JP7414444B2 - Laser processing equipment, laser processing method, and article manufacturing method - Google Patents

Description

The present invention relates to a laser processing device, a laser processing method, and an article manufacturing method.

A laser processing device focuses laser light using a plurality of optical elements and a reflecting member. This device melts or vaporizes the target object by increasing the laser energy density and performs processing such as marking, cutting, drilling, welding, and hardening. In processing using a laser processing apparatus, when the surface of the workpiece is uneven or curved, it is necessary to accurately match the surface position of the object with the focal position of the laser beam.

Examples of means for adjusting the focal length include a method of aligning the workpiece with the laser condensing point, and a method of adjusting the focus by adjusting the position of an optical lens in the laser processing device in the optical axis direction. Further, in Patent Document 1, the curvature of the reflecting surface is made concave or convex by controlling the pressure of the fluid inside the mirror, and the focal length is changed.

JP2016-215222A

However, with the method proposed in Patent Document 1, in order to change the curvature of the lens, the constraints on the lens shape are actually limited, making it difficult to adjust the focal length flexibly. .

Therefore, an object of the present invention is to provide a laser processing device that can adjust the focal position more flexibly and accurately, for example.

In order to solve the above problems, the present invention provides a processing device that irradiates a target object with light from a laser light source and processes the target object, which includes a plurality of optical elements that guide the light to the target object. an optical unit, an inflow section that flows fluid between the plurality of optical elements, and an injection section that injects gas between the optical unit and the object , and an amount of gas that is injected by the injection section. The light is irradiated from the optical unit to the object by changing the refractive index of the fluid between the plurality of optical elements by adjusting the inflow amount of the fluid by the inflow portion according to . do.

According to the present invention, for example, it is possible to provide a laser processing device that can adjust the focal position more flexibly and accurately.

It is a schematic diagram showing the composition of the processing device concerning a 1st embodiment. 1 is a schematic diagram showing the configuration of a processing device according to Example 1. FIG. FIG. 3 is a diagram illustrating a process of flowing fluid between a plurality of optical elements according to the first embodiment. FIG. 2 is a flowchart showing an example of a process for adjusting the focal point position according to the first embodiment; FIG. FIG. 2 is a schematic diagram showing the configuration of a processing device according to a second embodiment. FIG. 7 is a schematic diagram of the vicinity of a nozzle part according to a second embodiment. FIG. 7 is a flow diagram illustrating an example of a focusing point position adjustment process according to the second embodiment. It is a schematic diagram of the nozzle part periphery based on 3rd Embodiment.

Embodiments of the present invention will be described below with reference to the accompanying drawings. As a general rule (unless otherwise specified), the same members and the like are denoted by the same reference numerals throughout all the drawings for explaining the embodiments, and repeated explanations thereof will be omitted.

[First embodiment]
Hereinafter, a laser processing apparatus according to a first embodiment of the present invention will be described. FIG. 1 is a schematic diagram showing the configuration of a processing apparatus 100 according to the first embodiment. The processing device 100 is a laser processing device that processes a target (object) using light (laser light) from a light source. In the present embodiment, the processing apparatus 100 focuses a laser beam emitted from a laser oscillator 101 (light source section) including a laser light source onto an object 103 to form a focal point 107. Processing is performed on the processing area (target position) of the object while moving it.

The processing device 100 irradiates a target object 103 with a laser beam 102 emitted from a laser oscillator 101 . The processing apparatus 100 includes a plurality of optical elements 104 (optical units), a nozzle section 105 (injection section), a flow path 106, and a control section 108. A laser beam 102 emitted from a laser oscillator 101 passes through a plurality of optical elements 104 in the laser processing apparatus 100, is emitted through a nozzle section 105, and is irradiated onto a target object 103.

