Method of manufacturing ink jet circuit board with heaters and electrodes constructed to reduce corrosion

A method of fabricating an ink jet head circuit board, said ink jet head circuit board having heaters to generate thermal energy for ejecting ink as they are energized, the method comprising the steps of:

• laying a SiC layer a substrate;
• forming on the substrate with the SiC layer first electrodes having a gap therebetween in which to form the heater, said first electrodes being formed of a corrosion resistant metal;
• forming a resistor layer on the first electrodes including the gap;
• forming on the first electrodes and the resistor layer a layer for second electrodes, the second electrodes having a greater thickness than that of the first electrodes;
• and then
• removing from the layer a gap portion larger than the gap of the first electrodes to form second electrodes, the gap portion having its ends situated over the first electrodes.

A method of fabricating an ink jet head circuit board, said ink jet head circuit board having heaters to generate thermal energy for ejecting ink as they are energized, the method comprising the steps of:

• forming on a substrate first electrodes having a gap therebetween in which to form the heater;
• forming a resistor layer on the first electrodes including the gap;
• partially removing the resistor layer over the first electrodes to split the resistor layer;
• forming on the first electrodes and the resistor layer a layer for second electrodes, the second electrodes having a greater thickness than that of the first electrodes;
• and then
• removing from the layer a gap portion larger than the gap of the first electrodes to form second electrodes, the gap portion having its ends situated over the first electrodes.

A method of fabricating an ink jet head circuit board, said ink jet head circuit board having heaters to generate thermal energy for ejecting ink as they are energized, the method comprising the steps of:

• forming on a substrate first electrodes having a gap therebetween in which to form the heater;
• forming a resistor layer on the first electrodes including the gap;
• forming on the first electrodes and the resistor layer a layer for second electrodes, the second electrodes having a greater thickness than that of the first electrodes;
• then
• removing from the layer a gap portion larger than the gap of the first electrodes to form second electrodes, the gap portion having its ends situated over the first electrodes;
• and
• laying an electrode wire layer over the second electrodes through a protective layer and electrically connecting it to the second electrodes.