JP2513113B2 - Double resin sealing device for semiconductor device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin sealing device for a semiconductor device which seals a semiconductor chip mounted on a lead frame with a resin, and more particularly to a plurality of individual semiconductor chips mounted side by side on a lead frame. The present invention relates to a double resin sealing device for a semiconductor device, which is resin-sealed and collectively seals a plurality of resin-molded mold bodies.

[0002]

2. Description of the Related Art Generally, in a counter-directional semiconductor device such as a photocoupler, each semiconductor chip is individually resin-molded with a primary resin-sealing die, and then the semiconductor chips are resin-sealed. The bodies are arranged side by side and molded together with a secondary resin sealing mold to form the outer shell of the counter-directional semiconductor device.

FIGS. 4 (a) and 4 (b) are partial plan views showing a lower die of a primary and secondary resin sealing mold in an example of a conventional double resin sealing device. Conventionally, this type of double resin encapsulation device includes a primary resin encapsulation mold shown in FIG.
It was comprised with the secondary resin sealing metal mold | die shown to (b).

The structures of these resin-sealing molds are such that cavities 16 and 17 which form a closed space with a recess of an upper mold (not shown), and runners 12 in these cavities 16 and 17.
Gate 1 for injecting the molten resin supplied from a and 12b
Cross runners 13a and 13b having 4a and 14b were formed on the lower molds 11a and 11b, respectively. Also,
The cross runners 13 and 13b were provided at the same position for standardization of the resin sealing mold.

FIG. 5 is a partial plan view showing a mounting state of the lower die and the lead frame of FIG. 4A, FIG. 6 is a sectional view showing a resin burr generated in the vicinity of the cross runner generated after the primary resin sealing, and FIG. FIGS. 4A and 4B are partial plan views showing a mounting state of the lower die and the lead frame of FIG. 4B, and FIGS.
It is sectional drawing (b). Next, a resin sealing method for a semiconductor device by this double resin sealing device will be described. First, as shown in FIG. 5, the strip-shaped lead frame 20 is placed on the lower mold 11 a of the primary resin sealing mold, and the semiconductor chip 21 mounted on the lead frame 20 is inserted into each cavity 16.
Next, the upper mold (not shown) and the mold are closed. Then, the molten resin is flown from the runner 12a to the cross runner 13a, and the molten resin is injected into the cavity 16 from the gate 14a. After a predetermined curing time has elapsed after the completion of the injection, the mold is opened, and the resin-sealed mold body like a beaded string is removed from the primary resin-sealed mold.

Next, as shown in FIG. 7, the gate resin burr 24 attached to the lead frame 20 by the resin reservoir near the cross runner is attached to the mold body 22 removed from the primary resin sealing die. The gate resin flash, which is the remaining gate, is removed from the chipping mold body 22. Then, the resin burr protruding from the resin-sealed mold body to the lead side is removed by a resin burr removal type, and the process after the primary resin sealing is completed.

Next, as shown in FIG. 7A, the lead frame 20 is positioned and mounted on the lower mold 11b so that all of the mold bodies 22 which are lined and resin-sealed are housed in the cavity 17. And after closing the mold, runner 12
The molten resin is flowed from b to the cross runner 13b, and the gate 1
Molten resin is injected into the cavity 17 from 4b, and a plurality of molds are integrated to form the outer shell of the semiconductor device.

As described above, the individual semiconductor chips mounted side by side on the lead frame are resin-sealed, and then they are collectively molded while maintaining the positions of the individual molded bodies on the lead frame, so that the mutual positional relationship is maintained. It could be integrally molded without breaking.

[0009]

However, in the conventional double resin sealing device described above, the resin flash is removed in the resin flash removing step after the primary resin sealing, but FIG.
As shown in FIG. 7, the gate resin flash 24, which is the gate residue of FIG. 7 attached on the cross runner 13a, is not completely removed and often remains as the remaining portion 24a. Since the positions of the cross runners 13a and 13b of the respective lower molds 11a and 11b are aligned with each other, the remaining portion 24a enters the cross runner 13b of the secondary resin sealing die during the secondary resin sealing, The flow of the molten resin injected from the gate 14b is obstructed, and the molten resin adheres to the remaining portion of the resin along with the flow of the resin, and the flow resistance increases as the flow rate increases. As a result, the flow rate of the injected molten resin is insufficient, the resin is not sufficiently filled in every corner of the cavity 17, and the resin is cured, resulting in chipping or denting of the resin outer shell due to insufficient resin supply, which is a serious defect in quality. Becomes

For this reason, after removing the gate residue after the primary resin sealing, the presence or absence of the remaining portion is inspected, and if there is, the surface of the lead frame is smoothly finished by honing and then the secondary resin sealing is performed. . However, this work must be performed off-line, and it is difficult to operate the resin sealing line smoothly, and there is a drawback that a great number of man-hours are wasted. As a countermeasure against this, for example, in order to easily remove the remaining gate, a method of narrowing the resin inflow path of the cross runner close to the gate and providing a notch in the remaining gate, and making the remaining gate easily broken from the notch However, the rest of the gate cannot be completely removed and it has not been resolved.

