KR20190140392A - Processing apparatus and method - Google Patents

Abstract

Provided is a processing method capable of reducing a deviation between a predetermined position of a processing point and a position to be actually processed. The processing surface of a substrate is divided into a plurality of unit regions, and an alignment mark is provided corresponding to each of the unit regions. The positions of a plurality of processing points are defined inside the unit regions. When processing the above-mentioned processing point inside each of the unit regions, the position of the alignment mark corresponding to the unit region to be processed next is detected for each processing of the unit region. Then, the processing point is processed based on the detection result.

Description

Processing apparatus and method

This application claims priority based on Japanese Patent Application No. 2018-111015 filed on June 11, 2018. The entire contents of that application are incorporated herein by reference.

The present invention relates to a processing method and a processing apparatus.

Conventionally, when performing a punching process on a board | substrate using a laser beam, the position of the alignment mark formed in the prescribed position was measured for every board | substrate before a process (patent document 1). The position of the substrate is detected on the basis of the measurement result of the position of the alignment mark, and the laser beam is incident on the predetermined processing point. Thereby, laser processing of the to-be-processed point by which the position is previously determined based on an alignment mark, for example, drilling can be performed.

Patent Document 1: International Publication No. 2013/114593

According to the evaluation experiment by the inventor of the present application, even if the position of the alignment mark is detected (measured) accurately and the laser beam is incident on the processing point based on the detection result, the point that is actually processed by the incident laser beam is the target. It turned out that there may be a shift | deviation from the to-be-processed point. An object of the present invention is to provide a processing method and a processing apparatus which can reduce the deviation between a predetermined position of a processing point and a position to be actually processed.

According to one aspect of the present invention,

Each of the unit areas of the substrate on which the workpiece surface is divided into a plurality of unit areas, an alignment mark is provided corresponding to each of the unit areas, and the positions of the plurality of processed points are defined inside the unit area. Processing of the processing point in the interior of the

For each machining of the unit area, a machining method is provided which detects the position of the alignment mark corresponding to the unit area to be processed next and performs the machining point on the basis of the detection result.

According to another aspect of the present invention,

A laser light source for outputting a laser beam,

A beam scanner for injecting the laser beam output from the laser light source onto the surface of the substrate and moving the incident position on the surface of the substrate;

A sensor for detecting an alignment mark provided on the substrate;

The work surface is divided into a plurality of unit areas, and the positions of the plurality of work points of the work surface are stored, and the alignment mark corresponding to the unit area to be processed next is processed for each processing of the unit area. A processing apparatus is provided having a control device which detects the position of the laser beam from the detection result of the sensor, and controls the beam scanner on the basis of the detection result to sequentially enter the laser beam into the processing point.

According to another aspect of the present invention,

A process of detecting a position of at least a portion of the alignment mark of the substrate, on which a plurality of alignment marks are provided and the positions of the plurality of processing points to be processed are defined;

Based on the detection result of the position of the alignment mark, there is provided a machining method of alternately repeating a process of sequentially machining a portion of a plurality of processed points in turn.

According to another aspect of the present invention,

A laser light source for outputting a laser beam,

A beam scanner for injecting the laser beam output from the laser light source into the processing surface of the substrate and moving the incident position on the surface of the substrate;

A sensor for detecting each of a plurality of alignment marks provided on the substrate;

A control device for storing the positions of the plurality of processing points on the surface to be processed and controlling the laser light source and the beam scanner based on the detection result of the sensor;

The control device is configured to detect the position of at least part of the alignment mark based on a detection result of the sensor, and to control the laser light source and the beam scanner based on the detection result of the position of the alignment mark. A processing apparatus is provided which alternately repeats a process of sequentially processing a part of a plurality of processing points among a plurality of processing points.

The deviation between the position of a predetermined processing point and the position which is actually processed can be made small.

1 is a schematic diagram of a laser processing apparatus according to an embodiment.
2 is a plan view of a substrate to be processed.
3 is a flowchart of the processing method according to the embodiment.
4 is a diagram showing an example of the relationship between the scannable range of the beam scanner and the unit area.
5 is a diagram showing another example of the relationship between the scannable range of the beam scanner and the unit area.
6 is a plan view of a substrate processed by a processing method according to another embodiment.
7 is a plan view of a substrate to be processed by the processing method according to another embodiment.
FIG. 8 is a flowchart of a processing method according to the embodiment in which the substrate shown in FIG. 7 is processed.
9A is a sectional view of a substrate before processing of a processing method according to another embodiment, 9B of FIG. 9 is a sectional view of the substrate after processing the upper surface of the substrate, and 9C of FIG. 9 is a cross-sectional view of the substrate after the bottom surface of the substrate is processed.

With reference to FIGS. 1-3, the processing method and the processing apparatus by an Example are demonstrated.

1 is a schematic diagram of a laser processing apparatus according to an embodiment. The laser light source 10 outputs a pulsed laser beam. As the laser light source 10, for example, a carbon dioxide laser oscillator can be used. The pulsed laser beam output from the laser light source 10 is held on the stage 17 via the acoustic optical element (AOM) 11, the mirror 12, the beam scanner 13, and the condenser lens 14. Incident on the substrate 30 to be processed.

The AOM 11 cuts a part used for a process from the laser pulse of the pulsed laser beam output from the laser light source 10 according to the instruction | command from the control apparatus 20. FIG. The cut laser pulses are directed to the substrate 30 as the object to be processed, and the remaining pulsed laser beam is incident on the beam damper 15.

The beam scanner 13 receives a command from the control device 20 and scans the laser beam in a two-dimensional direction to move the incident position of the pulsed laser beam on the surface of the substrate 30. As the beam scanner 13, for example, a galvano scanner having a pair of galvano mirrors can be used.

The condenser lens 14 condenses the pulsed laser beam scanned by the beam scanner 13 on the surface (working surface) of the substrate 30. As the condenser lens 14, for example, an f? Lens can be used.

The sensor 16 is disposed above the stage 17. The sensor 16 detects an alignment mark provided on the substrate 30 held on the stage 17. For example, an imaging device is used as the sensor 16. The imaging device picks up the surface to be processed of the substrate 30 and generates image data. Image data generated by the imaging device is read into the control device 20.

The stage 17 receives a command from the control device 20 and moves the substrate 30 in a two-dimensional direction parallel to the work surface. As the stage 17, for example, an XY stage can be used. By moving the substrate 30 and placing the alignment mark provided on the substrate 30 in the detectable range of the sensor 16, the alignment mark can be detected by the sensor 16.

The control device 20 includes a storage device 21. In the storage device 21, the positions of the plurality of processing points defined in the processing surface of the substrate 30 are stored. The control apparatus 20 has a function of detecting the position of the alignment mark provided on the substrate 30 based on the detection result of the sensor 16. For example, the control apparatus 20 detects the position of the alignment mark by analyzing the image data acquired from the sensor 16. FIG. The control device also controls the beam scanner 13 so that the laser beam is incident on the processing point based on the detection result of the position of the alignment mark.

In the optical path of the pulsed laser beam from the laser light source 10 to the substrate 30, a lens system, an aperture, etc. may be arrange | positioned as needed.

2 is a plan view of the substrate 30 to be processed. The workpiece surface of the substrate 30 is divided into a plurality of unit regions 32. The term " division " here means treating the unit region 32 as one group at the time of processing, and does not mean that the unit region 32 can be identified in appearance. In FIG. 2, as an example, six unit regions 32 are arranged in a matrix of two rows and three columns, and an example in which each shape of the unit regions 32 is rectangular is shown. As another example, the number of the unit areas 32 may be other than six. The arrangement of the plurality of unit regions 32 may not be matrix-like. In addition, each shape of the unit area 32 may not be rectangular.

Corresponding to each of the unit regions 32, a plurality of alignment marks 31 are provided inside the unit region 32. In FIG. 2, as an example, the example in which the alignment mark 31 is arrange | positioned in the inside slightly of each four corners of the unit area 32 is shown. The alignment mark 31 may be arranged so that the position of the unit region 32 with respect to the stage 17 and the posture in the rotational direction about the axis perpendicular to the surface to be processed can be specified. In addition, what is necessary is just to arrange | position so that the deformation of the unit area | region 32 may be measured.

In each of the unit regions 32, the positions of the plurality of processing points 33 are predefined. Information defining the positions of the plurality of work points 33 is stored in the storage device 21 of the control device 20. Before processing, the processing point 33 cannot be visually recognized.

3 is a flowchart of the machining method according to the present embodiment. First, the control apparatus 20 detects the position of the alignment mark 31 corresponding to one unit area 32 (FIG. 2) which should be processed next (step SA1). Hereinafter, a procedure for detecting the position of the alignment mark 31 will be described. The control device 20 controls the stage 17 to move one alignment mark 31 corresponding to the unit area 32 to be processed next within the detectable range of the sensor 16 (FIG. 1). Let's do it. The control device 20 detects the position of the alignment mark 31 by analyzing the image data obtained by the sensor 16. Similarly, the positions of the remaining plurality of alignment marks 31 are detected.

The control device 20 controls the laser light source 10, the AOM 11, and the beam scanner 13 based on the detection result of the position of the alignment mark 31. As a result, the laser beam is incident on the plurality of processing points 33 in the unit region 32 corresponding to the alignment mark 31 from which the position is detected, so that all of the processing points 33 in the unit region 32 are located. Processing is performed (step SA2).

The control apparatus 20 repeats execution of step SA1 and step SA2 until the process of all the to-be-processed points 33 in all the unit areas 32 is completed (step SA3).

Next, the excellent effect of this Example is demonstrated.

According to an evaluation experiment conducted by the inventors of the present invention, if a through hole is formed at the processing point 33 of the substrate 30 (FIG. 2) by incidence of a laser beam, deformation (twist) may occur in the substrate 30. It turned out. In particular, when the thickness of the board | substrate 30 is 0.04 mm or less, it turned out that the phenomenon which the board | substrate 30 deforms easily occurs. Conventionally, before processing the board | substrate 30, the position of the alignment mark 31 was detected, and all the unit area | region 32 was processed based on the detection result. If deformation occurs in the substrate 30 as the processing proceeds, at the processing point 33 to be processed after the deformation occurs, the position of the original processing point 33 to be processed and the laser beam are incident. The position to say is shifted. Such a phenomenon was not known at the time of filing of the present application.

In the present embodiment, the position of the alignment mark 31 corresponding to the unit region 32 to be processed next is detected before the machining of the unit region 32. Even if a deformation occurs in the substrate 30 due to the processing of one unit region 32, the alignment mark 31 of the substrate 30 after the deformation occurs immediately before the processing of the unit region 32 to be processed next. ) Position is detected. Since the machining point 33 is processed based on the detection result of the position of the alignment mark 31, the influence of the deformation | transformation of the board | substrate 30 can be reduced. As a result, the shift | offset | difference of the position of the original to-be-processed point 33 in the to-be-processed surface of the board | substrate 30, and an actual machining position can be reduced.

Next, an example for reducing the influence of a deformation | transformation is demonstrated. For example, the control apparatus 20 acquires the information (deformation information) regarding the deformation | transformation of the board | substrate 30 based on the detection result of the position of the alignment mark 31 of the board | substrate 30 after a deformation | transformation generate | occur | produced. . The control apparatus 20 correct | amends the position specified by the positional information of the to-be-processed point 33 memorize | stored in the memory | storage device 21 based on the deformation | transformation information of the board | substrate 30, and the to-be-processed point ( A laser beam is incident at the position of 33). As a result, the laser beam can be made to enter the original position to be processed, thereby increasing the positional accuracy of the processing.

In particular, in the case of performing the process of forming the through hole in the substrate 30, when the through hole is formed, the suction force of the vacuum chuck decreases, so that deformation of the substrate 30 tends to occur. In addition, when the thickness of the substrate 30 is 0.04 mm or less, deformation is likely to occur in the substrate. Therefore, when performing the process which forms a through hole in the board | substrate of thickness 0.04mm or less, the remarkable effect of this embodiment is acquired.

Next, with reference to FIG. 4 and FIG. 5, the relationship between the scannable range of the beam scanner 13 (FIG. 1) and the magnitude | size with the unit area | region 32 is demonstrated.

4 is a diagram showing an example of the relationship between the scannable range 35 of the beam scanner 13 and the unit area 32. The beam scanner 13 can inject the laser beam at any point within the scanable range 35 without moving the substrate 30. In the example shown in FIG. 4, at least one unit region 32 enters into the scanable range 35. In this case, in the step SA2 of FIG. 3, when the machining point 33 in one unit area 32 is processed, the machining is performed while the substrate 30 is stopped without moving the stage 17. Is done. When the processing of one unit area 32 is completed, the stage 17 may be moved when detecting the position of the alignment mark 31 in step SA1.

FIG. 5 is a diagram showing another example of the relationship between the scannable range 35 of the beam scanner 13 and the unit area 32. In the example shown in FIG. 5, the unit area 32 is larger than the scannable range 35. In this case, in step SA2 of FIG. 3, when the machining point 33 in one unit area 32 is processed, the machining point 33 in the scanable range 35 is processed. Thereafter, the stage 17 may be moved to arrange a region within the scannable range 35 in which the unprocessed target point 33 in the unit region 32 during processing is distributed.

1 to 3 can be applied to any of the cases where the scanable range 35 is larger than the unit region 32 and the unit region 32 is larger than the scanable range 35. .

Next, another embodiment will be described with reference to FIG. 6.

6 is a plan view of a substrate 30 processed by a processing method according to another embodiment. In the embodiment shown in FIG. 2, a plurality of alignment marks 31 corresponding to each of the unit regions 32 are disposed inside the unit region 32. In the embodiment shown in FIG. 6, some of the alignment marks 31 are arranged on the virtual boundary lines of the adjacent unit areas 32. That is, one alignment mark 31 is shared by the plurality of unit areas 32. As in the present embodiment, one alignment mark 31 may correspond to the plurality of unit regions 32.

Next, another embodiment will be described with reference to FIGS. 7 and 8. Hereinafter, description is abbreviate | omitted about the structure common to the Example shown to FIGS. 1-3.

7 is a plan view of the substrate 30 to be processed by the processing method according to the present embodiment. In the embodiment shown in FIG. 2, the workpiece surface of the substrate 30 is divided into a plurality of unit regions 32. In the embodiment shown in FIG. 7, the workpiece surface is not divided into the unit regions 32, and a plurality of alignment marks 31 are disposed in the workpiece surface of the substrate 30.

8 is a flowchart of the machining method according to the present embodiment. First, the control apparatus 20 detects the position of at least one alignment mark 31 (step SB1). Based on the detection result just before the position of the alignment mark 31, the to-be-processed point 33 to be processed next is processed (step SB2). When the machining of one machining point 33 is completed, it is determined whether or not machining of all the machining points 33 is completed (step SB3). When the raw to-be-processed point 33 remains, the control apparatus 20 determines whether to redetect the position of the alignment mark 31 (step SB4). For example, re-detection may be performed when a predetermined number of the machining points 33 are processed from the time when the position of the alignment mark 31 is detected immediately before. In addition, when a predetermined time has elapsed from the time when the position of the alignment mark 31 was detected just before, redetection may be performed.

When the position of the alignment mark 31 is not redetected, the machining point 33 to be processed next is processed based on the detection result immediately before the position of the alignment mark 31 (step SB2). ). When redetection of the position of the alignment mark 31 is performed, the position of at least one alignment mark 31 is detected (step SB1). Then, the to-be-processed point 33 to be processed is processed (step SB2). At this time, some of the alignment marks 31 for detecting the position may not be the same as some of the alignment marks 31 for detecting the position before. Usually, at least one of the alignment marks 31 detected differs from the alignment mark 31 detected before.

The processing of the machining point 33 and the redetection of the position of the alignment mark 31 are repeated a plurality of times alternately until the machining of all the machining points 33 is completed.

In step SB1, in the process of detecting the position of at least some of the alignment marks 31, the position of the substrate 30 and the posture in the rotational direction about the axis perpendicular to the processing surface can be specified. What is necessary is just to select the alignment mark 31 which should be detected. In addition, the alignment mark 31 to be detected may be selected so that the deformation of the substrate 30 can be measured. Moreover, what is necessary is just to select the alignment mark 31 of the position near the to-be-processed point 33 to be processed next. For example, the positions of a plurality of, for example, four alignment marks 31 may be detected in the order close to the processing point 33 to be processed next.

As described above, in the present embodiment, the position of at least part of the alignment marks 31 is detected in the middle of the period in which the plurality of processing points 33 are sequentially processed. The processing point 33 to be processed after detecting the position of the alignment mark 31 is processed on the basis of the detection result immediately before the processing.

Next, the excellent effect of the Example shown to FIG. 7 and FIG. 8 is demonstrated. In this embodiment, the position of the at least one alignment mark 31 is detected in the middle of the period in which the plurality of processing points 33 are sequentially processed. In the subsequent processing, the processing point 33 is processed based on the detection result of the position of the alignment mark 31 detected immediately before. Thus, compared with the method of detecting the position of the alignment mark 31 only once before processing, before the deformation | transformation of the board | substrate 30 becomes large, the position of the to-be-processed point 33 can be corrected in consideration of a deformation | transformation. As a result, the shift | offset | difference between the position of the to-be-processed point 33 which should be originally processed, and the position which is actually processed can be reduced.

In order to reduce the positional shift, a plurality of alignment marks 31 may be employed as a part of alignment marks 31 for detecting the position in order of being close to the processing point 33 to be processed next. It is preferable that the number of the alignment marks 31 which detect a position shall be four or more in order to acquire the information regarding the deformation | transformation of the board | substrate 30. As shown in FIG.

Next, with reference to 9A of FIG. 9-9D of FIG. 9, the processing method by another Example is demonstrated.

9A of FIG. 9 is a sectional view of the substrate 30 before processing. The substrate 30 is held on the stage 17. The board | substrate 30 is a copper clad laminated board with copper foil 41 and 42 affixed on both surfaces of the core layer 40 which consists of resin, respectively. Let the surface of one copper foil 41 be an upper surface, and let the surface of the other copper foil 42 be a lower surface. The substrate 30 is provided with an alignment mark 31 formed of a through hole reaching from the lower surface to the upper surface. The positions of the plurality of processing points 33 are set in advance on the upper and lower surfaces of the substrate 30. The position of the processing point 33 of the upper surface and the processing point 33 of the lower surface are the same with respect to the inside of the board | substrate 30, and the position of the processing point 33 is the It is stored in the storage device 21.

9B is a cross-sectional view of the substrate 30 after the upper surface of the substrate 30 is processed. The control apparatus 20 detects the position of the alignment mark 31, and injects a laser beam in order to the to-be-processed point 33 (9A of FIG. 9) based on a detection result. Thereby, the recessed part 45 is formed in the to-be-processed point 33. As shown in FIG. The recess 45 penetrates through the copper foil 41 and reaches the middle of the core layer 40.

9C of FIG. 9 is a cross-sectional view of the substrate 30 after the front and back of the substrate 30 are inverted. The copper foil 41 of the upper surface side comes in close contact with the stage 17, and the surface of the copper foil 42 of the lower surface side faces upward. The control apparatus 20 detects the position of some alignment mark 31 in this state.

9D is a cross-sectional view of the substrate 30 after the bottom surface of the substrate 30 is processed. The control apparatus 20 injects a laser beam in order to the several to-be-processed point 33 (9A of FIG. 9) of the lower surface of the board | substrate 30 in order. At this time, the machining method according to the embodiment shown in Fig. 3 or Fig. 8 is adopted. By forming the recessed portion at the machining point 33 on the lower surface, the through hole 46 is formed in connection with the recessed portion 45 (9B in FIG. 9) formed on the upper surface.

Next, the excellent effect of the Example shown to 9A of FIG. 9-9D of FIG. 9 is demonstrated.

In this embodiment, even when the through-hole 46 (9D in FIG. 9) is formed in the substrate 30 and the deformation occurs in the substrate 30, the position where the laser beam is incident and the original processing point 33 The misalignment with the position of) can be reduced. For this reason, the through hole 46 (9D of FIG. 9) can be formed by connecting the recessed part 45 (9B of FIG. 9) formed in the upper surface, and the recessed part formed in the lower surface.

Next, a modification of the present embodiment will be described. In the present embodiment, the machining method according to the embodiment shown in FIG. 3 or FIG. 8 is not employed in the machining of the machining point 33 (9B in FIG. 9) on the upper surface of the substrate 30. This is because the through hole is not formed in the processing of the upper surface, and it is considered that the deformation of the substrate 30 is not large. In the case where it is assumed that the deformation of the substrate 30 becomes large even when the upper surface is processed, the processing method according to the embodiment shown in FIG. 3 or FIG. 8 may be employed even when the upper surface is processed. Thereby, the position shift between the recessed part 45 (9B of FIG. 9) formed in the upper surface, and the recessed part formed in the lower surface can be reduced more.

In this embodiment, first, a recess is formed on the upper surface of the substrate 30, and then, the front and rear surfaces of the substrate 30 are inverted to form recesses on the lower surface, thereby connecting the recesses from the upper surface and the recesses from the lower surface. A through hole was formed. The through hole may be formed at one time by incidence of the laser beam from one side of the substrate 30. In this case, when forming the through hole, the processing method according to the embodiment shown in Fig. 3 or Fig. 8 may be employed.

Each embodiment mentioned above is an illustration, It goes without saying that partial substitution or combination of the structure shown in the other embodiment is possible. The same effect by the same structure of several embodiment is not mentioned sequentially by embodiment. In addition, the present invention is not limited to the above embodiment. For example, it will be apparent to those skilled in the art that various changes, improvements, combinations, and the like are possible.

10 laser light source
11 Acoustic Optics (AOM)
12 mirrors
13 beam syringe
14 condenser lens
15 beam damper
16 sensors
17 stage
20 controls
21 memory
30 boards
31 alignment mark
32 unit area
33 processing point
35 beam scanner scannable range
40 core layer
41, 42 copper foil
45 recessed
46 through hole

Claims (6)

Each of the unit areas of the substrate on which the workpiece surface is divided into a plurality of unit areas, an alignment mark is provided corresponding to each of the unit areas, and the positions of the plurality of processed points are defined inside the unit area. Processing of the processing point in the interior of the
For each machining of the unit area, the position of the alignment mark corresponding to the unit area to be processed next is detected, and the machining point is processed based on the detection result. The method of claim 1,
After detecting the position of the alignment mark, the deformation information indicating the deformation of the substrate is obtained based on the detection result of the position of the alignment mark, and the position of the processing point is corrected based on the deformation information. The processing method of performing a process based on the position of the said process point after correction | amendment when processing a process point. A laser light source for outputting a laser beam,
A beam scanner for injecting the laser beam output from the laser light source into the surface of the substrate and moving the incident position on the surface of the substrate;
A sensor for detecting an alignment mark provided on the substrate;
The work surface is divided into a plurality of unit areas, and the positions of the plurality of work points of the work surface are stored, and each alignment mark corresponding to the unit area to be processed next is processed for each processing of the unit area. And a control device which detects the position of the laser beam from the detection result of the sensor, and controls the beam scanner based on the detection result to cause the laser beam to enter the processing point in order. A process of detecting a position of at least a portion of the alignment mark of the substrate on which a plurality of alignment marks are provided and the positions of the plurality of processing points to be processed are defined;
A processing method of alternately repeating a step of sequentially machining a part of the plurality of processing points among the plurality of processing points based on the detection result of the position of the alignment mark. The method of claim 4, wherein
After detecting the position of the alignment mark, the deformation information indicating the deformation of the substrate is obtained based on the detection result of the position of the alignment mark, and the position of the processing point is corrected based on the deformation information. The processing method of performing a process based on the position of the said process point after correction | amendment when processing a process point. A laser light source for outputting a laser beam,
A beam scanner for injecting the laser beam output from the laser light source into the processing surface of the substrate and moving the incident position on the surface of the substrate;
A sensor for detecting each of a plurality of alignment marks provided on the substrate;
And a control device for storing the positions of the plurality of processing points on the surface to be processed, and controlling the laser light source and the beam scanner based on the detection result of the sensor,
The control device is configured to detect the position of at least part of the alignment mark based on a detection result of the sensor, and to control the laser light source and the beam scanner based on the detection result of the position of the alignment mark. A processing apparatus for repeating a process of sequentially processing a part of a plurality of processing points among a plurality of processing points alternately a plurality of times.

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