Static and Corrosion Intercept Technology

Static Intercept® and Corrosion
Intercept® Technology
Reactive Polymer Technology
Developed by Lucent
Technologies Bell Labs
4
Corrosion Intercept®
and Static Intercept ®
• Advantages:
– Proven effective
– Long shelf life and long
life in service
– Cleanses the air trapped
within enclosure
– Cost Effective
• Replaces foil
• Faster packaging - labor
savings
• No need to completely
heat seal
• Why Switch?
–
–
–
–
Volatile Chemical Free
Recyclable
Re-usable
Excellent electrical
(ESD) protection
– Environmentally safe
– Flexible to be easily
adapted for many
packaging designs
Intercept Technology
• Developed and Patented by Lucent Technologies Bell
Labs
• Designed to Solve the Corrosion problems causing
defects in electronics and assemblies
• Designed to replace FOIL BARRIER packaging as
well as other traditional corrosion prevention systems
• Designed to be a reactive barrier system, not a passive
system like foil systems or volatile systems
• Designed to be inherently clean to avoid
contamination of sensitive components
• Designed to provide passive mildew protection
What is Corrosion?
• Corrosion can be a chemical reaction
between a metal and a reactive, or unstable
gas or liquid
• Corrosion can be an electrical reaction
between dissimilar metals
• Corrosion can be an electro-chemical
reaction between dust and a metal surface
• Basically, corrosion is something that alters
the chemical or physical structure of a metal
Why Do Metals Corrode?
• First, think of metals as they occur naturally
• Noble metals - such as gold and platinum - occur as chunks
of pure metal
• Non-noble metals, basically all the metals left over,
normally occur as salts or compounds
• To make non-noble metals useful they are chemically,
electrically or physically altered or modified to purify them
• The driving force of nature is for systems to revert to their
simplest forms - in the case of a metal, to return to being a
salt or some other stable compound
How does corrosion occur?
• Non-Ferrous Metals
– Primary mode of corrosion is atmospheric corrosion, or
reaction between the metal surface and reactive gases such
as Ozone, Sulfur, Chlorine or Nitrous compounds
• Overseas shipments are particularly sensitive to NOx and Sulfur
compounds that are present in high quantities on ocean surfaces
• Ferrous Metals
– Atmospheric corrosion is one of the common methods of
corrosion or rust
– Galvanic corrosion also occurs
• CD’s
– The metallic layer oxidizes (in the case of Aluminum
turning it clear, erasing the reflective frame of reference)
Common Corrosive Gases
• Ozone (O3) - reactive oxygen
– Considered a problem with paper and plastic
• Hydrogen Sulfide (H2S) and Sulfur Dioxide (SO2)
– Effluent from pulp mills, oil refineries, heavy industry,
fossil fuel combustion and decaying vegetation
• Carbonyl Sulfide (COS)
COS
– Produced from fossil fuel combustion, wood fires and
ocean surfaces
• Nitrous Compounds (NOx)
NOx
– Including amines, amides, ammonia, nitrates, nitrites
• Hydrogen Chloride (HCl)
HCl
– Fossil fuel combustion and ocean surfaces
Protection Against Corrosion
• Keep the corrosive or reactive gases away
from the surface of the material
• Provide a preferential corrosion site
• Provide a sacrificial anode to protect against
galvanic corrosion
– Such as using a zinc coating to protect the keel
of a boat
• Send a small electrical charge across the
surface or through the circuit
We Must Prepare for Corrosion
During the Design Stage
• 90% of the trouble with corrosion in missiles
originates on the drawing board. To be certain of
adequate protection from corrosion, the designer
must anticipate conditions during inert life
(transportation, storage, rework, and repair) as well
as during active operation. The designer’s
responsibility is (1) ascertain the environmental
extremes likely to be encountered - and (2) to provide
corrosion protection against these conditions.”
