JP2013200487A - Galvano scanner and laser processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a galvano scanner having no variation in thermal conductivity and stably exhibiting a high cooling performance.SOLUTION: A galvano scanner 100 comprises: a movable element 200 including a revolving shaft 3 supporting a galvanomirror 1, and a permanent magnet 10 disposed about the revolving shaft 3; a stator 300 including a coil 15, a yoke 16 and a housing case 17 which are disposed about the movable element 200; and a water-cooling jacket 22 cooling the stator 300. The galvano scanner 100 swings the movable element 200 at a predetermined angle range, and is provided with a highly heat conductive member, for example, heat conductive meshes 20 and 21, in at least one of a portion between the coil 15 and the yoke 16 and a portion between the housing case 17 and the water-cooling jacket 22.

Description

  The present invention relates to a galvano scanner and a laser processing apparatus, and more particularly, a galvano scanner that scans a laser beam with respect to a workpiece, and a laser that performs drilling, cutting, or marking using laser light that is scanned and deflected by the galvano scanner. It relates to a processing apparatus.

Along with the downsizing and high-density mounting of electronic devices, printed circuit boards are mainly multilayer wiring boards in which a plurality of wiring patterns are stacked. In a multilayer wiring board, it is necessary to electrically connect conductive layers between substrates stacked one above the other. Therefore, a via hole (hole) reaching the lower conductive layer is formed in the insulating layer of the multilayer wiring board, and conductive plating is applied to the inside of the via hole, thereby electrically connecting the conductive layers between the substrates stacked one above the other. Connected. In the manufacture of via holes, in addition to conventional mechanical drilling devices, laser processing devices using high-power CO ₂ lasers or UV lasers using YAG harmonics are used in conjunction with miniaturization. (For example, patent document 1).

  On the other hand, the demand for portable information terminals represented by mobile phones is increasing year by year, and the demand for printed circuit boards, which are key parts of portable information terminals, is also increasing. For this reason, a laser processing machine for drilling printed circuit boards is also required to improve productivity, and a galvano scanner that positions a laser beam at a hole processing position is required to operate at high speed.

  At this time, in order to obtain acceleration / deceleration torque, it is necessary to flow a large current through the coil. When a large current is flowed, the coil generates heat due to the resistance of the coil itself. In addition, when the flowing current has a high frequency component, the magnet and the yoke generate heat due to the eddy current. When the internal temperature of the carbano scanner increases due to heat generation, demagnetization occurs in the magnet, and the response of the servo mechanism deteriorates due to a decrease in drive torque or a decrease in torsional rigidity of the rotating shaft. Therefore, special consideration must be given to cooling in the electromagnetic actuator type galvano scanner.

  On the other hand, as a cooling structure of a rotary motor that repeats a severe swinging motion like a galvano scanner, for example, a cooling structure provided with a heat transfer bypass means that contacts a cooling jacket, a case, and a coil has been proposed (Patent Literature). 2).

Japanese Patent Laid-Open No. 2002-137074 (see page 6, FIG. 6) Japanese Patent Laying-Open No. 2008-43133 (see page 9, FIG. 1)

  By the way, in recent years, the hole diameter has been reduced and the number of holes has been increased by increasing the density of printed circuit boards. In order to reduce the diameter of the hole, it is necessary to increase the diameter of the beam incident on the fθ lens. Therefore, an increase in the size of the galvanometer mirror is inevitable. However, when the size of the galvanometer mirror is increased, the moment of inertia applied to the oscillating motor increases, so that it is necessary to supply a larger driving current to the coil, and the amount of heat generated by the coil further increases accordingly. Therefore, in order to realize a high-speed positioning operation with the swing motor, it is indispensable to cool the generated coil efficiently.

  In order to cool the heat generated by the coil, in the invention described in Patent Document 2, as shown in FIG. 1, a heat transfer bypass means that contacts the cooling jacket, the case, and the coil is newly provided in the swing actuator. Improves sex. Further, a gap material such as an adhesive, grease, or a heat conductive sheet is interposed on the bonding surface between the cooling jacket, the case, and the constituent members of the coil to suppress the contact thermal resistance.

  However, the gap material has an extremely low thermal conductivity compared to the case where the other constituent members are metal materials. For this reason, the thickness of the gap material is designed to be as thin as possible. However, if the processing accuracy is strict, it takes time to process and assemble the parts, and the cost becomes high. In addition, due to variations in gap layer thickness due to processing errors and uneven application of adhesive or grease, the thermal conductivity varies throughout the galvano scanner, and individual differences among galvano scanners have increased.

