JP2008182143A - Semiconductor device, laser light-emitting device, and method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a spot shape in which a radial/tangential direction is equal on an irradiated field of a beam light even if a spot-shaped beam light whose aspect ratio differs is emitted. <P>SOLUTION: A semiconductor device is used for a laser light-emitting device which irradiates the laser beam to the irradiated field. The semiconductor device includes: a light-emitting element 11 which emits the spot-shaped beam light whose aspect ratio differs; and an element loading side 12a on which the light-emitting element 11 is attached while being inclined to a reference plane by using an optical axis of the beam light as a center of rotation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductor device including a light emitting element, a laser light emitting device, and a method for manufacturing the semiconductor device.

  In recent years, semiconductor laser devices are widely known as one of semiconductor devices. The semiconductor laser device is used in, for example, a laser light emitting device that constitutes an optical pickup of a disk drive device.

  It is known that the light beam emitted from such a semiconductor laser device has a non-uniform light intensity distribution and a high light intensity distribution at the center of the beam. Therefore, when a laser light emitting device is configured using a semiconductor laser device, for example, as shown in FIG. 8, the center position of the light intensity distribution of the beam light from the semiconductor laser device is set to the center of the optical system (lens, etc.). It has been proposed to adjust the tilt of the semiconductor laser device in order to meet the above and improve the light utilization efficiency of the light beam (see, for example, Patent Documents 1 and 2).

Japanese Patent No. 3759422 International Publication No. 01/011615 Pamphlet

  By the way, the light beam emitted from the semiconductor laser device has an elliptical spot shape on the irradiated surface. That is, from the semiconductor laser device, for example, as shown in FIG. 9, spot-shaped light beams having different aspect ratios are emitted. Therefore, the light intensity distribution is not uniform in the radial direction and the tangential direction on the irradiated surface of the beam light.

  This also occurs when the center position of the light intensity distribution of the beam light is matched with the center of the optical system. That is, the light intensity distribution in the radial direction and the tangential direction on the irradiated surface of the beam light cannot be made uniform by simply matching the center position of the light intensity distribution of the beam light with the center of the optical system.

  On the other hand, the spot shape of the light beam on the surface irradiated with the light beam is an optimal spot shape having a uniform radial and tangential direction length. This leads to the creation of recording pits, and is extremely important for improving the recording density and miniaturization of the optical disc.

  Therefore, the present invention provides a semiconductor device and a laser emitting device capable of obtaining a spot shape having a uniform radial and tangential direction on the surface irradiated with the beam light even when the beam light having a spot shape having a different aspect ratio is emitted. An object is to provide a device and a method for manufacturing the semiconductor device.

  The present invention is a semiconductor device devised to achieve the above object, a light emitting element that emits spot-shaped light beams having different aspect ratios, and the light emitting element having an optical axis of the light beam as a rotation center. And an element mounting surface that is attached in an inclined state with respect to the reference surface.

  In the semiconductor device having the above configuration, when the light emitting element is mounted on the element mounting surface, the light emitting element is attached to be inclined with the optical axis of the beam light as the rotation center. As the beam tilts, the spot shape of the beam light on the irradiated surface also tilts around the optical axis of the beam light. That is, the aspect ratio of the spot shape of the light beam changes on the surface irradiated with the light beam in accordance with the inclination of the light emitting element. Therefore, even if the light emitting element emits spot-shaped light beams having different aspect ratios, the light intensity distribution between the radial direction and the tangential direction on the irradiated surface of the light beams by appropriately setting the inclination angle of the light beam. Can be made even.

  According to the present invention, the spot shape of the light beam on the surface irradiated with the light beam from the light emitting element can be an optimum spot shape having a uniform radial / tangential length. Therefore, for example, when configuring an optical pickup for an optical disc, it is possible to make recording pits that are uniform in length and width, and as a result, it is very effective in improving the recording density and miniaturization of the optical disc.

