JPS6248372B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a resin sealing molding apparatus for semiconductor devices such as semiconductor integrated circuits.

Resin encapsulation molding of semiconductor devices such as semiconductor integrated circuits is generally performed using a thermosetting resin by an injection molding method known as transfer molding.

Some semiconductor integrated circuits incorporate light-emitting elements and light-receiving elements, and the sealing resin in this case is a clear thermosetting resin that does not contain any fillers or pigments. An epoxy resin called resin must be used. Unlike the epoxy resin used in general resin-sealed semiconductor devices, this clear resin has a weight limit (approximately 30 g) of the encapsulating resin tablet before injection molding due to the heat of reaction. I can't do more than that.

Conventional resin encapsulation molding equipment using the injection molding method is
It was designed as shown in the front view in Figure 1. Reference numeral 1 denotes a stand frame, which supports a mold clamping mechanism 2 inside, and has four support columns 3 fixedly attached thereto and protrudes upward. 4 is a molding die, which consists of an upper die 5 and a lower die 6. The upper mold 5 is attached to the lower part of the upper mold support stand 7 fixed to the upper part of each support column 3, and upper half molds (not shown) for a large number of sealing bodies are provided on the lower surface. There is.
The lower mold 6 is mounted on a lower mold support stand 8 that is vertically movably supported by each support column 3, and has a lower half noodle mold for a large number of sealing bodies on the upper surface corresponding to the upper mold 5. (not shown) is provided. Lower die support stand 8
is raised and lowered by the mold clamping mechanism 2. Reference numeral 9 denotes a resin tablet inlet provided in the upper mold 5, and 10 denotes a resin receiving portion provided penetrating from the center of this inlet toward the lower mold 6 side, and is generally called a pot or chamber. Reference numeral 11 denotes an injection mechanism, which is comprised of a hydraulic cylinder 12 mounted on the upper mold support 7, a piston 13, and a piston rod 14 extending downward from the piston. 15 is a control panel for operating the electrical system, hydraulic system, etc.

The main parts of the mold clamping mechanism 2 are shown in a front view in FIG. A fixed stand 16 is fixed within the stand frame 1, and each support column 3 is fixed to this fixed stand and extended. The mold clamping mechanism 2 has a hydraulic cylinder 17, a piston 18, and a piston rod 19 attached to a fixed base 16, and the piston rod 19 extended upward comes into contact with the lower part of the lower mold support base 8. and raise and lower it.

A main part of the injection mechanism 11 is shown in a longitudinal sectional view in FIG. A plunger 2 is attached to the lower end of the piston rod 14.
0 is fixed to the resin tablet inlet 9 of the upper mold 5.
The inner diameter part of the resin receiving part 10, which is provided in communication with the center of the resin receiving part 10, is lowered and raised as shown by the chain line.

In the conventional apparatus described above, each lead frame mounted with an integrated circuit is placed into each of the lower molds 6 of the molding die 4 which has been heated to 150 DEG to 180 DEG C. in advance. Next, the lower mold holding table 8 is raised by the mold clamping mechanism 2, and mold clamping pressure is applied between the lower mold 6 and the upper mold 5. Next, we made a sealing resin tablet made by preforming thermosetting resin into a cylindrical shape.
The resin is preheated to around 90 degrees Celsius, charged into the resin receiver 10 from the tablet input port 9 of the upper mold 5, and then inserted into the injection mechanism 1.
1 is activated to lower the plunger 20, a sealing resin is injected into the molding die 4 under pressure, and each semiconductor integrated circuit is molded with the resin.

In addition, as mentioned above, when the weight of the sealing resin tablet is limited by the clear resin and the number of molded products that can be obtained from one molding die 4 is small, or when using a small molding die, Conventionally, there has been a molding apparatus as shown in a front view in FIG. The figure shows a case where two sets of molding molds 4 are installed and resin sealing molding is performed at the same time. A mold clamping mechanism 2 is attached to the platform frame 21. Two sets of upper molds 5 are attached to the lower part of the upper mold holder 22 fixed to the upper part of each support column 3, and two sets of injection mechanisms 11 are attached to the upper part, corresponding to each upper mold 5. ing. Lower mold holding stand 23
is supported by each support column 3 so that it can move up and down, and 2
A lower mold 6 of the set is attached, and is raised and lowered by the mold clamping mechanism 2.

