JP2003146672A - Substrate molding apparatus and middle die for molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate molding die which secures a high releasability irrespective of the presence or absence of a recess, and in which a load of maintenance is reduced. SOLUTION: In a substrate molding apparatus in which a lower die 12 faces an upper die 14, a middle die 21 having a direct molding action is placed on the lower die 12 as a new die element. A through hole 21a is formed in the central part of the middle die 21 in the case of molding a glass substrate 31 with a shaft-shaped projected part 31a. The middle die 21 consists of a noble metal or a noble metal alloy (an alloy essentially consisting of a noble metal) in order to make a releasing layer unnecessary.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate molding apparatus for manufacturing a substrate by press molding, and a molding medium die used in the substrate molding apparatus.

[0002]

2. Description of the Related Art In recent years, the adoption of glass substrates as substrates for information recording media has become a technical trend. A magnetic disk is one of the typical examples of the information recording medium.

In recent years, magnetic disks have been rapidly increased in recording density. In the magnetic disk device,
Random access is realized by slightly moving a recording / reproducing head over a magnetic disk that rotates at a high speed for scanning. In order to achieve both high recording density and high-speed access, increase the rotation speed of the magnetic disk,
It is required to reduce the distance between the magnetic disk and the head (head flying height). Conventionally, as a substrate material for a magnetic disk, a substrate made of Ni-P plating on aluminum has been the mainstream, but in recent years, a glass having a high surface smoothness that is hard to be deformed even when rotated at a high speed due to its high rigidity. Substrates have come into use.

Conventionally, a method of manufacturing a glass substrate for an information recording medium has been a polishing method. That is, after cutting into a predetermined size, precision polishing is performed to obtain a smooth surface.

However, the polishing method has a problem that extremely high precision is required for polishing, the number of steps is large, and the obtained glass substrate is very expensive.

Therefore, recently, a press molding method has been adopted. The press molding method is well known for optical glass products, but the press molding method for optical glass cannot be simply applied as it is to the production of a glass substrate for an information recording medium. This is because the required accuracy of surface flatness and surface smoothness is completely different.

FIG. 7 is a sectional view showing a schematic structure of a conventional substrate molding die. 50 is a lower presser, 51 is a lower heater block, 52 is a lower mold, 53 is a body mold, 54
Is an upper die, 55 is an upper heater block, 56 is an upper pusher, and 57 is a cylinder piston. The heater block 51 is fixed on the presser 50,
A lower mold 52 is fixed on the top. The lower mold 52 is composed of a mold base portion 52a and a molding convex portion 52b having a smaller diameter than that, and is fitted to the outer peripheral surface of the molding convex portion 52b in an externally fitted state.
3 is mounted on the upper surface of the mold base 52a. Upper mold 5
4 is fixed to the lower surface of the upper heater block 55, the heater block 55 is fixed to the lower surface of the upper presser 56,
The pusher 56 is attached to the cylinder piston 57. The upper mold 54 is composed of a mold base portion 54a and a molding convex portion 54b having a diameter smaller than that of the base portion 54a.
It can be inserted and removed freely. The lower surface of the mold base portion 54a of the upper mold 54 is in contact with the upper surface 53a of the body mold 53, so that the lower limit of movement of the upper mold 54 is determined.

The base materials of the lower mold 52 and the upper mold 54 are made of tungsten carbide. Release layers 58 and 59 are formed on the surfaces of the respective molding protrusions 52b and 54b.

A cylinder (not shown) of the cylinder piston 57 contracts, and together with the cylinder piston 57, the pressing element 56, the heater block 55, and the upper mold 54 as a whole move upward to perform mold opening. In this state, the glass material 60 is placed on the lower mold 52.

Then, the cylinder is extended, and the pressing element 56, the heater block 55 and the upper die 54 are moved downward together with the cylinder piston 57. The molding convex portion 54b of the upper mold 54 is inserted into the body mold 53 while being guided to the inner peripheral surface of the body mold 53, and the molding surface 54c of the upper mold 54 is moved to the lower mold 5.
It comes into contact with the glass material 60 placed on the second molding surface 52c. This is the state shown in FIG.

A glass material 60 is attached to a lower mold 52 and an upper mold 54.
The heaters 51a, 55a of the upper and lower heater blocks 51, 55 are energized in a state of being sandwiched by and pressed with a comparatively small force, and the respective heat generations generate a lower mold 52 and an upper mold 54.
Is heated to preheat the glass material 60.

When the temperature of the glass material 60 rises above the glass transition point Tg to near the glass softening point Ts by this preheating, the pressing process starts.

That is, the cylinder is further extended and further moved downward while the upper die 54 is guided by the body die 53, and as shown in FIG. 8, the molding surface 52c of the lower die 52.
The glass material 60 is heated and pressed by the molding surface 54c of the upper mold 54. The downward movement of the upper die 54 is restricted by the lower surface of the die base 54a contacting the upper surface 53a of the body die 53. As a result, the glass material is formed into the flat flat glass substrate 61. The thickness of the glass substrate 61 is determined by the contact between the mold base 54a and the body mold 53.