Therefore, an object of the present invention is to provide a dual semiconductor device which can be molded into a resin outer body having no defects even if some resin burrs remain after the primary resin encapsulation and the operation of the resin encapsulation line can be smoothly performed. It is to provide a resin sealing device.

[0012]

A feature of the present invention is that a plurality of first semiconductor chips, each of which is mounted on a strip-shaped lead frame and arranged side by side in the width direction of the strip, are individually wrapped and housed. A primary resin sealing die having a cavity, a first gate for injecting a molten resin into each of these first cavities, and a first cross runner derived from the first runner, and this primary resin sealing A second cavity for enclosing and accommodating a plurality of mold body rows formed by resin-sealing with a mold and connected to the lead frame in a beaded shape;
A double resin encapsulation of a semiconductor device including a secondary resin encapsulation mold having a second gate for injecting a molten resin into the second cavity and having a second cross runner derived from the second runner. In the apparatus, the primary resin sealing die and the secondary resin sealing die are arranged side by side with the direction in which the first cavities are aligned and the longitudinal direction of the second cavities in parallel and are moved in parallel to each other. 1 cavity and the second
Is a double resin encapsulation device for a semiconductor device in which the positions of the first cross runner and the second cross runner are different when they are aligned with each other.

Further, it is desirable to form a recess in the lower mold surface of the secondary resin sealing mold corresponding to the position of the first cross runner of the primary resin sealing mold.

[0014]

Next, the present invention will be described with reference to the drawings.

FIGS. 1 (a) and 1 (b) are partial plan views showing a lower die of a primary and secondary resin sealing die in an embodiment of a double resin sealing device of the present invention. This double resin sealing device is provided with a position of the cross runner 1a in the lower die 9a of the primary resin sealing die shown in FIG. 1 (a) and a lower die of the secondary resin sealing die shown in FIG. 1 (b). The cavities 16, 1 of the cross runner 1b so that they do not coincide with the positions of the cross runner 1b
The cross runner 1a is symmetrically displaced from the center position of 7
And 1b are formed.

As described above, if the position of the cross runner 1a of the primary resin sealing die and the position of the cross runner 1b of the secondary resin sealing die are different, the resin remaining on the gate formed in the primary resin sealing operation The remaining portion is not inserted into the cross runner 1b of the secondary resin sealing die during the secondary resin sealing. Also,
Since the portion of the lead frame to be inserted instead is a smooth metal surface on which nothing is adhered, it does not become a resistance to the flow of the molten resin, and the molten resin does not adhere to that portion. As a result, there has been no loss of the resin outer shell due to the insufficient supply of resin, which has occurred conventionally.

The remaining portion of the resin that cannot be removed is sandwiched between the lead frame and the die surface when the die is closed, and the gap between the lead frame and the die surface increases by the thickness of the remaining portion. Although the resin flash becomes larger, the resin flash itself is thin and can be easily removed, so that the efficiency of the resin flash removal work is not reduced.

2 (a) and 2 (b) are partial plan views showing the lower molds of the primary and secondary resin sealing molds in another embodiment of the double resin sealing device of the present invention. As shown in FIG. 2, this double resin sealing device includes a runner 4 and a cross runner 6 of a lower die 10a in a primary resin sealing die and a runner 5 and a cross of a lower die 10b in a secondary resin sealing die. Runner 7
And are provided at positions opposite to each other across the cavities 16 and 17.

On the lower die surface of the secondary resin sealing die,
This is to form a recess 8 which is a relief of the remaining resin at a position corresponding to the cross runner 6 of the primary resin sealing die. This recess 8 is formed at this portion as compared with the above-described embodiment, by allowing the remaining portion of the gate remaining that could not be removed during the primary resin sealing to be completely closed during the secondary resin sealing. This means that the amount of resin flash used is reduced. In particular, in the case where the outer casing of the semiconductor device is large, it is expected that the remaining portion of the silicate and its remaining portion will become larger with the increase in size, so it is recommended to apply the double resin sealing device of this embodiment. desirable.

3 (a) to 3 (e) are partial plan views showing the order of steps for explaining the double resin sealing method of the semiconductor device by the double resin sealing device of FIG. Next, a double resin sealing method will be described in the order of the resin sealing steps so that the semiconductor device double resin sealing device of the present invention can be easily understood.

First, as shown in FIG. 3A, the strip-shaped lead frame 20 having the semiconductor chip 21 mounted thereon is placed on the lower mold 10a of the primary resin-sealed mold, and the semiconductor chip 21 is housed in each cavity 16. Position as required. This positioning is usually performed by inserting a pin of the lower mold 10a into a hole formed in the outer frame of the lead frame 20.

