JPH04339623A - Resin sealing mold - Google Patents

Abstract

PURPOSE:To provide resin sealing mold capable of performing molding of a box type resin molded body provided with a lead frame, by preventing generation of flashes in an inner lead part of the lead frame without increasing the cost of equipment and a molding time. CONSTITUTION:A template 13 on which a lead frame 21 is put is fitted to the top of a movable mold 11 movably vertically and a through hole 16 is formed in the center of the template 13. Then a core 15 which is inserted into a through hole 16 is fixed on the movable mold 11 and a pair of slide cores 18 are fitted within the through hole 16 movably in a facial direction of the template 13. Then the pair of the slide cores 18 are pushed open through the core 15 by a rise of the movable mold 11 and an inner lead frame 21 is placed between a hook part 18c formed on the top of the slide core 18 and the top of the template 13 and fixed, through which the inner lead part is prevented from being covered with flashlike resin by deforming the lead part at the time of filling of the resin.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for resin sealing used in manufacturing a box-shaped resin molded body with a lead frame constituting a semiconductor device.

0002

2. Description of the Related Art A box-shaped resin molded body constituting a semiconductor device such as a CCD is usually provided with a plurality of lead frames on each of two opposing sides. One end of these lead frames protrudes to the outside of the box-shaped resin molded body, and the internal leads at the other end protrude into the recess in the center of the molded body, with one side in close contact with the surface of the recess and the other side exposed. There is.

Conventionally, a mold for molding the above-mentioned box-shaped resin molded body has a lower movable mold 1 as shown in FIG.
and an upper fixed mold 2. Movable mold 1
A recess 3 having a rectangular cross section is provided on the upper surface of the box-shaped resin molded body, and a convex portion 4 is provided on the lower surface of the fixed mold 2, forming the central recess of the molded product. It is being Then, a plurality of lead frames 5 are placed on the upper surface of the movable mold 1 along two opposing sides of the concave portion 3, one end of the lead frame 5 is made to protrude into the concave portion 3, and a step on the outer periphery of the convex portion 4 is formed. Hit part 6. After that, the movable mold 1 is raised and the lead frame 5 is sandwiched between it and the fixed mold 2, and the recess 3
Fill the inside with resin and perform injection molding.

However, according to the conventional resin sealing mold configured as described above, the internal lead portion protruding into the recess 3 of the lead frame 5 has an upper surface that is in contact with the stepped portion 6 of the fixed mold 2. They are in contact, but the bottom surface is not held. Therefore, when molds 1 and 2 are closed and resin injection molding is performed,
As shown in FIG. 8, the internal lead portion of the lead frame 5 is deformed due to the flow pressure of the resin. Then, the wire bonding surface on the upper surface of the internal lead portion protruding into the central recess of the box-shaped resin molded body is covered with burr-shaped resin. Therefore, in this state, the lead frame 5 and the wire will not be electrically connected and the original function cannot be achieved, so conventionally, secondary processing such as deburring has been required.

[0005] As a proposal for eliminating the need for the above-mentioned secondary processing work, there is a known proposal described in Japanese Patent Application Laid-Open No. 2-222551. In this proposal, as shown in FIG. 9, a vacuum hole 7 is provided which opens at a portion of the fixed mold 2 that is scheduled to come into contact with the internal lead portion of the lead frame 5 and penetrates the fixed mold 2. After the lead frame 5 is sandwiched between the molds 1 and 2, the vacuum hole 7 is evacuated and the resin is inserted while the lead frame 5 is suctioned and fixed to the stepped portion 6 of the fixed mold 2. .

[0006]

SUMMARY OF THE INVENTION As mentioned above, the conventional resin sealing molds have the problem of requiring secondary processing operations such as deburring. Further, according to the configuration described in the above publication, secondary processing work is not required, but the diameter of the vacuum hole 7 must be 1 mm or less because the width of the internal lead part is narrow, and deformation due to the flow pressure of the resin is prevented. It was difficult to suction and fix the lead frame 5 with enough force to prevent this. In addition, a vacuum pump is required, and the vacuum suction operation must be performed after the molds 1 and 2 are completely closed, which increases equipment costs and molding time.

The present invention has been made in view of the above situation, and it is possible to prevent the occurrence of burrs on the internal lead portion of the lead frame without increasing the equipment cost and molding time, and to form a box-type structure with a lead frame. It is an object of the present invention to provide a mold for resin sealing that can mold a resin molded body.