–
Rebecca Sparling, Corrosion Prevention Should Begin on the Drawing Board, Materials Protection,
December 1963, pp 8-15
Fungal Attach Can be as
Detrimental as Corrosion
• Microbial attack came to widespread notice during
World War 2 when so much damage was done by
fungus in the South Pacific. Although they thrive best
in warm, humid environments, fungi can exist under
cold or dry conditions. As more non-metallic
materials are used in electrical and electronic
assemblies, increased attention must be devoted to
protection from fungal attack. Even the use of
materials that do not support fungal growth may not
solve the problem because fungi can exist on a given
material without feeding on it, creating an undesirable
film deposit on the material.
•
Rebecca Sparling, Corrosion Prevention Should Begin on the Drawing Board, Materials Protection,
December 1963, pp 8-15
Volatile Corrosion Inhibitors (VCI)
•
•
•
•
These materials use volatile oils coated on the surface of paper or internally
loaded into plastics
These oils volatize from the VCI re-deposit and are absorbed on the metal
surface being protected - providing a barrier to corrosive gases - an
equilibrium within the enclosure appears to occur
A chemical change to the metal surface does seem to occur
Advantages:
– Minimizes Corrosion, have been proven effective in various applications
•
Disadvantages:
–
–
–
–
–
Can alter and potentially contaminate protected surfaces
Effective shelf life and effective life may be short and unpredictable
Amine based VCI’s may cause stress crazing in Polycarbonate
Lifetime can be reduced by heat and storage conditions
According to a military document VCI’s do not protect all metals from
corrosion; in fact they appear to increase the rate of corrosion in some metals
– May cause more severe corrosion then if parts had been unprotected
Corrosion Protection of Copper
Versus Industrial Coatings
150
Bare Copper
100
BTA
MDA
50
Intercept
2320
1880
1440
900
420
240
120
60
0
5
Corrosion Thickness
(nm)
Intercept vs. Industrial Inhibitors
Minutes of Exposure
Note
Note––Copper
Copperwould
wouldhave
have
been
beenbetter
betterprotected
protectedwithout
without
the
theuse
useof
ofsurface
surfaceinhibitors
inhibitors
INTERCEPT
INTERCEPTIS
IS
NOT
NOTAAVCI
VCI
Ionic Contamination of Commercial Films Currently
Sold Into the Electronics Industry
PPB of Ionic Constituents
100000
1000
Intercept
VCI - A
100
VCI- B
VCI - C
10
VCI - D
VCI - D
1
Intercept
Potassium
Calcium
Magnesium
Sodium
Sulfate
Nitrate
VCI- B
Chlorine
Floride
Parts Per Billion
10000
Static Intercept ® and
Corrosion Intercept ®
•
•
Intercept is manufactured by reacting highly reactive, high surface area
Copper into a polymer matrix
The plastic's Copper backbone acts in three ways to prevent corrosion
– Gas Barrier
– Preferential Corrosion Site
– Sacrificial Anode
•
•
Advantages:
– Effective corrosion protection for ferrous and non-ferrous metals
– Non-contaminating and Non-coating
– Reacts with and neutralizes corrosive gases
Disadvantages:
– Opaque
How Does Intercept Work?
• Bell Labs determined and found a specific
Copper that had a slight contaminate on it that
caused an exothermic chemical reaction when
combined with a polymer during the heat and
pressure of a compounding (extrusion) operation
• The resulting new polymer enables the plastic to
act as a solid sheet of high surface, highly
reactive Copper sheet
• The resulting new polymer still seals and
functions like a plastic as well
How Does Intercept work (cont.)
