WO2009002011A1

WO2009002011A1 - Method of dividing marking objects in multi-laser marking system

Info

Publication number: WO2009002011A1
Application number: PCT/KR2008/002397
Authority: WO
Inventors: Kyu-Dong Sung; Mi-Jin Choi; Byung-Duk Woo
Original assignee: Eo Technics Co., Ltd.
Priority date: 2007-06-28
Filing date: 2008-04-28
Publication date: 2008-12-31

Abstract

Provided is a method of dividing marking objects in which the marking objects are divided so that some of the marking objects including a characteristic or figure to be marked are marked using a first laser beam and other remaining marking objects are marked using a second laser beam. The method includes: dividing a predetermined marking region into a first sub-marking region on which the first laser beam is used and a second sub-marking region on which the second laser beam is used; calculating respective estimated marking times taken to mark the marking objects; adding estimated marking times taken to mark marking objects included in the first sub-marking region and adding estimated marking times to mark marking objects included in the second sub-marking region; calculating a half value of a difference between a total value of the estimated marking times of the first sub-marking region and a total value of the estimated marking times of the second sub-marking region; selecting a marking object having an estimated marking time that is the same as or similar to the half value from among marking objects included in a sub-marking region corresponding to one of the first and second sub-marking regions, depending on which has the greater total estimated marking time value; and marking the selected marking object by using a laser beam different to that used for the sub-marking region including the selected marking object.

Description

METHOD OF DIVIDING MARKING OBJECTS IN MULTI- LASER MARKING SYSTEM

Technical Field

[1] The present invention relates to a method of dividing marking objects, and more particularly, to a method of dividing marking objects in which characters or figures are grouped and then the characteristics or figures are marked using different laser beams in order to reduce a marking time in a multi-laser marking system. Background Art

[2] A multi-laser marking system comprises an apparatus that can collectively perform a plurality of marking operations by using a plurality of laser beams in order to reduce a time taken to mark a plurality of characters and figures on a substrate. Conventionally, laser marking is performed using a single laser beam due to issues of performance and control of hardware. However, recently, a plurality of laser beams can be collectively controlled due to the improved performance of hardware. In addition, as consumer demand for a processing apparatus having high production efficiency has increased due to a drop in price of a semiconductor chip, a multi-laser marking system that can perform a plurality of marking operations by using a plurality of laser beams has replaced a conventional apparatus.

[3] FIG. 1 is illustrates a conventional multi-laser marking system. FIG. 2 illustrates a conventional method of dividing marking objects.

[4] Referring to FIGS. 1 and 2, in the conventional multi-laser marking system, 50% of a laser beam that is emitted from a laser oscillator 10 towards a beam splitter 20 passes through the beam splitter 20, and the other 50% of the laser beam is reflected by the beam splitter 20. A laser beam reflected by the beam splitter 20 passes along a first path Ia to pass through a scanner pair 41 and then is emitted onto a substrate 2 to be processed. A laser beam transmitted through the beam splitter 20 passes along a second path Ib to pass through a reflective mirror 30, a scanner pair 42, and the scan lens 50 and then is irradiated onto the substrate 2.

[5] In the conventional multi-laser marking system, when a single laser beam is divided into two laser beams, for example, a first laser beam and a second laser beam, a marking region 60 that is an entire region onto which the two laser beams can be irradiated is divided into two sub-marking regions 61 and 62, according to the number of laser beams. In this regard, the marking region 60 is divided into the two sub- marking regions 61 and 62 so that the two sub-marking regions 61 and 62 are of the same area. That is, when the marking region 60 is marked using the two laser beams, the marking region 60 is divided into the two sub-marking regions 61 and 62 of the same area, regardless of the number of characters or figures i.e., marking objects 71, 72 and 73 that are to be marked in the two sub-marking regions 61 and 62, as illustrated in FIG. 2. Thus, the marking objects 71, 72 and 73 are divided so that only marking objects 71 and 72 in the first sub-marking region 61 are marked using the first laser beam, and only marking object 73 in the second sub-marking region 62 is marked using the second laser beam. Disclosure of Invention Technical Problem

