JP5950674B2 - Optical axis checking jig - Google Patents

Description

  The present invention relates to an optical axis confirmation jig for confirming whether an optical axis of an optical unit and a laser beam incident on the optical unit are positioned on a straight line.

  A wafer such as a silicon wafer or a sapphire wafer formed on the surface by dividing a plurality of devices such as IC, LSI, LED, etc. by dividing lines is divided into individual devices by a processing apparatus, and the divided devices are mobile phones, Widely used in various electronic devices such as personal computers.

  A dicing method using a cutting device called a dicer is widely used for dividing the wafer. In the dicing method, a wafer is cut by cutting a wafer into a wafer while rotating a cutting blade having a thickness of about 30 μm by solidifying abrasive grains such as diamond with a metal or a resin at a high speed of about 30000 rpm. Divide into chips.

  On the other hand, in recent years, a method of dividing a wafer into individual device chips using a laser processing apparatus has been developed and put into practical use. As a method of dividing a wafer into individual device chips using a laser processing apparatus, first and second processing methods described below are known.

  In the first processing method, a condensing point of a laser beam having a wavelength transparent to the wafer (for example, 1064 nm) is positioned inside the wafer corresponding to the division line, and the laser beam is aligned along the division line. This is a method in which a modified layer is formed inside the wafer by irradiation, and then an external force is applied to the wafer by a dividing device to divide the wafer into individual device chips using the modified layer as a starting point (for example, Japanese Patent No. 3408805). reference).

  In the second processing method, a processing groove is formed by ablation processing by irradiating a condensing point of a laser beam having a wavelength (for example, 355 nm) having an absorptivity with respect to a wafer to an area corresponding to a division-scheduled line. Is used to divide the wafer into individual device chips with the processing groove as a starting point (see, for example, JP-A-10-305420).

  The processing method using a laser beam can increase the processing speed as compared with a dicing method using a dicer, and can relatively easily process even a wafer made of a material having high hardness such as sapphire or SiC. .

  In addition, since the modified layer or the processed groove can be made to have a narrow width of, for example, 10 μm or less, there is an advantage that the amount of devices taken per wafer can be increased as compared with the case of processing by the dicing method. ing.

  A laser processing apparatus irradiates a workpiece with a laser beam oscillated from a mounted laser oscillator through many optical components such as a mirror and a lens. The optical path of the laser beam is precisely configured with as little angle and position deviation as possible.

  For example, in an optical unit having a plurality of lenses typified by a beam expander, etc., after adjusting the optical axis of each lens on the base in advance using an autocollimator, each lens is fixed to the base, and further in the box. By storing and installing each box in the laser processing device, optical axis adjustment work that requires space is not carried out on the device, and the occurrence of optical axis misalignment of each lens during installation work is suppressed. .

Japanese Patent No. 3408805 JP-A-10-305420

  However, after such an optical unit is mounted on the laser processing apparatus, an adjustment operation of an optical system disposed on the upstream side of the optical unit may be performed. In such a case, it is necessary to adjust the optical axis of the optical system and the optical axis of the optical unit during the adjustment operation. For example, an adjustment operation for making a laser beam from a laser oscillator incident on the optical unit coincide with the optical axis of the optical unit is indispensable.

  At present, a reflection mirror is attached to the entrance of the optical unit box, the laser beam oscillated from the laser oscillator is reflected by the reflection mirror, and the return position of the reflected light is the same as the emission position of the laser beam. Although the angle of the laser beam is adjusted, the wall surface of the box where the entrance is formed is not necessarily highly accurate and perpendicular to the optical axis of the optical unit.

  Therefore, since the angle of the reflection mirror is not perpendicular to the optical axis of the optical unit, the angle of the laser beam incident on the optical unit cannot be adjusted precisely, and the laser beam is distorted and oscillated from the laser oscillator. However, there was a problem that the power of the laser beam was not fully utilized for processing.

  The present invention has been made in view of these points, and the object of the present invention is to accurately adjust the optical path of a laser beam incident on the optical unit after the optical unit is mounted on the apparatus. An optical axis checking jig is provided.

