JP5487002B2 - Semiconductor laser device - Google Patents

Description

  The present invention relates to a semiconductor laser device, and more particularly, to a semiconductor laser device including a monolithic type semiconductor laser element integrally including a plurality of laser light emitting units.

  In recent years, an optical pickup device capable of recording / reproducing information on two types of optical discs of CD (Compact Disc) and DVD (Digital Versatile Disc), and three types of CD, DVD, and BD (Blu-ray Disc). 2. Description of the Related Art Optical pickup devices capable of recording / reproducing information with respect to optical discs are widely used.

  Conventionally, in such an optical pickup device corresponding to a plurality of types of optical discs, a monolithic unit is integrally provided with a plurality of laser light emitting units having different oscillation wavelengths in order to simplify the device configuration and reduce the size and weight of the device. A type of semiconductor laser element (hereinafter sometimes referred to as “laser chip”) is used (for example, see Patent Document 1).

  For example, a two-wavelength type laser chip for CD / DVD has a single infrared laser emitting unit for CD whose oscillation wavelength is 780 nm band and red laser emitting unit for DVD whose oscillation wavelength is 660 nm band. The semiconductor substrate is electrically separated and formed on one surface of the semiconductor substrate, and further, individual electrodes are formed on the surface opposite to the semiconductor substrate of each laser emitting portion, and the one surface of the semiconductor substrate is A common electrode is formed on the opposite surface. Thereby, each laser emission part can be driven individually.

  By the way, in a semiconductor laser device, in a package on which a laser chip is mounted, it is difficult to obtain unevenness flatness on the order of several μm on the mounting portion of the package, and thermal distortion to the laser chip is partly on the package. Since it is difficult to adopt a member that is difficult to be hooked, that is, a member having a thermal expansion coefficient equivalent to the material of the laser chip, the laser chip is generally packaged via a submount (also referred to as a heat sink) made of a dielectric. Mounted on. The submount is also used as a heat radiating member that absorbs heat generated by the laser chip and releases it to the outside.

  Conventionally, when a laser chip is mounted on a submount, the laser light emitting portion faces the submount in order to efficiently dissipate heat generated in the laser light emitting portion and suppress the temperature rise of the laser chip. In many cases, a so-called junction down method is employed, which is mounted in a posture.

  FIG. 7 is a perspective view showing a configuration of a part of a conventional semiconductor laser device 100 configured by mounting a two-wavelength laser chip 110 on a submount 120 by a junction down method. It is cut out.

  In the laser chip 110, an infrared laser light emitting unit 112 and a red laser light emitting unit 113 are electrically separated by a separation groove 117 on one surface of a common semiconductor substrate 111 and formed in a stripe shape. The individual electrodes 114 and 115 having the same shape and size are formed on the surface of the light emitting units 112 and 113 opposite to the semiconductor substrate 111, respectively, and further on the surface opposite to the one surface of the semiconductor substrate 111. The common electrode 116 is formed in common to each of the laser light emitting units 112 and 113.

  Further, the submount 120 has a flat mounting surface 121a on which the laser chip 110 is mounted, which is one surface of a dielectric member 121 made of a dielectric, and the laser chip 110 is mounted on the mounting surface 121a. Connection electrodes 122 and 123 to which the individual electrodes 114 and 115 are fixed are formed, and are further electrically connected to the connection electrodes 122 and 123. The laser chip 110 and an external circuit are electrically connected by wire bonding. Bonding pads 124 and 125 to which bonding wires 130 are connected to each other are formed for each of the connection electrodes 122 and 123.

  Each connection electrode 122, 123 is formed in a shape and size corresponding to the shape and size of each individual electrode 114, 115 formed on the laser chip 110, and each individual electrode 114, 123 is mounted on the mounting surface 121a. They are arranged in stripes with an interval corresponding to the interval between 115. Therefore, by connecting and electrically connecting the connection electrodes 122 and 123 and the individual electrodes 114 and 115, it is possible to individually drive the laser light emitting units 112 and 113 in the laser chip 110.

JP 2001-345514 A

  Conventionally, when the connection electrodes 122 and 123 and the individual electrodes 114 and 115 are fixed to each other in a junction down mounting process, for example, the connection electrodes 122 and 123 formed of a brazing material made of gold tin (AuSn), for example. Is melted by heating, and the individual electrodes 114 and 115 of the laser chip 110 are pressed from above onto the melted connection electrodes 122 and 123.

  At this time, if the brazing material that oozes out from the connection electrode 122 along the surface direction of the mounting surface 121 a by pressing the individual electrodes 114 and 115 comes into contact with the adjacent connection electrode 123, red The electrodes 114 and 122 on the outer laser light emitting unit 112 side and the electrodes 115 and 123 on the red laser light emitting unit 113 side are electrically connected, and the semiconductor laser device 100 in such a state is driven. In this case, current leakage occurs. Therefore, in the electronic device including the semiconductor laser device 100 in such a state, there is a possibility that a malfunction such as a decrease in function or malfunction occurs.

  However, in the semiconductor laser device manufactured by the junction down method, the laser light emitting units 112, 122 between the electrodes 114, 122 on the infrared laser light emitting unit 112 side and the electrodes 115, 123 on the red laser light emitting unit 113 side are each 113 is covered with a common semiconductor substrate 111, the electrodes cannot be observed from the outside, and it is easily determined whether or not the electrodes are electrically connected to each other. There is a problem that you can not.

  An object of the present invention is to use a brazing material for each electrode provided for each laser light emitting portion in a semiconductor laser device manufactured by mounting a semiconductor laser element having a plurality of laser light emitting portions on a submount by a junction down method. It is an object of the present invention to provide a semiconductor laser device that can easily determine the presence or absence of electrical connection.

