CN1740388A - Method of manufacturing a disk substrate for a magnetic recording medium - Google Patents
Method of manufacturing a disk substrate for a magnetic recording medium Download PDFInfo
- Publication number
- CN1740388A CN1740388A CN 200510088454 CN200510088454A CN1740388A CN 1740388 A CN1740388 A CN 1740388A CN 200510088454 CN200510088454 CN 200510088454 CN 200510088454 A CN200510088454 A CN 200510088454A CN 1740388 A CN1740388 A CN 1740388A
- Authority
- CN
- China
- Prior art keywords
- plating
- magnetic recording
- glass
- weight
- disk substrate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Manufacturing Of Magnetic Record Carriers (AREA)
- Magnetic Record Carriers (AREA)
Abstract
An object of the present invention is to provide a plating method on a glass base plate. The method allows forming a plating film on a base plate composed of a glass material with excellent adhesivity and homogeneity by means of an electroless plating method even to a thickness of 1 mum or more. Before forming a plating film by a step of electroless plating S 6, a surface treatment process is conducted on a surface of the base plate composed of a glass material. The surface treatment process comprises at least a step of glass activation treatment S 2 to increase quantity of silanol groups on the surface of the base plate at least by a factor of two using an aqueous solution of diluted acid, a step of silane coupling agent treatment S 3, a step of palladium catalyst treatment S 4, and a step of palladium bonding treatment S 5.
Description
The cross-reference to related applications relation
The application is based on and requires following right of priority: the application number 2005-038617 that the Japanese publication 2004-219195 that on July 27th, 2004 submitted to and on February 16th, 2005 submit to, above-mentioned application all is incorporated herein by reference in full.
Technical field
The present invention relates to a kind of substrate (base plate) that constitutes at glass material and go up the method for plating (plating), a kind of method and a kind of method of using the method manufacturing perpendicular magnetic recording media of this manufacturing disk substrate that is used for the disk substrate of magnetic recording medium with the plating manufactured.Especially, these methods can be used to be installed in the magnetic recording medium on the hard disk drive effectively.
Background technology
In recent years, hard disk drive is through being commonly used for the storing device of computer or digital home appliance.In vertical magnetic register system, normally make with following method as the disk that is installed in the magnetic recording medium on the hard disk drive (hard disk).Use dectroless plating on the non-magnetic matrix surface of collar plate shape, to form the Ni-P layer.Necessary smoothing processing and structurizing (texturing) processing are carried out in the surface of Ni-P layer.Then, in turn form the non-magnetic metal bottom on this surface, ferromagnetic alloy thin film magnetic layer, protective layer and other layer with sputtering process or other technologies.
Traditionally, use aluminium alloy as non-magnetic matrix material.Recently, hard disk drive develops by leaps and bounds, and has had bigger capacity, littler size and lighter weight.Corresponding to this trend, require disk to have than higher in the past planeness, littler diameter and thinner thickness.Traditional aluminum alloy base material almost can't satisfy these needs in market.Therefore, using glass as substrate material.
Glass baseplate also needs to show and the similar surface properties of aluminium base by form the Ni-P layer on the surface, thereby obtains the disk of the satisfactory performance of performance.Yet technical being difficult to forms the plated film with gratifying binding property, homogeneity and smoothness by dectroless plating on the substrate that glass material constitutes.In order to address this problem, people have proposed pre-treatment and the aftertreatment of the whole bag of tricks as dectroless plating.
In the example of a this method, before carrying out plated film, use the aqueous solution that contains Palladous chloride and tin chloride (II) to handle, also use aqueous alkali carbonate solution, the alkali metal hydrocarbonate aqueous solution, or these aqueous mixtures are handled.(seeing patent document 1) is in other method, before carrying out plated film, carried out two-step etch process with chromic acid-sulfuric acid mixed solution and salpeter solution, carried out etch processes with strong base solution, (II) carried out the sensitization processing with rare tin chloride, also carried out activation treatment with silver salt solution and palladium salts solution.(seeing patent document 2) before carrying out plated film, cleans with warm sulfuric acid and potassium dichromate solution in another example, uses tin chloride (II) sensitization of hcl acidifying, and activates with palladium chloride solution.(seeing patent document 3) before plated film, uses alkali degreasing in other method, use hydrofluoric acid etch, with the sensitization of tin chloride (II) solution, also activates with palladium chloride solution.
Thereby patent document 4 has proposed a kind ofly to form the method that the Ni-P layer with enough binding propertys and smoothness obtains good disk with plated film on glass baseplate.
In this method, before carrying out chemical Ni-P plated film, carried out following pre-treatment: to the abundant degreasing of glass baseplate, be etched with the raising anchor effect, remove the pollutent that in etching process, produces and be attached to substrate surface, the surface modulation that is used for substrate surface chemistry homogenizing, sensitization processing and activation treatment.Present method preferably uses the aqueous solution of hydrofluoric acid containing and potassium hydro-fluoride as etching solution, preferably removes surface contaminant with hydrochloric acid, and the preferred aqueous solution that contains sodium methylate that uses carries out surface modulation.
Simultaneously, the vertical magnetism register system is causing concern, replaces the technology that traditional vertical magnetic register system is used to reach the high-density magnetic recording.
Especially, described a kind of double-deck perpendicular magnetic recording media in patent document 6, this medium is called as the perpendicular magnetic recording media that is used for high density recording.This bilayer perpendicular magnetic recording media has the soft magnetic film that is called the soft magnetism backing layer under a kind of magnetic recording layer that is in recorded information.Described soft magnetism backing layer is easy to see through the magnetic flux that magnetic head produces, and shows high saturation magnetic flux metric density Bs.Described double-deck perpendicular magnetic recording media has increased the intensity and the gradient in magnetic field that magnetic head produces, and has improved log resolution and has also increased medium leakage flux.
The film that the soft magnetism backing layer usually uses 200 nanometers to form to the sputtering process (sputtering) of 500 nanometer thickness, by the Ni-Fe alloy, Fe-Si-Al alloy or mainly be that the amorphous alloy of cobalt constitutes.Yet from manufacturing cost and mass-produced angle, sputtering process also is not suitable for forming this thick relatively film.
For addressing this problem, the someone proposes to use the soft magnetic film of dectroless plating formation as the soft magnetism backing layer.For example, patent document 7 has proposed with the plating method to be used for the soft magnetism backing layer having on the al alloy disk base material of non magnetic NiP plated film the NiFeP of manufacturing film.
The CoNiFeP plated film that non-patent document 1 has proposed to form on glass baseplate.Non-patent document 2 has proposed the soft magnetism NiP plated film that forms on the al alloy disk base material of non magnetic Ni-P plated film having.
If the soft magnetism backing layer has formed domain structure and produced magnetic transition (transition) district that is known as neticdomain wall (magnetic domainwall), can reduce the performance of perpendicular magnetic recording media by the noise that is known as sharp noise of this neticdomain wall generation.Therefore, in the soft magnetism backing layer, must suppress the formation of neticdomain wall.
Aforesaid NiFeP plated film is easy to form neticdomain wall.Therefore, disclose need be by forming the formation that the MnIr alloy firm comes the inhibition zone wall with sputtering process on plated film for non-patent document 3.The formation that can suppress neticdomain wall in the aforesaid CoNiFeP plated film by plating in magnetic field is also disclosed.It is said that soft magnetism NiP plated film does not produce sharp noise.
Patent document 8 proposes to have 30 by formation and arrives the cobalt of 300Oe Coercive Force Hc or the backing layer that cobalt-base alloy is formed, thereby shows magneticanisotropy along the disk substrate circumferential direction, can suppress sharp generating noise.Make though the backing layer in this method is the dry method with sputtering process, method of evaporation etc. and so on, patent document 9 has proposed a kind of Co-B film that has 30Oe Hc at least and can suppress sharp noise that forms with plating (plating) method.This film is considered to can be used as the soft magnetism backing layer.
[patent document 1]
The uncensored patent application publication number H1-176079 of Japan
[patent document 2]
The uncensored patent application publication number S53-19932 of Japan
[patent document 3]
The uncensored patent application publication number S48-85614 of Japan
[patent document 4]
The uncensored patent application publication number H7-334841 of Japan
[patent document 5]
The uncensored patent application publication number 2000-163743 of Japan
[patent document 6]
Japanese Unexamined Patent Publication No S58-91
[patent document 7]
The uncensored patent application publication number H7-66034 of Japan
[patent document 8]
The uncensored patent application publication number H2-18710 of Japan
[patent document 9]
The uncensored patent application publication number H5-1384 of Japan
[non-patent document 1]
The 9th international magnetic (intermag) conference summary of associating MMM/, EP-12, p.259 (2004)
[non-patent document 2]
The 9th international magnetic (intermag) conference summary of associating MMM/, GD-13, p.368 (2004)
[non-patent document 3]
Japan's magnetics meeting periodical (Japan), Vol.28, No.3, p.289-294 (2004)
Aforementioned NiFeP plated film need form the generation that one deck MnIr alloy firm suppresses neticdomain wall with sputtering process on plated film, to suppress sharp noise.The requirement that adds the new film of last layer with sputtering process in order to suppress neticdomain wall has weakened the advantage of plating method from manufacturing cost and mass production aspect.
In aforesaid CoNiFeP plated film, in actual production process, be difficult in the plating bath base material is applied homogeneous magnetic field.Produce in enormous quantities also influenced easily.Iron content plated film with high Bs value is suitable for the soft magnetism backing layer.Yet,, be difficult to guarantee the stable of plating bath usually because iron forms divalent ion and trivalent ion.Therefore the production in enormous quantities of iron content plated film also is very poor.
Consider the relation between neticdomain wall forms in the soft magnetism backing layer that coercive force and plating method form, verified, although observe the trend of certain inhibition, the plated film coercivity value that is not less than 30Oe can not stop the formation of neticdomain wall fully.Prove further that also coercitive increase reduces read.
As mentioned above, can the glass disc base material of crystal glass or chemically reinforced glass is the same with the aluminum alloy base material with non magnetic NiP plated film, be installed in the magnetic recording medium disk substrate on the hard disk drive.Described have a magnetic recording medium that high-intensity glass baseplate is mainly used in the hard disk drive that needs high shock resistance.The above-mentioned soft magnetism plated film that is used to form also can effectively improve productivity as the glass disc base material of perpendicular magnetic recording media as the dectroless plating of backing layer.
Be actually used in aluminum alloy base material by the plated film of non magnetic Ni-P alloy composition, and mass-produced manufacture method is widely known by the people also with using the polished surface smoothing technique as hard disk.Therefore, on glass baseplate, if can form the adequate thickness (at least 1 micron) that is used as the superperformance disk with dectroless plating, conduct with good adhesive property has the non magnetic or soft magnetism coating of the bottom of gratifying smoothness, from the angle of production cost, the glass baseplate with plated film also gets a good chance of the base material as magnetic recording medium.
Very unfortunate, above-mentioned known dectroless plating all can't form Co-Ni-P on glass baseplate, Ni-P, the soft magnetism plated film of Ni-Fe-P or Co-Ni-Fe-P and have the thickness (1 micron to 3 microns) that is suitable for obtaining good disk, and have the non magnetic Ni-P plated film of this thickness of satisfactory binding property, homogeneity and smoothness.
