JP2005190520A - Optical head device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical head device mounted with a semiconductor device of a frame type capable of increasing heat radiating efficiency while maintaining the characteristics of a thin type. <P>SOLUTION: In semiconductor laser devices 21 and 22, a metal frame 211 having a semiconductor laser chip 215 mounted thereon is provided with a resin part 218 integrally formed to surround the semiconductor laser chip 215. The metal frame 211 is provided with fin parts 216 protruding to both sides from the resin part 218 and an exposed part 217 on the backside of an element mounting part 212a, and heat is radiated from these parts. Besides, in an optical head device 1 having the semiconductor laser devices 21, 22 mounted on a first package 31, the exposed part 217 is directed to the first package 31. Thus, heat generated on the semiconductor laser chip 215 is efficiently dissipated from the exposed part 217 to the first package 31. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical head device provided with a frame type semiconductor laser device. More specifically, the present invention relates to a heat dissipation technique for a semiconductor laser device.

  In an optical head device used for recording and reproduction of an optical recording medium such as a CD or a DVD, light emitted from a light source is guided to an objective lens through a light guide system, and the light guided by the objective lens is disc-shaped light. It converges on the recording medium. At this time, driving of the objective lens in the tracking direction and the focusing direction is performed by a lens driving device. The return light from the optical recording medium is guided to the light receiving element via the light guide system.

  Here, the light source, the objective lens, the light guide system, the lens driving device, and the like are mounted on a device frame that is scanned in the radial direction of the optical recording medium.

  Conventionally, as a light source, a semiconductor laser device called a stem type, in which a semiconductor laser chip is mounted on a metal stem and sealed with a cylindrical metal cap having a glass window on an emission surface, is used. .

In addition, a semiconductor laser called a frame type in which a semiconductor laser chip is mounted on the upper surface side of a plate-shaped metal frame and a resin portion is formed so as to surround an element mounting portion on which the semiconductor laser chip of the metal frame is mounted. An apparatus is used (for example, see Patent Document 1).
JP 2002-43672 A

  However, the stem type semiconductor laser device is excellent in heat dissipation because the semiconductor laser chip is mounted directly on the stem made of a metal block having a large heat capacity or via a submount, but the outer size is reduced. However, there is a problem that the optical head device cannot be thinned.

  On the other hand, the frame type semiconductor laser device has a configuration in which only a part of the plate-like metal frame on which the semiconductor laser chip is mounted is covered with resin, which is advantageous for reducing the thickness of the optical head device. In this frame type semiconductor laser device, heat radiation is performed only by the fin portions of the metal frame projecting on both sides of the resin portion, so that the heat radiation efficiency is low. Therefore, for example, when a high power laser device for DVD recording or the like is used, there is a problem that the thermal degradation of the semiconductor laser characteristics is remarkable.

  In view of the above problems, an object of the present invention is to propose an optical head device equipped with a frame type semiconductor laser device capable of improving heat dissipation efficiency while having the feature of being thin.

  In order to solve the above problems, the present invention provides a metal frame having a semiconductor laser chip mounted on the upper surface side, and the metal frame so as to surround an element mounting portion on which the semiconductor laser chip is mounted on the upper surface of the metal frame. In an optical head device in which a semiconductor laser device having a resin portion formed from the upper surface to the lower surface of a frame is mounted on a laser device mounting member, the metal frame extends to the outside of the resin portion on both sides of the element mounting portion. An exposed portion of the metal frame is provided on the back side of the element mounting portion by having a protruding fin portion and forming the resin portion on the lower surface of the metal frame so as to avoid the back side of the element mounting portion. In the semiconductor laser device, the exposed portion faces the laser device mounting member side, and the semiconductor laser chip is in front. The laser device mounting member, characterized in that mounted on the laser device mounting member so as to face the opposite side.

In the present invention, the laser device mounting member is made of metal, and the laser device mounting member includes a heat radiating member that contacts the exposed portion and releases heat generated in the semiconductor laser chip to the laser device mounting member side. It is preferable that it is mounted. If comprised in this way, the heat | fever generate | occur | produced with the semiconductor laser chip can be efficiently escaped to the laser apparatus mounting member side via a heat radiating member.

  In the present invention, the heat radiating member is made of metal, for example.

