Abstract: A transient voltage suppressor circuit is disclosed for a plurality (N) of LEDs connected in series. Only one zener diode is created for connection to each node between LEDs, and a pair of zener diodes (the “end” zener diodes) are connected to the two pins (anode and cathode pads) of the series string. Therefore, only N+1 zener diodes are used. The end zener diodes (Q1 and Qn+1) effectively create back-to-back zener diodes across the two pins since the zener diodes share a common p+ substrate. The n+ regions of the end zener diodes Q1 and Qn+1 have the highest breakdown voltage requirement and must be placed relatively far apart. Adjacent n+ regions of the intermediate zener diodes have a much lower breakdown voltage requirement so may be located close together. The zener diodes may be placed within a very small footprint or can be larger for better suppressor performance.

Abstract: A transient voltage suppressor circuit is disclosed for a plurality (N) of LEDs connected in series. Only one zener diode is created for connection to each node between LEDs, and a pair of zener diodes (the “end” zener diodes) are connected to the two pins (anode and cathode pads) of the series string. Therefore, only N+1 zener diodes are used. The end zener diodes (Q1 and Qn+1) effectively create back-to-back zener diodes across the two pins since the zener diodes share a common p+ substrate. The n+ regions of the end zener diodes Q1 and Qn+1 have the highest breakdown voltage requirement and must be placed relatively far apart. Adjacent n+ regions of the intermediate zener diodes have a much lower breakdown voltage requirement so may be located close together. Since there are fewer zener diodes and their spacings may be small, the zener diodes may be placed within a very small footprint or can be larger for better suppressor performance.

Abstract: A semiconductor light emitting device is packaged by forming a sealed compartment enclosing the device, at least one of the walls of the sealed compartment being formed of an elastomeric material. The elastomeric material is then penetrated with a needle and a quantity of softer material is injected through the needle into the sealed compartment. In some embodiments, a coaxial needle or two needles are used, one needle to inject the softer material and one needle to vent air from the compartment.

Abstract: One embodiment of the invention provides a backlight for an LCD display. The backlight uses a two-dimensional array of single color or white LEDs and a diffusing or phosphor coated cover plate. Various electrical connections of the LEDs and various phosphor color-conversion techniques are described.

Abstract: A structure includes semiconductor light emitting device and a wavelength converting layer. The wavelength converting layer converts a portion of the light emitted from the semiconductor light emitting device. The dominant wavelength of the combined light from the semiconductor light emitting device and the wavelength converting layer is essentially the same as the wavelength of light emitted from the device. The wavelength converting layer may emit light having a spectral luminous efficacy greater than the spectral luminous efficacy of the light emitted from the device. Thus, the structure has a higher luminous efficiency than a device without a wavelength converting layer.

Abstract: A light emitting device includes a first active region, a second active region, and a tunnel junction. The tunnel junction includes a layer of first conductivity type and a layer of second conductivity type, both thinner than a layer of first conductivity type and a layer of second conductivity type surrounding the first active region. The tunnel junction permits vertical stacking of the active regions, which may increase the light generated by a device without increasing the size of the source.

Abstract: A method of forming a photoresist mask on a light emitting device is disclosed. A portion of the light emitting device is coated with photoresist. A portion of the photoresist is exposed by light impinging on the interface of the light emitting device and the photoresist from inside the light emitting device. The photoresist is developed, removing either the exposed photoresist or the unexposed photoresist. In one embodiment, the photoresist mask may be used to form a phosphor coating. After the photoresist is developed to remove the exposed photoresist, a phosphor layer is deposited overlying the light emitting device. The unexposed portion of photoresist is stripped. In some embodiments, the light exposing the photoresist is produced by electrically biasing the light emitting device, or by shining light into the light emitting device through an aperture or by a focussed laser.

Abstract: An LED package includes a heat-sinking slug that is inserted into an insert-molded leadframe. The slug may include an optional reflector cup. Within this cup, the LED and a thermally conducting sub-mount may be attached. Wire bonds extend from the LEDs to metal leads. The metal leads are electrically and thermally isolated from the slug. An optical lens may be added by mounting a pre-molded thermoplastic lens and a soft encapsulant or by casting epoxy to cover the LED or by a cast epoxy lens over a soft encapsulant.