eastone
pfm Member
Bollocks, forgot all about this
init
Bollocks, forgot all about this
I managed to have a meeting in the first window and an interview during this mornings window.....must get my priorities right....
Lucky boy. Congrats :-DLikewise I have the Vfet 2 amp. Excellent amp imho.
IIRC you work in semi manufacturing, what would be the tooling costs for a SIT production run?
Not any more luckily, it's a dead art in the UK for the most part.
The costs would be large, it's not a matter just a matter of 'tooling' but more a matter of recipe.
You'd need to find a suitable fab to run it in.
You'd then need a modeled electrical and physical layer design before even committing to wafer.
If you needed something other than a standard off the shelf wafer type (undoped/predoped) then you need to specify that (will be OK if running it on a known process)
If you're using the fabs own process recipe then that's fine but if not then you need to design this.
Next comes the sets of masks you need to apply each layer, luckily not that many in a product like this.
Then you'll start a prototyping run, probably a half or full batch with 'splits' across wafers to try to find the sweet spot for the end product.
These will all have to be tested at wafer level to find out what meets the expectations and spec you've decided on in your electrical model.
Queue a few batches as you play with parameters and recipe (hopefully not that many iterations to get to an end result).
Once you've hit the sweet spot and proved it works you can start to run qualification batches to prove you can build it consistently and it doesn't 'pop' when its run within parameters.
You'll need to mount, encapsulate and run each part through a tester/test program and qualify using a stress test (e.g. HTOL/LTOL).
Now its probably ready to put in an amp.
And that's assuming you get it right first time, it's a game of snakes and ladders sometimes.
Commercially it would be a dead duck, the best way to get something like this done is through a University fab as a project for graduates.
Someone on DIYaudio stated as 'fact' that the small run NP ordered from Semi-South some years ago (which iirc they were already tooled up for) required a cheque for half a million dollars.
Nelson usually keeps that sort of info to himself, unsurprisingly, so where the figure came from is anyone's guess.
Not any more luckily, it's a dead art in the UK for the most part.
Nice story about raw talent being recognised, and rewarded! : )
I could ask them, not sure what they're currently doing but can always ask the ClasSiC boys at the next night out in Edinburgh.
By the way, these aren't big fabs left in the UK, it's old stuff and large geometries.
I decided to give it up when at an interview down south they asked me what I knew about the quality of the raw wafers because 'they struggled to get 50% yield'.....from Shin-Etsu wafers.