  In the present invention, it is preferable that the heat radiating member is a protruding portion protruding from the laser device mounting member toward the exposed portion of the semiconductor laser device, and the protruding portion and the exposed portion are in contact with each other. If comprised in this way, there exists an advantage that a protrusion part can be integrally molded with a laser apparatus mounting part.

  In the present invention, it is preferable that the protruding portion is in surface contact with the exposed portion of the semiconductor laser device. If comprised in this way, since the contact area of a heat sink and a laser apparatus mounting member is large, the heat transfer efficiency from the exposed part of a metal frame to a heat sink is high.

  In this invention, it is preferable to have an optical axis adjustment member for adjusting the optical axis of the emitted light emitted from the semiconductor laser chip. With this configuration, even if the mounting position of the semiconductor laser device is displaced due to the molding error of the protruding portion, the optical axis of the emitted light emitted from the semiconductor laser chip can be made coincident with the optical axis of the optical system.

  In the present invention, it is preferable that the exposed portion and the fin portion are separated from each other by the resin portion, and the fin portion is fixed to the laser device mounting member by an adhesive. If comprised in this way, when fixing a fin part to a laser apparatus mounting member with an adhesive agent, an adhesive agent will not flow out to the exposed part side and will not cover an exposed part. Therefore, the adhesive prevents the heat radiating member from contacting the exposed portion, and the heat dissipation performance is not impaired.

  In the present invention, heat radiation from the metal frame on which the laser chip is mounted occurs at the fin portion protruding outside the resin portion and the exposed portion from the resin portion on the lower surface of the metal frame, so the heat radiation area is wide. Moreover, in the optical head device in which the frame type semiconductor laser device according to the present invention is mounted on the laser device mounting member, the exposed portion formed on the back side of the element mounting portion of the metal frame faces the laser device mounting member side. Therefore, it is possible to easily dissipate heat simply by interposing a heat dissipating member for efficiently releasing heat generated in the semiconductor laser chip from the exposed portion to the laser device mounting member between the exposed portion and the laser device mounting member. Further, since the frame type semiconductor laser device is thinner than the stem type semiconductor laser device, the optical head device can be made thinner.

  An example of an optical head device to which the present invention is applied will be described with reference to the drawings.

(overall structure)
1A, 1B, and 1C are a perspective view of an optical head device to which the present invention is applied as viewed obliquely from above, a perspective view from obliquely below, and an optical module used in the optical head device. It is the perspective view which looked at the state which connected the flexible substrate for electric power feeding from diagonally upward. 2A and 2B are a perspective view of an optical module, a total reflection mirror prism, and an objective lens constituting an optical system in the optical head device of FIG. It is. In FIGS. 1A and 1B, illustration of the flexible substrate is omitted.

  An optical head device 1 shown in FIGS. 1 and 2 includes a laser beam having a wavelength of 650 nm in order to perform information recording and information reproduction on a DVD disk and a CD disk as an optical recording medium 2 (optical recording disk), This is a two-wavelength optical head device using laser light having a wavelength of 780 nm.

  In the optical head device 1 of the present embodiment, as will be described in detail later, a semiconductor laser device using a laser diode as a light source, a light receiving element such as a photodiode, and other optical elements are integrated as an optical module 3. As shown in FIG. 1C, the module 3 is mounted on a metal or resin device frame 4 with a flexible substrate 41 attached to the upper surface thereof. The apparatus frame 4 includes a total reflection mirror prism 42 that reflects the outgoing light L from the optical module 3 toward the optical recording medium, and an objective lens 51 that converges the laser light reflected by the total reflection mirror prism 42 onto the optical recording disk. An objective lens driving mechanism 5 for driving the motor is also mounted.

  As shown in FIGS. 1A and 1B, the objective lens driving mechanism 5 includes a lens holder 52 that holds the objective lens 51 at the center of the upper surface, and a tracking direction in which the lens holder 52 is connected by a plurality of wires 53. And a holder support member 54 that is movably supported in the focusing direction, and a yoke 55 fixed to the apparatus frame 4. The objective lens drive mechanism 5 includes a magnetic drive circuit configured by a drive coil attached to the lens holder 52 and a drive magnet attached to the yoke 55, and by controlling energization to the drive coil, The objective lens 51 held by the lens holder 52 is driven in the tracking direction and the focusing direction with respect to the optical recording disk 2.

