Temperature Humidity Testing
The temperature humidity test is designed to assess the effects of simultaneously exposing test samples to elevated temperature and high relative humidity. These conditions are often the root cause of product failure as they accelerate corrosion and the diffusion of moisture through plastic molding compounds and metal-plastic molding compound interfaces. The high vapor pressure on the test samples constitutes the “force” behind the moisture migration and penetration. The moisture penetration into packaging materials results in swelling, which in turn compromises their functional utility through increased wire-bond tension, wafer chip delamination, and subtle changes in the properties of the packaging material.
The temperature humidity test is also commonly referred to as “damp heat test” or “85/85 test” (the most used condition). During these tests, samples are typically subjected to temperature-humidity stress for periods of 100, 500, 1000-hours or more. For extended test duration, such as 1000 hours, samples may be removed from the chamber for interim electrical testing and inspection at customer designated intervals. Silicon Cert Laboratories has the capability to perform this test for all normal and reasonable temperature-humidity combinations. Test standards include, but are not limited to, MIL-STD-202 Method 103 and GR-468-CORE.
Temperature Humidity Bias (THB)
Temperature humidity bias testing adds electrical bias to the stress to more readily detect electro-corrosion which can occur in the presence of ionic contamination. Applying electrical bias is designed to better simulate the conditions of the device in its real-life applications. This process further accelerates the various failure modes in time, therefore predicting product/design failure in a much reduced time frame. Biasing for temperature humidity is normally limited to a maximum of 100 volts and low/negligible power dissipation since self-heating of the device from Joule heating will negate the effects of humidity on the intended process.
For the temperature humidity bias test, standards include, but are not limited to, JESD22-A101. Silicon Cert Laboratories has the capability to conduct a wide-range of temperature- humidity-voltage conditions while providing a source of current & voltage to the devices-under-test (DUT). Real-time per-device monitoring is also available during this test and this data can be recorded at any reasonable interval (minutes to hours) and provided to the customer at any desired time (hours, days). Because all test setups are custom designed, thermal runaway never occurs; this makes failure mode evaluation, if necessary, simpler and easier. Silicon Cert Laboratories are experts in THB Testing.