive source for driving the die is provided with a signal of the mold clamping force from the mold clamping force detecting means.

The press molding apparatus according to claim 9 of the present invention is
Distortion occurs when the mold is clamped 2 in the object to be clamped in the mold
Voltage clamping means for applying a voltage between the points to generate a current, and the current value generated between the two points by the voltage applying means changes due to the distortion, and the mold clamping is performed. And a mold clamping force detecting means for detecting force.

According to a tenth aspect of the present invention, in the press forming apparatus according to the ninth aspect, the object to be clamped is a semiconductor resin sealing device having a lead frame.

In the press molding method according to claim 11 of the present invention, the current value generated by applying a voltage between two points in the apparatus main body where distortion occurs during mold clamping changes due to the distortion. Based on this, the mold clamping force of the mold is detected.

According to the twelfth aspect of the press molding method of the present invention, a current value generated by applying a voltage between two points of the lead frame in the mold, which is distorted when the mold is clamped, is caused by the distortion. The mold clamping force of the mold is detected based on the change of the mold.

[0019]

In general, when a force acts on the resistor and the strain is generated, the resistance value also changes, so that the current value flowing through the resistance also changes. Therefore, the magnitude of the force acting on the resistance can be easily clarified by comparing the current values flowing in the resistance before and after the strain occurs. This is the basic idea when measuring stress using a strain gauge (resistance).

In the press molding apparatus according to claim 1 and the press molding method according to claim 11 of the present invention, the mold clamping force of the mold is detected by regarding a predetermined two points in the apparatus main body as a strain gauge. The mold clamping force of the mold is detected based on the fact that the current value flowing between two predetermined points in the apparatus body changes due to the distortion during mold clamping.

In the press molding apparatus according to the second aspect of the present invention, since the predetermined two points are set for the single member, it is difficult to be influenced by the disturbance and the mold clamping force of the mold is detected with high accuracy. Is possible.

In the press molding apparatus according to the third aspect of the present invention, since the predetermined two points are set on the long tie bar having a large strain amount, the change amount of the current value before and after the mold clamping is large. Therefore, it is possible to detect the mold clamping force of the mold with high accuracy.

In the press forming apparatus according to the fourth aspect of the present invention, the fact that the resistance between the two predetermined points changes not only due to the strain but also due to the influence of the temperature is used. The mold temperature can also be detected.

In the press molding apparatus according to the fifth aspect of the present invention, before the pair of molds come into contact with each other, no current flows between the two predetermined points, so that the operating cost can be reduced. Further, the contact timing of the mold can be easily recognized by the mold clamping force detecting means.

In the press molding apparatus according to the sixth aspect of the present invention, since the predetermined two points are provided at a plurality of points on the apparatus main body, the mold clamping force detection means can apply the mold clamping force from a plurality of points on the apparatus main body. Can be detected.

In the press-forming apparatus according to claim 7 of the present invention, when an abnormality occurs at any of a plurality of locations, the value of the mold clamping force detected from the abnormality becomes an abnormal value, and the abnormality detection means detects the abnormal value. Detect.

In the press forming apparatus according to claim 8 of the present invention, the press drive source is drive-controlled by the drive control means,
Appropriate continuous operation is possible.

In the press molding apparatus according to the ninth aspect of the present invention, the point between two points on the object to be clamped in the mold is regarded as a strain gauge, and the mold clamping force of the mold is detected. The mold clamping force of the mold is detected based on the fact that the value of the current flowing between two predetermined points of the body changes due to the strain during mold clamping.

In the press molding apparatus according to claim 10 and the press molding method according to claim 12 of the present invention, the semiconductor resin sealing device is used as the object to be clamped, and the mold clamping failure is directly detected by the object to be clamped. Therefore, the defect occurrence rate of the semiconductor resin sealing device is reduced due to the mold clamping defect.

[0030]

【Example】

Example 1. Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the same or corresponding parts as those in FIG. FIG. 1 is a block diagram of a transfer molding device as a press molding device showing an embodiment of the present invention, and FIG. 2 is a diagram showing a structure of a mold clamping force detector of the transfer molding device.

