JPH0982736A - Method of molding package mold part in electronic component and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cost for molding by preventing the loss of resin when molding the package mold parts for sealing semiconductor chips to lead frames. SOLUTION: Material resin is melted by heating inside each material resin filling chamber 4 arranged with an opening directed to the molding cavity 2a of package mold part of the metal mold 2a of either of metal molds 1 or 2 that press a lead frame between them and fills inside the molding cavity of the package mold part by pushing movement of a plunger 5 to the inside of the material resin filling chamber 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for forming a package mold part made of a thermosetting synthetic resin such as an epoxy resin for sealing a semiconductor chip part of an electronic component such as a transistor or an IC. It is about.

[0002]

2. Description of the Related Art Conventionally, when molding a package mold portion of an electronic component such as a transistor, for example, as described in Japanese Utility Model Laid-Open No. 4-45718, a lead frame used for manufacturing an electronic component is used. While sandwiching a plurality of cavity for molding the package mold part with a pair of upper and lower molds having a recess, the raw material resin loaded in the raw material resin loading chamber provided in one of the molds is placed in the raw material resin loading chamber. After being melted by heating, by pushing the plunger into the raw material resin loading chamber, through the runner groove and the gate groove extending from the raw material resin loading chamber along the longitudinal direction of the lead frame, each package mold part molding Distribute to cavity
The so-called multi-type transfer molding method of filling and hardening is adopted.

[0003]

However, in this conventional multi-type transfer molding method, a plurality of raw material resins melted in one raw material resin loading chamber are passed through runner grooves and gate grooves extending in the longitudinal direction of the lead frame. It is to be distributed to the individual molding cavities of the package mold, and the resin solidified in the runner groove and the gate groove of the raw material resin must be discarded as loss resin. There is a problem that not only a large amount of loss but also a step for separating the loss resin solidified in the runner groove and the gate groove from the lead frame after molding is required, which considerably increases the molding requirement. It was

Moreover, when the loss resin is separated from the lead frame, there is a problem that the package mold portion may be chipped or the lead frame may be deformed. It is a technical object of the present invention to provide a multi-type molding method and apparatus that solve these problems.

[0005]

In order to achieve this technical object, the method of the present invention is to provide a lead frame with a pair of molds in which a plurality of package mold part forming cavities are recessed in a mating surface. In this state, the raw material resin is heated and melted in each raw material resin loading chamber provided in at least one of the two molds so as to be directly opened at each of the mold cavities for molding the package. Then, the molten raw material resin is filled in the cavity for molding the package mold portion by the pushing movement of the plunger into the raw material resin loading chamber and molded, and each package mold portion after molding is By further pushing motion of each plunger, the mold is removed from the cavity for molding the package mold portion. "

Further, in the apparatus according to the present invention, "a plurality of mold cavities for molding a package are formed in the mating surfaces of a pair of molds so as to sandwich the lead frame, and the two molds are formed. A raw material resin loading chamber, which directly opens into the package molding portion molding cavity, is provided in one of the molds at each of the package molding portion molding cavity locations, and a plunger is provided in each of the raw material resin loading chambers. By pushing the plunger into the raw material resin loading chamber, filling the raw material resin heated and melted in the raw material resin loading chamber into the molding cavity of the package mold portion, and the package mold of the package mold portion after molding. It is slidably inserted so as to perform die cutting from the part forming cavity. "

[0007]

[Operation] As described above, according to the present invention, each raw material resin provided so that the molten raw material resin is filled in each package mold portion molding cavity is directly opened in the package mold portion molding cavity. Since it is performed by pushing the plunger into the loading chamber, multiple package mold parts can be formed on the lead frame at the same time without forming runner grooves and gate grooves in the mold as in the conventional case. You can do it.

[0008]

As described above, according to the present invention, since it is possible to eliminate the generation of loss resin during the molding of the package mold portion by the multi-type, it is possible to significantly reduce the consumption of the raw material resin and to reduce the loss after molding. Since the step of separating the resin is not required, it is possible to significantly reduce the molding process required for the package mold section.
There is an effect that it is possible to reliably reduce chipping of the package mold portion and deformation of the lead frame.

In addition, according to the present invention, the die of the molded package mold portion is removed from one die by a plunger, so that the die ejector pin to be provided in the one die. Since it can be omitted, it also has an effect of simplifying the structure of the mold.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.
The drawing of FIG. 6 will be described. Reference symbol A in this figure
Indicates a lead frame, and this lead frame 1 is
The island portions A1 are provided at a plurality of locations, and the semiconductor chips A2 connected to the lead terminals A3 by the metal wires 4 are mounted on each of the island portions A1.

Reference numerals 1 and 2 denote a pair of molds for sandwiching the lead frame A.
On the mating surface of 2, a plurality of cavities 1a, 2a for molding the package mold portion are formed to be recessed. Of the two molds 1 and 2, the upper mold 1 is provided with a die ejecting ejector pin 3 which is vertically moved by a reciprocating mechanism (not shown) arranged above the upper mold 1 for each package molding part. It is provided at each location of the molding cavity 1a.

