JP3132572B2 - Manufacturing method of stamper for optical disk duplication - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a stamper for duplicating an optical disk.

2. Description of the Related Art Conventionally, as a method of manufacturing a stamper for duplicating an optical disc, a conductive film is formed on a pregroove pattern formed on a glass substrate, and then the conductive film is used as a cathode.
A master is obtained by plating and peeling the glass substrate,
A mother is obtained by subjecting this master to a release coating treatment and then Ni plating and peeling from the master, and a mother (a stamper) is obtained by subjecting this mother to a release coating treatment and Ni plating and peeling from the mother. .

In such a stamper manufacturing method, Ni is added to the glass substrate.
When the temperature is returned to room temperature (25 ° C.) after plating (bath temperature: 50 ° C.), bimetallic warpage occurs due to a difference in linear expansion coefficient between the glass substrate and Ni. Therefore, as shown in, for example, JP-A-59-9012, after each plating step, the pressure is corrected and backed with a backing reinforcing material via an adhesive.

Problems to be Solved by the Invention However, when duplicating a large number of suns from a single master through an inverted mother by plating duplication, the master lowered to room temperature is put into a plating bath to duplicate the mother. Problems such as a change in flatness occur. That is, the flatness of the backed master is 5 μm or less, but when the mother is duplicated (plating bath temperature: 50 ° C.), the flatness changes greatly. This can be done at 50 ° C without duplicating the mother.
A similar change in flatness was caused only by allowing to stand in a drying oven for several hours.

More specifically, for example, according to US Pat. No. 4,440,586, Ni plating is performed in a plating bath at 70 ° C., and is backed with an araldite using an epoxy resin and an amine as a curing agent. However, in general, a room temperature curing type epoxy adhesive has a glass transition point at 50 to 60 ° C (corresponding to almost the plating bath temperature), and it is known that a sudden change in physical properties occurs at this temperature range. (See “Encyclopedia of Adhesion and Adhesion” published by Asakura Shoten, p.258). Therefore, the flatness change as described above occurs. In such a phenomenon, when the glass substrate is peeled off after the backing, the master (Ni) has no object to be pulled (glass substrate), so that the master itself contracts, but the flatness does not change due to the rigidity of the adhesive. However, since the plating bath temperature (50 ° C) at the time of replication corresponds to the glass transition point of the adhesive, the rigidity of the adhesive is relaxed and plastic deformation occurs, and the master releases the residual stress by that deformation, It is considered that the flatness changes.

This is the same in the step of duplicating the sun from the mother.

Means for Solving the Problems After forming a conductive film on a pregroove pattern formed on a glass substrate, Ni plating is performed using this conductive film as a cathode, and after plating, a backing is performed and the master is removed by peeling the glass substrate. After the release coating treatment of this master, Ni
A method for manufacturing a stamper for optical disc duplication, in which a mother is obtained by plating and backing after plating and peeling from the master, and then subjecting the mother to a release coating treatment and then performing Ni plating and peeling from the mother to obtain a sun. At the time of lining, the glass transition point was made to adhere with an adhesive having a temperature equal to or higher than the Ni plating bath temperature.

At this time, an adhesive having a glass transition point equal to or higher than the Ni plating bath temperature and having a high melting point material such as imidazole, hydrazine or dicyandiamide as a main component of the curing agent was used.

Action Backing using an adhesive whose glass transition temperature is equal to or higher than the temperature of the Ni plating bath reduces the flatness change even when duplicating in the plating bath after the backing. It becomes possible.

In particular, the thermal stability of the stamper is improved by backing with an adhesive having a glass transition point equal to or higher than the Ni plating bath temperature and using a high-melting substance such as imidazole, hydrazine or dicyandiamide as a main component of the curing agent.

