Abstract:
A semiconductor package and a semiconductor light-emitting device including the semiconductor package. The semiconductor package includes: a frame for mounting a semiconductor light-emitting element; and a lead integral with the frame. The frame and the lead are made of a resin. A metal film is located in a predetermined area on the frame.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2008-167148, filed Jun. 26, 2008, the entire contents of which are incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a semiconductor package and a semiconductor light-emitting device, and more particularly to a semiconductor light-emitting device and a semiconductor package of an open package structure in which a semiconductor light-emitting element is mounted on a mount section of a frame. 
         [0004]    2. Description of the Related Art 
         [0005]    Since a light-emitting element, such as a semiconductor laser diode, is difficult to handle as a single element, the element is packaged. Since the light-emitting element self-heats when it is used, a package having a good heat radiation characteristic is required to release heat. 
         [0006]    A can-type package has been used for a semiconductor optical device. In the package, a can that covers an optical semiconductor chip and that has a window into which a glass plate for leading light is sealed is placed on a header where the optical semiconductor chip is mounted, and the header and the can are sealed together. Recently, there has also been proposed a semiconductor laser device that has an optical semiconductor chip mounted in a mount section on a frame made of a metal plate by means of stamping, or the like, and that is molded by means of a resin-molded body. A semiconductor laser is described in JP-A-10-154848 as such a semiconductor laser device. 
         [0007]    However, in the semiconductor laser that has an optical semiconductor chip mounted in a mount section on a frame and that is molded of a resin molded body, a metallic material, such as copper (Cu), is used for the frame, and the frame is made by stamping a metal plate, or the like, whence there is a problem of a high price of material and difficulty in cutting cost. There are also problems of difficulty in simplifying machining resulting from use of a metallic material and low productivity achieved during mass production. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention has been conceived to solve the problems mentioned above and aims at providing a semiconductor optical device for which a reduction in material cost, simplification of machining, and enhancement of productivity are achieved by means of producing a material for a frame of a package from a resin and making a metal film on a mount section on the frame where an optical semiconductor chip is to be mounted. 
         [0009]    According to an exemplary embodiment of the present invention, there is provided a semiconductor package including: a frame for mounting thereon a semiconductor light-emitting element; and a lead formed integrally with the frame, wherein the frame and the lead are made of a resin, and wherein a metal film is formed in a predetermined area on the frame. 
         [0010]    According to another exemplary embodiment of the present invention, there is provided a semiconductor light-emitting device including: a frame; a semiconductor light-emitting element mounted on the frame; a lead formed integrally with the frame, wherein the frame and the lead are made of a resin, and wherein a metal film is formed in a predetermined area on the frame. 
         [0011]    According to the above configuration, a metal film is formed in a predetermined area on the frame made of a resin, whereby material cost is reduced and machining is simplified. Thus, a semiconductor package and a semiconductor light-emitting device, which are enhanced in terms of productivity achieved during mass production, can be acquired. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The above and other aspects of the present invention will become more apparent and more readily appreciated from the following description of exemplary embodiments of the present invention taken in conjunction with the attached drawings, in which: 
           [0013]      FIG. 1  is a perspective view schematically showing a semiconductor light-emitting device of an embodiment of the present invention; 
           [0014]      FIG. 2  is a top view schematically showing the semiconductor light-emitting device of the embodiment of the present invention; 
           [0015]      FIG. 3  is a schematic top view showing a semiconductor light-emitting device of another example of the embodiment of the present invention; 
           [0016]      FIG. 4  shows a schematic top view showing a semiconductor light-emitting device of a second embodiment of the present invention; 
           [0017]      FIG. 5  is a schematic top view showing a semiconductor light-emitting device of a third embodiment of the present invention; and 
           [0018]      FIG. 6  is a schematic top view showing a semiconductor light-emitting device of a fourth embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     First Embodiment 
       [0019]      FIG. 1  is a perspective view schematically showing a semiconductor light-emitting device of an embodiment of the present invention.  FIG. 2  is a top view schematically showing the semiconductor light-emitting device of the embodiment of the present invention. The embodiment will be described by reference to  FIGS. 1 and 2 . A semiconductor laser chip  101  corresponding to a semiconductor light-emitting element is mounted on a sub-mount  103  fixed onto a frame  105 . The frame  105  is configured by forming a metal film  107  on a base made of a resin, such as polyimide. The semiconductor laser chip  101  is mounted on the metal film  107  through the sub-mount. Plating, evaporation, sputtering, and the like, is used for generating the metal film  107 . Further, nickel (Ni), copper (Cu), gold (Au), platinum (Pt), titanium (Ti), and the like, is used for a material of the metal film  107 . Heat generated by the semiconductor laser chip  101  propagates to a metal film  107 B, where the heat is released. The frame  105  and a lead  111  are formed integrally with each other, and the metal film  107 B is formed except an exposed resin section  115  that is an insulation area around a lead  111 A requiring insulation. The lead  111 A is coated with the metal film  107 A and insulated from the metal film  107 B. The lead  111 B is a GND terminal and coated with the metal film  107 B, and the metal film  107 B is brought into a ground potential. Next, although unillustrated, an electrode on the sub-mount  103  connected to the semiconductor laser chip  101  is wire-bonded to the lead  111 A by a bonding wire  113 . Moreover, the semiconductor laser chip  101  and the metal film  107 B to be brought into a ground potential are wire-bonded together by the bonding wire  113 , whereupon a semiconductor light-emitting device of the present embodiment is obtained. 
