KR102495826B1 - Mask manufacturing method based on multi-layer laser irrdation - Google Patents

Abstract

According to the present invention, provided is a mask manufacturing method comprising: a step of setting an area of an opening on a metal sheet; and a step of forming the opening by irradiating a beam on the area of the opening, wherein the step of forming the opening further comprises a step of enabling the beam to be irradiated to a partial area among the area of the opening, and adjusting a taper angle of the opening based on irradiating the beam to at least one other partial area at least partially overlapping the partial area. Therefore, the present invention is capable of adjusting the taper angle of the opening.

Description

Mask manufacturing method based on multi-layer laser irradiation {MASK MANUFACTURING METHOD BASED ON MULTI-LAYER LASER IRRDATION}

The present invention relates to a method for manufacturing a mask based on multi-layer laser irradiation.

In general, a metal mask is used in a vacuum deposition process or the like when manufacturing organic EL or organic semiconductor devices. The metal mask has a three-dimensional hole structure in the form of a plurality of circular holes or tapered, and is used to manufacture semiconductor devices such as organic EL by aligning the mask on a substrate and depositing a light emitting layer of a desired pattern on a specific area on the substrate. used

One example of a method for manufacturing such a metal mask is using a pulsed laser. For example, as shown in FIG. 1, a metal mask may be manufactured by continuously irradiating a laser having a beam width (beam diameter) w along a lateral position of a metal sheet. As such, the energy of the laser is accumulated, which may be defined as accumulated energy (E _acc ), and the accumulated energy having the highest value among them may be defined as the maximum accumulated energy.

As described above, in the method of manufacturing a metal mask using a pulse laser, the metal mask may be manufactured to correspond to the shape of the cumulative energy distribution as shown in FIG. 2 . At this time, the angle corresponding to the inclined surface formed by the opening of the metal mask in FIG. 2 may be referred to as a taper angle, and the taper angle is defined as atan (AD _max / W) when the maximum processing depth is AD _max . It can be.

In order to increase the above-described taper angle of the metal mask, the width of the beam, that is, the size of the beam may be reduced or the maximum cumulative energy may be increased. Alternatively, in order to decrease the taper angle, the size of the beam may be increased or the maximum cumulative energy may be decreased. However, changing the size of a beam to control the taper angle of a work piece in a typical manufacturing environment can be inefficient. This is because the size of the beam is a factor of related optics (for example, the f-value of a lens), and thus the accessory lens needs to be changed. In addition, there is a problem in that the angle control based on accumulated energy is limited in use while being variable due to restrictions on processing time and processing threshold (ablation threshold).

Republic of Korea Patent Publication No. 10-2019-0049989 Republic of Korea Patent No. 10-1900281

Various embodiments of the present invention are to provide a mask manufacturing method capable of minimizing accumulated heat by adjusting the taper angle of an aperture through laser irradiation to multi-layers and adjusting the laser irradiation direction.

Technical problems to be achieved in various embodiments of the present invention are not limited to the above-mentioned matters, and other technical problems not mentioned are common knowledge in the art from various embodiments of the present invention to be described below. can be considered by those who have

In one embodiment of the present invention, setting a region of the opening on the metal sheet; and irradiating a beam onto an area of the opening to form the opening, wherein forming the opening comprises irradiating a beam to a portion of the area of the opening, and at least partially overlapping the portion of the area. A mask manufacturing method further comprising adjusting a taper angle of the opening based on irradiating a beam to at least one other partial area of the mask.

For example, beam irradiation to each of the partial area and the at least one other partial area is performed on a plurality of scan areas each defined along a first direction on the metal sheet, and among the plurality of scan areas adjacent to each other. The two scan areas may be spaced apart from each other by a predetermined distance along the second direction on the metal sheet.

For example, beam irradiation to each of the plurality of scan areas may be performed at predetermined intervals along the first direction.

For example, the plurality of scan areas may be defined for each of the partial area and the at least one other partial area.

For example, in the adjusting of the taper angle of the opening, the taper angle of the opening may be greatly adjusted based on making an area of the partial area equal to an area of the at least one other partial area.