Bottoms such as Ni-P also can form by sputtering process.Yet,, be difficult in and directly form bottom on the glass baseplate because the binding property between glass and the metal is very poor.In order to solve this difficult problem, need on glass baseplate, form the coating (this coating shows glass and intermetallic binding property relatively preferably) that contains titanium or chromium, on titanium or chromium adhesion layer, form bottom then.Titanium in this method in the adhesion layer or chromium do not have enough binding propertys.So when bottom or adhesion layer were very thick, the stress that can cause owing to coefficient of expansion difference caused fusible reduction.Recently the active perpendicular magnetic recording media that develops, its soft magnetism backing layer need be at 0.2 micron to 3.0 microns thick relatively coating.When with the spraying plating plated film, the problem that the soft magnetism backing layer has binding property to reduce also has the high problem of cost in addition.
Summary of the invention
Because top problem, an object of the present invention is to provide a kind of on glass substrate the method for plating (plating), this method can form the plated film with gratifying binding property and homogeneity with dectroless plating on glass substrate, coating film thickness is not less than 1 micron.Another object of the present invention provides a kind of by forming plated film with plating (plating) method on discoidal glass baseplate, make the method for the disk substrate of magnetic recording medium, satisfy thickness, binding property, homogeneity, smoothness and noise properties as the plated film that requires of the hard disk of magnetic recording medium.Also have another purpose to provide a kind of method of using the method for making disk substrate to make perpendicular magnetic recording media.
For finishing above-mentioned purpose, the present invention's method of plating on glass substrate comprises the treating processes of the substrate surface that glass material is constituted, this treating processes comprises the glass activation treatment step that substrate surface silanol group quantity is increased at least twice with dilute acid solution at least, the silane coupling agent treatment step, palladium catalyst treatment step and palladium be in conjunction with (bonding) step, and form process of plating with dectroless plating.
Described glass activation treatment step preferably includes the processing of sulfuric acid, nitric acid or the hydrochloric acid of the hydrochloric acid that uses 0.001-1 weight % and 0.1-1 weight %, or uses the hydrochloric acid of 0.001-1 weight % and the Neutral ammonium fluoride of 0.0005-0.5 weight % to handle.When the processing of glass activation step comprises with 0.1-10 weight % sulfuric acid, nitric acid or salt acid treatment and then uses 0.001-1 weight % hydrofluoric acid subsequent disposal, be more conducive to significantly increase silanol group quantity and improve binding property.When comprising in the glass activation treatment step, effective too with 0.001-1 weight % hydrofluoric acid aqueous solution and 0.0005-0.5 weight % ammonium fluoride aqueous solution mixture process.
The silane coupling agent treatment step preferably includes the processing of the silane coupling agent that uses the structure with following general formula (I) representative:
(C
mH
2m+1O)
3Si(CH
2)
nNHR (I)
Wherein R is selected from H, C
pH
2pNH
2, CONH
2And C
6H
5, m, n and p represent a positive integer separately.The palladium catalyst treatment step preferably includes the processing of using Palladous chloride and dilute sodium hydroxide mixing solutions or Palladous chloride and rare potassium hydroxide mixing solutions.The palladium integrating step preferably includes the processing of using the Hypophosporous Acid, 50 aqueous solution.
The production method that is used for the disk substrate of magnetic recording medium of the present invention, use above-mentioned plating method on disc glass baseplate substrate surface, to form non magnetic or soft magnetism plated film, the method of described production disk substrate comprises a kind for the treatment of processes, this treating processes comprises the glass activation treatment step that glass baseplate silane surface alcohol radical quantity is increased at least twice with dilute acid solution at least, the silane coupling agent treatment step, palladium catalyst treatment step and palladium are in conjunction with (bonding) treatment step; Form process of plating in addition.
For the smoothness of improving disk substrate after plating (plating) process with improve recording density, preferred maximum 0.5 nanometers of the surface roughness Ra of glass baseplate.The preferred dectroless plating that uses forms the plated film that the Ni-P alloy constitutes, and controls heat-up rate then and heat-treats.This step has been improved the binding property of Ni-P alloy coating.Thermal treatment preferably includes treatment temp is remained on 250 ℃ to 300 ℃ at least 1 hour operations and controls heat-up time, to be heated to the operation of above-mentioned treatment temp at least 2 hours from room temperature (25 ℃).
Manufacturing method according to the invention, can use dectroless plating to prepare the plated film that has from the soft magnetism to the non-magnetic material, this plated film does not contain the defective of foaming and so on and has fabulous binding property, can form with the Ni-P alloy that contains 1.0-13.0 weight % phosphorus, at least 1.0 microns of film thicknesses are enough to as the hard disk base material.
In the method for making disk substrate, by silane coupling agent processing on glass baseplate, formation silane coupling agent layer, on silane coupling agent layer, formed the palladium catalyst layer by the palladium catalyst processing, and on the palladium catalyst layer, formed soft magnetism coating with the chemical plating method; Made the disk substrate that is used for perpendicular magnetic recording media.
For described soft magnetism coating, can form soft magnetism coating with the chemical plating method, the soft magnetism plated film does not contain the defective of foaming and so on, shows fabulous binding property and noisiness, thickness is 0.2 micron to 3 microns, and this thickness is essential to the soft magnetism backing layer of perpendicular magnetic recording media.The soft magnetism plated film preferably by contain 3 atom % to 20 atom % phosphorus and also cobalt and nickle atom number than (Co/ (Co+Ni)) in the cobalt Co-Ni-P alloy that is at least 45 atom % constitute.
The perpendicular magnetic recording media of exhibits excellent noisiness and productive rate is made in the method manufacturing that can constructed in accordancely be used for the disk substrate of magnetic recording medium as the disk substrate of magnetic recording medium; and on disk substrate, form non magnetic kind layer (seed layer), magnetic recording layer and protective layer successively at least, wherein the soft magnetism coating in the disk substrate is used the part of the soft magnetism backing layer that acts on magnetic recording layer at least.
Of the present invention on glass substrate the method for plating (plating), use dectroless plating usually even can on the substrate that glass material constitutes, form at least 1 micron thick plated film with good adhesive property and homogeneity.
Manufacturing of the present invention provides the defective that does not contain foaming and so on as the method for the disk substrate of magnetic recording medium, and show outstanding fusible non magnetic or soft magnetism plated film, this plated film is formed on the glass baseplate, has essential thickness, homogeneity and smoothness.Therefore, present method provides a kind of disk substrate that is used to obtain the superperformance magnetic recording medium.
The method that is used to make perpendicular magnetic recording media of the present invention forms the soft magnetism plated film on glass baseplate, as the soft magnetism backing layer, thereby provide the perpendicular magnetic recording media with good noiseproof feature.Because the soft magnetism backing layer is to form with the dectroless plating of high yield, thus compare with the manufacturing of sputtering process and so on, even such thick film also can be with relatively low cost manufacturing.
Below described some according to the present invention on the glass chassis, use the preferred implementation of plating manufactured as the disk substrate of magnetic recording medium.Yet according to the present invention, the method for plating is not limited only to this kind application (application) on glass substrate.Usually the use dectroless plating forms at least 1 micron thickness on the glass material substrate, when having the non magnetic of good adhesive property and homogeneity or magnetic plated film, also can reach same effect.
The glass material substrate for example generally comprises, and is used for the glass of the flat-panel displays of liquid crystal, PDP, FED, EL and so on, is used for the glass as information equipments such as duplicating machine, also is useful on the glass of optical communication instrument, automobile, medical supply and material of construction.
Description of drawings
Fig. 1 has shown in an embodiment of the invention that a kind of manufacturing is used for the operation of the disk substrate method of magnetic recording medium;
Fig. 2 is the diagrammatic cross-section with the disk substrate that is used for magnetic recording medium of the manufacture method manufacturing of embodiment of the present invention;
Fig. 3 is the diagrammatic cross-section of the perpendicular magnetic recording media of embodiment of the present invention manufacture method manufacturing;
Fig. 4 is presented at after the various activation treatment, silanol group (Si-OH) the quantitative analysis result's that the glass baseplate surface of measuring with the thermal desorption mass spectrograph produces chart.
[denotational description]
1 glass baseplate
2 silane coupling agent layers
3 palladium catalyst layers
4 coating
10 disk substrates
20 non magnetic kind layers
30 magnetic recording layers
40 protective layers
The S1 skimming treatment
S2 glass activation treatment
The S3 silane coupling agent is handled
The S4 palladium catalyst is handled
The S5 palladium is in conjunction with processing
The S6 plated film
S7 thermal treatment
Embodiment
＜be used for the embodiment of manufacture method of the disk substrate of magnetic recording medium 〉
Fig. 1 has shown the embodiment process of making the method for the disk substrate that is used for magnetic recording medium according to an aspect of the present invention, and described manufacture method has been used the method for plating on glass substrate (plating) according to an aspect of the present invention.Fig. 2 is the diagrammatic cross-section with the disk substrate that is used for magnetic recording medium of the manufacture method manufacturing of present embodiment.
As shown in Figure 2, the glass baseplate 1 that comprises disc-shape with the disk substrate that is used for magnetic recording medium 10 of embodiment of the present invention manufacture method manufacturing, the silane coupling agent layer 2 that forms on glass baseplate 1 is at palladium catalyst layer 3 that forms on the silane coupling agent layer 2 and the coating 4 that forms on the palladium catalyst layer.
Although do not show among the figure that silane coupling agent layer 2, palladium catalyst layer 3 and coating 4 also can be at the another sides of glass baseplate 1.
The surface roughness Ra (JIS (Japanese Industrial Standards) B0601 definition) that is used as the base material of glass baseplate 1 mostly is 0.5 nanometer most.Base materials employed microcosmic surface waviness Wa (JIS B0601 definition) more preferably mostly is most 0.5 nanometer.
The surface roughness Ra of glass baseplate 1 has the physics anchor effect to coating 4.Use the base material of relatively large Ra can improve the binding property of coating 4 to a certain extent.Method of the present invention can be kept gratifying on the super smooth glass base material of surface roughness≤0.5 nanometer, and binding property coating 4 identical with the glass baseplate of surface roughness Ra＞0.5 nanometer almost do not have the physics anchor effect in the case.
Silanol group (Si-OH) that can be by glass baseplate 1 surface on the interface between glass baseplate 1 and silane coupling agent layer 2 interacts with the silanol group in the silane coupling agent that forms silane coupling agent layer, dehydration condensation takes place produce the extensive chemical bonding, thereby produce a kind of effect, this effect will be explained hereinafter.
By on glass baseplate, forming the non magnetic Ni-P plated film of high phosphorus concentration, described plated film 4 is used to the accurate smoothing of the high density recording that almost can't finish on the high rigidity glass baseplate, be used to make LZT base material (laser region structurizing (texturing) base material), be used for making (aligned) medium that anisotropy is arranged by band structureization (tape texturing), can also be by in magnetic film spraying plating process, on base material, applying the coercive force that bias voltage increases magnetic film.By forming the soft magnetism Ni-P plated film of low phosphorus concentration on glass baseplate, the soft magnetism backing layer that described Ni-P plated film is used to have the high saturation magnetic flux density forms the double-deck perpendicular magnetic recording media that promotes high density recording.
