Abstract:
Embodiments of light sources are disclosed herein. An embodiment of the light source comprises a lead frame having a first side and a second side. A hole extends through the lead frame between the first side and the second side. An adhesive is located in the hole and extends beyond the hole, wherein the adhesive extends beyond the diameter of the hole on the first side and the second side of the first lead frame. A light emitter adhered to the adhesive proximate the first side of the first lead frame.

Description:
BACKGROUND 
     Many light sources include a light emitter, such as a light-emitting diode, attached to a lead frame. The light emitter is then encapsulated. The light sources are subject to failure if the light emitter detaches from the lead frame. Detachment may occur if the encapsulant moves relative to the lead frame. For example, heating and cooling of the light source may cause the movement. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side cut away view of an embodiment of a light source. 
         FIG. 2  is a side perspective view of the lower substrate of  FIG. 1 . 
         FIG. 3  is a top plan view of and embodiment of the completed light source of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     A side cut away view of a light source  100  is shown in  FIG. 1 . In summary, the light source  100  uses a unique approach to adhere a light emitter  110  to a first lead frame  114 . More specifically, an adhesive  116  extends through a hole  120  in the first lead frame  114  to provide additional anchoring for the light emitter  110 . 
     The first lead frame  114  has a first side  126  and a second side  128  located opposite the first side. The hole  120  extends between the first side  126  and the second side  128 . The first lead frame  114  may be made of an electrically conductive material so as to conduct electricity to the light emitter  110 . 
     The adhesive  116  extends through the hole  120 , which enhances its ability to secure the light emitter  110  to the first lead frame  114 . The adhesive  116  may be an electrically conductive compound that is substantially rigid. The adhesive  116  may also cure and become substantially rigid after a curing process or time. In the embodiment of  FIG. 1 , the adhesive  116  has a first volume  132  that extends beyond the radius of the hole  120 . The first volume  132  may be adhered to the first side  126  of the first lead frame  114 . The adhesive  116  may substantially fill the hole  120  and may be adhered to the circumference of the hole  120 . A second volume  132  of adhesive  116  may be located adjacent the second side  128  of the first lead frame  114 . The second volume  132  may have a diameter that is greater than the diameter of the hole  120 . 
     As shown in  FIG. 1  and as described above, the diameters of the first volume  132  and the second volume  132  may be greater than the diameter of the hole  120 . This configuration of the adhesive  116  locks the adhesive in the hole  120 , which serves to improve its adhesion to the first lead frame  114 . Therefore, the adhesive  116  is not likely to peel or otherwise separate from the first lead frame  114 . 
     The light emitter  110  may be adhered to the first lead frame  114  by the adhesive  116 . More specifically, the light emitter  110  may be adhered to the first lead frame  114  by attaching the light emitter  110  to the first volume  130 . The attachment of the light emitter  110  to the first lead frame  114  via the adhesive  116 , which is secured to the first lead frame  114 , enhances the attachment of the light emitter  110  to the first lead frame  114 . Therefore, the light emitter  110  is less likely to move relative to or become detached from the first lead frame  114 . 
     In some embodiments, the adhesive  116  is electrically conductive and the adhesive contacts a conductor of the light emitter  110 . This contact creates an electrical path between the first lead frame  114  and the light emitter  110 . It is noted that in some embodiments, the adhesive  116  may not be conductive, which requires other methods of electrically connecting the light emitter  110  to the first lead frame  114 . 
     With additional reference to  FIG. 2 , the first lead frame  114  may be mounted into or onto a substrate  140 .  FIG. 2  is a top perspective view of the substrate  140  without any lead frames attached thereto. The substrate  140  may be adapted to receive a plurality of lead frames that may be substantially similar to the first lead frame  114 . In the embodiments of  FIG. 1  and  FIG. 2 , the substrate  140  has a plurality of channels  142  formed therein. 
     The embodiments of the substrate  140  described herein have two types of channels  142 . A first plurality of channels  144  is adapted to receive lead frames such as the first lead frame  114 . A second plurality of channels  146  is adapted to receive conventional lead frames or leads. The first channels  144  each have a surface  148  onto which a first lead frame  114  is set. 
     As described above, the first lead frame  114  has a second volume  132  of adhesive  116  extending from the second side  128 . Therefore, the first channels  144  have to be adapted to receive the second volume  132 . Reference is made to a channel  150 , which is substantially similar to all the first channels  144 . The channel  150  has a cavity  152  formed in the surface  148 . The cavity  152  is sized to receive the second volume  132  of adhesive  116 . The cavity  152  enables the first lead frame  114  to set on the surface  148  without rocking or becoming unstable. 
     A top plan view of an embodiment of the complete light source  100  is shown in  FIG. 3 . A second lead frame  160  is located in the channel opposite the channel  150 . The second lead frame  160  may be a conventional type lead frame that is received in a second channel  146 . A wire  164  connects the LED  110  to the second lead frame  160 . Thus, an electrical circuit is complete between the first lead frame  114  and the second lead frame  160  by way of the LED  110  and the wire  164 . It is noted that the substrate  140  may contain a plurality of lead frames and LEDs that operate independent of each other. 
     A lens  166  may be placed over the substrate  140 . The lens  140  may have a frame or the like that serves to physically hold the lead frames in their respective channels. The lens  166  may also include an opening to allow for an encapsulant to fill the volume above the substrate  140 . 
     Several different methods of manufacturing the light source  100  may be used. In some embodiments, the first lead frame  114  may be manufactured as described above. More specifically, the first lead frame  114  may have the hole  120  formed therein. The LED  110  may then be attached to the first lead frame  114  by use of the adhesive  116  as described above. The completed first lead frame  114  along with the other lead frames may then be attached to the substrate  140  so that the second volume  132  of adhesive  116  is in the cavity  152 . 
     In another embodiment, the first lead frame  114 , without the LED  110  attached thereto, may be placed in the channel  150 . The first lead frame  114  is placed in the channel  150  so that the hole  120  is adjacent the cavity  152 . After the first lead frame  114  is in place, the adhesive  116  is injected into the hole  120 . The adhesive  116  fills the cavity  150  so as to form the second volume  132 . The hole  120  is filled to also form the first volume  130 . The LED  110  may then be affixed to the first volume  130  in a conventional manner. The lens  166  may then be attached to the substrate  140 . 
     In some embodiments, the cavity  152  extends beyond the width of the first lead frame  114 . The wider cavity  152  provides for better filling of the cavity  152 . More specifically, air can escape from the cavity  152  as it is being filled.