JPH0451270B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a laser marking device that forms marks on a workpiece using a laser beam.

(Prior art) When marking a predetermined pattern on a workpiece with laser light, a mask on which a predetermined pattern is formed is irradiated with laser light, and the laser light that passes through the pattern is focused by an imaging lens. A method of irradiating an image onto a workpiece is known.

In such a method, for example, when the workpiece is a semiconductor package, the workpiece may be required to be marked with a daily code, weekly code, or other various patterns (data). In such cases, it may be necessary to replace the mask with one on which the desired pattern has been formed.

Mask replacement can be done either manually or automatically. However, since doing it manually is inefficient, it has been put into practical use to do it automatically.

FIG. 5 shows a conventional marking device in which masks can be replaced automatically. That is, 1 in the figure is a laser oscillator. A disk-shaped holder 2 is placed in the optical path of the laser beam L output from the laser oscillator 1. A plurality of masks 4, each having a different pattern 3, are provided around the periphery of the holder 2 at predetermined intervals in the circumferential direction.

The rotation shaft 6 of the motor 5 is located in the center of the holder 2.
are connected to each other, and the holder 2 is connected to the holder 2 by this motor 5.
is designed to be rotationally driven. One mask 4 is attached to the holder 2 by rotationally driving the holder 2.
When the mask 4 is located on the optical path of the laser beam L, the laser beam L passes through the pattern 3 of the mask 4, and the laser beam L is imaged by the imaging lens 7 and irradiates the workpiece 8. Thereby, the pattern 3 of the mask 4 is marked on the workpiece 8.

By the way, according to the laser marking device having such a configuration, the holder 2 must be rotated by the motor 5 in order to change the pattern 3 to be marked on the workpiece 8. Therefore, depending on the pattern to be marked, holder 2 can be moved up to 180 mm.
The predetermined pattern 3 cannot be positioned on the optical path unless it is rotated by a certain degree. Therefore, it takes time to control the rotation of the holder 2, resulting in a decrease in productivity. Further, in order to improve productivity, the holder 2 may be rotated at high speed, but for this purpose, a large-sized motor 5 with a large torque must be used. As a result, a problem arises in that the entire device becomes larger.

Furthermore, in order to mark a plurality of patterns 3 side by side on the workpiece 8, the workpiece 8 must be placed on, for example, an XY table, and the XY table must be driven for positioning. However, like the drive of the holder 2, there is a limit to how fast the drive of the XY table can be increased, and this also causes a decrease in productivity.

(Problems to be Solved by the Invention) As described above, in conventional laser marking devices, in order to automate laser replacement, it is necessary to rotate a holder provided with a plurality of patterns. In order to mark multiple patterns on a machine, the workpiece also had to be driven. Since the holder and the workpiece are large, it is not possible to drive them at high speeds, which greatly limits the efficiency of marking operations.

This invention was made based on the above circumstances, and provides a laser marking device that can mark a plurality of patterns on a target mask or workpiece without driving the target mask or workpiece. It is about providing.

[Structure of the Invention] (Means and Effects for Solving the Problems) This invention for solving the above problems includes a laser oscillator and at least one first mirror on which a laser beam output from the laser oscillator is reflected. a first driving source that drives the first mirror to set the direction of reflection of the laser beam reflected by the mirror; and a plurality of patterns, the reflection direction of which is set by the first driving source. a mask in which a predetermined pattern of areas is irradiated with the laser beam;
The laser beam is placed opposite to this mask, and even if the laser beam passes through any pattern of the mask, the laser beam that has passed through that pattern is incident on the imaging lens, and the imaging lens and the first
a relay lens arranged in a conjugate positional relationship with respect to the mirror, and at least one second mirror on which the laser light transmitted through the imaging lens is reflected;
A second drive source is provided which rotationally drives the second mirror and controls the reflection direction of the laser beam incident on the mirror to mark a predetermined position on the workpiece. Furthermore, it is possible to mark a plurality of patterns on the workpiece without driving the mask or the workpiece.

(Example) A first example of the present invention will be described below with reference to FIGS. 1 and 2.
This will be explained with reference to the figures. The laser marking device shown in FIG. 1 includes a laser oscillator 11. The laser marking device shown in FIG. The laser beam L oscillated from this laser oscillator 11 is reflected by a first X mirror 12 serving as a first mirror, and then enters a first Y mirror 13. That is, the laser beam L emitted from the laser oscillator 11 is incident on the first X mirror 12 and the first Y mirror 13 without being focused. The first X mirror 12 is attached to the rotation axis of a first X galvanometer scanner 14 as a first drive source, and the first Y mirror 13 is attached to the rotation axis of a first Y galvanometer scanner 15. is attached to.

The first X galvanometer scanner 14 and the first Y galvanometer scanner 15 are arranged such that the axes of their rotational axes are perpendicular to each other. Therefore, if the first X mirror 12 is rotationally driven by the first X galvanometer scanner 14, the laser beam L oscillated from the laser oscillator 11 and incident on the first galvanometer scanner 14 will be It can be swung in the X direction. Similarly, if the first Y mirror 13 is rotated by the first Y galvanometer scanner 15, the laser beam L reflected by the first X mirror and incident on the first Y mirror 13 will be It can be swung in the direction.

