CN103326233A

CN103326233A - Laser diode device

Info

Publication number: CN103326233A
Application number: CN2013100884737A
Authority: CN
Inventors: 乌韦·施特劳斯; 森克·陶茨; 艾尔弗雷德·莱尔; 卡斯滕·奥恩; 克莱门斯·菲尔海利希
Original assignee: Osram Opto Semiconductors GmbH
Current assignee: Ams Osram International GmbH
Priority date: 2012-03-19
Filing date: 2013-03-19
Publication date: 2013-09-25
Anticipated expiration: 2033-03-19
Also published as: CN103326233B; DE102012102306A1; CN105406351A; CN105406351B; TWI565169B; DE102012102306B4; TW201349689A

Abstract

The invention relates to a laser diode device. The laser diode device comprises a housing (1). The housing comprises a housing part (10) and an installation part (11) connected with the housing part (10). The installation part extends along an extension direction (110) away from the housing part (10). The laser diode device also comprises a laser diode chip (2) arranged on the installation part (11). The laser diode chip comprises semiconductor layers (21, 22, 23, 24, 26) on a substrate (20). The semiconductor layers include an active layer (23) for emitting light. The housing part (10) and the installation part (11) each have a basal body made of copper. Meanwhile, at least the housing part (10) is wrapped by steel. A first welding flux layer (3) with a thickness no less than 3 mu m is arranged between the laser diode chip (2) and the installation part (11).

Description

Laser diode device

Technical field

A kind of laser diode device has been proposed.

Present patent application requires the priority of German patent application 10 2,012 102 306.9, and its disclosure is incorporated herein by reference.

Background technology

Light source with high optical power density is the Primary Component for multiple application.For example, the laser diode of being made by the nitrilo compound semiconductor material has high market potential for the optical projection system that especially has the luminous flux 1000 to 10000 lumens.

Device and the compact housing that therefore, need to have high-output power for this application.Owing to the cost reason with in the standardization scope, TO metal shell (" TO metal can(TO metal can) ") the so-called TO structure series of form (TO: " transistor outline(transistor configuration) "), for example the housing with the form of known construction size TO38, TO56 and TO90 is common, and wherein the TO metal shell is formed from steel basically.Yet nowadays available this is defined in so far with kind of the laser diode of standard TO configuration (following also referred to as " TO housing ") and is lower than 3 watts optical power, and this is not enough for multiple application.Yet, not yet realize being higher than 3 watts optical power with this configuration so far.

Such as being shown by institutes such as C.Vierheilig and being published in Proc.SPIE, the nitrogen based laser diode of Bd.8277K, 2012 publication blue light-emitting in the TO housing (blau emittierende Nitrid-basierte Laserdioden in ) in be known that in the continuous firing at room temperature and can under maximum 2.5 watts of power outputs, radiation have the light to 460nm scope medium wavelength at 440nm.

The raising of optics power output is attempted usually in the following way: the size that increases optical resonantor, i.e. chip area especially, because in the nitrogen based laser diode, show the long-time aging characteristics relevant with current density, such as showing and be published in Proc.SPIE in institutes such as S.Lutgen, Bd.7953, S.79530G, described in 2011 the publication like that.In addition, also can improve from producing photosphere towards the heat transmission of heat sink direction by increasing active face.

Yet, the present inventor oneself exploration and research in find, the increase of chip area does not cause that power improves.For this reason, in for the Figure 1A based on the laser diode chip of the blue light-emitting of nitride compound semiconductor material, illustrated according to operating current I(take ampere as unit) the optics power output P(that carries out is take watt as unit) measurement.At this, the laser diode chip that is used for measuring lays respectively at the TO housing.Draw for two one single chips of the active face of the physical dimension that has respectively 200 μ m * 1200 μ m and 15 μ m * 1200 μ m and to measure curve 1001 and 1002.In order to realize higher power, explore above-described method in the mode that chip area is doubled.Illustrate with the form of dotted line 1003 from this power raising that doubles to expect the mode.Yet what illustrate is, as from corresponding to having the curve 1004 of comparing the laser diode chip that active area doubles with previously described one single chip finds out, on the contrary even also less in the situation than one single chip in attainable maximum power under the chip area that doubles and expectation.

In addition, for for example when being reduced in current flowing electronics and hole improve the product optical efficiency of laser diode chip to the mode of producing the injection barrier in the light quantum film, known following laser diode chip, it is at nonpolar or semi-polar Grown, such as showing and be published in physica status solidi in institutes such as U.Strau β, Bd.248., the 652-657 page or leaf is described like that in 2010 the publication.As showing and be published in IEEE Journal of Lightwave Technology in institutes such as D.Sizov, Bd.30, the 679-699 page or leaf, describe in 2010 the publication like that, be used for this attainable the voltage nonpolar or laser diode chip that semi-polarity is grown but better unlike the laser diode chip of corresponding polar growth.

Also known following TO housing except the standard TO housing that stainless steel is made, this TO housing has pedestal in order better to dispel the heat, this pedestal is based on copper or have the copper core and the steel surface, for example in document DE1184870, describe like that, and this TO housing should cause from the improvement of the heat radiation of laser diode chip owing to the copper of good heat conductive.

Exploration based on the inventor in Figure 1B shows according to operating current I(take ampere as unit) carry out to the operating voltage U(of the laser diode chip in the different TO housings take volt as unit) and optics power output P(take watt as unit)

measurement.Curve

1005 and 1007 shows has base steel seat (" base plate(substrate) ") with copper installing component (" stem(stem) ") common TO56 standard housings in the relevant optical power of the electric current of GaN laser diode chip of blue light-emitting and related operating voltage therewith, and

curve

1006 and 1008 shows the corresponding measurement for the laser diode chip in the alternative TO56 housing of the copper installing component of the copper pedestal with ladle envelope and ladle envelope.As easily identifying, this has the improvement that alternative housing based on the pedestal of the copper of ladle envelope is difficult for causing the maximum power of laser diode chip.Therefore, not laser diode manufacturer does not continue on for the nitrogen based laser diode with the method for this alternative TO housing.

Summary of the invention

At least one purpose of specific form of implementation is to propose a kind of laser diode device.

Described purpose realizes by a kind of laser diode device, and it has housing, and described housing has housing parts and the installing component that is connected with described housing parts, and described installing component deviates from described housing parts ground along bearing of trend and extends; With the laser diode chip on described installing component, described laser diode chip has semiconductor layer at substrate, described semiconductor layer has the active layer for radiating light, wherein said housing parts and described installing component have the matrix that is made of copper, and described at least housing parts is the ladle envelope, and is provided with thickness more than or equal to the first solder layer of 3 μ m between described laser diode chip and described installing component.The favourable form of implementation of this laser diode device and improvement project characterize hereinafter and draw from following description and accompanying drawing in addition.

According at least one form of implementation, laser diode device has the housing that wherein is provided with laser diode chip.Housing especially has housing parts and the installing component that is connected with housing parts, and this installing component deviates from housing parts ground along bearing of trend and extends.In other words, installing component stretches out and for example can constitute the bolt shape from housing parts.Installing component has and deviates from housing parts along the bearing of trend of installing component and extend and be provided with installed surface on the laser diode chip on it.Housing parts especially can arrange and constitute, so that case lid can be arranged on the housing parts to be used for closure casing.

Especially mutually housing parts and the installing component of single type formation have respectively the matrix that is made of copper or also have the common matrix that is made of copper in the single type designs.At least housing parts seals for ladle in addition.This explanation, housing parts cover by the copper one-tenth of matrix and with the steel layer basically.The steel layer for example can consist of by the layer that stainless steel is made.

