JPH09216247A - Device for resin molding and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the quality of a resin molded product by preventing the uneveness of the degree of filling resin into a cavity caused by using stick- shaped resin tablets. SOLUTION: In this resin molding device in which a plurality of cavity recessed sections are formed, and openings are formed in parallel with the arranging direction of the cavity recessed sections on the side of the cavity recessed sections and a molding die with a common pot 10 for filling the resin into the cavity constituted of the cavity resessed sections, pllungers 18a, 18b and 18c divided into a plurality and combined together on the longitudinal direction of the pot 10 are fitted on the pot 10 of the mold, and the divided and respectively combined plungers 18a, 18b and 18c are connected with driving mechanisms 34a, 34b and 34c of the plungers respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molding device and a resin molding method used for manufacturing a resin-sealed semiconductor device or the like.

[0002]

2. Description of the Related Art In a resin molding apparatus used for manufacturing a resin molding type semiconductor device or the like, an apparatus using a multi-pot type molding die is often used. This multi-pot type molding die supplies a resin tablet that is solidified into a cylindrical shape to a pot having a circular shape in a plan view and performs resin molding. On the other hand, recently, as shown in FIG. 4, a resin molding apparatus using a molding die provided with a pot 10 having a rectangular shape in plan view has been considered.

FIG. 4 is a plan view of the lower mold of the molding die, and shows a state in which cavity recesses 12 are arranged on both sides of the pot 10 and the pot 10 and the cavity recesses 12 are connected by a resin passage 14. The plunger 18 to be mounted on the mold having the pot 10 as described above has a pressing end face formed in an elongated rectangular shape in accordance with the shape of the pot 10. FIG. 5 shows a cross-sectional view of a state in which the resin is pressure-fed from the pot 10 by the plunger 18. The upper end surface of the plunger 18 is formed into a flat surface, and the plunger 18 is
The resin is pumped by moving up and down in parallel with the opening surface of.

FIG. 6 is a perspective view of a lapping resin 20 which is used by being supplied to the pot 10 of the molding die. The wrapping resin 20 is formed by molding a resin 20a in the shape of an elongated stick according to the shape of the pot 10 and sealing the molded resin 20a with a wrapping film 22. FIG. 7 shows a cross-sectional view of the wrapping resin 20. Resin 2
On the upper surface of 0a, the two wrapping films 22 are put together so that they can be peeled off and jut out in the lateral direction. The protruding portion is a portion through which the resin passes when the resin is pressure-fed by the plunger from the pot 10, and the lapping film 2 is formed by the resin pressure when the resin is pressure-fed.
2 is spread and a resin path is formed.

[0005]

By the way, when the resin molding is performed by using the stick-shaped wrapping resin 20 as described above, there are the following problems different from the case where the conventional cylindrical resin tablet is used. Occurs. That is, FIGS.
It is a plan view of a state in which 0 is set (in the figure, a mold die having a cavity recess 12 on one side of the pot 10 is shown for the sake of explanation), but the lapping resin 20 is different in length and the like as an assortment for production reasons. Since the products are not sufficiently prepared, the same wrapping resin 20 may be commonly used even when different types of products are resin-molded. In that case, the filling property of the resin into the cavities depends on the positional relationship between the wrapping resin 20 and the cavities. Variation occurs.

FIG. 8 shows a case in which the resin amount is set substantially evenly in each cavity, FIG. 9 shows a case in which the resin amount in the cavities at both ends of the pot 10 is smaller than that in the other, and FIG. This is an example of the case where the resin amount is larger than the others. Since the position of the cavity formed in the molding die is regulated according to the article to be molded such as the lead frame, when the lapping resin is commonly used, such an imbalance in the amount of the resin to be applied occurs.

If the amount of resin pumped from the pot 10 is unbalanced, the degree of resin filling in the cavities varies, and in the example shown in FIG. In the example shown, the cavities at both ends are filled with resin more quickly. Such variations in the filling degree of the resin cause non-filling of the resin and voids in the cavities, and variations in the molding quality among the cavities.

