JPS61199596A - Micro-shape processing method and mask for micro-shape processing - Google Patents

Abstract

PURPOSE:To process a hardly processable material to a fine shape with good accuracy and high efficiency by irradiating laser light on a work installed in an etchant through a mask having through-parts to allow the passage of the laser light and shielding parts which shield the laser light. CONSTITUTION:The work 5 is fixed onto a table 15 in an etching vessel 7 contg. the etching soln. and the etching soln. is put therein until the surface of the work is immersed therein. A pump 10 is then operated to feed forcibly the etching soln. to the inside of the vessel 7 and to circulate the etching soln. between a storage tank 6 and the vessel 7 to that always the fresh etching soln. flows to the surface of the work 5. The laser light is radiated from a laser oscillator 1 in this state and the height of the table 15 is adjusted so as to focus the laser atop the work 5 while a television monitor 4 is observed. An X-Y stage 14 is further driven in an X or Y direction according to the shape pattern to form desired bored holes atop the work 5.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application> The present invention relates to a micro-shape processing method for processing difficult-to-process materials into micro-shapes, and a processing mask used therein.

<Prior Art> Laser etching has conventionally been used as a micro-shape processing technology for materials such as ceramics.

The laser etching method uses a simple optical system to scan a narrowly focused laser beam onto the surface of a workpiece such as ceramics placed in an etching solution, thereby increasing the temperature of the workpiece in the area irradiated with the laser beam. This method takes advantage of the fact that etching is promoted by increasing the temperature.

FIG. 11 is a sectional view showing an example of an apparatus for performing laser etching. - This device consists of a laser optical system, an etching liquid circulation system, and a workpiece scanning system.

The laser optical system consists of an optical means consisting of a laser oscillator 1, a convex lens to be processed (II optical lens) 3 that transmits the laser light emitted from the laser oscillator 1, and a television monitor 4. Transparent mirror 2. convex lens 3
It is used to focus the laser beam focused on the ceramic substrate surface and to monitor the positioning of the processing.

The etching liquid circulation system includes an etching liquid storage tank 6, a container 7 in which the workpiece 5 is fixed and etched, and an etching liquid inlet pipe 8a and a delivery pipe 8b that connect the storage tank 6 and the etching processing volume N7. and a pump 10 which is disposed in the feed pipe 8a and pumps the etching liquid 9 from the storage tank 6 into the etching processing material 7. Furthermore, storage tank 6
A branch pipe 11 is disposed between a pipe 8a for feeding the etching liquid into the etching processing container 7 and a pipe 8b for sending it out.The feed pipe 8a and the branch pipe 11 each have a barrier pull valve 12.
．． The workpiece scanning system is arranged at the bottom of the etching processing container 7, and is configured to control the flow rate of the etching liquid sent into the etching processing container 7. It is composed of an XY stage 14 which is scan-driven in the directions, and is capable of scanning a workpiece 5 supported in an etching container with a laser beam.

In order to form a hole in the desired shape on the surface of the workpiece 5 using this device, first, place the workpiece 5 on the table 15 in the etching machine 7 containing an etching solution.
, and pour in the etching solution until the surface is immersed. (2) Next, the pump 10 is operated to pump the etching liquid into the etching volume #H7, and the etching liquid is circulated between the storage tank 6 and the etching volume #H7 so that new etching liquid always flows over the surface of the workpiece 5. ■In this state,
A laser beam is emitted from a laser oscillator 1, and the height of a table 15 is adjusted while watching a television monitor 4 so that the laser beam is focused on the upper surface of a workpiece 5. Furthermore, in order to form a perforation according to a desired shape, the desired perforation can be formed in the upper surface of the workpiece 5 by driving the XY stage 14 in the X or Y direction according to the shape pattern. . According to this device, bubbles generated from the upper surface of the workpiece 5 due to laser beam irradiation are quickly removed by the circulating etching liquid flowing over the substrate surface, and at the same time, the heat received from the laser beam is taken away to keep the substrate temperature constant. , the formed perforations are precisely machined.

In the laser etching method described above, the processing speed and the width and depth of the groove to be processed depend on the power of the laser beam, and as the power of the laser beam increases, the processing speed and the processing dimensions also increase.

There was a problem in that the power of the laser beam was lowered when processing the shape.

In view of the above problems, an object of the present invention is to process difficult-to-process materials such as ceramics and hard metals into fine shapes with high accuracy and efficiency.

Means for Solving the Problems〉 The structure of the present invention for achieving the above-mentioned object is to provide a mask that is formed in a predetermined pattern and has a light transmitting part that allows the laser light to pass through and a light shielding part that blocks the laser light. The method is characterized in that a workpiece placed in an etching agent is irradiated with the laser beam and etched into a shape corresponding to the pattern of the light passing portion.

Further, one configuration of a mask suitable for use in this micro-shape processing method includes a light transmitting part formed in a predetermined pattern and allowing laser light to pass through, and a light blocking part made of lead zirconate titanate and blocking the laser light. It is characterized by having.