In addition, housing parts for example can have hole or opening, and by these holes or opening, feed line for example can extend the side that is provided with installing component from the side that deviates from installing component of housing parts with the form of contact leg.Feed line can be set to be used to electrically contacting laser diode chip, for example is connected to contact with line between the laser diode chip by feed line.

According to another form of implementation, except housing parts, installing component is also sealed by ladle.

In this form of implementation, housing parts and installing component especially can have the common copper matrix that covers with the steel layer.

Especially, housing can constitute the so-called TO housing that for example has physical dimension TO38, TO56 or TO90.Housing parts may also be referred to as " base plate ", and installing component is called " stem ".Have at least one housing parts of basically being formed from steel and not having the copper base matrix or the standard TO housing of housing parts and installing component is compared with normally used, housing described here has the higher capacity of heat transmission owing to the housing parts of ladle envelope has copper.

According to another form of implementation, housing have be applied on the housing parts and with the case lid of housing parts welding.For this reason especially advantageously, housing parts is the ladle envelope, because thus as in having the standard TO housing of base steel seat, case lid can be welded with housing parts.Installing component reaches the case lid from housing parts along its bearing of trend so that laser diode chip in the situation that holder housing lid in the cavity that consists of by case lid and housing parts, be positioned on the installing component.Have window on this external side that deviates from housing parts of case lid, the light of being launched at work by laser diode chip can radiate from laser diode device by this window.Case lid for example can have steel, and especially stainless steel is perhaps made by it except window.

By with housing parts with hood-shaped formula on the installing component and then the case lid that also on the laser diode chip on the installing component, consists of welding, housing can be sealed shut airtightly or at least very.

According to another form of implementation, laser diode chip is arranged on the installing component by the first solder layer.This especially represents, is provided with the first solder layer between laser diode chip and installing component.The first solder layer has the thickness more than or equal to 3 μ m.Particularly preferably, the thickness of solder layer also can be more than or equal to 5 μ m.

Laser diode chip can be directly installed on the installing component by the first solder layer.To this as an alternative, between laser diode chip and installing component, also can be provided with the heat conducting element that constitutes so-called heat diffuser.Heat conducting element especially can be used in and the hot-fluid between laser diode chip and the installing component is expanded or spreads, so that in housing, namely especially the heat in the installing component realizes large transition face in transmitting.In addition, heat conducting element for example also can compensate the stress between laser diode chip and the housing, and this stress for example can cause by the housing thermal coefficient of expansion different with laser diode chip.

According to another form of implementation, heat conducting element is fixed on the installing component by means of the first solder layer.Laser diode chip is fixed on the heat conducting element by means of the second solder layer.For example the second solder layer also can have more than or equal to 3 μ m and preferably greater than or equal to the thickness of 5 μ m.The feature and advantage of describing in conjunction with the first solder layer also go for the second solder layer and vice versa.

According to another form of implementation, heat conducting element has carborundum (SiC), boron nitride (BN), copper tungsten (CuW) or diamond, is perhaps made by it.Carborundum, boron nitride, copper tungsten and adamantine feature can be the extra high capacity of heat transmission.To this as an alternative, heat conducting element also can have aluminium nitride.

Thus, in the laser diode device described here, between the matrix of the laser diode chip that usually has different heat expansion coefficient and copper base installing component, can there be one or more materials that have equally different thermal coefficient of expansions, especially the first solder layer and in addition for example the ladle envelope section of installing component and/or one or more other solder layers and/or heat conducting element.Thus, can be at work between laser diode chip and the housing or at formation temperature stress between laser diode chip and the heat conducting element and between heat conducting element and housing, this temperature stress can cause adverse effect to the work of laser diode device.As commonly in the prior art, laser diode chip is installed by means of solder layer, the thickness of this solder layer remains thin as far as possible, especially less than 2 μ m, in order to realize good as far as possible heat conduction, and in the laser diode device of here describing, use to have preferably obviously the first solder layer of larger thickness and in case of necessity the second solder layer.Tolerate the thermal resistance that this solder layer is higher at this, because the solder layer of this thickness proves the temperature stress that is conducive to compensate between housing and the laser diode chip.For example, solder layer described here can have the slicken solder based on indium, in order to can compensate especially well different thermal expansions.Possiblely in the laser diode device of here describing thus be, for example carborundum, boron nitride, copper tungsten or adamantine material are as heat conducting element, these materials have the higher capacity of heat transmission with respect to aluminium nitride, yet also have obviously more different thermal coefficient of expansion with respect to the common materials that is used for laser diode chip.

According to another form of implementation, laser diode chip is based on nitride semi-conductor material.Laser diode chip especially can have (In, Al, Ga) N of substrate, preferred conductive substrates, for example crystallization.On this substrate, can apply the epitaxial loayer sequence, i.e. epitaxially grown semiconductor layer, these semiconductor layers are based on nitride semi-conductor material and thus based on InAlGaN.

The III-V group iii v compound semiconductor material that especially has that belongs to InAlGaN based compound semiconductor material, (In, Al, Ga) N based compound semiconductor material and nitride semi-conductor material is In _xAl _yGa _1-x-yMaterial among the N, wherein 0≤x≤1,0≤y≤1 and x+y≤1 for example is GaN, AlN, AlGaN, InGaN, AlInGaN.Laser diode chip especially can have the semiconductor layer sequence at substrate, this semiconductor layer sequence have especially based on AlGaInN and/or InGaN, be provided for the at work active layer of radiating light.Light laser diode chip especially can be launched from ultraviolet to the green wavelength scope at work.

According to another form of implementation, laser diode chip has semiconductor layer at substrate, and these semiconductor layers for example have active layer between ducting layer and encapsulated layer.Especially can apply the first encapsulated layer at substrate, apply the first wave conducting shell at the first encapsulated layer, apply active layer at the first wave conducting shell, apply the Second Wave conducting shell and apply the second encapsulated layer at the Second Wave conducting shell at active layer.Semiconductor contact layer can also be set and can setting example on semiconductor contact layer such as the electric connection layer of metal level form on the second encapsulated layer.Laser diode chip electrically contact can be particularly preferably by carrying out with the opposed electric connection layer of substrate and by conductive substrates, wherein substrate also can have electric connection layer on the side that deviates from semiconductor layer.On the side that active layer and substrate deviate from, can between ducting layer and encapsulated layer, also be provided with carrier barrier layer, in order to avoid so-called charge carrier overshoot.

The semiconductor layer that for example arranges between substrate and active layer can be that n mixes, and the semiconductor layer that is arranged on the active layer from substrate can be that p mixes.To this as an alternative, doping-sequence also may be opposite.Active layer can be not mix or the n doping.Laser diode chip can for example have conventional pn knot, double-heterostructure or quantum well structure, especially preferably have multi-quantum pit structure (MQW structure) is used as active layer.The term quantum well structure comprises especially that in the application's scope wherein charge carrier can experience quantized each structure of its energy state by restriction (" confinement ").Especially, quantum well structure can have the combination of quantum well, quantum wire and/or quantum dot and these structures.For example, active layer can have the quantum film of InGaN base between the barrier layer that suitably consists of.

According to another form of implementation, laser diode chip as describing before based on nitride semi-conductor material and have nonpolar or semi-polar crystal structure.Nitride semi-conductor material has the buergerite lattice structure and usually is grown to so that crystallographic c-axis line corresponding to the direction of growth and thus growth plane corresponding to [0001] crystal face.This growth causes the polar crystal structure, is created in piezoelectric field semiconductor crystal inside, that cause internal polarization by this crystal structure, thus so that charge carrier in the active layer injection and charge carrier at the distribution difficult of active layer.Such as U.Strau β etc. work and at physica status solidi, Bd.246, the 652-657 page or leaf, describe in 2010 publications of delivering, the simulation of polar crystal structure is shown, in having with the polar crystal structure in the active layer of the quantum well structure of quantum film, can forms injection barrier hundreds of millivolts of every quantum films, relevant with the emission wavelength of quantum film.By the institutes such as D.Sizov works and be published in IEEE Journal of Selected Topics in Quantum Electronics, Bd.17, Nr.S, the 1390-1401 page or leaf has been described in 2011 the publication to reduce by semi-polarity crystal boundary face and has been injected barrier.

