JPH05200570A - Liquid crystal mask type laser marking method and device thereof - Google Patents

Abstract

(57) [Abstract] [Purpose] To realize marking of a large area pattern clearly with a small output laser light source and a small liquid crystal mask. [Structure] A mask pattern to be marked is divided into sub patterns 9a, 9b and 9c. When dividing, the dividing lines 24 and 25 are determined so that one character in the mask pattern does not straddle a plurality of sub patterns, and further, the coordinates of the reference points P1, P2, and P3 of each sub pattern are obtained, and each sub pattern is determined. Information on the shape and position of the pattern is stored in the storage device. At the time of marking, the sub-pattern 9a is displayed on the liquid crystal mask and irradiated with laser light to be transferred onto the work, and then the sub-pattern 9b is displayed on the liquid crystal mask and irradiated with laser light to be transferred onto the work. At this time, based on the position information of the reference points P1 and P2 of the sub patterns 9a and 9b, the tilt angle of the galvano mirror provided in the path of the laser beam is controlled so that the transfer positions of the sub patterns 9a and 9b are on the work. To be continuous.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a liquid crystal mask type laser laser.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a king method and an apparatus thereof, and more particularly to a liquid crystal mask type laser marking method and an apparatus thereof suitable for a large marking pattern.

[0002]

2. Description of the Related Art Conventionally, as this type of laser marking device, one described in Japanese Patent Laid-Open No. 64-11088 has been known. In this conventional technique, as shown in FIG.
The linearly polarized pulse laser light 102 output from the oscillator 101 is applied to the liquid crystal mask 103. The laser beam 104 transmitted through the liquid crystal mask 103 is converted by the polarization beam splitter 105 into laser beam 106 including pattern information displayed on the liquid crystal mask 103 and laser beam 107 in the background portion. The separated laser beam 106 is imaged by a focusing lens 108 on a work 109 such as an IC (integrated circuit) package which is a marking object. As a result, the mask pattern 110 displayed on the liquid crystal mask 103 is transferred onto the surface of the work 109 in a predetermined size. Display of the mask pattern 110 on the liquid crystal mask 103 is performed by the liquid crystal mask driving device 112 based on a signal from a control console 111 such as a computer.

[0003]

In the conventional liquid crystal mask type laser marking device, the area which can be marked is determined by the output per pulse of the laser light, so that a pattern having a large area is transferred. It is necessary to increase the output of the laser oscillator and use a large liquid crystal mask.
However, the large-sized liquid crystal mask has a problem that the number of scanning electrodes for controlling the mask pattern is increased and the contrast of the mask pattern transferred on the work is deteriorated and becomes unclear. Also, there is a problem that a high-power laser oscillator is expensive.

An object of the present invention is to provide a liquid crystal mask type laser marking method and apparatus capable of clearly transferring a large area pattern on the surface of a work by a laser oscillator having a small output.

[0005]

Means for Solving the Problems The above-mentioned object is to apply the laser light to a liquid crystal mask on which an arbitrary pattern is displayed, collect the transmitted laser light on the surface of a marking object, and transfer the pattern. This is achieved by dividing the pattern into a plurality of sub-patterns, sequentially displaying each sub-pattern on the same liquid crystal mask, and transferring the sub-patterns onto the surface of the marking object to complete the pattern.

Preferably, when the pattern is divided into sub-patterns, one character such as a character, a number or a logo mark in the pattern is divided by a dividing line which does not divide the pattern.

[0007]

[Function] Even if a pattern of a large area is divided into sub-patterns of a small area and each sub-pattern is transferred, the required liquid crystal mask can be made small, and the laser oscillator also has a small output. I just need one.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a liquid crystal mask type laser marking device according to a first embodiment of the present invention. The marking device control unit 1 controls the laser oscillator 2, the sub pattern storage unit 3, the mirror control unit 4, and the work carrier unit 5.
Linearly polarized laser light 6 emitted from the laser oscillator 2
Is irradiated on the liquid crystal mask 7. In the example shown in FIG. 1, the liquid crystal mask 7 has partial patterns (sub-patterns) 9a, 9b, which are obtained by dividing the mask pattern 8 into three, as shown in FIG.
Sub-pattern 9a of 9c is displayed. The laser beam 10 transmitted through the liquid crystal mask 7 is passed through a polarization beam splitter 11 to generate a laser beam 12 containing pattern information,
The latter laser light 13 is separated into the laser light 13 of the background portion.
Heads to the absorber plate 14. On the other hand, the former laser light 12 is
After being deflected by a pair of Galvanomila-15,16,
It is transferred to a predetermined position on the work 18a by the imaging lens 17. Reference numeral 20 is a liquid crystal mask control unit, and 21 is a carrier.

