JP2007335678A - Semiconductor laser light source apparatus, communication equipment using it, and lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor laser source apparatus superior in heat dissipation from a semiconductor laser element and is superior in long driving reliability in high output. <P>SOLUTION: The semiconductor laser source apparatus includes a substrate, a spot-facing hole formed on a surface of the substrate, and a first electrode which serves as a metal reflecting film arranged at least on a part of a surface of the spot-facing hole. In the semiconductor laser light source apparatus, the semiconductor laser element and a light scattering medium arranged around the semiconductor laser element are stored in the spot-facing hole in a state where the semiconductor laser element and the first electrode are electrically connected. A second electrode is arranged on the substrate, and the semiconductor laser element and the second electrode are connected by belt-like wiring. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductor laser light source device, and more particularly to improving long-term drive reliability of a high-power semiconductor laser element.

  In recent years, communication equipment using a semiconductor laser light source has been required to have a longer communication distance and further improved communication speed, and illumination equipment using a semiconductor laser light source device has been required to further improve brightness. It has been demanded. In order to meet this demand, it is necessary to improve the radiation intensity of the semiconductor laser light source device itself as the main body.

  On the other hand, when the semiconductor laser light source device is used indoors or the like, it is necessary to ensure safety for human eyes. For this reason, the maximum allowable radiation intensity is defined by IEC standards and the like.

  Here, the maximum allowable radiation intensity according to the IEC standard is also influenced by the laser wavelength and driving conditions (laser current, optical power, etc.). The main factor that determines the intensity is the apparent light source diameter (apparent light source diameter). It is known that the maximum allowable radiation intensity can be increased by increasing the diameter of the apparent light source.

  Therefore, a technique for increasing the maximum allowable radiation intensity by increasing the diameter of the apparent light source without increasing the size of the semiconductor laser light source itself has been proposed (for example, see Patent Document 1).

WO03-077389

  In order to increase the apparent light source diameter using the above technique, it is necessary to increase the intensity of the light emitted from the semiconductor laser element itself. Further, as described above, there is an increasing demand for increasing the radiation intensity, and attempts have been made to increase the light intensity of the semiconductor laser element by increasing the driving current and driving voltage of the semiconductor laser element.

  However, when the drive current or drive voltage is increased, the amount of heat generated by the semiconductor laser element increases accordingly. It is known that the light emission characteristics of a semiconductor laser element are greatly affected by changes in element temperature. In order to obtain a semiconductor laser light source with excellent long-term driving reliability, a semiconductor laser element (especially its active layer) is used. It is desired to quickly dissipate the generated heat to the outside of the light source device.

  FIG. 18 is a schematic sectional view of a conventional semiconductor laser light source device. As shown in FIG. 18, the periphery of the semiconductor laser element 1 is surrounded by a resin 4 containing light scattering particles 3, but this resin 4 has very poor thermal conductivity compared to metal or the like. For this reason, it is difficult to release heat from the upper surface side of the semiconductor laser element 1. Further, since the upper surface side of the semiconductor laser element 1 is a side from which light is extracted, it is difficult to process the heat radiation on the upper surface side of the semiconductor laser element 1.

  For this reason, attempts have been made to dissipate heat from the lower surface side of the semiconductor laser element 1. However, since the light emitting surface may be blocked by an adhesive material such as silver paste when the semiconductor laser element 1 is mounted, the semiconductor layer below the active layer (light emitting layer) in the semiconductor laser element 1 is provided to some extent. It needs to be thick. For this reason, in order to release the heat generated in the active layer of the semiconductor laser element 1 to the lower end portion, the semiconductor layer having a lower thermal conductivity than the metal must pass through a certain distance, resulting in poor heat dissipation efficiency.

  The present invention has been made in view of the above, and an object of the present invention is to provide a semiconductor laser light source device that has good heat dissipation from a semiconductor laser element and is excellent in long-term drive reliability at high output.

  The first aspect of the present invention for solving the above problem also serves as a substrate, a concave counterbore hole formed on the surface of the substrate, and a metal reflection film provided on at least a part of the surface of the counterbore hole. A first electrode; and the semiconductor laser element and a light scattering medium disposed around the semiconductor laser element in the counterbore, wherein the semiconductor laser element and the first electrode are electrically In the semiconductor laser light source device housed in a connected state, a second electrode is provided on the substrate, and the semiconductor laser element and the second electrode are connected by a strip-shaped wiring. It is characterized by.

