JP2018139238A - Laser light source module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser light source module capable of making the laser light source module compact, while reducing etendue.SOLUTION: A laser light source module 101 includes a substrate 1, a first light source 21 installed on the principal surface, while loading a laser element radiating laser light along the optical axis in a direction perpendicular to the principal surface of the substrate 1, and a second light source 22 installed on the principal surface, while loading a laser element radiating laser light along the optical axis in a direction perpendicular to the principal surface on the loading surface of a holding member 5. In the laser light source module 101, the first light source 21 and the second light source 22 are positioned so that the loading surfaces of the first and second light sources 21, 22 face each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laser light source module equipped with a plurality of laser elements such as laser diodes.

  Conventionally, a light source using a halogen lamp or a metal halide lamp is used as a light source included in a display device typified by a projector. In recent years, laser light sources having characteristics of long life, low power consumption, high luminance, and high color purity have been actively applied to display devices.

  Optical devices such as large projectors used in digital cinema increase the output by adding a laser light source to obtain the required light output. However, there is a disadvantage that the size of the apparatus is increased or the cost is increased with the expansion. Therefore, it is possible to increase the light output of the laser light source alone, reduce the cost of the optical coupling member by reducing the number of laser light sources used in the optical equipment, and reduce the cost per oscillation output of the optical equipment. It is requested.

  Therefore, as an example of increasing the oscillation output of the laser light source alone, as disclosed in Patent Document 1, a plurality of laser elements are mounted on each side surface of a common holding member in the module to improve the light output. A package structure is disclosed. Patent Document 1 also discloses a package structure in which a plurality of holding members on which laser elements are mounted are installed in the center of the module so that the laser elements face each other, thereby improving light output.

JP 2004-77779 A

  However, in the structure disclosed in Patent Document 1, the distance between the laser diode chips cannot be shortened by holding a plurality of laser elements with one holding member, and Etendue (Etendue), which is the divergence angle of the light beam. ) Is large, and there is a disadvantage that the apparatus becomes large. In addition, in a structure in which a plurality of holding members on which laser elements are mounted are installed so that the laser elements face each other in the center of the module, there is a problem that the number of holding members increases, and manufacturing is difficult.

  The present invention has been made in view of the above, and an object of the present invention is to obtain a laser light source module that can reduce the etendue while reducing the size of the laser light source module.

  In order to solve the above-described problems and achieve the object, the present invention mounts a substrate and a laser element that emits laser light along an optical axis in a direction perpendicular to the main surface of the substrate on the mounting surface of the holding member. A first light source unit installed on the main surface and a laser element that emits laser light along an optical axis in a direction perpendicular to the main surface are mounted on the mounting surface of the holding member, And an installed second light source unit. The present invention is characterized in that the first light source unit and the second light source unit are positioned so that the mounting surface of the first light source unit and the mounting surface of the second light source unit face each other.

  According to the present invention, the laser light source module can be reduced in size and the etendue can be reduced.

1 is a perspective view of a laser light source module according to a first embodiment of the present invention. FIG. 3 is a top view of the laser light source module according to the first embodiment. 1 is a perspective view showing a configuration of a light source unit of a laser light source module according to a first embodiment. The perspective view which shows the detailed structure of the submount of the laser light source module concerning Embodiment 1. FIG. The perspective view seen from the back side which shows the detailed structure of the submount of the laser light source module concerning Embodiment 1. FIG. A bottom view of the laser light source module according to the first embodiment. Side view of the laser light source module according to the first embodiment.

  Below, the laser light source module concerning embodiment of this invention is demonstrated in detail based on drawing. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a perspective view of a laser light source module 101 according to the first embodiment of the present invention. FIG. 2 is a top view of the laser light source module 101 according to the first embodiment. FIG. 3 is a perspective view illustrating a configuration of the light source unit 21 of the laser light source module 101 according to the first embodiment.

  The laser light source module 101 includes a stem 1 that is a substrate, a light source unit 21 that is a first light source unit that is installed on a main surface 1a of the stem 1 and is equipped with a multi-emitter LD (Laser Diode) bar 2, and a light source A light source unit 22 that is a second light source unit installed on the main surface 1a of the stem 1 so as to face the unit 21, and a lead pin 31a for external connection that supplies power to the light source units 21 and 22 through the stem 1 , 31b, 31c, 31d, 32a, 32b, 32c and 32d. The light source unit 22 is configured in the same manner as the light source unit 21, but is symmetrical with the light source unit 21 with a facing surface therebetween. The lead pins 31a, 31b, 32a, and 32b are collectively referred to as the lead pin 3 below, and the lead pins 31c, 31d, 32c, and 32d are collectively referred to as the lead pin 3 'below. In FIG. 2, the lead pin 3 ′ is disposed below so as to be vertically symmetrical with the lead pin 3 with the light source parts 21 and 22 interposed therebetween.