         [0020]    As shown in  FIG. 1 , in the present embodiment, the frame  105  is formed from a resin, such as polyimide. Since the material of the package is changed from related-art metal to a resin and thermal conductivity thereof are difference from each other, a countermeasure to release heat of a light-emitting element is required. Accordingly, the frame  105  is configured by forming a metal film over the front and back surfaces of the resin base, to thus enhance a heat radiation characteristic of the frame. In the present embodiment, the metal film  107  is formed essentially overall the resin base and patterned so as to prevent generation of a metal film in only an area that requires insulation. Even when essentially the entire surface of the resin base is coated with the metal film so as to enhance the heat radiation characteristic as mentioned above, the amount of metal used becomes smaller when compared with the case where a metal frame is used, so that manufacturing cost can be reduced. 
         [0021]    With regard to the lead  111 , the metal film  107  is formed on a resin, to thus configure a lead section. In the case of the metal package, three sections; namely, a metal base section, the lead section, and an insulation section for insulating the base section from the lead section, are required. However, in the present embodiment, these sections can be formed from one member by forming metal films in areas of a resin, which is originally insulative, so that the numbers of processes and components can be reduced. Moreover, in the present embodiment since the sections are configured by one member and a plurality of products such as TAB film can be handled, work along a manufacturing line is facilitated. 
       First Modification 
       [0022]      FIG. 3  is a schematic top view showing another semiconductor light-emitting device of the first embodiment of the present invention. The present modification shows a monolithic two-wavelength laser into which two laser chips; namely, the semiconductor laser chips  101  having different oscillation wavelengths, are assembled into one chip. A metal film is patterned in such a way that two leads requiring insulation are insulated from each other, and the respective leads are connected to the semiconductor laser chips  101  by a wire bonding. As mentioned above, only the areas requiring insulation are insulated, and the metal film is formed over the almost entire surface of the device, so that a heat radiation characteristic can be enhanced. Further, the areas requiring insulation can be insulated by patterning a metal film, so that machining can be easy. 
       Second Embodiment 
       [0023]      FIG. 4  shows a schematic top view showing a semiconductor light-emitting device of a second embodiment of the present invention. Although the metal film is formed over the almost entire surface of the resin base in the first embodiment, the metal film is formed partially in the present embodiment. In the present embodiment, a metal film can be formed on the mount section where the semiconductor laser chip  101  is to be mounted in an amount required to enable radiation of heat generated in the semiconductor laser chip  101 . Thus, when compared with the case where the metal film is formed over the almost-entire surface of the resin base, the amount of metal used can be reduced, so that manufacturing cost can be reduced. 
       Third Embodiment 
       [0024]      FIG. 5  is a schematic top view showing a semiconductor light-emitting device of a third embodiment of the present invention. When the semiconductor laser chip  101 , which presents little problems in heat radiation, is mounted, the metal film for the mount section can be omitted. In this case, the areas requiring conductivity are only the lead sections. Therefore a metal film is formed in only such areas. Thus, an amount of metal used is reduced, so that manufacturing cost can be further reduced. 
       Fourth Embodiment 
       [0025]      FIG. 6  is a schematic top view showing a semiconductor light-emitting device of a fourth embodiment of the present invention. In the first, second, and third embodiments, the lead and the frame are formed integrally with each other, and the lead section is also embodied as a lead by forming a metal film on a resin. In the fourth embodiment, a metal lead is used. The metal lead is insulated from the frame  105  configured by forming a metal film on the resin base and secured by a resin frame  109 . In this case, it is required that the metal film  107  formed on the frame  105  is insulated from the lead  111 . Therefore, when the metal film  107  is formed only on the mount section of the semiconductor laser chip  101 , the resin base may be in contact with the metal lead  111 . When the semiconductor laser chip  101 , which presents little problems in a heat radiation characteristic, is mounted, the metal film  107  of the resin base can be omitted. In the case of reflow soldering, soldering is performed at a temperature around 230° C. to 250° C.; hence, a resin lead surface provided with a metal film can be used. However, soldering is usually performed at a temperature of about 300° C. Use of a metal lead allows soldering to be performed in higher temperature compared with reflow soldering. 
         [0026]    While the present invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.