TPS2051BDR Heat Resistance Enquiry

"a) May I know how many times this package can go through reflow soldering?"

We qualify these packages for 3 reflow cycles.  We don't recommend more cycles, but that does not mean specific devices will not survive more. 

"b) May I know can this part go through wave/flow soldering? If yes, can you advise on the flow soldering profile?"

The D package is qualified for reflow according to the J-STD-020 standard for maximum 260°C reflow temperature on the package, with a slow preheating to this temperature.  Commonly a full convection reflow oven is used for this process.

Using the TPS2051BD in a wave solder process (bottom-side mounted, and  immersed in solder wave) is not qualified by TI and is at the customer's risk.  The reason is that the package sees a thermal shock when the board  moves from the preheating stage (around 150-180°C) into the liquid solder wave which may exceed 260°C for leadfree soldering.  A part mounted to the topside (not in the solder) during wave will be OK with normal process temperatures..

"c) For repairing with soldering iron after reflow/flow soldering, what is the guaranteed spec for this part? For example 5 seconds at 350 degree Celcius?"

I have a question out to the packaging team and will provide a response when I hear from them.

Additional information about soldering / rework from our packaging team:

"For rework of a 8pin D package( true for DBV too), best option is to use a hot air rework station and unsoldering the old component, cleaning up the  PCB pads from old solder if necessary and than solder the new part in.  Some customers are cutting the leads close to the package, remove the plastic and than individually remove the leads if the old package is not needed.

The solder iron should not be touching leads too long, the package Is rated for a lead temperature of 260°C for 10 seconds.
Solder Irons usually are in the 300-350°C range, so the lead will heat up quickly.

Recommendation would be to place the solder iron on the PCB pad / lead tip and add solder. If a hot air nozzle can be used instead for heating up the solder joint, it would be preferred. Care neet to be taken to not overheat the package and surrounding PCB area, package maximum rating is 260°C. Heating the board from bottom side is recommended to preheat the board and shortening the temperature exposure during the soldering at the joints. If the board stayed longer in assembly process, it may need to be baked prior rework due to moisture absorption."