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Lead - Free , Unfortunate Reality

Lead - Free , Unfortunate Reality. … Facing Its Challenges. Presented by Lawrence Weber Senior Electronics Engineer Tobyhanna Army Depot. Presentation Content. Part 1 - The Challenge Part 2. - Great Expectations Part 3. - Brave New World. Part 1 - The Challenge.

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Lead - Free , Unfortunate Reality

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  1. Lead - Free , Unfortunate Reality …Facing Its Challenges Presented by Lawrence Weber Senior Electronics Engineer Tobyhanna Army Depot

  2. Presentation Content • Part 1 - The Challenge • Part 2. - Great Expectations • Part 3. - Brave New World

  3. Part 1 - The Challenge • Clear and Present Danger • Avionics Study • Problems • Lead-Free Depot View

  4. 1a. Clear and Present Danger • World market swings manufacturers toward: • ROHs (Restriction on Hazardous Substances) • Lead-Free coated products compliancy • Electronic Short-Term Reliability consumer market swamps High Reliability Military market • ROHs- imposed standards shift industry quickly to change part coating, solder alloy and board design practices • Lead acid Batteries -88% of problem – exempt • Alloy changes to Part/Board go unopposed as substitutions occur • Coating and soldering formulations remain nonstandard • Catastrophic failures dropping satellites identified • Reliability issues emerge as causes

  5. 1b. Avionics Study - Hits Home Mfg / Delivery Changes Expected ( JCAA Study* Surveyed 42 companies delivering High Rel and Consumer parts ) • CO. SOLDER/OPERATION • 5% of (42) have/will convert from lead by 2008 • 50% of (42) solder choice unsettled • CO. OEM SOURCES • Part Source - Asian only 30% are 100% Tin-Lead US only 10% are 100% Tin-Lead • Part Purchase - (2) 95-100% lead free by 2008 (40) 20- 50% lead free by ___ • SOURCE OVERALL PROD (NA, EUR,ASIA) • Part finishes 87% NOT Tin-Lead (est.) • PWB finishes 88% NOT Tin-Lead (est.) • ORDERS (drawn from above sources): • Military/ High Rel orders are only 1.1% • Other 98.9% • PART ID • ID with part #s , markings, symbols or vendor certificates • PWB ASSEMBLY • 40% Separate Lines • 30% Combine Lines • 30% Not Sure * Final Report

  6. 1c. The Problems Tin Whiskers • Conductive crystalline structure • Few microns to over 5mm length • Soldering • New processes & equipment • 35 C increase in processing temp • Thermal stress of PCB & parts Select Picture above to Start Video • Tin Plague • Metal disintegrates into powder • Low temperature phenomenon (<13C) • Solder Joint Reliability • Less robust in severe environments • Incompatibility between alloys • Cannot mix tin-lead and lead-free solder

  7. 1d. Pure Tin Failures • 6 Satellites • 5 Navy Missiles 1985-1992 • F-15 Radar • Patriot Missile • Heart Pacemakers • Communications Equipment • Data Processing Equipment • Power Switching Equipment

  8. 1e. LEAD-FREE DEPOT VIEW as seen by the … R - eliability Hi-Rel vs Short-Term-Rel E - xemption Limited, with Review A - ccountability Unprepared Supply L - ogistics Impacts source/support I - nspections Assurance required S - ituations Life Cycle challenge T - esting Incomplete

  9. Part 2. - BRAVE NEW WORLD with Great Expectations • Lead-Free-Included Repair Plan • Quality Spot-Check • Source Chain Management • Repair / Operational Cost Avoidance

  10. 2a. Lead-Free Included Repair Plan Focused Lead-Free Awareness and Quality Spot Checks • Training on LF/NLF • XRF Screen for Lead Parts • Screen for ROHs labels • Surface Test for lead • Repair/Replace LF,NLF • Verify Repair • Final Test Focused Lead-Free Scrutiny Targeted • Inspection Points • Monitor • Repair

  11. 2b. Source Chain Management for Hi-Rel Electronic Parts WHY CERTIFY? - ITS NOT ROCKET SCIENCE ! - Given: 1) Trusted sources 99% reliable to avoid LF 2) Other sources only 90% reliable to avoid LF 3) 1000 orders placed for High Rel Leaded Part METHOD A. Using only Trusted source we get: 990 - As required 10 - ( could have LF) METHOD B. Using Trusted 90% and Other 10% we get 891- As required from Trusted 9 - ( could have LF) from Trusted 90 - As required from Other 10 - ( could have LF) from Other Total 981 as required 19 - ( could have LF ) RESULT>> We have nearly DOUBLED chances of getting LF by using a slightly less reliable source for only 10% of the orders . This board’s repair parts may come from… …. some unexpected part source. WHAT TO DO Impose tight rein on High Rel Electronic part source suppliers. Certify! RESULTS Traceable Certification Chain. assures High Reliability parts are “as expected”, particularly during the change-over to Lead-Free (LF). BOGUS parts discouraged from entering the supply chain

