JPH10144709A - Plastic packaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust pressure with high accuracy in a manner such that a detecting means for detecting the pressure of an upper-half molding die to a lower-half molding die is provided between a fixed member fixed to a tie bar on the other side of the side on which the lower-half molding die is provided so as to accurately detect the pressure of the molding die. SOLUTION: An upper-half molding die 5 is provided below a moving platen 4, and a lower-half molding die 6 is provided above a lower platen 2. A lower fixed nut 11 is fixed to a tie bar 3 on the opposite side of the side on which the lower-half molding die 6 is provided. A load cell 12 for detecting the pressure of the upper-half molding die 5 to the lower-half molding die 6 is provided between the lower fixed nut 11 and the lower platen 2. The pressure of the upper-half molding die 5 to the lower-half molding die 6 is therefore directly transmitted to the load cell 12. Consequently, a pressure detection error caused by influences such as backlash or deformation of component elements due to aging of the apparatus and expansion of the tie bar 3 by a heat is reduced, and the pressure can be more accurately detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin sealing device for sealing a semiconductor element on a lead frame with a resin, and more particularly to a resin sealing device provided with a pressing force detecting mechanism.

[0002]

2. Description of the Related Art In general, a resin sealing apparatus has an upper mold and a lower mold, and a semiconductor element is resin-sealed on a lead frame placed between the upper mold and the lower mold. Used for A conventional resin sealing device is disclosed in, for example,
As disclosed in Japanese Unexamined Patent Publication No. 185938/1985, there has been proposed an apparatus provided with a pressing force detecting mechanism for controlling the pressing force of a mold with high accuracy.

As shown in FIG. 3, this conventional resin sealing device includes an upper mold 20 and a lower mold 21 for accommodating a lead frame and a semiconductor element and sealing the resin.
, A lower platen 23 disposed at a predetermined distance from the upper platen 22, a tie bar 24 provided between the upper platen 22 and the lower platen 23, and movably provided on the tie bar 24. Moving platen 25 for pressing lower mold 21 against upper mold 20
A servomotor 26 for applying a driving force to the movable platen 25 to drive the movable platen 25 upward, a strain gauge 27 for detecting distortion generated by pressing, a pressing force detected by the strain gauge 27 and a target pressing force. A control device 28 for controlling the driving force of the servo motor 26 so that the difference from the pressure becomes zero.

In FIG. 3, reference numeral 29a denotes a servo motor 26;
, A small bevel gear 29b is engaged with the small bevel gear 29a, and 30 is a large bevel gear 2
The ball screw 31 fixed to 9b is a ball screw 30.
, 32 are the ball screw 30 and the nut 3
1 is a double toggle mechanism for applying the vertical thrust obtained by 1 to the moving platen 25.

[0005] According to the conventional resin sealing device, the rotational force of the servo motor 26 is controlled by the small bevel gear 29a and the large bevel gear 29a.
b to the ball screw 30 and the ball screw 30
And the nut 31 converts the force into a vertical thrust. The thrust is applied to the moving platen 2 via the double toggle mechanism 32.
5 given. Thereby, the moving platen 25 is raised, and the lower mold 21 is pressed against the upper mold 20 to perform resin sealing. At this time, the pressing force between the dies 20 and 21 is detected by the strain gauge 27 from the strain generated in the tie bar 24 and the like, and the servo motor 26 is driven by the control device 28 so that the detected pressing force reaches the target pressure. The force is controlled.

[0006]

According to the conventional resin sealing device, a strain gauge 27 is attached to the tie bar 24,
Since the pressing force of the mold is detected from the extension, it is easily affected by rattling or deformation of mechanical parts due to aging of the device, expansion of the tie bar due to heat generated from the device, and variation due to the material of the tie bar. Therefore, it has been difficult to accurately detect the pressing force. Therefore, there is a problem that the yield of the product after resin sealing is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a resin sealing device capable of detecting a pressing force of a mold more accurately and adjusting the pressing force to a higher precision. The purpose is to provide.

