MIL- STD-883F 2004 TEST METHOD STANDARD MICROCIRCUITS.pdf - 第648页

MIL-STD-883F METHOD 5009.1 25 August 1983 6 3.6.6 Cer amic fl at-pac k . a. Pref erred met hod. Pass an oxygen/butane flame over the li d of the s ample while t he part i s under l ight pr essur e from t he blades of a d…

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MIL-STD-883F
METHOD 5009.1
25 August 1983
5
3.5.10 Die shear. Die shear tests shall be performed on at least two samples in accordance with MIL-STD-883, method
2019. Record the die force required to separate the die from substrate and the interface appearance in terms of area
affected in the break. Test a representative sample of each chip type in each package under test. Samples of each other
chip type such as resistors and capacitors shall also be tested for shear strength in accordance with the requirements of the
applicable specification, and the force required to separate the active and passive components from the substrate shall be
recorded.
3.5.11 Evaluation criteria
. The lot shall be considered suspect if parts exhibit any defects when inspected or tested to the
criteria listed below. Each defect shall be photographed, measured, and described in the DPA report. In the absence of
defects or based on a decision by the responsible parts authority that any observed anomalies do not constitute rejectable
defects, the lot may be considered acceptable for use (see 3.7.1 for disposition of suspect lots).
INSPECTION REQUIREMENT
MIL-STD-883 EVALUATION CRITERIA, Sample Size
External visual Method 2009
Radiography Method 2012
PIND Method 2020
Seal Method 1014
Internal water vapor Method 1018
Internal visual Methods 2017, 2010 test condition A or B
or alternate 2 of Method 5004 as applicable;
2013 and 2014
Bond strength Method 2011
SEM Method 2018
Die shear Method 2019
Configuration Baseline design documentation
3.6 Delidding procedures
. The devices shall be delidded using one of the procedures below or other suitable means.
Caution should be exercised to preclude damage to the device or the generation of internal contamination as the result of
delidding.
3.6.1 Solder seals
. Do not reflow the solder. After these cans are opened, the interior shall be examined for excess
solder or flux. Reflowing the solder seal will destroy the evidence. To open, grind can just above the header until it is thin
enough to be cut with a sharp instrument.
3.6.2 TO-5 type enclosures
. Semiconductors, microcircuits, and other devices are often packaged on TO-5 type
enclosure that can be quickly opened using a commercial device known as a "Head Remover, Silicon" or, more commonly,
as a TO-5 can opener. This device can be modified to accept various lid heights and a metal guide bar may be added over
the cutting wheel to maintain minimum clearance between the TO-5 flange and the cutting wheel.
3.6.3 Flange welded enclosures
. Grind off flange until can is thin enough to be cut with a sharp instrument.
3.6.4 Tubulated enclosures
. Before opening, file or dry grind into the crimp to ensure that it has properly engaged the
conductor. Note whether the number and placement of the crimps are normal and check for over crimping. Free the center
conductor from the crimp before removing the device cover by using a can opener or grinder.
3.6.5 Solder sealed flat-pack or DIP
. Hold the sample flat against a dry Buehler grinding wheel (180 grit paper) until the
lid becomes thin enough to make the cavity indentation visible. Clean the sample, then puncture the lid with a sharp
instrument and peel it off.
MIL-STD-883F
METHOD 5009.1
25 August 1983
6
3.6.6 Ceramic flat-pack.
a. Preferred method. Pass an oxygen/butane flame over the lid of the sample while the part is under light pressure
from the blades of a delidding vise. Each pass of the torch should last two or three seconds and the vise should
be tightened slightly between passes. Two or four passes are normally required. The blades of the delidding vise
should be positioned above the leads and not at the ends of the sample.
b. Alternate method. Hold the sample firmly by its lower body (this may require careful bending of the leads). Place
the point of a sharp blade on the seal line above the lead frame and strike the blade lightly with a small hammer.
Continue this process around the package circumference until the seal fractures to release the lid.
NOTE: The "flat-pack delidding vise" referred to in 3.6.6 is a special fixture which can be assembled or may be acquired
from a commercial source.
3.6.7 Dual-in-line package
.
a. Preferred method. This technique is suitable for all types of ceramic packages, including those types where the
lid seal is formed at the lead frame interface. Position the package between the knife blades of a delidding vise
contacting the seal region. The physical condition of the seal regions (i.e., the determination of the optimum
package sides exhibiting the maximum seal glass dimensional length) to be clamped between the parallel cutters,
will generally dictate the orientation. Apply sufficient pressure to just hold the package in place. Heat the
package lid for approximately 5 seconds with a oxygen/butane microflame torch, remove the heat and slowly
increase pressure on the package seal. Repeat the heat/pressure sequence until the entire lid, intact, is sheared
off at the seal.
b. Alternate method. Place abrasive paper (e.g., Buehler emery paper or equivalent) on a flat surface. Abrade the
package lid by repeated strokes across the paper. The sample may optionally be placed in a fixture containing a
mounted dual-in-line socket for ease in handling. Continue abrading, with frequent visual checks, until the lid is
almost completely gone. Remove the remainder of the lid over the cavity by attaching a piece of tape and lifting
off.
3.7 Failure criteria
. The inspection lot shall be considered suspect if the devices exhibit any defect when inspected or
tested to the criteria in 3.4 or 3.5. Each defect shall be photographed, measured, and described in the DPA report.
3.7.1 Disposition of suspect lots
. Inspection lots which are found to have one or more defects as the result of evaluation
of a DPA sample shall be: a. subjected to resampling if the results of the first sample were inconclusive, b. screened, c.
scrapped, or d. returned to supplier, as applicable.
3.7.2 Resampling
. In the event that results of the initial DPA sample are inconclusive, a second DPA sample may be
selected in accordance with 3.1 except that the sample size shall be determined by the cognizant authority for the parts and
approved by the acquiring or qualifying activity on the basis of the type of defect that is being investigated and the number of
devices remaining in the inspection lot. Final disposition shall be made of the inspection lot after completion of the
evaluation of the second sample.
3.7.3 Rescreened lots
. Inspection lots which are found to have parts with screenable defects may be subjected to 100
percent nondestructive screening tests to eliminate the nonconforming items. After completion of screening the remaining
devices may be accepted for shipment.
3.7.4 Retention of samples
. When requested, all DPA samples shall be submitted to the acquiring activity or qualifying
activity along with the DPA report.
MIL-STD-883F
METHOD 5009.1
25 August 1983
7
4. SUMMARY. The following details shall be specified in the applicable acquisition document.
a. DPA sample size if different than specified in 3.1.
b. Radiography requirement (see 3.4.2 and 3.5.2).
c. Disposition of suspect lots and DPA samples if different than specified (see 3).
d. Any additional requirements for tests or for documentation in DPA report (see 3.2)
e. Electrical test requirement, if applicable.
f. Die shear strength for resistor and capacitor chips (see 3.5.10).
g. Internal water vapor requirement (see 3.4.4 and 3.5.5).
h. A manufacturer listing of defects, if applicable (see 3.4.5).