Be called " nonpolar " or " semi-polarity " crystal structure at this and crystal structure hereinafter, this crystalline structure growth direction and then its vertical sense of current depart from from the crystallographic c-axis line of nitride semi-conductor material at work, and especially not in parallel, and this crystal structure has thus from [0001] plane and departs from and growth axis not in parallel.The example of Non-Polar Crystal structure for example is following direction or growth plane: [1-100], [11-20] and all crystal faces between this.The semi-polarity plane is all crystal faces between [0001] plane and nonpolar crystal face.Nonpolar or semi-polarity crystal structure for example can be realized by the growth of semiconductor layer on nonpolar or semi-polarity substrate surface.

Thus, by the nonpolar of laser diode chip or semi-polarity crystal structure possible be, with the pressure drop in the active layer of laser diode chip and then loss power with respect to reducing based on nitride semi-conductor material and laser diode chip with polar crystal structure.Yet, in the laser diode chip with nonpolar or semi-polarity crystal structure, can't be achieved as follows forward voltage so far, this forward voltage is lower than the light-emitting diode die with polar crystal structure in the direct current situation.The inventor with this owing to higher contact resistance, especially owing on the side of the away from substrate of semiconductor layer for electric connection layer than high contact resistance.Be that this for example can be owing to the p-type heavy doping ability of nitride semi-conductor material in the p situation of mixing at the semiconductor contact layer on the side of the away from substrate of active layer.

Laser diode chip described herein especially may be embodied as, so that have more lossy power in laser diode chip and the semiconductor layer of comparing based on nitride semi-conductor material and laser diode chip with polar crystal structure at work on the side of the away from substrate of active layer, and in active layer, have than based on the less loss power of the laser diode chip of the nitride semi-conductor material with polar crystal structure.

Such as described above, for example be based on copper or have the copper core and the application of the housing of the TO housing on steel surface is compared with the application of the standard TO housing of being made by stainless steel and do not improved in itself laser power, and the application with laser diode chip of the nonpolar or semi-polarity crystal structure in the nitride compound semiconductor material does not improve forward voltage.Have more than or equal to the application of the solder layer of 3 μ m thickness because higher thermal resistance and also show as disadvantageous.

Yet, the inventor recognizes, above-described housing with copper matrix, realizes the power output higher than known laser diode apparatus based on being beneficial to especially more than or equal to the combination of the first solder layer of 3 μ m with the laser diode chip of the nitride semi-conductor material of nonpolar or semi-polarity crystal structure and thickness.From for example the prior art of the laser diode chip of the GaAs base in the TO housing is different in other laser systems, the inventor recognizes, advantageously produce at work large temperature gradient in laser diode chip, this realizes by the parts of suitably selecting and make up laser diode device described herein.Especially by from common based on comparing with the nitride semi-conductor material of polar crystal structure that different loss powers distributes and the copper of matrix by housing is realized again temperature gradient large in the laser diode chip, and realization opposite to it is in the medium and small temperature gradient of case material, the good thermal conductivity of copper matrix wherein, such as described above, be not that self is separately favourable, but be favourable during with laser diode chip combination described here.The combination of housing described herein and laser diode chip described herein also realizes just in the following way: use compared with prior art obviously thicker and in view of higher thermal resistance disadvantageous the first solder layer that seems.

In addition advantageously, compare the area of increase laser diode chip active layer here in the laser diode device of describing with known laser diode chip.Especially, active layer can have more than or equal to 10000 μ m ²And preferably greater than or equal to 20000 μ m ²Until 30000 μ m ²Area.At this, with current density from the decline of maximum to 10% as area constraints.

Such as described above, in view of realizing the higher power output of laser diode chip, it is disadvantageous only increasing the active layer area.Yet the inventor recognizes, only have by with above-described laser diode chip in the temperature gradient combination could realize higher output power, this temperature gradient can be switched on by large tracts of land, lasing chip face is realized.Temperature gradient in the laser diode chip only can be again by will less heat release and to the active layer neutralization from active layer out higher heat conduction compared with prior art on the side of the away from substrate of active layer hotter electrically contacting combine to realize.

At this, on the side of the away from substrate of active layer electrically contact deteriorated, compared with prior art higher loss power namely is set targetedly not only to be compensated by loss lower in the active layer, and by possible high current work, for example come overcompensation by the temperature gradient that arranges targetedly in the larger area of active layer and the laser diode chip, so that just can realize by the combination of measure described herein compared with prior art to improve the obvious improvement of power output form.In the laser diode device of here describing, especially can realize several watts, especially greater than the high light power output of 3W, and electric input power arrives the higher conversion coefficient of optics power output.

According to another form of implementation, installing component and bearing of trend vertically have following cross section, and this cross section extends in a side at least and is arranged on the installing component and is applied to case lid on the housing parts.In other words, installing component is thick extremely so that installing component extends case lid in the plane perpendicular to bearing of trend.At this, between installing component and case lid, can also there be the slit.To this as an alternative, installing component also can be touched case lid.Particularly advantageous is that installing component reaches case lid with large as far as possible area.

According to another form of implementation, housing parts and case lid have circular cross section in the plane perpendicular to the installing component bearing of trend.Installing component can in perpendicular to the plane of bearing of trend, particularly advantageously have occupy greater than semicircular fan-shaped, namely greater than the cross section of semi circular surface.Installing component more heavy back consists of and installing component is larger perpendicular to the cross section of bearing of trend thus, and the heat conduction of then being undertaken by housing is larger.In case lid, be not mounted the spatial placement of parts filling for being used for installing laser diode chip.

Also possible in addition is that the cross section of installing component increases towards housing parts.For example installing component can have wedge-shaped cross-section in the plane of bearing of trend, so with its of installing component on be provided with laser diode chip mounting plane compare wider and/or thicker.Compare with standard TO housing, the laser diode chip on this installing component can along inclined direction radiate, and for example can realize thus: installing component can have large as far as possible thickness and width, and it can not covered by the window by case lid.

Have in the wedge-shaped cross-section situation for the radiation direction of compensating for tilt at installing component, housing parts can have wedge-shaped cross-section in being parallel to the plane of bearing of trend.To this alternative or be additional to this place, the joint angle between housing parts and the installing component also can be not equal to 90 °, and wherein 90 ° joint angle is corresponding to the standard arrangement of installing component on the housing parts of standard TO housing.Can realize thus: although will radiate by the laser diode chip inclined orientation, the wide right angle of showing with respect to the housing installed surface that laser diode device still can produce laser diode chip radiates, and laser diode device can be installed in by this installed surface on the supporting mass of circuit board for example.To this as an alternative, also can for example subring be installed on the housing parts, the inclination that can realize thus housing is installed and then can be realized that the inclination of laser diode device installs.

According to another form of implementation, laser diode chip has the radiation coupling output face, and the light that produces in the active layer is at work by this radiation coupling output face radiation.Laser diode chip preferably is embodied as limit emission laser diode chip, and wherein the radiation coupling output face for example can realize by interruption, division and/or the etching of semiconductor layer compound along crystal face.In addition, laser diode chip has and the opposed dorsal surface of radiation coupling output face.Especially the zone of the leading flank of laser diode chip can be called the radiation coupling output face, the coherent light that produces in laser diode chip is by this zone radiation.Leading flank, especially also have radiation coupling output face and dorsal surface in the emission laser diode chip of limit, usually to be also referred to as so-called faceted pebble (Facetten).In addition, laser diode chip has such as downside, and these sides are connected to each other dorsal surface and radiation coupling output face, and these sides by semiconductor layer perpendicular to the growth of semiconductor layer and setting party to direction on side consist of.

