JP2016092288A - Light source device and illumination device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device capable of turning off a semiconductor light emitting element, and turning on an alarm by determining the falling of a wavelength conversion member and the prediction of the falling.SOLUTION: A strain gauge 21a for detecting an internal stress is formed on the upper face of a holding member 21. The strain gauge 21a is formed with electrodes 21a-1 and 21a-2 at both ends on the upper face of the holding member 21. Extraction electrodes 22b-1 and 22b-2 are also formed on the upper face of the holding member 21. A strain gauge 22a for detecting an internal stress is formed on the lower face of a wavelength conversion member 22. The strain gauge 22a is formed with electrodes 22a-1 and 22a-2 at both ends on the lower face of the wavelength conversion member 22. The wavelength conversion member 22 is joined via a metallic bump 231 to the holding member 21, and electrodes 22a-1 and 22a-2 of the strain gauge 22a are also connected via a metallic bump 231' to the extraction electrodes 22b-1 and 22b-2 of the holding member 21.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a light source device using, for example, laser light and an illumination device using the same.

  Conventionally, in a light source device using laser light, a wavelength conversion member is provided, and wavelength conversion is performed by absorbing a part of the laser light, and color-mixed light such as white is obtained by mixing the wavelength-converted light and the light that is not wavelength-converted. Emits light. In this case, since the laser light is coherent light, if it is directly irradiated to a person or an object, damage is caused, and in particular, if it is irradiated to the human eye, it causes serious adverse effects such as blindness. However, since the laser light is usually scattered by the above-described wavelength conversion member to become incoherent light and spread in a Lambertian shape, it does not adversely affect humans.

  By the way, when the wavelength conversion member falls off due to some internal factor or external factor, the laser beam is directly emitted to the outside and directly illuminates a person or an object. Therefore, there is a need for a fail-safe mechanism that prevents such laser light from being emitted directly to the outside.

  In the first conventional light source device provided with the fail-safe mechanism, an optical sensor for detecting the light intensity of the emitted light is provided on an optical path for separating a part of the emitted light of the wavelength conversion member. At this time, if the coherent light is converted into incoherent light by the wavelength conversion member, the emitted light becomes incoherent light, and the light intensity of the emitted light is reduced. However, if the wavelength conversion member is dropped, the emitted light is reduced. Remains coherent and the intensity of the emitted light increases. Therefore, it is determined whether or not the light intensity detected by the optical sensor exceeds a threshold value, and when the light intensity exceeds the threshold value, it is determined that the wavelength conversion member has been dropped, and laser light emission is stopped (see : Patent Document 1). In this case, the wavelength conversion member can be predicted to drop according to the output of the optical sensor.

  In the second conventional light source device provided with the fail safe mechanism, the first energization path of the laser diode element and the second energization path in which the conductor pattern is connected to the wavelength conversion member are connected in series. As a result, when the second energization path is cut by dropping the wavelength conversion member, the first energization path is also cut to stop laser light emission (see Patent Document 2).

JP 2012-2871 A JP 2014-165450 A

  However, in the first conventional light source device described above, since the optical sensor is provided in the vicinity of the optical system, the size of the device is increased, and the optical sensor is expensive.

  Further, in the above-described second conventional light source device, it is possible to determine whether the wavelength conversion member is dropped by cutting the second energization path in which the conductor pattern is connected to the wavelength conversion member, but there is no prediction of the wavelength conversion member being dropped. There is a problem that it is possible.

  In order to solve the above-described problems, a light source device according to the present invention includes a semiconductor light emitting element, a wavelength conversion member that converts a part of light emitted from the semiconductor light emitting element, and a holding member that holds the wavelength conversion member. And a strain gauge provided on at least one of the wavelength conversion member and the holding member. Furthermore, a control unit for controlling the semiconductor light emitting element according to the voltage of the strain gauge is provided. The control unit turns off the semiconductor light emitting element when it is judged that the wavelength conversion member is dropped by the voltage of the strain gauge, and the control unit turns on the alarm when it is judged that the wavelength conversion member is likely to fall off by the voltage of the strain gauge. .

  According to the present invention, the semiconductor light emitting element can be turned off and the alarm can be turned on by determining whether or not the wavelength conversion member is dropped and without predicting the dropping without increasing the size of the apparatus and increasing the manufacturing cost. .

