Patent Abstract:
A Plastic Leaded Chip Carrier (PLCC) package is disclosed. The PLCC package includes a lead frame with an integrated reflector cup. The reflector cup is directly connected to a heat sink, which improves the ability of the PLCC package to distribute heat away from the light source that is provided in the reflector cup.

Full Description:
FIELD OF THE DISCLOSURE 
     The present disclosure is generally directed toward light emitting devices and packages for the same. 
     BACKGROUND 
     Light Emitting Diodes (LEDs) have many advantages over conventional light sources, such as incandescent, halogen and fluorescent lamps. These advantages include longer operating life, lower power consumption, and smaller size. Consequently, conventional light sources are increasingly being replaced with LEDs in traditional lighting applications. As an example, LEDs are currently being used in flashlights, camera flashes, traffic signal lights, automotive taillights and display devices. 
     Among the various packages for LEDs, an LED package of interest is the Plastic Leaded Chip Carrier (PLCC) package for a surface mount LED. Surface mount LEDs in PLCC packages may be used, for example, in automotive interior display devices, electronic signs and signals, and electrical equipment. 
     To increase the capacity of an LED package to dissipate more heat, various designs are used in the industry; however, each of these designs results in LED packages with limited heat dissipation capacities which simultaneously increase the complexity and the costs associated with manufacturing the LED packages. 
     For example, some LED package designs utilize a large heat sink slug that is distinct from the lead frame. The heat sink slug increases the capacity of the LED package to dissipate heat; however, because the heat sink slug is a separate component, the costs associated with manufacturing LED packages according to this design are relatively difficult and more costly, particularly because the number of manufacturing steps are increased due to the need to assembly the multiple pieces together. Furthermore, LED packages which incorporate a separate heat sink slug are larger in size due to the increased number of components in the LED package. Another shortcoming is that because a large LED package is required to accommodate the separate heat sink slug, a larger lens is also required to fit onto the larger LED package. All of this increases the cost of the LED package. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure is described in conjunction with the appended figures: 
         FIG. 1A  is a top perspective view of a first package assembly in accordance with embodiments of the present disclosure; 
         FIG. 1B  is a top perspective view of a first lead frame in accordance with embodiments of the present disclosure; 
         FIG. 2A  is a top perspective view of a first partially-completed PLCC package in accordance with embodiments of the present disclosure; 
         FIG. 2B  is a cut-away perspective view of the partially-completed PLCC package depicted in  FIG. 2A ; 
         FIG. 3A  is a top perspective view of a first PLCC package in accordance with embodiments of the present disclosure; 
         FIG. 3B  is a cut-away perspective view of the PLCC package depicted in  FIG. 3A ; 
         FIG. 3C  is a bottom perspective view of the PLCC package depicted in  FIG. 3A ; 
         FIG. 4  is a top perspective view of a second package assembly in accordance with embodiments of the present disclosure; 
         FIG. 5A  is a top perspective view of a second PLCC package in accordance with embodiments of the present disclosure; 
         FIG. 5B  is a top view of the PLCC package depicted in  FIG. 5A ; 
         FIG. 5C  is a side view of the PLCC package depicted in  FIG. 5A ; 
         FIG. 6A  is a top perspective view of a second partially-completed PLCC package relative to a package carrier in accordance with embodiments of the present disclosure; 
         FIG. 6B  is a bottom perspective view of the second partially-completed PLCC package depicted in  FIG. 6A ; 
         FIG. 7A  is a top view of a second lead frame in accordance with embodiments of the present disclosure; 
         FIG. 7B  is a top perspective view of the second lead frame depicted in  FIG. 7A ; 
         FIG. 8A  is a top view of a second PLCC package in accordance with embodiments of the present disclosure; 
         FIG. 8B  is a cross-sectional side view of the second PLCC package depicted in  FIG. 8A ; 
         FIG. 9  is a top perspective view of a third partially-completed PLCC package in accordance with embodiments of the present disclosure; and 
         FIG. 10  is a flow diagram depicting a method of manufacturing a PLCC package in accordance with embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The ensuing description provides embodiments only, and is not intended to limit the scope, applicability, or configuration of the claims. Rather, the ensuing description will provide those skilled in the art with an enabling description for implementing the described embodiments. It being understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the appended claims. 
