LED device and method by which it is produced
A LED device formed of LED chips bonded to an exoergic member by the LED chips being bonded to an Au—Sn alloy layer formed on an upper surface of the exoergic member with columnar crystals being formed within the Au—Sn alloy layer extending in a direction perpendicular to the upper surface of the exoergic member. The method of producing the LED device forms an Sn film directly on the upper surface of the exoergic member, an Au film on a lower surface of the LED chips, mounts the LED chips with the Au film thereon onto the Sn film formed on the upper surface of the exoergic member, and the exoergic member with LED chips mounted thereon is heated in an atmosphere in which a forming gas flows, so that the LED chips are bonded to the exoergic member.
1. An LED device, comprising an LED chip that has been bonded to an Au—Sn alloy layer formed on an upper surface of an exoergic member, columnar crystals being formed within the Au—Sn alloy layer extending in a direction perpendicular to the upper surface of the exoergic member.
2. An LED device as described in claim 1 , in which multiple LED chips are bonded to said exoergic member.
3. An LED device as described in claim 2 , wherein at least one of the LED chips has a nitride semiconductor layer stacked on an upper surface of a sapphire substrate and wherein a lower surface of the sapphire substrate is bonded to the exoergic member.
4. An LED device as described in claim 2 , in which said exoergic member comprises a silicon substrate, and a red light-emitting LED, a green light-emitting LED and a blue light-emitting LED, each of said light-emitting LEDs having been bonded to the upper surface of the silicon substrate.