It is sectional drawing which shows 1st Embodiment of the light source device which concerns on this invention. It is sectional drawing which shows the detail of the wavelength conversion module of FIG. The strain gauge of FIG. 1 is shown, (A) is a top view of a holding member, (B) is a bottom view of a wavelength conversion member. It is a detailed circuit diagram of the control module of FIG. It is a flowchart for demonstrating operation | movement of the control unit of FIG. It is a graph which shows the example of the correction coefficient (alpha) of steps 504 and 507 of FIG. It is a flowchart for demonstrating the manufacturing method of the light source device of FIG. It is sectional drawing which shows 2nd Embodiment of the light source device which concerns on this invention. It is a flowchart for demonstrating the manufacturing method of the light source device of FIG. FIG. 1 shows a vehicle headlamp using the light source device of FIG. 1 or FIG. 8, (A) shows a projector type vehicle headlamp, and (B) shows a reflector type vehicle headlamp. C) is a view showing a direct projection type vehicle headlamp.

FIG. 1 is a sectional view showing a first embodiment of a light source device according to the present invention. In FIG. 1, the light source module 1 and the wavelength conversion module 2 are separated from each other and are connected by an optical fiber 3. An incident side optical fiber connector 31 and an output side optical fiber connector 32 are provided at both ends of the optical fiber 3. The control module 4 detects the strain gauge voltages V _g1 and V _g2 from the wavelength conversion module 2 and controls the light source module 1 and the alarm 5. A light source switch 6 is connected to the control module 4. A temperature sensor 7 made of a thermistor or the like is provided in the vicinity of the strain gauge of the wavelength conversion module 2, and the control module 4 corrects the strain gauge voltages V _g1 and V _g2 according to the temperature T of the temperature sensor 7. An optical system such as a mirror or a lens can be used instead of the optical fiber 3.

  The light source module 1 includes a laser diode element 11, a stem 12 on which the laser diode element 11 is mounted, and a light emitted from the laser diode element 11 on the incident end face of the incident side optical fiber connector 31 of the optical fiber 3. For example, a convex lens 13 made of an aspherical lens, a metal holding the convex lens 13, for example, a stainless steel housing 14, and an external terminal 15 provided on the stem 12, the CAN type package is used. The laser diode element 11 is, for example, a GAInN blue semiconductor laser diode element that emits blue light of about 400 to 460 nm.

  The wavelength conversion module 2 receives the laser light emitted from the light source module 1 through the optical fiber 3 and is connected to the output-side optical fiber connector 32 of the optical fiber 3, a wavelength conversion member 22, It consists of the junction part 23 which joins the wavelength conversion member 22 on the holding member 21, and the reflection member 24 which reflects the light from the wavelength conversion member 22 and the junction part 23.

  For example, the laser light is blue laser light, and the wavelength conversion member 22 includes a diffusion material such as a YAG phosphor that converts blue laser light into yellow light and aluminum oxide (alumina). In this case, yellow light that has been partially wavelength-converted in a complementary color relationship and blue light that has not been converted are mixed, and white light is emitted from the wavelength conversion member 22.

  The upper surface of the holding member 21 is provided with a later-described strain gauge 21a (see FIG. 3A) for detecting the internal stress of the holding member 21, and the lower surface of the wavelength converting member 22 is provided with the inside of the wavelength converting member 22. A strain gauge 22a (see FIG. 3B) to detect stress is provided.

  FIG. 2 is a sectional view showing details of the wavelength conversion module 2 of FIG.

  The holding member 21 is for holding the wavelength conversion member 22, and a cap 211 made of a metal such as aluminum, nickel, stainless steel, zirconia, and the like, and aluminum nitride and aluminum oxide into which the output side optical fiber connector 32 of the optical fiber 3 is inserted. It is comprised by the submount 212 which consists of ceramics. The cap 211 and the submount 212 are joined by a heat conductive adhesive layer 213 (or a brazing agent layer or an AuSn solder layer). The optical fiber 3 in FIG. 1 passes through the through hole 211 a of the cap 211 of the holding member 21 and contacts the center of the wavelength conversion member 22.

  The wavelength conversion member 22 absorbs a part of the laser light emitted from the light source module 1 and converts the wavelength, and mixes the wavelength-converted light and the light that is not wavelength-converted to emit mixed color light. And a wavelength conversion layer 221, and more preferably includes a light scattering layer 222, a dielectric multilayer reflection layer 223, and a metal reflection layer 224.

  The wavelength conversion layer 221 is made of a translucent material containing a phosphor. For example, a phosphor-dispersed glass in which a phosphor is dispersed in glass, a glass phosphor in which a luminescent center ion is added to a glass matrix, a phosphor-dispersed resin in which phosphor particles are dispersed in, for example, a silicone resin, and a phosphor in which a phosphor material is sintered It is composed of a sintered body, a phosphor ceramic sintered body obtained by sintering a ceramic in which a phosphor material is dispersed, or a glass / ceramic coated phosphor particle fixed body in which phosphor particles coated with glass or ceramic are fixed to each other. In particular, a phosphor-dispersed glass, a glass phosphor, a phosphor sintered body, or a phosphor ceramic sintered body having a relatively high heat resistance can be suitably used. For example, a YAG ceramic sintered body having a thickness of about 50 μm in which a YAG phosphor is dispersed in aluminum oxide is used.