Except above-mentioned high phosphorus concentration Ni-P plated film and low phosphorus concentration plated film, by forming the non magnetic of medium phosphorus concentration to soft magnetism Ni-P plated film, described Ni-P film is used for bottom plated film (strike plating), as the adhesion layer of the low phosphorus concentration Ni-P plated film that forms on the bottom plated film.
Except above-mentioned Ni-P soft magnetism plated film, Co-Ni-P, Ni-Fe-P and Co-Ni-Fe-P soft magnetism plated film also can be used as the soft magnetism backing layer of perpendicular magnetic recording media.
Especially, a kind of contain 3 atom % to 20 atom % phosphorus and also cobalt and nickle atom number than (Co/ (Co+Ni)) in the cobalt Co-Ni-P alloy soft magnetic plated film that is at least 45 atom % be well suited for being used for the soft magnetism backing layer, avoid the soft magnetism backing layer to produce impulse noise.
Aspect this of embodiment, the manufacture method that is used for the disk substrate 10 of magnetic recording medium comprises, skimming treatment S1 step, glass activation treatment S2 step, silane coupling agent treatment S 3 steps, palladium catalyst treatment S 4 steps and palladium carry out on the glass baseplate surface as the glass material substrate in conjunction with handling the S5 steps in sequence, and plated film S6 step and thermal treatment S7 step subsequently.
Glass activation treatment S2 step preferably includes uses 0.001-1 weight % hydrochloric acid and 0.1-1 weight % sulfuric acid, nitric acid or salt acid treatment, or using 0.001-1 weight % hydrofluoric acid and 0.0005-0.5 weight % Neutral ammonium fluoride to handle, this is in order silicon amino on the glass baseplate 1 to be increased at least twice and to increase binding property.Especially, use 0.1-10 weight % sulfuric acid, nitric acid or salt acid treatment and subsequently with the combination treatment of 0.001-1 weight % hydrofluoric acid treatment the silanol group quantity on glass baseplate 1 surface has been increased three-to-four-fold or more.Use the mixture process of 0.001-1 weight % hydrofluoric acid aqueous solution and 0.0005-0.5 weight % ammonium fluoride aqueous solution, the quantity of silanol group has been increased at least 3 times.So these are handled has unusual effect to improving binding property.
Of the present invention on glass substrate the method for plating, can be used for above-mentioned multiple application by changing the material of the plated film that in plated film S6 step, forms.In the application of some material or plated film, heat treated S7 step can be omitted.However, plated film is still effectively improving binding property.
[first aspect of embodiment]
Next described first aspect of embodiment, promptly a kind of preparation method who is used for the disk substrate of magnetic recording medium has formed plated film 4 by non magnetic to soft magnetism Ni-P alloy coating by plated film S6 step in this method.
(skimming treatment S1 step)
The first step of this aspect of embodiment is in the skimming treatment S1 on glass baseplate 1 surface step.Described skimming treatment S1 step can be carried out a step with the alkaline inorganic compound aqueous solution and be handled.Yet this step is preferably carried out with two steps, comprises with alkaline cleaning agent solution and handles and handle with the alkaline inorganic compound aqueous solution.
The alkaline cleansing agent that uses in this step, its pH value of solution value is 9.0-11.0, specifically comprises a kind of aniorfic surfactant.This alkaline cleaning agent solution preferably comprises 1-10 weight % alkaline cleansing agent.Use the processing of alkaline cleaning agent solution preferably will to carry out in the glass baseplate 1 immersion alkaline cleaning agent solution.As required, can stir detergent solution simultaneously or the ultrasonic wave radiation.Generally handled 1 to 10 minute down at 20-70 ℃.
The alkaline inorganic compound that uses in this step comprises NaOH, KOH, LiOH and Ba (OH)
2Preferred 1 to the 15 weight % of the alkaline inorganic compound that the aqueous solution of alkaline inorganic compound comprises, more preferably 5 to 10 weight %, pH value preferred 13.0 to 14.0.The processing of using the alkaline inorganic compound aqueous solution is preferably by carrying out in the aqueous solution that glass baseplate 1 is immersed alkaline inorganic compound.As requested, can stir detergent solution simultaneously or the ultrasonic wave radiation.Generally handled 1 to 10 minute down at 20 to 70 ℃.
By implementing skimming treatment S1 step, removed the organic film or the particle that are adsorbed on the glass baseplate 1, cleaned the surface of glass baseplate 1.
(glass activation treatment S2 step)
Next carry out glass activation treatment S2 step.Described glass activation treatment S2 step has been peeled the torpescence oxide film that is present in glass baseplate 1 surface off, and simultaneously the functional group modification on glass baseplate 1 surface has been become to have the silanol group (Si-OH) of active character, thereby be that hereinafter the surface with reaction pair glass baseplate 1 silane coupling agent that will describe activates.
As described in patent document 5, can handle on the glass baseplate surface with warm water and generate minor amount of silicon silane alcohol base (Si-OH).But, only with seldom being dissociated into H in essence
++ OH
-Water (H
2O) molecularity, the amount of the silanol group of increase is very limited.On the contrary, glass baseplate is immersed specific a large amount of H that contain
+Handle in the ionic dilute acid soln, can produce with respect to four times of warm water treatment effects or more silanol group (Si-OH).
Glass activation treatment S2 step is undertaken by glass baseplate 1 is immersed in the dilute acid solution.The acid that can be used for dilute acid solution comprises the material that contains fluorine atom and can remove oxide film from glass surface, for example hydrofluoric acid (HF), fluoroboric acid (HBF
4), hexafluorosilicic acid (H
2SiF
6) and phosphofluoric acid (HPF
6).Wherein preferred acid is hydrofluoric acid.Can in dilute acid solution, add inorganic salt compound.The inorganic salt compound preferred fluorinated thing that adds, for example Neutral ammonium fluoride or Sodium Fluoride.
The hydrofluoric acid of the used preferred 0.001-1 weight of dilute acid solution % in this step, or the mixing solutions of 0.001-1 weight % hydrofluoric acid and 0.001-1 weight % sulfuric acid, hydrochloric acid or nitric acid.The mixing solutions of preferred too 0.001-1 weight % hydrofluoric acid and 0.0005-0.5 weight % Neutral ammonium fluoride.The processing that use contains the dilute acid solution of fluorion was preferably carried out extra processing with the diluted mineral acid aqueous solution that does not contain fluorion before or after handling, comprise with dilute sulphuric acid (H
2SO
4) processing, the processing of dilute hydrochloric acid (HCl), rare nitric acid (HNO
3) processing and/or the processing of 0.1-10 weight % dilute hydrogen peroxide.Generally under 20 to 50 ℃ of temperature, handled 1 to 10 minute.
(silane coupling agent treatment S 3 steps)
Next, the glass baseplate 1 that carried out glass activation treatment S2 is carried out silane coupled treatment S 3 steps, thereby on glass baseplate 1, form silane coupling agent layer 2.Spendable silane coupling agent preferably comprises the compound with following general formula (I) structure for to have the alkyltrialkoxysilaneand (so-called amino one type of silane coupling agent) of nitrogen substituting group (amino) on alkyl in this step:
(C
mH
2m+1O)
3Si(CH
2)
nNHR (I)
Wherein R is selected from H, C
pH
2pNH
2, CONH
2And C
6H
5, m, n and p represent a positive integer separately.Preferred m is 1 or 2, and n is 2 to 4 integer, and p is 2 to 4 integer.Compound used therefor is the compound to (IX) or its mixture Zi (II) more preferably.
(CH
3O)
3SiC
3H
6NH
2(II)
[3-aminopropyl trimethoxysilane]
(C
2H
5O)
3SiC
3H
6NH
2(III)
[3-aminopropyl triethoxysilane]
(CH
3O)
3SiC
3H
6NHC
2H
4NH
2(IV)
[N-(2-aminoethyl)-3-aminopropyl trimethoxysilane]
(C
2H
5O)
3SiC
3H
6NHC
2H
4NH
2(V)
[N-(2-aminoethyl)-3-aminopropyl triethoxysilane]
(CH
3O)
3SiC
3H
6NHC
6H
5(VI)
[N-phenyl-3-aminopropyl trimethoxysilane]
(C
2H
5O)
3SiC
3H
6NHCONH
2(VII)
[3-urea groups propyl-triethoxysilicane]
(C
2H
5O)
3SiC
3H
6N＝C(C
4H
9)CH
3(VIII)
[3-triethoxysilyl-N-(1,3-dimethyl butylidene)-propylamine]
(CH
3O)
2(CH
3)SiC
3H
6NHC
2H
4NH
2(IX)
[N-(2-aminoethyl)-3-aminopropyl methyl dimethoxysilane]
Silane coupling agent generally uses in the aqueous solution of 0.1-4.0 weight %.For the silane coupling agent (for example, the compound of chemical formula (VII)) of low solubility in water, be dissolvable in water in the mixed solvent of 0.1-2.0 weight % acetic acid aqueous solution or water-alcohol (for example, alcohols such as methyl alcohol, ethanol) and use.(described mixed solvent also can contain acetate.)
Silane coupling agent treatment S 3 steps preferably immerse glass baseplate 1 in the silane coupler solution carries out.As required, can stir solution simultaneously or the ultrasonic wave radiation.Generally handled 1 to 10 minute down at 20 to 30 ℃.The thickness of the silane coupling agent layer 2 that forms is the 10-50 nanometer.
Following texts and pictures are separated shown in 1, the alkoxy grp in the silane coupling agent by with the aqueous solution or aqueous solution in water generation hydrolysis become silanol group, silane coupling agent partly is condensed into oligomeric states of matter then.Silane coupling agent under this state is bonded together securely by the silanol group that is created on the glass baseplate surface in hydrogen bond action and the glass activation treatment S2 step.
[Chemical formula 1]
Diagram 1
(palladium catalyst treatment S 4 steps)
Then the glass baseplate 1 with the silane coupled layer 2 that forms is carried out palladium catalyst treatment S 4 steps in previous step.Described palladium catalyst treatment S 4 steps are undertaken by glass baseplate 1 is immersed in the aqueous solution that contains the divalent palladium ion.Palladous chloride (PdCl for example
2) can be used for containing the aqueous solution of divalence palladium ion.In this step, can be by in containing aqueous palladium, adding the basic cpd of NaOH or KOH and so on, promote the reaction between the N-functional group (functional groups such as amino, imino-, urea groups) of palladium ion and silane coupling agent.This step is preferably containing 0.01-1.0 weight % palladium ion (PdCl
2Conversion content) and in 0.01-1.0 weight % basic cpd (the KOH conversion content) aqueous solution carry out.This is handled generally and handled 1 to 10 minute in 20 to 30 ℃ of scopes.
This step is attached to palladium ion in the N-functional group of silane coupling agent by effects such as coordinate bonds, has formed the palladium catalyst film 3 as the plated film catalyzer.Palladium catalyst film 3 thickness of described formation are 1 to 10 nanometer.
