There are several effective methods for removing solder from a pcb hole. Excess solder filling a hole happens quite often. pcb board Usually, the clog is residual solder that occurs when an existing electronic component is desoldered and removed.
Desoldering Bulb
My favorite desoldering tool is a desoldering bulb, pcb board which is also called a solder sucker.
To remove excess solder from a hole:
The printed circuit board is held in a vise or PCB holder
The tip of the desoldering bulb is placed behind the hole and the bulb is squeezed.
The tip of a heated soldering iron is pressed against the hole to melt the solder
Keeping the bulb against the hole, the bulb pcb board is released (unsqueezed) either with the soldering iron in place or just as the iron is being withdrawn. I’ve found both techniques pcb board helpful depending on the size of the hole and amount of remaining solder. In either case, the molten solder is drawn into the desoldering bulb pcb board.
Desoldering hole with soldering iron and desoldering bulb
Desoldering pcb board hole with soldering iron and desoldering bulb
Unfortunately, the vacuum action of the bulb also removes the solder from the tip of the soldering iron. To prevent damage pcb board and to allow for maximum transfer of heat to the next clogged hole, regularly reapply a coating of fresh solder to the tip of the soldering iron. (This is called “tinning”.)
Drill
Another effective technique is to use a small hand drill or a pcb board pin vise (McMaster-Carr #8455A31 or #8455A16) with a miniature drill bit.
For many PCB layout programs, the default hole size is 0.029 inches, which is a #69 drill (McMaster-Carr #2912A247). Of course, you'll want to purchase a variety pcb board of drills depending on the sizes of the holes that you need to unclog.
Be pcb board careful. Using an oversize drill will remove the through-hole plating that connects the trace from one layer of the board to another layer. The loss of electrical connectivity may prevent the circuit from working.
Select carbon, cobalt, or high-speed steel drill bits, not carbide. Carbide will stay sharper longer, but is brittle pcb board. Therefore, carbide is only appropriate for industrial repeated drilling in a rigid setup, not a hand drill.
Only the tip of a drill has cutting blades. pcb board The sides of a drill are dull channels for the material. So, reinsert the tip multiple times if necessary rather than spinning the sides of the drill in pcb board place.
I find that sucking out the solder with a desoldering bulb and then drilling out any remaining solder is great combination.
Desoldering Braid
On the other side of the aisle, there are people that swear by desoldering braid. It consists of tiny pcb board woven copper wires that wick up adjacent solder when heated.
The idea is that you place fresh desoldering braid on top pcb board of the hole (or anywhere with excess solder), and then apply heat to the braid using the tip of the soldering iron. When the braid is saturated with old solder, you simply snip off the end.
Pencil Lead, Stainless Steel Needle, or Toothpick
Other people recommend pressing a thin rod into the solder-clogged hole while heating it from the other side with a soldering iron. pcb board The rod mechanically pushes out the molten solder.
To prevent the rod from becoming soldered in pcb board the hole, people use materials that are difficult or impossible to solder. Examples include: carbon pencil lead, stainless steel, or wood (toothpick).
Leave the Solder in the Hole
There is one last approach that is practical if only one hole is clogged per component -- do nothing. Later on, when you want to solder a wire or pcb board component in the hole, simply heat the wire or component lead while pressing it into the hole. The solder will melt pcb board.
If you have a better approach than those mentioned above, please let me know.
On the next page, I show how to make your own desoldering tips out of Teflon. Specifically, I made a narrower pcb board tip for my desoldering bulb.
