CN100385511C - Manufacturing method of glass substrate for disc and manufacturing method of disc - Google Patents
Manufacturing method of glass substrate for disc and manufacturing method of disc Download PDFInfo
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- CN100385511C CN100385511C CNB2005100804117A CN200510080411A CN100385511C CN 100385511 C CN100385511 C CN 100385511C CN B2005100804117 A CNB2005100804117 A CN B2005100804117A CN 200510080411 A CN200510080411 A CN 200510080411A CN 100385511 C CN100385511 C CN 100385511C
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- Manufacturing Of Magnetic Record Carriers (AREA)
- Re-Forming, After-Treatment, Cutting And Transporting Of Glass Products (AREA)
- Magnetic Record Carriers (AREA)
Abstract
To provide a manufacturing method of a glass substrate for a magnetic disk which can carry out mass-supply of the glass substrate for magnetic disk in which occurrence of a defect such as a chip, a flaw and a crack at an inner diameter edge of a circular hole is suppressed when forming the circular hole in a center section of the glass substrate, and sufficient shock resistance is secured, stably and at a low cost without variation of quality.A one side concave part 4 is formed by a 1st core drill 3 having a 1st outer diameter d1 from one main surface 2a side of a glass disk 2. Then, the other side concave part 6 is formed from the other main surface 2b side of this glass disk 2 by a 2nd core drill 5 having a 2nd outer diameter d0 which is a smaller diameter than the 1st outer diameter d1 and a larger diameter than the inner diameter of the 1st core drill 3, and a through hole covering one side concave part 4 is drilled.(C)2006,JPO&NCIPI.
Description
Technical field
The present invention relates to the manufacture method of the glass substrate for disc that uses in the disk devices such as hard disk drive and the manufacture method of disk.
Background technology
Current, along with the fast development of IT industry, require information recording technique, particularly magnetic recording technology to carry out technical renovation.The disk different with other magnetic recording body such as tape or floppy disk, that the hard disk drive (HDD) that uses as the storer of computing machine etc. loads on disk set, its information recording density constantly increases.The support that increased by this disc information recording density, personal computer can the canned data amount rapidly increase.
Glass substrate is highly suitable for doing the disk substrate, because glass substrate has level and smooth surface, therefore for the magnetic head that carries out record regenerating on disk when sliding fast, its suspension quantitative change is little.That is to say, use glass substrate, can access the high disk of information recording density.
Usually, as being of value to the glass substrate that improves magnetic disc storage density, what use now is the glass substrate of following manufacturing: the glass preparation compression moulding that at first utilizes fusion is discoideus glass disk, again this glass disk is ground successively and cut processing and grind (polishing) processing etc., thereby make glass substrate.
For this glass substrate, as described in patent documentation 1, use the adamas core drill, at the central portion of substrate circular hole is set.This circular hole is used for making the disk of devices such as hard drive to be supported by central shaft.And in document 1,, on glass disk, form through hole by making the eccentric rotation of adamas core drill.
[patent documentation 1] spy opens flat 7-108523 communique
Summary of the invention
In recent years, the information recording density of disk has surpassed 40 gigabits per square inch, further will realize surpassing per square inch the superelevation recording density of 100 gigabits.Compare with disk in the past, current disk can be realized high information recording density like this, even very little area also has the feature that can store very large quantity of information in actual use.
In addition, compare with the out of Memory recording medium, the information writing speed of disk and reproduction speed (answer speed) also are extremely fast, have in time writing information and the feature that reads information.
The various features of this disk have caused people's attention, consequently, demand to miniature hard-drive has appearred in recent years, it is more much smaller and require on the machine of high answer speed than the volume of personal computer device to require this miniature hard-drive to be loaded in, carry with information device or such as vehicle mounted information devices such as auto-navigation systems such as mobile phone, digital camera, PDA (personal digital assistant, personal digital assistant) etc.
The miniature hard-drive of using in this what is called " mobile device " of carrying usefulness, vehicle mounted, often because of drop, generation such as vibration clashes into and exposes to the open air under impact.Therefore, for the disk that the hard disk drive that uses in this machine uses, the attention that the serviceability of the disk of use glass substrate is received more.That is to say, compare that the glass substrate that is made of hard material has the high characteristics of rigidity with the metal substrate that constitutes by soft material.Simultaneously, glass substrate also has the characteristics that can access desired intensity by means such as chemical enhanced processing.
For example, be equal to or less than headed by " the 1.8 inches dishes " that 48mm, internal diameter be equal to or less than 12mm with external diameter, the ratio littler disk of size of dish has in the past been proposed, for example external diameter is equal to or less than " the 1 inch dish " that 27.4mm, internal diameter are equal to or less than 7mm, or external diameter is equal to or less than 22mm, internal diameter is equal to or less than 6mm " 0.85 inch dish " etc.
