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particle-iot / core

Hardware design files for the Spark Core, a tiny Wi-Fi development kit.
https://www.spark.io/
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Use through-hole USB micro connector #23

Closed zsup closed 11 years ago

zsup commented 11 years ago

Suggestion from Bunnie: replace the USB micro connector with the through-hole version (which is really sort of a hybrid through-hole/SMT) to improve the mechanical stability, so no one rips it off by accident (which I have done many times to my poor little Arduino Pro Micros)

andyw-lala commented 11 years ago

problem is that the LDO is on the other side of the board.

On Thu, Jul 11, 2013 at 2:12 PM, cazzo notifications@github.com wrote:

Suggestion from Bunnie: replace the USB micro connector with the through-hole version (which is really sort of a hybrid through-hole/SMT) to improve the mechanical stability, so no one rips it off by accident (which I have done many times to my poor little Arduino Pro Micros)

— Reply to this email directly or view it on GitHubhttps://github.com/sprk/core/issues/23 .

Andy

zsup commented 11 years ago

Yes but looking at USB footprints like this: http://www.digikey.com/product-detail/en/10118193-0001LF/609-4616-2-ND/2785388

The tabs are about 6mm apart, so they basically straddle the LDO

technobly commented 11 years ago

Looking a little closer, I think the pins and pads and solder fillet of the USB connector will be too narrow to allow the SOT-223 body of the regulator to pass comfortably.

regulator dimensions

usb dimensions

It's close, so I think you might need to just put it on there and play with it. Also be careful with the oblong holes... they are basically plated through routes... not super hard but can get board houses to complain about those. This would make it rock solid though.

zsup commented 11 years ago

Agreed, seems like something we'll have to test. Also will depend on exactly how deep those USB legs go; they may be shallow enough that even if they overlap with the regulator body a bit, it might not present a problem, so long as we can get a soldering iron in there.

technobly commented 11 years ago

Good point, you would assume the pins go through for a proper fillet... wave soldering, mechanical strength.. but it appears this one would end up half way through the board. Honestly I don't see the value in this since it might not even be soldered properly (without hand soldering) http://i.imgur.com/HDRSFJc.png

andyw-lala commented 11 years ago

What would the production flow be to include wave and reflow ? What would the additional assembly cost be for manual soldering ?

On Fri, Jul 12, 2013 at 10:31 AM, DubbyTT notifications@github.com wrote:

Good point, you would assume the pins go through for a proper fillet... wave soldering, mechanical strength.. but it appears this one would end up half way through the board. Honestly I don't see the value in this since it might not even be soldered properly (without hand soldering) http://i.imgur.com/HDRSFJc.png

— Reply to this email directly or view it on GitHubhttps://github.com/sprk/core/issues/23#issuecomment-20883946 .

Andy

technobly commented 11 years ago

Even though out of stock, this one is a bit wider and has two more pins for stability and same low price. http://www.digikey.com/product-detail/en/10118194-0001LF/609-4618-2-ND/2785389

Pins are even shallower though...

zsup commented 11 years ago

Ah here's a little mixup - the PCB doesn't actually go to the end of the USB profile, the USB sticks off a bit. The end of the PCB is roughly where that 0.80 arrow is. So the through-hole pins are actually further north, straddling the top pad of the voltage regulator instead of its body, which provides more clearance. Plus it gives us a nice little heatsink for the voltage regulator.

On Friday, July 12, 2013 at 10:31 AM, DubbyTT wrote:

Good point, you would assume the pins go through for a proper fillet... wave soldering, mechanical strength.. but it appears this one would end up half way through the board. Honestly I don't see the value in this since it might not even be soldered properly (without hand soldering) http://i.imgur.com/HDRSFJc.png

— Reply to this email directly or view it on GitHub (https://github.com/sprk/core/issues/23#issuecomment-20883946).

technobly commented 11 years ago

Apparently these are supposed to be Dip soldered... See the TE Quick Reference Guide direct link here

Back of the guide: http://i.imgur.com/RSTyj3z.png

http://en.wikipedia.org/wiki/Dip_soldering

zsup commented 11 years ago

The datasheet for the USB module is now in the 'Datsheets' folder (in the dev branch).

satishgn commented 11 years ago

Implemented and pushed the update to Dev branch

zsup commented 11 years ago

Looks good, except it would be great to have the oval-shaped holes if possible. @mohitbhoite is going to look into this to see how to do this in EAGLE

andyw-lala commented 11 years ago

Has anyone checked with the board house for cost with this ?

On Wed, Jul 17, 2013 at 12:42 PM, cazzo notifications@github.com wrote:

Looks good, except it would be great to have the oval-shaped holes if possible. @mohitbhoite https://github.com/mohitbhoite is going to look into this to see how to do this in EAGLE

— Reply to this email directly or view it on GitHubhttps://github.com/sprk/core/issues/23#issuecomment-21130409 .

Andy

zsup commented 11 years ago

We haven't checked the price yet, only way to get a meaningful quote is to show them exactly how it would look on the board.

@mohitbhoite created a new part for this in the library that includes a milling layer for the router. @satishgn can you replace the current USB connector with the version that @mohitbhoite created as you go through your changes today? Once we have this we can send the new Gerber in for a quote and see how it affects the price.

satishgn commented 11 years ago

Replaced the USB connector with the slotted hole version