The problem in the resin molding apparatus using the molding die provided with the elongated rectangular pot 10 is not limited to the case of using the resin tablet sealed with the wrapping film 22 as described above, and is adjusted according to the shape of the pot 10. It also occurs when using a resin tablet that is simply formed into a stick shape. The present invention has been made to solve these problems, and when resin molding is performed using a molding die provided with the elongated pot 10 as described above, each cavity is uniformly filled with resin. This makes it possible to eliminate problems such as resin unfilling,
The objective is to make the molding quality uniform for each cavity and to enable high-quality resin molding.

[0009]

The present invention has the following constitution in order to achieve the above object. That is, a plurality of cavity recesses are provided, a common pot for opening a side of the cavity recesses parallel to the arrangement direction of the cavity recesses, and filling a resin formed in the cavity formed by the cavity recesses is provided. In a resin molding apparatus using a molding die, the pot of the die is equipped with a plunger provided with a step on the pressing end surface for feeding the resin so that the resin can be evenly fed to each of the cavities. . Further, a combination plunger which is divided into a plurality of pieces in the longitudinal direction of the pot is attached to the pot of the mold, and each of the divided combination plungers is individually connected to a drive mechanism of the plunger. Further, a step is provided on the inner surface of the mold cull facing the pot so that the resin can be uniformly pumped to each of the cavities. Further, it is characterized in that the resin molding apparatus is used to supply a wrapping resin in which resin is sealed with a wrapping film to the pot for resin molding.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below. FIG. 1 is an explanatory view showing a first embodiment of a resin molding device according to the present invention. In the figure, a cross section of the pot 10 is shown by the upper die 30a and the lower die 30b of the molding die, the die cull 32 provided on the upper die 30a facing the pot 10 and the plungers 18a, 18b for pushing out the resin from the pot 10. , 18c, and their drive mechanisms.

The upper mold 30a and the lower mold 30b are provided with cavity recesses (not shown) for resin-molding a molded product, and the cavity formed by clamping the molded product is filled with resin to mold the resin. To be done. The pot 10 is formed in the shape of a slender rectangle in a planar shape like the conventional example shown in FIG. To the pot 10, a resin tablet formed in a stick shape according to the shape of the pot 10 is supplied.

When resin molding is performed using a molding die provided with an elongated rectangular pot 12, a rectangular plunger 18 whose end face has the same shape as that of the pot 10 as described above is used. The conventional plunger 18 is integrally formed, and the resin melted in the pot 10 is pushed out of the pot 10 by the upward movement of the plunger 18.
On the other hand, in the resin molding apparatus according to the present embodiment, as shown in FIG.
It is composed of a plurality of combination plungers 18a, 18b, 18c divided into a plurality in the longitudinal direction of 0, and each combination plunger 18a, 18b, 18c is independently connected to the drive mechanism 34a, 34b, 34c of the plunger and separately It is characterized in that it is configured to perform drive control.

Plunger drive mechanisms 34a, 34b, 3
As 4c, there is a method of driving by hydraulic pressure or a method of driving by using an electric motor. In the present embodiment, since the hydraulic drive is used, the plunger drive mechanisms 34a, 3
4b and 34c are connected to the hydraulic unit 36, and the hydraulic unit 36 drives the plunger drive mechanisms 34a, 34b and 34c.
It was configured to control the drive by adjusting the flow rate to c.

In the arrangement of the combination plungers 18a, 18b, 18c in the pot 10 in this embodiment, the combination plunger 18a occupying approximately 3/5 of the entire length of the pot 10 is arranged at the center of the pot 10. The combination plungers 18b and 18c, which occupy approximately ⅕ of the entire length of the pot 10, are arranged on both sides thereof. this is,
This is to change the amount of resin pumped at the center and both ends of the pot 10 in the longitudinal direction.

That is, as in the case shown in FIG. 9, when the filling property of the resin into the cavities arranged at both ends of the pot 10 is inferior to the cavity arranged near the central portion of the pot 10, When the resin is pressure-fed from the pot 10, the combination plungers 18b and 18c arranged on both end sides of the pot 10 are moved up earlier than the combination plunger 18a in the central portion, so that the pot 10
By extruding the resin early from both end sides of the above and compensating the application of the resin to the cavities at both end sides, the resin can be uniformly filled in the entire cavity.

