JP2002219729A - Seal molding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal molding apparatus wherein no slide resistance occurs in respect to plungers and a pressure holding process is free of a pressure loss, while occurrence of unfilling or voids is suppressed. SOLUTION: The plungers 4 for injecting and filling a powder-like or tablet- shaped molding resin in a lower cavity 1 and an upper cavity 14 and movable plungers 17 for pressing and holding the molding resin with a prescribed hydraulic pressure at arbitrary timing, corresponding to the plungers 4 on injection of the resin, just before completion of filling or after the filling, on the occasion when a strip-shaped or hoop-shaped lead frame 11 whereon forming elements 10 constituting molded bodies 20 are placed is subjected to resin seal molding by molding tools, are provided in the apparatus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing molding apparatus for sealing and molding electronic parts, semiconductors and the like with a thermosetting resin or the like.

[0002]

2. Description of the Related Art A conventional sealing molding apparatus will be described with reference to the drawings. FIG. 10 is a perspective view of a main part of a conventional sealing molding apparatus, FIGS. 11A and 11B are cross-sectional views showing operations of a plunger before and after resin injection during the sealing molding, and FIG. Cal, runner layout, Fig. 1
FIG. 3 is a front view of a main part of the hoop-shaped lead frame in cutting the cull.

In FIG. 10, reference numeral 11 denotes a lead frame made of a strip-shaped metal material or the like, on which one or both sides of an element 10 such as an electronic component or a semiconductor are mounted at regular intervals by welding, bonding or caulking. Pilot holes 8a are also provided at regular intervals on both side ends.

A lower cavity block 5 made of steel or the like has a pair of lower cavities 1, a gate 27, a gate 29, and a runner 28 provided on the upper surface. The lower cavity 1 has gates 29, 27 and a gate 29. , 27
Are connected to and connected to the runner 28 at the center. A plurality of pilot pins 8b are provided outside the lower cavity 1 at equal intervals so as to protrude from the upper surface of the lower cavity block 5, and are inserted into the pilot holes 8a of the lead frame 11 so that the lead frame 11 is inserted into the lower cavity 1. Is positioned at a predetermined position.

A vertically movable ejector pin 3 made of steel or the like has a lower end fixed to an upper surface of an ejector plate 6, and a lower cavity block 5 is inserted to project a tip end into the lower cavity 1 from the bottom surface. 10
Molded body 20 obtained by sealing molding with thermosetting resin
Is removed from the lower cavity 1 and taken out.

Numeral 12 is an upper cavity block which is movable up and down corresponding to the lower cavity block 5 made of steel or the like. The insertion hole through which the tip of the pilot pin 8b is inserted. An upper cavity which forms a cavity for stopping is provided.

Reference numeral 4 denotes a vertically movable plunger made of steel or the like, which is slidably and movably inserted into a lower pot 25 fixed and held on the lower cavity block 5, and has a plunger driving mechanism (not shown). By raising the plunger 4 by a predetermined dimension, the thermosetting resin, which is a molding resin for sealing molding, is pressed and sent out to the cavity formed by the lower cavity 1 and the upper cavity in which the molded body 20 is formed. The compression spring 22 is maintained at a predetermined resin pressure by the tension generated when the compression spring 22 is compressed.

Reference numeral 9 denotes a structural block serving as a frame for forming a lower mold portion including the lower cavity block 5, the plunger plate 7, the plunger 4, and the like.

FIG. 11A shows a state immediately after the tablet 2 made of a thermosetting resin, which is a molding resin, is supplied to the lower pot 25. In this state, the plunger 4 is raised by the plunger plate 7 and the plunger 4 is lifted. When the tablet 2 is heated and compressed when the jar 4 is held, the compression spring 22 is compressed.
Are in a compressed state.

