I have a friend who consults for TI on switching power supply design
(Nathan Sokal). If you don't feel you are getting TI's attention to
solve this problem you could ask Nate if he's got any suggestions?
Sent from my iPhone
On Mar 23, 2010, at 4:14 PM, "Nowland, Russell Howard
(Russell)" <[log in to unmask]> wrote:
> Thanks for all of the advice. The leads that are being used look
> like the autosplice pin you sent the URL for. I can tell you the co-
> planarity of the pins is more of a concern to me than the PWB. I
> add a photo to Kim's newly installed IPC photo repository under the
> title "Power Supply Butt Joints".
>
> There were a couple of suggestions about trying to apply glue. We
> have done this on some SMT Electrolytics but unfortunately these
> Power Supplies have a standoff that would prevent it. So I don't
> see gluing as an option.
>
> TI's only suggestion was to go to a 6 mil stencil which we are going
> to try. Right now the pin diameter is 40 mils and the pad diameter
> is 85 mils so I am hesitant to ad another 20-40 mils. Plus I am not
> sure designers would give me the added real estate.
>
> I have been trading emails with a guy at TI hoping someone else has
> reported an issue but so far he has only confirmed what I have
> already identified.
>
> And Werner, I believe John Manock has already done an attachment
> reliability study on these and bought in to it. I do not like Butt
> Joints either.
>
> Thanks guys, keep the ideas coming.
>
> Russell Nowland
> Alcatel-Lucent
> Advanced Manufacturing Engineer
> Address: 14000 Quail Spring Parkway, Suite 300
> Oklahoma City, OK 73134
> email: [log in to unmask]
> Desk: 405-302-1660
> Cell: 405-203-0034
> Fax: 405-302-1622
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Bob Landman
> Sent: Tuesday, March 23, 2010 1:43 PM
> To: [log in to unmask]
> Subject: Re: [TN] TI/Emerson SMT Board Mounted Power
>
> Graham,
>
> While I have not tried this clever device, it seems like a good way
> to solve the problem.
>
> See http://www.autosplice.com/solderball-pins/
>
> "Eliminates Coplanarity Concerns When Soldering Parallel PC Boards
>
> Packaged in Tape Reel for use with standard feeders for automated
> placement. The product contains a Solderball that maintains its
> shape during multiple solder reflow processes. The PC board or
> device can then easily be soldered to pads on another parallel PC
> board. The Solderball pins accommodate up to .020" (0.5mm)
> coplanarity variation with high current reliability."
>
> Bob Landman
> H&L Instruments, LLC
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Graham Collins
> Sent: Tuesday, March 23, 2010 8:45 AM
> To: [log in to unmask]
> Subject: Re: [TN] TI/Emerson SMT Board Mounted Power
>
> Hi Russell
> Is it skewed before it goes into the reflow oven? If yes, then a
> placement issue. If it looks OK before reflow oven and is skewed
> after the reflow oven then obviously is moving in there - which
> points to a pad size problem.
>
> If their placement is good and it is skewing in the oven, one trick
> we have used in the past is to dispense a glue dot under the
> component body
> - it will hold the alignment during reflow. We have used this
> method when pad layout is not quite right and the alignment is
> critical to meet IPC-A-610 requirements (e.g. for heel fillet).
> They would need to have glue dispense capability though.
>
> regards,
> - Graham
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Nowland, Russell
> Howard (Russell)
> Sent: Monday, March 22, 2010 4:57 PM
> To: [log in to unmask]
> Subject: [TN] TI/Emerson SMT Board Mounted Power
>
> Hello Technetters,
>
> I have a problem I hope someone out there has a solution for.
>
> I have on a PCA that uses a Texas Instrument/(Emerson Power/Artesyn)
> (dual sourced but part of the POLA) SMT board mounted power converter.
> The MPN is PTH03050WAS. It is actually combination PTH and SMT.
> The device has 40 mil diameter pins for PTH and to make it SMT they
> simply add a donut (solder dam) on the pin and round the edges and
> call it a solder ball. I think the problem my EMS is having is
> really with pick-n-place because the pick-up point (Actually the top
> of a
> transformer) is off-center, fairly small, and it has a plastic label
> on it.
