1 / 41

Application of Controlled Thermal Expansion in Diffusion Bonding for the

Master Defense. Christoph Pluess Oregon State University Corvallis September 10, 2004. Application of Controlled Thermal Expansion in Diffusion Bonding for the High-Volume Microlamination of MECS Devices. 1 of 36. Literature & Patent Review. Questions & Discussion.

meadow
Download Presentation

Application of Controlled Thermal Expansion in Diffusion Bonding for the

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Master Defense Christoph Pluess Oregon State University Corvallis September 10, 2004 Application of Controlled Thermal Expansion in Diffusion Bonding for the High-Volume Microlamination of MECS Devices

  2. 1 of 36 • Literature & Patent Review • Questions & Discussion • Theoretical Concept & Device Design • Introduction • Results & Conclusions • Experimental Approach • Finite Element Analysis (FEA) • Table of Contents  2004 Christoph Pluess

  3. 2 of 36 Bulk m-Fluidic Devices (MECS) • Introduction  2004 Christoph Pluess

  4. 3 of 36 t p T p OSU Device • Introduction Microlamination (Paul et al., 1999) • Patterning • Laser Micromachining • Chemical Etching • Registration • Pin Alignment • TEER (Thermal Enhanced Edge Registration) • Bonding • Diffusion Bonding • Diffusion Brazing  2004 Christoph Pluess

  5. 4 of 36  Production Capability: • Pump-down: 0.75-1h • Ramp-up: 0.75-1h • Bonding: 0.5-1h • Cool-down: 2-3h • Cycle Time: 4-6h • Introduction Why is this topic relevant? Example: Solid-State Diffusion Bonding within a Vacuum Hot Press Vacuum Hot Press, Nano/Micro Fabrication Facility  2004 Christoph Pluess

  6. 5 of 36  Device Size: • Large Substrate MECS Devices • Large Hot Press System ($) • Pressure Uniformity • Introduction Why is this topic relevant? Example: Solid-State Diffusion Bonding within a Vacuum Hot Press Vacuum Hot Press, Nano/Micro Fabrication Facility  2004 Christoph Pluess

  7. 6 of 36 Conveyor Furnace “Sequoia”, MRL Industries • DCTE Fixture • DCTE, free source of pressure • low expanding frame • high expanding inner parts • Continouous Furnace System • Similar to microelectronics industry • high-volume microlamination • Introduction Using thermal expansion? Possible solution?  2004 Christoph Pluess

  8. 7 of 36 • Introduction DCTE Bonding Fixture • Is this a plausible approach for microlamination? • Can a particular fixture design provide control over: • Pressure magnitude? • Pressure timing? • Pressure sensitivity?  2004 Christoph Pluess

  9. 8 of 36 • Literature & Patent Review Is this idea unique? • Use of thermal expansion for pressure application first stated by PNNL in 1999 • Most papers/publications try to minimize effects of thermal expansion • Patents where thermal expansion is used to apply pressure/force: • Clamping ring for wafers US 5,460,703 (1995) • Belt press using DCTE US 6,228,200 (2001)  2004 Christoph Pluess

  10. 9 of 36  2003, McHerron, IBM • Literature & Patent Review Is this idea unique? Patent Application Publication US 2003/0221777 A1 McHerron et al. International Business Machines Corp. (IBM) Method and Apparatus for Application of Pressure to a Workpiece by Thermal Expansion  2004 Christoph Pluess

  11. 10 of 36 • Is this a plausible approach for microlamination? • Can a particular fixture design provide control over: • Pressure magnitude? • Pressure timing? • Pressure sensitivity? • Literature & Patent Review IBM Patent Application • Lamination of multilayer thin film structures (MLTF) • Use for continuous production and high throughput • Reduction of capital expenditures for lamination of MLTF  2004 Christoph Pluess

  12. 11 of 36 Theoretical Study and Model Development • Theoretical Model Gap closure function: Resulting strain in z-direction: Resulting pressure in z-direction :  2004 Christoph Pluess