For example, in the adjusting of the taper angle of the opening, the taper angle of the opening may be adjusted to be small based on making the area of the partial area different from that of the at least one other partial area.

For example, the diameter of the beam irradiated to the partial area and the diameter of the beam irradiated to the at least one other partial area may be the same.

For example, beam irradiation to at least one of the partial region and the at least one other partial region may be performed in a direction inclined at a predetermined angle with respect to at least one side of the opening when the metal sheet is viewed on a plane.

For example, the opening may be rectangular, and the predetermined angle may be 45 degrees.

In another embodiment of the present invention, a mask manufactured by any one of the above mask manufacturing methods.

The various embodiments of the present invention described above are only some of the preferred examples of the present invention, and various examples reflecting the technical features of various embodiments of the present invention will be described in detail below by those skilled in the art. It can be derived and understood based on the detailed description.

According to various embodiments of the present invention, the following effects are obtained.

According to various embodiments of the present disclosure, the taper angle of the aperture may be adjusted through laser irradiation of the multi-layers.

In addition, by adjusting the direction of laser irradiation, accumulated heat can be minimized and processing quality can be improved.

The accompanying drawings are intended to aid understanding of various embodiments of the present invention, and provide various embodiments of the present invention together with detailed descriptions. However, the technical features of various embodiments of the present invention are not limited to specific drawings, and the features of the invention in each drawing may be combined with each other to form a new embodiment. Reference numerals in each figure mean structural elements.
1 is a diagram for explaining accumulated energy according to positioning of a mask.
2 is a diagram for explaining a taper angle.
3A is a plan view of a metal mask.
3B is a side view of a metal mask.
4 is a diagram for explaining the layers of the present invention.
5 is a diagram for explaining a scan interval.
6 is a diagram for explaining multi-layers.
7A to 7C are views for explaining the adjustment of the taper angle of the opening.
8 is a diagram for explaining an interval during beam irradiation.
9 is a graph of accumulated columns according to intervals.
10 is a diagram for explaining heat accumulation of an opening according to a scan direction and a step direction.
11A to 11C are for explaining a beam irradiation method according to scan direction control according to an embodiment of the present invention.

Hereinafter, implementations according to the present invention will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The detailed description that follows, together with the accompanying drawings, is intended to describe exemplary implementations of the invention, and is not intended to represent the only implementations in which the invention may be practiced. The following detailed description includes specific details for the purpose of providing a thorough understanding of the present invention. However, one skilled in the art recognizes that the present invention may be practiced without these specific details.

Terms such as first or second may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another component, for example, without departing from the scope of rights according to the concept of the present invention, a first component may be named a second component, Similarly, the second component may also be referred to as the first component.

In various embodiments of the present invention, “/” and “,” should be interpreted as indicating “and/or”. For example, “A/B” may mean “A and/or B”. Furthermore, “A, B” may mean “A and/or B”. Furthermore, “A/B/C” may mean “at least one of A, B and/or C”. Furthermore, “A, B, C” may mean “at least one of A, B and/or C”.

Hereinafter, various embodiments of the present invention relate to a mask manufacturing method for manufacturing a metal mask based on setting multi-layers and irradiating a laser beam to the multi-layers.

3A is a plan view of the metal mask, and FIG. 3B is a side view of the metal mask.

Referring to FIGS. 3A and 3B , the metal mask 1 includes a plurality of openings 20 on the metal sheet 10 . For convenience, although the number of openings 20 is shown as four in FIGS. 3A and 3B, it is not limited thereto and may be provided in various ways according to design.

Each of the plurality of openings 20 includes an inclined region 21 inclined at a predetermined angle and a flat region 22 formed flat. At this time, as shown in FIG. 3B , an inclination angle formed by the inclination region 21 may be referred to as a taper angle. Depending on the thickness of the metal sheet 10, the plane region 22 may be a region through which the metal sheet 10 is penetrated, as shown in FIG. there is.

As shown in FIGS. 3A and 3B , the metal mask 1 includes a plurality of openings 20, and the area of these openings 20 may be formed according to laser irradiation, which will be described later. It is necessary to set in advance in which area on the metal sheet 10 the opening 20 is to be formed. Accordingly, the method of manufacturing a metal mask according to an embodiment of the present invention may include first setting an area of the opening 20 on the metal sheet 10 .

