Dear Chen
Please refer to disposal way of low yield lots as below on the basis of an engineer’s opinion
PTU13005G
Mode : hFE low with 5~6 (SPEC : hFE(100uA) min7.0 )
Cause : Some of the wafer can’t meet hFE specification
Disposal of Products : Ship Good products and Scrap fail products
PFU3N90
Mode : CURVE ( IDSS leakage high) /Distribution of IDSS 200~970nA
Cause : Not clear / Need to investigate cause of low yield
=>. PDK engineer suggests that the Test equipment is needed to verify if there is any problem and/ or any difference among test machines
=>. Please perform retest for failure units by using another test equipment which was not used before
=>. please submit electrical retest result with another test equipment and the photos of the BVdss Curve Tracer for good and fail respectively
Thanks and best regards
Tom Choi.