Then, the process proceeds to the cooling process. The energization of the heaters 51a and 55a in the heater blocks 51 and 55 is cut off to lower the temperature of the glass substrate 61. When the temperature drops to a predetermined temperature, the mold is opened and the glass substrate 61 is taken out.

In the above, since the glass material is heated and pressed at high temperature and high pressure, the softened glass material and the molding surface of the mold come into close contact with each other, and the glass material easily adheres to the molding surface. As a countermeasure against this, release layers 58 and 59 are formed on the surfaces of the molding protrusions 52b and 54b of the lower mold 52 and the upper mold 54, respectively. The release layers 58 and 59 form a molding surface for the glass material 60, and facilitate the mold release after the molding in the heating and pressing state.

By the way, recently, as a glass substrate for a high recording density hard disk, as shown in FIG.
As shown in (b), a shaft-shaped convex portion 61a is formed at the center on the back surface side.
A disk-shaped glass substrate 61 that integrally has is used.

FIG. 10 shows a schematic structure of a substrate molding apparatus for molding a glass substrate having such a shaft-shaped convex portion.
Instead of the lower mold 52 having a flat molding surface in the case of FIGS. 7 and 8, a lower mold 62 having a recess 62u in the center is used.

The lower mold 62 has a mold base portion 62a and a molding convex portion 62b having a smaller diameter than that, and a concave portion 62u is formed at the center of the surface of the molding convex portion 62b. The recess 62u is for molding the shaft-shaped protrusion 61a in the glass substrate 61. On the surface of the molding convex portion 62b,
The release layer 63 is formed including the inner surface of the recess 62u. The release layer 63 has a surface flat region 63a on the flat surface of the molding projection 62b and a release layer recess region 63b corresponding to the recess 62u.

[0019]

In the case of the substrate forming apparatus shown in FIGS. 7 and 8, the release layers 58 and 59 are deteriorated or peeled off due to thermal deterioration, oxidation or chemical change in long-term use. If this happens, high precision and good quality molding of the glass substrate will be hindered, so it is necessary to interrupt the molding work and perform maintenance of the release layer. That is, it is necessary to remove the mold release layer which is deteriorated or partially peeled, and to newly form a mold release layer. If this happens, the productivity will be significantly reduced and the cost of the product will increase.

A lower mold 62 having a recess 62u shown in FIG.
In the case of the substrate forming apparatus having the above, there are the following problems in addition to the above problems in maintenance. Figure 1
As shown in FIG. 1, in the release layer recess region 63b corresponding to the recess 62u in the release layer 63, in the film formation,
It is difficult to make the film thickness uniform.

Generally, the film is formed by sputtering,
Due to the difference between the distance from the target to the surface flat region 63a and the distance to the release layer recess region 63b, the accuracy of film formation tends to be low in the release layer recess region 63b.

Further, also in the release layer recessed region 63b, the bottom portion a and the peripheral wall portion b are likely to have a non-uniform film thickness. In the refraction portion c at the boundary between the bottom surface portion a and the peripheral wall portion b and the refraction portion d at the boundary between the peripheral wall portion b and the surface flat region 63a,
In particular, the shape accuracy is likely to decrease.

Further, the release layer recessed region 63b tends to be inferior in strength as compared with the surface flat region 63a, and deterioration in the release layer recessed region 63b is likely to proceed in long-term use.

Due to one or a combination of any of the above plurality of factors, the shape accuracy and dimensional accuracy of the axial convex portion 61a of the glass substrate 61 are likely to be low.

In a long-term use, the release layer recessed region 63b is apt to deteriorate or peel off. In such a case, it is possible to form a glass substrate having a shaft-shaped protrusion with high accuracy and good quality. It causes trouble. In particular, when the shape accuracy and the dimensional accuracy of the shaft-shaped convex portion are lowered, when an information recording medium is manufactured, the recording / reproducing performance of the information recording medium is seriously affected.

If the shape and size of the shaft-shaped convex portion are abnormal, the information recording medium rotating at a high speed is likely to be vibrated or corrugated. Further, if the central axis of the axial convex portion deviates from the accurate normal direction to the glass substrate surface, the information recording medium causes a precession movement (swinging movement of the top).

The recording / reproducing head floats on the air flow generated on the surface of the information recording medium that rotates at a high speed, and the floating keeps a constant distance from the surface of the information recording medium. This is called the levitation characteristic. When the information recording medium undergoes the above-mentioned vibration, waviness, precession, etc., the levitation characteristic of the head deteriorates.

The floating distance is called spacing.
Poor flying characteristics impose restrictions on the improvement of the recording density of the information recording medium. The higher the recording density, the smaller the spacing, and if the flying characteristics are poor in that state,
The slider on which the head is mounted may hit or crash the information recording medium.

