Automotive Electronic Material Challenges. Anitha Sinkfield, Delphi

Transcription

1 Automotive Electronic Material Challenges Anitha Sinkfield, Delphi

2 Automotive Electronic Material Challenges Project Update About inemi Project Participants Problem Statement Project Details Summary and next steps Timeline Agenda 1

3 About inemi Mission: Forecast and Accelerate improvements in the Electronics Manufacturing Industry for a Sustainable Future. 5 Key Deliverables: Technology Roadmaps Collaborative Deployment Projects Research Priorities Documents Proactive Forums Position Papers International Electronics Manufacturing Initiative (inemi) is an industry-led consortium of over 100 global manufacturers, suppliers, industry associations, government agencies and universities. A Non Profit Fully Funded by Member Dues; All Funding is Returned to the Members in High Value Programs and Services; In Operation Since Visit us at 2

4 Project Participants 3 3

5 Problem Project Summary For passenger compartment automotive electronics lack of proper materials/interface understanding is impacting long term reliability predictions Opportunity Predict and understand functional performance of small geometries in harsh environments through measurement of material and interface properties Goal Measure functional performance of small geometries through understanding a combination of material properties and interface properties. Gaps and recommendations will be identified and closed, where possible in the project timeframe. End goal is to have the necessary information to predict reliability of technology to reduce design cycles. This would optimize reliability and reduce costs for the industry as a whole. 4

6 10+ year lifetime The Challenge Electronics Technology and Materials 2 year lifetime Harsh Environment Ambient Environment Automotive Electronics Requirements Consumer Electronics Requirements 5

7 Consequences of Changing Intended Use Consumer Military Issues in Automotive Application Cameras Capacitive Touch Curved Displays Under tested/designed - reliability Under tested/designed - reliability Under tested/designed - reliability Radar GPC/Navigation Over tested/designed - cost Over tested/designed - cost 6

8 Background Automobiles are incorporating more and more electronics from various industry sectors. The conditions within a vehicle include thermal cycles, shock, vibration and heat aging with reliability expectations beyond typical consumer electronics (10 20 years). The drive for miniaturization coupled with automotive reliability expectations requires better understanding of material properties beyond standard bulk analysis. 7

9 Camera - Seeing, Sensing & Knowing Today, cameras are designed for consumer applications Could you take a readable image of a road sign at 60mph with your cell phone? Need modifications for automotive environment Higher temperature materials (+20 to 50C) Increased Shock and vibration Increased UV and low temperature cure assembly adhesives Vehicles will have multiple cameras Front, Rear, Side, Stereoscopic Increasing camera production volume Continued miniaturization Increased processing power Front view Rear view 8

10 Displays - Connectivity Trends Vehicle displays are becoming ubiquitous Cluster Center stack Back seat Displays are often designed for normal consumer environment Customer s expect same performance in a moving vehicle Automotive displays come in non-standard sizes to meet styling needs Display modules LCD vs. OLED Increased EMI shielding Touch layer technology Optical Bonding materials 9

11 Project Objectives While keeping automotive requirements in mind Identify dominant failure mechanisms Focus on particular materials or categories of materials and/or components. Prioritize key properties for predictive modeling of reliability and performance Identify existing test methods for small geometries and relevant interfaces Recommend future projects to develop new test methods 10

