JP2007305205A - Optical pickup light source device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress deterioration in a recording modulation wave form with speeding up of recording speed of an optical disk drive. <P>SOLUTION: A heat dissipation member 3 which has a nearly rectangular shape is sandwiched between a semiconductor laser 1 and a laser driving IC 4. Adhesion fixing of an opposing surface 1a to a radiation direction of an optical beam F of a laser radial axis center L of the semiconductor laser 1 and a face 3a by the semiconductor laser 1 side of the heat dissipation member 3, and a face 4a to which the terminal lead 4b of the laser driving IC 4 is looking and the face 3b by the side of the laser driving IC 4 of the heat dissipation member 3, are carried out respectively. Solder connection of a terminal lead 4b of the laser driving IC 4 and the terminal electrode 2 of the semiconductor laser 1 is carried out. Thereby while it becomes possible to radiate promptly the heat generated by the semiconductor laser 1 or/and the laser driving IC 4 to the heat dissipation member 3, short distance of wiring length between the semiconductor laser 1 and the laser driving IC 4 can be achieved and detorioration of the recording modulation wave form can be suppressed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical pickup light source device mounted on an optical pickup device or the like.

  In recent years, an optical pickup device has been used for reproducing or recording an optical recording medium such as a DVD (Digital Versatile Disc) and a CD (Compact Disc). A semiconductor laser and a laser drive IC for driving the semiconductor laser are mounted. At the time of recording on the optical recording medium, a signal such as a recording modulation waveform is sent from the laser driving IC to the semiconductor laser through the metal wiring on the flexible substrate. With the recent increase in recording speed, the rise time and fall time of the recording modulation waveform are as short as a few nanoseconds, making it difficult to design to maintain these response characteristics and ensure a high-quality modulation waveform. ing. In order to suppress the deterioration of the modulation waveform, it is desirable to shorten the wiring length from the laser driving IC to the semiconductor laser, and the method of arranging them close to each other is the mainstream. However, in a thin optical pickup device, it is difficult to flexibly arrange a semiconductor laser and a laser driving IC because a plurality of chip components and optical components must be accommodated in the device. Further, both the semiconductor laser and the laser drive IC are heat sources, and if they are simply arranged close to each other, adverse effects such as performance degradation and shortening of the lifetime are caused by thermal interference. Therefore, in order to suppress the deterioration of the modulation waveform, it is necessary to design not only the proximity arrangement of the semiconductor laser and the laser driving IC but also the heat dissipation structure.

In the prior art, for example, as disclosed in Patent Document 1, a heat sink is installed in a housing incorporating a semiconductor laser, and the laser driver is mounted on the heat sink by a pressable flexible board utilizing the spring property of the bent portion. In some cases, the semiconductor laser and the laser driver can be arranged close to each other and radiated by a structure in which the heat generated by the laser driver is radiated to the heat radiating plate.
JP 2002-252408 A

  However, in the structure disclosed in Patent Document 1, the laser driver and the heat radiating plate are only pressed and brought into close contact with each other by a flexible substrate having a spring property. The heat radiating member is not intervened, and it is difficult to say that the contact by pressing alone is sufficient to quickly transfer the heat generated by the laser driver to the heat radiating plate. Further, when viewing the drawing disclosed in Patent Document 1, the surface area of the heat sink of the contact portion is small with respect to the laser driver, and the radiant heat generated by the laser driver is transmitted to the semiconductor laser, which may adversely affect the semiconductor laser such as performance degradation. Can be considered. Further, in recent increases in recording speed, the amount of heat generated has been increasing due to higher output of the semiconductor laser and higher switching speed of the laser driver. In the heat dissipation structure disclosed in Patent Document 1, It is not easy to sufficiently dissipate a semiconductor laser or a laser driver.

  An object of the present invention is to provide an optical pickup light source device having a structure in which a laser driving IC and a semiconductor laser are arranged close to each other and taking into consideration their heat dissipation structure in order to suppress deterioration of a recording modulation waveform.

  In order to achieve the above object, an optical pickup light source device of the present invention includes a laser light source that emits a light beam, and a terminal electrode that is connected to the laser light source and supplies a driving current that emits the light beam to the laser light source. A laser drive IC that supplies the drive current or / and recording modulation waveform signal to the laser light source from a terminal lead; and a heat dissipation member that radiates heat generated by the laser light source or / and the laser drive IC, The heat radiating member is in close contact with the surface of the laser light source opposite to the light beam emitting direction and the surface of the laser drive IC facing the laser light source.

  The heat dissipating member may be a highly heat conductive metal having a substantially rectangular parallelepiped shape.

