JP2003203748A - Hot plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot plate excellent in the thermal conductivity and the temperature rising/falling characteristic, having a high thermal efficiency in cooling, and in particular excellent in the temperature falling characteristics. <P>SOLUTION: The hot plate is structured so that a resistance heat emitting body is formed at the surface of or inside a ceramic base board, wherein a leak amount of the board measured by a helium leak detector is 10<SP>-7</SP>Pa.m<SP>3</SP>/sec (He) or less. <P>COPYRIGHT: (C)2003,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] [0001] The present invention mainly relates to the semiconductor industry.
Hot plate with excellent temperature rise and fall characteristics
About. [0002] 2. Description of the Related Art Etching equipment and chemical vapor deposition equipment
In semiconductor manufacturing and inspection equipment, including
Using a metal substrate such as stainless steel or aluminum alloy
Heaters and wafer probers have been used. [0003] However, such a metal heater has the following problems.
There were the following problems. First, because it is made of metal,
The thickness of the heater plate must be as thick as 15 mm
Absent. This is because, in thin metal plates, thermal expansion caused by heating
Warping, distortion, etc. may occur due to tension.
The placed silicon wafer may be damaged or tilted.
Because However, increasing the thickness of the heater plate
Then, the weight of the heater becomes heavy and it becomes bulky
There was a problem. [0004] Also, the amount of voltage or current applied to the resistance heating element
The heating target such as a silicon wafer.
It controls the temperature of the heating surface (hereinafter called the heating surface)
However, since the metal plate is thick, it is not
The temperature of the heater plate does not follow quickly, making it difficult to control the temperature.
There was another problem. Accordingly, Japanese Patent Application Laid-Open No. 11-40330 discloses
Is a nitride with high thermal conductivity and high strength as a substrate
Using ceramic or carbide ceramic, these ceramics
Metal particles are sintered on the surface of a plate made of
Ceramic substrate (hot
Plate) has been proposed. [0006] A hot plate having such a structure is generally used.
It is usually stored in a support container, and when cooling after heating
In order to increase the cooling rate,
The lamic substrate was rapidly cooled. [0007] However, these security measures
Hot plate using Lamic is a metal heater
Although the rate of temperature rise and fall is better than that of
Required for cooling characteristics when cooling using
Was not fully satisfied. [0008] Means for Solving the Problems The present inventors have set forth the above object.
As a result of diligent research to solve such a hot
The reason why the temperature drop characteristics of the plate are not sufficient is that the sinterability is not sufficient.
The cooling gas passes through the sintered body during cooling because it is
To the cooling section, which lowers the cooling heat efficiency
The degree of sintering is determined by a helium leak detector.
10 in the measurement^-7Pa ・ m^Three / Sec (He) or less
To solve the above problem.
It was newly found that it can be done. More specifically, raw material particles such as nitride ceramics
First oxidize the surface of the element, then add the oxide
Helium leak detection by pressure sintering, etc.
The leak amount was 10^-7Pa ・ m^Three / S
ec (He) or less
did. Furthermore, at this time, the withstand voltage at the time of temperature rise and helium leakage
Have been found to have a correlation with
It was completed. [0010] That is, the present invention is to
In a ceramic substrate on which a resistance heating element is formed,
The ceramic substrate is mounted on a helium leak detector.
10 in the measurement^-7Pa ・ m^Three / Sec (He) or less
It is a hot plate characterized in that it is the amount of heat. The hot plate of the present invention is a helium-free hot plate.
The leak amount measured by the detector was 10^-7P
am^Three / Sec (He) or less. This degree of Lee
Above, the ceramic substrate is sintered sufficiently densely
And achieves a thermal conductivity of 150 W / mk
The ceramic substrate can be heated and cooled.
Gas is used as a refrigerant during cooling.
It does not fall through the Mic substrate, has high cooling heat efficiency,
In particular, it has excellent temperature drop characteristics. Further, the ceramic substrate is
Due to excellent mechanical properties, the ceramic substrate warps
It does not occur and has excellent withstand voltage and Young's modulus at high temperatures.
It is. When measuring the leak amount, the diameter 30
mm, area 706.5mm^Two , 1 mm thick,
Prepare a sample similar to that of the
To the detector. Then, pass through the sample
By measuring the helium flow rate,
It is possible to measure the leak amount of the work substrate. [0013] The helium leak detector detects
The partial pressure of helium is measured, and the absolute value of the gas flow rate is measured.
It is not specified. Helium partial pressure at known leak
Is measured in advance, and the unknown leak amount is
Calculated from the partial pressure of um by a simple proportional calculation. Helium lee
The detailed measurement principle of Detector is described in “Monthly Semico
nductor World 1992.111 p11
2-115 ". That is, the above-mentioned ceramic
If the backing board is sintered sufficiently densely,
Shows a fairly small value. On the other hand, the above ceramic substrate
If the sinterability is insufficient, the above leakage amount shows a large value.
You. In the present invention, for example, a nitride ceramic
First oxidize the surface of the non-oxide ceramic of the
Next, we decided to add oxide and perform pressure sintering.
Oxide layer such as nitride ceramic and added oxide
An integrated sintered body is formed, and such a sintered body is
10 by measurement with lium leak detector^-7Pa ・ m^Three
/ Sec (He) or less, which is an extremely small leak amount.
In addition, the compact before sintering is cold isostatically pressed (CIP).
Pressing evenly promotes sintering evenly and the sintering density
And the amount of leakage becomes extremely small. Pressure during CIP
Is 0.5 to 5 t / cm^Two Is preferred. The leak amount
Is 1 × 10 as measured by helium leak detector^-8
~ 1 × 10^-12 Pa ・ m^Three / Sec (He) is preferred
No. In addition to ensuring thermal conductivity at high temperatures
This is because the cooling efficiency at the time of cooling increases. Incidentally, Japanese Patent Application Laid-Open No. Hei 9-48668,
JP-A-9-48669, JP-A-10-72260
In some patent publications, there are nitrides with some ALON crystal phases.
Although a luminium sintered body is disclosed, a metal oxide is added.
It is not added, and is manufactured by the reduction nitriding method.
Comparative example with no oxygen on the surface and poor sinterability
10 as in^-6Pa ・ m^Three / Sec (He)
A relatively large leak amount occurs. JP-A-7-153
In Japanese Patent No. 820, yttria is added.
Because the surface of aluminum nitride raw material powder is fired
However, as is clear from the comparative example, the sinterability was poor.