  Hereinafter, a semiconductor device, a laser light emitting device, and a method for manufacturing the semiconductor device according to the present invention will be described with reference to the drawings.

  First, a laser light emitting device configured using a semiconductor device will be described. Examples of the laser light emitting device include those used as an optical pickup of a disk drive device.

  FIG. 1 is an explanatory diagram illustrating a configuration example of an optical pickup. The optical pickup shown in the figure is configured to irradiate an information recording medium 1 typified by an optical disc with laser light and to detect reflected light obtained from the information recording medium 1. For this purpose, in the optical pickup, a polarizing beam splitter 20 having a reflecting surface and an optical system 30 including a collimator lens and an objective lens are sequentially arranged along the emission direction of the beam light from the semiconductor laser device 10. The light beam emitted from the semiconductor laser device 10 is condensed on the irradiated surface of the information recording medium 1. A signal detector 40 having a signal detecting optical element or the like is disposed on the optical axis of the reflected light reflected by the reflecting surface of the polarizing beam splitter 20, and the signal detector 40 is an information recording medium. 1 is configured to read information from 1.

  Next, a specific example of the semiconductor laser device 10 used in the laser light emitting device (optical pickup) having the above-described configuration, that is, a semiconductor device according to the present invention will be described.

FIG. 2 is an explanatory diagram showing a configuration example of the semiconductor laser device. In the semiconductor laser device 10 shown in the figure, a light emitting element 11 for emitting beam light is disposed on a base 13 via a submount 12, and further, the base 13 is in a recess 14 a provided in a substrate package 14. It arrange | positions so that it may be located in.
The light emitting element 11 is formed of, for example, a III-V group compound semiconductor, and emits a laser beam having a spot shape (for example, an elliptical shape) having a different aspect ratio.
The submount 12 has at least an element mounting surface and a submount installation surface. The light emitting element 11 is mounted on the element mounting surface, and the submount installation surface has good heat conduction such as silver paste or solder. It joins on the base 13 using an adhesive agent. For the submount 12, it is conceivable to select a material having a high thermal conductivity such as silicon carbide (SiC), copper tungsten (CuW), diamond or the like.
The base 13 is formed of a metal material having good thermal conductivity such as copper (Cu), receives heat generated by the light emitting element 11 from the light emitting element 11 via the submount 12, and cools the light emitting element 11. It functions as a heat sink that contributes to prevention of high temperature.
The substrate package 14 is formed of a ceramic material and functions as a substrate of the semiconductor laser device 10. With respect to the substrate package 14, it is easy to ensure wiring flexibility by using a ceramic material. For example, the power source line of the light emitting element 11 is embedded in a ceramic material because of its good sealing property, and is wired to the inside of the recess 14a in which the base 13 and the like are disposed. The substrate package 14 is provided with an opening 14b for transmitting the light beam at the position of the optical axis of the light beam emitted from the light emitting element 11.

  Further, the light emitting element 11, the submount 12, and the base 13 disposed in the recess 14 a of the substrate package 14 are sealed with a metal cap 15. That is, a metal cap 15 formed of a metal material having good thermal conductivity is disposed in the recess 14a of the substrate package 14, and the periphery of the metal cap 15 is resin-bonded with good sealing properties. Filled with agent 16. In addition, the metal cap 15 shall be distribute | arranged so that it may have a part which contacts the base 13 directly.

  Further, the opening 14 b of the substrate package 14 is sealed with a lid 17. That is, a lid 17 made of a light-transmitting glass material or the like is disposed in the opening 14b and bonded with a resin adhesive or the like. The light beam emitted from the light emitting element 11 passes through the opening 14 b of the substrate package 14, passes through the lid 17, and is disposed on the surface opposite to the metal cap 15 on the optical element 18. It is emitted in the direction. The optical element 18 is for giving a predetermined optical characteristic to the light beam from the light emitting element 11, but is not a main part of the semiconductor laser device 10 of the present embodiment, and uses a known technique. Since it is only necessary to realize it, the description thereof is omitted here.

