JP2001052978A - Hot plate unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot plate unit where the entire is cooled evenly in a short time. SOLUTION: In this hot plate unit 1, a hot plate 3 comprising a resistor 10 is provided to an opening part 4 of a casing 2 having bottom. Between the casing 2 and hot plate 3, a space S1 which is almost tightly closed is formed. In a bottom part 2a of the casing 2, two fluid supply ports 17 and opening parts 31 are formed, respectively.

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 that has undergone a photosensitive resin coating step is heated and dried, a heating device called a hot plate is usually used.

As a conventional example of this type of apparatus, there is one disclosed in, for example, Japanese Patent Publication No. 4-13873.
The apparatus disclosed in the publication includes a hot plate made of an aluminum nitride sintered body as an electric heating member, and a resistor as a hot plate provided on the plate. The resistor is sandwiched between ceramic substrates constituting the hot plate. Both ends of the resistor projecting to the side of the plate are connected to a power source via wiring.

[0004] A silicon wafer to be heated is placed on the upper surface of the hot plate, and a current is applied to the resistor in this state, whereby the silicon wafer is heated to several hundred degrees Celsius.

[0005]

When the photosensitive resin is dried by heating the resistor for a predetermined period of time by energizing the resistor, the hot plate is first cooled to a somewhat lower temperature, and then the silicon is cooled. The wafer needs to be removed. However, cooling requires a certain amount of time, which has been an obstacle to improving productivity.

Therefore, for example, Japanese Patent Publication No. 8-8246 discloses a technique in which a radiating fin type cooling body is attached to a hot plate. However, in this cooling body,
Although the hot plate could be locally cooled, the whole could not be uniformly cooled.

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 capable of uniformly cooling the entire hot plate in a short time with a simple structure and low cost. It is in.

[0008]

According to the first aspect of the present invention, a hot plate having a resistor is provided at an opening of a bottomed casing. A plate unit, wherein an opening is formed at a bottom of the casing.

According to a second aspect of the present invention, in the hot plate unit according to the first aspect, a fluid supply port for communicating the inside and the outside is formed in the casing.

Hereinafter, the "action" of the present invention will be described. According to the first aspect of the invention, the fluid inside and outside the casing flows through the opening formed in the bottom of the casing. Therefore, the heat of the hot plate is effectively cooled by the fluid flowing inside and outside the casing. Therefore, the entire hot plate can be uniformly cooled in a short time. Moreover, since it is only necessary to provide an opening in the casing, the entire hot plate can be uniformly cooled in a short time with a simple structure and at low cost.

According to the second aspect of the present invention, the casing is provided with a fluid supply port for communicating the inside and the outside. Therefore, by flowing the fluid from the port into the casing, the fluid can be uniformly sprayed on the entire hot plate. Then, the sprayed fluid can be efficiently discharged from the opening. Therefore,
The flow of the fluid can be promoted, and the hot plate can be forcibly cooled. Therefore, the entire hot plate can be uniformly cooled in a shorter time.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a hot plate unit 1 according to an embodiment of the present invention will be described in detail with reference to FIGS.

The hot plate unit 1 shown in FIGS. 1 and 2 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.

The hot plate 3 of the present embodiment is formed by mounting the silicon wafer W1 coated with the photosensitive resin on the hot plate 200 to 300.
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 substrate 9 is installed in the opening 4 of the casing 2 via a seal ring 14 described later. By installing this, an internal space S1 is formed between the inner surface side of the casing 2 and the lower surface side of the hot plate 3.

[0015] As shown in FIG.
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-like base material 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 according to 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, lead oxide, zinc oxide, silica, boron oxide, alumina, yttria, titania and the like.

As shown in FIG. 2, the resistance pattern 10
Is formed with a pad 10a as an external connection terminal. 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. Accordingly, a current is supplied to the resistance pattern 10 through the lead wire 6 and the terminal pin 12, and as a result, the temperature of the resistance pattern 10 increases, and the entire hot plate 3 is heated.

As shown in FIG. 2, a plurality of screw holes 13 are formed in the upper edge of the opening 4 of the casing 2 at regular intervals. Similarly, a seal ring 14 as a seal structure is disposed on the upper edge of the opening 4. The seal ring 14 has an annular shape and is substantially equal to the size of the opening 4. As a material for forming the seal ring 14, for example, an elastic body such as a resin or rubber is preferable. A plurality of screw holes 15 are provided in a position corresponding to each screw hole 13 in the seal ring 14. On the inner peripheral surface of the seal ring 14, a supporting 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 seal ring 14 and the height of the upper surface of the hot plate 3 are substantially the same.

The seal ring 14 in the present embodiment seals a gap formed between the upper edge of the opening 4 of the casing 2 and the outer peripheral portion of the lower surface of the hot plate 3 so that air flows through the gap. Has a role to prevent.

As shown in FIGS. 1 and 2, on the upper surface of the seal ring 14, a locking ring 21 is fixed by screws 25. The locking ring 21 has an annular main body 22.
And a plurality of screw holes 23 and a plurality of locking pieces 24. The hot plate 3 set on the supporting step 16 is
By being pressed from the plate thickness direction by each locking piece 24, it is clamped and fixed to the seal ring 14.