  As shown in FIG. 3, the light source unit 21 is provided with a multi-emitter LD bar 2 that oscillates fundamental laser light, a submount 4 having electrical insulation for installing the multi-emitter LD bar 2, and a submount 4. And a block 5 which is a holding member. The multi-emitter LD bar 2 includes a plurality of light emitting emitters that are light emitting points. As described above, the multi-emitter LD bar 2 which is a laser element is installed on the mounting surface 51 of the block 5 via the submount 4. Similarly, the light source unit 22 includes the multi-emitter LD bar 2, the submount 4, and the block 5. However, as described above, the light source unit 21, the mounting surface 51, and the multi-emitter LD bar 2 are connected to each other. It has a symmetrical configuration that can be opposed to each other.

  The multi-emitter LD bar 2 shown in FIG. 3 is composed of a semiconductor chip using GaAs or AlGaN. The multi-emitter LD bar 2 is a laser diode in which a plurality of light-emitting stripes 2a and drive electrodes 2b serving as light-emitting emitters are alternately formed on the main surface 20 of the semiconductor chip. Laser light is emitted from the light emitting stripe 2a along the optical axis 2c parallel to the main surface 20 of the semiconductor chip. The end face of the semiconductor chip of the multi-emitter LD bar 2 can be seen in the direction perpendicular to the paper surface of FIG. 2, and the direction perpendicular to the paper surface of FIG. 2, that is, the direction perpendicular to the main surface 1a of the stem 1 is the direction of the optical axis 2c. . The direction of the optical axis 2 c is parallel to the mounting surface 51 of the block 5. Accordingly, laser light is emitted from each light emitting stripe 2a along the optical axis 2c perpendicular to the end face of the semiconductor chip. As a result, the optical axes of the laser beams emitted from the light source units 21 and 22 are parallel to each other.

  FIG. 4 is a perspective view illustrating a detailed configuration of the submount 4 of the laser light source module according to the first embodiment. FIG. 5 is a perspective view of the detailed configuration of the submount 4 of the laser light source module according to the first embodiment, viewed from the back side.

  The submount 4 has an electrical insulation function and a heat transfer function, and is configured by a flat electrical insulator 4a as shown in FIG. A plurality of conductive metallized patterns 4b and 4c are formed on the surface of the electrical insulator 4a. As shown in FIG. 5, a metallized pattern 4d is formed on the entire back surface of the electrical insulator 4a.

  The metallized pattern 4b, which is the first metallized pattern of the submount 4, and the multi-emitter LD bar 2 are joined using solder. The metallized pattern 4c, which is the second metallized pattern of the submount 4, and each drive electrode 2b of the multi-emitter LD bar 2 are electrically connected by ultrasonic vibration pressure bonding using a wire 6 formed of a conductive material such as gold. The

  A specific example of the block 5 is a material having a high thermal conductivity such as copper (Cu) plated with gold, and is bonded to the metallized pattern 4d of the submount 4 using solder. Further, the block 5 and the stem 1 are joined using solder, but this solder preferably has a lower melting point than the solder used when joining the block 5 and the submount 4.

  The stem 1 is formed in a plate shape, and a specific example thereof is a stem base of a conductive metal material in which gold is plated on a surface of a material having high thermal conductivity such as copper. The stem 1 serves to fix the light source parts 21 and 22 and to release the heat generated by the light source parts 21 and 22 to a heat radiating part 161 (described later) installed on the back surface 1b opposite to the main surface 1a of the stem 1. I'm in charge. In addition, the stem 1 includes a plurality of lead pins 3 and 3 ′ that penetrate the stem base.

  The lead pins 3 and 3 ′ play a role of supplying power to the light source units 21 and 22 and are electrically insulated from the stem 1. Generally, a low melting point glass is filled in a gap between a stem base hole constituting the stem 1 and the lead pins 3 and 3 ′. One or more anode electrodes and one or more cathode electrodes exist on the left and right sides of the light source unit 21, and one or more anode electrodes and one or more cathode electrodes exist on the left and right sides of the light source unit 22, respectively. Lead pins 3 and 3 'are provided.