Next, as shown in FIG. 3B, the lead frame 20 is removed from the primary resin sealing mold, and the resin flash around the mold 22 and the gate flash 24 near the cross runner 6 are attached. Then, the lead frame 20 having the primary resin sealed therein is transferred to a resin flash removing device (not shown). Then, first, as shown in FIG. 3C, the gate resin burr 24 is chipped off, and the remaining portion 24 a remains on the back surface of the lead frame 20. Subsequently, the resin flash around the mold body 22 is removed, and FIG.
As shown in, the lead frame 20 is transferred to the lower die 10b of the secondary resin sealing die.

Next, the mold body is placed in the cavity 17.
The remaining portion 24a attached to the lead frame 20 is positioned so as to enter the recess 8. Then, after the mold is closed, the molten resin is flown from the runner 5 through the cross runner 7, and the molten resin is injected into the cavity 17 from the gate. At this time,
The portion of the lead frame 20 on the upper part of the cross runner 7 is a clean metal surface on which nothing is attached, so that the molten resin is smoothly injected without any resistance. After the injection is completed and a predetermined curing time has elapsed, the mold is opened and the lead frame 20 on which the secondary resin sealing is completed is removed from the lower mold 10b. And
Resin burrs attached to the periphery of the resin shell 25 shown in FIG. 3E, the remaining portion 24a and newly attached gate resin burrs 2
Complete with 6 removed.

As described above, by simply changing the position of the cross runner, the operation can be performed without sticking to the removal of the remaining gate, so that it is not necessary to temporarily stop the apparatus and finish the surface of the lead frame offline. The operation of the stop line was made smooth, and the operating rate of the equipment could be dramatically improved.

[0025]

As described above, according to the present invention, the positions of the cross runners having the gates for injecting the molten resin into the cavities of the primary and secondary resin sealing molds are different from each other so that the primary resin sealing is performed. Occasionally, the remaining portion of the remaining gate does not enter the cross runner of the secondary resin sealing die, and the resin is smoothly injected without any resistance during the secondary resin encapsulation. There is an effect that molding can be performed without causing defects. Further, there is no need to completely remove the remaining portion and finish the surface, which has been conventionally performed off-line, and there is an effect that the resin sealing line including these resin sealing molds can be operated extremely smoothly.

[Brief description of drawings]

FIG. 1 is a partial plan view showing a lower die of a primary and secondary resin sealing die in an embodiment of a double resin sealing device of the present invention.

FIG. 2 is a partial plan view showing a lower die of a primary and secondary resin sealing mold in another embodiment of the double resin sealing device of the present invention.

3A and 3B are partial plan views showing the order of steps for explaining a double resin sealing method for a semiconductor device by the double resin sealing device of FIG.

FIG. 4 is a partial plan view showing a lower die of a primary and secondary resin sealing mold in an example of a conventional double resin sealing device.

5 is a partial plan view showing a mounted state of the lower die and the lead frame of FIG. 4 (a).

FIG. 6 is a cross-sectional view showing a resin flash generated in the vicinity of the cross runner generated after the primary resin sealing.

FIG. 7 is a partial plan view (a) and a BB sectional view (b) showing a mounted state of the lower die and the lead frame of FIG. 4 (b).

[Explanation of symbols]

 1a, 1b, 6, 7, 13a, 13b Cross runners 2a, 2b, 4,5, 12a, 12b Runners 3a, 3b, 6a, 7a, 14a, 14b Gate 8 recess 9a, 9b, 10a, 10b, 11a, 11b Lower mold 16,17 Cavity 20 Lead frame 21 Semiconductor chip 22 Molded body 24,26 Gate resin burr 24a Remaining 25 Resin outer shell

Claims (2)

(57) [Claims] 1. A plurality of first cavities for individually enclosing and accommodating a plurality of single semiconductor chips mounted side by side in the width direction of the band on a band-shaped lead frame, and each of these first cavities. A primary resin encapsulation mold having a first gate for injecting a molten resin into the resin and a first cross runner derived from the first runner; The second frame has a second cavity for enclosing and accommodating a plurality of mold body rows connected in a bead shape in a lead frame, and a second gate for injecting molten resin into the second cavity.
In a double resin encapsulation device for a semiconductor device, which comprises a secondary resin encapsulation mold having a second cross runner derived from the above runner, the primary resin encapsulation mold and the secondary resin encapsulation are described above. First
When the first cavity and the second cavity are aligned by arranging the cavities of the first cavity and the second cavity in the longitudinal direction in parallel and arranging the first cavity and the second cavity in parallel, A double resin encapsulation device for a semiconductor device, wherein the runner and the second cross runner are different in position. 2. A depression is formed in a lower mold surface of the secondary resin sealing mold corresponding to a position of the first cross runner of the primary resin sealing mold. 2. A double resin sealing device for a semiconductor device according to 1.