JP2001313249A - Hot plate unit - Google Patents

Abstract

(57) Abstract: A hot plate capable of uniformly heating a silicon wafer W1 is provided. A hot plate (3) is fixed to an opening (4) of a casing (2) via a heat-insulating seal ring (14), and the heat-insulating seal ring (14) is formed of resin containing fibers. Therefore, even if the heat insulating seal ring 14 is softened by heat, the plate-shaped substrate 9 is maintained in a flat state. Therefore, the silicon wafer W1 can be heated uniformly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a hot plate unit.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, for example, when a silicon wafer having undergone a photosensitive resin coating step is heated and dried, an apparatus called a hot plate unit is usually used. The conventional example is shown in FIG.

The hot plate unit 41 includes a casing 42 having a bottom and a hot plate 43 made of a ceramic sintered body. The casing 42 is made of a metal material such as aluminum, and has an opening 44 at an upper portion thereof. On the lower surface of the hot plate 43, a resistor 45 having a predetermined pattern is formed, and on the upper surface, a silicon wafer W1, which is an object to be heated, is placed. Screw holes 46 are provided in a plurality of places on the outer peripheral portion of the hot plate 43, and a through hole 47 is formed in the upper edge of the opening of the casing 42 corresponding to the screw holes 46. Then, a screw 48 is inserted into the screw hole 46 and the through hole 47.
Into the hot plate 4
3 is fixed to the upper edge of the opening of the casing 42.

[0004]

However, in the case of the conventional hot plate unit 41, a metal casing 4 is required.
2, the fastening means such as the screw 48 is provided with the holes 46, 4
7 and is fastened. Therefore, the heat of the hot plate 43 was easily transmitted to the casing 42 via the screw 48. As a result, there is a problem that the outer peripheral temperature of the hot plate decreases.

Therefore, in order to solve the above problem,
It is conceivable to fix the hot plate to the opening 44 of the casing 42 via a heat insulating member. However, if the heat insulating member is made of a general-purpose synthetic resin, the heat insulating member is easily softened by heat, and
3 leans. As a result, the heated surface and the silicon wafer W1
Since the distance from the wafer was not constant, the silicon wafer could not be heated uniformly.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a hot plate unit having excellent temperature uniformity by preventing the hot plate from tilting.

[0007]

According to the first aspect of the present invention, a hot plate made of a ceramic sintered body having a resistor is disposed at an opening of a casing. A hot plate unit, wherein the hot plate is fixed to an opening of the casing via a heat insulating member, and the heat insulating member contains fibers.

According to a second aspect of the present invention, in the hot plate unit according to the first aspect, the heat insulating member comprises:
The gist consists of fibers and resin. Claim 3
The gist of the present invention is that in the hot plate unit according to claim 1 or 2, the fiber contains 1 to 60% by weight.

The invention described in claim 4 is the first or second invention.
In the hot plate unit described in the above, the gist is that the heat insulating member is made of an inorganic fiber and a fluororesin.

Hereinafter, the "action" of the present invention will be described. According to the present invention, since the hot plate is fixed to the casing via the heat insulating member, the heat of the hot plate is less likely to be transmitted to the metal casing, and the temperature of the outer peripheral portion of the hot plate can be prevented from lowering. .
In addition, because the fiber is contained in the heat insulating member,
Even if the heat insulating member is softened by heat, the hot plate made of the ceramic sintered body does not tilt. Further, the coefficient of thermal expansion of the heat insulating member can be reduced, and the hot plate can be prevented from tilting.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] A hot plate unit 1 according to a first embodiment of the present invention will now be described in detail with reference to FIGS.

The hot plate unit 1 shown in FIGS. 1 to 3 includes a casing 2 and a hot plate 3 as main components. The casing 2 is a metal member having a bottom (in this case, an aluminum member), and has an opening 4 having a circular cross section on an upper side thereof. Pin insertion sleeves 5 through which lift pins (not shown) are inserted are provided at three places at the center of the bottom 2 a of the casing 2. These lift pins raise and lower the silicon wafer W1 while supporting the silicon wafer W1 at three points. A hot plate 3 is provided on the outer periphery of the bottom 2a.
A lead wire drawing hole 7 for inserting a lead wire 6 for supplying a current to the lead wire is formed. A seal packing 8 is mounted in the lead wire drawing hole 7. Each lead wire 6
Is inserted through the through hole of the seal packing 8 and is drawn out of the casing 2.

