JP3166404B2 - Transfer molding die and method of attaching / detaching pot in transfer molding die - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer molding die used for sealing a semiconductor element provided on a lead frame with a resin, and a method of attaching and detaching a pot in the transfer molding die.

[0002]

2. Description of the Related Art Conventionally, as a transfer molding die of this type, a plurality of cavities, one pot for heating and melting a resin tablet supplied from the outside, and a resin melted in the pot are supplied to each cavity. And a driving mechanism for driving the plunger, a one-pot type plunger has been used. However, in this one-pot transfer mold, if the number of cavities is increased in order to improve productivity, the amount of resin charged in the pot increases, and it takes time to melt the resin. Also, the length of the melting passage from each of the cavities to the respective cavities becomes extremely non-uniform, which causes variations in the pressure and temperature of the resin before filling into each of the cavities. In addition, there is a problem that the quality of the molded product in each cavity varies. Therefore, in order to solve this problem, a multi-pot type transfer molding die is provided in which a plurality of pots are provided to reduce the amount of resin melted in each pot and to make the length of each resin passage as uniform as possible. It has been developed.

[0003]

In each of the above pots, the plunger slides along the inner peripheral surface thereof.
Tool steel (for example, SKD11) is hardened and chromium-plated, or wear resistance is increased by using a cemented carbide. Is worn, and backlash occurs with the plunger. Then, when the play is generated between the pot and the plunger, a problem arises in that air is entrapped in the molten resin supplied into the cavity, which adversely affects the quality of the molded product. The pot is replaced by disassembling the mold. In this case, since the pot is mounted between the chase defining the cavity and the template supporting the chase, if the chase is removed from the template, the pot can be replaced for the time being. Although it is a structure that can be done, in fact, if you remove the chase, many projecting pins stand from the template, and these projecting pins are in the way and you can not replace the pot There is a problem.

The present invention has been made in view of the above circumstances, and an object of the present invention is to allow a worn pot to be easily replaced without being disturbed by a protruding pin. It is an object of the present invention to provide a transfer molding die and a method of attaching and detaching a pot in the transfer molding die, which can smoothly and reliably perform the transfer.

[0005]

In order to achieve the above object, in the transfer molding die of the present invention, a cavity is formed between an upper die and a lower die, and a pot is formed in a through hole of the lower die. A transfer molding die that is mounted and a plunger is movably provided in the pot, and that extrudes a tablet loaded in the pot by the plunger and supplies molten resin into the cavity. The lower end of the pot is fixed to the lower surface of the lower die by fastening means, and a mounting plate is attached to the lower surface of the lower die. Further, in the method of attaching and detaching a pot in the transfer molding die of the present invention, a cavity is formed between an upper mold and a lower mold, a pot is mounted in a through hole of the lower mold, and a plunger is inserted in the pot. A method of detachably attaching and detaching the pot of the transfer molding die, which is provided movably, and extrudes the tablet loaded in the pot by the plunger to supply the molten resin into the cavity. In the above, while the engagement state of the mounting plate attached to the lower surface of the lower die and the lower die is released, and the upper die and the lower die are engaged with each other, the upper die and the lower die are Separated from the mounting plate, the lower surface of the lower mold is exposed, and the pot fixed to the lower surface of the lower mold by fastening means is removed from the lower mold by removing the fastening means. One in which Nuku come.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In these figures, reference numeral 10 denotes an upper die, and the upper die 10 is provided so as to be vertically movable relative to a lower die 20. In the upper mold 10 and the lower mold 20, the mold plates 102, 202 are provided on the base plates 100, 200 via the spacers 101, 201, respectively, and the mold supports 103,
203, and these mold supports 103, 20
3. Center dies 104 and 204 and product dies 105 and 205
Are fitted, and these molds 104, 105,
Protruding mechanisms 106 and 206 for releasing the solidified resin and the molded product in the resin passage from the molds 204 and 205 are provided, while the base plate 200, the protruding mechanism 206, and the mold plate 2 are provided.
02, the mold support 203 and the center mold 204 are provided with a large number (2 rows × 8 = 16) of pots 207.

The protruding mechanism 106 is provided on the base plate 10.
0, and a protruding plate 106a and a holding plate 106b movably provided in the mold opening / closing direction between the pressing plate 106b and the pressing plate 106b. Template 102, mold support 1
03 and the protruding pins 106c, 106d, and 106e penetrating the center mold 104 or the product mold 105, and are mounted between the base plate 100 and the protruding plate 106a.
A projecting spring 106f for biasing the projecting plate 106a, a biasing device 106g movably provided on the projecting plate 106a and abutting against a base end surface of the projecting pin 106c, The shock-absorbing spring 10 provided between the plate 106a and the urging tool 106g to urge the urging tool 106g toward the protruding pin 106c
6h. The protruding pin 106c is provided to face the pot 207, and is formed in the resin mold portion 104a formed in the center mold 104.
This is for releasing the solidified resin in the mold. In the drawing, reference numeral 106i denotes the protruding plate 106a, the holding plate 1
06b and a return pin for returning the protruding pins 106c to 106e to their original positions.