In FIG. 13, reference numeral 43 denotes a forming upper die provided on the lower surface of the crown 43a; 44, a forming lower die provided on the upper surface of a platen 44a immediately below the upper forming die 43;
The same number of plungers 4 as the culls formed by the lower pot 25 in the lower molding die 44 are arranged at positions adjacent to the respective dies. Reference numeral 30 denotes a lower runner cutting die for cutting a runner mark formed by the cull 21 and the runner 28 of the lead frame 11 into a predetermined shape, and reference numeral 30a denotes a runner cutting upper die which faces the runner cutting lower die 30 and is driven by an air cylinder 31a. , 32 are drive rollers for transporting the hoop-shaped lead frame 11, 31 are air cylinders for moving the lead frame 11 up and down, and 3
Reference numeral 3 denotes a chute for discharging cut culls and runners.

Next, the sealing molding operation will be described. Powder or tablet-like thermosetting resin is supplied into the lower pot 25 by a supply mechanism (not shown), and the lower mold 44 is raised by a mold clamping mechanism (not shown), and the forming element 10 is placed thereon. The pilot pin 8b is inserted into the pilot hole 8a of the lead frame 11, positioned and clamped.

Then, the thermosetting resin in the lower pot 25 is sent out into the cavity composed of the upper cavity and the lower cavity 1 by driving up the plunger 4, and the plunger 4 is filled at the position where the filling is completed. To stop.

On the other hand, during the mold clamping operation, the cull 21 adhered to the lead frame 11 which has been formed in the previous cycle,
The runner trace by the runner 28 is cut and removed. That is, the upper runner cutting die 30a is moved downward by the driving of the air cylinder 31a, and the lead frame 11 is sandwiched and held between the upper die 30 and the lower runner cutting die 30. (2) to cut the cull 21 and the runner mark and discharge it through the chute 33.

After a predetermined time has passed and the thermosetting resin has cured, the lower molding die 44 is lowered and stopped, and
And the lead frame 11 having the cull 21 and the runner trace attached thereto are separated from the lower cavity 1 by driving the ejector pins 3 in the upward direction and taken out. Thereafter, the lead frame 11 is raised by the driving of the air cylinder 31, the lead frame 11 is conveyed by a predetermined amount by the rotation of the driving roller 32, and the process proceeds to the next cycle.

[0015]

However, the conventional sealing molding apparatus has the following problems. The pressure-holding operation after the injection and filling of the thermosetting resin, which is a molding resin, is performed by generating a predetermined pressure in the plunger 4 by the tension of the compression spring 22. Then, for example, a pressure change due to deterioration due to the life of several million shots occurs.

Further, it is difficult to maintain a constant pressure with respect to the weight variation of the thermosetting resin in the form of powder or tablet, or the difference in volume of the forming element 10 mounted on the lead frame 11.

Further, when the thermosetting resin is injected and filled, the resin having reached a low viscosity enters the gap between the plunger 4 and the lower pot 25 and adheres in a solidified state. Sliding resistance is generated, and there is a possibility that the cavity is not filled or voids are generated due to pressure loss in the pressure holding process.

In the continuous cycle operation, since the pressure loss corresponding to the sliding resistance of each plunger 4 cannot be measured individually, it is impossible to suppress the occurrence of molding failure in the plunger due to abnormal sliding. Had.

In molding a two-row lead frame as shown in FIG. 12, when the volume of the molded body exceeds a predetermined amount, the difference between the completion time of resin filling in one row and the other row is reduced. And there is a problem at the time of filling that the rate of void generation of the molded body on the other row side increases.

Further, when cutting the cull and the trace of the runner in the arrangement shown in FIG. 13, the longitudinal dimension of the runner cutting die is determined by the number and arrangement of the pots on the molding die. It is necessary to install a mold with almost the same dimensions as the mold. The larger the number of pots, the larger the size of the runner cutting die, resulting in an increase in cost and an increase in the size of the entire apparatus.

In contrast to a system in which a predetermined weight of tablet-shaped molding resin is supplied by using a supply alignment mechanism such as a parts feeder, a plurality of tablets of different specifications are required for a type requiring a tablet having a different weight. There was a management issue that needed to be prepared.

Further, when cleaning the molding die using a cleaning resin or a release resin, the tablet is manually supplied into the molding die using a tablet supply jig (not shown). Start the molding operation. At this time, there was a problem of safety due to manual work for a plurality of times of cleaning molding.