[0008]

According to the present invention, there is provided a resin sealing apparatus for sealing a lead frame and a semiconductor element at a predetermined interval. A first platen and a second platen, a tie bar provided between the first platen and the second platen, a moving platen movably attached to the tie bar, and a moving means for moving the moving platen. A first mold provided on the movable platen, a second mold provided on the second platen opposite to the first mold, and a second mold provided on a side opposite to the side provided with the second mold. It has a fixing member fixed to the tie bar, and a detecting means provided between the fixing member and the second platen for detecting a pressing force of the first mold to the second mold. Things.

According to the present invention, the detecting means for detecting the pressing force of the first mold to the second mold is a fixing member fixed to the tie bar opposite to the side where the second mold is provided. And the second platen, the pressing force of the first mold to the second mold is directly transmitted to the detecting means. for that reason,
Due to the effects of rattling or deformation of mechanical parts due to aging of the device, extension of the tie bar due to heat, etc., occurrence of pressure detection errors is reduced, and more accurate pressing force can be detected.

[0010] When a control means for controlling the moving means in accordance with the pressing force detected by the detecting means is provided, it is possible to adjust the pressing force to a higher precision.

[0011] The resin sealing device of the present invention is also a resin sealing device for resin sealing a lead frame and a semiconductor element, wherein an upper platen and a lower platen, and an upper platen and a lower platen are arranged at predetermined intervals. A tie bar provided between the platen, a movable platen movably attached to the tie bar, a drive motor for applying a driving force to the movable platen to move the movable platen, A mold, a lower mold provided on a lower platen facing the upper mold, a fixing member fixed to a tie bar on a side opposite to a side on which the lower mold is provided, and the fixing member A load cell that is provided between the lower platen and detects a pressing force on the lower die of the upper die, and a driving force of a driving motor according to the pressing force detected by the load cell. And control means for controlling, is characterized in that it has a.

It is preferable that an opening for inserting a tie bar with a predetermined gap is formed inside the load cell.

[0013]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIG. FIG. 1 is a side view showing a resin sealing device of the present invention, and FIG. 2 is a sectional view showing an internal structure of a load cell.

As shown in FIG. 1, the resin sealing device of the present invention comprises an upper platen 1 disposed in parallel at a predetermined interval.
And a lower platen 2, a tie bar 3 provided between the upper platen 1 and the lower platen 2, and the tie bar 3
And a movable platen 4 movably mounted on the movable platen. An upper mold 5 is provided below the movable platen 4, and a lower mold 6 is provided above the lower platen 2 so as to face the upper mold 5.

The upper platen 1 is fixedly supported on the tie bar 3 by an upper fixing nut 10. Upper platen 1
, A screw member 7 such as a roller screw or a ball screw is vertically and rotatably attached via a nut or the like. A toggle mechanism 8 for transmitting a vertical thrust to the moving platen 4 is provided at a tip 7 a of the screw member 7.

A drive motor 9 such as a servo motor is provided to rotate the screw member 7, and the rotational force from the drive motor 9 is transmitted to the screw member 7 via a pulley 9a.

A lower fixing nut 11 is fixed to the tie bar 3 on the side opposite to the side where the lower mold 6 is provided. Between the lower fixing nut 11 and the lower platen 2, a load cell 12 for detecting a pressing force on the lower die 6 of the upper die 5 is provided. The load cell 12 is formed in a cylindrical shape as shown in FIG.
Is formed with an opening 12a into which the tie bar 3 is inserted with a predetermined gap. In the load cell 12,
A control device 13 that optimally controls the driving force of the driving motor 9 according to the pressing force detected by the load cell 12 is connected.

Next, the operation of the resin sealing device according to the present invention will be described.

The rotational force obtained from the drive motor 9 is transmitted to the screw member 7 via the pulley 9a, and is converted by the screw member 7 into a vertical thrust. The thrust is applied to the movable platen 4 via a toggle mechanism 8 attached to the tip 7a of the screw member 7. Thereby, the moving platen 4 descends, and the upper mold 5 is pressed against the lower mold 6,
Resin sealing is performed.