  FIG. 3 is an explanatory view showing another configuration example of the semiconductor laser device. The semiconductor laser device 10 shown in the drawing is different from the above-described configuration example (see FIG. 2) in the attachment of the metal cap 15. That is, the metal cap 15 is not fitted into the recess 14a of the substrate package 14, but is connected to the ring 19a via a ring 19a made of a metal material or the like installed using silver wax or the like around the recess 14a. The light emitting element 11, the submount 12 and the base 13 disposed in the recess 14a are attached so as to be completely airtight. However, in such an attachment mode, it is not expected to absorb the dimensional error of each component as in the case of fitting into the recess 14a, and the metal cap 15 may not be in direct contact with the base 13. Therefore, a high heat transfer material 19b made of a highly heat conductive adhesive or the like is disposed between the base 13 and the metal cap 15 so as to fill the gap. Contact shall be ensured.

  That is, in any of the configurations of FIGS. 2 and 3, the semiconductor laser device 10 includes the light emitting element 11, the submount 12, and the base 13 disposed in the recess 14 a of the substrate package 14 sealed with the metal cap 15. Yes. And the said metal cap 15 is distribute | arranged so that it may contact with the base 13 directly or via the high heat-transfer material 19b.

  Next, a characteristic configuration of the semiconductor laser device 10 as described above will be described. FIG. 4 is an explanatory diagram showing an outline of a characteristic configuration of the semiconductor laser device.

  In the semiconductor laser device 10 described in the present embodiment, as shown in FIG. 4A, the light emitting element 11 is inclined with respect to the reference plane with the optical axis of the beam light emitted from the light emitting element 11 as the rotation center. There is a big feature in that it is attached in the state. Here, the “reference plane” means that when a light emitting element is arranged as in the conventional case, that is, a light emitting element that emits beam light having a spot shape (for example, an elliptical shape) having a different aspect ratio is the long axis of the spot shape. When the light emitting element is disposed in such a manner that the direction is along the radial direction on the surface to be irradiated with the beam light and the short axis direction is along the tangential direction on the surface to be irradiated with the beam light. It refers to the corresponding virtual surface.

  That is, in the semiconductor laser device 10 according to the present embodiment, on the element mounting surface provided with an inclination such that the light emitting element 11 is inclined with respect to the reference plane with the optical axis of the light beam from the light emitting element 11 as the rotation center. The light emitting element 11 is attached. The inclination angle of the element mounting surface with respect to the reference surface, that is, the angle formed between the reference surface and the element mounting surface may be determined according to the spot shape of the light beam from the light emitting element 11, as will be described later. For example, the angle may be about 40 °.

  When the light emitting element 11 is mounted on the element mounting surface provided with such an inclination angle, the light emitting element 11 is attached to be inclined with the optical axis of the beam light as the rotation center. Therefore, as shown in FIG. 4B, the spot shape of the light beam is tilted about the optical axis of the light beam as the light emitting element 11 is tilted. It will be. That is, the aspect ratio of the spot shape of the light beam changes in accordance with the inclination of the light emitting element 11 on the surface irradiated with the light beam. Specifically, as shown in the figure, the size of the spot shape in the short axis direction is “b” and the size in the long axis direction is “c”, which are different from each other and “b ≠ c”. However, by tilting the optical axis about the center of rotation, the radial size “a” and the tangential size “a” of the spot shape on the irradiated surface of the beam light become substantially equal.

  Thus, in the semiconductor laser device 10 according to the present embodiment, therefore, even if the light emitting element 11 emits spot-shaped beam light having different aspect ratios, by appropriately setting the inclination angle of the element mounting surface, FIG. As shown in C), the light intensity distribution (FFP: far field pattern) in the radial direction and the tangential direction on the surface irradiated with the light beam can be made uniform.

