I have a lot of experience with PCB thru-hole repairs but only some SMD replacements such as 0805 parts or SOT-23 transistors where i have tacked the pins to the pads manually with a fine solder tip. I am now replacing several TO-220D-A1 diodes on a TV pcb and all of these need the cathode backside of the component soldered to a large ground pad. I have a XYtronic LF-8800 80W hot air pencil (minimum setting is 300C, max is 450C) and used Chipquick low temp lead free solder paste. I have pre-warmed the SMD with the hot air pencil at 300C held about 1" above the SMD for about 1-2mins then turned up the heat to 400C and held that for another 1-2 minutes. Slowly cooled off and the SMD was still not soldered to the ground pad. I unbderstand the ground pad is basically the entire pcb copper plane so big heat sink. How do you do this without destroying things? I have a small IR over for small parts < 6" but this TV board is 18" x 7". Any advice would be greatly appreciated.
Jerry NY2KW
Jerry NY2KW
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