JP2003201147A - Precision drilling method for glass, method of manufacturing ferrule for optical fiber connector and method of manufacturing magnetic disk glass substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate the difficulty in high-accuracy drilling of submicron order in a machining method, etching method and thermal processing method in subjecting glass to precision drilling and to prevent the occurrence of flashes in molding and the possibility of the occurrence of crack in the glass in a method of forming through-holes in glass substrates together with molding as the clearances exists in the mold. <P>SOLUTION: The extremely inexpensive precision drilling method for the glass involving only the forming and surface polishing process steps is provided by holding a blank for forming consisting of the glass between a mold for forming having a high-accuracy projecting shape of a height above the necessary pore depth and a plane mold, heating the blank for forming up to a temperature at which the blank can be deformed, press forming the blank to form a recess precisely transferred with an inverted shape of the projecting shape, cooling the formed body, parting the formed body from the molds and polishing the formed body from a plane side until the thickness to provide the prescribed pore depth is attained. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for highly accurately punching a glass material and a method for producing a glass product with through holes that has been highly accurately drilled.

[0002]

2. Description of the Related Art Conventionally, as a method for making a hole in a glass product, a mechanical processing method such as a rotary grindstone, a drill, an ultrasonic processing, a blast processing, an etching processing method by a chemical treatment, or a burner is used for burning. Thermal processing method
No. 00-16815, Japanese Patent Laid-Open No. 2000-53435), and an energy beam processing method using an ion beam, a laser, an electron beam, etc. (Japanese Patent Laid-Open No. 2000-6166).
No. 7) or a method of press-molding heat-softened glass with a mold (Japanese Patent Laid-Open No. 2000-319026).
and so on.

Using the above-described drilling method, glass substrates for magnetic disks, ferrules for optical fiber connectors, etc. are manufactured.

As a general method for manufacturing a glass substrate for a magnetic disk, a polishing step for obtaining a predetermined surface smoothness, an outer die processing by a machining method, an inner hole drilling step, and an inner and outer circumference are then performed. It consists of a final finishing process by chamfering.

Further, Japanese Patent Laid-Open No. 2000-319026 proposes that the polishing step and the punching step are simultaneously performed by molding.

The ferrule for the optical fiber connector is
In order to connect the optical fibers so that their axes coincide with each other, the inner and outer diameters of the ferrule are required to have extremely high accuracy (submicron order).

As a method of manufacturing such a ferrule, a method of finishing the inner and outer diameters of a metal material or a ceramic material by a machining method using a highly accurate processing machine is carried out, but the processing cost is very high. . On the other hand, according to the method described in Japanese Patent Application Laid-Open No. 10-186176, a method of manufacturing a ferrule at low cost by molding a molten amorphous alloy with a mold is proposed.

[0008]

However, the mechanical working method, the etching working method, and the thermal working method are difficult to perform submicron-order high-precision drilling, especially when fine drilling is required. Is not possible with these construction methods.

In the energy beam processing method, the apparatus is generally expensive, the processing speed is slow, and mass production is not possible. JP 200
In the method described in Japanese Patent Publication No. 0-61667, a glass material contains a component having a high YAG laser absorption rate,
Although the processing efficiency is increased by increasing the absorptance of the YAG laser, it is necessary to preliminarily include a component having a high absorptivity in the glass material.

In the manufacturing method by molding a magnetic disk glass substrate described in Japanese Patent Laid-Open No. 2000-319026, as shown in FIG. 11, the press molding surfaces are flat from the center of a pair of upper and lower molds 111 and 112. The inner molds 113 and 114 are arranged in the through holes formed in a concentric shape so that the through holes are formed in the glass substrate during molding, but the outer molds 111 and 112 and the inner mold 113 are formed. , 114 always have a gap, so that the glass 115 may enter the gap at the time of molding to cause burrs, and cracks may occur in the glass at the time of releasing.

Further, in the method of manufacturing a ferrule described in Japanese Patent Laid-Open No. 10-186176, the amorphous synthetic financial fluid 123 is injected into the mold shown in FIG.
Burrs are generated in the gap between the core pin 122 and the base mold 121.

In both cases, a special finishing process is required to remove these burrs, and there is a problem that the surface formed with high precision may be damaged.

[0013]

In view of the above, according to the present invention, firstly, a molding material made of glass is formed on a molding die having a highly precise projection shape having a height not less than a required hole depth and a flat surface. It is sandwiched between a mold and heated to a temperature at which the molding material can be deformed, and press-molded to form a recess in which the inverted shape of the protrusion is precisely transferred, and then cooled and released from the mold. The present invention provides a very inexpensive precision drilling method for glass by polishing from a flat surface side to a thickness that achieves a predetermined hole depth by only molding and flat surface polishing steps.