12 Failure Mode Examination Component/ Subassembly/ Material Failure Mode Consumer Spec Automotive Spec Spec DIFFERENCES Lead-less Device (BGA, Pb-Free Solder QFN, ) joint Thermal Cycle Fatigue IPC 9701A -40 / +85C Fracture (Drop) Fracture (Vibration) For component JEDEC 22-B110 JEDEC 22-B111 For module IEC IEC For component JEDEC 22-B103B For Module IEC For component AEC Q100 (Shock Test)/ Q101 / Q200 For module ISO Shock / Drop For component AEC Q100 / Q101 / Q200 For module ISO Vibration AEC Q100 / Q005 Governing Material Property(ies) or the Physics of the failure as typically understood Temp range - Total cycles Alloy Type. Solder alloy properties: Temperature dependent Youngs Modulus, yield strength; creep and visco-plastic constitutive models; CTE 2 falls per DUT (ISO)? IMC properties (Intermetallic). Solder alloy (yield strength defines stress transfer) + IMC properties: fracture Strength, Youngs Modulus; CTE JEDEC 22-A201A JEDEC 201A Component lead Tin whisker -40~85c, 1000Cycle -40~85c, 1500cycle 500 more cycles; 3000 Tin Alloy Type 55c/85%, 1000hr 55c/85%, 4000hr more hr EMC Delamination Adhesion strength (to chip and leadframe) Wire bond Thermal Cycle Fatigue Fracture (material degradation) are the reliability tests same for component as listed Thermal Cycle Fatigue above Kirkendall voiding/ IMC growth Joule heating/electromigrati on CTE, E --> stresses applied to solder interconnections (low EMC inemi project) Fracture strength Temp range - Total cycles Yield strength (plastic deformation to be avoided) Slightly higher operating temp? Activation energy (known) Slightly higher operating Activation energy (known) temp? (Joule heating: Currents above 1A; Electromigration: 105 (Al) (Cu) A/cm2) Die attach Delamination Adhesion strength Leadframe/EMC SIR Cleaning issue Thermal interface materials Adhesive Cracking, DelaminationThermal Cycling Thermal Cycling Delamination Adhesion strength / Thermal conductivity (thermal resistance measurement) Thermal Pad bake out /dry cracks Humidity Humidity Hardening Pre-cured Gel Hardening Thermal Grease Pump-out Pump-out Lens fixturing (camera, display) Adhesive Delamination Lens seal (Camera, display) Adhesive Moisture intrusion Gasket 11

13 Test Method Comparison Drop/Mechanical Shock Consumer Automotive Component Module Component Module [IC] AEC Q100 JESD22-B104 (# shocks: 5x 6 directions) + Y1 plane only, 5 pulses, 0.5 msec duration, IEC g peak acceleration. TEST before and after at room temperature. JEDEC 22-B drops in each of 6 directions depending on state of application JEDEC 22-B111 Board level drop test of components for handheld electronics IEC [PASSIVE] AEC Q101 JESD22-B Hz to 2 KHz to 20 Hz (logarithmic variation) in >4 minutes, 4X in each orientation, 50 g peak acceleration. TEST before and after at room temperature. [DISCRETE] AEC Q200 SMD components: MIL-STD-202 Method 213 ; Figure 1 of Method 213 : Condition F Leaded components: MIL-STD-202 Method 213; Figure 1 of Method 213. Condition C ISO Shock / Drop test 3 DUTS w/ each 2 drops for 1m drop height onto concrete/steel 12

14 Test Methods Team is learning how the products are tested Can we say the materials are being tested appropriately? For instance, material test specimens are much larger than functional materials in electronics 13

15 Consumer Electronics Pb-Free Solder Alloy SAC 305 alloy selected as BGA ball alloy High reliability in Thermal Cycle Cell Phones get dropped! BGA solder joint damage Cell phone solution is to switch BGA balls to a low-ag alloy But in the automotive environment we must consider both failure modes simultaneously 14

16 Automotive Electronics Unstressed à Drop/Shock/Vibe à Elongation Adhesion Thermal Cycleà CTE mismatch Strength 15

17 Anticipated Project Outputs Identify the key material characteristics that drive reliability of systems in Automotive Electronics Limit scope to 2-3 material categories (eg. adhesive, TIM, solder) Recommend alternative sample preparation or test methodology for more accurate simulation of material performance in micro-electronics Similar to Jeffrey C. Suhling, et. al. in Auburn University study of SAC alloy aging 16

18 Project Schedule & Tasks The Timetable for this project is about 12 months TASK LIST Q1 Q2 Q3 Q4 Q5 Identify dominant failure mechanisms interface) Identify materials/categories to focus on Prioritize key properties for predictive modeling of reliability and performance Identify tests/test methods for small geometries for selected materials/categories (May result in a recommendation to develop a method) Identify relevant interface properties/ test methods Develop Gap Analysis and Recommendations 17

19 contacts: Mark Schaffer