Indium Blog

QFN Reliability in SMT Electronics Assembly


Let's look in on Rob:

Rob looked at the new photo of Patty and their twin sons Peter and Michael. What a handful those two 18 month-olds were. Just like their mother! Rob was still pinching himself that he was lucky enough to have Patty as his wife. Rumors were that she would make VP soon, and a few of his buddies asked him if her success bothered him. 

He would always respond, “Let’s see: beautiful, successful, athletic, fun to be with, great mother, and most of all she loves me. What’s not to like?”

Rob really meant it. He felt Patty deserved her success. One of her great assets was her high energy level. She went to bed at 11:30PM and was up at 5AM to run two miles, lift weights, shower, and then take care of the kids. Rob just couldn’t keep up on less than seven and a half hours of sleep. So he got up at 7AM. Rob had to insist that they have some quiet time each night after the boys were in bed, to talk and maybe even watch some mindless TV. But Patty would often sneak her laptop out to work while NCIS was on. Patty, the workaholic!

Rob and Patty spoke Mandarin at home one day each week and Spanish another night. The boys were picking up all three languages. It was amazing to both Patty and Rob as they watched this miracle.

Well anyway, Rob did have one thing up on Patty: math. Rob was close to a math genius and also good at writing software. He was the “go to” guy for math modeling and writing software for the math models. He even helped the Professor improve ProfitPro. Rob also wrote a program that could be used to design an SMT line for maximum throughput. The software could do what Arena did in hours of simulation, in seconds.

Rob was startled from his daydreaming by the phone ringing. It was Sam the site GM.

“Hey Rob, we need your help in our plant in Guadalajara. Can you come right down to discuss it?” Sam asked.

“I’ll be right there,” Rob replied.

Rob walked to Sam’s office with a feeling of exhilaration. It was always fun and exciting to be sent on a trouble shooting mission.

“Rob, thanks for coming right down. This issue is QFN reliability. About 5% of the Druid mobiles phones in our Guadalajara plant are coming back with some of the QFNs burned out,” Sam began.

“Sounds like a voiding issue under the QFN thermal pad,” Rob interrupted.

“Wow, you seem to know quite a bit about this type of problem,” Sam remarked.

“Remember how I pleaded with you to go to SMTAI,” Rob teased.

“Yep,” Sam replied.

Seth Homer gave a talk on this issue at the show last week. It was a terrific overview of the problem. From what you described the connection may need more solder. We may have to use solder fortification® preforms to solve this. Optimizing the solder paste printing process may not be enough,” Rob summarized.

“Well, go there and solve the problem. The warranty issues are costing us a fortune,” Sam commanded.

After a moment of contemplative silence, Sam asked, “Do you need anything?”

“It would be nice to have Pete come. He knows the people there and is well connected. His Spanish is also terrific,” Rob said.

“OK, no problem. Since you sleep with Pete’s boss, you can work out the details with her. I need you to go this week,” Sam said.

“No problem,” Rob said.

As Rob left the office, he was elated with his new assignment. He had to admit though, he thought it was unprofessional and a little annoying of Sam to say, “since you sleep with Pete’s boss, you can work out the details with her,” but it wasn’t the first time someone said this. Truth be told, Patty might be a little annoyed. She really depended on Pete.

Will Patty be angry at Rob for taking Pete to Guadalajara? 
Will Rob solve the QFN problem?
How does Patty get by on only 5.5 hrs of sleep each night?
Stay tuned for the exciting conclusion.


Dr. Ron