Exam Revisit (I) • Diagonal term vs. Off-diagonal term • Matrix rearrangement ⎧ FR1 ⎫ ⎡ X ⎪ FR 2⎪ ⎢ X ⎪ ⎢ ⎪ ⎬= ⎨ ⎪ FR3 ⎪ ⎢ O ⎪⎩ FR 4⎪⎭ ⎢⎣ O O X X X O X X X O ⎤ ⎧ DP1 ⎫ O ⎥⎥ ⎪⎪ DP 2⎪⎪ ⎬ ⎨ O ⎥ ⎪ DP3 ⎪ ⎥ X ⎦ ⎪⎩ DP 4⎪⎭ Taesik Lee © 2005 Exam Revisit (II) • Allowable tolerance / Probability of Success ⎧ DPa ⎫ ⎪ DPb ⎪ ⎪ 2 0 2 2 0 ⎤⎪ ⎧ FR1 ⎫ ⎧2⎫ ⎡ 1 ⎪⎪ DPc ⎪⎪ ⎪ ⎪ ⎪ ⎪ ⎢ ⎥ ⎨ FR 2⎬ = ⎨1 ⎬ = ⎢0.5 1 0 0 1 0 ⎥ ⎨ ⎬ DPd ⎪ FR3 ⎪ ⎪3 ⎪ ⎢ 0.1 0.2 0 0 3 0.5⎥ ⎪ ⎪ ⎩ ⎭ ⎩ ⎭ ⎣ ⎦ ⎪ DPe ⎪ ⎪ ⎪ ⎪⎩ DPf ⎪⎭ ⎧ FR 2⎫ ⎧2⎫ ⎡0.5 0 0 ⎤ ⎧ DPa ⎫ ⎪ ⎪ ⎪ ⎪ ⎢ ⎪ ⎥⎪ ⎨ FR1 ⎬ = ⎨1 ⎬ = ⎢ 1 2 0 ⎥ ⎨ DPd ⎬ ⎪ FR3 ⎪ ⎪3 ⎪ ⎢ 0.1 0 0.5⎥ ⎪ DPf ⎪ ⎭ ⎦⎩ ⎭ ⎩ ⎭ ⎣ ⎩ ∆DP 2 + = 2∆FR 2 + = 0.2 ∆DP1+ = −0.5∆DP 2 + + 0.5∆FR1+ = −0.05 ∆DP3 = −0.2∆DP 2 + 2∆FR3 = 0.16 Taesik Lee © 2005 Exam Revisit (III) DP1 A DP1 0.2 0.19 0.16 0.05 0.1 -0.2 0.2 -0.1 DP2 0.1 -0.2 -0.1 -0.05 0.05 0.2 DP2 -0.05 -0.19 -0.2 DP1 DP3 0.2 Joint p.d.f. for (DP1,DP2) 0.16 0.1 0.1 0.1 -0.2 0.2 -0.1 DP2 0.1 -0.2 0.2 -0.1 DP2 -0.1 -0.1 Joint p.d.f. for (DP2,DP3) A Taesik Lee © 2005 -0.2 Design of Manufacturing Systems Taesik Lee © 2005 • What is a manufacturing system? Photo removed for copyright reasons. Photo removed for copyright reasons. 1910… Ford Motor Company Taesik Lee © 2005 2010… Semiconductor Fab Design of fixed manufacturing systems for discrete identical parts Small Scale Problems Taesik Lee © 2005 Ι. Simple deterministic scheduling problem C D E B F A Robot G IN OUT Part Process module for X X Design a manufacturing system to eliminate the root cause of a problem (symptom) In/Out buffer Taesik Lee © 2005 Photoresist processing Vapor Prime VP chill Adhesion promoter Coating Photoresist film Soft Bake SB chill Solvent evaporation Substrate Developed image (negative resist) HB chill Hard Bake Developing Taesik Lee © 2005 Chemical reaction in exposed area PEB chill PEB (Post Exposure Bake) Exposure Deterministic scheduling problem Machine diagram removed for copyright reasons. D C E B F Robot A G IN OUT Part X Process module for X In/Out buffer Taesik Lee © 2005 Process Time (sec) # of modules A 40 2 B 20 1 C 17 1 D 60 2 E 15 1 F 40 2 G 35 2 Level 1 FRs #.1 #.2 Perform process steps with desirable quality Satisfy process flow and throughput DPs Process modules System configuration ⎡ FR1⎤ ⎡X ⎢FR2⎥ = ⎢ ⎣ ⎦ ⎣X X ⎤ ⎡ DP1⎤ ⎥⎢ ⎥ X ⎦ ⎣DP2⎦ Level 2 FRs #.1 Manage the recipe #.2 Support the system physically Move wafer when process is over #.3 DPs Recipe handling module System layout Transport system Taesik Lee © 2005 ⎡ FR2.1⎤ ⎡X ⎢FR2.2⎥ = ⎢O ⎢ ⎥ ⎢ ⎢⎣ FR2.3⎥⎦ ⎢⎣X O X X O ⎤ ⎡ DP2.1⎤ X ⎥⎥ ⎢⎢DP2.2⎥⎥ X ⎥⎦ ⎢⎣ DP2.3⎥⎦ Level 3 - Sub FRs/DPs of FR2.1 FRs #.1 #.2 #.3 Keep TAKTprocess below TAKTsystem Maintain # of moves by main robot not to degrade target throughput Locate process modules into 200-APS frame DPs Number of each process module Number of IBTA Layout (module arrangement) ⎡ FR2.2.1⎤ ⎡X ⎢FR2.2.2⎥ = ⎢O ⎢ ⎥ ⎢ ⎢⎣ FR2.2.3⎥⎦ ⎢⎣X O X X O ⎤ ⎡ DP2.2.1⎤ X ⎥⎥ ⎢⎢DP2.2.2⎥⎥ X ⎥⎦ ⎢⎣ DP2.2.3⎥⎦ Level 3 - Sub FRs/DPs of FR2.2 FRs #.1 #.2 #.3 #.4 #. #. Coordinate transport function Move wafer from CES to VP From VP to VPC From VPC to CT M From HB to HBC From HBC to CES DPs) Command and control algorithm CES handler IBTA Central handler M