Abstract:
The invention provides a semiconductor high-power light-emitting module including a heat-dissipating member, a heat-conducting device, and a diode light-emitting device. The heat-dissipating member includes an isolator member coupled to a first side of the heat-dissipating member. The heat-dissipating member has a second side opposite to the first side. The isolator member has a third side opposite to the first side. The environment temperature at the third side is higher than that at the second side. The heat-conducting device has a flat end and a contact portion tightly mounted on the heat-dissipating member. The diode light-emitting device is disposed on the flat end of the heat-conducting device. The semiconductor light-emitting module of the invention, applied to a headlamp of an automobile, has properties of saving electricity and long life, and furthermore the capability of integrating the heat-dissipating member into a shell of the automobile is both artistic and practical.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates to a semiconductor light-emitting module and, more particularly, to a semiconductor high-power light-emitting module with heat isolation. 
         [0003]    2. Description of the Prior Art 
         [0004]    Due to the advantages such as power saving, shock-resistance, fast response time, and adaptability for mass production, illumination equipment which applies light-emitting diodes is being researched and developed continuously. However, the heat which is generated by a high-power light-emitting diode also generates a lot of heat, so how to solve the problem of heat dissipation becomes a main issue in the field. Traditionally, a common way to dissipate heat is to put a heat-dissipating member (may includes a plurality of fins) at low temperature environment to dissipate heat. But in many practical applications, the heat-dissipating member is disposed in an environment with higher temperature. The junction temperature of the light-emitting diode remains high so that the luminous efficiency and the service life of the light-emitting diode are highly affected. 
         [0005]    For example, halogen lamps are the mainstream in the traditional automobile headlight market, but the halogen lamps have disadvantages such as insufficient illumination and short service life. In order to improve the disadvantages, high intensity discharge lamps are adopted in the market presently. However, the lighting principle of the high intensity discharge lamps is to generate an electric arc between two electrodes to emit light, so a steady and continuous high voltage power supply is required. With regard to safety, drivers should be prevented from the circumstance with high voltage. If the headlight is replaced with the high-power light-emitting diode in the present market, at least one parts of its heat-dissipating member will be disposed in the vehicle body. It will cause the light-emitting diode to bear the heat generated by apparatuses such as the engine and thus become difficult to dissipate heat. 
         [0006]    Accordingly, a semiconductor high-power light-emitting module which is capable of sufficiently dissipating heat in an environment with temperature differences should be provided to solve the above-mentioned problems. 
       SUMMARY OF THE INVENTION 
       [0007]    A scope of the invention is to provide a semiconductor light-emitting module. 
         [0008]    According to a preferred embodiment, the semiconductor light-emitting module of the invention includes a heat-dissipating member, a strip-shaped heat-conducting device, and a diode light-emitting device. The heat-dissipating member has an isolator member coupled to a first side of the heat-dissipating member. The heat-dissipating member has a second side opposite to the first side. The isolator member has a third side opposite to the first side. The environment temperature at the third side is higher than that at the second side. The heat-conducting device has a flat end and a contact portion. The contact portion is disposed between the heat-dissipating member and the isolator member and tightly mounted on the heat-dissipating member. The length-width ratio of the heat-conducting device is larger than 2. A bottom of the diode light-emitting device is tightly mounted on the flat end of the heat-conducting device. The diode light-emitting device is capable of transforming electric energy to a light. The heat-conducting device can be a heat pipe or other devices with high thermal conductivity efficiency. The diode light-emitting device includes at least one light-emitting diode die or at least one laser diode die. The contact portion of the heat-conducting device is mounted to the heat-dissipating member with a slab. During the operation of the diode light-emitting device, the generated heat can be conducted via the heat-conducting device to the heat-dissipating member and then be dissipated out. 
