Editing Desoldering (section)

==Tools==
[[File:Desoldering with desoldering gun 2.jpg|thumb|300px|Desoldering with a desoldering gun.]]
Desoldering tools and materials include the following:

*Solder wick
*[[Heat gun]]s, also called hot air guns
*Desoldering pump
*Removal alloys
*Removal fluxes
*Heated soldering tweezers
*Various picks and tweezers for tasks such as pulling at, holding, removing, and scraping components.
*Vacuum and pressure pumps with specialized heater tips and nozzles
*[[Rework station]]s, used to repair printed circuit board assemblies  that fail factory test.
Terminology is not totally standardised. Anything with a base unit with provision to maintain a stable temperature, pump air in either direction, etc., is often called a "station" (preceded by rework, soldering, desoldering, hot air); one, or sometimes more, tools may be connected to a station, e.g., a rework station may accommodate a soldering iron and hot air head. A soldering iron with a hollow tip and a spring-, bulb-, or electrically operated suction pump may be called a {{visible anchor|desoldering iron}}.<ref name="mccomb"/> Terms such as "suction pen"<ref>{{Cite web |url=http://www.circuitspecialists.eu/blackjack-solderwerks-hot-air-system-w-suction-pen-bk-4050-p-209.html |title=Terminology: commercial equipment described as "hot air system" with "suction pen" (in this case a vacuum-style IC handler). |access-date=2012-05-01 |archive-url=https://web.archive.org/web/20120608045932/http://www.circuitspecialists.eu/blackjack-solderwerks-hot-air-system-w-suction-pen-bk-4050-p-209.html |archive-date=2012-06-08 |url-status=dead }}</ref> may be used; the meaning is usually clear from the context.

===Pumps===
Electrically operated [[pump]]s are used for several purposes in conjunction with a hand-held head connected by a tube.

Suction pumps are used to suck away molten solder, leaving previously joined terminals disconnected. They are primarily used to release [[through-hole]] connections from a PCB. The desoldering head must be designed so that the extracted solder does not solidify so as to obstruct it, or enter the pump, and can be removed and discarded easily. It is not possible to remove a multi-pin part by melting solder on the pins sequentially, as one joint will solidify as the next is melted; pumps and solder wick are among methods to remove solder from all joints, leaving the part free to be removed.

Suction pumps are also used with a suction head appropriate for each part to pick up and remove tiny surface mount devices once solder has melted, and to place parts.

Hot air pumps blow air hot enough to melt all the solder around a small surface mounted part, and can be used for soldering parts in place, and for desoldering followed by removal before the solder solidifies by a vacuum pump or with tweezers. Hot air has a tendency to [[Oxidisation|oxidise]] metals; a non-oxidising gas, usually [[nitrogen]], can be used instead of air, at increased cost of equipment and consumables.

====Desoldering pump====
[[Image:Solder sucker.jpg|thumb|left|A typical spring-loaded solder sucker]]
[[Image:Solder sucker with spring taken out.jpg|thumb|A solder sucker partially dismantled showing the spring]]

A '''desoldering pump''', colloquially known as a '''solder sucker''', is a manually-operated device which is used to remove solder from a [[printed circuit board]]. There are two types: the ''plunger'' style and ''bulb'' style.<ref name="mccomb">{{Citation | last = McComb | first = Gordon | last2 = Shamieh | first2 = Cathleen | title = Electronics For Dummies | page = 251 | publisher = For Dummies | year = 2009 | edition = 2nd | url = https://books.google.com/books?id=0yJ3blaI7b8C&pg=PA251 | isbn = 978-0-470-28697-5 | postscript =.}}</ref> (An electrically operated pump for this purpose would usually be called a [[vacuum pump]].)

The plunger type has a cylinder with a [[spring (device)|spring]]-loaded [[piston]] which is pushed down and locks into place. When triggered by pressing a button, the piston springs up, creating suction that sucks the solder off the soldered connection. The bulb type creates suction by squeezing and releasing a rubber bulb.

The pump is applied to a heated solder connection, then operated to suck the solder away.

===Desoldering braid===
[[File:Solder wick rolled.jpg|thumb|left|Solder wick on a reel]]'''Desoldering braid''', also known as '''desoldering wick''' or '''solder wick''', is finely braided 18 to 42 [[American wire gauge|AWG]] [[copper]] wire coated with [[rosin]] [[Solder flux|flux]], usually supplied on a roll.[[File:Solder wick-close up-part PNr°0104.jpg|thumb|Solder wick, before use]]
[[File:Solder wick-close up-solder impurities PNr°0112.jpg|thumb|... and soaked with solder and residue]]

The end of a length of braid is placed over the soldered connections of a component being removed.  The connections are heated with a [[soldering iron]] until the solder melts and is wicked into the braid by [[capillary action]]. The braid is removed while the solder is still molten, its used section cut off and discarded when cool. Short lengths of cut braid will prevent heat being carried away by the braid instead of heating the joint.