MIL- STD-883F 2004 TEST METHOD STANDARD MICROCIRCUITS - 第691页

MIL-STD-883F METHOD 5011.4 31 October 1995 11 3.8.11. 2 Type II pol ymer mater ials . Type II mat erials shall be t ested in ac cor dance with ASTM D257 at t emperat ures of 25°C and 125° C. 3.8.12 Di elect ric c onstant…

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MIL-STD-883F
METHOD 5011.4
31 October 1995
10
3.8.9 Coefficient of linear thermal expansion. The coefficient of linear thermal expansion shall be determined in
accordance with ASTM D3386 over the temperature range of -65°C to 150°C. The glass transition temperature, coefficients,
and temperature ranges corresponding to different slopes of the curve shall be noted.
3.8.10 Thermal conductivity
. The thermal conductivity, in watt/meter-K, shall be determined at 121°C ±5°C in accordance
with ASTM C177 or ASTM C518.
NOTE: 1 cal/cm-s-k = 418.4 W/m-K.
3.8.11 Volume resistivity
.
3.8.11.1 Type I polymers
.
3.8.11.1.1 Paste materials
. Test specimens shall be prepared using a standard 1 inch x 3 inch glass slide. A jig capable
of holding this slide, with two scribed lines 100 mil apart and parallel to the length, shall be the guide for applying two strips
of transparent tape. There shall be no wrinkles or bubbles in the tape. The slide shall be cleaned with alcohol and air dried.
A drop of the type I material shall be placed between the two strips of tape. Using a single edge razor blade maintaining a
30° angle between the slide surface and the razor blade, the material shall be squeezed between the tape strips. The length
of the applied strip shall be at least 2.5 inches. The tape shall be removed, and the material shall be cured according to
3.5.1. After cure, the test specimens shall be allowed to cool to room temperature.
3.8.11.1.2 Film materials
. Test specimens shall be prepared using a standard 1 inch x 3 inch glass slide. The slide shall
be cleaned with alcohol and air dried. A thin strip of the uncured film approximately 100 mil wide and at least 2.5 inches
long shall be placed on the glass slide. The film shall be covered with a strip of copper foil or Teflon film and a second 1
inch x 3 inch glass slide shall be placed over the foil or Teflon film. Sufficient force (weight, clip, etc.), shall be applied to the
assembly to compress the material during cure. The material shall be cured according to 3.5.1. After cure, the test
specimen shall be allowed to cool to room temperature, and the top slide and foil or Teflon shall be removed. The exact
width and thickness of each polymer strip shall be measured with a precision caliper and micrometer respectively. These
measurements, after conversion to the appropriate units, shall be used to calculate the volume resistivity using the formula
given in 3.8.11.1.3.
3.8.11.1.3 Resistance measurements
. Resistance measurements shall be made using a milliohm meter in conjunction
with a special four-point probe test fixture. (This fixture can be made of an acrylic material with four spring-loaded contacts.
The contacts must be set into the acrylic so that the current contacts are 2 inches apart, the voltage contacts are between
the two current contacts, and the voltage contacts are separated from each current contact by 0.5 inch.) The four-point
probe fixture shall be placed on the strip of conductive polymer and contact between each probe and the material shall be
ensured. The measured resistance shall be recorded in ohms, and the resistivity shall be determined from the following
formula:
P =
R (w x t)
l
Where:
P = resistivity, ohm-m
R = measured resistance, ohms
w = width, (100 mil = 2.54 mm)
t = thickness, (micrometer reading of the material plus glass side) minus (micrometer reading
of the glass slide)
l = length between inner pair of probes, (1 inch = 25.4 mm)
A minimum of three specimens shall be tested at 25°C, at 60°C, at 150°C, and at 25°C after 1,000 hours at 150°C in an air
or nitrogen ambient. The same specimens may be used for each test.
MIL-STD-883F
METHOD 5011.4
31 October 1995
11
3.8.11.2 Type II polymer materials
. Type II materials shall be tested in accordance with ASTM D257 at temperatures of
25°C and 125°C.
3.8.12 Dielectric constant
. The dielectric constant of type II materials shall be determined as required in the user's
material specification in accordance with ASTM D150 at frequencies of 1 kHz and 1 MHz at room temperature.
3.8.13 Dissipation factor
. The dissipation factor of type II materials shall be determined as required in the user's material
specification in accordance with ASTM D150 at frequencies of 1 kHz and 1 MHz at room temperature.
3.8.14 Sequential test environment
. Testing shall be performed using either 3.8.14.1 or 3.8.14.2.