  As described above, according to the semiconductor laser device 10 and the laser light emitting device using the semiconductor laser device according to the present embodiment, the spot shape of the light beam on the irradiated surface of the light beam from the light emitting element 11 is changed to the radial tangential. It is possible to obtain an optimum spot shape having a uniform direction length. Therefore, for example, when a laser light emitting device is used as an optical pickup of a disk drive device, it becomes possible to create recording pits that are uniform in length and width, and as a result, it is very effective in improving the recording density and miniaturization of the optical disk. It becomes. In addition, since it is only necessary to incline the light emitting element 11 with the optical axis of the beam light as the center of rotation, it is possible to realize with a simple configuration, and it is easy to cope with downsizing and thinning of the apparatus.

  Next, a configuration for realizing the inclination of the light emitting element 11 as described above will be described.

  FIG. 5 is an explanatory diagram showing a configuration example of a main part of the semiconductor laser device. The illustrated example shows a case where the surface mount angle θ for making the light emitting element 11 tilted is given to the submount 12 on which the light emitting element 11 is mounted. That is, the submount 12 is provided with an element mounting surface 12 a on which the light emitting element 11 is mounted and a submount installation surface 12 b for mounting the submount 12 on the base 13. The element mounting surface 12a and the submount installation surface 12b are configured to have a surface inclination angle θ.

  If the submount 12 having such a configuration is used, the element mounting surface 12a and the submount installation surface 12b are in a relation of forming a surface inclination angle θ, so that the submount installation surface 12b is a surface parallel to the reference surface of the base 13. By mounting upward, the element mounting surface 12a is given an inclination such that the light emitting element 11 is inclined by the surface inclination angle θ with respect to the reference plane with the optical axis of the beam light as the rotation center. . Therefore, the inclination of the light emitting element 11 mounted on the element mounting surface 12a can be easily and reliably realized.

For the reasons described later, the submount 12 is desirably provided with an element mounting reference surface 12c parallel to the element mounting surface 12a in addition to the element mounting surface 12a and the submount installation surface 12b.
Further, it is desirable to provide a connection terminal 12 d for electrical connection with the light emitting element 11 on a surface other than the element mounting surface 12 a in the submount 12.

  FIG. 6 is an explanatory diagram showing another configuration example of a main part of the semiconductor laser device. The illustrated example shows a case where a surface tilt angle θ for tilting the light emitting element 11 is given to the base 13 on which the submount 12 on which the light emitting element 11 is mounted is disposed. In other words, the base 13 is provided with a submount mounting surface 13a parallel to the element mounting surface 12a of the rectangular or cubic submount 12, and a base surface 13b parallel to the reference surface. The submount mounting surface 13a and the base surface 13b are configured to have a surface inclination angle θ.

  If the base 13 having such a configuration is used, the submount mounting surface 13a and the base surface 13b are in a relation of forming a surface inclination angle θ, so that the submount mounting surface of the submount 12 is relative to the submount mounting surface 13a. Thus, by mounting the submount 12 on the base 13, the element mounting surface 12a of the submount 12 faces the light emitting element 11 with respect to the reference plane with the optical axis of the beam light as the rotation center. An inclination that is inclined by the inclination angle θ is given. Therefore, the inclination of the light emitting element 11 mounted on the element mounting surface 12a can be easily and reliably realized.

  Even in such a configuration, it is desirable that a connection terminal 12 d for electrical connection with the light emitting element 11 is provided on a surface other than the element mounting surface 12 a of the submount 12.

  As described above with reference to FIG. 5 or FIG. 6, the inclination of the light emitting element 11 may be realized by giving the surface inclination angle θ to one of the submount 12 and the base 13, thereby The tilt can be realized easily and reliably.