  According to this configuration, the heat generated inside the semiconductor laser element is efficiently radiated to the outside of the semiconductor laser element by the strip-shaped wiring having a cross-sectional area larger than that of the conventional bonding wire. Therefore, long-term reliability during high output driving is improved.

  Here, the strip-shaped wiring means all wirings whose width is larger than the thickness.

In the above configuration, it is preferable that the cross-sectional area of the strip-like wiring is 2000 μm ² or more from the viewpoint of improving heat dissipation.

  Further, when the first electrode and the semiconductor laser element are in direct contact with each other, wiring between the first electrode and the semiconductor laser element can be eliminated.

  In addition, if an insulating film is formed on the surface of the strip-shaped wiring on the counterbore hole side, contact (short circuit) between the strip-shaped wiring and the first electrode can be reliably prevented.

  In the above configuration, the first electrode is formed on the entire surface of the counterbore hole, a part of the surface of the first electrode is covered with an insulating film, and the strip-shaped wiring is formed on the insulating film. It can be configured.

  The said structure WHEREIN: It can be set as the structure by which the said strip | belt-shaped wiring is formed in the part which is the said counterbore hole surface and the said 1st electrode is not formed.

  According to these configurations, the strip-like wiring can be formed by a method such as vapor deposition, and the manufacturing cost can be reduced.

  In the above-described configuration, the surface of the counterbore hole is electrically insulated from the first electrode also serving as the metal reflection film, the second electrode, and the first electrode and the second electrode. And the semiconductor laser element is mounted on the region where the first electrode is formed.

  According to this configuration, the length of the strip-like wiring can be shortened as compared with the case where the second electrode is formed on the substrate portion outside the counterbore hole, thereby further improving the heat dissipation. When this configuration is adopted, in order to increase the light efficiency of the semiconductor laser element, the laser emission end face of the semiconductor laser element is positioned on the first electrode (metal reflective film) side.

  As the strip-shaped metal wiring material, a known wiring material such as aluminum, gold, copper, or silver can be used.

  Moreover, as the strip-shaped wiring material, a conductive resin such as epoxy can be used. The thickness of the conductive resin is preferably 10 μm or more in order to ensure sufficient conductivity.

  The second aspect of the present invention for solving the above problem also serves as a substrate, a concave counterbore hole formed in the surface of the substrate, and a metal reflective film provided on at least a part of the surface of the counterbore hole. A first electrode; and the semiconductor laser element and a light scattering medium disposed around the semiconductor laser element in the counterbore, wherein the semiconductor laser element and the first electrode are electrically In the semiconductor laser light source device housed in a connected state, a second electrode is provided on the substrate, and the semiconductor laser element and the second electrode are connected by wiring, and the semiconductor A heat dissipation band for releasing heat generated by the laser element to the outside connects the semiconductor laser element and the substrate.

  According to the present invention, it is possible to improve the heat dissipation of a semiconductor laser element driven at a high output. By suppressing the increase in the operating temperature of the semiconductor laser element, the long-term driving reliability of the light source device can be improved. By using this, it is possible to realize a communication device that can perform high-speed communication and has a long communication distance, and a lighting device with high luminance.

(Embodiment 1)
FIG. 1 is a perspective view of a semiconductor laser light source device (module) according to the present embodiment.
In the light source device according to the present embodiment, a counterbore hole 2 is formed in a glass epoxy resin substrate 9, and the surface of the counterbore hole 2 is plated with gold to form a first electrode that also serves as a metal reflection film. In the center of the bottom surface of the counterbore hole 2, the semiconductor laser element 1 is mounted in a state of being electrically connected to the first electrode by silver paste or the like.

  Around the semiconductor laser element 1 and in the counterbore hole 2, a silicone resin 4 in which a light scattering material 3 is kneaded is accommodated, thereby forming a scattering region that functions as a light scattering medium. For this reason, the coherent light emitted from the semiconductor laser element 1 is sufficiently scattered by the surrounding light scattering material 3, and the light emitted from the light scattering region becomes incoherent and eye-safe light with a sufficiently wide light source diameter. .