(Description of optical system of optical head device)
FIG. 3 is an explanatory view showing an optical system in the optical head device of FIG.

  As shown in FIGS. 2B and 3, the optical module 3 includes a first semiconductor laser device 21 for DVD that emits a first laser beam having a wavelength of 650 nm and a second laser having a wavelength of 780 nm. And a second semiconductor laser device 22 for CD which emits light.

  In addition, the optical module 3 converts the first laser light emitted from the first semiconductor laser device 21 and the second laser light emitted from the second semiconductor laser device 22 into a partially reflective film (partially reflective surface). ) Is guided to a common optical path toward the optical recording disk 2 through first and second prisms 23 and 24, which are optical elements for separating optical paths, and on this common optical path, λ / 4 The plate 25 and the collimating lens 26 are arranged in this order. In the optical head device 1, a total reflection mirror prism 42 mounted on the device frame 4 and an objective lens 51 are disposed between the optical recording disk 2 and the collimating lens 26 in the common optical path.

  In the optical head device 1 of the present embodiment, in the optical module 3, the first semiconductor laser device 21 is disposed opposite to the first prism 23, and the second semiconductor laser device 22 is disposed opposite to the second prism 24. Yes. Also, a first optical axis adjusting element 73 and a first diffractive element 71 as optical axis adjusting members are arranged between the first semiconductor laser device 21 and the first prism 23, and the second semiconductor. Between the laser device 22 and the second prism 24, a second optical axis adjusting element 74, a second diffractive element 72, and a λ / 2 plate 79 as optical axis adjusting members are arranged. The first diffractive element 71 generates three beams for detecting a tracking error from the first laser light, and the second diffractive element 72 is 3 for detecting a tracking error from the second laser light. A beam is generated. Each of the first and second diffraction elements 71 and 72 has a flat plate shape in which a grating surface is formed of a dielectric film on a glass substrate. The first optical axis adjusting element 73 is for adjusting the optical axis of the emitted light emitted from the semiconductor laser chip 215 of the first semiconductor laser device 21 in the H direction in FIG. 74 is for adjusting the optical axis of the emitted light emitted from the semiconductor laser chip 215 of the second semiconductor laser device 22 in the H direction in FIG. Each of the first and second optical axis adjusting elements 73 and 74 is a parallel plate made of a glass substrate, and an antireflection film is formed on the surface as necessary.

  Further, on the side opposite to the side where the second semiconductor laser device 22 is disposed with respect to the first prism 23, a sensor lens 27 as an astigmatism generating element and a return emitted from the sensor lens 27 are provided. A signal detection total reflection mirror 28 (signal detection deflection mirror) that reflects light by 90 ° and a signal detection light receiving element 91 that receives light guided by the signal detection total reflection mirror 28 are arranged. The sensor lens 27 is a lens for generating astigmatism with respect to the return light of the laser light.

  Further, on the opposite side of the second prism 24 from the second semiconductor laser device 22, that is, on the same side as the side on which the signal detection light receiving element 91 is disposed, the first semiconductor laser device 21 and A total reflection mirror 29 for monitoring (a deflection mirror for monitoring) through which a part of light emitted from the second semiconductor laser device 22 toward the first and second prisms 23 and 24 is guided, and this total reflection for monitoring A monitor light receiving element 92 that receives the light reflected by 90 ° by the mirror 29 is disposed.

  In this embodiment, the first and second prisms 23 and 24 are configured as a composite prism 20 joined by an adhesive, and one of the entrance surfaces and the exit surface of the composite prism 20 has λ / 4. The plate 25 and the λ / 2 plate 79 are bonded and fixed.

  In the optical head device 1 configured as described above, a part of the first laser light emitted from the first semiconductor laser device 21 is transmitted through the partial reflection surfaces of the first and second prisms 23 and 24. The light is emitted toward the objective lens 51 through the collimating lens 26. The second laser light emitted from the second semiconductor laser device 22 is partly reflected by the partial reflection surface of the prism 24, and its optical axis is bent by 90 °, and the objective lens is passed through the collimator lens 26. It is emitted toward 51.