Furthermore, in the formation of a hoop-shaped lead frame having a plurality of culls and runner marks, the molding may be performed due to defective mold release after molding or breakage of culls or runners during transport of the lead frame before the next cycle molding. There is a problem that the mold may be damaged at the time of mold clamping in the next molding due to the remaining of the cull and the trace of the runner on the lower mold.

The present invention has been made to solve the above-mentioned conventional problems, and has little variation in holding pressure after filling with a molding resin. Resin can be injected evenly,
Regardless of the number of mold pots, the runner and cull can be cut in a space-saving manner, and the weight change of the tablet can be easily switched within the device. Automatic supply of the cleaning resin tablet and the mold custom resin tablet within the device, It is an object of the present invention to provide a sealing molding apparatus capable of performing continuous molding and detecting a remaining runner or cull to prevent mold damage.

[0025]

Means for Solving the Problems In order to solve the above problems, a sealing molding apparatus of the present invention has the following configuration.

According to the first aspect of the present invention, a strip or hoop-shaped lead frame on which a forming element constituting a molded body is mounted is transferred, and resin sealing is performed on the forming element of the lead frame. A molding die, a plunger for injecting and filling powder or tablet-like molding resin from the pot of the molding die into the cavity, and actuated in response to the movement of the plunger to complete the filling when the molding resin is injected. Immediately before or after filling, it is a sealing molding device equipped with a movable plunger that pressurizes and holds the molding resin at a predetermined pressure by hydraulic pressure at an arbitrary timing, arbitrarily switches the resin pressure before and after completion of filling, and melts the molding resin It has an effect that air bubbles and the like that have entered inside in this state can be discharged to the outside, and the air bubbles and the like can be compressed.

According to a second aspect of the present invention, there is provided a sealing molding apparatus according to the first aspect of the present invention, wherein a predetermined pressure is applied to the plunger using hydraulic pressure to inject or hold the molding resin. Even when the weight of the powder or tablet-shaped thermosetting resin varies, or the volume of the forming element in the lead frame varies, the pressure of the molding resin can be maintained at a constant pressure for each plunger. This has the effect that a uniform pressure can be applied to the cavity of the mold.

According to a third aspect of the present invention, in the first or second aspect, the plunger and the movable plunger are used as an eject mechanism for releasing a cull formed by their operation. It is a stop forming device, and has an effect that a plurality of ejector pins originally provided in the periphery of the cull can be eliminated, and the mold structure can be simplified.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the resin burrs attached to the sliding surfaces of the movable plunger and the pot are removed by cleaning with a brush and suction. The sealing molding device is configured to prevent an increase in sliding resistance beforehand and to prevent a pressure loss in a pressure holding step after injection of a molding resin.

According to a fifth aspect of the present invention, in the fourth aspect, the pressure inside the hydraulic mechanism for driving the movable plunger is switched to a low pressure at a predetermined timing, and the operation of the movable plunger thereafter. Is a sealing molding apparatus to which a detection mechanism for detecting whether or not the molding is affected by the sliding resistance is provided, and has an operation of confirming and displaying that molding is performed at a predetermined pressure during continuous operation.

According to a sixth aspect of the present invention, there is provided a method as set forth in any one of the first to fifth aspects, wherein the forming element mounted on the two-strip strip or the hoop-shaped lead frame is resin-sealed. In a sealing molding device in which a pot and a runner are arranged near both side ends of the lead frame so that the resin flows evenly into all the cavities,
This has the effect of preventing the molding resin from being unfilled into the cavity and the occurrence of voids.

According to a seventh aspect of the present invention, in the invention according to any one of the first to sixth aspects, a roller for bending and cutting the cull and a roller for supporting and transporting the lead frame during the transport of the lead frame. This is a sealing molding device equipped with a cull removal mechanism consisting of: The cull is removed in synchronization with the lead frame transfer operation to shorten the cycle time, and the lead frame transfer mechanism is independent of the number of pots and the number of molds. It has the effect of being able to be incorporated in the inside, thereby enabling space saving.

According to an eighth aspect of the present invention, in the invention according to any one of the first to seventh aspects, the powdered resin is supplied to the tablet in order to supply the tablet-shaped molding resin into the pot of the molding die. This is a sealing molding apparatus to which a tablet molding mechanism for molding is added, and has an effect that the thickness of a cull can be set to be thin or small, and the yield of sealing molding can be improved.