  Therefore, a problem to be solved by the present invention is to stably exhibit high cooling performance without variation in thermal conductivity.

  In order to solve the above-described problems, the present invention provides a movable element including a rotating shaft that supports a galvanometer mirror, and a permanent magnet disposed around the rotating shaft, and a coil and a yoke disposed around the movable element. And a stator provided with a housing case, and a cooling means for cooling the stator, and a galvano scanner for swinging the mover within a predetermined angular range, between the coil and the yoke, and A high heat transfer member is disposed in at least one of the housing case and the cooling means.

  According to the present invention, there is no variation in thermal conductivity, and stable high cooling performance can be exhibited.

It is a longitudinal section showing the composition of the galvano scanner concerning an embodiment of the present invention. The magnetic circuit portion is shown in the AA line cross-sectional view of the galvano scanner shown in FIG. It is a figure which shows the structure of the coil in FIG. It is a figure which shows the structure of the 1st heat conductive mesh in FIG. It is explanatory drawing which shows the adhesion method of the 1st heat conductive mesh. It is a figure explaining the effect of the 1st heat conductive mesh. It is a perspective view which shows the structure of the 2nd heat conductive mesh in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a longitudinal sectional view of a galvano scanner according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line AA of FIG.

  In FIG. 1, a galvano scanner 100 according to this embodiment includes a mover 200 and a stator 300. The mover 200 includes the galvanometer mirror 1, the rotating shaft 3, and the permanent magnet 10, and the stator 300 includes the coil 15, the yoke 16, the housing case 17, the first thermal conductive mesh 20, and the second thermal conductivity. A mesh 21 is included. A water cooling jacket 22 is provided on the outer periphery of the fixed 300, and an inlet pipe 24 and an outlet pipe 25 are connected to the water cooling jacket 22.

  The galvanometer mirror 1 is fixed to one end of the rotating shaft 3 via a mirror mount 2. The rotating shaft 3 is supported by the first and second bearings 4 and 5 and performs a smooth swinging motion within a predetermined range. The first bearing 4 is held in the first bearing case 6 by the first screw ring 8, and the second bearing 5 is held in the second bearing case 7 by the second screw ring 9. A cylindrical permanent magnet 10 having an inner diameter slightly larger (about several μm) than the outer diameter of the rotating shaft 3 is attached to the rotating shaft 3. The permanent magnet 10 is fixed to a predetermined position in the axial direction of the rotary shaft 3 coaxially with the rotary shaft 3 by an adhesive, and thereby swings integrally with the rotary shaft 3 and the galvanometer mirror 1.

  A scale 12 having a grating (not shown) is fixed to the other end of the rotating shaft 3 via a hub 11. A sensor head 13 is fixed to the bearing case 7 at a position facing the grating of the scale 12 via a sensor support 14. The scale 12 and the sensor head 13 form a rotary encoder for controlling the angle of the galvanometer mirror 1 and are protected by a cover 19 attached to the bearing case 7 for dust-proof measures.

  A coil 15 and a yoke 16 are arranged coaxially with the rotary shaft 3 at a position facing the permanent magnet 10. The yoke 16 is formed by laminating iron-based thin plates having high magnetic permeability and low magnetism in the axial direction of the rotary shaft 3 in order to suppress eddy current, and the outer diameter is slightly smaller (several μm) than the inner diameter of the housing case 17. is there. The yoke 16 is held on the housing case 17 by a yoke pressing ring 18. The coil 15 is bonded and fixed to the yoke 16 via the first heat conductive mesh 20.

  A water cooling jacket 22 is detachably disposed on the outer periphery of the housing case 17 via a second heat conductive mesh 21. As shown in FIG. 2, the water cooling jacket 22 is composed of symmetrical first and second water cooling jackets 22 a and 22 b and a hinge 23 that are divided into two in plan view. The first and second water cooling jackets 22a and 22b are in close contact with the housing case 17 via the second heat conductive mesh 21 when the hinge 23 is closed. Flow paths 22c and 22d indicated by broken lines are formed in the water cooling jacket 22, and cooling water is supplied from the cooling water supply means (not shown) to the first and second water cooling jackets 22a and 22b via the inlet pipe 24, respectively. Supplied. The cooling water enters the first and second water cooling jackets 22a and 22b, exchanges heat while flowing through the flow paths 22c and 22d, and is discharged from the outlet pipe 25.