But,, when the central portion of glass substrate forms circular hole, be easy to generate the defect problem as damaged, crack, breakage around this circular hole for example according to above-mentioned patent documentation 1 described technology.If around circular hole, have such defective,, the intensity of substrate fully strengthened even carry out chemical enhanced processing.Can predict that under this substrate state, in the disk internal diameter end face of supporting disk and the contact portion of central shaft, the probability that the crack takes place the end face of dish is very big, and be related to magnetic disc substrate and be impacted and destroy.
In view of above-mentioned actual conditions, first purpose of the present invention provides a kind of manufacture method of glass substrate for disc, wherein when the central portion of glass substrate forms circular hole, the defective of internal diameter end face generation as damaged, crack, breakage that can suppress this circular hole, and this method can be produced the glass substrate for disc of guaranteeing to have abundant impact resistance in a large number at a low price, and steady quality bias free aborning.
Second purpose of the present invention can suppress this circular hole when being to form circular hole by the central portion that is provided at glass substrate internal diameter end face takes place as the manufacture method of the glass substrate for disc of defectives such as damaged, crack, breakage, improved the impact resistance of the disk that uses this glass substrate for disc, can provide to be suitable for the disk of work such as the miniature hard-drive in " mobile device ".
The inventor studies above-mentioned problem, found that, on the first type surface of a side of glass disk, utilize the 1st core drill forming a side recess with the 1st external diameter, then, on the first type surface of the opposite side of this glass disk, that utilization has is littler than the 1st external diameter, the 2nd core drill of 2nd external diameter bigger than the internal diameter of the 1st core drill is forming the opposite side recess, and then forms and pass the through hole of a side recess, thereby has solved above-mentioned problem.
The present invention has following formation.
Constitute 1: the manufacture method of glass substrate for disc, it has the operation that is drilled with circular hole at the central portion of plate glass disk.It is characterized in that, described method comprises the 1st operation and the 2nd operation, in the 1st operation, uses the 1st core drill with the 1st external diameter, from the first type surface of above-mentioned glass disk one side, at side recess that this glass disk thickness of depth ratio is little of central portion formation of this glass plectane; In the 2nd operation, the 2nd core drill has the 2nd external diameter, described the 2nd external diameter is littler, bigger than the internal diameter of above-mentioned the 1st core drill than above-mentioned the 1st external diameter, use the 2nd core drill, first type surface from above-mentioned glass disk opposite side, the central portion of pulling at this glass circle roughly is concentric opposite side recess to above-mentioned side recess direction formation with an above-mentioned side recess, and passes the through hole of an above-mentioned side recess from the opposite side recess by this opposite side concave depth setting of slow intensification.
Constitute 2: have the manufacture method that the present invention constitutes the glass substrate for disc shown in 1, it is characterized in that, the external diameter of glass substrate for disc is equal to or less than 65mm, and the internal diameter of central part circular hole is equal to or less than 20mm, and thickness is equal to or less than 0.635mm.
Constitute 3: the manufacture method of disk of the present invention is characterized in that having the glass substrate for disc surface that the manufacture method that constitutes 1 or 2 glass substrate for disc makes in utilization and formed magnetosphere at least.
In the manufacture method of glass substrate for disc of the present invention with formation 1, on the first type surface of a side of glass disk, the core drill that use has the 1st external diameter forms a side recess, then, on the first type surface of the opposite side of above-mentioned glass disk, use the 2nd core drill with the 2nd littler than above-mentioned the 1st external diameter, bigger external diameter than the 1st internal diameter of above-mentioned core drill, form the recess of opposite side, pass an above-mentioned side recess, be drilled with and be through hole.
In the manufacture method of this glass substrate for disc, when forming the degree of depth less than a side recess of glass circle plate thickness, produce some cracks around this side recess sometimes, but because this side concave depth is less than the glass circle plate thickness, enlarge towards periphery so can control the crack, make its enlarged degree little.Then, when forming the opposite side recess, because be that the opposite side recess passes side recess formation through hole, so produce the crack around the opposite side recess sometimes.But the crack that produces around the opposite side recess is to produce to a side recess bigger than opposite side recess diameter, does not further enlarge to peripheral direction so a side recess can not be crossed in the crack that produces around the opposite side recess.
That is to say, in the manufacture method of this glass substrate for disc, can suppress to follow opposite side to form the expansion in the crack of recess generation, so can suppress the defective of internal diameter end face generation as damaged, crack, breakage of through hole.
Manufacture method with glass substrate for disc of the present invention of formation 2 is the manufacture method with glass substrate for disc of formation 1, wherein the external diameter of the glass substrate for disc internal diameter that is equal to or less than 65mm, central part circular hole is equal to or less than 20mm, thickness is equal to or less than 0.635mm, can be suitable for the glass substrate that the little disk of diameter uses so this method can provide.
