mSATA PCIe connector

[Winfield Hill]

I'm thinking of using a standard mSATA / PCIe
card-edge connector in a miniature pocket-sized
project. Its small 30mm width, with 52-contacts
at 0.8mm, is good. The typical 50 max-uses spec
is a bit troubling, but we may not need more uses
than that. Inserted PCBs swing down into place.
Its low price and reliability reputation are good.
Does anybody have some advice to offer? I'm not
yet under an NDA on this project, but maybe ...

A typical p/n is Molex 67910-0002, although that
one only allows for 1mm = 40mils of space under.
We do need to use both sides of our PCB, but the
attached PCB won't have any parts on its bottom.


--
Thanks,
- Win

 

Winfield Hill <winfieldhill@yahoo.com> wrote in news:r65l47030l1
@drn.newsguy.com:

I'm thinking of using a standard mSATA / PCIe
card-edge connector in a miniature pocket-sized
project. Its small 30mm width, with 52-contacts
at 0.8mm, is good. The typical 50 max-uses spec
is a bit troubling, but we may not need more uses
than that. Inserted PCBs swing down into place.
Its low price and reliability reputation are good.
Does anybody have some advice to offer? I'm not
yet under an NDA on this project, but maybe ...

A typical p/n is Molex 67910-0002, although that
one only allows for 1mm = 40mils of space under.
We do need to use both sides of our PCB, but the
attached PCB won't have any parts on its bottom.

Is the plan to utilize it for multiple insertions/releases?

I mean it is low stress on the pins because of the method by which
it works, which is a good thing for insertion count MTBF.

So, if you are incorporating it because it and the art is
available, it sounds like a good choice. Insertion is easy and single
screw lockdown insures high connection reliability over long time
periods, just like when it gets used on a storage device as the
connection to a computer. You said pocket device though, so short of
carrying a computer in your pocket... weird visions come to mind...
Could be a drive duplicator with quick external 'hot bay' for putting
drives in and out. Anyway. permanent install or not, it is a good
coice for your pin count need and size and part availablity. Sounds
great to me.

Like we used cheap cat6 wire for proprietary module to module
interrack communications links at one place I was at.

I would not gang them width wise though and try to double up on pin
count on a bigger board kind of thing. The clamping pressure
increases and alignment precision has to be there...

 

[Rick C]

On Thursday, April 2, 2020 at 5:23:38 PM UTC-4, Winfield Hill wrote:

I'm thinking of using a standard mSATA / PCIe
card-edge connector in a miniature pocket-sized
project. Its small 30mm width, with 52-contacts
at 0.8mm, is good. The typical 50 max-uses spec
is a bit troubling, but we may not need more uses
than that. Inserted PCBs swing down into place.
Its low price and reliability reputation are good.
Does anybody have some advice to offer? I'm not
yet under an NDA on this project, but maybe ...

A typical p/n is Molex 67910-0002, although that
one only allows for 1mm = 40mils of space under.
We do need to use both sides of our PCB, but the
attached PCB won't have any parts on its bottom.

Is there a reason why you need such a fine pitch connector? I suppose you can manage the mechanical issues, but an older spec with larger pin spacing and tolerance will likely give you more room to manage the mechanical issues. It sounds like some sort of automated something if the boards are not inserted by hand and "swing" down into the connectors.

I seem to recall the now ancient ISA connector was very durable and had very generous tolerances.

Why a card edge connector rather than a two piece connector? They can be bought with guide pins to prevent mangling. Or is the "swing" insertion something other than automated?

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

[Joe Chisolm]

On Thu, 02 Apr 2020 14:23:19 -0700, Winfield Hill wrote:

I'm thinking of using a standard mSATA / PCIe
card-edge connector in a miniature pocket-sized project. Its small
30mm width, with 52-contacts at 0.8mm, is good. The typical 50
max-uses spec is a bit troubling, but we may not need more uses than
that. Inserted PCBs swing down into place. Its low price and
reliability reputation are good.
Does anybody have some advice to offer? I'm not yet under an NDA on
this project, but maybe ...

A typical p/n is Molex 67910-0002, although that one only allows for
1mm = 40mils of space under. We do need to use both sides of our PCB,
but the attached PCB won't have any parts on its bottom.

We have used a bunch of these in the past - Mouser 694-498-0090
They stand taller. There is no issue with placement for most
components under the daughter card. You can also hand solder them
if needed.

I think these are rated at 100 cycles for a given contact resistance.
We never went anywhere near 100 cycles in the field but I know in the
lab we went well over that number with no issues.

