JPS60155359A - Holeless polishing method of ceramic material - Google Patents

Abstract

PURPOSE:To prevent a microbore from being disclosed, by polishing a surface of ceramic material by abrasive fluid of Al2O3, SiO2, diamond of higher hardness in a grain size below the specific value using Sn, Pb, etc. as a polisher under a specific lapping load. CONSTITUTION:An abrasive grain of fine dust dispersed in abrasive fluid, selecting a king of the grain and its dispersed quantity from Al2O3, SiO2, diamond in accordance with the melting point and hardness of a ceramic material because the grain of hardness higher than that of a material to be polished effectively acts, is formed to a grain size of 0.5mum or less polishing the material to be polished to fine surface roughness and decreasing the thickness of its layer which changes quality by polishing. While the surface roughness is improved by preventing the grain from its secondary agglomeration and powder from melting to adhere to the material to be polished, if glycol, sulfonated oil, etc. of 5% or less are added in order to enhance a dispersion effect to pure water. Next, a polisher, selecting its material from Sn, Pb, solder in accordance with the material to be polished and the abrasive grain of fine dust, is used at a lapping pressure of 0.5-2kg for ensuring rigidity of a polishing device and holding its accuracy of rotation. In such way, a plastic fluidized layer is formed, crushing a microbore and enabling the material to be holelessly polished.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a precision polishing method for the surface of a Reramix material, which can make the surface of a ceramic material containing micropores, that is, micropores with a diameter of 1 coral or less, non-porous (relating to a σ1 polishing method). .

Today, magnetic heads are widely used for magnetic recording and reproduction of A-dio and VTR tape recorders, data recorders, computer disks, drums, etc., and in the future, magnetic heads will be used for magnetic recording and reproduction of A-dio and VTR tape recorders. Progress is being made in converting HIs to metal tapes, to PCM recording systems, and to increasing the speed and recording density of computers. Therefore, in order to meet these demands, instead of the conventional wire-wound bulk head, a thin film magnetic head that uses IC technology and can easily be made into a multi-layer magnetic head with a narrower track is considered to be the most suitable. There is.

The substrate material used for this thin film magnetic head is soft magnetic 4J1'31 or N203 such as soft ferrite.
- TLC-based materials A densified non-magnetic material is used, and is manufactured by hot isostatic pressing or Hola l-pressing.

In the production of thin film magnetic heads, it is necessary to form a predetermined pattern on the plate material, so it is required to have excellent surface roughness and to have few defects such as pores on the surface. For example, an MR type film-forming magnetic head used for reproduction has an X element thickness of several hundreds of layers, and the substrate surface must be polished to a roughness of 50 Å or less.

In addition, even if the surface has been polished to such a roughness, if there is a 1'1' degraded layer in the process, the original bulk properties of the magnetic material will not be satisfied, and the magnetic properties of the magnetic material will deteriorate.
Non-magnetic properties may lead to deterioration of the properties of the coated thin film.
It is necessary to have a small amount of processed damaged layer.1゜Furthermore, in Table 1, the roughness of Table 1 is good and there is little processing distortion. When a large number of microphone holes are exposed, problems arise in terms of manufacturing and magnetic rad properties as the patterns of magnetic heads become finer and multi-layers become easier. However, there is a risk of disconnection of the contactor or 710 circuit in the micropore area.In MR type magnetic heads, the stripe width is about several micrometers, so there is a concern that the playback output will decrease. The presence of strain creates a non-uniform stress field, which may be transferred to the magnetic IQ formed above.

Conventionally, diamond polishing and mechanochemical polishing (hereinafter M) have been used to polish thin film magnetic head substrate materials.
CP law) was applied.

The die A7 Mondoboritsushi method involves lapping processing using Gui)7mondo powder with a particle size of about 1 μmh, and has the advantage of no edge surface sagging during processing and less error in shape accuracy, but the surface roughness is several 100. There was a problem that only about 100 angstroms of YJI layer could be obtained, and that more than 100 Å of processed YJI layer remained.

In addition, the M CP method converts fine powder, which is softer than the target material (σIy'F) and is more likely to promote solid phase reaction with the material to be polished, into pure water! , cloth, etc., which is lapped with [・-] has the advantage of suppressing processing distortion to the target 1σII?i+J, and processing the surface roughness to the order of 1 quantum of 208°. Significantly less processing distortion 4[
[Si, GGG, Ferrite] with fewer lattice defects such as dislocations] -
The U1 polishing method is most suitable for single crystal IJ diagonals such as.

