KR860001386B1 - Improved molding stamper and method of making same - Google Patents

Abstract

The surface for holding master imformation is formed on a supporting body which can then hold information in a discontinuous state on its surface. The entire surface of the supporting body is electrolessly coated with a Ni layer in a Ni plating bath contg. sodium hypophosphite. Hereon, the thermal conductivity of the coating layer is controlled to 0.006-0.008 cal/cm/sec/deg.F by adjusting the content of sodium hypophosphite in the Ni plating bath. Packing material is applied onto the coating layer to form a synthetic stamper having an information holding surface reversed to the information holding surface of the supporting body. The synthetic stamper is detached from the supporting body.

Description

Casting stamper and its manufacturing method

1 is a partially enlarged view showing a somewhat exaggerated information bearing surface of a stamper for forming an optically readable information containing disk.

2 is a partial cross-sectional view showing a state before developing this photoresist layer on a substrate coated with a photoresist material.

3 is a partial cross-sectional view showing a state after developing this photoresist layer on the substrate of FIG. 2 coated with a photoresist material.

4 is a partial cross-sectional view showing a state in which the first layer of nickel / nickel phosphide alloy is deposited by the electrodeless method on the photoresist surface of the developed substrate as shown in FIG.

FIG. 5 is a partial sectional view showing a state in which another layer of support material is deposited on top of the first layer shown in FIG.

6 is a partial cross-sectional view showing a state in which a stamper, which is composed of a first layer deposited by an electrodeless method and another layer of a blocking material, is separated from a substrate.

* Explanation of symbols for main parts of the drawings

2: disc 4: drow

6 protrusion 8 glass substrate

9: top surface of disk 10: photoresist layer

12: protrusion 14: flat portion

16: information containing layer 18: base layer

The present invention relates to a metal stamper for use in copying an optically readable information containing member. More specifically, the present invention relates to replicating an optically readable information-containing member by an injection molding method using a stamper made of a cured material bounding an encoding surface.

The improved stamper and the method of manufacturing the improved stamper according to the present invention can be used for the production of a plastic information-containing surface of any phenomenon in which discontinuous portions having a fine size are formed on the surface. The known technology and the present invention will be described taking the disk-shaped information containing member as an example. As the improvement of the present invention compared to the conventional method includes the interfacial property between the stamper and the plastic, it is understood that the concept of the present invention is widely applied to the injection molding of information-containing plastic article having an arbitrary geometric shape. Please.

Duplicating optically readable information bearing members by injection molding of plastics is well known in the art. In such an injection molding method, a liquid plastic is injected into a mold in the form of a disc, and then a coded stamper surface (typically made of nickel, which contains voice information, video information, and digital information) and rigidity is used. There is a method of compression between the supporting surfaces. The liquid plastic may be separated from the sign and surface of the nickel stamper after curing and cooling.

In the past, it was typical to use nickel as a stamper material, because nickel has the following unique structural properties. That is, nickel has sufficient strength to withstand the release phase of the injection molding method and the weakening of the mold, it is very easy to electrolytically weld nickel metal in large quantities, and relatively inexpensive as a stamper material. This is because the tolerances for the controls and variables can be widened and are immune to corrosive environments.

One method of making a stamper for a video disc is described in US Pat. No. 4,211,615 (July 8, 1980) to Csaba K. Hunyar, assigned to the applicant. In this patent, a multilayer stamper composed of copper and nickel has been proposed. The metal layer is applied by vapor shock, vapor deposition, or deposition from an electrodeless plating solution. The photoresist encoded "matrix" surface on which the original of the information is recorded is first plated with silver by an electrodeless method similar to that used to make the surface of a mirror. This silver coating is deposited only to a thickness sufficient to maintain electrical conductivity (typically near the bottom in the range of about 0.25 to about 50 microns) so that subsequent electroplating steps can be performed. Then, the corresponding layers of nickel and copper are welded by electroplating so that the total thickness is about 0.075 to 0.75 mm, wherein the last layer on which plastic molding is to be made is a nickel layer.