According to a ninth aspect of the present invention, in the first aspect of the present invention, the cleaning resin tablet and the release resin tablet are continuously connected to each other to clean the molding die. This is a sealing molding device with a mechanism for supplying the inside of the pot. It is safe and easy to operate as in the normal molding process without the trouble and risk of manually supplying the tablet to the mold using a dedicated jig. It has the effect of being able to.

The tenth aspect of the present invention is the first to ninth aspects.
In the invention described in any one of the above, in the molding of a hoop-shaped lead frame having a plurality of culls, a detection mechanism of the presence or absence of cull damage during the lead frame transport before the next cycle molding or mold release failure after molding. This is a sealing molding apparatus added in a molding die, and has an effect of preventing breakage of the die by detecting residual cull on the molding die.

[0036]

(Embodiment 1) A sealing molding apparatus according to Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a cutaway perspective view of a main part of a sealing molding apparatus according to Embodiment 1 of the present invention, FIGS. 2A and 2B are cross-sectional views of a main part showing a resin sealing portion before and after the molding, and FIG. FIG. 4 is a cross-sectional view showing the movable plunger in the normal position immediately after the mold is opened, FIG. 4 is a cross-sectional view showing the movable plunger in the abnormal position in the same state, and FIG. 5 detects an abnormality of the movable plunger in the same state. FIG. 6 is a perspective view of a main part showing a cull removing mechanism, FIG. 7 is an enlarged side view showing a local structure of the mechanism, and FIGS. 8 (a) and 8 (b) are local structures of the mechanism. FIG.

The same components and members as those of the prior art are denoted by the same reference numerals, and detailed description will be omitted.

In FIGS. 1, 2 and 3, a plurality of movable plungers 17 are arranged in the upper cavity block 12 at equal intervals so as to be vertically movable. Hydraulic constant pressure pin 18
Can generate a predetermined pressure by one path in the flow passage in the hydraulic block 19, and is always added in a direction to lower the hydraulic constant pressure pin 18.

The movable plunger 17 has two lower pots 2 arranged corresponding to the two lower cavities 1.
The upper pot 26 provided in the holder 13 is inserted and slidably inserted through the center of the upper pot 26 provided on the holder 13. That is, the lower pot 25 and the upper pot 26 are arranged at equal and equal intervals in the vicinity of both ends in the width direction of the lead frame 11, and the resin is injected into the upper pot 26 evenly from both directions of the lower pot 25. That is.

Reference numeral 7 denotes a plunger plate which holds a plurality of plungers 4 which do not have a built-in spring mechanism, and which is raised by driving a plunger driving mechanism (not shown) using hydraulic pressure. By raising the plunger 4 by a predetermined dimension at 7, a molding resin is injected and filled into a cavity portion formed of the upper cavity 14 and the lower cavity 1 and forming the molded body 20. The upper cavity 14 is formed in the upper cavity block 12 so as to face the lower cavity 1 (see FIG. 2).

15 is the upper pot 26 and the movable plunger 1.
7, the culls 21 on both sides thereof are formed by the lower pot 25 and the plunger 4, and the culls 15 and 21 are connected by a runner mark formed by the runner 16. , Molded body 20
And the cull 21 are connected by a runner mark formed by a runner 24 provided between the lower cavity 1 and the lower pot 25.

Reference numerals 23a and 23b denote a plurality of sets of transmission type sensors, whose optical axes are made to coincide with the hydraulic pressure equalizing pin 18 in the vicinity of the upper end at a regular position. Then, the movable plunger 17 at a position different from the normal position and at a different height from the normal position has the optical axis in a light shielding state, and the abnormal state is detected.

Next, the injection and filling operations of the molding resin in the encapsulation molding will be described with reference to FIGS. First, a strip or hoop-shaped lead frame 11 on which forming elements constituting a molded body are mounted is transferred to a transfer mechanism (not shown).
As a result, it is transferred into a molding die for resin sealing molding. Then, as shown in FIG. 2B, after the tablet 2 is supplied to the lower pot 25 in the lower cavity block 5 and the mold is closed, the plunger 4 is moved upward by driving the plunger driving mechanism (not shown). By moving a predetermined dimension to
As shown in FIG. 2A, a molten thermosetting resin, which is a molding resin, is injected and filled into a cavity portion formed by the lower cavity 1 and the upper cavity 14.