After forming the mask pattern 8 shown in FIG. 2, the pattern forming section 19 displays the displayable area of the liquid crystal mask 7,
From the size of the pattern to be transferred onto the work 18a and the imaging magnification, the number of pattern divisions, that is, the number of sub-patterns,
How to draw the dividing line is determined as described later in detail, and pattern information and position information are stored in the sub-pattern storage unit 3 for each sub-pattern.

A mask pattern creating procedure in the pattern creating section 19 will be described with reference to FIGS. 3 and 4. As shown in FIG. 3, a mask pattern area (approximately equivalent to the size of the work) 23 is set on the display screen 22 of the pattern creating section 19, and alphanumeric characters to be marked are appropriately arranged.
From the displayable area of the liquid crystal mask 7, the size of the pattern to be transferred onto the work 18a, and the imaging magnification, the number of divisions, that is, the number of sub-patterns and how to draw the division line are determined. At this time, in this embodiment, the dividing lines 24 and 25 are formed so that one character, numeral, logo mark or the like forming the mask pattern is not divided over two or more sub patterns.
Decide. After the division, each sub-pattern 9a, 9b, 9
The coordinates (x1, y1), (x2, of the reference points P1, P2, P3 of c
y2) and (x3, y3) are stored in the sub-pattern storage unit 3 as position information of each sub-pattern. Further, information such as the shape of each sub-pattern 9a, 9b, 9c and the alphanumeric characters contained therein is temporarily stored in the storage unit 3 for each sub-pattern.

Next, as shown in FIG. 4, the pattern forming unit 1
Liquid crystal mask display area of display screen 21 of 9 (all characters, numbers, etc. included in this area can be transferred onto a work) 2
6, the sub-pattern 9a temporarily stored in the storage unit 3 is called and displayed. At this time, the display area 2
The sub-pattern 9a is moved on the display screen 22 so that the reference point L of 6 and the reference point P1 of the sub-pattern 9a coincide with each other. After this work is completed, it is stored in the storage unit 3 as pattern information regarding the sub-pattern 9a. Then
After calling the sub-pattern 9b on the display screen 21 and matching the reference point L and the reference point P2 of the sub-pattern 9b,
The storage unit 3 stores pattern information regarding the sub-pattern 9b.
Remember. The same operation is performed for the sub pattern 9c, and the pattern information regarding the sub pattern 9c is stored in the storage unit 3. Thus, all the information about the positions of the sub-patterns 9a, 9b, 9c that form the mask pattern 8 and the information about the pattern (shape) are stored in the storage unit 3.

Next, a procedure for transferring the mask pattern 8 onto the work 18a will be described. In response to a command from the marking device control unit 1 in FIG. 1, of the sub-pattern information stored in the storage unit 3, the pattern information regarding the sub-pattern 9a is first called and displayed on the liquid crystal mask 7 by the liquid crystal mask control unit 20. Then, the tilts of the Galvano mirrors 15 and 16 are set by the mirror control unit 4 so that the laser light 12 passing through the liquid crystal mask 7 and the polarization beam splitter 11 is irradiated to a predetermined position on the work 18a. At this time, the information about the position of the sub-pattern 9a stored in the storage unit 3 is used for setting. Next, laser light is emitted from the laser oscillator 2 to the liquid crystal mask 7.
The laser light 12 that has passed through the liquid crystal mask 7 and transmitted through the polarization beam splitter 11 is reflected by the galvano mirrors 15 and 16, passes through the imaging lens 17, and is irradiated onto a predetermined position on the work 18a. As a result, the sub-pattern 9a becomes the work 1
8a is transferred.

