MIL- STD-883F 2004 TEST METHOD STANDARD MICROCIRCUITS - 第689页
MIL-STD-883F METHOD 5011.4 31 October 1995 9 3.8.7. 2 Extrac tion pr ocedure . 3 grams (equival ent res in) of the ground or cut equi valent p olymer shall be added to a cleaned; tarr ed, 250-ml flas ks made of pyre x, o…
MIL-STD-883F
METHOD 5011.4
31 October 1995
8
3.8.5.1 Thermal stability. The thermal stability of the polymeric material shall be determined by heating the specimens
from room temperature to not less than 210°C, at a heating rate between 10°C/minute and 20°C/minute, in a nitrogen
atmosphere with 20-30 milliliter/minute nitrogen flow. The weight loss at 200°C shall be determined.
3.8.5.2 Filler content
. The filler content of polymeric materials using a filler to promote properties such as electrical or
thermal conductivity shall be determined by heating the specimen from room temperature to 600°C, at a heating rate
between 10°C/minute and 20°C/minute, in an air atmosphere with 20-30 milliliter/minute air flow. The temperature shall be
maintained at 600°C until constant weight is obtained. It is permitted to perform 3.8.5.1, followed by heating from 210°C to
600°C as detailed above. The filler content shall be reported as weight percent of the cured specimen.
3.8.6 Outgassed materials
. Ten test specimens shall be prepared using gold- or nickel-plated Kovar or ceramic
packages, (dielectric materials may be prepared using aluminum coated silicon as the substrate). (The use of "leadless"
packages is permitted to reduce moisture contributions due to package construction). The material shall be cured using the
minimum cure schedule and shall receive the minimum pre-seal bake specified in the assembly document(s) (see 3.5.1).
After a pre-seal bake, the packages shall be hermetically sealed. Only those packages that meet the fine and gross leak
test requirements of test method 1014 shall be submitted for moisture content analysis. If less than 10 test specimens
remain after hermetically testing, the failed packages shall be replaced by additional hermetical packages processed and
tested in the same manner as the original group.
3.8.6.1 Testing for short term outgassing of moisture and other gaseous species
. Five packages containing polymer
prepared in accordance with 3.8.6 shall be heated in accordance with MIL-STD-883, method 1008, 24 hours at 150°C. The
packages shall then be immediately (less than or equal to 5 minutes) inserted into the ambient gas analysis apparatus. The
packages shall be subjected to ambient gas analysis in accordance with MIL-STD-883, method 1018, procedure 1. In
addition to moisture, other gaseous species present in quantities greater than or equal to 100 ppmv (0.01 percent V/V) shall
be reported in ppmv or percent V/V. This test shall meet the requirements of 3.5.3.
NOTE: From the 5 packages prepared in accordance with MIL-STD-883, method 1008, only 3 packages are required to
be subjected to the ambient gas analysis testing and the pass criteria of 3 packages (0 failures) shall apply (see
3.5.3). However, in the event of a failure, the testing of the remaining 2 packages shall be required in order to
pass with the criteria of 5 packages (1 failure).
All polymeric materials tested shall have quantities of material equivalent in mass and exposed surface area to that of
the intended application. Gold plated Kovar tabs and alumina blanks may be used as facsimile device elements.
Several polymeric materials of different application may be tested in combination with each other in this test, however
their combined moisture content shall not exceed 5,000 ppmv.
3.8.6.2 Testing for long term outgassing of moisture and other gaseous species
. Provided that the moisture requirement
of 3.5.3 has been met by packages tested in 3.8.6.1, the remaining five devices containing polymer from the group prepared
in accordance with 3.8.6 shall be heated in accordance with MIL-STD-883, method 1008 for 1,000 hours at 150°C. The
packages shall then be immediately (less than or equal to 5 minutes) inserted into the ambient gas analysis apparatus. The
packages shall be subjected to ambient gas analysis in accordance with MIL-STD-883, method 1018, procedure 1. In
addition to moisture, other gaseous species present in quantities greater than or equal to 100 ppmv (0.01 percent V/V) shall
be reported in ppmv or percent V/V.
