1. A method of manufacturing an inkjet printhead, comprising:
forming a nozzle plate on a top surface of a top portion of a substrate;
forming a heater on the nozzle plate;
forming electrodes electrically connected to a heater on the nozzle plate;
forming a nozzle by etching the nozzle plate;
forming a manifold by etching a bottom portion of the substrate to a predetermined depth, and forming a channel-forming layer on a bottom surface of the etched bottom portion of the substrate;
forming a substantially cylindrical ink chamber by etching the substrate exposed through the nozzle; and
forming an ink channel in the channel-forming layer to communicate between the ink chamber and the manifold.
2. The method of claim 1, wherein the forming of the channel forming layer comprises forming a first material layer on the etched bottom surface of the substrate to form a bottom of the ink chamber.
3. The method of claim 2, wherein the forming of the first material layer comprises forming a silicon oxide layer by depositing silicon oxide on the etched bottom surface of the substrate by PECVD (Plasma Enhanced Chemical Vapor Deposition).
4. The method of claim 2, wherein the forming of the substantially cylindrical ink chamber comprises isotropically etching the top portion of the substrate exposed through the nozzle using the first material layer as an etch stop layer.
5. The method of claim 2, wherein the forming of the substantially cylindrical ink chamber comprises:
forming a trench by anisotropically etching the top portion of the substrate exposed through the nozzle;
depositing a material layer over the entire surface of the anisotropically etched top portion of the substrate to a predetermined thickness;
exposing a bottom of the trench by aniostropically etching the material layer and simultaneously forming a nozzle guide of the material layer along a side wall of the trench; and
forming the substantially cylindrical ink chamber by isotropically etching the exposed substrate through the bottom of the trench using the first material layer as an etch stop layer.
6. The method of claim 4, wherein the isotropically etching of the substrate comprises isotropically dry etching using a XeF2 gas as an etching gas.
7. The method of claim 2, wherein the forming of the channel-forming layer comprises forming a second material layer on the first material layer opposite to the ink chamber as a buffer layer of the first material layer.
8. The method of claim 7, wherein the forming of the second material layer comprises forming a polycrystalline silicon layer by depositing polycrystalline silicon on the first material layer.
9. The method of claim 7, wherein the forming of the substantially cylindrical ink chamber comprises:
forming a trench by anisotropically etching the top portion of the substrate exposed through the nozzle;
depositing a material layer over the entire surface of the anisotropically etched top portion of the substrate to a predetermined thickness;
exposing a bottom of the trench by aniostropically etching the predetermined material layer and simultaneously forming a nozzle guide of the predetermined material layer along a side wall of the trench; and
forming the substantially cylindrical ink chamber by isotropically etching the exposed substrate through the bottom of the trench using the first material layer as an etch stop layer.
10. The method of claim 7, wherein the forming of the substantially cylindrical ink chamber comprises isotropically etching the substrate exposed through the nozzle using the first material layer as an etch stop layer.
11. The method of claim 10, wherein the isotropically etching of the substrate comprises isotropically dry etching using an XeF2 gas as an etching gas.
12. The method of claim 1, wherein the forming of the ink channel comprises etching the channel forming layer from the manifold to the ink chamber by RIE (Reactive Ion Etching).
13. The method of claim 1, wherein the forming of the ink channel comprises processing the ink channel-forming layer in a direction from the manifold to the ink chamber by laser processing.
14. The method of claim 1, wherein the forming of the substantially cylindrical ink channel comprises forming a plurality of ink channels.
15. The method of claim 14, wherein the ink channels are arranged in the ink chamber at equal intervals along a circumference having a predetermined radius.
16. The method of claim 14, wherein the forming of the ink channels comprises etching the channel-forming layer from the manifold to the ink chamber by RIE (Reactive Ion Etching).
