Surface laminar circuit

Such layers consist of unsupported dielectric layers where small vias or blind holes are formed by laser or plasma etching or are photoformed and then plated using additive or semiadditive metalhzation processes. While this approach requires some extra area beyond the chip perimeter to complete the signal transfer and increases the costs of substrates, it permits the mounting of flip-chips and CSPs on PWBs. A typical method for forming such redistribution layers, called surface laminar circuit (SLC), has been develojied at IBM s Yasu plant. 

Y. Tsukada et al., A Novel Solution for MCM-L Utilizing Surface Laminar Circuit and Flip Chip Attach Technology, Proceedings of the 2d International Conference on Multichip Modules, Denver, CO, April 1993, pp. 252-259. 

Surface Laminar Circuits (SLCs). The most notable MLB technology developed to form vias is the sequential fabrication of multilayers without press operations. This is particularly important for surface bhnd via holes. 

The process for fabricating a board using surface laminar circuits is as follows (see Fig. 5.5) ... 

FIGURE 5 Example of surface laminar circuit (SLQ board cross section. (Courtesy IBM Yasu and Ciba-Geigy Limited.)... 

The first production build-up or sequential printed boards appeared in 1984, starting with the Hewlett Packard laser-driUed FINSTRATE computer boards, followed in 1991 in Japan with Surface Laminar Circuits (SLC) by IBM and in Switzerland with DYCOstrate by Dyconex. Eigure 21.1 in the 5th Edition of the PCB Handbook shows one of those first Hewlett Packard FINSTRATE boards and one of the first IBM SLC boards. 

Tsukada, Y., and Tsuchida, S., Surface Laminar Circuit, A Low Cost High Density Printed-Circuit Board, Proceedings of the Surface Mount International Conference and Exposition, San Jose, CA, September 1992. 

Surface Laminar Circuits. SLC technology was the first of the PID microvia,... 

Tsukada, Yutaka, et al., Surface Laminar Circuit and Flip Chip Attach Packaging, Proc. 7th IMQ 1992. 

Surface Laminar Circuitry (SLC) developed by IBM is one of the earliest board build-up fabrication methods. This technology provided a solution to the high occurrence of broken drill bits and mis-drilled cores commonly encountered with drilled vias with fine dimensions by using blind and buried via structures. Neither construction method requires through holes, but only vias between layers that require interconnection. There are several categories of via structures being used in the printed circuit board industry which are discussed in the following sections. 

Modelling plasma chemical systems is a complex task, because these system are far from thennodynamical equilibrium. A complete model includes the external electric circuit, the various physical volume and surface reactions, the space charges and the internal electric fields, the electron kinetics, the homogeneous chemical reactions in the plasma volume as well as the heterogeneous reactions at the walls or electrodes. These reactions are initiated primarily by the electrons. In most cases, plasma chemical reactors work with a flowing gas so that the flow conditions, laminar or turbulent, must be taken into account. As discussed before, the electron gas is not in thennodynamic equilibrium... 

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