JP2002067071A - Method and apparatus for molding resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for molding resin which do not leave a powdery resin material to be supplied to a pot, inside a material hopper of material supply equipment or on a shoot being a passage of introduction into the pot, and consequently can prevent occurrence of a problem that a prescribed amount of material is not supplied to the pot and a problem that the material supply equipment is clogged with the material. SOLUTION: The material supply equipment A has vibrators 59 exerting vibration on the material hoppers 51 and the shoots 53. When a shutter is opened for supplying the powdery resin material 2 to the pot 1, the vibration is exerted on the material hoppers 51 and the shoots 53 by the vibrators 59.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molding method and a resin molding apparatus for transfer molding, which are used for sealing electronic parts such as semiconductor elements with resin.

[0002]

2. Description of the Related Art When encapsulating electronic parts such as semiconductor elements using a thermosetting resin such as an epoxy resin,
Conventionally, transfer molding has been generally performed. The mold of the resin molding apparatus in transfer molding is formed by providing a resin flow path such as a pot and a cavity and a runner connecting the pot and the cavity, and an injection plunger is provided in the pot so as to be able to advance and retreat. is there. Then, a resin material such as a thermosetting resin is supplied to the pot, and while the resin material is heated in the pot, the injection plunger is advanced to pressurize the resin material in the pot. The resin material is melted by pressure, the resin material is injected into the cavity from the resin flow path, and molding is performed. When the resin material to be supplied to the pot is powdery and granular, when the resin material is supplied into the pot and molding is performed, air between the particles of the resin material is wrapped around the resin material and enters the cavity together with the resin material. And void defects may occur in the molded product. Therefore, conventionally, a tablet has been prepared in which a powdery or granular resin material is pressed and compressed in advance to expel air between particles, and the tablet is supplied to a pot.
However, in the method using this tablet, a molding step for tableting is required when manufacturing the resin material, which requires man-hours for manufacturing tablets of various types of tablet diameters and weights, which causes an increase in cost. Had become. In addition, it takes a long time for the tableted resin material to be melted in the pot, which causes a problem that the molding cycle is delayed. Accordingly, the present applicant has developed a new resin molding apparatus which does not require the use of a resin material molded into a tablet and can obtain a molded product with less void defects. Japanese Patent Application Laid-Open No. 10-180792 and Japanese Patent Application Laid-Open No.
No. 0-86173 (the material supply device is not described). As a resin molding apparatus of a type in which the resin material is expelled by being compressed in the pot, as disclosed in JP-A-10-180792,
When the upper mold and the lower mold of the molding die apparatus are open, the material supply apparatus moves above the lower mold to supply the granular resin material to the pot, and is formed by opening the upper surface to the lower mold. A pot to which a granular resin material is supplied, and a resin material once compressed in the pot while melting the granular resin material supplied to the pot, and a molding material in the compressed pot is injected into a cavity. There is a resin molding apparatus including a molding die apparatus having compression and injection means. In this resin molding device, the powdery and granular resin material supplied from the material supply device to the pot is once compressed and melted in the pot to expel the air of the resin material, and the resin material that has expelled the air is subjected to a cavity. Therefore, even if a powdery resin material is used, it is possible to obtain a molded product with less void defects.

[0003]

