JPH11176852A - Semiconductor resin sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor resin sealing device that is made small in size. SOLUTION: A lead frame is inserted to a metallic die consisting of an upper die 11 and a lower die 15, and resin is sealed by filling the resin to upper and lower parts of the lead frame in the metallic die in a semiconductor resin device 100. The device 100 is provided with a die tightening screw 31 placed on the upper die 11, a worm wheel 29 screw-mounted on the die tightening screw 31, and a slide lever support plate 21 that prevents the die tightening screw 31 from moving upward. The worm wheel 29 is turned, and the length of the die tightening screw 31 is increased by moving a die tightening nut to produce a die tightening force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor resin sealing device, and more particularly to a semiconductor resin sealing device capable of reducing the size of the device.

[0002]

2. Description of the Related Art In general, a semiconductor resin encapsulating apparatus inserts a lead frame shown in FIG. 7 into a mold composed of an upper mold and a lower mold, applies a mold clamping force to the mold, and presses the mold in the mold. Resin sealing is performed by pouring resin above and below the lead frame.

In the conventional semiconductor resin sealing device, it is necessary to generate a large clamping force in order to apply the lead frame 109 shown in FIG. 7, and a hydraulic, pneumatic, high-output electric motor or the like is used as a mechanism for this. I was

[0004]

When a mold clamping force is generated using a hydraulic, pneumatic, high-output electric motor, or the like, the size of the device cannot be reduced, and the size of the device increases. . For this reason, such a device can only be installed in firm factories and the device cannot be easily moved.

[0005] Further, since the conventional semiconductor resin sealing device is large in size, it is expensive and requires a considerably long delivery time. In order to speed up the development of products, it is required to manufacture devices in a very short period of time.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a semiconductor resin sealing device capable of reducing the size of the device.

[0007]

In order to solve the above-mentioned problems, a semiconductor resin sealing apparatus according to the present invention comprises inserting a lead frame into a mold comprising an upper mold and a lower mold, and forming the lead in the mold. A semiconductor resin sealing device for performing resin sealing by pouring a resin above and below a frame, comprising: a mold clamping screw provided on the upper mold; and a worm screwed and attached to the mold clamping screw. And means for preventing upward movement of the clamping screw, wherein the worm is rotated to generate a clamping force by moving the clamping screw upward relative to the worm. It is characterized by making it.

In the above-described semiconductor resin sealing device, when the worm is rotated in a state where the upward movement of the clamping screw is prevented, the clamping screw tends to move upward with respect to the worm. However, the clamping screw cannot move upward, so that the clamping nut moves downward.
Thereby, a mold clamping force can be generated.

A movable platen connected to the upper mold, a rack connected to the movable platen, a gear meshed with the rack, a gear that rotates according to the vertical movement of the rack, It is preferable to further include an upper die up-and-down mechanism having a lever for rotating. In this upper die up-and-down mechanism, when the gear is rotated by moving the lever, the rack moves upward according to this rotation, and accordingly, the movable platen and the upper die rise.

[0010] The means may include a holding plate attached to the upper end of the clamping screw for stopping movement of the lever in a direction in which the rack moves upward.

[0011] A mold clamping force concentration mechanism comprising: a plurality of mold clamping nuts connected to a lower portion of the worm; and a mold clamping ball tapered inside the lower portion of the mold clamping nut. It is preferable that a mold clamping force concentration mechanism in which at least a part of the lower surface of the mold clamping ball is formed in a spherical shape is further included.

In this mold clamping force concentration mechanism, when the worm moves downward while rotating, the mold clamping nut also moves downward while rotating. At this time, since the mold clamping ball is taperedly fitted inside the lower part of the mold clamping nut, the mold clamping force concentrates inside the plurality of arranged mold clamping nuts. Further, since at least a part of the lower surface of the mold clamping ball is formed in a spherical shape, the mold clamping force can be further concentrated on the central portion of the spherical surface.

In the semiconductor resin sealing device according to the present invention, a lead frame is inserted into a mold composed of an upper mold and a lower mold, and the resin is pushed into the mold with a plunger above and below the lead frame. A semiconductor resin sealing device for performing resin sealing by using a driving mechanism for driving the plunger.

The drive mechanism includes a plunger push rod connected to the plunger, a slide plate connected to the push rod, a ball screw screwed to the slide plate, and a ball screw connected to the ball screw. And a motor. In this drive mechanism, when the ball screw is rotated by the motor, the slide plate is raised by the rotation. Thereby, a pushing pressure can be applied to the plunger via the plunger pushing rod.

It is preferable that the apparatus further includes a pressure sensor for detecting a pressure for pressing the resin with the plunger.