Then, a molding material made of glass, a molding die having a projection shape which is an inverted shape of the through hole shape of the ferrule for a high-precision optical fiber connector having a height higher than a required hole depth, and a plane metal mold. It is sandwiched between a mold and a ring-shaped body mold for regulating the outer shape, which is heated to a temperature at which the molding material can be deformed and press-molded to form a recess in which the inverted shape of the protrusion shape is precisely transferred. Provided is a method for manufacturing a ferrule for an optical fiber connector in which the outer shape and the through hole are processed with high precision by cooling, releasing from the mold, and polishing from the flat surface side to a thickness that provides a predetermined hole depth. is there.

Secondly, a glass material having a heat resistance higher than that of the glass forming material is used as a master die having a highly accurate through hole or groove shape having a depth not less than a required hole depth and a plane substrate. It is sandwiched with a material, heated to a temperature at which the glass material can be deformed, and press-molded to form a projection in which the reverse shape of the through hole or groove shape is precisely transferred, and is joined to a flat base material. After cooling and releasing from the mold, a step of forming a replica metal mold having a highly precise projection shape having a height equal to or higher than a required hole depth by forming a precious metal alloy thin film on the surface, and from the glass A molding material consisting of the following is sandwiched between the replica mold and the flat mold, heated to a temperature at which the molding material can be deformed, and press-molded to form a recess in which the inverted shape of the protrusion shape is precisely transferred. Forming, cooling and releasing from the mold A precision glass drilling method that consists of polishing from the flat side to a thickness that achieves a predetermined hole depth, enabling the production of a glass substrate with surface smoothness and highly accurate through holes at a lower cost. Is.

Then, a glass material having better heat resistance than a molding material made of glass is formed into a super-smooth surface with a highly accurate through hole or groove shape having a depth not less than the required hole depth. It is sandwiched between a processed master die and a flat base material, and is heated to a temperature at which the glass material can be deformed through a ring-shaped body die for regulating the outer shape, and press-formed to form a through hole or groove. By forming a protrusion that is a precise transfer of the inverted shape of, joining with a flat base material, cooling and releasing from the mold, a precious metal alloy thin film is formed on the surface, so that The process of making a replica mold with high-precision projection shape and excellent surface smoothness, and the molding material made of glass, through the ring-shaped body mold for outer shape regulation, It has a highly precise projection shape with a height greater than the hole depth, and has a smooth surface. Sandwiched between a replica mold and a flat mold, heated to a temperature at which the molding material can be deformed, and press-molded to form a recess in which the inverted shape of the protrusion shape is precisely transferred, and then cooled. And a method of manufacturing a magnetic disk glass substrate, which comprises a step of releasing from a mold and a step of polishing from a flat surface side up to a thickness of a predetermined disk thickness,
It is possible to manufacture a magnetic disk glass substrate having a surface smoothness, a highly accurate outer shape and an inner hole at an extremely low cost.

Thirdly, a molding material made of glass is sandwiched between a molding mold having a plurality of highly accurate projection shapes having a height equal to or larger than a required hole depth and a flat mold, and the molding is carried out. The material is heated to a temperature that allows it to be deformed, press-molded to form dents that precisely transfer the inverted shapes of multiple protrusions, release at that temperature, and then cooled to a predetermined hole depth. By polishing from a flat surface side up to a certain thickness, it is possible to provide a plurality of very precise precision drilling methods only by molding and flat polishing steps.

Then, the molding material made of glass is used as a molding die having a plurality of protrusions which are the inverted shapes of the through-holes of the high-precision ferrule for an optical fiber connector having a height not less than the required hole depth. A dent that is sandwiched between a flat mold and heated to a temperature at which the molding material can be deformed through a body shape regulating die, and press-molded to precisely transfer the inverted shapes of multiple protrusions. And mold release at the same temperature, followed by cooling, until the thickness reaches a predetermined hole depth,
It is intended to provide a method for manufacturing a ferrule for an array-shaped optical fiber connector having a plurality of precision holes which is very inexpensive only by molding and polishing by polishing from the flat surface side.

Fourthly, a glass material having a heat resistance higher than that of the glass forming material is used as a master mold having a highly precise through hole or groove shape having a depth not less than a plurality of required hole depths. It is sandwiched between a flat base material, heated to a temperature at which the glass material can be deformed, and press-formed to form a projection in which a plurality of through-holes or groove-shaped inverted shapes are precisely transferred. Replica with a highly precise projection shape with a height higher than the required hole depth by joining the material and releasing from the master mold without cooling and forming a precious metal alloy thin film on the surface after cooling. A step of producing a mold, a molding material made of the glass is sandwiched between the replica mold and a flat mold, heated to a temperature at which the molding material can be deformed, press-molded, A recess that is an accurate transfer of the inverted shape of the Formed, after releasing from the replica mold at the temperature as it is, by a precision drilling method of glass, which comprises a step of cooling and a step of polishing from a flat surface side up to a thickness of a predetermined hole depth, It enables multiple low-cost precision drilling.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) A method for precisely punching glass according to Embodiment 1 of the present invention will be described with reference to FIG.