• Water and Corrosive Gases
• Corrosion is caused by the reaction of these corrosive
gases and the metal surface
• Water helps the process go faster as well as drops of
water (condensate) can leave staining on the surface as
well as cause rust
• Intercept acts in three primary ways:
1 Intercept acts as a gas barrier - reacting with and
neutralizing gases as they try to penetrate bag
2 Intercept acts as a preferential corrosion site inside the
bag - creating a clean, micro-environment
3 In intimate contact Intercept can act as sacrificial anode
Worldwide Corrosive Gas Levels
Levels of H2S in the Environment
Copper Corrosion
Figure 2
1E+03
Corrosion Thickness (um)
Reactivity
Reactivityof
of
Copper
is
a
Copper is a
straight
straightline
line
relationship
relationship
- -allowing
allowing
easy
easy
prediction
predictionof
of
Intercept
life
Intercept life
1E+02
(Linear Fit)
1E+01
1E+00
1E-01
1E+05
1E+04
1E+03
1E+02
1E+01
H2S Total Exposure (PPB-HR @ 4PPM)
Corrosive Gases Try To
Penetrate Intercept -- But Fail
Intercept
Interceptprovides
providesaa
reactive
reactivebarrier
barrierto
tothe
the
corrosive
corrosivegases
gases---reacting
reactingand
and
permanently
permanently
neutralizing
neutralizingthem.
them.
As
Asthe
theIntercept
Interceptisis
used
usedup
upititchanges
changes
colors:
colors:
Corrosion
Corrosion Intercept®:
Intercept®:
Copper
to
Gray
Copper to Gray
Static
StaticIntercept®:
Intercept®:
Dark
Brown
Dark Brownto
toBlack
Black
Chlorine
Chlorine15
15yr./mil
yr./mil
Sulfur
Sulfur 10
10yr./mil
yr./mil
Intercept - Sulfur Penetration
10 Equiv. Years
Exposure to
7ppb H2S
S/Cu Ratio
14
12
12
um
58 um
10
H2S
8
6
4
Penetration
2
0
0
5
10
15
Depth (um)
20
25
Bell Labs Testing
Corrosion Intercept
10 Year Exposure at 7 ppb
DuPont Chlorine Test
Years to Breakthrough
Time Chlorine Takes to Move Through the Plastic
50
Intercept
Polyethylene
40
30
20
10
0
1 Part Per Million Chlorine - .002" Thick Film
Intercept - 35 Years
Polyethylene - 7 Days
The
Thesame
sameSclar
SclarLDPE
LDPE
resin
resinwas
wasused
usedfor
for
both
bothmaterials
materials
Note:
Note:
11ppm
ppmChloride
Chlorideisisnormal
normal
environmental
level
environmental level
Copper Bus Bar - Real Time
Aging
• Copper Bus Bars
• Protected for 7 years
in an Intercept Bag
– No Corrosion
• Unprotected
– Massive Corrosion
– Noticeable Corrosion
within days
Copper Bus Bar Exposure
Junction Resistance of Copper Bus Bars (Micro Ohms)
Metals Become Insulative as They Corrode
RR
ee
ss
ii
ss
tt
aa
nn
cc
ee
50
Intercept
45
40
Unprotected
35
Satisfactory Resistance
30
25
20
15
10
0
3
5
14
28
42
56
72
(Days) At 7 Parts Per Billion H2S
90
Intercept
Interceptsheets
sheets
were
being
were beingused
used
as
interleaves
as interleaves
Contact Protection
Junction Power Loss (m watts)
25
Effectiveness of Intercept as Replacement for
Inert Atmosphere Packaging
20
15
10
5
0
0
50
100
150
200
250
Applied Current (Amperes)
Bare
No Ox
Intercept.
Gold Plated Lead Frame
Accelerated Aging - Unprotected
• This gold plated lead
frame was left
unprotected in a
moderate level Sulfur
chamber for 2 months
• The resulting is called
undercoat corrosion
• Lead Frame will not
work
Gold Plated Lead Frame
Accelerated Aging - Protected
• The same lead frame
protected with
Intercept
• The lead frame was
left in the chamber
after the unprotected
sample failed
• No corrosion
IC Chips - Real Time Aging
• Note the serious
Galvanic corrosion on
unprotected chip - the
area where the solder
contacts Copper Leads
– Unprotected - 6 month
• Protected in Intercept
Bag for 7 years
– No Corrosion
Intercept versus VCI Testing
Testing
TestingPerformed
Performedat
at
the
theRoyal
RoyalDutch
DutchMint:
Mint:
1,000
1,000Euro
Eurocoins
coinswere
were
placed
into
an
Intercept
placed into an Intercept
bag
bag(3
(3mil)
mil)and
andinto
intoaa
VCI
VCIbag.
bag.