  At that time, a part of the first laser light emitted from the first semiconductor laser device 21 and a part of the second laser light emitted from the second semiconductor laser device 22 are used as monitor light. The light is guided to the monitor light receiving element 92 via the two prisms 24 and the monitor total reflection mirror 29. The monitoring result of the monitoring light receiving element 92 is fed back to the first semiconductor laser device 21 and the second semiconductor laser device 22, and the intensity of the laser light emitted from each is controlled.

  On the other hand, the return light from the optical recording disk 2 returns to the objective lens 51 and the total reflection mirror prism 42 in reverse, and is emitted toward the sensor lens 27 through the collimator lens 26 and the first and second prisms 24 and 23. Then, after astigmatism is given by the sensor lens 27, it is guided to the signal detecting light receiving element 91 by the signal detecting total reflection mirror 28 and detected by the signal detecting light receiving element 91.

  The return light detected by the signal detecting light receiving element 91 includes three beams obtained by diffracting the first laser light emitted from the first semiconductor laser device 21 by the first diffraction element 71 or the second semiconductor. 3 beams obtained by diffracting the second laser light emitted from the laser device 22 by the second diffractive element 72, and among these three beams, signal reproduction and A focusing error signal is detected, and a tracking error signal is detected by a sub beam composed of ± first-order diffracted light.

(Configuration of optical module)
FIG. 4 is a perspective view showing a state where the second package is removed from the first package in the optical module used in the optical head device of FIG. 5A, 5B, and 5C are perspective views of the optical module used in the optical head device of FIG. 1, in which the second package is viewed obliquely from above, and the second package is viewed from obliquely below. It is the perspective view which looked at the state which removed the metal plate from the perspective view, and the 2nd package from diagonally downward.

  In this embodiment, when the optical head device 1 is configured, the total reflection mirror prism 42, the objective lens 51, and the objective lens driving mechanism 5 are directly mounted on the device frame 4, but the first and second semiconductor laser devices are provided. 21 and 22, prisms 23 and 24 (compound prism 20), λ / 4 plate 25, λ / 2 plate 79, collimating lens 26, sensor lens 27, signal detection total reflection mirror 28, monitor total reflection mirror 29, first The first diffraction element 71, the second diffraction element 72, the first optical axis adjustment element 73, the second optical axis adjustment element 74, the signal detection light receiving element 91, and the monitor light reception element 92 are shown in FIG. It is mounted on the apparatus frame 4 in an integrated state as the optical module 3 shown. In the optical module 3, the prisms 23 and 24, the λ / 4 plate 25, and the λ / 2 plate 79 are mounted in an integrated state.

  As shown in FIGS. 2A and 2B, the optical module 3 includes a metal first package (main package) 31 such as magnesium die cast, aluminum die cast, and zinc die cast, and a second package. 32 (sub-package) are overlapped and joined. In the second package 32, the signal light-receiving element 91 and the monitor light-receiving element 92 are arranged adjacent to each other, and the other optical elements are the first package. 31. For the first package 31, a material other than metal may be used as long as the thermal conductivity is high.

  As shown in FIG. 2A, the first package 31 has a wall portion 310 that is bent and has a frame shape. As shown in FIG. The laser devices 21 and 22, the composite prism 20, the collimator lens 26, the sensor lens 27, the first diffraction element 71, the second diffraction element 72, the first optical axis adjustment element 73, and the second optical axis adjustment element 74 are provided. It is installed.

  On the other hand, as shown in FIGS. 2A, 2B, and 4, the signal detection total reflection mirror 28 and the monitor total reflection are provided on the upper surface side of the wall portion 310 of the first package 31. A mirror 29 is attached adjacently, and a second package 32 is mounted so as to cover the first package 31 so as to cover these mirrors 28 and 29. Accordingly, the second package 32 is mounted on the upper surface side of the wall portion 310 of the first package 31, while the first and second semiconductor laser devices 21 and 22, the composite prism 20, the collimator lens 26, and the sensor. The lens 27, the first diffractive element 71, the first optical axis adjusting element 73, the second optical axis adjusting element 74, and the second diffractive element 72 are opposite to the second package 32 in the first package. It is in the state mounted in the lower surface side of the wall part 310 of 31.

