JPH0746025B2 - Device for heating and drying optical disc masters - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a heating / drying device that radiatively heats an optical disc master using a far infrared ray or an infrared heater.

BACKGROUND ART A so-called heat tunnel shown in FIG. 6 is known as a conventional heating and drying apparatus. In this heating / drying apparatus, the object 61 to be heated is transferred by the belt conveyor 62 and the object 61 to be heated is transferred by the ambient temperature in the tunnel when passing through the tunnel constituted by the heater 63.
It is configured to be heated and dried.

In this heating / drying device, the temperature distribution on the heating surface of the object to be heated 61 depends on the heat quantity of the heater 62, the transfer speed of the belt conveyor 62, the thermal properties and the shape of the object to be heated 61, and therefore the temperature distribution. There was a drawback that control of was not hopeful.

Further, due to the heat conduction heating by the ambient temperature in the tunnel, the temperature distribution on the surface of the object to be heated is low in the central portion and the outermost peripheral portion as shown by the chain line in FIG. The height of the part is high, and it is not uniform over the entire surface. Therefore, when an optical recording glass master having a photoresist coated on one surface is used as the object to be heated, the surface temperature increases from the inner circumference to the outer circumference, as shown in FIG. It becomes lower at the outer circumference. As described above, if the heating temperature varies during heating and drying, the sensitivity of the resist also varies, which adversely affects the pit shape when information is recorded as a pit. Further, the present applicant has also confirmed that the glass master disk is easily broken when the heating temperature of the outermost peripheral portion is low.

As a heating and drying device that can control the temperature distribution,
There was one shown in FIG. In this heating / drying device, the object to be heated 61 is heated and dried by the heater 63 provided with a variable distance from the object to be heated 61. In this case, the object to be heated 61 can be heated, dried, or moved while it is moving, rotating, or stationary.

According to this heating / drying apparatus, although it is possible to control the temperature distribution to some extent, since the control is performed by the distance, the space efficiency of the apparatus is deteriorated, and the size of the heater 63 depends on the size of the object to be heated 61. Due to this, there is a drawback that precise control of the temperature distribution becomes impossible.

SUMMARY OF THE INVENTION The present invention has been made to eliminate the above-mentioned drawbacks of the conventional ones, and provides a heating / drying device for an optical disk master that enhances space efficiency and enables more precise control of temperature distribution. With the goal.

A heating / drying apparatus for an optical disk master according to the present invention comprises heating means for heating the optical disk master by infrared rays, rotation driving means for carrying and rotating the optical disk master so as to face the heating means, the optical disk master and the optical disk master. And a radiant heat control plate which is arranged between the heating means and has a fan-shaped opening.

Example Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an external view of an apparatus showing an embodiment of the present invention, and FIG. 2 is a structural view thereof. In each of these figures, a glass master disk 1 which is an optical disk master disk is coated with a photoresist on one surface thereof, and is supported by a spindle 2 so that the surface coated with the photoresist is the lower surface. The spindle 2 is rotationally driven by a spindle motor 4 housed in a housing 3. Spindle 2 and spindle motor 4
Is attached to a spindle base 5, and is driven by a spindle base drive motor 8 to be transferred on the main base 7 while being guided by a linear slide 6, so that the spindle 2 is mounted on the upper surface of the housing 3 and the glass master 1
It moves between the position shown by the solid line and the position shown by the alternate long and short dash line along the long hole 9 formed to have a length substantially equal to the radius of.

The position indicated by the solid line of the glass master 1 and the spindle 2 is the standby position, and the glass master 1 is loaded and unloaded and the cooling process after the heating process is performed at this standby position. The position indicated by the alternate long and short dash line is a heat drying (baking) position, and the heat drying process is performed at this position. This device is installed in a horizontal airflow type clean bench and used in a clean room. The left side of the figure is the operator side and the right side is the clean bench side. Due to this positional relationship, it is possible to minimize the contamination in the drying process which is the most sensitive to contamination. That is, in a clean room, when a worker who is a dust source always works in the leeward direction and particles that settle down under the influence of gravity, a clean air flow is indicated as shown by an arrow in FIG. And to set the heated surface of the glass master 1 to the lower side, and further, for dust from the mechanism part, by exhausting the inside of the housing 3 with the exhaust tube 10, Dealing with pollution.
In addition, the upper surface of the housing 3 is in principle the same plane except that there are some openings, which prevents accumulation of contaminant particles and facilitates cleaning.