The lower mold 2 of the molds 1 and 2 has a cavity 2 for molding the respective package mold parts.
A raw material resin loading chamber 4 is provided at each location a so as to directly open into the cavity 2a for molding the package mold portion, and each of the raw material resin loading chambers 4 has a lower die 2 inside.
Plunger 5 which is vertically moved by a reciprocating mechanism (not shown) disposed below is slidably inserted.

First, as shown in FIG. 1, the upper die 1
In a state of being largely moved up from the lower die 2, the raw material resin 6 is loaded in each of the raw material resin loading chambers 4 of the lower die 2, and the lead frame A is placed between the two dies 1 and 2. insert. Next, by lowering the upper die 1 toward the lower die 2, as shown in FIG.
Is sandwiched between the molds 1 and 2, and in this state, the raw material resin 6 in each raw material resin loading chamber 4 is heated and melted.

In this way, when the raw material resin 6 is heated and melted in the respective raw material resin loading chambers 4 of the lower mold 2, the molten raw material resin 6 is transferred to the raw material resin loading chambers 4 by the plunger 5 As shown in FIG. 4, by the pushing motion, the cavities 1a and 2a for molding the package mold portions of the two dies 1 and 2 are filled, so that a plurality of package mold portions A5 are attached to the lead frame A. At the same time.

In this case, the volume of each raw material resin 6 should be equal to the volume of the package mold portion A5, but the volume of each raw material resin 6 is a little more than the volume of the package mold portion A5. By making the flanger 5 smaller and pushing the flanger 5 into a state in which the tip of the flanger 5 projects into the cavity 2a by a slight dimension S, the volume difference between the raw material resin 6 and the package mold portion A5 is caused. In addition, there is an advantage that it is possible to avoid the generation of a protrusion in the package mold portion A5.

Then, the package mold portion A5 described above.
When the molding of is completed, as shown in FIG.
By downwardly projecting movement of each die-cutting ejector pin 3, the package mold portion A5 is lifted while being die-cut from the cavity 1a. Next, as shown in FIG. 6, the respective flanges 5 of the lower mold 2 are further pushed and moved, whereby the respective package mold parts A5 can be removed from the cavity 2a of the lower mold 2. Of.

That is, according to the present invention, the molten raw material resin 6 in the respective cavity 1a, 2a for molding the package mold portion
Is performed by pushing the plunger 5 into the respective raw material resin loading chambers 4 provided so as to be directly opened in the package molding portion molding cavities 1a and 2a. It is possible to simultaneously form a plurality of package mold parts A5 on the lead frame A without providing the runner groove and the gate groove as in the conventional case.

In the above embodiment, the lower mold 2 of the molds 1 and 2 is provided with the raw material resin loading chamber 4, but the present invention is not limited to this. Needless to say, the raw material resin loading chamber 4 may be provided in the upper mold 1 of the molds 1 and 2.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing an embodiment of the present invention.

FIG. 2 is a plan view taken along the line II-II of FIG.

FIG. 3 is a vertical cross-sectional front view showing a state in which a lead frame is sandwiched by both molds.

FIG. 4 is a vertical cross-sectional front view showing a state in which a package mold portion is molded.

FIG. 5 is a vertical cross-sectional front view showing a state in which an upper die is raised.

FIG. 6 is a vertical cross-sectional front view showing a state where the molded package portion after molding has been removed from the lower mold.

[Explanation of symbols]

1 Upper Die 2 Lower Die 1a, 2a Package Mold Mold Molding Cavity 3 Mold Ejector Pin 4 Raw Material Resin Loading Chamber 5 Plunger 6 Raw Material Resin A Lead Frame A2 Semiconductor Chip A5 Package Mold Section

Claims (2)

[Claims] 1. A lead frame is sandwiched between a pair of molds in which a plurality of package mold part forming cavities are formed on the mating surfaces, and in this state, at least one of the molds is molded. The raw material resin is heated and melted in each raw material resin loading chamber provided so as to be directly opened at each of the package molding section molding cavities, and the molten raw material resin is then planed into each raw resin loading chamber. By pushing the jar into the cavity for molding the package mold portion and molding, each package mold portion after molding is pushed from the cavity for molding the package mold portion by further pushing movement of each plunger. A method for molding a package mold portion of an electronic component, which comprises die-cutting. 2. A plurality of cavities for molding a package mold portion are formed in a concave shape on a mating surface of a pair of molds so as to sandwich a lead frame, and one of the molds is provided with the mold. A raw material resin loading chamber that directly opens into the package molding portion molding cavity is provided for each of the package molding portion molding cavities, and a plunger is provided in each of the raw material resin loading chambers. By pushing into the resin loading chamber,
Sliding so as to fill the cavity for molding the package mold part with the raw material resin heated and melted in the chamber for molding the raw material resin, and to perform die-cutting from the cavity for molding the package mold part of the package mold part after molding. A molding device for a package mold part in an electronic component, which is freely inserted.