This transfer molding apparatus has the same main structure as that of the transfer molding apparatus shown in FIG. 9, and the difference between them is the mold clamping force detecting section.
Therefore, the mold clamping force detection unit of this transfer molding apparatus will be mainly described below.

In the figure, the mold clamping force detecting section of this transfer molding apparatus comprises a detecting circuit section 10 as a mold clamping force detecting means and a power supply circuit section 20 as a voltage applying means.

The detection circuit section 10 will be described in detail. In the figure, 11 is constituted by a tie bar 1 between a point P near the upper platen 2 of the tie bar 1 and a point Q near the lower platen 3 of the tie bar 1. The resistor 12 is a temperature-compensating resistor 12 whose temperature is controlled to be the same as that of the tie bar 1, 13 is a fixed resistor, and 14 is a variable resistor. Also,
Resistance values R1, R2, R of the resistors 11, 12, 13, 14
3 and R4 are set to have substantially the same size.

Reference numerals 15 and 16 denote the resistor 11 and the resistor 1 respectively.
Wires for electrically connecting to the 2 and 14 sides, 17 is a point c between the resistors 11 and 12, and the resistors 13 and 14
The mold clamping force detector 18 is provided so as to connect the point d between the platen and the platen, and is an insulator for insulating the tie bar 1 from the upper platen 2, the lower platen 3 and the middle platen 4.

The power supply circuit section 20 is composed of a power supply 21, a wire, etc., and is located at a point a between the resistor 11 and the resistor 14.
And a point b between the resistor 12 and the resistor 13 between the power source 2
A constant voltage V is applied via 1.

Next, a basic method of detecting the mold clamping force by the mold clamping force detecting section will be described. In the figure, points c and d
When the potentials of and are equal, no current flows on the mold clamping force detector 17 side, and the resistance value R of the resistors 11, 12, 13, 14 is R.
From the concept of the Wheatstone bridge, the relationship of R1 × R3 = R2 × R4 (1) is established between 1, R2, R3, and R4.

Further, if the resistance value R1 of the resistor 11 formed between the point P and the point Q of the tie bar 1 increases by ΔR1 while the expression (1) is satisfied, the resistance values R1 and R2 are Since the flowing current value changes, a potential difference ΔV is generated between the points c and d as follows: ΔV = (ΔR1 / R1) × R3 × R4 / (R3 + R4) ² (2) A predetermined current flows through the mold clamping force detector 17.

On the other hand, from the viewpoint of a strain gauge or the like, if strain occurs in the resistance, the resistance value changes. That is, resistance 1
If strain ε1 occurs at 1 and the resistance value R1 increases by ΔR1, the relationship of ΔR1 / R1 = Ks × ε1 (3) occurs when the gauge factor is Ks. Here, the gauge factor Ks is a unique value determined by the material.

Therefore, from the relationship between the equations (2) and (3), when the potential difference ΔV and the resistance values R3 and R4 are known, the strain ε1 of the resistor 11 is calculated. Since the strain ε1 and the mold clamping force have a constant relationship, the resistance R1 is calculated from the value of the strain ε1.
The mold clamping force applied to 1 is calculated. Then, this calculation is performed by the mold clamping force detector 17.

By the way, the resistance value of the resistor changes variously depending on the temperature. Therefore, if the temperature of the resistor 11 changes with the passage of time from the state where the equation (1) is established,
The equation (3) does not always hold, and the strain ε1 generated in the resistor 11 cannot be calculated. Therefore, the temperature compensating resistor 12 that follows the same temperature as the resistor 11 is connected in series to the resistor 11 to eliminate the influence of the temperature change of the resistor 11.

Next, the operation of the transfer molding apparatus will be described mainly with respect to the operation of the mold clamping force detecting section.

First, the power supply circuit section 20 which is a voltage applying means.
The power supply 21 is turned on and a predetermined voltage V is applied between the point a and the point b of the detection circuit section 10 which is the mold clamping force detection means.
In this case, the resistance values R1, R of the resistors 11, 12, 13, 14
Since 2, R3 and R4 are almost equal, the potentials at points c and d are equal, and no current flows on the mold clamping force detector 17 side. However, when the potentials between the points c and d are not equal due to changes in environmental conditions, the variable resistor 14 is operated to make the potentials of the points c and d equal.

