ITAR_Compliantsmta-logoipc-logoiso-logo

Your BEST choice
In Solder Rework/Repair, Solder Training and Tools

Call us Now! +1 (847) 797 9250

Gold Embrittlement Mitigation

goldThere are both advantages and disadvantages to having a gold finish on your components. Gold does not tarnish, it is a solderable surface, has a long shelf life and does not oxidize. The disadvantage of gold finish on a component is that gold is porous, it dissolves in eutectic tin/lead solder and creates embrittled (weaker) solder joints. Gold embrittlement mitigation through lead tinning is the answer to this uncertainty as defined by the J-STD-001F criteria. See an article on this topic here

So what is the problem?  Gold embrittlement and voiding appears in SMT solder joints when using gold-finished components. This means that over time the components are not as reliable in terms of their mechanical bond strength to the PCB. Components at some point and under the right conditions, can fall of the PCB.

Gold embrittlement in solder joints shows up when a percentage ratio of the weight of the gold versus the weight of the solder and the going maximum number for the amount of gold has been 3% of the total weight of the solder alloy. (Recent findings indicate that gold embrittlement can occur at even lower percentages!)

In the J-STD-001 F version the criterion was changed in order to address the problems experienced by users. Due to the consistent lack of turbulence in the plated throughhole during the wave solder operation, these embrittlement problems can become more pronounced. Therefore there is a need for the gold embrittlement mitigation process.

Per the IPC-JSTD-001F, gold needs to be removed for BOTH Class 2 and Class 3 assemblies in the following cases:

  1. From all of the surfaces to be soldered of solder terminals plated with greater than 2.54 um in thickness of gold
  2. ALL solder cup terminals regardless of the thickness of the gold layer
  3. From 95% of all surfaces which need to be soldered regardless of how much gold thickness exists (new for version “F”)
  4. All throughhole leads which will be hand soldered (new for version “F”)
  5. From at least 95% of the surfaces to be soldered of THOLE component leads with 2.54um of gold thickness


When the components are manually soldered, the amount of solder being added to the solder joint in a supported hole is minimal due to the physical volume of the hole minus the volume of the lead could create a gold rich environment. This would leave it prone to crack propagation within the plated through hole.    

Finally, if the components are surface mount components, the amount of solder paste added to the pads is small in volume. The ability of the gold to dissolve in that molten solder paste does increase the amount of gold per given volume of solder paste. This means that the Au dendrites within the solder joint would have a greater chance of serving as a catalyst for the propagation of cracks within the solder joint.  

Therefore in order to be safe, removal of the gold eliminates the potential reliability impact concerns based for the exact amount of gold on the leads and terminals. Gold embrittlement mitigation can be done by BEST Inc. through lead tinning in order to ensure proper, long lasting solder joints can be formed.

 

 

Get a cuote

Testimonials

  • You Guys Freaking Rock with turnaround time.
    Thank you all SOOOOO much!!

    You Guys Freaking Rock with turnaround time.
    Thank you all SOOOOO much!!

    Welch Allyn

  • BEST is excellent in meeting delivery dates and are very good with clear communication of shipments, quantities, issues, etc. Their quality and technical assistance has been superb.

    BEST is excellent in meeting delivery dates and are very good with clear communication of shipments, quantities, issues, etc. Their quality and technical assistance has been superb.

    RW Technologies

  • BEST has solid high quality service every time, and at the right price. They are very dependable. I am able to start a project in less then 24 hours with no hassles. The teams always work to meet the... View More..

    BEST has solid high quality service every time, and at the right price. They are very dependable. I am able to start a project in less then 24 hours with no hassles. The teams always work to meet the demands placed on them by the customer, and are very honest about what they can do and when they can do it. They offer great value to the customer; they are willing to go the extra mile to make the customer happy.

    Motorola

  • Best has always come through when we needed them. We started using them for board repairs, now they assemble all of our boards. BEST is always responsive to our needs. On many occasions, we needed... View More..

    Best has always come through when we needed them. We started using them for board repairs, now they assemble all of our boards. BEST is always responsive to our needs. On many occasions, we needed boards repaired immediately. They have always come through for us.

