In the last two days, we reviewed the PCB manufacturing technology history of initial stage and develop stage, today we are reviewing the stage of expanding.
While during expanding stage, the typical technologies are
1990, Yasu of IBM in Japan developed SLC (Surface Laminar Circuit) technology PCB, using to connect the flip chip in semi-conductors.
1993, Paul T. Lin of Motorola applied patent of one type of BGA sealing (US5216278A), it started the era of BGA PCB sealing.
1995, Panasonic developed ALIVH (Any Layer Interstitial Via structure) technology for build-up PCBs
1996, Toshiba developed B2it(Buried Bump Interconnection Technology) Technology
North of Japan developed NMBI(Neo-Manhattan Bump Interconnections) technology, later Tessera of America improved it
Ibiden developed FVSS (Free Via Stacked up structure) technology, it was called SSP(Single Step Process) technology initially and now called FVSS
While we take an overall look of these PCB technologies, the core idea is to realize connection between layers. Basic it has two ways, first one is by direct drilling, plating or fill with conductor, such as SLC, HITAVIA, ALIVH, FVSS, VIL), the second is to using lug (make hole in-directly), such as (B2it, NMBI).
What's worth to mention is most of the technologies were developed by Japanese companies. The Japanese companies has made a huge contribution for PCB manufacturing technology, especially on new technology experiment, new material development, new equipment, etc).
For making holes directly, there were five main technologies: photoinduced, laser(UV/CO2), plasma, excimer and mechical drilling. But since there is varies limitation of different technologies, and the progress of laser technology, the most popular choice was laster. In the other hand, making holes in-directly was chosen less and less due to limitation of technology.
So currently, the main via fill technology is laser drill+plating. There were two directions at that time: HDI substractive based on FR4, and substrate based on BT, ABF material. Started from 2014, the trend comes as combination of HDI and substrate by modeling of APPLE INC.