Next, the press drive source 8 is operated to raise the lower die 6 to the upper die 5 side through the link mechanism 7 and the middle platen 4, and the upper and lower die 5, 6 are clamped. To do. In this case, a pulling force as a reaction force of the mold clamping force acts on the tie bar 1 in the vertical direction. Therefore, strain ε1 is generated between the point P1 and the point Q1 in the tie bar 1, and the resistance value of the resistor 11 between the point P1 and the point Q1 is R.
Increase from 1 to R1 + ΔR1. Therefore, the resistance 11
The value of the current flowing therethrough changes, and a potential difference ΔV occurs between points c and d based on the change in the current value. The strain ε1 of the tie bar 1 is known from this potential difference ΔV, and the tensile stress of the tie bar 1 is calculated from the Young's modulus E. The mold clamping force applied to the upper and lower molds 5 and 6 is calculated by multiplying this tensile stress by the cross-sectional area of the tie bar 1 and the number of tie bars 1. This series of calculations is performed by the mold clamping force detector 17, and the value is calculated.

Since the upper and lower molds 5 and 6 are heated through a resin heating heater or the like at the time of mold clamping, the temperature of the tie bar 1 gradually rises. Since the temperature compensating resistor 12 that traces is eliminated the influence of the temperature of the tie bar 1, no error occurs in the detected mold clamping force.

As described above, in this transfer molding apparatus, a strain gauge is not used, and a voltage is directly applied between two predetermined points P and Q of the tie bar 1 where distortion occurs during mold clamping, and these two points P, Since the mold clamping force is detected based on the fact that the current flowing between Q changes due to the strain of the tie bar 1 at the time of mold clamping, there are disadvantages such as deterioration, disconnection, and peeling that easily occur in the strain gauge. It is possible to reliably detect the accurate mold clamping force of the mold.

Further, in this transfer molding apparatus,
The two points P and Q are provided on both ends of the long tie bar 1 where large distortion is generated by the mold clamping force, and the tie bar 1 is insulated from the upper platen 2 and the lower platen 3, etc. The mold clamping force of the molds 5 and 6 can be detected.

Example 2. Here, the two points P and Q may be set in any of the apparatus main bodies in which distortion occurs during mold clamping of the transfer molding apparatus. FIG. 3 is a configuration diagram showing another embodiment of the present invention. In the case of this embodiment, a point P is defined on the upper part of the link mechanism 7 and a point Q is defined on the lower part of the link mechanism 7.

Example 3. FIG. 4 is a configuration diagram showing still another embodiment of the present invention, in which a point P is defined on the upper platen 2 and a point Q is defined under the upper platen 2.

Example 4. FIG. 5 is a configuration diagram showing another embodiment of the present invention, in which point P is defined on the upper part of the middle platen 4 and point Q is defined on the lower part of the middle platen 4.

Example 5. FIG. 6 is a configuration diagram showing still another embodiment of the present invention, in which a point P is set on the upper side of the lower platen 3 and a point Q is set on the lower side of the lower platen 3. In each of the above embodiments, a force proportional to the mold clamping force of the molds 5 and 6 acts between the two points P and Q of each member, so that the mold clamping force of the molds 5 and 6 is detected as the mold clamping force. Easily detected by the department.

In each of the embodiments shown in FIGS. 1, 3, 4, 5 and 6, the tie bar 1 at which the points P and Q are defined, the link mechanism 7, the upper platen 2 and the middle platen 4 are provided. , The lower platen 3 is a single member, and the single member defined by the two points P and Q is insulated from other members via the insulator 18. Further, the two points P and Q are not limited to a single member, but may be defined on both ends of a combination of a plurality of single members such as the middle platen 4, the link mechanism 7, and the lower platen 3. However, in this case, since the connecting portion is interposed between the single members, the disturbance is increased, so that the accuracy of detecting the mold clamping force is slightly lowered.