When the area of the opening 20 to be irradiated with the laser is set, a step of forming the opening 20 by irradiating a laser, that is, a beam, on the area of the opening 20 is performed. The irradiation of the beam may be performed by a laser irradiation device such as a scanner or a galvo mirror. Forming the opening 20 by irradiating a beam is performed for multiple layers as described above. In the present invention, the layer 30 included in the multi-layer means one area included in the area of the preset opening 20 .

4 is a diagram for explaining the layers of the present invention.

Referring to FIG. 4 , a layer 30 includes a plurality of scan areas 31 . Each of the plurality of scan areas 31 includes a plurality of geometric waveforms as shown, and each waveform may mean that the beam is irradiated once. A plurality of waveforms are formed at predetermined intervals along the a-axis, for example, as shown, which means that beam irradiation to each of the plurality of scan areas 31 is performed at predetermined intervals in a straight line along the a-axis direction. do.

In the present invention, the a-axis direction of FIG. 4 may be referred to as a scan direction or a first direction, and an irradiation interval of beams within one scan area 31 may be referred to as a scan interval. The a-axis direction means a direction in which a shot of the laser irradiation device travels on the metal sheet 10 when the beam is continuously irradiated.

Specifically regarding the scan interval, the scan interval may be defined as an irradiation interval of one beam within one scan area 31 and the irradiation interval of the next continuous beam, mathematically defined as scan interval. It can be defined as interval = scan speed / laser frequency. For example, if the constant scan velocity is 100 [mm/s] and the laser frequency is 100,000 [Hz], the scan interval is 1 μm.

5 is a diagram for explaining a scan interval.

FIG. 5 is a side view of FIG. 4 . An interval between a plurality of waveforms included in one scan area 31 , more specifically, an interval between central axes of a plurality of waveforms may be defined as a scan interval.

Returning to FIG. 4 again, each waveform included in the plurality of scan areas 31 is provided at every scan interval as described above, and two scan areas 31 adjacent to each other among the plurality of scan areas 31 are also arranged at a predetermined interval. spaced out every Specifically, as shown in FIG. 4, a plurality of scan areas 31 are formed at predetermined intervals along the b-axis. In other words, when irradiation of a beam to one scan area 31 is finished, the adjacent next scan area ( 31) means that beam irradiation is performed at a predetermined interval along the b-axis.

In the present invention, the b-axis direction of FIG. 4 may be referred to as a step direction or a second direction, and an interval between two scan areas 31 adjacent to each other may be referred to as a step interval. The b-axis direction means a direction in which a movement to the next scan area 31 is made by a step interval after beam irradiation on one scan area 31 is finished.

As described above, the layer 30 may be defined as a plurality of scan areas 31 each formed at step intervals in the second direction. In this case, each of the plurality of scan areas 31 includes a plurality of scan areas 31 along the first direction. A waveform of is formed at every scan interval.

If the step of irradiating a beam on one layer 30 is described in terms of the scan interval and the step interval, one of the scan areas 31 included in one layer 30 is located at the far end in the b axis. A beam is first irradiated to one scan area 31 , and at this time, a beam is irradiated at every scan interval along a first direction within one scan area 31 .

When the irradiation of the beam on one scan area 31 is finished, the above-described beam irradiation is performed on the scan area 31 located at the next step interval. Irradiation of such a beam is repeatedly performed for each scan area 31 along the second direction, and is performed until the remaining one scan area 31 located at the extreme end in the b-axis.

6 is a diagram for explaining multi-layers.

Referring to FIG. 6 , a multi-layer, that is, a plurality of layers 30 may be set. The multi-layer may be set to include a partial region 30_1 of the regions of the opening 20 and at least one other partial region 30_2 overlapping at least a portion of the partial region 30_1. That is, each layer 30 included in the multi-layers may be included in the area of the opening 20 and at least partially overlap each other, but may have areas of different sizes.