Bags
Bagsthen
thenplaced
placedin
inthe
the
facility
near
an
acid
facility near an acid
bath
bathfor
for11month
month
Results
Resultswere
weredramatic
dramatic- Coins
Coinsprotected
protectedin
inthe
the
Intercept
InterceptBag
Bagremained
remained
pristine
pristineand
andwithout
without
any
visible
corrosion
any visible corrosion
As can be observed the Corrosion Intercept® film placed in an
atmosphere containing chlorine performs significantly better
than normal packaging films and better than Volatile Corrosion
Inhibitors.
VCI Versus 1 Sided Intercept (Equivalent to a 3
to 4 mil full Intercept bag) in Humidity Test
Bell
BellLabs
Labs
Testing
Testing---Corrosion
Corrosion
occurred
occurred
rapidly
rapidlyas
as
soon
as
soon as
paper
paperVCI
VCI
became
became
saturated
saturated
Shotgun Test - Intercept Vs. VCI
• Light manufacturer’s oil left on new shotguns
• Guns placed inside bags
– 3 mil Static Intercept Bag
– 3 mil VCI Bag
• Bag filled with truck exhaust to introduce ozone,
nitrous groups, some sulfur into the bag, water vapor
(replicates truck gun-rack storage)
• Bags sealed
– VCI bag had faster gas permeation rate
• Guns stored outside 2 months in NJ (Nov/Dec)
– Intercept maintained pristine condition
– VCI allowed significant rust formation
VCI stored shotgun
Intercept stored shotgun
Corrosion Properties
•
•
•
•
Reacts with and permanently neutralizes corrosive gases
Leaves no deposits on product
Cleanses trapped air of corrosive gases
Up to 10 years of corrosion protection per mil of
Intercept - long stable shelf life and useful life
• Effective Corrosion & Corrosive Gas Protection for:
– Silver and Silver Alloys
– Copper, Brass, Bronze
– Ferrous Metals and Galvanic Corrosion*
– Garments / Leather
Corrosion Properties (cont..)
• Uses no volatile chemicals
• Built in saturation indicator
• Environmentally friendly and fully recyclable
– Meets German recycle standards (Green Dot) to be
reprocessed in the colored polyethylene stream
– Can be re-used
• Acts a preferential corrosion site
• Acts as a sacrificial anode when in intimate
contact with a galvanic couple
Corrosion and Electronics
• When metals corrode they go from being
conductive to being insulative
• Spots of corrosion on a lead or a conductive
trace can cause narrowing of the metal that
can be used to flow electricity, leading to
decrease in the ability of the path to
dissipate heat causing premature failure
• Corrosion affects solderability - new fluxes
often cannot clean off corrosion
Corrosion and Electronics
• How does Corrosion damage show up in
electronic devices, components, etc.?