Visual inspection has shown that a replica disc made from a nickel stamper may exhibit orange-like stains with a stained appearance when observed with conducted light, a so-called "plow effect" that occurs during injection molding. It is common by the surface distortion phenomenon called ". The term "plow effect" here, after observing the micrograph of the discontinuity of the surface of the replica disc, found that the ridges that bound the information track fell off as if by plowing or hitting a sharp object. It is a new term attached. The introduction of discs made from nickel stampers into a variety of unique tests reveals a direct correlation between the visually observable plow effect and the quality of information reproduction of the discs. In this regard, the inventor is Gary Slaten and the applicant is the same as the applicant of the present invention and the name of the invention is a "stamper and method for injection molding an information-containing member" US Patent Application No. 505,565 (filed 1983.6. 17) (hereinafter abbreviated as "the invention of Slaton"), the use of chromium as the corresponding layer to be deposited on the upper surface of the nickel stamper to improve the stamper plastic interface to substantially improve the quality of the disc. It is described.

Visually and electronically inspecting the replica discs formed from nickel stampers also reveals an "orange peel" effect in some of the most heavily stained areas. The term " orange shell " refers to the form of the outer surface of the information storage disk which must be passed before the reading light beam reaches the information containing surface in the information storage disk. In other words, the roughness and uniformly distributed surface defects visually look like an orange crust. This "orange peel" effect results in a change in the index of refraction between the points on the disk surface, thus reducing the controllability of tracking. The possibility of sub-normal regenerative capacity is shown by the interaction between the plow effect and the orange peel effect.

Some of the defects found in injection molded discs are due to "waffling" of the stamper. This waffle effect was observed to be a permanent surface irregularity due to the casting force exceeding the yield strength of the stamper. In fact, the conventional nickel stamper lacks sufficient strength to be physically stretched or distorted in a somewhat uniformly distributed local area, and thus has an appearance similar to that of a waffle having a groove-like impression having a separation portion of about 1000 mm 3. do. This waffle effect was found after only 10 castings on a 0.38 mm nickel stamper. In the improved nickel stamper according to the present invention, the hardness associated with the thickness is increased so that the waffle effect does not actually appear.

Another problem associated with injection molding of video discs is that the plastic material is pre-cured while moving from its introduction point along the mold cavity to the end of the mold. Since the plastic material is forced into the mold cavity, the cold wall of the mold tends to cause the plastic material to be slightly hardened, and thus a thin shell layer is formed, which is formed until the casting process is completed. As they remain in the same state or as the plastic material flows to fill the mold voids, their position changes or peels off from the plastic material and flows with the molten plastic, resulting in a roughened surface of the cast final product. Randomly distributed irregular stress points are created along the surface of the product. Therefore, the coding surface has sufficient strength to preserve the information characteristics of the cast product, and has the characteristics of removing or minimizing the waffle effect and the thin layer due to the rapid curing of the plastic injected in the mold. There is a need in the art to develop a stamper with a. The present invention satisfies this need. In addition, there is a need to improve the voice and screen quality of the optically readable information-bearing member, and the present invention reduces the plowing effect and the orange peel effect by allowing a clean separation at the interface between the stamper and the stamped article. Or by eliminating this need, too.

The present invention eliminates harmful surface defects from the replication method by injection molding by providing an improved stamper, thereby increasing the signal quality and increasing the signal quality at the optically readable information-containing member, thereby improving the signal quality. All the deficiencies in the prior art as described above are substantially overcome.