  The phosphor described above can be appropriately selected according to the wavelength of the light emitted from the light source module 1 and the desired emission color of the light source device, and may contain a plurality of types of phosphors. May be.

Examples of the phosphor include those excited by blue light having a wavelength of about 440 nm to about 470 nm, such as CaAlSiN ₃ : Eu ²⁺ , (Ca, Sr) AlSiN ₃ : Eu ²⁺ , Ca ₂ Si ₅ N ₈ : Eu ^2+. , (Ca, Sr) ₂ Si ₅ N ₈ : Eu ²⁺ , KSiF ₆ : Mn ⁴⁺ , KTiF ₆ : Mn ^{4+ and} other red phosphors, Y ₃ Al ₅ O ₁₂ (YAG): Ce ³⁺ , (Sr, Ba) ₂ SiO ₄ : Eu ²⁺ , Ca _x (Si, Al) ₁₂ (O, N) ₁₆ : Eu ²⁺ , (La, Y) ₃ Si ₆ N ₁₁ : Ce ^{3+ and} other yellow phosphors, Lu ₃ Al ₅ O ₁₂ : Ce ³⁺ , (Lu, Y) ₃ Al ₅ O ₁₂ : Ce ³⁺ , Y ₃ (Ga, Al) ₅ O ₁₂ : Ce ³⁺ , Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce ³⁺ , CaSc ₂ O ₄ : Eu ²⁺ , (Ba, Sr) ₂ SiO ₄ : Eu ²⁺ , Ba ₃ Si ₆ O ₁₂ N ₂ : Eu ²⁺ , (Si, Al) ₆ (O, N) ₈ : Eu ²⁺ A phosphor can be used.

  The light scattering layer 222 is made of a translucent material having a thickness of about 300 μm, such as glass or resin, which contains light scattering particles made of ceramic such as polycrystalline aluminum oxide (alumina), in particular, a translucent material having high heat resistance. Become. The light scattering layer 222 is preferably provided between the wavelength conversion layer 221 and the light source module 1 as shown in FIG.

The dielectric multilayer reflective layer 223 is configured as SiO _2, a dielectric material are laminated alternately, for example a thickness of about 3μm such as TiO _2, and transmitted by for example the blue light emitted from the light source module 1, the wavelength conversion layer It is optically designed to reflect, for example, yellow light converted by the phosphor 221. Thereby, the return light to the light source module 1 is suppressed. The dielectric multilayer reflective layer 223 is formed over the entire light source module 1 side of the wavelength conversion layer 221.

  The metal reflection layer 224 is made of a metal such as aluminum having a high reflectivity with respect to the light emitted from the optical module 1, for example, 85% or more. The metal reflection layer 224 is formed in a region other than the region where the optical fiber 3 exists.

The joint portion 23 between the holding member 21 and the wavelength conversion member 22 has metal bumps 231. The metal bump 231 preferably has high thermal conductivity, and is made of a metal such as Au, Al, Cu, Ag, or Ni, a solder such as SnAg, or an alloy such as AuSn. The metal bump 231 has, for example, a diameter of about 75 μm and a height of about 20 μm, and melts the tip of the metal wire into a ball shape, or a sintered material of metal particles such as Au particles, Ag particles, or Cu particles. The binder is formed by supplying it onto the holding member 21.

Ti (0.06 μm) / Pt (0.2 μm) / Au (1.0 μm) or Ti (0.06 μm) is provided in the joining region of the holding member 21 and the wavelength conversion layer 22 joined via the metal bump 231. Bonding metal layers 232 and 233 made of / Ni (0.2 μm) / Au (1.0 μm) are formed. As a result, metal atoms are diffused between the metal bumps 231 and the bonding metal layers 232 and 233 to form solid phase diffusion bonding, thereby ensuring sufficient mechanical strength. As a method for forming the metal bump 231, the metal bump 231 can be formed by a plating method depending on the composition of the bump, or a ball bonding method using a fine metal wire by a ball bonder used at the time of wire bonding. The joint 23 using the metal bump 231 is superior in joining reliability and heat dissipation compared to a heat conductive adhesive such as low melting point glass or resin.
In addition, it is preferable that the linear expansion coefficients of the holding member 21 and the wavelength conversion member 22 are close to each other in order to suppress generation of thermal stress on the joint portion 23.