  By the way, when the inclination of the light emitting element 11 is realized by the surface inclination angle θ in the submount 12 or the base 13, if the connection terminal 12d is provided on a surface other than the element mounting surface 12a, the electrical connection with the light emitting element 11 is achieved. It is possible to prevent the wire bonding process necessary for securing the connection from becoming complicated. If the light emitting element 11 is tilted, the connection terminal connected to the light emitting element 11 and the counterpart terminal of the wire bond do not exist in the same plane due to the tilt, and the wire bonding process may be complicated. This is because by providing the connection terminal 12d on a surface other than the element mounting surface 12a, it is possible to make the connection terminal 12d face the formation surface of the wire bond mating terminal.

  Even if the tilt of the light emitting element 11 is realized by either the submount 12 or the base 13, if the metal cap 15 is in contact with the base 13 directly or through the high heat transfer material 19b, the light emitting element 11, While maintaining the completely airtight state of the submount 12 and the base 13, the heat generated in the light emitting element 11 is transmitted to the base 13 through the submount 12 and further from the base 13 to the metal cap 15. Can be directly dissipated. That is, by using the metal cap 15 as a heat radiating means while functioning the base 13 as a heat sink, heat in the light emitting element 11 becomes a problem even when the light emitting element 11 or the like is sealed with the metal cap 15. Can be avoided as much as possible.

  Next, a procedure for configuring the semiconductor laser device 10 as described above, that is, a method for manufacturing the semiconductor laser device 10 will be described. Here, the inclination of the light-emitting element 11 is realized by giving the surface inclination angle θ to the submount 12, and the case where the element mounting reference surface 12c is provided on the submount 12 is taken as an example. A procedure for mounting the light emitting element 11 on the mount 12 will be described. FIG. 7 is an explanatory view showing an example of a method for manufacturing a semiconductor laser device.

  In mounting the light emitting element 11 on the submount 12, first, as shown in FIG. 7A, the element mounting reference surface 12c provided on the submount 12 is set on a horizontal plane. As a result, the submount 12 is set in a state where the element mounting surface 12a parallel to the element mounting reference surface 12c is horizontal.

  After the submount 12 is set, as shown in FIG. 7B, the light emitting element 11 is placed on the element mounting surface 12a of the submount 12 and fixed with solder or the like. As a result, the light emitting element 11 is mounted on the element mounting surface 12 a of the submount 12. However, since the element mounting surface 12a is in a horizontal state at this time, the light emitting element 11 can be mounted using the same equipment (element handling robot or the like) as in the past, that is, existing equipment.

  Then, when the light emitting element 11 is mounted on the element mounting surface 12 a, the submount 12 on which the light emitting element 11 is mounted is connected to the submount mounting surface 13 a in the base 13. In a state of being opposed to each other, it is placed on the base 13 and fixed. As a result, the light emitting element 11 is attached with an inclination of the surface inclination angle θ with respect to the submount installation surface 12b with the optical axis of the beam light as the rotation center.

  In addition, about the manufacturing procedure other than the process mentioned above, since it is sufficient to use a known technique similar to the conventional one, the description thereof is omitted here.

  If the semiconductor laser device 10 is configured according to the procedure as described above, even when the light emitting element 11 is tilted and attached with the optical axis of the beam light as the rotation center, the element mounting reference plane 12c is used as a reference. Since the submount 12 is set so that the element mounting surface 12a is in a horizontal state, the light emitting element 11 can be mounted using the existing equipment, and at that time, the tilt angle of the light emitting element 11 is adjusted. There is no need for jigs. Further, since the element mounting reference surface 12c is parallel to the element mounting surface 12a, it can be expected that the formation accuracy can be maintained high. Therefore, if the light emitting element 11 is mounted on the submount 12 using the element mounting reference surface 12c, the semiconductor laser device 10 having a configuration in which the light emitting element 11 is inclined with the optical axis of the beam light as the rotation center, This makes it possible to manufacture easily and with high accuracy.

