1. A method, comprising:
disposing a sacrificial mask on a plurality of contact pads on a second level interconnect side of a coreless package substrate, the side being adapted to package-to-board interconnection;
forming a molded stiffener around the sacrificial mask without increasing the effective thickness of the substrate; and
removing the sacrificial mask to form a plurality of cavities in the molded stiffener corresponding to the contact pads.
2. The method of claim 1, wherein the sacrificial mask is a thermally decomposable and photoimagable polymer.
3. The method of claim 2, wherein the sacrificial mask is a polycarbonate-based polymer decomposable at around 180\xb0 C. and higher.
4. The method of claim 1, wherein the molded stiffener has a lower coefficient of thermal expansion and a higher flexural modulus than the coreless substrate.
5. The method of claim 4, wherein the molded stiffener has a coefficient of thermal expansion value at room temperature between 3 ppm\xb0 C. and 15 ppm\xb0 C. and flexural modulus value between 10 kNmm2 and 50 kNmm2.
6. The method of claim 1, wherein forming the molded stiffener comprises molding portions of the second level interconnect side not masked by the sacrificial mask with a molding compound.
7. The method of claim 6, further comprising curing the molding compound at around 125\xb0 C. and above.
8. The method of claim 7, wherein removing the sacrificial mask comprises thermally decomposing the sacrificial mask.
9. The method of claim 8, further comprising simultaneously curing the molding compound and thermally decomposing the sacrificial mask at around 180\xb0 C. and higher.
10. The method of claim 1, further comprising plating the surface of the contact pads and the sidewalls of the cavities with an electrically conductive surface finish.
11. The method of claim 10, further comprising:
patterning a photoimagable material on the molded stiffener other than on the surface of the contact pads and the sidewalls of the cavities; and
depositing the surface finish on the surface of the contact pads and the sidewalls of the cavities.
12. A method of forming a semiconductor substrate, comprising:
disposing sacrificial polymer layer on a second level interconnect side of a coreless package substrate, the side having a plurality of contact pads and being adapted to package-to-board interconnection;
patterning the sacrificial polymer layer to yield a plurality of polymer islands remaining on the contact pads;
molding the second level interconnect side to yield a stiffening layer planar with the polymer islands;
thermally decomposing the polymer islands to form a plurality of cavities in the stiffening layer; and
plating the surface of the contact pads and the sidewalls of the cavities with an electrically conductive surface finish.
13. The method of claim 12, wherein the sacrificial polymer is thermally decomposable at around 180\xb0 C. and higher.
14. The method of claim 13, wherein the stiffening layer contributes insignificant increase in the effective thickness of the coreless substrate.
15. The method of claim 14, wherein the stiffening layer has a lower coefficient of thermal expansion and a higher flexural modulus than the coreless substrate.
16. The method of claim 15, wherein the stiffening layer has a thickness about half the height of solder balls configured for connection with the contact pads.
17. The method of claim 16, further comprising removing residual polymer in the cavities.
18-20. (canceled)
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A LED directional illumination energy-saving luminaire, characterized in that, it comprises: a plane circuit board with an X direction and a Y direction defined; and illumination units comprising a plurality of LEDs mounted to said circuit board in a tilted state with LED bodies thereof being positioned at a predetermined height from the plane circuit board, and said plurality of LEDs are arranged at intervals in an array along said X direction and said Y direction and are symmetrically distributed with respect to the center of said array, each of said LEDs is deviated by a predetermined angle with respect to said X direction and said Y direction, thereby allowing said illumination units having predetermined projection angles in said X direction and said Y direction, respectively.
2. The LED directional illumination energy-saving luminaire according to claim 1, characterized in that, said illumination units comprise a first illumination unit located in the middle area of said circuit board and second illumination units that are symmetrically arranged at both sides of said first illumination unit, each of said illumination units comprises a plurality of LEDs mounted to said circuit board in a tilted state with LED bodies thereof being positioned at a predetermined height from the plane circuit board, said plurality of LEDs of each of said illumination units are arranged in an array with predetermined intervals therebetween along said X direction and said Y direction and are symmetrically distributed with respect to the center of said array, each of said LEDs is deviated by a predetermined angle with respect to said X direction and said Y direction, thereby allowing said illumination units having predetermined projection angles in said X direction and said Y direction, respectively.
