Selectively bonding light-emitting devices via a pulsed laser

Abstract

The invention is directed towards enhanced systems and methods for employing a pulsed photon (or EM energy) source, such as but not limited to a laser, to electrically couple, bond, and/or affix the electrical contacts of a semiconductor device to the electrical contacts of another semiconductor devices. Full or partial rows of LEDs are electrically coupled, bonded, and/or affixed to a backplane of a display device. The LEDs may be μLEDs. The pulsed photon source is employed to irradiate the LEDs with scanning photon pulses. The EM radiation is absorbed by either the surfaces, bulk, substrate, the electrical contacts of the LED, and/or electrical contacts of the backplane to generate thermal energy that induces the bonding between the electrical contacts of the LEDs' electrical contacts and backplane's electrical contacts. The temporal and spatial profiles of the photon pulses, as well as a pulsing frequency and a scanning frequency of the photon source, are selected to control for adverse thermal effects.

What is claimed is: 
     
         1 . A system for electrically coupling a first semiconductor device to a target substrate, the system comprising:
 a pick-up head that positions the first semiconductor device proximate to the target substrate, wherein an electrical contact of the first semiconductor device is spatially aligned with an electrical contact of the target substrate; and   a photon source that transmits a photon pulse with a temporal profile that is selected to control thermal effects associated with thermal energy induced by the photon pulse, the thermal energy bonding the electrical contact of the first semiconductor device to the electrical contact of the target substrate.   
     
     
         2 . The system of  claim 1  wherein the photon pulse is incident upon a top surface of the first semiconductor device. 
     
     
         3 . The system of  claim 1 , wherein the photon pulse is incident upon a bottom surface of the target substrate. 
     
     
         4 . The system of  claim 1 , wherein the temporal profile of the photon pulse is selected based on a spatial distance between the electrical contact of the first semiconductor device and another electrical contact of the first semiconductor device when the first semiconductor device is positioned proximate to the target substrate. 
     
     
         5 . The system of  claim 1 , wherein the pick-up head positions a linear array of semiconductor devices proximate to the target substrate, the linear array of semiconductor devices including the first semiconductor device, and wherein a spatial profile of the photon pulse is selected to localize the thermal effects to the first semiconductor device thereby maintaining the spatial alignment of the semiconductor devices in the linear array of semiconductor devices with electrical contacts of the target substrate. 
     
     
         6 . The system of  claim 1 , wherein the thermal effects are further controlled by selecting at least one of a scanning frequency of the photon source or a pulsing frequency of the photon source. 
     
     
         7 . The system of  claim 1 , wherein the thermal energy is induced by a plurality of photon pulses including the photon pulse and each of the plurality of photon pulses is comprised of photons of separate wavelengths. 
     
     
         8 . A method for electrically coupling a first semiconductor device to a target substrate, the method comprising:
 positioning the first semiconductor device proximate to the target substrate, wherein an electrical contact of the first semiconductor device is spatially aligned with an electrical contact of the target substrate; and   bonding the electrical contact of the first semiconductor device to the electrical contact of the target substrate, by a photon pulse with a temporal profile that is selected to control thermal effects associated with thermal energy induced by the photon pulse.   
     
     
         9 . The method of  claim 8 , wherein the photon pulse is incident upon a top surface of the first semiconductor device. 
     
     
         10 . The method of  claim 8 , wherein the photon pulse is incident upon a bottom surface of the target substrate. 
     
     
         11 . The method of  claim 8 , wherein the temporal profile of the photon pulse is selected based on a spatial distance between the electrical contact of the first semiconductor device and another electrical contact of the first semiconductor device when the first semiconductor device is positioned proximate to the target substrate. 
     
     
         12 . The method of  claim 8 , wherein positioning the first semiconductor device proximate to the target substrate positions a linear array of semiconductor devices. 
     
     
         13 . The system of  claim 12 , wherein the spatial profile of the photon pulse is selected to localize the thermal effects of the first semiconductor device, thereby maintaining the spatial alignment of the semiconductor devices in the linear array of semiconductor devices with the electrical contacts of the target substrate. 
     
     
         14 . The method of  claim 8 , wherein the thermal effects are further controlled by selecting a scanning frequency of the photon source. 
     
     
         15 . The method of  claim 8 , wherein the thermal effects are further controlled by selecting a pulsing frequency of the photon source. 
     
     
         16 . The method of  claim 8 , wherein the thermal energy is induced by a plurality of photon pulses including the photon pulse. 
     
     
         17 . The method of  claim 16 , wherein each of the plurality of photon pulses is comprised of photons of separate wavelengths. 
     
     
         18 . A method for electrically coupling a light emitting diode (LED) to a target substrate, the method comprising:
 positioning the LED proximate to the target substrate, wherein an electrical contact of the LED is spatially aligned with an electrical contact of the target substrate; and   bonding the electrical contact of the LED to the electrical contact of the target substrate, by a photon pulse with a temporal profile that is selected to control thermal effects associated with thermal energy induced by the photon pulse.   
     
     
         19 . The method of  claim 18 , wherein the temporal pulse is selected based on a spatial distance between the electrical contact of the LED and another electrical contact of the LED when the LED device is positioned proximate to the target substrate. 
     
     
         20 . The method of  claim 18 , wherein positioning the LED proximate to the target substrate positions a linear array of LEDs.