1. An LED module comprising:a substrate having a first thermal conductivity;
a plurality of LED dies electrically and thermally mounted on the substrate, wherein the LED dies are connected in parallel;
a wavelength conversion material having a second thermal conductivity substantially lower than the first thermal conductivity, the wavelength conversion material located overlying the LED dies;
a light transmitting top plate having a third thermal conductivity greater than the second thermal conductivity, the top plate being positioned over the wavelength conversion material; and
a hermetic seal formed by a sealant material between the top plate and the substrate surrounding the plurality of LED dies and wavelength conversion material,
the LED module having first flat sidewall edges around its periphery, the top plate having second flat sidewall edges around its periphery, and the substrate having third flat sidewall edges around its periphery, wherein the second flat sidewall edges and the third flat sidewall edges coincide to form the first flat sidewall edges of the LED module due to the top plate and the substrate being sealed during a wafer level process and the wafer then singulated to form the LED module,
the plurality of LED dies being located in a reflective single cavity formed in the substrate, the cavity having walls that surround all the LED dies, wherein the wavelength conversion material overlies the LED dies and at least partially fills the cavity,
wherein the wavelength conversion material is deposited into the cavity using the cavity as a mold for the wavelength conversion material, and wherein the top plate has one or more openings formed in it which are located directly over the cavity for depositing the wavelength conversion material into the cavity after the hermetic seal is formed.