[6] When a marking region is divided according to only its area, like in the case of the convention method of dividing marking objects, the number of marking objects can be different for respective sub-marking regions. Thus, times taken to mark marking objects are different for respective sub-marking regions. That is, when a predetermined sub-marking region includes more marking objects than other sub-marking regions, other laser beams need to be on standby until a marking operation is completed with respect to the predetermined sub-marking region even though marking operations are completed with respect to the other sub-marking regions. This is because the marking operation is not completed with respect to the predetermined sub-marking region. In the conventional method of dividing marking objects, the number of marking objects can be different for respective sub-marking regions, thereby increasing the total processing time and deteriorating the production efficiency of a multi-laser marking system. Technical Solution

[7] The present invention provides a method of dividing marking objects in which marking objects are divided into a plurality of groups according to the number of laser beams so that times taken to mark marking objects included in respective groups are the same as or similar to each other.

[8] According to an aspect of the present invention, there is provided a method of dividing marking objects in which the marking objects are divided so that some of the marking objects comprising a character or figure to be marked are marked using a first laser beam and other remaining marking objects are marked using a second laser beam, the method comprising: dividing a predetermined marking region into a first sub- marking region on which the first laser beam is used and a second sub-marking region with which the second laser beam is used; calculating respective estimated marking times taken to mark the marking objects; adding estimated marking times taken to mark marking objects included in the first sub-marking region and adding estimated marking times to mark marking objects included in the second sub-marking region; calculating a half value of a difference between a total value of the estimated marking times of the first sub-marking region and a total value of the estimated marking times of the second sub-marking region; selecting a marking object having an estimated marking time that is the same as or similar to the half value from among marking objects included in a sub-marking region corresponding to one of the first and second sub-marking regions, depending on which has the greater total estimated marking time value; and marking the selected marking object by using a laser beam different to that used for the sub-marking region including the selected marking object.

[9] The selecting of the marking object may comprise selecting a marking object that is the closest to a boundary line between the first and second sub-marking regions when a plurality of marking objects have estimated marking times that are the same as or similar to the half value.

[10] The marking objects may each comprise a plurality of draw vectors used for moving the laser beam during emitting of the laser beam, and a plurality of jump vectors used for moving a laser beam that is to be emitted, to an initial point of a subsequent vector from among the draw vectors while the laser beam is not being emitted, and the calculating of the estimated marking time comprises adding a time taken to move along the draw vectors and a time taken to pass move along the jump vectors. Advantageous Effects

[11] In the method of dividing marking objects according to the present invention, by dividing marking objects in a marking region into a plurality of groups so that a time taken to mark marking objects included in a group is similar to a time taken to mark marking objects included in another group, an entire system does not have to be on standby when marking with a laser beam is not completed even though marking with another laser beam is completed, thereby reducing an unnecessary period of time. Thus, a processing time taken for a substrate can be reduced, thereby improving the production efficiency of a multi-laser marking system. Description of Drawings

[12] The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: [13] FIG. 1 is illustrates a conventional multi-laser marking system;

[14] FIG. 2 illustrates a conventional method of dividing marking objects;

[15] FIG. 3 is a flow chart of a method of dividing marking objects, according to an embodiment of the present invention;

[16] FIG. 4 illustrates an operation, which is performed in the method of FIG. 3, of

[17] dividing a marking region into a first sub-marking region and a second

[18] sub-marking region;

[19] FIG. 5 illustrates that a marking object illustrated in FIG. 4 includes a plurality of draw vectors and a plurality of jump vectors; and

[20] FIG. 6 illustrates an operation, which is performed in the method of FIG. 3, of marking a selected marking object, by another laser beam. Best Mode

[21] Hereinafter, a method of dividing marking objects will be described with regard to exemplary embodiments of the invention with reference to the attached drawings.