In the first place, the reason why the glass substrate is provided with the axial convex portion is to promote the high recording density of the information recording medium. Nevertheless, if the above-mentioned problems remain in the substrate molding apparatus for press-molding the glass substrate, which is a component of the information recording medium, the high performance of the information recording medium is ultimately caused. This may impose a great limitation on increasing the recording density.

The present invention was devised in view of such circumstances, and in general, regardless of the presence or absence of a recess,
An object of the present invention is to provide a substrate molding die that can reduce the burden of maintenance while ensuring high mold releasability.

It is another object of the present invention to provide a substrate forming apparatus suitable for manufacturing a substrate having a shaft-shaped convex portion.

[0032]

[Means for Solving the Problems] (1) The present invention with respect to a substrate forming apparatus is achieved by taking the following means.
The above problems are solved.

There is a pair of molds facing each other, and a middle mold for molding is installed on one of these molds. This middle die faces the other die. Then, the medium size is made of a noble metal or an alloy containing the noble metal as a main component. Hereinafter, an alloy containing a noble metal as a main component is abbreviated as “noble metal alloy”. A molding material is pressed by the middle mold and a mold facing the middle mold to mold the substrate.

In the prior art, the release layer was formed on the surface of the base metal of the base metal not containing the noble metal as the main component, whereas in the present invention, the noble metal or the noble metal is formed. By using a medium size alloy, the need for a release layer is eliminated. This can eliminate the above-mentioned various inconveniences caused by separately forming the release layer.

The medium type made of a noble metal or noble metal alloy is
Even if a release layer is not separately formed on the surface, the surface itself has a sufficiently large releasability. In the case of the conventional technique, there is a problem that the release layer is easily peeled off due to the difference in thermal expansion coefficient between the mold base material and the release layer. . On the other hand, the middle-sized mold made of a noble metal or a noble metal alloy may have a single layer structure because it has releasability. No release layer is required and therefore there is no problem of release layer peeling.

The medium size made of precious metal or precious metal alloy is
Compared with the conventional mold base material containing base metal as the main component,
It has sufficiently high resistance to thermal deterioration, oxidation, chemical changes, etc.

When the release layer is peeled off or deteriorated, the work of pressing the substrate, the work of removing the deteriorated release layer, and the work of re-deposition of a new release layer are inevitable for maintenance. However, in the case of the present invention, such concerns are greatly reduced. Although adopting a medium-sized precious metal or precious metal alloy is a burden for initial investment, it is possible to improve productivity and reduce product cost in long-term use because of its maintenance-free property as described above. .

(2) Another embodiment of the substrate forming apparatus according to the present invention is to solve the above problems by taking the following means.

There is a pair of molds facing each other, and the middle mold is placed on one of these molds. This middle die faces the other die. The middle mold is formed with a recess for forming a shaft-shaped protrusion on the substrate which is a molded product. Further, the middle die is made of a noble metal or a noble metal alloy (alloy containing noble metal as a main component) including the recessed region.

The recess in the middle die is for integrally forming a shaft-shaped protrusion on the substrate, but since the entire middle die is made of a noble metal or a noble metal alloy including the area of this recess. is there. The axial length of the axial projection depends on the depth of the recess.

In the case of the prior art, the release layer film formation in the release layer recessed region tends to have a non-uniform film thickness, and the shape accuracy and the dimensional accuracy of the shaft-shaped convex portion are low. In the case of invention,
Since the entire medium size including the recess is a noble metal or a noble metal alloy, the release layer is unnecessary even in the recess. As described above, since there is no separate release layer, problems such as uneven film thickness and deterioration of shape at the boundary refraction portion do not occur. The shape accuracy and the dimensional accuracy of the recess are high, so that the shape accuracy and the dimensional accuracy of the shaft-shaped convex portion can be improved. This, in turn, makes it easy to obtain good floating characteristics when an information recording medium is manufactured using a molded substrate, and thus contributes to increasing the recording density of the information recording medium. There is also the action of (1) above.

(3) According to the present invention of a substrate forming apparatus of still another aspect, by taking the following means,
The above problems are solved.

There is a pair of molds facing each other, and the middle mold is placed on one of these molds. This middle die faces the other die. A through hole for forming a shaft-shaped convex portion on a substrate, which is a molded product, is formed in the middle mold in a state of facing the molding surface of the mold on the side where the middle mold is installed. Furthermore, this medium size, including the area of the through hole,
Noble metal or noble metal alloy (alloy containing noble metal as main component)
It consists of.

The molding surface of the mold is exposed in the inner part of the through hole in the middle mold, and the molding surface of the mold in the region of the through hole becomes the molding surface for the shaft-shaped convex portion of the substrate. The entire medium size is made of noble metal or noble metal alloy, including the through hole region. The axial length of the axial convex portion depends on the depth of the through hole, that is, the thickness of the medium size.