10 as in the comparative example^-6Pa ・ m^Three / Sec (H
A relatively large leak amount as shown in e) occurs. Further
In Japanese Patent Application Laid-Open No. 10-279359, low temperature, normal pressure
Since the firing is performed, the amount of leakage also increases. Also,
Japanese Unexamined Patent Publication No. Hei 10-158002 discloses a semiconductor mounting substrate.
It is an AlN substrate to be used.
It is not used for inspection equipment. In addition, Japanese Patent Application Laid-Open No. 10-1
No. 67859 discloses that the amount of yttria is 0.2% by weight.
Low and insufficient sintering, resulting in high leakage
It becomes. Thus, in the prior art, the present invention
Helium leak rate is 1 × 10^-7Pa ・ m^Three / Sec (H
e) Semiconductor manufacturing using a sintered body that can be adjusted as follows
・ The inspection device has not been realized. Also, in these references
For isostatic pressing such as cold isostatic pressing (CIP)
It is not described, there is no suggestion,
The amount of murk has not been reduced. The oxide to be added is a nitride ceramic.
And the like. Nitriding
The same as the surface oxide layer of the ceramic, extremely sintered
This is because it is easier to do so. The surface of the nitride ceramic
To oxidize, 500 to 100 in oxygen or air
It is desirable to heat at 0 ° C. for 0.5 to 3 hours. Further, a nitride ceramic used for sintering may be used.
The average particle diameter of the powder is preferably about 0.1 to 5 μm.
No. This is because sintering is easy. In addition, these sera
Mic powder, the content of Si is 0.05 to 50 ppm,
When the content of S is 0.05-80 ppm (all by weight)
Desirably. These are nitride ceramic surfaces
It possible to combine the oxide film with the added oxide film?
It is. For other firing conditions,
The rate manufacturing method will be described in detail. It is obtained by performing calcination using the above method.
The ceramic substrate used is 0.05 to 10% by weight of oxygen.
It is desirable to contain. Less than 0.05% by weight
Means that sintering does not proceed, fracture occurs at the grain boundaries, and thermal conductivity
If the oxygen content exceeds 10% by weight, the acid
Element segregates at the particle boundary, causing fracture at the particle boundary,
This is because the conductivity is lowered and the temperature raising / lowering characteristics are lowered. In the present invention, a cell constituting a hot plate is provided.
Lamic substrate is made of nitride ceramic containing oxygen.
And the maximum pore diameter is 50 μm or less.
The porosity is desirably 5% or less. Also,
The ceramic substrate has no pores,
If pores are present, the pore size of the largest pore is 50 μm.
m or less. When no pores are present, withstand voltage at high temperature
Is particularly high, and conversely, if pores are present, the fracture toughness
The value increases. Or to either of the design for this purpose, request
It depends on the characteristics. Destroyed by the presence of pores
Although the reason for the increase in toughness is not clear,
Presumably because the expansion is stopped by stomata
You. In the present invention, when the maximum pore diameter is 50 μm or less,
Desirably, if the pore size exceeds 50 μm
Ensure withstand voltage characteristics at high temperatures, especially at 200 ° C or higher
And it is easy for gas to escape during cooling.
This is because the cooling heat efficiency is reduced. Maximum pore porosity
The diameter is desirably 10 μm or less. Warping over 200 ° C
This is because the amount becomes small. The porosity and the maximum pore diameter are determined by the sintering process.
Adjust by pressure time, pressure, temperature, additives such as SiC and BN
I do. Pores are introduced to prevent sintering of SiC and BN
Can be done. When measuring the pore diameter of the largest pore, the sample
Are prepared, and the surfaces thereof are mirror-polished, and 2000 to 50
The surface is photographed at 10 times with an electron microscope at a magnification of 00 times.
Then, the largest pore size was selected from the photographed photos, and
The average of the peaks is defined as the maximum pore diameter. The porosity is measured by the Archimedes method.
You. Pulverized sintered body and pulverized in organic solvent or mercury
Put the material in, measure the volume, and calculate the true ratio from the weight and volume of the pulverized material.
Weight and calculate the porosity from the true specific gravity and the apparent specific gravity.
Because The ceramic constituting the hot plate of the present invention
The diameter of the backing board is desirably 200 mm or more. Especially 12
Desirably, it is not less than inches (300 mm). Next generation
This is because it becomes the mainstream of semiconductor wafers for generations. In addition,
The problem of warping that Ming solves is that the diameter is less than 200 mm.
This is because it hardly occurs on a lamic substrate. The thickness of the ceramic substrate is 50 mm or less.
The lower part is desirable, and in particular, is preferably 25 mm or less. Ceramic
If the thickness of the ceramic substrate exceeds 25 mm,
The heat capacity may be too large.
Once installed and heated and cooled, the heat
This is because the degree followability may be reduced. Ma
Also, the problem of the warpage of the ceramic substrate is that the thickness is 25 mm.
It is unlikely to occur with a thick ceramic substrate that exceeds
It is. The thickness of the ceramic substrate is particularly preferably 5 mm or less.
Suitable. The thickness is desirably 1 mm or more. Ma
Further, the ceramic substrate of the present invention is desirably at least 150 ° C.
Is used at 200 ° C. or higher. The ceramic constituting the hot plate of the present invention
Although there is no particular limitation on the material of the
And carbide ceramics are preferred. The above nitride ceramic
Mick is a metal nitride ceramic, for example, nitrided
Aluminum, silicon nitride, boron nitride, titanium nitride, etc.
Is mentioned. Examples of the above carbide ceramic include:
For example, silicon carbide, titanium carbide, tantalum carbide, titanium carbide
Nesten, zirconium carbide and the like. Also,
Even if an oxide ceramic is used as the above ceramic material,
Often, the above oxide ceramics include metal oxide ceramics.
Mick, for example, alumina, zirconia, cordurai
And mullite. Among these nitride ceramics, in particular,
Aluminum nitride is preferred. Thermal conductivity 180W / m
-Because it is the highest, K. In the present invention, acid is added to the ceramic substrate.
It is desirable to contain a compound. As the above oxide
Is, for example, an alkali metal oxide, an alkaline earth metal acid
And rare earth oxides can be used.
Among the binders, in particular, CaO, Y_Two O_Three , Na_Two O,
Li_Two O, Rb_Two O is preferred. In addition, alumina, silicon
Mosquitoes may be used. As the content of these, 0.5
-20% by weight is desirable. If less than 0.5% by weight,
10^-7Pa ・ m^Three / Sec (He) or less
Sometimes. As the oxide to be added, a silicon nitride
In this case, silica is most suitable. In the present invention, 5 to 50 ceramic substrates are used.