At this time, a pressure equal to the pressing force of the upper mold 5 and the lower mold 6 is generated between the lower fixing nut 11 and the lower platen 2. Then, by the cylindrical load cell 12 sandwiched between the lower fixing nut 11 and the lower platen 2,
By measuring the pressing force, the upper mold 5 and the lower mold 6
Pressure can be obtained.

The pressing force measured by the load cell 12 is compared with a target reference pressing force.
Is controlled by the control device 13 so that the difference between the measured pressing force and the reference pressing force becomes zero.

According to the present invention, the load cell 12 for detecting the pressing force on the lower mold 6 of the upper mold 5 is fixed to the tie bar 3 opposite to the side where the lower mold 6 is provided. Since it is provided between the fixed nut 11 and the lower platen 2, the pressing force of the upper die 5 on the lower die 6 is transmitted directly to the load cell 12. For this reason, pressure detection errors are less likely to occur due to the effects of rattling and deformation of mechanical parts due to aging of the apparatus, extension of the tie bar 3 due to heat, and the like, and more accurate pressing force can be detected. As a result, finer molding conditions can be set, resin leakage due to insufficient mold clamping pressure, occurrence of thin burrs, and the like can be prevented, and the product yield after resin sealing is improved.

It should be noted that the present invention is not limited to the above embodiment, and various changes can be made within the scope of the technical matters described in the claims. For example, a piston cylinder device may be used as a moving means of the moving platen 4. Further, a gear mechanism may be used as a transmission unit of the rotational force of the drive motor 9.

[0024]

According to the present invention, the detecting means for detecting the pressing force of the first mold on the second mold is fixed to the tie bar opposite to the side on which the second mold is provided. Fixing member and second
It is provided between the platen and the second mold of the first mold.
The pressing force on the mold is transmitted directly to the detecting means. Therefore, pressure detection errors are less likely to occur due to the effects of rattling and deformation of mechanical parts due to aging of the device, and extension of the tie bar due to heat, and more accurate pressing force can be detected. As a result, finer molding conditions can be set, resin leakage due to insufficient mold clamping pressure, occurrence of thin burrs, and the like can be prevented, and the product yield after resin sealing is improved.

[Brief description of the drawings]

FIG. 1 is a side view showing a resin sealing device of the present invention.

FIG. 2 is a sectional view showing an internal structure of a load cell.

FIG. 3 is a partial side sectional view showing a conventional resin sealing device.

[Explanation of symbols]

 1: Upper platen 2: Lower platen 3: Tie bar 4: Moving platen 5: Upper mold 6: Lower mold 7: Screw member 8: Toggle mechanism 9: Drive motor 10: Upper fixing nut 11: Lower fixing nut 12: Load cell 12a: Opening 13: Control device

Claims (4)

[Claims] 1. A resin sealing device for sealing a lead frame and a semiconductor element with a resin, comprising: a first platen and a second platen arranged at a predetermined interval; and a first platen and a second platen. A tie bar, a moving platen movably attached to the tie bar, a moving means for moving the moving platen, and a first mold provided on the moving platen.
A second mold provided on the second platen opposite to the first mold, a fixing member fixed to a tie bar on a side opposite to the side on which the second mold is provided, and the fixing member And a detecting means provided between the first mold and a second platen for detecting a pressing force of the first mold on the second mold. 2. The resin sealing device according to claim 1, further comprising control means for controlling said moving means in accordance with the pressing force detected by said detecting means. 3. A resin sealing device for resin sealing a lead frame and a semiconductor element, wherein the resin sealing device is provided between an upper platen and a lower platen arranged at a predetermined interval, and between the upper platen and the lower platen. A tie bar, a moving platen movably attached to the tie bar, a driving motor for applying a driving force to move the moving platen to the moving platen, an upper mold provided on the moving platen, and an upper metal A lower mold provided on the lower platen facing the mold, a fixing member fixed to a tie bar on a side opposite to the side where the lower mold is provided, and between the fixing member and the lower platen. A load cell provided for detecting a pressing force on the lower die of the upper die, and controlling a driving force of the driving motor in accordance with the pressing force detected by the load cell. And a control unit. 4. The resin sealing device according to claim 3, wherein an opening for inserting the tie bar with a predetermined gap is formed inside the load cell.