JP2538730Y2 - Resin molding equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a resin molding apparatus for releasing a resin filled and solidified in a runner and a cavity between upper and lower molds from a lower mold by an eject pin inserted into the lower mold. More particularly, the present invention relates to a resin molding apparatus that can easily replace a broken eject pin.

[0002]

2. Description of the Related Art A conventional example of a resin molding apparatus used for manufacturing a semiconductor device will be described with reference to FIGS.

The resin molding apparatus comprises upper and lower dies (1) and (2) which are separated from each other, four columns (3) erected around the upper and lower dies, and upper ends of the four columns (3). A roof (4) that is provided and holds the upper mold (1) on the lower surface, and is also penetrated by four columns (3), and the lower mold (2) is placed on the upper surface and moves up and down. A movable plate (5). A pot (not shown) for storing a resin tablet (not shown) is formed in the upper mold (1), and a through hole (not shown) communicating with the pot is formed in the top plate (4). ). A cull (not shown) communicating with the pot is provided on the upper surface of the lower mold (2).
And a runner for flowing molten resin from there (6)
And are formed. Numerous (one in the drawing) cavities (7) are formed on the side surfaces of the runner (6) and on the joint surfaces of the upper and lower molds (1) and (2). The runner (6) and the cavity (7) communicate with each other by a gate (8) formed on the upper surface of the lower mold (2). The lead frame (9) is set between the upper and lower molds (1) and (2).
The lead frame (9) has a semiconductor pellet (10) mounted thereon and has been subjected to wire bonding. Semiconductor pellet (10) is cavity (7)
It is housed inside and resin molded. An eject pin (11) is inserted into the lower mold (2). The upper surface of the eject pin (11) projects and retracts from the bottom surface of the runner (6) and the cavity (7), and the lower portion of the eject pin ()
It extends downward from the bottom surface of the lower mold (2). An enlarged portion (11a) is formed at the lower end of the eject pin (11), and the enlarged portion (11a) is sandwiched between upper and lower plates (12) and (13). The lower plate (13) has an ejector rod (1
Supported by 4). A compression coil spring (15) is interposed between the upper plate (12) and the movable platen (5), and the eject pin (11) is urged downward via the upper plate (12). As the eject pin (11) moves up and down,
The position where the upper end surface of the eject pin (11) is flush with the bottom surfaces of the runner (6) and the cavity (7) and the runner (6)
And a position protruding from the bottom surface of the cavity (7).

[0004] The resin molding apparatus is configured as described above. Next, a method of resin molding the semiconductor pellet (10) will be described.

First, a lead frame (9) on which a semiconductor pellet (10) is mounted and wire-bonded is separated from an upper mold (1) by a lower mold (2).
The upper and lower dies (1) and (2) are clamped by raising the movable plate (5) as shown in FIG. Also, raise the ejector rod (14) to the maximum,
The upper surface of the eject pin (11) is flush with the bottom surfaces of the runner (6) and the cavity (7). Then, the upper and lower molds (1) and (2) are heated to supply a resin tablet (not shown) into a pot and a cul (both not shown). The resin tablet melts while being pressed by a plunger (not shown) inserted into the pot. The molten resin passes through the gate (8) from the runner (6), is filled in the cavity (7), and resin-molds a main part such as the semiconductor pellet (10). When the molten resin solidifies, the movable platen (5) and the ejector rod (14) are lowered to separate the lower mold (2) from the upper mold (1). Since the descending amount of the ejector rod (14) is smaller than the descending amount of the movable plate (5), the eject pin (11) protrudes from the bottom surface of the runner (6) and the cavity (7), and is shown in FIG. As such, the runner (6), gate (8) and cavity (7)
The resin (16) solidified therein is released from the lower mold (2) by the eject pin (16). At this time, the compression coil spring (15) is compressed between the movable plate (5) and the upper plate (12). And a carrier (not shown)
Holds the outer peripheral portion of the lead frame (9).
After being slightly raised, the lead frame (9) is moved in the horizontal direction, and the lead frame (9) is discharged from between the upper and lower molds (1) and (2).

[0006]

[Problems to be Solved by the Invention] Resin (16) solidified in runner (6), gate (8) and cavity (7)
Is released from the lower mold (2) by ejecting the eject pin (11) from the bottom of the runner (6) and the cavity (7).

In order to facilitate this release, a release agent is mixed into the resin (16), or the upper opening side of the runner (6), gate (8) and cavity (7) is widened. Such a device has been devised.