  A strip-shaped metal wiring 5 is electrically connected to the second electrode 6 at the upper end of the semiconductor laser element 1 instead of the conventional bonding wire as shown in FIG. The strip metal wiring 5 becomes a path for releasing heat from the upper surface side of the semiconductor laser element 1. The metal wiring 5 is mounted on the upper surface of the semiconductor laser element 1 and on the end portion on the laser reflection end face side (end on the left end face in the drawing). Thereby, a light source diameter can be enlarged.

  In addition, an IC 8 for driving the semiconductor laser element 1 and a wire 7 for connecting the IC 8 and the electrode are formed on the substrate 9.

  FIG. 2 is a view of the module after forming the lens as viewed obliquely from above the substrate. FIG. 3 is a view of the completed module viewed from the substrate cross-sectional direction.

  As shown in FIGS. 2 and 3, a lens 10 made of an epoxy resin and integrated with a module element protection film 11 is formed on the substrate 9 and the resin 4.

  The semiconductor laser element 1 has a length of 500 μm, a width of 200 μm, and a height of 100 μm. The lower end surface of the semiconductor laser element 1 is electrically connected to the first electrode 2a through gold plating on the surface of the counterbore hole 2. On the other hand, the upper surface of the semiconductor laser element 1 is connected to the second electrode 6 via the strip-shaped metal wiring 5. As the metal wiring material, a highly conductive metal such as gold, aluminum, copper, or silver is used.

  As a method of bonding the band-shaped metal wiring 5 to the upper end surface of the laser element 1, a method similar to a conventional wire bonding method using heat, ultrasonic waves, pressure, or the like can be used. Moreover, you may adhere | attach the lower surface of a strip | belt-shaped metal wiring other than the method of adhere | attaching the edge part cross section of a strip | belt-shaped metal wiring. When such an adhesion method is used, the adhesion area becomes several times larger than that of the conventional one. However, by making the film thickness of the band-like metal wiring 5 about the diameter of the conventional bonding wire (about 25 μm), the pressure bonding is performed. In this case, it is possible to eliminate the need to change the amount of energy applied per unit area.

  The other end of the strip-shaped metal wiring 5 is connected to a second electrode 6 formed outside the counterbore hole 2. The thickness of the band-shaped metal wiring 5 was 25 μm (a value corresponding to the diameter of a general bonding wire), the width was 200 μm, and the length was 1 mm.

  In this state, the semiconductor laser device 1 was driven, and the state of the temperature rise was schematically examined. FIG. 4 shows a model of the heat dissipation mechanism of the light source device used in this embodiment. The driving conditions of the semiconductor laser element 1 are an injection current of 0.1 A, an applied voltage of 2.0 V, and an optical output of 0.08 W. Under these conditions, the amount of heat generated from the semiconductor laser element 1 is 0.12 W.

  The thermal resistance from the lower end surface of the semiconductor laser element 1 to the outside of the module is about 200 ° C./W, of which the thermal resistance from the active layer of the semiconductor laser element 1 to the electrode on the lower surface of the semiconductor laser element is 20 ° C./W, The thermal resistance from the bottom surface to the outside is 180 ° C./W. On the other hand, the thermal resistance from the second electrode 6 to which the wiring coming out from the upper end surface of the semiconductor laser element 1 is connected to the outside of the module is 180 ° C./W.

  When gold is selected as the material of the strip-shaped metal wiring 5, the thermal conductivity coefficient of gold is 315 W / m · ° C., and the thermal resistance is 630 ° C./W when calculated by applying to the above wiring shape. Under these conditions, the temperature rise due to heat generated from the semiconductor laser element 1 is 19.4 ° C. In addition, 0.096 W corresponding to 80% of the heat 0.12 W generated from the semiconductor laser element 1 flows from the lower end surface of the laser element 1 to the outside of the module, and 0.024 W corresponding to the remaining 20% flows from the upper end surface to the strip-shaped metal wiring 5. Flows out through.

  Here, when the material is made of aluminum in the band-shaped metal wiring, the temperature rise is 20 ° C. The thermal conductivity coefficient of aluminum is 237 W / m · ° C. Moreover, when copper with a thermal conductivity coefficient of 503 W / m · ° C. is used, the temperature rise is 18.6 ° C. From these facts, it can be seen that the higher the thermal conductivity coefficient, the more the temperature rise can be suppressed.