More specifically, the present invention provides a mold by using a composition that has a hardness sufficient to preserve the information content of the surface and also has a low thermal conductivity composition to remove or reduce the thin layer due to rapid curing of the plastic injected into the mold. A method and means for creating a thermal barrier on the surface of a substrate are provided. The material chosen to create the thermal barrier has a lubrication characteristic over pure nickel and a thermal conductivity of 5-100 times lower than pure nickel, thus allowing the injected plastic to fill the mold before it is substantially cured. In addition, this novel stamper material improves the separation characteristics of the stamper in the injection molding method, thereby reducing the defects associated with the stamper, thereby increasing the production rate of the stamper and improving the quality of the recovered signal. In addition, this novel stamper material has an exceptionally high hardness, which is substantially more durable than a pure nickel stamper under stress during injection molding, and has a production rate of 2-5 times that of a pure nickel stamper.

In summary, the present invention is a layer of an alloy of nickel / nickel phosphide (hereinafter, abbreviated as “electrode nickel”) that is electrodeless deposited by an electrodeless method so as to boundary the information containing surface of the stamper; An improved stamper is provided, preferably consisting of a support layer of a layer of molybdenum, chromium, iron, tungsten, copper, nickel, or a nickel / copper composite as described in the above-mentioned US Pat. No. 4,211,617.

In the invention of Slaton as described above, a smooth and hard information bearing surface is produced by depositing chromium on the encoded information bearing surface of a conventional nickel stamper which is formed by forming a thick nickel layer on a photoresist substrate. The present invention not only selects the material to be used for the interface between the stamper and the mold, but also directly deposits a layer of electrodeless nickel according to the present invention on a photoresist substrate, and then adds a support layer made of a material of high hardness. It is different from Slaton's invention. When the stamper of the invention made of such a composite is separated from the substrate, the exposed surface, that is, the information containing surface, of the stamper is a layer made of an electrodeless nickel material.

In this regard, the loss of clarity of the surface discontinuity in the invention of Slaton described above by depositing a chromium layer on top of the information bearing surface of the conventional nickel stamper means that the sharp edges of the surface discontinuity are rounded off in the cast product. It proved to be quite advantageous in that it contributed to reducing the plowing effect. In the present invention, since the information-bearing side of the final stamper is formed directly to the substrate, there is no additional layer deposited to sharpen the sharp edges. Despite these facts, however, the improved information reproducing ability of the cast product, the reduction of the plowing effect, and the improved separation characteristics of the stamper from the cast product are distinguishing features of the present invention. Improvements in various parameters of this casting method contribute to particularly unique properties of electrodeless nickel such as high lubrication, low thermal conductivity, smoothness, and substantially increased hardness compared to conventional nickel stampers. will be. The excellent smoothness of the electrodeless nickel and the excellent thermal conductivity have been possible only with molds and coatings made of glass or ceramic. By forming the stamper's information bearing surface with electrodeless nickel, the final cast product can consistently obtain a much smoother surface than would have been possible with a conventional nickel stamper. In addition, the production rate is an important concern in the manufacture of optically readable discs today, and considering that the production rate is improved by 2 to 5 times according to the present invention, the heat barrier on the mold plate of the electrodeless nickel injection molding apparatus is It is clear that the use of the present invention has made a significant contribution to the art.

According to the present invention, a layer of nickel / nickel phosphide plated by the electrodeless method is deposited on the photoresist code and the substrate. The surface to be coated is not necessarily conductive in this electrodeless method, but the first step in the method of depositing a layer of electrodeless nickel is to immerse the encoded substrate in a solution containing a salt of palladium or gold to nuclei the nuclei. Is to form a layer of resistive phase. This layer then serves as a catalyst for promoting deposition in that an electrodeless nickel layer of uniform thickness can be formed on all surfaces to which the electrodeless plating liquid can freely access. US Patent No. 2939804 (Patent date June 6, 1960) describes the formation of a coating of chemical nickel on a thermoplastic material after the first step of preparing the surface. According to this patent, a thin discontinuous coating of metallic copper is first deposited on a thermoplastic material. The copper-coated article is then immersed in a solution containing palladium so that copper is replaced by a small amount of palladium. This copper-palladium coating plays a catalytic role in activating the nickel coating liquid to be added later.

