MIL- STD-883F 2004 TEST METHOD STANDARD MICROCIRCUITS - 第690页

MIL-STD-883F METHOD 5011.4 31 October 1995 10 3.8.9 Coef fic ient of l inear t hermal expans ion . The c oeffi cient of linear thermal e xpansi on shall be det ermined i n accor dance wit h ASTM D3386 over the temper atu…

MIL-STD-883F

METHOD 5011.4

31 October 1995

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

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)

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

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.