Characteristic length and cooling circle
Modular design, outsourcing and open innovation create a complex network of possible end product embodiments in product design for the consumer market. Analyzing each and every possibility in detail is out of the question as resources are limited and module details are often proprietary information. To meet this challenge the thermal engineer needs a feeling about what will and what will not work out, without getting bogged down in too much detail. This paper presents the concepts of characteristic length and cooling circle as an approximate measure for the extent of heat spreading in beam and in flat thin plate geometries. Beam and flat thin plate geometries are widely used by mechanical designers, and being able to assess how much of the geometry is actually thermally affected by a heat source is of great value in thermal decision making and communication. For both geometries an application is discussed and compared to CFD simulations to assess the validity of the approach.
Thermal design in the Design for Six Sigma — DIDOV framework
Fierce competition drives continuous improvement of products and product development processes in consumer electronics. The DIDOV (Define, Identify, Design, Optimize, and Verify) version of the Design for Six Sigma (Dfss) approach is widely recommended a means to improvement, especially in R&D environments. Due to the wide field of application, the Dfss-DIDOV method is formulated in very abstract terms, which makes it difficult to relate it to the engineering world. In this paper, the method is assessed in the context of the thermal design of electronics cooling in a consumer electronics product. The paper starts with a discussion of the DIDOV methodology and a comparison to thermal design flow. Next, the method is illustrated on a thermal design case.
Cooling of a 32 inch plasma display monitor
The development of the cooling design of a 32-inch plasma display monitor for consumer use is described. Two distinct challenges were met. First: abandon the use of fan cooling while coping with a 3-fold energy density increase. Second: meet a strict timing schedule of market introduction. Different thermal design methodologies were used in the different product development phases to meet these challenges, resulting in a successful market introduction and an EISA award for best plasma TV 2001-2002. Cooling the monitor was not a case of identifying and eliminating a single problem cause, but rather an exercise of systematic risk assessment and follow up in the entire development tract. Essential for this complex cooling job were the use of CFD, transferring the geometry directly from the CAD database, careful determination of measurement conditions and a measurement plan, and continuous measurements on prototypes of increasing complexity, starting as early as possible.