In the case of the prior art, the release layer film formation in the release layer recessed region is likely to have a non-uniform film thickness, and the shape accuracy and the dimensional accuracy of the axial convex portion are lowered. In the case of invention,
Since the entire medium size including the through holes is a noble metal or noble metal alloy, the release layer is not necessary even in the through holes. As described above, since there is no separate release layer, problems such as uneven film thickness and deterioration of shape at the boundary refraction portion do not occur. The through hole has high shape accuracy and dimensional accuracy, and therefore, the shape accuracy and dimensional accuracy of the shaft-shaped convex portion can be improved. Although the material of the molding surface itself of the die behind the through hole is not mentioned, it does not have to be a noble metal or noble metal alloy.

What is important for the axial convex portion in order to prevent the information recording medium rotating at a high speed from vibrating or corrugating is to sufficiently enhance the shape accuracy and dimensional accuracy of the peripheral surface of the information recording medium. This is because the end face does not need to be so accurate. This, in turn, makes it easy to obtain good floating characteristics when an information recording medium is manufactured using a molded substrate, and thus contributes to increasing the recording density of the information recording medium. There is also the action of (1) above.

In any of the above (1) to (3),
By exchanging the middle mold according to the specification change of the board to be molded, the main body of the board molding machine can be allowed for the manufacture of boards with multiple specifications, improving productivity and reducing capital investment. Can be planned.

As a preferred embodiment in the above (1) to (3), the following can be mentioned with respect to the noble metal constituting the medium size. That is, iridium (Ir), platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), osmium (O
s), at least 1 selected from the group of rhenium (Re)
The medium size is made up of a precious metal containing seed components.

These noble metals are excellent in corrosion resistance and have sufficiently high releasability.

Alternatively, as a preferred embodiment in the above (1) to (3), the following can be mentioned with respect to the noble metal alloy constituting the medium size. That is, at least one component selected from the group of iridium (Ir), platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), osmium (Os), and rhenium (Re), and chromium. The medium size is made of an alloy composed of a combination of at least one component selected from the group consisting of (Cr) and aluminum (Al).

When the noble metal of each of the above components is used alone to form a medium size, there is a possibility that the problems of roughening and abrasion of the noble metal film due to long-term use may still remain. When chromium or aluminum is combined with a noble metal to form a noble metal alloy, the noble metal film becomes rougher than when noble metal alone is used.
Abrasion can be suppressed. In particular, when the molding material is a glass material, oxidation occurs due to the water content in the glass, but if a precious metal alloy containing chromium or aluminum is used, the toughness is improved as compared with the case where only chromium oxide is used. Since the outermost surface of the medium-sized molding surface is coated with an oxide of Cr or Al, it exhibits excellent releasability with respect to glass.

In the above, the preferred embodiment further comprises
It is equipped with the following body dies. It is fitted on either one of the above-mentioned molds, and the inside mold is fitted inside to regulate the position, and when the mold is clamped, the other mold is brought into contact to regulate the position. It defines the mold clamping dimensions. Although the structures of the lower mold, the upper mold, and the body mold are also conventional techniques, here, it is described that the above-described middle mold is further added to the substrate molding apparatus having such a structure. As the medium size, (1) above
The flat plate-shaped one, the recessed part (2) above, or the through-hole (3) above may be used. The body mold defines the relative positional relationship among the lower mold, the upper mold, and the middle mold. It also defines the thickness of the substrate to be molded. In addition, the escape of heat during heating and pressurization is suppressed, and a rapid temperature rising characteristic is obtained.

In the above, the preferred embodiment refers to the constituent material of the base material of each mold member other than the middle mold among the mold members of the above-mentioned pair of mold, middle mold, and body mold.

As one embodiment, a preferable example can be given in which the die base material is a cemented carbide containing tungsten carbide (WC) as a main component. In this case, the corrosion resistance and wear resistance can be made excellent.

In another embodiment, the mold base material is made of titanium nitride (TiN) or titanium carbide (Ti).
C), chrome carbide (Cr ₃ C ₂ ), alumina (Al
A preferred example is a cermet containing ₂ O ₃ ) as a main component. Cermet is a composite material composed of ceramic and sintered metal. In this case, the corrosion resistance, heat resistance and wear resistance can be made excellent.

In still another embodiment, the mold base material is alumina (Al ₂ O ₃ ) or silicon carbide (Si).
C), chrome carbide (Cr ₃ C ₂ ), silicon nitride (Si
A preferable example is at least one ceramic selected from the group consisting of ₃ N ₄ ) and boron nitride (BN). Also in this case, the corrosion resistance, heat resistance and wear resistance can be made excellent.

In the above, a preferable embodiment is that the mold release layer is formed on at least the molding surface of the pair of molds. Suitable examples can be given. As for the medium-sized mold, the problem as described above is solved by using this as a noble metal or noble metal alloy, but if even the pair of molds is made of noble metal or noble metal alloy, the cost burden becomes too large. . Therefore, with respect to the pair of molds, the mold release properties are ensured by forming these molds from different materials and forming a mold release layer.