The method of electroless plating nickel on a metal surface is described by Burns and Bradley, "Protective Coatings for Metals", 2nd edition (1955), pp. 205-206. It is described in. Electroless plating, as described in this book, includes surface coating of various possible base metals, including iron, aluminum, brass, bronze, and stainless steel. According to Buruns and Bradley, the obvious purpose of using nickel-free electroless plating is to form a relatively pore-free protective layer on the base metal to provide protection from corrosive environments and to harden the surface of the base material. To give. The present invention recognizes additional physical properties, especially lubricity, smoothness, thermal conductivity, and preferably increased hardness compared to pure nickel in nickel coatings deposited by the electrodeless method. By incorporating a layer of electrodeless nickel, adjusting the thickness of the electrodeless nickel layer and the ratio of nickel to phosphate in the layer, and adding a support layer of electrically deposited metal, for example, copying of a video disc Various problems related to are solved. That is, as long as surface defects and signal degradation are easily observed by one skilled in the art, the exact cause of such defects is very ambiguous for those skilled in the art to present a theoretically ideal model for a stamper. In other words, it is not clear which physical properties affect which defects, and which physical variables should be adjusted in which direction to reduce each defect, and more importantly, when one physical property changes The effects of correlating with other physical properties add to the complexity of process analysis.

Therefore, in the present invention, the electrodeless welded nickel / nickel phosphide is newly used as the active surface for casting the thermoplastic information-containing member, not as a protective coating for the base metal. By controlling the manufacturing method of the stamper, the optimum content of the phosphate in the electrodeless nickel layer and the thickness of the electrodeless nickel layer and the support layer is maintained, so that the lubricity is high, the thermal conductivity is low, and an exceptionally hard and smooth surface is possible. Thus, the plastic material flowing into and out of the mold wall can be prevented from being hardened quickly to form a thin layer.

As briefly mentioned above, one of the difficulties with casting thermoplastics in the form of thin discs is that the relatively hot liquid plastics cure quickly because the walls of the molds are relatively cold. When the plastic material is introduced into the mold cavity, the plastic material is cooled by the wall of the mold, forming a coating on the open side of the plastic / mold that duplicates the surface of the encoded stamper representing one wall of the mold cavity. Once the coating is formed, as the liquid plastic body underneath this film moves continuously, part of the film breaks and some of the film flows together in the form of a cooled plastic piece, thus distorting the surface of the final disc product. Distortion of the signal recovered from this disk occurs.

Of course, this problem is due to the fact that the plastic must ultimately be cooled so that it can be removed from contact with the mold and the information side of the stamper is duplicated on the corresponding side of the disc. One solution to this problem is to circulate the cooling and heating fluids in a controlled state around the walls of the mold. This method is very disadvantageous in equipment for mass production because of the thickness of the mold cavity wall required to withstand the injection molding pressure, it is difficult to cool and heat in a short time, resulting in limitations in the production rate. In addition, since one side of the mold cavity surface must be a rather thick stamper of about 0.38 to 1.0 mm, no matter how quickly the adjacent mold wall to the support layer of the stamper cools and heats, the stamper itself, especially at the interface with the molten plastic Actual time is required for the temperature to be fixed.

Therefore, the prerequisite in the present invention is that forming a heat barrier between the wall of the mold and the molten plastic will help to improve the thermal properties of the wall of the mold cavity, and also a much better replica, ie orange peel effect or plow. It would be possible to obtain a replica disc having a good shape and a good surface, in which the stamper's shape is more correctly replicated without any effect or waffle effect. The use of nonmetals in stampers, however, exhibits thermal conductivity to the extent that the plastic material actually prevents the rapid hardening of the plastic material (ie, the formation of a thin layer) as it passes through the mold cavity. Due to its heat transfer properties, it takes a substantially long time to cure the molten plastic. Moreover, the known nonmetallic surfaces that can be used to form stampers for injection molding of thermoplastic discs are extremely flexible and brittle, and thus wear or break under pressure during injection molding.

