JPH0340579Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a mold for resin sealing used in a molding press in semiconductor manufacturing equipment.

(Prior art) Conventionally, in a molding press, synthetic resin in multiple pots is pressurized by corresponding plungers connected to one transfer cylinder, and molten resin is poured into multiple molds. When injecting at the same time, even if there are variations in the amount of synthetic resin injected between pots, the plungers in the pots with the largest amount of synthetic resin injected are sequentially retracted, and the force to push each plunger is maintained while maintaining the set pressure (injection pressure). By pushing all the plungers at a set speed (injection speed) with a transfer cylinder, the resin injected into each mold is made homogeneous and the occurrence of defective products is prevented (Japanese Patent Laid-Open No. 59-225913 (see publication).

(Problems to be Solved by the Invention) However, this conventional press is provided with one plunger holding frame that is moved by a transfer cylinder, and this frame is provided with a plurality of back pressure chambers that communicate with each other. The plunger is inserted into the back pressure chamber and supported by back pressure liquid, and a hydraulic circuit equipped with a pressure regulating valve is connected to the back pressure chamber, so the configuration is extremely complicated and maintenance is essential. At the same time, the inconvenience of having to use expensive equipment was unavoidable.

The present invention was made in order to solve the above-mentioned conventional problems, and its purpose is to make it possible to absorb variations in the amount of synthetic resin input between pots by simply modifying the mold itself.

(Means for Solving the Problems) The resin sealing mold of the present invention pressurizes the synthetic resin in a plurality of pots with corresponding plungers connected to one transfer cylinder. A mold for resin sealing in which molten resin is injected into a plurality of molds at the same time, characterized in that each of the pots is communicated with each other by a runner.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

In the figure, reference numeral 1 denotes an upper mold, which is attached to the lower surface of the upper platen 2 that can move up and down. On the lower surface of the upper mold 1, there are a plurality of molds (20 molds in the example) not shown.
and a resin passage (not shown), which is connected at one end to each mold, are recessed.

3 is a lower mold, which is mounted on the upper surface of the lower platen 4 of the press so as to face the upper mold 1;
The lower mold 3 has a plurality of pots 5 (5 in the embodiment).
) are perforated.

The mold is divided into equal parts according to the number of pots, and corresponds to each pot 5. A mold is provided in communication with the corresponding pot 5 via a resin passage.

Reference numeral 6 denotes a plunger, which is fitted into each pot 5 so as to be movable up and down with its bottom closed.
The lower end of the piston is connected to a plate 7, and it can be operated by a transfer cylinder 8 (only the piston rod is shown in the drawing) connected to the plate 7.

A runner 9 is recessed between the pots 5 provided on the upper surface of the lower mold 3 so as to allow the insides of adjacent pots 5 to communicate with each other.

(Function) After setting the lead frame 10 on which the semiconductor element is placed directly under each mold of the lower mold 3, and putting the preheated tablet-shaped synthetic resin 11 into each pot 5, as shown in the figure. By the mold closing operation of the press using the mold clamping device, the lead frame 10 is closed with the semiconductor element side placed in the mold.
is fixed between upper and lower molds 1 and 3.

Next, when the entire plunger 6 is moved upward via the plate 7 by the rod extension operation of the transfer cylinder 8, the synthetic resin in the pot 5 is moved by the plunger 6 in the pot 5 sealed by the upper mold 1. It is pressurized and injected into the mold through the resin passage, filling the inside of the pot 5.

If there is variation in the amount of synthetic resin input between the pots 5, the synthetic resin 11 flows from the pot with a large amount of synthetic resin input to the pot with a small amount of synthetic resin input through the runner 9, and the synthetic resin is injected into the mold. Therefore, the injection pressure into the mold is the same for each pot 5.

After the synthetic resin 11 is filled into the mold at a predetermined injection pressure and injection rate, the pressure is maintained until it is thermally cured, resulting in a molded article as shown in FIG. 2. This molded product includes the resin sealing part 12 on the lead frame 10, the other gate 13, and the cull 1.
4 and a runner 15.

(Effects of the invention) As described above, the present invention allows the pots of the mold to communicate with each other using runners, so even if there is variation in the amount of synthetic resin put into each pot, this variation is absorbed. Since the injection pressure can be made the same for each pot, it is possible to ensure homogenization of the resin injected into each mold, and it is also possible to significantly reduce equipment costs and eliminate the need for maintenance.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing an embodiment of the present invention, and FIG. 2 is a plan view of a molded product. 1... Upper mold, 3... Lower mold, 5... Pot,
6... Plunger, 7... Plate, 8... Transfer cylinder, 9... Runner, 10... Lead frame, 11... Synthetic resin, 12... Resin sealing part.

Claims (1)

[Scope of utility model registration request] A resin sealing mold that simultaneously injects molten resin into multiple molds by pressurizing the synthetic resin in multiple pots with corresponding plungers connected to one transfer cylinder. A mold for resin sealing, characterized in that each of the pots is communicated with each other by a runner.