MIL- STD-883F 2004 TEST METHOD STANDARD MICROCIRCUITS - 第179页

MIL-STD-883F METHOD 1034.1 18 June 2004 5 3.1.6 Crossse ctioning . a. Normal cro sssection ing pro c edures can be perf ormed on the s amples . b. Make s ure that str ay parti cles of dye do not s mear or become embedded…

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MIL-STD-883F
METHOD 1034.1
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3.1.3 Vacuum setup.
a. Place the parts in the premix/accelerator mixture.
b. Place the beaker in a petri dish to catch any spill solution that spills over during the vacuum operation.
c. Place a larger beaker over the beaker with solution in it to prevent splattering all over the vacuum oven.
3.1.3.1 Vacuum
. Many vacuum ovens can be used for this procedure as long as the oven is able to reach 1 to 0.3 torr.
The oven should have a gauge that can accurately measure the pressure at this level. One method is given below.
a. Place the door of the vacuum chamber by unscrewing the handle counter clockwise.
b. Place the beaker set-up into the vacuum chamber.
c. Close the vacuum oven door. Close the door latch and turn it clockwise until tight.
d. Close the valves on both sides of the oven. The vacuum is monitored by the gauge on the top of the oven. The
vacuum meter is connected to the outtake of the oven.
e. Turn on the vacuum pump.
f. Monitor the outgassing of the solution while its under vacuum. Violent outgassing will start at approximately 10
torr. The valves on either side of the oven (one on the left side and one on the right side of the oven) can be
cracked open to lessen the vacuum on the inside of the oven. By doing this, the outgassing can be controlled, so
that the mixture doesn't spill over.
g. Once the outgassing stops, close the valves on the vacuum oven and wait for the pressure to decrease to 1 torr.
The working vacuum for the procedure is 1 to 0.3 torr.
h. Once the Granville-Phillips vacuum gauge reaches 1 torr, wait for 15 minutes.
3.1.3.2 Post vacuum procedure
.
a. At the end of 15 minutes, turn off the vacuum pump.
b. Open both of the intake valves until the vacuum inside the chamber is equal to the outside pressure. Leave the
devices in this state for 15 minutes.
c. At the end of the 15 minutes, open the door and remove the beakers from the vacuum chamber.
3.1.4 Cleaning the devices
.
a. Remove the devices from the solution.
b. Pad off the excess solution with a paper towel and cotton swab.
c. The remaining mixture can now be discarded into the bottle marked "RESINOL, YELLOW DYE G, AND
ACCELERATOR WASTE".
d. The beakers, pipettes, and glassware can all be cleaned in soap and water.
3.1.5 Baking the devices
.
a. Place the devices in a petri dish, and place the dish into an oven preheated to 100 degrees C. Bake for 1 hour.
b. After the bake, the parts can be mounted for crosssectioning.
MIL-STD-883F
METHOD 1034.1
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3.1.6 Crosssectioning
.
a. Normal crosssectioning procedures can be performed on the samples.
b. Make sure that stray particles of dye do not smear or become embedded in the cross-sectioned surfaces. This
will give you a false representation of the dye in the sample. (Smearing looks like little stars when viewed through
the ultraviolet filtering.) Be sure to clean the samples thoroughly after grinding and polishing operations to avoid
these complications.
3.1.7 Viewing crosssections on a microscope
. The exposure time will vary from sample to sample and from microscope
to microscope. The best scope for viewing dye penetration will have a bright light source (200 W mercury lamp).
a. View the crosssection under normal bright field conditions. To take a photo, use the green filter, set the proper
exposure, then take the photo using Polaroid 52 film (ASA 400).
b. Slide out the bright field mirror cube.
c. For the Olympus PMG3, slide in the blue excitation fluorescence cube (BH2-UDMB). For the Polyvar, remove the
B1 filter from the filter box and insert it into the left hand side of the Polyvar.
d. Remove the green viewing filter. The fluorescence of the dye will be difficult to see if the filter is in place.
e. Insert the Polaroid 57 film. Though the ASA for 57 film is 3200, leave the ASA at 400 to take the photo. This will
give you a good approximation for the proper exposure. Make adjustments as necessary to obtain the desired
exposure. The exposure time will vary depending upon the amount of fluorescent dye there is in frame.
3.2 Die penetrant evaluation criteria
. The following cross sections or other relevant cross sections shall be evaluated.
a. One cross section on the long axis of the package (examine tie bar)
b. Three cross sections on the short axis (examine shortest lead, die or paddle edge, and one other).
As a minimum the following criteria shall be used for evaluation and any discrepancies shall be reported:
a. Any evidence of fracture or other packaging related defects.
b. Any evidence of delamination.
c. Any evidence of dye reaching the die attach or die surface.
d. Any evidence of dye penetration of more than 50 percent at a lead egress.
e. Any evidence of dye penetration of more than 50 percent of the length of any lead in the package.
4. SUMMARY
. The following details shall be specified in the applicable acquisition document.
a. Any failure criteria different than that specified in 3.2.
b. Test sample if no sample is specified.
MIL-STD-883F
METHOD 1034.1
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