–
–
–
–
–
–
–
–
Latent Defects
Soldering Problems
Low Yield
Increased Resistance
Reduction in Performance
Poor Connections
Physical Discoloration, Staining
Contamination
6 Case Studies
1 Computer Manufacturer
– Corrosion on Stainless Steel plotters
2 Computer Manufacturer
– Corrosion issues on frames
3 CT Scanner manufacturer (US)
– Corrosion from International shipping using foil bags
4 US Army Testing
5 Aerospace – long term storage issues
6 Lucent Technologies
– Equipment storage and shipment
– Testing showing Corrosion caused ESD
Computer Manufacturer - Spain
• Stainless steel cabinet for table top plotter had
corrosion/staining after a few weeks because of
green wood pallets
• Wood outgasses Formic Acid, among other acids,
especially when "green"
• Obtaining properly aged pallets was difficult, so
they needed a fail safe method - which Intercept
provided
• Use of Intercept bags eliminated problems
Computer Manufacturer Shipment of Frames
• This manufacturer was having problems with
shipping frames and metal hardware overseas
• Ocean travel - with excesses of Sulfur and
Chlorine ravaged many systems
• Customs cutting open barrier films compromised
barriers causing failures
• Use of volatiles which attracted dust contaminated
components causing intermittent failures
• Switching to Intercept resolved issues
International Shipping of Large
Equipment – CT Scanner
• A manufacturer of CT Scanners and bomb Scanners
had repeated failures shipping equipment overseas
• Foil bags were used, however customs would open the
bags, or inadvertent tears in the barrier would
compromise the bag exposing the product and causing
rust. Once a barrier is compromised there is no
further protection that is afforded the product
• Switched to Intercept bags, no corrosion issues. Even
if the bag is compromised, there is still protection for
the product inside, because Intercept is reactive and
continues to work, though for a much shorter lifespan
US Army Testing - Picatinny
Arsenal
• Designed testing program entitled VCI Free Barrier
Packaging
• 4 and 6 mil Intercept bags showed to be as effective
or more effective than mil 131 foil bags
• When barrier bags are compromised they lose their
effectiveness
• Intercept can continue providing protection even if
the bag is compromised
• Mil Specification PRF 131-J will list 4 and 6 mil
Static Intercept as meeting the foil requirements
Aerojet / Hughes / Boeing
Long Term Storage of Items
• Aerospace companies have issues with long
term storage of parts, boards and assemblies
• The components or assemblies in storage
need to have protection from ESD damage,
as well as from corrosion and contamination
• Intercept was specifically designed for this
type of long term protection, without having
to use expensive dry boxes or special rooms
Lucent Technologies
• Bus Bars
– Above acceptable resistance in 7 days
– Had to clean bars prior to use
– Use of Intercept eliminated cleaning
• Equipment
– Replaced foil barrier bags for all export shipments –
eliminated rusting that occurred when foil bags were
opened or punctured
– Non-contaminating and safe for optical systems
– Intermittent shorts caused by dust accumulation to
oily residue on boards eliminated, because Intercept Is
Non outgassing and Non contaminating
Contamination
• A design criteria for many electronics
applications has to be low or minimal
contamination
– Care should be taken to ensure that your
method of corrosion protection does not
contaminate your part
– Fingerprints and particles can increase the
probability that you will have corrosion issues
or intermittent defects
Apex Paper by Boeing
• Airbus industries issued a technical follow up
bulletin (number 212600011) concerning
problems with dust causing failures of
computer systems
• Examination of subject computers revealed
failure to be caused by intermittent internal
computer board short circuits due to the
presence of hygroscopic conductive dust
inside the computer – as the dust hydrates
they become conductive allowing for shorts.
Protecting Against ESD Damage
is also Critical
• ESD or Electro-Static Discharge is the rapid
transfer of electricity or fields from one
object to another - think of lightning
• ESD is a silent killer of electronics
• Complete packaging for electronics or
assemblies containing electronics includes
protecting against ESD
Static Intercept Electrical Properties
• Permanently Static Dissipative-10e6 to 10e8 Ohms/Sq
• Completely Humidity Independent
• Contains no volatile additives - no or low outgassing
(Meets NASA and Raytheon outgassing
specifications)
• Tribo Charging < 20 volts
• Clean room compatible - no sloughing
• ESD properties unaffected by humidity, temperature or
moisture
• Intercept is CDM (charged device) Safe
Static Intercept® Products
•
•
•
•
•
•
•
•
•
•
•
Bags - Flat and Zipper Closure
New – Polyester Corrosion Intercept ® Bags (Clear)
Extrusion coated paper and fabric
Moisture Barrier Bags - SIF 2000
Export Bags – replacing foil for export shipments
Cushion Bags, Pouches and Rolls
Archival boxes lined with Intercept
PP Plastic Corrugate - Boxes and Sheet
NEW - Corrosion Intercept® Stretch Film
NEW – Static Intercept Shrink Film
NEW – Clear Intercept Coated PET