Lens compression molded over LED die
View Patent ↗One or more LED dice are mounted on a support structure. The support structure may be a submount with the LED dice already electrically connected to leads on the submount. A mold has indentations in it corresponding to the positions of the LED dice on the support structure. The indentations are filled with a liquid optically transparent material, such as silicone, which when cured forms a lens material. The shape of the indentations will be the shape of the lens. The mold and the LED dice/support structure are brought together so that each LED die resides within the liquid silicone in an associated indentation. The mold is then heated to cure (harden) the silicone. The mold and the support structure are then separated, leaving a complete silicone lens over each LED die. This over molding process may be repeated with different molds to create concentric shells of lenses. Each concentric lens may have a different property, such as containing a phosphor, providing a special radiation pattern, having a different hardness value, or curable by a different technique (e.g., UV vs. heat).
1. An intermediate product during the fabrication of a light emitting device, the device having been separated from a mold, defining a lens, to form an encapsulating lens over the die, the mold not including a liquid channel through which liquid lens material is injected into the mold, the device being at a time immediately after the LED die and lens are separated from the mold, the device comprising:
a light emitting diode (LED) die attached to a support structure; and
a molded lens, entirely formed of cured lens material as a continuous homogeneous member, directly over, encapsulating, and contacting the LED die, the lens being completely composed of the cured lens material, wherein there is no lens material extending from the lens that is remaining from a liquid channel immediately after the LED die and lens are separated from the mold,
wherein there is no additional solid material covering and in contact with the molded lens.
2. The device of claim 1 wherein the support structure comprises a submount having metal leads in electrical contact with metal contacts on the LED die.
3. The device of claim 1 wherein the LED die is one of a plurality of LED dice affixed to the support structure.
4. The device of claim 1 wherein the lens is generally hemispherical to emit light in a Lambertian pattern.
5. The device of claim 1 wherein the lens is generally rectangular with rounded edges.
6. The device of claim 1 wherein the lens contains a first phosphor.
7. The device of claim 1 further comprising a backlight for a liquid crystal display, the backlight incorporating the LED and the lens.
8. The device of claim 1 further comprising a rear projection television, the television incorporating the LED and the lens.
9. The device of claim 1 wherein a shape of the lens is symmetrical about a center axis.