Sponsor

Maintenance: The Basics of Cleaning Series Part 4
This is the final paper in a series and discusses some of the common mistakes in maintenance cleaning applications found in electronic assembly operations.
KYZEN

Sponsor

Die-Module Attach (Pastes & Films)
Die-Attach Adhesives with low moisture absorption for MSL Level-1 applications for reliability. Outstanding thermal conductivity with low moisture absorption- stress-free bonding.
AI Technology, Inc.

Ask the Experts

August 5, 2007 - Updated
August 5, 2007 - Originally Posted

Changing PCB finish from FR2 OSP to FR4 HASL-Lead Free

We have changed PCB finish from FR2 OSP to FR4 HASL-LEAD FREE and have encountered pinholes in the PCB solder joints. We have tried different wave settings but are still unable to solve this problem. We did not have this problem when using FR2 OSP. Is there a way to keep these pin holes from occurring?

R.B.

Expert Panel Responses

Pin holes as well as blow holes are usually a sign of excess moisture in the PCB or poor PTH plating. The moisture in the PCB heats up over the wave and ruptures the PTH plating, then the steam escapes through the bottom of the fillet causing a pin hole or the larger blow hole. Bottom line is that you have boards from your vendor that are of poor quality. The only thing that may help you is to bake the boards at 120C for 4-6 hours. If it is just too much moisture this will fix the problem but if the plating in the PTH is bad it may not make a difference. Either way your board vendor needs to work on their process..

Greg Hueste
Senior Applications Engineer, Speedline Technologies

Greg joined Electrovert in February 1984. Based out of the Electrovert applications laboratory in Camdenton Missouri, Greg has been in the process applications support role since 2000. His primary responsibilities include providing process and machine applications support for the wave soldering lines as well as process, machine and operations training. He also provides applications support for the reflow and cleaner lines. Greg is a PBET certified trainer and holds two patents on wave solder nozzle design.

Free Newsletter Subscription
Circuitnet is built for professionals who bear the responsibility of looking ahead, imagining the future, and preparing for it.

Insert Your Email Address

Sponsor

High-Reliability for Low-Temp Processes
Durafuse® LT low-temp, high-rel solder paste is bismuth-free, reduces warpage in large BGAs, enhances thermal cycling, drop shock reliability and reduces energy use up to 15%.
Indium Corporation