[0008]

[Means for Solving the Problems] The resin sealing mold of the present invention has a lead frame sandwiched between an upper fixed mold and a lower movable mold, filled with resin, and one end of the lead frame. In a resin sealing mold for molding a box-shaped resin molded body in which a lead frame protrudes toward the outer periphery and one end of the other end is exposed on the inner periphery, the lead frame a rectangular hole formed through the center of the template and whose opposing inner surface corresponds to the inner peripheral end of the lead frame; A locking member is attached to the mold plate so as to be slidable in the surface direction of the mold plate, and has a hook portion at the upper end that engages with the inner peripheral end of the lead frame, and a locking member is fixed to the movable mold and the locking member is attached to the mold plate. It is characterized by comprising a driving means for driving in the plane direction of the plate.

[0009]

[Operation] In the resin encapsulation mold having the above configuration, when the lead frame is positioned and placed on the mold plate, the movable mold is raised, and the lead frame is sandwiched between the mold plate and the fixed mold. Then, the driving means is raised together with the movable mold. Then, the driving means pushes open the locking member attached to the template in the direction of the surface of the template, and the hook provided at the upper end of the locking member clamps the tip of the lead frame between it and the template. In this state, even if the mold is not filled with resin, the lead frame will not be deformed, and no burr-like resin will adhere to the exposed surface at the tip of the lead frame. When the mold is opened, the driving member descends, and the hook at the upper end of the locking member can be removed from the tip of the lead frame.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a mold for resin sealing of the present invention will be described below with reference to the drawings.

FIGS. 1 to 4 show the structure of an embodiment of the present invention. In FIG. 1, a movable mold 11 is driven up and down by a drive means (not shown). Four guide bars 12 are vertically erected on the upper surface of the movable mold 11, and a cubic mold plate 13 is provided so as to be movable up and down while being guided by the guide bars 12. Further, a plurality of first springs 14 are installed between the upper surface of the movable mold 11 and the lower surface of the mold plate 13, and bias the mold plate 13 in a direction away from the movable mold 11. ing. The movement stroke of the template 13 relative to the movable mold 11 is about 5 mm. In addition, movable mold 1
A core 15, which is a driving member with a rectangular cross section, protrudes from the top surface and is fixed in the vertical direction at the center of the core 15.
Both sides of the upper end are tapered surfaces, and the plate thickness becomes thinner toward the top.

A through hole 16 with a rectangular cross section into which the core 15 is inserted is formed vertically in the center of the template 13, and horizontally extending holes are formed on both longitudinally opposing inner surfaces of the through hole 16, respectively. A recess 17 is provided in the. A flange 18a at the lower end of the slide core 18, which is a locking member, is fitted into each of the recesses 17 so as to be slidable in the horizontal direction. As shown in FIGS. 2 to 4, the slide core 18 has a substantially L-shaped cross section, and has a flange 18a at the bottom. Further, the side surfaces 18b opposite to each other in the vertical direction are
The tapered surface has the same slope as the tapered surface at the upper end of the core 15. Further, a hook portion 18c is integrally formed at the upper end of the slide core 18, protruding outward and having a tapered portion on the lower surface. Further, second springs 19 are installed between the opposing inner surfaces of the through holes 16 formed in the template 13 and the outer surfaces of the slide cores 18, respectively.
The inner tapered surface 18b of the slide core 18 and the tapered surface at the upper end of the core 15 are pressed so as to come into close contact with each other.

Between the longitudinally opposite end surfaces of the slide core 18 and the longitudinally opposing inner surfaces of the hole 16 of the template 13,
As shown in FIG. 2, a core insert 20 is installed, and the core insert 20 is fixed in the hole 16. Also, core insert 2
The sliding contact surface with the slide core 18 of 0 is a finished surface with low sliding resistance, and is also subjected to a bending treatment to provide resistance to wear and tear. Further, a guide pin 22 for positioning the lead frame 21 is implanted on the upper surface of the template 13 in the figure, and a resin is introduced into the upper surface of the template 13 at the position where the lead frame 21 is placed. A recess 23 is formed. Further, a fixed mold 25 fixed to an apparatus frame 24 is provided on the upper part of the mold plate 13 facing the mold plate 13, and the bottom of the box-shaped resin molded body is formed on the lower surface of the fixed mold 25. A recess 26 is provided.

Next, the operation of manufacturing a box-shaped resin molded body using the resin sealing mold according to this embodiment constructed as described above will be explained with reference to FIGS. 1, 5, and 6.