  The bearing case 6, the bearing case 7, the housing case 17, the yoke pressing ring 18, and the water cooling jacket 22 are made of a material having high thermal conductivity such as aluminum or copper.

  As shown in FIG. 2, the permanent magnet 10 is a combination of 4-pole magnet pieces having a central angle of 90 degrees, and each magnet piece is magnetized in the radial direction. Magnetic fluxes 101, 102, 103, 104 emitted from the N pole of the permanent magnet 10 intersect with the coil 15, return to the S pole through the yoke 16, and draw a closed loop.

  3A and 3B are views showing a coil shape as a material. FIG. 3A is a front view, and FIG. 3B is a cross-sectional view taken along line BB in FIG. As shown in FIG. 3, the coil 15 as a material is obtained by winding a wire such as copper in a flat rectangular frame shape. The coil 15 as such a material is bent into an arc shape in accordance with the inner diameter of the yoke 16, the four are electrically connected, and the effective length C is parallel to the rotary shaft 3, so that the inner circumference of the yoke 16 is increased. The surface is bonded and fixed with an adhesive via the first thermally conductive mesh 20. Since the magnetic fluxes 101, 102, 103, 104 and the current flowing through the effective length C of the coil 15 are orthogonal, a tangential electromagnetic force acts on the permanent magnet 10 when a current flows through the coil 15. The rotating shaft 3 is rotated by this electromagnetic force, and the galvanometer mirror 1 is also rotated integrally.

  FIG. 4 is a diagram showing a configuration of the first heat conductive mesh 20. As shown in the perspective view of FIG. 4A, the developed front view of FIG. 4B, and the plan view of FIG. 4C, the first thermal conductive mesh 20 has an inner peripheral length of the housing case 17. It is a sheet shape having an outer dimension matching L1 and height H1 and having a thickness d of about several tens of μm. The material is graphite, copper, aluminum, or stainless steel. In particular, an extended metal produced by rolling a metal mesh is uniform in thickness and can be obtained at low cost.

  The adhesive 26 is thinly applied to both surfaces of the first heat conductive mesh 20. In this state, the yoke 16 is inserted into the housing case 17 mounted on the inner peripheral surface, and thereafter, between the coil 15 and the yoke 16 using a taper pressing jig 27 and a spun ring 28 as shown in FIG. The coil 15 is pressed against the housing case 17 from the inside in a state where the first heat conductive mesh 20 is disposed. As a result, as shown in FIG. 6, excess adhesive 26 on the surface of the first thermal conductive mesh 20 enters the mesh of the first thermal conductive mesh 20. Therefore, the distance between the effective length C portion of the coil 15 and the yoke 16 and the distance between the end portion D of the coil 15 and the housing case 17 and the yoke pressing ring 18 are not limited to the thickness d of the first heat conductive mesh 20. Moreover, since the excess adhesive 26 stays in the mesh, leakage of the adhesive can be suppressed. In this state, holding for a predetermined time until the adhesive 26 is cured. After the adhesive 26 is cured, the taper pressing jig 27 and the spun ring 28 are removed to complete the stator.

  The thermal conductivity of a general adhesive is about 4 W / m · k even with a filler, whereas copper is 398 W / m · k. For example, even if the area ratio between the copper portion and the mesh portion of the first thermal conductive mesh 20 is 1: 1 and the mesh portion is all air, the thermal conductivity is 199 W / m · k, which is an efficient coil. The heat generated at 15 can be transferred to the yoke 16 and the housing case 17.

  Next, the 2nd heat conductive mesh 21 is demonstrated.

  As shown in FIG. 7, the second thermal conductive mesh 21 has an external dimension that matches the inner peripheral length L2 and the height H2 of the water cooling jacket 21, and the thickness and material are the same as those of the first thermal conductive mesh 20. It is. Grease (not shown) is thinly applied to both surfaces of the second heat conductive mesh 21. In this state, after being inserted into the inner periphery of the first and second water-cooling jackets 22a and 22b, the housing case 17 is attached to the center of the outer periphery. When the hinges 23 of the first and second water-cooling jackets 22 a and 22 b are closed, the water-cooling jacket 22 is in close contact with the outer peripheral surface of the housing case 17 via the second heat conductive mesh 21. As a result, like the first thermal conductive mesh 20 shown in FIG. 6, excess grease on the surface of the second thermal conductive mesh 21 enters the mesh of the second thermal conductive mesh 21, and the water cooling jacket 22. Is in close contact with the housing case 17 via the second thermally conductive mesh 21. As a result, the heat generated in the coil 15 can be efficiently transmitted to the water cooling jacket 22, and the water cooling jacket 22 can efficiently cool.