The plurality of layers 30 included in the multi-layer may have areas of different sizes, but the same beam energy may be applied and the same scan interval and the same step interval may be applied. That is, only the areas of the plurality of layers 30 are set to be different, and all other beam energy, scan interval, and step interval can be applied in common.

Alternatively, according to another embodiment, the plurality of layers 30 may be applied with different areas, beam energies, scan intervals, and step intervals. This means that the plurality of scan areas 31 included in the layer 30 may be differently defined for each layer 30 .

If multi-layers are set, the step of irradiating the beam sequentially to a partial area 30_1 of the areas of the opening 20 and at least one other partial area 30_2 overlapping at least a portion of the partial area 30_1. irradiate the beam

Based on setting multi-layers and irradiating beams to each layer 30 as described above, the step of irradiating the beam may include adjusting the taper angle of the opening 20 .

7A to 7C are views for explaining the adjustment of the taper angle of the opening.

Referring to FIG. 7A , when it is desired to greatly adjust the taper angle of the opening 20, the step of adjusting the taper angle of the opening 20 is the area of a partial region 30_1 and the area of at least one other partial region 30_2 The taper angle of the opening 20 can be greatly adjusted based on making the energy the same. It may be understood that the partial region 30_1 and at least one other partial region 30_2 refer to layers 30 included in multi-layers. Since the horizontal axis in FIG. 7A represents the positioning of the metal sheet 10, the areas of the first layer 30 and the second layer 30 are the same.

In this way, when the area of each layer 30 is set to be the same, as can be seen in FIG. 7A, the profile of the accumulated energy according to irradiation of the beam on each layer 30 also appears the same. Here, the profile may mean a graph of accumulated energy according to positioning, as shown in FIGS. 7A to 7C. When a plurality of layers 30 having the same cumulative energy profile are overlapped, the angle defined by the ratio of the beam width and the cumulative energy in the overlapped cumulative energy profile is formed somewhat more gently than in FIGS. 7B and 7C.

The profile of the overlapped accumulated energy corresponds to the shape of the aperture 20 created after the beam irradiation is finished, and the taper angle of the aperture 20 can be greatly adjusted, similar to the angle of the profile of the overlapped accumulated energy. This means that the taper angle of the opening 20 can be greatly adjusted by irradiating a beam to multiple layers having the same cumulative energy profile.

Referring to FIGS. 7B and 7C , when it is desired to adjust the taper angle of the opening 20 to be small, the step of adjusting the taper angle of the opening 20 is to adjust the area of the partial area 30_1 and at least one other partial area 30_2. ), the taper angle of the opening 20 can be adjusted to be small based on different energies. In the case of FIG. 7B, the areas of the first layer 30 and the second layer 30 are different, and in the case of FIG. 7C, the areas of the first layer 30 to the fourth layer 30 are different.

In this way, when the area of each layer 30 is set to be different from each other, as can be seen in FIGS. 7B and 7C , the profile of the accumulated energy according to irradiation of the beam on each layer 30 is also different. When a plurality of layers 30 having different accumulated energy profiles are overlapped, the angle defined by the ratio of the beam width and the accumulated energy in the overlapped accumulated energy profiles is formed somewhat steeper than in FIG. 7A. Accordingly, the taper angle of the opening 20 may also be adjusted to be small, similar to the angle of the overlapping accumulated energy profiles. This means that the taper angle of the opening 20 can be adjusted small by irradiating beams to multi-layers having different cumulative energy profiles.

When using layers 30 having different cumulative energy profiles, the number of layers 30 used may be set in various ways.

For example, when the number of layers 30 is set to be relatively large as shown in FIG. 7C, the taper angle can be adjusted to be relatively smaller than that of FIG. 7B. In other words, in the step of adjusting the taper angle, the taper angle may be adjusted smaller based on setting the number of layers 30 to be relatively large.

Alternatively, when using layers 30 having different cumulative energy profiles, positional offsets of the layers 30 may be set in various ways. Here, the positioning offset of the layer 30 means a distance between points at which the accumulated energy becomes 0 in the profile of the accumulated energy between different layers 30 .