  As shown in FIGS. 5A and 5B, the second package 32 has a wiring board 321 (light receiving element mounting board) and a flexible board 41 connected to the wiring board 321 interposed therebetween. The wiring board 321 includes a metal plate 322 superimposed on the wiring board 321, and the signal detecting light receiving element 91 and the monitoring light receiving element 92 are mounted on the wiring board 321 at adjacent positions. The wiring board 321 has the mounting surface of the signal detection light-receiving element 91 and the monitor light-receiving element 92 facing the metal plate 322, and the signal detection light-receiving element 91 and the monitor light-receiving element 92 are exposed on the metal plate 322. An opening 323 is formed. Therefore, the second package 32 is arranged on the upper surface side of the first package 31 so that the opening 323 faces the signal detection total reflection mirror 28 and the monitor total reflection mirror 29. Further, as shown in FIG. 5C, the signal detecting light receiving element 91 and the monitor light receiving element 92 are covered with a molded or cast transparent resin 324 while being mounted on the wiring substrate 321. Therefore, even if the wiring board 321 is overlapped with the metal plate 322, it is insulated from the metal plate 322.

(Configuration of semiconductor laser device)
6A and 6B are a perspective view of the semiconductor laser devices 21 and 22 to which the present invention is applied as viewed obliquely from above and a perspective view of the light emitting element as viewed obliquely from below. In addition, since the 1st and 2nd semiconductor laser apparatuses 21 and 22 have the same structure, in the following description, they are demonstrated collectively.

  In this embodiment, as shown in FIGS. 6A and 6B, the first and second semiconductor laser devices 21 and 22 are copper or copper having a thickness of 0.25 to 0.6 mm and good thermal conductivity. A frame type semiconductor laser device in which a submount substrate 214 and a semiconductor laser chip 215 are mounted in this order on an upper surface 212 of a horizontally long flat metal frame 211 such as an alloy is used. In these semiconductor laser devices 21 and 22, The semiconductor laser chip 215 mounted on the metal frame 211 is protected by being surrounded by a frame-shaped resin portion 218.

  In the first and second semiconductor laser devices 21 and 22, the central portion of the upper surface 212 of the metal frame 211 is an element mounting portion 212 a, and the element mounting portion 212 a is surrounded by the resin portion 218. Further, both sides of the element mounting portion 212 a in the metal frame 211 are fin portions 216 protruding outward from the resin portion 218.

  The resin portion 218 is formed integrally with the metal frame 211 by insert molding or the like so as to straddle the upper surface 212 and the lower surface 213 of the metal frame 211. The resin portion 218 is formed in a frame shape around the element mounting portion 212a on the upper surface 212 side of the metal frame 211, and becomes a frame portion 219a surrounding the submount substrate 214 and the semiconductor laser chip 215 mounted thereon. ing. Further, the frame portion 219a has a concave portion that faces the emission surface 215a of the semiconductor laser chip 215, and is a concave portion 219c that allows the emission light of the semiconductor laser chip 215 to pass therethrough.

  On the other hand, on the lower surface 213 side of the metal frame 211, the resin portion 218 has a U shape avoiding the back side of the element mounting portion 212a. For this reason, on the lower surface 213 of the metal frame 211, the resin portion 218 has a structure in which a part thereof is cut out and a cutout portion 219d is provided. Therefore, the metal frame 211 includes an exposed portion 217 exposed on the lower surface 213 on the back side of the element mounting portion 212 a, and the exposed portion 217 and the fin portion 216 are isolated by the resin portion 218.

Here, the resin portion 218 is formed integrally with the metal frame 211 by insert molding or the like before the semiconductor laser chip 215 or the submount substrate 214 is mounted on the metal frame 211. In addition, as a fusion material used for fixing the semiconductor laser chip 215 and the submount substrate 214, and as a fusion material or adhesive used for fixing the submount substrate 214 to the metal frame 211, Au-Sn, A solder material such as Pb—Sn or an Ag paste is used. These melting materials have a high melting point. For example, the melting point of Au—Sn is 280 ° C. For this reason, when the submount 214 on which the semiconductor laser chip 215 is mounted is mounted on the metal frame 211, the resin portion 218 may be deformed even if heated to melt the fusion material or to cure the Ag paste. As a resin material for forming the resin portion 218, a liquid crystal polymer or an epoxy resin having a deflection temperature under load exceeding 300 ° C. is used.
(Mounting structure of semiconductor laser device)

  7A and 7B were used for the optical head device of FIG. 1 and the cross-sectional view schematically showing the cross section when the optical module shown in FIG. 2B was cut along AA ′. It is the perspective view which looked at the state which removed the semiconductor laser in the optical module from diagonally downward.

