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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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Solder Pads on Antenna #31

Closed brandoaire closed 10 years ago

brandoaire commented 10 years ago

Need to double check the size of the solder pads for the antenna. Based on most recent build, the component was difficult to place accurately, especially if solder paste was not completely or precisely covering the pad. See attached picture (best I can do with an iPhone). It seems to sit on the inner 25-50% of the pad on each side.

img_0098

brandoaire commented 10 years ago

I have no idea why that inserted the photo upside down--trying again.

img_0098

andyw-lala commented 10 years ago

Why are both the cap to the u.FL and the cap to the chip antenna populated ?

On Mon, Jul 15, 2013 at 1:06 PM, Will Hart notifications@github.com wrote:

I have no idea why that inserted the photo upside down--trying again.

[image: img_0098]https://f.cloud.github.com/assets/4020511/799651/29cafba6-ed79-11e2-97e6-70dc84b45e92.jpeg

— Reply to this email directly or view it on GitHubhttps://github.com/sprk/core/issues/31#issuecomment-20989718 .

Andy

technobly commented 10 years ago

I was thinking that was an optional stuff as well... stuff C5 for ANT1, or C6 for uFL. pic1

And the iPhone takes great macro images, you must be holding it wrong :) pic2

andyw-lala commented 10 years ago

I will double check the eagle footprint against the datasheets tonight.

On Mon, Jul 15, 2013 at 1:04 PM, Will Hart notifications@github.com wrote:

Need to double check the size of the solder pads for the antenna. Based on most recent build, the component was difficult to place accurately, especially if solder paste was not completely or precisely covering the pad. See attached picture (best I can do with an iPhone). It seems to sit on the inner 25-50% of the pad on each side.

[image: img_0098]https://f.cloud.github.com/assets/4020511/799638/fa25f2e8-ed78-11e2-99e9-047dd335c032.jpeg

— Reply to this email directly or view it on GitHubhttps://github.com/sprk/core/issues/31 .

Andy

zsup commented 10 years ago

The double-populate was a misunderstanding between Will and I :-)

andyw-lala commented 10 years ago

Well, well done for getting both parts on that pad, without tombstoning :)

On Mon, Jul 15, 2013 at 5:05 PM, cazzo notifications@github.com wrote:

The double-populate was a misunderstanding between Will and I :-)

— Reply to this email directly or view it on GitHubhttps://github.com/sprk/core/issues/31#issuecomment-21007458 .

Andy

andyw-lala commented 10 years ago

I checked the footprint against the Johanson 2500AT44M0400/ACX AT8010 and it seems to match (1mmx1mm pads with 7mm spacing edge to edge.)

Would be worth contacting ACX and/or Johanson to check to see if they DFM guidelines.

However, I can quite imagine that they intentionally limit the intrusion of the pads under the antenna, meaning that it will rely on the fillet a lot more.

On Mon, Jul 15, 2013 at 5:08 PM, Andy Warner andyw@pobox.com wrote:

Well, well done for getting both parts on that pad, without tombstoning :)

On Mon, Jul 15, 2013 at 5:05 PM, cazzo notifications@github.com wrote:

The double-populate was a misunderstanding between Will and I :-)

— Reply to this email directly or view it on GitHubhttps://github.com/sprk/core/issues/31#issuecomment-21007458 .

Andy

Andy

technobly commented 10 years ago

I wonder if they'd recommend gluing it down? I don't suppose the spec mentions that at all.

andyw-lala commented 10 years ago

I highly doubt they want any additional material near the antenna - especially with unknown RF characteristics.

On Tue, Jul 16, 2013 at 9:42 AM, DubbyTT notifications@github.com wrote:

I wonder if they'd recommend gluing it down? I don't suppose the spec mentions that at all.

— Reply to this email directly or view it on GitHubhttps://github.com/sprk/core/issues/31#issuecomment-21046482 .

Andy

technobly commented 10 years ago

Well they seem to care more about something that's got metal in it. I'd be surprised if glue affected it that much http://johansontechnology.com/tuning

Here's a 915MHz ant that recommends a drop of glue to secure it http://www.vishay.com/docs/45207/vj5301m915mxbsr.pdf

That said, someone just needs to call one of their application engineers and ask for a recommendation. http://www.johansontechnology.com/contact.html

zsup commented 10 years ago

@andyw-lala put together a few boards and agreed that while it might be a bit tricky for hand-soldering, it should be fine for a pick and place machine. Closing this issue.