LED lamp and method for manufacturing the same

1. An LED lamp comprising:

at least one LED chip mounted on the principal surface of a substrate; and

an optical wavelength converting portion, which includes a phosphor for converting the emission of the LED chip into light having a longer wavelength than that of the emission and which covers at least a portion of the LED chip,

wherein the optical wavelength converting section has an upper surface and a side surface and the side surface of the optical wavelength converting portion has at least one concave curved surface portion which is recessed toward the LED chip.

2. The LED lamp of claim 1 , further comprising a cover member that covers at least a part of the optical wavelength converting portion.

3. The LED lamp of claim 1 , further comprising:

a reflective surface, which is spaced apart from the side surface of the optical wavelength converting portion; and

a cover member that covers at least a part of the optical wavelength converting portion,

wherein the refractive index of the cover member is different from that of the optical wavelength converting portion.

4. The LED lamp of claim 3 , wherein the refractive index of the cover member is greater than that of the optical wavelength converting portion.

5. The LED lamp of claim 4 , wherein the cover member is made of a resin, and

wherein the cover member fills a gap between the side surface of the optical wavelength converting portion and the reflective surface.

6. The LED lamp of claim 3 , wherein the cover member functions as a lens.

7. The LED lamp of claim 1 , wherein the optical wavelength converting portion is made of a resin including the phosphor.

8. The LED lamp of claim 1 , wherein the optical wavelength converting portion is in the form of revolution having concave sides.

9. The LED lamp of claim 1 , wherein the optical wavelength converting portion substantially has the shape of a truncated cone, of which the side surface defines the concave curved surface portion.

10. An LED lamp comprising:

at least one LED chip mounted on the principal surface of a substrate; and

an optical wavelength converting portion, which includes a phosphor for converting the emission of the LED chip into light having a longer wavelength than that of the emission and which covers at least a portion of the LED chip,

wherein a side surface of the optical wavelength converting portion has at least one concave curved surface portion, and

wherein as viewed on a plane perpendicular to the principal surface of the substrate, a cross section of the optical wavelength converting portion, taken across the concave curved surface portion of its side surface, has a profile including a curve that defines the concave curved surface portion, and

wherein R/t, obtained by dividing the radius of curvature R of the curves by the thickness t of the optical wavelength converting portion from the top of the wavelength converting section to the substrate is from 0.5 to 8.5.

11. An LED lamp comprising:

at least one LED chip mounted on the principal surface of a substrate; and

an optical wavelength converting portion, which includes a phosphor for converting the emission of the LED chip into light having a longer wavelength than that of the emission and which covers at least a portion of the LED chip,

wherein a side surface of the optical wavelength converting portion has at least one concave curved surface portion, and

wherein d/t, obtained by dividing the depth d of the concave curved surface portion on the side surface of the optical wavelength converting portion by the thickness t of the optical wavelength converting portion from the top of the wavelength converting section to the substrate is from 0.03 to 0.5.

12. The LED lamp of claim 11 , wherein the depth d of the concave curved surface portion on the side surface of the optical wavelength converting portion is from 0.01 mm to 0.17 mm.

13. An LED lamp comprising:

a plurality of LED chips, which are arranged on the principal surface of a substrate;

a plurality of reflective surfaces, each of which surrounds the side surface of an associated one of the LED chips;

a plurality of optical wavelength converting portions having an upper surface and a side surface, each of which includes a phosphor for converting the emission of its associated LED chip into light having a longer wavelength than that of the emission and which covers the associated LED chip; and

a plurality of cover members, each of which covers an associated one of the optical wavelength converting portions,

wherein the side surface of each said optical wavelength converting portion has at least one concave curved surface portion which recessed toward the LED chip, and

wherein each said cover member fills a gap between the side surface of its associated optical wavelength converting portion and its associated reflective surface.

14. A method for manufacturing an LED lamp, the method comprising the steps of:

(A) mounting at least one LED chip on the principal surface of a substrate; and

(B) providing an optical wavelength converting portion having an upper surface and a side surface on the substrate, the optical wavelength converting portion including a phosphor that converts the emission of the LED chip into light having a longer wavelength than that of the emission and covering at least a portion of the LED chip,

wherein the step (B) includes the step of forming at least one concave curved surface portion on the side surface of the optical wavelength converting portion which is recessed toward the LED chip.

15. The method of claim 14 , wherein the step (B) includes the steps of:

(b1) providing an isolated pattern of the material of the optical wavelength converting portion on the substrate; and

(b2) forming the concave curved surface portion by deforming the side surface of the isolated pattern.