  As shown in FIGS. 7A and 7B, between the pair of laser device mounting portions 313 and 313 to which the pair of fin portions 216 and 216 of the first semiconductor laser device 21 are fixed and the second semiconductor laser. Between the pair of laser device mounting portions 323 and 323 to which the pair of fin portions 216 and 216 of the device 21 are fixed, concave portions 31d and 32d into which a U-shaped resin portion 218 surrounding the exposed portion 217 is dropped are provided. Protruding portions 31a and 32a are formed to protrude from the bottom portions 31b and 32b, respectively, in the recessed portions 31d and 32d. That is, the protrusions 31 a and 32 a are integrally formed with the first package 31. Accordingly, the protruding portions 31 a and 32 a are formed of a metal having high thermal conductivity such as magnesium die cast, aluminum die cast, and zinc die cast, like the first package 31.

  In the first semiconductor laser device 21, the lower surface of the fin portion 216 is fixed to the laser device mounting portion 313 of the first package 31 with a UV curable adhesive 550 as shown in FIG. 7A. For this reason, the exposed portions 217 face the first package 31 and are arranged close to each other. Similarly to the first semiconductor laser device 21, the lower surface of the fin portion 216 is also fixed to the laser device mounting portion 323 of the first package 31 by the UV curable adhesive 550 in the second semiconductor laser device 22. . For this reason, the exposed portions 217 face the first package 31 and are arranged close to each other. Further, the top portions 31c and 32c of the protruding portions 31a and 32a are in surface contact with the exposed portion 217, respectively, as shown in FIG.

(Main effects of this form)
8A, 8 </ b> B, and 8 </ b> C, the optical axis adjusting member is disposed perpendicular to the optical axis direction, tilted forward in the optical axis direction, and tilted rearward in the optical axis direction. It is explanatory drawing which shows the optical axis change of the emitted light by a state.

  In this embodiment, since the frame type semiconductor laser devices 21 and 22 are used as the light source, the optical head device 1 can be made thinner than the stem type semiconductor laser device.

  In the first and second semiconductor laser devices 21 and 22, the metal frame 211 has an exposed portion 217 from the resin portion 218 on the lower surface 213 side. Therefore, in the first and second semiconductor laser devices 21 and 22, heat can be radiated by heat radiation and heat conduction at the fin portion 216 and heat radiation and heat conduction at the exposed portion 217. Moreover, since the exposed portion 217 is located immediately below the back side of the element mounting portion 212a in the metal frame 211, heat generated in the semiconductor laser chip 215 can be effectively released. Therefore, a sufficient heat radiation effect can be obtained even when a high power type for DVD recording is used as the semiconductor laser chip 215. Further, in the optical head device 1 of the present embodiment, the semiconductor laser devices 21 and 22 are mounted so that the semiconductor laser chip 215 faces outward and the exposed portion 217 and the first package 31 face each other. The heat generated in the semiconductor laser chip 215 can be efficiently released from the exposed portion 217 to the laser device mounting member with a simple configuration by simply forming the protruding portion 32a that contacts the exposed portion 217 from the package 31.

The first package 31 is made of metal, and provided with projecting portions 31a and 32a projecting from the bottom portion 32b of the first package 31 toward the exposed portions 217 of the semiconductor laser devices 21 and 22, and the projecting portions 31a, Since the top portions 31c and 32c of the 32a are in contact with the exposed portion 217, the heat generated in the semiconductor laser chip 215 is efficiently conducted through the protrusions 31a and 32a to the first package 31 side through the shortest path. I can escape. In addition, there is an advantage that the protruding portions 31 a and 32 a can be integrally formed with the first package 31.

  Furthermore, since the top portions 31c and 32c of the protruding portions 31a and 32a are in surface contact with the exposed portion 217, the contact area between the top portions 31c and 32c and the exposed portion 217 is wide. Therefore, the heat generated from the first and second semiconductor laser devices 21 and 22 can be efficiently released to the first package 31 side through the protrusions 31a and 32a. Therefore, the temperature rise can be suppressed in spite of the frame type semiconductor laser devices 21 and 22.

