Scheduled Repeat Supply of Semiconductor Wafer Chuck Ring: Planning, Stock and Kanban

A scheduled supply programme for an aluminium ring retaining wafers during processing: how releases were agreed, how stock and tooling were held, and how forecast changes were handled without disruption.

From orders to a programme

The customer was releasing an aluminium ring retaining wafers during processing in irregular batches, and each release restarted tooling decisions, material ordering and queue time.

We proposed a rolling programme with agreed release quantities, which turns a repeated emergency into planned capacity.

Agreeing the rules

We agreed minimum and maximum stock, a fixed lead time from release to despatch, and how many weeks of forecast the customer would share.

The quality requirement, flatness within 0.01 mm and cleanroom-clean finishing, was written into the same agreement so that expediting never became a reason for shortcuts.

What we hold

Tooling and fixtures are retained between releases, critical inserts are stocked, and raw material is held against the forecast rather than against a purchase order.

Finished safety stock sits packed and labelled, ready to despatch on the agreed call-off.

Handling changes

Forecast increases above the agreed band are reviewed immediately, and engineering changes trigger a new first article rather than a silent swap.

Both rules are simple, and both have prevented arguments that would otherwise be settled on the phone at five in the afternoon.

Result after twelve months

On-time delivery across the programme ran at 100 per cent, and inventory at the customer's plant dropped because parts arrive when needed rather than in bulk.

Stability like this is created by agreement and record keeping rather than by heroic expediting.

Summary

The figures quoted in this case come from the inspection reports supplied with the shipment rather than from the quotation stage.