Next, the display content of the liquid crystal mask 7 is changed to the sub-pattern 9b based on the information on the sub-pattern 9b stored in the storage unit 3, and the galvano mirror 15,
The inclination of 16 is adjusted. The adjustment amount of the tilt angles of the Galvano mirrors 15 and 16 is calculated from the distance between the coordinates (x1, y1) of the reference point P1 of the sub pattern 9a and the coordinates (x2, y2) of the reference point P2 of the sub pattern 9b. Then, the sub-pattern 9b is transferred onto the work 18a by the same procedure as described above. The sub-pattern 9c is also transferred onto the work 18a by the same procedure. Sub pattern 9
When the transfer of a, 9b, and 9c is completed, the mask pattern 8
Is completed on the work 18a. After that, the work transfer controller 5 moves the transfer table 21 to feed the next work 18b, and the mask pattern 8 is transferred onto the work 18b by the same procedure as described above.

According to the above-described embodiment, the information regarding the patterns (shapes) of the plurality of sub-patterns stored in the storage unit 3 is sequentially called and displayed on the liquid crystal mask 7 in order, and the transmitted laser light is irradiated at the time of laser light irradiation. So that each sub-pattern image is formed at each predetermined position on the workpiece, the galvano mirrors 15 and 16 forming the laser light transmission unit are controlled by information about the position of the sub-pattern, and further, a plurality of sub-patterns are formed. Since the dividing line was drawn so that one character, number, logo mark, etc. would not be divided over the entire area, even when transferring a large area pattern, there is no double striking of the marking pattern or clear characters. Marking can be realized with a small output laser light source and a small liquid crystal mask.

FIG. 5 shows the work 1 of the laser marking device.
FIG. 8 is an explanatory diagram of a configuration near 8a. During marking, soot and smoke are generated from the work 18a because the laser light burns the surface of the work 18a. An air blowing nozzle 22 is provided to quickly remove the soot and smoke from the vicinity of the work surface. A particular consideration in the arrangement of the nozzles 22 is that the air 23 is made to flow from the place where the sub pattern is already transferred on the work surface to the place where the next sub pattern is transferred. It is a point. This prevents the marking pattern, which has already been transferred, from being contaminated by soot and smoke generated during the transfer of the subsequent sub pattern.

FIG. 6 is a block diagram of the marking device according to the second embodiment of the present invention. In this embodiment, a plurality of liquid crystal masks 29 and 30 for displaying sub patterns and a plurality of laser oscillators 31 and 32 are provided corresponding to the respective liquid crystal masks. The laser oscillator 3 is provided on each of the liquid crystal masks 29 and 30.
The linearly polarized laser light 33, 34 from 1, 32 is emitted. Laser light 3 transmitted through each liquid crystal mask 29, 30
Laser light 37, 3 including pattern information out of 5, 36
Numeral 8 is separated by a polarization beam splitter 11, passes through galvano mirrors -15 and 16, and is turned into a work 1 by an imaging lens 17.
It is transferred to a predetermined position on 8a.

In this embodiment, the procedure for transferring the mask pattern 8 to the work 18a will be described. First, information about the pattern (shape) of the sub-pattern 9a stored in the storage unit 3 is called by a command from the marking device control unit 1, and the liquid crystal mask 29 is controlled by the liquid crystal mask control unit 20 to display the sub-pattern 9a. Is displayed. Next, the information about the pattern (shape) of the sub-pattern 9b stored in the storage unit 3 is called, and the liquid crystal mask control unit 2 is called.
By controlling 0, the sub-pattern 9b is displayed on the liquid crystal mask 30. On the other hand, the laser light 3 transmitted through the liquid crystal mask 29
Laser light 37 including pattern information out of 5 is work 1
The mirror control unit 4 sets the inclinations of the galvano mirrors 15, 16 based on the information on the position of the sub-pattern 9a stored in the storage unit 3 so that the predetermined position on the 8a is irradiated. After that, the laser light 33 output from the laser oscillator 31 is applied to the liquid crystal mask 29. The laser light transmitted through the liquid crystal mask 29 is Galvanomila-15,
After passing through 16, an image is formed at a predetermined position on the work 18a by the image forming lens 17, and the sub-pattern 9a is transferred.