[22] FIG. 3 is a flow chart of a method of dividing marking objects, according to an embodiment of the present invention. FIG. 4 illustrates an operation, which is performed in the method of FIG. 3, of dividing a marking region 60 into a first sub-marking region 61 and a second sub-marking region 62. FIG. 5 illustrates that a marking object 91 illustrated in FIG. 4 includes a plurality of draw vectors 81 and a plurality of jump vectors 82. FIG. 6 illustrates an operation, which is performed in the method of FIG. 3, of marking a selected marking object, by another laser beam.

[23] In the current embodiment, referring to FIGS. 3 through 6, a laser beam emitted from a single laser oscillator is divided into two laser beams, and then the two divided laser beams are used for marking, or alternatively, two laser beams that are each emitted from two laser oscillators are used for marking.

[24] First, the marking region 60, which is an entire region onto which laser beams can be irradiated, is divided into the first and second sub-marking regions 61 and 62, according to the number of laser beams Operation SlO). At this time, the marking region 60 is divided into the first and second sub-marking regions 61 and 62 so that the first and second sub-marking regions 61 and 62 are of the same area. In FIG. 4, marking objects 91 and 92 that are respectively 'E' and 'O' are illustrated and are to be marked in the first sub-marking region 61, and marking objects 93 through 97 that are respectively ' ¹^ ', ' H] \ ' 5-]] \ ' o] ' _and ' x\ ' are illustrated and are to be marked in the second sub-marking region 62. However, FIG. 4 illustrates the locations of the first and second sub-marking regions 61 and 62, on which the marking objects 91 through 97 are to be marked, and thus FIG. 4 illustrates a state in which the marking of the marking objects 91 through 97 is not performed.

[25] Referring to FIG. 5, the marking objects 91 through 97 that are to be marked in the marking region 60 each include the plurality of draw vectors 81 and the plurality of jump vectors 82, wherein the draw vectors 81 are used for moving a laser beam during emitting of the laser beam, and the jump vectors 81 are used for moving a laser beam that is to be emitted, to an initial point of a subsequent vector from among the draw vectors 81 while the laser beam is not being emitted.

[26] As illustrated in FIG. 1, in a conventional multi-laser marking system, a pair of scanners 41 and 42 are used for controlling a location onto which a laser beam is irradiated. The laser beam is incident on mirrors 43 installed in the pair of scanners 41 and 42, and is reflected by the mirrors 43. By adjusting the degrees of mirrors 43, the location on a substrate 2 can be controlled. The draw vectors 81 are used for marking performed by a laser beam while the mirrors 43 are moved by a predetermined degree during the emitting of the laser beam. On the other hand, the jump vectors 82 are used for moving a laser beam that is to be emitted, to an initial point of a subsequent vector from among the draw vectors 81 while the mirrors 43 are moved by a predetermined degree while the laser beam is not being emitted.

[27] In order to mark a stroke of the marking objects 91 through 97, the stroke is divided into the plurality of draw vectors 81, and then, instead of using a single draw vector, the stroke is marked by connecting the draw vectors 81. Likewise, by dividing the stroke to be marked into the plurality of draw vectors 81 having lengths which are each shorter than the stroke, and then connecting the draw vectors 81 which are each rectilinear so as to mark the stroke, not only a rectilinear stroke but also a curved line can be realized. After a stroke is marked, a laser beam is moved to another stroke by the plurality of jump vectors 82, instead of using a single jump vector.

[28] The magnitude of the draw vector 81 is defined as a draw step, and the magnitude of the jump vector 82 is defined as a jump step. In addition, a time taken to move a laser beam from an initial point to a terminal point in the draw vector 81 is defined as a draw step period, and a time taken to move a laser beam from an initial point to a terminal point in the jump vector 82 is defined as a jump step period.

[29] Next, an estimated marking time taken to mark the marking objects 91 through 97 is calculated Operation S20).

