摘要
DDR5 SSD和内存为一体的最新一代CXL大容量AI存储产品,为了实现高存储小尺寸、高信号传输、金手指板厚、挠性层过大电流、大挠曲以及阻抗要求,前沿客户通过两张挠性芯板airgap结构刚挠板实现。两张挠性芯板air-gap结构刚挠板的制作方法受半固化片溢胶影响,在airgap结构层间经常采用低流动半固化片压合,采用全部低流动半固化片一次压合工艺板面会存在凹凸不平树脂塞孔打磨困难;采用所有与挠性接触层为低流动半固化片,硬板层间为流动半固化片的PP混压技术,会存在板厚超标风险,填胶不足的可靠性风险。相比此两种工艺,采用仅air-gap结构层间低流动半固化片,其它层间为流动半固化片(其它层间包含:硬板与软板层间,以及硬板与硬板层间)的新PP混压技术,通过新阻胶技术对air-gap结构的流动半固化片进行阻胶控制,不仅可以解决板面不平整、air-gap结构挠性区域流动半固化片溢胶控制问题,也可以解决金手指板厚超标风险以及填胶不足的可靠性风险。该方法可靠性能稳定,良率高,效率快,是一种实现高端air-gap结构刚挠板产品极具竞争力的批产制作工艺。
The latest generation CXL high-capacity AI storage product integrates DDR5 SSD and memory.In order to achieve high storage size,high signal transmission,thick gold finger board,excessive current in the flexible layer,large deflection,and impedance requirements,cutting-edge customers have implemented two flexible core boards with air gap structure rigid flex boards.The production method of two flexible core boards in the air gap structure rigid flex board is affected by the overflow of PP sheets.Low flow PP sheets are often used for lamination between the layers of the air gap structure.Using a one-time lamination process with all low flow PP sheets will result in uneven surface and difficulty in polishing resin plug holes;The use of PP mixed pressing technology with low flow PP sheets in contact with the flexible layer and flow PP sheets between the hard board layers poses a risk of excessive board thickness and insufficient adhesive filling reliability.Compared to these two processes,the new PP mixing technology uses only low flow PP sheets between the layers of the air gap structure,while the other layers are flow PP sheets(including between hard and soft layers,as well as between hard and hard layers).By using the new adhesive blocking technology to control the flow of PP sheets in the air gap structure,it can not only solve the problems of uneven surface and overflow control of flow PP sheets in the flexible area of the air gap structure,but also solve the reliability risks of excessive thickness of the gold finger board and insufficient filling.This method is reliable,stable in performance,high in yield,and fast in efficiency.It is a highly competitive batch production process for high-end air gap structured rigid flex board products.
作者
李冲
黎钦源
Li Chong;Li Qinyuan
出处
《印制电路信息》
2025年第S1期209-216,共8页
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