Light emitting module for a light emitting display
A light emitting module for a light emitting display, including a first backplane and a third backplane arranged in a stackup. The first backplane includes a thin film transistor (TFT) layer deposited on a first substrate, the TFT layer further including a plurality of light emitting elements, associated contact pads and conducting tracks. The third backplane is provided on top of the light emitting elements, includes cavities at the locations of the light emitting elements and comprises includes at least a ground layer and a power layer. The upper and lower layers of the third backplane are provided by alternatively the ground layer and the power layer for contacting the light emitting elements.
1 . A light emitting module for a light emitting display, comprising:
a first backplane and a third backplane arranged in a stackup,
wherein the first backplane comprises a thin film transistor (TFT) layer deposited on a first substrate, the thin film transistor layer further comprising a plurality of light emitting elements, associated contact pads, conducting tracks and semiconductor material,
the third backplane is provided on top of the light emitting elements, wherein the third backplane comprises cavities at the locations of the light emitting elements and at least a ground layer and a power layer, arranged each alternatively as a lower layer or an upper layer of the third backplane, wherein the lower layer is arranged on top of the thin film transistor layer of the first backplane, the lower and upper layers being configured to provide power to the light emitting elements.
2 . The light emitting module according to claim 1 , wherein the upper layer is the power layer, the lower layer is the ground layer or wherein the upper layer is the ground layer and the lower layer is the power layer.
3 . The light emitting module according to claim 1 , wherein an insulating layer is provided between the upper layer and the lower layer.
4 . The light emitting module according to claim 1 , wherein the cavities are metalized for connecting the upper layer to the lower layer, and/or wherein each cavity is surrounded by an insulating ring thereby providing an isolated island around each cavity, such that the functionality of the upper layer is transmitted to the isolated island, the isolated island thereby comprising the power if the upper layer is the power layer or the ground if the upper layer is the ground layer.
5 . The light emitting module according to claim 1 , wherein conducting tracks of the light emitting elements connect each contact pad to a ground connection and a power connection, said ground and power connection configured to be in contact with the lower layer and the isolated island or the opposite.
6 . The light emitting module according to claim 1 , wherein the third backplane further comprises intermediate conducting layers.
7 . The light emitting module according to claim 6 , wherein the intermediate conducting layers are any one of a scanning line layer, a R data layer, a G data layer, and a B data layer.
8 . The light emitting module according to claim 6 , wherein the cavities are metalized for connecting the upper layer and the intermediate layers to the lower layer and/or are funnel shaped.
9 . The light emitting module according to claim 8 , wherein the lower layer comprises an isolated island around each cavity, the isolated island being surrounded by an insulating ring, and the isolated islanded being configured to connect to another layer by means of the metalized cavity wall and/or wherein the layers which are to be connected by the metalized cavity wall to the lower layer comprise an isolated island on the layer around the cavity wall.
10 . The light emitting module according to claim 8 , wherein an insulating ring is provided around the metalized cavity wall on the layers not to be connected.
11 . The light emitting module according to claim 1 , wherein the signals are routed to at least one layer of the third backplane by side connections.
12 . The light emitting module according to claim 1 , wherein the third backplane is a PCB backplane.
13 . The light emitting module according to claim 1 , wherein a pixel is composed of a red, a green and a blue sub-pixel, the sub-pixels being provided by light emitting elements.
14 . The light emitting module according to claim 1 , wherein the first substrate is made of an insulating material configured to receive the TFT layer.
15 . The light emitting module according to claim 1 , wherein the light emitting elements are any one of LEDs, OLEDs, QD-LEDs, EL-QLEDs, AMOLEDs, mini-LEDs, or micro-LEDs.
16 . The light emitting module according to claim 1 , wherein the cavities are used for providing at least one secondary optics, wherein the at least one secondary optics includes quantum dots, light scattering means, contrast enhancing means, light directivity means, light absorbing particles, polarization filters.
17 . The light emitting module according to claim 16 , wherein the quantum dots and appropriate blue/UV light emitting elements are provided for any one of the red and/or the green and/or the blue color.
18 . The light emitting module according to claim 16 , wherein all light emitting elements are identical, and the quantum dot fillings are configured to provide any of red and/or green and/or blue colors.
19 . The light emitting module according to claim 1 , wherein the upper layer of the third backplane is covered by a black mask.
20 . The light emitting module according to claim 19 , wherein the additional layers are provided by a printed circuit board (PCB) multilayer stack up.
21 . The light emitting module according to claim 1 , wherein the third backplane is connected to the first backplane by means of any one of anisotropic conductive film (ACF), conductive glue, nano entanglements, or solder ball.
22 . The light emitting module according to claim 1 , wherein the surface of the third backplane is greater than the surface of the first backplane and/or wherein the third backplane is provided by the core of a multi layer PCB and/or wherein the thickness of the PCB core laminate is comprised in the range of 50 to 300 microns and/or wherein the diameter of the cavities is larger than the diameter of the light emitting elements.
23 . The light emitting module according to claim 1 , wherein a solder mask is printed on the upper surface of the third backplane.
24 . The light emitting module according to claim 1 , further comprising a second backplane, wherein the second backplane is arranged in the back of the first substrate of the first backplane, opposite the third backplane, wherein the second backplane is configured to provide at least driving currents and/or power supply to the light emitting elements.
25 . The light emitting module according to claim 24 , wherein the second backplane is connected to the first backplane by means of a flexible PCB, and/or nano entanglements arranged on the side and/or wherein the second backplane is connected to the third backplane by means of a flexible PCB and is configured to transmit at least one of power signals, data signals, ground.
26 . The light emitting module according to claim 24 , wherein the first backplane further comprises first contact pads for contacting the light emitting elements, and associated conducting tracks, the second backplane comprises second contact pads configured to provide driving currents and/or power supply to the first contact pads of the light emitting elements, wherein the first backplane further comprises through holes provided in the first substrate at the locations of each first contact pad, and wherein first electrical binding means are provided in the through holes of the first backplane and second electrical binding means are provided on the second contact pads of the second backplane the first and second electrical binding means being connected such that driving currents and/or power supply from the second backplane are transmitted to the first backplane.
27 . A display module comprising the light emitting module according to claim 1 .
28 . A tiled display comprising at least one display module according to claim 27 .