As shown in FIG. 1, a fluid supply port 17 is provided at the bottom 2a of the casing 2 using bolts or the like. Two fluid supply ports 17 are formed. An opening 31 communicating the inside and outside of the casing 2 is provided through the bottom 2 a of the casing 2. In the present embodiment, the fluid supply ports 17 are juxtaposed substantially at the center of the bottom 2a. Further, each opening 31 is disposed at a position separated from the fluid supply port 17 with the fluid supply port 17 interposed therebetween. That is, each opening 31
The fluid supply ports 17 are disposed at positions separated from each other in both end directions of the bottom portion 2a. The fluid supply port 17 has a flow path that opens on both the inner end face and the outer end face. For this reason, the inside and the outside of the casing 2 are communicated via the flow path.

A female screw groove is formed on the inner peripheral surface of the opening on the outer end surface side of the fluid supply port 17, and one end of a fluid supply pipe (not shown) is detachable from the opening. Since the other end of the pipe is connected to a gas pressure pump, air as a cooling fluid is supplied through the pipe. The other end of the pipe is open at a location slightly away from the apparatus.

As shown in FIG. 2, the above-mentioned lead wire drawing hole 7 is provided with a seal packing 8 as a seal structure.
Is installed. The seal packing 8 has an annular shape and is formed of a suitable elastic body such as rubber. Each lead wire 6 is inserted into the through hole of the seal packing 8 and then drawn out of the casing 2. That is, the seal packing 8 in the present embodiment has a role of preventing a flow of air through the gap by sealing a gap formed between each lead wire 6 and the lead wire drawing hole 7.

Next, this hot plate unit 1
How to use will be described. The silicon wafer W1 coated with the photosensitive resin is placed on the hot plate 3, and the resistance pattern 10 is energized in this state. Then, the temperature of the silicon wafer W1 gradually increases due to the contact with the heated hot plate 3. When the photosensitive resin is sufficiently dried by heating for a predetermined time, the power supply to the resistance pattern 10 is stopped.

Here, the gas pressure pump is driven to supply cooling air to the fluid supply port 17 side.
The air is introduced into the internal space S1 via the air. The air discharged through the fluid supply port 17 is blown vertically to the lower surface of the hot plate 3 in the internal space S1. The air flows toward the opening 31 while contacting the entire lower surface of the hot plate 3. At this time, the heat removes the heat of the hot plate 3 almost uniformly as a whole. The air whose temperature rises due to heat is
Further, it flows out of the space again from the opening 31. In addition,
A series of air flows is schematically indicated by the bold arrows in FIG. Then, when the hot plate 3 is cooled down to a somewhat low temperature, the silicon wafer W1 is removed from the hot plate 3.

Therefore, according to the present embodiment, the following effects can be obtained. (1) In this hot plate unit 1, two openings 31 are formed in the bottom 2a of the casing 2. Therefore, the fluid inside and outside the casing 2 flows through the opening 31. Therefore, the heat of the hot plate 3 is effectively cooled by the fluid flowing inside and outside the casing 2. Therefore, the entire hot plate 3 can be uniformly cooled in a short time. Moreover, since it is only necessary to provide the opening 31 in the casing 2, for example, the casing 2
The structure and the cost are simpler than those in the case where a fluid discharge port is provided. Therefore, the entire hot plate 3 can be uniformly cooled in a short time with a simple structure and at low cost.

(2) Two fluid supply ports 17 are formed in the bottom 2a of the casing 2. Therefore, cooling air can be circulated from the port 17 into the internal space S1 of the casing 2. By bringing this air into contact with the entire lower surface side of the hot plate 3, the hot plate 3 can be forcibly cooled. For this reason, the hot plate 3 can be forcibly cooled, and the air from which the heat of the hot plate 3 has been removed can be discharged from the opening 31 to the outside. Therefore, the flow of air can be further promoted, and the entire hot plate 3 can be uniformly cooled in a shorter time.

(3) In the hot plate unit 1, each fluid supply port 17 is formed at the bottom 2a of the casing 2. Therefore, the air circulated from the port 17 into the casing 2 can be blown vertically to the lower surface of the hot plate 3. Therefore, the hot plate 3 can be cooled in a relatively short time.

(4) Since two fluid supply ports 17 are formed, the air can uniformly contact the entire hot plate 3, and the plate 3 can be cooled uniformly. Further, since two openings 31 are provided, the air from which the heat of the hot plate 3 has been taken can be efficiently discharged to the outside.

(5) In this hot plate unit 1, an internal space S1 is formed between the casing 2 and the hot plate 3. Although there are projections such as terminal pins 12 on the lower surface side of the hot plate 3, they are spaces S formed between the casing 2 and the hot plate 3.
1. That is, the protrusions are not exposed to the outside of the device, and are in a protected state. Therefore, the bottom surface of the casing 2 can be attached to the support stage (not shown) without difficulty regardless of the presence of the protrusion.