Therefore, in the present invention, a kind of manufacture method of glass substrate for disc can be provided, when this method forms circular hole at the glass substrate central portion, can suppress the defective of internal diameter end face generation as damaged, crack, breakage of this circular hole, can under the agonic situation of steady quality, provide a large amount of glass substrate for disc that can guarantee abundant impact resistance by qurer.
In disk manufacture method of the present invention with formation 3, have in utilization on the surface of the glass substrate for disc that the manufacture method that constitutes 1 or 2 glass substrate for disc obtains and form magnetosphere at least, so it is very level and smooth to access main surface portion, and has the disk of abundant intensity.
That is to say, in the present invention, can suppress the manufacture method that the glass substrate for disc of defective as damaged, crack, breakage takes place circular hole internal diameter end face when utilizing this central portion to form circular hole at glass substrate, improved the impact resistance of the disk that uses this glass substrate, the disk of the miniature hard-drive of using in the what is called " mobile device " that is suitable for carrying usefulness can be provided.
Description of drawings
Fig. 1 is explanation disk of the present invention is used substrate with the disk of the manufacture method manufacturing of substrate a stereographic map.
Fig. 2 is the process chart of the order of explanation the present invention when the glass disk central portion forms circular hole.
Fig. 3 is the sectional view that the fracture morphology that can produce when glass plectane central portion forms circular hole among the present invention is described.
Symbol description
1 circular hole
2 glass disk
The first type surface of 2a one side
The first type surface of 2b opposite side
3 the 1st core drills
4 one side recesses
5 the 2nd core drills
6 opposite side recesses
7 whetslates
D1 the 1st external diameter
D0 the 2nd external diameter
Embodiment
Below, with reference to accompanying drawing best implementation condition of the present invention is described.
According to the glass substrate for disc that the manufacture method of the glass substrate for disc that the present invention relates to is made, for example can be used as the substrate use that HDD (hard disk drive) waits the disk that loads.This disk for example can be to adopt perpendicular magnetic recording to carry out the recording medium of highdensity information signal recording and regeneration.
The stereographic map of Fig. 1 disk usefulness substrate that to be explanation make with the manufacture method of substrate according to disk of the present invention.
This glass substrate for disc, its external diameter can be 15mm～48mm, and internal diameter can be 5mm～12mm, and thickness can be 0.35mm～0.6mm.Can make the disk that has certain diameter as " 0.8 inch type disk " (internal diameter 6mm, external diameter 21.6mm, thickness of slab 0.381mm), " 1.0 inches type disks " (internal diameter 7mm, external diameter 27.4mm, thickness of slab 0.381mm), " 1.8 inches type disks " (internal diameter 12mm, external diameter 48mm, thickness of slab 0.508mm) etc.Also can make disks such as " 2.5 inches type disks ", " 3.5 inches type disks " in addition.Here, " internal diameter " refers to the internal diameter of magnetic disc substrate central part circular hole 1 as shown in Figure 1.
In the manufacture method of glass substrate for disc of the present invention, at first, the surface of plate glass ground to cut be processed into base glass material, again base glass material is cut off, cut out glass disk.Plate glass of the present invention can use various glass.This plate glass for example can utilize known manufacture method manufacturing such as pressing, floating method or fusion method to form with melten glass as material.In these methods, adopt pressing can make plate glass at a low price.
The shape of this plate glass can be rectangular-shaped, also can be discoid.And discoid plate glass can use that the employed turning device that grinds grinds and cuts processing in the manufacture method of glass substrate for disc in the past, and can implement the high processing of reliability at a low price.
The plate glass material that the present invention uses can be amorphous glass or glass ceramics (also being called sintered glass ceramics).In the amorphous glass,, put, can preferably use aluminosilicate glass from this from the disk substrate of the good and substrate excellent strength of front planarization can be provided.
Grinding the purpose of cutting processing is, improves form accuracy (for example flatness), the dimensional accuracy (for example thickness and precision of plate) of the first type surface of plate glass.Cut in the processing this grinding,, these plate glass and whetslate or price fixing are relatively moved, cut processing thereby the first type surface of plate glass ground by using the first type surface extruding of whetslate or price fixing to plate glass.Can use the two sides that has pinion gear structure to grind turning device carries out this grinding and cuts processing.
Cut in the processing this grinding, supply with to grind by the first type surface of giving plate glass and cut liquid, be rinsed to remove and grind swarf from grinding bevel, and can grind the bevel cooling.And, also can cut grinding to cut to grind on the first type surface that the slurries that contain free abrasive grains in the liquid supply to operation.