(palladium is in conjunction with handling the S5 step)
Then, carry out palladium in conjunction with handling the S5 step.This step immerses Hypophosporous Acid, 50 (H by the glass baseplate 1 that will have the palladium catalyst film that forms in front
3PO
2) carry out in the aqueous solution.By the processing in the Hypophosporous Acid, 50 aqueous solution, chlorine dissociates from the complex compound that forms with palladium, and has set up the strong bonding condition between silane coupling agent and the palladium as catalyst component.In this process, remove unnecessary free palladium.The described Hypophosporous Acid, 50 aqueous solution preferably contains 0.1 to 1.0 weight % Hypophosporous Acid, 50.Carried out 1 to 5 minute at 20 to 30 ℃ as this step 1.
(plated film S6 step)
Next, carrying out carrying out Ni-P plated film step S6 on the glass baseplate 1 of palladium in conjunction with processing S5, form Ni-P alloy coating coating 4.This step preferably immerses glass baseplate 1 in the chemical plating fluid carries out.According to phosphorus concentration, gained Ni-P coating 4 shows various magnetic properties, from soft magnetism (under the situation of low phosphorus concentration) to non magnetic (under the situation at high phosphorus concentration).
This step can be used the chemical plating fluid of various phosphorus concentrations.The example of described chemical plating fluid comprises: non magnetic high phosphorus concentration Ni-P plating bath (phosphorus concentration 10-13 weight %; C.Uyemura﹠amp; Co.Ltd. make NIMUDENHDX), non magnetic to the medium phosphorus concentration Ni-P of soft magnetism plating bath (phosphorus concentration 6-10 weight %; Meltex Inc. makes MELPLATE NI-867 and phosphorus concentration 3-6 weight %; Meltex Inc. makes MELPLATENI-802) and low phosphorus concentration Ni-P plating bath (the phosphorus concentration 1-2 weight % of soft magnetism; C.Uyemura﹠amp; Co.Ltd. make NIMUDEN LPY and Okuno chemical industry company limited and make TOP NICORON LPH).This step also can be used the high phosphorus concentration Ni-P chemical plating fluid greater than 14 weight % phosphorus concentrations of having that can commercial buy, and promotes the precipitin reaction of plating.
This step can be carried out in suitable time and temperature by Ni-P plated film 4 thickness as required.Ni-P plated film 4 thickness are at least 1.0 microns, preferred 1 micron to 5 microns, generally can obtain in 10 to 45 minutes by handling at 70 to 90 ℃ in this step.
(thermal treatment S7 step)
At last, on glass baseplate 1, heat-treat the S7 step with Ni-P plated film 4.This step has been improved the binding property of 4 pairs of glass baseplates 1 of Ni-P coating in the homogeneity and Ni-P coating 4 surface smoothnesses that keep coating film thickness.This step has triggered the silanol group on glass baseplate 1 surface and by the dehydration condensation between the hydrogen bond adherent silane coupling agent silanol group, has formed strong chemical bond (covalent linkage) between them.Therefore, improve the binding property between glass baseplate 1 and the silane coupling agent layer 2, also improved the binding property between glass baseplate 1 and the Ni-P coating 4.
Heat treatment step was preferably handled 1 hour under 250 ℃ to 300 ℃ temperature at least, and preferred 2 to 12 hours, more preferably 3 to 6 hours.Herein, be rapidly heated can be owing to the coefficient of linear expansion of glass baseplate 1 coefficient of linear expansion and Ni-P coating 4 different, and between glass baseplate 1 and Ni-P coating 4, produce stress, in Ni-P coating 4, cause and bubble or the defective in crack and so on.In order to lower the generation of this stress, in this step, temperature is elevated to treatment temp from room temperature (25 ℃) with at least 2 hours, preferably at least 6 hours, more preferably at least 12 hours.Promptly heat-up rate is limited in 135 ℃/hour in the heat-processed of this step, preferably in 40 ℃/hour, more preferably in 20 ℃/hour.
For stoping the Ni-P plated film that the purpose of thermooxidizing takes place when the thermal treatment, this step is preferably carried out under rare gas element (for example, nitrogen, helium or argon gas) atmosphere.
The Ni-P plated film 4 that forms with the inventive method can access the magnetic plate base material with excellent properties.The thickness of the Ni-P coating 4 that the inventive method forms is at least 1 micron, has uniform thickness, and highly level and smooth film surface does not have defectives such as foaming, crack.
More particularly, Ni-P coating 4 of the present invention can be used for following application according to phosphorus concentration.
By on non magnetic glass baseplate, forming non magnetic high phosphorus concentration Ni-P coating, these application may comprise: (a) the accurate smoothing of very difficult high density recording in the high rigidity glass baseplate, (b) by band structure manufacturing LZT base material and anisotropy calibrate medium, and (c) by in the spraying plating process, on base material, applying the coercive force that bias voltage increases magnetic film.
By form the low phosphorus concentration Ni-P plated film of soft magnetism on non magnetic glass baseplate, described plated film can be used as the soft magnetism backing layer of perpendicular magnetic recording media.Be called as perpendicular magnetic recording media double-deck perpendicular magnetic recording media, that have the soft magnetism backing layer, has the soft magnetism backing layer that shows hypertonicity and high saturation magnetic flux metric density under the magnetic recording layer that plays the information writing function, can also promote returning of magnetic flux that magnetic head produces, thereby reach high density recording.
By on non magnetic glass baseplate, forming non magnetic medium phosphorus concentration Ni-P plated film to soft magnetism, the same with low phosphorus concentration Ni-P plated film Application Areas with above-mentioned high phosphorus concentration Ni-P plated film, described plated film is used for bottom plated film (strike plating) as the bonding coat between low phosphorus concentration Ni-P plated film and the glass baseplate.
[second aspect of embodiment]
Next described second aspect that is used for perpendicular magnetic recording media disk substrate manufacture method embodiment, wherein formed coating 4 with soft magnetism Co-Ni-P alloy coating by plated film S6 step.
Because step S1 is identical with first aspect of above-mentioned embodiment to S5 in aspect second of this embodiment, and plated film S6 step and thermal treatment S7 step are described below.
In plated film treatment S 6 steps, carrying out having formed coating 4 on the glass substrate 1 of palladium in conjunction with processing S5 step.
For soft magnetism backing layer as the vertical magnetism record, described plated film 4 be preferably the Co-Ni-P alloy composition contain 3 atom % to 20 atom % phosphorus and also cobalt and nickle atom number than (Co/ (Co+Ni)) in cobalt be at least 45 atom %, the soft magnetism plated film that thickness is 0.2 micron to 3 microns.Described soft magnetism Co-Ni-P alloy coating also preferably comprises 2 atom % tungsten or manganese at the most, because these add composition when not influencing the soft magnetism backing layer function of plated film 4, has improved erosion resistance.Also can be added to the germanium or the lead compound of many several per-cents, when not damaging effect of the present invention, stablize plating bath.
Soft magnetism coating 4 needs at least 0.2 micron thickness with the soft magnetism backing layer as perpendicular magnetic recording media that can high density recording, from 3 microns at the most of the angle thickness requirements of productivity.
About the composition of soft magnetism plated film 4, the phosphorus concentration that is lower than 3 atom % almost can't form stable plated film, causes low saturation flux density Bs and be higher than 20 atom % phosphorus concentrations, can't exercise the function of soft magnetism backing layer.
Cobalt and nickle atom number are not suitable for being lower than 45 atom % than (Co/ (Co+Ni)) middle cobalt concentration, and this is because saturation flux density Bs can't keep enough height, and the saturation magnetostriction constant becomes the negative value with big absolute value.
Although to the upper limit of cobalt concentration not strictness be restricted to certain particular value, cobalt and nickle atom number are higher than the CoNi alloy that 90 atom % trend towards obtaining having the macrocrystal magnetic anisotropy constant of sexangle intensive (hcp) structure than (Co/ (Co+Ni)) middle cobalt concentration, can increase coercive force, be disadvantageous therefore.Form preferred cobalt and nickle atom number than comprising at least 10 atom % cobalts in (Co/ (Co+Ni)), with stable face-centered cubic (fcc) structure that forms.
After forming soft magnetism coating 4, can heat-treat the S7 step, although in this one side of embodiment of the present invention, needn't just can obtain required performance to the plated film heating.As long as the saturation magnetostriction constant of relation of the thermal expansivity between glass baseplate 1 and the coating 4 and soft magnetism plated film 4 maintains the degree of describing in the above-mentioned patent document, heat-processed just seldom can reduce the magnetic behavior and the noisiness of soft magnetism coating 4 owing to the magneticanisotropy that thermal dilation difference between glass baseplate 1 and the soft magnetism plated film 4 causes.
When having between palladium catalyst layer 3 on the glass baseplate 1 and the soft magnetism coating 4 when being used to improve the fusible bonding coat of being made up of non magnetic NiP film and so on, effect of the present invention is kept.After forming soft magnetism coating 4 or above-mentioned thermal treatment, can carry out polished finish smoothing is carried out on the surface of soft magnetism coating 4 with dectroless plating.Can use free abrasive (free abrasive) that effective polishing and level and smooth is carried out on the surface of soft magnetism coating 4.Can use double head type polishing machine and polish the abrasive material that adds suspension aluminum oxide or colloidal silica and so on polyurethane foam polishing sheet.After the polished finish, can heat-treat.
The following condition that requires emphasis has for formation that the inventive method of excellent adhesiveness forms, and comprises that soft magnetism coating 4 is extremely important in glass baseplate 1/ silane coupling agent layer 2/ palladium catalyst layer 3/Co-Ni-P soft magnetism coating 4 structures shown in Figure 2.
1) forms the high-density palladium catalyst layer 3 that deposits coating thereon.
2) for above-mentioned condition 1), the highdensity silane coupling agent layer 2 of formation of deposits below palladium catalyst layer 3.
3) for above-mentioned condition 2), on glass baseplate 1 surface, exist a large amount of can with the silanol group (Si-OH) of silane coupling agent bonding.
Therefore, must reach: the high-density of the high-density=silane coupling agent layer of the good adhesive property of plated film=palladium catalyst layer=glass baseplate surface high-density generates silanol group.Glass activation treatment S2 step has increased the silanol group quantity on glass baseplate surface.
Graphical presentation among Fig. 4 the detected result of silanol group (Si-OH) quantity that the glass baseplate surface generates after the different activation treatment of measuring with the thermal desorption mass spectrograph.Table 1 has been listed the silanol group quantity of being measured.
[table 1]
| The glass activation treatment | Si-OH base set amount (group quantity/square centimeter) |
| Before the processing | 0.92×10 15 |
| HF → warm water is handled | 1.16×10 15 |
| HF+NH 4F handles | 2.88×10 15 |
| H 2SO 4→ HF handles | 4.08×10 15 |
The silanol group quantity on glass baseplate surface before the comparison process, the effect of warm water glass activation treatment is very little.On the contrary, use HF+NH
4The F mixing solutions is handled and is produced about triple silanol group, and ensuing H
2SO
4→ HF handles to have produced and surpasses four times silanol group.Like this, can expect obviously to improve the fusible effect of plated film with processing of the present invention.
