# 5 Easy Steps to Calculate ASIC Unit Cost

July 25, 2012, anysilicon

It happened to all of us. You come to your office one morning and find a note from your manager “what will be the ASIC’s unit cost?”

Although an ASIC unit cost has a direct impact on revenues, it is typically only visited twice: before the design starts and when design ends. It’s also interesting to note that ASIC cost tends to escalate during development phase. Which probably means, you need to run your calculations more often.

Here are 5 easy steps for calculating the final ASIC unit cost of your project.

The model I show here is a simplified version of the one we are using. There are more details related to ASIC manufacturing price to be taken into account, such as minimum order value, wafer-level yield etc. But for now, these are ignored. They will be covered in one of the next posts together with a neat and handy Excel ASIC price calculator.

### Step 1:

Get the wafer price.

Find the number of dies per wafer.

### Step 2:

Get the package price.

### Step 3:

Find the test cost (both wafer test and package test)

### Step 4:

Find the logistics and shipping price.

### Step 5:

Guesstimate the yield.

### Here is an example:

Wafer price: 2000\$

DPW: 1000

QFN Package price: 0.2\$

Test price: 0.3\$

Logistics price: 0.1\$

Yield: 90%

Final ASIC cost: 2.889\$

• http://ASICpricing Bill martin

If you are working with a supplier that ships units to you, the price is their quote to you Including FOB designation.

If you are closer to production and oversea operations, then each step will have a yield that gets calculated into the overall cost
Process line yield: #of wafers out/# of wafers started
Process parametric test cost/wafer
Probe yield: # of die out/# of die in
Probe test cost/die
Pkg/assy cost
Assembly yield: # of pkg units out/# of pkg units in
Final test cost/unit
Final test yield:# tested units out/ # test units in
Brand/marking cost/unit
Brand yield:# branded units out/# units in
QA test cost/unit
QA yield

It is obvious to minimize cost, you improve yields from the back end (BE) of the process since the accumulated cost (\$s invested in producing the part) is highest at the end. So you might want a very tight criteria at wafer probe with lower yields to maximize Final test yields. If you have loose criteria at wafer probe, you might pass through more marginal product to Final Test at which point marginal units will fail more expensive WIP.