  Next, for comparison with the first embodiment, heat dissipation when a conventional bonding wire (diameter 25 μm) is used will be examined. In the case of a gold bonding wire, the thermal resistance is about 6450 ° C./W with a length of 1 mm, and 0.004 W, which is about 3% of the total heat generated from the semiconductor laser element 1, passes through the bonding wire from the upper end surface. The heat escapes to the outside, and the other heat of 0.116 W corresponding to 97% escapes from the lower end surface of the laser element 1. Further, the temperature rise due to heat generation of the laser element 1 is 23.2 ° C. Comparing the above results, in the case of the gold wiring, by using the strip-shaped metal wiring 5, 6 times or more of heat can be released from the upper surface compared to the case of the wire, and the temperature rise is reduced by about 4 ° C. Recognize.

Next, the temperature rise was measured when the thickness of the strip wiring was 10 μm. The width of the strip-shaped metal wiring is 200 μm. Therefore, the cross-sectional area of the strip-shaped metal wiring is 2000 μm ² . As a result, the amount of heat radiated from the upper end surface of the semiconductor laser element 1 through the strip metal electrode is 0.012 W, and the temperature rise is 21.6 ° C., which is 1.6 ° C. lower than the conventional bonding wire. It is done. From this result, even if the thickness of the strip-shaped metal wiring is reduced to about the minimum diameter of the conventional bonding wire, the effect of reducing the temperature rise is about three times that of the conventional bonding wire (0.004 W). It can be seen that it can be enlarged.

  Next, the temperature rise when a ceramic substrate was used instead of the glass epoxy substrate was examined. The thermal resistance from the counterbore or external electrode of the ceramic substrate to the outside of the device is 100 ° C./W. When the conventional bonding wire is used, the temperature rise is 14.1 ° C. In this case, the heat escaping from the upper end surface of the semiconductor laser element is 0.0024 W corresponding to 2% of the total calorific value, and the strip-like wiring is used. In this case, the temperature rise was 12.4 ° C., and the heat escaping from the upper end surface of the semiconductor laser element was 0.0168 W corresponding to 14% of the total calorific value.

  Since the heat dissipation of the ceramic substrate itself is better than that of the glass epoxy substrate, the difference from the conventional one is 1.7 ° C., which is smaller than that of the glass epoxy substrate, but the amount of heat escaping from the upper end surface of the semiconductor laser element is about 7 Can be doubled. In addition, it can be seen that the effect of temperature reduction in the case of forming the strip-shaped wiring is larger when the thermal resistance of the substrate is larger than the temperature difference in the case of the glass epoxy substrate. Here, although the ceramic substrate has high thermal conductivity, the price is expensive and easily broken, and the glass epoxy substrate is cheap and difficult to break, but the thermal conductivity tends to be poor. It is preferable to appropriately select the substrate material based on these.

(Embodiment 2)
In this embodiment, as shown in FIG. 5, a plurality of (three) band-like metal wirings 5 are mounted on the upper surface of the semiconductor laser element 1 to further improve the heat dissipation compared with the first embodiment. In this embodiment, the plurality of second electrodes 6 are electrically connected in the substrate so that signals from the plurality of strip-shaped metal wirings are not mixed. The material of the strip-shaped metal wiring 5 is gold.
Note that only one second electrode may be provided, and wirings other than the wiring connected to the second electrode may not be connected to the electrode, and may be a heat dissipation band (a band that is involved only in heat dissipation and does not send an electrical signal).

  FIG. 6 shows a model of the heat dissipation mechanism in the present embodiment. In FIG. 6, 1a represents a heat generation source. Specifically, it represents heat generated in the active layer of the laser element, and corresponds to a constant current source in the electric circuit. Moreover, 1b represents the thermal resistance of the semiconductor layer between the active layer and the laser bottom face electrode, and is about 20 ° C./W. And 12 connected to that is the thermal resistance between the counterbore surface and the outside of the module, which is about 180 ° C./W. On the other hand, R5a to R5c represent the thermal resistance of the three strip metal wires. If the width of the band-like metal wiring 5 on both side surfaces is 500 μm and the length is 1.1 mm, the thermal resistance of one side-band metal wiring is 280 ° C./W. It is 115 ° C./W when the thermal resistance of the wiring portion is measured on the assumption that the three strip metal wirings are connected in parallel. Reference numeral 13 denotes a thermal resistance between the external electrode to which the strip-shaped metal wiring is connected and the outside of the module.

