Static Intercept and Corrosion Intercept Technology. ReactivePolymerTechnology DevelopedbyLucent TechnologiesBel Labs

Transcription

1 Static Intercept and Corrosion Intercept Technology ReactivePolymerTechnology DevelopedbyLucent TechnologiesBel Labs 4

2 Corrosion Intercept For Export Packaging Advantages: Proven effective Long effective life Cost Effective Replaces foil Faster packaging - labor savings No need to completely heat seal Why Switch? Volatile Chemical Free Recyclable Re-usable Cost Savings Environmentally safe Effective packaging

3 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 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

4 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

5 OK, So 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

6 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

7 Common Corrosive Gases Ozone (O 3 ) - reactive oxygen Considered a problem with paper and plastic Hydrogen Sulfide (H 2 S) and Sulfur Dioxide (SO 2 ) Effluent from pulp mills, oil refineries, heavy industry, fossil fuel combustion and decaying vegetation Carbonyl Sulfide (COS) Produced from fossil fuel combustion, wood fires and ocean surfaces Nitrous Compounds (NOx) Including amines, amides, ammonia, nitrates, nitrites Hydrogen Chloride (HCl) Fossil fuel combustion and ocean surfaces

8 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

9 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

10 Fungal Attack 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.

11 Volatile Corrosion Inhibitors (VCI) These materials use volatile organic oils coated on the surface of paper or internally loaded into plastics Organic oils volatize from the VCI re-deposit and are absorbed on the metal surface being protected - providing a barrier to corrosive gases A chemical change to the metal surface does seem to occur Advantages: Minimizes Corrosion, has 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

12 Corrosion Thickness (nm) Corrosion Protection of Copper Versus Industrial Coatings Intercept vs. Industrial Inhibitors Bare Copper BTA MDA Intercept Minutes of Exposure Note Copper would have been better protected without the use of surface inhibitors INTERCEPT IS NOT A VCI

13 Floride Chlorine Nitrate Sulfate Sodium Magnesium Calcium Potassium Parts Per Billion Ionic Contamination of Commercial Films Currently Sold Into the Electronics Industry PPB of Ionic Constituents VCI - D VCI- B Intercept VCI - A VCI- B VCI - C VCI - D Intercept

14 Charcoal Paper Inhibitors These materials absorb gases on charcoal impregnated in paper - they act as a sponge Advantages: Minimize corrosion to some degree Inexpensive Disadvantages: Effective shelf life and use life less than 2 yrs Must have relatively stable temperature and humidity or system reverses re-emitting gases No indicator of inhibition depletion Does not and cannot discriminate between corrosive and inert gases

15 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

16 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

17 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

18 Corrosive Gases Try To Penetrate Intercept -- But Fail Intercept provides a reactive barrier to the corrosive gases -- reacting and permanently neutralizing them. As the Intercept is used up it changes colors: Corrosion Intercept : Copper to Gray Static Intercept : Dark Brown to Black Chlorine 15 yr./mil Sulfur 10 yr./mil

19 Preferential Corrosion Site? If a material is a barrier designed to keep things out (except Tyvek and Gortex ) it is also a barrier from the inside out Meaning - gases trapped within the bag cannot escape, so they will turn on what is in the bag Intercept, because of its extremely high Copper surface area, is preferential for these gases -- meaning it is easier to react with the inner Intercept layer than what is stored within Gases will be neutralized by the Intercept layer creating a clean, micro-environment for your components or parts

20 Worldwide Corrosive Gas Levels Levels of H 2 S in the Environment

21 Bell Labs Testing Corrosion Intercept 10 Year Exposure at 7 ppb

22 DuPont Chlorine Test Years to Breakthrough Time Chlorine Takes to Move Through the Plastic Intercept Polyethylene 0 Intercept - 35 Years Polyethylene - 7 Days The same Sclar LDPE resin was used for both materials 1 Part Per Million Chlorine -.002" Thick Film Note: 1 ppm Chloride is normal environmental level

23 Copper Bus Bar Exposure R e s i s t a n c e JunctionResistanceofCoperBusBars(MicroOhms) MetalsBecomeInsulativeasTheyCorode (Days)At7PartsPerBilionH2S Intercept Unprotected SatisfactoryResistance Intercept sheets were being used as interleaves

24 Copper Bus Bar - Real Time Copper Bus Bars Protected for 7 years in an Intercept Bag No Corrosion Unprotected Massive Corrosion Noticeable Corrosion within days Aging

25 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

26 VCI Versus 1 Sided Intercept (Equivalent to a 3 to 4 mil full Intercept bag) in Humidity Test Pinhole in bag Bell Labs Testing -- Corrosion occurred rapidly as soon as paper VCI became saturated

27 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

28 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

29 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

30 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

31 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

32 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

33 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

34 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

35 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

36 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

37 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

38 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

39 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

40 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

41 Apex Paper by Boeing Airbus industries issued a technical follow up bulletin (number ) 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.

42 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

43 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

44 Static Intercept Products Bags - Flat and Reusable 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 Heavy Duty Carrying Bags Intercept Lined 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

45 FPM Inc. Contact: Red Bickerstaff Tel: Cell Presentation Copyright of EMI 2001