First, a high-strength material such as cemented carbide is machined by a grinding process or an electric discharge machining method to form a cylindrical projection shape at the center, and a projection mold 11 is formed with a precious metal alloy thin film for surface protection. Similarly, a high-strength material such as cemented carbide is processed into a flat surface by polishing, and a flat metal mold 13 on which a precious metal alloy thin film is formed for surface protection is prepared.
The molding material 12 made of glass is sandwiched between the flat mold 13 and the flat mold 13, and the molding material is heated to a temperature at which it can be deformed by a press and does not penetrate to the flat mold side as shown in FIG.
Pressing is performed by applying pressure until the shape of the protruding mold is completely transferred so that a little glass thickness remains.

After cooling while holding these molds,
The protrusion die 11 and the flat die 13 are released from the glass.
The surface side on which the shape of the projection mold 11 of the glass substrate is precisely transferred is protected and fixed with resin or the like, and the flat surface side 1
A predetermined through hole 15 can be formed in the glass substrate by performing surface polishing from 4 to a predetermined glass thickness.

According to the present invention, it is possible to perform a precision drilling process on a glass substrate only by a molding process and a flat polishing process, and it becomes possible to perform a drilling process on the glass substrate at a very low cost.

According to this method, the ferrule for an optical fiber connector, which has been difficult to manufacture up to now, can be easily manufactured. An embodiment of a method of manufacturing a ferrule for an optical fiber connector will be specifically described below with reference to FIG.

First, a cemented carbide containing WC having a diameter of 5 mm and a thickness of 10 mm as a main component (coefficient of thermal expansion: 50 × 10 ^-7 /
K) The material is processed into a protrusion shape having a pin shape and a taper portion with a diameter of the tip of 125 μm and a length of 2 mm in the central portion as shown in FIG. 2 by the electric discharge machining method, and by the sputtering method on the surface, The protrusion die 21 was produced by forming a Pt-Ir alloy thin film to 1 μm.

Subsequently, a cemented carbide material mainly composed of WC having a diameter of 5 mm and a thickness of 2 mm is flat-polished, and then a Pt-Ir alloy thin film is formed to a thickness of 1 μm on the surface by a sputtering method. Was produced. The flat mold 23 is inserted into a ring-shaped body mold 24 (made of cemented carbide) for controlling the outer shape, and a diameter of 4 mm and a thickness of 5 are formed on it as a molding material.
A cylindrical Pyrex (registered trademark) glass 22 (coefficient of thermal expansion: 32 × 10 ⁻⁷ / K) of mm was placed thereon, and the protruding mold 21 was inserted into the ring-shaped barrel mold from above.

In that state, it is put into a molding machine (not shown) in a nitrogen atmosphere, the whole die is heated from the outside to 730 ° C., and 100 N from above the protruding die 21.
Was applied. As it is, pressure is applied and the projection mold 2
Press molding was performed until the shape of 1 was completely transferred to the Pyrex glass 22, and when completely transferred, it was cooled to room temperature while applying pressure.

At this time, the height was regulated by the barrel mold 24 so that the tip of the protruding mold 21 did not penetrate to the flat surface side and 0.2 mm glass remained from the flat mold 23. After cooling, the Pyrex glass 22 was released from the mold and taken out from the molding machine. At this time, since the protruding mold 21 has a larger thermal expansion coefficient than the Pyrex glass 22, the mold shrinks earlier than the glass during cooling, so that the mold can be easily released. From the back surface 25 of the molded product taken out, cerium oxide and diamond abrasive grains are used to planarly polish the through hole 2
Got 6. The length (tip portion) of the through hole was 1.5 mm.

The cost of the ferrule manufactured in this manner was about ⅕ of that of the conventional ferrule which was machined to make a hole. It was found that the outer diameter, through hole diameter, concentricity, roundness, and cylindricity of the finished ferrule were completed with a dimensional accuracy of 0.5 μm or less, which is within a sufficient tolerance for practical use.

By the above method, a ferrule having a highly accurate through hole can be manufactured at a very low cost.

(Second Embodiment) In the method shown in the first embodiment, the projection mold is directly machined,
When making a through hole in a glass substrate with a very good surface smoothness such as a magnetic disk substrate, it is difficult to polish the flat surface other than the protrusions to be super smooth, so it is difficult to fabricate a protrusion die by machining. .

Therefore, a method of precisely punching a glass substrate having a super smooth surface and a through hole will be described with reference to FIGS. 3 and 4.

FIG. 3 shows a method for manufacturing a protrusion die.
FIG. 4 shows a method of forming a through hole by using the protrusion die manufactured by the method described above.

First, a high-strength material such as cemented carbide is surface-polished to form a super-smooth surface, and a cylindrical recess is formed at the center by electric discharge machining. A precious metal alloy thin film is formed to protect the surface. Similarly to the formed master die 31, a high-strength material such as cemented carbide is processed into a flat surface by polishing, and a flat base material 33 having a bonding layer formed on the surface for bonding with glass is prepared, Master mold 31 and flat substrate 3
Glass material 3 with better heat resistance than molding material between 3
2 is sandwiched, the glass material is heated to a temperature at which it can be deformed by pressing, until the shape of the master mold is completely transferred,
Press and apply pressure.

