The Week the Back-End Asked for Cash Upfront — WinWay's Prepayment Talks and TSMC's Ten-Year Amkor Deal Rewrote Packaging's Payment Terms

The quietest shift in Taiwan's back-end supply chain last week was a change in payment terms. On June 17, wet-process equipment maker Gallant Precision (3131-TW) told its AGM that current capacity meets only one-third to one-quarter of orders and lead times now stretch past twelve months. The same day, probe-card leader WinWay Tech (6223-TW) disclosed it is negotiating prepayments with AI customers. Standard payment in back-end equipment is sixty to ninety days. Asking a customer who is already waiting a year for delivery to pay cash up front is the supplier reclaiming pricing power.

This is not an isolated signal. In the same week, TSMC (2330) signed a ten-year strategic partnership with Amkor immediately after raising CoWoS capacity guidance to 120,000 wafers per month. Ten-year back-end contracts are familiar in memory LTAs but uncommon in packaging. They mark the end of the era when buyers could acquire packaging capacity on a quarterly book.

Demand justifies the shift. At CompuForum 2026, TrendForce projected global AI server shipments would grow more than 28% YoY in 2026, with combined capex from the four North American hyperscalers jumping 79% to $830B. Capital Securities raised its H2 TAIEX upper bound to 53,000 on TSMC 2nm pricing power. Cathay-NTU's academic team nearly doubled its 2026 Taiwan GDP forecast in a single revision — from 5.8% to 10.1% — citing sustained upward revisions to AI infrastructure capex flowing into Taiwan's real economy.

The bottleneck appears when that capex tries to reach back-end capacity. Marvell announced it will adopt TSMC A14 (1.4nm) for its next-generation AI connectivity chips. AMD's next Threadripper, codenamed Mustang Peak, runs on TSMC's 2nm-class Zen 6. VIA Technologies (2388) chairman Wen-Chi Chen said at the AGM that AI demand is creating a 'tech tsunami' tighter than COVID and disclosed a 3nm ASIC project running through TSMC. Foxconn (2317) confirmed its partnership with French AI specialist Bull entered execution phase, producing components and assembly for NVIDIA's Vera Rubin NVL72 in Europe. Intel's appointment of former SK hynix CEO Seok-Hee Lee as Foundry EVP for Advanced Packaging confirms that both sides now treat advanced packaging as the real competitive surface of the next five-year capex cycle.

Adding packaging capacity, however, requires the wet-process tools Gallant ships, the probe cards WinWay sells, and the glass substrate stack TSMC unveiled on June 18 with Ibiden and Innolux. TSMC's CoWoS glass substrate validation reported 16% better coplanarity, 19% lower CTE, 31% higher modulus, and 27% lower warpage. For Korean rivals, those are the numbers that lock the panel-based glass substrate supply chain to a Taiwan-Japan axis.

In this multi-layered picture, ASE Technology (3711) sits in an awkward seat. The TSMC-Amkor ten-year deal hands capacity insurance to a potential competitor. ASE simultaneously faces the same equipment-supplier prepayment demands that Gallant and WinWay are now extracting from the broader market. With margin pressure from one layer above (TSMC capturing the 1.4nm Marvell and 2nm AMD economics) and one layer below (equipment vendor prepayments plus glass substrate unit costs), the OSAT middle layer thins.