JPH05235189A - Manufacture of semiconductor and device thereof - Google Patents

Abstract

PURPOSE:To prevent the generation of a defective sealing, such as perforating in a resin, at the time of resin sealing by a method wherein a sealing work using the resin is conducted under a reduced pressure and after the sealing, the quantity of gas, which is sealed in a cap, is lessened. CONSTITUTION:The interior of a vacuum chamber 3 is decompressed to the pressure of several (m) to several tens (m) Torr. There are a first heat block 4 and a second heat block 5 in the chamber 5 and a sealing work is conducted like a conventional technique. As the sealing work is conducted under a reduced pressure like this, a difference between the pressures in the interior and the outside of a cap is hardly generated because the quantity of gas, which is sealed in the cap, is little. Accordingly, even if a resin is stood to cool from a high- temperature state when it is in the state of a liquid, there is no passage of gas on the sealing surface of the cap and perforating is not generated in the resin. As the resin is solidified in several minutes before the atmosphere in the chamber 3 is returned to the atmospheric pressure, the time for standing to cool the resin is not necessarily provided specially and the sealing work can be conducted time wise efficiently.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus and a method of manufacturing a semiconductor device, and more particularly to a semiconductor manufacturing apparatus and a method of manufacturing a semiconductor device which are sealed with a resin.

[0002]

2. Description of the Related Art Conventionally, when a semiconductor pellet mounted and bonded to a lead frame is sealed with a cap, a cap to which a sealing resin is previously attached has been used.

A conventional sealing process will be described with reference to FIGS. 3 and 4. The semiconductor pellet 12 is mounted on a pellet mount portion 16 formed along the lead frame 2 and electrically connected by a bonding wire 13.

The lead frame 2 is sent onto the first heat block 4 heated to about 300 ° C. in a nitrogen (or air) atmosphere, and the portions to be sealed are heated sequentially. Once fully heated, the cap 14 is placed and pressure is applied.

At this time, the resin 15 attached to the cap 14 is liquefied by heat, the lead frame 12 and the cap 14 are adhered, and the high temperature gas is sealed in the cap 14.

Next, in a nitrogen (or air) atmosphere, 300
The lead frame 2 is sent onto the second heat block 5 heated to about 0 ° C., and the resin 15 is sequentially kept at a high temperature. The resin 15 is polymerized by being kept at a high temperature,
It is solidified again in a few seconds to a dozen seconds and the cap 14 is completely fixed.

After that, the lead frame 2 is sent to the lead frame feed rail 17 and allowed to cool to room temperature. At this time, the high-temperature gas trapped in the cap 14 is cooled to room temperature and is therefore compressed, resulting in a pressure difference from the outside.

[0008]

If the sealing is carried out normally, the resin 15 is completely solidified and no problem occurs. However, in reality, the liquefaction time or re-solidification time of the resin is not always constant, and the quality of the resin,
Variations such as amount and adhesion state, and corresponding changes or other factors change sealing conditions, resulting in large fluctuations.

Therefore, pressure may be applied after the resin is solidified again, or the pressure may be released and allowed to cool before it is solidified in a liquid state, resulting in defective adhesion and defective semiconductor devices. There was a problem.

That is, if the resin 15 is cooled in a state where it is not completely solidified, the gas will pass through the sealing surface of the cap 14 due to the pressure difference between the gas inside and outside the cap 14, and the resin will be perforated.

However, if the pressure is applied to the cap 14 for a long time so that the resin is not punctured, the resin is broken and the sealing strength is lowered. Further, when the application time is increased in actual production, the productivity is deteriorated, so it is necessary to prevent resin drilling with a limited pressure application time.

It is an object of the present invention to provide a semiconductor manufacturing method and an apparatus therefor, which eliminates a sealing failure such as resin hole punching at the time of resin sealing.