However, the lead frame (9) may be deformed, and the positioning holes (not shown) of the lead frame (9) are provided with fitting pins (not shown) projecting from the lower mold (2). ) May not be easily removed. In addition, since the mixing state of the release agent is not uniform, the solidified resin (16)
May be difficult to release from the lower mold (2). If the eject pin (11) is made to protrude from the bottom surface of the runner (6) and the cavity (7) in such a state, an excessive force is applied to the eject pin (11), and the eject pin (11) is particularly damaged. , May be broken in the lower mold (2).

In such a case, the eject pin (11)
Need to be replaced. However, the eject pin (1
The upper part of 1) is inserted through the lower mold (2), and the enlarged diameter part (11a) at the lower end is sandwiched between upper and lower plates (12) and (13). Therefore, in order to replace the eject pin (11), it is necessary to disassemble the upper and lower plates (12) and (13) in addition to removing the lower mold (2) from the movable plate (5). But,
This disassembly work is large and takes a long time,
It is difficult to secure this time during a normal manufacturing cycle. Therefore, the broken eject pin (11)
In many cases, the production is continued without using the part of the cavity (7) having the problem, which causes a reduction in production efficiency.

Accordingly, an object of the present invention is to provide a resin molding apparatus that can easily replace a broken eject pin.

[0011]

According to the present invention, in order to achieve the above object, a resin filled and solidified in a runner and a cavity formed on the upper surface of a lower mold is filled with a lower mold from below the lower mold. In a resin molding apparatus that is inserted into a mold and is released by an eject pin that projects and retreats from the bottom of the runner and the cavity, a recess is formed in the bottom of the lower mold, and the eject pin is moved in the recess. Divided into an upper part with a different diameter part and a lower part that extends below the lower mold,
A retainer is engaged with the different diameter portion, and a compression spring is interposed between the top surface of the concave portion and the retainer.

[0012]

The upper eject pin protrudes from the lower mold runner and the bottom surface of the cavity when the lower eject pin abutting on the lower end surface thereof rises. The protruding upper eject pin is forcibly retracted by the compression spring pressing the retainer downward. If the upper eject pin is broken in the lower mold, the lower mold is separated and replaced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment according to the present invention will be described with reference to FIGS. However, the same parts as those in the related art are denoted by the same reference numerals, and description thereof will be omitted.

The lower mold (17) of the resin molding apparatus according to the present invention has a recess (17a) formed on the bottom surface. The eject pin (18) is vertically divided, for example, in the movable plate (5) so that the upper and lower eject pins (18a) and (18b) can move up and down integrally without displacement. For example, a reduced-diameter portion (18c) having a reduced diameter is formed at an intermediate portion of the upper eject pin (18a). A plate-shaped retainer (19) is detachably fitted to the different diameter portion (18c). Retainer (19)
As shown in FIG. 4, the two plate members (19a) and (19a) are joined so as to be able to come and go, and a cutout portion (19b) is formed at the joint portion to engage with the different diameter portion (18c). . A compression spring (20) is placed between the upper surface of this retainer (19) and the top surface of the recess (17a).
To urge the retainer (19) downward.

The other configuration is the same as the conventional one,
Next, a method of resin-molding a main part of the semiconductor pellet (10) and the like by using the resin molding apparatus will be described.

First, the semiconductor pellet (10) is mounted, the lead frame (9) to which the wire bonding is performed is set in the lower mold (17), and the movable platen (5) is raised as shown in FIG. Then, with the upper and lower molds (1) and (17) joined, a main part such as the semiconductor pellet (10) is used as a resin mold. At this time, in the initial state of the compression spring (20), the retainer (19) is urged to the lower side of the concave portion (17a), and the upper surface of the upper eject pin (18a) holds the runner (6) and the cavity (7). And the same surface as the bottom surface.

When the resin molding is completed, the lower mold (17)
The movable plate (5) and the ejector rod (14) are lowered in order to separate from the upper die (1). Since the descending amount of the ejector rod (14) is smaller than the descending amount of the movable plate (5), the eject pin (18) protrudes from the bottom of the runner (6) and the cavity (7), as shown in FIG. The resin (16) solidified in the runner (6), gate (8) and cavity (7) is released from the lower mold (17). Then, the resin-molded lead frame (9) is slightly raised by a carrier (not shown), and then discharged from between the upper and lower molds (1) and (17).

