Hello Technician:
I am a CCL producer.My customer told me that there are some resin recession at the hole wall in the 4 layer boards after hot air leveling by using our materials.Would you tell me what's the reasons cause this defect?And how should we improve this defect?What's the standard of resin recession?
Much thanks!
Looking forward to hearing of you soon.
Regards,
Kevinyeah [log in to unmask]
SYST,CHINA