A flow path 106 for flowing fluid is formed in the space between the plurality of optical elements. By flowing the fluid between the plurality of optical elements, the refractive index of the fluid between the plurality of optical elements can be changed. In other words, the control unit 211 can adjust the position of the laser convergence point by controlling the amount of fluid flowing into the inlet. Here, the fluid includes liquid and gas, but gas is preferable because gas is easier to control than liquid.

The control unit 108 controls each part of the processing apparatus 100 and the laser oscillator 101, and may be connected to, for example, a PC (personal computer) 109 as an external device. A user can operate the processing apparatus 100 by operating the PC 109.

(Example 1)
FIG. 2 is a schematic diagram showing the configuration of a processing apparatus 200 according to the first embodiment. The details of the processing apparatus 200 of this example will be explained using FIG. 2. The processing device 200 includes a collimating lens section 203, galvano mirrors 204 and 205, a condensing lens section 206, a nozzle section 208, and a control section 211.

Laser light 202 entering processing device 200 passes through a collimating lens group arranged in collimating lens section 203 and becomes collimated light. In addition to the collimating lens group, for example, the laser may include an optical system for adjusting the laser beam from the oscillator to a predetermined light amount and luminous flux diameter. The collimated light passes through galvanometer mirrors 204 and 205, a condensing lens group disposed in a condenser lens section 206, and a cover glass 207 to deflect the output direction, and is emitted through an exit section of a nozzle section 208.

Galvano mirror 204 is supported by galvano motor 209, and galvano mirror 205 is supported by galvano motor 210. The galvano motors 209 and 210 rotate in response to a drive signal from the control unit 211 to arbitrarily deflect the output angles of the galvano mirrors 204 and 205, respectively, and scan the laser beam 202 on the target object. can. That is, the galvano mirrors 204 and 205 function as a deflection optical system, and the galvano mirrors 204 and 205 can be said to be a mechanism for adjusting the incident position (x, y) of light. Galvano mirrors 204 and 205 adjust the incident position at which the laser beam is incident on the object in a direction perpendicular to the focal direction of the laser beam.

The condensing lens group (condensing optical system) is an optical system that changes the focal position (z) of light in order to condense the light onto an object.

The processing device 200 may include, for example, a focus adjustment mechanism 212 for changing the position of a light condensing point (light condensing position, focal position). For example, as shown in FIG. 2, the focus adjustment mechanism 212 is arranged between the collimating lens section 203 and the galvano mirrors 204 and 205. The focus adjustment mechanism 212 adjusts the optical path of the laser beam so that the laser beam is focused on a predetermined z position with respect to the object, that is, a target position (z). The focus adjustment mechanism 212 includes, for example, a movable optical element such as a drive lens, and adjusts the focusing position of the laser beam on the object by driving the drive lens with a drive mechanism 217 such as an actuator. In the focus adjustment mechanism 212, the target position (z) can be made into a light condensing position by driving the drive lens. However, the focus adjustment mechanism 212 is not limited to the configuration shown in FIG. 2, and may have the function of making the target position (z) a light condensing position. When the processing device 200 includes the focus adjustment mechanism 212, arbitrary 3D processing becomes possible in combination with the galvano motors 209 and 210.

The control unit 211 is composed of a computer including a CPU, a memory, etc., and operates the processing apparatus 200 by controlling each part of the processing apparatus 200 in an integrated manner according to a program stored in the memory. For example, the control unit 211 gives a processing command to each part of the processing device 200 in order to perform a predetermined processing (for example, drilling) on the object. The processing command is, for example, a drive command regarding adjustment of the incident angle, adjustment of the condensing position, and adjustment of the incident position, and includes the drive amount, drive speed, drive order, drive standby time, etc. of each part.