However, in a new resin molding apparatus of the type in which the powdery resin material is melted and compressed in a pot to expel air from the resin material, a heat is supplied from the material supply device. When the powdered resin material is supplied to the pot, the resin material to be supplied to the pot remains in the material hopper of the material supply device or in the chute serving as a path for introducing the resin material into the pot. was there. This phenomenon tends to occur when the resin molding apparatus is operated continuously. That is, as shown in FIG. 5A, when the shutter 52 is in the closed state, the granular resin material 2 held in the material hopper 51 of the material supply device is removed as shown in FIG. 5B. Then, when the shutter 52 is opened and the operation of supplying the lower mold pot from the chute 53 is repeated, the powder of the resin material 2 adheres little to the inner wall of the material hopper 51 at the beginning of the operation. And continue driving, the heated upper mold,
The temperature of the material supply device rises due to the heat of the lower mold, so that the powder of the resin material 2 easily adheres to the inner wall of the material hopper 51 as shown in FIG. However, even at the initial stage of the operation, a phenomenon in which the powder of the resin material 2 adheres to the inner wall of the material hopper 51 may occur depending on the type of the powdery resin material. As described above, when a phenomenon in which the powder of the resin material 2 adheres to the inner wall of the material hopper 51 occurs, a predetermined amount of material is not supplied to the pot, or a trouble such as material clogging occurs, thereby causing molding failure. There was something to do.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a method in which the upper and lower dies of a molding apparatus are opened when the upper and lower dies are opened. A material supply device movable to the lower mold, a pot formed by opening the upper surface to the lower mold, and supplied with the granular resin material, and once in the pot while melting the granular resin material supplied to the pot. An electronic component fitted in the cavity by using a resin molding device having a molding die device having a compression and injection means for compressing the resin material and injecting the molding material in the compressed pot into the cavity. In the case of resin sealing, the powdery and granular resin material to be supplied to the pot does not remain in the material hopper of the material supply device or the chute serving as an introduction path of the resin material to the pot, and as a result, A pot with a certain amount of ingredients Problems and not so fed is to provide a resin molding method and a resin molding apparatus of the occurrence of the problem that the material clogging can be prevented in the material supply apparatus.

[0005]

According to a first aspect of the present invention, there is provided a resin molding method having an upper die and a lower die, which is formed by opening the upper surface of the lower die to supply a powdery resin material. A pot, and a molding apparatus having compression and injection means for compressing the resin material once supplied in the pot while melting the resin material supplied to the pot, and injecting the compressed resin material into the cavity; A material hopper for holding the resin material,
A shutter for controlling the supply of the resin material to the pot, and a chute for introducing the resin material into the pot, and when the upper mold and the lower mold of the molding apparatus are open, Using a resin molding device having a material supply device that moves above the lower mold and supplies a powdery resin material to the pot, the powdery resin material supplied from the material supply device into the pot is removed. Once compressed in the pot,
In a resin molding method for injecting into a cavity and resin-sealing an electronic component fitted in the cavity, the material supply device includes a vibrator for applying vibration to a material hopper and a chute. When opening the shutter to supply the resin material to the pot,
A resin molding method characterized by applying vibration to the material hopper and the chute by the vibrator.

In the resin molding method according to the first aspect of the invention, when the powdery and granular resin material is supplied from the material supply device to the pot, vibration is applied to the material hopper and the chute by the vibrator. The resin material to be formed can be prevented from remaining in the material hopper or the chute serving as a path for introducing the resin material into the pot. Therefore, according to the resin molding method of the present invention, it is possible to prevent a problem that a predetermined amount of material is not supplied to the pot and a problem of material clogging in the material supply device.

According to a second aspect of the present invention, there is provided a resin molding apparatus having an upper mold and a lower mold, a pot formed by opening an upper surface of the lower mold, and supplying a powdery resin material. A molding die apparatus having a compression and injection means for temporarily compressing the resin material supplied to the pot while melting the resin material in the pot and injecting the compressed resin material into the cavity, and a material for holding the granular resin material A hopper, a shutter for controlling the supply of the resin material to the pot, and a chute for introducing the resin material into the pot are provided, and an upper mold and a lower mold of a molding apparatus are open. sometimes,
In a resin molding device having a material supply device that moves above a lower mold and supplies a granular resin material to the pot, the material supply device includes a vibrator that applies vibration to a material hopper and a chute. A resin molding apparatus.

[0008] In the resin molding apparatus according to the second aspect of the present invention, when the powdery or granular resin material is supplied from the material supply device to the pot, vibration can be applied to the material hopper and the chute by the vibrator. The resin material to be supplied to the
It is possible to prevent the resin material from remaining on the chute serving as an introduction path to the pot. Therefore, according to the resin molding apparatus of the second aspect of the present invention, it is possible to prevent the problem that a predetermined amount of material is not supplied to the pot and the problem of material clogging in the material supply device.

