SEMICONDUCTOR LASER DEVICE
20230033309 ยท 2023-02-02
Inventors
Cpc classification
H01S5/02469
ELECTRICITY
H01S5/02326
ELECTRICITY
H01S5/026
ELECTRICITY
H01S5/02257
ELECTRICITY
International classification
Abstract
Provided is a semiconductor laser device enabling efficient emission of a laser beam without damaging a light emitting surface of a light emitting element. Semiconductor laser device includes light emitting element, optical element, first heat radiation part, and second heat radiation part. Laser beam emitted from light emitting element enters optical element. First heat radiation part is connected to light emitting element. Second heat radiation part is connected to light emitting element. First heat radiation part includes first recess. Second heat radiation part includes second recess. One end of optical element is fitted into first recess, and the other end of optical element is fitted into second recess.
Claims
1. A semiconductor laser device comprising: a light emitting element that emits a laser beam; an optical element on which the laser beam emitted from the light emitting element is incident; a first heat radiation part connected to the light emitting element; and a second heat radiation part connected to the light emitting element, wherein the first heat radiation part includes a first recess, and the second heat radiation part includes a second recess, and one end of the optical element is fitted into the first recess, and another end of the optical element is fitted into the second recess.
2. The semiconductor laser device according to claim 1, wherein the second heat radiation part is combined with the first heat radiation part to form a housing space for the light emitting element and the optical element.
3. The semiconductor laser device according to claim 1, wherein the optical element is a plate-formed member having a lens for narrowing an angle of radiation of the laser beam.
4. The semiconductor laser device according to claim 1, wherein the optical element is sandwiched and fixed between the first recess and the second recess by combining the first heat radiation part and the second heat radiation part.
5. The semiconductor laser device according to claim 1, wherein a buffer material is interposed at least one of between the optical element and the first recess and between the optical element and the second recess.
6. The semiconductor laser device according to claim 1, wherein the first heat radiation part and the second heat radiation part are combined to form a box, the box includes an opening for allowing the laser beam having transmitted through the optical element to pass therethrough, and further includes a cover that closes the opening, and the cover includes a window member that transmits the laser beam having passed through the opening.
7. The semiconductor laser device according to claim 1, wherein the light emitting element includes a plurality of light emitting parts, and the optical element includes a plurality of the lenses on which laser beams emitted from the plurality of light emitting parts are incident.
8. The semiconductor laser device according to claim 1, wherein the first heat radiation part and the second heat radiation part are made of a conductive metal material, and are electrically connected to the light emitting element by a first fixing part and a second fixing part, respectively, and the first heat radiation part and the second heat radiation part are combined with each other via an electrical insulating part.
9. The semiconductor laser device according to claim 8, wherein the electrical insulating part includes an insulating layer and heat-melting layers on upper and lower surfaces of the insulating layer, and the first heat radiation part and the second heat radiation part are combined with each other via the electrical insulating part by melting of the heat-melting layers by heating.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DESCRIPTION OF EMBODIMENTS
[0031] In the following, exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. For the sake of convenience, an
[0032] X-axis, a Y-axis, and a Z-axis perpendicular to each other are added to the drawings. An X-axis positive direction is an emission direction of a laser beam in the semiconductor laser device, and a Y-axis positive direction is a height direction of the semiconductor laser device.
First Exemplary Embodiment
[0033]
[0034] As illustrated in
[0035] First heat radiation part 10 and second heat radiation part 20 are connected by electrical insulating part 30. Electrical insulating part 30 has a closed annular shape. Electrical insulating part 30 has a shape along outer peripheries of first heat radiation part 10 and second heat radiation part 20. Electrical insulating part 30 includes annular insulating layer 33 having a predetermined thickness, heat-melting layer 31, and heat-melting layer 32. Heat-melting layer 31 is arranged on a lower surface of insulating layer 33, and heat-melting layer 32 is arranged on an upper surface of insulating layer 33. Heat-melting layer 31 and heat-melting layer 32 are made of a material that is melted by heating and solidified by cooling. Insulating layer 33 is made of a non-conductive material. Heat-melting layer 31, heat-melting layer 32, and insulating layer 33 are all made of a material having high thermal conductivity. Heat-melting layer 31 and heat-melting layer 32 are made of, for example, AuSn. Insulating layer 33 is made of, for example, AlN.
[0036] Electrical insulating part 30 transfers heat of second heat radiation part 20 to first heat radiation part 10 while maintaining second heat radiation part 20 in an electrically non-contact state with first heat radiation part 10. The heat transferred to first heat radiation part 10 is radiated to the water-cooling block (not illustrated) as described above.