After cooling while being held in these molds,
The master mold 31 is released. The flat base material 33 and the molded glass 32 are a bonding layer 34 and are completely bonded together with molding. After that, a noble metal alloy thin film 35 is formed on the surface to complete the protrusion die (FIG. 3).

The projection mold thus produced has a very smooth surface and projection shape.

Subsequently, a high-strength material such as cemented carbide is processed into a flat surface by polishing, and a flat mold 43 having a precious metal alloy thin film formed thereon for surface protection and a completed projection mold 41.
A molding material 42 made of glass is sandwiched between the two, and the molding material is heated to a temperature at which it can be deformed by a press and does not penetrate to the flat mold side as shown in FIG. As described above, pressure is applied and press molding is performed until the shape of the protrusion die is completely transferred.

After cooling while being held in these molds,
The protrusion die 41 and the flat die 43 are released from the glass.

By precisely protecting the surface of the glass substrate on which the shape of the protrusion die 41 is precisely transferred and fixing it with a resin or the like, and polishing the surface from the flat surface 44 to a predetermined glass thickness by flat polishing. A predetermined through hole 45 can be formed in the glass substrate.

According to the present invention, it becomes possible to perform precision drilling on a glass substrate only by a molding process and a flat polishing process, and it becomes possible to perform drilling on a glass substrate having excellent surface smoothness at a very low cost. .

According to this method, it is easy to manufacture a magnetic disk glass substrate having a through hole in the center and excellent surface smoothness, which has been difficult to manufacture. Hereinafter, one embodiment of a method for manufacturing a magnetic disk glass substrate will be specifically described with reference to FIG.
And FIG. 6 will be described.

First, the surface of a cemented carbide columnar material having a diameter of 65 mm and a thickness of 2 mm and containing WC as a main component is ground by polishing to a surface roughness (Ra) of 0.5 nm, and then the center part is polished. Diameter 2 by electric discharge machining and machining
By forming a 0 mm through hole and forming a 1 μm-thick Ir—W alloy thin film on the surface by a sputtering method, a master mold 51 having a through hole at the center with excellent surface smoothness was produced.

Subsequently, an SK having a diameter of 65 mm and a thickness of 2 mm
After flat-polishing the H steel material, a Cr thin film was formed as a bonding layer to a thickness of 0.2 μm on the surface by a sputtering method to prepare a flat base material 53.

The flat base material 53 is inserted into a ring-shaped body 54 (made of cemented carbide) for controlling the outer diameter, and a diameter of 50 m is placed on the ring-shaped body 54.
A columnar crystallized glass (mother glass before crystallization) 52 having a thickness of m and a thickness of 3 mm was placed, and the master mold 51 was inserted into the ring-shaped barrel mold from above.

In that state, the mold is put into a molding machine (not shown) in a nitrogen atmosphere, the whole mold is heated from the outside, the whole mold is heated to 700 ° C., and the master mold 51 is heated from above. A pressure of 50,000 N was applied. When pressure is applied as it is, press molding is performed until the surface shape of the master die 51 is completely transferred to the crystallized glass 52, and as shown in FIG. 5, the crystallized glass rises in the through-hole portion,
A protrusion shape was formed along the through hole. In this state, the temperature was raised to 850 ° C. to crystallize the crystallized glass 52.

Then, it was cooled to room temperature while applying pressure, the master mold 51 was released, and it was taken out from the molding machine. The molded product is a crystallized crystallized glass 52 and a flat substrate 5.
No. 3 and No. 3 were joined by the joining layer 55, and there was a protrusion with a rounded tip (height was 1.5 mm), and the surface roughness (Ra) of the plane portion was 0.6 nm. After forming a mixed thin film of SiO ₂ and W to a thickness of 0.1 μm on this molded product by a sputtering method, an Ir—W alloy thin film of 1 μm was formed as a surface protective film 56 by a sputtering method.
By forming m, a protrusion replica mold having good heat resistance was completed.

Next, a cemented carbide material having a diameter of 65 mm and a thickness of 2 mm and containing WC as a main component is flat-polished, and then an Ir—W alloy thin film is formed to a thickness of 1 μm on the surface by a sputtering method to form a flat mold 63. Was produced.

The flat mold 63 is inserted into a ring-shaped barrel mold 64 (made of cemented carbide), and a diameter of 5 is formed on it as a molding material.
A cylindrical aluminosilicate glass 62 having a thickness of 0 mm and a thickness of 3 mm was placed thereon, and the projection replica mold 61 produced by the above-described method was inserted into the ring-shaped barrel mold 64 from above.

In this state, the mold is put into a molding machine (not shown) in a nitrogen atmosphere, the whole mold is heated from the outside, the whole mold is heated to 680 ° C. A pressure of 50,000 N was applied.

