JPH0831776A - Pattern processing method and ceramic member having pattern - Google Patents

Abstract

PURPOSE:To ease a decrease in strength due to a pattern which is created by removing part of ceramic surface by heat processing by forming grooves without intrersecting or superimposing the radiated portions by an energy beam. CONSTITUTION:A predetermined of a ceramic member 6 is positioned in opposite to a beam scan equipment 3. Thereafter, a laser beam emitted from a laser oscillator 1 is condensed and applied by a beam scan equipment 3. The beam scan equipment scans the beam into an arbitrary pattern by a controller 5, and condenses the laser beam to arbitrary positions on the ceramic member. The pattern is formed by grooves created by apply the energy beam along straight lines or curves constituting the pattern. The groove is disassembled to elements such as longitudinal, lateral and diagonal ones, the energy beam is applied along respective elements, and the radiation portion of energy beam is fromed without intersecting or superimposing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for imparting identification symbols (patterns) such as characters, symbols, pictures, and bar codes to the surface of a ceramic member, for example, a Si wafer lapping plate, and particularly to the surface of the ceramic member. The present invention relates to a pattern processing method in which the strength is less reduced even if a pattern is applied, and a ceramic member provided with a pattern formed by the processing method.

[0002]

2. Description of the Related Art Symbols such as markings or prints for identification (hereinafter, collectively referred to as "pattern") are provided on the surface of a ceramic member.
As the processing method, mechanical removal processing using a grindstone or sandblast, thermal removal processing using a laser beam, etc. are widely known.

In mechanical removal processing using a grindstone, identification is difficult because the identification is based only on the depth of the groove.
There was a problem that the dimensional accuracy was poor and the efficiency was not improved because of the manual work by the hand grinder.

In the mechanical removal processing by sandblasting, it is difficult to identify as in the case of using a grindstone, and a mask for adjusting the pattern to a part which is not processed is newly required, which makes the patterning work complicated. was there.

The above-mentioned mechanical removal processing method has a problem that it is difficult to process a fine line which requires identification and dimensional accuracy, whereas the method using a laser beam is easy to identify because it is colored. In addition, it has a large degree of freedom in pattern enlargement / reduction, and has been widely used in ceramics processing, as a high-power laser beam oscillator was developed.

[0006]

However, in the thermal removal processing using a laser beam, a heat-affected zone is generated in the processed section, which causes a partial decrease in strength and may be destroyed during pattern formation.

FIG. 2 is a diagram showing a pattern (numeral "4") formed by laser beam irradiation by a conventional method, and FIG. 2 (a) is a diagram showing a pattern formed by one irradiation,
(b) And (c) is a figure which shows the pattern formed by irradiating a plurality of times by shifting the irradiation position. As shown in the figure, in the normal pattern forming method, the beam irradiation position is increased along the line of the programmed pattern once or by widening the line width of the character, so that the beam is displaced (interval 100 μm or less). ) Process multiple times. At this time, in the overlapping portions A, B and C of the lines of the pattern to be irradiated, the depth of the groove becomes deep, and the strength of this portion decreases, so that it cannot be used for mechanical parts or electronic parts requiring high strength, or May be destroyed during pattern formation.

[0008] In this case, overlapping irradiation can be avoided by irradiating with a mask on the overlapping portion of the groove of the pattern, but there is a problem that the mask needs to be replaced every time the pattern changes, which is complicated.

An object of the present invention is to provide an irradiation method capable of reducing the strength reduction due to a pattern formed by removing a part of the ceramic surface by thermal processing.
It is to provide a ceramic member having a pattern formed on the surface by the method.

[0010]

As a result of investigating the groove depth of the pattern by irradiating the surface of the ceramics with a laser beam under various conditions, the present inventor has found that (a) the intersection of the pattern forming line Yes, the laser beams are overlapped and the groove depth is deeper in that part than in other parts.
(B) Since the laser beam is irradiated with a slight shift in order to widen the line width of the pattern, the laser beams are overlapped and irradiated on the bent part of the line, and as a result, those parts are irradiated more than other parts. It was confirmed that the depth of the groove was deep, and the present invention was completed.