In the state shown in FIG. 1 in which the molds 11 and 25 are open, the mold plate 13 is positioned on the movable mold 11 with a predetermined stroke due to the biasing force of the first spring 14. At this time, the core 15 is lowered with respect to the mold plate 13 together with the movable mold 11, and the pair of slide cores 18 are brought closer together by the biasing force of the second spring 19. The hook portion 18c of the slide core 18 is separated from the place where the lead frame 19 of the template 13 is placed. In this state, the lead frame 21 is mounted and fixed at a predetermined position on the template 13 using the guide pins 22.

When the movable mold 11 rises and the molds 11 and 25 are closed via the mold plate 13, the core 15 rises relative to the mold plate 13, and the slide core 18 moves on both sides as shown in FIG. It is pushed open. As a result, the internal lead portion of the lead frame 19 is clamped and fixed between the hook portion 18c of the slide core 18 and the upper surface of the template 13. In this state, resin injection molding is performed. The gate positions at this time are 27 and 28 as shown in Figure 5.
It may be in any position. If the resin to be filled is a thermoplastic resin, the resin is injection molded using a vertical injection molding machine, and if the resin is a thermosetting resin, the resin is filled using a transfer molding machine.

After the resin is filled in the recesses 23 of the mold plate 13 and the recesses 26 of the fixed mold 25 and the box-shaped resin molded body 30 is molded, in order to take out the molded body 30 from the fixed mold 25 and the mold plate 13. , the movable mold 11 is lowered. At this time, as shown in FIG. 6, the mold plate 13 is raised in a direction away from the movable mold 11 by the urging force of the first spring 14. Therefore, the core 15 is lowered relative to the slide core 18, and 1
The pair of slide cores 18 are moved toward each other by the biasing force of the second spring 19. As a result, lead frame 2
The internal lead portion of No. 1 is released from the hook portion 18c of the slide core 18, and the molded body 30 integrally formed with the lead frame 21 can be taken out from the template 13. Note that the molded body 30 is usually taken out by protruding the molded body 30 using an ejector pin (not shown).

According to this embodiment, when the fixed mold 25 and the mold plate 13 are filled with resin, the internal lead portion of the lead frame 21 is connected to the mold plate 13 and the hook portion 18c of the slide core 18.
Since the lead frame 21 is firmly sandwiched between the lead frame 21 and the lead frame 21, the lead frame 21 is not deformed by the flow pressure of the resin. Therefore,
The exposed surface of the internal lead portion is in close contact with the surface of the template 13, and can be prevented from being covered with burr-like resin. Further, since the internal lead portion is held by lifting the movable mold 11, there is no need to provide a separate driving means, and the structure of the apparatus is simplified. Moreover, the molding time does not become long.

[0019]

Effects of the Invention As explained above, according to the resin sealing mold of the present invention, the internal lead portion of the lead frame is fixed on the mold plate by raising the movable mold, which reduces equipment costs. The generation of burrs can be prevented without increasing molding time.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing the structure of an embodiment of a resin sealing mold of the present invention.

FIG. 2 is a front view showing the configuration of the slide core in FIG. 1.

FIG. 3 is a side view of FIG. 2;

FIG. 4 is a plan view of FIG. 2;

FIG. 5 is an explanatory diagram showing a state when the mold shown in FIG. 1 is closed.

FIG. 6 is an explanatory diagram showing a state when the mold shown in FIG. 5 is opened.

FIG. 7 is an explanatory diagram showing the configuration of an example of a conventional resin sealing mold.

8 is an explanatory diagram showing a deformed state of the lead frame in FIG. 7; FIG.

FIG. 9 is an explanatory diagram showing the configuration of another example of a conventional resin sealing mold.

[Explanation of symbols]

11 Movable mold 13 Template 15 Core (driving means) 16 Through hole 18 Slide core (locking member) 18c hook part 21 Lead frame 25 Fixed mold 30 Box-shaped resin molded body

Claims (1)

[Claims] 1. A lead frame is sandwiched between an upper fixed mold and a lower movable mold and filled with resin, one end of the lead frame protrudes toward the outer circumference, and one surface of the other end protrudes toward the inner circumference. In a resin sealing mold for molding a box-shaped resin molded body exposed at the side, the mold is attached to the upper surface of the movable mold so as to be movable up and down, and the lead frame is placed on one side of the resin molded body. A template to be molded, a rectangular hole formed through the center of the template and whose opposing inner surface corresponds to the inner circumferential end of the lead frame, and a rectangular hole formed in the hole in the direction of the surface of the template. a locking member that is slidably mounted and has a hook portion at its upper end that engages with the inner end of the lead frame; 1. A mold for resin sealing, comprising a driving means for driving the mold.