There is a mating spring latch we used but our units where not
in a rough and tumble environment either.

--
Chisolm
Texas-American

 

[Winfield Hill]

Rick C wrote...

On Thursday, April 2, 2020 at 5:23:38 PM UTC-4, Winfield Hill wrote:
I'm thinking of using a standard mSATA / PCIe
card-edge connector in a miniature pocket-sized
project. Its small 30mm width, with 52-contacts
at 0.8mm, is good. The typical 50 max-uses spec
is a bit troubling, but we may not need more uses
than that. Inserted PCBs swing down into place.
Its low price and reliability reputation are good.
Does anybody have some advice to offer? I'm not
yet under an NDA on this project, but maybe ...
=20
A typical p/n is Molex 67910-0002, although that
one only allows for 1mm =3D 40mils of space under.
We do need to use both sides of our PCB, but the
attached PCB won't have any parts on its bottom.

Is there a reason why you need such a fine pitch connector?

Thanks, Rick, for your comments.

The 30mm width is critical, it's fitting where a 32mm
20-pin card-edge connector goes now. The cards will
be inserted by hand, usually by professionals. My
experience with using mSATA cards in computers, is
that with a good connector, and a PCB that carefully
follows the spec details, it's hard to get it wrong.

We need more pins. Since I started considering a 0.5mm
pitch, 0.8mm seems huge! Most connectors are one fixed
piece, but some have a swinging portion.

We need to use card edge, because it's best if the cards
can be assembled without any soldering; they will have
considerable other lithographic treatments.


--
Thanks,
- Win

 

[Winfield Hill]

Joe Chisolm wrote...

On Thu, 02 Apr 2020 14:23:19 -0700, Winfield Hill wrote:

I'm thinking of using a standard mSATA / PCIe
card-edge connector in a miniature pocket-sized project. Its small
30mm width, with 52-contacts at 0.8mm, is good. The typical 50
max-uses spec is a bit troubling, but we may not need more uses than
that. Inserted PCBs swing down into place. Its low price and
reliability reputation are good.
Does anybody have some advice to offer? I'm not yet under an NDA on
this project, but maybe ...

A typical p/n is Molex 67910-0002, although that one only allows for
1mm = 40mils of space under. We do need to use both sides of our PCB,
but the attached PCB won't have any parts on its bottom.

We have used a bunch of these in the past - Mouser 694-498-0090
They stand taller. There is no issue with placement for most
components under the daughter card. You can also hand solder them
if needed.

I think these are rated at 100 cycles for a given contact resistance.
We never went anywhere near 100 cycles in the field but I know in the
lab we went well over that number with no issues.

There is a mating spring latch we used but our units where not
in a rough and tumble environment either.

That looks good, but the Mouser datasheet is a disaster!
But the company's website has a better copy. I like the
huge 4.4mm clearance.


--
Thanks,
- Win

 

[Buzz McCool]

On 4/2/20 2:23 PM, Winfield Hill wrote:

I'm thinking of using a standard mSATA / PCIe
card-edge connector in a miniature pocket-sized
project. ...

Card edge connectors, in my experience, always have connectivity
problems. (STD-BUS, ISA, EISA, PCI, PCI-X, PCIe, DIMM ... )

Had the best luck with dual wiper DIMM connectors (I think they were
sourced from Fujitsu).

My motto is "Card edge connectors don't connect."

 

[Don Kuenz]

Buzz McCool <buzz_mccool@yahoo.com> wrote:

On 4/2/20 2:23 PM, Winfield Hill wrote:
I'm thinking of using a standard mSATA / PCIe
card-edge connector in a miniature pocket-sized
project. ...

Card edge connectors, in my experience, always have connectivity
problems. (STD-BUS, ISA, EISA, PCI, PCI-X, PCIe, DIMM ... )

Had the best luck with dual wiper DIMM connectors (I think they were
sourced from Fujitsu).

My motto is "Card edge connectors don't connect."

That motto's a subset, a specialized case of the super-motto "connectors
don't connect." Soldered connections give me the best luck.
IIRC, either in his book or in here, Win ranked bad connections near
the top as a source of failure. That certainly mirrors my own modest
experience.
OTOH, the card connectors that you enumerate almost always connect
without a problem for me. Memory modules are handled a lot more by me
and they are probably more reliable.

Thank you,

--
Don Kuenz KB7RPU
There was a young lady named Bright Whose speed was far faster than light;
She set out one day In a relative way And returned on the previous night.