Central handler SI handler Taesik Lee © 2005 * Design matrix depends on a process plan and selection of DPs. • • • • FR1: move wafer from process 1 to 2 FR2: move wafer from process 2 to 3 : FR5: move wafer from process 5 to 6 • • DP1: robot 1 DP2: robot 2 • • • t=0 t = t1 t = t2 FR = {FR1} FR = {FR4} FR = {FR2, FR3, FR5} DP = {DP1} DP = {DP2} DP = {DP1, DP2} Coupling due to an insufficient number of DPs Taesik Lee © 2005 D C • Problem definition B – Conflict : more than one modules competing for a robot – The conflicts make the waiting time of wafers inconsistent, which degrades onwafer result variation. Robot A SP T1 P2 P1 SP T2 T1 P1 SP SP P1 SP T2 T1 In/Out buffer P3 P2 P1 T2 T1 P3 P2 T2 P3 Delay time T1 P1 P3 P2 Conflict P1 T3 T2 T1 Process module for X X P3 P2 G IN OUT Part P1 E P2 T2 T1 P2 P1 SP P3 T2 P3 T1 P2 P1 SP T3 T2 T1 P1 T3 P3 P2 T1 T2 P2 P3 T2 Example : Process timing diagram with a sending period(6 unit) Taesik Lee © 2005 T3 P3 Deterministic scheduling problem i i −1 i j =1 j =0 j =1 t i = ∑ Pj + ∑ MvPk j + ∑ MvPl j + n ⋅ SP , n = 0,1,2,... Dividing both sides by its SP yields ′ i ′ i −1 i ′ t i = ∑ Pj + ∑ MvPk j + ∑ MvPl j + n , n = 0,1,2,... j =1 ′ j =0 j =1 Original pick-up time Taking only the decimal, G τ i = ti ′ − int(ti ′ ) moment of ith transport task within a period τD E Process τi indicates the (normalized) F τC D C B A IN Conflict 0 0.5 1 1.5 Time (normalized by sending period) Taesik Lee © 2005 2 Solution • Basic concept – Break the conflicts among number of transport requests from process modules – Use predetermined “queue” as a decoupler between process and transport – Insert optimum queue at possible process steps i i −1 i i j =1 j =0 j =1 j =1 t = ∑ Pj + ∑ MvPk j + ∑ MvPl j + n ⋅ SP + ∑ q j , n = 0,1,2,... * i Taesik Lee © 2005 Solution Condition for no-conflict: ~ ≤ τ * −τ * ≤ − ~ tmax 1 tmax i j Where * * τ i −τ j = τ i −τ j + i ∑ k =1 for i = 1,2,... , N ; j = 1,2,… , (i − 1) qk ′ − ~ tmax : longest transport time j ∑ qk ′ = τ i − τ j + k =1 N ∑ (aik − a jk ) ⋅ qk' k =1 Optimize values of qk along with sending period, subject to no-conflict condition and process constraint (qcritical = 0 sec) N min ∑ q 'j j =1 Taesik Lee © 2005 Solution Process Time (sec) Delay (sec) A 40 2 B 20 8 C 17 0 D 60 5 E 15 9 A’ 40 9 F 35 3 Adjusted pick-up time A D B IN 0 0.5 1 1.5 2 Transforming a potentially combinatorial complexity problem to a periodic problem Solution is obtained for one (and repeating) period Taesik Lee © 2005 Manufacturing Systems Design Large Scale Problems Taesik Lee © 2005 Customer’s view on Toyota products Models rated at or below average GM Chrysler 28 7 3 19 10 Ford 10 1 Nissan Honda Models rated above average *The Wall Street Journal May 4, 2000 Toyota 5 1 8 1 10 • World’s No.2 Automaker • $12B profit (2003) • No1. JD Power Initial Quality Prize • Market capitalization of Toyota ($104B) > GM ($24B) + Ford ($23B) + DC ($37B) (2003.11.1) Taesik Lee © 2005 TPS / Lean manufacturing system Set of 19 slides removed for copyright reasons. Source: Production System Design presentation by Dr. David Cochran Taesik Lee © 2005 Conclusion Cartoon removed for copyright reasons. Taesik Lee © 2005