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SMD Crystal Oscillator for Hand Soldering... — Parallax Forums

SMD Crystal Oscillator for Hand Soldering...

cbmeekscbmeeks Posts: 634
in Propeller 1
I'm working on a design that will use a SMD Prop and, naturally, I want a SMD crystal oscillator too.

I can easily hand solder the LQFP Prop but I'm not sure what oscillator to get.

I found this one on Mouser because it seems to have small "notches" near the pads that I presume I could put an iron to in order to reach the pads underneath.

https://www.mouser.com/ProductDetail/Ecliptek/EC2600TS-5000M-TR?qs=sGAEpiMZZMt8zWNA7msRCuuLuz0BJnoljNA9np1S7NJeG/UBOTGZcQ==

I don't really want to deal with reflow ovens or hotplates at the moment so hand soldering only. Perhaps I could make the pads on the board larger, pre-tin then, then hold the oscillator down while heating up the pad. But this seems like a hack.

What do you guys suggest?

Thanks!

Comments

  • jmgjmg Posts: 15,173
    If the board is production ready, (gold plated or HASL etc) you do not need to pre-tin.
    It is no hack, KiCad has hand solder SMD footprints that have larger pads.
    7x5 is quite large these days, and you could look at SOT23-5 oscillators too.
  • cbmeekscbmeeks Posts: 634
    Ah, thanks for the feedback.

    Do you have a particular recommendation? I'm not looking for microscopic. But it would look silly if the oscillator was twice as big as the Prop. lol

  • Peter JakackiPeter Jakacki Posts: 10,193
    Sure, you could make the pads a little larger anyway but solder paste is still useful there too. However I don't understand why anyone in 2019 would still think you need a reflow oven (I'm pretending I didn't hear hotplates) when the $30 toaster oven works so well.

    Just design your board for SMD, hand solder-paste it if you have to but stencils are so cheap these days. I turn my oven on max with both top and bottom elements and after it's warmed up I placed the pcb on the middle tray for 4 minutes. BTW, the oven timer I leave jammed on and just have a digital kitchen timer beep me after 4 minutes (or use your phone). Use some folded foil as a "plate" for the pcb when placing and removing it. This also helps it to cool faster.
  • cbmeekscbmeeks Posts: 634
    Well, that is something I want to do one day. I have nothing against it. I just enjoy the "kit nature" of hand soldering things.
    Much like many wood workers enjoy using hand tools for everything.
  • Peter JakackiPeter Jakacki Posts: 10,193
    Saying that sounds like an excuse as you always have plenty of opportunity to hand solder stuff AND the surface-mount in the oven.

    Here is an early P2D2 test pcb in the oven, before P2 chips were available, and the result. Not hard at all.
    IMG_20180704_131205.jpg
    2257 x 1693 - 321K
    IMG_20180704_132225.jpg
    2256 x 1722 - 544K
  • cbmeekscbmeeks Posts: 634
    It's not a matter of being hard or not. It's simply something I don't want to do at the moment. No excuses. I just don't want to do it.

    Not to mention my current work area doesn't have the room for yet one more piece of equipment.
  • Peter JakackiPeter Jakacki Posts: 10,193
    All I can say is that you are missing out big time and it's such a shame that so many hold back because they think that it is too hard, they need a microscope (LOL), they need "equipment". You are missing out on being able to design it the way it should be, and to be very happy about the result. I've got one busted retina and I have to wear reading glasses normally and an extra pair when I pick and place. So what!?
  • cbmeekscbmeeks Posts: 634
    I never said it was hard. Never said that one time.

    What's wrong with designing it the way *I* want it to be? Instead of designing it the way you think it should be? I'm not missing out on anything. This is a hobby for me. Not my profession.

    Goodness gracious...I'm just asking for crystal oscillator suggestions...

  • Peter JakackiPeter Jakacki Posts: 10,193
    cbmeeks wrote: »
    I never said it was hard. Never said that one time.