  Based on these calculations, the amount of heat released from the upper end surface of the semiconductor laser device 1 to the outside is 0.048 W, which is 40% of the total heat generation amount, and the amount of heat released from the lower end surface is 0.072 W, which is 60% of the entire amount. The temperature rise due to heat generation is 14.4 ° C. Compared to conventional bonding wires, the temperature rise can be suppressed by about 9 ° C.

(Embodiment 3)
FIG. 7 is a schematic diagram of the third embodiment. This embodiment has the same structure except that the insulating resin film 14 is bonded to the back surface of the strip-shaped metal wiring 15 described in the first embodiment.

  The production method of the strip-shaped metal wiring with the resin film is as follows. A photosensitive resin is applied in advance to the back surface of the belt-like wiring 15, and then a mask is applied to irradiate light to cure only the portion of the resin that is desired to remain. Thereafter, the uncured resin is removed by etching. The portion from which the resin is removed has conductivity, and becomes a contact portion between the upper end surface of the laser element and the external electrode. Moreover, the resin film 14 can prevent a short circuit due to contact between the strip-shaped metal wiring and the first electrode formed on the surface of the counterbore.

(Embodiment 4)
FIG. 8 is a schematic diagram of the fourth embodiment. In this embodiment, the insulating resin film 16 is applied in a band shape on the surface of the counterbore hole, and a band-shaped metal wiring 17 is formed only by vapor deposition using a mask. As the insulating resin to be applied, the photocurable resin used in Embodiment Mode 3 is used. Further, the portions where the metal is deposited are the counterbore hole surface and the laser upper end surface, and these are not flat, so that the mask cannot be adhered. For this reason, it is necessary to increase the range in which the insulating resin is applied to some extent, but since there is no wiring above the semiconductor laser element 1, the light extraction efficiency is increased.

(Embodiment 5)
9 and 10 are schematic views of the light source device according to the fifth embodiment. This embodiment has two major differences from the first embodiment. The first difference is that the thickness of the band-like metal wiring 5 is several times thicker than that of the first embodiment. Specifically, three cases were considered in which the thickness of the strip-shaped metal wiring 5 was 25 μm, 50 μm, and 100 μm. Another difference is that by leaving a line-shaped insulating portion 18 that is not plated when metal plating is performed on the counterbore hole 2, a first electrode that also serves as a metal reflection film is formed on the inner surface of the counterbore hole 2, and 2 is formed, and the length of the strip-shaped metal wiring 5 is shortened. By adopting this configuration, it is possible to reduce the light extraction loss due to the band-shaped metal wiring 5.

  If the material of the band-shaped metal wiring 5 is gold, the length is 200 μm, and the width is 200 μm, the thermal resistance at a thickness of 25 μm is 127 ° C./W, and the thermal resistance at a thickness of 50 μm is 63.5 ° C./W. When the thickness is 100 μm, it is 31.8 ° C./W. From these numerical values, when the thickness of the band-shaped metal wiring 5 is 25 μm, the heat escaping to the outside through the upper surface of the semiconductor laser element 1 is 0.047 W corresponding to 39% of the total calorific value, and the temperature of the semiconductor laser element 1 When the temperature rises at 14.5 ° C. and 50 μm, the heat escaping to the outside through the upper surface of the semiconductor laser element 1 is 0.054 W corresponding to 45% of the total calorific value, and the temperature rise of the semiconductor laser element 1 is 13.2 ° C. and 100 μm. In this case, the heat escaping to the outside through the upper end surface of the semiconductor laser element 1 is 0.058 W corresponding to 48% of the total calorific value, and the temperature rise of the semiconductor laser element 1 is 12.3 ° C.

  Compared with the heat radiation by the conventional bonding wire, when the strip-like wiring thickness is 100 μm, the temperature rise of about 11 ° C. can be suppressed as compared with the conventional case.