The present invention relates to a semiconductor substrate, a plurality of laser light emitting parts formed on one surface of the semiconductor substrate and being electrically separated from each other, and each laser light emitting on the surface of each laser light emitting part opposite to the semiconductor substrate. A semiconductor laser element including an individual electrode formed for each part and a common electrode formed on a surface opposite to the one surface of the semiconductor substrate;
A plurality of connection electrodes each having a flat mounting surface on which the semiconductor laser element is mounted; the individual electrodes individually connected by a conductive brazing material; and stains from the connection electrodes. a submount and exuding determination unit for determining the degree exudation out brazing material is formed seen including,
The seepage determining unit is formed on the mounting surface in a region not covered by the semiconductor laser element when the semiconductor laser element is mounted, with a predetermined arrangement interval from the connection electrode. A semiconductor laser device is characterized.

Further, in the present invention, the individual electrode provided for each of the laser emission units is formed in a stripe shape,
The plurality of connection electrodes are formed in stripes with predetermined electrode intervals according to the intervals between the individual electrodes,
The oozing-out determination unit is characterized in that it is formed with a predetermined arrangement interval from a connection electrode arranged on the outermost side in a direction perpendicular to a direction in which the connection electrode extends.

  In the invention, it is preferable that the predetermined arrangement interval is not more than the predetermined electrode interval.

  Further, the present invention is characterized in that the seepage determination part is formed at a position close to a laser light emitting end face of the semiconductor laser element.

  Further, the present invention is characterized in that a plurality of the seepage judging sections are formed along a direction in which the connection electrodes extend.

Further, the present invention is characterized in that the seepage determination part is formed in a straight line along the direction in which the connection electrode extends.
In the present invention, the predetermined arrangement interval is 80 μm or less.

In the present invention, the mounting surface is one surface of a dielectric member constituting the submount,
The seepage determining unit is formed by exposing a part of the one surface of the dielectric member to the outside.

In the present invention, the mounting surface is one surface of a dielectric member constituting the submount,
The seepage judging unit is formed by laminating a member on the one surface of the dielectric member.

  According to the present invention, a conductive bonding pad for connecting the semiconductor laser element to an external circuit is formed on one surface of the dielectric member.

  According to the present invention, the dielectric member is formed of any one of AlN, SiN, and Si.

  In the invention, it is preferable that the laser light emitting portions are formed such that the interval between the light emitting points of the laser light emitting portions is 200 μm or less.

  Further, the invention is characterized in that each of the laser light emitting units is configured to emit laser beams having different oscillation wavelengths.

  In addition, the present invention is characterized in that each of the laser light emitting units is configured to emit laser light having the same oscillation wavelength.

According to the present invention, on the mounting surface of the submount, the degree of seepage for determining the degree of seepage when the brazing material for fixing the connection electrode and the individual electrode seeps out from the connection electrode. When the semiconductor laser element is mounted on the mounting surface, the portion is formed in a region that is not covered by the semiconductor laser element with a predetermined arrangement interval from the connection electrode. In the mounted submount, it is easy to check the presence or absence of electrical connection by the brazing material between the electrodes provided for each laser light emitting part by observing the vicinity of the seepage degree judging part from the outside using an observation device etc. Can be determined.

  Accordingly, there is a possibility that the respective electrodes provided for each laser light emitting unit are electrically connected to each other by the brazing material, and the respective electrodes may be electrically connected to each other by the brazing material. It is possible to discriminate the semiconductor laser device from a low semiconductor laser device and prevent the semiconductor laser device that is likely to be connected from being erroneously mounted on an electronic device, and collect it as a defective product. In other words, it is possible to provide only normal semiconductor laser devices that are not electrically connected by brazing material or are not likely to be connected as good products that can be mounted on electronic devices. It is possible to eliminate the cause of malfunction and improve the manufacturing yield.

1 is a perspective view showing a configuration of a semiconductor laser element 10 provided in a semiconductor laser device 1 according to an embodiment of the present invention. 1 is a perspective view showing a configuration of a submount 20 on which a semiconductor laser element 10 is mounted. 1 is a perspective view showing a partial configuration of a semiconductor laser device 1 according to an embodiment of the present invention. 4 is a flowchart showing a procedure of a manufacturing process of the semiconductor laser device 1. 3 is an enlarged plan view showing the vicinity of one end in the longitudinal direction Y2 of the submount 20 on which the semiconductor laser element 10 is mounted. FIG. It is a perspective view which shows the structure of the submount 70 in the semiconductor laser apparatus which is other embodiment of this invention. 1 is a perspective view showing a partial configuration of a conventional semiconductor laser device 100 configured by mounting a two-wavelength laser chip 110 on a submount 120 by a junction down method.

  FIG. 1 is a perspective view showing a configuration of a semiconductor laser element 10 provided in a semiconductor laser device 1 according to an embodiment of the present invention.

  In the semiconductor laser device 10, two laser light emitting portions 12 and 13 are electrically separated from each other by a separation groove 17 and formed in a stripe shape on one surface in the thickness direction Z1 of a semiconductor substrate 11 formed in a rectangular parallelepiped shape. The individual electrodes 14 and 15 are individually formed for the laser light emitting units 12 and 13 on the surfaces of the laser light emitting units 12 and 13 opposite to the semiconductor substrate 11, respectively. It is configured by forming a common electrode 16 common to the laser light emitting units 12 and 13 on the surface opposite to the surface on which the light emitting units 12 and 13 are formed. The semiconductor laser element 10 is a ridge waveguide type semiconductor laser element as will be described later.

