JPH0633392Y2 - Sees-type temperature measuring element - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is a sheath type thermocouple used for temperature measurement in the chemical industry, electrical machinery industry, and other heat treatment processes, and sheath type temperature sensors such as sheath type resistance temperature detectors. The present invention relates to a measuring element, and more particularly to its sheath structure.

[Conventional technology]

A sheath type temperature measuring element such as a sheath type thermocouple or a sheath type resistance temperature detector has a sheath structure,
Since it can be used under severe operating conditions such as locations with many bends and locations with severe vibration, it is extremely useful for measuring and controlling the temperature in processes involving heat treatment.

In recent years, the application of plasma technology has expanded, and especially in the semiconductor device manufacturing process, plasma etching method, plasma
The CVD (Chemical Vaper Deposition) method has been widely used. In such a process, it is necessary to measure and control the temperature of the plasma generating electrode or the object to be processed to which direct current or high frequency power is applied. The accuracy of this temperature control determines the yield, performance, etc. of the manufactured semiconductor element.

FIG. 4 is a partial cross-sectional view of an example of a conventional type, showing a case of a sheath type resistance temperature detector, and FIGS. 5 (a) and 5 (b) are perspective views showing another example of the conventional type and a cross-section thereof. In a side view, the case of a sheath type thermocouple is shown.

In each of these conventional examples, a metal sheath (capillary tube) 1 is provided with a temperature measuring element 2 such as a thermocouple of a temperature measuring resistance element in which a fixing core is mounted at the center of a platinum resistance element, and a metal sheath. The space inside 1 is filled with an insulator 3 having high thermal conductivity such as high-purity MgO, and the signal wire (conductor wire or wire) 4 of the temperature measuring element 2 is pulled out from the end of the metal sheath 1. It consists of a sheath type temperature measuring element, has excellent heat resistance, corrosion resistance, earthquake resistance, insulation characteristics and responsiveness, and can be used for temperature measurement in a high-pressure container or a vacuum container if the seal structure of the drawer part is properly selected. You can

[Problems to be solved by the invention]

However, in the conventional sheath type temperature measuring element as described above, since the sheath portion is brought into contact with the electrode as the object to be measured, even if the temperature measuring element 2 is insulated from the electrode, the influence of the potential change of the electrode or the external noise is not generated. Will receive. Especially when a high frequency voltage is applied, high frequency noise is superimposed on the signal from the temperature measuring element 2 which is a minute electric signal together with external noise, and measurement becomes impossible. For this reason, methods such as temperature measurement and stopping the control function during the application of the high frequency voltage are adopted. However, it is completely expected operation, high-precision temperature measurement and control are not executed, and eventually the semiconductor manufactured. There is a problem that the quality of the device is deteriorated.

[Means for solving problems]

The present invention reduces the influence of potential change and external noise as much as possible and measures more accurately than before even when the temperature of the electrode to which high voltage such as DC or AC or high frequency voltage is applied is being applied. The present invention is intended to provide a sheath-type temperature measuring element that enables the above.

That is, in the device of the present invention, as shown in FIG. 1, a temperature measuring element 2 is housed in a metal sheath 1 and the space inside the metal sheath 1 is filled with a heat conductive insulator 3. In a sheath-type temperature measuring element in which the signal line 4 of 2 is drawn out from the end of the metal sheath 1, a shield terminal 7 is connected to the metal sheath 1 and an outer sheath 5 is thermally conducted around the metal sheath 1. The structure is such that it is adhered via a flexible insulator 6.

[Action]

At the time of temperature measurement, the outer sheath 5 is brought into contact with the object to be measured to which a high DC or AC voltage or a high frequency voltage is applied. Therefore, when the outer sheath 5 is made of metal, the direct current applied to the DUT,
It has the same potential as the AC or high-frequency voltage.

The temperature of the object to be measured is measured from the outer sheath 5 through a heat conductive insulator 6, an inner metal sheath (hereinafter referred to as an inner sheath) 1 and a heat conductive insulator 3 to measure the temperature of the temperature measuring element 2. And transmitted as an electric signal.

When the inner sheath 1 is grounded, the minute electric signal generated in the temperature measuring element 2 is shielded from external noise and the influence of high voltage or high frequency voltage of direct current and alternating current applied to the object to be measured so that the temperature is more accurate than before. It serves to enable measurement.

This effect is the same when the outer sheath 5 is made of a heat conductive insulator instead of a metal.

〔Example〕

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

FIG. 1 is a cross-sectional view showing an embodiment of the device of the present invention, 1 is a metal sheath (capillary tube), and 2 is a thermocouple housed in the metal sheath 1. Reference numeral 3 is an electrically insulating electrical insulator, typically MgO, filled between the metallic sheath 1 and the thermocouple 2. The signal wire (strand) 4 of the thermocouple 2 is drawn out from the end of the metal sheath 1. 8 is a signal line terminal,
Reference numeral 7 is a shield terminal connected to the sheath 1. Reference numeral 5 denotes an outer sheath arranged around the temperature measurement side portion 1a of the metal sheath 1 and is made of metal in the present embodiment. Reference numeral 6 denotes the outer sheath 5 and the inner metal sheath (referred to as inner sheath) 1. It is an electrically insulating material having thermal conductivity represented by MgO filled in between.

