Constant Acceleration Test - Mil-Std-883 Method 2001

The Constant Acceleration Test, as its name implies, is a test performed to determine the effects of constant acceleration on semiconductor devices. Mil-Std-883 Method 2001 is the most widely-used industry standard for performing this test.

Constant acceleration testing is designed specifically to uncover structural and mechanical weaknesses in the semiconductor package that are not necessarily detectable by other mechanical stress tests, such as the mechanical shock test and the vibration test.

It may be used as a high-stress test to determine the limits of the mechanical strengths of the various features of the package, i.e., the internal metallization and lead system, the die and die attach system, the wire bond system, etc. At lower and non-destructive levels of stress settings, it may also be utilized as a 100% in-line screen to identify and reject devices that exhibit lower than nominal mechanical strengths in any of the package's structural elements.

The constant acceleration test employs an apparatus capable of applying the specified acceleration to the devices being tested for the required period of time. The devices to be subjected to constant acceleration testing shall be restrained by its case or body, or by normal mountings, with its leads and cables (if any) secured very well. Unless otherwise specified, the required value of constant acceleration shall then be applied to the samples for 1 minute in each of the following orientations: X1, X2, Y2, Y1, Z1, and Z2. For devices with internal elements mounted with the major seating plane perpendicular to the Y axis, the Y1 orientation is defined as the one that tends to displace the elements from their mount.

Table 1 shows the various test conditions for constant acceleration testing as defined by Mil-Std-883 Method 2001. Test condition E shall apply, unless otherwise stated.

Table 1. Test Conditions for Constant Acceleration Testing

per Mil-Std-883 Method 2001

Test Condition	Stress Level (g)
A	5,000
B	10,000
C	15,000
D	20,000
E	30,000
F	50,000
G	75,000
H	100,000
J	125,000

The following shall be indicated in the acquisition document: 1) test condition or amount of acceleration applied in gravity units (g); 2) measurements to be made after the stress test, if any; 3) any variations or limitations to the test orientation used; and 4) the sequence of orientations, if other than what was specified by Mil-Std-883 Method 2001.

Reference: Mil-Std-883 Method 2001

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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