  Furthermore, since the optical axis adjusting elements 73 and 74 for adjusting the optical axis of the emitted light emitted from the semiconductor laser chip 215 are provided, the mounting position of the semiconductor laser device is shifted due to the molding error of the protruding portions 31a and 32a. Even if it occurs, the optical axis of the emitted light emitted from the semiconductor laser chip 215 can coincide with the optical axis of the optical system. That is, in this embodiment, when placing importance on heat dissipation, the top portions 31c and 32c and the exposed portion 217 need to be in contact with each other, so that the height direction of the optical axis of the emitted light emitted from the semiconductor laser chip 215 ( The H direction shown in FIG. 3 is determined by mechanical dimensions. Therefore, if an error occurs in the mechanical dimensions, it becomes impossible to move the semiconductor laser devices 21 and 22 so that the optical axis of the emitted light emitted from the semiconductor laser chip 215 matches the optical axis of the optical system. However, in the case of this embodiment, by providing the optical axis adjusting elements 73 and 74 as the optical axis adjusting members, as shown in FIG. 8, the optical axis adjusting elements 73 and 74 are moved forward (B) or rear (C And the optical axis of the emitted light emitted from the semiconductor laser chip 215 can be moved in the H direction. For this reason, the optical axis of the emitted light can be made to coincide with the optical axis of the optical system by adjusting the tilt amount of the optical axis adjusting elements 73 and 74. At this time, since the top portions 31c and 32c and the exposed portion 217 are kept in contact with each other, the heat radiation efficiency can be secured at the same time.

  Moreover, in the metal frame 211, since the exposed portion 217 and the fin portion 216 are separated from each other by the resin portion 218, the fin portion 216 is applied to the fin portion 216 when the fin portion 216 is fixed to the first package 31 with the adhesive 550. The adhesive does not flow out toward the exposed portion 217. Therefore, the adhesive does not prevent contact between the exposed portion 217 and the top portions 31c and 32c of the protruding portions 31a and 32a.

(Other embodiments)
In the above embodiment, the first and second semiconductor laser devices 21 and 22 use the laser chips 215 that are individually packaged, but emit laser beams having different wavelengths from one light emitting element. The present invention may be applied to an optical head device using a two-wavelength light emitting element. In this case, by using the wavelength selective diffraction grating instead of the first and second diffraction gratings 71 and 72, the number of components mounted on the optical module 3 can be reduced. Further efforts are possible.

  In the above-described embodiment, the protruding portions 31a and 32a as the heat radiating members protruding from the bottom portion 32b of the first package 31 by integral molding are provided, but the heat radiating members are not necessarily molded integrally. That is, the portions corresponding to the projecting portions 31 a and 32 a may be configured by a member different from the first package 31. As long as the thermal conductivity is high, the portion corresponding to the protruding portions 31a and 32a made of different members may be made of a material other than metal.

  Furthermore, in the above embodiment, as shown in FIG. 6B and FIG. 7A, the lower surface 213 of the metal frame 211 has a pair of laser device mounting portions 313 and 313 (323 and 323) and the pair of laser devices. It is necessary to simultaneously contact the top portion 31c (32c) of the protruding portion 31a (32a) sandwiched between the laser device mounting portions 313 and 313 (323 and 323). For that purpose, it is only necessary to form the laser device mounting portions 313, 313 (323, 323) and the top portion 31c (32c) at the same height. By, for example, a metal coil spring having a contact, the first package 31 and the exposed portion are always contacted regardless of the positional accuracy of the laser device mounting portions 313 and 313 (323 and 323). Can be made.

  Furthermore, in the above embodiment, the first and second optical axis adjusting elements 73 and 74 are configured separately from the first and second diffractive elements 71 and 72. Similarly to the optical axis adjusting elements 73 and 74 shown in FIG. 8, the diffractive elements 71 and 72 may be configured such that the optical axis is adjusted by tilting forward (B) or backward (C) of the optical axis. With this configuration, since the function of adjusting the optical axis can be imparted to the diffraction elements 71 and 72, it is not necessary to provide the optical axis adjustment elements 73 and 74 separately from the diffraction elements 71 and 72, and the number of parts can be reduced.