In the above, a preferable embodiment is that the mold layer is formed with a release layer on at least the inner peripheral surface thereof. Regarding the body metal mold, the above problems can be solved by making it a noble metal or a noble metal alloy, but if the body metal mold is also made of a noble metal or noble metal alloy, the cost burden becomes large. Too much. Therefore, for the body mold, by forming it from another material and forming the release layer,
Ensure releasability. The molded product is not always molded by the body mold, but depending on the conditions, the molding material may be positionally regulated by the body mold to be subjected to the molding action. In that case, the releasability is secured.

In the above, in a preferred embodiment, the release layer for the pair of molds or the mold is made of silicon (S
i), nickel (Ni), chromium (Cr), titanium (T
i), niobium (Nb), vanadium (V), molybdenum (Mo), platinum (Pt), palladium (Pd), iridium (Ir), rhodium (Rh), osmium (O)
s), ruthenium (Ru), rhenium (Re), tungsten (W), and tantalum (Ta), the release layer may be composed of at least one component selected from the group. In this case, excellent releasability can be secured.

Alternatively, in the above, in a preferred embodiment, silicon (Si), nickel (Ni), chromium (Cr), titanium (Ti), niobium (Nb) is used for the mold release layer of the pair of molds or body molds. , Vanadium (V), molybdenum (Mo), platinum (Pt), palladium (Pd),
Main component is at least one component selected from the group consisting of iridium (Ir), rhodium (Rh), osmium (Os), ruthenium (Ru), rhenium (Re), tungsten (W), and tantalum (Ta). It can be mentioned that the release layer is made of an alloy. In this case, more excellent releasability can be secured.

Alternatively, in the above, in a preferred embodiment, alumina (Al ₂ O ₃ ), silicon carbide (SiC), chrome carbide (Cr ₃ C ₂ ) is used for the release layers of the pair of molds or body molds. The release layer may be formed of at least one component selected from the group consisting of silicon nitride (Si ₃ N ₄ ) and boron nitride (BN). Also in this case, excellent releasability can be secured.

Although the above is the invention concerning the substrate molding apparatus, the invention is constituted by the medium size alone.

The present invention for the medium size solves the above-mentioned problems by taking the following means. That is, in the substrate molding apparatus, a middle mold installed on one of a pair of molds facing each other and facing the other mold, the whole of which is made of a noble metal or a noble metal as a main component. Composed of alloy. By adopting this middle-sized mold, it is possible to realize a high mold-releasing property, realize a maintenance-free property, improve productivity, and reduce costs.

In the above, as the mode of the medium size, there is one in which a recess is formed in the central portion. Alternatively,
Some have a through hole formed in the center thereof.

With respect to the base material constituting the medium size, iridium (Ir), platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), osmium (Os) and rhenium are preferred. (R
The medium size may be constituted by a noble metal containing at least one component selected from the group e).

Alternatively, with respect to the base material constituting the medium size, in a preferred embodiment, iridium (Ir), platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), osmium (Os), rhenium (R
The alloy may be composed of a combination of at least one component selected from the group e) and at least one component selected from the group of chromium (Cr) and aluminum (Al). .

In the above, the present invention is particularly suitable for manufacturing a glass substrate for an information recording medium such as a magnetic recording medium, particularly a glass substrate having a shaft-shaped convex portion. However, it may be applied to a glass substrate having no axial convex portion or may be applied to a substrate made of a material other than glass.

[0068]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a substrate molding apparatus according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view showing a schematic structure of a substrate forming apparatus according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view showing an essential part of the substrate forming apparatus shown in FIG. 10 is a lower presser, 11 is a lower heater block, 11a is a heater embedded in the heater block 11, 12 is a lower die, 1
3 is a body mold, 14 is an upper mold, 15 is an upper heater block, 15a is a heater embedded in the heater block 15, 16 is an upper pressing member, 17 is a cylinder piston, 1
8, 19 and 20 are release layers, and 21 is a medium size.

A heater block 11 is fixed on the pressing element 10, and a lower die 12 is fixed on the heater block 11. The lower mold 12 is composed of a mold base portion 12a and a molding convex portion 12b having a smaller diameter than that, and the body mold 13 is placed on the upper surface of the mold base portion 12a while being fitted onto the outer peripheral surface of the molding convex portion 12b. Has been done. The upper die 14 is the upper heater block 15
The heater block 15 is fixed to the lower surface of the upper pressing element 16, and the pressing element 16 is attached to the cylinder piston 17. The upper mold 14 is the mold base 1
4a and a molding convex portion 14b having a smaller diameter than that, and the molding convex portion 14b can be inserted into and removed from the body metal mold 13. The lower movement limit of the upper mold 14 is determined by the lower surface of the mold base 14a of the upper mold 14 contacting the upper surface 13a of the body mold 13. The base materials of the lower mold 12 and the upper mold 14 are made of tungsten carbide. Release layers 18, 19 are formed on the surfaces of the respective molding protrusions 12b, 14b.
Is deposited. The body material of the body die 13 is also made of tungsten carbide, and the release layer 20 is formed on the inner peripheral surface thereof.

In this embodiment of the present invention, in the substrate forming apparatus having the above-described structure, the middle mold 21 of the noble metal or the noble metal alloy is prepared as a new component, and the middle mold 21 is placed inside the body mold 13. In, the lower mold 12 is placed on the upper surface of the molding surface 12c.