In this way, when there is a weight limit on the sealing resin tablets, a device that can perform a large number of resin sealing molds by installing multiple sets of molds and simultaneously injecting the sealing resin can be created. I have to.

In the conventional device described above, it took about 60 seconds to clamp the mold, insert the resin tablet, lower the injection, and pressurize. This is because the resin tablet must be manually inserted into the input slot 9 in the depth direction during the process, which takes time. In addition, the resin tablet inlet 9
Since it is located inside the upper mold 5, mold clamping pressure is not applied to this part, and resin leakage occurs in the part corresponding to the tablet inlet 9 during molding. Furthermore, when it is necessary to use clear resin and the number of molding molds 4 is increased, providing multiple sets of injection mechanisms 11 will take time to insert the resin tablets. 4 cannot be increased in number in the depth direction, but can only be increased by arranging them in the horizontal direction, which results in a special device, high cost, and disadvantages such as lack of versatility. It was hot.

This invention was made in order to eliminate the drawbacks of the above-mentioned conventional devices, and it simplifies the construction by incorporating the injection mechanism into the lower part of the device hole provided in the lower die of the molding die, and allows the sealing resin tablet to be lowered. The resin is injected into the mold from above into the resin receiving part at the top of the injection mechanism, which shortens the time from the introduction of the resin tablet to the injection lifting and pressurization, and the part of the mold that is not affected by the clamping pressure becomes extremely small, resulting in molding. In addition, the injection mechanism can be placed in the depth direction or the molds can be arranged side by side, eliminating the troublesome centering of the mounting hole and the injection mechanism when replacing the lower mold. It is an object of the present invention to provide a resin encapsulation molding apparatus for semiconductor devices that can be replaced in a short time without any need, can be reused, and has high versatility.

FIG. 5 is a front view of a resin sealing molding apparatus according to an embodiment of the present invention, in which numerals 1 to 3, 8, and 15 are the same as those of the conventional apparatus. A molding die 30 is composed of an upper die 31 and a lower die 32. The upper mold 31 is attached to the lower part of the upper mold holder 33 fixed to the upper part of each support column 3, and upper half molds (not shown) for a large number of sealing bodies are provided on the lower surface. There is. The lower mold 32 is mounted on the lower mold holder 8, and a number of lower half noodle molds (not shown) for sealing bodies are provided on the upper surface corresponding to the upper mold 31. Reference numeral 35 denotes an injection mechanism mounted below a mounting hole 34 provided vertically in the lower mold 32. The main parts of this injection mechanism 35 are shown in a vertical cross-sectional view in FIG.
Hydraulic cylinder 3 installed on lower mold support stand 8
6, a piston 37, a plunger reciprocating means having a piston rod 38, and a plunger 39 fixed to the upper end of the piston rod. Device hole 3
The upper side of 4 forms a resin socket 34a, and a plunger 39 moves up and down. The injection mechanism 35 is assembled into the mounting hole 34a, and centering of both can be done extremely easily.

Resin sealing molding using the apparatus of the above embodiment is performed as follows. Each relead frame equipped with an integrated circuit is placed in each of the lower molds 32 of the molding mold 30 which has been heated to 150° to 180° C. in advance. Preheat the sealing resin tablet to approximately 90°C and insert it into the resin socket 34a of the lower mold 32 using the plunger 39.
put on top. Next, the mold clamping mechanism 2 is operated to raise the lower mold holding table 8, and the lower mold 32 is clamped and pressurized with the upper mold 31. Subsequently, the injection mechanism 35 built into the lower mold 32 is activated to raise the plunger 39 by the piston rod 38, and the sealing resin is injected into the molding die 30 under pressure to seal each semiconductor integrated circuit with the resin. Perform stop forming.

In this way, the steps of loading the sealing resin tablet → mold clamping → injection lifting are shorter than before, and the distance for the injection lifting is shorter than before, and the subsequent steps can be automatically operated by manually loading the tablet at the beginning. Work time is reduced to approximately half of the conventional time. In addition, the lower mold 32
Unlike the conventional upper mold, there is no resin inlet in the depth direction, and the part where mold clamping pressure does not apply is the resin receptacle 34.
By using only a, the upper and lower molds will fit better and no resin leakage will occur.