  13. 12 of 36 • initial gap variations of 1mm  pressure change 1.6 MPa • assumed accuracy with feeler gage 5mm 8.0 MPa Geometrical Sensitivity: 1.6 MPa/mm • temperature fluctuations of 5°C  pressure change 4.7 MPa Thermal Sensitivity: 0.94 MPa/°C • Theoretical Model Sensitivity Analysis Applying reasonable material properties and sizes: • Lowering thermal sensitivity  increases geometrical sensitivity • Lowering geometrical sensitivity  increases thermal sensitivity  2004 Christoph Pluess

  14. 13 of 36 Pressure Timing: Initial gap adjustment Low expanding fixture frame Pressure Magnitude: Preloading and force storage with spring elements High expanding engagement block Pressure Sensitivity: Spring constant • Fixture Concept  2004 Christoph Pluess

  15. 14 of 36 • Fixture Design Fixture Frame: Initial gap setting Inner Parts: Load Cell Bonding Platens Inconel Disc Springs • Designed to fit in hot press ( 3”) • Max. service temperature 800°C • Bonding area 25x25mm (2 stations) Engagement Block Cu Laminae  2004 Christoph Pluess

  16. 15 of 36 Purpose of FE-Model • Validation of developed fixture design • Proof of feasibility • Theoretical assessment of pressure magnitude, timing and sensitivity • Fixture Model (FEM)  2004 Christoph Pluess

  17. 16 of 36 • Fixture Model (FEM) Expansion Behavior (in z-direction) • gap closure function:  2004 Christoph Pluess

  18. 17 of 36 • Fixture Model (FEM) p-Timing, p-Magnitude, p-Sensitivity • 150 times less sensitive than simple fixture model (0.94MPa/°C)  2004 Christoph Pluess

  19. 18 of 36 • Fixture Simulation  2004 Christoph Pluess

  20. 19 of 36 • Experimental DCTE-Fixture Prototype  2004 Christoph Pluess

  21. 20 of 36 • Experimental Experimental Overview Validation Experiments Test Article Orientation  2004 Christoph Pluess

  22. 21 of 36 • Experimental Experimental Overview Validation Experiments Test Article Orientation Load Cell Validation • Theoretical: 10’960 N/mm • Practical: 11’215 N/mm (+2.3%)  2004 Christoph Pluess

  23. 22 of 36 before: 3.0 3.5 4.0 4.5 5.0 5.5 6.0 MPa after: 3.0 3.5 4.0 4.5 5.0 5.5 6.0 MPa • Experimental Experimental Overview Validation Experiments Test Article Orientation • Fuji Pressure Sensitive Film Load Cell Validation p-Uniformity Bonding Platens  2004 Christoph Pluess

  24. 23 of 36 • Experimental Experimental Overview Validation Experiments DT Test Article Orientation 0°C Load Cell Validation 300°C p-Uniformity Bonding Platens 400°C p-Timing during Lamination 600°C 800°C • Experimental • Theoretical (FEM)  2004 Christoph Pluess

  25. 24 of 36 • Experimental Experimental Overview Validation Experiments • At low temperature (180°C): Test Article Orientation g0=0mm g0=30mm g0=50mm g0=70mm Load Cell Validation p-Uniformity Bonding Platens • T-limit of Fuji film 180°C • No contact situation with g0 > 63mm based on theoretical model • Experimental validation of DCTE- Fixture at low temperature! • Uniform pressure distribution p-Timing during Lamination p-Timing of DCTE-Fixture  2004 Christoph Pluess

  26. 25 of 36 • Experimental • T-profile optimization by connecting TC directly to temperature control unit: Experimental Overview Validation Experiments Test Article Orientation Load Cell Validation p-Uniformity Bonding Platens • Furnace cool down optimization with helium cooling: p-Timing during Lamination p-Timing of DCTE-Fixture TC Measurements  2004 Christoph Pluess

  27. 26 of 36 DCTE-Fixture Hot Press vs. • Experimental Experimental Overview Validation Experiments Final Experiment Test Article Orientation Fin warpage (timing) Load Cell Validation Void fraction (p-magnitude) p-Uniformity Bonding Platens p-Timing during Lamination p-Timing of DCTE-Fixture TC Measurements  2004 Christoph Pluess

