JP3304453B2 - Mold release mechanism for molded products of resin sealing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin sealing device, and more particularly to a release mechanism for releasing a molded product after resin molding.

[0002]

2. Description of the Related Art When molding a molded product such as a lead frame with a semiconductor sealing device, the molded product is clamped by an upper mold and a lower mold, filled with resin, and then opened to mold the molded product. Take out from. Since the resin filled in the cavity adheres to the mold and cures, in a conventional apparatus, a molded product is pushed with an eject pin when the mold is opened, and the molded product is released from the mold and taken out.

FIG. 2 is an explanatory view showing a release mechanism of a molded product in a conventional semiconductor sealing device. In the drawing, reference numerals 10 and 12 denote an upper cavity block and a lower cavity block, respectively, and the eject pins 14 are arranged at the inner bottom surface of the cavity 16 so as to be freely inserted and removed according to the position of each cavity 16. Reference numeral 15 denotes an eject pin for projecting the cull portion. The eject pins 14 and 15 are supported upright on an eject plate 18 on the back side of the cavity block. Reference numeral 20 denotes a return pin that stands on the eject plate 18 toward the facing mold surface. Return pin 20
The spring 2 which is brought into contact with the opposite mold surface when the mold is clamped, and which is built into the eject plate 18 by the mold clamping force.
The eject plate 18 is moved backward while compressing the ejector 2 to move the eject pins 14 and 15 to the retracted position.

FIG. 2 shows a state in which the mold is clamped and the eject pin 14 is retracted to a position flush with the inner bottom surface of the cavity. In this state, the cavity is filled with resin and molded. When the mold is opened after the resin molding, the upper mold first rises, and at this time, the eject plate 18 pushed up at the time of mold clamping is pushed down by the elastic force of the spring 22, and the eject pins 14 and 15 are pushed out with this. Then, the molded product is released from the upper cavity block 10 and left on the lower cavity block 12 side. And
By further opening the mold, the lower cavity block 1
The molded product adhered to 2 is pushed up by the eject pin 14 on the lower mold side and released from the mold, and the molded product is taken out. Since the lower die is fixed in the upper die movable type press device, a return pin 23 for driving an eject pin in the lower die and a hydraulic drive device for operating the return pin 23 are provided.

[0005]

As described above, in the conventional resin sealing device, the eject pin protrudes and separates with the mold opening, and the eject pin follows the mold opening by utilizing the spring force. It protrudes. The method of following the movement of the eject pin to the opening of the mold as described above is effective as a method of opening the mold while leaving the molded product in the other mold. However, in the case of the conventional apparatus, after the mold is opened, the eject pin remains protruding from the mold surface due to the elastic force of the spring 22, which causes a problem when cleaning the mold surface.

Further, in the conventional apparatus, since both the eject pin 14 and the spring 22 are provided on the eject plate 18, the strength of the eject plate 18 is reduced, and the deformation of the eject plate 18 lowers the positional accuracy of the end face of the eject pin. There was a problem. For example, in the case of a resin-sealed type lead frame, the eject plate 18
Since the eject pins 14 are installed for each cavity, the number of the eject pins 14 installed on the eject plate 18 becomes a considerable number. In order to arrange the springs 22 in the installation space of these eject pins 14, There was a problem that the design of the mold became difficult.

Further, when adjusting the amount of protrusion of the eject pin 14 by a conventional device, a spacer is arranged in the moving position of the eject plate 18, but the mold is disassembled for this adjustment. And the adjustment work is troublesome. The present invention has been made in order to solve these problems, and an object of the present invention is to increase the precision of a product, to facilitate the design of a mold, and to easily perform cleaning of a mold. An object of the present invention is to provide a release mechanism for a molded product of a stop device.

[0008]

The present invention has the following arrangement to achieve the above object. That is, in a mold release mechanism of a molded product of a resin sealing device for releasing a molded product using an eject pin, the eject pin is erected on an eject plate movably installed in the mold opening and closing direction to open and close the mold. A push mechanism for pushing the eject plate by motor drive is provided separately from the drive mechanism for performing the operation, and the eject mechanism is pushed to control the push mechanism in accordance with opening / closing of a mold, resin filling operation, and the like. A control mechanism is provided. Further, at the time of opening the mold, the eject plate and an eject plate drive plate pushed by a motor drive are provided in a mold on the side from which the molded product is first released, and the eject plate and the eject plate drive plate are provided. And a spring which is pressed by an eject plate driving plate at the time of mold clamping to elastically press the eject plate.