  The heat radiating member is a heat conductive sheet having high thermal conductivity, a part of the heat conductive sheet is connected to a metal base having a large heat capacity, and heat generated by the laser light source and / or the laser driving IC is Conductive to a metal base.

  The heat radiating member sandwiches a heat insulating member between the first heat radiating member and the second heat radiating member, and the first heat radiating member is in close contact with a surface of the laser light source opposite to the light beam emitting direction. The second heat radiating member is characterized in that the terminal lead of the laser driving IC is in close contact with the surface facing the direction of the laser light source. Here, the first heat radiating member and the second heat radiating member are substantially the same metal having good rectangular shape and good heat conductivity. Or, it is a metal having a substantially rectangular parallelepiped shape and different thermal conductivity. Or it is a heat conductive sheet of high thermal conductivity, a part of the heat conductive sheet is connected to a metal base having a large heat capacity, and heat generated by the laser light source and / or the laser driving IC is conducted to the metal base. .

  Since the optical pickup light source device of the present invention can be disposed close to each other without causing adverse effects due to thermal interference between the semiconductor laser and the laser driving IC, the wiring length between the semiconductor laser and the laser driving IC can be reduced. And the deterioration of the recording modulation waveform can be suppressed.

  Hereinafter, an embodiment of an optical pickup light source device of the present invention will be described with reference to the accompanying drawings.

(Embodiment 1)
FIG. 1 is a schematic diagram showing a main configuration of the optical pickup light source device according to the present embodiment. In FIG. 1, 1 is a semiconductor laser as a light source, 2 is a terminal electrode for supplying a laser drive current to the semiconductor laser 1, 3 is a heat radiating member, and 4 is a laser drive IC.

  As shown in the figure, the semiconductor laser 1 emits a light beam F around an optical axis center L. The heat dissipating member 3 is fixed to the surface 1a (hereinafter referred to as the back surface) opposite to the light beam F of the semiconductor laser 1 with heat curable grease or the like with ultraviolet curing resin or the like. The heat radiating member 3 is in close contact with the rear surface 1a of the semiconductor laser 1 with the side surface 3a having an area having the same length in the z-axis direction and the same length or more in the y-axis direction. And a substantially rectangular parallelepiped shape extending from the contact surface to the side opposite to the emission direction of the light beam F of the semiconductor laser 1 (x-axis direction). The laser drive IC 4 has a surface 4a (hereinafter referred to as an abdominal surface) with the terminal lead 4b facing the semiconductor laser 1 side and a side surface 3b opposite to the surface to which the semiconductor laser 1 of the heat radiating member 3 is in contact with heat conduction grease. Then, it is fixed in close contact with an ultraviolet curable resin or the like. FIG. 2 shows a state in which the semiconductor laser 1 and the laser driving IC 4 are closely fixed to the heat radiating member 3.

  Thereby, the heat generated in the semiconductor laser 1 and / or the laser driving IC 4 is quickly radiated to the heat radiating member 3. After the semiconductor laser 1 and the laser drive IC 4 are closely fixed to the heat radiating member 3, the terminal lead 4 b of the laser drive IC 4 is soldered to the terminal electrode 2 of the semiconductor laser 1. As a result, the wiring length between the laser driving IC 4 and the semiconductor laser 1 can be shortened.

  Depending on the difficulty of workability, the solder connection between the terminal lead 4b of the laser driving IC 4 and the terminal electrode 2 of the semiconductor laser 1 is performed before the semiconductor laser 1 and / or the laser driving IC 4 are firmly fixed to the heat radiating member 3. May be.

  As the material of the heat dissipation member 3 in the present embodiment, for example, a metal material having good thermal conductivity such as copper or aluminum can be used. For example, in the case of aluminum, surface treatment such as alumite treatment can be appropriately performed. Further, the distance in the extending direction from the contact surface of the heat radiating member 3 with the back surface 1a of the semiconductor laser 1 can be determined according to the amount of heat generated by the semiconductor laser 1 and / or the laser driving IC 4 used. .

(Embodiment 2)
As a material of the heat radiating member 3 in Embodiment 1, a heat conductive sheet having high thermal conductivity can also be used.

  FIG. 3 is a schematic diagram showing a main configuration of the optical pickup light source device according to Embodiment 2 of the present invention. In the element configuration of the optical pickup light source device of the first embodiment shown in FIG. 1, the present embodiment shows a case where a heat conductive sheet is used for the heat radiating member 3.