At this time, the pressure applied to the hydraulic pressure equalizing pin 18 is the predetermined pressure described above, that is, the pressure A in FIG. 5 from the start of the resin injection, and the injection of the molding resin into the cavity portion is performed. As the resin is filled into the upper pot 26 with the filling, the movable plunger 17 is pressed and moved upward, so that the predetermined pressure is applied to the molding resin in the cavity portion. Will be.

At this time, the cull 15 having the dimension l shown in FIG.
Due to the change in thickness, the pressure is maintained at a uniform pressure in any state.

That is, the holding pressure after the injection and filling of the molding resin is changed to the pressure B which is optimal for the holding pressure shown in FIG. By pressing the pressure B by the movable plunger 17 using hydraulic pressure that connects the pots 25 and 26 with the runner 16, a constant and uniform resin pressure is always applied to each cavity. The pressure A may be continued depending on the shape of the molded body 20, the number of the forming elements 10 or the number of sealing moldings performed at one time.

Next, the release operation after the completion of the pressure holding for a predetermined time will be described. First, the plunger 4 is slightly moved downward as shown in FIG. 5 to release the tip from the molding resin. And the movable plunger 17
The mold opening operation is performed in a state where the hydraulic pressure necessary to release the cull 15 from the upper pot 26, that is, the pressure A or the pressure B is applied, and the operation and the downward movement of the movable plunger 17 by the hydraulic pressure are performed. The mold is released (ejected) from the upper cavity 14 and the upper pot 26 by following the movement of the upper pot 14.

On the other hand, in this mold opening operation, the plunger 4 is formed by the lower pot 25 by being further raised upward from the position at the time of resin sealing molding (in a pressure holding state) as shown in FIG. The cull 21 is released from the lower cavity block 5 (eject). At the same time, it goes without saying that the ejector pin 3 is lifted upward to release the resin-sealed molded body 20 from the lower cavity 1.

If the molding resin enters the gap between the sliding portion of the movable plunger 17 and the upper pot 26 when the release of the molded body 20 is completed, as a result, the sliding surface of the movable plunger 17 is solidified. Resin burrs in a degraded state will adhere. In order to remove the resin burrs, when the mold release is completed, the side surface of the tip of the movable plunger 17 projecting below the upper parting surface as shown in FIG. (Not shown) and the cleaning operation by vacuum suction are performed for each molding cycle, so that a stable sliding surface free of resin burrs is always maintained.

Next, a description will be given of how the plurality of movable plungers 17 manage a state in which there is no pressure loss in the sliding resistance of the sliding portion caused by the resin burr, and that the pressure holding by a predetermined pressure is guaranteed. When the cull 15 is released from the upper pot 26, the hydraulic pressure for driving is increased from the strong pressure necessary for the cull 15 to be released from the upper pot 26 at the position where the cull 15 is released from the upper pot 26, as shown in FIG. C, for example, 98 × 10
By switching the pressure to a low pressure of ⁴ Pa or less, the movable plunger 17 is moved downward until the tip is at the moving end position of the holder 13 as shown in FIG.

At this time, if at least one of the plurality of movable plungers 17 has a sliding resistance equal to or higher than the set pressure at the low pressure, it does not move to the predetermined moving end position as shown in FIG. Due to the displacement of the movable plunger 17, the pair of sensors 23a and 23b is shielded from light by the tip of the movable plunger 17 and detected as abnormal. Therefore, based on this abnormality detection, necessary operations such as an abnormality display, a warning, or an operation stop of the apparatus are performed.

Next, as for the layout of the cull and the runner in the encapsulation molding of the double strip or hoop-shaped lead frame according to the present invention, the cull 21 is supplied with the tablet 2 as shown in FIGS. Lower pot 25
The cull 15 is formed in the upper pot 26 through which the movable plunger 17 is inserted, and is connected to each other by a runner trace by the runner 16. Further, the molding resin in the molten state is uniformly injected from the lower pot 25 via the runner 24 into the cavity formed by the lower cavity 1 and the upper cavity 14 and filled therein.