According to a third aspect of the present invention, in the resin molding apparatus, a cooling means for cooling an inner wall surface of the material hopper is provided in the material supply apparatus. .

In the resin molding apparatus according to the third aspect of the present invention, since the inner wall surface of the material hopper can be cooled by the cooling means, the rise in the wall surface temperature of the material hopper is suppressed. Therefore, according to the resin molding apparatus of the third aspect of the present invention, it is possible to more reliably prevent the resin material from remaining in the material hopper.

The resin molding apparatus according to a fourth aspect of the present invention is the resin molding apparatus according to the third aspect, wherein the cooling means is a cooling means using a Peltier element.

In the resin molding apparatus according to the fourth aspect of the present invention, since the cooling means is a cooling means using a Peltier element, the cooling means can be downsized.

[0013]

Embodiments of the present invention will be described below. FIG. 1 is a plan view for explaining a schematic configuration of an embodiment of the resin molding apparatus of the present invention. As shown in FIG. 1, the resin molding device includes a material supply device A and a molding die device B. In addition, a preheat table 33 for preheating the lead frame on which the semiconductor element is mounted to the molding apparatus B before setting the lead frame on which the semiconductor element is mounted, and a molded article with a runner cull which has been molded by the molding apparatus B are placed on the resin molding apparatus. Table 34, a molded product holding portion 35 for temporarily holding the molded product after the cull / runner is separated, and the like. Then, the mold 10 including the upper mold and the lower mold is set in the mold apparatus B at the mold setting position 36 (the position indicated by the two-dot chain line). In this embodiment, eight pots are set. 1 is used.

As shown in FIGS. 2 and 3, the material supply device A includes a material hopper 51 for holding the resin material 2 in the form of powder and a shutter 52 for controlling the supply of the resin material 2 to the pot 1. (Not shown in FIG. 2), and has a chute 53 for introducing the resin material 2 into the pot 1. In this embodiment, a total of eight sets each including a material hopper 51, a shutter 52, and a chute 53 are mounted on the base 54. The shutter 52 can be opened and closed by a shutter opening / closing cylinder 55 attached to the base 54. FIG. 3A shows a state in which the shutter 52 is closed, and FIG.
Indicates a state in which the shutter 52 is open. FIG.
The state (b) shows a state where the material hopper 51 and the chute 53 are vibrated as described later. As shown in FIG. 2, the base 54 can move up and down in the vertical direction by operating the elevating device 56 that holds the base 54. The elevating device 56 holding the base 54 is mounted on a loader 57. The loader 57 operates a driving device (not shown) to move the standby position 37 of the material supply device A shown in FIG. It can be moved to the mold setting position 36.

The material supply device A is provided with a vibrator 59 for applying vibration to the material hopper 51 and the chute 53, as shown in FIG. In this embodiment, the vibrator 59 attached to the base 54
By vibrating the base 54 on which the material hopper 51 and the chute 53 are attached, the material hopper 51 and the chute 53 are vibrated. Even if this vibrator 59 is a motor type,
It may be an air type. Further, a cooling device 60 using a Peltier element is mounted around the material hopper 51 as cooling means for cooling the inner wall surface of the material hopper 51. The cooling means may be a cooling means using a coolant such as cooling water in addition to the Peltier element. However, since the cooling device 60 using the Peltier element can achieve downsizing, material supply with a limited installation location is not possible. It is suitable for attaching to the device A.