  In the following, as shown in FIG. 1, the direction in which the short side extends defining one surface of the semiconductor substrate 11 in the thickness direction Z1 is defined as the width direction X1, and the direction in which the long side extends is defined as the emission direction Y1. The thickness direction Z1, the width direction X1, and the emission direction Y1 are directions orthogonal to each other.

  The semiconductor substrate 11 is made of N-type GaAs, and for example, the dimension in the width direction X1 is 240 μm, the dimension in the emission direction Y1 is 1500 μm, and the dimension in the thickness direction Z1 is 85 μm.

  The two laser light emitting portions 12 and 13 are formed on one surface of the semiconductor substrate 11 in the thickness direction Z1 so as to be separated from each other by a predetermined distance and extend along the emission direction Y1, that is, in a stripe shape. Yes. The laser light emitting portions 12 and 13 are preferably formed so that the interval T1 between the light emitting points is 200 μm or less within a range that can be accommodated within the width of the semiconductor substrate 11. In the present embodiment, the dimensions in the width direction X1 of the laser light emitting units 12 and 13 are each 100 μm, and the interval T1 between the light emitting point of the laser light emitting unit 12 and the light emitting point of the laser light emitting unit 13 is 110 μm. Is formed. Thus, by setting the interval T1 of the light emitting points to 200 μm or less, the heat generated in the laser light emitting units 12 and 13 can be efficiently released to the submount 20 described later.

  A separation groove 17 that electrically separates the laser emission units 12 and 13 from each other is formed between the laser emission units 12 and 13 along the emission direction Y1. The bottom of the separation groove 17 is formed in the semiconductor substrate 11. In the present embodiment, the dimension in the width direction X1 of the separation groove 17 is 40 μm.

  In addition, the two laser light emitting units 12 and 13 are formed so that their shapes and sizes are substantially equal to each other, and in the present embodiment, are configured to emit laser beams having different oscillation wavelengths. Specifically, the laser light emitting unit 12 is configured to emit laser light having an oscillation wavelength of 785 nm, and the laser light emitting unit 13 is configured to emit laser light having an oscillation wavelength of 660 nm. That is, the semiconductor laser element 10 is a two-wavelength type laser chip.

  The laser emission unit 12 includes an N-type buffer layer 41, an N-type cladding layer 42, a multiple quantum well active layer 43, a P-type first cladding layer 44, and an etching stop layer 45 on the semiconductor substrate 11. And a P-type second clad layer 46, an intermediate layer 47, and a contact layer 48 constituting the ridge portion 49 to be a waveguide, which are laminated in the order described above from the semiconductor substrate 11 side, and further, the ridge It is formed by laminating dielectric films 50 on both sides of the portion 49 in the width direction X1. The dielectric film 50 is laminated so as to cover the remaining surface except for one surface in the thickness direction Z1 of the contact layer 48 in the ridge portion 49 among the surfaces exposed to the outside in the laminated body of the layers 41 to 48. It has a refractive index that confines light in the quantum well active layer 43 in the lateral direction.

  The multiple quantum well active layers 43 are alternately formed between a pair of guide layers formed in contact with the N-type cladding layer 42 and the P-type first cladding layer 44 and a pair of non-doped guide layers, respectively. The well layer and the barrier layer are arranged so as to be in contact with the guide layer.

  The buffer layer 41 is made of N-type GaAs. The N-type cladding layer 42 is formed of N-type AlGaInP. The guide layer, well layer, and barrier layer of the multiple quantum well active layer 43 are formed of non-doped AlGaAs. The P-type first cladding layer 44 and the P-type second cladding layer 46 are formed of P-type AlGaInP. The etching stop layer 45 and the P-type intermediate layer 47 are made of P-type GaInP. The contact layer 48 is made of P-type GaAs. The ridge portion 49 is formed so that the dimension in the width direction X1 is, for example, 2 μm.

  The laser light emitting unit 13 includes an N-type buffer layer 61, an N-type cladding layer 62, a multiple quantum well active layer 63, a P-type first cladding layer 64, and an etching stop layer on the semiconductor substrate 11. 65, and a P-type second cladding layer 66 and an intermediate layer 67 and a contact layer 68 constituting a ridge 69 serving as a waveguide, which are stacked in the order described above from the semiconductor substrate 11 side, The dielectric film 50 is formed on both sides of the ridge portion 69 in the width direction X1. The dielectric film 50 includes one surface in the thickness direction Z1 of the contact layer 68 in the ridge portion 69 and one surface in the thickness direction Z1 of the etching stop layer 65 among the surfaces exposed to the outside in the stacked body of the layers 61 to 68. Are stacked so as to cover the remaining surface except for a part of the light, and have a refractive index that confines light in the multiple quantum well active layer 63 in the lateral direction. As shown in FIG. 1, a part of one surface of the etching stop layer 65 in the thickness direction Z1 is not covered with the dielectric film 50 because the individual electrode 15 is brought close to the optical waveguide. This is because the light at the end is absorbed and the generation of ripples at the bottom of the emitted light is reduced.

  The multiple quantum well active layers 63 are alternately formed between a pair of guide layers formed in contact with the N-type cladding layer 62 and the P-type first cladding layer 64 and a pair of non-doped guide layers, respectively. The well layer and the barrier layer are arranged so as to be in contact with the guide layer.