Next, the cull removing mechanism after the sealing molding according to the present invention will be described with reference to FIGS. 35 is a cutting wheel mounted on both sides of the pin roller 36,
A timing pulley 39 and a timing belt 40 attached to the outer surface of the pin roller 36 rotate and drive in synchronization with the hoop holding roller 34. The pin roller 37 moves the lead frame 11 by a pitch every sealing molding pitch by the rotation drive of the servo motor 38. Reference numeral 41 denotes a chute for discharging the cut and separated cull and the like, and reference numeral 42 denotes a cull plate which prevents the cull and the like from scattering and falling and guides the cull to the chute 41.

Next, the cull removing operation will be described with reference to FIG. The outer peripheral portion of the cutting wheel 35 is provided with irregularities at regular intervals, and the cull 15 having a projection thereon is fitted into the concave portion, and the cull 21 having no projection is fitted into the convex portion. The lead frame 11 is aligned as described above, and the cull 15,
By rotating the cutting wheel 35 in the direction of the arrow, the 21 is bent while being rotated downward, cut and separated. At this time,
Runner 1 for connecting culls 15, 21 and molded body 20
The runner traces 6 and 24 are located on the lower surface of the lead frame 11, so that the stress on the lead frame 11 can be minimized by matching the concave and convex shape of the cutting wheel 35 with the projection direction of the cull. .
As shown in FIGS. 8A and 8B, the cull cutting operation is performed using the runner trace by the runner 24 and the contact point of the hoop holding roller 34 as a fulcrum so that the molded body 20 itself is not stressed. Is refracted by the cutting wheel 35 to remove the culls 15 and 21 and sent out to the chute 41 to be eliminated.

That is, the cutting wheel 3 immediately before the conveying roller of the lead frame 11 immediately after the encapsulation molding.
5. A cull removing mechanism including a pin roller 36, a hoop holding roller 34, and the like is installed, and the lead frame is conveyed while the upper surface of the lead frame is wound around the cull removing mechanism and rotated to remove runner marks and culls. It is to be removed.

Next, a description will be given of a method for detecting the occurrence of buckling during the transfer of a hoop-shaped lead frame having a plurality of culls. In FIG. 1, reference numeral 60 denotes a reflection-type sensor comprising a photoelectric switch, which is provided corresponding to a row position near both side ends of the lead frame 11 where the culls 15 and 21 are formed. That is, the sensor 60 is installed in the direction in which the pots 25 and 26 provided in the molding die are arranged in the feed direction of the lead frame 11, and
Is located downstream in the transport direction. The sensor 60 detects the presence or absence of the culls 15 and 21 formed by the molding die based on whether or not a predetermined number of culls has passed during the transportation of the lead frame 11. The position of the sensor 60 set by the photoelectric switch may be any position where the culls 15 and 21 formed by resin molding can be detected in the transport path of the lead frame 11, and particularly the cull immediately after being formed by the molding die. Performing the detection is advantageous from the viewpoint of the safety of the device.

As described above, when the cull is broken or the cull falls onto the molding die during the transportation of the lead frame, the sensor 60 for detecting a defect in the molding die is provided, and the cull is attached immediately after molding. When transported in a state, the number of culls is counted, and when the number is less than a predetermined number, the apparatus is immediately stopped, a warning is displayed, and the like.

(Embodiment 2) Next, a sealing and molding apparatus according to Embodiment 2 of the present invention will be described with reference to FIG. In FIG. 9, 45 is a tablet forming mechanism,
This is a configuration of a rotary press that supplies a powdered resin from a hopper, measures a predetermined weight of the resin, and presses the resin.
A tablet take-out port is provided at one position of a rotary plate 59 provided in the tablet forming mechanism 45, and the tablets 2 to be continuously formed are transferred to a conveyor 47, aligned in a line, and passed through a photoelectric switch 48 as a sensor. Then, the tablet 2 is sent out and supplied until the photoelectric switch 49 blocks light.