The aspect of the method embodiment of＜production perpendicular magnetic recording media 〉
Next describe the disk substrate of making in aspect second of above-mentioned embodiment that is used for perpendicular magnetic recording media used according to the invention, made an aspect of perpendicular magnetic recording media method embodiment.As shown in Figure 3; the perpendicular magnetic recording media that the manufacture method of this aspect is made according to the present invention, its structure are included at least one non magnetic kind layer 20, magnetic recording layer 30 and the protective layer 40 that forms successively on the disk substrate 10 that is used for perpendicular magnetic recording media among Fig. 2.
Although do not show among Fig. 3, described non magnetic kind layer 20, magnetic recording layer 30 and protective layer 40 also can form at the other side of disk substrate 10.
The described layer 20 of planting can be made of the material of smooth control magnetic recording layer 30 crystal location and particle size, without any particular restriction.For example when vertical magnetized film that magnetic recording layer 30 constitutes for the CoCrPt alloy, described non magnetic kinds layers 20 can be made of CoCr alloy, titanium or titanium alloy or ruthenium or ruthenium alloy.When magnetic recording layer 30 be lamination cobalt-base alloy layer and platinum or palladium form so-called lamination vertical magnetism film the time, described non magnetic kinds layers 20 can be made of platinum or palladium.Under the situation that does not hinder effect of the present invention, on non magnetic kind layer 20 or below pre-kind layer (pre-seed layer) or middle layer can be arranged.
Described magnetic recording layer 30 can be write down in perpendicular magnetic recording media and the material of representation constitutes by any permission.Described material can be selected from the vertical magnetized film that is made of the CoCrPt alloy mentioned above, oxidiferous CoCrPt alloy, or comprise the so-called vertical magnetized film of cobalt-base alloy and platinum or palladium layer.Described protective layer 40 is films that one deck mainly is made of carbon and so on.Described protective layer also can be mainly formed by the film of carbon and liquid lubricant layer, and this film is applied on the carbon film by the liquid lubricant with PFPE and so on and forms.
Can form described non magnetic kind layer 20, magnetic recording layer 30 and protective layer 40 by being selected from sputtering process, CVD, vacuum-evaporation, plating film formation technology such as (plating).
Perpendicular magnetic recording media according to above-mentioned manufacturing has good read as double-deck perpendicular magnetic recording media, and this is because the soft magnetism coating 4 in the disk substrate 10 has played the soft magnetism backing layer.In addition, described soft magnetism backing layer forms with the dectroless plating of performance high yield.Therefore, described medium can be with low-down cost manufacturing, because backing layer need be with the expensive methods manufacturing of sputtering process and so on.
[embodiment]
Next some specific embodiments of some first and second aspect of above-mentioned embodiment according to the present invention will be described.
[embodiment of Ni-P plated film (plated) base material]
Table 2 has been summed up the step of Ni-P plating (plating) method and about the underlying condition of the embodiment 1 to 8 of first aspect of above-mentioned embodiment.Described coating 4 and other coating form at two faces of glass baseplate.
The step and the underlying condition of table 2Ni-P plating method
| Treatment step | Treatment liq | Concentration (weight %) | Temperature (℃) | Treatment time (minute) |
| (1) sanitising agent degreasing | Alkaline cleansing agent | 1.5 | 50 | 3 |
| (2) alkali degreasing | KOH | 7.5 | 50 | 3 |
| (3) glass activation | HF+NH 4F | 1.0+0.5 | 20 | 3 |
| (4) silane coupling agent is handled | Chemical formula (III) or (V) | 1.0 | 20 | 3 |
| (5) palladium catalyst is handled | PdCl 2+NaOH | 1.0+0.2 | 20 | 3 |
| (6) palladium is in conjunction with processing | H 3PO 2 | 1.0 | 20 | 3 |
| (7) Ni-P plated film | NIMUDEN HDX | 80 | 20 | |
| Melplate NI-867 | 70 | 35 | ||
| NIMUDEN LPY | 80 | 25 | ||
| (8) thermal treatment | 30 ℃ → (12 hours or 2 hours) → 250 ℃ (4 hours) → (12 hours or 2 hours) → at N 2In 30 ℃ | |||
(embodiment 1)
Chemical enhanced amorphous boron alumina silicate glass sheet (Ra=0.25 nanometer) is as glass baseplate 1.Form Ni-P coating 4 by carrying out the following step (1) successively to step (8).
(1) sanitising agent degreasing: handled in 3 minutes by the alkaline cleansing agent aqueous solution that immerses 1.5 weight % at 50 ℃.
(2) alkali degreasing: handled in 3 minutes by the KOH aqueous solution that immerses 7.5 weight % at 50 ℃.
(3) glass activation: by immersing HF (concentration 1.0 weight %) and NH at 20 ℃
4F (concentration 0.5 weight %) mixed aqueous solution was handled in 3 minutes.
(4) silane coupling agent is handled: by handling in 3 minutes in 3-aminopropyl triethoxysilane (compound of chemical formula (the III)) aqueous solution that immerses 1.0 weight % at 20 ℃.
(5) palladium catalyst is handled: by immersing PdCl at 20 ℃
2(concentration 1.0 weight %) and NaOH (concentration 0.2 weight %) mixed aqueous solution was handled in 3 minutes.
(6) palladium is in conjunction with processing: by the H that immerses 1.0 weight % at 20 ℃
3PO
2The aqueous solution was handled in 3 minutes.
(7) Ni-P plated film: by immersing plating bath " NIMUDEN HDX (phosphorus concentration 10 to 13 weight %) " (C.Uyemura﹠amp at 80 ℃; Co.Ltd. manufacturing) handle the Ni-P coating that formed 3.0 micron thickness in 20 minutes.
(8) thermal treatment: temperature was elevated to 250 ℃ from 30 ℃ in 12 hours, kept 4 hours at 250 ℃, dropped to 30 ℃ then in 12 hours.(temperature raises and the speed of reduction is 18.3 ℃/hour) (embodiment 2)
Except the step among the embodiment 1 (7) is replaced with the following step (7B), with embodiment 1 in identical step form Ni-P coating.
(7B) handle the 35 minutes thick 3.0 microns Ni-P coating of formation by immersing plating bath " Melplate NI-867 (phosphorus concentration 6 to 8 weight %) " (MeltexInc manufacturing) at 70 ℃.
(embodiment 3)
Except the step among the embodiment 1 (7) is replaced with the following step (7C), with embodiment 1 in identical step form Ni-P coating.
(7C) by immersing plating bath " NIMUDEN LPY (phosphorus concentration 1 to 2 weight %) " (C.Uyemura ﹠amp at 80 ℃; Co.Ltd. make) 25 minutes thick 3.0 microns Ni-P coating of formation of processing.
(embodiment 4)
Except the step among the embodiment 1 (4) is replaced with the following step (4B), with embodiment 1 in identical step form Ni-P coating.
(4B) handled in 3 minutes by N-(2-aminoethyl)-3-aminopropyl triethoxysilane (compound of chemical formula V) aqueous solution processing of immersing 1.0 weight % at 20 ℃.
(embodiment 5)
Except will the step among the embodiment 2 (4) replacing with the step of describing among the embodiment 4 (4B), with embodiment 2 in identical step form Ni-P coating.
(embodiment 6)
Except will the step among the embodiment 3 (4) replacing with the step of describing among the embodiment 4 (4B), with embodiment 3 in identical step form Ni-P coating.
(embodiment 7)
Except the step among the embodiment 3 (8) is replaced with the following step (8B), with embodiment 3 in identical step form Ni-P coating.
(8B) temperature was elevated to 250 ℃ from 30 ℃ in 2 hours, kept 4 hours at 250 ℃, was reduced to 30 ℃ then in 2 hours.(temperature raises and the speed of reduction is 110 ℃/hour.)
(embodiment 8)
Except will the step among the embodiment 6 (8) replacing with the step of describing among the embodiment 7 (8B), with embodiment 6 in identical step form Ni-P coating.
(Comparative Examples 1)
Chemical enhanced amorphous boron alumina silicate glass sheet (Ra=0.25 nanometer) is as glass baseplate 1.Form Ni-P coating by carrying out the following step (9) successively to step (15).
(9) sanitising agent degreasing: handled in 3 minutes by the alkaline cleansing agent aqueous solution that immerses 1.5 weight % at 50 ℃.
(10) alkali degreasing: handled in 3 minutes by the KOH aqueous solution that immerses 7.5 weight % at 50 ℃.
(11) glass surface roughening: by handling in 10 minutes at 60 ℃ of immersion chromic acid (concentration 40 weight %) and sulfuric acid (concentration 40 weight %) mixed aqueous solution.
(12) provide the catalyst treatment of catalyzer: by immersing PdCl at 20 ℃
2(concentration 0.3 grams per liter), SnCl
22H
2The mixed aqueous solution of O (concentration 15 grams per liters) and 36%HCl (200 milliliters/liter of concentration) was handled in 3 minutes.
(13) provide the accelerate process of catalyzer: by the H that immerses 100 grams per liter concentration at 50 ℃
2SO
4The aqueous solution was handled in 5 minutes.
(14) Ni-P plated film: by immersing plating bath " NIMUDEN HDX (phosphorus concentration 10 to 13 weight %) " (C.Uyemura ﹠amp at 80 ℃; Co.Ltd. manufacturing) handle the Ni-P coating that formed 0.4 micron thickness in 20 minutes.(owing to peeling off of film can occur in this plating (plating) process, thickness is impossible above 0.4 micron)
(15) thermal treatment: temperature under nitrogen atmosphere 250 ℃ kept 4 hours.
(Comparative Examples 2)
Except the step in the Comparative Examples 1 (14) is replaced with the step (14B) that describes below, with Comparative Examples 1 in identical step form Ni-P coating.
(14B) handle the Ni-P coating that formed 0.7 micron thickness in 9 minutes by immersing plating bath " Melplate NI-867 (phosphorus concentration from 6 to 8 weight %) " (Meltex Inc. manufacturing) at 80 ℃.(because peeling off of film taken place in the plating process, thickness can not be above 0.7 micron.)
(Comparative Examples 3)
Except the step in the Comparative Examples 1 (14) is replaced with the step (14C) that describes below, with Comparative Examples 1 in identical step form Ni-P coating.
(14C) by immersing plating bath " NIMUDEN LPY (phosphorus concentration from 1 to 2 weight %) " (C.Uyemura ﹠amp at 80 ℃; Co.Ltd. manufacturing) handle the Ni-P coating that formed 0.5 micron thickness in 3.0 minutes.(because peeling off of film taken place in the plating process, thickness can not be above 0.5 micron.)
(Comparative Examples 4)
Except the step among the embodiment 1 (8) is replaced with the step (8C) that describes below, with embodiment 1 in identical step form Ni-P coating.
(8C) thermal treatment: temperature was elevated to 250 ℃ from 30 ℃ in 1 hour, kept 4 hours at 250 ℃, was reduced to 30 ℃ then in 1 hour.(temperature raises and the speed of reduction is 220 ℃/hour.)
(Comparative Examples 5)
Except the step among the embodiment 2 (8) is replaced with the step of describing in the Comparative Examples 4 (8C), with embodiment 2 in identical step form Ni-P coating.
(Comparative Examples 6)
Except the step among the embodiment 3 (8) is replaced with the step of describing in the Comparative Examples 4 (8C), with embodiment 3 in identical step form Ni-P coating.
