JP3038275B2 - Resin sealing method and resin sealing 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 method for sealing a molded resin of an IC, an electronic component or the like.

In recent years, transfer molding dies have been used for sealing a molding resin for a semiconductor device (IC) or the like.
Depending on the type of molded product, the type of mold resin also differs, and the viscosity at the time of resin injection changes. Therefore, it is necessary to set conditions such as resin injection speed and time according to the resin,
It is desired that it can be easily set.

[0003]

2. Description of the Related Art FIG. 3 shows a configuration diagram of a conventional resin sealing device. FIG. 3A shows a mold included in the resin sealing device.
FIG. 3B is a schematic view of a lower mold, and FIG. 3B shows a pot portion of the upper mold.

In FIG. 3, a lower mold 11a has a cull 1
A plurality of runners 13 a communicating with the cull 2 and the cull 12 are formed. A plurality of grooves 14 are formed in the lower mold 11a,
A mold portion 17 having a runner 13b formed therein through which a plurality of cavities 15 communicate with each other via a gate 16 (see FIG. 4) is fitted into the groove 14. This mold part 1
7 is positioned so that the runner 13a and the runner 13b of the mold portion 17 communicate with each other at the time of fitting.

On the other hand, the upper mold 11 corresponding to the lower mold 11a
b, a pot 18 communicating with the cull 12 of the lower mold 11a.
Is formed, and a tablet-shaped mold resin 19 is inserted into the pot 18.

The upper mold 11b and the lower mold 11a are heated by heating means (not shown).
The mold resin 19 inserted in the mold 8 is melted.

FIG. 4 is a diagram for explaining the gate portion shown in FIG. FIG. 4A shows a part of the mold part 17, in which a cavity 15 is communicated via a gate 16 with a runner 13 b formed in the mold part 17. In this case, as shown in FIG. 4 (B), a gate insert pin 20 buried below is provided between the gate 16 and the cavity 15, and its tip serves as a gate port 16a. The dimensions of the gate opening 16a are set in consideration of the capacity of the cavity 15, the viscosity of the mold resin 19, and the gate breakability.
Fixed dimensions.

FIG. 5 is a view for explaining the mold. In FIG. 5A, for example, a lead frame 21 on which a chip of a semiconductor device to be resin-molded is mounted is placed on a mold portion 17 of a lower mold 11a, and clamped by an upper mold 11b.

Then, a tablet-shaped mold resin 19 is inserted into the pot 18 and is heated and melted. continue,
When pressure is applied and pushed in, molten resin 19 is injected into cavity 15 through gates 16 (gate openings 16a) through runners 13a and 13b to perform resin sealing.

In this case, since the dimensions of the gate opening 16a are fixed, the injection molding is performed while the viscosity of the molding resin 19 and the injection pressure are delicately controlled. Further, since the resin is injected into the cavity 15 several tens of times, the gate opening 16a becomes worn and becomes larger than the initial gate size, and the resin injection condition is changed.

[0011]

However, the gate port 16
It is complicated to finely set the resin injection conditions each time by fixing the dimension of a, and when the gate opening 16a becomes large due to wear, the gate breakability deteriorates, and the appearance of the package is impaired, resulting in poor quality and yield. There is a problem of causing a decrease.

In addition, the gate insert pins 20 must be periodically replaced due to abrasion of the gate opening, which requires many steps, a large amount of cost and a long time, and lowers production efficiency.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide a resin sealing method for reducing replacement due to gate wear and setting good resin injection conditions.

[0014]

SUMMARY OF THE INVENTION The object of the present invention is to provide a resin sealing method in which a predetermined number of molding objects are placed in a cavity provided in series and sealed with a resin. This is solved by controlling the amount of injection into the cavity by opening and closing the gate according to the injection pressure of the resin when injecting from the gate.

[0015]

As described above, when the molten resin is injected into the cavity through the gate, the injection amount is controlled according to the injection pressure of the resin. Therefore, it is not necessary to control the injection pressure for each resin injection condition such as the type of resin.

Further, by controlling the resin injection amount without being affected even if the gate opening of the gate is worn, it becomes possible to set a wide range of resin injection conditions, thereby improving the molding quality of the product. Can be achieved.

[0017]

FIG. 1 is a block diagram showing an embodiment of the present invention.
FIG. 1A is a schematic view of a lower mold among the molds provided in the resin sealing device of the present invention, and FIG. 1B is a view showing a pot portion of an upper mold, and FIG. () Is a diagram showing a gate portion. The same components as those in FIGS. 3 to 5 are denoted by the same reference numerals.

1A to 1C, similarly to FIG. 3, a lower mold 11a is formed with a cull 12 and a plurality of runners 13a communicating with the cull 12. Also, the lower mold 11
A plurality of grooves 14 are formed in a, and a mold portion 17 in which a runner 13b in which a plurality of cavities 15 are communicated via a gate 16 is fitted into each of the grooves 14. The position of the mold section 17 is adjusted so that the runner 13a and the runner 13b of the mold section 17 communicate with each other at the time of fitting.