3. The LED directional illumination energy-saving luminaire according to claim 1 or 2, characterized in that, the slantwise angle \u03b1n of each of said LEDs as viewed in the section which is perpendicular to the plane circuit board and extends along said X direction, is governed by the following formula:
\u03b1n=Arctg(tg55\xb7(n\u22120.5)(N2\u22120.5))
wherein: N is the total columns of said LEDs arranged along said X direction, and n is the sequence number of the column within which said LED is located, counted in the order from the center of the array of the LEDs towards the outside along said X direction; and
the slantwise angle \u03b2m of each of said LEDs as viewed in the section which is perpendicular to the plane circuit board and extends along said Y direction, is governed by the following formula:
\u03b2m=Arctg(W\xb7(m\u22120.5)MH)
wherein: W is the illumination width of said luminaire along said Y direction, M is the total rows of said LEDs arranged along said Y direction, m is the sequence number of the row within which said LED is located, counted in the order from the center of the array of the LEDs towards the outside along said Y direction, and H is the mounting height of said luminaire.
4. The LED directional illumination energy-saving luminaire according to claim 1 or 2, characterized in that, the projection angle of said illumination units in said X direction is 120 degrees.
5. The LED directional illumination energy-saving luminaire according to claim 1 or 2, characterized in that, said LED is a light-emitting diode with a projection angle less than or equal to 15 degrees.
6. The LED directional illumination energy-saving luminaire according to claim 1 or 2, characterized in that, said LED is a light-emitting diode with a luminous intensity higher than or equal to 20,000 mcd.
7. The LED directional illumination energy-saving luminaire according to claim 2, characterized in that, said circuit board is formed thereon with a first illumination unit mounting region and second illumination unit mounting regions, in said first illumination unit mounting region and said second illumination unit mounting regions there are respectively provided with a plurality of pairs of insertion holes that are arranged at intervals along said X direction and said Y direction respectively, the arranging direction of said pairs of insertion holes in said first illumination unit mounting region and that of said pairs of insertion holes in said second illumination unit mounting regions are perpendicular with each other, and said LEDs are inserted within said pairs of insertion holes of said circuit board and welded therein.
8. The LED directional illumination energy-saving luminaire according to claim 1 or 2, characterized in that, said plurality of LEDs of said illumination units are divided into multiple groups that can be independently controlled.
9. The LED directional illumination energy-saving luminaire according to claim 8, characterized in that, said circuit board has multiple groups of common power supply line patterns that are mutually independent, each group of said common power supply line patterns has an independent terminal.
10. The LED directional illumination energy-saving luminaire according to claim 9, characterized in that, said common power supply line pattern has a laterally widened portion with a square-wave-like profile.
11. The LED directional illumination energy-saving luminaire according to claim 1 or 2, characterized in that, it also comprises: a lamp body, which has a hollow shell formed by a pedestal and a transparent lampshade; and an apertured substrate for mounting said circuit board, as the substrate being provided within said shell and forming heat dissipation channels between itself both with said pedestal and with said transparent lampshade.
12. A method for manufacturing a LED directional illumination energy-saving luminaire, comprising the following steps:
Step 1: providing a plane circuit board with an X direction and a Y direction defined;
Step 2: mounting a plurality of LEDs on said circuit board at intervals along said X direction and said Y direction to form illumination units, with the body of each of said LEDs at a height of 8-10 mm from the plane circuit board;
Step 3, making the body of each of LEDs tilted and respectively deviated by a predetermined angle with respect to said X direction and said Y direction, so that said illumination units form predetermined projection angles in said X direction and said Y direction, respectively.