According to another form of implementation, laser diode chip has the protective layer of crystallization at least in the radiation coupling output face.At this with will be called such as lower floor hereinafter " crystallization " layer: these layers have crystalline texture generally at it, have namely that short-range order is arranged and long-range ordered arrangement.In contrast, unformed layer only has short-range order to be arranged, and imperfect crystal or local-crystalized layer only also have long-range ordered arrangement in part or zone, yet this long-range ordered arrangement is in whole layer extension.

Especially, protective layer that can the tight seal crystallization, tight seal in the zone of radiation coupling output face especially is namely preferably at its at work tight seal in the zone of lase radiation that passes through of the leading flank of laser diode chip.At this; the layer of tight seal especially can have such as seal performance; it is sufficiently high, so that the face that is covered by the tight seal layer of laser diode chip is protected in the length of life of laser diode device and laser diode chip, so that the infringement of reduction of service life do not occur.Especially, the protective layer of crystallization can have ratio such as the amorphous or local-crystalized higher sealing of layer.This for example can not have the lattice defect that can cause blow-by by crystallizing layer is preferably constituted, namely the mode of so-called " pin poles(pin hole) " realizes.

The crystallization protective layer can protect laser diode chip the face that is covered by the crystallization protective layer, namely the radiation coupling output face to be avoided for example be the environmental impact of pernicious gas.This environmental impact for example can be by oxygen, ozone, be included in material in the acid rain and other chemical substances form.For example; when laser diode device is used as light source in automotive engineering; in the situation that laser diode chip is not protected; because Korrosionsmedium, for example hydrocarbons and for example sulfide and the nitride of sulfohydrate and oxygen sulfur compound and oxynitrides, and can occur to laser diode chip with especially to the threat of its radiation coupling output face.In addition, when housing itself with respect to environment tight seal ground when sealing, this destructive environmental impact for example can invade in the housing of laser diode device until laser diode chip.In the housing of the laser diode device of here describing, be owing to different thermal coefficient of expansions has a special technological challenge, when closure casing, will weld with sufficiently high sealing based on copper or based on housing and the base steel case lid of the copper of ladle envelope.Especially when this parts of a large amount of manufacturings, this escapement ratio (" escape rate ") that can cause the parts with residual blow-by improves.Although the faceted pebble of known laser diode chip for backlight unit is provided with coating, yet these coating are normally amorphous to local-crystalized, and because its crystal boundary and fault location and only can stop deficiently the diffusion of the material that damages faceted pebble.Therefore, the crystallization protective layer is especially to be the supplementary protection section of the reliable use of the assurance laser diode device of crucial radiation coupling output face.

In addition, described herein between laser diode chip and housing thick solder layer, for example the first solder layer can cause that solder grain moves on the surface of laser diode chip, especially in the zone of laser faceted pebble.In the situation that the not sealing of faceted pebble coating, solder grain can be by the diffusion of faceted pebble coating, and this can cause passing the leakage current of laser faceted pebble.Can guarantee enough faceted pebble coating of sealing by crystallization protective layer described herein, it is impaired that this faceted pebble coating can stop laser diode chip to pass through solder grain.By the crystallization protective layer, in the situation that the dielectric material crystallization can also realize the obvious raising of disruptive field intensity, can realize thus for for example upwards flowing owing to solder layer or being suspended from the protection of the electrical breakdown that the p metal layer on the faceted pebble causes.

According to another form of implementation, laser diode chip is provided with the crystallization protective layer in the radiation coupling output face at least when making laser diode device.Use the applying method that to make the layer of crystallization dielectric semiconductor or conductor by it for this reason.For example, can select the method for the chemical vapour deposition (CVD) (CVD: " chemical vapor deposition ") when improving temperature, especially more than or equal to 500 ℃ with during preferably greater than or equal to 600 ℃ temperature for this reason.Particularly preferably, the crystallization protective layer also can be realized by the deposition by Atomic layer deposition method (ALD: " atomic layer deposition "), especially atom-layer-epitaxial method (ALE: " atomic layer epitaxy ") realization.Atomic layer deposition method can compare with the common manufacture method of faceted pebble coating raising, more than or equal to 500 ℃ with carry out during preferably greater than or equal to 600 ℃ temperature, in order to obtain the crystallization protective layer.For mentioned method, especially Atomic layer deposition method advantageously flawless, without " pin hole " though structure, the structure of well applied and few stress that from the teeth outwards well attached, high stability also has the uneven section with wide aspect ratio.Particularly advantageous in this protective layer is that it is with respect to the little penetrability of gas, for example oxygen or moisture; such as P.F.Carcia etc. show and at Journal of Applied Physics106; 023533 (2009) publication of delivering and T.Hirvirkorpia show and are published in Applied Surface Science257, describe like that in the publication that 9451-9454 (2011) delivers.

According to another form of implementation, the protective layer of crystallization has a crystallizing layer just.To this as an alternative, also possible is that the protective layer of crystallization has a plurality of crystallizing layers.A plurality of crystallizing layers for example can form by a plurality of crystallizing layers of being made by different materials.In addition, also possiblely be that a plurality of crystallizing layers form by the sequence that replaces of two crystallizing layers being made by different materials at least.

According to another form of implementation, be applied with optical layers in the radiation coupling output face.Optical layers for example can be the reflector or eliminate the reflector.This optical layers has or the preferred a plurality of layer of being made by transparent material usually, and these layers can form the periodicity order of different refractivity.

For example, the crystallization protective layer can form optical layers.In addition, this especially can advantageously realize when the crystallization protective layer has a plurality of crystallizing layer.To this as an alternative, also possiblely be except the crystallization protective layer, to apply not mandatory crystallization, but for example also can be the optical layers of amorphous or partially crystallizable.Optical layers in this case can by as apply from the well known in the prior art conventional applying method that is used for the faceted pebble coating.

Optical layers for example can be arranged between radiation coupling output face and the crystallization protective layer, and covers by the crystallization protective layer.Possible is that optical layers is also protected by the crystallization protective layer except the radiation coupling output face thus.To this as an alternative, also possible is that the crystallization protective layer is arranged between radiation coupling output face and the optical layers.The crystallization protective layer advantageously approaches as far as possible in this case and especially preferably is set directly on the laser diode chip, namely is arranged at least in the radiation coupling output face.With additional optical layers in combination, the crystallization protective layer also can have the part of the optical functional of coating, and is the part of optical layers thus.

According to another form of implementation, the crystallization protective layer is by the dielectric material formation or have at least a dielectric material.Especially at radiation coupling output face and directly and in the non-indirectly coating of other face of laser diode chip in case of necessity, dielectric layer is favourable, because can avoid thus the short circuit of laser diode chip.And the passivation layer between crystallization protective layer and the laser diode chip or also with optical layers combination, the crystallization protective layer also can have the material of semi-conductive or conductor or be made by it.

Particularly preferably, the crystallization protective layer can or have at least a oxide by the oxide formation.Oxygen by oxidation material for example can consist of Hydrogenbond with hydrone, can stop thus hydrone to penetrate in the crystallizing layer.Particularly preferably, oxide can be dielectric.