The hot plate 3 according to the present embodiment is configured such that a silicon wafer W1 coated with a photosensitive resin is
This is a low-temperature hot plate 3 for drying at a temperature of 0 ° C. The hot plate 3 is configured by providing a resistance pattern 10 as a resistor on a plate-like base material 9 made of a ceramic sintered body. This plate-shaped base material 9 is connected to the casing 2 via a heat insulating seal ring 14 described later.
Is installed in the opening 4. In addition, as shown in FIG. 3, in the present embodiment, the thickness 1 of the plate-shaped base material 9 is set to 3 mm. In addition to this value, the thickness l of the plate-shaped substrate 9 is set to 1 m
It may be changed to any value within the range of m to 10 mm.

As shown in FIG. 1, hot plate 3
The plate-shaped base material 9 constituting the casing 2 has a circular shape.
It is designed to have a slightly smaller diameter than the external dimensions of.
The resistance pattern 10 is formed concentrically or spirally on the lower surface side of the plate-shaped substrate 9. In the center of the hot plate 3, pin insertion holes 11 are provided at three positions corresponding to the respective lift pins.

As the ceramic sintered body constituting the plate-shaped substrate 9, it is preferable to select a nitride ceramic sintered body having excellent heat resistance and high thermal conductivity.
As the nitride ceramic, for example, aluminum nitride,
A sintered body of a metal nitride ceramic such as silicon nitride, boron nitride, titanium nitride or the like is preferable, and an aluminum nitride sintered body is particularly preferable. The reason is that the thermal conductivity is the highest in the above-mentioned sintered body. In addition to these, a sintered body of a metal carbide ceramic such as silicon carbide, zirconium carbide, titanium carbide, tantalum carbide, tungsten carbide, or the like may be selected.

The resistance pattern 10 of the present embodiment is formed by baking a conductive paste on a plate-like base material 9 which is a sintered body. As the conductive paste, those containing metal particles, metal oxides, resins, solvents and the like are generally used. Suitable metal particles used for the conductive paste include, for example, gold, silver, platinum, palladium, lead, tungsten, nickel and the like. This is because these metals are relatively unlikely to be oxidized even when exposed to a high temperature, and have a sufficient resistance value to generate heat when energized. Suitable metal oxides used for the conductive paste include, for example, metal oxides such as lead oxide, zinc oxide, silica, boron oxide, alumina, yttria, and titania.

As shown in FIG.
A pad 10a as an external connection terminal is formed at the end of the zero. The base ends of the terminal pins 12 made of a conductive material are soldered to these pads 10a. As a result, electrical continuity between each terminal pin 12 and the resistance pattern 10 is achieved. On the other hand, a socket 6 a at the tip of the lead wire 6 is fitted to the tip of each terminal pin 12. Therefore, the lead wire 6 and the terminal pin 12
As a result, a current is supplied to the resistance pattern 10 via the resistor pattern 10, so that the temperature of the resistance pattern 10 rises and the entire hot plate 3 is heated.

As shown in FIG. 3, a plurality of screw holes 13 are provided at equal intervals in the upper edge of the opening 4 of the casing 2 and a heat insulating seal ring 1 as a heat insulating member is provided.
4 are provided. Similarly, a plurality of screw holes 15 are also provided at locations corresponding to the respective screw holes 13 in the heat insulating seal ring 14. On the inner peripheral surface of the heat-insulating seal ring 14, a support step 16 for horizontally supporting the outer peripheral portion on the lower surface side of the hot plate 3 is formed over the entire periphery thereof. When the hot plate 3 is supported by the supporting step 16, the height of the upper end surface of the heat insulating seal ring 14 and the height of the upper surface of the hot plate 3 are substantially the same.

The material for forming the heat-insulating seal ring 14 is a resin containing fibers. Fibers include inorganic fibers and organic fibers, but inorganic fibers are optimal in consideration of the coefficient of thermal expansion and heat resistance. Examples of the inorganic fibers include glass fibers and glass wool ceramic fibers. Organic fibers include carbon fiber, aramid fiber, Kevlar fiber and the like. The average fiber length is preferably 0.1 to 50 mm. If the fiber is too long, the surface of the heat-insulating seal ring 14 becomes uneven, and the plate-like substrate 9 cannot be flattened. If the fiber is too short, there is no effect of reinforcing the fiber. In addition, the amount of fiber is 1 to 60% by weight.
Is good. If the amount is too large, the surface of the heat-insulating seal ring 14 becomes uneven, and the plate-shaped substrate 9 cannot be flattened. If the amount is small, there is no effect of fiber reinforcement.