         [0009]    According to the preferred embodiment, the semiconductor light-emitting module of the invention can be applied to a headlight of an automobile. The heat-dissipating member can be engaged on the body (e.g. the frame behind the bumper or the shell) of the automobile. Further, the position of the headlight is much closer to those of the apparatuses (e.g. an engine) with high temperature, so the semiconductor light-emitting module includes the isolator member for preventing the efficiency of the heat-dissipating member from the influence of the environment temperature produced by the above-mentioned apparatuses. Moreover, an isolator sleeve is used to cover the heat-conducting device between the diode light-emitting device and the contact portion to further reduce the influence of the heat generated by the above-mentioned apparatuses toward the environment temperature at the heat-dissipating member. In order to enhance heat dissipation efficiency, a plurality of fins are formed on the second side of the heat-dissipating member. Besides, the semiconductor light-emitting module further includes a control circuit which is electrically connected to the diode light-emitting device for controlling the diode light-emitting device to emit the light. 
         [0010]    Accordingly, the semiconductor light-emitting module of the invention utilizes an isolator member to prevent the heat dissipation efficiency of the heat-dissipating member of the semiconductor light-emitting module from the influence of the environment with high temperature, so that the heat-dissipating member is capable of dissipating heat effectively in an environment with low temperature. If applied in the headlight of the automobile, the heat-dissipating member of the semiconductor light-emitting module of the invention can be integrally designed with the shell, which is not only aesthetic but also functional. Furthermore, by dissipating the heat generated during the operation of the diode light-emitting device out of the body of the automobile to the environment with lower temperature by means of the heat-dissipating member, it is able to dispose the high-power semiconductor light-emitting module in the headlight of the automobile. 
         [0011]    The advantage and spirit of the invention may be understood by the following recitations together with the appended drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE APPENDED DRAWINGS 
         [0012]      FIG. 1A  is a schematic diagram illustrating a semiconductor light-emitting module X according to a first preferred embodiment of the invention. 
           [0013]      FIG. 1B  is a schematic diagram illustrating a semiconductor light-emitting module X′ according to another embodiment of the invention. 
           [0014]      FIG. 1C  is a schematic diagram illustrating a semiconductor light-emitting module X″ according to another embodiment of the invention. 
           [0015]      FIG. 1D  is a schematic diagram illustrating a semiconductor light-emitting module X′″ according to another embodiment of the invention. 
           [0016]      FIG. 1E  is a schematic diagram illustrating a semiconductor light-emitting module according to another embodiment of the invention. 
           [0017]      FIG. 2A  is a pictorial drawing illustrating a semiconductor light-emitting module according to a second preferred embodiment of the invention which is applied to a headlight of automobiles. 
           [0018]      FIG. 2B  is a cross-sectional view illustrating a lamp holder of the headlight. 
           [0019]      FIG. 2C  is a cross-sectional view illustrating a light-emitting diode package structure. 
           [0020]      FIG. 2D  is a cross-sectional view illustrating another light-emitting diode package structure. 
           [0021]      FIG. 2E  is a schematic diagram illustrating another kind of flat end of the heat-conducting device according to the second preferred embodiment of the invention. 
           [0022]      FIG. 3  is a pictorial drawing illustrating a semiconductor light-emitting module according to a third preferred embodiment of the invention which is applied to a headlight of an automobile. 
           [0023]      FIG. 4  is a pictorial drawing illustrating a semiconductor light-emitting module according to a fourth preferred embodiment of the invention which is applied to a headlight of an automobile. 