Desirably, it contains 00 ppm of carbon.
The inclusion of carbon makes the ceramic substrate black
Can be colored, radiant heat when used as a heater
Can be fully utilized. carbon
Is amorphous or crystalline
Good. If amorphous carbon is used,
Can be prevented from lowering the volume resistivity
If used, the thermal conductivity decreases at high temperatures
Is prevented. Therefore, depending on the application
Means that both crystalline and amorphous carbon
You may use together. The carbon content is 50 to 2
000 ppm is more preferred. The above ceramic substrate contains carbon.
If the brightness is higher, the lightness shall be based on JIS Z8721.
The carbon content should be less than N4.
Is desirable. Radiant heat with this level of lightness
This is because the amount and the concealing property are excellent. Here, the lightness N is an ideal black lightness.
0, the ideal white lightness is 10, and these black light
Between the brightness and the brightness of white, the perception of the brightness of the color is equal
Each color is divided into 10 so that
It is displayed. The actual measurement of lightness is N0 to N1
The comparison is made with the color chart corresponding to 0. Decimal point 1 in this case
The place is 0 or 5. [0034] BEST MODE FOR CARRYING OUT THE INVENTION
A resistance heating element is formed on or inside the
A hot plate, wherein the ceramic substrate comprises:
10 measured by helium leak detector^-7Pa ・ m
^Three / Sec (He) or less.
I do. FIG. 1 shows an example of the hot plate of the present invention.
FIG. 2 is a schematic bottom view, and FIG.
It is a partial expanded sectional view which shows a part of plate typically.
In this hot plate, the bottom of the ceramic substrate
A heating element is formed. As shown in FIG. 1, the ceramic substrate 11
Is formed in a disk shape, and the ceramic substrate 11
A plurality of concentrically shaped resistive heat
A body 12 is formed. These resistance heating elements 12 are
Double concentric circles close to each other form a single circuit,
These circuits are formed to be lines
Is designed so that the temperature on the heating surface 11a is uniform.
ing. Further, as shown in FIG.
2, a metal coating layer 12a is formed to prevent oxidation.
External terminals 13 are provided at both ends with solder or the like (not shown).
It is joined using. Also, the external terminal 13 includes
A socket 170 with wiring is attached, and
A connection is made. A temperature measuring element 18 is provided on the ceramic substrate 11.
A bottomed hole 14 for insertion is formed.
Is embedded with a temperature measuring element 18 such as a thermocouple.
You. Insert the lifter pin 16 in the part near the center.
A through-hole 15 for passing through is provided. The lifter pin 16 has a silicon
The wafer 9 can be placed and moved up and down.
As a result, the silicon wafer 9 is not shown.
Hand over the silicon wafer 9
The silicon wafer 9
Is placed on the heating surface 11a of the ceramic substrate 11 and heated.
Or the silicon wafer 9 is moved 50 to 20 from the heating surface 11a.
Can be supported and heated in a state of being separated by 00 μm
It has become so. The ceramic substrate 11 has through holes or recesses.
The tip of this through hole or recess is spire or semi-cylindrical.
After inserting the spherical support pin, the support pin is
It is fixed in a state where it is slightly protruded from the plate 11, and this support
By supporting the silicon wafer 9 with the pins, the heating surface
Heat at a distance of 50-2000 μm from 11a
May be. FIG. 3 shows a hot plate (ceramic) having the above structure.
Schematically shows a supporting container 30 for disposing the
FIG. In the upper part of the support container 30, a ceramic
The lock substrate 11 is fitted via the heat insulating material 35 and the bolt
It is fixed using 38 and holding metal fittings 37.
Also, a portion of the ceramic substrate 11 where the through-hole 15 is formed.
A guide tube 32 communicating with the through hole is provided in the
You. Further, this support container 31 has a refrigerant outlet 3
0a is formed, and the refrigerant is blown from the refrigerant injection pipe 39.
And discharged outside through the refrigerant outlet 30a.
The action of this refrigerant causes the ceramic
The cooling substrate 11 can be cooled. Therefore, when the hot plate is energized,
After heating the plate 10 to a predetermined temperature, the refrigerant injection pipe 3
The refrigerant is blown from the ceramic substrate 9 and the ceramic substrate 11 is cooled.
It is. The hot plate of the present invention is
The leak amount is 10^-7Pa ・ m
^Three / Sec (He) or less
11 can be efficiently cooled. FIG. 4 shows another example of the hot plate of the present invention.
It is a partial expanded sectional view which shows an example typically. This hotp
At the rate, a resistance heating element is formed inside the ceramic substrate
Have been. Although not shown, the hot spot shown in FIG.
Like the plate, the ceramic substrate 21 is formed into a disk shape.
The resistance heating element 22 is formed on the ceramic substrate 2.
1 has a pattern similar to the pattern shown in FIG.
In other words, it is formed of concentric circles, and is a double concentric
The circles are formed in a pattern that forms a set of circuits.
You. Then, immediately below the end of the resistance heating element 22
Is formed with a through hole 28.
A blind hole 27 exposing the hole 28 is formed in the bottom surface 21b.
The external terminal 23 is inserted into the blind hole 27,
(Not shown). Also shown in FIG.
However, the external terminal 23 is not connected to the hot press shown in FIG.
As with the case of the socket, for example, a socket having conductive wires
This conductive wire is connected to a power source etc.
You. The ceramic constituting the hot plate
The substrate 21 was measured by a helium leak detector,
The leak amount is 10^-7Pa ・ m^Three / Sec (He) or less
Since the bottom is small, the ceramic substrate 21 is sufficiently densely fired.
Tied. Therefore, this hot plate is shown in FIG.
Placed in a supporting container 30 as described above,
Performing temperature and temperature operations can raise and lower the temperature quickly.
You. The ceramic constituting the hot plate of the present invention
If a resistance heating element is provided inside the
It may be provided. In this case, the patterns of each layer complement each other.
It is formed to be complete, and some layers from the heating surface
It is desirable that a pattern is formed on the substrate. For example, each other
The structure is a staggered arrangement. As the resistance heating element, for example, metal or
Sintered conductive ceramics, metal foils, metal wires, etc.