     Furthermore, although one particular type of PLCC package is depicted and described, embodiments of the present disclosure are not so limited. In particular, embodiments of the present disclosure can be utilized in any type of known PLCC package and/or platform. Specifically, any type of PLCC package and/or platform or similar type of package for a light emitting device that uses a plastic molded lead frame can incorporate one or more features disclosed herein. 
     With reference now to  FIGS. 1A-3C , a first package assembly  100  comprising a first package carrier  104  used to create a first PLCC package  108  will be described in accordance with at least some embodiments of the present disclosure. The PLCC package  108  comprises a plastic housing  112  molded around a lead frame  120 . As can be seen in  FIGS. 1A and 1B , the lead frame  120  may be carried by the package carrier  104 . In some embodiments, the package carrier  104  comprises a plurality of lead frames  120 . Thus, batch manufacturing techniques can be employed to manufacture a plurality of PLCC packages  108  on a single package carrier  104 . 
     In some embodiments, the lead frame  120  is initially an integral part of the package carrier  104 . In particular, the package carrier  104  may comprise a sheet of metal or similar conductive material having one or more raised portions. The lead frame  120  may be constructed by removing certain portions of the package carrier  104 . As one example, the lead frame  120  may be formed by stamping the package carrier  104  and removing excess portions therefrom. Other manufacturing techniques such as machining, etching, and the like may additionally or alternatively be used to construct the lead frame. 
     With reference now to  FIG. 1B , further details of the lead frame  120  will be described in accordance with at least some embodiments of the present disclosure. Some or all of the features of the lead frame  120  may be created in a single manufacturing step (e.g., a single stamping step) or in multiple manufacturing steps (e.g., a stamping step followed by a machining or etching step). 
     In some embodiments, the lead frame  120  comprises a first lead  124   a  and a second lead  124   b . Although the lead frame  120  is depicted as having only two leads  124   a ,  124   b , a greater or lesser number of leads may be included in the lead frame  120  without departing from the scope of the present disclosure. 
     A gap may be provided between the first lead  124   a  and second lead  124   b . The gap ensures that an electrical potential can be applied between the first lead  124   a  and second lead  124   b . The electrical potential eventually applied between the first lead  124   a  and second lead  124   b  may be used to power a light source packaged within the PLCC package  108 . 
     During at least some of the manufacturing process, the first lead  124   a  and second lead  124   b  are connected to the package carrier  104  via one or more connectors  128   a ,  128   b . Although each lead  124   a ,  124   b  is depicted as having two connectors  128   a ,  128   b  associated therewith, a greater or lesser number of connectors may be provided for each of the leads without departing from the scope of the present disclosure. The connectors  128   a ,  128   b  of each lead  124   a ,  124   b  provide a mechanism which secures the leads  124   a ,  124   b  to the package carrier  104  and maintain a specific relative position between the leads  124   a ,  124   b  until a plastic housing  112  is formed around the lead frame  120 . After the manufacturing process has been completed, the relative position of the leads  124   a ,  124   b  are fixed and the connectors  128   a ,  128   b  can be severed, thereby separating the PLCC package  108  from the package carrier  104 . In some embodiments, the connectors  128   a ,  128   b  are provided as thin strips of metal which connect the outer edges of each lead  124   a ,  124   b  to the rest of the package carrier  104 . As can be appreciated, additional connectors can be provided between the outer edges of the lead to ensure a more secure connection between the lead frame  120  and package carrier  104  during the manufacturing process. 
