Multichip module system

Figure 6. Multichip module system. (Courtesy of Honeywell, Inc.)...

W. Maly, et al.. Smart-substrate multichip-module systems. IEEE Design Test of Computers, Vol. 11, Summer 1994, pp. 64 - 73. 

One example of a successful polymer CMP program is for the fabrication of ILD layers for multichip modules (MCM) at MCC. Figure 8.7 shows schematically a cross section view of an MCM interconnection system. Low dielectric constant ILDs are required in MCMs because the long interconnect lengths lead to long delays. In the MCC process, the polyimide is deposited by... 

Fine line circuitry can be obtained from current materials, and particularly with thin copper foils. Additive systems can take this further. In addition, multichip modules may be used for the most severe situations ... 

When molded or premolded packages cannot be used for whatever reason, for example, a need for hermetic sealing, modules using ceramic substrates (or PCB-printed circuit board) offer almost unlimited flexibility. They can be used for simple multichip modules containing two or more elements (e.g., a sensing element and an evaluation circuit), may include external components, or may be used to construct complete systems. Stress-optimized package configurations for sensitive microsystems and sensors are no problem (Fig. 5.8.4). 

Complex Electronic Hardware All devices that are not simple are considered to be complex. See the definition of Simple Hardware [EASA CM-SWCEH-OOl]. Complex Electronic Hardware Includes custom micro-coded components (such as ASICs, PLDs and associated macro functions) and integrated technology components (such as hybrids and multichip modules). RTCA-DO-254 (para 1.6) advises that hardware should be examined hierarchically at the levels of integrated circuit, board and LRU for complexity, including addressing functions that may not be testable, such as unused modes in multiple usage devices and potentially hidden states in sequential machines . An item constructed entirely from simple items may itself be complex. Complexity is an attribute of systems or items which makes their operation difficult to comprehend. Increased system complexity is often caused by such items as sophisticated components and multiple interrelationships. 

This flip chip bonding technique has high potential to replace conventional solder flip chip techniques for sensor and actuator systems, optical microelec-tromechanical systems, optoelectronic multichip modules, and electronic system applications (55). 

Dehkordi, P., Ramamurthi, K., Bouldin, D., Davidson, H., and Sandborn, P. 1995. Impact of packaging technology on system partitioning A case study. In 1995 IEEE MCM Conference, pp. 144—151. Doane, D.A. and Franzon, P.D., eds. 1992. Multichip Module Technologies and Alternatives The Basics. Van Nostrand Reinhold, New York. 

Messner, G., Turlik, I., Balde, J.W., and Garrou, P.E., eds. 1992. Thin Film Multichip Modules. ISHM. Sandborn, P.A. and Moreno., H. 1994. Conceptual Design of Multichip Modules and Systems. Kluwer,... 

This multichip module was designed for military airborne communications applications where small size, high density, and low weight were critical to system performance. The module shown in Figure 1.20 is a 25.4-mm (1-in.) square package with a multilayer thick-film substrate with 125-pm (5-mil)... 

Size is often the primary driver for MCM-based systems. The typical multicomponent discrete assembly provides a sihcon-to-board efficiency of <10 f>ercent (actual total die area versus the total printed circuit board area). MCM technology can often increase the sdicon-to-board efficiency to 35 or 40 percent with chip and wire assembly processes, and to 50 percent or higher with some of the higher-density processes. Thus, with reduced size and weight, MCMs offer a practical approach to reducing overall system size while providing enhanced performance due to a reduction in the interconnect distance between chips. Multichip modules typically use three to five times less board area than their equivalent discrete solution. ... 

MCM-D/C, Multichip Module Deposited and Cofired. This version of an MCM is a combination of a cofired, mnltilayer ceramic snbstrate containing the common wiring for a family of modules and deposited conductor and insnlation layers containing the personality wiring. It has all of the problems of each technology it nses pins problems related to mismatches in temperature coefficient of the two materials systems. 

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