  12. 2c. Repair/Operational Cost Avoidance Avoids field and long term failures as well as cost of added testing, and multiple faults isolation. • Locates unexpected mixed -metallurgy ( Lead-free w/ Leaded) • Separates Lead and Lead- Free circuit boards repairs • Tracks Lead-Free repairs

  13. Part 3 - The Brave New World • Adapted/New Technology • Observations • Recommendations • Opportunity • GOAL

  14. 3a. Adapted / New Technology WANTED for LEAD-FREE! • Advanced XRF (X-RAY Fluorescence Detector) • Hand held • Scanning and spectrum recognition • Tuned to likely damaging alloy mix • Detects low percentage Bismuth alloys • Advanced LEAD SWAB • Ignores “trace” amounts of metals • Self Contained Chemical test • Long term stability of indicator • Safe/ Odorless • Reduced costs – for expected high volume • Reduced cost • Lead Substitute Tin-Alloy Material • Alloyable with Tin • Lead-like Behavior • Metal-Like Outer Electron Shell • Elementally a Non- Metal • Repair Marker for Lead-free • Detectable Dye • Field -Scannable • Stable Long term • Conformal Coating- Compatible • High Rel Part./Board Certification • Physical Mark or Stamp • Standardized DOD wide • Difficult to counterfeit • Close held/registered use • Tin Whisker Removal System • Breaks off /Collects whiskers • Applied to any circuit-board • ESD safe • Minimize Vibration • >95% confidence level • Auto Re-dip Process* • Lead Solder Re-dip of Tin Coatings • Robotic handling of various part types • ESD safe • Adv XRF SCANNER • Adv LEAD SWAB • LEAD SUBSTITUTE • REPAIR MARKER • HIGH-REL PART/BD CTFY • TIN WHISKER REMOVAL • AUTO RE-DIP PROCESS *Ref - Final Report on the Transformational Manufacturing Technology Initiative (TMTI) ManTech Research Project S1057: Tin Whisker Mitigation The Use of Robotic Solder Dipping to Replace Electronic Part Surfaces Finishes of Pure Tin with a Tin-Lead Finish

  15. 3b. Observations 50+ years of Tin/Lead soldermethods have been successful, … Q. What about short term commercial usage reliability? A. So far High Tin content alloys appear effective but only observed in short-term commercial applications. Q. What about long term usage for military high reliability? A. It is an expected problem. Metal crystal growth promotes a SHORT-CIRCUIT because, features are decreasing in size Longer time to grow across shorter gaps leads to stress- induced crystal growth. With extended use and, it also causes an OPEN CIRCUIT repair with mixed Alloys leads to brittle fracture planes. Unfortunately, growth may go on unobserved for years; Tin Whisker damage can occur anywhere in the production, test, shipment or field use of equipment. Q. Can we guarantee no whiskers will occur with any High Tin content alloy? A. No. No Tenable scheme exists to guarantee that a whisker cannot form … but now, as of JULY 1, 2006, changes to remove Lead from finishes and solder are demanded for world sales! Non-leaded solder or coatings allows Lead-Free parts to find their way into High Reliability applications.  There WILL BE an increased likelihood of SHORTS and OPENS in High Rel parts over long terms!

  16. Recommendation - Depot IPT Lead-Free Process Integration Support Team OBJECTIVES • TECHNOLOGY SUPPORT • Advanced Lead Swab • Advanced XRF • Lead Substitute • Repair Marker • High-Rel Certif. Mark • Auto Re-Dip • LEAD FREE INCLUSION • Expect Lead-Free • Repair Differently • Avoid Mixing • LOGISTICS OVERHAUL • Improve DOD Source • Track Supply chain • Report Discrepancies • Track Failures • Qualify Sources • Certify Sources

  17. Opportunity Tobyhanna Army Depot has currently identified accelerating opportunity costs to control the inclusion of Lead Free and mitigate damages of approximately: $ X.XX Million /yr

  18. Sustainment while functioning within a Lead-Free Reality.. Is the GOAL. Lead-Free supplier process conversion rate since 2006 is projected to be 5% by 2008 Current Trends …Lead free ghosts… “They’re here..” NEWS FLASH --- MAY 2007 -- Intel Corporation today announced that its future processors are going 100 percent lead-free. The Present Value opportunity cost to remove lead-free intrusion will likely double by 2010 - Proactive approach is paramount.

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