The protruding mechanism 206 is provided on the base plate 20.
0 and the mold plate 202, and a protruding plate 206a and a holding plate 206b movably provided in the mold opening and closing direction, and a base end portion sandwiched between the pushing plate 206a and the holding plate 206b. Template 202, mold support 2
03 and the protruding pin 206 penetrating the product mold 205
c, 206d, provided on the protruding plate 206a,
And a projecting rod 206e for urging the projecting plate 106a, the mold plate 202 and the projecting plate 206a.
And a return spring 206f for returning the projecting plate 206a to its original position. The protruding plate 206a and the holding plate 206b
The protruding pins 206c and 206d are pushed out toward the upper die 10 by a protruding member 206g via a protruding rod 206e, and a return spring 206 is provided.
f and a return pin (not shown) sandwiched between the protruding plate 206a and the holding plate 206b, so that the upper die 10 returns to the original position.

Each of the above-mentioned pots 207 includes an upper pot body 207.
The lower end of a is screwed into the upper end of the lower pot body 207b, and a flange 207c is formed above the screw portion of the upper pot body 207a. A flange 207d is formed at the lower end of the lower pot body 207b. The flange portion 207d is mounted in the base plate 200, and is attached to the base plate 200 by mounting bolts 207e inserted from below the base plate 200.
It is fixed to. Further, each of the pots 207 includes
Plunger 30 of plunger unit 30 from below
0 is inserted, each plunger 300 is connected to one pressing plate 301, and each plunger 300 pushes out the resin tablet in the pot 207 by the movement of the pressing plate 301. Furthermore, the mounting plate 302 of the plunger unit 30 is attached to the base plate 200.
Are mounted by mounting bolts 40.

In the transfer molding die configured as described above, when the resin tablet is loaded into the pot 207, the resin tablet is extruded by each plunger 300, so that each center mold 1 is extruded.
After the molten resin is supplied into the cavities formed between the product dies 105 and 205 through the resin passages formed in the product dies 104 and 204 and the product dies 105 and 205, a molded product is formed in the cavities. In the opening process, the protrusion mechanism 1
In addition, the projecting pins 106c, 106d, and 106e release the solidified resin and the molded product in the resin passage from the center pool 104 of the upper die 10 and the resin reservoir 104a of the product mold 105, and the projecting mechanisms 206 project. The product mold 2 of the lower mold 20 is set by the pins 206c and 206d.
From 05, the solidified resin and the molded product are released from the mold and collected. When the inner peripheral surface of the pot 207 is worn due to repeated molding and needs to be replaced, the upper mold 10 and the lower mold 20 are connected by the connecting tool 41 in the mold clamped state, and the mounting bolt 40 After separating the base plate 200 and the mounting plate 302 of the plunger unit 30, the lower die 20 is lifted up together with the upper die 10 to expose the lower surface of the base plate 200 of the lower die 20. Let it. Next, by removing the mounting bolt 207e, the base plate 200 and the flange 207 of the pot 207 are removed.
d, the pot 207 is pulled out downward, a new pot 207 is attached, and the mounting bolt 20 is removed.
7e, it is fixed to the base plate 200. In this case, the upper pot body 207a is the lower pot body 2
Because it is configured to be screwed into the 07b and separable,
It is also possible to replace only the upper pot body 207a, which is heavily worn due to the clearance with the plunger 300 and which exclusively affects the entrainment of air into the molten resin.

[0012]

As described above, in the transfer molding die of the present invention, the lower end of the pot is fixed to the lower surface of the lower die by fastening means, and the mounting plate is attached to the lower surface of the lower die. In addition, the method of attaching and detaching the pot in the transfer molding die of the present invention releases the engagement state between the mounting plate attached to the lower surface of the lower die and the lower die, as well as the upper die and the lower die. In a state in which the mold is engaged, the upper mold and the lower mold are separated from the mounting plate, the lower surface of the lower mold is exposed, and a pot fixed to the lower surface of the lower mold by fastening means, By removing the fastening means, the lower mold is pulled out from the lower mold, so that the worn pot can be easily replaced without being disturbed by the protruding pins, so that the pot replacement work can be performed smoothly and smoothly. Surely It can be.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of the present invention.

FIG. 2 is a sectional view showing an example of an upper die.

FIG. 3 is an explanatory diagram of FIG. 2 as viewed from a mating surface side.

FIG. 4 is a sectional view showing an example of a lower mold.

FIG. 5 is an explanatory view of FIG. 4 as viewed from the mating surface side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Upper die 20 Lower die 41 Connector 207 Pot 207d Collar part 207e Mounting bolt 300 Plunger 302 Mounting plate

Claims (2)

(57) [Claims] 1. A cavity is formed between an upper mold and a lower mold, a pot is mounted in a through hole of the lower mold, and a plunger is movably provided in the pot. In a transfer molding die for extruding the loaded tablet by the plunger and supplying the molten resin into the cavity, a lower end of the pot is fixed to a lower surface of the lower die by fastening means. A transfer molding die, wherein a mounting plate is attached to a lower surface. 2. A cavity is formed between an upper mold and a lower mold, a pot is mounted in a through hole of the lower mold, and a plunger is movably provided in the pot, and is provided in the pot. In a method of exchanging the pot of the transfer molding die for extruding the loaded tablet with the plunger and supplying the molten resin into the cavity with respect to the lower die, the mounting attached to the lower surface of the lower die The upper mold and the lower mold are disengaged from each other while the upper mold and the lower mold are engaged with each other, and the upper mold and the lower mold are separated from the mounting plate to expose the lower surface of the lower mold. Then, the pot fixed to the lower surface of the lower mold by the fastening means is pulled down from the lower mold by removing the fastening means in the transfer molding die. How to attach and detach a pot.