Grind and cut the whetslate that uses in the processing and can use adamas whetslate, in addition, free abrasive grains can use hard abrasive grains such as alumina abrasive particles or silit abrasive grains.
Cut processing by grinding, improved the form accuracy of plate glass, when can make its first type surface shape planarization, with thickness of slab be cut to fixed thickness to form base glass material.The first type surface of base glass material ground cut processing, make its planarization, and, by cutting down the thickness of glass plate, in the generation that prevents as defectives such as damaged, crack, breakages, cut off this base glass material, can cut out glass disk from base glass material.
The thickness of base glass material preferably is equal to or less than 2mm.If the thickness of base glass material surpasses 2mm, then because the thickness of plate is too thick, existence can not accurate cut out the possibility of glass disk, in addition, when the thickness of base glass material is lower than 0.2mm, exist base glass material self can not bear the possibility of the pressure that cuts out glass disk.So the thickness of base glass material preferably is equal to or greater than 0.2mm.
Can use ciamond cutter, first-class cutting knife or the whetslate that contains the material harder of diamond drill machine that base glass material is cut off than glass.In addition, also can use the laser cutter that base glass material is cut off.
Then, use diamond head to form a circular hole, formed glass disk as the bagel shape at the central portion of glass plectane.
Fig. 2 is explanation the present invention forms the order of circular hole at the glass disk central portion a process chart.
In the present invention, when the glass disk central portion forms circular hole, as shown in Figure 2, in the 1st operation, utilization has the 1st core drill 3 of the 1st outside diameter d 1, from the first type surface 2a of a side of glass disk 2,, form the little side recess 4 of thickness of this glass disk 2 of depth ratio at the central portion of this glass disk 2.The degree of depth of this side recess 4 be preferably glass disk 2 thickness 30%～50%.
Then, shown in Fig. 2 (b), in 2 operations, utilization has the 2nd core drill 5 of 2nd outside diameter d 0 littler and bigger than the internal diameter of the 1st core drill 3 than the 1st outside diameter d 1, first type surface 2b from the opposite side of glass disk 2, at the central portion of glass disk to an aforementioned side recess 4, form one with the roughly concentric opposite side recess 6 of an aforementioned side recess 4.
Along with the degree of depth of opposite side recess 6 is slowly deepened, shown in Fig. 2 (c), pass an aforesaid side recess 4 from the recess 6 of opposite side, be drilled with the formation through hole.
Fig. 3 is the sectional view that the crack that can produce when the glass disk central portion forms circular hole among the present invention is described.
In the 1st operation and the 2nd operation, when the little side recess 4 of the thickness that forms depth ratio glass disk 2, as shown in Figure 3, around this side recess 4, produce some crack 4a sometimes, because the thickness of the depth ratio glass disk 2 of this side recess 4 is little, so suppressed the peripherad expansion of crack 4a, made its enlarged degree little.Then, when forming opposite side recess 6, opposite side recess 6 passes an aforementioned side recess 4 and forms through hole, so can produce crack 6a around the recess 6 of opposite side, as shown in Figure 3, the crack is towards producing than opposite side recess 6 big aforementioned side recesses 4, further not enlarging to peripheral direction so can not cross recess 4.
The the 1st and the 2nd core drill 3,5, its whetslate is cylindraceous.The the 1st and the 2nd core drill 3, the 5 preferred adamas core drills that use.The aperture of the boring of these core drills is preferably #150～#400.In addition, poor between the 1st outside diameter d 1 and the 2nd outside diameter d 0 preferably is equal to or less than 0.2mm.
In the 1st operation and the 2nd operation, the 1st core drill 3 and the 2nd core drill 5 are that the offset of benchmark preferably is equal to or less than 0.1mm with glass disk 2.In addition, represent angle between the normal of main surface portion 2a, 2b of the central shaft of the 1st and the 2nd core drill 3,5 and glass disk 2 with θ among Fig. 2 (a) and Fig. 2 (b), this angle preferably is equal to or less than 0.1 °.
In the 2nd operation, make glass disk 2 opposite side first type surface 2b up, optimal way is, uses the 2nd core drill 5, the first type surface 2b from the top in this another survey forms opposite side recess 6.That is, in this case, when using the 2nd core drill 5 to form through hole, separate the glass fragment that remains in the 2nd core drill 5 from glass disk 2 and drop downwards, operation is good.
In addition, in the operation that forms a side recess 4 and opposite side recess 6, grind by supply and to cut liquid, can wash away grinding the inner space of swarf, and can cool off and grind bevel by each core drill 3,5.
Form through hole by the 1st and the 2nd operation, can prevent and form the expansion that opposite side recess 6 is followed the crack of generation.
Then, shown in Fig. 2 (d), in the 3rd operation, using the both end sides hole enlargement is that interior all end faces of 7 pairs of through holes of cone shape cylindric whetslate grind and cut, at this moment, glass disk 2 and whetslate 7 can rotate respectively under interior all end face state of contact of the through hole of the side face of whetslate 7 and glass disk 2.