           [0024]      FIG. 5  is a schematic diagram illustrating another type of fin of the heat-dissipating member of the fourth preferred embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]    Please refer to  FIG. 1A .  FIG. 1A  is a schematic diagram illustrating a semiconductor light-emitting module  1  according to a first preferred embodiment of the invention. The lower drawing in  FIG. 1A  is a cross-sectional view of the upper drawing along line X-X. The semiconductor light-emitting module  1  includes a heat-dissipating member  11 , a heat-conducting device  12 , a diode light-emitting device  13 , an isolator sleeve  15 , and a carrier  16 . The heat-dissipating member  11  has an isolator member  14  which is coupled to a first side  112  of the heat-dissipating member  11 . The heat-dissipating member  11  has a second side  114  opposite to the first side  112 . The isolator member  14  has a third side  116  opposite to the first side  112 . The environment temperature at the third side  116  is higher than that at the second side  114 . The heat-conducting device  12  has a flat end  122  and a contact portion  124 . The contact portion  124  is disposed between the heat-dissipating member  11  and the isolator member  14  and tightly mounted on the heat-dissipating member  11 . The length-width ratio of the heat-conducting device  12  is larger than 2. The carrier  16  has a hole for the heat-conducting device  12  to pass through. The heat-conducting device  12  passes through the hole, and the flat end  122  is substantially at the same level with a surface of the carrier  16 . A bottom of the diode light-emitting device  13  is tightly mounted on the flat end  122  of the heat-conducting device  12  and the carrier  16 . The diode light-emitting device  13  is capable of transforming electric energy to a light. The heat-conducting device  12  can be a heat pipe or other devices with high thermal conductivity efficiency. The diode light-emitting device  13  includes at least one light-emitting diode die or at least one laser diode die. 
         [0026]    According to the first preferred embodiment, the contact portion  124  of the heat-conducting device  12  totally sinks into the heat-dissipating member  11 , and the heat-conducting device  12  directly mounts on the heat-dissipating member  11  with the isolator member  14 . Further, the isolator sleeve  15  covers the heat-conducting device  12  between the diode light-emitting device  13  and the contact portion  124 . The isolator member  14  is capable of preventing the heat-dissipating member  11  from the influence of the environment with high temperature. As shown in the lower drawing in  FIG. 1A , the configuration can make the semiconductor light-emitting module  1  to be applied to the situation that the environment temperature T A  of the isolator member  14  is higher than the environment temperature T B  of the heat-dissipating member  11 . Moreover, comparing the first preferred embodiment with another embodiment shown in  FIG. 1B , a plurality of fins are formed on a second side  114 ′ of a heat-dissipating member  11 ′ of a semiconductor light-emitting module  1 ′ to enhance heat dissipation efficiency. 
         [0027]    Besides, comparing the first preferred embodiment with another embodiment shown in  FIG. 1C , the contact portion  124  of a semiconductor light-emitting module  1 ″ can also partially sink into a heat-dissipating member  11 ″, and the heat-conducting device  1 ″ directly mounts on the heat-dissipating member  11 ″ with a isolator member  14 ′. Furthermore, comparing the first preferred embodiment with another embodiment shown in  FIG. 1D , an isolator member  14 ″ of a semiconductor light-emitting module  1 ′″ and the heat-dissipating member  11 ″ form a space which has a clearance to contain the contact portion  124 . The contact portion  124  still can be mounted by the isolator member  14 ″ or with a slab (not shown in  FIG. 1D ). Finally, according to another embodiment shown in  FIG. 1E , a semiconductor light-emitting module includes three diode light-emitting devices  13 ′ which are disposed between an isolator member  14 ″′ and a heat-dissipating member. Comparing with the first preferred embodiment, the diode light-emitting devices  13 ′ can be packaged entirely or individually. The package structure will be explained in more details below. 
         [0028]    It is notable that the space is not necessary to be sealed and it is better to enhance the thermal conductivity efficiency of the heat-conducting device  12  from the contact portion  124  to the heat-dissipating member  11 ,  11 ′, and  11 ″. For example, squash the contact portion  124  or fill the clearance between the contact portion  124  and the heat-dissipating member  11 ,  11 ′, and  11 ″ with a thermal conductive material to increase the contacting area. 
         [0029]    Please refer to  FIG. 2A  and  FIG. 2B .  FIG. 2A  is a pictorial drawing illustrating a semiconductor light-emitting module according to a second preferred embodiment of the invention which is applied to a headlight  3  of an automobile.  FIG. 2B  is a cross-sectional view illustrating a lamp holder  31  of the headlight  3 . According to the second preferred embodiment, a right headlight of an automobile is consisted of the structure of the semiconductor light-emitting module. It is notable that the invention is not limited to the right headlight. 
         [0030]    The semiconductor light-emitting module of the invention includes a heat-dissipating member  21 , three heat-conducting devices  22 , three diode light-emitting devices  23 , an isolator member  24 , a carrier  25 , and a supporter  26 . 