  The lead pins 31 a and 31 c that are first lead pins that supply power to the light source unit 21 and the lead pins 31 b and 31 d that are second lead pins are electrically independent from the light source unit 22, and supply power to the light source unit 22. The lead pins 32 a and 32 c as the first lead pins and the lead pins 32 b and 32 d as the second lead pins are electrically independent from the light source unit 21.

  A lead pin 3 composed of a plurality of first lead pins and a plurality of second lead pins and a lead pin 3 ′ composed of a plurality of first lead pins and a plurality of second lead pins are located in the center of the stem 1 with the light source parts 21 and 22 interposed therebetween. It arrange | positions in circular arc shape or a substantially circular shape centering on a part.

  The lead pin 31a and the metallized pattern 4b of the submount 4 of the light source unit 21 are suspended and connected in a loop shape using a conductive ribbon 71a which is a conductor formed of a material such as gold, and then ultrasonic vibration pressure bonding is performed. By doing so, both are electrically connected. The lead pin 31c and the metallized pattern 4b are similarly electrically connected using the conductive ribbon 71c. Further, the lead pins 32 a and 32 c and the submount of the light source unit 22 are also electrically connected in the same manner.

  Further, after the lead pin 31b and the metallized pattern 4c of the submount 4 of the light source unit 21 are suspended and connected in a loop shape using a conductive ribbon 71b which is a conductor formed of a material such as gold, ultrasonic vibration By performing crimping, both are electrically connected. The lead pin 31d and the metallized pattern 4c are similarly electrically connected using the conductive ribbon 71d. Further, the lead pins 32b and 32d and the submount of the light source unit 22 are similarly electrically connected.

  As described above, the light source unit 21 and the light source unit 22 are electrically independent from each other.

  When the conductive ribbon 71b is suspended between the lead pin 31b and the metallized pattern 4c, the block 5 may be contacted. Similarly, when the conductive ribbon 71d is suspended between the lead pin 31d and the metallized pattern 4c, there is a possibility of contacting the block 5. For this reason, the block 5 is provided with notches 151 on both sides of the mounting surface 51 as shown in FIG. 3, thereby improving the workability of suspension of the conductive ribbons 71b and 71d.

  When power is supplied from one side of the multi-emitter LD bar 2, the current distribution becomes uneven, and the light emission amount changes for each light emitting emitter. Therefore, one or more lead pins 3 and 3 ′ are arranged on the left and right sides of the light source portions 21 and 22, and power is supplied from both sides of the multi-emitter LD bar 2, so that uneven current distribution can be eliminated.

  FIG. 6 is a bottom view of the laser light source module 101 according to the first embodiment. FIG. 6 shows a configuration showing the lead pins 3, 3 ′ and the heat radiating part 161 constituting the power feeding part of the laser light source module 101. Positions sandwiched between lead pins 3 that are a plurality of first and second lead pins and lead pins 3 ′ that are also a plurality of first and second lead pins, arranged so as to sandwich light sources 21 and 22. The heat dissipating part 161 is provided on the back surface 1 b of the stem 1.

  In order to dissipate heat from the laser elements of the light source parts 21 and 22 below the stem 1, a heat dissipating part 161, which is a cooling device such as a heat sink or a Peltier element, is installed and cooled, thereby improving the heat dissipation of the laser element. Secure. Here, the lead pins 3 and 3 ′ are arranged in an arc shape or a substantially circular shape around the center of the stem 1. As a result, the cooling area of the light source portions 21 and 22 can be increased as compared with the case where the lead pins 3 and 3 ′ are arranged in a straight line, and the cooling capacity is improved. Photoluminescence efficiency can be improved.

  FIG. 7 is a side view of the laser light source module 101 according to the first embodiment. FIG. 7 is a side view of the light source unit 21 as viewed from behind the block 5. As shown in FIG. 7, a lens 8 for condensing the laser light from the multi-emitter LD bar 2 may be installed on the block 5 as necessary. A specific example of the lens 8 is a condensing lens or a collimating lens. The lens 8 may be provided separately for each of the light source units 21 and 22, or may be provided on both blocks 5 of the light source units 21 and 22 to collect the laser beams from the multi-emitter LD bars 2 together. It can be a single lens that shines. Furthermore, a cap 9 that surrounds the light source portions 21 and 22 may be installed on the stem 1.