In the embodiment described above, the preferred specific example of the present invention has been described, but the present invention is not limited to the content.
For example, the semiconductor laser device to which the present invention is applicable is not limited to the one formed by the group III-V compound semiconductor exemplified in this embodiment, and is also a laser light emitting device (optical pickup). It is not limited to what is used.
That is, the present invention can be modified as appropriate without departing from the scope of the invention.

It is explanatory drawing which shows the structural example of the optical pick-up which is an example of the laser light-emitting device concerning this invention. It is explanatory drawing which shows the structural example of the semiconductor laser apparatus which concerns on this invention. It is explanatory drawing which shows the other structural example of the semiconductor laser apparatus which concerns on this invention. It is explanatory drawing which shows the outline | summary of the characteristic structure of the semiconductor laser apparatus based on this invention. It is explanatory drawing which shows the principal part structural example of the semiconductor laser apparatus which concerns on this invention. It is explanatory drawing which shows the other principal part structural example of the semiconductor laser apparatus which concerns on this invention. It is explanatory drawing which shows an example of the manufacturing method of the semiconductor laser apparatus which concerns on this invention. It is explanatory drawing which shows the outline | summary of the laser beam light irradiation in the conventional semiconductor laser apparatus. It is explanatory drawing which shows the outline | summary of the light intensity distribution of the laser beam light by the conventional semiconductor laser apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Information recording medium, 10 ... Semiconductor laser apparatus, 11 ... Light emitting element, 12 ... Submount, 12a ... Element mounting surface, 12b ... Submount installation surface, 12c ... Reference surface at the time of element mounting, 12d ... Connection terminal, 13 ... Base, 13a ... Submount mounting surface, 13b ... Base surface, 14 ... Board package, 15 ... Metal cap, 16 ... Resin adhesive, 17 ... Lid, 19b ... High heat transfer material, 20 ... Polarizing beam splitter, 30 ... Optical 40, signal detector,

Claims (7)

A light-emitting element that emits spot-shaped beam light having different aspect ratios;
An element mounting surface on which the light emitting element is mounted in an inclined state with respect to a reference plane with the optical axis of the beam light as a rotation center.   The light emitting element is disposed on a base via a submount, and a surface inclination angle for making the light emitting element in the inclined state is given to either the submount or the base. The semiconductor device according to claim 1.   When the surface inclination angle is given to the submount, the submount includes an element parallel to the element mounting surface, in addition to the submount installation surface having the surface inclination angle with the element mounting surface. 3. The semiconductor device according to claim 2, further comprising a mounting reference surface.   The semiconductor device according to claim 2, wherein a connection terminal for electrically connecting to the light emitting element is provided on a surface other than the element mounting surface of the submount.   The light emitting device, the submount, and the base are sealed with a metal cap, and the metal cap is arranged to contact the base directly or through a heat transfer material. 2. The semiconductor device according to 2. A laser light emitting device for irradiating a surface to be irradiated with laser light,
A light-emitting element that emits spot-shaped beam light having different aspect ratios as the laser light;
A laser light emitting device comprising: an element mounting surface on which the light emitting element is attached in an inclined state with respect to a reference plane with the optical axis of the beam light as a rotation center. A light-emitting element that emits spot-shaped light beams having different aspect ratios is a method for manufacturing a semiconductor device, which is disposed on a base via a submount,
The sub in which an element mounting surface on which the light emitting element is mounted, a submount installation surface having a predetermined angle with the element mounting surface, and an element mounting reference plane parallel to the element mounting surface are formed. An element mounting step of mounting the light emitting element on the element mounting surface of the mount on the basis of the reference plane when the element is mounted;
The submount after the light emitting element is mounted is disposed on the base with respect to the submount installation surface, and the light emitting element is placed on the submount installation surface with the optical axis of the beam light as a rotation center. And a submount mounting step for mounting the device in a state inclined by the predetermined angle.

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