[0037] First heat radiation part 10 has a rectangular parallelepiped shape. On the other hand, second heat radiation part 20 has a shape in which recess 22 having a rectangular outline is formed on a lower surface of the rectangular parallelepiped. Rectangular opening 21 communicating with recess 22 is formed on a front surface (a surface on the X-axis positive side) of second heat radiation part 20. Rectangular window member 40 is disposed in opening 21. Window member 40 is made of a material that absorbs less laser beam L1 emitted from light emitting element 50. For example, in a case where laser beam L1 is a laser beam in a blue wavelength band, window member 40 is made of a glass material.
[0038] An external size of semiconductor laser device 1 is, for example, 3 cm in width in the Z-axis direction, 3 cm in depth in an X-axis negative direction, and 2 cm in height in the Y-axis positive direction. In the present exemplary embodiment, semiconductor laser device 1 emits three laser beams L1 via window member 40.
[0039] As illustrated in
[0040] Light emitting element 50 is connected to first heat radiation part 10 via submount 51. In addition, light emitting element 50 is connected to second heat radiation part 20 via stress relieving layer 52. Submount 51 is made of a conductive material having high thermal conductivity such as CuW. An AuSn layer (not illustrated) is formed at each of an interface between first heat radiation part 10 and submount 51 and an interface between submount 51 and light emitting element 50. Specifically, first heat radiation part 10 and submount 51 are fixed to each other by the AuSn layer and are thermally and electrically connected to each other. In addition, submount 51 and light emitting element 50 are fixed to each other by the AuSn layer and are thermally and electrically connected to each other. Stress relieving layer 52 includes a metal sheet and a gold bump mainly made of gold. Stress relieving layer 52 has a function of conducting electricity and heat and at the same time relieving stress.
[0041] Window member 40 is fixed to opening 21 of second heat radiation part 20 by low-melting-point glass 41. Low-melting-point glass 41 is provided from the inside of second heat radiation part 20 over an entire circumference of a joint between window member 40 and opening 21. Thus, a gap of the joint between window member 40 and opening 21 is filled with low-melting-point glass 41. An internal space of semiconductor laser device 1 is made airtight by heat-melting layer 31, heat-melting layer 32, and low-melting-point glass 41. As a result, siloxane or the like does not enter from the outside, so that light emitting element 50 can stably operate over a long period of time.
[0042] Furthermore, optical element 60 is housed inside semiconductor laser device 1. Optical element 60 is a rectangular plate-like member as viewed in the X-axis direction. Optical element 60 has three lenses 60a at positions corresponding to the three emitters (light emitting parts El) of light emitting element 50. Each lens 60a is formed in a convex shape on front and back surfaces of optical element 60. Each lens 60a narrows an angle of radiation of laser beam Ll emitted from each light emitting part El of light emitting element 50. For example, each lens 60a collimates laser beam Ll emitted from each light emitting part El of light emitting element 50.
[0043] Optical element 60 is disposed inside semiconductor laser device 1 by being sandwiched between first recess 11 formed on an upper surface of first heat radiation part 10 and second recess 23 formed on the lower surface of second heat radiation part 20. Each of first recess 11 and second heat radiation part 20 has a groove shape with constant width and depth.
[0044] Here, first recess 11 is formed on the upper surface of first heat radiation part 10 and second recess 23 is formed on the lower surface of second heat radiation part 20 such that gaps between first recess 11 and optical element 60 and between second recess 23 and optical element 60 are substantially eliminated. In this manner, in the disposition state shown in
[0045] Note that in a case where very highly accurate optical adjustment is required, semiconductor laser device 1 is assembled while the position of optical element 60 is adjusted in a state where laser beam L1 is emitted (so-called active alignment). This assembling method will be described later with reference to
[0046] First heat radiation part 10 and second heat radiation part 20 serve also as an electrode of light emitting element 50. Specifically, electric power for light emission is supplied to light emitting element 50 via first heat radiation part 10 and second heat radiation part 20.
[0047] Next, assembly processes of semiconductor laser device 1 will be described with reference to
[0048] First, as illustrated in
[0049] Next, as shown in
[0050] Here, in a case where the active alignment is required for optical element 60, adjustment illustrated in
[0051] Specifically, as illustrated in
[0052] Thus, when optical element 60 is positioned at an optimum position, the operator may temporarily fix optical element 60 with a very small amount of ultraviolet curing adhesive 61 in order to temporarily fix optical element 60. In this manner, the active alignment is completed.
