Other Reliability Tests

The Package Dimensions Test is an examination to verify that the external physical dimensions of the device are in accordance with the applicable acquisition document. Any device that exhibits a dimension outside the limits fails this test. Refer to Mil Std 883, Method 2016.

The Constant Acceleration Test is performed to determine the ability of parts to withstand high levels of constant acceleration. It may be used as either an indicator of the mechanical strength limits of a package or as an in-line screen for parts with structural or mechanical weaknesses. Refer to Mil Std 883, Method 2001.

Pls see separate article on: Constant Acceleration Test

The Mechanical Shock Test is performed to determine the suitability of a device to be used in electronic equipment that will be subjected to moderately severe shocks from suddenly applied forces or abrupt changes in motion. These may result from rough handling, transportation or field operation. Refer to Mil Std 883, Method 2002.

Pls see separate article on: Mechanical Shock Test

The Resistance to Solvents Test determines the ability of a part to withstand exposure to solvents. This test consists of immersing three (3) different groups of specimens in 3 different solvent solutions for a minimum of 1 minute. The first group is immersed in solution a, which is 1 part by vol (pbv) IPA Reagent Grade and 3 pbv mineral spirits or a solution composed of 80% kerosene/20% ethylbenzene. The second group is immersed in solution b, which is a semi-aqueous based solvent (defluxer). The third group is immersed in solution d, which is composed of 42 pbv DI water, 1 pbv monoethanolamine, and 1 pbv propylene glycol monomethyl ether. After immersion, the specimen is brushed. This immersion and brush cycle is conducted two more times for a total of three cycles, after which the parts are rinsed and blow-dried. Any evidence of damage to the device shall be a failure. Missing, faded, smeared, blurred, or shifted markings shall also be considered as failures. The Resistance to Solvents test detects, among others, poor ink quality, process issues like overcuring, and/or incorrect or non-conforming material compositions. Refer to Mil Std 883, Method 2015.

The Salt Atmosphere Test is an accelerated laboratory corrosion test to simulate the effects of seacoast atmosphere on the device and package. It consists of exposing the units to a salt fog, which is produced by atomizing a salt solution. After the exposure, the units shall be washed with free-flowing D/I water for at least 5 minutes. The units will then be inspected at 10X-20X magnification for pitting, blistering, flaking, and corrosion products. Refer to Mil-Std-883 Method 1009 for more details.

- exposure of parts to salt fog

- salt : sodium chloride meeting impurity level reqts.

- salt concentration: 0.5%-3% by wt. in DI/distilled water

- salt fog temperature : 35 deg C minimum

- exposure zone maintained between 32-38 deg C

- pH : 6.5 - 7.2 at 35 deg C

The Vibration Test (Variable Frequency) is conducted to determine the ability of parts to withstand vibration of varying frequency within a specified frequency range, and is considered to be destructive. It consists of subjecting the parts to a variable frequency vibration at specified levels. This is achieved by simple harmonic motion having a peak-to-peak amplitude of about 0.06 inch or a peak acceleration corresponding to the specified test condition. The vibration frequency shall be varied approximately logarithmically between 20 to 2,000 Hz. Refer to Mil Std 883, Method 2007.

The Vibration Test (Fatigue) is conducted to determine the ability of parts to withstand sustained vibration of constant amplitude within a specified frequency range. It consists of subjecting the parts to a constant amplitude simple harmonic motion having a peak acceleration corresponding to the specified test condition. Refer to Mil Std 883, Method 2005.

Pls see separate article on: Vibration Tests

Reliability Tests: Autoclave Test or PCT; Temperature Cycling; Thermal Shock; THB; HAST; HTOL; LTOL; HTS; Solder Heat Resistance Test (SHRT); Other Reliability Tests

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