Embodiment An embodiment of the present invention will be described with reference to the drawings. First,
A general outline of the steps up to duplicating the mother will be described with reference to FIG. After a conductive film is formed on the pregroove pattern formed on the glass substrate 1, Ni plating is performed using the conductive film as a cathode. 2 is Ni. In this case, due to the difference in the coefficient of linear expansion between the glass substrate 1 and Ni2, as shown in FIG.
μm). Therefore, as shown in FIG. 2B, a backing reinforcing material 5 is backed on the back surface of Ni2 with an adhesive 4 using a pressure correcting plate 3. Thereafter, the glass substrate 1 is peeled off as shown in FIG. The flatness of the backed master 6 is 5 μm or less. Next, as shown in FIG. 3D, after the surface of the master 6 is subjected to a release coating treatment, Ni plating is performed. 7 is plated Ni. Thereafter, as shown in FIG. 7E, the upper surface (back surface) of Ni7 is similarly backed, and further, as shown in FIG. in this case,
The master 6 has a convex shape and the mother 8 has a concave shape, but each of the flatness d ₁ and d ₂ is about 300 to 400 μm. The same is done for mother-to-sun duplication.

In this embodiment, as a specific example 1, a stamper was duplicated and manufactured as described below. After performing Ni plating on the glass substrate 1 in a plating bath at 50 ° C., an epoxy resin (having a glass transition point of 80 ° C. or higher and a high melting point of 200 ° C. or higher) with hydrazine as a main component of the curing agent is bonded. The backing reinforcing material 5 was backed using the agent 4, and the glass substrate 1 was peeled off to obtain a master 6. After the release coating treatment of the master 6, Ni plating is performed in a 50 ° C. plating bath using the treated surface of the release coating as a cathode, and then the backing is performed using the same adhesive 4, and the mother 8 is peeled off from the master 6. Obtained.
The mother was also subjected to release coating treatment, and Ni was plated in a plating bath at 50 ° C. using the treated surface of the release coating as a cathode, and then backed with the same adhesive, and peeled from the mother to obtain a sun.

As shown in FIG. 2, the flatness of each of the master, the mother, and the sun by such a manufacturing method is good.

Further, as a specific example 2, a master, a mother and a sun were obtained in the same manner except that the adhesive 4 of the specific example 1 was replaced with an epoxy resin whose main component of the curing agent was imidazole. The flatness of each of the master, mother and sun in the case of the specific example 2 is good as shown in FIG.

By the way, as a comparative example, the adhesive used for the backing was a normal temperature-curable adhesive (glass transition point 50 ° C.) as in the past, and the master, mother and sun were obtained in the same manner as in the above specific example, The flatness of each of the master, mother and sun in this comparative example is as shown in FIG. 4, and the mother and sun have poor flatness.

Advantageous Effects of the Invention As described above, the present invention has a glass transition point that is backed by using an adhesive having a temperature equal to or higher than the Ni plating bath temperature, so that the flatness does not change much even when copied in a plating bath after the backing. High quality stamper duplication with good flatness is possible, especially when the glass transition point is higher than the Ni plating bath temperature and using an adhesive whose main component of the curing agent is a high melting point substance such as imidazole, hydrazine, dicyandiamide, etc. The lining has the effect that the thermal stability of the stamper can also be improved.

[Brief description of the drawings]

1 shows an embodiment of the present invention, FIG. 1 is a process diagram, FIG. 2 is a characteristic diagram showing flatness characteristics according to a specific example 1,
FIG. 3 is a characteristic diagram showing the flatness characteristic according to the specific example 2, and FIG.
The figure is a characteristic diagram showing flatness characteristics according to a comparative example. 1 ... Glass substrate, 4 ... Adhesive, 6 ... Master, 8 ...
… Mother

Claims (2)

(57) [Claims] 1. A master is obtained by forming a conductive film on a pregroove pattern formed on a glass substrate, performing Ni plating using the conductive film as a cathode, backing after plating, and peeling the glass substrate to obtain a master. The master is subjected to Ni plating after the release coating treatment, and a mother is obtained by backing after plating and peeling from the master, and a Ni is obtained by subjecting the mother to Ni plating after the release coating treatment and peeling from the mother to obtain a sun. In the method of manufacturing a stamper for duplicating an optical disk, the glass transition point
A method of manufacturing a stamper for duplicating an optical disk, characterized in that the stamper is bonded with an adhesive having a plating bath temperature or higher. 2. An optical disk according to claim 1, wherein an adhesive having a glass transition point equal to or higher than the Ni plating bath temperature and a high-melting substance such as imidazole, hydrazine or dicyandiamide as a main component of a curing agent is used. A method of manufacturing a stamper for duplication.