JP2795526B2 - Transfer mold machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a transfer molding machine having a tablet preheating device.

(Conventional technology) When a semiconductor element mounted on a lead frame is resin-encapsulated by a transfer molding machine, a resin tablet is supplied to a mold pot, the resin tablet is heated and melted, and the molten resin is poured into a mold cavity. Press and mold.

In recent transfer molding machines, there is a type in which lead frames are arranged on both sides of a pot, and molding is performed using a tablet for each of a pair of opposed molding portions. This type of transfer molding machine has advantages in that the temperature of the tablet rises in a short time after the tablet is supplied to the pot, so that the molding cycle can be shortened and the moldability is good.

(Problems to be Solved by the Invention) However, as the size of the resin encapsulation increases with the increase in the size of the semiconductor element, a large tablet has recently been used. The problem of moldability has arisen.

In other words, the larger the tablet, the more air and moisture are contained in the tablet.When molding with this, air and moisture are mixed into the tablet, resulting in poor molding and complete sealing of the resin. Otherwise, it may cause defects such as lowering the moisture resistance of the mold portion.

In addition, if the tablet becomes large, the temperature will not rise immediately even when it is supplied to the mold pot, and the molding cycle will not be sufficiently shortened. In some cases, the tablet is forcibly molded before melting.

Therefore, even when a tablet is used, it is required to improve the moldability by preheating and then supplying it to a mold pot. In this preheating, it is required that the core of the tablet is heated effectively.

The transfer molding machine as described above must handle a large number of tablets inevitably, so the structure of the transfer molding machine must be complicated, but the device can be designed as compact as possible and the tablet once preheated Is required to be quickly transferred to a mold so that the temperature of the mold does not drop.

Therefore, the present invention has been made in view of the above-mentioned problems, and an object thereof is to reliably and easily preheat a tablet in a stable state at a heating position, to design a compact device configuration, and An object of the present invention is to provide a transfer molding machine capable of quickly transferring a tablet to a mold.

(Means for Solving the Problems) The present invention has the following configuration to achieve the above object.

That is, in a transfer molding machine having a transfer mechanism capable of transferring a tablet held in accordance with a pot arrangement of a mold, the transfer mold is disposed below the transfer mechanism in accordance with the pot arrangement of the mold, and A guide tube formed in a cylindrical shape that allows the tablet to pass therethrough, an electrode plate disposed opposite to the periphery of the guide tube, a high-frequency heating device that heats the tablet passing through the guide tube, and the guide tube And a holder having an accommodating hole for accommodating the tablet, and a tablet disposed below the holder and accommodated in the accommodating hole of the holder and pushed up through the guide cylinder to move the tablet. A push-up bar to be delivered to the loading mechanism, a drive unit that moves the push-up bar up and down, and a rotation unit that rotates the push-up bar around the axis of the guide cylinder. Characterized by comprising a mechanism.

(Operation) The tablet housed in the housing hole of the holder is pushed up from below by moving the push-up bar upward by the drive unit, pushed up to the heating position in the guide cylinder, and temporarily stopped.
The rotating mechanism performs preheating by the high frequency heating device while rotating the push-up bar at the heating position to rotate the tablet in the guide cylinder in a stable state. After the heating is completed, the push-up bar is further moved upward to transfer the tablet to the transfer mechanism. Since the accommodation hole of the tablet, the guide cylinder and the push-up bar are arranged on the same axis, the installation area can be reduced and the device configuration can be made compact. Further, since the transfer operation of the tablet from the holder through the heating position to the transfer to the transfer mechanism is performed consistently by the push-up bar, it is possible to contribute to shortening of the cycle time of the resin molding operation. In addition, the preheated tablet can be quickly transferred without cooling.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The transfer molding machine according to the present invention is characterized in that a tablet preheating device is additionally provided. FIG. 1 shows a preheating device for this tablet, and also shows a setting section for setting a lead frame in accordance with the arrangement of a mold.