[0009]

According to the present invention, the ejection of the eject pin is controlled by controlling the pushing operation of the eject plate pushed by a pushing mechanism provided separately from the driving mechanism for opening and closing the mold in accordance with a resin sealing operation such as opening and closing of the mold. Control and perform proper resin sealing. A spring is installed between the eject plate and the eject plate drive plate, and by applying a compressive force to the spring when clamping the mold to maintain the elastic force, the eject pin is projected to follow the mold opening and the mold From the mold.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is an explanatory view showing a mold release mechanism of a molded product of the resin sealing device according to the present invention. In the figures, 10 and 12 are an upper cavity block and a lower cavity block, 14a is an upper eject pin, and 14b is a lower eject pin. Eject pin 14a, 1
Reference numeral 4b stands on the eject plates 18a and 18b so as to be slidable in through holes formed in the cavity block in accordance with the position of the cavity 16. Reference numeral 20 denotes a return pin erected on the upper eject plate 18a, which is slidable in a through hole provided in the upper cavity block 10.

The upper eject plate 18a is elastically connected via a spring 32 to an eject plate driving plate 30 which pushes the eject plate 18a. The spring 32 is installed in a cylinder body 34 provided on the upper surface of the eject plate 18a. The end surface of a support rod 36 fixed to the eject plate driving plate 30 contacts the upper part of the spring 32 in the cylinder body 34 and The space between the eject plate drive plates 30 is resilient. The support rod 36 is guided and supported by the upper base 38, and is provided with an enlarged flange 36a on the lower end surface in the cylinder body 34 so as to engage with the reduced-diameter opening of the cylinder body 34. .

The lower end of a ball screw 40 is rotatably mounted and supported on the upper base 38, and the ball screw 40 is screwed and mounted on the eject plate driving plate 30.
A pulley 42 is attached to an upper shaft of the ball screw 40, and is driven by a servomotor 44 as a belt. The lower eject plate 18b supports the side surface by the support plate 50, and connects the eject plate drive plate 52 and the eject plate 18b by the support plate 50. Reference numeral 54 denotes a ball screw which is rotatably attached to the lower base 56 at an upper end thereof and is screwed to the eject plate driving plate 52. The ball screw 54 is also rotationally driven by the servo motor. The ball screws 40 and 54 both set the amount of rotation and the like by controlling a servomotor.

The resin sealing device of the present embodiment is characterized in that the ejecting pins 14a and 14b are controlled by a servomotor for projecting and retracting. However, in the embodiment, the upper eject pin 14a is configured to be released by a spring force in order to take advantage of the operation of the conventional eject pin. The operation of the eject pin in the resin sealing device of the above embodiment will be described. First, the cavity 16 is filled with resin in the mold-clamped state shown in FIG.
When 0 contacts the mold surface of the lower cavity block 12, the drawing position is defined. Although the end face of the eject pin 14a substantially coincides with the inner bottom face of the cavity 16, the position control of the end face of the eject pin 14a is adjusted by the relationship between the length of the eject pin 14a and the return pin 20.

On the other hand, the position of the end face of the lower eject pin 14b is defined by the moving position of the eject plate 18b.
The height of the eject plate driving plate 52 is adjusted by controlling the amount of rotation of the eject plate. In this clamped state, the upper plate eject plate drive plate 30 is at a position where the spring 32 is compressed. That is, in the mold clamping state, the servo motor 44 is driven to press the eject plate driving plate 30 downward, and the eject plate driving plate 30 is stopped in a state where a compressive force is applied to the spring 32.

When the resin filled in the cavity 16 has hardened, the operation proceeds to the mold opening operation. In the mold opening operation, the upper mold is first lifted, and as the upper mold rises, the eject pin 14a starts to protrude. This eject pin 1
The movement of 4a is exactly the same as the operation of the eject pin using the conventional spring force. The eject plate 18a always urges the eject pin 14a downward when the mold is opened by the elastic force of the spring 32, and this urging force follows the amount of mold opening of the upper mold and the eject pin 14a.
a so as to protrude a. The molded product is released from the upper cavity block 10 by the eject pins 14a protruding with the opening of the mold, and remains in the lower cavity 12 to open the mold.