The embodiment of the present invention may be modified as follows. If the hermeticity is ensured to some extent, the seal ring 14 may be omitted and the opening 4 of the casing 2 may be omitted.
The fixing ring 21 may be screwed directly onto the upper surface of the hot plate 3, and the hot plate 3 may be attached to the opening 4 in this state. That is, the hot plate 3 can be directly attached to the casing 2.

In the above embodiment, two fluid supply ports 17 are provided at the bottom 2 a of the casing 2.
However, the number of these ports 17 may be increased to three or more. By doing so, the hot plate 3 can be cooled in a shorter time and the hot plate 3 can be cooled more uniformly as the number of ports 17 is increased. The number of the openings 31 may be three or more.

For example, as shown in FIG. 3A, the resistance pattern 10 is divided into three divided resistance portions 32.
, The power is changed so as to independently supply power to each of the resistance units 32 to 34. That is, by dividing the resistance pattern 10 into three, a circuit for causing the resistance pattern 10 to generate heat is divided into three. In this case, as shown by hatching in FIG. 3B, three heat generating areas A1 to A3 are formed in the hot plate 3.

As shown in FIG. 3B, a plurality of (three in this embodiment) fluid supply ports 17 and openings 31 are provided for each of the heat generating areas A1 to A3. In the figure, the fluid supply ports 17 and the openings 31 provided in the same areas A1 to A3 are respectively arranged at positions that are vertices of an equilateral triangle.

In this way, the ON / OFF of each circuit can be achieved.
The operation allows temperature control to be performed.
In addition, since the cooling air can be blown to each of the heat generating areas A1 to A3 for cooling, the hot plate 3 can be cooled more uniformly.

Each fluid supply port 17 and the opening 3
1 is not limited to a position serving as a vertex of an equilateral triangle, and may be disposed at an arbitrary position. Further, the number of the fluid supply ports 17 and the openings 31 formed in the same region is not limited to three, and at least one is sufficient. That is, at least one fluid supply port 17 and at least one opening 31 may be formed for each of the heat generating areas A1 to A3.

Further, the number of divided circuits is not limited to three, but may be two or four or more. In this case, the total number of the fluid supply ports 17 may be 70% or more of the total number of divided circuits, and it is not always necessary to provide one or more fluid supply ports 17 for one circuit. Absent. That is, when the number of circuits is four, three or more fluid supply ports may be provided, and when the number of circuits is ten, seven or more fluid supply ports 17 may be provided.

A wiring drawing hole 7 serving as a wiring drawing portion;
May be provided at a place other than the bottom 2 a of the casing 2, for example, on a side wall of the casing 2. A gas other than air (air), for example, an inert gas such as carbon dioxide or nitrogen, can flow as a cooling fluid in the internal space S1 defined by the casing 2.
In addition, as long as it does not adversely affect the electrical configuration, it is acceptable to allow the liquid to flow as a cooling fluid.

A thermocouple may be embedded in the plate-like base material 9 constituting the hot plate 3 as needed. Measure the temperature of the hot plate 3 with a thermocouple,
This is because the temperature can be controlled by changing the voltage value or the current value based on the data. In this case, it is preferable that the lead wire of the thermocouple is also drawn out through the seal packing 8.

Next, in addition to the technical ideas described in the claims, technical ideas grasped by the above-described embodiment will be enumerated below. (1) The hot plate unit according to claim 2, wherein a plurality of the fluid supply ports are formed.

(2) Claims 1 and 2, technical idea (1)
In the hot plate unit according to any one of the above, a plurality of the openings may be formed. According to the inventions described in the technical ideas (1) and (2), the hot plate can be uniformly cooled in a shorter time.

(3) Claims 1 and 2, technical ideas 1 and 2
In any one of the above, the fluid is air. Therefore, according to the invention described in the technical idea 3, the reactivity is low, there is no fear of short-circuit between the resistors, and the cost is also advantageous.

[0044]

As described in detail above, according to the first aspect of the present invention, the entire hot plate can be uniformly cooled in a short time with a simple structure and at low cost.

According to the second aspect of the present invention, the entire hot plate can be uniformly cooled in a shorter time.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a hot plate unit according to an embodiment.

FIG. 2 is a partially enlarged sectional view of the same.

FIGS. 3A and 3B are schematic plan views showing a hot plate unit according to another embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Hot plate unit, 2 ... Casing, 3 ... Hot plate, 4 ... Opening, 7 ... Wiring lead-out hole, 8 ... Seal packing, 10 ... Resistance pattern, 14 ... Seal ring, 17 ... Fluid supply port, 31 ... Opening, S1 ... Internal space.

Claims (2)

[Claims] 1. A hot plate unit comprising a hot plate having a resistor and installed in an opening of a bottomed casing, wherein an opening is formed in the bottom of the casing. Hot plate unit. 2. The hot plate unit according to claim 1, wherein a fluid supply port for communicating the inside and the outside is formed in the casing.