Various embodiments may relate to an LED retrofit lamp, including a lamp tube, an LED light engine disposed in the lamp tube, and end caps arranged at two open ends of the lamp tube, the LED light engine including a circuit board and at least one light source disposed on the circuit board. The LED retrofit lamp further includes one pair of retaining structures fixed at two opposite ends of the circuit board, respectively, and at least one pair of elastic tension structures connected to the retaining structures. The elastic tension structure goes through the end cap from one side of the end cap and is locked at the other side of the end cap. In addition, various embodiments may also relate to a process for manufacturing the LED retrofit lamp.