17. The method of claim 14, wherein the forming of the ink channels comprises processing the ink channel-forming layer in a direction from the manifold to the ink chamber by a laser processing.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A system, comprising:
an underwater assembly, comprising:
a flow control device: and
an actuator coupled to the flow control device, wherein the actuator is configured to actuate the flow control device;
an insulated housing surrounding the flow control device and the actuator, wherein the insulated housing is configured to retain heat; and
a thermal control system comprising a heat exchanger configured to control a temperature of the actuator.
2. The system of claim 1, wherein the heat exchanger comprises a heat exchanger volume isolated from an interior of the insulated housing, and the thermal control system is configured to circulate a fluid through the heat exchanger volume.
3. The system of claim 2, wherein the thermal control system comprises an inlet passage extending from an exterior through a wall of the insulated housing, through the interior of the insulated housing, and to an inlet of the heat exchanger.
4. The system of claim 3, wherein the thermal control system comprises an outlet passage extending from an outlet of the heat exchanger, through the interior of the insulated housing, and through the wall to the exterior of the insulated housing.
5. The system of claim 4, comprising a valve coupled to the outlet passage, wherein the thermal control system is configured to open or close the valve in response to at least one temperature threshold.
6. The system of claim 5, wherein the valve comprises a thermally actuated valve unit having a thermal actuator coupled to a valve mechanism, and the thermal actuator is configured to open or close the valve mechanism in response to the at least one temperature threshold.
7. The system of claim 5, wherein the thermal control system comprises an actuation system configured to open or close the valve in response to the at least one temperature threshold, wherein the actuation system comprises a temperature sensor, a controller, and an actuator.
8. The system of claim 2, wherein the heat exchanger comprises a coil disposed about the actuator, and the coil is configured to circulate the fluid.
9. The system of claim 2, wherein the heat exchanger comprises a plurality of fins coupled to the actuator and a conduit coupled to the plurality of fins, and the conduit is configured to circulate the fluid.
10. The system of claim 2, wherein the heat exchanger comprises a jacket disposed about and coupled to the actuator, and the jacket defines a volume configured to circulate the fluid.
11. The system of claim 2, wherein the thermal control system comprises a pump configured to force circulation of the fluid through the heat exchanger volume.
12. The system of claim 2, wherein the fluid comprises sea water that enters the heat exchanger volume from an exterior of the insulated housing.
13. A system, comprising:
an underwater thermal control system, comprising:
a heat exchanger configured to control a temperature of an actuator disposed in an insulated housing;
an inlet passage configured to pass a water flow from an exterior of the insulated housing into the heat exchanger;
an outlet passage couple configured to pass the water flow from the heat exchanger to the exterior of the insulated housing; and
a valve coupled to the outlet passage, wherein the valve is configured to open and close to control circulation of the water flow through the inlet passage, the heat exchanger, and the outlet passage based on temperature feedback.
14. The system of claim 13, comprising a thermostat configured to operate the valve based on a comparison of the temperature feedback to at least one temperature threshold.
15. The system of claim 14, wherein the thermostat comprises a temperature sensor, a controller, and a valve actuator coupled to the valve
16. The system of claim 15, wherein the thermostat is configured to operate a pump to force the water flow through the heat exchanger.
17. The system of claim 13, comprising a mineral extraction component having the actuator.
18. A method, comprising:
sensing a temperature at or above an upper threshold temperature within an insulated underwater housing that contains an actuator coupled to a flow control device;
initiating a flow of water from a surrounding water through a heat exchanger within the insulated underwater housing if the temperature is at or above the upper threshold temperature;
sensing the temperature at or below a lower threshold temperature within the insulated underwater housing; and
terminating the flow of water through the heat exchanger if the temperature is at or below the lower threshold temperature.
19. The method of claim 18, comprising maintaining the temperature of an underwater mineral extraction component within a temperature range, wherein the underwater mineral extraction component comprises the insulated underwater housing, the actuator, and the flow control device.
20. The method of claim 19, wherein initiating the flow of water comprises opening a valve to enable the flow by natural buoyancy and temperature differences between the heat exchanger and the water surrounding the insulated underwater housing.