Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
  • H01S5/00—Semiconductor lasers
  • H01S5/02—Structural details or components not essential to laser action
  • H01S5/024—Arrangements for thermal management
  • H01S5/02469—Passive cooling, e.g. where heat is removed by the housing as a whole or by a heat pipe without any active cooling element like a TEC
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L23/00—Details of semiconductor or other solid state devices
  • H01L23/16—Fillings or auxiliary members in containers or encapsulations, e.g. centering rings
  • H01L23/18—Fillings characterised by the material, its physical or chemical properties, or its arrangement within the complete device
  • H01L23/26—Fillings characterised by the material, its physical or chemical properties, or its arrangement within the complete device including materials for absorbing or reacting with moisture or other undesired substances, e.g. getters
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
  • F02P23/00—Other ignition
  • F02P23/04—Other physical ignition means, e.g. using laser rays
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/0001—Technical content checked by a classifier
  • H01L2924/0002—Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/013—Alloys
  • H01L2924/0132—Binary Alloys
  • H01L2924/01322—Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
  • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
  • H01S3/09—Processes or apparatus for excitation, e.g. pumping
  • H01S3/091—Processes or apparatus for excitation, e.g. pumping using optical pumping
  • H01S3/094—Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
  • H01S3/094076—Pulsed or modulated pumping
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
  • H01S5/00—Semiconductor lasers
  • H01S5/02—Structural details or components not essential to laser action
  • H01S5/022—Mountings; Housings
  • H01S5/0235—Method for mounting laser chips
  • H01S5/02355—Fixing laser chips on mounts
  • H01S5/02365—Fixing laser chips on mounts by clamping
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
  • H01S5/00—Semiconductor lasers
  • H01S5/02—Structural details or components not essential to laser action
  • H01S5/022—Mountings; Housings
  • H01S5/0235—Method for mounting laser chips
  • H01S5/02355—Fixing laser chips on mounts
  • H01S5/0237—Fixing laser chips on mounts by soldering
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
  • H01S5/00—Semiconductor lasers
  • H01S5/02—Structural details or components not essential to laser action
  • H01S5/024—Arrangements for thermal management
  • H01S5/02476—Heat spreaders, i.e. improving heat flow between laser chip and heat dissipating elements

Definitions

• the invention relates to a semiconductor laser module having a substrate and having at least one semiconductor laser arranged on the substrate, wherein the substrate has a layer structure consisting of at least one first primary layer, which realizes a thermal contact to the semiconductor laser.
• the invention further relates to a production method for such a semiconductor laser module.
• the semiconductor laser is designed so that it emits heat pulses with a minimum specific heat amount of about 3 millijoules (mJ) per square millimeter (mm 2 ), preferably about 5 mJ / mm 2 , and having a pulse duration of about 100 microseconds ( ⁇ s) to about 2000 ⁇ s, and that the primary layer has a layer thickness of between about 200 microns ( ⁇ m) and about 2000 microns, preferably between about 400 microns and about 2000 microns.
• the layer thickness of the primary layer selected according to the invention it is ensured that at least a predominant proportion of a heat pulse emitted by the semiconductor laser can be absorbed by the primary layer, so that efficient and at the same time cost-effective cooling of the semiconductor laser is possible in its pulsed mode.
• the principle according to the invention does not require any layer thicknesses for the primary layer which amount to significantly more than two millimeters, so that the semiconductor laser module according to the invention can be manufactured inexpensively.
• the pulse frequency of the heat pulses is less than approximately 400 Hertz (Hz), preferably less than approximately 100 Hz, so that the heat "buffered" in the primary layer can be dissipated to a heat sink during the pulse pauses cooled advantageous and is then ready again for fast absorption of a heat pulse generated by the semiconductor laser.
• Pulse durations and pulse pauses of the aforementioned magnitude occur, in particular, when using the semiconductor laser for the optical pumping of other laser systems, especially of passively Q-switched laser systems, which are e.g. be used in laser spark plugs of internal combustion engines for generating laser ignition pulses. Therefore, the semiconductor laser module according to the invention is particularly suitable as a pump light source for laser-based ignition systems of internal combustion engines, in particular of motor vehicles or stationary large gas engines.