  The reflecting member 24 is disposed on the holding member 21 and surrounds the joint portion 23 between the holding member 21 and the wavelength converting member 22. The reflecting member 24 is disposed on the holding member 21 and separates the side surfaces of the frame 241 and the wavelength converting member 22. The surrounding frame 242 and the reflective layer 243 filled between the side surface of the wavelength conversion member 22 and the frame 241 are configured.

The frame 241 prevents the reflection layer 243 from entering the bottom of the wavelength conversion member 22 and prevents light from the joint 23 from entering the side surface of the wavelength conversion member 22. The frame 241 is formed of a thixotropic resin or glass that can be supplied onto the holding member 21 with a high viscosity when applied and formed with a material having fluidity. For example, it is formed of a silicone resin containing light scattering particles made of titanium dioxide.
The frame 242 serves to block the reflective layer 243. The frame 242 is formed of a thixotropic resin or glass that can be replenished on the holding member 21 with a high viscosity when it is applied and formed with a material having fluidity.
Since the reflective layer 243 is in close contact with the side surface of the wavelength conversion member 22, the light emitting surface shape and size of the wavelength conversion member 22 are determined, and the luminance difference between the light emitting portion and the non-light emitting portion is clarified. Can be clarified. For example, when the light source device is used as a vehicle headlamp, the cut-off line can be made clear. The reflective layer 243 is formed of a translucent material in which translucent scattering particles are dispersed, for example, resin or glass.

  A strain gauge 21 a for detecting internal stress of the holding member 21 is formed on the upper surface of the holding member 21, specifically, on the bonding metal layer 232 on the submount 212 so as not to contact the metal bump 231. Has been. That is, as shown in FIG. 3A, the strain gauge 21a is a zigzag-shaped resistor whose electrical resistance changes greatly due to deformation, such as an alloy such as a copper-nickel alloy or a platinum-tungsten alloy, or an electrical resistivity due to stress. It is made of a semiconductor such as carbon, germanium, silicon or the like to which an appropriate impurity is added that exhibits a so-called piezoresistance effect. In this case, if the wavelength converting member 22 is likely to fall off due to dropping or cracking, the resistance value of the strain gauge 21a increases. The strain gauge 21a is formed on the upper surface of the joining metal layer 232 of the holding member 21 via an insulating layer, for example, a silicon oxide layer 21b (see FIG. 2), along with the electrodes 21a-1 and 21a-2 at both ends. At this time, lead electrodes 22b-1 and 22b-2 connected to electrodes 22a-1 and 22a-2 of a strain gauge 22a described later are also formed on the upper surface of the holding member 21. 3A, the through hole 21c corresponds to the through hole 211a of the cap 211 in FIG.

  On the lower surface of the wavelength conversion member 22, more precisely, on the lower surface of the bonding metal layer 233, a strain gauge 22 a for detecting internal stress of the wavelength conversion member 22 is formed so as not to contact the metal bump 231. Has been. That is, as shown in FIG. 3B, the strain gauge 22a is also a zigzag resistor, an alloy having a large change in electric resistance due to deformation, or a semiconductor having a so-called piezoresistance effect in which the electric resistivity changes due to stress. It becomes more. Also in this case, the resistance value of the strain gauge 22a increases when the wavelength conversion member 22 is likely to drop due to dropping or cracking. The strain gauge 22a is formed on the lower surface of the wavelength conversion member 22a together with the electrodes 22a-1 and 22a-2 at both ends thereof via an insulating layer such as a silicon oxide layer 22c (see FIG. 2). The wavelength conversion member 22 has a predetermined shape that can be flattened in a flat plate shape. In the case of a vehicle headlamp, the wavelength conversion member 22 has, for example, a rectangle of about 0.4 mm × about 0.8 mm. In FIG. 3B, the laser beam irradiation range 22d substantially corresponds to the through hole 211a of the cap 211 in FIG.

  When the wavelength conversion member 22 is joined to the holding member 21 via the metal bump 231, the electrodes 22 a-1 and 22 a-2 of the strain gauge 22 a are also connected to the lead electrode 22 b-1 of the holding member 21 via the metal bump 231 ′. , 22b-2. In this case, the metal bump 231 ′ is made of the same material as the metal bump 231 and is formed at the same time, but is slightly smaller than the metal bump 231.

The electrodes 21a-1 and 21a-2 of the strain gauge 21a of the holding member 21 and the lead electrodes 22b-1 and 22b-2 of the strain gauge 22a of the wavelength conversion member 22 protrude to the outside of the frame 241 in FIG. The control module 4 is connected by an Au wire, a ribbon, a flexible substrate, or the like. Thereby, the voltages V _g1 and V _g2 of the strain gauges 21 a and 21 b are taken out to the control module 4.

  FIG. 4 is a detailed circuit diagram of the control module 4 of FIG.