  In the laser light source module 101 according to the first embodiment, since the mounting surface 51 of the light source unit 21 and the mounting surface 51 of the light source unit 22 face each other in parallel, the laser elements mounted on the light source units 21 and 22 It is possible to place them close to each other. Therefore, the etendue, which is the spread angle of the light beam synthesized from the laser beams emitted from the respective laser elements, can be reduced, and the laser light source module 101 can be miniaturized.

  One laser element is connected to a plurality of lead pins that are installed on one holding member and electrically independent of lead pins connected to other laser elements in the laser light source module 101. The light source parts 21 and 22 are electrically independent from each other. That is, when power is supplied from the power source, the light source units 21 and 22 can be connected in series or in parallel from the output terminal of the power source. Therefore, when mounted as a light source for a large projector, the laser light source module 101 has a structure that increases the degree of freedom in device design.

  When the output terminal of the power source connects the light source units 21 and 22 in series, the same amount of current may be supplied from the power source with respect to the amount of current desired to be supplied to one multi-emitter LD bar 2. As a result, it is possible to reduce the amount of current flowing through one of the lead pins 3 and 3 ′ as compared with the case where they are connected in parallel, and furthermore, since the heat generation of the lead pins 3 and 3 ′ can be suppressed, the reliability of the laser light source module 101 is improved. Will improve.

  Furthermore, since the light source units 21 and 22 are electrically independent from each other, the light source units 21 and 22 can be driven individually. As a result, the lens alignment work when installing the lens 8 for condensing the laser light on the block 5 having the multi-emitter LD bar 2 is facilitated. In addition, since the light sources 21 and 22 can be driven individually, the efficiency of characteristic inspection work such as confirmation of output, wavelength, and light emitting emitter for each of the light sources 21 and 22 is improved.

  Further, by using the multi-emitter LD bar 2 having a plurality of light emitting emitters as a plurality of light emitting points as the laser element, the number of laser elements can be reduced as compared with the case of using a laser element having one light emitting point. Can do. As a result, it is possible to improve the light output while reducing the number of holding members of the laser element.

  The configuration described in the above embodiment shows an example of the contents of the present invention, and can be combined with another known technique, and can be combined with other configurations without departing from the gist of the present invention. It is also possible to omit or change the part.

  1 stem, 1a, 20 main surface, 1b back surface, 2 multi-emitter LD bar, 3, 3 ', 31a, 31b, 31c, 31d, 32a, 32b, 32c, 32d lead pin, 4 submount, 4a electrical insulator, 4b 4c, 4d Metallized pattern, 5 blocks, 6 wires, 71a, 71b, 71c, 71d Conductive ribbon, 8 lenses, 9 caps, 21, 22 Light source part, 51 Mounting surface, 101 Laser light source module, 151 Notch, 161 Heat dissipation part.

Claims (7)

A substrate,
A laser element that emits laser light along an optical axis in a direction perpendicular to the main surface of the substrate is mounted on a mounting surface of a holding member, and a first light source unit disposed on the main surface;
A laser element that emits laser light along an optical axis in a direction perpendicular to the main surface is mounted on a mounting surface of a holding member, and a second light source unit installed on the main surface;
With
The laser light source module, wherein the first light source unit and the second light source unit are positioned so that a mounting surface of the first light source unit and a mounting surface of the second light source unit face each other. The laser light source module according to claim 1, wherein a mounting surface of the first light source unit and a mounting surface of the second light source unit are parallel. The substrate is provided with a plurality of first lead pins and a plurality of second lead pins,
The laser element is installed on the mounting surface through a submount having electrical insulation,
A plurality of metallization patterns are formed on the submount,
The laser element is bonded to the first metallized pattern using solder,
The drive electrode of the laser element is electrically connected to the second metallized pattern through a wire,
The first metallized pattern is electrically connected to the first lead pin through a conductor,
The laser light source module according to claim 1, wherein the second metallized pattern is electrically connected to the second lead pin through a conductor. The laser light source module according to claim 1, 2 or 3, wherein the first light source unit and the second light source unit are electrically independent. The laser light source module according to claim 3, wherein the plurality of first lead pins and the plurality of second lead pins are arranged in an arc shape with the first light source unit and the second light source unit interposed therebetween. . The substrate which is a position sandwiched between the plurality of first lead pins and the plurality of second lead pins arranged so as to sandwich the first light source unit and the second light source unit and which is the opposite surface of the main surface The laser light source module according to claim 3, wherein a heat radiating portion is provided on the back surface of the laser light source module. The laser light source module according to any one of claims 1 to 6, wherein the laser element is a laser diode having a plurality of light emitting points.