It is. Tungsten, molybdenum
At least one selected from These metals
Is relatively resistant to oxidation and has sufficient resistance to generate heat
This is because that. As the conductive ceramic, a tongue is used.
At least one selected from carbides of stainless steel and molybdenum
Seeds can be used. In addition, ceramic substrates
When forming a resistance heating element on the bottom, use a metal sintered body.
Noble metals (gold, silver, palladium, platinum), nickel
It is desirable to use Specifically, silver, silver-palladium
For example. Used for the above metal sintered body
The metal particles used are spherical, scaly, or spherical.
A flaky mixture can be used. Forming a resistance heating element on the surface of a ceramic substrate
When sintering, metal oxides may be added to the metal and sintered.
No. The above metal oxides are used for ceramic substrates and
This is for bringing the metal particles into close contact. By the above metal oxide
Improves the adhesion between the ceramic substrate and the metal particles
Although the reason is not clear, the surface of the metal particles is slightly oxidized
When the film is formed and the ceramic substrate is an oxide
Of course, even if it is a non-oxide ceramic, its surface
Is formed with an oxide film. Therefore, this oxide film
Sintering on ceramic substrate surface via metal oxide
And the metal particles do not adhere to the ceramic substrate
It is thought. As the metal oxide, for example, oxidized
Lead, zinc oxide, silica, boron oxide (B _Two O_Three ), Al
At least one selected from Mina, Yttria and Titania
Species are preferred. These oxides have the resistance value of the resistance heating element.
Between the metal particles and the ceramic substrate without increasing the
This is because adhesion can be improved. The metal oxide is 100 parts by weight of metal particles.
0.1 parts by weight or more and less than 10 parts by weight
desirable. By using a metal oxide in this range,
Resistance value does not become too large, metal particles and ceramic substrate
This is because the adhesiveness with the adhesive can be improved. In addition, lead oxide, zinc oxide, silica,
Udine (B_Two O_Three ), Alumina, yttria, titania
The ratio is based on 100 parts by weight of the total amount of the metal oxide.
1 to 10 parts by weight of lead oxide and 1 to 30 parts by weight of silica
Parts, 5 to 50 parts by weight of boron oxide, 20 to 7 parts of zinc oxide
0 parts by weight, 1-10 parts by weight of alumina, 1 part of yttria
-50 parts by weight and titania of 1-50 parts by weight are preferred.
However, the total amount of these should not exceed 100 parts by weight.
It is desirable to be adjusted. These ranges are particularly
This is because the adhesiveness to the substrate can be improved. A resistance heating element is provided on the bottom surface of the ceramic substrate.
In this case, the surface of the resistance heating element 12 is covered with a metal layer 12a.
Desirably, it is covered (see FIG. 2). Resistance heating element
Reference numeral 12 denotes a sintered body of metal particles, which is oxidized when exposed.
The oxidation easily changes the resistance value. So
Here, by coating the surface with the metal layer 12a,
Can be prevented. The thickness of the metal layer 12a is 0.1 to 100 μm.
m is desirable. Do not change the resistance of the resistance heating element.
Is within the range that can prevent oxidation of the resistance heating element
It is. The metal used for coating is a non-oxidizing metal
I just need. Specifically, gold, silver, palladium, platinum,
At least one selected from nickel is preferred.
Of these, nickel is more preferred. The resistance heating element
A terminal is required to connect to the
Attached to the resistance heating element through the field, but nickel is solder
This is because the thermal diffusion of the metal is prevented. The connection terminal
External terminals made of metal can be used. It should be noted that the resistance heating element is placed inside the ceramic substrate.
If formed, the surface of the resistance heating element may be oxidized.
There is no need for coating. Resistance heating element inside heater plate
If it is formed in the part, the surface of the resistance heating element
It may be. Using a metal foil or a metal wire as the resistance heating element
You can also. Nickel foil, stainless steel
Resistive heat generated by patterning of stainless steel foil by etching etc.
A body is desirable. Patterned metal foil
You may bond with a fat film etc. As a metal wire,
For example, tungsten wire, molybdenum wire, etc.
You. As the temperature control means, the resistance heating element 12
Another example is a Peltier element. As temperature control means
When using a Peltier device,
By changing, both heat generation and cooling can be performed
It is advantageous. Peltier elements are p-type and n-type thermoelectric elements
Connect them in series and join them to a ceramic plate, etc.
And is formed by As a Peltier element, for example,
Silicon-germanium-based, bismuth-antimony-based,
Lead / tellurium-based materials and the like can be mentioned. In the present invention, if necessary, a ceramic base may be used.
A thermocouple can be embedded in the bottomed hole of the plate. heat
Measure the temperature of the resistance heating element with a
The temperature can be controlled by changing the voltage and current
This is because that. The size of the junction of the thermocouple metal wire is
Same or larger than the wire diameter of each metal wire
And 0.5 mm or less. With this configuration
Therefore, the heat capacity of the joint becomes small,
In addition, it is quickly converted to a current value. For this reason,
Improved temperature control and small temperature distribution on the heated surface of the wafer
It becomes. As the thermocouple, for example, JIS
-C-1602 (1980).
Type, R type, B type, S type, E type, J type, T type thermocouple
Can be Next, a method for manufacturing the hot plate of the present invention
Will be described. FIGS. 5A to 5D show ceramics.
Manufacture of hot plate with resistance heating element on bottom of substrate
It is sectional drawing which showed the method typically. (1) Manufacturing process of ceramic substrate Required for ceramic powder such as aluminum nitride mentioned above
Add a sintering aid such as yttria or a binder
After preparing the slurry, spray dry this slurry
Into granules, put the granules in a mold, etc.
By pressing, it is formed into a plate shape, etc.
). Amorphous and crystalline
Carbon may be added. Next, the formed body is heated, fired and sintered.
Thus, a ceramic plate is manufactured. After this,
The ceramic substrate 11 is manufactured by
Shape that can be used as it is after firing
It may be. Further, the compact is cold isostatically pressed (C
By compressing using (IP), sintering can be performed evenly.
As the process proceeds, the sintering density can be improved. At CIP
The pressure of 0.5 to 5 t / cm^Two Is preferable (Figure
5 (a)). By heating and baking while applying pressure
It is possible to manufacture a ceramic substrate 11 having no pores.
It works. Heating and firing may be at least the sintering temperature.
However, in the case of nitride ceramics,
You. Next, the ceramic substrate 11 is
The support pins to support the silicon wafer.
Through holes, lifters for transporting silicon wafers, etc.
