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SN100C + phosphorus

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#53652

SN100C + phosphorus | 15 February, 2008

Hi,

I have heard that some have added small amounts phosphorus to SAC alloy in wave soldering and this way decreased drossing.

Does anyone experienced this with SN100C?

Regards, Juha

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#53691

SN100C + phosphorus | 18 February, 2008

SN100C contains no phosphorus. It has a dross rate equal or lower than tin-lead solder, where as SAC drosses at 2 to 3 times the dross rate of tin-lead solder.

Addition of solder dross inhibitors, such as phosphorus, can be effective inhibitors of dross formation, though phosphorus has been known to increase Sn corrosivity of copper [Sprovieri, 2004]. Higher dross rates may make the use of solder skimming or purifying equipment desirable, but care should be taken to not use the equipment on both SnPb and Pb-free solders to prevent lead contamination of the dross, which would preclude recycling. [Solders in Electronics: A Life-Cycle Assessment Summary, US EPA, EPA-744-S-05-001 August 2005]

We have no relationship, nor receive benefit from the company whose product is referenced above.

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#53753

SN100C + phosphorus | 21 February, 2008

We treat all our alloys with measured Phos additions. SAC alloys treated with Phos WILL/DO dross approximately half the amount of 63/37. Most Solder companies will not tell you this as they wish you to use more Solder. We are a Nitrogen Cast Solder producer and by using Phos do not receive the benefit of high short term usage but then again our customers are not forced out of business due to escalating costs.

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