It is preferable that the apparatus further includes a control unit for controlling the driving of the plunger using the data detected by the pressure sensor. With this control unit, the pressing pressure of the plunger can be controlled to an appropriate value.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing a semiconductor resin sealing device according to an embodiment of the present invention. FIG. 2 is a side view of the semiconductor resin sealing device shown in FIG.
FIG. 3 is a plan view showing a part of the semiconductor resin sealing device shown in FIG.

The semiconductor resin sealing device 100 includes a mold clamping mechanism 60 and an injection mechanism 90. First, the mold clamping mechanism 60 will be described. The mold clamping mechanism 60 includes an upper mold lifting / lowering mechanism 10 for raising and lowering the upper mold, a mold closing / holding mechanism 20 for preventing the PL surface 13 from opening, a mold clamping force generating mechanism 30 for generating a mold clamping force, and concentrating the mold clamping force. It is composed of a mold clamping force concentration mechanism 40 for performing the clamping and a mold clamping force balance mechanism (shown in FIG. 4) for balancing the mold clamping force.

The upper mold lifting mechanism 10 uses a rack and pinion to lift the upper mold 11 by the lever 1, open the PL surface 13, put the lower mold 15 in and out, and set the lead frame and the resin on the lower mold 15. And products (semiconductor devices)
It is a mechanism that can take out.

That is, the upper die up-and-down mechanism 10 has the lever 1. One end of the lever 1 is attached to a gear 3, which is housed in a gear box 4.
The gear 3 is attached so as to mesh with the teeth of the rack 5, and the rack 5 is connected to a movable platen 7. A member 9 for inserting an upper mold heater (not shown) is suspended from the movable platen 7 by a suspending bolt 7 a, and this member 9 is connected to the upper mold 11.

In such an upper-type vertical mechanism 10, when the operator lifts the lever 1 upward, the gear 3 is rotated by this, and the rack 5 is moved upward by this rotation. The upward moving force is applied to the movable platen 7 and the member 9.
To the upper mold 11, lift the upper mold 11, and
Surface 13 can be opened.

A lower die 15 is provided below the upper die 11, and the lower die 15 is placed on a member 16 for inserting a lower die heater (not shown).

The mold closing and holding mechanism 20 sets the lead frame and the resin on the lower mold 15 and performs the PL surface 1
This is a mechanism for fixing the lever 1 with the slide-type lever holding plate 21 in order to receive the force applied to the lever 1 so that the lever 3 does not open.

That is, the mold closing and holding mechanism 20 includes the lever 1
Has a sliding lever holding plate 21 for fixing the lever 1 from above while pulling down. A holding release lever 23 is attached to a lower portion of the lever holding plate 21, and the slide type lever holding plate 21 is slid by the holding release lever 23. A retraction spring 25 is attached to one end of the holding release lever 23, and the retraction spring 25 is adapted to apply a spring force in a direction in which the slide lever holding plate 21 fixes the lever 1.

In such a mold closing and holding mechanism 20, when performing mold clamping, an operator pulls the lever 1 downward, and slides the slide lever holding plate 21 by the holding release lever 23. Thereby, the lever 1 is moved to the lever holding plate 2
1 can be fixed from above. Further, by using the retraction spring 25, the operator operates the lever 1 with one hand and holds the release lever 23 with the other hand.
Can be quickly moved to the next operation.

The mold clamping force generating mechanism 30 rotates the worm by rotating the handle, the mold clamping nut connected to the worm wheel is driven, and the clamping force acts on the PL surface side by the clamping screw to perform the mold clamping. Mechanism.

That is, the mold clamping force generating mechanism 30 has a handle 27, and the shaft 27a of the handle 27 is connected to the worm. This worm is connected to a worm wheel 29. The worm wheel 29 transmits the torque of the shaft 27a as a torque having a rotation axis perpendicular to the rotation axis of the shaft 27a.
Are connected so as to be able to move the mounting distance. Therefore,
The rotation of the shaft 27a is transmitted to the mold clamping screw 31 via the worm wheel 29, whereby the mold clamping screw 3 is rotated.
1 is moved up and down.

The upper end of the clamping screw 31 is connected to the rack 5, and the lower end of the clamping screw 31 is fitted to a clamping ball 33. The mold nut 35 is connected to the worm wheel 29 by a connection bolt 35a.

