An LED module is an assembly of LED packages or dies on a printed circuit board or substrate, configured in order that an LED substrate has thereon an LED chip and the LED chip is composed of an assembly member sealed by translucent resin. An LED module includes a printed circuit board or an SMD mount and at least one LED chip, which is attached to the board or the mount. The LED module may well incorporate optical elements (such as lenses) and additional thermal, mechanical, and electrical interfaces that are designed to connect to the load side of a LED driver. The lens covers the LED whereby light produced by the LED can have a desired pattern of distribution. The lens is fixed to the substrate by glue directly coated on a flat surface of the substrate. When an LED chip is provided with electric power and emits light, the LED chip has an increased temperature as a consequence of electric power not contributing to the light emission from the LED chip. In this situation, when the LED chip has insufficient heat dissipation measures, the LED chip fails or is broken. To maximize the capacity of an LED package to dissipate heat, in one LED package design, a heat sink slug is added into the package. The heat sink slug draws heat from the LED chip.