Eliminate Coil Wire Breakage On Passive Anti-Theft System (PATS)

Eliminate Coil Wire Breakage on Passive Anti-Theft System (PATS) 1

Six Sigma Team Passive Anti-Theft System Black Belt Candidate: Sam. H.– OEM Master Black Belt: Tom R. – OEM Project Champion: Greg B. - OEM Black Belt: Wayne T. - OMRON Project Champion: Warren. W. – OMRON Process Owner: Tom S. – OMRON Financial Analyst: Bill N. – OMRON 2

D M A I C R DEFINE VOICE OF THE CUSTOMER Electronics Functional Area Name – Passive Anti-Theft System PATS PROJECT CLASSIFICATION: Passive Anti-Theft System (PATS). Wayne Tollefsen TREND CHARTS and BREAKDOWN OF ISSUE: New component – 55 parts (50 Plant & 5 Warranty) returned for no function due to broken coil wire. Y f(x) CASCADE: See Fishbone Diagram The wire breaks here when the PATS is flexed during assembly at the customer location. VOICE OF THE CUSTOMER: Parts may not operate when compressed into the Key Lock Cylinder during assembly. Failure of the part to operate after assembly has been determined to be due to a broken coil wire. Failures have been observed at both the assembly plant and in warranty. CTQ STATEMENT (Customer Requirement): Part must function as designed. Part should be robust to multiple platform applications. DEFECT DEFINITION for Y (Engineering Metric): Parts Inoperable. When the part is compressed into the Key Lock Cylinder the coil wire on the outside location breaks. For analysis purposes we will use only one opportunity per part. COST OF POOR QUALITY: 900,000 PROBLEM STATEMENT, SCOPE, AND GOAL: 55 parts have been rejected due no function, 50 plant and 5 warranty returns. In each case, no function was due to broken coil wire. 3

D M A I C R MEASURE CTQ (y) CAPABILITY Broken Coil Wire on PATS C & E Diagram RED Indicates primary areas of investigation. 4

D M A I C R ANALYZE y f(x) Potential Critical Inputs to be investigated: – Parts handling – Coil Winder Coil Pin deflection to increase coil wire elongation via process modification. Increase coil wire elongation by optimizing Coil Winding process using Design of Experiments. – Plastic Coil Design Remove plastic strain relief. 5

ANALYZE y f(x) D M A I C R Process Flow: OMRON RED Indicates primary areas of investigation. 6

ANALYZE y f(x) D M A I C R Process Flow: Supplier(s) to End Customer Defective parts are encountered at Tier 1 during assembly into Instrument Panel. Customer Tier 1 Parts test OK Tier 2 3XX: Key Lock Cylinder without ridge Tier 1 Parts test OK OMRON Parts test OK 2XX: Key Lock Cylinder with ridge 7

ANALYZE y f(x) D M A I C R PATS Key Lock Cylinders used on 3XX & 2XX 6.98mm 3XX: 6.98mm of deflection 3.34mm 2XX: 3.34mm of deflection 8

D M A I C R ANALYZE y f(x) Coil Pin deflection during coil winding process. 0mm 1mm 2mm Data Summary Deflection Average Std. Elongation Dev. 1mm 6.34mm 2.62mm 2mm 7.38mm 1.84mm Ref Capability Studies on slides 13 & 14. 9

D M A I C ANALYZE y f(x) PATS Coil Winder -- Coil Pin Deflection @ 1mm LSL Process Data USL Target USL 12.0000 Target LSL 6.9800 1.0000 Mean 6.3385 Sample N Within Overall 24 StDev (Within) 2.62002 StDev (Overall) 2.96708 Potential (Within) Capability Cp 0.87 CPU CPL 0.90 0.85 Cpk 0.85 Cpm 0.84 Overall Capability 0 2 4 6 8 10 12 Pp 0.87 Observed Performance PPM LSL 0.00 Exp. "Within" Performance PPM LSL 5509.20 Exp. "Overall" Performance PPM LSL 5637.58 PPU 0.90 PPM USL 0.00 PPM USL 3509.70 PPM USL 3600.82 PPL 0.84 PPM Total 0.00 PPM Total 9018.90 PPM Total 9238.40 Ppk 0.84 10 R

D ANALYZE y f(x) M A I C PATS Coil Winder -- Coil Pin Deflection @ 2mm LSL Process Data Target USL 12.0000 USL Target 6.9800 LSL 1.0000 Mean 7.3765 Within Overall 24 Sample N StDev (Within) 1.84068 StDev (Overall) 1.95129 Potential (Within) Capability Cp 0.93 CPU CPL 0.72 1.13 Cpk 0.72 Cpm 0.97 Overall Capability 0 2 4 6 8 10 Exp. "Within" Performance PPM LSL 354.65 12 14 Pp 1.05 Observed Performance PPM LSL 0.00 Exp. "Overall" Performance PPM LSL 64.21 PPU 0.82 PPM USL 0.00 PPM USL 15090.57 PPM USL 7110.36 PPL 1.28 PPM Total 0.00 PPM Total 15445.22 PPM Total 7174.57 Ppk 0.82 11 R

