Liquid discharge head substrate, liquid discharge head using the substrate, and manufacturing method therefor

Abstract

Provided is a liquid discharge head substrate including: a substrate; a heating resistor layer formed on the substrate; a flow path for a liquid; a wiring layer stacked on the heating resistor layer and having an end portion which forms a step portion on the heating resistor layer; and a protective layer covering the heating resistor layer and the wiring layer including the step portion, and formed between the heating resistor layer and the flow path, in which the protective layer is formed by a Cat-CVD method.

1 . A liquid discharge head substrate, comprising: 
 a substrate;    a heating resistor layer formed on the substrate;    a flow path for a liquid;    a wiring layer stacked on the heating resistor layer and having an end portion which forms a step portion on the heating resistor layer; and    a protective layer covering the heating resistor layer and the wiring layer including the step portion, and formed between the heating resistor layer and the flow path,    wherein the protective layer is formed by a Cat-CVD method.    
   
   
       2 . A liquid discharge head substrate according to  claim 1 , wherein the protective layer comprises any one of an SiN film, an SiON film, an SiCN film, and an SiOC film.  
   
   
       3 . A liquid discharge head substrate according to  claim 1 , wherein the protective layer comprises an SiN film having a thickness of 100 nm to 500 nm.  
   
   
       4 . A liquid discharge head substrate according to  claim 1 , further comprising: 
 a common wiring formed by a plating method; and a protective layer formed on the common wiring by the Cat-CVD method.    
   
   
       5 . A liquid discharge head substrate according to  claim 4 , wherein the protective layer comprises an SiN film.  
   
   
       6 . A liquid discharge head, comprising the liquid discharge head substrate according to  claim 1 .  
   
   
       7 . A liquid discharge head substrate, comprising: 
 a substrate;    a heating resistor layer formed on the substrate;    a flow path for a liquid;    a wiring layer stacked on the heating resistor layer and having an end portion which forms a step portion on the heating resistor layer; and    a plurality of protective layers which covers the heating resistor layer and the wiring layer including the step portion, and is formed between the heating resistor layer and the flow path,    wherein the plurality of protective layers includes a protective layer closest to the flow path, which is formed by a Cat-CVD method.    
   
   
       8 . A liquid discharge head substrate according to  claim 7 , wherein the plurality of protective layers includes a protective layer closest to the heating resistor layer, which is formed by the Cat-CVD method.  
   
   
       9 . A liquid discharge head substrate according to  claim 8 , wherein the protective layer comprises a silicon-nitride-based film.  
   
   
       10 . A liquid discharge head substrate according to  claim 7 , wherein the protective layer closest to the heating resistor layer, of the plurality of protective layers, is formed by a plasma CVD method.  
   
   
       11 . A liquid discharge head substrate according to  claim 10 , wherein the protective layer comprises a silicon-based film.  
   
   
       12 . A liquid discharge head substrate according to  claim 8 , wherein the protective layer closest to the heating resistor layer, of the plurality of protective layers, is softer than a protective layer closest to the flow path.  
   
   
       13 . A liquid discharge head, comprising the liquid discharge head substrate according to  claim 7 .  
   
   
       14 . A method of manufacturing a liquid discharge head substrate, 
 the liquid discharge head substrate comprising:    a substrate;    a heating resistor layer formed on the substrate;    a flow path for a liquid;    a wiring layer stacked on the heating resistor layer and having an end portion which forms a step portion on the hating resistor layer; and    a protective layer covering the heating resistor layer and the wiring layer including the step portion, and formed between the heating resistor layer and the flow path,    the method comprising forming the protective layer by supplying at least a gas containing silicon and a gas containing nitrogen at a substrate temperature of 50° C. to 400° C. by a Cat-CVD method.    
   
   
       15 . A method of manufacturing a liquid discharge head substrate according to  claim 14 , wherein: 
 the protective layer comprises a plurality of layers; and    the plurality of layers includes a protective layer closest to the heating resistor layer which is formed at a substrate temperature that is a substrate temperature or higher for forming a protective layer closest to the flow path.    
   
   
       16 . A method of manufacturing a liquid discharge head substrate according to  claim 14 , further comprising forming another protective layer which covers the heating resistor layer and the wiring layer including the step portion by a plasma CVD method prior to formation of the protective layer.  
   
   
       17 . A method of manufacturing a liquid discharge head substrate, 
 the liquid discharge head substrate comprising:    a substrate;    a heating resistor layer formed on the substrate;    a flow path for a liquid;    a wiring layer stacked on the heating resistor layer and having an end portion which forms a step portion on the hating resistor layer; and    a protective layer covering the heating resistor layer and the wiring layer including the step portion, and formed between the heating resistor layer and the flow path,    the method comprising performing hydrogen treatment on the substrate when the protective layer is formed by supplying at least a gas containing silicon and a gas containing nitrogen at a substrate temperature of 350° C. to 400° C. by a Cat-CVD method.    
   
   
       18 . A method of manufacturing a liquid discharge head, comprising providing a flow path forming member having a discharge port for discharging a liquid, to a substrate manufactured by the method of manufacturing a liquid discharge head substrate according to  claim 14 .  
   
   
       19 . A method of manufacturing a liquid discharge head, comprising providing a flow path forming member having a discharge port for discharging a liquid, to a substrate manufactured by the method of manufacturing a liquid discharge head substrate according to  claim 17.