Next, based on the information on the position of the sub-pattern 9b stored in the storage unit 3, the mirror control unit 4
Sets the inclination of Galvanomila-15,16. After that, the laser light 34 from the laser oscillator 32 is applied to the liquid crystal mask 30. Laser light 38, which contains pattern information, of the laser light that has passed through the liquid crystal mask 30 passes through the galvano mirrors 15, 16 and is focused by the imaging lens 17 into a work beam.
Image at a predetermined position on the mask 18a and the sub pattern 9b
Is transcribed.

During the transfer of the sub pattern 9b, the liquid crystal mask 29 is instructed by the device control section 1 to receive the sub pattern 9b.
Information on the pattern (shape) of c is displayed. Then, after the transfer of the sub-pattern 9b is completed, the mirror control unit 4 again controls the galvano mirror-1 based on the information on the position of the sub-pattern 9c stored in the storage unit 3.
Set the slope of 5,16. After that, the laser oscillator 31
The laser light 33 from irradiates the liquid crystal mask 29, and the transfer of the sub pattern 9c is completed. Thus, the mask pattern 8 consisting of the sub-patterns 9a, 9b, 9c
The transfer onto the mask 18a is completed.

Of the laser beams 35 and 36 emitted from the liquid crystal masks 29 and 30, the lines containing pattern information are used.
The laser beams 33 and 3 from the laser oscillators 31 and 32 are previously set so that the polarization directions of the beams 37 and 38 are different by 90 degrees.
The polarization direction of 4 is set. The laser light 37 passes through the polarization beam splitter 11, and the laser light 38 passes through the polarization beam splitter 11.
Galvanomilla-15,1 after being reflected by the splitter 11
Go to 6. In this case, it is preferable that the optical axes of the laser beams 37 and 38 are parallel to each other, but they need not be coaxial.

In the present embodiment, two sets of laser oscillators and two liquid crystal masks are prepared, respectively, and while the sub-pattern displayed on one liquid crystal mask is transferred onto the work, the other liquid crystal mask is transferred. It is configured to rewrite the sub pattern of. Therefore, the influence of the time required for rewriting the sub-pattern of the liquid crystal mask (0.3 seconds to 0.5 seconds) is reduced, and the time required for transferring the pattern is shortened.

In the above two embodiments, a TN (twisted nematic) liquid crystal is used as a liquid crystal mask, and linearly polarized laser light is applied to this. However, the present invention is not limited to this structure, and a combination of another liquid crystal such as a smectic liquid crystal and non-polarized laser light can be used.

[0023]

According to the present invention, even when transferring a pattern of a large area, clear marking can be performed with a small liquid crystal mask and a laser light source with a small output, and the cost of the laser marking device can be reduced. Can be planned.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a liquid crystal mask type laser marking device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a mask pattern.

FIG. 3 is an explanatory diagram of a mask pattern dividing method.

FIG. 4 is an explanatory diagram of a method of creating a sub pattern.

FIG. 5 is an explanatory view of the arrangement of air blowing nozzles.

FIG. 6 is a configuration diagram of a liquid crystal mask type laser marking device according to a second embodiment of the present invention.

FIG. 7 is a configuration diagram of a conventional laser marking device.

[Explanation of symbols]

1 ... Marking device control unit, 2, 31, 32 ... Laser oscillator, 3 ... Sub pattern storage unit, 4 ... Mirror control unit,
7, 29, 30 ... Liquid crystal mask, 8 ... Mask pattern, 9
a, 9b, 9c ... Sub pattern, 18a, 18b ... Work, 19 ... Sub pattern creating section.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Minoru Suzuki 1-1-1 Kokubuncho, Hitachi City, Ibaraki Prefecture Hitachi Co., Ltd. Kokubun Plant

Claims (10)