According to the present invention, there is provided an optical axis confirmation jig for confirming whether or not an optical axis of an optical unit and a laser beam incident on the optical unit are positioned in a straight line. An optical axis confirmation treatment comprising: a housing having a first opening for incidence and a second opening for emitting a laser beam; and a lens body having an optical axis adjusted accommodated in the housing. The tool includes a reflecting jig having a reflecting surface for reflecting the laser beam, and a fixing jig that is disposed in the first opening of the housing and detachably supports the reflecting jig. The jig includes a reflecting plate having the reflecting surface, and an angle adjusting plate having at least three supporting portions and capable of fixing the reflecting plate at a predetermined angle, and the fixing jig includes the supporting portion. A number of fixing portions corresponding to the number of the supporting portions to be fixed; One of the fixed parts is composed of a permanent magnet and the other is composed of a ferromagnetic material, and the angle adjusting plate is fixed to the fixing jig disposed in the first opening of the casing. After adjusting the reflecting surface of the reflecting plate so as to be perpendicular to the optical axis of the lens body constituting the optical unit, the reflecting plate is fixed to the angle adjusting plate by an instantaneous adhesive or solder , When confirming whether the optical axis of the unit and the laser beam emitted from the optical system arranged on the upstream side of the optical unit are positioned on a straight line, the reflecting jig is fixed to the fixing jig. When the optical system is adjusted so that the laser beam incident on the optical system overlaps with the reflected light reflected by the reflecting surface of the reflecting jig on the incident side, and the laser beam is guided to the optical unit, the fixed treatment is performed. The reflecting jig is removed from the tool. Axis confirmation jig is provided.

  Preferably, the support portion of the reflecting jig is formed in a spherical shape, and the fixing portion of the fixing jig supports the spherical support portion by two round bars positioned in parallel. The reflecting jig and the fixing jig are provided with marks indicating the direction and position of overlapping each other.

  If the optical axis confirmation jig of the present invention is used, the reflecting plate is fixed to the angle adjusting plate with the joining base while the reflecting surface of the reflecting plate is adjusted to be perpendicular to the optical axis of the optical unit. Since the fixing jig fixed to the housing of the optical unit is detachably mounted by magnetic force, the optical path of the laser beam incident on the optical unit can be adjusted with high accuracy after the optical unit is mounted on the apparatus. There is an effect.

It is a perspective view of an optical axis adjustment jig concerning an embodiment of the present invention. It is a disassembled perspective view of an optical axis adjustment jig. It is a back surface side perspective view of an angle adjustment board. It is a disassembled perspective view of 2nd Embodiment of an angle adjustment board and a reflecting plate. It is a perspective view of an optical unit. It is a longitudinal cross-sectional view of an optical unit. It is a perspective view at the time of angle adjustment of an optical axis confirmation jig.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Referring to FIG. 1, a perspective view of an optical axis adjusting jig according to an embodiment of the present invention is shown. FIG. 2 is an exploded perspective view of the optical axis checking jig.

  As best shown in FIG. 2, the optical axis confirmation jig 2 includes a reflection jig 4 and a fixing jig 6 to which the reflection jig 4 is detachably attached. The reflecting jig 4 includes a reflecting plate 8 having a reflecting surface 8a and an angle adjusting plate 10 for adjusting the angle of the reflecting plate 8. Preferably, the reflecting plate 8 is made of glass.

  Three protrusions 12 that are spaced apart from each other in the circumferential direction are disposed on the surface 10 a of the angle adjustment plate 10. The angle adjusting plate 10 is preferably made of metal or synthetic resin, and the protrusion 12 is preferably made of glass.

  Three through holes 14 are formed in the reflecting plate 8 at positions corresponding to the protruding portions 12 of the angle adjusting plate 10. In this embodiment, three protrusions 12 and three through holes 14 are provided, but these are not limited to three, and three or more may be provided.

  The diameter of the through hole 14 is formed larger than the outer diameter of the protrusion 12. Thereby, after the protrusion 12 of the angle adjusting plate 10 is inserted into the through hole 14 of the reflecting plate 8, the angle of the reflecting plate 8 with respect to the angle adjusting plate 10 can be adjusted.

  As shown in FIG. 3, three spherical support portions 16 are formed on the back surface 10b of the angle adjusting plate 10 so as to be spaced apart from each other at equal intervals in the circumferential direction. Preferably, the spherical support 16 is formed from a permanent magnet. Referring again to FIG. 2, a mark 18 is formed on the outer periphery of the angle adjustment plate 10.

  The fixing jig 6 has three fixing portions 20 at positions corresponding to the spherical support portions 16 of the angle adjusting plate 10. Each fixing portion 20 is formed by embedding two round bars 22 so as to contact each other. The round bar 22 is made of a ferromagnetic material such as iron. Three spherical support parts 16 and three fixing parts 20 are provided, but three or more may be provided.

  As another embodiment, the spherical support portion 16 of the angle adjustment plate 10 may be formed of a ferromagnetic material, and the round bar 22 of the fixing jig 6 may be formed of a permanent magnet. The fixing jig 6 is made of metal or synthetic resin.

  The fixing jig 6 has a center hole 24 that allows passage of the laser beam, and a mark 26 for positioning with respect to the mark 18 of the angle adjusting plate 10 is formed on the outer periphery thereof. The fixing jig 6 further has two fixing holes 27 for fixing the fixing jig 6 to the housing of the optical unit.