  FIG. 11 is a graph showing the relationship between the thickness of the band-like wiring and the temperature rise when the length of the band-like metal wiring is 200 μm and 1000 μm. The lower curve is the value when the wiring length is 200 μm, and the upper curve is the value when the wiring length is 1000 μm. Comparing these, when the wiring length is 200 μm, the temperature rise can be lowered by 5 ° C. from 1000 μm. Further, when the length is 200 μm and the thickness of the wiring is changed from 25 μm to 100 μm, the change in temperature rise can be reduced by about 2.5 ° C. From these results, it can be seen that if the length of the strip metal wiring is shortened and the thickness is increased, the temperature rise can be largely suppressed.

  If the shortest wiring distance between the laser element and the external electrode is 200 μm, the temperature rise when heat does not escape from the upper end surface of the semiconductor laser element is 24 ° C., and in the case of conventional wire bonding, 2.8 from there In the case of a strip-shaped metal wiring having a temperature of 25 ° C. and a temperature of 25 μm, a temperature increase of 9.5 ° C. can be suppressed. Therefore, the effect of this embodiment is great.

(Embodiment 6)
FIG. 12 is a schematic diagram of the light source device used in the sixth embodiment. In this embodiment, there are three strip metal wires 5 as in the second embodiment, and the strip metal wires 5 extended from the side surface as in the fifth embodiment are in contact with the second electrode. In addition, the first electrode, the second electrode, and the insulating line 18 that insulates them are formed on the surface of the counterbore 2 as shown in FIG. The insulating line 18 is formed along three surfaces of the mounted semiconductor laser device 1 except for the light emitting surface (right side surface in the drawing). In this embodiment, the case where the thickness of the strip-like wiring is 25 μm and 100 μm is considered.

  The width of the band-shaped metal wiring 5 on the side surface portion is 500 μm and the length is 200 μm. When the thickness of the strip metal wiring 5 is 25 μm, the thermal resistance of the strip metal wiring 5 is 51 ° C./W. In this case, since the three strip metal wires 5 extending from the upper end surface of the semiconductor laser element 1 are connected in parallel as shown in FIG. 5, the total thermal resistance is 21.3 ° C./W. Based on this numerical value, the amount of heat released from the upper surface to the outside is 0.06 W corresponding to 50% of the total calorific value, and the temperature rise is 12 ° C. When the thickness of the strip-shaped metal wiring 5 is 100 μm, the total thermal resistance of the three parallel connections is 5.3 ° C./W. Therefore, the heat escaping from the upper end surface of the semiconductor laser device 1 is totally generated. It will be 0.062W which is 52% of the quantity, and the temperature rise will be 11.5 ° C. In this case, the heat escaping from the upper end surface is greater than the amount of heat escaping from the lower end surface.

(Embodiment 7)
13 to 15 are schematic views of the light source device according to the present embodiment. Although it can be understood from the first to sixth embodiments that the heat radiation performance is remarkably improved when a band-shaped wire is used for the wiring, when the width or thickness of the band-shaped wiring is increased, it is added when the upper end surface of the semiconductor laser element and the wiring are bonded. Energy also increases.

  In this embodiment, an attempt was made to simplify the bonding process. This embodiment is different from the above-described first to sixth embodiments in that a conductive resin 20 is used instead of a metal as a wiring connecting the upper end surface of the semiconductor laser element 1 and the electrode. The thermal conductivity coefficient of the conductive resin 20 is about 50 W / m · ° C.

  The manufacturing procedure of this light source device is as follows. First, the semiconductor laser element 1 is mounted on the bottom surface of the counterbore 2 with a conductive resin paste or the like. Thereafter, an insulating resin 19 is applied so as to cover the side surface of the semiconductor laser element 1 and the paste protruding from the bottom surface of the semiconductor laser element 1.

  FIG. 14 shows the shapes of the laser element and the insulating resin 19. If the upper end surface of the semiconductor laser element 1 is covered with the resin 19 when the resin 19 is applied, then the upper end surface and the second electrode cannot be electrically connected. Therefore, while the resin 19 is being applied, the semiconductor laser The upper end surface of the element 1 is covered and protected by another member. Thereafter, the conductive resin 20 is applied so as to connect the upper end portion of the semiconductor laser element 1 and the electrode. The cross-sectional area and length of the heat dissipation path are set to be approximately the same as those of the 100 μm metal plate of the sixth embodiment. As a result, a semiconductor laser light source device as shown in FIG. 15 is obtained.