[0013]

In order to achieve the above object, a semiconductor manufacturing method according to the present invention is a method of manufacturing a semiconductor device in which a semiconductor element mounted and bonded to a lead frame is sealed with a resin. Then, a step of reducing the pressure of the atmosphere around the lead frame, a step of liquefying the resin for sealing the semiconductor element, and a step of solidifying the resin while reducing the pressure are included.

A semiconductor manufacturing apparatus according to the present invention is a semiconductor manufacturing apparatus for sealing a semiconductor element with a resin, and has a decompression chamber for decompressing a sealing atmosphere of the semiconductor element,
The decompression chamber includes means for liquefying the resin and means for solidifying the resin.

[0015]

[Function] The sealing operation using the resin is performed under reduced pressure. This reduces the amount of gas sealed in the cap after sealing.

[0016]

The present invention will be described below with reference to the drawings. FIG. 1 is a top view showing a sealing work portion of a semiconductor manufacturing apparatus according to an embodiment of the present invention.

In FIG. 1, a lead frame 2 on which a semiconductor pellet 12 is mounted and bonded is sent from a lead frame magazine 1 on the sending side to a decompression chamber 3 for sealing work.

Inside the decompression chamber 3 is several mTorr to several tens mTorr.
The pressure is reduced to r. The decompression chamber 3 has a first heat block 4 and a second heat block 5, and the sealing work is performed as in the conventional technique. First, the first heated to about 300 ℃
The lead frame 2 is sent onto the heat block 4 and sequentially heats the portions to be sealed. Once fully heated, the cap 14 is placed and pressure is applied.
At this time, the resin 15 attached to the cap 14 is liquefied by heat, and the lead frame 12 and the cap 14 are bonded.

Next, the lead frame 2 is sent onto the second heat block 5 heated to about 300 ° C., and the resin 15 is sequentially kept at a high temperature to polymerize and re-solidify, and the cap 1
Fix 4 completely.

After that, the lead frame 2 is allowed to cool to room temperature. After all the semiconductor pellets on the lead frame 2 are sealed, nitrogen or air is introduced into the decompression chamber 3 to return to atmospheric pressure, and the lead frame 2 is sent to the lead frame magazine 18 on the receiving side.

Since the sealing operation is performed under reduced pressure, the amount of gas sealed in the cap 14 is small, and therefore the amount of gas compressed when left to cool is small, so that the pressure difference between the inside and outside of the cap is small. It rarely happens. Therefore, even if the resin 15 is allowed to cool from the high temperature state when it is in a liquid state, no gas passes through the sealing surface and no holes are formed in the resin.

Since the resin is solidified within a few minutes until the atmosphere in the decompression chamber 3 returns to the atmospheric pressure, it is not necessary to provide a cooling time, and the sealing work can be performed efficiently in time.

Next, a sealing work portion of a semiconductor manufacturing apparatus according to another embodiment of the present invention will be described with reference to FIG. In this embodiment, load lock chambers are provided for magazine transportation and lead frame transportation, respectively, and a third heat block is added to improve mass productivity and sealing accuracy.

The lead frame magazine 1 containing the lead frame 2 is placed in the magazine feed load lock chamber 6 at atmospheric pressure. Several meters of load lock chamber 6 for magazine feed
The pressure is reduced to Torr to several tens of mTorr. The magazine feed load lock chamber 7 may be decompressed from normal pressure in the same manner as the magazine feed load lock chamber 6, but it is always several mTorr.
If it is kept at r to several tens of mTorr, the decompression time can be omitted.

In the depressurized state, the lead frame magazine 1 is transported to the lead frame load lock chamber 7 by the magazine transport rail 10, and the lead frame 2 is transported to the sealing depressurizing chamber 3.

On the other hand, the empty magazine feed load lock chamber 6 is returned to atmospheric pressure in preparation for the installation of the next magazine. The sealing work is performed in the same manner as in the first embodiment. The third heat block 11 is additionally provided so that pressure-solidification in the second heat block 5 can be performed when pressure-solidification is not sufficient, and control is performed so that temperature and pressure load are changed according to the characteristics of the resin. it can.