D M A I C ANALYZE y f(x) Coil Pin Deflection Experiment Conclusion After conducting the experiment on Coil Pin Deflection it was determined that there was no way to assure the integrity of the solder joint between Coil Pin and PCB when the Coil Pin is bent 2mm. Therefore the team decided not to change the Coil Winding process to include Coil Pin Deflection 12 R

D M A I C ANALYZE y f(x) Potential Critical Inputs to be investigated: – Parts handling – Coil Winder Coil Pin deflection to increase coil wire elongation via process modification No Effect on Failure Mode Increase coil wire elongation by optimizing Coil Winding process using Design of Experiments. – Plastic Coil Design Remove plastic strain relief. 13 R

IMPROVE y f(x) D M A I C The team further speculated that the coil wire elongation could be increased by optimizing the Coil Winder process. Combining brainstorming and process knowledge, the team identified three (3) factors and levels: Tension (g) Speed 1 (rpm) Speed 2 (rpm) -1 -1 0 1 -1 0 1 170 180 190 200 500 800 0 1 850 1100 1350 Note: Level 0 is a center point, which represents standard operating condition. 14 R

D M A I C IMPROVE y f(x) Each of the three factors was studied at two levels so the arrangement is a (2 x 2 x 2) or 23 8 run factorial design. The eight combinations are shown in the following table with the factor levels coded by plus and minus signs. 15 R

D M A I C IMPROVE y f(x) A 23 factorial design coded in standard order with center point. Standard Order Tension Speed 1 Speed 2 0 0 0 0 1 -1 -1 -1 2 1 -1 -1 3 -1 1 -1 4 1 1 -1 5 -1 -1 1 6 1 -1 1 7 -1 1 1 8 1 1 1 Note: run 0 is a center point, which represents standard operating condition. 16 R

D M A I C IMPROVE y f(x) The eight-factor combinations and center point can be conveniently represented geometrically by the vertices of a cube. If you imagine the center of the cube to be the origin of a three dimensional coordinate system, then the eight-factor combinations can be identified by runs 1 through 8. 17 R

IMPROVE y f(x) Centerpoint Factorial Point D M A I C Cube Plot for Standard Run Order 8 7 4 3 1 0 Speed 1 -1 5 6 Speed 2 2 1 1 -1 -1 1 Tension 18 R

IMPROVE y f(x) D M A I C Data collected from 2-Level, 3 Factor Experiment with center points: Std Order Tension (g) Speed 1(rpm) 0 180 500 1 170 200 2 190 200 3 170 800 4 190 800 5 170 200 6 190 200 7 170 800 8 190 800 Speed 2(rpm) Elongation 1100 5.3703 850 5.5553 850 5.4258 850 6.2433 850 4.7570 1350 6.1183 1350 5.1212 1350 5.6427 1350 5.1595 Note: run 0 is a center point, which represents standard operating condition. 19 R

IMPROVE y f(x) Centerpoint Factorial Point D M A I C Cube Plot for Elongation PATS Coil Winder DOE -- Phase 1 5.6427 5.1595 6.2433 800 4.7570 5.3703 Speed 1 6.1183 5.1212 1350 5.4258 200 5.5553 Speed 2 850 170 190 Tension 20 R

IMPROVE y f(x) D M A I C The main effects, (i.e. average rate of change over the factor levels studied), are calculated as follows: Factors: Names: Std Run Order Average Avg 5.503 Effect A Tension 170g 5.890 190g 5.116 -0.774 B Speed 1 200 5.555 800 5.451 -0.105 C Speed 2 850 5.495 1350 5.510 0.015 The main effects for factor A, Tension, is the difference between the average at the high level, (190g) and the low level (170g), i.e. 5.116mm – 5.890mm -0.774mm. Elongation is decreased on the average 0.774mm when Tension is increased from 170g and 190g. The main effects, are summarized on the following slide. 21 R

D IMPROVE y f(x) M A I C PATS Coil Winder DOE Main Effects Plots Centerpoint Centerpoint Average 5.370g 0 17 5.9 0 19 0 20 0 80 0 85 50 13 5.890 Elongation 5.7 5.555 5.510 5.5 5.451 5.495 5.3 5.1 5.116 T ension (g) Speed 1 (rpm) Speed 2 (rpm) The slope of the line drawn between the two levels is indicative of the significance level of each factor. Clearly Tension is considerably more 22 significant that either Speed 1 or Speed 2. R

D M A I C R IMPROVE y f(x) The interaction effects are calculated as follows: AB Interaction Effects The -1 5.608 AC 1 5.398 -0.211 -1 5.486 BC 1 5.520 0.034 -1 5.560 ABC 1 5.446 -0.114 -1 5.269 1 5.737 0.468 Interaction effects, are summarized on the following slide. 23