 

[Winfield Hill]

Winfield Hill wrote...

I'm thinking of using a standard mSATA / PCIe
card-edge connector in a miniature pocket-sized
project. Its small 30mm width, with 52-contacts
at 0.8mm, is good. ...

The suggested Digi mSATA version provides 4.4mm
of space below the PCB, compared to 3.9mm with
our present 20-pin connector. And it'll use up
only about half the PCB space. Nice!

One issue, standard mSATA and PCIe devices use
a 1.0mm thick PCB, compared to the usual 62-mil
1.57mm-thick PCB. We can probably change to
1.0mm, but it also appears these connectors
won't mind a thicker PCB. Comments about that?


--
Thanks,
- Win

 

[Buzz McCool]

On 4/3/20 8:52 AM, Don Kuenz wrote:

Buzz McCool <buzz_mccool@yahoo.com> wrote:
My motto is "Card edge connectors don't connect."
That motto's a subset, a specialized case of the super-motto "connectors
don't connect." Soldered connections give me the best luck.

Roger that comment with the exception of large parts (e.g. DC/DC
converter bricks) through hole soldered to a multi-layer board. The
solder tends to crack due to mechanical stress/less than perfect soldering.

Note that while I have found card edge connectors to be problematic, I
have had good success with all pin & socket type connectors (once
connected - bent pins don't count!)

 

[Ricky C]

On Friday, April 3, 2020 at 6:16:33 AM UTC-4, Winfield Hill wrote:

Rick C wrote...

On Thursday, April 2, 2020 at 5:23:38 PM UTC-4, Winfield Hill wrote:
I'm thinking of using a standard mSATA / PCIe
card-edge connector in a miniature pocket-sized
project. Its small 30mm width, with 52-contacts
at 0.8mm, is good. The typical 50 max-uses spec
is a bit troubling, but we may not need more uses
than that. Inserted PCBs swing down into place.
Its low price and reliability reputation are good.
Does anybody have some advice to offer? I'm not
yet under an NDA on this project, but maybe ...
=20
A typical p/n is Molex 67910-0002, although that
one only allows for 1mm =3D 40mils of space under.
We do need to use both sides of our PCB, but the
attached PCB won't have any parts on its bottom.

Is there a reason why you need such a fine pitch connector?

Thanks, Rick, for your comments.

The 30mm width is critical, it's fitting where a 32mm
20-pin card-edge connector goes now. The cards will
be inserted by hand, usually by professionals. My
experience with using mSATA cards in computers, is
that with a good connector, and a PCB that carefully
follows the spec details, it's hard to get it wrong.

We need more pins. Since I started considering a 0.5mm
pitch, 0.8mm seems huge! Most connectors are one fixed
piece, but some have a swinging portion.

We need to use card edge, because it's best if the cards
can be assembled without any soldering; they will have
considerable other lithographic treatments.

Ok, I get the space constraint. Two other questions. What did you mean when you said, "Inserted PCBs swing down into place" if they are hand inserted? Is one edge of the board hooked in a slot and the board levered into the connector.

Can you help me picture what you meany about "considerable other lithographic treatments". What sort of card is this that won't be soldered???

--

Rick C.

+ Get 1,000 miles of free Supercharging
+ Tesla referral code - https://ts.la/richard11209

 

[Ricky C]

On Friday, April 3, 2020 at 1:07:32 PM UTC-4, Winfield Hill wrote:

Winfield Hill wrote...

I'm thinking of using a standard mSATA / PCIe
card-edge connector in a miniature pocket-sized
project. Its small 30mm width, with 52-contacts
at 0.8mm, is good. ...

The suggested Digi mSATA version provides 4.4mm
of space below the PCB, compared to 3.9mm with
our present 20-pin connector. And it'll use up
only about half the PCB space. Nice!

One issue, standard mSATA and PCIe devices use
a 1.0mm thick PCB, compared to the usual 62-mil
1.57mm-thick PCB. We can probably change to
1.0mm, but it also appears these connectors
won't mind a thicker PCB. Comments about that?

Not fully understanding the need to not solder a connector to a board I would recommend the Amphenol Conan series of connectors. They have a vertical receptacle and a right angle header in 1 mm, 51 pin configuration which is 30.3 mm wide. Using alignment pins along with the mechanical solder pads will help relieve strain on the pins when inserting.

I've always found two piece connectors to be great for reliability as well as making the circuit board easy to design and fabricate. Having an odd number of pins, the connectors are self orienting needing no alignment key.