3.8.7 Ionic impurities
. A water-extract analysis shall be performed to determine the level of ionic contamination in the
cured polymeric material. The total ion content (specific electrical conductance) and the specific ionic content for the
hydrogen (pH), chloride, sodium, fluoride and potassium ions shall be measured. Other ions present in quantities > 5 ppm
shall also be reported in ppm. The methods of analysis submitted in the following paragraphs are suggested techniques.
Alternate methods of analysis may be selected where it can be shown that the techniques are equivalent and the method of
analysis is approved by the qualifying activity.
3.8.7.1 Sample preparation
. Adequate material shall be cured to obtain 3 gram samples of polymer following grinding, for
final preparation. The material shall be cured on teflon or other inert surface in a forced draft oven. When possible the
cured specimen shall be removed from the curing substrate and ground to 60-100 mesh particles; polymeric film samples
less than or equal to 0.025 cm thick shall be cured and cut into less than or equal to 0.25 cm
2
samples; gels or low modulus
materials may be cast directly into the flat bottom of the sample flask for the extraction. Smaller sample sizes may be
selected where it can be shown that the accuracy of the test method has not changed.
MIL-STD-883F
METHOD 5011.4
31 October 1995
9
3.8.7.2 Extraction procedure
. 3 grams (equivalent resin) of the ground or cut equivalent polymer shall be added to a
cleaned; tarred, 250-ml flasks made of pyrex, or equivalent. The weight of the cured material in each flask shall be recorded
to the nearest milligram. 150.0 grams of deionized water with a measured specific conductance less than or equal to 0.1
millisiemens/meter (specific resistivity greater than or equal to 1.0 megohm-centimeter) shall be added to the flask. A blank
shall be prepared by adding 150.0 grams of the deionized water and a boiling chip to a second 250-ml flask. The flasks
shall be refluxed for 20 hours.
NOTE: 1.0 mho = 1.0 siemens; 1.0 mho/cm = 100.0 siemens/meter.
3.8.7.3 Measurement of ionic content
.
3.8.7.3.1 Total ionic content
. The total extractable ionic content shall be determined by measuring the specific electrical
conductance of the water-extract samples and the blank using a conductivity meter with an immersion conductivity cell
having a cell constant of 0.01/centimeter (alternatively 0.1 cm
-1
to adjust for proper analysis of the solution). The total ionic
content, in millisiemens/meter, shall be obtained by subtracting the specific conductance of the blank from the specific
conductance of the samples.
3.8.7.3.2 Hydrogen ion content (pH)
. The pH of the water extract shall be determined using a pH meter with a standard
combination electrode.
3.8.7.3.3 Specific ion analysis
. Specific ion analysis of the water extract shall be conducted using ion chromatography or
a demonstrated equivalent. The ion concentrations in the extract shall be converted to the sample extractable
concentrations by multiplying the ratio of the deionized water weight (W) to polymer sample weight (S); that is, by (W/S).
The chloride, sodium, fluoride and potassium ion levels and all other ions detected in quantities > 5 ppm shall be reported in
ppm.
3.8.8 Bond strength
. The bond strength of the polymeric material shall be determined in accordance with 3.8.8.1, 3.8.8.2
or 3.8.8.3 below. As a minimum, five elements shall be tested to failure at the following conditions:
a. At 25°C.
b. At 25°C after 1,000 hours at 150°C in an air or nitrogen ambient.
The average bond strength at each test condition shall be determined in kilograms (force).
3.8.8.1 Bond strength
. The bond strength shall be determined in accordance with method 2019 of
MIL-STD-883. A gold-metallized substrate or a gold- or nickel-plated package shall be used as the bonding surface for bond
strength testing.
3.8.8.1.1 Type I materials
. Suppliers shall use 0.08 inch-square (0.2 centimeter-square) gold-plated Kovar tabs.
3.8.8.1.2 Type II materials
. Suppliers shall use 0.08 inch-square (0.2 centimeter-square) alumina chips.
3.8.8.2 Bond strength
. The bond strength may be determined in accordance with ASTM D1002 as an alternative to test
method 2019. If ASTM D1002 is used, the results must be correlated to assure that the bond strength of the adhesive is
shown to be equivalent to the Method 2019 failure criteria.
3.8.8.3 Molding compounds or encapsulants.
Molding compounds or encapsulants shall be tested in accordance with
MIL-STD-883, test method 1034.
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.