The release operation utilizing the elastic force of the spring 32 is effective in that the release operation can be performed following the mold opening. The eject pin 14a can be protruded by pushing the eject plate 18a with the servo motor 44 in accordance with the mold opening without using the spring 32, but it is easier to use the elastic force of the spring 32. Therefore, there is an advantage that accurate control is possible.
For example, even when the mold opening speed varies depending on the product or the like, it is possible to accurately cope with the case where the spring force is used.

The eject pin 14a protrudes to release the compressive force of the spring 32, and when the flange 36a of the support rod 36 comes into contact with the opening of the cylinder body 34, the ejection of the eject pin 14a is completed. Ascend to position. On the other hand, lower mold cavity block 1
The molded article adhering to 2 is released by pushing up the lower eject plate 18b. The molded product after the mold release is taken out by the chuck mechanism.

The lower eject pin 14b is thus directly connected to the drive of the ball screw 54, and moves up and down by servo drive. Therefore, when cleaning the mold after molding, the eject plate 18b is lowered, and the upper end surface of the eject pin 14b is aligned with the inner bottom surface position of the cavity 16. On the other hand, since the eject pin 14a of the upper mold protrudes from the mold surface after the mold release, the eject plate 18a is lifted and cleaned until the end face of the eject pin 14a coincides with the inner bottom surface position of the cavity 16. By driving the servo motor 44, the eject plate drive plate 30 is lifted, and the support rod 3
By engaging the cylinder 6 with the cylinder body 34, the eject pin 14a can be lifted as it is. Also,
If necessary, after the mold is opened, the eject pins can be slightly taken in and out of the cavity before cleaning, and resin residues adhering to the periphery of the eject pins can be removed to improve the gas release from this portion.

According to the apparatus of this embodiment, the eject pins 14a, 14b
Is retracted to the retracted position, so that the mold can be properly cleaned. In addition, by operating the eject pins 14a and 14b with the mold opened, it is possible to easily confirm a malfunction of the eject pins 14a and 14b. Further, in the apparatus of the embodiment, since the spring 32 is provided outside the eject plate 18a, the eject plate 18a
The design of the eject plate 18 becomes easy.
The strength of “a” can be improved, and the protrusion amount of the eject pin and the like can be set with high accuracy, and the accuracy of the product can be improved. Further, since the protrusion amount of the eject pin can be set by an external operation, there is an advantage that the adjustment of the eject amount and the like can be easily performed. In the above embodiment, the eject pins are provided on both the upper mold and the lower mold. However, in some cases, the eject pins may be provided on only one of them.

[0020]

According to the mold release mechanism of the molded article of the resin sealing device according to the present invention, as described above, the strength of the eject plate can be improved, and thus the accuracy of the mold can be improved. This makes it possible to increase the accuracy of the product. In addition, the ejection of the eject pin from the mold surface can be controlled, so that the mold can be more appropriately cleaned. In addition, by connecting the eject plate and the eject plate drive plate via a spring, it is possible to obtain a remarkable effect such that a favorable releasability of the molded product when the mold is opened can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a release mechanism of a molded product of a resin sealing device.

FIG. 2 is an explanatory view showing a conventional example of a mold release mechanism of a molded product.

[Explanation of symbols]

 Reference Signs List 10 Upper cavity block 12 Lower cavity block 14, 14a, 14b Eject pin 16 Cavity 18, 18a, 18b Eject plate 20 Return pin 30, 52 Eject plate drive plate 34 Cylinder body 36 Support rod 40, 54 Ball screw 44 Servo motor

Claims (2)

(57) [Claims] 1. A mold release mechanism for a molded article of a resin sealing device for releasing a molded article using an eject pin, wherein the eject pin is erected on an eject plate movably installed in a mold opening and closing direction. A push mechanism for pushing the eject plate by motor drive is provided separately from a drive mechanism for opening and closing the mold, and the eject plate is controlled by controlling the push mechanism in accordance with opening and closing of the mold, resin filling operation, and the like. A mold release mechanism for a molded product of a resin sealing device, wherein a release control mechanism is provided. 2. The method according to claim 1, wherein the eject plate and an eject plate driving plate pushed by a motor are connected to a mold on a side from which a molded product is first released when the mold is opened. 2. The molded product separating device according to claim 1, further comprising a spring pressed between the plate driving plate and the eject plate driving plate when the mold is clamped to elastically press the eject plate. Type mechanism.