     Another feature which may be formed in the lead frame  120  during a stamping process, for example, is one or more anchorage holes  132 . The anchorage holes  132  may correspond to vias or cavities which provide an anchor point between the plastic housing  112  and lead frame  120 . More specifically, when the plastic housing  112  is formed around the lead frame  120 , plastic from the plastic housing  112  may fill some or all of the anchorage holes  132 , thereby creating a more secure connection between the lead frame  120  and plastic housing  112 . Similar to the connectors  128   a ,  128   b , although each lead  124   a ,  124   b  is depicted as having two anchorage holes  132 , a greater or lesser number of anchorage holes  132  may be provided in a lead without departing from the scope of the present disclosure. 
     Yet another feature which may be formed in the lead frame  120  is a lead frame cavity  144 . The lead frame cavity  144  may be an integral portion of the lead frame  120 , meaning that the lead frame cavity  144  is directly connected to one of the leads  124   a ,  124   b  of the lead frame  120 . In the embodiment depicted in  FIG. 1B , the lead frame cavity  144  is directly connected to the first lead  124   a . In some embodiments, the lead frame cavity  144  may be provided on a first raised portion  136  of the first lead  124   a . A corresponding second raised portion  140  may be provided on the second lead  124   b.    
     In some embodiments, the top of the first raised portion  136  is approximately the same height as the top of the second raised portion  140 . The lead frame cavity  144  may be formed as a reflective cup that has been stamped into the first raised portion  136 . As can be seen in  FIGS. 2A and 2B , the bottom surface of the lead frame cavity  144  may correspond to a bonding pad  148 , which is configured to receive a light source  152 . The reflective cup of the lead frame cavity  144  may comprise an upper ridge that has a larger area than the bonding pad  148 . 
     The walls of the reflective cup between the upper ridge and the bonding pad  148  may be configured to reflect light emitted by the light source  152 , thereby increasing the efficiency with which the PLCC package  108  emits light. In some embodiments, the package carrier  104  and, therefore, the lead frame  120  is constructed of a metal or similar material that has a sufficient reflectance. In other embodiments, the walls of the reflective cup are plated with a reflective material to enhance the reflectance of the reflective cup. If the walls of the reflective cup are plated with a material that is different from the material used to construct the lead frame  120 , any known plating or material deposition technique may be employed. For instance, electroless or electro-plating techniques may be employed to deposit a highly-reflective material (e.g., Al, Au, Ag, Ni, W, Pi, and/or Pt) onto the walls of the reflective cup. 
     As can be seen in  FIGS. 1B ,  2 B, and  3 B, the first raised portion  136  may be connected to the non-raised portion of the first lead  124   a  via an integral heat sink  164 . In some embodiments, the heat sink  164  is an integral part of the first lead  124   a . In other words, the heat sink  164 , the lead frame cavity  144 , and all other parts of the first lead  124   a  are formed of a single piece of material. By providing an integral heat sink  164  between the lead frame cavity  144  and the lower portions of the first lead  124   a , a heat sink  164  can be included in the lead frame  120 , thereby reducing the number of components required to achieve a PLCC package  108  that is efficient at dissipating heat produced by the light source  152 . The integral heat sink  164  is dual-purposed to transfer heat away from the light source  152  while simultaneously carrying current to/from the light source  152 . 
     The light source  152 , in some embodiments, comprises an LED or array of LEDs. Where an LED or similar light source is used, a bonding wire  156  may be used to connect a top surface of the light source  152  to the second raised portion  140  of the second lead  128   b  while the bottom surface of the light source  152  is electrically connected to the first lead  124   a  via the bonding pad  148 . In such a configuration, one surface of the light source  152  may correspond to an anode of the light source  152  and another surface of the light source  152  may correspond to a cathode of the light source  152 . By connecting the light source  152  to two different leads  124   a ,  124   b  an electrical potential can be applied to the anode and cathode of the light source  152  thereby energizing the light source  152  and causing it to emit light. In some embodiments, the light source  152  is configured to emit light from its top surface. 