  In the same figure, 5 is a heat conductive sheet. The heat conductive sheet 5 has an area longer in the y-axis direction than the back surface 1a of the semiconductor laser 1, and is closely fixed to the back surface 1a of the semiconductor laser 1 and the abdominal surface 4a of the laser driving IC 4 with an adhesive tape or the like. A portion of the heat conducting sheet 5 protruding in the y-axis direction from the back surface 1a of the semiconductor laser 1 is connected to a member having a large heat capacity such as a metal base of an optical pickup device.

  Thereby, the heat generated by the semiconductor laser 1 and / or the laser driving IC 4 can be quickly conducted and dissipated to other members having a large heat capacity by the heat conductive sheet 5 having high thermal conductivity. Thus, if the heat conductive sheet 5 is used as the heat radiating member 3, the terminal electrode 2 of the semiconductor laser 1 can be further shortened as shown in FIG.

(Embodiment 3)
Next, a third embodiment of the optical pickup light source device of the present invention will be described with reference to FIG.

  In the figure, 1 is a semiconductor laser, 2 is a terminal electrode for supplying a laser drive current to the semiconductor laser 1, 4 is a laser drive IC, 6 is a heat radiating member, 7 is a heat radiating member, and 8 is a heat insulating member. The heat insulating member 8 is tightly fixed in a form sandwiched between the heat radiating member 6 and the heat radiating member 7.

  A different configuration from the previous embodiment is that a heat insulating member 8 is provided between the heat radiating member 6 and the heat radiating member 7. By providing the heat insulating member 8 between the heat radiating member 6 and the heat radiating member 7 as described above, the heat conduction from the semiconductor laser 1 to the laser driving IC 4 and / or from the laser driving IC 4 to the semiconductor laser 1 can be cut off. The thermal influence of the semiconductor laser 1 on the laser drive IC 4 and / or the laser drive IC 4 on the semiconductor laser 1 can be prevented.

  As the material of the heat radiating member 6 and the heat radiating member 7, for example, a metal material having good heat conductivity such as copper or aluminum, the heat conductive sheet having high heat conductivity shown in FIG. it can. The heat radiating member 6 and the heat radiating member 7 may be the same material or different materials.

  Since the optical pickup light source device of the present invention can ensure a high-quality recording modulation waveform, it can be applied to an optical disk device that requires a high recording speed.

The perspective view which shows the relationship of the principal part structure of the optical pick-up light source device by Embodiment 1 of this invention. The perspective view which shows the principal part structure of the optical pick-up light source device The perspective view which shows the relationship of the principal part structure of the optical pick-up light source device by Embodiment 2 of this invention. The perspective view which shows the relationship of the principal part structure of the optical pick-up light source device by Embodiment 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor laser 2 Terminal electrode 3 Heat radiation member 4 Laser drive IC
5 Thermal Conductive Sheet 6 Heat Dissipation Member 7 Heat Dissipation Member 8 Heat Insulation Member

Claims (7)

A laser light source that emits a light beam; a terminal electrode that is connected to the laser light source and supplies a driving current that emits the light beam to the laser light source; and the driving current or / and a recording modulation waveform signal are supplied to the laser light source. A laser drive IC supplied from a terminal lead; and a heat radiation member that radiates heat generated by the laser light source or / and the laser drive IC,
An optical pickup light source device, wherein the heat radiating member is in close contact with a surface of the laser light source opposite to the light beam emitting direction and a surface of the laser driving IC facing the laser light source. . The optical pickup light source device according to claim 1, wherein the heat radiating member is a metal having a substantially rectangular parallelepiped shape and good heat conductivity. The heat radiating member is a heat conductive sheet having high thermal conductivity, a part of the heat conductive sheet is connected to a metal base having a large heat capacity, and heat generated by the laser light source and / or the laser driving IC is the metal base. The optical pick-up light source device according to claim 1, wherein The heat dissipating member sandwiches the heat insulating member between the first heat dissipating member and the second heat dissipating member,
The first heat radiating member is in close contact with a surface opposite to the light beam emitting direction of the laser light source,
2. The optical pickup light source device according to claim 1, wherein the second heat radiating member is in close contact with a surface of the laser drive IC where the terminal lead faces the direction of the laser light source. 5. The optical pickup light source device according to claim 4, wherein the first heat radiating member and the second heat radiating member are made of the same metal having a substantially rectangular parallelepiped shape and good thermal conductivity. The optical pickup light source device according to claim 4, wherein the first heat radiating member and the second heat radiating member are substantially rectangular parallelepiped metals having different good thermal conductivities. The first heat radiating member and the second heat radiating member are heat conductive sheets having high thermal conductivity, a part of the heat conductive sheet is connected to a metal base having a large heat capacity, and the laser light source and / or the laser The optical pickup light source device according to claim 4, wherein heat generated in the driving IC is conducted to the metal base.

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