4, the control module 4 includes a voltage detection circuit 41 that detects the strain gauge voltage V _g1 of the holding member 21, a voltage detection circuit 42 that detects the strain gauge voltage V _g2 of the wavelength conversion member 22, and a laser diode of the light source module 1. It comprises a laser diode element driving circuit 43 for driving the element 11 and a control unit 44 comprising a microcomputer. The microcomputer includes a CPU, a ROM, a RAM, an analog / digital (A / D) converter, and the like.

  The voltage detection circuit 41 includes resistors 4111, 4112, and 4113, and includes a bridge circuit 411 configured with the strain gauge 21a, an operational amplifier 4121, and resistors 4122 and 4123, and amplifies a differential voltage between two outputs of the bridge circuit 411. Differential amplifier 412. Similarly, the voltage detection circuit 42 includes resistors 4211, 4212, and 4213, and includes a bridge circuit 421 configured with the strain gauge 22a, an operational amplifier 4221 and resistors 4222 and 4223, and a difference between two outputs of the bridge circuit 421. And a differential amplifier 422 for amplifying the voltage.

  FIG. 5 is a flowchart for explaining the operation of the control unit 44 of FIG. The routine shown in FIG. 5 is executed every predetermined time.

  First, in step 501, it is determined whether or not the light source switch 6 is on. The process proceeds to step 502 only when the light source switch 6 is on. On the other hand, when the light source switch 6 is off, the laser diode element 11 is turned off at step 511 and the alarm 5 is turned off at step 512.

  In step 502, the temperature T of the temperature sensor 7 is A / D converted and captured.

Next, in step 503, the strain gauge voltage V _g1 of the strain gauge 21a (actually, the output voltage V _d1 of the voltage detection circuit 41) is A / D converted and captured.

Next, in step 504, the temperature dependence of the strain gauge voltage _Vg1 is corrected. For example, when the temperature T rises, the strain gauge voltage V _g1 rises, so the correction coefficient α shown by the solid line in FIG.
V _g1 ← V _g1・ α
The strain gauge voltage V _g1 is corrected as follows. When the strain gauge 21a is formed of a semiconductor, it shows negative temperature dependence, so the correction coefficient α indicated by the dotted line in FIG. 6 is read.

Next, in step 505, it is determined whether or not the wavelength conversion member 22 has dropped out depending on whether or not V _g1 ≧ V _R1 (predetermined value). As a result, when V _g1 ≧ V _R1 , it is considered that the wavelength conversion member 22 has dropped, and the laser diode element 11 is turned off in step 511 to prevent the generation of coherent light, and the alarm 5 is turned off in step 512. And On the other hand, when V _g1 <V _R1 , the process proceeds to step 506.

In step 506, the strain gauge voltage V _g2 (actually, the output voltage V _d2 of the voltage detection circuit 42) is A / D converted and taken in, and then in step 507, as in step 504, the strain gauge voltage V _g2
V _g2 ← V _g2・ α
Correction and, at step _508, the wavelength conversion member 22, it is determined whether or not to fall off depending on whether the _{V g2} ≧ _{V R1.} As a result, when V _g2 ≧ _VR1 , it is considered that the wavelength conversion member 22 has dropped, and the laser diode element 11 is turned off in step 511 to prevent the generation of coherent light, and the alarm 5 is turned off in step 512. And On the other hand, when V _g2 <V _R1 , the process proceeds to step 509.

Thus, when either of the strain gauge voltages V _g1 and V _{g2 is} equal to or higher than V _R1, it is considered that the wavelength conversion member 22 has fallen, and the laser diode element 11 is turned off, thereby emitting coherent light. Stop.

In step 509, the wavelength conversion member 22 is cracked by, for example, the joint 23 depending on whether or not the strain gauge voltage V _g1 is V _d1 ≧ V _R2 (predetermined value), but V _R2 is smaller than V _R1. It is determined whether or not is in a state where it is likely to drop out. As a result, when V _g1 ≧ _VR2 , it is considered that the wavelength conversion member 22 is likely to fall off, and the laser diode element 11 is turned on at step 513, but the alarm 5 is turned on at step 514 as a prediction of dropping. To do. On the other hand, when V _g1 <V _R2 , the _routine proceeds to step 510.

In step 510, the strain gauge voltage _{V g2} is the wavelength conversion member 22 by whether _{V g2} ≧ _{V R2} it is determined whether the likely condition falling. As a result, when V _g2 ≧ _VR2 , it is considered that the wavelength conversion member 22 is likely to fall off, and in step 513, the laser diode element 11 is turned on. In step 514, the alarm 5 is turned on as a prediction of dropping. . On the other hand, when V _g2 <V _R2 , the process proceeds to step 515.