The nozzle section 208 is arranged on the rear side (later stage) of the cover glass 207 and injects gas between the condenser lens group and the object. The nozzle portion 208 is connected to one end of a flow path 214a (supply pipe, tube) via a joint 213a. The other end of the flow path 214a for the nozzle section is connected to a supply source 215a, and supplies the gas supplied from the supply source 215a to the nozzle section 208. The gas supply amount, supply timing, etc. are controlled by the control unit 211. The gas supplied to the nozzle section 208 passes through the inside of the nozzle and is sprayed (injected) from the injection port of the nozzle section 208 onto the workpiece. Note that here, the amount of gas supplied to the nozzle section 208 can also be said to be the amount of gas sprayed onto the object by the nozzle section 208. This kind of gas is also called assist gas, and it promotes processing when processing the object, removes processing debris generated when processing the object, and protects the optical members of each adjustment mechanism that constitutes the processing device 200. The purpose is to prevent the adhesion of processing waste. The gases used vary depending on the application, but for things like welding, nitrogen, argon, helium, etc. are used, and to protect processed lenses from spatter and fumes, air is used at high pressure.

The cover glass 207 is arranged between the nozzle section 208 and the condensing lens group, and partitions the nozzle internal space from the space where the condensing lens group is arranged. As the amount of assist gas supplied increases, the nozzle internal pressure increases, so the refractive index of the assist gas in the nozzle internal space changes, and as a result, the focal position changes. The amount of variation (deviation amount) in the focal position increases as the nozzle internal pressure increases. If the focal point position deviates from the ideal position, the laser energy density will become weaker and desired laser processing will not be possible.

The use of nitrogen (N2) and argon (Ar), which are commonly used as assist gases in laser processing, also has a different refractive index compared to air, which causes focal position fluctuations. The wider the nozzle internal space is, the more susceptible it is to the refractive index, so it is preferable to make the nozzle internal space narrower.

An inflow portion is formed in the space between the plurality of optical elements included in the condenser lens group. The inflow section includes a joint 213b, a flow path 214b (inflow pipe, tube) for the inflow section, and an inflow source 215b. The space between the plurality of optical elements included in the condenser lens group is connected to one end of the flow path 214b via the joint 213b. The other end of the flow path 214b is connected to an inflow source 215b, and the fluid supplied from the inflow source 215b flows into the space between the optical elements. By flowing fluid between the optical elements, the refractive index of the fluid between the optical elements can be changed, and as a result, the position of the focal point can be adjusted. At this time, it is preferable that the space into which the fluid is placed is in contact with a highly sensitive optical element. With such a configuration, a range of adjustment of the focal position can be ensured by causing fluid to flow between the optical elements. The amount of fluid flowing in, the timing of fluid flowing in, and the like are controlled by the control unit 211 . That is, the control section 211 controls the amount of fluid flowing into the inflow section so as to adjust the position of the focal point of the light emitted from the optical unit.

表１中の圧力を示す数値は、空間Ｓの圧力を示している。「屈折率」は、圧力に対応する空間Ｓにおける流体の屈折率を示している。「近軸焦点位置」は、屈折率が変化したことによる焦点位置の変化量を示している。変化量の数値が上がるほど、焦点位置は－Ｚマイナス方向へ変化する。図３（Ｃ）および、表１からわかるように、空間Ｓの圧力が上昇するほど、焦点位置は大きく変化する。換言すると、空間Ｓへの流体の流入量を多くするほど焦点位置を大きく変化させることができる。 FIG. 3 is a diagram illustrating a process of flowing fluid between a plurality of optical elements according to the first embodiment. FIG. 3A is an enlarged view of the nozzle section 208 and the condensing lens section 206. FIG. 3(B) is a schematic diagram of the condenser lens group. In this embodiment, the condenser lens group includes, for example, three optical elements 206a, 206b, and 206c. In this embodiment, the fluid flows into the space S between the optical element 206b and the optical element 206c, which is between the plurality of optical elements. FIG. 3(C) is a diagram showing a numerical example of a change in air pressure in the space S and a change in the focal position accompanying the change. Table 1 below is a table of FIG. 3(C). Note that here, as an example, the fluid flowing into the space S is air.