     As discussed above, the top surface of the first raised portion  136  may be approximately the same height as the top surface of the second raised portion  140 . This configuration of the first and second leads helps reduce the amount of stress imparted on the bonding wire  156 . As the bonding wire  156  is often a point of failure in PLCC packages, reducing the amount of stress imparted on the bonding wire  156  can increase the operational reliability of the PLCC package  108 . In some embodiments, it may not be necessary to have the top surface of the first raised portion  136  be approximately the same height as the top surface of the second raised portion  140 . Rather, it may be desirable to ensure that the top surface of the second raised portion  140  is at least higher than the bonding pad  148 . By providing the second raised portion  140  at a position higher than the bonding pad  148 , the wire bonding process can be simplified because less stress is imparted on the bonding wire  156  as compared to traditional PLCC packages and because the amount of wire looping required can be minimized. Furthermore, the relative heights of the first and second raised portions  136 ,  140 , respectively, help reduce the overall height of the PLCC package  108 . 
     As can be seen in  FIGS. 3A and 3B , after the bonding wire  156  has been connected to the light source  152  and the opposite terminal (i.e., the second lead  128   b ), the lens  116  may be positioned over the top of the plastic housing  112 , thereby enclosing the light source  152 . The lens  116  may be configured to improve the light extraction efficiency of the PLCC package  108 . The lens  116  may also shape the light as it exits the PLCC package  108  and can also improve the reliability of the PLCC package  108  by reducing the amount of moisture that reaches the lead frame cavity  144  (as well as any encapsulant provided therein). 
     In some embodiments, the lens  116  may be positioned above the plastic reflector cup  160 . In other embodiments, a PLCC package  108  may be provided without the lens  116 . Specifically, the lens  116  height can be reduced or the need for the lens  116  can be eliminated depending upon the intended use for the PLCC package  108 . For example, the lead frame cavity  144  provides a first light-shaping option and the plastic reflector cup  160  provides a second light-shaping option without requiring a lens  116 . If the properties of the lead frame cavity  144  and plastic reflector cup  160  are sufficient to achieve the desired light-shaping requirements, then no lens  116  may be needed and the overall height of the PLCC package  108  can be greatly reduced. 
       FIG. 3C  shows in further detail how the outer edges of the first lead  124   a  and second lead  124   b  are exposed at the opposite outside edges of the plastic housing  112 . Additionally, the bottoms of the first and second leads  124   a ,  124   b  are exposed at the bottom of the plastic housing  112 . This enables the PLCC package  108  to be electrically connected via bottom or side electrical connections. Furthermore, the heat sink  164  is exposed on the bottom surface of the plastic housing  112 , thus providing a way for heat generated by the light source  152  to efficiently exit the PLCC package  108  (i.e., because the material used for the lead frame  120  is a more efficient conductor of thermal energy than the material used for the plastic housing  112 ). 
     With reference now to  FIGS. 4-8B , a second package assembly  200  comprising a second package carrier  204  used to create a second PLCC package  208  will be described in accordance with at least some embodiments of the present disclosure. The PLCC package  208  is similar to PLCC package  108  in that both PLCC packages comprise a plastic housing  112  and each may optionally comprise an external lens  116 , which is attached about or around a plastic reflector cup  160  provided on the plastic housing  112 . However, where the first PLCC package  108  comprises a lead frame  120  having a first lead  124   a  and a second lead  124   b , where one of the leads also included the integral heat sink  164  and lead frame cavity  144 , the second PLCC package  208  comprises a lead frame  212  having a first lead  220   a , a second lead  220   b , and a separate heat sink  248 . 
     The package carrier  204  may be similar or identical to the package carrier  104  except that the package carrier  204  is configured with three raised portions instead of two. The materials used to construct the package carrier  104  may also be used to construct the package carrier  204 . 
     As can be seen in  FIGS. 6B ,  7 A, and  7 B, the first lead  220   a  may be electrically and physically isolated from both the second lead  220   b  and the heat sink  248 . Similarly, the second lead  220   b  may be electrically and physically isolated from both the first lead  220   a  and the heat sink  248 . This means that each component of the lead frame  212  comprises separate connectors for connecting to the package carrier  204  during the manufacturing process. In particular, the first lead  220   a  may comprise a first and second lead connector  224   a ,  224   b , respectively, which connect the first lead  220   a  to the package carrier  204 . Similarly, the second lead  220   b  may comprise a first and second lead connector  224   a ,  224   b , respectively, which connect the second lead  220   b  to the package carrier  204 . Much like the lead frame  120 , the first and second leads  220   a ,  220   b  may be oppositely-disposed at the outer edges of the PLCC package  208 . 