Particularly preferably, the crystallization protective layer can have one or more in the material beneath: Al in one or more crystallizing layers ₂O ₃, Si ₃N ₄, Nb _xAl _yO ₂, Al ₂O ₃/ TiO ₂, Al ₂O ₃/ Ta ₂O ₅, HfO ₂, Ta ₂O ₅/ ZrO ₂, Ta ₂O ₅, Ta _xTi _yO ₂, Ta ₂O ₅/ NbO ₅, TiO ₂, ZrO ₂, HfO ₂, Ta ₂O ₅, Nb ₂O ₅, Sc ₂O ₃, Y ₂O ₃, MgO, B ₂O ₃, SiO ₂, GeO ₂, La ₂O ₃, CeO ₂, PrO _x, Nd ₂O ₃, Sm ₂O ₃, EuO _x, Gd ₂O ₃, Dy ₂O ₃, Ho ₂O ₃, Er ₂O ₃, Tm ₂O ₃, Yb ₂O ₃, Lu ₂O ₃, SrTiO ₂, BaTiO ₃, PbTiO ₃,, PbZrO ₃, Bi _xTi _yO, Bi _xSi _yO, SrTa ₂O ₆, SrBi ₂Ta ₂O ₉, YScO ₃, LaAlO ₃, NdAlO ₃, GdScO ₃, LaScO ₃, LaLuO ₃, Er ₃Ga ₅O ₁₃, HfSiO, HfTiO, AlSiO, LaAlO, LaHfO, In ₂O ₃, ZnO, Ga ₂O ₃, V ₂O ₅, HfAlO, HfTaO, HfZrO, Ru, Pt, Ir, Td, Rh, Ag, W, Cu, Co, Fe, Ni, Mo, Ta, Ti, Al, Si, Ge, In ₂O ₃, In ₂O ₃: Sn, In ₂O ₃: F, In ₂O ₃: Zr, SnO ₂, SnO ₂: Sb, ZnO:Al, ZnO:B, ZnO:Ga, RuO ₂, RhO ₂, IrO ₂, Ga ₂O ₃, V ₂O ₅, WO ₃, W ₂O ₃, BN, AlN, GaN, InN, SiN _x, Ta ₃N ₅, Cu ₃N, Zr ₃N ₄, Hf ₃N ₄, NiO, CuO, FeO _x, CrO _x, CoO _x, MnO _xTiN, Ti _xSi _yN _z, NbN, TaN, Ta ₃N ₅, MoN _x, W ₂N, GaAs, AlAs, AlP, InP, GaP, InAs, TaC.

According to another form of implementation, laser diode chip with the opposed dorsal surface of radiation coupling output face on be applied with equally the crystallization protective layer.By can effectively protect the faceted pebble for the environmental impact sensitivity of laser diode chip at radiation coupling output face and the crystallization protective layer on dorsal surface.

Also can apply optical layers, reflector especially on this external dorsal surface.The coating that as above regards to the radiation coupling output face is described like that, also can between crystallization protective layer and dorsal surface optical layers be set on the dorsal surface.To this as an alternative, the crystallization protective layer also can be arranged between optical layers and the dorsal surface.Especially favourable can also be: the optical layers of the dorsal surface of laser diode chip forms by the crystallization protective layer.

According to another form of implementation, at laser diode chip the dorsal surface side that output face is connected with radiation coupling is applied with one or more crystallization protective layers.Especially can be advantageously: on the side that arranges and at the faceted pebble of laser diode chip, apply the crystallization protective layer perpendicular to the growth of semiconductor layer and setting party at all so that the boundary face between semiconductor layer and the semiconductor layer around all protected.

Description of drawings

Other advantages, favourable form of implementation and improvement project draw from the embodiment that describes below in conjunction with accompanying drawing.

Wherein:

Figure 1A and 1B show the measurement for the conventional laser diode apparatus,

Fig. 2 A and 2B show the schematic diagram according to the laser diode device of an embodiment,

Fig. 3 shows the schematic diagram according to the laser diode chip of an embodiment,

Fig. 4 to 5B shows the measurement of laser diode device,

Fig. 6 to 9 shows the schematic diagram according to the laser diode device of other embodiment, and

Figure 10 to 16 shows the schematic diagram according to the part of the laser diode device of other embodiment.

In embodiment and accompanying drawing, identical, similar or act on identical element and can be respectively arranged with identical Reference numeral.Shown element and its size relationship each other are not considered as conforming with ratio, and on the contrary, discrete component, for example layer, parts, device and zone can be for better illustrating property and/or better understandings and illustrating large.

Embodiment

The embodiment of a laser diode device 100 has been shown in Fig. 2 A, 2B, wherein in schematic cross sectional view shown in Fig. 2 A, and the vertical view from the front side of laser diode device 100 that is in reverse in the direction 110 shown in Fig. 2 A has been shown in 2B.Following description relates to Fig. 2 A and 2B equally.

Laser diode device 100 has the housing 1 that consists of with so-called TO housing form.Housing 1 has housing parts 10 and the installing component 11 that is arranged on the housing parts.Installing component 11 deviates from housing parts 10 along bearing of trend 110 and extends and consist of with housing parts 10 single type ground in the illustrated embodiment.For this reason, housing parts 10 and installing component 11 have the matrix that is made of copper.Housing parts 10 also has the section that seals 12 that is formed from steel, and this is sealed section and is formed by the coating of copper matrix in housing parts 10 zones.

In addition, housing parts 10 for example can have hole or opening, is provided with the feed leg in these holes or opening, and it stretches to the side of installing component 11 from the side that deviates from installing component 11 of housing parts 10.The feed leg that arranges and be fixed therein for example can constitute electric penetrating part, and the possibility that electrically contacts is provided.

Installing component 11 has installed surface 13, is provided with laser diode chip 2 at this installed surface.Especially, laser diode chip 2 is installed on the installed surface 13 of installing component 11 by the first solder layer 3, and is connected to housing 1 with electricity and calorifics mode thus.

At installing component 11 and then on laser diode chip 2 case lid 14 can be set, it represents by a dotted line.The case lid 14 that can also have a window 15 for example can have steel and preferably be formed from steel except window 15.By making housing parts 10 have the mode of ladle envelope section 12, case lid 14 can be applied on the housing parts 10 of housing 1, and as in the common TO housing with base steel seat, in standard technology, fixing by welding.In addition, can by being connected of case lid 14 and the section that seals 12 welding of housing parts 10 preferably being realized seal as far as possible, can protect laser diode chip 2 to avoid the damaging environmental impact by this connection.

As from seeing Fig. 2 B, housing parts 10 and case lid 14 consist of in perpendicular to the plane of bearing of trend 110 circularly.Installing component 11 have in the illustrated embodiment again occupy greater than semicircular fan-shaped, namely greater than the cross section of semi circular surface.In addition, installing component 11 reaches on the case lid 14 in the side that deviates from installed surface 13.Thus, installing component 11 can be in its cross section as far as possible heavy back consist of, can realize high thermal conductivity thus.

For optimum heat conduction in the standard laser diode component commonly, laser diode chip is coupled on the housing by thin as far as possible solder layer, in order to realize as far as possible little thermal resistance, and the first solder layer 3 in the embodiment shown in this has more than or equal to 3 μ m and preferably greater than or equal to the thickness of 5 μ m.Can compensate thermic stress thus, it is at work owing to the heat that produces in laser chip 2 occurs with housing 1 different thermal coefficient of expansion with laser diode chip 2.In addition, for example also can compensate the smooth property of air spots on the installed surface 13 of installing component 11 by thick like this solder layer.The smooth property of these air spotss especially also can be as shown in Figure 6 following, installing component 11 as housing parts 10, have be formed from steel seal section 12 time occur.

Laser diode chip 2 preferably constitutes as shown in Figure 3 has the radiation coupling output face 27 that forms by the side and the laser diode chip of launching with the limit of the opposed dorsal surface 28 of radiation coupling output face.Radiation coupling output face 27 especially can be by laser diode chip 2 the forming such as lower area of leading flank, the laser emission that produces in laser diode chip 2 at work is by the radiation of described zone.