On the other hand, the molding apparatus B is shown in FIGS.
As shown in (d), the lower mold 11 and the upper mold 12 are formed, and the cavity 5 is formed between the upper and lower molds 11 and 12. Further, a cylindrical sleeve 11a is attached to the lower mold 11, and a pot 1 having an open upper surface is formed in the sleeve 11a. A cylindrical sleeve 1 is formed on the upper mold 12 so as to face the sleeve 11a.
2a is attached, and a pressure adjusting pot 13 having a lower surface opened in the sleeve 12a is formed. The diameter of the pressure adjusting pot 13 is formed larger than the diameter of the pot 1. A runner 4 communicating with the cavity 5 is provided on the upper surface of the lower mold 11 and the lower surface of the upper mold 12, and the opening 7 at the end of the runner 4 opposite to the cavity 5 is provided in the upper mold 12.
The pressure adjusting pot 13 is opened. Therefore, the opening 7 of the runner 4 opens to the pot 1 via the pressure adjusting pot 13. An injection plunger 3 is provided in the pot 1 so as to be able to move forward and backward (movable up and down), and a pressure adjusting plunger 6 is provided in the pressure adjusting pot 13 so as to be movable forward and backward (movable up and down). In this embodiment, the injection plunger 3 and the pressure regulating plunger 6 compress the resin material 2 supplied to the pot 1 once in the pot 1 while melting the resin material 2. It acts as a compression and injection means for injection.

Next, an embodiment of a resin molding method in which molding is performed using a resin molding apparatus having the above-described structure will be described. First, a predetermined amount of the powdery resin material 2 measured using a measuring means (not shown) is supplied to each material hopper 51 of the material supply device A at the standby position 37 shown in FIG. At this time, the shutter 52 is kept closed. Next, in a state where the resin material 2 is supplied to all the material hoppers 51, a driving device (not shown) of the loader 57 is provided.
To feed the material supply device A to the preheat table 33.
, And the lead frame 8 on which the semiconductor element mounted on the preheat table 33 is mounted is sucked by the suction device 61 provided in the material supply device A. Next, the chute 53 of the material supply device A is located above the lower die 11 of the molding die apparatus B in which the lower die 11 and the upper die 12 are open, and the chute 53 of the material supply device A corresponds to the pot 1 of the lower die 11. ,
The material supply device A is moved. At this time, the position of the semiconductor element mounted on the lead frame 8 is set to a position corresponding to the cavity 5 of the lower mold 11.

Next, a material hopper 51 and a chute 53
And the base 54 to which the suction device 61 is attached,
When the elevating device 56 is moved down to reach a predetermined position, the suction of the suction device 61 is released, and the held lead frame 8 is set at the predetermined position of the lower mold 11, and at the same time, the shutter is opened and closed. By operating the cylinder 55, the shutter 52 of the material supply device A is changed from the closed state to the open state, and the powdery resin material 2 in the material hopper 51 is supplied to the pot 1 via the chute 53. When the shutter 52 is opened to supply the powdery resin material 2 to the pot 1, the vibrator 59 is driven for a predetermined time to move the material hopper 51 and the chute 53 as shown in FIG. Vibration is applied to it. After a lapse of a predetermined time, the driving of the vibrator 59 is stopped, and the shutter 52 is returned to the closed state.
Is operated to raise the base 54, and then return the material supply device A to the standby position 37 shown in FIG.

As described above, when the shutter 52 is opened and the vibrator 59 is driven to apply vibration to the material hopper 51 and the chute 53 as shown in FIG. Resin material 2 for inner wall
Powder is less likely to adhere. In particular, even when the temperature of the material supply device A rises due to the heat of the upper mold 12 and the lower mold 11 that are heated when the operation is continuously performed, the powder of the resin material 2 on the inner wall of the material hopper 51 is not removed. There is an advantage that adhesion is difficult.

Further, if the cooling device 60 using the Peltier element mounted around the material hopper 51 is always operated, the inner wall surface of the material hopper 51 is cooled. Therefore, when the operation of the resin molding apparatus is continuously performed, the heated upper mold 12,
The material hopper 5 of the material supply device A is heated by the heat of the lower mold 11.
As a result, it is possible to prevent the powder of the resin material 2 from adhering to the inner wall of the material hopper 51 more reliably.

