Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Reflow process

Henry

#24792

Reflow process | 12 June, 2003

I would like to ask a question about SMT reflow process. I did 10 pcs samples but all is fail. The sample is double faces to have components (up-side has 4 pcs of BGA and down-side has 3 BGA and 2 QFP). And I saw some of BGA which is tilting in the PCB, so I suspect that it's caused by 2nd reflow. I understand that the solder join may melt again to make the components tilting when 2nd reflow. What can I do to prevent it?

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#24793

Reflow process | 12 June, 2003

> I would like to ask a question about SMT reflow > process. I did 10 pcs samples but all is fail. > The sample is double faces to have components > (up-side has 4 pcs of BGA and down-side has 3 BGA > and 2 QFP). And I saw some of BGA which is > tilting in the PCB, so I suspect that it's caused > by 2nd reflow. I understand that the solder join > may melt again to make the components tilting > when 2nd reflow. What can I do to prevent it?

Henry

As I understand the BGA that tilt are on the bottom side and the reason may be that the temp for the bottom side heaters is more and because of its own weight BGAs move in the reflow zone.What I suggest is to keep the bottom heater temp low so that even in reflow zone the solder is not in the eutectic form and take a profile again for the top side BGAs.

Sanjeev

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shaun

#24881

Reflow process | 19 June, 2003

what type of oven do you have . How many zones? and what are the board attributes sizes. We run alot of doublesided reflow with BGA. maybe I can help

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reflow oven profiler

Reflow Oven