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 PAGE 2 OLE Technology Corporation Project NameNotebookcase1. a back cover of LCDcase2. an upper case of keyboardProject No.2000-7-1 2000-7-2Requested ByPrepared ByConsultancy EngineeringServices DivisionReviewed ByCharles HsuDate2000/7/18 PAGE 2  PAGE 16 Case 1 An upper case of keyboard Original Design: Adopting 4 gates and 11 cooling channels Figures 1 and 2 show the layouts of cooling channels and runners on the core and cavity sides respectively. Figure 3 shows the melt-front advancement. Where blue indicates first area to fill, and red indicates last area to fill. Figures 4 ~ 6 show the short shot sequences, while each short shot is showing the pressure distribution. Where red indicates regions of high pressure, and blue indicates regions of low pressure. By checking these figures, one knows that the lower region is filled before the upper region, and the filling of the part is not well balanced. The required injection pressure is 75.4Mpa. Figure 7 shows the bulk temperature distribution (281oC ~ 245oC). Where red indicates high temperature and blue indicates low temperature. Figure 8 shows the distribution of weld lines. Figure 9 shows the distribution of air traps. Figure 10 shows the distribution of volumetric shrinkage. Where red indicates high volumetric shrinkage, blue indicates low volumetric shrinkage, and the color table at the lower left corner indicates the maximum and minimum volumetric shrinkage values at a specific time. The smaller the two extreme values differ, the less residual stress will be induced by non-uniform shrinkage. In other words, it will be a better design. In order to accommodate the assembly inside the keyboard cover, the inner side of the cover is thinned to form 4 square dents. The inside wall and outside wall are 0.9mm and 1.8mm thick respectively. Furthermore, the wall thickness changes from 1.8mm to 0.9mm and is abrupt like a step. Therefore, the volumetric shrinkage diff