Bridgelux Incorporated

Michael Solomensky

Tao Tong

R Scott West

Mike Kwon

Tao Xu

Alex Shaikevitch

Shanquan Bao

Wei Shi

Standardized photon building blocks are packaged in molded interconnect structures to form a variety of LED array products. No electrical conductors pass between the top and bottom surfaces of the substrate upon which LED dies are mounted. Microdots of highly reflective material are jetted onto the top surface. Landing pads on the top surface of the substrate are attached to contact pads disposed on the underside of a lip of the interconnect structure. In a solder reflow process, the photon building blocks self-align within the interconnect structure. Conductors in the interconnect structure are electrically coupled to the LED dies in the photon building blocks through the contact pads and landing pads. Compression molding is used to form lenses over the LED dies and leaves a flash layer of silicone covering the landing pads. The flash layer laterally above the landing pads is removed by blasting particles at the flash layer.

Packaging a substrate with an LED into an interconnect structure only through top side landing pads on the substrate

A white LED assembly includes a string of series-connected blue LED dice mounted on a substrate. The substrate has a plurality of substrate terminals. A first of the substrate terminals is coupled to be a part of first end node of the string. A second of the substrate terminals is coupled to be a part of an intermediate node of the string. A third of the substrate terminals is coupled to be a part of a second end node of the string. Other substrate terminals may be provided and coupled to be parts of corresponding other intermediate nodes of the string. A single contiguous amount of phosphor covers all the LED dice, but does not cover any of the substrate terminals. In one example, the amount of phosphor contacts the substrate and has a circular periphery. All the LEDs are mounted to the substrate within the circular periphery.

White LED assembly with LED string and intermediate node substrate terminals

Packaging photon building blocks having only top side connections in a molded interconnect structure

A substrate for an LED assembly can have a plurality of cups formed therein. At least one cup can be formed within another cup. The cups can be co-axial with respect to one another, for example. A machined surface of the substrate can enhance reflectivity of the LED assembly. A transparent and/or non-global solder mask can enhance reflectivity of the LED assembly. A transparent ring can enhance reflectivity of the LED assembly. By enhancing reflectivity of the LED assembly, the brightness of the LED assembly can be increased. Brighter LED assemblies can be used in applications such as flashlights, displays, and general illumination.

Multi-cup LED assembly

Transparent ring LED assembly

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Fremont, CA, United States of America

Michael Solomensky