Laser light L reflected by the first Y mirror 13
is arranged to be incident on the relay lens 16. An imaging lens 17 is arranged on the output side of this relay lens 16. Furthermore, a rectangular mask 18 is disposed on the output side of the relay lens 16 in close proximity to the relay lens 16 . As shown in FIG. 2, a large number of patterns 19 are formed in a matrix on this mask 18. Therefore, no matter which pattern 19 of the mask 18 the laser beam L whose traveling direction is controlled by the first X and Y mirrors 12 and 13 is incident on, that pattern 19
The laser beam L that has passed through is made incident on the imaging lens 17 by the relay lens 16. That is, when considering the relay lens 16, the position of the imaging lens 17 is the same as that of the first X mirror 13.
It is placed at a position conjugate to the position of . The laser beam L transmitted through the imaging lens 17 is reflected by the second X mirror 21 and then reflected by the second Y mirror 22.
It is designed to be incident on . The second X mirror 21 is attached to the rotation axis of the second X galvanometer scanner 23, and the second YY mirror 22 is attached to the rotation axis of the second Y galvanometer scanner 24. These galvanometer scanners 23 and 24 are arranged with their rotation axes perpendicular to each other. Therefore, if the second X mirror 21 is rotated in the X direction by the second galvanometer scanner 23, the laser beam L that has passed through the imaging lens 17 can be swung in the X direction. 2 Y
The mirror 22 is connected to the second Y galvanometer scanner 2.
4, the second X mirror 2
The laser beam L reflected by 1 can be swung in the Y direction, and the marking position can be changed on the workpiece 25.

Since the relay lens 16 and the imaging lens 17 are arranged in a conjugate positional relationship, the focal position of the imaging lens 17 is located farther (deeper) than the surface of the workpiece 25. As a result, although the predetermined pattern 19 of the mask 18 is projected onto the surface of the workpiece 25 with a predetermined size, the laser beam L is not imaged on the surface of the workpiece 25. .

Laser light L reflected by the second Y mirror 22
A workpiece 25 is arranged in the direction of movement.
This workpiece 25 is intermittently transported in the X direction by a transport mechanism (not shown), such as a conveyor.

Each of the above galvanometer scanners 14, 15, 2
3 and 24 are electrically connected to a control device 27 via a driver 26, respectively. The first X, Y galvanometer scanners 14, 15 are driven by a driver 26 based on signals from the control device 27 depending on which of the patterns 19 formed on the mask 18 is to be marked. The angles of the X and Y mirrors 12 and 13 of 1 are controlled. Further, the second X, Y galvanometer scanners 23 and 24 are controlled by the control device 2 depending on where on the workpiece the pattern 19 is to be marked.
7 is driven by the driver 26, thereby causing the second X, Y mirrors 21, 22
It is now possible to control the angle of the

In the laser marking device configured as described above, marking a plurality of patterns 19 on the workpiece 25, for example, three patterns 19 such as "T No.""3" and "8", is performed as follows. First, the laser beam L oscillated from the laser oscillator 11 is directed by the control device 2 so that the traveling direction of the laser beam L irradiates the “T No.” portion of the pattern 19 of the mask 18.
7 via the driver 26 with the signal from the first X,
Drives Y galvanometer scanners 14 and 15,
The angles of the first X and Y mirrors 12 and 13 attached to these rotating shafts are controlled. Thereby, the laser beam L transmitted through the portion of the pattern 19 "T No." of the mask 18 is incident on the imaging lens 17 by the relay lens 16.

The laser beam L imaged in this manner is sequentially reflected by the second X mirror 21 and the second Y mirror 22 to mark the workpiece 8. At that time, the second X, Y mirror is scanned by the second X, Y galvanometer scanners 21, 22 so that the "T No." pattern 19 is imaged on the left end of the workpiece 8 in FIG. The angles of 12 and 13 are controlled.

Next, the first X, Y mirror 12,
Controls 13 angles. Further, the angles of the second X and Y mirrors 21 and 22 are controlled so that the laser beam L reflected by these mirrors is directed substantially toward the center of the workpiece 25. By controlling the angle of each mirror in this way, the pattern 19 of "3" will be marked in the center portion of the workpiece 25.

Next, the first X and Y mirrors 12 and 13 are moved so that the laser beam L emitted from the laser oscillator 11 passes through the "8" portion of the pattern 19 of the mask 18.
control the angle of the Further, the second X, Y mirror 2 is arranged so that the laser beam L that is imaged after passing through the pattern 19 of “8” irradiates the right end of the workpiece 25.
By controlling the angles 1 and 22, the "8" pattern 19 can be marked on the right end of the workpiece 25.

In this manner, by rotating the four mirrors, it is possible to mark the workpiece 25 with a plurality of patterns 19 side by side. Since the mirror has only to have a size that can reflect the laser beam L, it can be made smaller. Therefore, each of the mirrors can be rotated at high speed by the galvanometer scanner, so that marking of a plurality of patterns 19 can be performed efficiently. Furthermore, since it is not necessary to drive the workpiece 25 to mark the plurality of patterns 19 at predetermined positions on the workpiece 25, marking can be performed at high speed.