The numerical values indicating the pressure in Table 1 indicate the pressure in the space S. "Refractive index" indicates the refractive index of the fluid in the space S corresponding to the pressure. The "paraxial focal position" indicates the amount of change in the focal position due to a change in the refractive index. As the value of the amount of change increases, the focal position changes in the -Z minus direction. As can be seen from FIG. 3C and Table 1, the focal position changes more greatly as the pressure in the space S increases. In other words, the larger the amount of fluid flowing into the space S, the more the focal position can be changed.

As described above, as the pressure in the nozzle internal space increases, the amount of deviation of the focal point from the target position increases. Therefore, the control section 211 controls the inflow section so that the higher the pressure in the nozzle internal space, in other words, the greater the amount of gas supplied to the nozzle section 208, the greater the amount of fluid flowing between the plurality of optical elements. control.

Next, with reference to FIG. 4, the adjustment process of the focal point position of this embodiment will be described. FIG. 4 is a flow diagram illustrating an example of a focusing point position adjustment process according to the first embodiment. Each operation (step) shown in this flow diagram can be executed by the control unit 211. First, the control unit 211 injects assist gas from the nozzle unit 208 (S401). Then, the control unit 211 obtains the amount of shift of the focal point due to the assist gas (S402). Specifically, for example, the deviation amount may be calculated by the control unit 211 based on the amount of assist gas supplied to the nozzle portion 208, or a table of deviation amounts corresponding to the amount of assist gas supplied, etc. may be stored, and the deviation amount may be obtained based on the stored table.

After that, the control unit 211 determines the amount of fluid flowing between the optical elements based on the amount of deviation obtained in S402 (S403). Then, the supply amount of fluid determined in S403 flows between the optical elements (S404). Thereby, it is possible to correct the shift in the focal point caused by the assist gas.

Note that the number of spaces into which the fluid flows in order to change the refractive index does not need to be one, and it is preferable to configure the structure so that the fluid flows into a plurality of spaces. Specifically, a fluid between a plurality of optical elements separate from the space S is introduced. With this configuration, it becomes possible to adjust the focal position more flexibly. Furthermore, the adjustment range of the focal position can be expanded.

Furthermore, the fluid need not be of one type, and the focal length may be adjusted by flowing a plurality of fluids between a plurality of optical elements. Specifically, for example, multiple types of fluids may be selectively flowed between multiple optical elements, such as air into a space between a certain optical element and nitrogen into a space between another optical element. It's good as well.

Furthermore, it is preferable to create a sealed space between the optical elements through which the fluid flows, using an O-ring or a sealing material, since this further increases the efficiency of changing the refractive index. In this case, it is necessary to prevent the flow path side with a valve or the like, but increasing the degree of sealing is effective in controlling the focal position over a long period of time.

Further, the refractive index of the fluid in the space S may be further changed by adjusting not only the inflow pressure but also the temperature of the fluid. In this case, the inflow section includes a temperature adjustment section that adjusts the temperature of the fluid, such as a heater or a Peltier element, and the control section 211 adjusts the refractive index of the fluid by controlling the temperature adjustment section. At this time, it is preferable that the temperature of the space into which the fluid flows can be adjusted, so for example, a heat insulating material may be sandwiched before and after the holding part surrounding the space into which the fluid flows, or a low thermal expansion material (such as an invar material) may be used. ) is recommended. Further, it is desirable that the holding portion itself be made of a low thermal expansion material.

Further, in this embodiment, an example has been described in which the shift in the focal point caused by the assist gas is corrected, but the present invention is not limited to this. For example, the focus adjustment mechanism 212 is used to adjust the focal point position above a threshold, and the focal point position below the threshold is adjusted by flowing fluid between optical elements, depending on the amount of adjustment. It's okay. This configuration allows for more fine adjustment of the focal point position, which is advantageous when performing fine 3D processing, for example.