Example 6. Further, the two points P and Q may be provided on the lead frame of the semiconductor resin sealing device, which is the object to be clamped in the upper and lower molds 5 and 6. This is because the current value flowing through the semiconductor resin sealing device changes due to the distortion of the lead frame during mold clamping, and the mold clamping force of the molds 5 and 6 can be detected by the change in the current value.

Example 7. FIG. 7 is a block diagram of a transfer molding apparatus showing another embodiment of the present invention. In this transfer molding apparatus, for example, a point P is set at one end on the upper side of the lower mold 6 and a point Q is set at the other end on the lower side, and the lower mold 6 between the points P and Q is set. The constructed resistance is referred to as resistance 11. In this case, an insulator 18 is attached to the lower mold 6 on the upper end face and the lower end face side for insulation from the middle platen 4 and the upper mold 5. The rest of the configuration is the same as the transfer molding apparatus shown in FIG.

Also in this transfer molding apparatus, by applying a voltage between the point P and the point Q through the power supply circuit section 20 of the mold clamping force detecting section, distortion of the molds 5 and 6 at the time of mold clamping is caused. Due to the change in the current value flowing in the resistor 11,
The mold clamping force of the molds 5 and 6 can be detected through the mold clamping force detector 17, and the same effect as that of the transfer molding apparatus of the first embodiment can be obtained.

On the other hand, the lower die 6 is heated to a high temperature by a heater for heating resin, and in this case, the resistor 11
The resistance value R1 of the resistor changes almost in proportion to the temperature, but since the temperature compensating resistor 12 that follows the same temperature as the resistor 11 is connected in series to the resistor 11, it is affected by the temperature change of the resistor 11. You don't have to. In addition, the temperature compensation resistor 12
In advance, the relationship between the temperature and the resistance value should be understood in advance.
The temperature of can be easily detected.

That is, in this transfer molding apparatus, since the two points P and Q are provided on the lower mold 6, the mold clamping force of the molds 5 and 6 as well as the temperature rise of the lower mold 6 can be detected. It is also possible to control the temperature of the lower mold 6 without providing such a thermometer. Of course, the two points P and Q may be set on the upper die 5 side.

Example 8. FIG. 8 is a sectional view of a transfer molding apparatus showing still another embodiment of the present invention. In this transfer molding apparatus, for example, a point P is provided on the upper die 5 side.
And the point Q on the lower die 6 side, and the point P
The resistance constituted by the upper and lower molds 5 and 6 between the point Q and the point Q is defined as the resistance 11. In this case, the upper and lower molds 5,
6 is for insulation from the upper platen 2 and the middle platen 4,
An insulator 18 is attached to the upper mold 5 and the lower mold 6. The rest of the configuration is the same as the transfer molding apparatus shown in FIG.

Also in this transfer molding apparatus, by applying a voltage between the point P and the point Q through the power supply circuit section 20 of the mold clamping force detecting section, the upper mold 5 and the lower mold at the time of mold clamping can be obtained. Since the current value flowing through the resistor 11 changes due to the distortion of the mold 6, the mold clamping force of the molds 5 and 6 can be detected through the mold clamping force detector 17, and the transfer molding apparatus of the first embodiment The same effect as can be obtained.

Further, in this transfer molding apparatus,
Since the current flows through the resistor 11 from the time when the upper mold 5 and the lower mold 6 come into contact with each other immediately before the mold clamping, the time for flowing the current through the resistor 11 is shortened, and the operating cost can be reduced accordingly. it can. Also, with this transfer molding device,
Joining the upper mold 5 and the lower mold 6 through the mold clamping force detector.
It is now possible to easily know the timing of separation, which eliminates the need for a special switch, and
It becomes possible to easily know the timing of starting mold clamping (trigger timing).