FIG. 7 is a front view of a molding apparatus according to another embodiment of the present invention, which is applied when the weight of a resin tablet for sealing with clear resin is limited. Four support columns 3 are protruded from the side of the stand frame 39.
The molding die 40 includes an upper mold 41 mounted on an upper mold holder 43 and a lower mold 42 mounted on a lower mold holder 44. The figure shows an example in which two sets of injection mechanisms 35 are disposed in the lower die 42 in the horizontal direction, and a required number of sets are also disposed in the depth direction.
In this way, the number of resin-sealed bodies molded at one time is increased. The upper mold holder 43 is fixed to the top of each support column 3. Lower holding stand 44
is supported by each support column 3 so as to be able to move up and down, and is raised and lowered by the mold clamping mechanism 2.

According to the apparatus of the above-mentioned other embodiments, the resin tablets are put into each resin receptacle 34a with the lower mold 42 lowered and before mold clamping, and thereafter the resin sealing is carried out in the same manner as the apparatus shown in FIG. 5 above. Form the stopper.

In the embodiment shown in FIG. 7, the area of the mold 40 is increased and the number of injection mechanisms 35 is increased, but the number of molds may be increased.

As described above, according to the present invention, the injection mechanism is incorporated into the lower part of the mounting hole provided in the lower die of the molding die, so that the configuration and assembly of the apparatus is simplified. In addition, since the resin tablet for sealing is introduced from above into the resin receiver above the injection mechanism of the lower mold, the time from feeding the resin tablet to sealing molding is shortened to approximately half of the conventional method, and production is reduced. In addition, the size or number of molds can be increased in the depth direction, and the device can be used with high versatility by replacing the necessary molds. Furthermore, when replacing the lower mold, the injection mechanism is built into the lower part of the mounting hole, making it extremely easy to center both parts.
Molds can be replaced in a short time.

[Brief explanation of the drawing]

Fig. 1 is a front view showing a conventional resin sealing molding device, Fig. 2 is a front view of the mold clamping mechanism shown in Fig. 1, and Fig.
The drawings are an enlarged vertical sectional view of the injection mechanism shown in FIG. 1, FIG. 4 is a front view showing another conventional resin sealing molding apparatus, and FIG. 5 is a resin sealing molding apparatus according to an embodiment of the present invention. 6 is an enlarged vertical sectional view of the injection mechanism section of FIG. 5, and FIG. 7 is a front view of a resin sealing device according to another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Stand frame, 2... Mold clamping mechanism, 3... Support column, 8... Lower die support stand, 30... Molding die, 31
...Upper mold, 32...Lower mold, 33...Upper mold support,
34...Mounting hole, 34a...Resin socket, 35...
. . . Injection mechanism, 39 . . . Stand frame, 40 . . . Molding die, 41 . Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. An upper die attached to the lower part of an upper support stand fixed to the upper part of a plurality of support columns fixed to the side of the frame, and supported so as to be movable up and down on the support columns. In a resin encapsulation molding machine equipped with a molding die that is made up of a lower die mounted on a lower die support that is raised and lowered by a mold clamping mechanism installed below, a device that is perpendicular to the lower die is A hole is provided, the upper part of the device hole is used as a resin receptacle into which the sealing tablet is inserted, and the lower part of the mounting hole is a plunger on which the sealing tablet is placed, and a reciprocating plunger that moves the plunger up and down. A semiconductor device characterized in that an injection mechanism having means is installed, and a sealing resin tablet is put into the resin socket from above the resin socket and is injection-molded by the injection mechanism. Resin sealing molding equipment. 2. The resin encapsulation molding apparatus for a semiconductor device according to claim 1, wherein a plurality of mounting holes are provided in the lower mold, and an injection mechanism is mounted in each of the mounting holes. 3. A resin encapsulation molding apparatus for a semiconductor device according to claim 1, characterized in that a plurality of molding mold sets each consisting of an upper mold and a lower mold equipped with one injection mechanism are disposed. .