  28. 27 of 36 • Experimental DOE Final Experiment • 24 full-factorial design with 1 replicate (32 runs) • Mode: Hot Press / Fixture • Pressure: 3 MPa / 6 MPa • Temperature: 500°C / 800°C • Time: 30’ / 60’ • 2 samples each run for a total of 64 test samples 32 32 • ANOVA on fin warpage (128 measurements) • ANOVA on void fraction (160 measurements)  2004 Christoph Pluess

  29. 28 of 36 • Results ANOVA Fin Warpage • No statistical significant difference observed (p-value 0.92) • Average fin warpage hot press: 3.99 mm  0.44 mm • Average fin warpage DCTE-fixture: 4.02 mm  0.44 mm  2004 Christoph Pluess

  30. 29 of 36 • Results Void Fraction Inspection • Metallographic preparation of the 16 samples • 10 inspection locations for each DB set (160 measurements) • Voids were marked on a • transparency at 384X • Calculation of void fractions • (reference length 250 mm)  2004 Christoph Pluess

  31. 30 of 36 • Results Metallographic Pictures Bond Lines (Void Shrinkage) Hot Press DCTE-Fixture 500°C 3 MPa 60 min 78.8% 70.5% 800°C 3 MPa 60 min 15.8% 23.2% 800°C 6 MPa 60 min 8.0% 9.6%  2004 Christoph Pluess

  32. 31 of 36 • Results ANOVA & Table of Means for Void Fraction • Statistical significant difference observed • Since T & t are equal, variation is due to pressure applied  2004 Christoph Pluess

  33. 32 of 36 • Results ANOVA for Void Fraction (Interactions) • Less significant difference at low pressures • (frame stiffness maintained) • Less significant differences at high temperatures • (void fraction less pressure sensitive at high temp.)  2004 Christoph Pluess

  34. 33 of 36 • Results Comments • Timing of pressure within the DCTE-fixture did not show • any problems • Although void fractions showed a difference, bond quality is comparable • Source of p-variation due to the use of high expanding stainless steel bolts (potential loss of preload) • Level of pressure was dampened due to spring • implementation in frame (loss of rigidity)  2004 Christoph Pluess

  35. 34 of 36 • Conclusions • Is this a plausible approach for microlamination? • Can a particular fixture design provide control over: • Pressure magnitude? • Pressure timing? • Pressure sensitivity?  yes ( yes)  yes  yes  2004 Christoph Pluess

  36. 35 of 36 • Future Research • DCTE-Fixture design for large substrates • Validation of large substrate fixture design with FEM: • Structural, p-uniformity • Thermal, T-gradients • Process optimization for continuous production line • Experimental investigation of large substrate bonding  2004 Christoph Pluess

  37. 36 of 36 • Questions & Discussion Thanks for your attention! M.S. Defense Presentation Christoph Pluess September 10th 2004 Oregon State University Corvallis USA Special thanks to: Major Professor Dr. Brian K. Paul Committee Members: Dr. Sundar V. Atre Dr. Kevin M. Drost Dr. Timothy C. Kennedy Dr. Zhaohui Wu Special thanks to: Steven Etringer  2004 Christoph Pluess

  38. Additional Slides  2004 Christoph Pluess

  39. Experimental First DCTE-Prototype • 7 MPa at 800°C • 5 Cu-layers bonded: 02/20/2004 • 1st successful DCTE-bond  2004 Christoph Pluess

  40. Fixture Model (FEM) FE-Model Features (ANSYS) • ¼ model • 6655 elements (17’000 nodes) • LINK10 prevented use of contact elements • One solid structure (SOLID95) • Spring constant, initial gap, preload of load cell defined over real constants • Input of bonding parameters over Scalar Parameter Menu • Automatic load step definition and execution with APDL-macro  2004 Christoph Pluess

  41. FE-Model Settings Real Constant Settings  2004 Christoph Pluess

More Related