         [0031]    Each heat-conducting device  22  has a flat end  222  and a contact portion  224 . The contact portion  224  is tightly mounted to the heat-dissipating member  21 . The carrier  25  has a hole for the heat-conducting device  22  to pass through. The heat-conducting device  22  passes through the hole, and the flat end  222  is substantially at the same level with a surface of the carrier  25 . The diode light-emitting devices  23  are disposed on the flat ends  222  of the heat-conducting devices  22  respectively. Each diode light-emitting device  23  is capable of transforming electric energy to a light. The heat-conducting devices  22  can be a heat pipe or other devices with high thermal conductivity efficiency. The diode light-emitting devices  23  include at least one light-emitting diode die or at least one laser diode die. 
         [0032]    According to the second preferred embodiment, the contact portions  224  of the heat-conducting devices  24  are mounted to the heat-dissipating member  21  with a slab  27 . During the operation of the diode light-emitting devices  23 , the generated heat can be conducted via the heat-conducting devices  22  to the heat-dissipating member  21  and then be dissipated out. 
         [0033]    Further, the position of the headlight is much closer to those of apparatuses (e.g. an engine) with high temperature, so the isolator member  24  is disposed between the above-mentioned apparatuses and the heat-dissipating member  21  for preventing the efficiency of the heat-dissipating member  21  from the influence of the environment with high temperature (usually over 80° C.) produced by the above-mentioned apparatuses. Therefore, the isolator member  24  can be used as the slab  27  which has functions of isolating heat and mounting. 
         [0034]    Besides, the contact portion  224  of the heat-conducting device  24  can also be mounted by other ways, such as attaching the contact portion  224  on the heat-dissipating member  21  with a material like gel, or welding. And, in order to increase the thermal conductivity efficiency from the contact portion  224  to the heat-dissipating member  21 , the contact portion  124  can be squashed to form a larger contact area, or the clearance between the contact portion  224  and the heat-dissipating member  21  can be filled with a thermal conductive material to increase thermal conductivity area. In another embodiment, a plurality of fillisters can be formed on a heat-dissipating member to respectively contain a plurality of heat-conducting devices, or a fillister can be formed on the heat-dissipating member to contain the heat-conducting devices. The shape of the fillisters can be formed in accordance with the heat-conducting devices, or the shape of the heat-conducting devices can be formed in accordance with the fillisters. Meanwhile, an isolator member can directly cover the fillisters to provide functions of isolating heat and mounting. 
         [0035]    It is notable that according to the second preferred embodiment, the effect of preventing the efficiency of the heat-dissipating member  21  from the influence of the environment with high temperature produced by the above-mentioned apparatuses also can replace the action of covering the isolator member  24  or the like on the heat-dissipating member  21  and the contact portions  224  of the heat-conducting devices  22 . 
         [0036]    Moreover, an isolator sleeve (not shown in figures) can be used to cover the heat-conducting device  22  between the diode light-emitting device  23  and the contact portion  224  or the heat-conducting device  22  which is exposed out of the isolator member  24  to further reduce the influence of the environment with high temperature produced by the above-mentioned apparatuses toward the efficiency of the heat-dissipating member. The isolator sleeve can cover a plurality of heat-conducting devices  22 , or a plurality of isolator sleeves respectively cover the heat-conducting devices  22 . The isolator sleeve is not limited to the form of a sleeve; it can work in the form of an adhesive tape or by directly spreading an isolation material layer on it to achieve the effects of thermal isolation/reduction of thermal conductivity. Besides, in order to enhance the heat dissipation efficiency, a plurality of fins  212  can be formed on the heat-dissipating member  21  to increase the area for dissipating. It is worthy to be mentioned that in the preferred embodiments, the area of which the isolator members cover the heat-dissipating member should be enlarged as possible to effectively prevent the efficiency of the heat-dissipating member from the influence of the environment with high temperature produced by the above-mentioned apparatuses. 
