Method and apparatus for the formation of conductive films on a substrate
View Patent ↗Provided herein are a method and apparatus for the formation of conductive films on a substrate using precise sintering of a conductive film and thermal management of the substrate during sintering. In particular, a method may include depositing a conductive metal-based ink on a translucent or transparent substrate, positioning a mask between the deposited conductive metal-based ink and a light source, exposing the mask and the underlying deposited conductive metal-based ink to the light source, sintering the conductive metal-based ink exposed to the light source, and cleaning the non-sintered conductive metal-based ink from the translucent or transparent substrate. The mask may be configured to shield at least a portion of the conductive metal-based ink from the light source. The portion of the conductive metal-based ink shielded from the light source may remain non-sintered in response to the sintering of the conductive metal-based ink exposed to the light source.
1. A method comprising:
depositing a conductive metal-based ink on a translucent substrate;
positioning a mask between the deposited conductive metal-based ink and a light source, wherein the mask comprises a gradient light filter;
exposing the gradient light filter mask and the underlying deposited conductive metal-based ink to the light source;
causing the conductive metal-based ink exposed to the light source to become at least partially sintered in response to being partially shielded from the light source by the gradient light filter mask; and
cleaning non-sintered conductive metal-based ink from the translucent substrate.
2. The method of claim 1 , wherein the mask is configured to shield at least a portion of the conductive metal-based ink from the light source, and wherein the portion of the conductive metal-based ink shielded from the light source remains non-sintered in response to the sintering of the conductive metal-based ink exposed to the light source.
3. The method of claim 2 , wherein the mask is configured to be positioned between one millimeter and ten millimeters above the deposited conductive metal-based ink.
4. The method of claim 2 , wherein the conductive metal-based ink exposed to the light source is sintered and has a first electrical conductivity, and wherein the portion of the conductive metal-based ink shielded from the light source has a second electrical conductivity which is lower than the first electrical conductivity.
5. The method of claim 1 , wherein the light source comprises a visible light source with an emission spectrum of between about 200 nanometers and about 900 nanometers.
6. The method of claim 1 , wherein the gradient filter comprises a gradient haze quartz mask.
7. The method of claim 1 , further comprising:
providing for a cooling stream of air proximate the translucent substrate.
8. An apparatus comprising:
a flash lamp;
a reflector disposed about at least a portion of the flash lamp, wherein the reflector is configured to cooperate with a xenon flash lamp to focus emitted energy from the flash lamp to a line on a substrate;
a mask positioned between the flash lamp and the substrate, wherein the mask is configured to shield at least a portion of the substrate from the flash lamp, wherein the mask comprises a gradient mask, and wherein at least a portion of an emitted energy from the flash lamp is configured to pass through at least a portion of the gradient mask; and
a blower configured to direct a cooling stream of air proximate the line on the substrate.
9. The apparatus of claim 8 , wherein the line on the substrate is about 2 centimeters wide by about 25 centimeters long.
10. The apparatus of claim 8 , wherein the flash lamp comprises a xenon flash lamp having an emission spectrum of between about 200 nanometers and about 900 nanometers.
11. The apparatus of claim 8 , further comprising a controller configured to control a pulse frequency, a pulse duration, and an irradiation time of the flash lamp.
12. The apparatus of claim 11 , wherein a pulse frequency range is about 1 Hertz to about 50 Hertz.
13. The apparatus of claim 12 , wherein a pulse duration range is about 10 microseconds to about 5 milliseconds.
14. The apparatus of claim 8 , wherein the gradient mask comprises a gradient haze quartz mask.
15. The apparatus of claim 8 , further including a controller and temperature sensor, wherein the controller is configured to adjust a flow rate of the cooling stream of air in response to a temperature sensed by the temperature sensor.