Especially, laser diode chip 2 is based on nitride semi-conductor material.Laser diode chip 2 has substrate 20 for this reason, and it preferably consists of conductively and for example has (In, Al, the Ga) N of crystallization or made by it.At Grown semiconductor layer sequence based on nitride semi-conductor material is arranged, preferably by epitaxy method for example the organic vapour phase epitaxy of metal (MOVPE, " metal organic vapor phase epitaxy ") grow.Laser diode chip 2 has the active layer 23 that is arranged between ducting layer 22 and the encapsulated layer 21 at substrate 20.Especially, laser diode chip 2 has the first encapsulated layer 21 at substrate 20, is provided with first wave conducting shell 22 and is provided with active layer 23 at this first wave conducting shell at this first encapsulated layer.Following other ducting layers 22 and other encapsulated layers 21 and the semiconductor contact layer on this encapsulated layer 24 along the direction of growth on the active layer 23, this semiconductor contact layer is contacted by for example electric connection layer 25 with the metal electrode layer form.The electrical connection of laser diode chip 2 is undertaken by electric connection layer 25 and conductive substrates 20, this substrate can deviate from semiconductor layer 21,22,23,24 side has other electric connection layer (not shown).

In the illustrated embodiment, be that n mixes from active layer 23 towards the semiconductor layer of substrate 20, and the semiconductor layer that is arranged on the side of away from substrate 20 of active layer 23 is that p mixes.As an alternative, opposite doping sequence also is possible.Active layer 23 for example can be n doping or unadulterated, and has especially in the illustrated embodiment multi-quantum pit structure.

Especially realize the improved thermal conductivity of standard TO housing made with respect to steel by copper based shell 1.For this reason in Fig. 4, laser diode chip for the GaN base of blue light-emitting,

curve

401 and 402 illustrates optics power output P(take watt as unit), and

curve

403 and 404 respectively according to operating current I(take ampere as unit) operating voltage U(is shown take volt as unit), wherein explored laser diode chip in the copper based shell of the housing parts that the laser diode chip in having the standard TO56 housing of steel pedestal and having of describing become by the copper of ladle envelope, that install by the layer thickness that is about 5 μ m here.For the curve 401 of the situation of copper based shell described herein and thick solder layer and 403 and for the curve 402 of situation and 404 relatively illustrate of standard TO housing and thin solder layer: although the thermal resistance of thicker scolder is higher when using housing described herein, as to have the first solder layer 3 described herein, still improved power output.

In order to realize large as far as possible power output for the light of being launched at work by laser diode chip 2, according in laser diode device 100, producing specific temperature gradient by Fig. 2 A, 2B and 3 another embodiment that set forth equally.Especially, in housing 1, there is the minimum temperature gradient that realizes by the copper base matrix of housing 1 at this.

Opposite with the housing 1 of high as far as possible heat conduction, in order to produce as far as possible little temperature gradient in housing 1, laser diode chip 2 is constructed to exist large as far as possible temperature gradient between electric connection layer 25 and substrate 20.In order to set so preferred temperature gradient, laser diode chip 2 and housing 1 must be coordinated with each other.The inventor's exploration especially illustrates, and must treat discretely electrical loss in laser diode chip 2.At first, consider to constitute in the embodiment shown the pressure drop of the upside contact site of p doping contact site in layer 26 zone, this pressure drop causes by the p-type heavy doping ability in nitride semi-conductor material system.

For this reason in Fig. 5 A, in 1 ampere operating current with pulse mode with 1 μ m pulsewidth and 1% duty ratio, show the voltage of the laser diode chip 2 of the nitride based polarity in the TO housing for different temperatures (take ℃ as unit).In Fig. 5 B, compare with the laser diode device with steel standard TO56 housing (curve 502), for the laser diode device with copper based shell (curve 501) according to operating current I(take ampere as unit) show operating voltage U(take volt as unit).Operating voltage rises in the copper based shell, can infer thus, layer 26 in curve 501 situations based on improved heat conduction, than colder in curve 502 situations.

In addition, consider in layer and the especially pressure drop in active layer 23 under the active layer 23.Because active layer 23 constitutes the stacked multi-quantum pit structure with a plurality of product light quantum films in the illustrated embodiment, so especially produce pressure drop in the boundary face of quantum well structure.At this, laser diode chip 2 be embodied as so that with the almost identical loss power of standard laser diode chip for backlight unit in tolerance near electric barrier and the resistance of upside contact site, and minimize near active layer or the loss under active layer 23.

For this reason, laser diode chip 2 is embodied as based on nitride semi-conductor material and has the laser diode chip of the nonpolar or semi-polarity crystal structure of partly describing at summary of the invention.Can realize by the nonpolar of laser diode chip 2 or semi-polarity crystal structure: with compare based on nitride semi-conductor material and standard laser diode chip for backlight unit with polar crystal structure, on the side of the away from substrate 20 of active layer 23, namely in layer 26, exist at work than lossy power, and in active layer 23, realize less loss power.

In layer 26 the zone above active layer 23 electrically contact owing to deterioratedly not only compensating by loss less in active layer 23 of causing based on the electrical loss power of comparing high with the conventional laser diode chip for backlight unit of the nitride semi-conductor material of polar crystal structure.More precisely, realize overcompensation by possible high current work and the temperature gradient in laser diode chip 2, set targetedly, so that by the combination of housing 1 described herein with nonpolar or semi-polarity laser diode chip 2 and the first solder layer 3, realize obviously improving with respect to known laser diode device.

Particularly advantageously be, the chip area of laser diode chip 2 described here is compared increase with known laser diode chip, especially, and with more than or equal to 10000 μ m ²And preferably approximately or equal 20000 μ m ²To 30000 μ m ²The electric current of area in the active layer 23 to inject be favourable, wherein with current density from the decline of maximum to peaked 10% as area constraints.By the above-described measure that causes temperature gradient large as far as possible in laser diode chip 2, i.e. improved heat conduction and the combination of hotter upside contact site in layer 26 zone from active layer 23, the area that causes electric current to inject wherein increases, and compared with prior art causes the raising of optics power output.

Other embodiment of laser diode device shown in the accompanying drawing below, it is illustrated in remodeling and the modification of the embodiment shown in Fig. 2 A, 2B and 3.Therefore, following description is limited to the difference with before embodiment basically.Especially, the laser diode device that the following describes can have case lid, even case lid does not clearly illustrate in the accompanying drawings.

Figure 6 illustrates the embodiment of laser diode device 101, wherein with compare not only housing parts 10 but also installing component 11 according to the laser diode device 100 of Fig. 2 A and 2B and have steel and seal section 12.Thus as in the standard TO housing, can realizing the installed surface 13 of steel, and can realize by the improved thermal conductivity of copper simultaneously.

Fig. 7 A in the 7C with schematic cross sectional views (Fig. 7 A), show laser diode device 102 according to another embodiment with the vertical view (Fig. 7 B) that is in reverse to bearing of trend 110 and with the vertical view (Fig. 7 C) to installed surface 13.Compare with embodiment before, in this laser diode device 102, between the installing component 11 of laser diode chip 2 and housing 1, be provided with heat conducting element 4.Heat conducting element especially constitutes so-called heat diffuser and is used for hot-fluid is spread between the installing component 11 of laser diode chip 2 and housing 1, in order to realize large as far as possible transition face in the heat in housing 1 is transmitted.

At this, heat conducting element 4 is installed in by means of the first solder layer 3 on the installing component 11 of housing 1, described the first solder layer 3 can be as described above like that with more than or equal to 3 μ m and particularly preferably consist of more than or equal to the thickness of 5 μ m.In addition, be provided with the second solder layer 5 between heat conducting element 4 and laser diode chip 2, by this second solder layer, laser diode chip 2 is installed on the heat conducting element 4.The second solder layer 5 can preferably have equally more than or equal to 3 μ m and particularly preferably more than or equal to the thickness of 5 μ m.To this as an alternative, also possiblely be, the only solder layer in two

solder layers

3,5, for example only the first solder layer 3 has large like this thickness.

