Editor’s note: Like most industrial machinery, wind turbines rely on electronic controls and devices for peak performance. This article, from analysis software firm Mentor Graphics provides 10 tips for streamlining PCB thermal design, a general component in the controls and devices. A link to the full paper is below.
为什么PCB热设计很重要？
Many aspects of a PCB’s performance are determined during detailed design, e.g. making a trace a specific length for timing reasons. Timing issues are also affected by temperature differences between components. Thermal issues with the PCB design are largely ‘locked in’ during the component (i.e. chip package) selection and layout
阶段。在此点之后，只有发现组件运行得太热，才有可能进行补救措施。我们主张从系统或外壳级别开始的自上而下方法，以了解电子产品的流动环境，这对于气冷电子至关重要。关于早期设计中气流均匀性的假设，后来证明无法实现的情况可能会对产品的商业可行性产生灾难性的影响并满足市场窗口。
优化热布局
黄金法则是提早开始并简单地开始。负责产品热完整性的机械工程师应旨在向电子工程师提供尽可能多的有用反馈，以指导设计，尤其是在早期设计期间，尤其是在选择的热影响。
From the mechanical engineer’s perspective, at the PCB level this entails helping with package selection and the best positioning of components to utilize system air flow for cooling. Inevitably both layout and package selection are driven primarily by a combination electronic performance and cost considerations, but the consequences of those choices on thermal performance should be made as clear as possible, as temperature and cooling also affect performance and cost.
1：开始预录 - 预读
在电气设计流程中布局完成之前，可以做很多工作。实际上，在此之前，需要考虑任何影响热考虑对设计的影响。可以通过简单的围栏来完成很多工作，以提供有关板上空气流量的信息。
You can start by simply smearing the total board power over the total board surface. This will give you a temperature map that will give an indication of any hot regions that are caused by a maldistributed air flow, and the enclosure-level air flow should be optimized ahead of the PCB design. For this you can treat the board as a block with an isotropic conductivity of between 5Wm-1K-1 and 10Wm-1K-1. The results at this stage will be quite insensitive to the value chosen.
A word of caution – components inject heat locally into the board, so the heat flux density into the board below a component will be higher than the average for the board. As a result, the local board temperature will be higher than that predicted in the simulation, so at this stage the board temperature should not be used to try to estimate component temperatures. To do that the model needs to be refined.
如果任何点的板温度接近最大组件案例温度，那么一旦离散代表组件热源，就很可能会超过此限制。例如，如果已知一个或多个需要散热器，则可能会期望这是期望的。
对于本文的其余部分：
导师图形
http://s3.mentor.com/public_documents/whitepaper/resources/mentorpaper_82956.pdf
Windpower Engineering & Development
Filed Under:Renewable energy