  The buffer layer 61 is made of N-type GaAs. The N-type cladding layer 62 is made of N-type AlGaInP. The guide layer of the multiple quantum well active layer 63 is formed of non-doped AlGaInP, the well layer is formed of non-doped GaInP, and the barrier layer is formed of non-doped AlGaInP. The P-type first cladding layer 64 and the P-type second cladding layer 66 are formed of P-type AlGaInP. The etching stop layer 65 and the P-type intermediate layer 67 are made of P-type GaInP. The contact layer 68 is made of P-type GaAs. The ridge portion 69 is formed so that the dimension in the width direction X1 is 2 μm, for example.

  A P-type electrode 51 and a plating electrode 52 are described from the laser emission part 12 side on the surface of the laser emission part 12 opposite to the semiconductor substrate 11, that is, on the contact layer 48 and the dielectric film 50 of the laser emission part 12. In this order, the layers are stacked so as to extend along the emission direction Y1. Similarly, a P-type electrode 51 and a plating electrode 52 are formed on the surface of the laser light emitting unit 13 opposite to the semiconductor substrate 11, that is, on the contact layer 68 and the dielectric film 50 of the laser light emitting unit 13. The layers are stacked in the order described from the side and extend along the emission direction Y1.

  The individual electrode 14 is configured by a stacked body of the P-type electrode 51 and the plating electrode 52 on the laser light emitting unit 12 side, and the individual electrode 15 is configured by a stacked body of the P-type electrode 51 and the plated electrode 52 on the laser light emitting unit 13 side. Is done. The individual electrodes 14 and 15 are individually formed for each of the laser light emitting units 12 and 13 and are electrically separated from each other, and are formed in stripes so that their shapes and sizes are substantially equal to each other. The P-type electrode 51 is formed by laminating a layer made of titanium (Ti), a layer made of molybdenum (Mo), and a layer made of gold (Au) from the ridge portions 49 and 69 side in the order described above. The plating electrode 52 is made of Au.

  A common electrode 16 common to the laser light emitting portions 12 and 13 is formed on the surface of the semiconductor substrate 11 opposite to the surface on which the laser light emitting portions 12 and 13 are formed.

  FIG. 2 is a perspective view showing a configuration of the submount 20 on which the semiconductor laser element 10 is mounted. The submount 20 includes a base body 21 formed in a rectangular parallelepiped shape, two connection electrodes 22 and 23, two bonding pads 24 and 25, and a brazing material bleeding determination pattern 26.

  Hereinafter, as shown in FIG. 2, the direction in which the short side extends to define one surface of the base 21 in the thickness direction Z2 is defined as the width direction X2, and the direction in which the long side extends is defined as the longitudinal direction Y2. The thickness direction Z2, the width direction X2, and the longitudinal direction Y2 are directions orthogonal to each other.

  For example, the substrate 21 that is a dielectric member is selected such that the dimension in the width direction X2 is 600 μm, the dimension in the longitudinal direction Y2 is 1500 μm, and the dimension in the thickness direction Z2 is 300 μm. The base 21 is made of a material having electrical insulation and good thermal conductivity, and is formed of any one of aluminum nitride (AlN), silicon nitride (SiN), and silicon (Si), for example. Since AlN, SiN, and Si are excellent in thermal conductivity (heat dissipation), heat generated in the semiconductor laser element 10 can be efficiently dissipated, and yield and heat dissipation characteristics can be stabilized and improved. . In the present embodiment, the substrate 21 is made of AlN. The base body 21 is one surface in the thickness direction Z2 and has a flat mounting surface 21a on which the semiconductor laser element 10 is mounted.

  The two connection electrodes 22 and 23 are formed on the mounting surface 21a of the base 21 so that the shapes and sizes thereof are equal to each other, and are formed to extend along the longitudinal direction Y2, that is, in a stripe shape. . The connection electrodes 22 and 23 are formed at a predetermined interval T2 according to the interval between the individual electrodes 14 and 15 formed in the semiconductor laser element 10, that is, the groove width of the separation groove 17. The connection electrodes 22 and 23 are preferably formed such that the interval T2 is 80 μm or less. In the present embodiment, the connection electrodes 22 and 23 are both selected with a dimension in the width direction X2 of 105 μm and a dimension in the longitudinal direction Y2 of 1500 μm, and are formed with a spacing T2 of 20 μm along the width direction X2. The base 21 is provided at an intermediate portion in the width direction X2. Thus, by setting the distance T2 between the electrodes to 80 μm or less, the heat generated in the laser light emitting units 12 and 13 can be efficiently released to the submount 20 described later.

  In the present embodiment, the connection electrodes 22 and 23 are made of AuSn solder used as a brazing material.

  Of the mounting surface 21a of the substrate 21, a region where the semiconductor laser element 10 is mounted, that is, a region where the connection electrodes 22 and 23 are formed is referred to as a mounting region, and the remaining region is referred to as a non-mounting region. Bonded pads 24 and 25 to which bonding wires 30 for electrically connecting the semiconductor laser element 10 mounted on the submount 20 and an external circuit (not shown) to each other by wire bonding are connected to the non-mounting region. Each of the electrodes 22 and 23 is formed. In the present embodiment, the connection electrode 22 and the bonding pad 24 are provided so as to contact from one end to the other end in the longitudinal direction Y2. Similarly, the connection electrode 23 and the bonding pad 25 are provided so as to contact from one end to the other end in the longitudinal direction Y2.

  Moreover, when the connection electrodes 22 and 23 and the individual electrodes 14 and 15 are individually connected to the mounting surface 21a of the submount 20 according to the present embodiment by the brazing material, the brazing material oozes out from the connection electrodes 22 and 23. A brazing material bleeding determination pattern 26 which is a bleeding determination unit for determining the degree of bleeding is formed. The brazing material bleeding determination pattern 26 is formed on the mounting surface 21a in a predetermined area along the width direction X2 from the connection electrodes 22 and 23 in a region not covered by the semiconductor laser element 10 when the semiconductor laser element 10 is mounted. It is formed with an interval T3.

