- 1. For both CEM and ODM, high-cost (typically 300,00 to 500,000 USD) specialist die-bonder platforms are required with operational, training and financial implications.
- 2. Assembly speeds tend to be slow, for example, 5,000 cph in comparison to 50,000 cph+ available from traditional PCB assembly platforms.
- 3. Users also need to take account of quality implications in underpinning quality policy. As experienced by at least one major CEM the presence of both good and reject WLP devices from wafer using such die-bonder platforms can provide catastrophic yield effects as wafers may exhibit only 10% device yield.
- 4. Where customers do not use many die or flip chips in one production lot, the remaining part wafer is difficult to store and the blue or ultra violet (UV) activated film frame and foil does not respond well to multiple setups where repeated stretching is required every time a device needs to be removed for placement. Invariably wafers are rendered unusable due to foil tears.