The gist of the present invention is a method () for processing a pattern as shown in FIG. 1, for example, by a groove formed by irradiating an energy beam, and a ceramic member () having the pattern on its surface.

A method of patterning a ceramic surface by irradiating an energy beam, wherein a groove is formed without intersecting or overlapping irradiation parts of the energy beam and a pattern is processed on the ceramic surface.

The irradiation parts of the energy beam are formed without intersecting or overlapping, and the maximum depth is 200 μm or less,
A ceramic member having on its surface a pattern formed of grooves whose difference between the maximum depth and the minimum depth is 30 μm or less.

It is desirable to impregnate the groove portion described above with glass or resin.

[0015]

The pattern obtained by the method of the present invention is formed by a groove created by irradiating an energy beam along a straight line or a curved line forming the pattern. The groove is formed, for example, by disassembling it into vertical, horizontal and oblique elements and irradiating the energy beam along the respective elements so that the irradiation parts of the energy beam do not intersect or overlap.

Further, the ceramic member of the present invention is
The surface is provided with a pattern formed by grooves such as lateral and oblique grooves with a maximum depth of 200 μm or less and a difference between the maximum depth and the minimum depth of 30 μm or less. If necessary, glass or resin may be added to the groove. Impregnation is desirable.

Lasers for processing grooves for forming patterns on the surface of ceramics are commonly used YAG, CO
_2. Any of the excimer laser oscillators may be used.

FIG. 3 is a view showing the arrangement of a beam scanning type laser beam processing machine.

Reference numeral 1 is a laser oscillator, 2 is a laser oscillation power source, 3 is a beam scanning device, 4 is a driving device, 5 is a control device, and 6 is a ceramic member.

This will be described according to the processing procedure. First, a predetermined portion of the ceramic member 6 is scanned by the beam scanning device 3.
It is placed facing to. After that, the laser beam emitted from the laser oscillator 1 is condensed and irradiated by the beam scanning device 3. The beam scanning device causes the control device 5 to scan the beam into an arbitrary pattern, focus the laser beam at an arbitrary position on the ceramic member, and scan a desired character or symbol according to the pattern to form a pattern. .

For the ceramic member, conventionally known materials such as alumina, zirconia, silicon nitride, silicon carbide, mullite, forsterite, and aluminum nitride are used.

It is preferable to use a glass having a coefficient of thermal expansion smaller than that of ceramics by 0 to 10 × 10 ⁻⁷ / ° C. for the glass to be embedded in the groove in order to enhance the strength of the ceramic member. To be fired. Similarly, acrylic resin, Teflon, or the like having excellent heat resistance is used.

I. Regarding the pattern forming method: In the conventional pattern forming method using a laser beam, the control device 5 shown in FIG. 3 is irradiated once or a plurality of times along the lines of the pattern programmed in advance, and the overlapping portions and bending of the lines are performed. In the part, the groove depth increases. That is, in the case of forming the numeral "4" shown in FIG. 2, the portion A where the vertical line and the horizontal line intersect with each other is irradiated twice and the depth of the groove is deepened even if the irradiation processing is performed once. In the irradiation processing, the depth of the groove at the portion A where the vertical line and the horizontal line intersect and the portion B and C where the oblique line bends and intersects the vertical line and the horizontal line becomes deep. This depth increase is about 50%
In some cases, it was found that the local strength was reduced.

FIG. 1 is a view showing an example of a pattern formed by laser beam irradiation according to the method of the present invention,
(a) is a diagram showing a pattern formed by one irradiation, (b)
And (c) are diagrams showing patterns formed by multiple irradiations. In order to prevent the groove depth from becoming locally deep as shown in FIG. 1, the pattern processing method of the present invention decomposes the lines forming the pattern into vertical line, horizontal line and diagonal line elements, and Are combined without intersecting and overlapping, and an energy beam is irradiated along the element to form the element. In (b) and (c), the beam is radiated multiple times with a beam interval to widen the line width, and the method of character construction is the same as in (a).

The reason why the maximum depth of the groove is 200 μm or less and the difference between the maximum depth and the minimum depth is 30 μm or less is to prevent the strength reduction due to the notch effect (notch effect) of the groove formed by laser irradiation. is there.

