Slotted substrates and techniques for forming same

Abstract

Techniques for fabricating an inkjet printhead include providing a printhead substrate, fabricating a thinfilm structure on the substrate, forming a break trench in a surface region of the substrate in which a feed slot is to be formed, and subsequently abrasively machining the substrate through the break trench to form the feed slot. The break trench can be formed by an etch process, prior to applying a barrier layer to the thinfilm structure in a preferred embodiment.

1 - 18 . (canceled)  
   
   
       19 . A fluid ejection device produced by a process, the process comprising: 
 fabricating a thinfilm structure on a device substrate;    forming a peripheral break trench structure in a first surface of the device substrate circumscribing a region in which a feed slot is to be formed through the substrate;    forming a guide break trench in the first surface within the peripheral break trench structure; and    subsequently abrasively machining the device substrate from a second surface of the substrate to the break trench structure to form the feed slot.    
   
   
       20 . The fluid ejection device of  claim 19  further comprising: 
 a barrier layer applied to the thinfilm structure after forming the break trench structure and before abrasively machining the substrate.    
   
   
       21 . The fluid ejection device of  claim 19  wherein the thinfilm structure is fabricated on the first surface of the substrate.  
   
   
       22 . The fluid ejection device of  claim 19  wherein the forming a break trench structure includes anisotropically etching the trench during a wet etch process.  
   
   
       23 . The fluid ejection device of  claim 19  wherein the guide break trench structure is formed to a depth deeper than a depth of the peripheral break trench structure.  
   
   
       24 . The fluid ejection device of  claim 23 , wherein the guide break trench structure is formed with a trench width greater than a width of the peripheral break trench structure.  
   
   
       25 . The fluid ejection device of  claim 19 , 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.    
   
   
       26 . A fluid ejection device produced by a method, the method comprising: 
 fabricating a thinfilm structure on a substrate;    forming a break trench structure in a first surface of the substrate, the thinfilm structure comprising a plurality of break trenches arranged along a slot axis;    subsequently abrasive 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 small substrate islands in areas separating the small feed slots.    
   
   
       27 . The fluid ejection device of  claim 26 , wherein the defining a plurality of small substrate islands comprises: 
 forming a mask structure defining the small substrate islands; and    etching the first surface through the mask structure to define the plurality of small substrate islands.    
   
   
       28 . The fluid ejection device of  claim 26 , 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.    
   
   
       29 . A fluid ejection device produced by a method, the method comprising: 
 fabricating a thinfilm structure on a substrate wafer for a plurality of fluid ejection devices to be formed on the wafer;    for each printhead to be formed, 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 for each fluid ejection device to be formed on the wafer;    applying a barrier layer to the thinfilm structure;    subsequently abrasively machining the wafer from a second surface of the substrate to the peripheral break trench structure to form the feed slot for each fluid ejection device to be formed on the wafer;    attaching an orifice plate structure for each fluid ejection device to be formed on the wafer;    sawing the wafer to separate individual fluid ejection devices; and    attaching the fluid ejection devices to device circuitry.    
   
   
       30 . The fluid ejection device of  claim 29 , wherein the wafer is a silicon substrate wafer, and the forming a peripheral break trench structure includes etching the silicon substrate wafer with a TMAH (Tetra Methyl Ammonium Hydroxide) wet etch process.  
   
   
       31 . A fluid ejection device comprising: 
 a thinfilm structure fabricated on a device substrate;    a peripheral break trench structure formed in a first surface of the device substrate circumscribing a region having a feed slot;    a guide break trench formed in the first surface within the peripheral break trench structure; and    a feed slot formed in the region.    
   
   
       32 . The fluid ejection device of  claim 31  where the feed slot is formed by subsequently abrasively machining the device substrate from a second surface of the substrate to the break trench structure to form the feed slot.