FIG. 3 shows the shape of the middle die 21. Figure 3 (a)
Is a plan view, FIG. 3 (b) is a sectional view, and FIG. 3 (c) is a perspective view. The middle die 21 has a through hole 21a formed at the center thereof so as to vertically pass therethrough. The middle die 21 is the lower die 12
However, the molding surface 12c of the lower mold 12 is exposed in the through hole 21a. The molding surface 12c is the surface of the release layer 18.

Lower mold 12, upper mold 14 and body mold 13
For, the following can be cited as the mold base material.

(A) A cemented carbide whose main component is tungsten carbide (WC).

(B) Titanium nitride (TiN), titanium carbide (TiC), chrome carbide (Cr ₃₎
C ₂ ), a cermet containing alumina (Al ₂ O ₃ ) as a main component.

(C) Alumina (Al ₂ O ₃ ), Silicon Carbide (SiC), Chromium Carbide (Cr ₃ C ₂ ),
At least one ceramic selected from the group consisting of silicon nitride (Si ₃ N ₄ ) and boron nitride (BN).

Lower die 12, upper die 14 and body die 13
Releasing layers 18, 19 and 20 are formed on each of the above. The releasing layers include the following.

(A) Silicon (Si), nickel (N
i), chromium (Cr), titanium (Ti), niobium (N
b), vanadium (V), molybdenum (Mo), platinum (Pt), palladium (Pd), iridium (Ir),
At least one component selected from the group consisting of rhodium (Rh), osmium (Os), ruthenium (Ru), rhenium (Re), tungsten (W), and tantalum (Ta).

(B) Silicon (Si), nickel (N
i), chromium (Cr), titanium (Ti), niobium (N
b), vanadium (V), molybdenum (Mo), platinum (Pt), palladium (Pd), iridium (Ir),
An alloy containing as a main component at least one component selected from the group consisting of rhodium (Rh), osmium (Os), ruthenium (Ru), rhenium (Re), tungsten (W), and tantalum (Ta).

(C) Alumina (Al ₂ O ₃ ), Silicon Carbide (SiC), Chrome Carbide (Cr ₃ C ₂ ),
At least one component selected from the group consisting of silicon nitride (Si ₃ N ₄ ) and boron nitride (BN).

The release layer is formed by a sputtering method or the like, and the thickness thereof is 0.2 to 1.5 μm, preferably
It is around 0.5 μm.

When the middle die 21 is made of a noble metal, the following can be given as the noble metal.

(A) Iridium (Ir), platinum (P
t), palladium (Pd), rhodium (Rh), ruthenium (Ru), osmium (Os), rhenium (Re)
A noble metal containing at least one component selected from the group of.

Alternatively, when the middle die 21 is made of a noble metal alloy, the following can be given as the noble metal alloy.

(B) Iridium (Ir), platinum (P
t), palladium (Pd), rhodium (Rh), ruthenium (Ru), osmium (Os), rhenium (Re)
At least one component selected from the group of
r), an alloy composed of a combination with at least one component selected from the group of aluminum (Al).

Next, the operation of the substrate forming apparatus according to the embodiment configured as described above will be described.

A cylinder (not shown) of the cylinder piston 17 contracts, and together with the cylinder piston 17, the pressing element 16, the heater block 15 and the upper die 14 are entirely moved upward to open the die. In this state (see the state of the chain double-dashed line in FIG. 2), the spherical glass material 30 is placed on the middle mold 21. At this time, a part of the glass material 30 is dropped into the through hole 21a in the center of the middle die 21.

Next, the cylinder is extended, and the pusher 16, the heater block 15 and the upper die 14 are moved downward together with the cylinder piston 17. The molding convex portion 14b of the upper mold 14 is inserted into the body mold 13 while being guided to the inner peripheral surface of the body mold 13, and the molding surface 14c which is the surface of the release layer 19 of the upper mold 14 is It contacts the glass material 30 placed on the middle mold 21. This is the state shown by the solid lines in FIGS.

While the glass material 30 is pressed by the middle mold 21 and the upper mold 14 with a comparatively small force, each heater of the upper and lower heater blocks 11 and 15 is energized, and the respective heat generation causes the lower mold 12 and the middle mold. 21 and the upper mold 14 are heated,
The glass material 30 is preliminarily heated.

When the temperature of the glass material 30 exceeds the glass transition point Tg to near the glass softening point Ts by this preheating, the pressing step is started.

That is, the cylinder is further extended and further moved downward with the upper mold 14 being guided by the body mold 13, and as shown in FIG. 4, the molding surface 21b of the middle mold 21 and the upper mold 14 are separated. The glass material 30 is heated and pressed while being sandwiched by the molding surface 14c. The downward movement of the upper mold 14 is restricted by the lower surface of the mold base 14a contacting the upper surface 13a of the body mold 13. As a result, the glass material 30 is formed into the glass substrate 31 with the shaft-shaped convex portions 31a. The contact between the mold base 14a and the body mold 13 determines the thickness of the glass substrate 31.