In this way, the present invention provides a micro-shaped TF as described above.
It is possible to irradiate a high-density laser beam such as f471chimiisufu"J-17)h÷Jψwa or Q switch to etching the four shapes of the microphone. Therefore, the processing method according to the present invention is as follows. , is a processing technology based on laser etching, which scans the workpiece material with a laser beam through a mask with a predetermined pattern, or irradiates it with a large-diameter laser beam to create the desired pattern on the workpiece material. It can be said that this is a technology that processes shapes with high precision and efficiency.

The technical point of the micro-shape processing method according to the present invention is to manufacture a mask that satisfies the following conditions.

■ The mask must not be processed even when irradiated with laser light.■ The mask material must be able to be machined with light transmitting parts that are formed in a good pattern with high precision.

■ Do not allow laser light to pass through any area other than the pattern of the light transmitting part.

The present inventors discovered that ``As for the materials of the above-mentioned mask, alumina (Al□0.) and lead zirconate titanate (hereinafter PZT) were used.
) was found to be promising.

Since alumina is not processed by laser etching, a mask made of alumina has the advantage that it can be used repeatedly.

However, since alumina material cannot be processed by laser etching, the pattern of the mask on alumina material must be processed by normal laser processing, and the contour of the formed pattern is rough (4), and it is difficult to form a fine pattern. There is a drawback. Furthermore, the alumina material has the problem that if the power of the laser beam is too large, the alumina material cannot completely block the laser beam and allows it to pass through. However, such a mask with a relatively large pattern of light transmitting parts made of alumina material can be used in cases where much laser light power is not required, and in this case, it is possible to perform laser etching processing with high efficiency. can do.

On the other hand, PZT can be processed into an extremely sharp shape using a high-power Q-switched laser beam in laser etching, but it has a property that it is extremely difficult to process using a CW laser beam. Therefore, a mask made of PZT has a characteristic that it is not etched even by a high power CW laser beam. Further, in the method of the present invention, since it is only necessary to scan the laser beam, a Q-switch laser beam can also be used, and various shapes can be processed.

As a result of further research, it was discovered that a metal film such as chromium, which has a high melting point and high reflectance, can also be used as a material for the light-shielding part of a mask for micro-shape processing.

The details of the mask using this material will be described below in Example 3, and will therefore be omitted here.

The micro-shape processing method according to the present invention is carried out by using a mask for micro-shape processing made of a material that satisfies the above conditions. Note that the above-described mask for micro-shape processing may be reinforced or protected using a transparent material such as glass, as will be described later in Examples.

FIG. 1 is an explanatory diagram showing an example of implementation of the method of the present invention.

Since the apparatus shown in this drawing is the same as that described in the section of the prior art, the same parts are given the same numbers and redundant explanation will be omitted.

The mask 20 according to the present invention may be placed in a non-contact manner with the workpiece 5 by inserting a spacer 21 between it and the workpiece 5 as shown in FIG. 1, or may be in complete contact with the workpiece 5. You can leave it behind.

There are two possible laser beam irradiation methods in the micro-shape processing method according to the present invention. The first method is to scan with a narrowly focused laser beam, and the second method is to irradiate with a large-diameter laser beam.

FIG. 2 is an explanatory diagram conceptually showing the first method. As shown in the figure, the narrowed laser beam 30 is focused so as to include the peripheral part of the light transmitting part 20b of the mask 20, which is composed of a light shielding part 20a and a cross-shaped light transmitting part 20b. It is scanned as indicated by the arrow.

Thereby, the workpiece 5 is processed into the same shape as the pattern of the light passing portion 20b.

Scanning with such a laser beam 30 can be done by moving the workpiece 5 and the mask 20 placed on the table 15 when using the apparatus shown in FIG. It is also possible to scan optically.

FIG. 3 is an explanatory diagram conceptually showing an example of the second method. As shown in the figure, the laser beam 30 emitted from the laser oscillation wr1 is converted into a large-diameter laser beam 30 using a beam expander 31, and then is reflected by a reflective mirror 32 (or prism) through a mask 20. The workpiece 5 is irradiated.

It can also be easily obtained by removing the focus as shown in FIG.

As the laser light used in the method of the present invention, both Q-switched laser light and CW laser light can be used. When a Q-switched laser beam or a CW laser beam is used as the laser beam, there will be a difference in the processing state, as will be shown in later embodiments. Therefore, the method of the present invention has the advantage that various types of processing can be performed by selectively using both laser beams.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples.

Examples Example 1 A mask for micro-shape processing made of PZT was manufactured using the apparatus shown in FIG.

After fixing the PZT substrate on the table 15 of the same device, x
By operating the Y stage 14, a laser beam is scanned on the PZT substrate, and the − side is 40. m, 60-. 80 voices,
100. m, ljO, cm.

1504.200M, 3004,400pm, 600-
The light transmitting portions were formed in a square pattern, and in various other geometric pattern shapes. The laser beam irradiation conditions at this time were scanning at a speed of 2 ydmin using an 11&Q switch laser beam with a power of 12 W (equivalent to CW laser beam). In addition, as an etching solution, 20% by weight
An aqueous KOH solution was used.