         [0037]    According to the second preferred embodiment, the carrier  25  has three holes for the heat-conducting devices  22  to pass through and allows the diode light-emitting devices  23  to be disposed on the flat end  222  of the heat-conducting devices  22 . The substrate  232  of the diode light-emitting devices  23  is disposed on the carrier  25 . An electrode of a control circuit  28  is formed on or carried to connect to a surface  272  of the substrate  232 . The electric wire which is connected to the electrode is electrically connected to the control circuit  28  via an aperture  262  of the supporter  26 . The supporter  26  engages the heat-conducting devices  22  to the lamp holder  31 . The supporter  26  and the carrier  25  can be monolithically molded. According to the second preferred embodiment, the supporter  26  is locked on the lamp holder  31  with screws. However, the supporter  26  can also be mounted on the lamp holder  31  by attaching or hooking, or be alternatively mounted on other portions of the lamp holder  31 . 
         [0038]    Besides, the diode light-emitting devices  23  can be packaged together with the substrate  232 . Please refer to  FIG. 2C .  FIG. 2C  is a cross-sectional view illustrating a light-emitting diode package structure  4 . The package structure  4  includes a substrate  41 , a lower sub-mount  42 , at least one semiconductor light-emitting die  43 , and a package material  44 . The substrate  41  thereon defines a top surface  411 , and a plurality of outer electrodes  46  are disposed on the top surface  411 . The lower sub-mount  42  thereon defines a first surface  421 , and the at least one semiconductor light-emitting die  43  is mounted to the first surface  421  of the lower sub-mount  42  with an inter electrode (i.e. a bond pad) of the bottom  431 . A first recess portion  4111  is formed on the top surface  411  of the substrate  41 . The substrate  41  thereon defines a bottom surface  412 . A second recess portion  4121  is formed on the bottom surface  412  of the substrate  41 , and the second recess portion  4121  and the first recess portion  4111  are connected to each other. The lower sub-mount  42  is embedded in the second recess portion  4121 . The lower sub-mount  42  thereon further defines a second surface  422 , and the first surface  421  of the lower sub-mount  42  is exposed to the interior of the first recess portion  4111 . The bottom  431  of the at least one semiconductor light-emitting die  43  is mounted to the part of the first surface  421  of the lower sub-mount  42  which is exposed to the interior of the first recess portion  4111 . The package material  44  is used to be filled into the first recess portion  4111  to cover the at least one semiconductor light-emitting die  43 . The at least one semiconductor light-emitting die  43  has an inter electrode which is electrically connected to the outer electrodes  46  of the top surface  411 . The connection between the inter electrode of at least one semiconductor light-emitting die  43  and the outer electrode  46  is a series connection, but the connection between the electrodes can also be a parallel connection to achieve the same purpose of the invention. 
         [0039]    Furthermore, a heat-conducting gel  45  can be disposed between the first surface  421  of the lower sub-mount  42  and the bottom of the first recess portion  4111 , so as to combine the first surface  421  of the lower sub-mount  42  with the bottom of the first recess portion  4111 . That is to say, the heat-conducting gel  45  is used to connect the substrate  41  with the lower sub-mount  42 . The substrate  41  can be formed by metal, ceramic, a flexible printed circuit board, or a rigid printed circuit board. The lower sub-mount  42  can be composed of semiconductor. It is worthy to be mentioned that the package of the diode light-emitting devices  23  are not limited to the above description. The diode light-emitting devices  23  can also be disposed on the substrate  41 ′ rather than adopting the design of the first recess portion  4111  and the second recess portion  4121 , as shown in  FIG. 2D . Two electrodes  47  exposed on the substrate  41 ′ are used for connecting outer circuits. 
         [0040]    It is notable that each heat-conducting device  22  is not limited to carry only one diode light-emitting device  23 . Each heat-conducting device  22  can carry a plurality of diode light-emitting devices  23 . In the situation, the flat end  222 ′ of the heat-conducting device  22  is different from the foregoing flat end  222 . The larger flat end  222 ′ is formed by extruding an end of the heat-conducting device  22 , as shown in  FIG. 2E . The selection of the two kinds of flat end depends on the actual design of a product. And, the number of the diode light-emitting device and the space are important factors for making the decision. In this circumstance, both the geometric dimensions of the carrier  25  and the substrate  232  need to be modified accordingly. 