     The heat sink  248  may comprise a plurality of its own heat sink connectors  228   a - d , which connect the heat sink  248  to the package carrier  204 . Although two connectors  224   a ,  224   b  are depicted on each lead, a greater or lesser number of connectors may be utilized without departing from the scope of the present disclosure. Likewise, although the heat sink  248  is depicted as having four connectors, a greater or lesser number of connectors can be used without departing from the scope of the present disclosure. In some embodiments, the first and second heat sink connectors  228   a ,  228   b  extend around one lead (e.g., the second lead  220   b ) and the second and third heat sink connectors  228   c ,  228   d  extend around the other lead (e.g., the first lead  220   a ). 
       FIGS. 7A and 7B  depict further details of the lead frame  212 . One or more portions of the lead frame  212  may comprise anchorage holes  244 . The anchorage holes  244  may be similar or identical to the anchorage holes  132 . 
     The heat sink  248  may comprise a heat sink raised portion  216 , the first lead  220   a  may comprise a first raised portion  240   a , and the second lead  220   b  may comprise a second raised portion  240   b . In some embodiments, the top surfaces of each raised portion  216 ,  240   a , and  240   b  are approximately the same height. 
     The heat sink raised portion  216  may comprise a lead frame cavity  232  formed therein that is similar or identical to the lead frame cavity  144 , except that the lead frame cavity is formed in the heat sink  248  rather than a lead. The lead frame cavity  232  may comprise a bonding pad  236  that is configured to receive a light source  252 . The bonding pad  236  may be similar or identical to the bonding pad  148  except that the bonding pad  236  is not used to carry electrical current to/from the light source  252 . Instead, the heat sink  248  is primarily used to shape light emitted by the light source  252  (e.g., via the lead frame cavity  232 ) and transfer heat generated by the light source  252  to the bottom of the PLCC package  208 . 
     Thus, the light source  252  is configured with first and second terminals on the same upper surface of the light source  252 . In some embodiments, both the cathode and anode of the light source  252  may be provided on the same upper surface of the light source  252 . The cathode may be electrically connected to one of the leads (e.g., the first lead  220   a ) while the cathode may be electrically connected to the other of the leads (e.g., the second lead  220   b ). 
     The electrical connections of the leads  220   a ,  220   b  to the light source  252  may be achieved with first and second bonding wires  256   a ,  256   b . The bonding wires  256   a ,  256   b  may be similar or identical to the bonding wire  156 . In some embodiments, the bonding wires  156 ,  256   a ,  256   b  are made of an electrically conductive material such as Au, Ag, Cu, and the like. Often times the bonding wires  256   a ,  256   b  are extremely fine and are, therefore, susceptible to breaking or coming un-bonded under stresses. Accordingly, the first raised portion  240   a  and second raised portions  240   b  may be the same height as the top of the heat sink raised portion  216 . It may be, however, suitable for the first and second raised portions  240   a ,  240   b  to be lower than the top of the heat sink raised portion  216  as long as they are higher than the surface of the bonding pad  236 . As can be seen in  FIG. 8B , it may also be suitable to position the first and second raised portions  240   a ,  240   b  above the top surface of the heat sink raised portion  216 . 
     Another difference between the lead frame  120  and lead frame  212 , is that the raised portions  240   a ,  240   b  of the first and second leads  220   a ,  220   b  may be configured on a J-bend structure. This enables the raised portions  240   a ,  240   b  to extend over the gap between the leads  220   a ,  220   b  and the heat sink  240  and be positioned closer to the light source  252 . This reduces the length of bonding wire  256   a ,  256   a  required to electrically connect the light source  252  to the leads  220   a ,  220   b.    