• a further improved derivation of the heat pulses generated by the semiconductor laser is given according to an advantageous embodiment of the invention, when a second primary layer is provided, which is in thermal contact with the semiconductor laser, in particular with a surface of the semiconductor laser, which faces away from the first primary layer ,
• a further advantageous embodiment provides for the primary layer and a secondary layer of the substrate connected to the primary layer to be designed, in particular matched to one another, such that a resulting coefficient of thermal expansion of the two layers is in the range a surface facing the semiconductor laser is approximately equal to the thermal expansion coefficient of the semiconductor laser.
• the deviation of the respective thermal expansion coefficients from each other is at most about 20 percent, preferably about 10 percent.
• the primary layer comprises copper and / or gold and / or silver and / or further materials with comparable heat capacity and comparable thermal conductivity.
• Ductile materials are preferably used to form the primary layer to enable efficient microstructuring of the surface facing the semiconductor laser, with the aim of producing plastically deformable microstructures on the surface which, upon assembly of the components, provide improved positive engagement and hence lower thermal resistance ,
• a method according to claim 7 is given.
• the method according to the invention for producing a semiconductor laser module having a substrate and having at least one semiconductor laser arranged on the substrate, wherein the substrate has a layer structure consisting of at least one first primary layer, which realizes thermal contact with the semiconductor laser, is characterized by the following steps:
• a primary layer having a layer thickness of between about 200 ⁇ m and about 2000 ⁇ m, preferably between about 400 ⁇ m and about 2000 ⁇ m, connecting the semiconductor laser to the primary layer.
• the step of connecting the semiconductor laser to the primary layer is carried out by:
• At least one surface of the two components to be joined is subjected to microstructuring which generates regular and / or randomly distributed, preferably plastically deformable, microstructures on the surface.
• a further improved connection between the semiconductor laser and the primary layer according to the invention is given by the fact that the surfaces to be joined together are coated with a gold layer or a gold-nickel layer.
• the surfaces of which can also be coated with a suitable microstructurable material, such as a gold layer, and the microstructure according to the invention is produced in the gold layer, for example by electronic removal with pulsed current.
• FIG. 1a shows a first embodiment of the invention
• FIG. 1b shows the semiconductor laser module according to FIG. 1a with a deactivated one
• 3a, 3b show a further embodiment of the semiconductor laser module according to the invention in different operating modes
• FIG. 4 shows yet another embodiment of the invention
• FIG. 5 schematically shows a side view of an embodiment of the semiconductor laser module according to the invention before the semiconductor laser is connected to the primary layer receiving it
• FIG. 6 shows a simplified flowchart of an embodiment of the method according to the invention.
• FIG. 1a schematically shows a side view of a first embodiment of the semiconductor laser module 100 according to the invention in a first operating state.
• the semiconductor laser module 100 has a semiconductor laser 120 connected to a substrate 110.
• the semiconductor laser 120 In the first operating state, preferably in a pulsed mode, the semiconductor laser 120 generates laser radiation 200, which i.a. for optical pumping of other laser systems (not shown) can be used.
• the substrate 110 serves, in addition to the mechanical support of the semiconductor laser 120, primarily for the temperature control, in particular cooling, of the semiconductor laser 120.
• the substrate 110 has a primary layer 111 receiving the semiconductor laser 120, which is in good thermal contact with the semiconductor laser 120.
• the primary layer 111 is connected to a secondary layer 112 on its surface facing away from the semiconductor laser 120.
• the secondary layer 112 in turn is disposed on a heat sink 113, which is formed for example as a heat sink and / or as a Peltier element and / or as a heat pipe ("heat pipe").
• the primary layer 111 is preferably formed of silver and / or gold and / or copper, while the secondary layer 112 is preferably made of a ceramic material, such as e.g. Aluminum nitride, AIN, is formed or also comprises material systems of copper and diamond.
• a ceramic material such as e.g. Aluminum nitride, AIN, is formed or also comprises material systems of copper and diamond.
