This is especially true in stress tests for prototype boards. The outputs can be monitored during a dynamic test, giving some view of exactly which points on the board are most vulnerable to failure.Īny burn-in test that leads to failure needs to be followed up with a thorough inspection. This provides a more comprehensive view of component reliability, as internal circuitry in ICs can be assessed for reliability. This type of test involves applying input signals to each component while a burn-in board is exposed to extreme temperatures and voltage. Applying a static voltage during the test will not activate all nodes in the device, so it does not give a comprehensive view of component reliability. This type of test is best used as a thermal test to mimic storage at extreme temperatures. Probes simply need to run into an environmental chamber, the chamber is brought up to temperature, and the device is brought up to the desired applied voltage. This is a simple, low-cost, accelerated lifetime test. Burn-in testing comprises two different types of tests: Static TestingĪ static burn-in involves simply applying extreme temperatures and/or voltages to each component without applying input signals. This will provide some extreme data on mechanical stress failures for the board alongside data on component failures. Bathtub curve showing product reliabilityīurn-in tests and environmental stress tests can be performed with a prototype board at 125 ☌, or above the glass transition temperature for the intended substrate material. The test could be performed at a variety of temperatures while operated electrically to get a complete view of product reliability. These tests are normally performed at 125 ☌, which just happens to be the upper limit for high-reliability semiconductors. The unfortunately-named “infant mortality” portions comprises early component failures due to manufacturing defects. The goal in these reliability tests is to gather enough data to form a bathtub curve (an example is shown below). These types of stress tests are sometimes called accelerated lifetime tests (a subset of HALT/HASS), as they mimic the operation of a component for an extended period of time and/or under extreme conditions. These varied operating conditions can include temperature, voltage/current, operating frequency, or any other operating conditions that are specified as an upper limit.
What is Burn-in Testing?ĭuring burn-in testing, components on a special burn-in circuit board are stressed at or above their rated operating conditions in order to eliminate any assemblies that would prematurely fail before the rated lifetime of their components. If you’re planning to produce at scale, this is best performed before ramping up to high volume. In addition to in-circuit tests, functional tests, and possibly mechanical tests, the components and boards themselves can benefit from burn-in testing. However, you may intend for your product to operate for an extreme period of time, and you’ll need some data to reliably place a lower limit on your product’s lifetime. These tests often focus on functionality and, for high speed/high frequency boards, signal/power integrity. Once you’re planning for production of any new board, you’ll likely be planning a battery of tests for your new product.