More specifically, as shown in FIG. 5, the glass material 30 softened by heating is pressed by the medium size 2
It is pushed into the first through hole 21a and is shaped in accordance with the shape of the through hole 21a.

Unlike the prior art, there is no release layer in the through hole 21a, and there is no problem of nonuniform film thickness of the release layer. Medium size 21 made of precious metal or precious metal alloy
Through the through hole 21a even on the molding surface 21b of the surface.
Also on the inner peripheral surface 21a ₁ of the above, the noble metal or the noble metal alloy forming the same directly contacts the glass material 30. Here, the problem of deterioration and peeling of the release layer does not occur.
Even after long-term use, the inner peripheral surface 21a ₁ of the through hole 21a does not deteriorate or peel off. Inner peripheral surface 21a of the through hole 21a
The refraction portion e at the lower end of ₁ and the refraction portion f at the boundary between the inner peripheral surface 21a1 and the surface molding surface 21b maintain the original shape accuracy of the right angle thereof even in long-term use. Therefore, in press-molding the glass substrate 31 with the shaft-shaped protrusions 31a, the shape accuracy and the dimensional accuracy of the shaft-shaped protrusions 31a can be maintained with high accuracy.

When the above pressing process is completed, then,
Proceed to the cooling process. Energization to the heaters 11a and 15a in the heater blocks 11 and 15 is cut off, and the shaft-shaped convex portion 31a
The temperature of the attached glass substrate 31 is lowered. When the temperature drops to a predetermined temperature, the mold is opened and the glass substrate 31 is taken out.

In the above embodiment, the case where the through hole 21a is provided as the middle die 21 has been described, but the present invention is not necessarily limited to this, and the middle die may have other forms. Good. For example, as shown in FIG. 6 (a), instead of the through hole, a middle mold 22 having a recess 22a with a bottom formed in the center may be used, or as shown in FIG. 6 (b). Alternatively, the middle mold 23 having a flat surface may be used. Then, if the plurality of types of medium molds are exchanged according to the specifications of the glass substrate to be molded, this can be shared by the main body of the substrate molding apparatus.

In the above description, the upper mold 14 is configured to move up and down, but instead of this, the lower mold 12 and the middle mold 21 may be moved up, or the upper and lower molds may be moved up and down. The molds may be separated from each other.

In the above description, the substrate material is glass, but the material is not limited to this and may be resin or the like.

[0098]

As described above, according to the present invention, by adopting a new medium size mold made of a noble metal or a noble metal alloy, which is more excellent in releasability than a base metal, deterioration, peeling, etc. relating to the release layer, etc. It is possible to solve the various problems described above and improve the maintenance-free property, and as a result, it is possible to improve the productivity and reduce the product cost in long-term use.

In this case, in particular, if the middle die having the through hole or the recess for molding the substrate with the axial convex portion is made of the noble metal or the noble metal alloy, the shape accuracy and the size of the axial convex portion are increased. The accuracy can be sufficiently high. This can contribute to good flying characteristics of the recording / reproducing head when the substrate with the axis is used for the information recording medium, and as a result, to high recording density of the information recording medium.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of a substrate molding apparatus according to an embodiment of the present invention.

2 is a cross-sectional view showing a main part of the substrate forming apparatus shown in FIG.

FIG. 3 is a plan view, a cross-sectional view, and a perspective view showing a middle mold of the substrate molding apparatus according to the embodiment of the present invention.

FIG. 4 is a sectional view showing the operation of the substrate molding apparatus according to the embodiment of the present invention.

5 is an enlarged cross-sectional view showing a region of a through hole in the middle die of the substrate forming apparatus shown in FIG.

FIG. 6 is a schematic explanatory view of another embodiment of the medium size according to the present invention.

FIG. 7 is a cross-sectional view showing a schematic configuration of a substrate forming apparatus according to a conventional technique.

FIG. 8 is a cross-sectional view showing an operation of a substrate forming apparatus according to a conventional technique.

FIG. 9 is a side view and a perspective view showing a substrate with an axial convex portion.

FIG. 10 is a cross-sectional view showing a schematic configuration of a substrate molding apparatus for molding a substrate with a shaft-shaped convex portion in a conventional technique.

11 is an enlarged cross-sectional view showing a release layer recessed region in the substrate molding apparatus shown in FIG.