    Lovejoy Controls Corporation

  • Your company name exemplifies exactly what you are, the BEST!!!

    Your company name exemplifies exactly what you are, the BEST!!!

    Alpha Circuits

  • You guys are really soldering geeks. Keep inventing those cool products.

    You guys are really soldering geeks. Keep inventing those cool products.

    Analog Devices

  • …always are very friendly and try to accommodate my short lead times

    …always are very friendly and try to accommodate my short lead times

    Qualcomm

  • There was not doubt that Francisco know the material, how to present it, and how to make the class participants feel at ease..all of my guys came to me and how me how much they had learned.

    There was not doubt that Francisco know the material, how to present it, and how to make the class participants feel at ease..all of my guys came to me and how me how much they had learned.

    Alabama Power

  • Just wanted to let you know what a fantastic job/effort James put in too insure our guys were thoroughly training and qualified. Everyone involved was very impressed with his knowledge, flexibility,... View More..

    Just wanted to let you know what a fantastic job/effort James put in too insure our guys were thoroughly training and qualified. Everyone involved was very impressed with his knowledge, flexibility, and work ethic. We really appreciate the fact that he went above and beyond.

    EMAC

  • Man, you guys are unbelievably fast!

    Man, you guys are unbelievably fast!

    Blur Development Product

Throughole Part Tinning

SOLDERING TIPS

soldering-img

Newsletter

WHAT'S NEW?

ARTICLE: Multiple Methods for Applying Paste Flux or Solder Paste for BGA Rework

ARTICLE: IPC-A-620 Gets a Facelift

 

 

LATEST NEWS

WHAT PEOPLE ARE SAYING ABOUT US

  • You Guys Freaking Rock with turnaround time.
    Thank you all SOOOOO much!!

    You Guys Freaking Rock with turnaround time.
    Thank you all SOOOOO much!!

    Welch Allyn

  • BEST is excellent in meeting delivery dates and are very good with clear communication of... View More..

    BEST is excellent in meeting delivery dates and are very good with clear communication of shipments, quantities, issues, etc. Their quality and technical assistance has been superb.

    RW Technologies

  • BEST has solid high quality service every time, and at the right price. They are very dependable. I... View More..

    BEST has solid high quality service every time, and at the right price. They are very dependable. I am able to start a project in less then 24 hours with no hassles. The teams always work to meet the demands placed on them by the customer, and are very honest about what they can do and when they can do it. They offer great value to the customer; they are willing to go the extra mile to make the customer happy.

    Motorola

  • Best has always come through when we needed them. We started using them for board repairs, now they... View More..

    Best has always come through when we needed them. We started using them for board repairs, now they assemble all of our boards. BEST is always responsive to our needs. On many occasions, we needed boards repaired immediately. They have always come through for us.

    Lovejoy Controls Corporation

  • Your company name exemplifies exactly what you are, the BEST!!!

    Your company name exemplifies exactly what you are, the BEST!!!

    Alpha Circuits

  • You guys are really soldering geeks. Keep inventing those cool products.

    You guys are really soldering geeks. Keep inventing those cool products.

    Analog Devices

  • …always are very friendly and try to accommodate my short lead times

    …always are very friendly and try to accommodate my short lead times

    Qualcomm

  • There was not doubt that Francisco know the material, how to present it, and how to make the class... View More..

    There was not doubt that Francisco know the material, how to present it, and how to make the class participants feel at ease..all of my guys came to me and how me how much they had learned.

    Alabama Power

  • Just wanted to let you know what a fantastic job/effort James put in too insure our guys were... View More..

    Just wanted to let you know what a fantastic job/effort James put in too insure our guys were thoroughly training and qualified. Everyone involved was very impressed with his knowledge, flexibility, and work ethic. We really appreciate the fact that he went above and beyond.

    EMAC

  • Man, you guys are unbelievably fast!

    Man, you guys are unbelievably fast!

    Blur Development Product

ABOUT BEST

action-imgView BEST in Action

innovation-best-icoBEST Innovation

listen-imgListen to BEST
Fanfare