b'Electronics & Semiconductor | Engineer InnovationFully-Calibrated Thermal Models Keep Customer Designs CoolThe benefits of Transient Thermal Tests and Thermal simulations for ASE Group and their customersBy H.E. Chen, Ian Hu, and Penny Yang ASE Global, Taiwan; Jay Chien EFD Corporation; and Hon Wong, Siemens Digital Industries SoftwareThe age of 5G is upon us. It promisesIntroductionvast improvements to existing mobile(Watt)networks, allowing improved250 High performanceconnectivity between users, machines and smart devices. Besides benefitting200consumers with faster mobile network communications, mission critical150Power dissipationcommunications such as those forHigh performance devicesautonomous vehicles, robotics, medical100equipment and industrial, the Internet of Things (IoT) will stand to benefit too.50ASE Group is designing and developingData Center High Speed Networkthe integrated circuit (IC) packages used30in a wide range of applications such as vehicles, smart devices such as10smartphones, wearables, smartCost competitivenessclothing, augmented/virtual reality5x510x1030x3050x5065x65devices etc. (mm2)Package sizeIncreased functionality and additionalFigure 1: Increasing complexity, size and power dissipation of packagesfeatures has resulted in the IC packages for these devices to be ever moreThe inaccuracy of 2-Resistor models is complex in terms of layout and design.well known. For example, the model is Their power dissipations and overall sizeboundary condition dependent, as it has also correspondingly becomedoes not take into account changes in greater as shown in Figure 1. the 3D heat conduction within the package. Consequently it is not suitable Traditional workflow for all package types.The thermal metrics such as,, JA JB JCand compact thermal models have to beDELPHI models on the other hand, give supplied to end customers to assist theirgreater accuracy compared to the design efforts. These system integrators2-Resistor models. However, this comes are responsible for board layouts,at the expense of increased thermal chassis and cooling solutions for the ICnetwork complexity. The methodology packages designed and supplied by ASE.for obtaining the DELPHI models is In the past, 2-Resistor and DELPHIdescribed in JEDEC standard JESD15-4 models were supplied, based on theand it requires a simulation-based detailed IC package simulation modelsapproach, rather than physical tests. So created in Simcenter Flotherm software.the accuracy of the compact model is The detailed IC package models werecompromised by an uncalibrated not calibrated against experimental testdetailed model.results prior to creating compact thermal models. The measurement andBesides having to supply accurate simulation routes were entirelycompact thermal models to customers, separate.ASE typically needs to carry out design 67'