When preparing the wire for cable assembling, there may be some some damage on the wire insulation. Normally we follow IPC-A-620 to judge the good or no good parts.
3.4 Damaged Insulation
Target - Class 1,2,3
• Insulation has been trimmed neatly with no signs of pinching, pulling, fraying, discoloration, charring or burning
Acceptable - Class 1,2,3
• Slight uniform impression in the insulation from the gripping of mechanical strippers.
• Insulation thickness is not reduced by more than 20%.
• Uneven or ragged pieces of insulation is less than 50% of the insulation outside diameter or 1.0 mm [0.039 in] whichever is less.
• Insulation is discolored from the thermal stripping operation.
Defect - Class 1,2,3
• Any cuts or breaks in insulation (not shown).
• Insulation thickness is reduced by more than 20% (Figures 3-11, 3-12).
• Uneven or ragged pieces of insulation are greater than 50% of the insulation outside diameter or 1.0 mm [0.039 in] whichever is more (Figure 3-13).
• Insulation is charred (Figure 3-14).
• Insulation is melted into the wire strands (not shown).