(evaluation)
Each glass baseplate that embodiment 1 to 8 and Comparative Examples 1 to 6 are obtained with the Ni-P plated film that forms with dectroless plating, by observation by light microscope (ratio of enlargement: * 50) estimate the foaming of Ni-P coating, and by crosscut (cross-cut) stripping test (JIS (Japanese Industrial Standards) K5600-3-4) evaluation binding property.In addition, carry out the surface roughness measurement with atomic force microscope (AFM) and estimate plating (plating) average rugosity Ra afterwards.Evaluation result is listed in table 3.
The thickness of [table 3] described Ni-P plated film, binding property and surface roughness evaluation
| Coupling agent *1 | Coating *2 | Thickness of coating (micron) | Heating condition | Bubble | Binding property *3 | Surface roughness Ra (nanometer) | |
| Embodiment 1 | Chemical formula (III) | HDX | 3.0 | (8) | Do not observe | ○ | 0.32 |
| Embodiment 2 | Chemical formula (III) | NI-867 | 3.0 | (8) | Do not observe | ○ | 0.33 |
| Embodiment 3 | Chemical formula (III) | LPY | 3.0 | (8) | Do not observe | ○ | 0.32 |
| Embodiment 4 | The chemistry formula V | HDX | 3.0 | (8) | Do not observe | ○ | 0.33 |
| Embodiment 5 | The chemistry formula V | NI-867 | 3.0 | (8) | Do not observe | ○ | 0.33 |
| Embodiment 6 | The chemistry formula V | LPY | 3.0 | (8) | Do not observe | ○ | 0.32 |
| Embodiment 7 | Chemical formula (III) | LPY | 3.0 | (8B) | Do not observe | ○ | 0.34 |
| Embodiment 8 | The chemistry formula V | LPY | 3.0 | (8B) | Do not observe | ○ | 0.33 |
| Comparative Examples 1 | Sn/Pd | HDX | 0.4 | (15) | Observe | × | 0.52 |
| Comparative Examples 2 | Sn/Pd | NI-867 | 0.7 | (15) | Observe | × | 0.68 |
| Comparative Examples 3 | Sn/Pd | LPY | 0.5 | (15) | Observe | × | 0.57 |
| Comparative Examples 4 | Chemical formula (III) | HDX | 3.0 | (8C) | Observe | × | 0.32 |
| Comparative Examples 5 | Chemical formula (III) | NI-867 | 3.0 | (8C) | Observe | × | 0.34 |
| Comparative Examples 6 | Chemical formula (III) | LPY | 3.0 | (8C) | Observe | × | 0.32 |
*1 chemical formula (III) compound: 3-aminopropyl triethoxysilane
Chemistry formula V compound: N-(2-aminoethyl)-3-aminopropyl triethoxysilane
*2HDX:NIMUDEN HDX (C.Uyemura﹠amp; CO.Ltd. make)
NI-867:Melplate NI-867 (Meltex Inc manufacturing)
LPY:NIMUDEN LPY (C.Uyemura﹠amp; CO.Ltd. make)
*All do not occur peeling off in 3 zero: ten samples
*: peeling off appears at least one sample in ten samples
Result according to embodiment in the table 31 to 8 clearly finds, uses the inventive method all can reach 3.0 microns from low phosphorus concentration to high phosphorus concentration Ni-P coating film thickness.The chemical Ni-P plated film that obtains with the inventive method does not produce the foaming defective, and shows fabulous binding property.The Ni-P coating surface that obtains has the surface roughness level that remains on the hard disk base material requires with approximately equalised surface roughness of base material (Ra=0.25 nanometer) and numerical value.
On the contrary, using (seeing patent document 3) Comparative Examples 1 to 3 of tin chloride (II) and palladium catalyst that thickness is provided according to currently known methods only is 0.4 to 0.7 micron Ni-P coating, and can't obtain the Ni-P coating that thickness is not less than 1.0 microns.Gained Ni-P coating has the foaming defective, shows obvious reduction and binding property glass baseplate, and has very big surface roughness.
The Comparative Examples 4 to 6 that has the temperature rising of increase and underspeed has produced Ni-P coating and has bubbled, and this is owing to glass baseplate when thermal treatment causes with the stress of the different generations of Ni-P plated film coefficient of linear expansion.The binding property of Ni-P coating and glass baseplate has also significantly reduced.
[plating Co-Ni-P base material embodiment]
Table 4 has been summed up the step of Co-Ni-P method for plating and about the underlying condition of second aspect embodiment of above-mentioned embodiment 9 to 18.Described coating 4 and other coating form at two faces of glass baseplate.
[table 4] Co-Ni-P method for plating step and underlying condition
| Treatment step | Treatment liq | Concentration | Temperature (℃) | Treatment time (minute) |
| (1) sanitising agent degreasing | Alkaline cleansing agent | 1.5 weight % | 50 | 3 |
| (2) alkali degreasing | KOH | 7.5 weight % | 50 | 3 |
| (3) glass activation | H 2SO 4→ HF, HCl → HF, or HF+NH 4F | Various | 20 | 3 |
| (4) silane coupling agent is handled | Chemical formula (III) or (V) | 1.0 weight % | 20 | 3 |
| (5) palladium catalyst is handled | PdCl 2+NaOH | 1.0+0.2 weight % | 20 | 3 |
| (6) palladium is in conjunction with processing | H 3PO 2 | 1.0 weight % | 20 | 3 |
| (7) Co-Ni-P plated film | Single nickel salt rose vitriol sodium hypophosphite Trisodium Citrate boric acid | 10 grams per liters, 10 grams per liters, 20 grams per liters, 60 grams per liters, 30 grams per liters | 90 | 75 |
| (8) thermal treatment | 100 ℃, 6 hours, N 2Atmosphere | |||
(embodiment 9)
Chemical enhanced amorphous boron alumina silicate glass sheet (Ra=0.25 nanometer) is as glass baseplate 1.Carry out the following step (1) successively and form Co-Ni-P coating 4 to (8).
(1) sanitising agent degreasing: handled in 3 minutes by the alkaline cleansing agent aqueous solution that immerses 1.5 weight % at 50 ℃.
(2) alkali degreasing: handled in 3 minutes by the KOH aqueous solution that immerses 7.5 weight % at 50 ℃.
(3) glass activation: by the H that immerses 1.0 weight % at 20 ℃
2SO
4The aqueous solution 3 minutes was handled at 20 ℃ of HF aqueous solution that immerse 1.0 weight % then in 3 minutes.
(4) silane coupling agent is handled: by handling in 3 minutes in 3-aminopropyl triethoxysilane (compound of chemical formula (the III)) aqueous solution that immerses 1.0 weight % at 20 ℃.
(5) palladium catalyst is handled: by immersing PdCl at 20 ℃
2(concentration 1.0 weight %) and NaOH (concentration 0.2 weight %) mixed aqueous solution was handled in 3 minutes.
(6) palladium is in conjunction with processing: by the H that immerses 1.0 weight % at 20 ℃
3PO
2The aqueous solution was handled in 3 minutes.
(7) Co-Ni-P plated film: the Co-Ni-P coating that formed 3.0 micron thickness by the compositions-treated of forming by following component 90 ℃ of immersions in 75 minutes.
1) metal component: single nickel salt: 10 grams per liters
2) metal component: rose vitriol: 10 grams per liters
3) reductive agent: sodium hypophosphite: 20 grams per liters
4) complexing agent: Trisodium Citrate: 60 grams per liters
5) buffer reagent: boric acid: 30 grams per liters
(8) thermal treatment: heat treated is 6 hours under 100 ℃ of nitrogen atmospheres.
(embodiment 10)
Except the step among the embodiment 9 (3) is replaced with following step (3B), with embodiment 9 in identical step form Co-Ni-P coating.
(3B) by immersing the 1.0 weight %HCl aqueous solution 3 minutes down, immerse the 1.0 weight %HF aqueous solution at 20 ℃ then and handled in 3 minutes at 20 ℃.
(embodiment 11)
Except the step among the embodiment 9 (3) is replaced with following step (3C), with embodiment 9 in identical step form Co-Ni-P coating.
(3C) by immersing 1.0 weight %H down at 20 ℃
2SO
4The aqueous solution 3 minutes immerses the 0.05 weight %HF aqueous solution down at 20 ℃ then and handled in 3 minutes.
(embodiment 12)
Except the step among the embodiment 9 (3) is replaced with following step (3D), with embodiment 9 in identical step form Co-Ni-P coating.
(3D) by immersing the 1.0 weight %HCl aqueous solution 3 minutes, immerse the 0.05 weight %HF aqueous solution at 20 ℃ then and handled in 3 minutes at 20 ℃.
(embodiment 13)
Except the step among the embodiment 9 (3) is replaced with following step (3E), with embodiment 9 in identical step form Co-Ni-P coating.
(3E) by immersing HF (concentration 1.0 weight %) and NH at 20 ℃
4F (concentration 0.5 weight %) mixed aqueous solution was handled in 3 minutes.
(embodiment 14)
Except the step among the embodiment 9 (4) is replaced with following step (4B), with embodiment 9 in identical step form Co-Ni-P coating.
(4B) handled in 3 minutes by N-(2-the aminoethyl)-3-aminopropyl triethoxysilane (compound of chemical formula V) that immerses 1.0 weight % at 20 ℃.
(embodiment 15)
Except the step among the embodiment 10 (4) is replaced with the step (4B) described in the embodiment 14, with embodiment 10 in identical step form Co-Ni-P coating.
(embodiment 16)
Except the step among the embodiment 11 (4) is replaced with the step (4B) described in the embodiment 14, with embodiment 11 in identical step form Co-Ni-P coating.
(embodiment 17)
Except the step among the embodiment 12 (4) is replaced with the step (4B) described in the embodiment 14, with embodiment 12 in identical step form Co-Ni-P coating.
(embodiment 18)
Except the step among the embodiment 13 (4) is replaced with the step (4B) described in the embodiment 14, with embodiment 13 in identical step form Co-Ni-P coating.
(Comparative Examples 7)
Chemical enhanced amorphous boron alumina silicate glass sheet (Ra=0.25 nanometer) is as glass baseplate 1.Carry out the following step (9) successively and form Co-Ni-P coating 4 to (15).
(9) sanitising agent degreasing: handled in 3 minutes by the alkaline cleansing agent aqueous solution that immerses 1.5 weight % at 50 ℃.
(10) alkali degreasing: handled in 3 minutes by the KOH aqueous solution that immerses 7.5 weight % at 50 ℃.
(11) glass surface roughening: by handling in 10 minutes at 60 ℃ of immersion chromic acid (concentration 40 weight %) and sulfuric acid (concentration 40 weight %) mixed aqueous solution.
(12) provide the catalyst treatment of catalyzer: by immersing PdCl at 20 ℃
2(concentration 0.3 grams per liter), SnCl
22H
2The mixed aqueous solution of O (concentration 15 grams per liters) and 36%HCl (200 milliliters/liter of concentration) was handled in 3 minutes.
(13) provide the accelerate process of catalyzer: by the H that immerses 100 grams per liters at 50 ℃
2SO
4The aqueous solution was handled in 5 minutes.