    What's wrong with designing it the way *I* want it to be? Instead of designing it the way you think it should be? I'm not missing out on anything. This is a hobby for me. Not my profession.

    Goodness gracious...I'm just asking for crystal oscillator suggestions...

    Goodness gracious indeed.
  • RaymanRayman Posts: 14,640
    edited 2019-09-20 15:50
    I'm using XC1264CT-ND (Digikey part number).
    Takes up a lot of space, but works well.
    Easily soldered by hand.
  • cbmeekscbmeeks Posts: 634
    Anyways...

    @Rayman

    Thanks for the suggestion. I actually like that one better than the one I found earlier. Even if it is ginormous compared to the Prop. lol

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    Peter Jakacki wrote:
    However I don't understand why anyone in 2019 would still think you need a reflow oven (I'm pretending I didn't hear hotplates) when the $30 toaster oven works so well.
    Indeed. But if you're doing larger boards, invest a little more in a convection oven (but not one powerful enough to blow parts off the board). It will help avoid uneven heating.

    -Phil
  • cbmeekscbmeeks Posts: 634
    edited 2019-09-20 18:18
    Let it be known that my original mistake was calling a cheapo toaster oven a "reflow oven". I know people are using those ovens all the time. I just don't care to do so.

    But if I did start, I'll certainly do some research before I buy.

    Many of the things I build/design (like my Potpourri6502 computer) are geared towards hand soldering because I find it fun.

    I can solder some pretty small components by hand using only my normal eyeglasses. As you can see in the two pics, they are quite small. I think they are 2012 IIRC. I soldered many of those by hand sometime ago.

    If I had a lot of those, then yeah...I would consider an oven. But until I do that, I just don't see the need.

    :-)

    IMG-0349.JPG
    3024 x 4032 - 1M
    IMG-0350.JPG
    4032 x 3024 - 624K
  • RaymanRayman Posts: 14,640
    0805 are easy to solder by hand and not too big.
    2512 are giant, but good for high power or voltage...
  • cbmeekscbmeeks Posts: 634
    Yeah, I probably got the numbers wrong. I can't remember what they were. But you can see the comparison in the pics. They were pretty small for my old eyes. :-)
  • RaymanRayman Posts: 14,640
    Pic looks like it might be 0603. That's about the smallest that is easy to hand solder without magnifier...
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2019-09-20 19:40
    The way to hand-solder 0603s is to tin one pad, place the device with non-magnetic tweezers, melt the solder on the tinned pad while holding the device down, then solder the other end after the first joint solidifies.

    Don't tin both pads before placing the device, though, as it will not sit level. And don't use too much heat or time on the second pad, else you'll melt the joint on the first pad. If your joints look globbed instead of filleted, use solder wick — either pre-tinned or with a little flux — to clean them up. Neatness counts!

    -Phil
  • RaymanRayman Posts: 14,640
    I compared the photo with a resistor on my hand and now think it is an 0805 you have there.

    But, Phil's instructions work for that size too...

    0805 is a comfortable size, I think.
  • Peter JakackiPeter Jakacki Posts: 10,193
    Phil Pilgrim (PhiPi) wrote: »
    Peter Jakacki wrote:
    However I don't understand why anyone in 2019 would still think you need a reflow oven (I'm pretending I didn't hear hotplates) when the $30 toaster oven works so well.
    Indeed. But if you're doing larger boards, invest a little more in a convection oven (but not one powerful enough to blow parts off the board). It will help avoid uneven heating.

    -Phil

    I do larger boards too but I find that the foil helps avoid hotspots and I even place a foil baking dish over the boards to even it out too. But do you have any particular convection ovens in mind? I mainly work with 0603 parts now although I have reels of 0805s that I hardly use anymore, they look HUGE compared to 0603 which are actually quite easy to work with.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2019-09-21 03:29
    Peter Jakacki wrote:
    But do you have any particular convection ovens in mind?
    I do not, sorry. I just know that attempting to solder larger boards in my IR-element toaster oven resulted in hot- and cold-spots -- i.e. burnt areas and places where the solder did not even melt. I had read somewhere that a convection oven would solve this problem. But I typically only solder very small boards, so I did not follow up with a new purchase at Costco.

