Selective gold VS immersion gold on memory and other boards

On most finger boards (ISA/PCI/PCIx) the plating process is "selective" meaning only the fingers are plated and all other copper features (traces, vias and pads) are not gold plated, but most likely HASL (Hot Air Solder Leveled). There are some power boards and processor boards and in older cases, RAM sticks that are immersion plated meaning under the solder mask, all copper is gold plated.



My question is does any vendor look for specific immersion RAM or boards and pay accordingly? I've checked the vendor section and found nothing. Anyone have information on what that would be priced (MoBo, trimmed finger pricing)?
Thanks

I find it hard to believe that the older manufacturing processes weren't a good bit less capable of scrimping on the application of precious metals, than the newer, more highly sophisticated, engineered, and refined processes are. I mean, let's get real, any manufacturers bottom line anymore is strictly profit, and it is increasingly obvious there are no longer any exceptions to this rule, which includes the "preservation" of their precious metals. IF they can possibly manufacture it cheaper, they will definitely do so, and their techniques are more highly refined on a daily basis.
I've even had responses to my questions about older boards that they were (happily, no doubt) mixed in with the newer boards to increase the overall yield of a batch.
Personally, I cannot understand why they are not given better treatment in the buying process, as they without a doubt provide a higher yield.

Originally Posted by NobleMetalWorks

For large refineries there is no difference in the way that boards with as soldering mask, and boards without are processed.
Scott

I appreciate the answer, but where I was going was the issue of more gold plating on a fully plated board compared to one where only the fingers are plated. The solder mask point I was making was to illustrate that some boards are entirely plated in gold. As a board designer myself, we spec out to the board house whether we want full immersion gold or selective and I wondered if that comes into play with any pricing.

Originally Posted by JPete

I appreciate the answer, but where I was going was the issue of more gold plating on a fully plated board compared to one where only the fingers are plated. The solder mask point I was making was to illustrate that some boards are entirely plated in gold. As a board designer myself, we spec out to the board house whether we want full immersion gold or selective and I wondered if that comes into play with any pricing.

Any chance of photos in the two different boards you're referring to ?

Originally Posted by Bear

Any chance of photos in the two different boards you're referring to ?

I will take pictures when I get home. Miserable weather here in NJ, so it will be later tonight. On some RAM sticks you can see nice bright gold on the vias and non-populated pads, on the other sticks it is dull faded dark copper.

Originally Posted by NobleMetalWorks

Only on a small refining scale, so far as the large refiners are concerned they are either toll refining, in which case their percentages are always the same and never change, or they are purchasing the material at such a small fraction of the actual value that it wouldn't matter.

As a small or medium refiner, I do pay attention to the material I am purchasing. And because there is such a hot market for small home refiners, hobby refiners and medium refiners, you have to pay much closer, and have far less room for profit taking than the big refineries do.

I buy punchouts from a manufacturer in Silicon Valley that are totally gold plated for example, I end up paying **** near close to the actual value in gold. If I did not, they would just simply sell to someone else.

Scrap yards grade and pay according to their own grading systems. I know someone who regularly sells to two scrap yards. The reason is because one grades better than the other for high grade material, and the other better for low grade. If the board is fully plated, it would most likely be thrown in with the medium to high grade material, but classification outside low, medium and high is not common for most scrap yards, so far as my experience has been.

If you want to make more money on your boards, the only way to do so really is to either find a refiner willing to purchase them at whatever price you negotiate, or the other option is to save up enough material, and represent your melt at the refinery when the time comes to process it. There are a few really good refineries that do this type of work, but if you are not representing your material as it's being processed, you will be ripped off. Your other option is to sell them on ebay. I only buy what I consider high grade boards, and only when I am able to make a decent profit margin. I particularly love seeing that real dull buttery look I find on QA targets and RF shielding. So many fully gold plated boards didn't use immersion but instead deposition, in those cases where the gold is really shiny, and darker, the actual value of the gold is less than the amount you make on just the fingers. The technology is being pushed because of the price of gold. Industry responds with more and more efficient methods of depositing gold plating, so newer material is worth a mere fraction of older material.

Do you know how many micro-inches thick the total gold plating is? Up until recently it's almost always between 10-30 micro-inches thick.

Scott

Thanks for all the information. You answered more questions than I had asked and I appreciate that.
All the boards I designed for telecom, military and COTS were all 1/2 ounce copper with hard nickel plate and immersion gold from 20-25 micro inches.
Thanks again.

Originally Posted by Bear

Any chance of photos in the two different boards you're referring to ?

Here you go. The selective gold where just the fingers are plated is on the left. The full immersion gold where all external copper is plated gold, is on the right. You can see the difference in the three pictures.

There is a very noticeable difference in your pictures.

I think, like everything else, it's all about volume. If you have a pound, maybe you can get a little better price taking a chance and going the ebay route. There is someone always willing to overpay, but you take a lot of risks with ebay. If you had 20 or 30 pounds maybe a buyer here will give you a little bit of a better price.

Originally Posted by jghilino

agreed, just put it on ebay as high yield scrap gold ram, you will get a premium for it there

That is the conclusion I am finding. There are some items that buyers on the site will give top dollar and that is easy money and a no brainer. Other "special" items are of more value to someone looking for it on Ebay or other sites. The difference will be if that anticipated price on Ebay will be 20% more than the price given by the regular buyers here. I think that is the case with fully gold plated boards that have never been populated or tinned. I think that has been proven more than once with the posts and links JGHILINO has posted in the past.
Thanks to all.