[30] For example, in FIG. 5, the marking object 91 that is ' E] ' includes the plurality of draw vectors 81 and the plurality of jump vectors 82. The total length of strokes to be marked is divided by the draw step, thereby obtaining the number of the draw vectors 81 constituting the strokes to be marked. This resulting value is multiplied by the draw step period, thereby obtaining a draw time taken to actually mark the strokes to be marked. In addition, a total distance between the strokes to be marked is divided by the jump step, thereby obtaining the number of jump vectors 82 constituting the total distance. This resulting value is multiplied by the jump step period, thereby obtaining a jump time taken to move a laser beam between the strokes to be marked. The draw time is added to the jump time, thereby obtaining an estimated marking time taken to mark the marking object 91 that is ' E] '. With regard to other marking objects 92 through 97, estimated marking times can be obtained by using the same method.

[31] Next, the estimated marking times taken to mark the marking objects 91 and 92 included in the first sub-marking region 61 are added, and the estimated marking times taken to mark the marking objects 93 through 97 included in the second sub-marking region 62 are added Operation S30). The estimated marking time taken to mark the marking object 91 that is 'E' is added to the estimated marking time taken to mark the marking object 92 that is '0', thereby obtaining the total value of the estimated marking times of the first sub-marking region 61. Likewise, the estimated marking time taken to mark the marking object 93 that is ' ¹Il ', the estimated marking time taken to mark the marking object 94 that is ' E] \ the estimated marking time taken to mark the marking object 95 that is ' 5]1 ', the estimated marking time taken to mark the marking object 96 that is ' °] ', and the estimated marking time taken to mark the marking object 97 that is ' ^i ' are added, thereby obtaining the total value of the estimated marking times of the second sub-marking region 62.

[32] Next, a difference between the total value of the estimated marking times of the first sub-marking region 61 and the total value of the estimated marking times of the second sub-marking region 62 is divided by 2, thereby obtaining a half value of the difference between the total values Operation S41). In the current embodiment, since the number of strokes of the marking objects 93 through 97 included in the second sub-marking region 62 is greater than the number of strokes of the marking objects 91 and 92 included in the first sub-marking region 61, the total value of the estimated marking time taken to mark the second sub-marking region 62 is greater than the total value of the estimated marking time taken to mark the first sub-marking region 61. The half value is a criterion based on which the marking object 93 is selected from among the marking objects 93 through 97 included in the second sub-marking region 62 of which a total value of the estimated marking times is greater than that of the first sub-marking region 61, as will be described later.

[33] Next, a marking object having an estimated marking time that is the same as or similar to the half value is selected from among the marking objects 93 through 97 included in the first sub-marking region 62 of which the total value of the estimated marking times is greater than that of the first sub-marking region 61 Operation S42). An error criterion is previously set so as to determine whether an estimated marking time is the same as or similar to the half value. For example, with regard to the error criterion set as 0.1 seconds, when a difference between an estimated marking time taken to mark a marking object and the half value is less or equal to 0.1 seconds, the marking object is selected from among the marking objects 93 through 97.

[34] In the current embodiment, since the total value of the estimated marking times of the second sub-marking region 62 is greater than that of the first sub-marking region 61, one of the marking objects 93 through 97 that are ' ¹U ', ' H] ', ' e]] ', ' O] ' _and ^• *-j ', respectively, is selected from among marking objects 93 through 97 included in the second sub-marking region 62. At this time, if a plurality of marking objects have estimated marking times that are the same as or similar to the half value from among the marking objects 93 through 97 included in the second sub-marking region 62, a problem is introduced in terms of selecting a marking object from among the marking objects 93 through 97.

[35] In this case, in the current embodiment, the marking object 93 may be selected since the marking object 93 is the closest to a boundary line 63 between the first and second sub-marking regions 61 and 62. For example, when a difference between the half value and each of the estimated marking times of the marking object 93 that is ' ¹Il ' and the marking object 95 that is ' sfl ' is within the error criterion that is previously set, both the marking objects 93 and 95 can be selected. However, since a distance ' I Y between the boundary line 63 and the marking object 93 that is ' ¹Il ' is shorter than a distance ' I 2' between the boundary line 63 and the marking object 95 that is ' sfl ', the marking object 93 that is ' ¹Il ' and is closer to the boundary line 63 is selected.

