A submount comprising a chip mounting area, a first bonding pad and a connecting portion is provided. An LED chip is mounted on the chip mounting area. The first bonding pad is electrically connected to an electrode of the LED chip. The connecting portion has a first hollow portion and is disposed between the chip mounting area and the first bonding pad. The first hollow portion is located between the chip mounting area and the first bonding pad. The first hollow portion is located in a central region of the connecting portion.