    I like your idea of using foil to even out the heat, although I typically like to watch the solder melt and the joints fuse, in case I have to turn off the oven before time-out.

    -Phil
  • jmgjmg Posts: 15,173
    edited 2019-09-22 04:29
    cbmeeks wrote: »
    Ah, thanks for the feedback.

    Do you have a particular recommendation? I'm not looking for microscopic. But it would look silly if the oscillator was twice as big as the Prop. lol

    You could look at the Osc used on FLiP ?
    There was a thread on that, and a part code for better RFI, a while back...

    Addit: I find this comment...

    “SIT8918BEL13-33E-5.000000G 3.3V ±50ppm -40°C ~ 105°C 4.7mA 2.50mm x 2.00mm $0.96288/1000

    Hehe, look, it is the lower slew variant, & the same part code Tracy Allen confirmed with FLiP+GPS
    - which make sense to be a default for a 5MHz Osc”

    Addit: and if you want better stability, Mouser stock the slightly larger
    ECS-3225S33-050-EN-TR Miniature Crystal Oscillator HCMOS Tight Stability 3.3V 5MHz ±15ppm -40 to 85°C 3.2x2.5x0.9mm SMD T/R

    You can design a PCB that can accept 2520 and 3225 cases.
  • Cluso99Cluso99 Posts: 18,069
    My eyes are no longer that great so I use my glasses with a pair of jewellers glasses too. They go around the head with a strap. They are not the eBay kind - my brother was a diamond setter and he donated them to me :). I wouldn’t want to do it for a long time though.
  • RaymanRayman Posts: 14,640
    BTW: for reflow oven, I shelled not too much for a T-962 a couple years ago. Works pretty nicely...
  • frank freedmanfrank freedman Posts: 1,983
    Phil Pilgrim (PhiPi) wrote: »
    The way to hand-solder 0603s is to tin one pad, place the device with non-magnetic tweezers, melt the solder on the tinned pad while holding the device down, then solder the other end after the first joint solidifies.

    Don't tin both pads before placing the device, though, as it will not sit level. And don't use too much heat or time on the second pad, else you'll melt the joint on the first pad. If your joints look globbed instead of filleted, use solder wick — either pre-tinned or with a little flux — to clean them up. Neatness counts!

    -Phil

    My method was to use a dab of ZephPaste on each pad which will hold the part in place and a very gentle bit of hot air from an old re-purposed Radio Shack solder removal tool for heat and an aquarium pump for the air source. Replaced some 0603 H smd fuses this way. Also, mounted some SMD only parts on TI and AdaFruit PCBs for use on breadboards. Cost about $30 or so vs spending $$$$$ for a fully kitted out Zephtronics rework station.
  • cbmeekscbmeeks Posts: 634
    Phil Pilgrim (PhiPi) wrote: »
    The way to hand-solder 0603s is to tin one pad, place the device with non-magnetic tweezers, melt the solder on the tinned pad while holding the device down, then solder the other end after the first joint solidifies.

    Don't tin both pads before placing the device, though, as it will not sit level. And don't use too much heat or time on the second pad, else you'll melt the joint on the first pad. If your joints look globbed instead of filleted, use solder wick — either pre-tinned or with a little flux — to clean them up. Neatness counts!

    -Phil

    That's pretty much how I do it. I recently recapped my Amiga 600 (many SMD parts) and was quite proud that my fillets looked like curved ramps going up to the pin. All hand soldered. No magnification other than eyeglasses.

    Now, will I be able to do that in a few more years? Probably not. lol

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