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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Cracking solder joints

Dave Waddick

#12751

Cracking solder joints | 1 February, 1999

I have a product using high temperature solder to connect terminal pins to a PCB. The board is single sided copper, no plaiting. The solder is 95% tin 5 % silver. The flux is low activity rosin. The product is a subassembly. When the product is assembled to its final board; the terminals are mounted by through hole. The final board is soldered by pin & past, convection reflow. We are having a lot of failures with the terminals soldered to the subassembly. The solder is not reflowing in the final oven but the solder joint is cracking off of the subassembly PCB. What am I doing wrong? Is it the solder or the PCB? I need to use solder that wont reflow to hold the terminals to the subassembly. Any suggestions?

reply »

John

#12752

Re: Cracking solder joints | 2 February, 1999

| I have a product using high temperature solder to connect terminal pins to a PCB. The board is single sided copper, no plaiting. The solder is 95% tin 5 % silver. The flux is low activity rosin. The product is a subassembly. When the product is assembled to its final board; the terminals are mounted by through hole. The final board is soldered by pin & past, convection reflow. We are having a lot of failures with the terminals soldered to the subassembly. The solder is not reflowing in the final oven but the solder joint is cracking off of the subassembly PCB. What am I doing wrong? Is it the solder or the PCB? I need to use solder that wont reflow to hold the terminals to the subassembly. Any suggestions? |Q1:Do the solder joints crack at the terminal or the PCB? Q2: What is the terminal coated with?

If the plating on the terminals contains lead, that may be a contributing factor. Just a thought.....

reply »

ii-feed SMD Intelligent Feeder

SMT Machines china