Classifications of control charts are depending on the type of data:
1.Variables data
- A characteristic measured on a continuous scale resulting in a numerical value
- Examples: Void Size, Bond Pull Strength, Coplanarity, Ball Height, etc.
2.Attributes data
- A characteristic measured by # of conforming & non-conforming to a specification. Output is classified as pass/fail or accept/reject.
- E.g. Broken Wire, Lifted Bond, FM, Chipping, Bent Lead, etc.
- Can be expressed in terms of fraction, percentage, count or DPM
Control Charts For Variables
Control Charts For Attributes