The present invention proposes a unique solution to the above-mentioned problem in that it uses electrodeless nickel having thermal properties such as semimetals and strengths like metals. The microstructure of electrodeless nickel is characterized by the fact that a number of thin layers with good bonding force are parallel to the base metal on the base metal deposited thereon, and each layer has a columnar structure perpendicular to the base metal. do. This microstructure is due to the fact that the heat transfer rate of electrodeless nickel is only 1/5 to 1/100 of that of pure nickel or most pure metals.

In the invention of Slaton as described above, the use of a chrome stamper surface has been proposed to increase the hardness compared to a normal stamper made of pure nickel, but the electrodeless nickel in the welded state is harder than pure nickel, and subsequently heated. When hardened by the step, the hardness of the chromium is almost equal to that of chromium, and the thermal conductivity is not only desirable, but also has lubrication characteristics not found in chromium. That is, since electrodeless nickel has inherent lubricating properties, the use of electrodeless nickel eliminates the casting process of applying wax or other release agent to the surface of the stamper as in chromium.

When the conventional stamper is produced, first, a thin layer of photoresist is applied on top of a glass plate having a disk shape of 0.635 cm size. Thereafter, the photoresist is selectively exposed to a laser beam to encode layer example information of the photoresist, and when developed, information recorded in the form of fine recesses is present in the layer. A fine nickel layer having a thickness of a few angstroms is vacuum-welded onto the encoding surface. Thus, another nickel layer is electrolytically deposited on top of the vacuum-welded nickel layer so as to have a thickness (typically 0.38 mm or more) sufficient to withstand the pressure required to perform the injection molding method. Separating the glass plate from the nickel exposes the encoded nickel surface, with the fine projections projecting from the base surface flat about 0.6 microns wide and about 0.6 to 2 microns long, present as tracks. This is schematically illustrated in FIG. 1 in a processed and enlarged form, in which from the flat base surface 4 of the disc 2 a series of protrusions 6 protrude in a circular track. An improvement according to the present invention is shown by the formation of an information-containing layer 16 of electrodeless nickel supported by a relatively thick base layer 18. 2 shows a partial cross-sectional view of a glass substrate 8 with a thin photoresist layer 10 bonded to the glossy top surface 9 of the disc 2.

After exposure and development to the modulated light beam, the glass substrate 8 has a series of photoresistive protrusions 12 protruding from the flat portion 14, which complements the product as shown in FIG. It will be referred to as a "substrate" for producing a stamper having an encoding surface.

In order to catalyze the information-bearing side of the substrate, the substrate has a thin, ball-continuous copper layer immersed in a solution containing copper salt and formed on its surface. Copper in the solution is reduced to a metallic state and plated on the immersed substrate. Preliminary steps of this method are described in detail in US Pat. No. 2,939,804. When such a coating of copper is satisfactorily applied on the substrate, the substrate is immersed in a solution containing a salt of palladium or gold. As a result, a portion of the copper coating is oxidized and dissolved into the solution, and a portion of the palladium or gold salt is reduced to the metal state to be combined with the copper coating. Satisfactory solutions for this purpose can be constructed using palladium chloride in an amount of about 100 ppm. When the substrate is thus treated with palladium to form a mixed coating of copper and palladium, the preparation for coating nickel is complete.

The catalyst coated substrate is then washed and then rinsed with ultra-filtered deionized water and introduced into an electrodeless bath composed of water, acid, buffer, reducing agent, nickel salt. It is preferable to immerse and rotate this base material in a circulation bath to improve the uniformity of the electrodeless plating solution.

The breakdown of the electrodeless bath is as follows.

