TFT substrate having compensation capacitance unit for change in capacitance formed between gate electrode and drain electrode

A Thin Film Transistor (TFT) substrate comprising:

• a plurality of pixels arranged in a matrix having a plurality of rows and a plurality of columns;
• a substrate;
• and
• a plurality of TFTs supported on the substrate and each connected to one of the plurality of pixels, wherein
• the TFT substrate includes
• a first conductive layer including gate electrodes of the plurality of TFTs,
• a gate insulating layer formed on the first conductive layer,
• a semiconductor layer formed on the gate insulating layer and including a channel region, a source region, and a drain region,
• a protective insulating layer including a portion which covers the channel region and having a first opening portion reaching the source region and a second opening portion reaching the drain region, and
• a second conductive layer formed on the protective insulating layer and including a source electrode which is formed on the protective insulating layer and in the first opening portion and which is in contact with the source region in the first opening portion, and a drain electrode which is formed on the protective insulating layer and in the second opening portion and which is in contact with the drain region in the second opening portion,
• each of the plurality of pixels has a compensation capacitance unit,
• the first conductive layer further includes a first electrode unit electrically connected to a respective gate electrode of one of the plurality of TFTs and forming the compensation capacitance unit,
• the second conductive layer further includes a second electrode unit electrically connected to the drain electrode, overlapping the first electrode unit, and forming the compensation capacitance unit, and
• the protective insulating layer further includes a third opening portion which does not overlap the semiconductor layer, which includes a first portion overlapping the first electrode unit and the second electrode unit and a second portion adjacent to the first portion in a direction from the second opening portion to the first opening portion, and which does not overlap the first electrode unit and/or the second electrode unit.