[36] Next, the marking object 93 that is selected is marked using a laser beam different to that used for the first sub-marking region 62 including the marking object 93 Operation S50). Likewise, when the marking region 60 is divided according to its area, the marking object 93 that is ' ¹Il ' is included in the second sub-marking region 62 so as to be marked using a second laser beam. However, by dividing the marking region 60 into regions having the same total value of the estimated marking times, the marking object 93 that is ' ¹Il ' is marked by a first laser beam together with the marking objects 91 and 92 that are 'E' and 'O' included in the first sub-marking region 61 (i.e., in FIG. 6, the marking objects 91, 92 and 93 in a region indicated as '64' are marked using the first laser beam). In the meantime, the marking objects 94 through 97 that are ' Ε] ', ' sfl ', ' °1 ' ^and ' ^i ' included in the second sub-marking region 62 are marked using the second laser beam (i.e., in FIG. 6, the marking objects 94 through 97 in a region indicated as '65' are marked using the second laser beam).

[37] Accordingly, a time taken to mark the marking objects 91 through 93 that are 'E', 'O' and ' ¹S ' by using the first laser beam can be similar to a time taken to mark the marking objects 94 though 97 that are ' Ε] ', ' sfl ', ' °1 ' ^and ' ^i ' by using the second laser beam. Thus, an entire system does not have to be on standby when marking with a laser beam is not completed even though marking with another laser beam is completed, thereby reducing an unnecessary period of time .

[38] In the method of dividing marking objects according to the above-described embodiment of the present invention, two laser beams are used, and the marking objects are divided into two groups according to the number of laser beams. However, marking objects in a marking region may be divided into groups equal to or greater than three, according to the number of laser beams used in a multi-laser marking system

[39] As described above, in the method of dividing marking objects according to the present invention, by dividing marking objects in a marking region into a plurality of groups so that a time taken to mark marking objects included in a group is similar to a time taken to mark marking objects included in another group, an entire system does not have to be on standby when marking with a laser beam is not completed even though marking with another laser beam is completed, thereby reducing an unnecessary period of time. Thus, a processing time taken for a substrate can be reduced, thereby improving the production efficiency of a multi-laser marking system.

[40] While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by one of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.

Claims

[1] A method of dividing marking objects in which the marking objects are divided so that some of the marking objects comprising a character or figure to be marked are marked using a first laser beam and other remaining marking objects are marked using a second laser beam, the method comprising: dividing a predetermined marking region into a first sub-marking region on which the first laser beam is used and a second sub-marking region with which the second laser beam is used; calculating respective estimated marking times taken to mark the marking objects; adding estimated marking times taken to mark marking objects included in the first sub-marking region and adding estimated marking times to mark marking objects included in the second sub-marking region; calculating a half value of a difference between a total value of the estimated marking times of the first sub-marking region and a total value of the estimated marking times of the second sub-marking region; selecting a marking object having an estimated marking time that is the same as or similar to the half value from among marking objects included in a sub- marking region corresponding to one of the first and second sub-marking regions, depending on which has the greater total estimated marking time value; and marking the selected marking object by using a laser beam different to that used for the sub-marking region including the selected marking object.

[2] The method of claim 1, wherein the selecting of the marking object comprises selecting a marking object that is the closest to a boundary line between the first and second sub-marking regions when a plurality of marking objects have estimated marking times that are the same as or similar to the half value.

[3] The method of claim 1, wherein the marking objects each comprise a plurality of draw vectors used for moving the laser beam during emitting of the laser beam, and a plurality of jump vectors used for moving a laser beam that is to be emitted, to an initial point of a subsequent vector from among the draw vectors while the laser beam is not being emitted, and the calculating of the estimated marking time comprises adding a time taken to move along the draw vectors and a time taken to pass move along the jump vectors.