Next, the molding method using the molding apparatus B will be described.
The method is almost the same as the method described in Japanese Patent No. 173. As shown in FIG. 4A, the upper and lower dies 11, 12 of the molding die apparatus B are clamped. Upper and lower molds 1 of molding apparatus B
Heating means 1 and 12 are provided so that the powdery resin material 2 supplied into the pot 1 is heated. After supplying the resin material 2 into the pot 1, FIG.
As shown in (b), the injection plunger 3 is advanced. Here, the injection plunger 3 controls the pressurization acting on the injection plunger 3 so that the injection plunger 3 advances with a constant force after the resin material 2 is supplied to the pot 1 until the resin material 2 is injected into the cavity 5. I have to do it. Further, in the initial stage in which the injection plunger 3 moves forward, the pressure regulating plunger 6 is controlled so that a force larger than the force of the injection plunger 3 acts on the plunger 6. Therefore, as shown in FIG. 4B, even if the injection plunger 3 moves forward, the pressure regulating plunger 6 does not retreat, and the resin material 2 in the pot 1 moves between the injection plunger 3 and the pressure regulating plunger 6. Pressed and compressed. By compressing the resin material 2 in this manner, the air between the particles of the powdery resin material 2 is expelled. The air expelled from between the particles of the resin material 2 is discharged through the clearance between the parting lines of the lower mold 11 and the upper mold 12 and the like. At this time, since the opening 7 of the runner 4 is closed by the side surface of the pressure regulating plunger 6, the resin material 2 is not pushed out to the runner 4 by the pressure of the injection plunger 3.

As described above, after the resin material 2 in the pot 1 is compressed, the pressure of the pressure regulating plunger 6 is controlled to be released. When the injection plunger 3 moves forward with a constant force, the pressure-releasing plunger 6 which is released and has no pressure is subjected to the force of the injection plunger 3 while receiving the elastic force of the pressure adjusting member such as a spring. Then, as shown in FIG. 4C, the opening 7 of the runner 4 is opened. At this time, the resin material 2 in the pot 1 is in a molten state by heating and pressing, and when the opening 7 of the runner 4 is opened in this way, the injection plunger 3
The resin material 2 in the pot 1 flows into the runner 4 from the opening 7 through the pressurization, and is injected through the runner 4 into the cavity 5 in which a semiconductor element as an electronic component is fitted. At this time, the pressure in the pot 1 is adjusted to a predetermined constant pressure by retreating the pressure adjusting plunger 6 while receiving the elastic force of the pressure adjusting member such as a spring, and the resin material 2 is caved at a constant pressure. 5 can be injected.

After the injection plunger 3 is advanced until the tip of the injection plunger 3 slightly protrudes from the parting line surfaces of the upper and lower dies 11, 12, the advance of the injection plunger 3 is stopped. When the advancement of the injection plunger 3 is stopped in this way, the pressure regulating plunger 6 is controlled so that a force smaller than the force of the injection plunger 3 is applied to advance. The pressure-regulating plunger 6 advances so as not to close the opening 7 of the runner 4, and pressurizes the resin material 2 with the pressure-regulating plunger 6 as shown in FIG. The resin material 2 remaining in the cavity 5 is sent to the cavity 5, and the injection of the resin material 2 into the cavity 5 is completed. Next, the resin material 2 is cured in the cavity 5. After curing is completed, the upper and lower dies 11, 1
The mold 2 is opened, and a molded product in the cavity 5 is taken out with an ejector pin (not shown). After the molded product is taken out from the cavity 5 in this way, the molded product provided with the cull runner is grasped by a takeout device (not shown), placed on the takeout table 34, and then the cull runner is punched or the like. They are removed to obtain molded products.

Further, the molded product from which the cull runner has been removed is temporarily held by the molded product holding section 35, and then stored in a storage rack (not shown).

As described above, in the molding die apparatus B of this embodiment, the injection plunger 3 and the pressure regulating plunger 6 temporarily melt the resin material 2 supplied to the pot 1 in the pot 1. The molding die apparatus has a structure that functions as a compression and injection means for compressing and injecting the compressed resin material 2 into the cavity 5. In addition, the compression and injection means in the present invention may be, other than this form, only the injection plunger 3 as disclosed in, for example, JP-A-10-180792.

[0026]

In the resin molding method according to the first aspect of the present invention, when the powdery resin material is supplied from the material supply device to the pot, vibration is applied to the material hopper and the chute by the vibrator. The resin material to be removed can be prevented from remaining in the material hopper or the chute serving as a path for introducing the resin material into the pot. Therefore, according to the resin molding method of the present invention, it is possible to prevent a problem that a predetermined amount of material is not supplied to the pot and a problem of material clogging in the material supply device.