Pressure was applied as it was, press molding was performed until the shape of the projection replica mold 61 was completely transferred to the aluminosilicate glass 62, and when completely transferred, it was cooled to room temperature while applying pressure.

At this time, the projection replica mold 6 extends to the plane side.
The height was regulated by the barrel mold 64 so that 0.2 mm glass remained from the flat mold 63 without the tip of No. 1 penetrating. After cooling, the aluminosilicate glass 62 was released from the mold and taken out from the molding machine.

The surface of the molded product taken out was covered with a resin adhesive and attached to a flat substrate, and then the back surface 65 was flat-polished using cerium oxide and diamond abrasive grains to obtain a through hole 66. The length of the through hole, that is, the disc thickness was 0.635 mm. The manufacturing cost of the magnetic disk glass substrate manufactured in this way was about 1/3 of that of the conventional magnetic disk glass substrate that was perforated by mechanical processing. It was found that the outer diameter and the through-hole diameter of the magnetic disk glass substrate thus produced were within the tolerances practically sufficient.

By the above method, it becomes possible to manufacture a magnetic disk glass substrate which has a very low cost, a highly accurate through hole, and an excellent surface roughness.

(Third Embodiment) Next, a method of forming a plurality of through holes in the glass substrate of the present invention will be described with reference to FIG.

In the case of forming a plurality of through holes in the glass substrate, in the molding method in which cooling is carried out after molding, which is described in the first embodiment, this occurs due to the difference in thermal expansion coefficient between the mold and the glass. There is a problem that the molded glass cannot be released from the mold due to the stress, or the glass breaks due to the stress generated.

Therefore, first, a protrusion having a noble metal alloy thin film formed for protecting the surface by machining a plurality of cylindrical protrusion shapes at the center by grinding or electric discharge machining of a high-strength material such as cemented carbide. Similarly to the die 71, a high-strength material such as cemented carbide is processed into a flat surface by polishing, and a flat die 73 having a precious metal alloy thin film formed thereon for surface protection is prepared. A molding material 72 made of glass is sandwiched between flat molds 73, and the molding material is heated to a temperature at which it can be deformed by a press. As shown in FIG. So that the thickness of
Pressure is applied and press molding is performed until the shape of the protrusion die is completely transferred.

Up to this point, the molding method is the same as the molding method described in the first embodiment, but the projection mold 71 is not cooled as it is.
Is released from the glass. After cooling, from the flat mold 73,
By taking out the molded glass substrate, protecting and fixing the surface side on which the shape of the protrusion die 71 is accurately transferred with resin or the like, and polishing the surface from the flat surface 74 to a predetermined glass thickness by flat polishing. A predetermined plurality of through holes 75 can be formed in the glass substrate.

According to the present invention, since the mold having a plurality of protrusions is released from the mold without cooling in the molding process, stress due to the difference in the coefficient of thermal expansion between the mold and the glass does not occur, and the molding process and the flat surface can be prevented. A plurality of precision holes can be formed in the glass substrate only by the polishing step, and the holes can be formed in the glass substrate at a very low cost.

According to this method, it is easy to manufacture a ferrule for an array-shaped optical fiber connector for aligning a plurality of optical fibers used for wavelength division multiplexing optical communication in an array, which has been difficult to manufacture. Hereinafter, one embodiment of a method for manufacturing a ferrule for an array-shaped optical fiber connector will be specifically described with reference to FIG.

First, a cemented carbide material containing WC having a size of 5 mm square and a thickness of 10 mm as a main component was processed to 250 μm by an electric discharge machining method.
As shown in FIG. 8, eight m-pitch and equally spaced tips were processed into a pin shape having a tip diameter of 125 μm and a length of 2 mm and a protrusion shape having a tapered portion, and Pd- A protrusion metal mold 81 was produced by forming a Re alloy thin film with a thickness of 1 μm.

Then, a 5 mm square and 2 mm thick cemented carbide material containing WC as a main component is flat-polished, and then a Pd-Re alloy thin film is formed to a thickness of 1 μm on the surface by a sputtering method. Was produced.

The flat mold 83 is inserted into the rectangular barrel mold 84 (made of cemented carbide), and 4 mm is used as a molding material on it.
A column-shaped Pyrex glass 82 having a square shape and a thickness of 5 mm was placed thereon, and the projection mold 81 was inserted into the rectangular barrel mold 84 from above.

In this state, the mold is put into a molding machine (not shown) in which nitrogen gas is mixed with 5% CF ₄ gas, and the whole mold is heated from the outside to make the whole mold. 73
The temperature was set to 0 ° C., and a pressure of 1000 N was applied from above the protrusion die 81.

The pressure is applied as it is, press-molding is performed until the shape of the protrusion die 81 is completely transferred to the Pyrex glass 82, and when completely transferred, the protrusion metal 81 is not cooled and the temperature is kept as it is. The mold 81 was released. At this time, the height was regulated by the barrel mold 84 so that the tip of the protruding mold 81 did not penetrate to the flat surface side and 0.2 mm glass remained from the flat mold 83.