Cut by using this columned whetslate to grind, shown in Fig. 2 (e), form the circular hole 1 that the edge with regulation inside diameter D and two peristomes forms chamfering.Chamfered part is to carry out chamfering by the rib portion to the end face of glass disk, forms conical of connecting these main surface portion and end face and form between first type surface and end.Like this, preferably the rib portion to the end face both sides of glass disk carries out chamfering.Carry out chamfering by rib portion, can improve resistance of failure, can carry out good grinding simultaneously the glass disk end face.
In addition, in the 1st above-mentioned operation, when forming a side recess 4, even follow the crack taking place, in the 3rd operation, also can remove this crack.
Then, for the outer circumference side edge face of this glass disk implement fixed chamfer machining the time, at least also to implement attrition process, make the first type surface mirror-polishing of this glass disk, become glass substrate for disc.In described attrition process, at the first type surface of glass disk the price fixing that has attached pad is pushed, supply with lapping compound for the first type surface of glass disk on one side, these glass disk and price fixing are relatively moved on one side.
At this moment, as long as the grinding abrasive grains that contains in the lapping compound can produce grinding effect to glass substrate for disc, other are not particularly limited.For example, can be cerium oxide (CeO
2) abrasive grains, colloid silicon abrasive grains, alumina abrasive particles, diamond lap particle etc.Grind the particle diameter of abrasive grains, can suitably select, but preference is as 0.5 μ m～3 μ m.In addition,, preferably in containing the lapping compound that grinds abrasive grains, add entry liquid such as (pure water), this lapping compound is used with the form of slurries for lapping compound.
In addition, preferred elder generation becomes mirror shape with the end surface grinding of glass disk.Because the end face of glass disk is to cut off shape,, can suppress granular generation by earlier end surface grinding being become minute surface.Use the disk of this glass substrate for disc manufacturing to can be good at preventing the generation of so-called thermal crack(ing obstacle.
After implementing this attrition process, the surfaceness Rmax of the first type surface of glass substrate for disc is equal to or less than 6nm, and Ra is equal to or less than 0.6nm.The first type surface of glass substrate for disc is if such minute surface, the disk that uses this glass substrate for disc to make so, even head gimbal amount 10nm for example, the generation of also can suppress to burst apart obstacle, thermal crack(ing obstacle.
Then, after glass disk is implemented grinding step, preferably implement intensive treatment such as chemical enhanced, air-cooled reinforcement, or implement crystallization and handle, improve resistance of failure.When implementing chemical enhanced processing, can make the surface of glass substrate for disc produce high compression stress, improve impact resistance.
When using aluminosilicate glass as the glass disk material, be particularly suitable for chemical enhanced processing, aluminosilicate glass can be realized good mirror smooth, can implement chemical enhanced processing again, so can improve the resistance of failure of glass.In the aluminosilicate glass, be preferably the SiO that contains 62 weight %～75 weight %
2, 5 weight %～15 weight % Al
2O
3:, the Li of 4 weight %～10 weight %
2O, 4 weight %～12 weight %Na
2O:, 5.5 weight %～15 weight %ZrO
2As major component and Na
2O and ZrO
2Weight ratio be 0.5～2.0, Al
2O
3With ZrO
2Weight ratio be 0.4～2.5 the chemical enhanced glass of using.
In addition, for such glass substrate, in order to reduce ZrO
2The protrusion of surface problem of the glass substrate that causes of insolubles, the preferred SiO that contains 57mol%～74mol% that uses
2, 0mol%～2.8mol% ZrO
2, 3mol%～15mol% Al
2O
3, 7mol%～16mol% LiO
2, 4mol%～14mol% Na
2The chemical enhanced glass of using of O.After the aluminosilicate glass of this composition was implemented chemical enhanced processing, rupture strength increased, and the degree of depth of compressive stress layers is deepened, and has good Knoop hardness.
As mentioned above, make the present invention of glass substrate for disc, be specially adapted to make " 1 inch hard disk drive " or than the glass substrate for disc that loads on " 1 inch type " littler miniature hard-drive.And the diameter that is manufactured on the glass substrate that uses when " 1 inch type hard disk drive " goes up the disk that loads is about 27.4mm.The diameter of the glass substrate that uses when in addition, the disk that loads is gone up in manufacturing " 0.85 inch type hard disk drive " is about 21.6mm.
Disk of the present invention, the magnetosphere for forming on glass substrate for disc 4 for example, can use the material that contains cobalt (Co) class strong magnetic material.Particularly, be preferably formed the magnetosphere that contains cobalt-platinum (Co-Pt) class strong magnetic material that can produce high magnetic force.Magnetospheric formation method can be used the DC magnetron sputtering method.