The fibers contained in the heat-insulating seal ring 14 are mixed with a resin or an inorganic binder, but a resin is preferred from the viewpoint of heat insulation. As the resin, a fluorine resin, a polyimide resin, an epoxy resin, a urethane resin, a styrene resin, or the like is preferable. As the inorganic binder, silica sol, alumina sol and the like are preferable.

In the present embodiment, the heat-insulating seal ring 14 is made of a fluororesin containing the above-mentioned inorganic fibers. When a fluororesin is used for the heat-insulating seal ring 14, there is an advantage that it is excellent in heat resistance, insulation, and flame retardancy. As for heat resistance, there is a characteristic that the operating temperature range is wider than that of general-purpose synthetic resins.
In addition, with respect to insulation, there is a characteristic that dielectric loss is small and insulation resistance is large. Furthermore, regarding flame retardancy,
There is a characteristic that it does not burn in air or in a gas having an oxygen concentration of 95% or less. More specifically, the fluororesin is polytetrafluoroethylene (ethylene tetrafluoride resin, PTFE), ethylene tetrafluoride-perfluorovinyl ether copolymer (PFA),
There are propylene hexafluoride copolymer (FEP), ethylene tetrafluoride-ethylene copolymer (ETFE), polyvinylidene fluoride (PVdF), and ethylene trifluorochloride resin (PCTFE).

As shown in FIG. 3, the thickness L of the heat insulating seal ring 14 in this embodiment is set to 7 mm. In addition to this value, the thickness L of the heat-insulating seal ring 14 may be changed to any value within a range of 1 mm to 10 mm.

The bottom 2a of the casing 2 is provided with a fluid supply port 17 and a fluid discharge port 18 for communicating the inside and outside of the casing 2 with each other. Air as a fluid is supplied to the sealed space S1 in the casing 2 from the fluid supply port 17, and the air is discharged to the outside of the sealed space S1 from the fluid discharge port 18.

Next, the mounting structure of the hot plate 3 in the hot plate unit 1 of the present embodiment will be described. The hot plate unit 1 further includes a locking ring 21 as a locking tool. The locking ring 21 has an annular main body 22, a plurality of screw holes 23, and a plurality of locking pieces 24. The main body 22 includes the casing 2
Is a ring-shaped spring material having a size corresponding to the size of the opening 4 of FIG. The screw holes 23 are formed at equal intervals in the main body 22. These screw holes 23 are located at positions corresponding to the respective screw holes 15 on the heat-insulating seal ring 14 side. Each of the screw holes 15 and 23 has a screw 2 as a fastening means for fixing the locking ring 21 to the upper end surface of the heat-insulating seal ring 14.
5 are respectively inserted. The locking pieces 24 that can be locked to the outer peripheral portion of the hot plate 3 protrude at a plurality of spaced apart locations (here, six locations) on the inner peripheral edge of the main body 22. As shown by a dashed line in FIG.
4 may be slightly bent toward the lower surface of the main body 22. The above-described locking ring 21 can be relatively easily manufactured by punching a spring steel material or the like having a thickness of about 1 mm to 3 mm into a predetermined shape.

With the locking ring 21 arranged, each screw 2
5 is tightened, a spring force (elastic return force) generated against the tightening force acts on each locking piece 24, and the locking pieces 24 press the hot plate 3 from above along the thickness direction. I do. As a result, the outer peripheral portion of the hot plate 3 is sandwiched between the locking pieces 24 and the heat-insulating seal ring 14 (specifically, the upper surface of the support step 16). In this manner, the hot plate 3 is fixed to the casing 2 by the locking ring 21.

Next, a procedure for attaching the hot plate 3 using the locking ring 21 will be described. Prior to the mounting of the hot plate 3, the terminal pins 12 are soldered to the pads 10a of the plate-shaped substrate 9 in advance, and the sockets 6a of the lead wires 6 are attached to the respective terminal pins 12. The other end of the lead wire 6 is drawn out of the casing 2 through the lead wire drawing hole 7.

In this state, the heat insulating seal ring 14 is positioned and arranged on the upper surface of the opening 4 of the casing 2.
Further, the outer peripheral portion on the lower surface side of the plate-shaped base material 9 is supported by the supporting step 16, and the hot plate 3 is set horizontally on the heat-insulating seal ring 14. Next, the locking ring 21 is positioned and arranged on the upper surface side of the heat insulating seal ring 14. Thereafter, a screw 25 is inserted into each of the screw holes 13, 15, and 23 located coaxially, and the screw 25 is securely tightened to fix the three members 2, 14, and 21 so that they cannot be displaced from each other. I do. It can be understood that the means for fixing the heat insulating seal ring 14 to the casing 2 and the means for fixing the locking ring 21 to the casing 2 are shared.

