JPH10119082A - Resin molding method and apparatus - Google Patents

Abstract

(57) [Problem] To provide a resin molding method in which a cull in transfer molding is eliminated to save a resin material. SOLUTION: A cavity 3 is formed between an upper mold 1 and a lower mold 2, a resin material 7 is injected into the cavity, molded, and an ejection pin which slides a molded product 7a along an ejector guide passage 5. 6, a resin material 7 is inserted into the ejector guide passage 5, and the resin material heated and melted is injected into the cavity 3 by the ejection pin 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin molding method and apparatus. More specifically, the present invention relates to a method and an apparatus for injecting a resin material in transfer molding.

[0002]

2. Description of the Related Art In a final step of manufacturing a semiconductor device, a lead frame on which a semiconductor element is mounted is molded with a resin material and commercialized as a semiconductor package. Transfer molding is used as such a resin molding means.

FIG. 2 shows a main configuration of a conventional transfer molding apparatus. (A) shows a state before molding, and (B) shows a state after molding.

A plurality of package-shaped cavities 13 to be molded are formed between an upper mold 11 and a lower mold 12. An ejection pin 15 for extruding and discharging a molded product is provided facing the cavity 13. A common pot 16 is provided at an intermediate portion of the plurality of cavities 13 and communicates with each cavity 13 via a runner 17. A plunger 19 that slides in the pot is mounted in the pot 16. (A) shows a state where the resin material 19 is inserted into the pot 16. In transfer molding, the resin material 19 is inserted into the pot 16 in the form of a predetermined amount of preheated tablet required for one molding, and is heated and melted here. (B) shows that the resin material in the molten state is extruded by the plunger 18 and the cavity 1 is passed through the runner 17.
3 shows the state of the injection. By curing in this state at a predetermined temperature for a predetermined time, a resin molded product 19 a in a package shape is formed in the cavity 13. At this time,
The resin material remaining in the upper portion of the pot 16 and in the runner 17 is also cured, and the cull 20 is formed. This cull 20
It is taken out for each molding process and disposed of as industrial waste.

[0005]

However, in the above-mentioned conventional transfer molding, since the cull 20 is inevitably formed in the pot portion and the runner portion, the cull 20 causes loss of the resin material.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional technology, and has as its object to provide a resin molding method and apparatus which eliminates culls in transfer molding and saves resin material.

[0007]

In order to achieve the above object, according to the present invention, a cavity is formed between an upper mold and a lower mold, and a resin material is injected into the cavity to mold the molded article. In a resin molding method of projecting by an ejection pin sliding along a passage, a resin material is inserted into the ejector guide passage, and the resin material heated and melted is injected into the cavity by the ejection pin. To provide a resin molding method.

According to this method, the pot and the plunger are omitted in the transfer molding, and the resin is injected into the cavity using the ejection pin without passing through the runner, so that no cull is formed.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As an apparatus for carrying out the resin molding method of the present invention, the present invention further comprises an upper mold and a lower mold for forming a cavity having a shape to be molded, and a resin material in the cavity. In a resin molding apparatus having a resin supply means for injecting and a projecting means for discharging a molded product from a cavity, a resin material injection port of the resin supply means is common to a projecting port of the projecting means. And a resin molding apparatus characterized by the following.

According to this apparatus, since the resin is directly injected into the cavity from the projecting opening of the projecting means such as an ejection pin for extruding the molded product from the cavity, the cured resin remains in the mold after molding. No culls are formed.

[0011]

FIG. 1 is an explanatory view of the configuration of a resin molding apparatus according to an embodiment of the present invention. (A) shows a state before molding, and (B) shows a state after molding.

A cavity 3 in the shape of a semiconductor package to be molded is formed between the upper mold 1 and the lower mold 2. The plurality of cavities 3 are provided in parallel. A lead frame (not shown) on which a semiconductor element is mounted is set in each cavity 3. An ejector guide passage 5 is formed in the lower die 2 and opens at the bottom of each cavity 3, and an ejection pin 6 slides in the ejector guide passage 5.

In this embodiment, a resin material 7 is inserted into the ejector guide passage 5 as shown in FIG. The resin material 7 is in the form of a preheated solid tablet having a predetermined amount required for molding in one formation, and is inserted into the ejector guide passage 5 to be heated and melted. As a heating means, a heater for heating the upper mold and the lower mold is provided. The heat-melted resin material 7 is injected into the cavity 3 by the ejection pin 6. Here, by curing at a predetermined temperature for a certain time,
(B) As shown in the figure, a package-shaped molded product 7 a is formed in the cavity 3. After separating the upper mold 1 from the lower mold 2, the molded product 7 a is extruded from the lower mold 2 by ejecting the projection pins 6 and discharged.

Compared with the configuration of the conventional transfer molding apparatus shown in FIG. 2 described above, the configuration of the present embodiment is different from that of the conventional transfer molding apparatus shown in FIG.
The resin 7 and the plunger 18 are eliminated, and the resin is injected into the cavity 3 without using a runner by using the ejection pin 6 for projecting the molded product. For this reason, the cull conventionally formed in the runner portion is not formed, and the resin injection port is common to the projection exit of the projection pin. No cured resin remains.

[0015]

As described above, in the present invention, the pot and the plunger in the transfer molding for molding the thermosetting resin are omitted, and the resin is formed in the cavity without using a runner by using an ejection pin. The cull, which was inevitably formed in the runner part and was disposed of as industrial waste, is not formed.
Therefore, the waste of the resin material is omitted, and the cost is reduced and the resources are effectively used.

Further, since a pot and a plunger are omitted and a conventional projection pin is also used as a resin injection means, a runner dedicated to resin injection is not required, and the configuration of the mold and the entire molding apparatus is simplified.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a molding procedure using a resin molding apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory view of a molding procedure using a conventional transfer molding apparatus.

[Explanation of symbols]

1: Upper mold, 2: Lower mold, 3: Cavity, 5: Ejector guide passage, 6: Ejection pin, 7: Resin material,
7a: Molded product.

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // B29L 31:34

Claims (2)

[Claims] A cavity is formed between an upper mold and a lower mold,
In a resin molding method in which a resin material is injected into the cavity and molded, and a molded product is projected by an ejection pin sliding along the ejector guide passage, the resin material is inserted into the ejector guide passage and heated and melted. A resin molding method, wherein the injected resin material is injected into the cavity by the ejection pin. 2. An upper mold and a lower mold for forming a cavity having a shape to be molded, a resin supply means for injecting a resin material into the cavity, and a projecting means for discharging a molded product from the cavity. The resin molding apparatus according to claim 1, wherein a resin material injection port of the resin supply unit is common to a projection port of the projection unit.