  Referring to FIG. 4, an exploded perspective view of the second embodiment of the reflecting jig 4A is shown. The reflecting jig 4A includes a reflecting plate 8A having a reflecting surface 8a and an angle adjusting plate 10A. The angle adjusting plate 10A of the present embodiment has a relatively large arcuate protrusion 13 on the surface 10a.

By providing the arcuate protrusion 13 as described above, the reflector 8A is mounted on the arcuate protrusion 13 of the angle adjustment plate 10A, and then the angle of the reflector 8A with respect to the angle adjustment plate 10A is adjusted. Both can be fixed with an instantaneous adhesive or solder .

  Referring to FIG. 5, a perspective view of the optical unit 30 is shown. FIG. 6 is a longitudinal sectional view of the optical unit 30. The optical unit 30 is composed of, for example, a beam expander, and includes three lens bodies 34 mounted on a base 32. Each lens body 34 includes a mounting plate 36, an annular frame 38 standing on the mounting plate 36, and a lens 40 held by the frame 38.

  In the optical unit 30, the optical axis of each lens body 34 is adjusted on the base 32, and then the mounting plate 36 of the lens body 34 is fixed to the base 32. The optical axis of each lens body 34 is adjusted using a well-known autocollimator. The optical axis adjustment is performed for each lens body 34 using an autocollimator, and the mounting plate 36 is fixed to the base 32 in a state where the optical axes of the three lens bodies 34 are finally matched.

  After the optical axis adjustment, the optical unit 30 is completed by covering the base 32 with a rectangular casing 42. An incident opening (first opening) 44 through which a laser beam is incident is formed in the front wall 42a of the housing 42, and an emission opening (outgoing opening (outgoing) of the laser beam that has passed through the optical unit 30 is formed in the rear wall 42b. A second opening 46 is formed. Reference numeral 35 denotes an optical axis of the optical unit 30.

  As shown in the sectional view of FIG. 6, the fixing jig 6 of the optical axis confirmation jig 2 of the present invention is attached to the front wall 42 a of the housing 42 so as to close the incident opening 44 of the optical unit 30. That is, when the optical system on the upstream side of the optical unit 30 is adjusted so that the optical axis of this optical system coincides with the optical axis 35 of the optical unit 30, the reflecting jig 4 is attached to the fixing jig 6 by magnetic force. The fixed optical axis checking jig 2 is attached to the front wall 42a of the housing 42 of the optical unit 30 so as to block the incident opening 44.

  Here, when the optical system arranged in the front stage of the optical unit 30 is a laser oscillator, the laser beam oscillated from the laser oscillator is directly aligned with the optical axis 35 of the optical unit 30 using the optical axis adjustment jig 2. Adjust to align on the line.

  Hereinafter, the mounting method of the optical axis confirmation jig 2 will be described. First, screws are inserted into the fixing holes 27 of the fixing jig 6 of the optical axis confirmation jig 2 to fix the fixing jig 6 to the front wall 42 a of the housing 42 of the optical unit 30.

  Next, the angle adjusting plate 10 of the reflecting jig 4 is attached to the fixing jig 6 by magnetic force in a state where the mark 18 is aligned with the mark 26 of the fixing jig 6. That is, when the mark 18 of the angle adjusting jig 10 is aligned with the mark 26 of the fixing jig 6, the spherical upper support portion 16 of the angle adjusting plate 10 corresponds to the fixing portion of the fixing jig 6. The plate 10 is attracted by a magnetic force and fixed to the fixing jig 6.

  Next, the reflecting plate 8 is attached to the angle adjusting plate 10 so that the protruding portion 12 of the angle adjusting plate 10 is inserted into the through hole 14 of the reflecting plate 8. Then, as shown in FIG. 7, the reflection plate 8 is held by a hand 54 attached to the tip of the arm 52 of the angle adjustment unit 50.

  In this state, the reference light emitted from the light source of the autocollimator passes through the center of the cross line of the illumination-side focusing plate, and the optical path is bent at a right angle by the half mirror. The reference light passes through the objective lens and becomes a parallel light beam (collimated beam) and is reflected by the reflecting surface 8a of the optical axis adjusting jig 2. The reflected light again passes through the objective lens and the half mirror, and forms an image on the incision-side focusing plate.

  Therefore, the angle adjustment unit 50 adjusts the angle of the reflecting plate 8 so that the reflected light reflected by the reflecting surface 8a forms an image at the center of the cross line on the eyepiece-side focusing plate. In this state, the reflecting surface 8 a of the reflecting plate 8 is in a state of being accurately perpendicular to the optical axis 35 of the optical unit 30.

