An invention by a British semiconductor company allows dies to be assembled directly on copper based circuit boards. That allows dies to be tested at the wafer level at a minimal cost.
Semi-Dice UK Ltd describes the technique as μPost and claims it allows for the increased use of die-per-wafer acreage – for example manufacturers could create 400 connections 2.5×2.5mm with 100μ spacing. BGA packaging, claims the company, will be outperformed by its techniques, with a superior height to radius and improved tolerance to mismatched coefficient thermal expansion.
The technology, says the company, addresses the problems for breaking the flip chip pitch barrier. Other companies, such as Amkor and Texas Instruments are developing traditional packaging technologies.
As the μPOST technology allows pins to be attached to the die directly, and then llets the die be attached to the circuit board with no substrate, it removes the need for separate packaging companies to complete a chip design.Wafers could be pinned and the “bed of nails” tested before cutting in a fab.
Further savings on production means that overall component height can be reduced to 0.2mm, and devices can be attached to yielded SMT boards.
The technology was created by two people, one of them developed packages for the Inmos Transputer and has a long history in the packaging industry. You can find the company’s web page here.