Embodiment
Below, embodiments of the invention are elaborated.
Embodiment 1
In embodiment 1, make glass substrate for disc through following operation.
(1) the processing and forming operation, grind and cut operation
The aluminosilicate glass press process of fusion is become collar plate shape, obtain glass disk.
As aluminosilicate glass, use SiO with 57mol%～74mol%
2, 0mol%～2.8mol% ZrO
2, 3mol%～15mol% Al
2O
3, 7mol%～16mol% LiO
2, 4mol%～14mol% Na
2O is the chemical enhanced glass of using of major component.
In this operation, at first grind and cut processing, glass disk is processed into the disk of the about 0.6mm of thickness.
Then, the central portion in glass disk forms a circular hole.
In the 1st operation that circular hole forms, at first on estrade, determine the position firmly with the glass disk vacuum suction, the anchor clamps that load cylindric (donut-like) made by resin material on this glass disk are removed vacuum suction with the fixing glass disk.Then,, use the 1st adamas core drill, form 30%～50% the side recess that the degree of depth is a glass disk thickness at the central portion of this glass disk with the 1st external diameter from the first type surface of a side of glass disk.The hole diameter of the 1st adamas core drill is #170.
It then is the 2nd operation that forms circular hole, first type surface from the opposite side of glass disk, central portion in this glass disk 2, that use has is littler than the 1st external diameter, the 2nd adamas core drill of 2nd external diameter bigger than the internal diameter of the 1st adamas core drill, to a side recess direction form with this recess roughly be concentric opposite side recess.The hole diameter of the 2nd adamas core drill is #170.
The difference of the 1st external diameter and the 2nd external diameter is equal to or less than 0.2mm, and the 1st adamas core drill and the 2nd adamas core drill are that the offset of benchmark is equal to or less than 0.1mm with the glass disk.In addition, the angle between the normal of the first type surface of the central shaft of the 1st adamas core drill and the 2nd adamas core drill and glass disk is equal to or less than 0.1 °.
Then,, pass last side recess, be drilled with and be through hole from this opposite side recess along with the opposite side concave depth is slowly deepened.
In the 2nd operation, the first type surface of the opposite side of glass disk is placed up, the 2nd adamas core drill faces toward this first type surface from top formation opposite side recess.In addition, in forming the operation of a side recess and opposite side recess, grind by supply and to cut liquid, be cleaned and flow away grinding the inner space of swarf, and cool off simultaneously and grind bevel by each core drill.
In forming the 3rd operation of circular hole, be that cone shape cylindric whetslate grinds interior all end faces of cutting through hole with the two ends hole enlargement, formation have decide the circular hole of two peristome edges of internal diameter through chamfering.
With the outer circumference side edge face of the glass disk that makes implement fixed chamfer machining, first type surface is implemented to grind to cut processing.Cut in the processing grinding, use the two sides to grind turning device and alumina abrasive particles is processed, make glass substrate have fixed dimensional accuracy and form accuracy.
The internal diameter of the glass disk that makes is 7mm, and external diameter is 27.4mm, and the thickness of plate is 0.427mm, after the first type surface attrition process, determines that it is the glass disk of " 1 inch type " disk with institute's sizing of substrate.
The surface configuration of sight glass disk, the about 3.0 μ m of the surfaceness Rmax of first type surface, the about 0.3 μ m of Ra.Observe the surfaceness of end face, find its Rmax=4.0 μ m, Ra=0.5 μ m.
(2) the mirror ultrafinish operation of end face
At first, the glass disk lamination is arranged on the support fixture, inserts abrasive brush at the central part of circular hole then, the inner peripheral surface of circular hole is ground.The grinding abrasive grains that uses in the grinding step is the slurries (free abrasive grains) that contain cerium oxide.
Then, use abrasive brush that the peripheral end face of glass disk is carried out mirror ultrafinish.
Glass substrate is overlaped when grinding, and for fear of produce cut etc. on the first type surface of glass substrate, preferably before the 1st grinding step described later, or described end surface grinding operation is carried out in the front and back of the 2nd grinding step.
Then, the glass substrate after with alkaline rinse the end surface grinding operation being finished is cleaned.
Afterwards, measure the size of the internal diameter end face part of glass disk, find to have ground away 10 μ m～20 μ m.In addition, the mirror status of end face portion is confirmed that find that the surfaceness of end face is: Ra is 0.05 μ m～0.10 μ m, and Rmax is 0.3 μ m～1.0 μ m.
(the 1st grinding step)
Then, implement the 1st grinding step as the first type surface grinding step.The fundamental purpose of the 1st grinding step is to remove above-mentioned grinding to cut in the operation cut or irregular part residual on the first type surface.Use two sides lapping device and hard resin sanding machine, adopt the pinion gear structure that first type surface is ground, use cerium oxide abrasive particles as lapping compound.