Example 9. In the transfer molding apparatus of this embodiment, a plurality of pairs of two points P and Q are respectively defined in various apparatus main bodies that are distorted during mold clamping, such as the tie bar 1, the upper platen 2, the lower platen 3, and the link mechanism 7, A voltage is applied from a plurality of mold clamping force detection units to each of the two points P and Q, and the mold clamping force of the molds 5 and 6 is detected by the plurality of mold clamping force detection units. Then, more accurate mold clamping force of the molds 5 and 6 can be known from the values of the plurality of mold clamping forces. Also, there is no problem if the mold clamping force of the same mold 5 or 6 is detected from all the mold clamping force detectors. However, if abnormal data is detected from one mold clamping force detector, A signal from the mold clamping force detector activates an alarm device, which is an abnormality detection means, causing an abnormality in the detected portion, such as loosening of the tightening screw or cracks in the parts that make up the single member. The worker can immediately know that there is something. Generally, when an abnormality occurs in a part of the device body,
Although the discovery of this abnormality is delayed, in the case of this embodiment,
The abnormality can be immediately detected, and the transfer molding apparatus can be repaired before a serious accident occurs.

Example 10. Further, in the transfer molding apparatus of the ninth embodiment, the signals from the mold clamping force detectors from a plurality of locations may be transmitted to the drive control means, and the drive control means may drive the press drive source 8 properly. it can. Although the transfer molding device for molding the semiconductor resin sealing device has been described in each of the first to tenth embodiments, the present invention is also applicable to, for example, a press molding device for cutting or bending a plate-shaped material. You can

[0062]

As described above, according to the press molding apparatus of claim 1 and the press molding method of claim 11 of the present invention, the value of the current flowing between the two predetermined points in the apparatus main body is Based on the change caused by the strain at the time of mold clamping, the mold clamping force of the mold is detected, deterioration and disconnection that are conventionally used are likely to occur, and without using a strain gauge that is easy to peel off, The mold clamping force of the mold can be detected reliably and accurately.

Further, according to the press molding apparatus of claim 2 of the present invention, in the invention of claim 1, since the predetermined two points are defined for a single member, the resistance change between the same members can be prevented. It should be detected, and it is less likely to be affected by disturbance,
It is possible to detect the mold clamping force with high accuracy.

Further, according to the press forming apparatus of claim 3 of the present invention, in the invention of claim 1, since the predetermined two points are set on the long tie bar having a large strain amount, the two points are set between the two points. The amount of change in the value of the generated current becomes large, and the mold clamping force of the mold can be detected with higher accuracy.

Further, according to the press molding apparatus of claim 4 of the present invention, in the invention of claim 2, two predetermined points are set in any one of the pair of molds. The effect of the invention can be obtained, and the temperature of the mold can also be detected by utilizing the change in the resistance value of the mold clamping force detection means that changes due to the influence of temperature as well as strain.

Further, according to the press molding apparatus of claim 5 of the present invention, in the invention of claim 1, before the pair of molds come into contact with each other, no current flows between two predetermined points. In addition to the effect of the invention described in claim 1, the operation cost can be reduced. Further, there is an effect that the contact timing of the mold can be easily recognized by the mold clamping force detecting means.

Further, according to the press molding apparatus of the sixth aspect of the present invention, since the predetermined two points are set at a plurality of points on the apparatus main body, the mold clamping force detecting means respectively clamps the mold from a plurality of points on the apparatus main body. The force is detected, and the more accurate mold clamping force of the mold can be known.

According to the press molding apparatus of claim 7 of the present invention, in the invention of claim 6, when an abnormality occurs at any of a plurality of locations, the value of the mold clamping force detected from the abnormality is also abnormal. Since the value becomes a value, the abnormality detecting means operates according to the abnormal value, and there is an effect that an abnormality of the press molding apparatus can be easily found.

According to the press molding apparatus of claim 8 of the present invention, in the invention of claim 6 or 7,
Since the press drive source is drive-controlled based on the mold clamping force detected at a plurality of points by the drive control means, it is possible to obtain the effect of the invention described in claim 6 or 7, and it is appropriate for a long period of time. There is also an effect that the press molding apparatus can be continuously operated.

According to the press molding apparatus of claim 9 of the present invention, the mold clamping force is detected by regarding the two points in the mold clamping body in the mold as strain gauges. A more appropriate pressing force is applied to the tightening body, which has the effect of increasing the product yield.