(Example 2)
FIG. 5 is a schematic diagram showing the configuration of a processing device 250 according to the second embodiment. The processing device 250 of this embodiment does not include the focus adjustment mechanism 212. The processing device 250 does not include the focus adjustment mechanism 212 and adjusts the focal position so that the laser beam is focused on the target position (z) only by flowing fluid between the plurality of optical elements. In this embodiment, the control unit 211 determines the amount of fluid inflow according to the target position (z) of the focal point. Note that at this time, it is preferable to determine the inflow amount by taking into consideration the shift amount of the focal point caused by the assist gas. Then, the fluid flows between the optical elements according to the determined inflow amount.

When the laser processing apparatus does not include the focus adjustment mechanism 212 as in this embodiment, it is preferable to flow fluid between highly sensitive optical elements. Specifically, for example, the fluid flows into a space between a plurality of optical elements in which at least one surface is a curved surface. More preferably, the fluid flows into a space of the condensing lens that is in contact with a curved surface having a higher curvature. Moreover, it is more preferable to configure the structure so that fluid can flow into a plurality of spaces.

According to this embodiment, since it is not necessary to include the focus adjustment mechanism 212, the device configuration can be simplified. Further, compared to the case where the focus adjustment mechanism 212 is provided and the focal position is adjusted only by the focus adjustment mechanism 212, it becomes possible to perform fine adjustment, and is suitable for, for example, fine 3D processing.

[Second embodiment]
FIG. 6 is a schematic diagram of the vicinity of the nozzle section 208 according to the second embodiment. Descriptions of parts similar to those in the above embodiment will be omitted. The configuration not shown in this figure is almost the same as the embodiment described above. In this embodiment, in addition to the first embodiment, a pressure sensor 303 is arranged in the flow path 214a as a measuring section for measuring the internal pressure of the nozzle section 208. Further, a pressure sensor 305 is arranged in the flow path 214b as a measurement unit for measuring the pressure between the plurality of optical elements.

With reference to FIG. 7, a process for adjusting the focal point position according to the second embodiment will be described. FIG. 7 is a flowchart illustrating an example of a focusing point position adjustment process according to the second embodiment. Each operation (step) shown in this flow diagram can be executed by the control unit 211. Note that the operations in S401, S403, and S404 in this flow are almost the same as those in FIG. 4, so the description thereof will be omitted here.

After injecting the assist gas (S401), the pressure sensor 303 measures the internal pressure of the nozzle portion 208 (S702). Then, the control unit 211 obtains the amount of shift of the focal point using the assist gas based on the measurement result of the pressure sensor 303. Specifically, for example, the amount of deviation may be calculated by calculation by the control unit 211, or a table of deviation amounts corresponding to pressure may be stored, and the amount of deviation may be obtained based on the stored table. Also good. Next, the control unit 211 determines the amount of fluid to be supplied based on the amount of deviation obtained in S703 (S403), and causes the inflow unit 99 to flow the fluid between the optical elements (S404). Then, the pressure between the optical elements into which the fluid has flowed is measured by the pressure sensor 305 (S706). The control unit 211 determines whether the pressure between the optical elements has reached the target value (S707). If the pressure between the optical elements does not reach the target value (No), S404 and S706 are repeated until the pressure between the optical elements reaches the target value. In S707, if the pressure between the optical elements has reached the target value (Yes), the process ends.

According to this embodiment, it is possible to perform feedback based on the measurement results from the pressure sensor and adjust the fluid flow rate inserted between the optical elements, so it is possible to adjust the focal position with more precision. .

Note that the pressure sensor 303 and the pressure sensor 305 may be arranged at a separate port from the inside of the flow path, for example, as shown by the pressure sensor 304 in FIG. Further, only one of the pressure sensor 303 and the pressure sensor 305 may be provided.

[Third embodiment]
FIG. 8 is a schematic diagram of the vicinity of the nozzle section 208 according to the third embodiment. Descriptions of parts similar to those in the above embodiment will be omitted. The configuration not shown in this figure is almost the same as the embodiment described above. In this embodiment, in addition to the first embodiment, a distributor 413 (branching part) is arranged in the flow path through which the fluid passes, and the gas is branched between the nozzle internal space and the optical element. ing.