Buried temperature measuring elements such as through holes 15 for inserting pins and thermocouples
A bottomed hole 14 and the like are formed to be inserted. (2) Conductor paste is printed on the ceramic substrate
Printing process The conductive paste is generally made of metal particles, resin, and solvent.
It is a high viscosity fluid. Apply this conductive paste
Where a resistance heating element is to be provided using screen printing
The conductive paste layer is formed by performing printing on the conductive paste.
In addition, the resistance heating element makes the entire ceramic substrate a uniform temperature.
For example, it is necessary to use concentric circles
Or a combination of concentric and bent line shapes
It is preferable to print on a pattern. Conductive paste layer
Indicates that the cross section of the resistance heating element 12 after firing is square and flat.
It is preferable to form them so as to have a shape. (3) Baking of conductor paste The conductor paste layer printed on the bottom surface of the ceramic substrate 11
Heat and bake to remove resin and solvent,
Sintering and baking on the bottom surface of the ceramic substrate 11,
The resistance heating element 12 is formed (FIG. 5B). Heating and baking
The temperature is preferably from 500 to 1000C. The above metal oxide is added to the conductor paste.
If added, metal particles, ceramic substrate and metal acid
Compound is sintered and integrated, so the resistance heating element and ceramic
The adhesion to the substrate is improved. (4) Formation of metal coating layer Next, a metal coating layer 12a is provided on the surface of the resistance heating element 12.
(FIG. 5C). The metal coating layer 12a is formed by electrolytic plating,
Can be formed by electroless plating, sputtering, etc.
However, considering mass productivity, electroless plating is
is there. (5) Mounting of terminals and the like An end of the circuit of the resistance heating element 12 for connection with a power supply is provided.
Attach the external terminal 13 via the solder paste layer 130
(FIG. 5 (d)). Thereafter, a temperature measuring element 18 such as a thermocouple is provided.
Embedded in the bottom hole 14 and sealed with heat-resistant resin such as polyimide
Stop. Although not shown, for example, this external terminal
17 is a detachable socket etc.
Attach. (6) Thereafter, the resistance heating element 12
A ceramic substrate having a cylindrical shape, for example.
And connect the lead extending from the socket to the power supply.
Then, the production of the hot plate is completed. When manufacturing the above hot plate,
By providing electrostatic electrodes inside the
Can be manufactured, and the chuck on the heating surface
A top conductor layer is provided and a guard electrode is provided inside the ceramic substrate.
By providing poles and ground electrodes, the wafer prober
Can be manufactured. In the case where electrodes are provided inside a ceramic substrate
Embed metal foil inside the ceramic substrate.
No. When a conductor layer is formed on the surface of a ceramic substrate,
In this case, sputtering or plating can be used.
And these may be used in combination. Next, a resistor is provided inside the ceramic substrate of the present invention.
A method of manufacturing a hot plate with an anti-heating element
I will tell. FIGS. 6 (a) to 6 (d) show the above hot plate.
It is sectional drawing which showed the manufacturing method typically. (1) Green Sheet Production Step First, the nitride ceramic powder is mixed with a binder, solvent, etc.
Paste to prepare a green sheet
Is prepared. As the ceramic powder described above, nitrided aluminum
Luminium etc. can be used.
A sintering aid such as tritur may be added. Also green
Adds crystalline or amorphous carbon when making sheets
May be. The binder is an acrylic binder.
, Ethyl cellulose, butyl cellosolve, polyvinyl alcohol
At least one selected from alcohols is desirable.
Further, as the solvent, α-terpineol, glycol
At least one selected from The paste obtained by mixing these components is
Green sheet 5
0 is produced. The thickness of the green sheet 50 is 0.1 to
5 mm is preferred. Next, on the obtained green sheet,
If necessary, support pins for supporting the silicon wafer
Carry the silicon wafer, the part that becomes the through hole for inserting the silicon wafer
It becomes a through hole 25 for inserting a lifter pin for
Hole 2 for embedding a temperature measuring element such as a part or a thermocouple
4 to connect the resistance heating element to the external terminal
A portion serving as a through hole 28 is formed. See later
After forming the lean sheet laminate, perform the above processing
Is also good. (2) Conductor paste on green sheet
Printing process On the green sheet 50, place a metal paste or a conductive cell.
Print conductor paste containing lamic, conductor paste layer
220 is formed, and a conductive paste is
To form a filling layer 280. These conductive pastes
Contains metal particles or conductive ceramic particles
ing. Tungsten particles or metal particles
The average particle diameter of the particles such as the molybdenum particles is preferably 0.1 to 5 μm.
New Average particle size is less than 0.1 μm or more than 5 μm
This is because it is difficult to print the conductor paste. As such a conductor paste, for example,
For example, metal particles or conductive ceramic particles 85 to 87 weights
Amount: acrylic, ethyl cellulose, butyl cellosol
And at least one selected from polyvinyl alcohol
1.5 to 10 parts by weight of a binder; and α-terpine
At least one solvent selected from all and glycols
(Paste) obtained by mixing 1.5 to 10 parts by weight of
No. (3) Green Sheet Laminating Step The conductor paste prepared in the above step (1) is printed.
A green sheet 50 which is not prepared in the above step (2).
Sheet 50 on which conductive paste layer 220 is printed
(FIG. 6A). At this time, the product
Grease for stacking the number of green sheets 50 to be layered on the lower side
The number of the heating sheets 22 is larger than the number of
The formation position is eccentric toward the bottom. Specifically, the upper
The number of stacked green sheets 50 is 20 to 50,
The number of stacked green sheets 50 is preferably 5 to 20 sheets. (4) Firing step of green sheet laminate Heat and pressurize the green sheet laminate, and further stack
After calcining the layer at 300-1000 ° C, cold isostatic pressing
Sintering by compressing using lacquer (CIP)
Reduction of variations in thermal conductivity due to differences in density
Can be. The pressure at the time of CIP is 0.5 to 5 t /
cm^Two Is preferred. As described above, the green sheet 50
And sinter the internal conductor paste, ceramic substrate
21 is manufactured. The heating temperature is 1000-2000 ° C
Preferably, the pressure is 10 to 20 MPa.
No. Heating is performed in an inert gas atmosphere. With inert gas
For example, it is possible to use argon, nitrogen, etc.
it can. The obtained ceramic substrate 21 is provided with a lifter
Insert a through hole 25 for inserting a pin or a temperature measuring element
6 (FIG. 6 (b)).