  The interval T3 between the connection electrodes 22 and 23 and the brazing material bleeding determination pattern 26 is preferably equal to or less than the interval T2 between the connection electrodes 22 and 23. In the present embodiment, the interval T3 between the connection electrodes 22 and 23 and the brazing material bleeding determination pattern 26 is selected to be 20 μm, which is equal to the interval T2 between the connection electrodes 22 and 23. By arranging the brazing material seepage determination pattern 26 so that the interval T3 is equal to or less than the interval T2 as described above, the degree of exudation of the brazing material that exudes from the connection electrodes 22 and 23 can be reliably determined.

  In the present embodiment, two brazing material bleeding determination patterns 26 are formed in the vicinity of one end and the other end in the longitudinal direction Y2, respectively, and are not mounted on the mounting surface 21a adjacent to the connection electrodes 22 and 23. The bonding pads 24 and 25 formed in the region are partially removed by etching or the like to expose the mounting surface 21a.

  FIG. 3 is a perspective view showing a partial configuration of the semiconductor laser device 1 according to the embodiment of the present invention, in which a part of the semiconductor laser element 10 is cut away. The semiconductor laser device 1 according to the present embodiment mounts the semiconductor laser device 10 on the submount 20 by a junction down method, that is, in a posture such that the laser light emitting units 12 and 13 of the semiconductor laser device 10 face the submount 20. It is produced by doing. Thereby, the heat generated in the laser light emitting units 12 and 13 can be efficiently dissipated by the submount 20 and the temperature rise of the laser light emitting units 12 and 13 can be suppressed. The thus configured semiconductor laser device 1 is incorporated in electronic equipment such as OA (Office Automation) equipment (for example, a laser printer) and optical information processing equipment (for example, an optical fiber communication system, an optical measurement system, and an optical disk device). It is.

  FIG. 4 is a flowchart showing the procedure of the manufacturing process of the semiconductor laser device 1. When the manufacturing process is started, the process proceeds from step s0 to step s1. In step s1, first, both ends of the submount 20 in the width direction X2 are held by a pair of heater blocks with the mounting surface 21a facing upward, The common electrode 16 of the laser element 10 is sucked and held by the suction head of the suction moving device. The suction moving device is realized by, for example, a six-axis robot, and can move the suction head in a three-dimensional direction. A suction force is given to the suction head of the suction moving device, and the semiconductor laser element 10 can be held by vacuum suction.

  Next, the process proceeds to step s2, and the semiconductor laser element 10 is moved to a position near the upper portion of the submount 20 by the suction moving device so that the individual electrodes 14 and 15 of the semiconductor laser element 10 face the connection electrodes 22 and 23, respectively. It is arranged in alignment with. When this alignment is performed, a CCD (Charge Coupled Device) camera is installed above the submount 20 held by the pair of heater blocks and in the emission direction Y1 of the semiconductor laser device 10, respectively. And the image of the semiconductor laser element 10 is taken in and this image is displayed by the display device. The CCD camera and the display device constitute an observation device.

  The operator first looks at the image acquired by the CCD camera above the submount 20 and operates the suction moving device so that the emission direction Y1 of the semiconductor laser element 10 and the longitudinal direction Y2 of the submount 20 are parallel to each other. Thus, the relative position between the semiconductor laser element 10 and the submount 20 is adjusted. Whether or not the emitting direction Y1 of the semiconductor laser element 10 is parallel to the longitudinal direction Y2 of the submount 20 depends on the side parallel to the emitting direction Y1 among the peripheral edges of the common electrode 16 of the semiconductor laser element 10 and the connection electrode. Judgment is made based on whether 22 and 23 are parallel.

  Next, the operator looks at the image acquired by the CCD camera installed in the emission direction Y1 of the semiconductor laser element 10, and the positions of the connection electrodes 22 and 23 and the positions of the individual electrodes 14 and 15 are determined by the semiconductor laser. The position is adjusted by moving the suction head so as to match in the width direction of the apparatus 1.

  In the present embodiment, when aligning the individual electrodes 14 and 15 of the semiconductor laser element 10 and the connection electrodes 22 and 23 of the submount 20, the brazing material bleeding determination pattern 26 formed in the non-mounting region is used. Can be used. Since the connection electrodes 22 and 23 are formed in the mounting region where the semiconductor laser element 10 is mounted as described above, when the semiconductor laser element 10 is moved above the connection electrodes 22 and 23, the submount 20. The connection electrodes 22 and 23 can no longer be imaged from the CCD camera above, but the brazing material seepage determination pattern 26 is formed in the non-mounting area. Images can also be taken with a CCD camera. As described above, the alignment of the individual electrodes 14 and 15 of the semiconductor laser element 10 and the connection electrodes 22 and 23 of the submount 20 can be performed with high accuracy by using the brazing material bleeding determination pattern 26 at the time of alignment. Can be done. That is, the semiconductor laser element 10 can be mounted on the submount 20 with the position adjusted with high accuracy.

  In step s2, while moving the semiconductor laser element 10, the pair of heater blocks are heated to a predetermined temperature for melting the connection electrodes 22 and 23, which are brazing materials. The predetermined temperature is, for example, 300 ° C. When the connection electrodes 22 and 23 are melted, the process proceeds to step s3.