However, when this MCP method is applied to a polycrystalline Relamix grindstone plate obtained by the hot isostatic pressing method or the Botto pressing method, which has micropores although the density is low, Since a non-uniform stress field is formed in the material, the chemical effect tends to selectively etch the same bore area, causing the problem that the internal micropores are exposed on the surface to the same extent as inside the bulk. In addition, if the lithium L1 is used for the borish 17, there is a problem that sagging of the bore part or nodule is likely to occur, and the size of the micropore is enlarged more than it actually is.

This invention targets micropores with a diameter of 17 zm or more, and uses the σfl * 7j method as a target, and has a surface IIJ of less than 5 o 8 and a thickness of 100 Å or less for the altered layer. The object of the present invention is to provide a polishing method that can obtain a flat surface, prevent the exposure of phycropores on the surface, and make the surface virtually non-porous.

In other words, this invention has a ceramic surface with micropores that has a grain size of 0.5 AI with a sandiness higher than that of the ceramic surface.
M2O3 below In, 5j02. To prevent secondary agglomeration of diamond powder alone or mixed fine powder, dilute it in pure water for 11 minutes. 2
The ceramics are rotated and polished under pressure to form a plastic fluidized layer on the surface of the substrate.
This is the ll method.

As mentioned above, in the conventional MCP method, the solid phase reaction with the abrasive material (d1 and the abrasive material II) is promoted by the soft abrasive material.
Using an abrasive liquid made by suspending fine powder in pure water, lapping with a polystyrene such as a cloth suppresses processing distortion to the target (IIF abrasive, for example, a polycrystalline saw. In the case of light can be processed to less than 508, but due to the lamical effect,
The micropores where a non-uniform stress field was formed were likely to be selectively etched, and the micropores inherent in the material were exposed to the inside of the bulk and to the surface to the extent that -C was expected.

On the other hand, in this invention, the tI! The polishing method of the present invention has the following 1il + polishing mechanism: it is optimal, has less processing distortion, has the same level of surface IJ as the MCP method, and can reduce micropores. This is thought to be due to the following.

In other words, the fracture phenomenon caused by scratching of ceramic materials is generally accompanied by a brittle fracture phenomenon, and the microscopic 11i11
+ IJ for high-pressure wrapping of ceramics using powder
It is thought that there is an extremely high pressure action between the tip of the effective abrasive grain and the workpiece, and the contact surface changes from brittle to ductile behavior and enters the state of the J transition point, causing plastic tη deformation. ) The destruction progresses, and the formation of human blood in which a plastic fluidized layer exists is irritated.
It is possible that the polishing process is progressing.

Due to the above action, the micropores existing in the surface layer are crushed, and the micropores on the tiled surface are significantly reduced compared to the bulk.

According to the above-mentioned idea of plastic flow, the temperature of the unabrasive grains is higher than the temperature of the machining point of the abrasive grains 411'41. It has a melting point, and its strength, or hardness, is more effective than the hardness of the coating (ill), so (σ
Depending on the melting point and hardness of the Relamix U material, the AI
ao3.5LOp, the type and dispersion m are selected appropriately from diamond.

Furthermore, if the grain size of the abrasive grains exceeds 0.5)tn+, the unit of processing removal during processing becomes large and the thickness of the plastic fluidized layer becomes large, resulting in a roughness in Table 17ij and a 1
It also increases wrinkles, which is not desirable. In addition, in order to enhance the dispersion effect in pure water, adding 5% or less of glycol, L]-1-oil, or sodium hekylymetaphosphate prevents secondary agglomeration and welding of the powder to the RJI polish. The surface roughness is improved. moreover,? IIl 1? Liquid 1. ) By adjusting the eyes to 6 to 8, the reduction of micropores will be improved by suppressing the cumical reaction with (σ).

Bolishki! The abrasive qualities of - are Sn, Pb, and 1. : It may be selected as appropriate depending on the type of fine powder abrasive grains.

In addition, the (σ1 polishing lap I)-horn strip I'1 of this invention is characterized by being polished at a higher pressure than the conventional tie A7 polishing. Grain embedding depth is 0.5k
Compared to a low cart of less than iJ, the depth is sufficiently deep, the embedding is uniform, the transferability of abrasive grains is stable, and the surface is in a state where regional scratches f are accumulated, but the flaw depth ( fU
1lIli is possible, and a surface roughness of 508 or less can be obtained. In addition, for loads exceeding 2ki4, the rigidity of the polishing device is ensured and the rotation accuracy is 4! j ff1l bad things, 0
．． 5 to 2 to 34 lap pressure and cover.