Thus, even if considered as the wavelength conversion member 22 is not falling, the strain when any of the gauge voltage V _g1, V _g2 is equal to or higher than V _R1 below and V _R2, likely the wavelength conversion member 22 falls off Assuming that the laser diode element 11 is turned on, the alarm 5 is turned on as a prediction that the laser diode element 11 will drop off.

  On the other hand, in step 515, the laser diode element 11 is turned on as a normal state, and then in step 516, the alarm 5 is turned off.

  In step 517, this routine ends.

  FIG. 7 is a flowchart for explaining a method of manufacturing the light source device of FIG.

  In the holding member (excluding the cap) forming step 701, for example, about 0.6 μm thick Ti, about 0.2 μm thick Pt, and about 1.0 μm thick Au are sputtered onto the submount 212 made of, for example, AlN. Then, the bonding metal layer 232 is formed by sequentially forming the layers. Next, a silicon oxide layer 21b is formed by a CVD method, a strain gauge alloy or a semiconductor is formed thereon by a sputtering method or the like, and is patterned by a photolithography / etching method to form a strain gauge 21a in FIG. Electrodes 21a-1, 21a-2 and lead electrodes 22b-1, 22b-2 are formed. Next, the through hole 21c corresponding to the through hole 211a of the cap 211 is opened and separated into pieces by dicing.

On the other hand, in the wavelength converting member forming step 702, for example, a YAG ceramic sintered body is prepared as the wavelength converting layer 221, and thin polycrystalline alumina is dispersed and laminated on the wavelength converting layer 221 and integrally sintered to form a light scattering layer. 222 is formed. Next, a dielectric multilayer reflective layer 223 composed of alternating layers of SiO ₂ and TiO ₂ , a metal reflective layer 224 composed of aluminum, for example, Ti having a thickness of about 0.6 μm, P having a thickness of about 0.2 μm, and a thickness of about 1 A bonding metal layer 233 made of 0.0 μm Au is formed by sputtering. Next, a silicon oxide layer 22c is formed by a CVD method, and a strain gauge alloy or semiconductor is formed on the silicon oxide layer 22c by a sputtering method or the like, and is patterned by a photolithography / etching method to form the strain gauge 22a in FIG. Electrodes 22a-1 and 22a-2 are formed. Next, it is separated into pieces by dicing.

  Next, in the wavelength conversion member / holding member (excluding cap) bonding step 703, a metal bump 231 made of Au is formed on the bonding metal layer 232 of the holding member 21 using a wire bonding apparatus using a gold wire. At the same time, a metal bump 231 ′ made of Au is formed on the extraction electrodes 22b-1 and 22b-2. The size of the metal bump 231 ′ is slightly smaller than the size of the metal bump 231. Next, the wavelength conversion member 22 is bonded onto the metal bumps 231 and 231 ′ of the holding member 21 by thermocompression bonding with ultrasonic vibration. As a result, the bonding metal layer 232 on the holding member 21 and the bonding metal layer 233 on the wavelength conversion member 22 are connected by the metal bumps 231 and, at the same time, the electrode 22a of the strain gauge 22a on the wavelength conversion member 22 side. -1 and 22a-2 are connected to the extraction electrodes 22b-1 and 22b-2 on the holding member 21 side by metal bumps 231 '.

  Next, in the cap bonding step 704, the submount 212 in which the wavelength conversion member 22 is bonded to the cap 211 is bonded by the thermally conductive adhesive layer 213 containing Ag filler.

  Next, in the reflecting member process 705, a silicone resin containing light scattering particles made of titanium dioxide is applied on the submount 212 so as to cover the joint portion 23 using a liquid dispensing apparatus, and a height of about 200 μm is applied. A frame 241 is formed. In this case, the wavelength conversion layer 221 is not covered. Thereby, the junction part 23 becomes a closed space. Next, a silicone resin containing light scattering particles made of titanium dioxide is applied onto the cap 211 by using a liquid quantitative discharge device to form a frame 242 having a height of about 880 μm and approximately the same height as the wavelength conversion layer 221. At this stage, a flexible substrate or the like is connected so that the electrodes 22 a-1 and 22 a-2 and the extraction electrodes 22 b-1 and 22 b-2 on the holding member 21 can be connected to the control module 4. Next, the reflective layer 243 is formed by filling a silicone resin containing light scattering particles made of titanium dioxide having high fluidity between the frame 241 and the frame 242 using a liquid quantitative discharge device, and the wavelength conversion layer 221. The side surface is completely covered by the reflective layer 243. Thereby, the wavelength conversion module 2 is completed.