When the above screwing is performed, each locking piece 24 of the locking ring 21 is engaged with the outer peripheral portion of the hot plate 3 on the upper surface side. As a result, the sandwiching and fixing of the hot plate 3 with respect to the heat insulating seal ring 14 is achieved. When the hot plate 3 is mounted as described above, the mounting of the hot plate unit 1 is completed.

[0029]

EXAMPLE In this example, 80 parts by weight of a powder of a fluororesin (Preflon (TFE) manufactured by Daikin) and an average length of 5 mm were used.
The mixture with 20 parts by weight of the glass fiber was placed in a ring-shaped mold, and a heat insulating seal ring 14 having a ring shape was produced while heating and pressing at 330 ° C. As a comparative example with respect to the present example, a heat insulating seal ring 14 made of only a fluororesin containing no fiber was manufactured.

Then, the temperature of the hot plate made of aluminum nitride is raised to 200 ° C., the silicon wafer W1 is heated at a distance of 100 μm from the heating surface, and the difference between the maximum temperature and the minimum temperature of the silicon wafer W1 is determined. Was examined. As a result, the temperature difference of the example was 0.5 ° C., and the temperature difference of the comparative example was 4 ° C. Therefore, in the comparative example, when the heat insulating seal ring 14 is softened by heat,
The distance between the heating surface of the plate-shaped base material 9 and the silicon wafer W1 was not constant because of the sinking and inclination due to its own weight. Therefore, the silicon wafer W1 could not be heated uniformly.

On the other hand, in the embodiment, even if the heat-insulating seal ring 14 is softened by heat, the plate-like base material 9 is not inclined.
And the distance was constant. Therefore, the silicon wafer W1
Was heated uniformly. Further, the heat-insulating seal ring 14 was manufactured at a ratio of 30 parts by weight of the fluororesin, 70 parts by weight of the glass fiber, 99.5 parts by weight of the fluororesin, and 0.5 part by weight of the glass fiber. ° C.

Therefore, according to the present embodiment, the following effects can be obtained. (1) According to the present embodiment, the hot plate 3 is fixed to the opening 4 of the casing 2 via the heat-insulating seal ring 14. Therefore, the heat of the outer peripheral portion of the hot plate 43 can be hardly transmitted to the casing 42 via the screws 48 and the like. Therefore, it is possible to prevent the outer peripheral temperature of the hot plate from lowering, and to make the temperature of the processed surface of the silicon wafer W1 uniform. Moreover, since the heat-insulating member contains fibers, the plate-shaped substrate 9 can be kept horizontal even if the heat-insulating seal ring 14 is softened by heat. Therefore, the silicon wafer W1
Can be more uniformly heated.

(2) In the hot plate unit 1 of the present embodiment, the hot plate 3 is mounted using the locking ring 21 having the above structure as a locking tool. Therefore, each locking piece 24 of the locking ring 21 is
By fixing the hot plate 3 to the outer peripheral portion, the hot plate 3 is fixed. Therefore, unlike the related art, it is not necessary to form a screw hole for screw insertion in the outer peripheral portion of the hot plate 3. Therefore, it is possible to manufacture the hot plate 3 without drilling a hard ceramic sintered body, thereby facilitating the manufacture and reducing the cost.

(3) Further, since the hot plate 3 can be fixed without inserting any fastening means such as screws, no stress is applied to a specific portion, and the hot plate 3 is hardly damaged. .

(4) In addition, since the hot plate 3 is fixed in a sandwiched state, it is difficult for rattling to occur and the hot plate 3 is securely fixed to the casing 2. (5) The locking ring 21 used in the present embodiment has a main body 22 made of a spring steel material having a size substantially equivalent to the size of the opening 4, and is provided at a plurality of separated locations in the main body 22. It has a locking piece 24. Therefore, each locking piece 24 is locked at a plurality of locations separated from the outer peripheral portion of the hot plate 3. At this time, the hot plate 3 is securely clamped and fixed to the opening 4 of the casing 2 via the heat insulating seal ring 14 by a suitable spring force acting on each locking piece 24. Also, with this configuration, since only one locking ring 21 needs to be used, there is an advantage that the number of components can be reduced as compared with the case where a plurality of locking tools are used. Therefore, the assembling can be facilitated.

