Do We Have an Accelerated Aging
for ESD Packaging Materials
by: Steve Fowler, Fowler Associates, Inc.
In Federal test Standard 101C, Method
4046.1 the original accelerated aging test for ESD packaging materials
was born. This is the Static Decay test called out in the Mil-B-81705
series standards. This standard called for: (sic)
"Prior to testing,
expose one third of the specimens for 12 days in an oven at 160
degrees F ..."
Dr. Marv Havens in his definitive paper
at the EOS/ESD Symposium in 1989, "Understanding Pink Poly",
showed this test actually tested the"'reservoir effect"
of pink poly samples. 6 mil pink poly samples began to lose their
static decay after 12 days at 160 degrees F. This test evolved the
additives (under heat conditions) out of the polyethylene and determined
an acceptable level of loading of this thick plastic film. This
was designed for these films to simulate one year of package life.
The 160 degrees F temperature was chosen to simulate the back of
a saleman's car in the southwest in the summer.
This specification was never designed
to be applied to the resistitivty of ESD packaging films.
Over the years, many companies transferred
this aging test to the resistance measurements of their specifications
for ESD protective materials.
Most Type III (static shielding) materials
failed this aging test for resistance due to the low coating weights
of the outside or the inside sealing layer of the films. This is
not a negative statement. It only points out the problem of applying
the old static decay tests to today's films.
Today some companies have a misunderstanding
of this specification in regards to ESD protective packaging films
Make no mistake, this test was designed
to determine the amount of antistatic additive in a thick polymer
film. It was never designed to test the coatings of thermoformable
sheets, static shielding bag films or other thin film materials
So... Do we now have any acceptable
aging test for ESD protective packaging????????
The qualified answer is .. NO!
The following are some discussions
of the needs and acceptable expectations of today's packaging films.
The new version of Mil-B-81705: Mil-PRF-81705D
(1998) , has removed the static decay tests for ay materials except
the Type II materials- Static Dissipative. This test is not
required for Type I - Moisture Barrier or for Type III
- Static Shielding materials. This is an indication of the understanding
of the problems associated with accelerated aging of these materials
especially in regards to surface resistivity or surface resistance.
This does not mean that companies do
not wish some sort of accelerated aging tests for all ESD protective
A few years ago after many tests performed
by Fowler Associates on static shielding films, Hewlett-Packard
adopted their new test specification: A-5951-1589-1 Revision
H, Appendix P
This specification revise the old military
specification to state that all ESD protective packaging films will
pass for dissipated materials ( less than 10 to the 11 Ohms per
ESD S11.11) an accelerated aging test of 12 days at 140 degrees
F or 8 days at 160 degrees F. This was in response to the Fowler
associates tests showing normal static shielding films will pass
Is this a reasonable test?
The qualified answer is .. YES!
The ESDJournal therefore states that
for ESD protective packaging the accelerated aging tests that will
give good discriminatory results are:
ESD Protective Materials shall be
static dissipative after 8 days at 160 degrees F.
Also, the best test are real life tests
at the expected humidity and temperature levels.
Aging test are best performed live.
Let the tests begin.........
Do we have an accelerate
aging test? NO!
But we may begin
to establish one!