• the semiconductor laser 120 is optimized for use in pulsed operation, in particular pulse operation as required for optically pumping other laser devices (not shown).
• the semiconductor laser 120 can emit pump light pulses 200, with which optical devices with passive Q-switching are optically pumped.
• Such systems are preferably suitable for use in laser-based ignition systems of internal combustion engines, for example of motor vehicles.
• the semiconductor laser 120 is designed to emit heat pulses having a minimum specific heat amount of about 3 mJ per mm 2 , preferably about 5 mJ per mm 2 , the pulse duration being from about 100 ⁇ s to about 2000 ⁇ s.
• a thickness d1 of the primary layer 111 is selected according to the invention to be about 200 ⁇ m to about 2000 ⁇ m, preferably between about 400 ⁇ m and about 2000 ⁇ m.
• the primary layer 111 can absorb a complete heat pulse emitted by the semiconductor laser 120 before it reaches the secondary layer 112 arranged underneath in FIG. 1a. That is, the primary layer 111 according to the invention operates as a kind of local buffer for the heat pulses to be dissipated by the semiconductor laser 120.
• the semiconductor laser module 100 according to the invention has a particularly cost-effective design, since the principle according to the invention provides an intermediate storage of the heat pulses generated by the semiconductor laser 120 in the primary layer 111, combined with a subsequent, during a pulse pause, heat dissipation 111 via the secondary layer 112 to the heat sink 113th.
• the semiconductor laser module 100 according to the invention can be operated with comparatively high pulse powers, without at the same time requiring considerably more extensive cooling due to a corresponding formation of the substrate 110, as is known from conventional systems.
• a material may be chosen that has a lower thermal conductivity than the material of the primary layer 111, because the heat conduction through the secondary layer 112, the relatively long pulse pauses are used.
• FIGS. 2a, 2b depict another embodiment 100a of the semiconductor laser module according to the invention.
• the semiconductor laser module 100a has two primary layers 111, 111 ', whereby a heat storage capacity of the primary layers 111, 111' is increased compared to the embodiment according to FIGS. 1a, 1b.
• This variant of the invention enables operation of the semiconductor laser 120 with higher pulse powers.
• FIG. 2 a once again illustrates a first operating state of the semiconductor laser module 100 a with an active semiconductor laser 120 which emits a laser pulse 200.
• the resulting heat pulse is illustrated by the outgoing from the semiconductor laser 120 in the primary layers 111, 111 'arrows.
• FIG. 2b shows a further, corresponding to a pulse pause, operating state of the semiconductor laser module 100a according to the invention, in which the semiconductor laser 120 is deactivated and the previously ( Figure 2a) in the primary layers 111, 111 'registered heat via the semiconductor laser 120, the secondary layer 112 and the heat sink 113 is removed.
• 3a, 3b show a further embodiment of the semiconductor laser module according to the invention, in which a combination of a primary layer 111, 111 'and a secondary layer 112, 112' assigned to it is provided on both sides of the semiconductor laser 120.
• the heat sink 113 is arranged in the present embodiment on the left in Figure 3a end faces of the substrate layers 111, 112, 111 ', 112'.
• FIG. 3a in turn indicates an operating state in which a heat pulse generated by the semiconductor laser 120 is stored in the primary layers 111, 111 ', while FIG. 3b shows the derivation of the previously stored heat pulse from the primary layers 111, 111' via the secondary layers 112, 112 '. to the heat sink 113 illustrated.
• FIG. 4 shows a further particularly advantageous embodiment of the semiconductor laser module 100 according to the invention, in which the primary layer 111 and the secondary layer 112 are constituents of a direct copper bonded, DCB, substrate whose primary layer 111 consists of copper and has a layer thickness of approximately 400 ⁇ m, and its secondary layer 112 consists of aluminum nitride (AIN), which in the present case has a thickness of approximately 630 ⁇ m.
• DCB direct copper bonded
• AIN aluminum nitride
• a further layer 114 is assigned to the layer structure 111, 112, so that a configuration 111, 112, 114 of materials relative to the secondary layer 112 results with regard to their thermal expansion coefficient.