A part of the upper surface of the housing 3 on the clean bench side is a radiant heat control plate 12 having a substantially fan-shaped opening 11. The radiant heat control plate 12 is made of stainless steel, for example, and may be integrated with the housing 3. Below the opening 11, a heater unit including a far infrared ray or infrared heater element 13 for radiatively heating the glass master 1 through the opening 11.
14 are arranged. In this heater unit 14,
As is particularly clear from FIG. 3, the heater element 13 is attached to the heater mounting plate 15 so as to face a part of the radius area of the glass master 1 in the heating and drying position, and the outer plate 16 is supported by a support (not shown). It is fixed to. The radiant heat control plate 12 is fixed to the upper part of the outer plate 16 via a spacer 17 that also serves as heat insulation. The jacket portion formed by the heater mounting plate 15 and the outer plate 16 is exhausted by the exhaust tube 18, whereby the heater element 13 is kept at a negative pressure so as not to generate heat diffusion type contamination due to heating. Further, by exhausting the heater unit 14, unnecessary heat transfer is prevented and the temperature of the device is prevented from rising. The temperature of the heater element 13 is measured by a thermocouple (not shown) attached to the heater element 13.

A radiation thermometer 19 is provided inside the housing 3, and the radiation thermometer 19 measures the surface temperature of the glass master 1 through a measurement window 20 formed on the upper surface of the housing 3. The measurement output of the radiation thermometer 19 is supplied to the controller 21. The controller 21 is composed of, for example, a microcomputer, and is a series of controls for heating and drying the glass master 1 such as temperature control of the heater element 13, start and stop of rotation of the spindle 2 and transfer control of the spindle 2. Do.

Next, the basic sequence of the heating and drying processing procedure executed by the processor of the controller 21 will be described with reference to the flowchart of FIG.

When the device power is turned on, the processor first
Start preheating of heater element 13 (step
S1). The temperature of the heater element 13 is set to 215 ° C., for example, and the preparation is completed at 215 ± 5 ° C. The purpose of preheating is that the time constant of heating the heater is large,
This is because the heating and drying time becomes long if the heater element 13 is not heated in advance, and the temperature is measured by the thermocouple attached to the heater element 13.

When the glass master 1 is set on the spindle 2 and then the start switch (not shown) is turned on (step S
2), the processor sets the spindle 2 to, for example, 3 [rpm]
When it is detected that the temperature of the heater element 13 has reached the set temperature T ₁ based on the measured output of the thermocouple (step S4), the spindle base drive motor 8 is drive-controlled. This advances the spindle 2 from the standby position to the heating / drying position (step
S5). Then, at this position, the photoresist of the glass master 1 is heated and dried by radiant heating of the heater element 13 (step S6).

In this heating and drying step, the surface temperature of the glass master 1 is determined to be a predetermined temperature T ₂ , for example, based on the measurement output of the radiation thermometer 19.
When it is detected that the temperature has reached 90 ± 0.5 ° C (step S7),
The spindle 2 is retracted from the heating / drying position to the standby position by driving and controlling the spindle base drive motor 8 (step S8). At this standby position, the glass master 1 after heating is cooled (step S9). In this cooling process, the surface temperature of the glass master 1 is set to a predetermined temperature T ₃ , for example 55, based on the measurement output of the radiation thermometer 19. When it is detected that the temperature becomes ± 0.5 ° C. or less (step S10), the rotation of the spindle 2 is stopped (step S11). And
By removing the glass master 1 from the spindle 2,
A series of processing is completed.

