https://www.wantgoo.com/stock/2330/...urnover-in-days
台積電存貨週轉天數從2017年不到40天增加至2022 Q2的85天
應收帳款從45天往35天靠近
隨著製程先進製程占比越來越高，存貨週轉天數也是相應增加，代表平均製造時間越來越長
除非台積電空白晶圓都是先在廠裡壓一個月以上才投片
要不然絕對不可能投片後2個月後下游就能拿到3nm晶圓
台積電之前法說會表示本季稍後量產3nm，就算他真的拖到最後一天12月31日才量產好了
如果真的台積電3nm製程投片後只要2個月下游就可以拿到晶圓
台積電就不會說3nm 2023年上半年開始貢獻營收
而是說2023年Q1就會貢獻營收，也就是最遲3月1號就可以開始貢獻營收了
https://wccftech.com/amd-to-commenc...s-next-quarter/
拿ZEN4做例子，計畫要9月27開賣，傳言4、5月就開始投片量產
假如真如您所說投片後只要2個月就能拿到5nm晶圓
AMD請台積電6月初再開始投片不就好了，8月初拿到第一批晶圓，8月底封測好，還有20天可以繼續備貨
台積電晶圓一出廠，35天左右就要付錢
提早一~兩個月備貨的貨款少說也要幾千萬上億美元
AMD先留在手裡生利息不好嗎??幹嘛這麼早就急忙著給台積電送錢??
美國半導體產業協會說搞一片晶圓平均12週，先進工藝要14~20週
把封測加進來最多可以來到26週，大半年就過去了
https://www.semiconductors.org/chip...hat-takes-time/
"Manufacturing a finished chip for a customer can take up to 26 weeks. Here’s why: manufacturing a finished semiconductor wafer, known as the cycle time, takes about 12 weeks on average but can take up to 14-20 weeks for advanced processes. To perfect the fabrication process of a chip to ramp-up production yields and volumes takes even much more time – around 24 weeks."
2017年2月7nm還沒量產的時候，晶圓代工普遍處理一層光罩要0.8~1.5天
https://semiengineering.com/battling-fab-cycle-times/
"Generally, the most common metric for cycle time in the fab is “days per mask layer.” On average, a fab takes 1 to 1.5 days to process a layer. The best fabs are down to 0.8 days, Leachman said."
台積電5nm用了EUV製程減少至81道光罩，假設平均處理一層光罩要一天，81層就要花81天=2個又21天
https://fuse.wikichip.org/news/3398/tsmc-details-5-nm/
"14/16nm using around 60 masks, 10 nm is roughly 78 masks, 7 nm is roughly 87 masks, and 5 nm is back down to 81 masks."