Apart from using a solder iron and solder wire, a solder preform can be used to rework the through-hole joint.

In this case, donut preform (that comes prefluxed) can be placed on top of the pins.

A heat gun is used to melt the preforms for complete hole fill.

The manual component is removed;eliminates the fluxing step; the solder volume is consistent from pin-to-pin; and all preforms can be melted in 1 shot.

Karthik Vijay Technical Manager, European Operations, Indium Corp. Karthik Vijay is the Technical Manager for Indium Corporation's European Operations. He is based in the UK and is responsible for technology programs and the technical support function for Indium Corporation's customers in Europe. His expertise is focused on solder paste, engineered solders, thermal interface materials, and semiconductor-grade electronics materials.

IPC has an entire rework standard which will directly specify the proper method of PTH rework.

In most cases, you will address the solder joint from the solder side with the iron touching the lead/pad simultaneously and for the minimum amount of time. The solder wire, will be introduced from the opposite side.

Rework and what you are accomplishing, is specific by part and iron technology. IPC 7711 is your best source to decipher your issue and approach.

Rodney Miller Capital Equipment Operations Manager, Specialty Coating Systems Rodney is currently Operations manager at SCS coatings, Global Leader in Parylene and Liquid Coating equipment. Rodney applies his 20+ years of diverse manufacturing to the Equipment Business at SCS Coatings. We provide unique value added coating equipment solutions for our customers. Including conformal, spin and Parylene coating expertise.

If you try to touch up from the top side, you could create a void within the plated thru hole. I would suggest you apply flux, desolder the connection and then solder the joint properly and preferably with a direct power soldering iron, this will ensure sufficient heating to reflow the entire connection from top to bottom.

Edward Zamborsky Regional Sales Manager, OK International Inc. Mr. Zamborsky serves as one of OK's technology advisers to the Product Development group. Ed has authored articles and papers on topics such as; Low Volume SMT Assembly, Solder Fume Extraction, SMT Rework, BGA Rework, Lead Free Hand Soldering, Lead Free Visual Inspection and Lead Free Array Rework.