As described above, according to the present embodiment,
1) Since the first heat conductive mesh 20 is disposed between the coil 15 and the yoke 16 and is bonded and fixed as close as possible to the thickness d of the first heat conductive mesh 20, heat conduction The rate can be greatly improved compared to the case where the adhesive is bonded and fixed only with an adhesive.
2) As a result, the heat transfer efficiency from the coil 15 to the yoke 16 side is greatly improved, and the coil 15 can be efficiently cooled.
3) Since the water cooling jacket 22 is in close contact with the housing case 17 via the second heat conductive mesh 21, it is possible to efficiently transmit the heat generated in the coil 15 to the water cooling jacket 22. can do.
4) Since the temperature rise of the coil 15 can be stably suppressed, the temperature rise of the permanent magnet 10 can be suppressed as a result. As a result, a galvano scanner capable of high-speed positioning can be provided.
5) Since the galvano scanner 100 can efficiently cool the heat generated in the coil 15, for example, a processing apparatus that requires a severe operation that repeats positioning continuously at high speed, such as a drilling laser processing apparatus for a printed circuit board. Can be used for
There are effects such as.

  In this embodiment, the galvanometer mirror in the claims is denoted by reference numeral 1, the rotational axis is denoted by reference numeral 3, the permanent magnet is denoted by reference numeral 10, the mover is denoted by reference numeral 200, the coil is denoted by reference numeral 15, and the yoke is denoted by reference numeral 16. The housing case is denoted by reference numeral 17, the stator is denoted by reference numeral 300, the high heat transfer member is denoted by the first and second heat conductive meshes 20 and 21, the galvano scanner is denoted by reference numeral 100, and the adhesive is denoted by reference numeral 26. The means correspond to the water cooling jacket 22 respectively.

  Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention, and all the technical matters included in the technical idea described in the claims are all included. The subject of the present invention. Although the above-described embodiments and preferred examples are shown, those skilled in the art can realize various alternatives, modifications, variations, and improvements from the contents disclosed in this specification, These are included in the technical scope described in the appended claims.

DESCRIPTION OF SYMBOLS 1 Galvano mirror 3 Rotating shaft 10 Permanent magnet 15 Coil 16 Yoke 17 Housing 20 1st heat conductive mesh 21 2nd heat conductive mesh 22 Water cooling jacket 26 Adhesive 100 Galvano scanner 200 Movable element 300 Stator

Claims (7)

A rotating shaft that supports the galvanometer mirror, and a mover that includes a permanent magnet disposed around the rotating shaft;
A stator including a coil, a yoke, and a housing case disposed around the mover;
Cooling means for cooling the stator;
In a galvano scanner that swings the movable element within a predetermined angle range,
A galvano scanner comprising a high heat transfer member disposed between at least one of the coil and the yoke and between the housing case and the cooling means. The galvano scanner according to claim 1,
The galvano scanner, wherein the high heat transfer member is a heat conductive mesh member. The galvano scanner according to claim 2,
The galvano scanner, wherein the heat conductive mesh member is made of expanded metal. The galvano scanner according to any one of claims 1 to 3,
The galvano scanner, wherein the high heat transfer member is graphite or any one metal of copper, aluminum, and stainless steel. The galvano scanner according to claim 1,
The high heat transfer member is a heat conductive mesh member,
Applying an adhesive on both sides of the mesh member, mounting between the coil and the yoke to apply a surface pressure from the coil side, and retain the adhesive remaining in the mesh of the mesh member A galvano scanner, wherein the coil and the yoke are bonded in a state of being in contact with the mesh member. The galvano scanner according to claim 1,
The high heat transfer member is a heat conductive mesh member,
Grease is applied to both surfaces of the mesh member, and is applied between the housing case and the cooling means to apply pressure from the cooling means side, so that excess grease remains in the mesh member mesh. And holding the housing case and the cooling means in contact with the mesh member.   A laser processing apparatus comprising the galvano scanner according to claim 1.

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