I do agree with Les Connally . We have in our plant 100K clean room for
innerlayers . It is being check periodically by external source . But what
makes the biggest difference is the cultural behaviour imposed by clean room :
1 ) controlled environment ( temp . humidity )
2 ) restricted entrance of the operators via pass through with a proper
pressurure difference across clean room and pass through
3 ) very clear procedures what and how is introduced to the clean room
4 ) protective closing for the staff used only in the clean room
5 ) procedures describing how maintenance is done , what is allowed to do in
the clean room while maitenance people are working inside etc .
As Les Connaly said , for 4 - 5 mills , what is killing the quality are
relatively big particles , most of them originated from outside . I do not
thing , that 10K class can improve quality keeping operational mess .
Edward Szpruch
Eltek Ltd - Israel
Tel  972 3 9395050
Fax 972 3 9309581
E-mail :  [log in to unmask]