JPH05211185A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To improve the utilization efficiency of a resin to be used by a method wherein a pot part is provided in the vicinity of a cavity part and the resin is directly injected in the cavity part through a gate part. CONSTITUTION:In a metal mold, a pot part 1 for injecting a resin in a cavity part 3 through a gate part 2 is provided in the vicinity of the cavity part 3. When the resin is encapsulated, a lead frame is arranged at a prescribed position in the cavity part 3 in the metal mold and after a proper quantity of a powdery resin 6 is fed in the pot part 1 through a nozzle or the like, top and bottom forces are pressure-welded together, the lead frame is inserted between the top and bottom forces and after the resin 6 is molten, high-temperature and high-pressure air is sent though a high-pressure air injection port 5 and the molten resin is made to inject in the cavity part 3 through the gate part 2. The control of the amount of the resin 6 can be easily exercised and moreover, if a plurality of feed nozzles are provided, it becomes also possible to feed two kinds or more of powdery resins to one place of the pot.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a semiconductor device including an encapsulation method using a thermosetting resin.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, an encapsulating mold used for manufacturing a resin-sealed semiconductor device is press-contacted so that upper and lower molds are engaged with each other, and a pot portion 1, a runner portion 8 and a gate are formed. The portion 2 and the cavity portion 3 are formed so as to be hollow inside the mold.

During resin encapsulation, a lead frame having a semiconductor chip mounted therein is placed in a predetermined position in a cavity 3 of a sealed die which is mounted on a hydraulic press and heated. A thermosetting resin tablet (hereinafter referred to as a resin) tablet 10 formed into a cylindrical shape is supplied to the pot portion 1 by sandwiching it, and the resin melted at a high temperature is pressurized by the plunger 9 on the pot portion 1, It is poured into the runner section 8 and further the gate section 2
The molten resin is injected into the cavity portion 3 formed by shaping the resin portion which will be the envelope of the semiconductor device so as to cover the semiconductor chip.

After the resin has been hardened for a predetermined time after the resin has been injected, the upper and lower enclosing molds are opened, and as shown in FIG. 4, the pot portion 1 to the runner portion 8, the gate portion 2, and the cavity portion 3 are opened. The resin that has hardened into a shape is removed from the mold together with the lead frame 7, and the mold surface is cleaned with a brush or high-pressure air so that no resin residue remains.
Place the next lead frame and inject resin as described above,
By curing, semiconductor device resin molding is continuously performed.

The resin taken out of the mold and the lead frame 7 are separated from the tip of the gate 2 and the cavity 3 and unnecessary potting resin such as the pot 1 and runner 8 is discarded. A lead frame having a resin portion, which serves as an envelope of a semiconductor device, is obtained.

[0006]

In the conventional resin encapsulation method for a semiconductor device, since the resin formed on the runner portion from the pot portion is discarded as an unnecessary material, the resin volume of the semiconductor device is reduced. However, there is a drawback that the amount of resin used becomes large and the utilization efficiency becomes very poor. Especially in small signal semiconductor devices, the utilization efficiency is 5%.
It became the following and became a big problem.

Recently, a multi-plunger system has been adopted in which the pot portion, which was conventionally formed only on one place on the mold, is divided into two or more places, but even in this method, the runner portion is slightly different. It is only about shortening, it is not possible to improve the resin utilization efficiency, and when the number of pots is increased, the size of the resin doublet used becomes smaller and the doublet processing ratio in the resin manufacturing process becomes extremely large. There is a problem that it will rise.

An object of the present invention is to provide a method of manufacturing a semiconductor device in which the used resin has a high utilization efficiency.

[0009]

According to the present invention, a lead frame on which a semiconductor chip is mounted is arranged at a predetermined position and is sandwiched between upper and lower encapsulating molds in a high temperature state, and then a thermosetting property is applied to an encapsulating mold pot portion. By supplying a resin, melting the thermosetting resin, and press-fitting it into each cavity of the encapsulating mold to cure it,
In a method of manufacturing a semiconductor device including a step of forming an encapsulating resin to be an envelope for covering the semiconductor chip, a thermosetting resin is supplied in a powder form and melted, and then high temperature and high pressure air is applied to the encapsulating mold. The method further includes the step of injecting the melted thermosetting resin into each of the cavities and encapsulating it by adding it to the pot to form the sealing resin. The powdery thermosetting resin to be supplied is supplied from a nozzle, and the amount of the thermosetting resin is controlled by the supply time. The thermosetting resin contains at least two thermosetting resins having different flow characteristics and curing characteristics.