Forming a blind hole 27 to expose the hole 28
(FIG. 6 (c)). Through hole 25, bottomed hole 24 and blind hole 2
7 、 Drilling and sandblasting after surface polishing
Can be formed by blasting
You. Next, the through hole exposed from the blind hole 27
The external terminal 23 is connected to the external terminal 28 using a gold solder or the like (FIG. 6).
(D)). Further, although not shown, the external terminal 23
For example, detachably attach a socket with a conductive wire
You. The heating temperature is 90 to 45 in the case of soldering.
0 ° C. is preferred, and in the case of brazing material treatment, 900 ° C.
~ 1100 ° C is preferred. Furthermore, as a temperature measuring element
Seal a thermocouple with a heat-resistant resin to form a hot plate.
You. (5) After that, resistance heat is generated inside such
The ceramic substrate 21 having the body 12 is supported in a cylindrical shape.
Attach it to the container and use the lead wire extending from the socket
Connection completes hot plate manufacturing
You. In the above hot plate, a silicon
Place a silicon wafer, etc., or a silicon wafer, etc.
After holding the support pins, heat or cool the silicon wafer, etc.
Various operations can be performed while performing the operation. When manufacturing the hot plate,
By providing electrostatic electrodes inside the
Can be manufactured, and the chuck on the heating surface
A top conductor layer is provided and a guard electrode is provided inside the ceramic substrate.
By providing poles and ground electrodes, the wafer prober
Can be manufactured. In the case where electrodes are provided inside a ceramic substrate
Is the same as when forming a resistance heating element.
A conductor paste layer may be formed on the surface of the conductor. Also,
When forming a conductor layer on the surface of the
It is possible to use a sputtering method or a plating method.
You may use together. [0086] DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail. (Examples 1 to 7) Production of hot plate (see FIG. 6) (1) Aluminum nitride fired at 500 ° C for 1 hour in air
Powder (manufactured by Tokuyama Corporation, average particle size 0.6 μm) 100
0 parts by weight, 40 weights of yttria (average particle size: 0.4 μm)
Parts, 115 parts by weight of acrylic binder, 5 parts by weight of dispersant
And alcohol comprising 1-butanol and ethanol
Using a paste mixed with 530 parts by weight of
Molding by the reed method
Was obtained. (2) Next, the green sheet is heated to 80 ° C.
After drying for 5 hours, the diameter is 1.8m by punching
m, 3.0mm, to connect with 5.0mm external terminal
And the like to be a through hole. (3) Tungsten powder having an average particle diameter of 1 μm
-Bite particles 100 parts by weight, acrylic binder 3.0
Parts by weight, 3.5 parts by weight of α-terpineol solvent and
0.3 parts by weight of powder was mixed to prepare a conductor paste A
Was. 100 weight of tungsten particles having an average particle diameter of 3 μm
Parts, 1.9 parts by weight of acrylic binder, α-terpineo
3.7 parts by weight of dispersant and 0.2 parts by weight of dispersant
Thus, a conductor paste B was prepared. This conductive paste A
Is printed on the green sheet 50 by screen printing, and the resistance is
A conductor paste layer 220 for the heating element 22 was formed. printing
The pattern is a concentric pattern as shown in FIG.
And the width of the conductor paste is 10 mm and its thickness is 12 μm.
And In addition, a conductor pen
The paste B was filled to form a filling layer 280. The green sheet 50 after the above processing is completed
Green sheet without printing tungsten paste
37 are stacked on the upper side (heating surface) and 13 on the lower side,
These were placed at 130 ° C. and 80 kgf / cm^Two Pressure
Thus, a laminate was formed (FIG. 6A). (4) Next, the obtained laminated body is
Medium, degreased at 600 ° C for 5 hours.
Using a cold isostatic press (CIP), 3 t / cm^Two of
Compressed under pressure, then 1890 ° C, as shown in Table 1
Pressure 0-200kgf / cm^Two Hot for 3 hours
To obtain a 3 mm-thick aluminum nitride plate.
This is cut out into a 230 mm disk shape, and the thickness is 6 μm inside.
m, width 10mm (aspect ratio: 1666)
Ceramic substrate having body 22 and through hole 28
21 (FIG. 6B). (5) Next, the plate obtained in (4) is
After polishing with a diamond grindstone, a mask is placed and Si
Bottom hole for thermocouple on the surface by blasting with C etc.
(Diameter: 1.2 mm, depth: 2.0 mm)
Was. (6) Further, a through hole 28 is formed.
The part that has been cut out is cut out to form a bag hole 27 (FIG. 6).
(C)) A gold solder made of Ni-Au is inserted into the blind hole 27.
Used, heated and reflowed at 700 ° C to make Kovar external end
The child 23 was connected (FIG. 6D). In addition, external terminal
For connection, the structure is supported by a tungsten support at three points.
desirable. Because connection reliability can be ensured.
You. (7) Next, a plurality of thermoelectric devices for controlling temperature
The pair is embedded in the bottomed hole (not shown), and the resistance heating element 22 is
The production of a hot plate having the same was completed. (8) Next, this hot plate is shown in FIG.
The glassware is placed in the stainless steel support container 30 of the shape shown.
Through a heat insulating material 35 made of fluororesin reinforced with
I was fitted. After completing the production of the hot plate,
Leakage, thermal conductivity, oxygen content, etc. of the mic substrate
Is measured by the following method to support this hot plate.
After being inserted into the container and energized, the temperature was raised to 300 ° C.
When a refrigerant is introduced into the holding container and cooled, and required to raise or lower the temperature
The interval was measured. The results are shown in Table 1 below. (Embodiment 8) Production of hot plate (FIG. 5)
reference) (1) Aluminum nitride fired in air at 500 ° C for 1 hour
Powder (manufactured by Tokuyama Corporation, average particle size 0.6 μm) 100
0 parts by weight, it (Y_Two O_Three , Average particle size: 0.4μ
m) 40 parts by weight, 115 parts by weight of acrylic binder and
Spray dry the composition consisting of alcohol,
A granular powder was produced. (2) Next, this granular powder is put into a mold.