Glass substrate after the 1st grinding step finishes is cleaned with alkaline rinse.
(the 2nd grinding step)
Then implement the mirror ultrafinish operation of the 2nd grinding step as first type surface.The purpose of the 2nd grinding step is that first type surface is ground to form mirror shape.Use two sides lapping device and flexible foamed resin sanding machine, adopt the pinion gear structure that first type surface is implemented mirror ultrafinish.Lapping compound adopts the fine cerium oxide abrasive particles of cerium oxide abrasive particles that uses than the 1st grinding step.
Glass substrate after the 2nd grinding step finishes is immersed in above-mentioned each rinse bath successively according to the order of neutral wash solution, pure water, silicofluoric acid, pure water, neutral wash solution, pure water, IPA (isopropyl alcohol), IPA (steam drying), cleans.And, implement ultrasonic cleaning in each rinse bath.
(6) chemical enhanced operation
Then, to cutting the glass disk of handling with grinding step and implement chemical enhanced processing through above-mentioned grinding.In chemical enhanced processing, preparation potassium nitrate (60%) and sodium nitrate (40%) mix the chemical enhanced solution that forms, should be heated to 380 ℃ by chemical enhanced solution, and will clean and in this chemical enhanced solution, flood 4 hours in the glass disk after 300 ℃ of preheatings.During dipping,, when being contained in fixator, several glass disk support with its end face for all surfaces that makes glass disk obtains chemical enhancedly.
Like this, by the dip treating of chemical enhanced liquid, the lithium ion on glass disk top layer, sodion are replaced by sodium particle, potassium ion in the chemical enhanced liquid respectively, and glass disk has obtained reinforcement.
The thickness of the compressive stress layers that the top layer of glass disk forms is about 100 μ m～200 μ m.
Glass disk after chemical enhanced processing finished is put into cooling fast in 20 ℃～25 ℃ the tank, keeps 30 minutes.
Quick cooled glass disk is immersed in above-mentioned each rinse bath successively according to the order of pure water, dilute sulfuric acid, pure water, neutral wash solution, pure water, IPA (isopropyl alcohol), IPA (steam drying), cleans.And, in each rinse bath, implement ultrasonic cleaning.
The disk that the above-mentioned operation of process obtains with the surfaceness of interior all side end faces of the circular hole of substrate is: the Rmax of chamfered section is that 0.4 μ m, Ra are 0.04 μ m, and the Rmax of side wall portion is that 0.4 μ m, Ra are 0.05 μ m.The surface roughness Ra of peripheral end face is: chamfered section is 0.04 μ m, side wall portion 0.07 μ m.So just can determine that interior all side end faces and outer circumference side edge face have become mirror shape equally.
In addition, the surface roughness Ra of the first type surface of glass substrate is 0.3nm～0.7nm (an AFM mensuration).Use electron microscope (4000 times) that the surface of end face is observed, find that it is a mirror status.In addition, not finding has foreign matter, crack etc. on interior all side end faces of circular hole, the particle that does not also produce because of foreign matter, thermal crack(ing on the surface of glass substrate.
Use rupture strength Instrument measuring rupture strength, find the rupture strength of goods is greatly improved through after the chemical enhanced processing.
In embodiment 2, the disk substrate that uses the foregoing description 1 to make is made disk by following operation.
With on two first type surfaces of substrate, use static subtend type DC magnetic control sputtering device, at above-mentioned disk according to the order film forming of Al-Ru alloy the 1st basalis, Cr-Mo alloy the 2nd basalis, Co-Cr-Pt-B alloy magnetic layer, hydrocarbon protective seam.Then, use infusion process to make the PFPE lubricating layer film forming of pure modification, make disk with this.
For the disk that makes, do not occur on films such as magnetosphere, producing damaged because of foreign matter through affirmation.In addition, by implementing coasting test, do not find collision (magnetic head and the friction of magnetic disk surface jut), broken (the part bump of magnetic head and protrusion of surface is broken) phenomenon.Use the magnetic reactance magnetic head to carry out regeneration test, do not find the regeneration mistake that the thermal crack(ing obstacle causes.
More than test is that the used test method of disk of 40 gigabits is carried out per square inch with information recording density.Specifically: the suspension amount of magnetic head is 10nm, and the information wire recording density of record regenerating test is 700fci.
The disk that the present invention makes, the problem that can avoid the foreign matter of glass baseplate surface to cause utilizes the magnetic reactance magnetic head can make good disk.
Among the present invention, be not particularly limited for the diameter (size) of glass substrate for disc.But the present invention can bring into play its excellent serviceability when making the glass substrate for disc of minor diameter.