FIG. 5 shows a micrograph showing the processed surface of the mask thus formed. As shown in the figure, the surface of the mask and the processed side wall of the light transmitting section are almost perpendicular to each other, forming a sharp angle, and the corners of the square pattern also form an ideal right angle.

The mask formed as described above is very suitable for use as a mask for micro-shape processing according to the present invention.

Example 2 After fixing a PZT substrate onto a quartz glass plate aQc using Ceramabond (trade name), a heat-resistant adhesive, as shown in FIG. Formed.

The thus obtained mask 30 has a very ideally processed light transmitting part 30b, similar to that of Example 1, and also has a quartz glass plate 30c attached. It also has increased strength and is easier to handle.

Example 3 FIG. 7 shows a cross-sectional view of the mask of this example.

To manufacture this mask 30, first, a quartz glass plate 30 is
A chromium metal film formed by vapor deposition on c is processed by photoetching to form a light passing portion 33b. Next, an Al 2 f (Al 2 O,) film is formed by chemical vapor deposition (CVD) to protect the light shielding portion 33 a formed of this metal film.

The mask thus obtained is suitable for use in the micro-shape processing method according to the present invention.

Example 4 Using the mask obtained in Example 1, a micro-shape processing method according to the method of the present invention was carried out using the apparatus shown in FIG.

An AIOTiC ceramic plate was used as a workpiece, and a CW laser beam with an output of 6 W was scanned as shown in FIG.

Note that a KOH aqueous solution was used as the etching agent.

FIG. 8 is a micrograph showing the processed surface of the workpiece processed as described above. As shown in this drawing, the pattern of the light passing portion of the mask is faithfully reproduced on this workpiece.

Furthermore, the center portion of the processed pattern shape is processed to have a depth.

Additionally, processing time has been significantly reduced compared to conventional methods.

Example 5 Using another mask manufactured in the same manner as in Example 1, processing was performed by scanning with a Q-switched laser beam of Al2O (corresponding to the tip) using the apparatus shown in FIG. Etching agent is KO
It is an H aqueous solution.

The 9th photomicrograph showing the machined surface of the workpiece in this example is
As shown in the figure. As shown in this drawing, the pattern of the light transmitting portion of the mask is faithfully reproduced in this example as well. Further, in this embodiment, since Q-switched laser light was used, the side walls of the processed pattern stood steeply and a sharp shape was obtained.

Furthermore, the processing time is significantly reduced compared to the conventional method.

Example 6 An A 1203T i C ceramic plate was processed in the same manner using a mask having a square light transmitting portion with sides of 60 mm. Here, processing conditions were compared using the Q-switched laser beam used in Example 5 and the CW laser beam of 2 to 4 W.

A microscopic photograph showing the surface condition of the workpiece thus obtained is shown in FIG. As shown in the figure, the f-turn processed by the CW laser beam has a shallow processing depth as a whole and has a forest-like shape with a depression in the center. On the other hand, according to the Q-switched laser beam, the entire square is processed to approximately the same depth. By utilizing such processing characteristics, various processing can be performed freely.

Also, according to FIG. 10, Q-switched laser light or C
It can be seen that the pattern shape of the light-transmitting portion of the mask can be accurately and uniformly reproduced using either W-ray beam.

<Effects of the Invention> As described above in detail with Examples, the micro-shape processing method according to the present invention uses a mask for micro-shape processing) to irradiate a high-power laser beam. By doing so, laser etching of fine shapes on difficult-to-process materials can be performed with high accuracy and high efficiency.

In addition, if lead zirconate titanate is used as the material for the above-mentioned mask for micro-shape processing, it is possible to process the light transmitting part formed in a micro-shape with high precision, and the fabricated mask can be manufactured using the micro-shape processing method. It can be used repeatedly and can produce good quality workpieces.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of the implementation of the micro-shape processing method according to the present invention, and FIGS. 2, 3, and 4 conceptually represent examples of laser light irradiation in the method of the present invention. The explanatory diagram, FIG. 5, is a microscopic photograph showing the surface of the processed surface of the mask for micro-shape processing according to the embodiment of the present invention, and FIG.
FIG. 7 is a cross-sectional view of a mask for micro-shape processing according to another embodiment, and FIG. 8, FIG. 9, and FIG. FIG. 11 is an explanatory diagram showing an apparatus for performing laser etching according to the prior art. In the drawings, 1 is a laser oscillation unit, 5 is a workpiece, 7 is an etching processing container, 20 is a mask, 20a is a light shielding part, 20b is a light transmitting part, and 30 is a laser beam.

Claims (1)

[Scope of Claims] 1) The laser beam is applied to a workpiece placed in an etching agent through a mask formed in a predetermined pattern and having a light transmitting portion that allows the laser beam to pass through and a light shielding portion that blocks the laser beam. A micro-shape processing method characterized by etching a shape corresponding to the pattern of the light-transmitting part by irradiating the light-transmitting part. 2) A mask for micro-shape processing, characterized by having a light transmitting part formed in a predetermined pattern and allowing laser light to pass therethrough, and a light shielding part made of lead zirconate titanate and blocking the laser light.