This was molded into a flat plate to obtain a molded product (green). Further
Then, this compact was cold isostatically pressed by Kobe Steel (C
IP), 3 t / cm^Two And then compress the surface
Polished. (3) Temperature of the formed body after processing is 1800
℃, pressure: hot press at 20MPa, thickness 3mm
Was obtained. Next, this sintered body
Cut out a disk with a diameter of 230 mm from the
A plate-shaped body (ceramic substrate 11) was formed (FIG. 5A). [0098] Next, a drilling process is performed on this plate-shaped body, and
Through holes 15 for inserting lifter pins of recon wafer, and
And forming a bottomed hole 14 for inserting a temperature measuring element 18
did. (4) On the bottom surface of the sintered body obtained in (3),
The conductor paste was printed by screen printing. Printing putter
The pattern is a concentric pattern as shown in FIG.
Was. As the conductive paste, use the through-hole of the printed wiring board.
Sorbeth manufactured by Tokuriki Chemical Laboratory
GPS603D was used. This conductive paste is a silver-lead paste.
Per 100 parts by weight of silver, lead oxide (5% by weight), acid
Zinc oxide (55% by weight), silica (10% by weight),
From urine (25% by weight) and alumina (5% by weight).
7.5 parts by weight of metal oxide. Also,
The silver particles have an average particle size of 4.5 μm and are scaly.
there were. (5) Next, sintering with printed conductor paste
The body is heated and fired at 780 ° C. to obtain silver in the conductor paste,
Sinters lead and sinters it to a sintered body to create a resistance heating element
No. 12 was formed (FIG. 5B). Silver-lead resistance heating element 1
No. 2 has a thickness of 5 μm, a width of 2.4 mm, and a sheet resistivity of 7.
It was 7 mΩ / □. (6) Nickel sulfate 80 g / l, hypophosphorous acid
Acid sodium 24 g / l, sodium acetate 12 g / l,
Water with a concentration of boric acid 8 g / l and ammonium chloride 6 g / l
In the electroless nickel plating bath consisting of a solution,
The surface of the silver-lead resistance heating element 12 is immersed in the manufactured sintered body.
1m thick metal coating layer (nickel layer) 12a
(FIG. 5 (c)). (7) External for ensuring connection to power supply
By screen printing on the part to attach the terminal 13
Solder by printing silver-lead solder paste (Tanaka Kikinzoku Co., Ltd.)
A paste layer was formed. Then, on the solder paste layer
Place Kovar external terminals 13 and heat at 420 ° C
Reflow, and connect one end of the external terminal 17 via the solder layer 130.
And attached to the surface of the resistance heating element 12 (FIG. 5).
(D)). (8) Next, this hot plate is shown in FIG.
The ceramic support container 30 of the shape shown
Ibar (product name of IBIDEN)
And fitted through a heat insulating material 35. After completing the production of the hot plate,
The amount of leak, thermal conductivity, oxygen content, etc.
Measure according to the following method,
It is energized by being inserted into a vessel, and after heating to 300 ° C, it is supported
Time required for cooling by introducing a refrigerant into a container, and for raising and lowering the temperature
Was measured. The results are shown in Table 1 below. (Example 9) Baking in air at 500 ° C for 1 hour
Silicon nitride powder (Tokuyama Co., average particle size 0.6μ)
m) 100 parts by weight, yttria (average particle size: 0.4 μm)
m) 40 parts by weight, 20 parts by weight of alumina, 40 parts by weight of silica
Parts, acrylic binder 11.5 parts by weight, dispersant 0.5 weight
Parts, and 1-butanol and ethanol
Use a paste mixed with 53 parts by weight of alcohol,
Formed by tar blade method, thickness 0.50mm
Green sheet was obtained. Using this green sheet
A laminate was prepared and degreased at 600 ° C. in the same manner as in Example 1.
Later, using a cold isostatic press (CIP) manufactured by Kobe Steel
And 3t / cm^Two At pressure. Next, the firing conditions
Temperature 1900 ° C, pressure 200kgf / cm^TwoOther than
Manufactured a hot plate in the same manner as in Example 1,
It was installed in the holding container 30. After finishing the production of the hot plate,
The amount of leak, thermal conductivity, oxygen content, etc.
Measure according to the following method,
It is energized by being inserted into a vessel, and after heating to 300 ° C, it is supported
Time required for cooling by introducing a refrigerant into a container, and for raising and lowering the temperature
Was measured. The results are shown in Table 1 below. Example 10 300 kgf / cm^Two Add
Hot play was performed in the same manner as in Example 1 except that pressure was applied.
And manufactured and placed in the support container 30. After completing the production of the hot plate,
The amount of leak, thermal conductivity, oxygen content, etc.
Measure according to the following method,
It is energized by being inserted into a vessel, and after heating to 300 ° C, it is supported
Time required for cooling by introducing a refrigerant into a container, and for raising and lowering the temperature
Was measured. The results are shown in Table 1 below. (Comparative Example 1) Production of hot plate Aluminum nitride powder (manufactured by Tokuyama Corporation, average particle size 1.1
μm) 1000 parts by weight, yttria (average particle size: 0.4
μm) 40 parts by weight, acrylic binder 115 parts by weight, min
From 5 parts by weight of powder and 1-butanol and ethanol
Paste containing 530 parts by weight of alcohol
Then, forming by the doctor blade method was performed to obtain a thickness of 0.1 mm.
Same as Example 1 except that a 47 mm green sheet was obtained.
In the same way, a hot plate is manufactured and
Was. After the production of the hot plate is completed,
The amount of leak, thermal conductivity, oxygen content, etc.
Measure according to the following method,
It is energized by being inserted into a vessel, and after heating to 300 ° C, it is supported
Time required for cooling by introducing a refrigerant into a container, and for raising and lowering the temperature
Was measured. The results are shown in Table 1 below. (Comparative Example 2) Production of hot plate Aluminum nitride powder (manufactured by Tokuyama Corporation, average particle size 1.1
μm) 1000 parts by weight, acrylic binder 115 parts by weight
Parts, 5 parts by weight of a dispersant and 1-butanol and ethanol
Containing 530 parts by weight of alcohol consisting of
Using the doctor blade method
Example 1 except that a 0.47 mm green sheet was obtained.
A hot plate is manufactured in the same manner as
Was placed. After completing the production of the hot plate,
The amount of leak, thermal conductivity, oxygen content, etc.
Measure according to the following method,
It is energized by being inserted into a vessel, and after heating to 300 ° C, it is supported
Time required for cooling by introducing a refrigerant into a container, and for raising and lowering the temperature
Was measured. The results are shown in Table 1 below. (Comparative Example 3) The amount of yttria was 0.2 weight
Hot plate in the same manner as in Example 7 except that
Was prepared and placed in a supporting container. After completing the production of the hot plate,
The amount of leak, thermal conductivity, oxygen content, etc.
