Please make sure you have advanced soldering skill to solder the chips that you will order from us. When you receive before using it, please confirm the chip you received is brand new as described,if you suspect the chip is not new or not as described. Please don't use it and contact us immediately. Once it has been used, no return will be accepted. Please check before you buy it.Thanks for your understanding. Lead solder balls' melting point is 180?, 210?-215? is the best melting temperature. Lead Free solder balls' melting point is 217?, 235?-245? is the best melting temperature. The temperatures listed above are the chip's solder balls actual temperatures (they are measured by the measuring wire on theBGA machine),but not the temperatures from the BGA rework station's top bottom heat guns. *If soldering a new Lead solder balls chip with Lead Free temperature curve (profile), it will overheat the new chip.* *If soldering a new Lead Free solder balls chip with Lead temperature curve (profile), it will not completely melt the lead free solder balls on the new chip.*