• the thermal expansion coefficient in the region of the contact surface to the semiconductor laser 120 resulting from the layer structure 111, 112, 114 is preferably matched to the coefficient of thermal expansion of the semiconductor laser 120 in order to prevent damage to the semiconductor laser 120 due to thermo-mechanical stresses occurring during the heating.
• a DC40 substrate which has a layer structure 111, 112, 114 comprising a copper layer 111, a DC40 (copper-diamond) layer 112 and a copper layer 114 .
• this has the advantage that the DC40 material having secondary layer 112 due to their higher thermal conductivity allows better heat spreading than a layer containing aluminum nitride.
• the copper layers 111, 114 may preferably be bonded to the DC40 material 112, for example by thermocompression bonding, or soldered.
• the DC40 layer 112 may, for example, have a layer thickness of about 400 ⁇ m.
• FIG. 5 schematically shows a side view of a semiconductor laser module according to the invention before the semiconductor laser 120 is connected to the primary layer 111 receiving it.
• the primary layer 111 has, on its surface 111a facing the semiconductor laser 120, a microstructure 111b which, for example, consists of regular or randomly distributed microstructures in the form of trenches and / or turrets and / or sponge-like structures.
• the microstructuring 111b preferably comprises plastically deformable microstructures which are plastically deformed when the semiconductor laser 120 is joined to the primary layer 111 and thereby ensure an optimized positive connection between the contact surfaces of the components 111, 120, which advantageously also reduces the thermal resistance of this connection.
• the microstructures 111b comprise elements such as e.g. Turret whose largest dimension is perpendicular to the surface 111a in the range of about 5 microns to about 100 microns.
• the diameter of the turrets is preferably less than about 10 microns, more preferably less than about 2 microns, and an average distance between adjacent turrets should be less than about 4 microns, preferably about 0.5 microns.
• FIG. 6 shows a simplified flow diagram of an embodiment of the method according to the invention.
• the primary layer 111 according to the invention is produced with a layer thickness d1 (FIG. 1a) of approximately 200 ⁇ m to approximately 2000 ⁇ m, preferably approximately 400 ⁇ m to approximately 2000 ⁇ m.
• the microstructure 111b described above with reference to FIG. 5 is applied to at least one of the surfaces 111 a of the connection partners 111, 120.
• the semiconductor laser 120 and the primary layer 111 are connected to one another, which takes place in step 310 and can be realized, for example, by clamping the components 111, 120.
• a sufficiently high pressure is exerted in order to deform the plastically deformable microstructures 111b, so that possibly existing surface defects of the connection partners 111, 120 are compensated.
• connection 310 of the semiconductor laser 120 to the primary layer 111, 111 'can also take place by:
• the alloying of the components 111, 111 ', 120 preferably takes place at temperatures of less than or equal to approximately 150 ° C.
• a further improved connection between the semiconductor laser 120 and the primary layer 111 is given when the surface 111 a (FIG. 5) of the primary layer 111 is coated with a gold layer or a gold-nickel layer or the like.
• a conventional one can also be used Surface treatment done with the aim of the lowest possible surface roughness, for example by diamond milling or the like.
• the above-described measures according to the invention for connecting the surfaces or for reducing the respective thermal resistances can also be applied to one another or combined with one another on the layers 111, 112, 113.

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• Physics & Mathematics (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Computer Hardware Design (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Power Engineering (AREA)
• Electromagnetism (AREA)
• Optics & Photonics (AREA)
• Semiconductor Lasers (AREA)

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• 2009
  • 2009-05-22 DE DE102009026413A patent/DE102009026413A1/de not_active Withdrawn
• 2010
  • 2010-05-18 US US13/259,292 patent/US8891567B2/en not_active Expired - Fee Related
  • 2010-05-18 JP JP2012511254A patent/JP5843756B2/ja not_active Expired - Fee Related
  • 2010-05-18 EP EP10721017A patent/EP2433343A1/de not_active Withdrawn
  • 2010-05-18 WO PCT/EP2010/056779 patent/WO2010133572A1/de not_active Ceased

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