Further, as shown in FIG. 10, when the filling of the resin into the cavity near the center of the pot 10 is delayed, the combination plunger 18a at the center is first raised, and after this, the combination plungers 18 on both sides are delayed.
By raising b and 18c, it is possible to uniformly fill the resin in each cavity as a whole, and it is possible to mold the resin in a good balance in each cavity.

As described above, the number of plungers installed in the pot 10 is particularly limited in the method in which the plungers mounted in the pot 10 are constructed by combining a plurality of plungers and each plunger is independently driven and controlled. Not a thing. Therefore, it is also possible to divide the plunger into more parts such as four or more and combine them. In this case as well, each plunger may be individually connected to the drive mechanism of the plunger and the drive may be controlled separately.

When the plunger is divided into a plurality of parts and mounted as in the present embodiment, it is difficult to install the adjacent combination plungers 18a, 18b and 18c so that they can slide with respect to each other. There is a problem that molten resin may enter the sliding portion. However, when using the wrapping resin 20 sealed with the wrapping film 22 as shown in FIG. 6, the combination plungers 18a, 18b, 18c are used to pump the resin. When the lapping film 22 covers the inner surface of the pot 10 and the upper end surfaces of the combined plungers 18a, 18b, 18c, the molten resin can be prevented from entering the sliding parts of the combined plungers 18a, 18b, 18c. is there.

In addition, the combination plungers 18a, 18
When using b and 18c, the resin pressure acting on each plunger is detected by a pressure sensor 40 such as a load cell,
It is also possible to control the drive mechanisms 34a, 34b, 34c so that the pressing force by each combination plunger 18a, 18b, 18c becomes equal based on the detection signal of the pressure sensor 40. Also, the combination plungers 18a, 1
Instead of providing a pressure sensor 40 such as a load cell on 8b, 18c, an internal pressure sensor 42 is installed on the inner surface of the mold cull 32 to detect the resin pressure in the cull to control the drive of the combination plungers 18a, 18b, 18c. It is also possible to do so. In this way, the combination plunger 18
By controlling a, 18b, and 18c, it becomes possible to control the resin pressure at the time of resin filling to an equal pressure and perform resin molding.

FIG. 2 shows a second embodiment of the resin molding device. The above embodiment is characterized in that the plunger to be mounted in the pot 10 is divided into a plurality of parts. However, in the present embodiment, a single plunger 19 is used, and a step is formed on the upper end surface of the plunger 19 which is the pressing end surface for pushing out the resin. Is provided. By providing a step on the upper end surface of the plunger 19, when the resin is started to be pumped by the plunger 19, a difference in the resin pumping amount is provided depending on the position of the pot 10 in the longitudinal direction, whereby each cavity is uniformly filled with resin. It is a thing. Reference numeral 34 is a plunger drive mechanism, which is connected to a hydraulic unit 36 and is drive-controlled by hydraulic pressure.

In the plunger 19 of this embodiment, a recess 19a is provided at the center of the upper end surface and projections 19b are provided at both ends. The action of the plunger 19 is similar to the action of the combination plungers 18a, 18b, 18c shown in FIG.
By extruding the resin earlier on both end sides than the central portion of 0, the cavity filled at both end sides of the pot 10 is compensated for inferior resin filling property, and the entire cavity is uniformly filled with the resin. .

In the conventional resin molding apparatus, the plunger 19 is detachably attached to the drive mechanism 34 of the plunger, and it is easy to replace the plunger 19 depending on the product. Therefore, when the integral plunger 19 as shown in FIG. 2 is used, the plunger 19 having an appropriate shape can be exchange-set and resin-molded according to the product to be molded. For example, pot 10
If it is desired to push out the resin first from the central portion of the above, it is sufficient to replace the plunger 19 with a protrusion provided at the central portion of the upper end surface and perform resin molding.

FIG. 3 shows a third embodiment of the resin molding device. The resin molding apparatus of the present embodiment uses the plunger 18 whose upper end surface is a flat surface as in the conventional example,
By providing the recess 32a in the mold cull 32 provided in the upper mold 30a, the amount of resin extruded into the cavity communicating with the pot 10 is made different so that each cavity is uniformly filled with the resin.