     As can be seen in  FIG. 8A , the shape of the reflector cup formed in the lead frame cavity  232  does not necessarily have to be the same as the shape of the plastic reflector cup  160 , although such a configuration is possible. Rather, the reflector cup in the lead frame cavity  232  may comprise an oval or elliptical shape whereas the plastic reflector cup  160  may comprise a circular shape. Other shapes (e.g., rectangular, square, polygonal, etc.) may be used for either the reflector cup in the lead frame cavity  232  and/or plastic reflector cup  160 . Similarly, different shapes can be utilized for the reflector cup in the lead frame cavity  144  and plastic reflector cup  160  of the PLCC package  108 . 
       FIG. 9  depicts yet another type of PLCC package that may be provided in accordance with embodiments of the present disclosure. More specifically, the PLCC package depicted in  FIG. 9  is a hybrid of the previously depicted PLCC packages in that the light source  252  may be used in the first PLCC package  108 . Here, the light source  252  comprises both an anode and cathode on its top surface. One of the anode and cathode is connected to the second raised portion  140  via bonding wire  156 . The other of the anode and cathode (i.e., that which is not already connected via bonding wire  156  to the second raised portion  140 ) is connected to a bonding area  308  established on an upper surface of the first raised portion  136  by a second bonding wire  304 . The bonding area  308  and second bonding wire  304  enable the first PLCC package  108  to accommodate a light source  252  having both an anode and cathode on a common surface. 
     Referring now to  FIG. 10 , a method of constructing a PLCC package will be described in accordance with at least some embodiments of the present disclosure. Although the steps depicted in  FIG. 10  are shown in a particular order, those of ordinary skill in the LED manufacturing arts will appreciate that certain steps may be combined and/or the order of steps may be altered without departing from the scope of the present disclosure. Additionally, although a number of steps are depicted in  FIG. 10 , embodiments of the present disclosure greatly simplify the process of manufacturing a PLCC package. Specifically, a PLCC package can be constructed in as little as three manufacturing steps in accordance with embodiments of the present disclosure: (1) stamping the lead frame from its package carrier; (2) plating the lead frame cavity with a reflective material; and (3) molding the plastic housing around the lead frame. 
     Furthermore, the some or all of the steps described herein can be utilized to construct either PLCC package  108  or PLCC package  208 . For simplicity and ease of understanding, the description of the method depicted in  FIG. 10  will not refer to a specific PLCC package or the components thereof. 
     Initially, a lead frame material is provided in the form of a package carrier (step  1004 ). In some embodiments, the package carrier comprises one or more raised portions that will ultimately be formed into an electrical terminal and/or a lead frame cavity. 
     The lead frame or a plurality of lead frames can then be formed from the lead frame material (step  1008 ). In some embodiments, this step involves stamping the lead frame material and removing unnecessary material away from the package carrier. However, connectors between the lead frame and the package carrier are maintained to as to maintain the relative position of the components of the lead frame. The lead frame cavity may also be formed in this stamping step. During or after formation of the lead frame, a plating step may also be performed where some or the entire reflector cup in the lead frame cavity is coated with a highly reflective material. 
     After the lead frame has been formed, the plastic housing is formed around the lead frame (step  1012 ). In some embodiments, the plastic housing may be formed with an injection molding process, in which case the plastic housing may comprise a single piece of plastic. However, it may also be possible to construct the plastic housing with one, two, three, or more separate parts that are connected to one another using a bonding or fusing process or agent. 
     In some embodiments, the plastic housing is a single piece of plastic that has been formed by an injection molding process. Also in this step, the plastic reflector cup may be formed in the top portion of the plastic housing by using a machining, etching, and/or stamping process. The plastic reflector cup may have been formed during the injection molding process or an alternative approach would be to first form the plastic housing and then stamp or machine the top of the plastic housing until the plastic reflector cup has been formed. Different alternatives may be more desirable for different types of PLCC packages. In some embodiments, a white plastic material may be used to form some or all of the plastic housing to improve the brightness of the PLCC package. In other embodiments, a black plastic material may be used to form some or all of the plastic housing to improve the contrast of the PLCC package. 