In the apparatus of the embodiment, the lead frame is preheated simultaneously with the tablet, and the transfer mechanism moves the lead frame and the tablet in parallel on the mold and transfers them.

 Hereinafter, each part of the apparatus of the embodiment will be described in order.

(Preheat section)

The preheating apparatus of the embodiment is used for a molding apparatus in which pots are arranged in two rows in a mold. In this preheating apparatus, the tablets are arranged in two rows in accordance with the arrangement of the molds, and are preheated.

As shown in FIG. 1, the preheating device is installed below a lead frame set portion, which will be described later, and has a box-shaped heating portion 10 having an interior formed in a hollow space, and a lower surface of the heating portion 10. It comprises a connected waveguide 12 and a high-frequency generator 14 to which the waveguide 12 is connected. The high frequency generator 14 has a built-in transmission tube, power supply, and the like. The waveguide 12 is detachable with respect to the high frequency generator 14.

A rod-shaped electrode 16 extends from the high-frequency generator 14 through the waveguide 12 to the center of the heating unit 10. Electrode 16
The supporting electrode 18 extends in the lateral direction by being connected to the top of the support electrode 18, and the electrode plates 20a and 20b are fixed to both extending ends of the supporting electrode 18.

The electrode plates 20a and 20b serve as one electrode of the high-frequency circuit, but are fixedly supported on the lower surface of the heating unit 10 so as to be opposed to and parallel to the respective electrode plates 20a and 20b.
Install a and 22b. Since the guide tube 24 is provided between the electrode plates, the electrode plates 20a and 22a and the electrode plates 20b and 22b are provided with an interval for installing the guide tube 24.

FIG. 2 shows the supporting electrode 18, the electrode plates 20a and 22a and the guide cylinder.
24 shows a plan layout. As shown in the figure, the electrode plates 20a and 22a are formed in an elongated plate shape, and a plurality of guide cylinders 24 are arranged in the longitudinal direction. The guide cylinders 24 are arranged in two rows in the heating unit 10, and the interval between the rows of the guide cylinders 24 corresponds to the pot arrangement of the mold used in the transfer molding. And match the pot arrangement.

In an actual operation, various lead frames are resin-sealed, so that the number of arranged pots differs depending on the mold. Therefore, the guide cylinder 24 is configured to be detachable so that the arrangement and the number of the guide cylinders 24 can be changed according to the pot arrangement, and the diameter size of the guide cylinder 24 also depends on the size of the tablet to be used. It is variable.

As shown in FIG. 1, the guide tube 24 is installed so as to penetrate the upper and lower surfaces of the heating unit 10, and the upper end and the lower end of the guide tube 24 are fixed to the upper and lower surfaces of the heating unit 10 by a fixing member 26. As shown in FIG. 2, each guide tube
A through hole 28 is provided in accordance with the arrangement of 24.

[Tablet support mechanism]

One tablet is inserted into each of the guide cylinders 24 and preheated, but in order to support the tablet in each guide cylinder 24, a push-up bar 30 is provided below the heating unit 10.
A drive unit for reciprocating the push-up bar 30 up and down is provided.

The push-up bars 30 are arranged one by one in each guide tube 24, and move up and down in the axial direction of the guide tube 24. In the embodiment, since six guide tubes 24 are provided in each row, six push-up bars 30 are also provided. This push-up bar 30 is also a guide cylinder
Like the case 24, the guide tube 24 is detachable, and is variably configured according to the number and positions of the guide tubes 24.

The push-up bar 30 is provided with a rotation mechanism for rotating the push-up bar 30 around an axis. 31 is a rotation guide of the push-up bar 30, 32 is a rotary connection pulley for connecting the push-up bar 30 to the rotation drive unit, and 33 is a rotation actuator.

The lifting position of the lifting bar 30 is appropriately controlled by the control unit, and the rotation actuator 33 is drive-controlled.