Examples will now be explained.

Example 1 Polycrystalline NL of 50X sox 1n+m increased in density by nibless brushing (17jj Shisui J)
[Zn] Irai 1 ~ (melting point 1500~1600℃, hardness 7 (l eye V) was used. ＞
C-rJIlIlKoDoiX'l,105ri4Tel
h'Iko.

(σI I!X 8'i is q diameter 0.02; m(7)
JV203 (2000''C9200011V) fine powder was dispersed in pure water at 0.2 wt%, and 2 wt% of hexyl metaphosphoric acid sorter was added.

SnW of 350 nunφ was used as the borisher, and the borissher surface [J to be polished; At this time, the wrap load of 0.7 kiJ was rotated at 40 rpi+ for 1 knot, and 100 c
Polishing fluid was added continuously at a ratio of c/l+r. (According to the present invention) 01131 surface after polishing Table 1lIi step measurement'i
a (1-alys-Lep, 5tylus O
, 1a + R) to measure the surface roughness, use an ellipsometer to measure the relative machining alteration B thickness with the MCP surface,
Furthermore, the number of micropores was counted using a Western-style microscope for V/I powder. The results are shown in Table 1.

Furthermore, the above-mentioned Ai-oriented L-Zn grinder of the present invention was coated (ill), and the hll of Table 1 was applied using a specific 0 abrasive grain.
l! , ``Condition-rMcPr4.'' (Comparison 1 series C) and when the paddy of the same month was subjected to Thai 17 months 1 to Boritsushi 1 (Comparative example D) under the negative eye condition, the (ill-milling results) are shown in this book. Measurement was performed under the same conditions as Invention A, and the results shown in Table 1 were obtained.

Example 2 For the subject III J Che, 50X 50x 1+nm Mz03 (iM
'JVa2015°c, ++m20 (+011V) was used. The number of phyclobores of this Jllll friction H is 10
It was 6 4.

The polishing liquid was Dai A7 Monde (3700) with a particle size of 0.1μ
℃, 10000Ilv) 0.2wt of fine powder in pure water
% dispersion, and further add 1w of hekyly sodium metaphosphate.
Add t%.

PJf of 350 mntφ was used for the polish V, and the surface of the polish 21 was polished 1! I'i brought the moon into contact with each other and rotated them relatively -((σ)1. At this time, 1,
A wrap load of 2 kg 4 was applied to the rotor, rotating at 40 rl 1 m, and ωll liquid was continuously added at a rate of 200 cc/br. (Present invention [3) J, l For comparison, the same relamic as the above-mentioned present inventions B and C was applied (υ1 mill, 5L
O2 (1610℃, ioo.

HV) M C using abrasive grains under the rtll polishing conditions shown in Table 1.
Pγm (Comparative Example [)] was conducted.

The polishing conditions of the above two types of materials to be polished were as shown in Example 1.
1, and the measurement results shown in Table 1 are 441.

As is clear from the (IT thickness result comparison table) in Table 1, the σ1 machining (inventions A and B) of the present invention is equivalent to the conventional MCI method (comparative example C1E). One level of surface roughness of the melon was obtained.Although it is more than the processed altered layer thickness method CP method, it is significantly reduced compared to the conventional die X7 molded surface (comparative example D).Furthermore,
It can be seen that while the number of micropores is about the same as the number of bulk bores in the case of the MCI' method, it is significantly reduced as the number of micropores differs by one order of magnitude.

As described above, the polishing method according to the present invention can process a ceramic material containing micropores into a precision flat surface with a surface roughness of 150 Å or less and a process-altered layer thickness of 100 Å or less,
What's more, the exposure of micropores on the surface is prevented, making the actual soil non-porous! , 1 will be given. Therefore, of this invention?
If a substrate polished by the IIl polishing method is used for a magnetic strip film, it will have a great effect on improving reliability, zero yield, and electromagnetic conversion characteristics.

Below margin Table 1 Below margin

Claims (1)

[Claims] 1 Presence of micropores /V2O3 with higher hardness than the material and particle size of 0.5 μm or less
, 5LO2, Dai-2mond powder alone or mixed fine powder is dispersed in pure water to prevent secondary agglomeration to make a polishing liquid.
Using either n, Pb, or solder as a polish, polishing is performed by pressing and rotating with a lap load of 0.5ki4''-2kgJ to form a plastic fluid layer on the surface of the material and reduce micropores on the surface of the material. U1 polishing method to make Reramix material non-porous.