What is claimed is:1. An electronic device module, comprising:a substrate;an exothermic device disposed on a first surface of the substrate;a sealing portion embedding the exothermic device disposed on the first surface of the substrate; anda heat radiating portion at least partially embedded in the sealing portion,wherein a lower surface of the heat radiating portion is bonded to one surface of the exothermic device, a side surface of the heat radiating portion is curved and is entirely in contact with the sealing portion, and a plurality of grooves are disposed in the side surface of the heat radiating portion.2. The electronic device module of claim 1, wherein the heat radiating portion comprises an exposed surface exposed to an outside of the sealing portion and opposing the lower surface of the heat radiating portion.3. The electronic device module of claim 2, wherein the heat radiating portion has a horizontal cross-section area increasing toward the exposed surface.4. The electronic device module of claim 3, wherein the side surface of the heat radiating portion is inclined.5. The electronic device module of claim 3, further comprising an electronic component mounted on the substrate in a position adjacent to the exothermic device,wherein a portion of the heat radiating portion faces an upper surface of the electronic component.6. The electronic device module of claim 2, wherein the exposed surface of the heat radiating portion has a surface area larger than a surface area of the one surface of the exothermic device.7. The electronic device module of claim 6, wherein a surface area of the lower surface of the heat radiating portion is smaller than the surface area of the one surface of the exothermic device.8. The electronic device module of claim 1, wherein the side surface of the heat radiating portion comprises a first side surface portion formed to have an arch shape and a second side surface portion having a ridge and a valley repeatedly disposed therein.9. The electronic device module of claim 1, further comprising a bonding layer disposed between the exothermic device and the heat radiating portion and bonding the exothermic device to the heat radiating portion.10. The electronic device module of claim 1, further comprising an electronic component mounted on the substrate in a position adjacent to the exothermic device,wherein a mounting height of the electronic component is greater than a mounting height of the exothermic device.11. The electronic device module of claim 1, further comprising an electronic component mounted on the first surface of the substrate and disposed outside of the sealing portion.12. The electronic device module of claim 10, further comprising an antenna disposed inside the substrate or on a second surface of the substrate.13. The electronic device module of claim 12, wherein the antenna comprises a patch antenna disposed in a region opposing the sealing portion.14. The electronic device module of claim 12, wherein the antenna comprises a dipole antenna disposed in a region not opposing the sealing portion.15. The electronic device module of claim 1, further comprising a shielding layer disposed on a surface of the sealing portion and configured to shield an electromagnetic wave,wherein one surface of the heat radiating portion is bonded to the shielding layer.16. The electronic device module of claim 15, further comprising a shielding wall disposed inside the sealing portion and electrically connecting the substrate to the shielding layer.17. An electronic device module, comprising:a substrate;an exothermic device disposed on a first surface of the substrate;a sealing portion embedding the exothermic device disposed on the first surface of the substrate; anda heat radiating portion at least partially embedded in the sealing portion and comprising a lower surface bonded to one surface of the exothermic device,wherein an entire interface between the heat radiating portion and the sealing portion is curved, andwherein a side surface plane of the heat radiating portion and a side surface plane of the exothermic device are laterally spaced apart from each other by 150 μm or more.18. The electronic device module of claim 17, wherein the heat radiating portion comprises an upper surface having a same shape as the lower surface of the heat radiating portion.