Dear all, I am doing a survey on the double sided assembly. Please take a few minutes to complete the following questions. I will be grateful to inform you the result once I have finished compiling. If you have filled this before, please ignore it. Would you care to reply, please email to [log in to unmask] Thank you very much. Best regards, Victor TN3------------------------------------------------------- Questionaire for double sided reflow soldering ============================================== Type of oven used : ( ) IR conventional ( x ) Forced Air ( ) Forced Air with Nitrogen ( ) Others, pls. specify _____________ Brand Name of the oven : __HELLER____________________ How often does your shop floor perform double sided reflow process? ( ) 75 % of the time, or above ( ) 50 < x < 75 % of the time ( ) 25 < x < 50 % of the time ( X ) less than 25 % of the time What is the length of the PCB commonly used in double sided reflow process? ( X ) 200 mm or above ( ) 100 < x < 200 mm ( ) 100 mm or less Which connecting medium do you use in the double sided reflow process? ( ) conductive adhesive + solder paste (melting pt. 183 C) ( X ) the same kind of solder paste ( ) high temp. solder paste + solder paste (melting pt. 183 C) ( ) low temp. solder paste + solder paste (melting pt. 183 C) ( ) Others : ____________________________________________________ ____________________________________________________ Do you find this process difficult to control? Why? NO BUT IT SHOULD PAY ATTENTION TO THE HEAT PROFILE ,WHICH HAS A BIG DEPENDENCE ON THE CHIP'S DIMENTIONS._________________________________________________________________ ________ ____________________________________________________________________________ ____________________________________________________________________________ When doing the second pass, how often did the components on the bottom side fall off? ( X ) 1. Never happen ( ) 2. 0 < x < 20% of the time ( ) 3. 20< x < 40% of the time ( ) 4. 40< x < 60% of the time ( ) 5. 60< x < 80% of the time ( ) 6. 80% or above If you answer 2. to 6. please list the components which caused problems : ( ) BGA, # of pins : _____ Size: _____ mm x _____ mm ( ) PLCC # of pins : _____ Size: _____ mm x _____ mm ( ) QFP # of pins : _____ Size: _____ mm x _____ mm ( ) Others(Pls. specify) : Type _______ # of pins _____ Size: ____mm x ____mm : Type _______ # of pins _____ Size: ____mm x ____mm What might be the suspected reasons for the fallen components? __RATIO OF THE WEIGHT AND THE NUMBER OF LEADS ________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ Thank you very much for your time. *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * *************************************************************************** *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************