MIL- STD-883F 2004 TEST METHOD STANDARD MICROCIRCUITS.pdf - 第649页
MIL-STD-883F METHOD 5009.1 25 August 1983 7 4. SUMMARY . The f ollowing det ails shall be speci fied i n the appli cable ac quisi tion doc ument. a. DPA sampl e size i f dif ferent t han spec ified i n 3.1. b. Radiogr ap…
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).
MIL-STD-883F
METHOD 5009.1
25 August 1983
8
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