According to the press molding apparatus of claim 10 and the press molding method of claim 12 of the present invention, a voltage is applied between two points of the lead frame to detect the strain between the two points. Molding defects of the semiconductor resin sealing device can be directly detected, and the product yield of the semiconductor resin sealing device can be improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a transfer molding apparatus according to an embodiment of the present invention.

FIG. 2 is a detailed explanatory diagram of a mold clamping force detection unit shown in FIG.

FIG. 3 is a configuration diagram of a transfer molding apparatus according to another embodiment of the present invention.

FIG. 4 is a configuration diagram of a transfer molding apparatus according to another embodiment of the present invention.

FIG. 5 is a configuration diagram of a transfer molding apparatus according to another embodiment of the present invention.

FIG. 6 is a configuration diagram of a transfer molding apparatus according to another embodiment of the present invention.

FIG. 7 is a configuration diagram of a transfer molding apparatus according to another embodiment of the present invention.

FIG. 8 is a configuration diagram of a transfer molding apparatus according to another embodiment of the present invention.

FIG. 9 is a configuration diagram of a conventional transfer molding apparatus.

[Explanation of symbols]

1 tie bar (single member), 2 upper platen (single member), 3 lower platen (single member), 4 middle platen (single member), 5 upper mold (mold), 6 lower mold (mold) Mold), 7 link mechanism (single member), 8 press drive source, 10 detection circuit section (mold clamping force detection means), 20 power supply circuit section (voltage application means), P point, Q point.

Claims (12)

[Claims] 1. A press forming apparatus for clamping a pair of molds, comprising: voltage applying means for applying a voltage between two points in an apparatus main body where distortion occurs when the molds are clamped to generate a current; And a mold clamping force detection unit that detects a mold clamping force of the mold based on a change in a current value generated between the two points by the voltage applying unit due to the strain. Press molding equipment. 2. The press molding apparatus according to claim 1, wherein the two points on the apparatus main body are defined by a single member insulated from other members. 3. The single member is a tie bar for fixing one of the molds and supporting a reaction force of the other mold when the mold is clamped. Press molding equipment. 4. The single member is one of a pair of molds heated to a predetermined temperature.
The press molding apparatus described. 5. One of the two points in the device body is
The press molding apparatus according to claim 1, wherein the press molding device is defined on one side of the pair of molds, and the other of the two points is defined on the other side of the pair of molds. 6. A press forming apparatus for clamping a pair of molds, wherein a voltage applying means for generating a current by applying a voltage between two points in an apparatus main body which is distorted when the molds are clamped. And a mold clamping for detecting the mold clamping force of the mold at a plurality of points based on the fact that the current value generated between two points of the apparatus main body by the voltage applying means changes due to the strain. A press forming apparatus comprising: force detecting means. 7. The press forming apparatus according to claim 6, further comprising an abnormality detecting unit that detects an abnormal portion of the apparatus main body by a signal of the mold clamping force from the mold clamping force detecting unit. 8. The drive control means for driving and controlling a press drive source for driving a die according to a signal of the mold clamping force from the mold clamping force detecting means. Press molding equipment. 9. A press molding apparatus for clamping a pair of molds, wherein a voltage is applied between two points in a clamped body in the mold that is distorted when the molds are clamped to generate a current. The mold clamping force of the mold is changed based on that the voltage applying unit and the current value generated between the two points by the voltage applying unit change due to the distortion of the object to be clamped in the mold. A press molding apparatus, comprising: a mold clamping force detecting means for detecting. 10. The press molding apparatus according to claim 9, wherein the object to be clamped is a semiconductor resin sealing device having a lead frame. 11. A voltage is applied between two points in a device body where distortion occurs during mold clamping, a current value between the two points is measured, and the current value that changes due to the distortion at that time causes A press molding method characterized by detecting a mold clamping force. 12. A voltage is applied between two points of a lead frame of a semiconductor resin encapsulation device in the mold, which is distorted when the mold is clamped, and changes due to the distortion of the lead frame at that time. A press-molding method, wherein the mold clamping force of the mold is detected by an electric current value.