When the surface of the ceramic member is thermally removed, a heat-affected layer such as microcracks is generated at the bottom of the groove after processing, and the bending strength is particularly lowered. It is known that the bending strength has a correlation with the depth of the groove. For example, in 99% alumina, it is known that a groove having a depth of 200 μm causes a decrease in the bending strength of about 50%. Further, since ceramics is a brittle material, when microcracks are present, when tensile stress acts on the entire member, the microcracks open and become cracks that lead to cracks, which quickly propagate and break. From these things, make the groove depth formed by laser irradiation processing as shallow as possible, and reduce the difference between the maximum depth and the minimum depth (30 μm or less).
Is desirable.

However, since such a pattern is provided for identification, it should not disappear due to wear during use. Therefore, in order to prevent the pattern portion from disappearing due to mechanical abrasion and to secure the bending strength, it is desirable that the depth of the pattern groove is at least 200 μm or less.

Variations in groove depth due to laser beam irradiation also occur due to variations in density of ceramic members and variations in laser processing conditions, but here it is assumed that these are adjusted to the same level and can be ignored. To do.

When irradiation is performed a plurality of times, the number of times is arbitrarily determined according to the size of the line width desired to be obtained. For example, if the line width is 0.5 mm, the interval is 0.05 to 0.1 mm and 5
Stagger ~ 10 times.

II. Regarding embedding of glass or resin: In the present invention, glass or resin is embedded in the groove formed by the irradiation of the laser beam in order to reduce the decrease in strength of the heat-affected zone due to the irradiation of the laser beam. This is to block the opening of the microcracks existing in the groove bottom with glass or resin, so that even if tensile stress is applied, stress concentration does not occur at the tip of the microcracks,
It is intended to reduce the decrease in strength.

The surface shape of the embedding material after embedding may be concave, identical or convex with respect to the surface of the base material. Further, the embedding material does not have to reach the tip of the microcracks, and the opening of the microcracks may be closed by the embedding material. When tensile stress is applied in such a state, stress acts on the glass or resin and stress concentration does not occur at the tip of the microcracks, so that the reduction in strength can be reduced.

Since some microcracks at the groove bottom have a considerably large aspect ratio, when glass or the like is used as an embedding material, even if heat treatment is performed at a working temperature such that the viscosity becomes 10 ³ dPa · s or less. The bubbles remaining at the crack tip are difficult to escape. However, as described above, if the opening of the microcrack is closed by the embedding material, the strength reduction can be reduced.

As a method of embedding glass or resin, a coating method is used, and strength and visibility can be improved by using not only transparent glass but also glass mixed with pigments such as black, blue and red. it can.

Although the strength reduction of alumina in the presence of microcracks has been described above, the same applies to silicon nitride, zirconia and other ceramic members.

[0035]

Embodiments of the present invention will be described below.

Various ceramic surfaces were marked with the numeral "4" shown in FIGS. 1 and 2 by the beam scanning type laser processing machine shown in FIG. 3 (Q switch YAG laser processing machine having a maximum output of 60 W).

As the material ceramics, 99% alumina, silicon nitride, and zirconia sintered body are used, and each has a thickness of 3 m.
The shape of the JIS analysis sample was m, width 4 mm, and length 40 mm.

The embedding material is PbO-based on 99% alumina.
SiO ₂ -B ₂ O ₃ glass, against the silicon nitride ZnO-B ₂ O ₃ -SiO ₂
Na ₂ O—BaO—SiO ₂ glass was used for glass and zirconia. After coating, the PbO-SiO ₂ -B ₂ O ₃ glass in an electric furnace
800 ° C., the ZnO-B ₂ O ₃ -SiO ₂ glass and Na ₂ O-BaO -SiO ₂ glass was heated to 700 ° C., was treated to cool to room temperature after the one hour hold.

The laser beam irradiation is 4 mm wide and 40 mm long.
A plurality of irradiations were performed by shifting the pattern of the numeral "4" in a 3 mm × 3 mm square in the central part of the surface of mm once, and shifting the pattern 5 times at intervals of 50 μm. The Q switch frequency and the lamp current value were set, and the groove depth was adjusted by changing the beam scanning speed.

