| Summary: | 碩士 === 逢甲大學 === 航空工程所 === 92 === As the product’s form factor continues decrease while the number of chips keeps on rising, the power densities in MCMs become dramatically increasing. This would lead to a higher temperature field that would generally result in high stress and eventually lower the fatigues life of packages. In this aspect, thermal management becomes exceptionally critical to both the reliability and operation performance of multiple-chip modules (MCMs). Successful thermal management requires an effective and robust design optimization scheme to perform automated design as well as an effective thermal characterization approach to systematically assess the thermal performance of electronic packages under various configurations.
The underlying goal of the study is to find the optimal thermal placement design of chips in MCMs in natural convection. The problem attempts to seek the minimum system temperature through the finding of optimal chip locations. Two techniques are proposed in the study: 1) an effective thermal characterization technique, and 2) an effective thermal optimization technique. The direct thermal finite element (FE) modeling technique that employs empirical local heat transfer (HT) coefficient correlation models (Ellison [36], and Ridsdale et al. [37]) to describe the MCM’s surface heat transfer to the ambient through convection and radiation is proposed for thermal characterization. The validity of the thermal characterization technique would be verified through the published experimental data (Cheng et al. [12]). Furthermore, the FE-based force-directed (FD) algorithm is proposed for thermal optimal design of MCMs. The basic idea behind the FD algorithm can be analogous to the Hooke’s law in applied mechanics. It employs a repulsive and attractive force between two objects, respectively, to keep those unconnected objects apart and to define the degree of connections between two connected objects. Essentially, the proposed FE-based FD technique directly adopts actual temperature information that is obtained from FE analysis to build up the attractive and repulsive forces. The effectiveness and applicability of the proposed optimization technique are extensively demonstrated through the design case studies involving various types of MCMs, and in addition the associated correctness is confirmed through those published data in literature (Huang and Fu [33] and Lee [34]).
|
|---|
