Hi, Steve

In looking at the data sheet, you are correct, these are Olin C194 pins, which is a very hard copper alloy that is 97% hardened and annealed copper, with 2.5% iron and .5% phosphate bronze finish for oxidation resistance. I have soldered these before in automotive and industrial applications. It may take a longer dwell time to achieve a good IMF with the hardened base copper. This, along with the fact that you have two rows of these pins encased in a silicon chip makes the package extremely stiff. These are common in applications such as automotive connectors, etc. where good resistance to corrosion is required. But they do need extra care when soldering to ensure you get a good IMF, or they crack if there is a significant CTE delta between the board and the part and they are in a harsh environment (thermal cycling and vibration during operation). I suspect that is what is happening.

I would recommend pre-tinning the leads first to get a good IMF established, then assembling and soldering the parts. That way you do not need to worry about annular ring erosion and/or damage to the component itself during normal selective/wave solder processing.

Odin



-----Original Message-----

From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory

Sent: Friday, March 22, 2019 2:11 PM

To: [log in to unmask]

Subject: [TN] HDSP-2502 Smart Display through hole Solder Joints Failing



Hi All,



This just a shot in the dark, but have any of you used this display in a

board that experiences vibration and have the solder joints fail?



We have a board that we're building using leaded solder, and use a

selective solder to solder it into the board. We electrically test it here

before we ship it. It goes out in the field and then the display will stop

working at some point. We've gotten the boards back, and discovered that it

usually is a cracked solder joint. In fact, you can pull the display

completely out of the board, the leads pull out of the solder joints. None

of the other through hole components have any issues, and there's quite a

few other through hole components on the board.



The leads are very stiff, they are some sort of copper alloy I think.

Olin194, does that sound right? I've had a hard time finding what they are

actually made from, or what the lead finish is. Supposedly they are ROHS

compliant. They've changed names a few times, started out as Agilent, then

Avago, now Broadcom.



Like I said this is a shot in the dark...



Thanks,



Steve



-- 

Steve Gregory

Kimco Design and Manufacturing

Process Engineer

(208) 322-0500 Ext. -3133



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