Then, it is cooled and the Pyrex glass 8
2 was released from the flat mold 83 and taken out.

The surface of the molded product taken out was covered with a resin adhesive and attached to a flat substrate.
Planar polishing was performed using cerium oxide and diamond abrasive grains to obtain eight through holes 86. The lengths of the through holes (tip portions) were all 1.5 mm.

The cost of the arrayed ferrule manufactured in this way was about 1/10 of that of the conventional ferrule that was machined to have a hole. It was found that the outer diameter, through hole diameter, concentricity, circularity, and cylindricity of each ferrule were completed with a dimensional accuracy of 0.5 μm or less, which is within a sufficient tolerance for practical use.

By the method described above, it has become possible to manufacture an array-shaped ferrule having a plurality of through holes with a high accuracy and at a very low cost.

(Fourth Embodiment) In the glass precision drilling method shown in the third embodiment, a protrusion die having a plurality of protrusion shapes is manufactured by a direct machining method or an electric discharge machining method. It takes a lot of time to make the mold.

Therefore, a method of forming a plurality of through holes in the glass substrate in order to further reduce the cost of forming holes will be described with reference to FIGS. 9 and 10.

FIG. 9 shows a method of manufacturing a projection mold having a plurality of projection shapes, and FIG. 10 shows a method of forming a plurality of through holes using the projection mold manufactured by the method of FIG.

First, a master metal in which a high-strength material such as cemented carbide is ground by polishing to form a plurality of cylindrical recesses by electric discharge machining and a precious metal alloy thin film is formed for surface protection. Similarly to the mold 91, a flat base material 93 in which a high-strength material such as cemented carbide is processed into a flat surface by polishing and a bonding layer is formed on the surface for bonding with glass
, A glass material 92 having better heat resistance than the molding material is sandwiched between the master mold 91 and the flat base material 93, and the glass material is heated to a temperature at which the glass material can be deformed by a press to obtain the shape of the master mold. Until pressure is completely transferred,
Press molding.

The process up to this point is the same as the method for forming the projection mold shown in the second embodiment, but the master mold 91 is released from the glass without cooling as it is.

The flat base material 93 and the molded glass 92 are a bonding layer 94 and are completely bonded together with molding. After cooling, a noble metal alloy thin film 95 is formed on the surface, and the projection replica mold is completed (FIG. 9).

In this way, a replica mold having a plurality of protrusion shapes can be manufactured very easily.

Subsequently, a high-strength material such as cemented carbide is processed into a flat surface by polishing, and a flat mold 103 having a precious metal alloy thin film formed thereon for surface protection is prepared. Replica mold 1 having the shape of a protrusion
The molding material 102 made of glass is sandwiched between 01 and the flat mold 103, and the molding material 102 is heated to a temperature at which it can be deformed by a press, and does not penetrate to the flat mold side as shown in FIG. As the thickness of the glass remains a little,
Until the shape of the protrusion replica mold 101 is completely transferred,
Press and apply pressure.

Without cooling as it is, the protrusion replica mold 1
01 is released from the glass. After cooling, flat mold 103
Then, the molded glass substrate is taken out, the surface side on which the shape of the projection replica mold 101 is precisely transferred is protected and fixed by a resin or the like, and flat surface polishing is performed from the flat surface side 104 to a predetermined glass thickness. By doing so, a predetermined plurality of through holes 105 can be formed in the glass substrate.

According to the present invention, it becomes very easy to manufacture a mold having a plurality of protrusion shapes, and in the molding process,
Since it is released from the mold with multiple protrusions without cooling, stress due to the difference in thermal expansion coefficient between the mold and glass does not occur, and multiple precision holes are formed in the glass substrate only by the molding process and the flat polishing process. Drilling is possible, and a plurality of holes can be drilled in the glass substrate at a very low cost.

[0080]

As described above, according to the method for precision drilling of glass of the present invention, burrs are formed by forming a recess in a glass substrate with high precision by molding and polishing the surface from the back surface. Therefore, a highly accurate through hole can be formed at a very low cost. This method has also made it very easy to manufacture ferrules for optical fiber connectors.

Further, by manufacturing the mold having the projection shape by press molding of glass, it becomes possible to manufacture a glass substrate having a through hole having excellent surface smoothness, and it is possible to manufacture a magnetic disk glass substrate at a very low cost. It has become possible to manufacture.

Further, by using a mold having a plurality of protrusion shapes and releasing the mold without cooling, the glass is molded to form a plurality of dents with a high accuracy. By forming it on the glass substrate and polishing the surface from the back surface, it is possible to form a plurality of highly accurate through holes at a very low cost without the occurrence of burrs. By this method, the ferrule for an array-shaped optical fiber connector can be manufactured very easily.

Further, a mold having a plurality of protrusion shapes is
The glass substrate having a plurality of through-holes can be manufactured at a lower cost by manufacturing the glass by press molding with a method of releasing the mold without cooling.