For example, when it is desired to adjust the taper angle relatively large in a situation in which layers 30 having different cumulative energy profiles are used, the positioning image offset may be set small.

In various embodiments of the present invention described above, the diameters of beams for beam irradiation may be the same. In other words, according to the present invention, the taper angle of the opening 20 of the mask 1 can be adjusted by variously setting the layer 30 even if a laser irradiation device having the same beam diameter is used.

In addition, in various embodiments of the present invention described above, the maximum cumulative energy of each layer 30 may be equal to each other. In other words, according to the present invention, the taper angle of the opening 20 of the mask 1 can be adjusted by variously setting the layer 30 without limitations such as processing time and processing threshold.

According to various embodiments of the present invention described above, the taper angle of the opening 20 can be adjusted based on setting the layer 30 without changing the optical characteristics (eg, lens, etc.) of the laser irradiation device. . Accordingly, it is possible to adjust the taper angle without changing an optical product such as a lens related to the beam diameter. In addition, instead of changing the maximum accumulated energy of each layer 30, it is possible to adjust the taper angle by changing the profile of the accumulated energy of the multi-layers while the maximum accumulated energy of each layer 30 is the same.

Hereinafter, in the above-described multi-layer-based beam irradiation step, a beam irradiation technique applicable to beam irradiation of each layer 30 will be described.

According to one embodiment of the present invention, the processing quality of the mask 1 can be secured based on adjusting the irradiation direction when the beam is irradiated based on the setting of the layer 30 .

8 is a diagram for explaining an interval during beam irradiation.

In FIG. 8 , an interval means a processing delay between a plurality of scan areas 31 included in one layer 30 . As described above, one layer 30 includes a plurality of scan areas 31 and each scan area 31 is spaced apart from each other by a step interval. At this time, the time interval between waveforms within one scan area 31, that is, the time interval between beam shots may be referred to as a first shot interval, and the time point at which beam irradiation for one scan area 31 starts An interval between a time point at which beam irradiation on the scan area 31 located at the next step interval is started may be referred to as a second shot interval.

Since there is an interval as described above when irradiating a beam, heat accumulated during beam irradiation, ie, an accumulated heat, appears differently depending on the interval.

9 is a graph of accumulated columns according to intervals.

Referring to FIG. 9 , the shorter the interval, the higher the accumulated heat due to beam irradiation, and this accumulated heat acts as a main cause of deterioration in processing quality. In particular, the first shot interval described above in the interval has a worse effect on processing quality than the second shot interval.

For example, when irradiating a beam under the condition of a scan speed of 100 [mm/s] and a laser frequency of 100 [kHz], the first shot interval along the scan direction is 10 [us], but the second shot interval along the step direction is 10 [us]. The shot interval reaches several [ms]. That is, in the case of the second shot interval, compared to the first shot interval, the residual heat on the metal sheet 10 can be regarded as a time to sufficiently cool down, so the heat accumulation is negligible, but the first shot interval is very Because of the short time, the heat is not sufficiently cooled.

10 is a diagram for explaining heat accumulation of an opening according to a scan direction and a step direction.

Referring to FIG. 10 , when the above-described inclined area 21 of the opening 20 is viewed from a plan view, an area parallel to the scan direction is referred to as a first area 21_1, and an area parallel to the step direction is referred to as a second area. Referring to (21_2), the first region 21_1 has a relatively high accumulated heat, so the processing quality is relatively deteriorated, but the second region 21_2 has a low accumulated heat, so the processing quality is relatively excellent.

As described above, in consideration of the difference in processing quality in the inclined region 21 of the opening 20 according to the accumulated heat, according to an embodiment of the present invention, the step of forming the opening 20 described above is performed in the scan direction. It may include the step of irradiating the beam by adjusting the. More specifically, the irradiation of beams on at least one of the partial region 30_1 and at least one other partial region 30_2 of the regions of the opening 20 causes the opening 20 when the metal sheet 10 is viewed on a plane. It may be performed in a direction inclined at least one side and a predetermined angle. Here, among the regions of the opening 20, the partial region 30_1 and at least one other partial region 30_2 correspond to multi-layers as described above.