  In step s3, the semiconductor laser element 10 is vertically lowered by moving the suction head, and the individual electrodes 14 and 15 are pressed against the melted connection electrodes 22 and 23, so that the connection electrodes 22 and 23 and the individual electrodes 14 and 23 are pressed. 15 is alloyed with the plating electrode 52 and rapidly fixed. During the rapid cooling, heating of the pair of heater blocks is stopped, and air is locally applied to the joining portion between the plating electrode 52 and the connection electrodes 22 and 23 by the air blowing device to cool the air.

  Next, the process proceeds to step s4, on the basis of an image taken by the CCD camera above the submount 20 of the submount 20 on which the semiconductor laser element 10 is mounted, the electrodes 14 and 22 on the laser emission unit 12 side, and laser emission. It is determined whether or not the electrodes 15 and 23 on the part 13 side are short-circuited, that is, electrically connected, due to the leakage of the brazing material.

  FIG. 5 is an enlarged plan view showing the vicinity of one end in the longitudinal direction Y2 of the submount 20 on which the semiconductor laser element 10 is mounted. After the semiconductor laser element 10 is mounted, the molten brazing material partially expands. Therefore, if the brazing material W that has oozed out from the connection electrode 22 has reached the brazing material oozing-out determination pattern 26 as shown in FIG. 5A, the brazing material W may have reached the connection electrode 23 as well. Therefore, it is determined that the electrodes 14 and 22 on the laser emission unit 12 side and the electrodes 15 and 23 on the laser emission unit 13 side are short-circuited. Further, as shown in FIG. 5B, if the brazing material W that has oozed out from the connection electrode 22 does not reach the brazing material oozing determination pattern 26, there is a possibility that the brazing material W has reached the connection electrode 23. Therefore, it is determined that the electrodes 14 and 22 on the laser light emitting unit 12 side and the electrodes 15 and 23 on the laser light emitting unit 13 side are not short-circuited.

  In step s4, the submount 20 on which the semiconductor laser element 10 determined that the electrodes 14 and 22 on the laser light emitting unit 12 side and the electrodes 15 and 23 on the laser light emitting unit 13 side are short-circuited is not mounted. Collected as a good product.

  Next, the process proceeds to step s5, where the submount 20 mounted with the semiconductor laser element 10 determined that the connection electrodes 22 and 23 are not short-circuited is taken out from the pair of heater blocks, and the semiconductor device is moved by a transfer device such as a robot. The submount 20 on which the laser element 10 is mounted is transported to a package to be accommodated, and is fixed on the mount portion of the package using silver paste. This package is made of a material such as copper or iron, and is particularly preferably formed of copper, which is a material having excellent thermal conductivity (heat dissipation) and insulating properties.

  Next, the process proceeds to step s6, in which each bonding pad 24, 25 on the submount 20 and a plurality of package terminals provided in the package are individually bonded by bonding wires (gold wires) 30 and the semiconductor laser element 12 is shared. Bonding is performed with a bonding wire to a package terminal different from the package terminal to which the electrode 16 and the bonding pads 24 and 25 are connected.

  Next, the process proceeds to step s7, where the submount 20 and the semiconductor laser element 10 are sealed with a synthetic resin material having translucency, and the mounting process is terminated in step s8. As a result, the semiconductor laser device 1 including a two-wavelength laser chip in which the interval between light emitting points that can be independently driven is 110 μm can be manufactured.

  As described above, in the semiconductor laser device 1 according to the present embodiment, the brazing material for determining the degree of oozing when the brazing material oozes from the connection electrodes 22 and 23 on the mounting surface 21a of the submount 20. Since the bleeding determination pattern 26 is formed, the vicinity of the brazing material bleeding determination pattern 26 is observed from the outside using an observation device or the like in the submount 20 on which the semiconductor laser element 10 is mounted. It is possible to easily determine whether or not the electrodes 14 and 22 on the laser light emitting unit 12 side and the electrodes 15 and 23 on the laser light emitting unit 13 side are electrically connected by a brazing material.

  Thus, the semiconductor laser device 1 that is highly likely to be electrically connected to the electrodes 14 and 22 on the laser light emitting unit 12 side and the electrodes 15 and 23 on the laser light emitting unit 13 side by the brazing material, and the laser light emitting unit. It is possible to discriminate and connect the semiconductor laser device 1 which is unlikely to be electrically connected to the electrodes 14 and 22 on the 12 side and the electrodes 15 and 23 on the laser light emitting unit 13 side by the brazing material. The highly reliable semiconductor laser device 1 is prevented from being erroneously mounted on an electronic device, and can be recovered as a defective product. That is, it is possible to provide only a normal semiconductor laser device 1 that is not electrically connected by brazing material or has a low possibility of being connected as a non-defective product that can be mounted on an electronic device. In addition, it is possible to eliminate the cause of malfunction and improve the manufacturing yield.

  FIG. 6 is a perspective view showing a configuration of a submount 70 in a semiconductor laser device according to another embodiment of the present invention. The semiconductor laser device according to the present embodiment employs a submount 70 in place of the submount 20 in the semiconductor laser device 1 shown in FIG. Since the submount 70 shown in FIG. 6 is similar to the configuration of the submount 20 shown in FIG. 2, the same reference numerals are given to the same configurations, and the description thereof is omitted.

  The submount 70 includes a base body 21 formed in a rectangular parallelepiped shape, two connection electrodes 22 and 23, two bonding pads 74 and 75, a brazing material bleeding determination pattern 76, and connection electrodes 77 and 78. It is comprised including.

