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IEC - 60601 compliant LF-NC Wire Solder

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#50478

IEC - 60601 compliant LF-NC Wire Solder | 1 June, 2007

Im having problems with electromigration post a IEC - 60601 test (95% humidity for 48 hours). Im looking for a lead-free NC wire solder that will pass. Does anyone know of any that will work?

Thanks, Chris

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#50479

IEC - 60601 compliant LF-NC Wire Solder | 1 June, 2007

Chris,

Some knucklehead named HOSS asked the same question a couple weeks ago. All he got in return was crickets.

Rock on!

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#50485

IEC - 60601 compliant LF-NC Wire Solder | 4 June, 2007

Chris,

This is probably one of the reasons medical equipment and implants are exempt from the directive.

Below a quote from an article published by the medical device network.

RoHS excludes medical devices (category 8) and monitoring and control instruments (category 9), due to concerns over the reliability of substitute materials, particularly of lead in solders, in safety-critical equipment. The directive states, however, that the European Commission will present proposals for including these categories at some point in the future.

I assume that the last sentence is the reason you look into lead-free now.

I�m not familiar with the IEC - 60601 test, only with Bellcore electromigration which is 85RH/85C 500 hours.

Is the test pattern similar to the IPC-B-25? You specify 95%RH but what is the temperature in the test chamber and voltage supplied to the test coupons? Does this test include pH, copper mirror and silver chromate paper test (presence of halides) for the flux? Also do you have restrictions in alloy selection?

Does the test coupon with the lead-free solder wires you tested show filament growth?

Answering these questions would let me know if I can help.

Patrick

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#50489

IEC - 60601 compliant LF-NC Wire Solder | 4 June, 2007

Patrick

Q1) Is the test pattern similar to the IPC-B-25? A1) - No - Tests were run on a prototype assembly.

Q2) what is the temperature in the test chamber and voltage supplied to the test coupons? A2) 25C with 3.3VDC.

Q3) Does this test include pH, copper mirror and silver chromate paper test (presence of halides) for the flux? A3) No

Q4) Also do you have restrictions in alloy selection? A4) Target alloy for this product is SAC305. Not negotiable.

Q5) Does the test coupon with the lead-free solder wires you tested show filament growth? A5) None observed. Electromigration occured between solder joint and adjacent trace. See attached.

Thanks, Chris

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#50558

IEC - 60601 compliant LF-NC Wire Solder | 7 June, 2007

Chris,

You say see attachment, does that mean you have a picture of the spot that causes problems. Please email the attachment to my email below. Attachments are stripped from the threads in this forum.

Patrick Patrick@interfluxusa.com

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