For example, when the injection amount of assist gas is constant, if the amount of fluid flowing between the optical elements is known in advance with respect to the refractive index of the assist gas in the internal space of the nozzle, the distributor 413 can be used to control one flow. It becomes possible to adjust the focal point from the road. In this case, it is not necessary to provide feedback. Therefore, depending on the amount of adjustment, the distributor is not limited to two branches, but may have a greater number of branches. In addition, when using a distributor, the same fluid will flow into a plurality of spaces.

According to this embodiment, there is no need to configure a supply source and an inflow source, and they can be combined into one, thereby simplifying the apparatus.

[Embodiment related to article manufacturing method]
The processing apparatus according to the embodiment described above can be used in an article manufacturing method. The article manufacturing method may include a step of processing an object (object) using the processing apparatus, and a step of processing the object processed in the step. The processing may include, for example, at least one of processing different from the processing, transportation, inspection, sorting, assembly (assembly), and packaging. The article manufacturing method of the present embodiment is advantageous over conventional methods in at least one of article performance, quality, productivity, and production cost.

[Other embodiments]
Although preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist thereof.

100,200 Processing device 101 Laser oscillator 103 Target object 105,208 Nozzle section 108,211 Control section 212 Focus adjustment mechanism

Claims (11)

A processing device that processes an object by irradiating the object with light from a laser light source,
an optical unit having a plurality of optical elements that guide the light to the target object;
an inflow portion that flows fluid between the plurality of optical elements;
an injection unit that injects gas between the optical unit and the target object ,
The refractive index of the fluid between the plurality of optical elements is changed by adjusting the amount of fluid inflow by the inflow section according to the amount of gas injected by the injection section, and the refractive index of the fluid between the plurality of optical elements is changed, and the object is removed from the optical unit. A laser processing device characterized in that the laser beam is irradiated with the light. A processing device that processes an object by irradiating the object with light from a laser light source,
an optical unit having a plurality of optical elements that guide the light to the target object;
an inflow portion that flows fluid between the plurality of optical elements;
an injection unit that injects gas between the optical unit and the target object;
a control section that controls the inflow section;
A measurement unit that measures the pressure within the injection unit ,
The control unit changes the refractive index of the fluid between the plurality of optical elements by controlling the inflow amount of the fluid based on the measurement result, and directs the light from the optical unit to the object . A laser processing device characterized by irradiation . 3. The laser processing apparatus according to claim 2 , wherein the control section controls the inflow section such that the higher the pressure within the injection section, the greater the amount of fluid inflow. The fluid is a gas,
4. The laser processing apparatus according to claim 1 , wherein the inflow section includes a branch section that branches the gas between the injection section and the optical element. The optical unit includes a movable optical element;
comprising a drive mechanism that drives the movable optical element,
5. The laser processing apparatus according to claim 1 , wherein the position of the light condensing point is adjusted by driving the movable optical element. 6. The laser processing apparatus according to claim 5 , wherein the position of the focal point of the light is adjusted by controlling the inflow section and the drive mechanism. 7. The laser processing apparatus according to claim 1 , wherein the inflow section allows the fluid to flow between a plurality of optical elements other than between the plurality of optical elements. 8. The laser processing apparatus according to claim 1, wherein the inflow section selectively allows a plurality of types of fluid to flow between the plurality of optical elements. comprising a temperature control unit that adjusts the temperature of the fluid;
9. The laser processing apparatus according to claim 1, wherein the refractive index of the fluid is adjusted by controlling the temperature control section. 10. The laser processing apparatus according to claim 1, wherein at least one surface between the plurality of optical elements is a curved surface. A processing step of processing an object using the laser processing device according to any one of claims 1 to 10 ;
A method for manufacturing an article, the method comprising: performing a treatment different from the treatment on the object processed in the treatment step, and obtaining an article from the treated object.

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