Hi Charles, I think assemblied boards should follow IPC-A-610D 10.2.7. BR Rick _____ From: TGAsia [mailto:[log in to unmask]] On Behalf Of charles.lee Sent: Friday, April 11, 2008 1:19 PM To: [log in to unmask] Subject: [TGA] 答复: [TGA] Bow and Twist standard after Reflow/Wave oven Dear Choi, Thanks for your kind reply. Per my understanding, below standard is aimed at PCB board flatness--->Bare board,without components on it But we would like to know PWA flatness standard after reflow /wave soder ??--->PCB With Assembly, PCB with SMD components or other parts Best regards Charles Lee _____ 发件人: 최천형 [mailto:[log in to unmask]] 发送时间: 2008年4月11日 12:57 收件人: Asia Committe Task Group Forum; charles.lee 主题: Re: [TGA] Bow and Twist standard after Reflow/Wave oven For SMD the bow and twist shall be 0.75% or less. Another PCB they shall be 1.50% or less. For more details please find IPC_A_600 2.11. Choi ----- Original Message ----- From: charles.lee <mailto:[log in to unmask]> To: [log in to unmask] Sent: Friday, April 11, 2008 1:20 PM Subject: [TGA] Bow and Twist standard after Reflow/Wave oven Dear All, Do you have PWA bow and twist standard afetr reflow/wave solder ? Our customer is really concerned PCB flatness after assembly . Thanks in advance. Best regards Charles Lee @ SVA DD&TT