OMAP-L138: Soldering of Pb-free and SNPB Lead/Ball Finish BGA Packages

Hi, Imran,

There isn't page 99 in the document you mentioned, but on Page 18, it shown two separate example of Pb free and SnPb reflow profile.

You can’t mixed two alloy on the same board.

Pb free reflow profile temperature is too high for SnPb solder balls and SnPb reflow profile temperature is too low for Pb free solder ball. Either combination will result in poor solder joints. OMAP-L138 is a SnPb solder ball package, it should follow the SnPb reflow profile.  

Rex

Dear Rex Chang, Thanks a lot for your kind technical response. You are right that it was Page 18. Now my question is: 

1) If I want to use a component (OMAP-L138) with SnPb solder balls and some other component with SnPb free solder balls on a single PCB, is there any process of reflow to consider this situation?

If the answer is NO, then

2) The TI OMAP-L138  is a SnPb solder package. However mostly supporting and necessary components including FPGA, Memory etc are available only in SnPb free (ROHS compliant). Then how should I design my PCB? Do I need to search all supporting components FPGA, Memory in SnPb solder package? and is it possible to get all such components in SnPb solder package?

Thanks in advance. Best regards, Imran Ali.

Hi, Imran,

TI doesn't recommend mix-matching. As mentioned in earlier post, "OMAP-L138 is a SnPb solder ball package, it should follow the SnPb reflow profile.".

Rex

Dear Rex, Thanks for your reply. 

Form the discussion, I understood that I must choose all other components (FPGA, memories) in SnPb solder ball package. So that all components will get SnPb reflow profile. Am I right?

Regards,

Imran Ali. 

Imran,

Yes. That's correct.

Rex

Imran,

Just curious. Why can't you use pb-free OMAP-L138 part since all others are pb-free?

Rex

Dear Rex, 

Currently I am using OMAP-L138 pb-free package and I have used all other components (DDR Memory, Flash, FPGA) in Pb-free package and my design is working correctly. The reason behind asking the question regarding SnPb package was just to get the knowledge. As mentioned in the literature, the SnPb package OMAP has following advantages:

(1)  SnPb package is more reliable as compared to Pb-free (some documents on google claim it), (2) SnPb OMAP-L138 is available in super extended temperature range, (3) EP (Enhanced Performance) means extended product change notification, traceability, long life line, etc.   Actually my prime interest is using TI EP products as I guess the TI EP products remain in production for very very long time and therefore I always prefer to use TI EP products. The EP version of OMAP-L138 is available in SnPb package.     

Therefore, I was curious to know, is there any possibility that I can use SnPb package OMAP in my current design and if I can just replace the existing Pb-free OMAP-L138 with SnPb OMAP-L138 IC. But as per your advice, I cannot do so.

But now I am surprised that how SnPb package OMAP-L138 can be used in any design because of hardly availability of other supporting components (Memory, FPGA) in Pb-free package.

My last question is that do you have any idea, that Micron and Xilinx offer DDR memory, Flash Memory and FPGA in SnPb Packages? Or could you suggest me the manufacturers who make DDR memory, Flash and FPGA in SnPb Packages?  I will also google their web sites. 

Best regards and thanks for your detailed help.

Imran Ali