Installing component 11 can be as in the illustrated embodiment becomes by copper, perhaps as in conjunction with Fig. 6 description and also have ladle envelope section 12 illustrating by a dotted line among Fig. 7 A.

Laser diode chip 2 has different thermal coefficient of expansions with housing 1 owing to having different materials.Usually, nitride based semi-conducting material has about 5.6 * 10 ^-6The thermal conductivity of the thermal coefficient of expansion of 1/K and about 100W/mK, and copper has about 16 ... 18 * 10 ^-6The thermal conductivity of the thermal coefficient of expansion of 1/K and about 300W/mK.Wherein there is the multiple material have equally different thermal coefficient of expansions, so for example the ladle envelope section 12 of installing component 11, solder layer 3 and 5 and heat conducting element 4.Steel has about 6 ... 12 * 10 ^-6The thermal coefficient of expansion of 1/K and about 30 ... the thermal conductivity of 70W/mK.Heat conducting element 4 for example can have AlN or be made by it, and AlN has 4.5 ... 5.7 * 10 ^-6The thermal coefficient of expansion of 1/K and about 80 ... the thermal conductivity of 200W/mK.The thermal coefficient of expansion of AlN heat conducting element 4 is matched with the thermal coefficient of expansion of laser diode chip 2 thus relatively well.To the border transition section of housing 1, namely but there is the remarkable difference of thermal coefficient of expansion aspect at AlN heat conducting element 4 to copper or to the border transition section of the copper of ladle envelope.

Particularly preferably, can substitute for Al N and therefore with SiC, especially 6H-SiC is as the material of heat conducting element 4, although this material has about 4.4 * 10 ^-6The thermal coefficient of expansion of 1/K, however also have about 200 ... the higher heat-conductivity of 500W/mK.To this as an alternative, also can be with in the following material a kind of as heat conducting element 4: have about 6 ... 8 * 10 ^-6The thermal coefficient of expansion of 1/K and about 200 ... the CuW of the thermal conductivity of 250W/mK has about 2.5 ... 4 * 10 ^-6The BN of the thermal conductivity of the thermal coefficient of expansion of 1/K and about 600W/mK, diamond, the diamond that for example produces by CVD, it is 2.3 * 10 ^-6The also higher thermal conductivity that has about 1000W/mK under the thermal coefficient of expansion of 1/K.Although this material is being disadvantageous aspect the thermal stress for heat conducting element 4, yet preferably use in the laser diode device that these materials can here be described, because the larger thermal stress that causes by these materials can compensate by thick solder layer 3 described herein, 5.Solder layer 3,5 for example can have the slicken solder based on indium, in order to can realize the good as far as possible compensation of temperature stress.

Figure 8 illustrates another embodiment of laser diode device 103, it is pure exemplarily to have heat conducting element 4 between laser diode chip 2 and housing 1 as the laser diode device 102 of front embodiment.

Compare with embodiment before, laser diode device 103 has installing component 11, and described installing component and bearing of trend 110 vertically have towards housing parts 10 directions, namely be in reverse to the cross section that bearing of trend 110 increases.To this, installing component 11 has wedge-shaped cross-section in the section that illustrates, and described wedge-shaped cross-section is higher in the zone away from housing 1 near housing 1 place ratio.In other words, the thickness of installing component 11 increases towards housing 10.

This wedge-shaped cross-section of installing component 11 is particularly advantageous in the high as far as possible thermal conductivity of realization, and can be by laser diode chip 2 being favoured the case lid 14 that illustrates and window 15 thereof arrange and so that the window 15 by case lid 14 only covers or do not cover described laser diode chip on a small quantity.In order to guarantee to come directed installed surface for the radiation direction perpendicular to laser diode chip 2 of laser diode device 103, the housing parts 10 of housing 1 has wedge-shaped cross-section in the illustrated embodiment equally.To this as an alternative, also possible is that the joint angle between installing component 11 and the housing parts 10 is not equal to 90 ℃, and is matched with the subtended angle of the wedge that forms installing component 11.Also possiblely in addition be, the subring that will have respective cross section is installed on the housing parts 10, and housing 1 can be mounted obliquely within on the bearing-surface thus.

In Fig. 9, at another embodiment that there is shown laser diode device 104 to overlooking of installed surface 13, additional or as an alternative, the wedge-shaped cross-section of installing component that this laser diode device has 11 has the width that increases in the plane of installed surface 13 for the wedge-shaped cross-section of the installing component 11 of the embodiment of front.

Can be except housing 1 being constituted increase and the optimization of the thermal conductivity that also causes housing 1 the copper based shell by height and/or width towards housing parts 10 increases at the installing component 11 shown in Fig. 8 and 9.

The embodiment of laser diode chip 2 has been shown among Figure 10 to 16 below, and this laser diode chip can be by being installed in the solder layer shown in the section in previously described laser diode device 100,101,102,103,104 the housing 1.Not shown for the general view reason among the layer structure figure below of laser diode chip 2.

The laser diode chip 2 of the following examples has the protective layer 6 of crystallization at least in radiation coupling output face 27, described protective layer is suitable for and is set to avoiding the hostile environment impact that for example causes by surrounding air for the protection of radiation coupling output face 27 at least.This hostile environment impact in the surrounding air for example can be oxygen, ozone, acid rain, sulphur and sulfide and nitrogen oxide and hydrocarbons and other harmful chemicals.These materials may also penetrate in the housing 1 that seals with case lid 14 undesirably, because since between copper and the steel different thermal coefficient of expansions and so that a special technological challenge be, base steel case lid 14 be connected with housing parts 10 fully hermetically and weld.Especially when this housing 1 of a large amount of manufacturings, can cause the raising of the not principal component of the parts with residual blow-by.The protective layer 6 that therefore, can need crystallization comes for laser diode chip 2 being used reliably the housing 1 of the high heat conductance of description here as the supplementary protection of radiation coupling output face 27 at least.

Especially, the crystallization protective layer 6 that the following describes can be tight seal, and has thus sufficiently high sealing, so that laser diode chip 2 was adequately protected in its whole useful life.According to the following examples; the protective layer 6 of crystallization for example can be by Atomic layer deposition method; especially by atom-layer-epitaxial method; perhaps by chemical gaseous phase depositing process, especially more than or equal to 500 ℃ and preferably greater than or equal to 600 ℃ temperature in be applied on the laser diode chip 2.Especially the protective layer 6 that applies by ald advantageously generates the structure without nothing crystal defect, so-called " pin hole ", and it has from the teeth outwards well attached, high stability, good coating and the structure of few stress.

In addition, by the first thick solder layer 3 with in case of necessity also by the second thick solder layer 5, below laser diode chip 2, can access the bonding machine meeting of increase, so that solder grain can migrate to laser diode chip 2 and especially can migrate to radiation coupling output face 27, and can spread by the faceted pebble coating of non-tight sealing, this may cause the leakage current by radiation coupling output face 27.Protective layer 6 by crystallization can prevent also that thus scolder is diffused into laser diode chip 2 surfaces.In addition, the protective layer of crystallization can cause significantly improving of disruptive field intensity having in the dielectric material situation.

Show an embodiment of laser diode chip 2 in Figure 10 with cutaway view, the protective layer 6 of wherein crystallization is applied directly in the radiation coupling output face 27 of laser diode chip 2.The protective layer 6 of crystallization has dielectric material in addition, for example is one of dielectric material of partly mentioning at summary of the invention of front.To this as an alternative, what also can realize is, is provided with the passivation layer of dielectric between the protective layer 6 of crystallization and radiation coupling output face 27, so that the conductor of material also can use semiconductor or to(for) the protective layer 6 of crystallization is described in summary of the invention such as the front.