[Claims] 1. A liquid crystal mask laser marking method for irradiating a liquid crystal mask displaying an arbitrary pattern with laser light, condensing transmitted laser light on the surface of an object to be marked, and transferring the pattern. The liquid crystal mask type laser marking method, characterized in that the pattern is completed by dividing the pattern into sub-patterns, displaying each sub-pattern on the same liquid crystal mask in sequence, and transferring the sub-patterns to the surface of the marking object. 2. A liquid crystal mask type laser marking method for irradiating a liquid crystal mask displaying an arbitrary pattern with laser light, condensing transmitted laser light on the surface of an object to be marked and transferring the pattern, By dividing one character such as a letter, number, or logo mark in the pattern into a plurality of sub-patterns by a dividing line which is not divided, each sub-pattern is sequentially displayed on the same liquid crystal mask and transferred onto the surface of the marking object. A liquid crystal mask type laser marking method characterized by completing a pattern. 3. A liquid crystal mask type laser marking method for irradiating a liquid crystal mask displaying an arbitrary pattern with laser light, condensing transmitted laser light on the surface of a marking object and transferring the pattern, It is characterized in that the pattern is completed by dividing the pattern into a plurality of sub-patterns by a dividing line that passes through a blank area in the pattern, sequentially displaying each sub-pattern on the same liquid crystal mask and transferring it to the surface of the marking object. Liquid crystal mask type laser marking method. 4. The gas according to any one of claims 1 to 3, wherein when each sub-pattern is sequentially transferred, gas is directed from a position on the marking object surface where the sub-pattern has already been transferred to a position where the next sub-pattern is to be transferred. A liquid crystal mask type laser marking method characterized by performing transfer while flowing. 5. A liquid crystal mask type laser marking method for irradiating a liquid crystal mask displaying an arbitrary pattern with laser light, condensing transmitted laser light on the surface of a marking object and transferring the pattern, wherein a plurality of liquid crystal masks are used. It is characterized in that the composite pattern of each partial pattern is marked on the surface of the marking target object by irradiating the partial pattern displayed on the screen with laser light from different laser oscillators and transferring each partial pattern to the surface of the marking target object. Liquid crystal mask type laser marking method. 6. A liquid crystal mask type laser marking device for irradiating a liquid crystal mask displaying an arbitrary pattern with laser light, condensing transmitted laser light on the surface of a marking object and transferring the pattern, wherein a plurality of patterns are provided. Liquid crystal mask type laser marking apparatus, characterized in that the liquid crystal mask type laser marking apparatus comprises means for dividing into sub patterns and means for displaying the respective sub patterns in sequence on the same liquid crystal mask and transferring them to the surface of the marking object to complete the pattern. .. 7. A liquid crystal mask type laser marking apparatus for irradiating a liquid crystal mask displaying an arbitrary pattern with laser light, condensing transmitted laser light on the surface of an object to be marked and transferring the pattern, A means for dividing a single character such as a letter, number, or logo mark in a pattern into a plurality of sub-patterns by a dividing line, and displaying each sub-pattern in sequence on the same liquid crystal mask and transferring it to the surface of the marking object. And a means for completing the pattern. 8. A liquid crystal mask type laser marking device for irradiating a liquid crystal mask displaying an arbitrary pattern with laser light, condensing transmitted laser light on the surface of a marking object and transferring the pattern, A means for dividing the pattern into a plurality of sub-patterns by a dividing line passing through a blank area in the pattern, and a means for completing the pattern by sequentially displaying each sub-pattern on the same liquid crystal mask and transferring it to the surface of the marking object. A liquid crystal mask type laser marking device characterized by being provided. 9. The gas according to claim 6, wherein when the sub-patterns are sequentially transferred, gas is directed from a position on the marking object surface where the sub-pattern has already been transferred to a position where the next sub-pattern is to be transferred. A liquid crystal mask type laser marking device, characterized in that it is provided with a flowing nozzle. 10. A liquid crystal mask type laser marking apparatus for irradiating a liquid crystal mask displaying an arbitrary pattern with laser light, condensing transmitted laser light on the surface of a marking object and transferring the pattern, wherein a plurality of patterns are provided. Means for dividing into subpatterns, a plurality of liquid crystal masks for displaying the subpatterns, a plurality of laser light sources for irradiating each liquid crystal mask, and a laser beam from each laser light source for irradiating each liquid crystal mask to the marking object surface And a means for completing the pattern by transferring each sub-pattern to the liquid crystal mask type laser marking apparatus.