(6) Since fluorine resin is used as a material for forming the heat-insulating seal ring 14, the heat-resistance, insulation and flame retardancy of the heat-insulating seal ring 14 can be improved.

[Second Embodiment] Next, a hot plate unit 1 according to a second embodiment of the present invention will be described with reference to FIG. Here, the points different from the first embodiment will be mainly described, and the common points will be denoted by the same reference numerals, and the description thereof will be omitted.

In the hot plate unit 1 of the present embodiment, the structure of the locking plate 31, which is a locking tool, is different from that of the first embodiment. That is, the main body 22 of the locking plate 31 used here does not have a ring shape,
In other words, the shape is such that a ring-shaped object is divided at a plurality of locations. Further, unlike the first embodiment, the hot plate 3 is fixed here using a plurality of (specifically, six) locking plates 31.

The main body 22 of each locking plate 31 is arc-shaped and made of spring steel, and has a length that is not more than a fraction of the circumference of the opening 4 (in FIG. )have. Screw holes 23 are provided at both ends of the main body 22.
The locking piece 24 is formed only at one end of the main body 22.
These locking plates 31 are arranged at equal intervals, and a total of six locking pieces 24 press the hot plate 3 from above along the thickness direction.

Therefore, according to the present embodiment, the following effect can be obtained in addition to the effect described in the above (1) in the first embodiment. (3) In the present embodiment, the hot plate 3 is mounted using the six locking plates 31 having the above structure. Therefore, the locking pieces 2 of each locking plate 31
4 causes the hot plate 3 to be
To the opening 4 via a heat-insulating seal ring 14.

Further, if a plurality of small locking plates 31 are used as in this configuration, the deformation of the locking tool itself, which is likely to occur when only one large locking ring 21 is used as in the first embodiment, beforehand. To be avoided. Therefore, a more suitable spring force is obtained, and the hot plate 3 can be more securely fixed.

[Third Embodiment] Next, a third embodiment will be described. In the present embodiment, unlike the first embodiment, the resin material forming the heat insulating seal ring 14 is:
Polyimide (PI) resin or polybenzimidazole resin (PBI) is used instead of fluororesin. The reason for using this polyimide resin is that it is excellent not only in heat resistance, insulation properties and flame retardancy but also in mechanical strength. In the present embodiment, oxydianiline (ODA)
And a wholly aromatic polyimide composed of pyromellitic acid (PMDA). In the present embodiment, a glass fiber having a solid content of 1 to 60% by weight and an average length of 5 mm is mixed in a mixture of ODA and PMDA.

Therefore, according to the hot plate unit 1 of this embodiment, when each screw 25 is tightened when the hot plate 3 is fixed to the casing 2, the tightening force acts on the heat insulating seal ring 14. However, the heat insulating seal ring 14 made of a polyimide resin or a polybenzimidazole resin does not bend because of its high mechanical strength. Therefore, it affects the tightening force of the screw 25,
The screw holes 13 formed in the upper edge of the casing 2 and the screw holes 15 formed in the heat-insulating seal ring 14 are not displaced. As a result, each screw 25 is inserted into each screw hole 1.
It is possible to insert the screws 25 into the screws 3 and 15 without discomfort, and it is possible to prevent the screw 25 from being difficult to tighten. At the same time, the heat-insulating seal ring 1
Since the plate 4 does not bend, the hot plate 3 can be reliably horizontally supported.

Here, the silicon wafer W1 is set to 100 μm
Silicon wafer W1 when separated and heated at 200 ° C.
The difference between the highest temperature and the lowest temperature of the surface was measured. The measurement results are shown in Table 1 below.

[0045]

[Table 1] According to Table 1, when the temperature of the hot plate 3 is raised to 200 ° C., the temperature difference can be made relatively small due to the presence of the heat insulating seal ring 14 made of polybenzimidal resin. Polybenzimidal resin is 2
Since there is no thermal deformation even at 00 ° C., the temperature difference is small and the silicon wafer W1 can be heated uniformly.

The embodiment of the present invention may be modified as follows. A locking piece 24 protruding from the main body 22 of the locking ring 21
Can be arbitrarily changed. The shape and number of the locking plates 31 can also be arbitrarily changed. Further, the number of the locking pieces 24 protruding from the main body 22 of the locking plate 31 may be two or more instead of one.