Just thought I'd mention these. I've used them before and they have a nice, gentle snap action to hold the board in place while securing it mechanically. For light duty work the snap action can replace using a screw. No doubt the connector is mated fully which is not an uncommon failure mode for other connectors.

--

Rick C.

-- Get 1,000 miles of free Supercharging
-- Tesla referral code - https://ts.la/richard11209

 

[Winfield Hill]

Ricky C wrote...

Not fully understanding the need to not solder a connector
to a board I would recommend the Amphenol Conan series of
connectors. They have a vertical receptacle and a right
angle header in 1 mm, 51 pin configuration which is 30.3 mm
wide. Using alignment pins along with the mechanical solder
pads will help relieve strain on the pins when inserting.

I've always found two piece connectors to be great for
reliability as well as making the circuit board easy to
design and fabricate. Having an odd number of pins, the
connectors are self orienting needing no alignment key.

That's an attractive connector set. Its 7mm board-to-board
height spacing is a little excessive, but only by about 3mm.

There are four others involved in the project. I checked
again, and they prefer to have stacks of various board
patterns and build their microchannels, etc., on that,
without any soldering or other non-PDMA0-style technology.
However, they envision some applications with more than
50 to 100 connector cycles, so there may be pressure to
accept a reliable two-piece connector solution instead.


--
Thanks,
- Win

 

[Ricky C]

On Friday, April 3, 2020 at 4:52:38 PM UTC-4, Winfield Hill wrote:

Ricky C wrote...

Not fully understanding the need to not solder a connector
to a board I would recommend the Amphenol Conan series of
connectors. They have a vertical receptacle and a right
angle header in 1 mm, 51 pin configuration which is 30.3 mm
wide. Using alignment pins along with the mechanical solder
pads will help relieve strain on the pins when inserting.

I've always found two piece connectors to be great for
reliability as well as making the circuit board easy to
design and fabricate. Having an odd number of pins, the
connectors are self orienting needing no alignment key.

That's an attractive connector set. Its 7mm board-to-board
height spacing is a little excessive, but only by about 3mm.

Not sure what you are looking at. With the right angle header you would need there is no minimum board to board height is there? The right angle connector is surface mount so the board can project below that as much as desired until it hits the other board. The top of the receptacle is 3.28 mm tall but even that should clear the mating board easily.

The 7 mm board to board height is for the "vertical" connectors which mount the boards parallel. Even then, 7.52 mm is the largest spacing. The smallest is 4.15 mm.

There are four others involved in the project. I checked
again, and they prefer to have stacks of various board
patterns and build their microchannels, etc., on that,
without any soldering or other non-PDMA0-style technology.

Sorry, I don't follow any of this. What is a microchannel and what does it have to do with this? Don't know what you meany by "board patterns", do you just mean they will use various board shapes? I have no idea what PDMA0 is, Google thinks it's something biological.

I really don't get what you are saying about not soldering. Aren't these boards electronics? How do you build boards without soldering???

However, they envision some applications with more than
50 to 100 connector cycles, so there may be pressure to
accept a reliable two-piece connector solution instead.

Interesting. The Conan connectors are only rated for 30 cycles. So maybe this isn't the connector for you.

It seems like insertion cycles is something that would be relatively standardized into categories. Anyone know if 30 cycles is common for gear that is typically built and never touched again? Sounds right to me. If the connectors are going to get any real use, I expect there is a separate class of connector that is constructed very differently.

--

Rick C.

-+ Get 1,000 miles of free Supercharging
-+ Tesla referral code - https://ts.la/richard11209

 

[Randy Day]

In article <r687m0011nh@drn.newsguy.com>, winfieldhill@yahoo.com says...

[snip]

Avoid SMT connectors in multi-cycle applications
if at all possible. Actually, we have problems
with them even in insert-once situations.

Ham-fisted insertion/removal, dropped units,
vibration; anything that introduces lateral forces
can and will peel the traces off the board. At
least with through-hole, it takes a lot more force
to do an equivalent amount of damage to traces.

Just my opinion, take it for what it's worth...

RD

 

Buzz McCool <buzz_mccool@yahoo.com> wrote in news:r67kgd$ql3$1
@gioia.aioe.org:

On 4/2/20 2:23 PM, Winfield Hill wrote:
I'm thinking of using a standard mSATA / PCIe
card-edge connector in a miniature pocket-sized
project. ...

Card edge connectors, in my experience, always have connectivity
problems. (STD-BUS, ISA, EISA, PCI, PCI-X, PCIe, DIMM ... )

Early stuff was not even Gold microinch eplating like everything is
now.