(14) Co-Ni-P plated film: handle the Co-Ni-P coating that formed 0.5 micron thickness in 12.5 minutes by the plating bath of forming described in (7) of containing embodiment 9 90 ℃ of immersions.(owing to peeling off of film can occur in plating (plating) process, thickness is impossible above 0.5 micron)
(15) thermal treatment: 100 ℃ were heated 6 hours under nitrogen atmosphere.
(Comparative Examples 8)
Except the step among the embodiment 9 (3) is replaced with following step (3F), with embodiment 9 in identical step form Co-Ni-P coating.
(3F) by immersing the 1.0 weight %HF aqueous solution 3 minutes down, immerse warm water down at 90 ℃ then and handled in 3 minutes at 20 ℃.
(Comparative Examples 9)
Except the step among the embodiment 9 (3) is replaced with following step (3G), with embodiment 9 in identical step form Co-Ni-P coating.
(3G) by immersing 1.0 weight %H down at 20 ℃
2SO
4The aqueous solution 3 minutes immerses the 2.0 weight %HF aqueous solution down at 20 ℃ then and handled in 3 minutes.
(Comparative Examples 10)
Except the step among the embodiment 9 (3) is replaced with following step (3H), with embodiment 9 in identical step form Co-Ni-P coating.
(3H) by immersing the 1.0 weight %HCl aqueous solution 3 minutes down, immerse the 2.0 weight %HF aqueous solution down at 20 ℃ then and handled in 3 minutes at 20 ℃.
(evaluation)
Each glass baseplate that embodiment 9 to 18 and Comparative Examples 7 to 10 are obtained with the Co-Ni-P plated film that forms with dectroless plating, by observation by light microscope (ratio of enlargement: * 50) estimate the foaming of Co-Ni-P coating, and by crosscut (cross-cut) stripping test (JIS (Japanese Industrial Standards) K5600-3-4) evaluation binding property.In addition, carry out the surface roughness measurement with atomic force microscope (AFM) and estimate plating (plating) average rugosity Ra afterwards.Evaluation result sees Table 3.In addition, silanol group (Si-OH) quantity that the glass baseplate surface generates after the activation treatment detects with the thermal desorption mass spectrograph.These evaluations the results are shown in table 5.
[table 5]
| Coupling agent *1 | The glass activation treatment | Si-OH quantity (group/square centimeter) | Thickness of coating (micron) | Bubble | Binding property *2 | Surface roughness Ra (nanometer) | |
| Embodiment 9 | Chemical formula (III) | 1 weight %H 2SO 4→ weight %HF | 3.45×10 15 | 3.0 | Do not observe | ○ | 0.35 |
| Embodiment 10 | Chemical formula (III) | 1 weight %HCl → 1 weight %HF | 3.32×10 15 | 3.0 | Do not observe | ○ | 0.32 |
| Embodiment 11 | Chemical formula (III) | 1 weight %H 2SO 4→ 0.05 weight %HF | 4.01×10 15 | 3.0 | Do not observe | ○ | 0.39 |
| Embodiment 12 | Chemical formula (III) | 1 weight %HCl → 0.05 weight %HF | 3.88×10 15 | 3.0 | Do not observe | ○ | 0.40 |
| Embodiment 13 | Chemical formula (III) | 1 heavy %HF+05 weight %NH 4F | 2.81×10 15 | 3.0 | The end observes | ○ | 0.30 |
| Embodiment 14 | The chemistry formula V | 1 weight %H 2SO 4→ 1 weight %HF | 3.65×10 15 | 3.0 | Do not observe | ○ | 0.33 |
| Embodiment 15 | The chemistry formula V | 1 weight %HCl → 1 weight %HF | 3.48×10 15 | 3.0 | Do not observe | ○ | 0.32 |
| Embodiment 16 | The chemistry formula V | 1 weight %H 2SO 4→ 0.05 weight %HF | 4.08×10 15 | 3.0 | Do not observe | ○ | 0.36 |
| Embodiment 17 | The chemistry formula V | 1 weight %HCl → 0.05 weight %HF | 3.98×10 15 | 3.0 | Do not observe | ○ | 0.37 |
| Embodiment 18 | The chemistry formula V | 1 weight %HF+0.5 weight %NH 4F | 2.88×10 15 | 3.0 | Do not observe | ○ | 0.30 |
| Comparative Examples 7 | Sn/Pd | - | 0.91×10 15 | 0.5 | Observe | × | 0.72 |
| Comparative Examples 8 | Chemical formula (III) | 1 weight %HF+90 ℃ warm water | 1.16×10 15 | 3.0 | Do not observe | × | 0.35 |
| Comparative Examples 9 | Chemical formula (III) | 1 weight %H 2SO 4→ 2 weight %HF | 1.56×10 15 | 3.0 | Do not observe | × | 0.31 |
| Comparative Examples 10 | Chemical formula (III) | 1 weight %HCl → 2 weight %HF | 1.41×10 15 | 3.0 | Do not observe | × | 0.30 |
*1 chemical formula (III) compound: 3-aminopropyl triethoxysilane
Chemistry formula V compound: N-(2-aminoethyl)-3-aminopropyl triethoxysilane
*All do not occur peeling off in 2 zero: ten samples
*: peeling off appears at least one sample in ten samples
The result of embodiment 9 to 18 clearly finds from table 5, uses the inventive method, and the Co-Ni-P plated film on the glass baseplate can reach 3.0 micron thickness.The described Co-Ni-P coating that obtains according to the inventive method does not produce the foaming defective, also shows fabulous binding property.The Co-Ni-P coating surface that obtains has the surface roughness level that remains on the hard disk base material requires with approximately equalised surface roughness of base material (Ra=0.25 nanometer) and numerical value.
Method of the present invention not only is used to form Co-Ni-P coating.This method also is used to form Ni-P, Ni-Fe-P, Co-Ni-Fe-P etc. and can forms on glass baseplate with dectroless plating, has the necessary adequate thickness of the excellent in performance of being used for hard disk (1 micron to 3 microns) and gratifying binding property, homogeneity and smoothness soft ferromagnetic layer.
On the contrary, Comparative Examples 7 uses tin chloride (II) and palladium catalyst (seeing patent document 3) that the only Co-Ni-P coating of 0.5 micron thickness is provided according to currently known methods, and can't obtain the Co-Ni-P coating that thickness is not less than 1.0 microns.The Co-Ni-P coating that obtains has the foaming defective, shows significant decline with the glass baseplate binding property, and very big surface roughness is arranged.Can obviously find out from Comparative Examples 8,9 and 10, when the silanol group (Si-OH) that uses the glass activation treatment to generate when quantity is improper on the glass baseplate surface, even even all step is all constant except the glass activation step, also can reduce with the degree of adhesion of silane coupling agent.As a result, the binding property of Co-Ni-P coating and glass baseplate also reduces.
[making the embodiment of perpendicular magnetic recording media method]
Embodiment 19 to 28 is described below, and coating shown in Figure 3 in these embodiments is included in that disk substrate 10 two sides all have, and is used for the perpendicular magnetic recording media that obtains at the foregoing description 9 to 18, magnetic recording layer 30.
(embodiment 19)
To the disk substrate that is used for perpendicular magnetic recording media that in the foregoing description 9, obtains, polish with having the double head type polishing machine of polyurethane foam polishing sheet and adding colloidal silica abrasive.After by meticulous flushing clean surface, base material is introduced coating machine.Use the lamp well heater that base material was heated for 10 seconds, make surface temperature reach 200 ℃, use the titanium target to deposit non magnetic kind of film 20 of titanium of 10 nanometer thickness then, use Co then at substrate surface
70Cr
20Pt
10Target deposits the CoCrP alloy magnetic recording layer of 30 nanometer thickness, deposits the carbon protective layer of 40 nanometer thickness at last with the carbon target.Then, this base material with coating takes out in vacuum chamber.All these deposition process of carrying out with spraying plating all are to carry out with the DC magnetron sputtering system under the argon gas of 5 millitorrs (mTorr).Then, form the liquid lubricant layer of the PFPE of 2 nanometer thickness with pickling process, with the perpendicular magnetic recording media of shop print 3.
(embodiment 20)
The disk substrate that is used for perpendicular magnetic recording media 10 that in using the foregoing description 10, obtains, make perpendicular magnetic recording media shown in Figure 3 with the step identical with embodiment 19.
(embodiment 21)
The disk substrate that is used for perpendicular magnetic recording media 10 that in using the foregoing description 11, obtains, make perpendicular magnetic recording media shown in Figure 3 with the step identical with embodiment 19.
(embodiment 22)
The disk substrate that is used for perpendicular magnetic recording media 10 that in using the foregoing description 12, obtains, make perpendicular magnetic recording media shown in Figure 3 with the step identical with embodiment 19.
(embodiment 23)
The disk substrate that is used for perpendicular magnetic recording media 10 that in using the foregoing description 13, obtains, make perpendicular magnetic recording media shown in Figure 3 with the step identical with embodiment 19.
(embodiment 24)
The disk substrate that is used for perpendicular magnetic recording media 10 that in using the foregoing description 14, obtains, make perpendicular magnetic recording media shown in Figure 3 with the step identical with embodiment 19.
(embodiment 25)
The disk substrate that is used for perpendicular magnetic recording media 10 that in using the foregoing description 15, obtains, make perpendicular magnetic recording media shown in Figure 3 with the step identical with embodiment 19.
(embodiment 26)
The disk substrate that is used for perpendicular magnetic recording media 10 that in using the foregoing description 16, obtains, make perpendicular magnetic recording media shown in Figure 3 with the step identical with embodiment 19.
(embodiment 27)
The disk substrate that is used for perpendicular magnetic recording media 10 that in using the foregoing description 17, obtains, make perpendicular magnetic recording media shown in Figure 3 with the step identical with embodiment 19.
(embodiment 28)
The disk substrate that is used for perpendicular magnetic recording media 10 that in using the foregoing description 18, obtains, make perpendicular magnetic recording media shown in Figure 3 with the step identical with embodiment 19.
(evaluation)
The swinging strut determinator (spinning stand tester) of the single magnetic pole type magnetic head that is used for perpendicular magnetic recording media is equipped with in use, to the perpendicular magnetic recording media of making among the embodiment 19 to 28, write down ionization meter reproducing signal output (reproduction signaloutput) at 300kFCI (per inch magnetic flux change).With 50 milliamperes of write currents to the degaussing of medium direct current after, measure the noise that the soft magnetism backing layer of soft magnetism coating 4 produces from detected reproduction (reproduction output).In this detects,, can detect reproduction when the specific magnetising moment in the magnetic recording layer 30 and dc (direct current) demagnetization during in same direction.Therefore, can think that the noise that detects mainly produces from soft magnetism coating 4.In the next one is estimated, use the swinging strut determinator that the single magnetic pole type magnetic head that is used for perpendicular magnetic recording media is housed to measure sharp noise.At first, the logical 50 milliamperes of direct currents of write element by to magnetic head carry out dc erasing to perpendicular magnetic recording media.Electric current in the write element is reduced to zero then, reads the signal that produces in the perpendicular magnetic media under situation about not writing.The results are shown in table 6.
