Copper Wire Bonding

I have been working on copper wire bonding for a while and I must say that this is the best thing invented so far that beats using gold wire bonding. The differences are vast due to the fact that copper wires oxidizes easily and even when coated with Palladium, they have a tendency not to create a rounded free air ball after a certain period of floor life staging.

I have only seen memory makers shunning from using copper wire bonding so far. The study that was conducted has so far shown that problems would not occur up to DDR2 and I suspect should not even be a problem for DDR3 and DDR4. Looking at the characteristics of copper wire, the conductivity is much better with lower resistivity. Reliability wise is also much better due to the slower growth of IMC.

Of course, there is also the case of corrosion on copper wire bonding due to flourine and chlorine. The molding compound used so far helps to reduce this corrosion problem. What is your say about copper wire bonding?

GR&R for development?

I heard a funny request from my supervisor. He had wanted to perform a GR&R in development stage for any devices that are under qualification. I find this a bit wrong from a GR&R standpoint.

I believe that GR&R are equipment based and should be done for any equipment in a 6 or 12 month period to ensure that

1. Equipment are still able to measure accurately
2. The people handling these measurements are still well trained and have a standard set of measurement techniques

Why I say this is funny is wrong to perform for every device is that, we are effectively still using the same tools for measurement. It does not make any sense to perform it every time a product comes into development if the same set of tools are used. I would agree if it is development using a new set of purchased tools/equipments.

Do let me know your views and comments on this.