Method for producing a circuit board having LEDs and printed reflector surfaces, and circuit board produced according to the method
The invention relates to a circuit board having a light source for illumination purposes, having at least one LED electrically conductively connected to conductors of the circuit board, and the light thereof being converted into directed light by means of at least one mirror disposed on the circuit board, characterized in that the mirror is designed as a reflective coating printed onto the circuit board.
1. A method for the production of a circuit board having a reflective coating and at least one electroconductively contacted LED, whereby the reflective coating is printed onto a surface of the circuit board and a protective coating comprising one of a partially transparent and a transparent cover layer is printed onto the reflective coating by means of inkjet printing, wherein on the surface of the circuit board, first a base layer is applied with inkjet printing before the reflective coating is applied, whereby the reflective coating comprises an oxide layer with a noble metal, the method comprising:
a) exposing an uppermost conductor layer to form a recess for the purpose of exposing the underlying circuit board substrate and creating an installation surface for the LED;
b) disposing an electroconductive bonding surface in the neighborhood of the installation surface for the LED;
c) applying a solder mask onto the uppermost conductor layer;
d) printing of the base layer;
e) printing the reflective coating in a surrounding region of the installation surface for the LED and the bonding surface by means of inkjet printing; and
f) printing the cover layer at least partially covering the reflective coating.
2. The method according to claim 1 , wherein the base layer is three-dimensional in shape.
3. The method according to claim 2 , further comprising the step of forming, during a lamination process of the circuit board, a plurality of one of three-dimensional rises and depressions in the conductor layer at the location of the reflective coating to be applied later.
4. The method according to claim 2 , wherein the step of printing the reflective coating comprises the steps of: priming a silver layer and subsequently applying an electroplating with copper.
5. The method according to claim 2 , further comprising the step of smoothing out the reflective coating after application the step of electropolishing.
6. The method according to claim 2 , wherein the reflective coating is bowed in one of a convex and a concave shape.
7. The method according to claim 2 , further comprising the step of three-dimensionally shaping, the circuit board at least at the location of the reflective coating.
8. The method according to claim 1 , further comprising the step of forming, during a lamination process of the circuit board, a plurality of one of three-dimensional rises and depressions in the conductor layer at the location of the reflective coating to be applied later.
9. The method according to claim 1 , wherein the step of printing the reflective coating comprises the steps of: priming a silver layer and subsequently applying an electroplating with copper.
10. The method according to claim 1 , wherein the step of printing the reflective coating comprises the step of creating the reflective coating by means of a structured photo exposure.
11. The method according to claim 1 , further comprising the step of smoothing out the reflective coating after application the step of electropolishing.
12. The method according to claim 1 , wherein the reflective coating is bowed in one of a convex and a concave shape.
13. The method according to claim 1 , further comprising the step of three-dimensionally shaping, the circuit board at least at the location of the reflective coating.
14. The method according to claim 13 , wherein the step of shaping the circuit board comprises shaping a curvature of the circuit board at a location of the reflective coating.
15. The method according to claim 13 , wherein the step of shaping the circuit board comprises application processing in the form of ink jet printing a curvature of the circuit board at a location of the reflective coating.
16. The method according to claim 1 , wherein the printed reflective coating has a plurality of inclined slanted walls and the method further comprises the step of printing thereon an insulation layer likewise slanted towards the recess to form a plurality of inclined walls such that it forms, as a whole, inclined walls of a mirror.
17. The method according to claim 1 , wherein the step of printing the reflective coating comprises printing with a quickly hardening ink that runs during the step of printing with a quickly hardening ink in the region of a plurality of inclined walls, thereby forming inclined reflective surfaces, having a focusing effect on the LED, and wherein the step of installing the LED on the circuit board comprises the step of installing the LED in a region of the recess.
18. The method according claim 1 , wherein the method further comprises the step of covering the LED by a color conversion layer.
19. The method according to claim 1 , wherein the step of installing the LED on the circuit board comprises installing a plurality of LEDs on the circuit board and wherein the method further comprises the step of covering the plurality of LEDs each with a separate color conversion.
20. A circuit board, comprising:
a reflective coating and at least one electroconductively contacted LED, whereby the reflective coating is printed onto a surface of the circuit board and a protective coating comprising one of a partially transparent and a transparent cover layer is printed onto the reflective coating by means of inkjet printing, wherein on the surface of the circuit board, first a base layer is applied with inkjet printing before the reflective coating is applied, whereby the reflective coating comprises an oxide layer with a noble metal, and further comprising:
an uppermost conductor layer forming a recess for the purpose of exposing the underlying circuit board substrate and creating an installation surface for installing the LED on the circuit board;
an electroconductive bonding surface in the neighborhood of the installation surface for the LED;
a solder mask applied onto the uppermost conductor layer;
the reflective coating is printed on a surrounding region of the installation surface for the LED and the bonding surface; and
the cover layer is at least partially covering the reflective coating.
21. A circuit board according to claim 20 , wherein the reflective coating comprises a quick drying ink composition comprising an ink having non-metallic pigments.