[0053] Next, as illustrated in
[0054] Next, as illustrated in
[0055] In this state, heat-melting layer 31 and heat-melting layer 32 of electrical insulating part 30 are heated and melted to be brought into close contact with first heat radiation part 10 and second heat radiation part 20. Thereafter, heat-melting layer 31 and heat-melting layer 32 are cooled and solidified. As a result, first heat radiation part 10 and second heat radiation part 20 are combined via electrical insulating part 30, and the inside of semiconductor laser device 1 is airtightly sealed up. At this time, optical element 60 is sandwiched upon receiving the pressure in the Y-axis direction from first recess 11 and second recess 23, and is fixed inside semiconductor laser device 1. Thus, the assembly of semiconductor laser device 1 is completed.
Effects of Semiconductor Laser Device 1 According to First Exemplary Embodiment
[0056] Semiconductor laser device 1 according to the first exemplary embodiment has the following effects.
[0057] Laser beam L1 emitted from light emitting element 50 is adjusted by optical element 60. As a result, laser beam L1 can be efficiently emitted to the outside. In addition, a spatial position of optical element 60 is restricted by first recess 11 and second recess 23. Therefore, for example, even if optical element 60 is moved during position adjustment of optical element 60, optical element 60 does not accidentally come into contact with a light emitting surface of light emitting element 50. It is therefore possible to prevent optical element 60 from coming into contact with the light emitting surface of light emitting element 50 and damaging the light emitting surface during the position adjustment of optical element 60.
[0058] As illustrated in
[0059] As illustrated in
[0060] As illustrated in
[0061] As illustrated in
[0062] As shown in
[0063] As shown in
FIRST MODIFIED EXAMPLE
[0064]
[0065] In the first modified example, buffer material 62 is provided between optical element 60 and first recess 11, and buffer material 63 is provided between optical element 60 and second recess 23. Buffer material 62 and buffer material 63 are desirably, for example, rubber or aluminum foils not containing siloxane.
[0066] In a case where buffer material 62 and buffer material 63 are provided in this manner, an extremely strong pressure is not applied to optical element 60 when first heat radiation part 10 and second heat radiation part 20 are combined. This makes it possible to prevent optical element 60 from being damaged by the pressure from first recess 11 and second recess 23.
[0067] Although in the configuration of
SECOND MODIFIED EXAMPLE
[0068]
[0069] In the second modified example, recess 13 and opening 12 (an opening corresponding to opening 21 of the first exemplary embodiment) are provided in first heat radiation part 10, and second heat radiation part 20 has a rectangular parallelepiped shape. The other parts of the configuration are the same as those of the first exemplary embodiment. The present modification may achieve the same effects as those of the first exemplary embodiment described above.
[0070] Also in the configuration of
Second Exemplary Embodiment
[0071]
[0072] In the second exemplary embodiment, as compared with the first exemplary embodiment, cover 70 is added, and window member 80 is disposed in cover 70. No window member is disposed in opening 21 formed in second heat radiation part 20, the opening being a space through which laser beam L1 can pass. Window member 80 is fitted into rectangular opening 71 formed in cover 70, and is fixed to cover 70 from the inside by low-melting-point glass 81. Low-melting-point glass 81 is provided at a joint between opening 71 and window member 80 over an entire periphery of the joint. Cover 70 is made of, for example, copper.
[0073] Cover 70 is attached to a front surface of second heat radiation part 20 via heat-melting layer 90 made of AnSn or the like. After being collimated by optical element 60, laser beam L1 emitted from light emitting element 50 passes through opening 21 and window member 80, and is then output to the outside.
[0074] In the first exemplary embodiment, when the active alignment shown in
[0075] Assembly processes of semiconductor laser device 1 according to the second exemplary embodiment will be described with reference to
[0076] Processes up to disposition of electrical insulating part 30 on the upper surface of first heat radiation part 10 are similar to those in the first exemplary embodiment. After electrical insulating part 30 is disposed on the upper surface of first heat radiation part 10, as illustrated in
[0077] In the case of performing the active alignment, as illustrated in
[0078] The operator holds optical element 60 with holding rod (e.g., a vacuum chuck) 100 through opening 21. Next, the operator moves optical element 60 via holding rod 100 so as to optimize the distribution, the intensity, and the like of laser beam L1 while monitoring the emission state of laser beam L1 with the monitor device. At this time, since optical element 60 is in first recess 11 and second recess 23 (see
[0079] In this manner, when the alignment of optical element 60 is completed, while applying heat to electrical insulating part 30, the operator brings first heat radiation part 10 and second heat radiation part 20 into close contact with electrical insulating part 30 under pressure to attach second heat radiation part 20 to first heat radiation part 10. As a result, optical element 60 is sandwiched between first recess 11 and second recess 23 and fixed inside first heat radiation part 10 and second heat radiation part 20.
[0080] Thereafter, as illustrated in
[0081] Since opening 21 is closed by cover 70, the inside of semiconductor laser device 1 is airtightly sealed. Therefore, intrusion of siloxane from the outside is suppressed.