3.8.14.1 Sequential test environment
. A minimum of five test specimens shall be subjected to the environmental
conditions specified below. Specimens shall be prepared using the largest component/substrate/package combinations
representative of end-use applications in backing material, attach surface, and size. Component types include resistor,
capacitor, integrated circuit, and discrete semiconductor elements. Two components of each type shall be attached to the
substrate with the adhesive (type I or II) proposed for use with that component type. The test specimens shall be subjected
to the following environmental conditions in the sequence given:
a. Thermal shock (MIL-STD-883, method 1011, condition C, 15 cycles).
b. Temperature cycling (MIL-STD-883, method 1010, condition C, 100 cycles).
c. Mechanical shock (MIL-STD-883, method 2002, condition B, Y1 only).
d. Variable frequency vibration (MIL-STD-883, method 2007, condition A, Y1 only).
e. Constant acceleration (MIL-STD-883, method 2001, condition B, Y1 only).
3.8.14.2 Alternate sequential testing
. Alternatively, testing in accordance with Qualification Testing (QML sequences in
accordance with MIL-PRF-38534, using maximum baseline limits may be performed. The user is still required to satisfy the
requirements of 3.8.14.1 by completing the necessary supplemental testing, i.e., thermal shock and vibration.
Following the environmental exposures of 3.8.14.1 or 3.8.14.2, the test specimens shall be examined for possible
degradation in accordance with MIL-STD-883, method 2017. For adhesives, one of each type of component from each
sample shall be evaluated for die shear strength in accordance with MIL-STD-883, method 2019 and shall meet the
strength requirements of figure 2019-4.
3.8.15 Density
. The density of materials used as RF or microwave absorbers shall be determine in accordance with
principles outlined in ASTM D1564, paragraphs 69-74. Those RF absorbers that are foamed in-place are to be foamed,
cured, and cut to form the free standing material for this analysis.
MIL-STD-883F
METHOD 5011.4
31 October 1995
12
3.8.16 Mechanical integrity.
3.8.16.1 Getter integrity - short term
. Samples shall be prepared using hermetically sealed packages representative of
the maximum size and type which will incorporate the use of getter material. These samples will contain only "salted"
particles and getter material. The getter material shall be applied to the package in the location and approximate volume as
specified for a normal production part. The getter material coverage area shall be measured and recorded. The particles to
be salted shall consist of the following unless otherwise agreed upon by the user and the qualifying activity.
(1) Solder balls: 3-6 mils in diameter - 2 pieces required.
(2) Aluminum ribbon: Approximate dimensions of 2 mil thick by 5 mil wide by 10 mils long - 1
required. A piece of aluminum wire 2-6 mils in diameter may be substituted for the ribbon.
(3) Gold wire: 1 mil diameter by 15-20 mils in length - 1 piece required. Getter material
application and cure shall take place in the sequence normally followed for production parts.
The samples shall be processed through the same environmental conditioning steps as a
qualified production part. The samples shall be subjected to PIND test in accordance with
MIL-STD-883, method 2020, condition A or B, which shall be repeated three time for a total
of four cycles to verify the integrity of the getter material. During all PIND testing the
samples shall be mounted on the tester such that the shock pulses integral with the test
shall be in the direction most likely to dislodge the particles from the getter material. A
minimum of three samples shall be evaluated and all shall pass the defined PIND criteria.
3.8.16.2 Getter integrity - long term.
All of the conditions and requirements of 3.8.16.1 apply, except that the samples
either newly prepared or as received from the short term test, shall be stored at 150°C for 1,000 hours.
The samples shall then be subjected to mechanical shock in accordance with MIL-STD-883, method 2002, condition B,
in the Y
2
direction. Following mechanical shock the samples shall be PIND tested as specified above.
Following PIND, the samples shall be delidded and a visual inspection shall be performed to verify the following:
a. Determine if particles have separated from the getter material or have fallen into the package.
b. Determine if getter coverage has spread or bled out.
c. Check for any evidence of peeling from inside and/or getter becoming separated from package.
3.8.16.3 Vibration
. Samples shall be prepared as in 3.8.16.1 except that the lid shall be attached in such a manner that it
may be removed for visual inspection. After particle salting and immobilization as in 3.8.16.1, visual inspection shall be
done to verify entrapment of the salted particles. Location of the particles in the getter material shall be recorded for future
reference.
The lid shall then be reattached to the package securely enough to withstand the testing that follows. After PIND testing
in accordance with MIL-STD-883, method 2020, the samples shall be subjected to vibration in accordance with MIL-STD-
883, method 2007, condition A or B. At the end of this test, the lids shall be removed from the package by whatever
method is required. Location of the "salted" particles in the getter material shall be noted and compared with the location
prior to vibration. Particles other than the original "salted" particles shall be ignored. A minimum of three samples shall be
submitted for evaluation and all shall pass the defined PIND criteria initially and after vibration.