Nickel Chloride (NiCl ₂ · 6H ₂ O) 4oz / gal (30g / 1)

Sodium hypophosphite _{(NaH 2 PO 2 · H 2} O) 1.3oz / gal (10g / 1)

Sodium citrate _{(Na 3 C 6 H 5 O} 7 · 5 1 / 2H 2 O) 1.8oz / gal (14g / 1)

Volcanic Acid (50%) (HBF ₄ ) 0.5 oz / gal (4 g / 1) pH 4.0-5.5

Temperature 19 ₄ ° F (90 ° C)

Deposition rate about 5 microns (about 0.2 mil) / hour

A substrate 8 having a layer 16 of copper / copper phosphide deposited by the electrodeless method is shown in FIG. The layer of copper / palladium or copper / gold is not shown in the figures because the thickness is negligible compared to the other components shown.

The thermal conductivity of the surface of the stamper and the thermal gradient of the stamper body are important physical properties that influence the benefits of using electrodeless nickel as the stamper material, so the ratio of nickel (Ni) and phosphorus (P), in the plating process The action of temperature and time, and the thickness of the layer of electrodeless nickel plated, are variables that can be adjusted to produce certain thermal properties for a given mold and a given thermoplastic and the temperature and pressure associated with the injection molding process.

Typically, 4-10% of phosphorus (P) is contained in the form of nickel phosphide in a coating of electrodeless nickel, which is obtained from General American Transportation Corporation's "Canine". Kanigen) "can be deposited at a rate of 5 microns per hour. In the electrodeless nickel plating method, since the deposition rate is relatively slow, it is neither economically desirable nor practically necessary to form nickel phosphide in the entire thickness portion of the stamper. Therefore, after electrodeless nickel phosphide is deposited to a sufficient thickness by electrodeless plating, a substrate having a relatively thin electrodeless nickel phosphide deposition layer is introduced in a conventional galvanic procedure to support the electrodeless nickel layer. By forming a, it is possible to have a smoother, more convenient and economical electroplated metal support. The electroplated metal may be selected from the group consisting of chromium, nickel, molybdenum, iron, copper, tungsten. This plated article is shown in FIG. 5, that is, the electrodeless nickel layer 16 is covered with a relatively thick electroplated metal support layer 18. A detailed description of electrowelding nickel is described in the pages 191-205 of Buruns and Bradley as described above.

Electrodeless nickel can be electrodeless deposited to any thickness, even over the entire thickness of the stamper, but in practice it is typically plated to a thickness of only about 0.012-0.25 mm. Due to the inherent properties of the deposit as described above, a thick weld is necessary. The electroplated support layer 18 may be applied until the thickness of the composite stamper is about 0.38-1.0 mm. In certain applications, it may be considered to form a deposition layer of a nonmetallic support material when the thickness of electrodeless nickel is about 0.12 mm or more.

Further, depending on the thermal properties of the product and the stamper to be cast, the layer of electrodeless nickel may be coated with a thickness in the range of 0.012-0.25 mm, and the electrodeposited metal support layer 18 may be 0.12-10.0 mm thick. . Extremely, it is believed that, with a thickness of about 1 micron, only the coding layer of an electrodeless plated stamper will provide the maximum benefit of a relatively thick layer, and can be deposited within about 15 minutes. However, the minimum thickness recommended for the electrodeless nickel layer is 12 microns.

As one example, a preferred stamper with a minimum thickness of electrodeless nickel that is recommended is that a hard nickel support layer is deposited by plating to a thickness of up to 0.75 mm on top of electrodeless nickel of 12 microns thick. As an example of the maximum thickness required for the electrodeless nickel layer, a 0.12 mm thick electrodeless nickel layer with a 0.9 mm thick molybdenum layer is preferred.

Also preferably, the hard nickel or molybdenum support layer may be welded by chemical vapor deposition. For example, molybdenum hexacarbonyl can be deposited by chemical vapor deposition of relatively hard molybdenum, thereby making the total thickness of the stamper phase about 0.75 mm in a considerably shorter time than the deposition rate of electrodeless nickel.

