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.
A common high-power PLCC package utilizes a dual-gage leadframe. This type of PLCC package is relatively efficient at dissipating heat to an underlying Printed Circuit Board (PCB). However, dual-gage leadframes are far more expensive than single-gage leadframes. Moreover, the dual-gage leadframe is not very flexible (e.g., bendable, malleable, etc.), especially when compared to a single-gage leadframe. This lack of flexibility means that the dual-gage leadframe material is only suitable for specific package designs.
Another design that is used for high-power PLCC packages is to insert a separate metal slug between the PCB and light source. The metal slug is separate from the leadframe that is used to carry current to/from the light source(s). This separate metal slug significantly increases the costs of the package.
Currently-available PLCC packages that utilize a single-gage leadframe are simple in the leadframe design. Specifically, the single-gage leadframe designs tend to be relatively flat, which means that interconnections between the leadframe and the plastic housing of the package are not optimal. Therefore, currently-available PLCC packages having a single-gage leadframe design are somewhat unreliable and/or prone to failure.
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