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Example of a Pareto Chart

          

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Table 1. Example of a Tabulation of Causes of Ball Bond Lifting

for use in a Pareto Chart

Ball Lifting Cause

Frequency

Percent (%)

Cum Pct (%)

Bonder Set-up Issues

19

38%

38%

Unetched Glass on Bond Pad

11

22%

60%

Foreign Contam on Bond Pad

9

18%

78%

Excessive Probe Damage

3

6%

84%

Silicon Dust on Bond Pad

2

4%

88%

Corrosion

1

2%

90%

Bond Pad Peel-off

1

2%

92%

Cratering

1

2%

94%

Resin Bleed-out

1

2%

96%

Others

2

4%

100%

Total

50

100%

-

        

Figure 1. The Pareto Chart Corresponding to Table 1

     

The Pareto Chart in Figure 1 clearly shows that the greatest contributors to the ball bond lifting problems of the engineer who undertook the data collection are bonder set-up issues, unetched glass on bond pads, and foreign contaminants on bond pads. Thus, the engineer has to focus on these causes to reduce their ball lifting occurrences by as much as 78%.

           

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See Also:  Ishikawa Diagram    

    

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