The disk of minor diameter can use in window machine of so-called truck mounted machines such as " auto-navigation systems " or " PDA ", mobile phone etc. carries with the pen recorder in the instrument.Compare with the disk in the fixing instrument that uses, the disk request in these instruments has high useful life longevity and anti-collision.
Here said minor diameter for example is the glass substrate for disc that diameter is equal to or less than 30mm.
Claims (3)
1. the manufacture method of glass substrate for disc, it has the operation that is drilled with circular hole at the central portion of plate glass disk, it is characterized in that, the plate thickness of described glass disk is 0.2mm～2mm, and described method comprises the 1st operation, the 2nd operation and the 3rd operation, in the 1st operation, uses the 1st core drill with the 1st external diameter, from the first type surface of above-mentioned glass disk one side, at side recess that this glass disk thickness of depth ratio is little of central portion formation of this glass disk; In the 2nd operation, the 2nd core drill has the 2nd external diameter, the 2nd external diameter is littler, bigger than the internal diameter of above-mentioned the 1st core drill than above-mentioned the 1st external diameter, use the 2nd core drill, from the first type surface of above-mentioned glass disk opposite side, the central portion of this glass disk to an above-mentioned side recess direction form with an above-mentioned side recess roughly be concentric opposite side recess, along with this opposite side concave depth is slowly deepened, pass an above-mentioned side recess from the opposite side recess, be drilled with and be through hole; In the 3rd operation, interior all end faces of described through hole are ground cut.
2. the manufacture method of glass substrate for disc as claimed in claim 1 is characterized in that, the external diameter of above-mentioned glass substrate for disc is equal to or less than 65mm, and the circular hole internal diameter of central part is equal to or less than 20mm, and thickness is equal to or less than 0.635mm.
3. the manufacture method of disk is characterized in that, forms magnetosphere at least on the surface of the resulting glass substrate for disc of manufacture method that utilizes claim 1 or 2 described glass substrate for disc.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004195482A JP2006018922A (en) | 2004-07-01 | 2004-07-01 | Manufacturing method of glass substrate for magnetic disk, and manufacturing method of magnetic disk |
| JP2004195482 | 2004-07-01 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1725307A CN1725307A (en) | 2006-01-25 |
| CN100385511C true CN100385511C (en) | 2008-04-30 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2005100804117A Expired - Fee Related CN100385511C (en) | 2004-07-01 | 2005-07-01 | Manufacturing method of glass substrate for disc and manufacturing method of disc |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2006018922A (en) |
| CN (1) | CN100385511C (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4942428B2 (en) * | 2006-09-01 | 2012-05-30 | Ｈｏｙａ株式会社 | Manufacturing method and processing apparatus of glass substrate for magnetic disk, and manufacturing method of magnetic disk |
| JP5023113B2 (en) * | 2009-07-31 | 2012-09-12 | ブリヂストンプラントエンジニアリング株式会社 | Thin glass processing equipment |
| JP5967999B2 (en) * | 2011-03-31 | 2016-08-10 | Hoya株式会社 | Manufacturing method of glass substrate for magnetic disk |
| JP5695279B2 (en) * | 2012-08-31 | 2015-04-01 | セロンテクノロジーズ 株式会社 | Tempered glass processing method |
| KR101442460B1 (en) * | 2012-08-31 | 2014-09-22 | 히로노리 미나미 | Method of processing tempered glass and device of processing tempered glass |
| JP5715737B2 (en) * | 2012-08-31 | 2015-05-13 | セロンテクノロジーズ 株式会社 | Method of processing tempered glass, processing device for tempered glass, and method of using processing tool for tempered glass |
| CN113808627B (en) | 2017-09-29 | 2023-03-17 | Hoya株式会社 | Glass spacer and hard disk drive device |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6328527A (en) * | 1986-07-21 | 1988-02-06 | Asahi Glass Co Ltd | Shaping-working for daughnut-shaped circular substrate |
| JPH07108523A (en) * | 1991-09-06 | 1995-04-25 | Kiyokuei Kenma Kako Kk | Drilling of hard and fragile material and machining device thereof |
-
2004
- 2004-07-01 JP JP2004195482A patent/JP2006018922A/en active Pending
-
2005
- 2005-07-01 CN CNB2005100804117A patent/CN100385511C/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6328527A (en) * | 1986-07-21 | 1988-02-06 | Asahi Glass Co Ltd | Shaping-working for daughnut-shaped circular substrate |
| JPH07108523A (en) * | 1991-09-06 | 1995-04-25 | Kiyokuei Kenma Kako Kk | Drilling of hard and fragile material and machining device thereof |
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| Publication number | Publication date |
|---|---|
| JP2006018922A (en) | 2006-01-19 |
| CN1725307A (en) | 2006-01-25 |
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