Substrate and method of forming substrate for fluid ejection device

Abstract

A method of forming an opening through a substrate having a first side and a second side opposite the first side includes abrasive machining a first portion of the opening into the substrate from the second side toward the first side, and abrasive machining a second portion of the opening into the substrate from the first side toward the second side. Abrasive machining one of the first or second portion includes communicating the first or second portion with the. other of the first or second portion to form the opening through the substrate.

1 - 22 . (canceled)  
   
   
       23 . A substrate for a fluid ejection device, the substrate comprising: 
 a first side;    a second side opposite the first side; and    a fluidic channel communicated with the first side and the second side, the fluidic channel including a first portion communicated with the first side, a second portion communicated with the second side, and a neck between the first portion and the second portion, wherein the neck defines a minimum dimension of the fluidic channel.    
   
   
       24 . The substrate of  claim 23 , wherein a maximum dimension of the first portion of the fluidic channel is greater than a maximum dimension of the second portion of the fluidic channel.  
   
   
       25 . The substrate of  claim 24 , wherein the first portion of the fluidic channel includes a first region defined in part by the maximum dimension of the first portion and a second region defined in part by the minimum dimension of the neck.  
   
   
       26 . The substrate of  claim 25 , wherein the first region includes first concave sidewalls and the second region includes second concave sidewalls.  
   
   
       27 . The substrate of  claim 25 , wherein the first region converges from the second side toward the first side at a first gradient and the second region converges from the first region toward the first side at a second gradient greater than the first gradient.  
   
   
       28 . The substrate of  claim 23 , wherein the second portion of the fluidic channel includes at least one region defined in part by the minimum dimension of the neck.  
   
   
       29 . The substrate of  claim 28 , wherein the at least one region includes concave sidewalls.  
   
   
       30 . The substrate of  claim 28 , wherein the at least one region diverges from the neck toward the first side.  
   
   
       31 . The substrate of  claim 23 , wherein the first portion of the fluidic channel includes concave sidewalls.  
   
   
       32 . The substrate of  claim 31 , wherein the second portion of the fluidic channel includes concave sidewalls.  
   
   
       33 . A substrate for a fluid ejection device, the substrate comprising: 
 a first side;    a second side opposite the first side; and    a fluidic channel communicated with the first side and the second side, the fluidic channel including a first region having first concave sidewalls and a second region having second concave sidewalls.    
   
   
       34 . The substrate of  claim 33 , wherein the fluidic channel further includes a third region having third concave sidewalls, wherein the first concave sidewalls are contiguous with the second concave sidewalls and the second concave sidewalls are contiguous with the third concave sidewalls.  
   
   
       35 . The substrate of  claim 34 , wherein the first concave sidewalls communicate with the second side of the substrate.  
   
   
       36 . The substrate of  claim 33 , wherein a minimum dimension of the fluidic channel is defined at an interface of the first region and the second region.  
   
   
       37 . The substrate of  claim 36 , wherein a maximum dimension of the fluidic channel is defined at the second side of the substrate.  
   
   
       38 . The substrate of  claim 36 , wherein the first region of the fluidic channel communicates with the second side of the substrate and the second region of the fluidic channel communicates with the first region of the fluidic channel.  
   
   
       39 - 43 . (canceled)