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:[log in to unmask]>
Desk: 405-302-1660
Cell: 405-203-0034
Fax: 405-302-1622


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