After that, the shutter 46 is opened and the conveyor 47 is operated to transfer the tablet 2 to the escape slider 52. The transfer dimension pitch of the tablet 2 in the escape slider 52 is equal to the pitch dimension between the pots of the molding die 56 (same as that described in the first embodiment) placed on the platen 57, and all the transfer of the tablet 2 is performed. When the replacement is completed, escape slider 5
The tablet 2 is transferred to the tablet supply mechanism 54, and the escape slider 52 is waiting for the tablet 2 to be transferred again.

In the preceding step (not shown), the encapsulation molding is completed, and at the time when the feed operation of the lead frame 11 for the next cycle is completed by the driving of the hoop feeding mechanism 58, the tablet feeding mechanism 54 is advanced to form. Lower pot 25 of mold 56
The tablet 2 is supplied. That is, for a type of tablet having a different weight, a powder molding press is installed in the sealing molding apparatus, and the measurement setting of the powder resin is arbitrarily changed.

Next, the supply of the cleaning resin tablet and the release resin tablet will be described. Each of the cleaning resin tablet and the release resin tablet is transferred from the two parts feeders 50 to the escape slider 52 horizontally moved by the direct robot 53 via the conveyor 51 in the same manner as the molding tablet 2 and is replaced. The supply mechanism 54 supplies a portion (the lower pot 25) corresponding to a predetermined portion of the molding die 56. That is, at the time of cleaning molding, the cleaning resin tablet and the release resin tablet are each automatically supplied, and the number of operations can be set arbitrarily.

Although the cleaning of the molding die in the second embodiment has been described using a hoop-shaped lead frame and sequentially transporting the cleaning moldings by the lead frame, a strip-shaped lead frame has been described. When using the cleaning mechanism 55 shown in FIG. 9, a cleaning molded product molded by the molding die 56 may be carried out to the outside of the lead frame other than the transport path.

[0063]

As described above, according to the present invention, by using a plunger driven by hydraulic pressure, the weight difference of the tablet or the formation of the tablet mounted on the lead frame in the pressure holding step after the injection of the molding resin. With respect to the difference in the volume of the element, an equal pressure is applied to all the cavities, and the sliding resistance of all the movable plungers is simply measured to enable the quality assurance of the sealing molded body. Injection of molding resin into strip-shaped strips or hoop-shaped leadframes. Inflow from opposite directions (both sides in the width direction of the leadframe) to prevent molding defects such as unfilled cavities and voids. Can be.

The plunger itself can be used as a cull ejecting mechanism, a cull removing mechanism can be installed in a lead frame transport mechanism, and a cull detecting mechanism can be installed. In addition, the overall cost can be reduced and the mold can be prevented from being damaged.

Further, it is possible to install the tablet forming mechanism and the tablet supplying mechanism for cleaning in the sealing and forming apparatus, so that there is an effect that the type can be changed and the workability is improved.

[Brief description of the drawings]

FIG. 1 is a cutaway perspective view of a main part of a sealing molding apparatus according to a first embodiment of the present invention.

FIG. 2A is a cross-sectional view of a main part showing a resin-sealed portion after the molding. FIG. 2B is a cross-sectional view of a main part showing a resin-sealed portion before the molding.

FIG. 3 is a cross-sectional view showing the movable plunger in a normal position in a mold open state of the device.

FIG. 4 is a cross-sectional view showing the movable plunger at an abnormal position in a mold open state of the apparatus.

FIG. 5 is a hydraulic control operation diagram of a plunger by the same device.

FIG. 6 is a perspective view of a main part showing a cull removing mechanism in the apparatus.

FIG. 7 is an enlarged side view of a main part of the mechanism.

8 (a) and 8 (b) are enlarged cross-sectional views of main parts of the mechanism.

FIG. 9 is a plan layout diagram showing a sealing molding apparatus according to a second embodiment of the present invention.

FIG. 10 is a perspective view showing a main part of a conventional sealing molding apparatus.

11A is a cross-sectional view showing the operation of the plunger before resin injection of the same apparatus. FIG. 11B is a cross-sectional view showing the operation of the plunger of the same apparatus at the time of ejection.