Here, as shown in FIG. 1 (C), the cavity 15 of the mold portion 17 is
6 is communicated. A hole 16b (see FIG. 2) is formed in the gate opening 16a of the gate 16 to the cavity 15, and the tip of a gate insert pin 32, which is an opening / closing part of the control mechanism 31, enters and exits through the hole 16b. The tip of the gate insert pin 32 is
A taper portion 32a is formed so as to be higher toward the cavity 15 side than the side, and moves up and down by a spring 33 which is an elastic member to open and close the gate 16 (gate port 16a).

On the other hand, the upper mold 11 corresponding to the lower mold 11a
b, a pot 18 communicating with the cull 12 of the lower mold 11a.
Is formed, and a tablet-shaped mold resin 19 is inserted into the pot 18. The upper mold 11b and the lower mold 11a are heated by heating means (not shown), and melt the mold resin 19 inserted into the pot 18.

Next, FIG. 2 shows a diagram for explaining the mold of the present invention. In FIG. 2A, the lower mold 11a
Frame 21 on which a chip of a semiconductor device to be resin-molded, for example, is mounted
Is placed and clamped by the upper mold 11b.

In this state, the gate insert pin 32 of the control mechanism 31 is pushed upward by the urging force of the spring 33, and the tapered portion 32a at the tip comes into contact with the lead frame 21. That is, the gate port 16 a of the gate 16 is closed by the gate insert pin 32.

Therefore, in FIG.
The tablet-shaped mold resin 19 is inserted into the mold, and is melted by heating. Subsequently, when pressure is applied and pressed, the molten mold resin 19 reaches the gate port 16a of the gate 16 through the runners 13a and 13b. In this case, the gate insert pin 32 is pushed back downward by the injection pressure of the resin, the gate port 16a is opened, and the resin is injected into the cavity 15. At this time, the degree of opening of the gate port 16a is expanded in accordance with the injection pressure of the resin, and the injection speed and the injection time are automatically adjusted and controlled by the spring 33.

Next, in FIG. 2C, when the resin 19 is filled in the cavity 15 and the resin injection is completed, the injection pressure is reduced after the completion, so that the gate insert pin 32 is re-energized by the urging force of the spring 33. It is pushed back to close the gate port 16a.

As described above, the control mechanism 31 can automatically control the delicate injection speed and injection time at the time of resin injection in response to a change in viscosity or the like of the mold resin 19.

Therefore, as shown in FIG. 1 (A), the elastic force of the spring 33 in the control mechanism 31 of the cavity located farther from the pot 18 of the mold portion 17 is gradually weakened, so that the inside of one mold portion 17 is reduced. Multiple cavities 1
The resin injection of No. 5 can be performed in the same time, and the occurrence of defective products can be reduced. Thereby, the quality can be improved. Also, the gate insert pin 32
As a result, the gate break can be easily performed, the number of steps can be reduced, and the cost can be reduced.

On the other hand, even if the gate insert pin 32 is worn by the mold resin 19, the same control can be always performed as long as the tapered portion 32a is maintained. As a result, the frequency of replacement due to wear of the control mechanism 31 is greatly reduced, and the cost of parts, the number of steps required for replacement, the cost, and the like can be significantly reduced.

In the tapered portion 32a of the gate insert pin 32, a slight gap is formed at the tip without completely closing the gate port 16a depending on the viscosity of the molding resin 19 and the conditions of the injection pressure. By forming grooves or the like, resin sealing can be performed under a wider range of conditions.

[0029]

As described above, according to the present invention, when the molten resin is injected into the cavity through the gate, the amount of injection is controlled by the control mechanism in accordance with the injection pressure of the resin. In addition to reducing replacement due to abrasion, good resin injection conditions can be set, and production cost can be reduced and the quality of molded products can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a view for explaining a mold of the present invention.

FIG. 3 is a configuration diagram of a conventional resin sealing device.

FIG. 4 is a diagram for explaining a gate portion in FIG. 3;

FIG. 5 is a view for explaining the mold of FIG. 3;

[Explanation of symbols]

 11a Lower mold 11b Upper mold 12 Cull 13a, 13b Runner 15 Cavity 16 Gate 17 Mold part 18 Pot 19 Mold resin 21 Lead frame 31 Control mechanism 32 Gate insert pin (opening / closing part) 33 Spring

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/56 B29C 45/14 B29C 45/26

Claims (3)

(57) [Claims] 1. A resin sealing method for sealing a resin by positioning a predetermined number of molding objects in a cavity provided in series, wherein a molten resin is injected through a gate communicating with the cavity. And at the time of injection from the gate, according to the injection pressure of the resin.
Controlling the injection amount into the cavity by opening and closing the gate by the elastic force of the elastic member . 2. A method according to claim 1, wherein a predetermined number of objects are molded in a continuous cavity.
And put resin through gates
Resin sealing deviceThe For each gate,TheResin injected into cavity
A control mechanism to control the injection volume according to the injection pressure
Ke, An opening / closing unit that opens and closes the passage of the gate;
Elastic part for opening and closing the opening and closing part according to the injection pressure of the resin
Material and Resin sealing device characterized by the fact that
Place. 3. The method according to claim 1 , wherein the elastic force of said elastic member is adjusted by injection of said resin.
3. The method according to claim 2, wherein the setting is made in accordance with input conditions.
Resin sealing device.