  Therefore, the instantaneous adhesive or solder is filled in the through hole 14, and the protruding portion 12 of the angle adjusting plate 10 is fixed in the through hole 24. In this state, the reflection surface 8 a of the optical axis confirmation jig 2 is exactly perpendicular to the optical axis 35 of the optical unit 30.

  After adjusting the angle of the reflecting plate 8, when the reflecting plate 8 and the angle adjusting plate 10 are fixed with an instantaneous adhesive or solder, the optical axis 35 of the optical unit 30 on the reflecting surface 8 a even if a subsequent environmental change occurs, such as a temperature change. The perpendicularity to is accurately maintained.

  Whether or not the optical axis 35 of the optical unit 30 and the laser beam emitted from the optical system arranged on the upstream side of the optical unit 30 are positioned on a straight line after the optical unit 30 is mounted at a predetermined position of the laser processing machine Is confirmed, the reflecting jig 4 is fixed to the fixing jig 6 by a magnetic force.

  Then, the reference light is emitted from the light source of the autocollimator and incident on the optical system, and the reflected light reflected by the reflecting surface 8a of the reflecting plate 8 is connected to the center of the cross line on the eyepiece side focusing plate of the autocollimator. Adjust the optical system to image. When the optical system is adjusted and fixed in this way, the optical path of the laser beam emitted from the optical system is exactly coincident with the optical axis 35 of the optical unit 30.

  When the optical system is a laser oscillator, the laser beam oscillated from the laser oscillator is aligned with the optical axis 35 of the optical unit 30, and the power of the laser beam oscillated from the laser oscillator is used as the maximum source. It can be used for laser processing.

  When the laser beam oscillated from the laser oscillator is guided to the optical unit 30 after the adjustment of the optical system is completed, the reflecting jig 4 is removed from the fixing jig 6 as shown in FIG. Since the fixing jig 6 has the center hole 24 that allows the laser beam to pass therethrough, the fixing jig 6 is kept fixed to the housing 42. Then, when adjustment of the optical system arranged in the front stage of the optical unit 30 is necessary, the reflecting jig 4 in which the reflecting plate 8 and the angle adjusting plate 10 are integrated is mounted on the fixing jig 6 each time.

2 Optical axis checking jig 4 Reflecting jig 6 Fixing jig 8 Reflecting plate 8a Reflecting surface 10 Angle adjusting plate 12 Protruding part 14 Through hole 16 Spherical support parts 18, 26 Marking 20 Fixing part 22 Round bar 27 Fixing hole 30 Optical Unit 32 Base 34 Lens body 35 Optical axis 42 Housing 42a Front wall 44 Incident opening (first opening)
46 Output opening (second opening)
50 Angle adjustment unit 52 Arm 54 Hand

Claims (2)

An optical axis confirmation jig for confirming whether or not the optical axis of the optical unit and the laser beam incident on the optical unit are positioned on a straight line,
The optical unit includes a housing having a first opening through which a laser beam is incident and a second opening through which the laser beam is emitted, and a lens body that has been adjusted in the optical axis and is accommodated in the housing. Configured,
The optical axis checking jig includes a reflecting jig having a reflecting surface that reflects a laser beam, a fixing jig that is disposed in the first opening of the housing and detachably supports the reflecting jig, Including
The reflecting jig includes a reflecting plate having the reflecting surface, and an angle adjusting plate having at least three support portions and capable of fixing the reflecting plate at a predetermined angle.
The fixing jig has a number of fixing portions corresponding to the number of the supporting portions for fixing the supporting portions,
One of the support part and the fixed part is made of a permanent magnet and the other is made of a ferromagnetic material,
With the angle adjusting plate fixed to the fixing jig disposed in the first opening of the casing, the reflection is made perpendicular to the optical axis of the lens body constituting the optical unit. After adjusting the reflection surface of the plate, the reflection plate is fixed to the angle adjustment plate with an instantaneous adhesive or solder ,
When confirming whether the optical axis of the optical unit and the laser beam emitted from the optical system arranged on the upstream side of the optical unit are positioned on a straight line, the reflecting jig is used as the fixing jig. Adjust the optical system so that the laser beam fixed and incident on the optical system overlaps with the reflected light reflected by the reflecting surface of the reflecting jig on the incident side,
An optical axis checking jig, wherein when the laser beam is guided to the optical unit, the reflecting jig is removed from the fixing jig.   The support portion of the reflecting jig is formed in a spherical shape, and the fixing portion of the fixing jig is configured to support the spherical support portion by two round bars positioned in parallel. The optical axis checking jig according to claim 1, wherein the reflecting jig and the fixing jig are provided with marks indicating a direction and a position of overlapping each other.

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