Backlight unit and display device

A backlight unit configured for illuminating a rear of a transmissive display panel with light, comprising:

• a chassis;
• a plurality of light source substrates, each having a light source configured to face the rear of the display panel;
• a base member made of sheet metal on one side of which the light source substrates are mounted and which is fixed to a rear of the chassis;
• and
• a plurality of heat pipes attached to an opposite side of the base member and configured to receive via the base member heat generated by the light sources,
• wherein,
• the heat pipes are located in registry with the light sources,
• the base member has a lengthwise direction and is corrugated to have (a) a plurality of groove portions extending in the lengthwise direction and (b) a plurality of alternating upper and lower planes,
• the light source substrates extend in the lengthwise direction and are mounted on top of respective upper planes of the base member, and
• the heat pipes extend in the lengthwise direction of the light source substrates under the respective upper planes.