Measure according to the following method,
It is energized by being inserted into a vessel, and after heating to 300 ° C, it is supported
Time required for cooling by introducing a refrigerant into a container, and for raising and lowering the temperature
Was measured. The results are shown in Table 1 below. Comparative Example 4 The firing temperature was 1600 ° C.
Except that no pressurization was performed,
A plate was manufactured and placed in a support vessel. After the production of the hot plate is completed,
The amount of leak, thermal conductivity, oxygen content, etc.
Measure according to the following method,
It is energized by being inserted into a vessel, and after heating to 300 ° C, it is supported
Time required for cooling by introducing a refrigerant into a container, and for raising and lowering the temperature
Was measured. The results are shown in Table 1 below. [0118]Evaluation method (1) Thermal conductivity a. Used equipment Ligag Laser Flash Method Thermal Constant Measurement System LF / TCM-FA8510B b. Test condition. Temperature: 25 ° C, 450 ° C Atmosphere: vacuum c. Measuring method ・ Temperature detection in specific heat measurement uses silver paste on the back of the sample.
The measurement was performed using a thermocouple (platinel) adhered to the above. ・ At room temperature specific heat measurement, light receiving plate (glassy
Carbon) bonded with silicon grease
The specific heat (Cp) of the sample was calculated according to the following equation (1).
I asked. [0119] (Equation 1) In the above formula (1), ΔOIs the input
The energy, ΔT, is the saturation value of the temperature rise of the sample, Cp
_GC Is the specific heat of glassy carbon, W_GC Is
Sea carbon weight, Cp_SG Of the silicon grease
Specific heat, W_SG Is the weight of silicon grease, W is the sample
Weight. (2) Oxygen content Trials sintered under the same conditions as the sintered bodies according to the examples and comparative examples
The material is ground in a tungsten mortar and 0.01 g of this is collected.
Sample heating temperature 2200 ° C, heating time 30 seconds 1 condition
Oxygen / nitridation simultaneous analyzer (TC-13 manufactured by LECO)
6). (3) Leakage Trials sintered under the same conditions as the sintered bodies according to the examples and comparative examples
Fee (area 706.5mm ^Two , Thickness 1mm)
Type helium leak detector (“MSE” manufactured by Shimadzu Corporation)
-11AU / TP type ")
Was measured. (4) Withstand voltage Adhere the aluminum foil to the surface of the heating
To raise the temperature of the external aluminum foil and ceramic substrate.
Apply a voltage to the back and measure the voltage at which dielectric breakdown occurred.
Specified. The withstand voltage shown in the table indicates that this voltage
Is the value divided by the thickness of Voltage application and voltage during dielectric breakdown
The pressure was measured using Nichicon DCC-30K3T.
I went. (5) Temperature rise / fall time The time required to raise the temperature to 300 ° C and the
The time for the temperature to fall was measured. Temperature drop is 0.1m^Three Per minute
Performed by blowing air. [0125] [Table 1] As is clear from the results shown in Table 1, the actual
Ceramics constituting hot plate according to Examples 1 to 10
Substrate, the helicopter measured with a helium leak detector.
Um leak rate is 10^-7Pa ・ m^Three / Sec or less
And high thermal conductivity, so it has good temperature rise and fall characteristics.
During cooling, the temperature is lowered to 100 ° C. in a short time.
Also, the withstand voltage is high. On the other hand, the hot plates of Comparative Examples 1 to 4 were
Helium leaks in any ceramic substrate
The quantity is 10^-7Pa ・ m^Three / Sec
These have low thermal conductivity and do not have good temperature rise / fall characteristics.
It takes a relatively long time even when the temperature falls,
The values are inferior to those of Examples 1 to 10. Ma
Also, the withstand voltage is remarkably inferior. As described above, the hot plate of the present invention
Is 10 measured by a helium leak detector.^-7Pa
・ M^Three / Sec (He)
It has excellent temperature rise characteristics, especially excellent temperature fall characteristics.
It is. [0129] As described above, the hot press of the present invention is
Is measured by a helium leak detector and is 10
^-7Pa ・ m^Three / Sec (He) or less
As it is sintered, it has excellent thermal conductivity,
Excellent temperature rise / fall characteristics, especially excellent temperature fall characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a bottom view schematically showing an example of a hot plate in which a resistance heating element is formed on the bottom surface of the present invention. FIG. 2 is a partially enlarged sectional view schematically showing a part of the hot plate shown in FIG. FIG. 3 is a cross-sectional view schematically showing a support container for disposing the hot plate shown in FIG. FIG. 4 is a partially enlarged cross-sectional view schematically showing an example of a hot plate in which a resistance heating element is formed inside the present invention. FIGS. 5A to 5D are cross-sectional views schematically showing a part of a manufacturing process of a hot plate in which a resistance heating element is formed on a bottom surface according to the present invention. FIGS. 6A to 6D are cross-sectional views schematically showing a part of a manufacturing process of a hot plate having a resistance heating element formed therein according to the present invention. [Description of Signs] 9 Silicon wafer 10, 20 Hot plate 11, 21 Ceramic substrate 12, 22 Resistance heating element 13, 23 External terminal 14 Bottom hole 15 Through hole 16 Lifter pin 18 Thermocouple 25 Through hole 27 Bag hole 28 Through Hole 30 Support container 30a Refrigerant outlet 32 Guide tube 35 Insulating material 37 Holder 38 Bolt 39 Refrigerant injection tube 130 Solder paste layer 170 Socket

Continuation of front page    F term (reference) 3K034 AA03 AA10 AA16 AA21 AA34                       AA37 BA02 BA15 BA17 BB06                       BB14 BC04 BC12 BC17 BC27                       CA03 CA17 CA24 DA04 EA07                       JA04 JA10                 3K092 PP20 QA05 QB09 QB13 QB32                       QB44 QB47 QB63 QB75 QC07                       QC34 QC42 QC43 QC52 QC53                       QC58 RF11 RF17 RF22 UA05                       VV12 VV16 VV22                 4G030 AA12 AA51 BA12

Claims (1)

[Claims] A resistor is provided on the surface or inside of a ceramic substrate.
A hot plate on which a heating element is formed, wherein:
The ceramic substrate is measured with a helium leak detector.
Regularly 10^-7Pa ・ m ^Three / Sec (He) or less
A hot plate, characterized in that: