TW201932221A - Laser processing method - Google Patents

Abstract

Provided is a laser processing method for performing a conformal processing with a plurality of holes to be formed, which solves a problem in conventional laser processing methods in which protrusion of a glass cloth is easy to occur because an insulating material is selectively decomposed and removed due to the increasing amount of heat stored in one conformal mask when a pulsed laser is continuously irradiated to an outer peripheral portion, the laser processing method including a first processing step of irradiating laser light 1 to a region defined inside or outside the first mask 30a constituting a plurality of conformal masks 30a to 30f provided corresponding to the number of holes; and processing steps different from the first processing step of irradiating the laser light 1 on the inner side or the outer side of masks 30b~30f constituting a plurality of conformal masks 30a to 30f and different from the first mask 30a, a processing sequence of performing from the first processing step to the different processing steps being repeated several times, and the position where the laser light 1 being irradiated being changed every time when the processing sequence is repeated so as to complete the processing.

Description

Laser processing method

The present invention relates to a laser processing method for performing conformal processing.

In recent years, high-density mounting can be performed in electronic circuit forming steps such as in-vehicle electronic equipment that require connection reliability in hot and cold environments and vibration environments. The known drilling processing method has been replaced by a laser processing method. The laser processing method has been conventionally adopted as a method for forming a via hole for electrical connection between layers of a printed wiring board. The material of the circuit board newly used in the vehicle-mounted electronic equipment has a characteristic of using a composite material made of glass cloth cloth impregnated with resin at a high glass transition temperature as an insulating material.

On the other hand, in order to remove the insulating material, the higher the glass transition temperature, the more intense laser light must be irradiated. The thickness of the insulating layer used in the substrate of automotive electronic equipment is generally 100 μm or more. In order to efficiently remove the insulating material in the through-hole portion, a CO2 pulse laser with high light intensity is used as the light source.

[Prior technical literature] [Patent Literature]

Patent Document 1: Japanese Patent Application Laid-Open No. 2011-110598 (Page 17, FIG. 1).

Conventionally, although a processing method of sequentially irradiating a pulse laser along the outer periphery of a conformal mask using a laser scanning device has been used, when the pulse laser is continuously irradiated to the outer periphery, The outer part of the mask is decomposed and removed, and the laser light absorbing material after plasmaization will absorb the laser light that is irradiated and stay in place, and the heat storage inside the insulating material near the stay will be increase. When the heat storage capacity is increased, the glass fiber cloth inside the insulating material will not be sufficiently cooled below the glass transition temperature. As a result, the glass fiber cloth will not be sufficiently decomposed and removed, and the glass fiber cloth will easily protrude. Problems with beads remaining to the bottom of the well.

The present invention was developed by the inventors to solve the above-mentioned problems, and an object thereof is to efficiently form pores while suppressing the amount of heat stored in the insulating material.

In the laser processing method of the present invention, a laser processing method for sequentially performing laser light irradiation on M laser light irradiation points respectively set by N conformal masks formed on a substrate, wherein When M × N laser light irradiation spots are sequentially irradiated with laser light, M × N is repeatedly performed The second operation is as follows: one laser light irradiation is performed on one of the M laser light irradiation points in one conformal mask, and then one of the M laser light irradiation points on another conformal mask is performed. The next operation of laser light irradiation, thereby forming a hole for each conformal mask.

When the present invention focuses on one hole of an arbitrary conformal mask, the laser light that is irradiated thereafter will be irradiated to a laser light absorbing substance that is decomposed and removed and plasmatized after a certain period of time. The position is different, so the laser light absorbing substance will diffuse with time, and the heat storage of a conformal mask is suppressed, and the glass fiber cloth inside the insulating material can be cooled to a sufficient irradiation below the glass transition temperature. As a result, the glass fiber cloth is sufficiently decomposed and removed without causing the glass fiber cloth to protrude, and glass beads can be suppressed from remaining at the bottom of the hole, so that the hole can be efficiently formed.

1‧‧‧laser light

2‧‧‧laser oscillator

3‧‧‧ Energy Adjustment Device

4, 20‧‧‧ light scanning device

5‧‧‧fθ lens

6‧‧‧Machined material

7‧‧‧ focus plane

8‧‧‧ Face after parallel movement

9‧‧‧ mobile platform

10‧‧‧ Substrate

11, 12, 21, 22, 61‧‧‧ Peripheral

13, 62‧‧‧ laser light irradiation point

14‧‧‧ laser absorbing substance

16‧‧‧ surface conductor layer

17‧‧‧ Insulation

18‧‧‧ fiberglass cloth

19‧‧‧ back conductor layer

30a to 30f, 60a, 60b‧‧‧ conformal mask

50‧‧‧control device

a, b‧‧‧ laser light irradiation position

Fig. 1 is a block diagram showing a laser processing apparatus according to a first embodiment of the present invention.

Fig. 2 is a diagram showing the irradiation position of the laser light in the first embodiment of the present invention.

Fig. 3 is a cross-sectional view showing the surface of the material to be processed according to Example 1 of the present invention cut perpendicularly.

FIG. 4 is a diagram showing a laser light irradiation sequence in Embodiment 1 of the present invention.

Fig. 5 is a block diagram showing a laser processing apparatus according to a first embodiment of the present invention.

Fig. 6 is a diagram showing a laser light irradiation position in Embodiment 2 of the present invention.

Fig. 7 is a diagram showing a laser light irradiation position in Embodiment 3 of the present invention.

Example 1

Fig. 1 is a block diagram showing a laser processing apparatus according to a first embodiment of the present invention. The laser processing device shown in FIG. 1 includes: a laser oscillator 2 for generating laser light 1 belonging to a pulse; an energy adjusting device 3 for adjusting the energy of the laser light 1; and a light scanning device 4 for causing the laser light The irradiation direction of 1 is deviated; and the fθ lens 5 condenses the laser light 1. The work material 6 is set on a movable table 9 and the surface of the work material 6 is consistent with the focal surface 7 of the fθ lens 5 or the laser light 1 is shifted from the focus and irradiated. 6 is arranged on the surface 8 that has been moved in parallel from the focal plane 7 in the direction of the moving platform 9. The control device 50 controls the laser scanning operation of the laser oscillator and implements the processing method shown in the first embodiment of the present invention, and controls the light scanning device 4 and the mobile platform 9.

The laser light 1 generated by the laser oscillator 2 is adjusted by the energy adjustment device 3 to an optimal value for processing, and is incident on the light scanning device 4 to deflect the irradiation direction of the laser light 1. The light scanning device 4 controlled by the control device 50 deflects the irradiation direction of the laser light 1 in accordance with the laser light irradiation position calculated in advance. Laser light irradiation position The laser light 1 positioned by the optical scanning device 4 is incident on the fθ lens 5 and is irradiated onto the workpiece 6.

FIG. 2 shows the irradiation positions of the laser light 1 on the substrate 10 belonging to the work material 6 and formed with three conformal masks 30 a to 30 c. In FIG. 2, the conformal mask 30 a is used as an example. Although the surface of the substrate 10 was originally covered by the surface conductor layer 16, it is located on the inner side of the outer periphery 11 of the conformal mask 30 a. The surface conductor layer 16 has been previously removed in other steps. As the laser light irradiating point 13, it is tied to the inside of the conformal mask 30a. Based on the center of gravity of the conformal mask 30a, a peripheral portion 12 having a shape similar to the outer peripheral portion 11 of the conformal mask 30a is determined as an area. The laser light irradiation point 13 is determined in such a manner that the perimeter outside the outer peripheral portion 12 is equally divided. Alternatively, a radial isometric line may be extended from the center of gravity of the conformal mask 30a. Inside the conformal mask 30a, an outer peripheral portion 12 having a shape similar to that of the conformal mask 30a may be defined as an area, and The intersection point on the outer periphery of the portion 12 is defined as the irradiation point 13. When the conformal mask is circular, the center of gravity of the conformal mask is the center of the conformal mask.

In FIG. 2, although the outer peripheral portion 12 having a shape similar to the outer peripheral portion 11 of the conformal mask 30 a is defined as a region while being located inside the conformal mask 30 a and using the center of gravity of the conformal mask 30 a as a base point, The outer peripheral portion 12 having a shape similar to the shape of the conformal mask 30a can also be defined as an area outside the conformal cover 30a. For processing.

FIG. 3 is a vertical cut of the surface of the base material 10 belonging to the material 6 through the respective centers of gravity of the conformal masks 30 a to 30 c in FIG. 2. Broken section view. The base material 10 is composed of a surface conductor layer 16, an insulating layer 17, and a back conductor layer 19. Inside the insulating layer 17, a glass fiber cloth 18 containing a reinforcing material belonging to the base material 10 is contained. 14 is a laser absorbing substance generated after the laser light 1 is decomposed and removed.

FIG. 4 is a diagram showing a laser light irradiation sequence when the substrate has a plurality of conformal masks. In one conformal mask, four or more positions irradiating the laser light 1 are specified in advance. For example, in the conformal masks 30a to 30c, eight positions irradiating the laser light 1 are specified. In N conformal masks, when there are M laser light irradiation points in each conformal mask, there are M × N processing steps to irradiate the mth laser light in the nth conformal mask. The position is set to k (n, m). Here, 1 ≦ n ≦ N and 1 ≦ m ≦ M. For example, in FIG. 4, the number of conformal masks 30a to 30f is 6 (N = 6), and the number of laser light irradiation points is 8 (M = 8). The processing conditions when the laser light 1 is irradiated to the laser light irradiation position k (n, m) are set to the same conditions. In addition, FIG. 4 illustrates a case where the number of pulse irradiations of the laser light 1 is one pulse.

In FIG. 4, there are a total of M × N, that is, 48 laser light irradiation positions k (n, m), 1 ≦ n ≦ 6, 1 ≦ m ≦ 8, and the laser light 1 is irradiated in the following order.

First, k (1, 1) of the conformal mask 30a belonging to the first mask is irradiated with laser pulse 1 of 1 pulse as a first processing step. Next, a pulse of laser light 1 is irradiated to k (2, 1) belonging to the conformal mask 30b that is different from the second mask of the first mask as a second processing step. Then, k (3, 3, which belongs to the conformal mask 30c which is different from the third mask of the first mask 1) Irradiate 1 pulse of laser light 1 as the third processing step, and irradiate 1 pulse of laser light 1 on k (4, 1) belonging to the conformal mask 30d which is different from the first mask of the fourth mask For the fourth processing step, a pulse of laser light 1 is irradiated to k (5, 1) of the conformal mask 30e belonging to the fifth mask different from the first mask as the fifth processing step. The k (6, 1) of the conformal mask 30f of the first mask and the sixth mask irradiates the laser light 1 with one pulse as the sixth processing step.

When repeatedly performing a series of processing steps from the first processing step to the sixth processing step, when a conformal mask is to be irradiated with the laser light 1, the laser light 1 is irradiated to the distance. The farthest position is the unirradiated position of the laser light 1. First, after k (6,1) is irradiated to the conformal mask 30f for one pulse, laser beam 1 is irradiated with k (1,2) for one pulse to the conformal mask 30a as the second processing program. Next, the laser light 1 is irradiated with k (2, 2) for one pulse on the conformal mask 30b. Then, the laser light 1 is sequentially irradiated with 1 pulse on k (3, 2) of the conformal mask 30c, k (4, 2) of the conformal mask 30d, k (5, 2) of the conformal mask 30e, and K (6, 2) of the shape mask 30f.

Next, in the third processing sequence, k (1, 3) of the conformal mask 30a is irradiated with laser pulse 1 of one pulse. Next, k (2, 3) of the conformal mask 30b is irradiated with laser light 1 of one pulse. Then, one pulse of laser light 1 is irradiated to k (3, 3) of the conformal mask 30c, and one pulse of laser light 1 is irradiated to k (4, 3) of the conformal mask 30d, and the conformal mask is irradiated. K (5, 3) of 30e irradiates laser light 1 of 1 pulse, and k (6, 3) of conformal mask 30f irradiates laser light 1 of 1 pulse.

Next, in the fourth processing sequence, k (1, 4) of the conformal mask 30a is irradiated with one pulse of laser light 1. Next, k (2, 4) of the conformal mask 30b is irradiated with laser light 1 of one pulse. Then, k (3, 4) of the conformal mask 30c is sequentially irradiated with 1 pulse of laser light 1, and k (4, 4) of the conformal mask 30d is irradiated with 1 pulse of laser light 1, and the conformal mask is irradiated. K (5, 4) of 30e irradiates laser light 1 of 1 pulse, and k (6, 4) of conformal mask 30f irradiates laser light 1 of 1 pulse.

Next, in the fifth processing sequence, k (1, 5) of the conformal mask 30a is irradiated with one pulse of laser light 1. Next, k (2, 5) of the conformal mask 30b is irradiated with laser light 1 of one pulse. Then, k (3, 5) of the conformal mask 30c is sequentially irradiated with 1 pulse of laser light 1, and k (4, 5) of the conformal mask 30d is irradiated with 1 pulse of laser light 1, and the conformal mask is irradiated. K (5, 5) of 30e irradiates laser light 1 of 1 pulse, and k (6, 5) of conformal mask 30f irradiates laser light 1 of 1 pulse.

Next, in the sixth processing sequence, k (1, 6) of the conformal mask 30a is irradiated with one pulse of laser light 1. Next, k (2, 6) of the conformal mask 30b is irradiated with laser light 1 of one pulse. Then, one pulse of laser light 1 is irradiated on k (3, 6) of the conformal mask 30c, and one pulse of laser light 1 is irradiated on k (4, 6) of the conformal mask 30d, and the conformal mask is irradiated. K (5, 6) of 30e irradiates laser light 1 of 1 pulse, and k (6, 6) of conformal mask 30f irradiates laser light 1 of 1 pulse.

Next, in the seventh processing sequence, k (1, 7) of the conformal mask 30a is irradiated with one pulse of laser light 1. Next, k (2, 7) of the conformal mask 30b is irradiated with laser light 1 of one pulse. Then sequentially K (3, 7) of the conformal mask 30c irradiates 1 pulse of laser light 1, and k (4, 7) of the conformal mask 30d irradiates 1 pulse of laser light 1, and k ( 5. 7) One pulse of laser light 1 is irradiated, and k (6, 7) of the conformal mask 30f is irradiated with one pulse of laser light 1.

Finally, in the eighth processing program, k (1, 8) of the conformal mask 30a is irradiated with one pulse of laser light 1. Next, k (2, 8) of the conformal mask 30b is irradiated with laser light 1 of one pulse. Then, k (3, 8) of the conformal mask 30c is sequentially irradiated with 1 pulse of laser light 1, and k (4, 8) of the conformal mask 30d is irradiated with 1 pulse of laser light 1, and the conformal mask is irradiated. K (5, 8) of 30e irradiates laser light 1 of 1 pulse, and k (6, 8) of conformal mask 30f irradiates laser light 1 of 1 pulse, and the processing is completed.

Next, the processing steps in the general case where the number of conformal masks is N and there are M laser light irradiation points in each conformal mask will be described.

When the n-th conformal mask irradiating laser light 1 is not the last N-th conformal mask, the m-th laser light in the n-th conformal mask (1 ≦ n ≦ N) is irradiated After the laser light 1 is irradiated at a spot, that is, after the laser light 1 is irradiated to the laser light irradiation position k (n, m), the laser light irradiation point is sequentially repeated to the laser light irradiation position k (n + 1, m). Processing steps to irradiate the laser light 1.

When the n-th conformal mask to be irradiated with laser light 1 is the last N-th conformal mask and the m-th laser light irradiation point is not the last M-th laser light irradiation point, the N-th After the m-th laser light irradiation point in the conformal mask irradiates the laser light 1, that is, after the laser light 1 is irradiated to the laser light irradiation position k (N, m), the laser light irradiation point is returned to the first One conformal mask is moved to the laser light irradiation position k (1, m + 1) to irradiate the laser light 1. When moving from the laser light irradiation position k (N, m) to the laser light irradiation position k (1, m + 1), that is, the irradiation sequence in the same conformal mask, it is ideal to take the influence of heat storage as The smallest way is to select the diagonal positions in order.

When the n-th conformal mask to be irradiated with laser light 1 is the last N-th conformal mask and the m-th laser light irradiation point is the last M-th laser light irradiation point, the N-th After the M-th laser light irradiation point in the conformal mask irradiates the laser light 1, that is, after the laser light 1 is irradiated to the laser light irradiation position k (N, M), the processing is completed. Alternatively, after the laser light 1 is irradiated to the laser light irradiation position k (N, M), the laser light is returned to the laser light irradiation position k (1, 1) again, and the same processing steps are repeated several times to complete the processing.

The following description is based on an example where the number of pulses of the laser light 1 is 1 pulse. After irradiating the laser light 1 with a pulse of 1 at any laser light irradiation position k (n, m) of a conformal mask, The laser light 1 is irradiated to a laser light irradiation position k (n + 1, m) belonging to a different conformal mask. In addition, if focusing on a conformal mask, the laser light 1 is irradiated to the laser light irradiation position k (n, m) to which the conformal mask of the eye belongs, until the next time the laser light 1 is irradiated to the same conformal mask. The time interval up to the laser light irradiation position k (n, m + 1) to which the shape mask belongs is the same as the time to irradiate the laser light irradiation position to which other N-1 conformal masks belong by changing the position one by one every pulse. The time interval is the same.

Conformal masks of interest, after a processing After the completion of the sequence, the laser light 1 is irradiated again, but because the laser light irradiation position is different from the laser light irradiation position irradiated during the previous processing procedure, the laser light 1 performed later is passed by After a certain period of time, it is irradiated to a position different from the laser absorbing substance 14 generated after being decomposed and removed. Therefore, the laser absorbing substance diffuses with time, and the heat storage capacity of a conformal mask is suppressed, and the glass fiber cloth inside the insulating material can be cooled to a sufficient irradiation interval below the glass transition temperature.

In addition, conventionally, the same conformal mask is irradiated with the laser light 1, so it is affected by heat storage because of the laser absorbing substance 14 generated by the irradiation of the laser light 1 irradiated first, but in the embodiment of the present invention In 1, the laser light 1 that is carried out after a certain period of time will be irradiated to a position different from the laser absorbing substance 14 generated after being decomposed and removed, so the laser absorbing substance will diffuse with time. , It is not easy to generate the attenuation of the intensity of the laser light 1 to be irradiated or the change of the intensity distribution, and a good hole can be formed.

The irradiation position of the laser light 1 is the deflection by the light scanning device 4 controlled by the control device 50 or the parallel movement of the workpiece 6 by the driving of the mobile platform 9 or the light scanning Both the deflection performed by the device 4 and the driving of the mobile platform 9 are positioned. As long as it is within the scanning range of the optical scanning device 4, the irradiation position of the laser light 1 may be changed only by the scanning of the optical scanning device 4 while the mobile platform 9 is stationary.

Alternatively, the center of gravity with respect to each conformal mask may be located The same relative position, that is, m is the same laser light irradiation position k (n, m) grouping. In the irradiation of the same laser light irradiation position group with m being the same, only the deflection by the light scanning device 4 is used. The positioning of the irradiation laser light 1 is performed, and when the irradiation of the laser light irradiation position group located at a different relative position m, the mobile platform 9 is driven to drive the difference corresponding to the coordinates between the groups, so that the workpiece 6 is parallel By moving, a relative displacement is given to the laser light irradiation position between groups.

As an alternative to moving the workpiece 6 in parallel by the driving of the moving platform 9, as shown in FIG. 5, an optical scanning device may be additionally disposed at a position closer to the side of the oscillator 2 than the position of the fθ lens 5. 20, and a relative displacement is given to the laser light irradiation position by the light scanning device 20.

In the first embodiment, the case where one pulse is irradiated to each of the laser light irradiation positions k (n, m) has been described, but a plurality of pulses may be continuously irradiated to accelerate the progress of hole formation. .

In this way, when focusing on an arbitrary conformal mask, after a certain amount of time, the laser light that is irradiated will be irradiated to a different generation of the laser light absorbing material that was first decomposed and removed and plasmatized. Position, the laser light absorbing substance diffuses with the passage of time, the heat storage capacity of a conformal mask is suppressed, and the glass fiber cloth inside the insulating material can be cooled to a sufficient irradiation below the glass transition temperature As a result, the glass fiber cloth is sufficiently decomposed and removed without causing the glass fiber cloth to protrude, and glass beads can be suppressed from remaining at the bottom of the hole, so that the hole can be efficiently formed.

Example 2

In the first embodiment, although a case where the shape of the shape of the outer periphery of the conformal mask is set based on the center of gravity of the conformal mask as the base point of the laser light irradiation point, the center of gravity of the conformal mask can also be used as the base point. A plurality of outer peripheral portions having a shape similar to the outer peripheral portion of the conformal mask is determined. When the conformal mask is circular, the center of gravity of the conformal mask is the center of the conformal mask.

FIG. 6 shows the irradiation position of the laser beam 1 on the substrate 10 having two conformal masks 60a to 60b formed on the workpiece 6 belonging to the second embodiment of the present invention. In the second embodiment of the present invention, the conformal mask 60a is described as an example. The center of the conformal mask 60a is used as a base point on the inner side of the conformal mask 60a to determine the outer periphery of the conformal mask 60a. The outer peripheral portion 21 and the outer peripheral portion 22 having a similar shape to the portion 61 determine the laser light irradiation point 62 so that the outer peripheral lengths of the outer peripheral portion 21 and the outer peripheral portion 22 are evenly divided. In the N conformal masks, when there are P laser light irradiation points for the outer peripheral part 21 and Q laser light irradiation points for the outer peripheral part 22 in each of the conformal masks, the nth conformal mask is The p-th laser light irradiation position irradiated to the outer peripheral part 21 is set to a (n, p), and the q-th laser light irradiation position irradiated to the outer peripheral part 22 is set to b (n, q). Here, 1 ≦ n ≦ N, 1 ≦ p ≦ P, and 1 ≦ q ≦ Q.

Regarding the processing sequence, the laser light irradiation position a (n, p) irradiated to the outer peripheral portion 21 and the laser light irradiation position b (n, q) irradiated to the outer peripheral portion 22 are not distinguished, as long as it is as described in Embodiment 1. The laser light irradiation order may be determined in the same order. In a conformal mask, the positions of the laser light 1 to be irradiated are 4 or more in advance, and each time it is processed When the procedure is completed, when a conformal mask is irradiated with the laser light 1, the laser light 1 is irradiated to the position farthest from the position where the irradiation is completed and is the unirradiated position of the laser light 1. The processing conditions when the laser light 1 is irradiated to the laser light irradiation positions a (n, p) and b (n, q) are the same.

In this way, when focusing on an arbitrary conformal mask, the laser light that is irradiated thereafter will be irradiated to a position different from the generation position of the laser light absorbing material that is decomposed and removed and plasmatized after a certain period of time. Position, the laser light absorbing substance will diffuse with time, and the heat storage capacity of a conformal mask is suppressed, which can ensure that the glass fiber cloth inside the insulating material is cooled to a sufficient irradiation interval below the glass transition temperature. As a result, the glass fiber cloth is sufficiently decomposed and removed, and the glass fiber cloth does not protrude, and the glass beads can be suppressed from remaining at the bottom of the hole, so that the hole can be efficiently formed.

Example 3

In the second embodiment, the case where the processing conditions when the laser light 1 is irradiated to the laser light irradiation positions a (n, p) and b (n, q) is the same has been described, but it can also be described as As shown in FIG. 7, the pulse width, the beam intensity, the number of shots, the distance between the surface of the substrate 10 and the focal surface 7 of the fθ lens 5 are changed according to each outer peripheral portion of the laser light 1 to be irradiated. At least one of the parameters.

The conformal mask 60a is taken as an example for description. Considering that the center of gravity of the conformal mask 60a is used as a base point, the outermost peripheral portion 21 of the outer peripheral portion having a shape similar to the outer peripheral portion of the conformal mask 60a is first irradiated with lightning. The emitted light 1 is then irradiated with the laser light 1 to the inner peripheral portion 22. on Since most of the center of gravity of the conformal mask 60a has been removed by the laser light 1 that first irradiated the outer peripheral portion 21, the inner peripheral portion 22 should be irradiated to the outer peripheral portion 21 first. When the laser light 1 is irradiated under the same processing conditions, the linear energy may become excessive, and a molten portion may be generated in the bottom conduction layer. Therefore, the laser light 1 to be irradiated to the inner outer peripheral portion 22 can be processed by reducing the beam intensity, thereby avoiding melting and performing good hole formation.

In addition, when the thickness of the insulating layer 17 inside the conformal mask is, for example, 200 μm or more, in order to effectively remove the lower portion of the back conductive layer 19 side of the insulating layer 17, when the laser light 1 is to be irradiated to the inner peripheral portion 22 on the inner side, By focusing the laser light 1 on the lower side of the back conductor layer 19 of the insulating layer 17, the focal surface 7 of the fθ lens 5 is lowered or the workpiece 6 is raised, and the back conductor layer 19 of the insulating layer 17 is raised. The lower part of the side is formed with a hole having an enlarged insulation removal area.

In this way, when focusing on an arbitrary conformal mask, the laser light that is irradiated thereafter will be irradiated to a position different from the generation position of the laser light absorbing material that is decomposed and removed and plasmatized after a certain period of time. Position, the laser light absorbing substance will diffuse with time, and the heat storage capacity of a conformal mask is suppressed, which can ensure that the glass fiber cloth inside the insulating material is cooled to a sufficient irradiation interval below the glass transition temperature. As a result, the glass fiber cloth is sufficiently decomposed and removed, and the glass fiber cloth does not protrude, and the glass beads can be suppressed from remaining at the bottom of the hole, so that the hole can be efficiently formed.

Claims (8)

A laser processing method is a laser processing method for sequentially performing laser light irradiation on M laser light irradiation points respectively set by each of N conformal masks formed on a substrate. When M × N laser light irradiation points are sequentially irradiated with laser light, the following operations are repeatedly performed M × N times: one laser light is irradiated on one of the M laser light irradiation points in a conformal mask Then, the next laser light irradiation operation is performed on one of the M aforementioned laser light irradiation points of the other conformal masks, thereby forming a hole for each of the aforementioned conformal masks. A laser processing method is a laser processing method for sequentially performing laser light irradiation on M laser light irradiation points respectively set by each of N conformal masks formed on a substrate. When the mth (1 ≦ m ≦ M) laser light irradiation point k of the n (1 ≦ n ≦ N) conformal masks is marked as k (n, m), it is repeated from m = 1 to m = M The following steps: the step of fixing m while increasing n from 1 to N one by one, and performing laser light irradiation at each laser light irradiation point from k (1, m) to k (N, m). The laser processing method according to item 1 or 2 of the scope of patent application, wherein the laser light irradiation point is defined on the outer peripheral portion of the shape conforming mask based on the center of gravity of the shape conforming mask. . The laser processing method according to item 3 of the scope of the patent application, wherein the laser light irradiation point is set at a position where the outer peripheral portion is divided into a plurality of outer peripheral lengths. The laser processing method according to item 3 of the scope of the patent application, wherein the outer peripheral portion is provided on the inner side of the conformal mask, and a plurality of the outer peripheral portions are defined. The laser processing method according to item 1 or 2 of the scope of the patent application, wherein the laser light irradiation point is defined in advance to 4 or more for one of the conformal masks. The laser processing method according to item 1 or 2 of the scope of patent application, wherein the laser light is pulsed light. The laser processing method according to item 7 of the scope of patent application, wherein the number of the pulsed light is one pulse.