  In a non-mounting region on the mounting surface 21a of the base body 21, a rectangular shape to which a bonding wire 30 for electrically connecting the semiconductor laser element 10 mounted on the submount 70 and an external circuit (not shown) by wire bonding is fixed. Bonding pads 74 and 75 are formed for each of the connection electrodes 22 and 23. In the present embodiment, the bonding pad 74 is provided to be separated from the connection electrode 22, and the connection electrode 22 and the bonding pad 74 are electrically connected by the connection electrode 77. Similarly, the bonding pad 75 is provided so as to be separated from the connection electrode 23, and the connection electrode 23 and the bonding pad 75 are electrically connected by a connection electrode 78.

  Further, when the connection electrodes 22, 23 and the individual electrodes 14, 15 are individually connected to the mounting surface 21 a of the submount 70 according to the present embodiment by the brazing material, the brazing material oozes out from the connection electrodes 22, 23. A brazing material bleeding determination pattern 76, which is a bleeding determination unit for determining the degree of bleeding, is formed. The brazing material bleeding determination pattern 76 is formed on the mounting surface 21a in a predetermined area along the width direction X2 from the connection electrodes 22 and 23 in a region not covered by the semiconductor laser element 10 when the semiconductor laser element 10 is mounted. It is formed with an interval T3.

  The interval T3 between the connection electrodes 22 and 23 and the brazing material bleeding determination pattern 76 is preferably equal to or less than the interval T2 between the connection electrodes 22 and 23. In the present embodiment, the interval T3 between the connection electrodes 22 and 23 and the brazing material bleeding determination pattern 76 is selected to be 20 μm, which is equal to the interval T2 between the connection electrodes 22 and 23. By arranging the brazing material seepage determination pattern 76 so that the interval T3 is equal to or less than the interval T2 in this way, it is possible to reliably determine the degree of exudation of the brazing material that has exuded from the connection electrodes 22 and 23.

  In the present embodiment, a plurality of brazing material bleeding determination patterns 76 are formed at intervals from one end portion to the other end portion in the longitudinal direction Y2. The brazing material bleeding determination pattern 76 is formed by laminating metal members on the mounting surface 21a.

  The semiconductor laser device according to this embodiment is manufactured by a manufacturing process similar to the manufacturing process of the semiconductor laser device 1 shown in FIG. In the present embodiment, when the individual electrodes 14 and 15 of the semiconductor laser element 10 and the connection electrodes 22 and 23 of the submount 70 are aligned, the brazing material seepage determination pattern formed in the non-mounting region. In addition to 76, rectangular bonding pads 74 and 75 can be used. Since the connection electrodes 22 and 23 are formed in the mounting region where the semiconductor laser element 10 is mounted, when the semiconductor laser element 10 is moved above the connection electrodes 22 and 23, the CCD camera above the submount 70. The connection electrodes 22 and 23 can no longer be imaged, but the brazing material bleeding determination pattern 26 and the bonding pads 74 and 75 are formed in the non-mounting region. The image can also be taken with a CCD camera. In this way, when aligning, by using the brazing material bleeding determination pattern 26 and the bonding pads 74 and 75, the individual electrodes 14 and 15 of the semiconductor laser element 10 and the connection electrodes 22 and 23 of the submount 70 Can be aligned with high accuracy. In other words, the position of the semiconductor laser element 10 can be mounted on the submount 70 with high accuracy.

  In the semiconductor laser device according to the present embodiment, a brazing material seepage determination pattern for judging the degree of seepage when the brazing material seeps out from the connection electrodes 22 and 23 on the mounting surface 21a of the submount 70. Since a plurality of 76 are formed, in the submount 70 on which the semiconductor laser element 10 is mounted, the vicinity of the brazing material bleeding determination pattern 76 is observed from the outside by using an observation device or the like, whereby a laser light emitting unit It can be easily and reliably determined whether or not the electrodes 14 and 22 on the 12 side and the electrodes 15 and 23 on the laser light emitting unit 13 side are electrically connected by the brazing material.

  Accordingly, the laser light emitting unit 12 and the laser light emitting unit 12 are highly likely to be electrically connected to the electrodes 14 and 22 on the laser light emitting unit 12 side and the electrodes 15 and 23 on the laser light emitting unit 13 side by the brazing material. Of the semiconductor laser device which is unlikely to be electrically connected to the electrodes 14 and 22 on the side of the electrode and the electrodes 15 and 23 on the side of the laser light emitting unit 13 by the brazing material. A high semiconductor laser device is prevented from being erroneously mounted on an electronic device, and can be recovered as a defective product. In other words, it is possible to provide only normal semiconductor laser devices that are not electrically connected by brazing material or are not likely to be connected as good products that can be mounted on electronic devices. It is possible to eliminate the cause of malfunction and improve the manufacturing yield.

  In the present embodiment, a plurality of brazing material bleeding determination patterns 76 are formed along the extending direction of the connection electrodes 22, 23, that is, along the longitudinal direction Y 2, but for brazing material bleeding determination along the longitudinal direction Y 2. The pattern 76 may be formed linearly. This makes it possible to more reliably determine whether or not the electrodes 14 and 22 on the laser light emitting unit 12 side and the electrodes 15 and 23 on the laser light emitting unit 13 side are electrically connected by the brazing material. .

  In each of the embodiments described above, the case where the connection electrodes 22 and 23 are formed of AuSn solder used as a brazing material is illustrated, but the present invention is not limited thereto, and the connection electrodes 22 and 23 are made of gold (Au). Even if it is formed and AuSn solder is applied to the surfaces of the connection electrodes 22 and 23, the same effect can be achieved.