I got paid full repair session pay for showing up at the game room
where the PacMan or Centipede was on the fritz, for merely shutting
down and then pulling the edge connectors on and off a few times.
One could always tell if that was the problem too because there would
be garbage characters drawn on the screen. Otherwise, it was a real
repair like a fuse or such. ;-) had to charge a full 30 minutes
even though it only takes a few, and to keep game room operators from
going apeshit, we had to hang around in the back of the machine for a
while passing the time.

Had the best luck with dual wiper DIMM connectors (I think they
were
sourced from Fujitsu).

Memory module realm knew what they were doing and DIM tech is the
best tech for that many pins on a replaceable module. (leaving out
CPUs). But his choice is like DIMM because of they way it gets fixed
into place. They are very high integrity for very long term and
trhough vibe even.

> My motto is "Card edge connectors don't connect."

You should see some restoration videos of old computers and uprigt
video games, and old Oscopes and such. Lots of fun and very
informative.

 

[Ricky C]

On Friday, April 3, 2020 at 7:10:05 PM UTC-4, Randy Day wrote:

In article <r687m0011nh@drn.newsguy.com>, winfieldhill@yahoo.com says...

[snip]

Avoid SMT connectors in multi-cycle applications
if at all possible. Actually, we have problems
with them even in insert-once situations.

Ham-fisted insertion/removal, dropped units,
vibration; anything that introduces lateral forces
can and will peel the traces off the board. At
least with through-hole, it takes a lot more force
to do an equivalent amount of damage to traces.

Just my opinion, take it for what it's worth...

That is certainly true of connectors without alignment pins. The alignment pins take strain off the solder joints. I use a surface mount connector on my board with mating surface mount parts on the motherboard (which I didn't design). The motherboard parts don't have alignment pins and get used over and over with no failures so far, so I'm expecting my boards to do just fine. So far, no problems in around 10,000 units, 20,000 connectors. Can't be all bad.

--

Rick C.

+- Get 1,000 miles of free Supercharging
+- Tesla referral code - https://ts.la/richard11209

 

[Randy Day]

In article <a56eba46-3754-4ec4-92c3-5ac40472eb82@googlegroups.com>,
gnuarm.deletethisbit@gmail.com says...

[snip]

Just my opinion, take it for what it's worth...

That is certainly true of connectors without alignment pins.
The alignment pins take strain off the solder joints. I use a surface
mount connector on my board with mating surface mount parts on the
motherboard (which I didn't design). The motherboard parts don't have
alignment pins and get used over and over with no failures so far, so
I'm expecting my boards to do just fine. So far, no problems in
around 10,000 units, 20,000 connectors. Can't be all bad.

It will be interesting to see how they hold up long-term.
Your users must be less ham-fisted than ours.

If the alignment pins press-fit into the alignment holes,
yes, they can take up much of the strain. If it's the
common small-pin-in-a-larger-PCB-hole alignment, not so
much. If the alignment pins are soldered through-hole,
why not all the pins?

We tried an SMT USB connector with through-hole solder
tabs to hold it to the board; our crews still found ways
to break them loose. I've got name-brand laptops on the
dead equipment shelf with trashed charge jacks (SMT)
that ripped loose over time.

Even with alignment pins/tabs, I stand by my previous
statement: avoid SMT connectors if you can.

RD

 

Winfield Hill <winfieldhill@yahoo.com> wrote in news:r6aeiq01c02
@drn.newsguy.com:

Randy Day wrote...

Even with alignment pins/tabs, I stand by my previous
statement: avoid SMT connectors if you can.

The issue is less of concern if the connector has
many pins, providing strength, such as the 52-pin
mSATA connector. And its users are (carefully)
installing and fastening in place a fixed PCB,
rather than a connector with an attached cable.

It is a good choice. I even think one could make (design) a small
PCB that mounts there, and attach (solder in) a (presumably up to 52
pin) cable to THAT solidly mounted PCB (do it before you mount it).
Then, any tensions applied to the cable will never make it to the
connector header because the PCB is a mounted piece. Hey! That
would work!

 

[Winfield Hill]

Randy Day wrote...

Even with alignment pins/tabs, I stand by my previous
statement: avoid SMT connectors if you can.

The issue is less of concern if the connector has
many pins, providing strength, such as the 52-pin
mSATA connector. And its users are (carefully)
installing and fastening in place a fixed PCB,
rather than a connector with an attached cable.


--
Thanks,
- Win