Duane Benson

QFNs can be pretty annoying. It’s been said over and over that you don’t want to leave the solder paste opening wide open for a QFN center pad. 50 – 75% paste coverage will get you bets results. With full coverage, your QFN can end up floating too high and not connecting with all of the pads due to…

When you’re done with most of the hard work and it’s time to go build up some boards, you have a number of choices. If it’s a simple board with decent sized components, you can probably build everything by hand. With more complex boards, you most likely need to send it in to someone.

Most assembly…

Parts change and so do vias. My standard line is that open vias in pads are bad, but sometimes you do need to put vias in your pads. Generally, you have several options. Like putting soldermask caps over the via under the part or capping the vias on the back side of the board. However, with vias in…

I’m not talking about the final check that you get from an employer laying you off due to outsourcing. That’s a bummer of a final check. The final check I’m talking about is a good thing. It always pays to do this kind of final check. Of course the other kind of final check pays too, but only once….

It is insane. With normal process, this will never work. Pretty much all of the solder will wick down the via hole.

In a prototype environment, sometimes we can fiddle with things, like putting kapton tape on the back side and pre-filling the holes or pre-filling the holes with hi-temp solder….

Take a look at this land pattern for a BGA bluetooth module. Anyone see anything odd? Yeah. All of those really big open vias. I know what the designer was trying to do. A good number of the vias are ground connections of one sort or another that need to be connected to an internal ground plane…

When most people think of thermal issues, the considerations tend to be around operating conditions. Will the part generate too much heat? Will there be enough airflow or is there enough surrounding material for adequate conduction cooling? All of those are pretty important – especially with the…

Texas Instruments has been getting a lot of attention lately with it’s OMAP 35XX series of ARM Cortex-A8 processors. It’s a very high-powered chip for its size and power consumption – enough to get pretty close to netbook capabilities at a very low cost and size.

To keep size down and shorten the…

I was recently asked a question about QFN package varieties. The questioner wanted to know if different package variants of 16 contact QFN packages, such as HUQFN, DHVQFN, SQFN and such, all shared the same footprint.

If they did, the CAD work would be much easier. There would be one land pattern…

In this context, I’m primarily referring to chip-caps and any other tiny little two-connector components. When considering surface mount, most people think of the many-connector parts, like BGAs and QFNs as the challenging components. That’s mostly true. However, the little passives can be big…