Issue link: https://iconnect007.uberflip.com/i/1533904
APRIL 2025 I SMT007 MAGAZINE 51 and tube voltage were also varied on the machine. Different board thicknesses were also tested under the same inspection condi- tions to characterize the impact of the PCB material on radiation absorption. A functional test was set up using a vali- dation platform hardware that contained a motherboard, heatsink, keyboard, moni- tor, mouse and SSD. e hardware setup is equivalent to a functional laptop or desktop installed with Windows Operating system. Functional SOC with memory on package will then be installed on this socketed moth- erboard and tested using MemTest86. Mem- Test86 is an open-source memory testing tool for memory diagnostics and was used to test if the DRAM had errors upon exposure to radiation. Results and Discussion Figures 2a and 2b show the dosimeter loca- tions on BGA #1. Pos A is on the PCB on the same side of the board as the BGA, Pos B is on the memory, and Pos C is on the PCB on side of the board opposite to that of the BGA. Figures 2c and 2d show the locations of the Figure 4: BGA #3 X-ray dosage results. Package is facing away from X-ray source in both machines. Variability Chart for Dosimeter reading (rad) b a dosimeters with respect to the X-ray source on both the 2D X-ray and 3D X-ray machines. e 3D X-ray machine has a 0.5 mm thick aluminum on-unit filter attached to the X-ray source while additional filters can be added to the 2D X-ray machine as needed. Figure 2e shows the dosage readings for the BGA #1. e readings show that the PCB absorbs a significant amount of radiation and that Al filters help reducing the dosage. Figures 3a and 3b show the dosimeter loca- tions on BGA #2. Pos A is on the PCB on the same side of the board as the BGA, Pos B is on the memory, and Pos C is on the PCB the side of the board opposite to that of the BGA. Figures 3c and 3d show the locations of the dosimeters with respect to the X-ray source on both the 2D X-ray and 3D X-ray machines. Figure 3e shows the dosage readings for the BGA #2. e readings also show that PCB absorbs a significant amount of radiation and that Al filters help reduce the dosage. Figure 4a shows the dosimeter locations on BGA #3. Pos A is on the Si, Pos B is on the memory, and Pos C is on the PCB on the same side of the board as the BGA. Figure 4b