FIG. 12 is a layout diagram of a cull and a runner with respect to the same two-lead frame.

FIG. 13 is a front view showing a main part of the device in cull cutting;

[Explanation of symbols]

 Reference Signs List 1 lower cavity 2 tablet 3 ejector pin 4 plunger 5 lower cavity block 6 ejector plate 7 plunger plate 8a pilot hole 8b pilot pin 9 constituent block 10 forming element 11 lead frame 12 upper cavity block 13 holder 14 upper cavity 15 cull 16 runner 17 Movable plunger 18 Hydraulic constant pressure pin 19 Hydraulic block 20 Molded body 21 Cal 22 Compression spring 23a, 23b Sensor 24 Runner 25 Lower pot 26 Upper pot 27 Gate 28 Runner 29 Gate 30 Runner cutting lower mold 30a Runner cutting upper mold 31, 31a Air cylinder 32 Drive roller 33 Chute 34 Hoop holding roller 35 Cutting wheel 36 Pin roller 37 Pin roller 38 Servo Motor 39 Timing pulley 40 Timing belt 41 Chute 42 Cul plate 43 Mold upper mold 43a Crown 44 Mold lower mold 44a Platen 45 Tablet molding mechanism 46 Shutter 47,51 Conveyor 48,49 Photoelectric switch 50 Parts feeder 52 Escape slider 53 Direct robot 54 Tablet supply mechanism 55 Cleaning mechanism 56 Molding die 57 Platen 58 Hoop feed mechanism 59 Rotating plate 60 Sensor

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) B29L 31:34 B29L 31:34 (72) Inventor Keizo Nakagawa 1006 Kadoma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. In-house (72) Inventor Hiroaki Higashino 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (10)

[Claims] 1. A molding die including a cavity for transferring a strip or hoop-shaped lead frame on which a forming element constituting a molded body is mounted and performing resin sealing on the forming element of the lead frame; A plunger for injecting and filling a tablet-shaped molding resin from the pot of the molding die into the cavity, and actuated in response to the movement of the plunger; at the time of molding resin injection, immediately before completion of filling or after filling, A sealing molding device provided with a movable plunger that presses and holds the molding resin at a predetermined pressure by hydraulic pressure at the timing of (1). 2. The sealing molding apparatus according to claim 1, wherein a predetermined pressure is applied to the plunger corresponding to the movable plunger using hydraulic pressure so as to inject or hold molding resin. 3. The sealing molding apparatus according to claim 1, wherein the plunger and the movable plunger serve as an eject mechanism for releasing a cull formed by their operation. 4. The sealing molding apparatus according to claim 1, wherein resin burrs attached to the sliding surfaces of the movable plunger and the pot are removed by cleaning and suctioning with a brush. 5. A detection mechanism for switching the pressure inside a hydraulic mechanism for driving a movable plunger to a low pressure at a predetermined timing and detecting whether or not the subsequent operation of the movable plunger is affected by sliding resistance. The sealing molding device according to claim 4, which is added. 6. A resin sealing molding of a forming element mounted on a two-section strip or hoop-shaped lead frame, wherein a pot and a runner are connected to the lead frame so that the resin flows evenly into all the cavities. The sealing molding device according to any one of claims 1 to 5, which is arranged near both side ends. 7. A cull removing mechanism comprising a roller for bending and cutting a cull and a roller for supporting and conveying the lead frame is provided in the middle of the conveyance of the lead frame discharged from the molding die. The sealing molding apparatus according to any one of the above. 8. The encapsulation molding according to claim 1, further comprising a tablet molding mechanism for molding a powdered resin into a tablet in order to supply a tablet-shaped molding resin into a pot of a molding die. apparatus. 9. The method according to claim 1, further comprising a mechanism for continuously supplying the cleaning resin tablet and the release resin tablet into a pot of the molding die for cleaning the molding die. Seal molding equipment. 10. In a molding of a hoop-shaped lead frame having a plurality of culls, a mechanism for detecting whether there is a mold release defect after molding or the occurrence of cull damage during transport of the lead frame before the next cycle molding is provided in a molding die. The sealing molding device according to any one of claims 1 to 9, which is added.