How Cleaning PCBs Helps You Achieve Zero Defects

Dec 14, 2020
| By Tracy Riggan

How important is it to clean printed circuit boards to avoid electrical defects? According to Mike Konrad, Aqueous, a 4 percent reduction in peak reflow temperature can increase board contamination by up to 600 percent. This factor was one of many I took from Mike’s recent webinar, “The Proliferation of Electronics into Harsh Environments and the Effects on Reliability,” held on December 3.  For applications where performance is critical and any failure catastrophic, cleaning takes risks like process temperatures or board handling out of the equation and can do so for very little cost (Aqueous’ Tips & Tricks: https://vimeo.com/440157202/a864b0237a).

Another valuable point Mike made is that using “no-clean” flux doesn’t mean “don’t clean” – it just means, “clean if you need to.” As board density increases, making boards less tolerant of any type of residue, boards operate at higher voltages, and increased residues are present on the board (human and manufacturing process related), automakers will likely be choosing to clean more assemblies to prevent ECM, corrosion, or frequency distortion for long-term reliability. Mike provided examples from BMW, Ford, and Hyundai where foreign object debris caused recalls for issues such as sudden power loss, shutdown and battery fires, indicating to me that the financial investment in cleaning is worth it.

And, while there are solutions to reduce debris and conductive residue, Mike explained that coating no-clean boards locks in any process residues and won’t prevent moisture from leaking in, causing electro-chemical migration and parasitic electrical leakage issues, impacting board reliability. Mike mentioned many documents which address aspects of this, which I’ve linked to below for your reference. If you have board reliability challenges or solutions that need to be addressed, we invite you to join the automotive electronics standards development effort. We welcome increased collaboration and problem-solving to serve automotive reliability needs.

To view Mike’s webinar on demand, register at: https://tinyurl.com/IPC-Konrad

Resources mentioned in webinar: