Tham khảo tài liệu '21st century manufacturing episode 2 part 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 234 Computer Manufacturing Chap. 6 Figure Computer packaging levels from Computer Organization and Design 2nd ed. by David Patterson and John Hennessy 1996. Morgan Kaufmann Publishers. . From the top left from the previous chapter packaged integrated circuits ICs e-g. the main processor and memory chips are first assembled onto PCBs the motherboard and the eight main memory boards assembled vertically on the motherboard . System level packaging on the lower left also shows the secondary memory floppy and hard drive . The schematic shows the main functional abstractions of the physical devices. Printed Circuit Board Manufacturing 235 TABLE Key Functional Abstractions of a Computer System Component Function 1. Processor CPU data path 2. Processor CPU control Performs arithmetic operations Sends signals that determine the operation and sequencing of data paths memory and use of the input output devices 3. Memory a Primary main memory volatile memory of programs or data being used by the processor b Secondary floppy or hard drive memory nonvolatile memory or storage of programs 4. Input Includes keyboard mouse voice activation digital camera incoming e-mail fax and so forth 5. Output Includes screen printer outgoing e-mail fax and the like PRINTED CIRCUIT BOARD MANUFACTURING Introduction Printed circuit boards PCBs provide the foundation for the interconnections among subcomponents. The interconnections are provided by copper tracks that are applied to the drcuit board in a series of additive or subtractive processing steps similar to those used in the fabrication of integrated circuits ICs . Copper lands are also applied for the connections to individual ICs and components. Colloquially speaking the PCB is a subway map of circuit tracks that connect the ICs and other devices located at the stations. The board itself also provides the rigid structure that holds chips and other fragile system components in place and allows for the physical .
