D corrective action traning.pptVIP

DISCIPLINE 3 (cont.) History and background of VCM coil design change, cont.. 3. Experimentation confirmed the DSP microcode change was most effective as compared to the adhesive coat extension. However, the extended VCM coil adhesion area showed significant reduction on 800Hz vibration reduction and was easier to implement than the microcode change. Therefore, we implemented the extended adhesive area for the VCM coil. 4. Since notification of the failures, Design Engineering has modeled the adhesive residual stress on the VCM coil assembly under different temperature conditions (25C to 120C). The modeling shows higher residua stress at the corner (Area A) of E-Block arm. DISCIPLINE 3 DESCRIBE THE ROOT CAUSE DATE: 1/31/99 Good Example of Discipline: Differences between USA built and Japan built HDDs The VCM soil adhesion process is the same at both locations. There are no VCM coil crack failure reported from USA manufactured HDDs. The USA factory had more curing chambers and tools as compared the Japan factory, which allow uninterrupted, low stress adhesive curing of the VCM coils. The root cause of this problem was loosen screw of retract plate by no UV glue adhesion support. A operator did not provide UV glue by mistake. DISCIPLINE 3 DESCRIBE THE ROOT CAUSE DATE: 1/31/99 Bad Example of Discipline: DISCIPLINE 3 (cont.) Discipline 4 Implement Containment Action(s) Plans Containment actions are those that stop the problem NOW! They are quick to invoke and will result in drastic reduction or elimination of the problem. Remember, containment actions DO NOT attack root cause. Rather, they are screens in the process which effectively allow capture of the defects from getting to the customer. Unfortunately, many containment screens act like “sledge hammers” to the process, in that they will screen out the concerned parts as well as many good products as well. Items to consider when invoking a containment action are: a) Will it eliminate the problem from get