On the other hand, the laser beam L oscillated from the laser oscillator 11 is reflected without being focused on the reflection surfaces of the first X mirror 12 and the first Y mirror 13, and is further reflected by the relay lens 16 and the imaging lens. 17 is arranged in a conjugate positional relationship,
The light is also reflected on the reflecting surfaces of the second X mirror 21 and the second Y mirror 22 without being focused, and irradiates the workpiece 25, thereby projecting the pattern 19 of the mask 18 in a predetermined size. In other words, the laser beam L is not focused on the reflective surface of each mirror, thereby reducing the energy density per unit area of the laser beam L that irradiates each mirror.
These mirrors are prevented from being damaged early by the heat of the laser beam L.

FIG. 3 shows a second embodiment of the invention. In this embodiment, Y is moved at a predetermined speed by a conveyor belt 31.
A case is shown in which marking is performed on a workpiece 25 that is being continuously conveyed in the direction shown in FIG. That is, a mark 32 for detecting the running speed of the conveyor belt 31 is provided on the side surface of the conveyor belt 31, and the mark 32 is detected by a sensor 33. When the traveling speed of the conveyor belt 31 is detected by the sensor 33, the detection signal is input to the control device 27. Then, this control device 27 controls the second Y according to the running speed of the conveyor belt 31.
The galvanometer scanner 24 is driven and the second Y
The irradiation position of the workpiece 25 with the laser beam L reflected by the mirror 22 is controlled. In other words, the irradiation position of the workpiece 25 in the Y direction with the laser beam L is controlled to be constant. Therefore, workpiece 2
5 can be marked while being conveyed continuously in the Y direction.

FIG. 4 shows a third embodiment of the invention. In this embodiment, one pattern 19 is formed on one rectangular mask 34, and a plurality of masks 34 are formed.
A plurality of attachment parts 3 formed on the mask holder 35
6 can be detachably attached. In this way, the mask 34 of any pattern 19 can be attached to the mask holder 35.

In addition, in the above embodiment, two mirrors, X and Y, were used to make the laser beam enter the mask and to irradiate the workpiece, but the direction of the laser beam was changed only to one of the X and Y directions. In this case, only a mirror in either the X or Y direction may be provided. Furthermore, a motor may be used as the drive source instead of the galvanometer scanner. Furthermore, a polycon mirror may be used as the mirror.

[Effects of the Invention] As described above, the present invention provides a marking device in which laser light emitted from a laser oscillator passes through a pattern on a mask, forms an image with an imaging lens, and irradiates the workpiece with the mask. The laser beam before being incident on the mask is reflected by a first mirror rotationally driven by a first driving source, so that the laser beam can be made incident on any one of the plurality of patterns provided on the mask. In addition, the relay lens and the imaging lens are arranged in a conjugate positional relationship, and the laser light that has sequentially passed through these lenses is made incident on a second mirror, and this second mirror is rotated by a second driving source. By driving and controlling the angle,
It is now possible to mark a predetermined position on the workpiece. That is, since it is sufficient to drive a small mirror to mark a plurality of patterns, the driving speed can be increased and work efficiency can be improved. In addition, the laser beam oscillated from the laser oscillator is not focused and is
After being reflected by the second mirror, the relay lens, the focusing lens, and the first mirror are arranged in a conjugate positional relationship, so that the reflected light is also reflected on the second mirror without being focused. That is, since the focus of the laser beam is not located on the first mirror and the second mirror, these mirrors are not damaged early by the heat of the laser beam.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the entire device showing a first embodiment of the present invention, Fig. 2 is a perspective view of the same enlarged main part, and Fig. 3 is a partial diagram of the device showing a second embodiment of the invention. FIG. 4 is a perspective view of a mask holder showing a second embodiment of the present invention, and FIG. 5 is a perspective view of a conventional device. 11... Laser oscillator, 12... First X mirror,
13... First Y mirror, 14... First X galvanometer scanner, 15... First Y galvanometer scanner, 16... Relay lens, 17... Imaging lens, 18... Mask, 19... Pattern, 21...th 2
X mirror, 22...second Y mirror, 23...second
X galvanometer scanner, 24...second Y
Galvanometer scanner.

Claims (1)

[Claims] 1 a laser oscillator and at least one first laser beam from which the laser beam output from the laser oscillator is reflected;
a mirror, a first drive source that drives the first mirror to set the reflection direction of the laser beam reflected by the mirror, and a plurality of patterns, the reflection direction being set by the first drive source. A mask that is placed opposite to this mask and which irradiates parts of a predetermined pattern with a laser beam set to a relay lens disposed in a conjugate positional relationship with respect to the imaging lens and the first mirror; and at least one relay lens configured to reflect the laser light transmitted through the imaging lens. the second mirror; and a second drive source that drives the second mirror and controls the reflection direction of the laser beam incident on the mirror to mark a predetermined position on the workpiece. Laser marking equipment.