  When the heat dissipation of this embodiment is calculated, 0.058 W heat, which is 48% of the total heat amount, is dissipated through the conductive resin 20, and the temperature rise due to heat generation of the laser element 1 is 12.4 ° C. Compared with the conventional bonding wire described in the first embodiment, the temperature rise is significantly reduced. In addition, the temperature rise difference is about 1 ° C. as compared with the case of the sixth embodiment.

  Even when the paste is thin and the viscosity is lowered within the range of functioning as a wiring, the temperature rise is 17.3 ° C., and the temperature rise is sufficiently suppressed. In this case, the thermal resistance is substantially equal to that in the case of the band-like metal wiring having a thickness of 10 μm in the fifth embodiment.

(Embodiment 8)
In this embodiment, an illumination device using a blue semiconductor laser (wavelength 400 nm band) will be described. FIG. 16 shows a substrate portion of an illumination device using a blue array semiconductor laser element. FIG. 2B is a schematic view of the substrate, and FIG. 2A is a detailed view of the light source unit unit described in the first embodiment.

  The configuration of this lighting device will be described. The counterbored hole 2 on the two-dimensional surface provided in the high thermal conductivity glass epoxy substrate 9 and the semiconductor laser element 1 disposed in the hole 2 are mixed with the light scattering particles 3 as in the first embodiment. Surrounded by resin 4.

  Next, as shown in FIG. 17, this substrate is molded with a resin containing phosphor 21 to form the protective layer 11 and the lens 10. The phosphor 21 is made of indium nitride (InN) compound semiconductor particles, and the sizes thereof are about 5 nm, 6 nm, and 13 nm. These phosphors 21 are excited by light having a wavelength of 400 nm and emit blue, green and red fluorescence, respectively. As a result, it can be used as a white illumination device. In addition, since this fluorescent substance is sufficiently small with respect to a wavelength, light is not scattered.

Light scattering occurs in a region where the light scattering particles 3 are present, and an apparent light source diameter is determined in this region, and this is efficiently expanded by using a semiconductor laser element. Further, by improving the heat dissipation, the driving current of the semiconductor laser element can be increased, and the light output can be increased.
Therefore, it is possible to realize a lighting device that is thin, has high luminance, high strength, and suppresses uneven luminance. Moreover, since it is excellent in heat dissipation, long-term reliability does not fall even if it enlarges.

  Such a thin and large-sized lighting device can be used as a backlight of a liquid crystal display. By using this illumination device, it is possible to obtain a backlight that is thinner than conventional fluorescent lamps. In addition, compared with a backlight using a light emitting diode that has been realized in recent years, the backlight light source has a small amount of decrease in light intensity over a certain period of use and excellent long-term reliability.

  As described above, according to the present invention, the long-term reliability of a high-power semiconductor laser light source can be improved by increasing the heat dissipation of the semiconductor laser light source device. By using this, a communication device capable of high-speed and long-distance communication and a high-luminance lighting device can be realized. Therefore, industrial applicability is great.

FIG. 3 is a diagram illustrating a light source device substrate according to the first embodiment. 1 is a perspective view of a light source device according to a first embodiment. 1 is a cross-sectional view of a light source device according to a first embodiment. 3 is a conceptual diagram of a heat dissipation mechanism of a light source device substrate according to Embodiment 1. FIG. 4 shows a light source device substrate according to a second exemplary embodiment; It is a heat dissipation mechanism conceptual diagram of the light source device substrate according to the second embodiment. FIG. 5 is a cross-sectional view of a light source device according to a third embodiment. FIG. 6 is a cross-sectional view of a light source device according to a fourth embodiment. FIG. 10 is a diagram illustrating a light source device substrate according to a fifth embodiment. It is sectional drawing of the light source device concerning Embodiment 5. FIG. 14 is a graph showing the relationship between the thickness of a strip-shaped metal wiring of the light source device according to Embodiment 5 and the temperature rise. FIG. 10 is a diagram illustrating a light source device substrate according to a sixth embodiment. FIG. 10 is a diagram illustrating a light source device substrate according to a seventh embodiment. It is a figure which shows the laser element and insulating resin of the light source device concerning Embodiment 7. FIG. FIG. 10 is a cross-sectional view of a light source device according to a seventh embodiment. FIG. 10 is a diagram illustrating a lighting device substrate according to an eighth embodiment. FIG. 10 is a diagram showing an illumination apparatus according to an eighth embodiment. It is sectional drawing of the conventional light source device.

