1. Purpose of the gate
Output of the customer device scales up towards the customer's forecast, drawing on the wafer bank, with yield and delivery monitored.
The ramp is the first test of the platform's supply model with real demand. Each build pulls banked wafers of the device's array size, adds the custom layers and goes through test and packaging. The review checks that the bank holds enough wafers for the ramp, that replenishment is planned in time, and that foundry, test and packaging capacity are booked.
Because the bank is shared, the ramp of one device can draw down stock another customer relies on. The review checks the combined demand on the array size and agrees priorities if stock is short.
Yield and delivery are tracked against plan from the first builds. Yield loss is separated into base related loss, which would appear across devices on the same array size, and design or custom layer related loss specific to this device.
The review agrees how often the customer receives yield and delivery reports, and how forecast changes are handled. Base wafers take most of the processing time, so a forecast increase that exceeds banked stock cannot be met at the platform's usual turnaround; the customer should know how far ahead increases must be signalled.
Early production is also when test limits set on sample data meet larger numbers of parts. The review agrees when the limits will be reviewed and who approves changes.
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