[Explanation of symbols]

10 Lower pusher 11 Lower heater block 12 Lower mold 13 Body mold 14 Upper mold 15 Upper heater block 16 Upper pusher 17 cylinder piston 18, 19, 20 Release layer 21 Medium 21a through hole

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hidenao Kataoka             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Akihiko Okabe             1-1 Tanabe Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa             Within Fuji Electric Co., Ltd. F-term (reference) 5D121 AA02 DD04 DD18

Claims (19)

[Claims] 1. A pair of molds facing each other and a middle mold installed on one of the molds and facing the other mold, wherein the middle mold is made of a noble metal or a noble metal. A substrate forming apparatus comprising an alloy as a component. 2. A pair of molds facing each other and a middle mold installed on one of the molds and facing the other mold, wherein a recess is formed in the middle mold. The substrate forming apparatus is characterized in that the middle die is made of a noble metal or an alloy containing a noble metal as a main component. 3. A pair of molds facing each other, and a middle mold installed on one of the molds and facing the other mold, wherein the middle mold is provided with the middle mold. A through-hole that faces the molding surface of the die on the side where the metal mold is formed is formed, and the middle die is made of a noble metal or an alloy containing a noble metal as a main component. 4. The noble metal composing the medium-sized mold is composed of:
Iridium (Ir), platinum (Pt), palladium (P
d), a noble metal containing at least one component selected from the group of rhodium (Rh), ruthenium (Ru), osmium (Os), and rhenium (Re), according to any one of claims 1 to 3. The substrate forming apparatus described. 5. The medium-sized alloy is composed of iridium (Ir), platinum (Pt), and palladium (P).
d), at least one component selected from the group of rhodium (Rh), ruthenium (Ru), osmium (Os) and rhenium (Re), and selected from the group of chromium (Cr) and aluminum (Al). The substrate forming apparatus according to any one of claims 1 to 3, which is an alloy composed of a combination with at least one component. 6. A position is regulated by being fitted on one of the two molds and fitted on the middle mold.
2. A body mold for defining a mold clamping size by abutting the other mold during mold clamping to regulate its position.
The substrate forming apparatus according to any one of claims 1 to 5. 7. A base material of each of the mold members other than the middle mold among the mold members of the pair of molds, the middle mold, and the body mold is a cemented carbide containing tungsten carbide (WC) as a main component. The substrate forming apparatus according to any one of claims 1 to 6, which is an alloy. 8. Among the mold members of the pair of molds, the middle mold, and the body mold, each mold member other than the middle mold has a base material of titanium nitride (TiN) or titanium carbide (Ti).
C), chrome carbide (Cr ₃ C ₂ ), alumina (Al
The substrate forming apparatus according to claim 1, which is a cermet containing ₂ O ₃ ) as a main component. 9. A mold member other than the middle mold among the mold members of the pair of mold, middle mold, and body mold, whose base material is alumina (Al ₂ O ₃ ), silicon carbide (SiC) ,
Chromium Carbide (Cr ₃ C ₂ ), Silicon Nitride (Si
The substrate forming apparatus according to any one of claims 1 to 6, which is at least one ceramic selected from the group consisting of ₃ N ₄ ) and boron nitride (BN). 10. The substrate molding apparatus according to claim 1, wherein a mold release layer is formed on at least the molding surface of the pair of molds. 11. The substrate forming apparatus according to claim 1, wherein a release layer is formed on at least an inner peripheral surface of the body die. 12. The release layer is made of silicon (Si), nickel (Ni), chromium (Cr), titanium (Ti), niobium (Nb), vanadium (V), molybdenum (Mo). , Platinum (Pt), palladium (P
d), iridium (Ir), rhodium (Rh), osmium (Os), ruthenium (Ru), rhenium (R
The substrate forming apparatus according to claim 10 or 11, which comprises at least one component selected from the group consisting of e), tungsten (W), and tantalum (Ta). 13. The release layer is made of silicon (Si), nickel (Ni), chromium (Cr), titanium (Ti), niobium (Nb), vanadium (V), molybdenum (Mo). , Platinum (Pt), palladium (P
d), iridium (Ir), rhodium (Rh), osmium (Os), ruthenium (Ru), rhenium (R
The substrate forming apparatus according to claim 10 or 11, which is an alloy containing as a main component at least one component selected from the group consisting of e), tungsten (W), and tantalum (Ta). 14. The release layer has a constituent material of
Mina (Al₂O₃), Silicon Carbide (SiC),
ROM CARBITE (Cr₃C₂), Silicon nitride (Si ₃N_Four),
At least one compound selected from the group of boron nitride (BN)
Substrate molding according to claim 10 or 11,
apparatus. 15. A substrate molding apparatus, which is a middle mold installed on one of a pair of molds facing each other and facing the other mold, the whole of which is mainly made of noble metal or noble metal. A medium-sized mold for molding, which is composed of an alloy as a component. 16. The molding medium mold according to claim 15, wherein a recess is formed in the central portion. 17. The molding medium die according to claim 16, wherein a through hole is formed in a central portion. 18. The base material constituting the medium mold is iridium (Ir), platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), osmium (O).
s), at least 1 selected from the group of rhenium (Re)
18. A noble metal containing seed components.
The medium-sized mold for molding described in any of the above. 19. The base material constituting the intermediate mold is iridium (Ir), platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), osmium (O).
s), at least 1 selected from the group of rhenium (Re)
The alloy for molding according to any one of claims 15 to 17, which is an alloy composed of a combination of one component and at least one component selected from the group of chromium (Cr) and aluminum (Al). Medium size.