In such a mold clamping force generating mechanism 30, when the operator rotates the handle 27, the shaft 27
a rotates, and this rotation causes the worm wheel 29 to rotate. This rotation causes the mold clamping screw 31 to move upward relative to the worm wheel 29. At this time, since the lever 1 is fixed by the mold closing holding mechanism 20 described above, the rack 5 is prevented from moving upward, and as a result, the mold clamping screw 31 cannot move upward.
Therefore, the worm wheel 29 is subjected to a downward moving force. Such downward force is applied to the clamping nut 3
5 to the upper mold 11 and the tightening force is
3 and can perform mold clamping.

When the mold clamping force generated by the mold clamping force generating mechanism 30 is transmitted to the mold clamping ball 33 via a flat surface, the mold clamping force concentration mechanism 40 generates a bias in the force. Are collected at the axis center 37, and the collected force is applied to the axis center 37 accurately.

That is, a taper is provided on the contact surface between the mold clamping nut 35 and the mold clamping ball 33, and these are tapered. Thereby, the vector of the mold clamping force can be collected at the shaft center 37. Further, the lower part of the mold clamping ball 33 is formed in a spherical shape, and the mold clamping ball 33 and the member 9 are brought into point contact at the axial center 37. Thereby, it is possible to work to concentrate the force collected at the shaft center 37 accurately on the shaft center 37.

The mold clamping force balance mechanism is shown in FIG.
As shown in (b), a mold clamping force balance pin for moving the position of the center of gravity of the portion 53 receiving the mold clamping surface pressure to the position of the shaft center 37 of the mold is provided. this is,
If the center of gravity of the surface receiving the mold clamping force is not located at the center 37 of the mold, the fact that the mold clamping force is concentrated on the shaft center 37 by the mold clamping force concentration mechanism 40 does not make sense. This is to prevent FIG. 4A is a plan view schematically showing a lower mold, and FIG. 4B is a plan view schematically showing an upper mold.

That is, the mold clamping surface pressure receiving portion 53 is
This is a hatched portion shown in FIG. The position of the center of gravity of this part 53 is shifted from the axis center 37 of the mold. Therefore, for example, a cylindrical clamping force balance pin 51 is provided at the corner of the lower mold 15.
Is installed. The upper die 11 can be supported inside the lower die 15 by the balance pin 51, and as a result, a force repelling the clamping force can be applied to the mold. Therefore, by adjusting the height of the balance pin 51, the position of the center of gravity of the portion 53 receiving the mold clamping surface pressure can be moved to the position of the shaft center 37 of the mold.

The mold clamping force balance mechanism is not necessary when the center of gravity of the portion receiving the mold clamping surface pressure coincides with the axis 37 of the mold, and only when the position does not coincide. It must be attached to a resin sealing device.

Next, the injection mechanism 90 will be described. As shown in FIG. 2, the injection mechanism 90 includes a driving mechanism 70 for driving a plunger 71 for injecting a resin into a mold, and a pressure monitoring mechanism 80 for monitoring the pressing force of the plunger 71.

The driving mechanism 70 has a servomotor 61,
The rotation shaft of the servomotor 61 is connected to one end of a precision ball screw 65 by a coupling 63. Thus, the rotation of the servo motor 61 is transmitted to the precision ball screw 65. A slide plate 67 is screwed into the precision ball screw 65, and the slide plate 67 is attached to a slide plate guide post 69.
The rotation of the ball screw 65 causes the slide plate 67 to move up and down. One end of a plunger pushing rod 73 for pushing the plunger 71 is attached to the upper part of the slide plate 67. The other end of the push rod 73 is attached to the plunger 71.

In such a driving mechanism 70, the precision ball screw 65 is rotated by rotating the servomotor 61.
, Thereby moving the slide plate 67 up and down. By operating the plunger push rod 73 by this movement, the resin injection plunger 71 can be accurately moved, and the resin can be accurately injected into the mold.

The pressure monitoring mechanism 80 installs a load cell 75 below the plunger push rod 73, and feeds back the data output from the load cell 75 to a control unit (not shown) so that the pressure of the plunger is reduced. It is a mechanism that controls to be better.

That is, the pressure monitoring mechanism 80 has a load cell 75, and the load cell 75
7 is provided inside. The load cell 75 has a function of detecting the pressing force of the plunger 71, and data of the detected pressing force is sent to the control unit. This makes it possible to always check whether an appropriate pressing force is applied to the plunger 71 while operating the pressing rod 73. If the pressing pressure is not appropriate, the servo motor 61 is controlled by the control unit so that the pressing pressure becomes appropriate.

Next, a mechanism for pulling out the lower mold 15 from the position where the mold clamping force is applied will be described.

