Annealing apparatus

An annealing apparatus comprising:

• a plurality of light emitting diode (LED) arrays;
• a cooling member to which the LED arrays are fixed and made of aluminum or aluminum;
• a cooling unit configured to cool the cooling member by using a cooling medium;
• and
• a plurality of reflection plates,
• wherein each of the LED arrays is constituted as a single unit including
• a plurality of light emitting elements configured to emit lights to a target substrate to be processed,
• a supporter having a first surface on which the light emitting elements are mounted and a second surface opposite to the first surface, wherein the light emitting elements are mounted on the first surface by using a high thermally conductive first adhesive substance, and the supporter is made of a high thermally conductive insulating material,
• a thermal diffusion member adhered to the second surface of the supporter by using a high thermally conductive second adhesive substance, the thermal diffusion member being made of pyrolytic graphite,
• a reflection layer formed on the first surface of the supporter, and
• plural lens layers respectively covering the light emitting elements,
• wherein the LEDs array are fixed to the cooling member via a highly thermally conductive second adhesive substance;
• wherein the thermal diffusion member is adhered to the second surface of the supporter such that a thickness direction of the thermal diffusion member is identical to a direction in which a thermal conductivity of the pyrolytic graphite is high, and
• wherein, for a first LED array and a second LED array each of which comprising said single unit, a first reflection plate and a second reflection plate of the plurality of the reflection plates are respectively provided only along first and second sides of the first and second LED arrays, said first reflection plate is provided along at least one peripheral edge of the first LED array in a position adjacent a side of the second LED array where no reflection plate is provided.