     After the plastic housing has been attached to the lead frame, the method continues by mounting the light source into the bonding pad of the lead frame cavity (step  1016 ) and then electrically connecting the light source to one or more leads of the lead frame (step  1020 ). This particular step may include connecting one or more bonding wires between the light source and leads of the lead frame. Electrically connecting the light source may also be achieved by simply mounting the light source in the bonding pad since the lead frame cavity may be electrically conductive and included in one of the leads of the lead frame. 
     After the light source has been electrically connected to the leads of the lead frame, one or more optional steps may be performed. A first optional step involves filling at least a portion of the lead frame cavity with an encapsulant (step  1024 ). The encapsulant may be provided into the reflector cup of the lead frame cavity using known injection techniques. In some embodiments, the encapsulant only fills part of the lead frame cavity. In some embodiments, the entire lead frame cavity is filled with an encapsulant. In some embodiments, some or the entire cavity defined by the plastic reflector cup is also filled with an encapsulant, which may be the same or different from the encapsulant used to fill the lead frame cavity. Suitable types of encapsulants include, without limitation, epoxy, silicone, a hybrid of silicone and epoxy, phosphor, a hybrid of phosphor and silicone, an amorphous polyamide resin or fluorocarbon, glass, plastic, or combinations thereof. 
     The encapsulant may be provided for a number of reasons. First, the encapsulant may hermetically seal the light source and provide structural protection to the bonding wire(s). Second, the encapsulant may comprise optical properties for changing the color of light emitted by the light source before it exits the PLCC package. Third, the encapsulant may act as a lens for shaping light as it exits the PLCC package. 
     A second optional step involves attaching an external lens to the plastic housing (step  1028 ). This step may involve gluing the lens to the plastic housing. Alternatively, or in addition, this step may involve connecting the lens to the plastic housing with separate connector components. In other embodiments, a friction fit between the lens and the plastic reflector cup may be used to secure the lens to the plastic housing. 
     Thereafter, the method continues by removing additional excess material from the PLCC package (step  1032 ). Specifically, this step involves separating the PLCC package from the package carrier by severing the connections previously maintained between the lead frame and the package carrier. Separation of the PLCC package from the package carrier enables individual PLCC packages to be sold and distributed. Alternatively, the PLCC packages can be sold and distributed while connected to the package carrier and the customer can be responsible for removing the PLCC packages from the package carrier. 
     As can be appreciated, the PLCC packages may be manufactured individually or in a batch manufacturing process where each step described above is simultaneously performed on a plurality of PLCC packages. 
     A number of additional and/or alternative embodiments are envisioned, particularly for managing the optical characteristics of the PLCC packages described herein. As one example, where an external lens is utilized, the lens height could be reduced as compared to normal PLCC packages due to the optical properties provided by the lead frame cavity and plastic reflector cup. 
     As another example, for a white/blue LED, the lead frame cavity could be used to confine a first light-converting encapsulant (e.g., phosphor) while the plastic reflector cup could be used to confine a second encapsulant (e.g., a clear encapsulant) to achieve better light extraction efficiencies, better white light shaping (less yellow ring effect), and improve the reliability of the PLCC package by reducing the moisture allowed to reach the first light-converting encapsulant, which may be susceptible to adverse reactions to moisture. 
     As yet another example, for a white/blue LED, the lead frame cavity could be used to confine a first encapsulant (e.g., a clear encapsulant) while the plastic reflector cup could be used to confine a thin layer of a second light-converting encapsulant (e.g., phosphor). This second encapsulant is a remote phosphor and would not be as susceptible to negative adverse effects due to the heat produced by the light source since the remote phosphor is not in direct contact with the light source. 
     As still another example, for a white/blue LED using a blue LED die with near UV ray characteristics, the lead frame cavity could be coated/plated with a silver material to reduce the brightness degradation encountered as compared to the plastic reflector cup. 
     Specific details were given in the description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments. 
     While illustrative embodiments of the disclosure have been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed, and that the appended claims are intended to be construed to include such variations, except as limited by the prior art.

Technology Classification (CPC): 7