JPH04179243A - Vacuum drying apparatus for semiconductor device - Google Patents

Abstract

PURPOSE:To always maintain the pressure inside a vacuum tank within a definite range and to heat and seal a semiconductor device without a defect by providing a limit sensor which detects the upper limit and the lower limit of the degree of vacuum inside the vacuum tank and which adjusts the evacuation air amount of a vacuum pump used to vacuum-evacuate the vacuum tank. CONSTITUTION:The degree of vacuum in a vacuum tank 2 is made to reach a level of 5 by using a vacuum pump 3. When the degree of vacuum reaches the level of 5, the lower limit of a limit sensor is actuated. The evacuation capacity of the vacuum pump is reduced or stopped either by stopping the vacuum pump 3 or by shutting an opening and shutting valve. Then, a heater 1a is turned on; the heating and sealing operation of a semiconductor device as a half-finished product is started. After that, when a gas is generated from the semiconductor device 1 and the degree of vacuum is deteriorated, the upper limit of the limit sensor is actuated. The opening and shutting valve is opened or the vacuum pump is operated and its vacuum evacuation ability is displayed fully. Thereby, the degree of vacuum reaches the level of 5 again. The operation is repeated, the semiconductor device is heated and sealed for a prescribed time and this process is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vacuum drying apparatus for semiconductor devices that heat-seals semiconductor devices.

[Conventional technology]

Conventionally, this type of vacuum drying apparatus for semiconductor devices, which is not shown in the drawings, includes a vacuum chamber into which a semiconductor device is inserted and a heater that heats the semiconductor device, a vacuum pump that evacuates the vacuum chamber, and the like. The vacuum chamber has an inlet for introducing dry gas into the vacuum chamber, and has been used for heat sealing of semiconductor devices in the manufacturing process of semiconductor devices.

FIG. 3 is a graph of heating temperature and degree of vacuum over time, showing an example of the conventional method. When heat-sealing a semiconductor device with this vacuum dryer, first place the semiconductor device in a vacuum chamber, evacuate the vacuum chamber, and set the vacuum level to 5, as shown in Figure 3. After reaching this temperature, the heater in the vacuum chamber was turned on and heat-sealed for a predetermined period of time.

[Problem to be solved by the invention]

However, in the conventional vacuum drying apparatus described above, during heat sealing, scum is generated from the semi-finished semiconductor device, and the degree of vacuum in the vacuum chamber deteriorates. Therefore, there is a problem that the quality of the heat-sealed semiconductor device is deteriorated. Also,
If a vacuum pump with a large evacuation capacity is provided to prevent the degree of vacuum from worsening, there is a problem that the material in the outer body of the semiconductor device may be unnecessarily evaporated due to the degree of vacuum reached.

An object of the present invention is to provide a vacuum drying apparatus for semiconductor devices that solves this problem.

[Means to solve the problem]

A vacuum drying apparatus for a semiconductor device according to the present invention includes a vacuum chamber having a means for inserting a semiconductor device and heating the semiconductor device, a vacuum pump for evacuating the vacuum chamber, and an introduction for introducing gas into the vacuum chamber. The vacuum drying apparatus for semiconductor devices includes a mitt sensor that detects the upper and lower limits of the vacuum degree of the vacuum chamber and adjusts the exhaust capacity of the vacuum pump that energizes the vacuum chamber.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of a vacuum drying apparatus showing an embodiment of the present invention. As shown in the figure, this vacuum drying device
A vacuum chamber 2 in which a semi-finished semiconductor device MJ is placed, a heater 1a that heats the semiconductor device 1, an air decay pump 3 that exhausts the vacuum chamber 2, and a sensor that detects the degree of vacuum in the vacuum chamber 2)
A sensor (not shown) is provided.

This limit sensor may be, for example, a combination of an ion vacuum gauge that measures the ion current and a Meckl relay, or one that has a pull-in tube vacuum gauge and a relay that switches using its contacts. Also good.

FIG. 2 is a graph of superheating temperature and degree of vacuum over time when drying was carried out using the vacuum drying apparatus of the present invention. Here,
The operation of this vacuum drying device will be explained. First, as in the conventional case, the vacuum chamber 2 is brought to a vacuum level of 5 using the vacuum pump 3. When this level of vacuum level 5 is reached, the lower limit of the limit sensor is activated and the vacuum pump 3 is stopped, but the opening/closing valve is closed and the vacuum capacity of this vacuum pump is eliminated or stopped.

Next, heater A is turned on to start heating and sealing the semi-finished semiconductor device. After that, when gas is generated from the semiconductor device 1 and the degree of vacuum deteriorates, the upper limit of the limit sensor is activated again, the on-off valve is opened, or the vacuum pump is activated, and the evacuation capacity is fully opened. As a result, the degree of vacuum reaches level 5 again. By repeating these operations, the semiconductor device is heat-sealed for a predetermined period of time.
Complete this process.

〔Effect of the invention〕

As explained above, the present invention provides a limit sensor that detects the upper and lower limits of the degree of vacuum level, and adjusts the amount of exhaust to evacuate the vacuum chamber based on the upper and lower limit signals of this limit sensor. This has the effect of providing a vacuum drying apparatus for semiconductor devices that maintains the pressure within the vacuum chamber within a certain range and can heat-seal defect-free semiconductor devices.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a vacuum drying apparatus showing an embodiment of the present invention, Fig. 2 is a graph of superheating temperature and degree of vacuum over time when the vacuum drying apparatus of the present invention is used, and Fig. 3 is a conventional It is a graph of heating temperature and degree of vacuum over time showing an example. 1. Semiconductor device, 2.. Vacuum chamber, 3.. Vacuum pump, 4.. Waste inlet.

Claims (1)

[Claims] A vacuum drying apparatus for a semiconductor device, comprising a vacuum chamber having a means for inserting a semiconductor device and heating the semiconductor device, a vacuum pump for evacuating the vacuum chamber, and an inlet for introducing gas into the vacuum chamber, A vacuum drying apparatus for a semiconductor device, comprising a limit sensor that detects an upper limit and a lower limit of the degree of vacuum of the vacuum chamber and adjusts an evacuation capacity of the vacuum pump that evacuates the vacuum chamber.