For the measurement of the groove depth, a depth gauge equipped with a stylus having a pin tip diameter of 50 μm or less was used, and the depth of the groove central portion was measured.

To form the pattern of the present invention, the numeral "4" shown in FIGS. 1 (a) and 1 (b) is decomposed into vertical and horizontal line elements, and three vertical line elements and one horizontal line are used. It is a collection of elements. The length of one vertical line of each element
The scanning start coordinates of irradiation were set so that the length of each horizontal line was 1.2 mm and the length of each horizontal line was 2 mm. The composite irradiation of 5 times was performed by shifting the irradiation interval by 50 μm and forming elements. The figure numbers are shown in Table 1 as the character shapes.

[0042]

[Table 1]

The formation of the pattern of the comparative example is shown in FIG.
The numbers “4” shown in (a) and (b) are each a group of vertical line, horizontal line and diagonal line elements,
The irradiation start coordinates of each element were defined. The figure numbers are shown in Table 1 as the character shapes.

The laser processing condition, 2 kHz Q-switched pulse frequency, the pulse width is 100 nsec, 18A lamp current value for 99% Al ₂ O _3, 17A with respect to Zr ₂ O _3, Si ₃ N
_{It was set} to 16A for ₄ .

The test piece on which the pattern was formed was used as it was.
Alternatively, a JIS 3-point bending bending test was performed after embedding and baking glass or the like. In the bending test, a load was applied to the back surface of the pattern forming portion so that tensile stress acts on the pattern forming portion. The results are shown in Table 1. The strength of the ceramic material is 40 kgf / mm ^{2 for} 99% alumina and zirconia (Zr ₂ O ₃ ).
Was 80 kgf / mm ² , and silicon nitride (Si ₃ N ₄ ) was 60 kgf / mm ² .

The evaluation of the bending strength was shown by the ratio of the bending strength to the original strength, and the value of 50% or more was used as the standard of the present invention.

In No. 1 to No. 11 of the examples of the present invention, the line of the pattern was divided into the elements and the irradiation was performed along the elements. Therefore, the maximum groove depth was 200 μm or less, and the maximum depth and the minimum depth. And the difference in bending strength to the original strength was 50% or more.

On the other hand, Comparative Examples No. 12 to No. 17
Since the pattern was formed by the conventional irradiation method, the maximum value of the groove depth was as deep as 245 to 250 μm, and the difference between the maximum value and the minimum value of the patent was as large as 50 to 150 μm, which was larger than the original strength. The bending strength ratio was 48.75% or less.

Further, among the invention examples, in Nos. 3, 4, 7, 8 and 10 in which the glass was embedded in the laser irradiation groove, the ratio of the bending strength to the original strength was higher than that in the case of no embedding. There is.

[0050]

According to the present invention, overlapping of laser irradiation can be completely eliminated, variation in groove depth is small, and local strength reduction can be reduced. Further, by embedding glass or resin in the groove forming the pattern, the opening of the microcrack can be closed, and the reduction in strength can be further reduced. Further, by using glass mixed with a pigment, a pattern having excellent visibility can be formed.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a pattern formed by laser beam irradiation according to the method of the present invention.

FIG. 2 is a diagram showing a pattern formed by laser beam irradiation by a conventional method.

FIG. 3 is a diagram showing a configuration of a beam scanning type laser processing machine.

[Explanation of symbols]

1. Laser oscillator 2. Laser oscillation power supply
3. Beam scanning device 4. Drive device 5. Control device
6. Ceramics member

Claims (3)

[Claims] 1. A method of patterning a ceramic surface by irradiating an energy beam, wherein a groove is formed without intersecting or overlapping with the irradiation parts of the energy beam. 2. A pattern, which is formed by energy beam irradiation portions without intersecting or overlapping and has a maximum depth of 200 μm or less and a difference between the maximum depth and the minimum depth of 30 μm or less, on the surface. Ceramic member to be equipped. 3. A ceramic member having a pattern according to claim 2, wherein a groove portion forming the pattern is impregnated with glass or resin.