(A), (B), and (C) are perspective views of an optical head device to which the present invention is applied as viewed obliquely from above, a perspective view as viewed from obliquely below, and an optical module used for the optical head device. It is the perspective view which looked at the state which connected the flexible board | substrate from diagonally upward. (A), (B) is the perspective view which looked at the optical module, prism, and objective lens which comprise an optical system in the optical head apparatus of FIG. 1 from diagonally upward, and the perspective view which looked from diagonally downward. It is explanatory drawing which shows the optical system in the optical head apparatus of FIG. FIG. 3 is a perspective view showing a state in which a second package is removed from the first package in the optical module used in the optical head device of FIG. 1. (A), (B), and (C) are perspective views of the second package viewed obliquely from above and an oblique view of the second package viewed obliquely from below in the optical module used in the optical head device of FIG. It is the perspective view which looked at the state which removed the metal plate from the figure and the 2nd package from diagonally downward. (A), (B) is the perspective view which looked at the semiconductor laser apparatus to which this invention was applied from diagonally downward, and the perspective view which looked at the semiconductor laser apparatus from diagonally upward. 7A and 7B were used for the optical head device of FIG. 1 and the cross-sectional view schematically showing the cross section when the optical module shown in FIG. 2B was cut along AA ′. It is the perspective view which looked at the state which removed the semiconductor laser in the optical module from diagonally downward. 8A, 8 </ b> B, and 8 </ b> C, the optical axis adjusting member is disposed perpendicular to the optical axis direction, tilted forward in the optical axis direction, and tilted rearward in the optical axis direction. It is explanatory drawing which shows the optical axis change of the emitted light by a state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical head apparatus 2 Optical recording disk 3 Optical module 4 Apparatus frame 5 Objective lens drive mechanism 20 Compound prism 21 1st semiconductor laser apparatus 22 2nd semiconductor laser apparatus 23 1st prism 24 2nd prism 27 Collimating lens 28 Total reflection mirror for signal detection (deflection mirror for signal detection)
29 total reflection mirror for monitor (deflection mirror 31 for monitor first package (laser device mounting member)
31a Protruding part (heat dissipation member)
32 2nd package 32a Protruding part (heat radiating member)
41 flexible substrate 42 total reflection mirror prism 51 objective lens 71 first diffractive element 72 second diffractive element 73 first optical axis adjusting element (optical axis adjusting member)
74 Second optical axis adjustment element (optical axis adjustment member)
91 Light receiving element for signal detection 92 Light receiving element for monitor 211 Metal frame 212 Upper surface 212a Element mounting portion 213 Lower surface 214 Submount 215 Semiconductor laser chip 216 Fin portion 217 Exposed portion 218 Resin portion 219a Frame portion
219d Notch portions 313, 323 Laser device mounting portion

Claims (7)

A metal frame on which the semiconductor laser chip is mounted on the upper surface side, and a resin portion formed from the upper surface to the lower surface of the metal frame so as to surround the element mounting portion on which the semiconductor laser chip is mounted on the upper surface of the metal frame In an optical head device in which a semiconductor laser device having:
The metal frame has fin portions protruding to the outside of the resin portion on both sides of the element mounting portion,
On the lower surface of the metal frame, by forming the resin portion so as to avoid the back side of the element mounting portion, an exposed portion of the metal frame is formed on the back side of the element mounting portion,
The semiconductor laser device is mounted on the laser device mounting member such that the exposed portion faces the laser device mounting member and the semiconductor laser chip faces the opposite side of the laser device mounting member. An optical head device. The laser device mounting member according to claim 1, wherein the laser device mounting member is made of metal.
An optical head device characterized in that a heat radiating member is placed on the laser device mounting member so as to contact the exposed portion and release heat generated by the semiconductor laser chip to the laser device mounting member side.   3. The optical head device according to claim 2, wherein the heat radiating member is made of metal.   4. The light according to claim 3, wherein the heat dissipating member is a projecting portion projecting from the laser device mounting member toward the exposed portion of the semiconductor laser device, and the projecting portion and the exposed portion are in contact with each other. Head device.   5. The optical head device according to claim 4, wherein the protruding portion is in surface contact with the exposed portion of the semiconductor laser device.   6. The optical head device according to claim 4, further comprising an optical axis adjusting member for adjusting an optical axis of outgoing light emitted from the semiconductor laser chip. 7. The metal frame according to claim 1, wherein the exposed portion and the fin portion are separated from each other by the resin portion, and the fin portion is fixed to the laser device mounting member by an adhesive. An optical head device.

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