After the work in the third heat block 11 is completed, the system is left to cool and the lead frame 2 is returned to room temperature. An empty lead frame magazine 18 is prepared in the lead frame receiving load lock chamber 8 that has been decompressed in advance, and receives the sealed lead frame 2. If the magazine receiving load lock chamber 9 is in a depressurized state, the lead frame magazine 1 is transported by the magazine transport rail 10, and then the magazine receiving load lock chamber 9 is returned to normal pressure to complete a series of sealing operations. ..

In the present embodiment, load lock chambers are provided for transporting magazines and lead frames, respectively, and the lead frame can be prepared and taken out regardless of the work in the decompression chamber for sealing work. Compared with the example, the depressurization time and the atmosphere opening time can be largely omitted, and the mass productivity is remarkably improved. Further, since the third heat block enables additional pressure bonding to solidification depending on the resin characteristics, the sealing accuracy is improved and the defective rate is reduced.

[0029]

As described above, in the present invention, particularly when a resin is used as the sealing material, the sealing work can be performed under reduced pressure, so that the gas sealed in the cap after the sealing is performed. Is small. Therefore, since it is possible to prevent the pressure difference between the inside and the outside of the cap caused by the temperature history at the time of sealing, even if the resin is in a liquid state, gas does not pass through the sealing surface, and there is no perforation of the resin. Does not happen.

Further, the resin may be solidified by the time the ambient atmosphere returns to atmospheric pressure, and if the time required to return to atmospheric pressure is longer than the solidification time of the resin, it is not necessary to set the resin solidification time, so that the resin is efficiently sealed. You can wear it. Further, since the lead frame feeding or receiving load lock chamber can be depressurized or opened to the atmosphere regardless of the work in the sealing work depressurizing chamber, the depressurizing time and the atmospheric opening time can be shortened.

Further, especially by always keeping the depressurized state on the feed side, it is possible to prevent dust and the like from being mixed and to maintain high cleanliness. Therefore, characteristics due to defective sealing of the semiconductor device or adhesion of dust to the semiconductor pellets It has an excellent effect with no defects.

The present invention has been described with reference to an example in which a semiconductor pellet is sealed using a cap to which a resin is attached, but it can also be applied to a resin molding technique in which a resin is filled in a mold and sealed. ..

[Brief description of drawings]

FIG. 1 is a top view showing a semiconductor manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is a top view showing a semiconductor manufacturing apparatus according to another embodiment of the present invention.

FIG. 3 is a vertical sectional view showing a conventional sealing step.

FIG. 4 is a top view showing a conventional semiconductor manufacturing apparatus.

[Explanation of symbols]

 1,18 Lead frame magazine 2 Lead frame 3 Decompression chamber for sealing work 4 First heat block 5 Second heat block 6 Magazine feed load lock chamber 7 Lead frame feed load lock chamber 8 Lead frame receiving load lock chamber 9 Magazine load lock chamber 10 Magazine transport rail 11 Third heat block 12 Semiconductor pellet 13 Bonding wire 14 Cap 15 Resin 16 Pellet mount 17 Lead frame feed rail

Claims (2)

[Claims] 1. A method of manufacturing a semiconductor device in which a semiconductor element mounted and bonded to a lead frame is sealed with a resin, wherein a step of reducing an atmosphere around the lead frame, and a step of sealing the semiconductor element And a step of solidifying the resin while decompressing the resin, the method of manufacturing a semiconductor device. 2. A semiconductor manufacturing apparatus for encapsulating a semiconductor element with a resin, comprising a decompression chamber for decompressing a sealing atmosphere of the semiconductor element, the decompression chamber comprising means for liquefying the resin and the resin. And a means for solidifying the semiconductor.