By separating the composite stamper from the substrate as shown in FIG. 6, the encoding surface of the nickel / nickel phosphide layer can be cured by heat treatment. At this time, it contains 4-10% of phosphorus and the remainder of nickel phosphorus deposit has an amorphous structure. According to the heat treatment, the nickel phosphide is formed in the nickel lattice structure so that it can be precipitated and hardened. The hardness at this time is controlled according to the amount of such crystals, the maximum being obtained at a temperature of about 400 ° C. The heat treatment of the stamper in the range of 370 ° C.-400 ° C. increases the hardness of the electrodeless nickel layer from 40 Rockwell C to 70 Rockwell C. Exposure to high temperatures (above 400 ° C.) for a long time results in co-precipitation of both nickel phosphide and nickel crystals. According to this, although the deposit with malleableness can be obtained, hardness is infringed.

The foregoing describes an improved stamper for use in the injection molding method. Improvements made by using electrodeless nickel as the sign and information bearing surface for the stamper include, firstly, increased hardness, and secondly, the life of the stamper is extended (2-5 times compared to a pure nickel stamper), Third, there is no waffle effect. Fourth, because of excellent lubrication properties, the separation state of cast products is improved, and the orange peel effect and plow effect are not shown. Also, since the thermal conductivity is low, when the molten plastic fills the mold cavity, Can prevent hardening Since the electrodeless nickel layer has good wettability, the deposit has a natural lubricity unlike chromium in which the lubricant is not well fed. The coating maintains a definite inertness that lasts forever and is resistant to many types of organic and inorganic acids and chemicals.

While the invention has been described only with respect to specific embodiments as shown, of course, various modifications and changes can be made without departing from the concept of the invention as defined in the claims.

Claims (22)

Depositing a relatively thin plating catalyst layer of nuclei of a metal selected from the group consisting of palladium and gold on a glass substrate coated with a photoresist layer comprising fine recesses representing the recorded information; Electroless nickel plating of the plating catalyst layer in a nickel plating bath containing sodium hypophosphate provides an electrodeless nickel coating having a thickness in the range of 0.012 to 0.25 mm and a corresponding thermal conductivity in the range of 0.011 to 0.014 Cal / cm / sec / ° C. To form; Depositing a layer of support metal on the electrodeless nickel coating; And removing the composite stamper formed by separating the photoresist layer from the electrodeless nickel coating, from the substrate. 17. A method of manufacturing a stamper for forming an optically readable information bearing member. The method of claim 1, wherein the welding step includes electrowelding a layer of the supporting metal to a thickness in the range of 0.1 to 1.0 mm. 3. The method of claim 2 wherein the layer of electrowelded support metal is selected from the group consisting of chromium, nickel, molybdenum, iron and tungsten. The method of claim 1, wherein the depositing step comprises performing chemical vapor deposition of molybdenum hexacarbonyl on top of the coating of electrodeless nickel. The method of claim 1, wherein the content of phosphorus (P) in the electrodeless nickel is in the range of 4% to 8% by weight in the form of nickel phosphide. The method of claim 1, wherein the separating step comprises curing the electrodeless nickel coating to a hardness of 40 Rockwell C to 70 Rockwell C by heating the formed composite stamper to a temperature in the range of 370 ° C to 400 ° C. The method of claim 1, wherein the plating step includes electroless plating of the coating to a thickness of 1 to 8 microns, and the welding step is performed by welding the layer of the supporting metal to a thickness in the range of 0.12 to 1.0 mm. How to do. Preparing an information containing surface containing information in the form of a surface discontinuity on a substrate; Coating a coating of electrodeless nickel over the entire information-bearing surface of the substrate; Depositing a support material on the coating to form a composite stamper having a complementary electrodeless nickel information containing surface on the substrate information containing surface; During the plating step and the welding step, the thicknesses of the coating and the supporting material are adjusted, respectively, so that the heat transfer rate of the stamper on the information-bearing surface of the coating is 1/5 to 1/100 of the heat transfer rate of nickel having the same thickness as this stamper. To have a predetermined value; A method of manufacturing a stamper for forming an optically readable information-containing member comprising the steps of separating the thus formed composite stamper from a substrate. It is made of electrodeless nickel with phosphorus (P) content so that the thermal conductivity of the electrodeless nickel layer has a predetermined value in the range of 0.011 to 0.014Cal / cm / sec / ° C. A stamper for forming an optically readable information bearing member composed of an electrode nickel layer and a relatively thick support layer molecularly bonded to the surface of the electrodeless nickel layer without the information bearing surface. The stamper of claim 9, wherein the electrodeless nickel layer has a thickness in the range of 0.012 to 0.25 mm, and the support layer is a metal layer having a thickness in the range of 0.12 to 1.0 mm. 11. The stamper of claim 10, wherein said metal is selected from the group consisting of chromium, nickel, molybdenum, iron and tungsten. 10. The stamper according to claim 9, wherein a nucleus layer of a metal selected from the group consisting of palladium and gold is provided on the information containing surface of the electrodeless nickel layer. The stamper according to claim 9, wherein the content of phosphorus (P) in the electrodeless nickel is in the range of 4 wt% to 8 wt% in the form of nickel phosphide. The stamper according to claim 9, wherein the electrodeless nickel layer has a hardness of 40 Rockwell C to 70 Logwell C. 10. The stamper of claim 9, wherein the electrodeless nickel layer has a thickness of 1 to 8 microns and the support layer has a thickness in the range of 0.12 to 1.0 mm. It consists of a relatively thin electrodeless nickel layer having an information-bearing surface on one surface, and a relatively thick support layer molecularly bonded to the surface of the electrodeless nickel layer without the information-containing surface thereof. The thickness of the electrodeless nickel layer is 1/5 to 1/5 of the heat transfer rate of nickel having the same thickness as that of the composite stamper.