D M A I C IMPROVE y f(x) Centerpoint PATS Coil Winder DOE Interaction Plot 20 0 8 00 13 5 850 0 6.0 Tension 5.5 190 170 5.0 6.0 Speed 1 5.5 800 200 5.0 Speed 2 24 R

D M A I C R IMPROVE y f(x) The effects and p-values are summarized below using a normalized T-statistic Estimated Effects and Coefficients for Elongation (coded units) Term Constant Tension Speed 1 Speed 2 Tension*Speed Tension*Speed Speed 1*Speed Tension*Speed Ct Pt Effect 1 2 2 1*Speed 2 -0.7740 -0.1045 0.0150 -0.2107 0.0339 -0.1141 0.4677 Coef 5.5029 -0.3870 -0.0523 0.0075 -0.1054 0.0169 -0.0571 0.2339 -0.1326 SE Coef 0.09999 0.09999 0.09999 0.09999 0.09999 0.09999 0.09999 0.09999 0.22358 T 55.04 -3.87 -0.52 0.08 -1.05 0.17 -0.57 2.34 -0.59 P 0.000 0.000 0.603 0.940 0.297 0.866 0.571 0.023 0.556 The probability values (p-values) for Tension and the 3-way interaction between Tension, Speed 1 and Speed 2 are less than 5% and deemed statistically significant effects. Center points (Ct Pt) representing standard operating conditions, were not significant. 25

IMPROVE y f(x) D M A I C A Pareto chart of the effects vs. Decision Limit demonstrates that Effect A, Tension, and the ABC interaction are significant at the 5% level. Effects Pareto Chart 0.900 0.800 0.774 0.700 Effect Values 0.600 0.500 0.468 Effects Decision Limits 0.400 0.300 0.211 0.200 0.114 0.105 0.100 0.034 0.015 0.000 Tension ABC AB BC Factors Speed 1 AC Speed 2 26 R

D M A I C IMPROVE y f(x) The main effects plot for Tension demonstrates that increased elongation is obtained from a low Tension setting, 170g. Since the other significant effect is the three way interaction, we must now evaluate the effect of Tension on the other two factors, Speed 1 and Speed 2. 27 R

D M A I C IMPROVE y f(x) An interaction is best represented by a response plot, which provides a visual depiction of the response surface. Setting Tension at its low level, 170g, produces the following Response Plot (3D) and Contour Plot (2D) for Speed 1 and Speed 2. 28 R

IMPROVE y f(x) D M A I C PATS Coil Winder DOE Response Surface Plot 6.3 6.2 6.1 6.0 5.9 Elongation 5.8 5.7 5.6 5.5 200 300 400 Speed 1 950 500 600 700 1350 1250 1150 1050 Speed 2 850 800 Hold values: Tension: 170.0 29 R

IMPROVE y f(x) D M A I C PATS Coil Winder DOE Contour Plot 1350 Speed 2 1250 1150 1050 950 850 200 300 400 500 600 700 800 5.60120 5.64707 5.69293 5.73880 5.78467 5.83053 5.87640 5.92227 5.96813 6.01400 6.05987 6.10573 6.15160 6.19747 6.24333 Speed 1 Hold values: Tension: 170.0 30 R

D M A I C IMPROVE y f(x) Careful analysis of the Response Plot and Contour Plot demonstrates that increased elongation can be obtained from the following process setting: – Factor A, Tension, set at 170g. Process settings for Factors B and C, Speed 1 and Speed 2 respectively, will be determined by running a confirmation experiment. 31 R

IMPROVE y f(x) D M A I C A 2-level, 2 Factor confirmation experiment was conducted keeping Tension, Factor A at 170g and varying Speed 1 and Speed 2 as follows. Speed 1(rpm) 200 500 800 Speed 2 (rpm) 850 1100 1350 Note: midpoints, (500 & 1100) are center points, which represents standard operating condition. 32 R

D M A I C IMPROVE y f(x) 2 factors at 2 levels result in the following 4-run design matrix. Standard Order Speed 1 Speed 2 0 0 0 1 -1 -1 2 1 -1 3 -1 1 4 1 1 Note: run 0 is a center point, which represents standard operating condition. 33 R

D M A I C IMPROVE y f(x) Data collected from 2-Level, 2 Factor Confirmation Experiment with center points: Standard Order Speed 1 Speed 2 Elongation 0 500 1100 5.6657 1 200 850 6.2933 2 800 850 5.5997 3 200 1350 6.0403 4 800 1350 6.0183 Note: run 0 center point 34 R

IMPROVE y f(x) 6.0403 A I C 6.0183 5.6657 Speed 2 850 M Square Plot (data means) for Confirmation DOE Centerpoint Factorial Point 1350 D 6.2933 5.5997 800 200 Speed 1 35 R