[0010]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a sectional view of a sealed mold for explaining one embodiment of the present invention.

As shown in FIG. 1, in the mold, the pot portion 1 is provided near the cavity portion 3 through the gate portion 2. At the time of resin encapsulation, the lead frame is placed at a predetermined position of the cavity 3 on the encapsulating mold, and an appropriate amount of the powdery resin 6 is supplied to the pot part 1 by a nozzle or the like, and then the upper and lower molds are pressure-contacted to each other to lead. After sandwiching the frame and melting the powdery resin 6, high-temperature high-pressure air is sent from the high-pressure air inlet 5 to inject the molten resin into the cavity 3 through the gate 2.

After a predetermined time has elapsed after the resin injection, the upper and lower encapsulating molds are opened, the lead frame and the cured resin are removed from the mold, and after cleaning, the next lead frame is arranged and the same method as described above is performed. Resin molding of semiconductor devices is continuously performed.

FIG. 2 is a perspective view of the lead frame detached from the encapsulating mold of FIG. 1 and the cured resin.

As shown in FIG. 2, the cavity portion 3 forming the semiconductor device, the gate portion 2 and the pot portion 1 on the lead frame 7 can be separated to obtain a sealed lead frame 7.

Further, the amount of the powdery resin 6 can be easily controlled, and if a plurality of supply nozzles are provided,
It is also possible to supply two or more kinds of powdery resins to one pot.

[0017]

As described above, according to the present invention, the pot portion is provided in the vicinity of the cavity portion and the resin is directly injected into the cavity portion through the gate portion. The resin part that is discarded as a product can be made small, and it is possible to dramatically increase the utilization efficiency.Because the resin can be used in powder form, the pot part can be made smaller and the number can be increased.
There is an effect that tablet processing in the resin manufacturing process is unnecessary.

Further, in the conventional sealing method, since resin is injected from one pot portion into a large number of cavity portions through the runner portion, the resin is injected into each cavity portion depending on the distance from the pot portion. However, due to the difference in the molten state, defects such as unfilled parts were caused. However, in the present invention, it is possible to inject from one pot portion into one cavity portion, and Since the resin can be injected in the same state in all the cavity portions, defects such as unfilling can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a sealed mold for explaining an embodiment of the present invention.

FIG. 2 is a perspective view of a lead frame and cured resin removed from the encapsulating mold of FIG.

FIG. 3 is a cross-sectional view of an enclosed mold for explaining a conventional method for manufacturing a semiconductor device.

FIG. 4 is a perspective view of a lead frame and a cured resin removed from the encapsulating mold of FIG.

[Explanation of symbols]

 1 Pot Part 2 Gate Part 3 Cavity Part 4 Air Vent Part 5 High Pressure Air Inlet 6 Bowder Resin 7 Lead Frame 8 Runner Part 9 Plunger 10 Resin Tablet

Claims (3)

[Claims] 1. A thermosetting resin is supplied to the encapsulating mold pot portion after a lead frame having a semiconductor chip mounted thereon is placed at a predetermined position and sandwiched between upper and lower encapsulating molds in a high temperature state. In the method of manufacturing a semiconductor device, including the step of forming an encapsulated resin that serves as an envelope that covers the semiconductor chip by melting the resin and press-fitting it into each cavity of the enclosure mold to cure the resin, After the thermosetting resin is supplied in a powder form and melted, high-temperature high-pressure air is added to the encapsulating mold pot section to inject the molten thermosetting resin into each of the cavity sections and enclose the encapsulating resin. A method of manufacturing a semiconductor device, comprising the step of forming. 2. The method for manufacturing a semiconductor device according to claim 1, wherein the powdery thermosetting resin to be supplied is supplied from a nozzle, and the amount of the thermosetting resin is controlled by the supply time. 3. The method of manufacturing a semiconductor device according to claim 1, wherein the thermosetting resin contains at least two kinds of thermosetting resins having different flow characteristics and curing characteristics.