A stamper for forming an optically readable information bearing member, the thicknesses being relatively bonded to each other to be sufficient. An information-containing surface containing information in the form of surface discontinuities is prepared on a substrate, a coating of electrodeless nickel is plated in a plating bath over the information-containing surface of the substrate, and the stamper thus formed is separated from the substrate. And a method of producing a stamper for forming an optically readable information bearing member comprising the steps of curing the stamper to a hardness of 40 Rockwell C to 70 Rockwell C by heating the stamper to a temperature in the range of 370 ° C. to 400 ° C. . 18. The method of claim 17, wherein the plating step comprises electrodeless plating the electrodeless nickel coating to a thickness in the range of 0.12 to 1.0 mm. 18. The surface of claim 17, wherein the information containing surface includes a photoresist layer, the substrate is made of glass, the surface discontinuity is a fine recess in the photoresist layer, and before the electrodeless plating step, palladium and gold. Catalyzing the surface of the photoresist layer by depositing a relatively thin layer of nuclei of a metal selected from the group consisting on the surface of the photoresist layer to serve as a catalyst for the plating step. . A stamper for forming an optically readable information bearing member, comprising a layer of electrodeless nickel having an information bearing surface on one surface, the thickness of the electrodeless nickel being in the range of 0.12 to 1.0 mm. Preparing an information containing surface containing information in the form of a surface discontinuity on a substrate; A coating of electrodeless nickel is plated in the plating bath over the entire information bearing surface of the substrate; Depositing a support material on the coating to form a composite stamper having an electrodeless nickel information containing surface complementary to the information containing surface of the substrate; Optically readable information consisting of separating the thus formed composite stamper from a substrate and curing the coating to a hardness of 40 Rockwell C to 70 Rockwell C by heating the stamper to a temperature in the range of 370 ° C. to 400 ° C. Method for producing a stamper for forming the containing member. A relatively thick electrodeless nickel layer having an information-bearing surface on one surface and having a hardness between 40 Rockwell C and 70 Rockwell C, and a relatively thick molecular bond to the surface of the electrodeless nickel layer having no information bearing surface. A stamper for forming an optically readable information bearing member, comprising a support layer.

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