[0082] Also in the second exemplary embodiment, the configurations of the first modified example shown in
Effects of Semiconductor Laser Device 1 According to Second Exemplary Embodiment
[0083] In semiconductor laser device 1 according to the second exemplary embodiment, the same effects as those of the first exemplary embodiment can be obtained.
[0084] According to the second exemplary embodiment, as shown in
OTHER MODIFIED EXAMPLES
[0085] Although the exemplary embodiments of the present disclosure have been described in the foregoing, the present disclosure is not limited to the above exemplary embodiments, and various other modifications can be made.
[0086] For example, although in the first exemplary embodiment and the second exemplary embodiment, three light emitting parts E1 are provided in light emitting element 50, the number of light emitting parts E1 is not limited thereto. In addition, light emitting parts E1 may not necessarily be arranged in the Z-axis direction, and may be arranged in a matrix, for example. The arrangement of lenses 60a only needs to be changed according to the arrangement of light emitting parts E1.
[0087] In the first exemplary embodiment and the second exemplary embodiment, opening 21 through which laser beam L1 passes is formed in second heat radiation part 20, and in the second modified example, opening 12 through which laser beam L1 passes is formed in first heat radiation part 10. However, the form of the opening is not limited to this, and the opening may be formed in the box formed by combining first heat radiation part 10 and second heat radiation part 20. For example, a notch may be formed in each of first heat radiation part 10 and second heat radiation part 20, and first heat radiation part 10 and second heat radiation part 20 may be combined to combine the notches, thereby forming an opening.
[0088] In the first exemplary embodiment and the second exemplary embodiment, first recess 11 and second recess 23 each have a groove shape with constant width and depth. However, as long as the movement of optical element 60 can be restricted so as not to come in contact with the light emitting surface of light emitting element 50, first recess 11 and second recess 23 may have other shapes. For example, an inclined surface that increases a width of second recess 23 toward the lower surface of second heat radiation part 20 may be formed at an inlet of second recess 23. This enables optical element 60 to be smoothly fitted into second recess 23 at the time of combining second heat radiation part 20 with first heat radiation part 10. A similar inclined surface may be formed also in first recess 11.
[0089] Although in the first exemplary embodiment and the second exemplary embodiment, electric power is supplied to light emitting element 50 via stress relieving layer 52, second heat radiation part 20 and the upper surface of light emitting element 50 may be connected by wiring to supply electric power to light emitting element 50. It is noted that in this case, since it is necessary to separately provide wiring, the configuration becomes complicated, and assembly work becomes troublesome. In contrast, according to the configurations of the first exemplary embodiment and the second exemplary embodiment, since electric power is supplied to light emitting element 50 via stress relieving layer 52, it is possible to simplify the configuration and facilitate the assembly work.
[0090] Note that semiconductor laser device 1 may be used not exclusively for processing of a product, and may be used for other purposes. A wavelength band of laser beam L1 may be a wavelength band other than the blue wavelength band. A shape and a size of opening 21, and a material, composition, and a shape of each member constituting semiconductor laser device 1 can also be changed as appropriate.
[0091] In addition, various modifications can be appropriately made to the exemplary embodiments of the present disclosure within the scope of the technical idea disclosed in the claims.
[0092] In the configurations of the first exemplary embodiment and the second exemplary embodiment, in a case where a nitride semiconductor array having 40 light emitting parts E1 is used as light emitting element 50, and the lower surface of first heat radiation part 10 is cooled with water, 20,000 hours or more of life of the device can be secured for 100 watt operation.
INDUSTRIAL APPLICABILITY
[0093] According to the semiconductor laser device of the present disclosure, the internal space of the semiconductor laser device is made airtight without damaging the light emitting surface of the light emitting element. This prevents siloxane or the like from entering from the outside, and enables the light emitting element to efficiently emit a laser beam and stably operate for a long period of time. Therefore, the semiconductor laser device according to the present disclosure can be used for, for example, high quality processing. In other words, the semiconductor laser device of the present disclosure is industrially useful.
REFERENCE MARKS IN THE DRAWINGS
[0094] 1: semiconductor laser device
[0095] 10: first heat radiation part
[0096] 11: first recess
[0097] 12, 21, 71: opening
[0098] 20: second heat radiation part
[0099] 23: second recess
[0100] 30: electrical insulating part
[0101] 31, 32, 90: heat-melting layer
[0102] 33: insulating layer
[0103] 40, 80: window member
[0104] 50: light emitting element
[0105] 51: submount (first fixing part)
[0106] 52: stress relieving layer (second fixing part)
[0107] 60: optical element
[0108] 60a: lens
[0109] 62, 63: buffer material
[0110] 70: cover
[0111] E1: light emitting part