  Finally, in the wavelength conversion module / light source module joining step 706, one end of the optical fiber 3 is attached to the light source module 1 via the incident side optical fiber connector 31, and the other end of the optical fiber 3 is connected to the output side optical fiber connector 32. It is attached to the wavelength conversion module 2 via At this time, the optical fiber 3 passes through the through hole 211 a of the cap 211 and comes into contact with the wavelength conversion member 22. Thereby, the light source device of FIG. 1 is completed.

  FIG. 8 is a sectional view showing a second embodiment of the light source device according to the present invention. In FIG. 1, the light source module 1 and the wavelength conversion module 2 are connected by a ring-shaped attachment member 3 ′. Accordingly, the optical fiber 3 of FIG. 1, its incident side optical fiber connector 31 and emission side optical fiber connector 32. Is not provided.

  In FIG. 8, the convex lens 13 made of an aspheric lens concentrates the emitted light from the laser diode element 11 on the incident end face of the cap 211. Thereby, the laser light from the laser diode element 11 passes through the through hole 211a of the cap 211 and irradiates the wavelength conversion member 22.

  FIG. 9 is a flowchart for explaining a method of manufacturing the light source device of FIG. In FIG. 9, a wavelength conversion module / light source module joining step 706 'is provided instead of the wavelength conversion module / light source module joining step 706 of FIG.

  In the wavelength conversion module / light source module joining step 706 ', the lower end of the attachment member 3' made of SUS is joined to the light source module 1 by welding using a centering machine. Next, the cap 211 of the wavelength conversion module 2 and the upper end of the attachment member 3 ′ are connected by a heat conductive adhesive layer (not shown). Thereby, the light source device of FIG. 8 is completed.

  The light source device in the above-described embodiment is applied to the vehicle headlamp shown in FIG.

  For example, FIG. 10A shows a projector (projection) type vehicle headlamp, and the light source device 101 has the light source device of FIG. 1 or FIG. 8 arranged upward. A cut-off line forming light shield provided between the reflector 102 provided so as to cover from the side of the light source device 101 to the front and the projection lens 103 disposed on the front side of the vehicle so that the oncoming vehicle is not dazzled. The member (shade) 104 constitutes the projection optical unit U1.

  The reflector 102 has a spheroid made of a highly reflective metal reflective layer made of Al, Ag or the like formed on the inner surface of the molded resin base material. In this case, the first focal point F1 of the reflector 102 exists in the vicinity of the wavelength conversion member 22 (see FIGS. 1 and 8) of the light source device 101, while the second focal point F2 of the reflector 102 exists in the vicinity of the shade 104. Accordingly, an image in the vicinity of the wavelength conversion member 22 of the light source device 101 is formed as a light distribution pattern on the virtual vertical screen facing the front end of the vehicle by the projection optical unit U1. At this time, the projected light distribution pattern is shielded by the shade 104 to form a cut-off line.

  FIG. 10B shows a reflector type vehicle headlamp, and the light source device 201 has the light source device of FIG. 1 or FIG. 8 arranged upward. A reflector 202 provided so as to cover from the side of the light source device 201 to the front constitutes the projection optical unit U2.

  The reflector 202 has a paraboloid body made of a molded resin base material and a highly reflective metal reflective layer made of Al, Ag or the like formed on the inner surface thereof. However, in this case, the reflector 202 may be partitioned into small reflection areas. Moreover, it includes not only a rotating paraboloid but also a free-form surface based on a paraboloid. The focal point F3 of the reflector 202 exists in the vicinity of the wavelength conversion member 22 (see FIGS. 1 and 8) of the light source device 201. Accordingly, an image in the vicinity of the wavelength conversion member 22 of the light source device 201 is formed as a light distribution pattern on the virtual vertical screen facing the front end of the vehicle by the projection optical unit U2, that is, the reflector 202.

  Further, FIG. 10C shows a direct-projection type vehicle headlamp, and the light source device 301 is obtained by arranging the light source device of FIG. 1 or FIG. 8 sideways. A projection lens 302 disposed on the front side of the vehicle and a shade 303 provided between the light source device 301 and the projection lens 302 constitute a projection optical unit U3.

  The focal point F4 of the projection lens 302 exists in the vicinity of the wavelength conversion member 22 (see FIGS. 1 and 8) of the light source device 301. Therefore, an image in the vicinity of the wavelength conversion member 22 of the light source device 301 is formed as a light distribution pattern on the virtual vertical screen facing the front end of the vehicle by the projection optical unit U3. At this time, the projected light distribution pattern is shielded by the shade 303 to form a cut-off line.

In the above-described embodiment, the voltage detection circuits 41 and 42 are always turned on to detect the voltages V _g1 and V _g2 of the strain gauges 21a and 22a, but the voltage detection circuits 41 and 42 are intermittently turned on. It may be. Thereby, power consumption can be reduced. However, in this case, the execution of the routine of FIG. 6 is also synchronized with the ON operation of the voltage detection circuits 41 and 42.

