Are there plans for various package options when individual chips become available? The HiFive1 includes a FE310 in a QFN, but something with legs on the pins, like a QFP, would be much nicer for hand soldering, hacking and making custom boards.
Right now we only plan to provide the FE310 in the 48QFN package. Does the QFN simply make it harder, or does it become extremely prohibitive?
Adding multiple package options increases overall design and engineering costs. As you know, SiFive is all about driving the cost of prototyping down and obtaining custom silicon to as low as possible, so your feedback is valued and very important to us!
Thanks for such a quick reply, on a Sunday no less!
“Does the QFN simply make it harder, or does it become extremely prohibitive?”
Depends how cocky I’m feeling when I start designing.
Honestly, I’ve never had to work with a QFN part. Having said that, this last year I started a project at my company that involved building a PCB for a product which we’re expecting to sell between 1000 to 3000 units. At such a small volume, under a very tight deadline, and also taking into account our limited resources (we’re not a Google or a Microsoft. My team is extremely small) it was a very stringent requirement when selecting components that I felt confident we could work with them by hand while building prototypes.
When we start a proper production run it’ll be using a manufacturer equipped with proper pick-and-place machines, but it saved us a great deal of money and time (I think I just said “money” twice?) up front to not have to go to them until we had a fully completed PCB design and BOM in hand. Unless there was a dire need for a particular feature I was dismissing parts out of hand which had a more tricky package than, say, a 0.5mm pitch QFP.
Granted, others with greater skill and experience may be justified in viewing that account with a touch of derision …
“Adding multiple package options increases overall design and engineering costs.”
Understood. I certainly wasn’t expecting anything otherwise in the near-term, but if your road-map happens to include a continued focus on the low-end chief on my wish-list would be the package type, rather than, say, a specific peripheral.
We chose QFN for the first E310 reference SoC as it is cheap, small, and has good electrical properties. Some of our customers claim they can hand solder QFN just fine, though my soldering days are long past and I have no direct experience. Our team prefers to use quick turn shops over hand assembly.
Note that SiFive custom SoC customers can choose any package they like for their part, and maybe you can get a bunch of builders together to specify an E310-variant and package, then talk to Jack to get a quote for crowdfunding.