There are a whole lot of reasons why circuit boards are
scrapped, and it safe to say that none of them are good.
At Circuit Technology Center we're in the business of saving circuit
boards. We're able to correct most levels of design and fabrication
errors, or physical damage that would cause a circuit board to be
However, there are circumstances beyond rework and repair that cause a
circuit board to become non-functional. Does that make that circuit
board worthless junk? Maybe not.
In the unfortunate event a board is no longer useful you still may wish
to salvage some of the more valuable components for reuse elsewhere.
Recovering the soldered components from the circuit board safely, and in a
condition for reuse can be challenging.
or reclamation is becoming more commonplace and the value of many components provides easy justification for the effort associated
with reclaiming them.
When reviewing applications for component salvage it is important to
understand all of the requirements. "The devil is in the detail"
certainly holds true here; sometimes the littlest things can complicate
Important questions to ask yourself when considering a
What environmental elements have the circuit boards and components been exposed to? What is the moisture sensitivity level?
If the circuit boards and components were newly assembled, and
have been in a controlled environment then it will probably eliminate
the need to bake the components prior to exposure to the reflow process
for removal from the circuit boards.
If the circuit boards have been held in open storage, or are field
returns, or the moisture sensitivity level of the components deems it
necessary, a pre-bake of the components will be required prior to
exposure to reflow temperature to eliminate damage due to moisture
Are the circuit boards and components conformally coated or is there an under-fill applied? The impact conformal coating and under-fill have on the component
salvage process can be significant.
What is the ESD sensitivity level?
It's assumed that all components should be handled with proper ESD
precautions. There are different levels of ESD sensitivity, and
understanding the components that you are working with is important. The
component specification sheet will normally provide the level of detail
What temperature range can the component withstand?
Component salvage can be completed with a variety of processes
consisting of localized hot air, molten solder on mini-wave machines, as
well as conduction heat from a soldering iron, or desoldering tool.
All relatively sound processes when performed by a trained operator.
Will the components be machine, or hand placed in the upcoming re-assembly process?
It is important to know the assembly process to be used with the
salvaged components. If the salvaged components are to be hand soldered,
as opposed to machine placed, then the criteria for residual solder
left on the leads, and lead co-planarity can be adjusted.
What about packaging, trays, tubes or tape and reel?
Often overlooked is the need for safe packaging of the salvaged
Answering these questions will help in establishing the quality
requirements and set the stage for a successful recovery process.