Burn-in can be done in different product development stages: engineering (design, reliability, or quality), and production. It can be performed on a small sample of devices, or all devices. You can burn-in unpackaged devices, packaged devices or devices mounted on PC boards. The most common method is to burn-in devices in production after packaging and before final test.
When you burn-in IC devices, you electrically stress or "exercise" the device and apply hot or cold temperatures in a thermal chamber for an extended period of time. If the DUT (Device Under Test) is biased, but is not being exercised electrically, the burn-in is referred to as Static Burn-in. If the DUT is exercised, the burn-in is referred to as Dynamic Burn-in. The exercise can be dynamic activity (clock signals of various frequencies) or functional exercise (signals that simulate actual use). Functional signals exercise more of the internal nodes of the device and are considered to be a superior method for detecting defective devices. Dynamic burn-in is the most common method used today.
TDBI applies functional input patterns and monitors the outputs of the DUTs for correct functional response. This method identifies the precise time and conditions of any failures. Generally, TDBI systems are more costly and demand more programming time. TDBI signal timing must be precise and monitoring strobes must be carefully placed to capture the response.