In addition, in radiation coupling output face 27 and with radiation coupling output face 27 opposed dorsal surfaces 28 be applied with the layer stacking form optical layers 7, described optical layers constitutes elimination reflecting part or the reflecting part of corresponding laser faceted pebble.For example, the optical layers 7 that is applied in the radiation coupling output face 27 can constitute the elimination reflector, and the optical layers 7 that is applied on the dorsal surface 28 can constitute the reflector.Optical layers 7 can by applying for the coating of laser diode faceted pebble method commonly used, can produce the layer of typical amorphous or partially crystallizable by the method.

Thus in the embodiment shown, the protective layer 6 of crystallization is arranged between optical layers 7 and the radiation coupling output face 27.Enough for protection radiation coupling output face 27 can be: the protective layer 6 of crystallization has several nanometers until the thickness of tens nanometer; so that the protective layer 6 of crystallization does not affect the optical characteristics that is applied to the coating in the radiation coupling output face 27, described optical characteristics is determined by optical layers 7 basically in addition.To this as an alternative, also possible is that the protective layer 6 of crystallization constitutes the part of optical layers 7, and has the thickness of corresponding selection.

Figure 11 illustrates wherein except at the embodiment that also is provided with the protective layer 6 of the crystallization between dorsal surface 28 and optical layers 7 protective layer 6 of the crystallization in the radiation coupling output face 27 at dorsal surface 28.Can not only protect dorsal surface 28 for pernicious gas but also for the scolder that may move or be diffused on the dorsal surface 28 thus.

Figure 12 illustrates another embodiment, wherein optical layers 7 forms at the protective layer 6 of radiation coupling output face 27 by crystallization.In addition, the protective layer 6 of crystallization has one and preferred a plurality of layer of being made by different materials, these layers tool elimination reflection characteristic likely or reflection characteristic.

Figure 13 illustrates another embodiment, wherein optical layers 7 also forms at the protective layer 6 of dorsal surface 28 by crystallization.The protective layer 6 of in this case crystallization also can have respectively one and preferred a plurality of layer of being made by different materials, these layers tool elimination reflection characteristic likely or reflection characteristic.

Another embodiment shown in Figure 14; wherein compare with the embodiment that is applied in the radiation coupling output face 27 of the protective layer of crystallization among Figure 10; the protective layer 6 of crystallization is applied on the optical layers 7 so that optical layers 7 is arranged between the protective layer 6 of crystallization and the radiation coupling output face 27 and thus the protective layer 6 by crystallization cover.Thus, except radiation coupling output face 27, optical layers 7 also can be protected by the protective layer 6 of crystallization on the one hand.In addition, alternative is in dielectric material, also can be with semi-conducting material or conductor material, one of material of mentioning in the summary of the invention part above for example is used for the protective layer 6 of crystallization.

Also the optical layers on dorsal surface 28 7 applies the protective layer 6 of crystallization in the embodiment of Figure 15, and described protective layer can be protected dorsal surface 28 and the optical layers on dorsal surface 28 7.

Figure 16 illustrates another embodiment; it illustrates laser diode chip 2 with the vertical view from the top; and wherein except 29 protective layers 6 that are applied with crystallization in the side also the protective layer 6 of the crystallization on radiation coupling output face 27 and the dorsal surface 28, described protective layer is connected to each other dorsal surface 28 and radiation coupling output face 27.Can realize thus laser diode chip 2 and the especially boundary face protection in all directions between its semiconductor layer and the semiconductor layer, because all sides of laser diode chip 2 all cover with the protective layer 6 of crystallization.The protective layer 6 of crystallization can be applied on the optical layers 7 as shown in Figure 16 at this.To this as an alternative, also possiblely be that the protective layer 6 of crystallization is applied directly on radiation coupling output face and/or the dorsal surface 28.

Can mutually making up according to other embodiment with the feature of describing shown in the drawings and Examples, even these structures clearly do not illustrate in the accompanying drawings.Especially, can be with different housing forms, the application of heat conducting element 4 and the layout of one or more protective layer 6 on laser diode chip 2 make up mutually.In addition, embodiment illustrated in the accompanying drawings also can have alternative or the supplementary features according to the form of implementation of summary of the invention.

The present invention is not confined to this by the description by embodiment.More precisely, the present invention includes the combination in any of any new feature and feature, this especially comprises the combination in any of feature in the claim, even this feature maybe should not offer some clarification in claim or embodiment in combination itself.

Claims

1. laser diode device has:

Housing (1), described housing have housing parts (10) and the installing component (11) that is connected with described housing parts (10), and described installing component deviates from described housing parts along bearing of trend (110) and extends (10); With

Laser diode chip (2) on described installing component (11), described laser diode chip has semiconductor layer (21,22,23,24,26) at substrate (20), and described semiconductor layer has the active layer (23) for radiating light,

Wherein, described housing parts (10) and described installing component (11) have the matrix that is made of copper, and described at least housing parts (10) is the ladle envelope, and is provided with thickness more than or equal to the first solder layer (3) of 3 μ m between described laser diode chip (2) and described installing component (11).

2. laser diode device according to claim 1, wherein said laser diode chip (2) is based on nitride semi-conductor material and have nonpolar or semi-polar crystal structure.

3. laser diode device according to claim 2, wherein with based on nitride semi-conductor material and laser diode chip with polar crystal structure compare, described laser diode chip (2) has more lossy power in the layer (26) on the side that deviates from described substrate (20) of described active layer (23) at work, and has less loss power in described active layer (23).

4. according to the described laser diode device of one of the claims, wherein said active layer (23) has more than or equal to 10000 μ m ²Area.

5. according to the described laser diode device of one of the claims, the thickness of wherein said the first solder layer (3) is more than or equal to 5 μ m.

6. according to the described laser diode device of one of the claims, wherein between described laser diode chip (2) and described installing component (11), be provided with heat conducting element (4).

7. laser diode device according to claim 6, wherein said heat conducting element (4) is fixed on the described installing component (11) by means of described the first solder layer (3), and described laser diode chip (2) is fixed on the described heat conducting element (4) by means of the second solder layer (5), and described the second solder layer has the thickness more than or equal to 3 μ m.

8. according to claim 6 or 7 described laser diode devices, wherein said heat conducting element (4) has SiC, BN, CuW or diamond.

9. according to the described laser diode device of one of the claims, wherein be applied with case lid (14) and described case lid and described housing parts (10) welding at described housing parts (10), and described installing component (11) reaches the described case lid (14) from described housing parts (10) along described bearing of trend (110).

10. laser diode device according to claim 9, wherein said installing component (11) vertically extends described case lid (14) in a side at least with described bearing of trend (110).

11. according to claim 9 or 10 described laser diode devices, wherein said housing parts (10) and described case lid (14) have circular cross section in the plane perpendicular to described bearing of trend (110), and described installing component (11) has the cross section greater than semi circular surface in the plane perpendicular to described bearing of trend (110).

12. according to the described laser diode device of one of the claims, wherein said installing component (11) has the cross section that increases towards housing parts (10).

13. laser diode device according to claim 12, wherein said installing component (11) has wedge-shaped cross-section in the plane that is parallel to described bearing of trend (110).

14. laser diode device according to claim 13, wherein said housing parts (10) has wedge-shaped cross-section in the plane that is parallel to described bearing of trend (110).

15. according to the described laser diode device of one of the claims, wherein said laser diode chip (2) has radiation coupling output face (27), is applied with the protective layer (6) of crystallization in described radiation coupling output face.