As shown in FIG. 3, a lower die 15 is placed on a member 16 into which a heater for the lower die is inserted. The lower die 15 is formed on the member 16 by a lower die (not shown). The guide rail is movable as shown by the arrow. Further, a lower die pulling lever 15a is attached to the lower die 15, and the operator can pull out the lower die 15 by pulling the lower die pulling lever 15a.

Next, a mechanism for taking out a product (semiconductor device) from the lower mold 15 will be described. As shown in FIGS. 1 and 2, the mechanism has a projecting lever 81,
A protruding plate 83 is attached to one end of one.
On the protruding plate 83, base ends of a plurality of protruding pins 85 are provided, and the front ends of the protruding pins 85 are located below the product through the inside of the member 16.

In such a take-out mechanism, when the operator moves the projecting lever 81, the projecting plate 83
Moves up and down, and this movement is transmitted to the protruding pin 85.
Therefore, by moving the protruding pin 85 upward, the product in the pulled out lower mold 15 is separated from the lower mold 15, and the product can be taken out by the operator.

The M / C performance of the semiconductor resin sealing device 100 is as follows. The mold clamping force is about 3 tons. It is 2650-2850 kg in calculation. Moreover, the injection pressure of the resin is considered to be 100 kg / cm ² before and after, more because it did not test 100 kg / cm ² or more is unclear. The occupied area of the device 100 is about 0.5 m ² or less (using a two-stage trolley or the like). Also,
Utility uses only 100V power supply. Also, the cycle is equivalent to one molding cycle (about 80 seconds) of a normal large-sized apparatus.

The operation of the above-described semiconductor resin sealing device 100 will be described. First, the operator pulls out the lower die 15 by the lower die pulling lever 15a to the position of the lower die 15 indicated by the dotted line in FIG. 2, and inserts the lead frame 103 shown in FIG.
(A) is set on the lead frame pressing portion 55, and the resin in the form of a tablet, into which the powder is solidified, is fed into the resin feeding portion 72 of the lower die 15. The lead frame 103
Has a pilot hole 105 and a gate 107.

Next, the operator moves the lower mold 15 to a position where the mold clamping force is applied by the lower mold pulling lever 15a.
Thereafter, the lever 1 is fixed by the mold closing and holding mechanism 20, the mold is heated by the upper mold heater and the lower mold heater, and the mold clamping force is applied to the mold by the mold clamping force generating mechanism 30. Next, the resin is poured above and below the lead frame 103 through the runner / gate 57 by the injection mechanism 90.

Thereafter, the mold closing and holding mechanism 20 is released, the PL surface 13 is opened by the upper and lower mechanism 10 and the lower mold 15 is pulled out by the lower pull lever 15a. Next, the operator takes out the product from the lower mold 15 by the mechanism for taking out the product.

According to the above-described embodiment, when the mold is clamped, the mold closing holding mechanism 20 as described above for preventing the PL surface 13 from opening is provided, and the clamping force for performing the mold clamping is applied to the PL surface. Mold clamping force generating mechanism 3 as described above to work
0 is provided. By utilizing such a simple mechanical force, the semiconductor resin sealing device can be miniaturized (extremely compact). Therefore, the device 100 can be carried on a trolley or the like and carried to a required place, so that the device can be installed and operated anywhere. In addition, molding can be performed in a small space (reduction of equipment area space). It is also ideal as a research and small-scale prototype system.

Further, since the size of the apparatus can be reduced, the price of the apparatus can be reduced as compared with the conventional large-sized apparatus. Also, it is possible to shorten the production period of the device,
Speeds up product development.

Further, the semiconductor resin sealing device 100 includes:
Since it is applied to a lead frame as shown in FIG. 5 in which one semiconductor device is resin-sealed, it is suitable for small-quantity production.

FIG. 6A is a plan view showing a modification of the lead frame applied to the mold shown in FIG.
FIG. 6B is a plan view illustrating another modification of the lead frame applied to the mold illustrated in FIG. 4.

The lead frame 104 shown in FIG.
Has a larger PKG (package) size than the lead frame 103 shown in FIG. In such a case, the cull / runner / gate portion 104a is installed in the lead frame 104. Thus, the size of the die applied to the lead frame 104 having a large PKG can be reduced as compared with the case where no cull / runner is installed.

The lead frame 108 shown in FIG.
Has a significantly smaller PKG size than the lead frame 103 shown in FIG. In such a case, four semiconductor devices are arranged and the cull / runner / gate unit 108 is arranged.
a is set at the center of the lead frame 108. Thereby, four PKGs can be molded at once.

[0054]

As described above, according to the present invention, a mold clamping screw provided on an upper mold, a worm threadedly attached to the mold clamping screw, and an upper part of the mold clamping screw Means for preventing movement to Therefore, it is possible to provide a semiconductor resin sealing device capable of reducing the size of the device.