  In each of the above-described embodiments, the semiconductor laser device including the two-wavelength type laser chip is illustrated. However, as described above, the laser light emitting unit is electrically separated on one surface of the semiconductor substrate as described above. Light emission that emits laser light if multiple electrodes are formed and individual electrodes are formed on the opposite side of the laser light emitting portion from the semiconductor substrate, and a common electrode is formed on the surface opposite to the one surface of the semiconductor substrate. The structure is not particularly limited except that it has at least an active layer having a point. The active layer may have a multiple quantum well structure or a single layer structure.

  For example, the plurality of laser light emitting units may be configured to emit laser light having the same oscillation wavelength. Further, the laser emission section is not limited to the one having a ridge structure, and may be a buried type. A buffer layer may be formed between the semiconductor substrate and the N-type cladding layer, and at least one of the N-type cladding layer, the P-type first cladding layer, and the P-type second cladding layer. However, it may be formed of a plurality of layers, or may have a structure in which an insulating film or a protective film is formed above the ridge structure.

  Further, the thickness of each layer constituting the semiconductor laser element, the material, the number of laser light emitting portions, the interval between the light emitting points, the dimension in the width direction X1 of the laser light emitting portion are not limited to the above-described configuration, The design can be changed as appropriate according to the characteristics of the semiconductor laser device. For example, the semiconductor laser element is not limited to a semiconductor laser element of a specific material type, and any semiconductor laser element of GaAs type, AlGaAs type, GaInAs type, GaInAsP type, or AlGaInP type can be applied. is there.

  As described above, the semiconductor laser device according to the present invention has a configuration in which the semiconductor laser element can irradiate a plurality of laser beams having different oscillation wavelengths or the same oscillation wavelengths and irradiating a plurality of laser beams having different oscillation wavelengths. Also, in any configuration that irradiates multiple laser beams with the same oscillation wavelength, each channel electrode on the submount side according to the light emitting point can be accurately positioned, and yield and heat dissipation characteristics are stable. And can be improved. Each of the above-described embodiments is particularly preferably implemented in a semiconductor laser device in which an ultra-small multi-laser element having a light emitting point interval of 50 μm or less is mounted on a submount by a junction down method.

DESCRIPTION OF SYMBOLS 1 Semiconductor laser device 10 Semiconductor laser element 11 Semiconductor substrate 12, 13 Laser emission part 14, 15 Individual electrode 16 Common electrode 17 Separation groove 20 Submount 21 Base 21a Mounting surface 22, 23 Connection electrode 24, 25 Bonding pad

Claims (14)

A semiconductor substrate, a plurality of laser light emitting portions formed on one surface of the semiconductor substrate and electrically separated from each other, and each laser light emitting portion on a surface of each laser light emitting portion opposite to the semiconductor substrate, A semiconductor laser element including an individual electrode to be formed, and a common electrode formed on a surface opposite to the one surface of the semiconductor substrate;
A plurality of connection electrodes each having a flat mounting surface on which the semiconductor laser element is mounted; the individual electrodes individually connected by a conductive brazing material; and stains from the connection electrodes. a submount and exuding determination unit for determining the degree exudation out brazing material is formed seen including,
The seepage determining unit is formed on the mounting surface in a region not covered by the semiconductor laser element when the semiconductor laser element is mounted, with a predetermined arrangement interval from the connection electrode. A semiconductor laser device. The individual electrode provided for each laser emission unit is formed in a stripe shape,
The plurality of connection electrodes are formed in stripes with predetermined electrode intervals according to the intervals between the individual electrodes,
Determination unit exudes above, claim 1 of the connecting electrode which is disposed closest to the outside in the direction perpendicular to the extending direction of the connection electrode, characterized in that it is formed at a predetermined arrangement interval The semiconductor laser device described in 1. 3. The semiconductor laser device according to claim 2 , wherein the predetermined arrangement interval is equal to or less than the predetermined electrode interval. Determination unit exudes said semiconductor laser device according to claim 2 or 3, characterized in that it is formed at a position near the exit end face of the laser light in the semiconductor laser device. Determination unit exudes said semiconductor laser device according to claim 2 or 3, characterized in that formed in plural along the extending direction of the connection electrode. Determination unit exudes said semiconductor laser device according to claim 2 or 3, characterized in that it is formed in a linear shape along the extending direction of the connection electrode. Wherein the predetermined arrangement interval is, the semiconductor laser device according to any one of claims 2 to 6, characterized in that at 80μm or less. The mounting surface is one surface of a dielectric member constituting the submount,
Determination unit exudes said semiconductor laser device according to any one of claims 1-7, characterized in that it is formed by exposing a part of said one surface of said dielectric member to the outside . The mounting surface is one surface of a dielectric member constituting the submount,
Determination unit exudes said semiconductor laser device according to any one of claims 1-7, characterized in that it is formed by laminating the members on said one surface of said dielectric member. The On one surface of the dielectric member, the semiconductor laser device according to claim 8 or 9, characterized in that the bonding pads are formed with electrically conductive for connecting the semiconductor laser element to an external circuit. It said dielectric member, AlN, semiconductor laser device according to any one of claims 8 to 10, characterized in that it is formed by any one of SiN and Si. Wherein each laser light emitting portion, a semiconductor laser device according to any one of claims 1 to 11 in which the interval of light emitting point of the laser light emitting unit is characterized in that it is formed so as to be 200μm or less. Wherein each laser light emitting portion, a semiconductor laser device according to any one of claims 1 to 12, characterized in that is configured to respectively emit laser beams having different oscillation wavelengths. Wherein each laser light emitting portion, a semiconductor laser device according to any one of claims 1 to 12, characterized in that each oscillation wavelength is configured to emit the same laser beam.

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