>
> The problem is the device is coming out of the oven skewed and
> violating IPC 610D. The pad diameter is exactly what is recommended
> by the datasheet (.085-inches). The TI datasheet recommended a
> 0.080-0.085 diameter aperture @ six mils. Originally my EMS had
> 0.085-inch @ 5 mils but changed the aperture to a bull's-eye shape
> with the thought the bull's-eye would help center the device. Both
> of the stencils have failed to draw the device to the center.
>
> Because this is really a Butt Joint I am holding the EMS to no side
> overhang. This is causing them quite a headache. They have also not
> come up with a viable solution either.
>
> Here is the link to the data sheet
>
> http://www.emerson.com/sites/network_power/en-US/Products/Product_Detail
> /Product1/Documents/PTH03050%20DC-DC%20Converter/PTH03050%20Data
> %20Sheet
> .pdf
>
>
>
> Has anybody used these devices with good results? If so can you
> share your methodology?
>
> Thanks in advanced,
>
>
> Russell Nowland
> Alcatel-Lucent
> Advanced Manufacturing Engineer
> Address: 14000 Quail Spring Parkway, Suite 300 Oklahoma City, OK 73134
> email:
> [log in to unmask]<mailto:russell.nowland@alcatel-
> lucent
> .com>
> Desk: 405-302-1660
> Cell: 405-203-0034
> Fax: 405-302-1622
>
>
> ______________________________________________________________________
> This email has been scanned by the MessageLabs Email Security System.
> For more information please contact helpdesk at x2960 or [log in to unmask]
>
> ______________________________________________________________________
>
> ---------------------------------------------------
> Technet Mail List provided as a service by IPC using LISTSERV 15.0
> To unsubscribe, send a message to [log in to unmask] with following
> text in the BODY (NOT the subject field): SIGNOFF Technet To
> temporarily halt or (re-start) delivery of Technet send e-mail to
> [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE
> mailing per day of all the posts: send e-mail to
> [log in to unmask]: SET Technet Digest
> Search the archives of previous posts at:
> http://listserv.ipc.org/archives
> Please visit IPC web site
> http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional
> information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100
> ext.2815
> -----------------------------------------------------
>
> ______________________________________________________________________
> This email has been scanned by the MessageLabs Email Security System.
> For more information please contact helpdesk at x2960 or [log in to unmask]
>
> ______________________________________________________________________
>
> ---------------------------------------------------
> Technet Mail List provided as a service by IPC using LISTSERV 15.0
> To unsubscribe, send a message to [log in to unmask] with following
> text in the BODY (NOT the subject field): SIGNOFF Technet To
> temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]
> : SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all
> the posts: send e-mail to [log in to unmask]: SET Technet Digest
> Search the archives of previous posts at: http://listserv.ipc.org/archives
> Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16
> for additional information, or contact Keach Sasamori at [log in to unmask]
> or 847-615-7100 ext.2815
> -----------------------------------------------------
>
>
>
> ______________________________________________________________________
> This email has been scanned by the MessageLabs Email Security System.
> For more information please contact helpdesk at x2960 or [log in to unmask]
> ______________________________________________________________________
>
> ---------------------------------------------------
> Technet Mail List provided as a service by IPC using LISTSERV 15.0
> To unsubscribe, send a message to [log in to unmask] with following
> text in
> the BODY (NOT the subject field): SIGNOFF Technet
> To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]
> : SET Technet NOMAIL or (MAIL)
> To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]
> : SET Technet Digest
> Search the archives of previous posts at: http://listserv.ipc.org/archives
> Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16
> for additional information, or contact Keach Sasamori at [log in to unmask]
> or 847-615-7100 ext.2815
> -----------------------------------------------------
>
> ______________________________________________________________________
> This email has been scanned by the MessageLabs Email Security System.
> For more information please contact helpdesk at x2960 or [log in to unmask]
> ______________________________________________________________________
>
> ---------------------------------------------------
> Technet Mail List provided as a service by IPC using LISTSERV 15.0
> To unsubscribe, send a message to [log in to unmask] with following
> text in
> the BODY (NOT the subject field): SIGNOFF Technet
> To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]
> : SET Technet NOMAIL or (MAIL)
> To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]
> : SET Technet Digest
> Search the archives of previous posts at: http://listserv.ipc.org/archives
> Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16
> for additional information, or contact Keach Sasamori at [log in to unmask]
> or 847-615-7100 ext.2815
> -----------------------------------------------------
>
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or [log in to unmask]
______________________________________________________________________
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------
|
