Bare board test methods

RF parameters of interconnections can also be characterized in the frequency domain using instruments referred to as network analyzers, but this method is not common in bare board testing. Requirements for RF impedance testing are more commonly appUed as signal frequencies exceed 100 MHz. 

Although the main bare board testing technology is electrical, it is important to consider that nonelectricai methods are also important in the acceptance or rejection of bare printed wiring boards (PWBs).This chapter therefore includes detailed descriptions of both electrical and nonelectrical testing methods. 

The actual tests are usually conducted at elevated temperature and humidity with an applied dc bias. A test for moisture and insulation resistance of bare printed circuit boards is included in IPC-SM-840A.The severity of the test depends on the intended use environment for typical commercial products (Class 2), the test is conducted at 50°C, 90% RH, and 100 V bias for 7 days. The minimum insulation resistance requirement is 10 2. The military test procedure for moisture and insulation resistance is specified in MIL-P-SSllO." The moisture resistance test should be conducted in accordance with MIL-STD-202, Method 106, with... 

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