         [0041]    Please refer to  FIG. 3 .  FIG. 3  is a pictorial drawing illustrating a semiconductor light-emitting module according to a third preferred embodiment of the invention which is applied to a headlight  6  of an automobile. Compared with the second preferred embodiment, the heat-dissipating member  51  of the semiconductor light-emitting module of the third preferred embodiment is engaged to the shell near the hood of the automobile, which is different from the second preferred embodiment that the heat-dissipating member  21  of the semiconductor light-emitting module  2  is engaged on the body (e.g. the frame behind the bumper) of the automobile. Please refer to  FIG. 4 .  FIG. 4  is a pictorial drawing illustrating a semiconductor light-emitting module according to a fourth preferred embodiment of the invention which is applied to a headlight  8  of an automobile. Compared with the second preferred embodiment and the third preferred embodiment, the heat-dissipating member  71  of the semiconductor light-emitting module of the fourth preferred embodiment is engaged to the front side shell of the automobile. 
         [0042]    Taking the fourth preferred embodiment for example, the heat dissipation efficiency of the heat-dissipating member  71  can be increased by changing the outer structure of the heat-dissipating member  71  except for forming the fins  712  on the heat-dissipating member  71 . For example, the area for dissipating heat of the heat-dissipating member  71  can be increased by increasing the surface roughness or applying other patterns. Or the heat-dissipating member  71  can be formed a layer of fins outward and parallel to the fins  712  on the heat-dissipating member  71 . An included angle A (shown in  FIG. 5 , which is a top view illustrating the fourth preferred embodiment) between the two layers of fins can be designed not only to increase area for dissipating heat but also to increase the velocity and the density of fluid F which flows between the layers of fins to increase the heat dissipation efficiency. Furthermore, according to the third preferred embodiment, it is possible to have fins formed at the outside of the heat-dissipating member  51  although there is no one in this case. And, any fin or any structure assisting to dissipate heat, formed on the heat-dissipating member  51 , or any surface treatment applied to the heat-dissipating member  51  should comply with the design of the automobile. 
         [0043]    Therefore, according to the preferred embodiments, the semiconductor light-emitting module of the invention utilizes an isolator member to prevent the heat dissipation efficiency of the heat-dissipating member of the semiconductor light-emitting module from the influence of the environment with high temperature, so that the heat-dissipating member is capable of dissipating heat effectively at an environment with low temperature. In other words, the heat-dissipating member of the semiconductor light-emitting module is able to be normally operated at an environment with temperature differences. The application field of the semiconductor light-emitting module of the invention is not limited to the headlight of the auto mobile mentioned in the preferred embodiments. If there are existing temperature differences at operating environment and a requirement for dissipating heat, the semiconductor light-emitting module of the invention can be applied. But, the geometric dimension of the heat-dissipating member needs to comply with the operating environment. 
         [0044]    If applied in the headlight of the automobile, the heat-dissipating member of the semiconductor light-emitting module of the invention can be integrally designed with the shell, which is not only aesthetic but also functional. Furthermore, by dissipating the heat generated during the operation of the diode light-emitting device out of the body of the automobile to the environment with lower temperature by the heat-dissipating member, it is able to realize that the high-power semiconductor light-emitting module is disposed in the headlight of the automobile. At the same time, although a part of the heat-dissipating member is disposed at the environment with high temperature, the heat-dissipating member still has good heat dissipation efficiency by using the isolator to prevent the heat dissipation efficiency of the heat-dissipating member of the semiconductor light-emitting module from the influence of the environment with high temperature. Besides, because light-emitting diodes have various kinds of colors, the semiconductor light-emitting module can have functions of indication/illumination, such as integrating a fog lamp and common illumination functions into a semiconductor light-emitting module. 
         [0045]    With the example and explanations above, the features and spirits of the invention will be hopefully well described. Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teaching of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.