Resin-molded lead frame (9)
The upper eject pin (18a) protrudes from the bottom surface of the runner (6) and the cavity (7) of the lower mold (17) from which the water is discharged. Therefore, in preparation for the next resin mold, the upper eject pin (18a) is retracted to the same plane as the bottom surfaces of the runner (6) and the cavity (7). However, when the molten resin is filled into the runner (6) and the cavity (7), the molten resin flows into a gap between the upper eject pin (18a) and the lower mold (17), and the upper eject pin ( 18
In a), it is difficult to slide up and down, and does not retreat into the lower mold (17) by its own weight. Therefore, the upper eject pin (18a) is forcibly moved to the lower mold (1) by the compression spring (20).
7) Retreat inside. That is, the upper eject pin (18a)
Slightly lowers the ejector rod (14) in a state that the ejector rod (14) protrudes from the bottom surfaces of the runner (6) and the cavity (7). Then, the compression coil spring (15) presses the upper plate (12), and the lower eject pin (18b) descends. At this time, even if the upper eject pin (18a) does not follow the lower eject pin (18b), the retainer (19) engaged with the different diameter section (18c) of the upper eject pin (18a) is not The upper eject pin (18a) is forcibly retracted into the lower mold (17) by being urged downward by the compression spring (20) in contact with the top surface of (17a). Upper eject pin (18
On the upper surface of a), the lower mold (17) rises and the upper mold (1)
When the ejector rod (14) reaches the top dead center, it becomes flush with the bottom surfaces of the runner (6) and the cavity (7).

Resin-molded lead frame (9)
When the upper eject pin (18a) breaks when releasing the mold from the lower mold (17), the upper and lower plates (12) and (13)
Replace only the upper eject pin (18a) without disassembling. That is, the lower mold (17) is separated from the movable plate (5), and the retainer (19) composed of the two plate members (19a) (19a) is disassembled. Then, the upper eject pin (18
The different diameter part (18c) of (a) is the notch (19a) of the plate (19a) (19a).
b) Deviate from (19b). Upper eject pin (18a)
Together with the broken part is removed from the eject pin insertion hole of the lower mold (17), and a new upper eject pin (18
Replace with a). The different diameter part (18c) of the new upper eject pin (18a) is the plate material (19a) (19a) of the retainer (19).
Into the notches (19b) and (19b). Retainer (19)
A compression spring (20) is interposed between the lower mold (17) and the top surface of the recess (17a). In this way, only the upper eject pin (18a) can be easily replaced without disassembling the upper and lower plates (12, 13).

The above is a description of one embodiment according to the present invention. The present invention is not limited to this embodiment, and the design can be changed within the gist of the present invention.

For example, the different diameter portion of the upper eject pin is
It is also possible to use an enlarged diameter portion on which a retainer having a through-hole is placed. In addition, the upper eject pin and the lower eject pin are separated on the same plane as the bottom surface of the lower mold, and the displacement of the upper eject pin in the vertical direction is achieved by slightly increasing the diameter of the eject pin insertion hole of the movable platen. , Can also correspond.

[0022]

According to the present invention, since the operation of replacing the eject pins is improved, the replacement time can be shortened, and the efficiency of the resin mold can be improved.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional front view of a resin molding apparatus according to the present invention.

FIG. 2 is a partial cross-sectional front view of the resin molding apparatus according to the present invention.

FIG. 3 is a partial cross-sectional front view of the resin molding apparatus according to the present invention.

FIG. 4 is a perspective view of an upper eject pin and a retainer.

FIG. 5 is a partial cross-sectional front view of a conventional resin molding apparatus.

FIG. 6 is a front view, partially in section, of a conventional resin molding apparatus.

Claims (1)

(57) [Scope of request for utility model registration] An upper die supported on a lower surface of a fixed plate;
The upper mold is supported by a movable plate that moves and approaches and separates from the fixed plate.
And runner and cavity are formed on the upper surface
The lower die is inserted through the movable platen, penetrates the lower die, and the upper end is
Of the runner and cavity of the lower mold in abutment with the mold
It is almost flush with the bottom, and is relatively
Eject pin protruding from the bottom of the cavity and cavity
And into the cavity from the abutted mold runner
Supply the fluidized resin, mold the resin, and open the upper and lower molds
The eject pin protrudes into the cavity in conjunction with
A resin mold that releases the resin molded product from the lower mold
In field device, the eject pin is detachably connected with axially intermediate
And the part located in the recess formed in the lower surface of the lower mold
A different diameter part is formed, and the different diameter part of the eject pin is
With a flat plate-shaped retainer that has a notch to accommodate and pinch
Engage the eject pin and retain the lower mold
A resin molding device characterized in that a compression spring is interposed between the resin molding device and the resin molding device.