Methods of fabricating fluid ejection devices
View Patent ↗In one example embodiment, a method of fabricating a fluid ejection device is provided. The method can including fabricating a thinflim structure on a device substrate and forming a peripheral break trench structure in a first surface of the substrate circumscribing a region in which a feed slot is to be formed through the substrate. Subsequently the substrate can be abrasively machined from a second surface of the substrate to the break trench structure to form the feed slot.
1. A method of fabricating a fluid ejection device, comprising:
fabricating a thinfilm structure on a device substrate;
forming a peripheral break trench structure in a first surface of the substrate circumscribing a region in which a feed slot is to be formed through the substrate;
forming a guide break trench in said first surface within the peripheral break trench structure; and
subsequently abrasively machining the substrate from a second surface of the substrate to the break trench structure to form the feed slot.
2. The method of claim 1 further comprising:
applying a barrier layer to the thinfilm structure after forming the break trench structure and before abrasively machining the substrate.
3. The method of claim 1 wherein said fabricating the thinfilm structure includes fabricating the thinfilm structure on said first surface of the substrate.
4. The method of claim 1 wherein said forming a break trench structure includes anisotropically etching the trench during a wet etch process.
5. The method of claim 1 , wherein said guide break trench structure is formed to a depth deeper than a depth of said peripheral break trench structure.
6. The method of claim 5 , wherein the guide break trench structure is formed a trench width greater than a width of the peripheral break trench structure.
7. The method of claim 1 , wherein the substrate is a silicon substrate and wherein said forming a break trench structure includes:
etching the silicon substrate with a TMAH (Tetra Methyl Ammonium Hydroxide) wet etch process.
8. The method of claim 1 , further comprising:
fabricating the thinfilm structure on the device substrate for a plurality of fluid ejection devices to be formed on the substrate, where the substrate is a wafer;
attaching an orifice plate structure for each of the fluid ejection devices to be formed on the wafer;
sawing the wafer to separate individual fluid ejection devices; and
attaching the fluid ejection devices to device circuitry on the wafer.
9. A method of fabricating a fluid ejection device, comprising:
fabricating a thinfilm structure on a device substrate;
forming a break trench structure in a first surface of the substrate, said structure comprising a plurality of small break trenches arranged along a slot axis;
subsequently abrasively machining the substrate from a second surface of the substrate to the plurality of break trenches to form a plurality of small feed slots through the substrate; and
defining a plurality of the small substrate islands in areas separating the small slots.
10. The method of claim 9 , wherein said defining a plurality of small substrate islands comprises:
forming a mask structure defining the islands;
etching the first surface through the mask structure to define the plurality of small substrate islands.
11. The method of claim 9 , wherein said substrate is a silicon substrate, and wherein said forming a break trench structure includes:
etching the silicon substrate with a TMAH (Tetra Methyl Ammonium Hydroxide) wet etch process.