In this embodiment, the recess 32a is provided in the center of the mold cull 32, so that when the resin is pushed out by the plunger 18, the amount of resin filled in the cavities arranged at both ends of the pot 10 is reduced. To compensate for this, all the cavities are uniformly filled with resin. Of course, contrary to the present embodiment, the central portion of the mold cull 32 may be projected so as to compensate for this when the amount of resin applied to the cavity near the central portion of the pot 10 is small.

As described above, the inner surface shape of the die cull 32 can be appropriately formed according to the product. Upper mold 30a
Since the lower die 30b and the lower die 30b are individually manufactured for each product, by designing the shape of the mold cull 32 according to the product, variations in resin filling between cavities due to the use of a common resin tablet. Therefore, it is possible to obtain a resin molded product having the required molding quality. It is also possible to use a configuration in which the concave portion 32a is provided on the inner surface of the mold cull 32 and the plunger is divided into a plurality of parts and mounted.

In each of the embodiments described above, the lower mold 30b is provided with the pot 10, but the present invention is a so-called upper plunger type resin molding apparatus in which the pot 10 is provided on the upper mold 30a. Can also be applied in the same manner, and by adopting the same method as each of the above-mentioned methods, when resin molding is performed using a stick-shaped resin tablet, each cavity is unevenly filled with resin. Can be solved.

[0027]

According to the resin molding apparatus of the present invention, by virtue of the above-mentioned configuration, it is possible to prevent the resin filling into the cavity from being varied when the resin tablets supplied to the pot are commonly used, It is possible to obtain a high-quality resin molded product by preventing unfilled resin and generation of voids. Further, by supplying the lapping resin to the pot and performing the resin molding, it is possible to obtain a remarkable effect such as suitable resin molding becomes possible.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of a resin molding device.

FIG. 2 is a cross-sectional view showing a second embodiment of a resin molding device.

FIG. 3 is a sectional view showing a third embodiment of the resin molding device.

FIG. 4 is a plan view of a molding die having a square pot.

FIG. 5 is a sectional view showing a conventional configuration in which a plunger is attached to the pot.

FIG. 6 is a perspective view of a wrapping resin.

FIG. 7 is a cross-sectional view of a wrapping resin.

FIG. 8 is an explanatory diagram showing a state in which resin is pressure-fed from a pot.

FIG. 9 is an explanatory diagram showing a state in which resin is pressure-fed from a pot.

FIG. 10 is an explanatory diagram showing a state in which resin is pressure-fed from a pot.

[Explanation of symbols]

 10 Pot 12 Cavity Recess 14 Resin Path 16 Molded Product 18 Plunger 18a, 18b, 18c Combination Plunger 19 Plunger 20 Lapping Resin 20a Resin 22 Lapping Film 30a Upper Mold 30b Lower Mold 32 Mold Culls 34, 34a, 34b, 34c Plunger Drive mechanism 36 Hydraulic unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication // B29L 31:34

Claims (4)

[Claims] 1. A common pot provided with a plurality of cavity recesses, opening to the side of the cavity recesses in parallel with the arrangement direction of the cavity recesses, and for filling resin into a cavity formed by the cavity recesses. In a resin molding apparatus using a molding die provided with, a plunger provided with a step on the pressing end surface for feeding the resin evenly to each of the cavities is provided in the pot of the die. Characteristic resin molding equipment. 2. A common pot provided with a plurality of cavity recesses, which is open laterally of the cavity recesses in parallel with the arrangement direction of the cavity recesses and is used for filling resin into a cavity formed by the cavity recesses. In a resin molding apparatus using a molding die provided with, a plurality of combination plungers are attached to a pot of the die in the longitudinal direction of the pot, and each of the divided combination plungers has a plunger driving mechanism. A resin molding device characterized by being connected to. 3. A common pot provided with a plurality of cavity recesses, opening to the side of the cavity recesses in parallel with the arrangement direction of the cavity recesses, and for filling a cavity formed by the cavity recesses with resin. In the resin molding apparatus using a molding die provided with the above, a step is provided on the inner surface of the die cull facing the pot, and a step is provided so that the resin can be uniformly pumped to each of the cavities. 4. A resin molding method comprising: using the resin molding apparatus according to claim 1, 2 or 3, and supplying a lapping resin in which a resin is sealed with a lapping film to the pot to perform resin molding.