Explanation of symbols

1 ... Laser element
1a ... Laser element active layer (heat source)
1b: Thermal resistance of the laser element substrate
2 ... Counterbore hole
2a ... 1st electrode (metal reflective film)
3 ... Light scattering particles
4 ... Silicone low hardness resin
5 ... Striped metal wiring
R5a ~ R5c ・ ・ ・ Thermal resistance of strip metal wiring
6 ... second electrode
7 ... Wire
8 ... IC
9 ... Board
10 ... Lens
11 ... Protective film
12 ... Thermal resistance between counterbore surface and outside
13 ... Thermal resistance between external electrode and external
14 ... Insulating film (provided on the counterbore side of the strip-shaped wiring)
15 ... Strip metal wiring
16 ... Insulating film
17 ... Metal deposited film
18 ... Insulation line (insulating part)
19 ... Insulating resin
20 ... Conductive resin
21 ... phosphor

Claims (14)

A substrate,
A concave counterbore hole formed on the substrate surface;
A first electrode also serving as a metal reflective film provided on at least a part of the surface of the counterbore,
The semiconductor laser element and the light scattering medium disposed around the semiconductor laser element are accommodated in the counterbore hole in a state where the semiconductor laser element and the first electrode are electrically connected. In a semiconductor laser light source device,
A second electrode is provided on the substrate;
The semiconductor laser element and the second electrode are connected by a strip-shaped wiring,
A semiconductor laser light source device. In the semiconductor laser light source device according to claim 1,
A semiconductor laser light source device characterized in that the cross-sectional area of the strip-shaped wiring is 2000 μm ² or more. In the semiconductor laser light source device according to claim 1,
A semiconductor laser light source device, wherein the first electrode and the semiconductor laser element are in direct contact with each other. In the semiconductor laser light source device according to claim 1,
A semiconductor laser light source device, wherein an insulating film is formed on a surface of the band-like wiring on the counterbore side. In the semiconductor laser light source device according to claim 1,
The first electrode is formed on the entire counterbore surface,
A part of the surface of the first electrode is covered with an insulating film, and the strip-shaped wiring is formed on the insulating film. In the semiconductor laser light source device according to claim 1,
A semiconductor laser light source device, wherein the band-like wiring is formed on a portion of the counterbore hole where the first electrode is not formed. In the semiconductor laser light source device according to claim 1,
The strip-shaped wiring is a plurality of lines,
A number of the second electrodes corresponding to the number of the strip-shaped wirings are formed on the substrate,
The semiconductor laser light source device, wherein the plurality of second electrodes are electrically connected inside the substrate. In the semiconductor laser light source device according to claim 1,
On the surface of the counterbore hole, there are a first electrode that also serves as the metal reflection film, a second electrode, and an insulating portion that electrically insulates the first electrode and the second electrode. Formed,
A semiconductor laser light source device, wherein the semiconductor laser element is mounted on a region where a first electrode is formed. In the semiconductor laser light source device according to claim 1,
A semiconductor laser light source device characterized in that the belt-like wiring material is any one of aluminum, gold, copper, silver, or an alloy thereof. In the semiconductor laser light source device according to claim 1,
A semiconductor laser light source device, wherein the strip-shaped wiring material is a conductive resin. In the semiconductor laser light source device according to claim 8,
A semiconductor laser light source device, wherein the conductive resin has a thickness of 10 μm or more. A substrate,
A concave counterbore hole formed on the substrate surface;
A first electrode also serving as a metal reflective film provided on at least a part of the surface of the counterbore,
The semiconductor laser element and the light scattering medium disposed around the semiconductor laser element are accommodated in the counterbore hole in a state where the semiconductor laser element and the first electrode are electrically connected. In a semiconductor laser light source device,
A second electrode is provided on the substrate;
The semiconductor laser element and the second electrode are connected by wiring,
A heat dissipation band that releases heat generated in the semiconductor laser element to the outside connects the semiconductor laser element and the substrate.
A semiconductor laser light source device.   Communication equipment using the semiconductor laser light source device according to any one of claims 1 to 12.   An illumination device using the semiconductor laser light source device according to claim 1.

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