In addition, when the light source device is applied to an automotive headlamp, the environmental temperature increases, which may affect the voltages V _g1 and V _g2 of the strain gauges 21a and 22a. In this case, since the voltages V _g1 and V _g2 of the strain gauges 21a and 22a are corrected using the environmental temperature in steps 504 and 507 of FIG. 5, malfunction due to the environmental temperature can be prevented.

Furthermore, although the strain gauge is provided in both the holding member 21 and the wavelength conversion member 22, any one may be sufficient. In this case, the step relating to the strain gauge voltage V _g1 or the step relating to the strain gauge voltage V _g2 in FIG. 5 is omitted.

Furthermore, in the above-described embodiment, a light emitting diode (LED) element can be used instead of the laser diode element 11.
As the bonding portion 23, a heat conductive adhesive may be used instead of the metal bump 231 and the bonding metal layers 232 and 232.

  Furthermore, the present invention can be applied to any modifications within the obvious scope of the above-described embodiments.

  The present invention can be used for lighting devices for other vehicle lamps, indoor lighting, street lamps, endoscopes and the like in addition to the lighting device for a vehicle headlamp.

1: Light source module 11: Laser diode element 12: Stem 13: Convex lens 14: Housing 2: Wavelength conversion module 21: Holding member 211: Cap 211a: Through hole 212: Submount 213: Thermally conductive adhesive layer 21a: Strain gauge 21a-1, 21a-2: Electrode 21b: Silicon oxide layer 21c: Through hole 22: Wavelength conversion member 221: Wavelength conversion layer 222: Light scattering layer 223: Dielectric multilayer reflective layer 224: Metal reflective layer 22a: Strain gauge 22a -1, 22a-2: Electrodes 22b-1, 22b-2: Lead electrodes 22c: Silicon oxide layer 22d: Laser light irradiation range 23: Joining portion 231: Metal bump 231 ′: Metal bump 232, 233: Joining metal layer V _g1: strain voltage _{V g2} gauge 21a: voltage distortion gauge 22a 24: reflecting member 241: a frame 24 : Frame 243: Reflective layer 3: Optical fiber 31: Incident side optical fiber connector 32: Outgoing side optical fiber connector 3 ': Mounting member 4: Control module 41, 42: Voltage detection circuit 411, 421: Bridge circuit 412, 422: Differential amplifier 43: Laser diode element drive circuit 44: Control unit 5: Alarm 6: Light source switch 7: Temperature sensor 101: Light source device 102: Reflector 103: Projection lens 104: Shade 201: Light source device 202: Reflector 301: Light source device 302: Projection lens 303: Shades U1, U2, U3: Projection optical unit

Claims (9)

A semiconductor light emitting device;
A wavelength conversion member for wavelength-converting a part of the emitted light from the semiconductor light emitting element;
A holding member for holding the wavelength conversion member;
A light source device comprising: a strain gauge provided on at least one of the wavelength conversion member and the holding member. further,
The light source device according to claim 1, further comprising a control unit that controls the semiconductor light emitting element according to a voltage of the strain gauge.   3. The light source device according to claim 2, wherein when the voltage of the strain gauge is equal to or higher than a first predetermined value, the control unit considers that the wavelength conversion member is dropped and turns off the semiconductor light emitting element.   The control unit turns on an alarm as a prediction of dropout of the wavelength conversion member when the voltage of the strain gauge is less than a first predetermined value and greater than a second predetermined value smaller than the first predetermined value. 4. The light source device according to 3.   The light source device according to claim 1, wherein the semiconductor light emitting element is a laser diode element. Furthermore, it comprises a temperature sensor provided in the vicinity of the strain gauge,
The light source device according to claim 1, wherein the control unit corrects a voltage of the strain gauge according to a temperature of the temperature sensor. A semiconductor light emitting device;
A wavelength conversion member for wavelength-converting a part of the emitted light from the semiconductor light emitting element;
A holding member for holding the wavelength conversion member;
A first strain gauge provided on the wavelength conversion member side of the holding member, a first electrode connected to the first strain gauge, and an extraction electrode;
A second strain gauge provided on the holding member side of the wavelength conversion member and a second electrode connected to the second strain gauge;
A light source device comprising: a metal bump connecting the second electrode and the extraction electrode. further,
Control that is connected to the first electrode and the extraction electrode, detects the voltages of the first and second strain gauges, and controls the semiconductor light emitting element according to the voltages of the first and second strain gauges The light source device according to claim 7, further comprising a module. A light source device according to any one of claims 1 to 8,
An illumination device comprising: a projection optical unit that projects light emitted from the light source device in a predetermined direction.

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