[Brief description of the drawings]

FIG. 1 is a front view showing a semiconductor resin sealing device according to an embodiment of the present invention.

FIG. 2 is a side view of the semiconductor resin sealing device shown in FIG.

FIG. 3 is a plan view showing a part of the semiconductor resin sealing device shown in FIG. 1;

FIG. 4A is a plan view showing the inside of a lower mold;
FIG. 4B is a plan view showing the inside of the upper die.

FIG. 5 is a schematic view of a lead frame set in the mold shown in FIG.

FIG. 6A is a plan view showing a modified example of the lead frame applied to the mold shown in FIG. 4, and FIG.
FIG. 10 is a plan view showing another modified example of the lead frame applied to the mold shown in FIG. 4.

FIG. 7 shows PKG7 applied to a conventional semiconductor resin sealing device.
FIG. 4 is a plan view showing a continuous type lead frame.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Lever, 3 ... Gear, 4 ... Gear box, 5 ... Rack, 7 ... Movable platen, 7a ... Hanging bolt, 9 ... Member,
Reference numeral 10: Upper die up / down mechanism, 11: Upper die, 13: PL surface, 15
... lower mold, 15a ... lower mold pulling lever, 16 ... member, 20 ...
Mold closing and holding mechanism, 21 ... Sliding lever holding plate, 23 ...
Holding release lever, 25: retracting spring, 27: handle, 27a: shaft, 29: worm wheel, 3
0: mold clamping force generating mechanism, 31: mold clamping screw (mold clamping bolt), 33: mold clamping ball, 35: mold clamping nut, 35
a ... connecting bolt, 37 ... shaft center, 40 ... mold clamping force concentration mechanism, 51 ... mold clamping force balance pin, 53 ... part receiving mold clamping surface pressure, 55 ... lead frame pressing part, 57 ...
Runner / gate section, 60: mold clamping mechanism, 61: servo motor, 63: coupling, 65: precision ball screw,
67: slide plate, 69: slide plate guide post, 70: drive mechanism, 71: plunger, 72
... Resin charging section, 73 ... Plunger push rod, 75 ...
Load cell, 80: pressure monitoring mechanism, 81: projecting lever,
83: projecting plate, 85: projecting pin, 90: injection mechanism, 100: semiconductor resin sealing device, 103, 104: lead frame, 104a: cull / runner / gate section,
105: pilot hole, 107: gate, 108: lead frame, 108a: cull / runner / gate,
109 ... lead frame.

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // B29L 31:34

Claims (8)

[Claims] 1. A semiconductor resin sealing device that inserts a lead frame into a mold composed of an upper mold and a lower mold and pours resin above and below the lead frame in the mold to perform resin sealing. A mold screw provided on the upper mold, a worm screwed to the mold screw, and means for preventing the mold screw from moving upward. And a mold clamping force is generated by moving the mold clamping screw upward relative to the worm. 2. A movable platen connected to the upper mold,
The rack further includes an upper die vertical mechanism including a rack connected to the movable platen, a gear meshed with the rack, the gear rotating according to the vertical movement of the rack, and a lever rotating the gear. The semiconductor resin sealing device according to claim 1, wherein: 3. The means according to claim 2, wherein said rack has a holding plate attached to an upper end of said clamping screw and stopping movement of said lever in a direction in which said rack rises. Semiconductor resin sealing device. 4. A mold clamping force concentration mechanism comprising: a plurality of mold clamping nuts connected to a lower portion of the worm; and a mold clamping ball tapered inside the lower portion of the mold clamping nut. 4. The semiconductor resin sealing according to claim 1, further comprising a mold clamping force concentration mechanism in which at least a part of a lower surface of the mold clamping ball is formed in a spherical shape. apparatus. 5. A semiconductor resin encapsulation in which a lead frame is inserted into a mold composed of an upper mold and a lower mold, and a resin is pushed into and poured from above and below the lead frame in the mold with a plunger. A semiconductor device sealing device, comprising a driving mechanism for driving the plunger. 6. The drive mechanism includes a plunger push rod connected to the plunger, a slide plate connected to the push rod, a ball screw screwed to the slide plate, and a ball screw connected to the ball screw. The semiconductor resin sealing device according to claim 5, further comprising: a motor. 7. The semiconductor resin sealing device according to claim 5, further comprising a pressure sensor for detecting a pressure for pressing the resin with the plunger. 8. The semiconductor resin sealing device according to claim 7, further comprising a control unit for controlling driving of said plunger using data detected by said pressure sensor.