[table 6]
Reproduce the evaluation of output signal, soft ferromagnetic layer noise and sharp noise
| The reproduction output (millivolt) of write current 20-60 MAH | Noise measurement: the reproduction output after the direct current degaussing (millivolt pp) | The point noise produces | |
| Embodiment 19 | 0.92-0.98 | 0.25 | ○ |
| Embodiment 20 | 0.91-0.98 | 0.27 | ○ |
| Embodiment 21 | 0.90-0.97 | 0.24 | ○ |
| Embodiment 22 | 0.89-0.95 | 0.25 | ○ |
| Embodiment 23 | 0.94-0.99 | 0.29 | ○ |
| Embodiment 24 | 0.86-0.95 | 0.20 | ○ |
| Embodiment 25 | 0.86-0.94 | 0.21 | ○ |
| Embodiment 26 | 0.84-0.91 | 0.21 | ○ |
| Embodiment 27 | 0.85-0.98 | 0.19 | ○ |
| Embodiment 28 | 0.93-0.99 | 0.28 | ○ |
| Specification | 0.80-1.00 | ＜0.30 | ○ |
Zero expression does not produce sharp noise
All perpendicular magnetic recording medias of embodiment 19 to 28 obtain satisfied reproduction output when low writing current, and reach capacity in the output of 20-60 milliampere scope, and this proves that this medium helps practical application.Also having proved hardly from soft magnetism coating to produce noise and do not produce the medium of sharp noise, is required perpendicular magnetic recording media.
As description up to now, on glass baseplate, formed Co-Ni-P coating with the chemical plating method, above-mentioned coating has satisfied thickness, binding property and homogeneity, and also performance obtains to have the desired enough smoothnesses of soft magnetism backing layer of excellent read perpendicular magnetic recording media.
Claims (15)
1. the method for a plating on glass substrate, described method comprises
Treating processes on the substrate surface that glass material constitutes, described treating processes comprises at least
With dilute acid solution with the silanol group quantity increase of the substrate surface glass activation treatment step of twice at least,
The silane coupling agent treatment step,
The palladium catalyst treatment step and
The palladium integrating step; With
Form process of plating with dectroless plating.
2. as claimed in claim 1 on glass substrate the method for plating, it is characterized in that, described glass activation treatment step comprises the processing of sulfuric acid, nitric acid or the hydrochloric acid of the hydrofluoric acid that uses 0.001-1 weight % and 0.1-10 weight %, or uses the processing of the Neutral ammonium fluoride of the hydrofluoric acid of 0.001-1 weight % and 0.0005-0.5 weight %.
As claim 1 or claim 2 described on glass substrate the method for plating, it is characterized in that described glass activation treatment step is made up of the processing of the hydrofluoric acid of the processing of the sulfuric acid, nitric acid or the hydrochloric acid that use 0.1-10 weight % and use 0.001-1 weight % subsequently.
As claim 1 or claim 2 described on glass substrate the method for plating, it is characterized in that described glass activation treatment step is made up of the processing of the ammonium fluoride aqueous solution mixture of hydrofluoric acid aqueous solution that uses 0.001-1 weight % and 0.0005-0.5 weight %.
As each of claim 1 to 4 described on glass substrate the method for plating, it is characterized in that described silane coupling agent treatment step is made up of the processing that use has the silane coupling agent of general formula (I) representative structure:
(C
mH
2m+1O)
3Si(CH
2)
nNHR (I)
Wherein R is selected from H, C
pH
2pNH
2, CONH
2And C
6H
5, m, n and p represent a positive integer respectively.
As each of claim 1 to 5 described on glass substrate the method for plating, it is characterized in that described palladium catalyst treatment step is by using Palladous chloride and dilute sodium hydroxide mixing solutions, or the processing of Palladous chloride and rare potassium hydroxide mixing solutions is formed.
As each of claim 1 to 6 described on glass substrate the method for plating, it is characterized in that described palladium is made up of the processing of using the Hypophosporous Acid, 50 aqueous solution in conjunction with treatment step.
8. a manufacturing is used for the method for the disk substrate of magnetic recording medium, the method of described manufacturing disk substrate is used the method for plating of each definition of claim 1 to 7, on discoidal glass baseplate substrate surface, formed non magnetic or the soft magnetism plated film, it is characterized in that, the method of described manufacturing disk substrate comprises a treating processes, this treating processes comprises with dilute acid solution at least with the glass baseplate silane surface alcohol radical quantity increase glass activation treatment step of twice at least, the silane coupling agent treatment step, palladium catalyst treatment step and palladium are in conjunction with treatment step; Form process of plating with the use dectroless plating.
9. manufacturing as claimed in claim 8 is used for the method for the disk substrate of magnetic recording medium, it is characterized in that, the surface roughness Ra of described glass baseplate mostly is 0.5 nanometer most.
10. be used for the method for the disk substrate of magnetic recording medium as claim 8 or the described manufacturing of claim 9, it is characterized in that, formed the plated film that the Ni-P alloy constitutes, control heat-up rate then and heat-treat with dectroless plating.
11. manufacturing as claimed in claim 10 is used for the method for the disk substrate of magnetic recording medium, it is characterized in that, described thermal treatment is formed by treatment temp being remained on 250 ℃ to 300 ℃ 1 hour steps and will being controlled to be 2 hours heating step from room temperature to the heating-up time of handling temperature at least at least.
12. manufacturing as claimed in claim 11 is used for the method for the disk substrate of magnetic recording medium, it is characterized in that, described plated film is made of the Ni-P alloy that contains 1.0-13.0 weight % phosphorus, forms with dectroless plating, and thickness is at least 1.0 microns.
13. be used for the method for the disk substrate of magnetic recording medium as claim 8 or the described manufacturing of claim 9, it is characterized in that, by silane coupling agent processing on glass baseplate, formation silane coupling agent layer, handle formation palladium catalyst layer on silane coupling agent layer by palladium catalyst, also on the palladium catalyst layer, form soft magnetism coating with dectroless plating.
14. manufacturing as claimed in claim 13 is used for the method for the disk substrate of magnetic recording medium, it is characterized in that, described soft magnetism coating by 0.2 micron to 3 micron thickness, contain 3 atom % to 20 atom % phosphorus, and cobalt and nickle atom number than (Co/ (Co+Ni)) in cobalt account for the soft magnetism plated film that the Co-Ni-P of 45 atom % constitutes at least and form.
15. a method of making perpendicular magnetic recording media comprises:
Use is used for the method for the disk substrate of magnetic recording medium according to the manufacturing of claim 13 and 14, make the disk substrate that is used for magnetic recording medium step and
Be used for forming at least one non magnetic step of planting layer, a magnetic recording layer and a protective layer on the disk substrate of magnetic recording medium successively,
It is characterized in that the soft magnetism coating in the described disk substrate is used the part of the soft magnetism backing layer that acts on magnetic recording layer at least.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004219195 | 2004-07-27 | ||
| JP2004219195 | 2004-07-27 | ||
| JP2005038617 | 2005-02-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1740388A true CN1740388A (en) | 2006-03-01 |
Family
ID=36092917
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200510088454 Pending CN1740388A (en) | 2004-07-27 | 2005-07-27 | Method of manufacturing a disk substrate for a magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1740388A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104488028A (en) * | 2012-06-29 | 2015-04-01 | Hoya株式会社 | Information recording medium glass substrate, and manufacturing method of information recording medium glass substrate |
| CN110234794A (en) * | 2017-02-01 | 2019-09-13 | 株式会社Uacj | Magnetic disc substrate made of aluminum alloy and its manufacturing method |
| CN111479954A (en) * | 2018-11-08 | 2020-07-31 | 西部数据技术公司 | Enhanced nickel plating process |
| CN112703273A (en) * | 2019-01-22 | 2021-04-23 | 美录德有限公司 | Electroless Ni-Fe alloy plating solution |
-
2005
- 2005-07-27 CN CN 200510088454 patent/CN1740388A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104488028A (en) * | 2012-06-29 | 2015-04-01 | Hoya株式会社 | Information recording medium glass substrate, and manufacturing method of information recording medium glass substrate |
| CN104488028B (en) * | 2012-06-29 | 2017-10-27 | Hoya株式会社 | The manufacture method of glass substrate for information recording medium and glass substrate for information recording medium |
| CN110234794A (en) * | 2017-02-01 | 2019-09-13 | 株式会社Uacj | Magnetic disc substrate made of aluminum alloy and its manufacturing method |
| CN110234794B (en) * | 2017-02-01 | 2020-10-09 | 株式会社Uacj | Magnetic disk substrate made of aluminum alloy and method for manufacturing same |
| CN111479954A (en) * | 2018-11-08 | 2020-07-31 | 西部数据技术公司 | Enhanced nickel plating process |
| US11192822B2 (en) | 2018-11-08 | 2021-12-07 | Western Digital Technologies, Inc. | Enhanced nickel plating process |
| CN112703273A (en) * | 2019-01-22 | 2021-04-23 | 美录德有限公司 | Electroless Ni-Fe alloy plating solution |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1174416C (en) | Actuator, message recording/reproduction device and method for producing actuator | |
| CN1802697A (en) | Magnetic recording medium, method for producing thereof, and magnetic recording and reproducing apparatus. | |
| US8039045B2 (en) | Method of manufacturing a disk substrate for a magnetic recording medium | |
| CN1270293C (en) | Magnetic head slider having protrusions provided on the medium-facing surface and manufacturing method therefor | |
| CN1068949C (en) | Disk storage system, thin film magnetic head therefor and fabricating method thereof | |
| CN1042375C (en) | Method for manufacturing semiconductor base material | |
| CN1287397C (en) | Granular queueing body, its mfg. method and device using such queuecing body | |
| CN1078537C (en) | Ink jet printer head, method of manufacturing the same, and ink | |
| CN1052339C (en) | Manufacturing method for semiconductor matrix material | |
| CN1196114C (en) | Glass-ceramic substrate for information storage medium | |
| CN1694163A (en) | Nanoholes, magnetic recording media and production thereof, and magnetic recording apparatus and method | |
| CN1230397C (en) | Substrate for information recording medium constructed of micro crystalline glass and information recording medium | |
| CN1763245A (en) | Plating substrate, electroless plating method, and circuit forming method using the same | |
| CN1395726A (en) | Magnetic recording medium, method of mfg. thereof, and megnetic recording device | |
| CN1007847B (en) | Process for producing magnets having improved corrosion resistance | |
| CN1639288A (en) | CMP formulations for the use on nickel-phosphorus alloys | |
| CN1163916C (en) | Ultralow-iron-loss grain oriented silicon steel plate and process for producing same | |
| CN1684149A (en) | Disk substrate for a perpendicular magnetic recording medium and a perpendicular magnetic recording medium using the substrate | |
| CN1843997A (en) | Method of plating on a glass base plate, a disk substrate, method for manufacturing the same and a perpendicular magnetic recording medium | |
| CN1740388A (en) | Method of manufacturing a disk substrate for a magnetic recording medium | |
| CN101046980A (en) | Perpendicular magnetic recording medium and magnetic storage device | |
| CN1070305C (en) | Magnetic recording medium and its manufacture | |
| CN1735932A (en) | Magnetic recording medium, method of manufacturing therefor, and magnetic read/write apparatus | |
| CN1357647A (en) | Wiring substrate and its making process and chemical copper plating solution therein | |
| CN1513934A (en) | Grinding liquid composition |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20060301 |