US 7,179,670 B2 · Flip-chip light emitting diode device without sub-mount

Abstract

A light emitting diode (10) has a backside and a front-side with at least one n-type electrode (14) and at least one p-type electrode (12) disposed thereon defining a minimum electrodes separation (delectrodes). A bonding pad layer (50) includes at least one n-type bonding pad (64) and at least one p-type bonding pad (62) defining a minimum bonding pads separation (dpads) that is larger than the minimum electrodes separation (delectrodes). At least one fanning layer (30) interposed between the front-side of the light emitting diode (10) and the bonding pad layer (50) includes a plurality of electrically conductive paths passing through vias (34, 54) of a dielectric layer (32, 52) to provide electrical communication between the at least one n-type electrode (14) and the at least one n-type bonding pad (64) and between the at least one p-type electrode (12) and the at least one p-type bonding pad (62).

Claims32

Dependent claims

A method of flip chip bonding a light emitting diode to a support, the light emitting diode having front-side n-type and p-type electrodes defining a minimum electrodes separation therebetween, the method including:

disposing a dielectric layer over at least the front-side of the light emitting diode, the dielectric layer sealing the n-type and p-type electrodes;
disposing a first-type electrical contact over vias through the dielectric layer that access a first-type electrode selected from the group consisting of the p-type electrode and the n-type electrode, the first-type electrical contact extending over the dielectric layer between the vias that access the first-type electrode to define a first-type contact pad;
disposing a second-type electrical contact over one or more vias through the dielectric layer that access a second-type electrode selected from the group consisting of the other of the p-type electrode and the n-type electrode, the second-type electrical contact extending over the dielectric layer to define a second-type contact pad, the first-type contact pad and the second-type contact pad defining a minimum contact pads separation therebetween that is larger than the minimum electrodes separation;
and
flip-chip bonding the first-type contact pad and the second-type contact pad to a substrate via bonding bumps disposed on at least one of the contact pads and the substrate.

2 more elements

A method of flip chip bonding a light emitting diode having front-side n-type and p-type electrodes defining a minimum electrodes separation between the n-type and p-type electrodes to mechanically secure the light emitting diode to a printed circuit board and to electrically connect the front-side n-type and p-type electrodes with printed circuitry of the printed circuit board, the method including:

disposing a dielectric layer over at least the n-type and p-type electrodes, the dielectric layer having vias passing therethrough, the vias including at least one via accessing the n-type electrode and at least one via accessing the p-type electrode;
disposing electrical contact pads over the vias and the dielectric layer, the electrical contact pads including a p-type contact pad connecting with the p-type electrode through the at least one via accessing the p-type electrode and an n-type contact pad connecting with the n-type electrode through the at least one via accessing the n-type electrode, the contact pads being arranged over the dielectric layer with a minimum contact pads separation between the p-type contact pad and the n-type contact pad that is larger than the minimum electrodes separation between the n-type and p-type electrodes;
and
flip-chip bonding the contact pads to printed circuitry of the printed circuit board using bonding bumps arranged on one of the printed circuit board and the chip, the flip-chip bonding having a mechanical tolerance that is greater than the minimum electrodes separation and less than the minimum contact pads separation, there being no sub-mount arranged between the contact pads and the printed circuit board.

1 more element

A method of processing a wafer having a plurality of light emitting diodes fabricated thereon, each light emitting diode having front-side n-type and p-type electrodes defining a minimum electrodes separation between the n-type and p-type electrodes, the method including:

disposing a dielectric layer over at least the n-type and p-type electrodes, the dielectric layer having vias passing therethrough for accessing the n-type and p-type electrodes;
disposing electrical contact pads over the vias and the dielectric layer, the electrical contact pads for each light emitting diode including a p-type contact pad that connects with the p-type electrode and an n-type contact pad that connects with the n-type electrode, the connecting being through the vias, the contact pads for each light emitting diode being arranged over the dielectric layer with a minimum contact pads separation between the p-type and n-type contact pads that is larger than the minimum electrodes separation between the n-type and p-type electrodes;
and
after the disposing of the electrical contact pads, dicing the wafer to separate the light emitting diodes.

1 more element

Dependencies are inferred from the claim text.

Flip-chip light emitting diode device without sub-mount

Life of this patent

Flip-chip light emitting diode device without sub-mount

Life of this patent

Abstract

Claims32