That is, when preheating the tablet, the push-up bar 30 moves up to the heating position in the guide cylinder 24, and at that position, the rotation actuator 33 is driven, and the push-up bar 30 is rotated around the axis. As a result, the tablet rotates in the guide cylinder 24 and is heated at a high frequency. If the upper end surface of the push-up bar 30 is formed on the uneven surface 30a as shown in FIG. 3, it is preferable that the tablet stably rotates by itself.

Rotation actuator at the end of preheating
The drive of 33 is stopped, and the lifting bar 30 is raised to the setting section above the heating section 10.

The device that supplies tablets to the preheating device is the first
The holder 34 of the tablet is transferred from the back side to the front side below the row of the guide cylinders 24 at the back side of the apparatus shown in the figure, and the holder 34 is stopped at a predetermined position below the guide cylinder 24, and the holder 34 Push up the tablet with the push-up bar 30. holder
Numeral 34 denotes a row of accommodation holes for accommodating a tablet in accordance with the arrangement of the guide cylinder 24. The tablet is housed in the housing hole of the holder 34 in the previous step, and the holder 34 is guided to the support rail 36 and moved to below the guide cylinder 24. During preheating, the push-up bar is attached to the holder 34.
30 is inserted. After one cycle in which the push-up bar 30 returns from the upper position to the original lower position, the holder 34 returns to the back side to accommodate the next tablet for preheating.

[Set part of lead frame]

 Next, the setting portion of the lead frame will be described.

In FIG. 1, 40 is a turntable, and 42 is a fixed table. On the turntable 40 and the fixed table 42, the lead frame mounting portions 44a, 44b, 44c, and 4 on which the lead frames are mounted in accordance with the arrangement intervals of the lead frames on the mold.
4d is provided. Since the pot is arranged in the middle of the two opposing lead frames, when the guide cylinder 24 is viewed in a plane arrangement, the guide tube 24 is located between the lead frame placement sections 44a and 44b and the lead frame placement section 44c. And 44d are located in the middle. Reference numeral 46 denotes a tablet guide provided on the turntable 40 and the fixed table 42.

In this setting section, a heater 48 is provided below the turntable 40 and the fixed table 42 so that the lead frame can be heated in advance, so that the moldability during resin sealing is enhanced.

A transfer mechanism for transferring the lead frame and the tablet onto the mold is provided above the setting section. In the embodiment, the mold is arranged on the side of the set portion, and the mounting surface of the mold and the set portion are set at substantially the same height. The transfer mechanism is configured to transfer the lead frame and the tablet to the die by moving the lead frame and the tablet in a horizontal direction without changing the mutual positional relationship.

In the embodiment, the transfer mechanism is also provided with a mechanism for transferring the lead frame from the turntable to the fixed table. The lead frame set part was constituted by the turntable 40 and the fixed table 42 as described above,
This is because, on the mold, the lead frames must be arranged to face each other with the respective pots interposed therebetween. For this reason, the turntable 40 is set so as to rotate 180 ° at a time, and the lead frame is set by the following operation.

That is, the lead frame is supplied only from one of the mounting portions of the turntable 40. First, the lead frame is mounted on the mounting portion 44a, and the turntable 40 rotates by 180 °. In this state, the mounting portion 44b of the turntable 40 is located at the supply position of the lead frame.
put on b. When the two lead frames are placed on the turntable 40, the lead frame is transferred from the turntable 40 to the fixed table 42 by the transfer mechanism. At this time, the turntable 40 reverses and returns to the original position. Next, the lead frame is placed on the mounting portion 44a of the empty turntable 40, and the turntable 40 is rotated by 180 ° and the lead frame is mounted on the mounting portion 44b. In this way, the lead frames are set facing each other on the placement units 44a and 44b and the placement units 44c and 44d.

In the preheating apparatus, the tablet is pushed up from the holder 34 into the guide cylinder 24 by the push-up bar 30 while the lead frame is being set in the setting section, and is preheated while rotating by high frequency heating. High-frequency heating has the effect of heating the tablet evenly to the core, which can effectively remove water and the like contained in the tablet. In the embodiment, the guide tube 24
The tablet can be preheated more uniformly by rotating the tablet inside. The guide tube 24 is connected to the plate-like electrode plates 20a, 22
When the tablet is sandwiched between a, 20b, and 22b, directionality appears in the heating property of the tablet, but by rotating the tablet, this directionality can be eliminated and uniform preheating can be performed.