If a structure for fixing the locking ring 21 and the locking plate 31 to the casing 2 (or the heat-insulating seal ring 14) side is separately provided, the screw 25 can be omitted.

The locking ring 21 and the locking plate 31
It is permissible to use not only a material having elasticity but also a material having no elasticity. The heat-insulating seal ring 14, which is an annular attachment, is formed of, for example, an elastic body, and a structure corresponding to the locking piece 24 of the locking tools 21, 31 is formed on a part of the heat-insulating seal ring 14 so as to protrude. Good. That is, the locking members 21 and 31 may be formed integrally with the heat insulating seal ring 14.

The portions that can be locked to the hot plate 3 in the locking members 21 and 31 do not have to be plate-like (that is, locking pieces 24) as in the above-described embodiment, and may be rod-shaped or the like. Next, in addition to the technical ideas described in the claims, technical ideas grasped by the above-described embodiments are listed below together with their effects.

(1) In any one of claims 1 to 5,
The hot plate is disposed on the casing side, and a part of the hot plate is fixed by a lock that locks to an outer peripheral portion of the hot plate. The lock has a size substantially equal to the size of the opening. A hot spring, which is a ring-shaped spring material of a corresponding size, and the spring material has a locking piece that locks to an outer peripheral portion of the hot plate at two or more separated locations. Plate unit. According to this configuration, each locking piece of the spring material is locked at a plurality of locations separated from the outer peripheral portion of the hot plate. At this time, the hot plate is securely clamped and fixed to the opening of the casing by a suitable spring force acting on each locking piece. In addition, this configuration has an advantage that the number of parts can be reduced because only one locking tool needs to be used.

(2) The locking member according to any one of claims 1 to 5, wherein the locking member is a spring material having a length that is not more than a fraction of the circumference of the opening, and the hot plate is connected to the locking member. A hot plate unit characterized by being fixed using a plurality of tools. According to this configuration, the locking pieces of each spring material are locked at a plurality of locations separated from the outer peripheral portion of the hot plate. At this time, the hot plate is securely clamped and fixed to the opening of the casing by a suitable spring force acting on each locking piece. Further, if a plurality of small locking tools are used as in this configuration, the deformation of the locking tool itself, which is likely to occur when only one large locking tool is used, is avoided. Therefore, a more suitable spring force is obtained, and the hot plate is more securely fixed.

(3) A hot plate unit according to any one of claims 1 to 3, wherein the resin forming the heat insulating member is a polyimide resin or a polybenzimidazole resin. With this configuration, the heat insulating member can have higher heat resistance, insulating properties, and flame retardancy than fluororesin or the like. Therefore, the ceramic sintered body hot plate does not tilt even at a high temperature of 150 ° C. or higher.

[0053]

As described in detail above, according to the present invention,
A hot plate having excellent temperature uniformity can be obtained.

[Brief description of the drawings]

FIG. 1 is a partially exploded perspective view of a hot plate unit according to a first embodiment.

FIG. 2 is a schematic sectional view of the same.

FIG. 3 is a partially enlarged sectional view of the same.

FIG. 4 is a partially exploded perspective view of a hot plate unit according to a second embodiment.

FIG. 5 is a partially enlarged cross-sectional view of a conventional hot plate unit.

[Description of Signs] 1 hot plate unit, 2 casing, 3 hot plate, 4 opening, 10 resistive pattern as resistor, 14 heat insulating seal ring (heat insulating member), 2
DESCRIPTION OF SYMBOLS 1 ... Locking ring as locking tool, 24 ... Locking piece as a part of locking tool, 31 ... Locking plate as locking tool.

Continuation of the front page (72) Inventor Atsushi Ito 1- 1 north of Ibigawa-cho, Ibi-gun, Gifu Ibiden F-term in Ogaki-Kita Plant (reference) 3K092 PP20 QA03 QB02 QB04 QB18 QB26 QB44 QB75 QC02 QC16 QC52 TT17 VV02 VV03 5F046 KA04

Claims (4)

[Claims] 1. A hot plate unit in which a hot plate made of a ceramic sintered body having a resistor is disposed at an opening of a casing, wherein the hot plate is provided at an opening of the casing via a heat insulating member. A hot plate unit, wherein the heat insulating member contains fibers. 2. The hot plate unit according to claim 1, wherein said heat insulating member is made of fiber and resin. 3. The hot plate unit according to claim 1, wherein the fibers are contained in an amount of 1 to 60% by weight. 4. The hot plate unit according to claim 1, wherein said heat insulating member is made of an inorganic fiber and a fluororesin.