I have a power adapter PCB with through hole parts (only). The board itself has two external copper planes (3 oz) routed to the through hole parts without thermal reliefing (this is for a reason). At the assembly level, it is nearly impossible to fill the barrels of these through hole parts. I have a soldering iron and a IR reflow oven. Is there an efficient means of assembly using these two tools, to ensure 100% barrel fill. If not, are there any practical solutions for completing such a task?

  • \$\begingroup\$ Barrel fill? What do you mean by "barrel"? The pad holes? Also, is it for assembling a few units manually or are you looking for some automated process for higher volume? \$\endgroup\$ – dim Oct 1 '16 at 12:53
  • \$\begingroup\$ The barrel is the through hole pad. Filling it completely is a "filled barrel". Are you familiar with IPC-610?? And I am looking for a cheaper, non automated solution using an IR reflow oven. Preferably. \$\endgroup\$ – Optimizer Oct 1 '16 at 15:35
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    \$\begingroup\$ No, I'm not familiar with this at all, actually. So I can just give basic advice like preheat the board appropriately, given the amount of copper, but I guess you did it already. But I'm not sure reflow is really appropriate for through hole, however. \$\endgroup\$ – dim Oct 1 '16 at 19:46
  • \$\begingroup\$ That's OK. Prebake and solder seems to work; it's just slow for the amount of work I am doing. I am looking for someone who has encountered this specific problem. I am hoping for a magical compound that will heat in the oven and weep into the barrels. Cheers. \$\endgroup\$ – Optimizer Oct 1 '16 at 19:48
  • \$\begingroup\$ Dim, would you happen to know the best solder paste compound for this?? \$\endgroup\$ – Optimizer Oct 4 '16 at 18:29

The best method for this assembly is not IR reflow. There is a fairly cost effective method called dip soldering. The entire assembly bench I put together is less than $900.

A simple version of this assembly method is shown in the video below: https://www.youtube.com/watch?v=svLRtw18sXw

With all through hole parts (Assumed single staged with parts on one side), the entire board may be assembled, pre-baked, and then dipped to fill the barrels. The temperatures chosen at each stage must be crafted based on the design and tweaked experimentally to see what gives best results without damaging the hardware. Given my boards only house connectors, this is a simple process.


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