After the setting and heating of the lead frame are completed and the tablet is preheated, the tablet is pushed up to the setting section by the push-up bar 30, passes through the guide section 46, and is held by the upper transfer mechanism. The holding operation by the transfer mechanism is performed in synchronization with the mold operation on the mold side so that the tablet and the lead frame do not cool down during transfer to the mold.

The tablet supplying operation and the heating operation are performed during the resin sealing operation with the mold, and the resin sealing operation is continuously and automatically performed by repeatedly performing the above operation.

As shown in FIG. 1, the preheating apparatus according to the present embodiment is installed in a space below the lead frame set portion, and has a feature that the space arrangement can be designed to be extremely compact. In addition, since the tablet is heated by high frequency heating, the tablet can be heated evenly and effectively by rotating the tablet and heating.
In addition, there is an advantage that the arrangement of the guide cylinder and the like can be appropriately changed in accordance with the arrangement of the mold pots.

The transfer molding machine according to the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and it goes without saying that many modifications can be made without departing from the spirit of the invention. .

(Effect of the Invention) The transfer molding machine according to the present invention is provided with a device for preheating by high-frequency heating, and is configured to preheat while rotating the tablet in a stable state by pushing up the tablet to a heating position in the guide cylinder. Even in the case of a large tablet, the core portion can be uniformly preheated to the core portion, moisture in the tablet can be effectively removed, and moldability during molding can be improved.

Further, since the receiving hole of the tablet, the guide cylinder, and the push-up bar are arranged on the same axis, the installation area can be reduced and the apparatus configuration can be made compact. Further, since the transfer operation of the tablet from the holder to the transfer mechanism via the heating position is performed by the push-up bar, the cycle time of the resin molding operation can be reduced. In addition, the preheated tablet can be transported quickly without cooling, and the effect is remarkable.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a main part of a transfer molding machine according to the present invention, FIG. 2 is an explanatory diagram showing the inside of a preheating unit, and FIG. 3 is an explanatory diagram showing an upper part of a push-up bar. 10 ... heating part, 14 ... high frequency generation part, 16 ... electrode, 20
a, 20b, 22a, 22b ... electrode plate, 24 ... guide cylinder, 30 ...
Push-up bar, 31 ... Rotation guide, 32 ... Rotation connection pulley,
40: Turntable, 44a, 44b, 44c, 44d: Placement for lead frame.

Claims (3)

(57) [Claims] 1. A transfer molding machine having a transfer mechanism capable of transferring a tablet held in accordance with a pot arrangement of a mold, wherein the transfer mold is arranged below the transfer mechanism in accordance with the pot arrangement of the mold. A guide tube formed in a cylindrical shape that can pass the tablet, and a high-frequency heating device that has an electrode plate disposed to face around the guide tube and heats the tablet passing through the guide tube, A holder disposed below the guide tube and having a receiving hole for receiving the tablet, and a tablet disposed below the holder and passing the guide tube by pushing up the tablet stored in the receiving hole of the holder. A push-up bar for transferring the push-up bar up and down, a drive unit for vertically moving the push-up bar, and rotating the push-up bar about an axis of the guide cylinder. Transfer molding machine characterized by comprising a rotation mechanism, the that. 2. The drive section raises the push-up bar, pushes up the tablet from the holder to a heating position in the guide cylinder, temporarily stops the tablet, and further moves up the push-up bar after the heating is completed. 2. The transfer molding machine according to claim 1, wherein the tablet is transferred to the transfer mechanism by a transfer. 3. The high frequency heating device according to claim 1, wherein the rotation mechanism drives the push-up bar stopped at the heating position to rotate the tablet in the guide cylinder, and performs heating by the high-frequency heating device. 2. The transfer molding machine according to 2.