11A to 11C are for explaining a beam irradiation method according to scan direction control according to an embodiment of the present invention.

First of all, referring to FIG. 11A , the area of the set opening 20 may be subdivided into a first layer (a partial area 30_1) and a second layer (a partial area 30_2 overlapping the partial area 30_1). . It will be understood that each of the first layer 30 and the second layer 30 includes a plurality of scan areas 31 as described above.

Next, referring to FIG. 11B , beam irradiation is performed on the first layer 30 . At this time, the beam irradiation may be performed in a direction inclined at a predetermined angle with respect to at least one side of the opening 20 in order to minimize accumulated heat due to beam irradiation in the scanning direction.

Lastly, referring to FIG. 11C , beam irradiation is performed on the second layer 30 . At this time, the beam irradiation may be performed in a direction inclined at a predetermined angle with respect to at least one side of the opening 20 in order to minimize accumulated heat due to the beam irradiation in the scan direction, as in FIG. 11B.

According to an embodiment, when the opening 20 has a rectangular shape, a predetermined angle at which the beam is irradiated may be 45 degrees. When irradiated at 45 degrees, since the number of beam shots irradiated in the scan direction is minimized, accumulated heat can be minimized compared to other angles.

Alternatively, according to an embodiment, the shape of the opening 20 may have various shapes other than a rectangle, and in this case, a predetermined angle may be adjusted according to each shape so that the number of beam shots irradiated in the scan direction can be minimized. will be.

Alternatively, according to an embodiment, when a beam is irradiated to multiple layers, at least one layer 30 is irradiated with a beam parallel to the side of the opening 20, and at least one other layer 30 has the opening 20 ), the beam may be irradiated with a predetermined angle inclination.

According to various embodiments of the present invention described above, when the laser is irradiated in the scan direction to form the opening 20 of the mask 1, the laser is irradiated in a direction inclined at a predetermined angle with the side of the opening 20, A difference in accumulated heat according to the region 21 is minimized, and processing quality can be improved accordingly.

It goes without saying that the above-described embodiments related to multi-layers and embodiments related to scan direction control may be implemented independently or may be implemented in a combined form.

Since examples of the proposed schemes in the above description may also be included as one of the implementation methods of the present invention, it is obvious that they can be regarded as a kind of proposed schemes. In addition, the above-described proposed schemes may be implemented independently, but may also be implemented in a combination (or merged) form of some proposed schemes.

Claims (10)

setting the area of the opening on the metal sheet; and
forming the aperture by irradiating a beam onto a region of the aperture;
The step of forming the opening is:
Adjusting the taper angle of the opening based on irradiating a beam to a partial area of the area of the opening and irradiating a beam to at least one other partial area having the same or different area from the partial area ,
How to make a mask.
According to claim 1,
The beam irradiation to each of the partial area and the at least one other partial area is performed on a plurality of scan areas respectively defined along a first direction on the metal sheet,
Two scan areas adjacent to each other among the plurality of scan areas are spaced apart from each other by a predetermined distance along the second direction on the metal sheet.
How to make a mask.
According to claim 2,
The beam irradiation for each of the plurality of scan areas is performed at predetermined intervals along the first direction.
How to make a mask.
According to claim 2,
The plurality of scan areas are defined for each of the partial area and the at least one other partial area,
How to make a mask.
According to claim 1,
Adjusting the taper angle of the opening may include adjusting the taper angle of the opening to a large extent based on making the area of the partial area equal to the area of the at least one other partial area.
How to make a mask.
According to claim 1,
Adjusting the taper angle of the opening may include adjusting the taper angle of the opening to be small based on making the area of the partial area different from the area of the at least one other partial area.
How to make a mask.
According to claim 1,
The diameter of the beam irradiated to the partial area and the diameter of the beam irradiated to the at least one other partial area are the same as each other,
How to make a mask.
According to claim 1,
The beam irradiation to at least one of the partial region and the at least one other partial region is performed in a direction inclined at a predetermined angle with at least one side of the opening when the metal sheet is viewed on a plane.
How to make a mask.
According to claim 8,
The opening is rectangular, the predetermined angle is 45 degrees,
How to make a mask.
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