Peak temperature on BGA balls -reflow proccess

[Altera_Forum]

Hello. 

 I have a question about reflow profile of BGA components.   As I measured the temperature on several places of a BGA component , I found there were differences on temeprature of the case and the balls of the BGA.   I need to asure good reflow , meaning all the balls get strong metal connection with the pad after reflow, so I want to activate the max temperature on the reflow proccess. on the other hand of course, I definitely on't want to damage the component, so how can I know what min temperature I need to aplly on the balls so they melt the best?   I saw in all Altera's documents that max temperature of 220 c on case is recommended, but found no refering to balls max temperature, or min temperature above the reflow temp.   Thank you very much for your answer.   Mosh_p1

[Altera_Forum]

Try this doc: 

http://www.altera.com/literature/an/an353.pdf  Your question is answered in "Reflow Process Considerations"   Basically for ROHS, minimum reflow temp is 235C and maximum is 245C ->260C depending on package size. (217C melting point)  For non-rohs, it's 200C to 235C for reflow (melting point = 183C)  Pete

[Altera_Forum]

Thank you. 

 You are right, I forgot to mention, that I'm refering to Lead components, not RHOS compliant.   It is right that reflow Temperature are between 200-235{ most of companies, including Altera recommend on max temp. of 220 C} but since I deal with quite large BGA's , and there is a difference in temperature between it's parts, specialy between case and balls temp. , I want to know what temperature the balls must feel for good melting.   I'm asking that beacause I'm limmited on the top temp {218 C} of all proccess.   Thank you!