In the heating and drying step described above, the infrared rays generated by the heater element 13 have the property of traveling straight in the same manner as visible light, reach the opposite glass master 1 through the opening 11 of the radiant heat control plate 12, and reach the photoresist. It is absorbed and generates heat. The calorific value per unit area is generally determined by various conditions such as the time facing the heater element 13, the calorific value distribution of the heater element 13 itself, and the cooling efficiency received from the surroundings. Therefore, when the radiant heat control plate 12 is not provided, the temperature distribution on the resist surface of the glass master 1 is low at the central portion and becomes higher toward the outer periphery, as shown in FIG. It becomes low again due to the large cooling effect. On the other hand, the radiant heat control plate 12 having the opening 11 is provided, and the heat generation amount per unit area is corrected by the substantially fan-shaped shape of the opening 11 including all the factors related thereto. As shown in a), it is possible to obtain a uniform temperature distribution over the entire surface from the inner circumference to the outer circumference.

Further, the fan-shaped opening 11 is formed so that the time for heat transfer through the opening 11 with respect to the unit area of the glass master 1 is longer in the outermost peripheral portion than in other portions. As shown in FIG. 5 (a), the surface temperature of the outermost peripheral portion of the glass master 1 can be made higher than that of other portions.

In the above embodiment, the radiant heat control plate 12 having the fan-shaped opening 11 is used as the heat control means for controlling the distribution of the amount of infrared radiation emitted from the heater element 13 to the glass master 1.
Although the case of using is described, the shape of the opening 11 can be any shape depending on the use and purpose.

Further, the heat control means is not limited to the radiant heat control plate 12 having the opening 11, and the radiant heat control plate constituted by a combination of materials having different thermal properties, and the thermal property is partially. Different radiant heat control plates may be used, and the distribution of the amount of infrared radiation to the glass master 1 can be controlled by changing the amount of heat generated by the heater element 13.

Furthermore, in the above embodiment, the purpose was to make the temperature distribution uniform, but it goes without saying that the temperature control can be adjusted to an arbitrary temperature distribution within a possible range. Similarly, it is also possible to arbitrarily adjust the temperature and the temperature distribution by combining some means for detecting the temperature and the temperature distribution and the heat control means.

EFFECTS OF THE INVENTION As described above, the heating / drying apparatus for the optical disk master according to the present invention includes the heating means for heating the optical disk master by infrared radiation and the rotation driving means for carrying and rotating the optical disk master so as to face the heating means. And a radiant heat control plate arranged between the optical disc master and the heating means and having a fan-shaped opening, the infrared radiation amount reaching the optical disc master can be controlled, so that space efficiency is improved. It is possible to improve the quality of the product without deteriorating the temperature and without requiring complicated control of the heating means, to easily and simply control the temperature distribution more precisely.

Thus, in the case of a glass master having a photoresist coated on one surface, the heating temperature can be made uniform from the inner circumference to the outer circumference, so that the variation in the sensitivity of the photoresist can be suppressed to the minimum. Further, since the heating temperature of the outermost peripheral portion can be made higher than that of other portions, it is possible to prevent the glass master from cracking.

[Brief description of drawings]

FIG. 1 is an external view of an apparatus showing an embodiment of the present invention, FIG. 2 is its structural view, FIG. 3 is an enlarged sectional view of a heater unit in FIG. 2, and FIG. 4 is heat drying executed by a processor. 5 is a flow chart showing the basic sequence of the processing procedure, FIG. 5 is a characteristic diagram showing the temperature deviation of each radius with respect to a reference temperature, FIG. 6 (A) is an external view of a conventional device, (B) is its front sectional view, FIG. FIG. 7 is a block diagram showing another conventional device. Explanation of symbols of main parts 1 …… Glass master, 2 …… Spindle 4 …… Spindle motor 8 …… Spindle base drive motor 10,18 …… Exhaust tube 11 …… Opening part, 12 …… Radiation heat control plate 13… Heater element 14 Heater unit 19 Radiation thermometer, 21 Controller

Claims (1)

[Claims] 1. A heating means for heating an optical disk master by infrared rays, a rotation driving means for carrying and rotating the optical disk master so as to face the heating means, and between the optical disk master and the heating means. A radiant heat control plate that is arranged and has a fan-shaped opening, and a heating / drying device for an optical disk master.