The outer sheath 5 is brought into contact with an object to be measured 10 such as an electrode to which a DC or AC high voltage or a high frequency voltage is applied, which is provided in the vacuum container 9 as shown in FIG. It is mounted with a sealing O-ring 11 interposed. The signal line terminal 8 of the thermocouple 2 is connected to the input terminal of the temperature measuring and controller 12 for inputting a minute thermoelectromotive force or a minute thermal current (referred to as an electric signal) generated in the thermocouple 2 by the signal line of the shield cable 13. The shield terminal 7 of the inner sheath 1 is connected to its ground terminal by the shield wire (braided wire) of the shield cable 13.

Since the outer sheath 5 is attached in contact with the DUT 10 to which a high voltage of DC or AC or a high frequency voltage is applied, the outer sheath 5 has the same potential as that of the DUT 10.

The temperature of the object to be measured 10 is transmitted from the outer sheath 5 through the thermally conductive insulator 6, the inner sheath 1 and the thermally conductive insulator 3 to the temperature measuring portion of the thermocouple 2 and is taken out as an electric signal. . This electric signal is input to the temperature measuring / controlling device 12 to be measured or used for temperature control.

The temperature of the inner sheath 1 is measured by the shield wire of the shield cable 13. Since it is connected to the ground terminal of controller 12,
Accurate temperature measurement or temperature control because it works to shield the minute electric signal generated in the thermocouple 2 from external noise and the influence of high voltage and high frequency voltage of direct current and alternating current applied to the DUT 10. You can

FIG. 3 shows a safety box in which the inner sheath 1 is attached to the vacuum container 9.
Connect to 14 and ground, connect the signal wire terminal 8 of the thermocouple 2 to the input terminal of the temperature measurement and controller 12 with the signal wire of the shield cable 13, and connect the shield wire of this shield cable 13 to its ground terminal. The case is shown.

Signal line terminal 8 of thermocouple 2 and shield terminal 7 of inner sheath 1
Is guided to the temperature measurement, the input terminal of the controller 12 and the ground terminal by the shielded cable 13 as shown in the second diagram above, so it is most effective in preventing the influence of the potential of the DUT 10 and the mixing of external noise. Even when grounded near the temperature measuring section as shown in FIG. 3, the influence of the potential of the DUT 10 can be prevented. Also in this case, the influence of external noise can be reduced.

In this embodiment, the case where the thermocouple is used as the temperature measuring element 2 has been described, but the same structure can be obtained by using the temperature measuring resistance element.
Of course, it can be explained.

The same applies when the outer sheath 5 is not made of metal but made of a heat conductive insulator.

[Effect of device]

As described above, according to the present invention, the shield terminal 7 is connected to the metal sheath 1 and the outer sheath 5 is provided around the metal sheath 1.
Is adhered via an insulating material 6 made of heat conduction, a minute electric signal generated in the temperature measuring element 2 by grounding the metal sheath 1 is applied to the object to be measured.
Since it is possible to shield (electrostatic shield and / or electromagnetic shield) from noise and external noise due to AC high voltage or high frequency voltage, it is possible to apply a potential such as an electrode to which DC or AC high voltage or high frequency voltage is applied. The temperature of a certain object can be measured more accurately than before.

Since the temperature of an object to be measured having an electric potential can be accurately measured, temperature control in the chemical industry, electrical industry, and other heat treatment processes can be performed with high accuracy, which in turn leads to the quality of manufactured semiconductor device products. Can be improved.

Further, the device according to the present invention does not substantially impair the features of the device described in the section of the prior art.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the device of the present invention, and FIGS. 2 and 3 show the case of applying the device of the present invention to a vacuum container for temperature measurement and temperature control by a controller. Explanatory drawing, FIG. 4 is a diagram showing a partial example of a conventional example, and FIGS. 5 (a) and 5 (b) are a perspective view and a transverse sectional view showing another example of the conventional example. 1 ... Metal sheath, 2 ... Temperature measuring element (thermocouple), 3 ...
… Insulator with thermal conductivity, 4 …… Signal line, 5 …… Outer sheath, 6 …… Insulator with thermal conductivity.

Claims (1)

[Scope of utility model registration request] 1. A temperature measuring element 2 is housed in a metallic sheath 1, and a space inside the metallic sheath 1 is made of an insulating material 3 having thermal conductivity.
In the sheath-type temperature measuring element obtained by filling the signal wire 4 of the temperature measuring element 2 from the end portion of the metal sheath 1 while connecting the shield terminal 7 to the metal sheath 1,
A sheath-type temperature measuring element in which a metallic outer sheath 5 is attached to the periphery of a metallic sheath 1 with an insulating material 6 having heat conductivity interposed therebetween.