[Brief description of drawings]

FIG. 1 is a schematic process diagram showing a method for precision drilling of glass according to a first embodiment of the present invention.

FIG. 2 is a schematic process diagram showing a method for manufacturing a ferrule for an optical fiber connector according to the first embodiment of the present invention.

FIG. 3 is a schematic process diagram showing a method for manufacturing a projection replica mold used in the method for precision drilling of glass according to the second embodiment of the present invention.

FIG. 4 is a schematic process diagram showing a glass precision drilling method according to a second embodiment of the present invention.

FIG. 5 is a schematic process diagram showing a method for manufacturing a protrusion replica mold used in the method for manufacturing a magnetic disk glass substrate according to the second embodiment of the present invention.

FIG. 6 is a schematic process diagram showing a method of manufacturing a magnetic disk glass substrate according to a second embodiment of the present invention.

FIG. 7 is a schematic process diagram showing a method for precision drilling of a plurality of glasses according to a third embodiment of the present invention.

FIG. 8 is a schematic process diagram showing a method of manufacturing a ferrule for an array-shaped optical fiber connector according to a third embodiment of the present invention.

FIG. 9 is a schematic process diagram showing a method for manufacturing a projection replica mold used in the method for precisely punching a plurality of glasses according to the fourth embodiment of the present invention.

FIG. 10 is a schematic process diagram showing a method for precisely punching a plurality of glasses according to Embodiment 4 of the present invention.

FIG. 11 is a schematic view showing a method for manufacturing a conventional magnetic disk glass substrate.

FIG. 12 is a schematic view showing a conventional method for manufacturing a ferrule for an optical fiber connector.

[Explanation of symbols]

11, 71 Protrusion mold 12, 22, 42, 62, 72, 82, 102 Molding material 13, 23, 43, 63, 73, 83, 103 Flat mold 14, 25, 44, 65, 74, 85, 104 Surfaces to be polished 15, 26, 45, 66, 75, 86, 105 Formed through holes 21, 81 Ferrule molding protrusion dies 24, 54, 64, 84 Outer shape regulating body dies 31, 51, 91 Master dies Molds 32, 52, 92 Glass materials for replica molds 33, 53, 93 Flat base materials 34, 55, 94 Bonding surfaces 35, 56, 95 Precious metal alloy protective films 41, 101 Protrusion replica molds 61 Magnetic disk glass substrate molding Projection replica mold 111 Outer upper mold 112 Outer lower mold 113 Inner upper mold 114 Inner lower mold 115 Molding material 121 Base mold 122 Core pin 123 Amorphous financial solution

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) G11B 5/84 G11B 5/84 Z (72) Inventor Shoji Nakamura 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F-term (reference) 2H036 QA12 QA17 QA20 4G059 AA09 AB11 AC30 DA03 5D112 AA02 AA24 BA03 BA10

Claims (13)