In the resin molding apparatus according to the second aspect of the present invention,
When the powdery resin material is supplied from the material supply device to the pot, vibration can be applied to the material hopper and the chute by the vibrator, so that the resin material to be supplied to the pot is in the material hopper or the resin material. Can be prevented from remaining on the chute serving as an introduction path to the pot. Therefore, according to the resin molding apparatus of the second aspect of the present invention, it is possible to prevent the problem that a predetermined amount of material is not supplied to the pot and the problem of material clogging in the material supply device.

In the resin molding apparatus according to the third aspect of the present invention,
Since the inner wall surface of the material hopper can be cooled by the cooling means, an increase in the temperature of the wall surface of the material hopper is suppressed.
Therefore, according to the resin molding apparatus of the third aspect of the present invention, it is possible to more reliably prevent the resin material from remaining in the material hopper.

In the resin molding apparatus according to the fourth aspect of the present invention,
In addition to the effect of the invention according to claim 3, since the cooling means is a cooling means using a Peltier element, downsizing of the cooling means can be achieved.

[Brief description of the drawings]

FIG. 1 is an overall plan view of a resin molding apparatus according to an embodiment of the present invention.

FIG. 2 is a side view of a resin supply device of the resin molding device according to one embodiment of the present invention.

3A and 3B are views for explaining one embodiment of the present invention, in which FIG. 3A is a cross-sectional view showing a state in which a shutter is closed, and FIG.

FIG. 4 is a view for explaining one embodiment of the present invention, and (a) to (d) are cross-sectional views of a molding die apparatus in each step.

5A and 5B show a conventional example, in which FIG. 5A is a cross-sectional view showing a state in which a shutter is closed and FIG.

FIG. 6 shows a conventional example, and is a cross-sectional view showing a state during continuous operation.

[Explanation of symbols]

 Reference Signs List A Material supply apparatus B Molding apparatus 1 Pot 2 Resin material 5 Cavity 11 Lower mold 12 Upper mold 51 Material hopper 52 Shutter 53 Chute 59 Vibrator

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Claims (4)

[Claims] 1. A pot having an upper die and a lower die, formed with an upper surface opened in the lower die, to which a powdery resin material is supplied, and a resin material supplied to the pot is melted. While once compressed in a pot, a molding die device having a compression and injection means for injecting the compressed resin material into the cavity, and a material hopper for holding the powdery resin material,
A shutter for controlling the supply of the resin material to the pot, and a chute for introducing the resin material into the pot, and when the upper mold and the lower mold of the molding apparatus are open, Using a resin molding device having a material supply device that moves above the lower mold and supplies a powdery resin material to the pot, the powdery resin material supplied from the material supply device into the pot is removed. Once compressed in the pot,
In a resin molding method for injecting into a cavity and resin-sealing an electronic component fitted in the cavity, the material supply device includes a vibrator for applying vibration to a material hopper and a chute. When opening the shutter to supply the resin material to the pot,
A resin molding method, wherein vibration is applied to the material hopper and the chute by the vibrator. 2. A pot which has an upper mold and a lower mold, is formed with an upper surface opened in the lower mold, and is supplied with a powdery resin material, and melts the resin material supplied to the pot. While once compressed in a pot, a molding die device having a compression and injection means for injecting the compressed resin material into the cavity, and a material hopper for holding the powdery resin material,
A shutter for controlling the supply of the resin material to the pot, and a chute for introducing the resin material into the pot, and when the upper mold and the lower mold of the molding apparatus are open, In a resin molding device having a material supply device that moves above a lower mold and supplies a granular resin material to the pot, the material supply device includes a vibrator that applies vibration to a material hopper and a chute. A resin molding apparatus characterized in that: 3. The resin molding apparatus according to claim 2, wherein cooling means for cooling an inner wall surface of said material hopper is provided in said material supply device. 4. The resin molding apparatus according to claim 3, wherein said cooling means is a cooling means using a Peltier element.