We must go back in time to the era when AMD and Intel produced desktop computer motherboards in order to discuss the topic of gold content in computer motherboards. Back then, gold wasn't that pricey. As a result, the motherboards from these two companies had a lot more gold on them compared to motherboards made later by other Chinese businesses.
At that time, one kilogramme of BGA chips yielded 6.5 grammes of gold.
On motherboards, there were two kinds of black chips: PQFP (outward pins) and PLCC (inward pins). A kilogram of PQFP chips contained approximately 1.5 grams of gold. Additionally, each kilogramme of PLCC chips had between 700 and 800 milligrammes of gold.
We were able to obtain about 50 grams of these chips from one kilogram of motherboards. Additionally, the motherboard's gold-plated connectors contained between 100 and 150 mg of gold per kilogram. After that, they have tantalum capacitors, which are a reliable source of tantalum metal. MLCCs produce palladium, silver, and gold. Motherboard transistors also contain a significant amount of gold.
So, now if we calculate the total amount of gold from one kilo of motherboards, it is around 190 milligrammes.
Here are the specifics:
One big-size BGA chip on the motherboard weighs around 5 grams. We get three BGA chips from one kilo of motherboards.One gram of BGA chip yields 6.5 milligrams of gold.
So, from 15 grammes of BGA chip, we get 6.5x15=97.5 milligrammes of gold.
We receive 250 grams of gold-plated connectors from one kilo of motherboards. Let's keep 100 milligrams of gold from one kilo of connectors. So, for 250 grams of connectors, we get 25 milligrams of gold. We get 1.150 grams of gold for every kilogram of mixed chips. So, 50 grams of mixed chips yield 57.5 milligrams of gold. transistors and MLCCs contain 10 milligrams of gold.
Now let us total it all up: 97.5 + 25 + 57.5+ 10 = 190 milligrammes of gold.
The current price for 10 grams of 24 karat gold in New Delhi, India, is USD 812. One milligram of gold is 0.812 USD.
So, 190x0.812=154.28
As a result, the gold value per kilo of motherboard is around USD 15.
In addition to gold, motherboards also yield palladium, silver, copper, solder, and other metals.
There was about 10 to 20% less gold in later desktop motherboard models made by other companies.