[Claims] 1. A molding material made of glass is sandwiched between a molding die having a highly accurate projection shape having a required hole depth or more and a flat mold, and the molding material is deformed. Heat up to a temperature that is possible, press-mold it, form a dent that precisely replicates the inverted shape of the protrusion, cool it, and release it from the mold. Until the thickness reaches the specified hole depth, the flat surface side A method for precision drilling of glass, which comprises a step of polishing from. 2. The thermal expansion coefficient of the molding material made of glass is smaller than the thermal expansion coefficient of a molding die having a highly accurate projection shape having a required hole depth or higher. Item 2. A method for precision drilling of glass according to Item 1. 3. A molding die and a flat metal having a molding material made of glass, having a projection shape that is an inverted shape of the through hole shape of a high-precision ferrule for an optical fiber connector having a height not less than a required hole depth. It is sandwiched between a mold and a ring-shaped body mold for regulating the outer shape, which is heated to a temperature at which the molding material can be deformed and press-molded to form a recess in which the inverted shape of the protrusion shape is precisely transferred. Then, the method for producing a ferrule for an optical fiber connector, which comprises the steps of cooling and releasing from the mold, and polishing from a flat surface side to a thickness that provides a predetermined hole depth. 4. A master die having a highly accurate through hole or groove shape having a depth equal to or greater than a required hole depth and a flat base material made of a glass material having heat resistance higher than that of the glass forming material. Sandwiched between the glass material and heated to a temperature at which the glass material can be deformed, and press-formed to form protrusions that accurately transfer the inverted shape of the through-hole or groove, and also to join the flat base material and cool it. And mold release from the mold, and then forming a replica metal mold having a highly precise projection shape with a height higher than the required hole depth by forming a precious metal alloy thin film on the surface, and molding from the glass Sandwiching the molding material between the replica mold and the flat mold, heating to a temperature at which the molding material can be deformed, and press-molding to form a recess in which the inverted shape of the protrusion shape is precisely transferred. Cooling, releasing from the mold, A method for precision drilling of glass, comprising a step of polishing from a flat surface side up to a thickness that is a hole depth. 5. A glass material having a glass transition temperature equal to or higher than the molding temperature of the molding material made of the glass is used as the glass material having higher heat resistance than the molding material made of the glass. 4. The method for precision drilling of glass according to 4. 6. A crystallized glass having a heat-resistant temperature after crystallization that is equal to or higher than the molding temperature of the molding material made of glass is used as the glass material having better heat resistance than the molding material made of glass. The method for precision drilling of glass according to claim 4. 7. A master die having a highly accurate through hole or groove shape having a depth equal to or greater than a required hole depth and a flat base material are made of a glass material having heat resistance higher than that of the glass forming material. Sandwiched between the glass material and heated to a temperature at which the glass material can be deformed, and press-formed to form protrusions that accurately transfer the inverted shape of the through-hole or groove, and also to join the flat base material and cool it. After releasing from the mold, Pt, Pd, Ir, R are used as noble metal alloy thin films formed on the surface.
At least one of h, Os, Ru, Re, W, and Ta
The method for precision drilling of glass according to claim 4, wherein an alloy containing more than one kind of metal is used. 8. A master die having a highly accurate through hole or groove shape having a depth equal to or larger than a necessary hole depth and a flat base material are made of a glass material having heat resistance higher than that of the glass forming material. Sandwiched between the glass material and heated to a temperature at which the glass material can be deformed, and press-formed to form protrusions that accurately transfer the inverted shape of the through-hole or groove, and also to join the flat base material and cool it. 5. The precision hole of glass according to claim 4, wherein after releasing from the mold, an intermediate film containing a component of the precious metal alloy thin film and a component of the glass material is formed on the surface, and then the precious metal alloy thin film is formed. How to open. 9. A glass material having higher heat resistance than a molding material made of glass, having a highly precise through hole or groove shape having a depth equal to or larger than a necessary hole depth, and polishing the surface to a super smooth surface. It is sandwiched between a processed master die and a flat base material, and is heated to a temperature at which the glass material can be deformed through a ring-shaped body die for regulating the outer shape, and press-formed to form a through hole or groove. Highly accurate projection shape with a height higher than the required hole depth by forming a projection in which the inverted shape of is accurately transferred, cooling and releasing from the mold, and then forming a precious metal alloy thin film on the surface. And a step of producing a replica mold having excellent surface smoothness, and a molding material made of glass, through a ring-shaped body mold for outer shape regulation, with a height of a required inner hole depth or more. Between highly precise replica shape and excellent surface smoothness between replica mold and flat mold A step of sandwiching, heating to a temperature at which the molding material can be deformed, press-molding to form a recess in which the inverted shape of the projection shape is precisely transferred, cooling and releasing from the mold, and a predetermined disk A method of manufacturing a magnetic disk glass substrate, comprising a step of polishing from a flat surface side up to a thickness. 10. A molding material made of glass is sandwiched between a molding die having a plurality of highly accurate projection shapes having a height equal to or larger than a required hole depth and a flat mold, and the molding material is formed. Is heated to a temperature at which it can be deformed, press-molded to form dents in which the inverted shapes of multiple protrusions are precisely transferred, and then mold-released at the same temperature and cooling, and a predetermined hole depth. A method for precision drilling of glass, comprising the step of polishing from a flat surface side up to a thickness of 11. A molding die comprising a molding material made of glass and having a plurality of protrusion shapes which are the inverted shapes of the through-hole shapes of a high-precision ferrule for an optical fiber connector having a height not less than a required hole depth. A dent that is sandwiched between a flat mold and heated to a temperature at which the molding material can be deformed through a body shape regulating die, and press-molded to precisely transfer the inverted shapes of multiple protrusions. The method for producing a ferrule for an array-shaped optical fiber connector, which comprises the steps of forming a mold, releasing the mold at the same temperature, and then cooling, and polishing from a flat surface side to a thickness that provides a predetermined hole depth. . 12. A master die having a highly accurate through hole or groove shape having a depth of a plurality of required hole depths or more and a flat substrate made of a glass material having heat resistance higher than that of the glass forming material. It is sandwiched with a material, heated to a temperature at which the glass material can be deformed, and press-formed to form projections in which a plurality of through-holes or inverted shapes of grooves are precisely transferred, and a flat base material is formed. A replica mold that has a highly precise projection shape with a height higher than the required multiple hole depths by joining, releasing from the master mold without cooling, and forming a precious metal alloy thin film on the surface after cooling. And a molding material made of the glass is sandwiched between the replica mold and a flat mold, heated to a temperature at which the molding material can be deformed, press-molded to form a plurality of protrusions. Form a recess that is a precise transfer of the inverted shape of the shape. Precision drilling method for glass, characterized by comprising the steps of cooling, and releasing from the replica mold at the same temperature, followed by cooling, and polishing from the flat surface side to a thickness of a predetermined hole depth. . 13. The press molding in an atmosphere in which an inert gas such as N ₂ or Ar is mixed with a gas containing C or F in its constituent molecule or a mist-like liquid. 12. The method for precision drilling of glass according to item 12.