21st Century Manufacturing Episode 10 docx

.84 Computer Manufacturing Chap. 6 6.6.15 Printed Circuit Board Assembly (or Printed Wiring Assembly IPWA] A PCB with all components mounted and interconnected on it. 6.6.18 Sliders The heads, or magnetic coils, of the read/write unit of the disc. 6.8.17 Substrate On a PCB., the base material that provides a supporting surface for etching circuit patterns, as well as attaching components. 6.6.18 Surface Mount Technology (SMT) The process of attaching components directly to the surface of a PCB. Increasingly, SMf is replacing the older pin-in-hole method. 6.6.19 Tape Automated Bonding A process in which precisely etched leads (supported on a flexible tape or plastic car- rier) are interconnected to the chip or a substrate by a heated pressure head. This process simultaneously creates a bond for all leads at once. 6.6.20 Test Coupon A preset pattern of copper pads and/or holes for testing during manufacture. 6.6.21 Tracks Parts of the PCB that provide the interconnections among components and variouslCs. 6.6.22 Wave Soldering Teclutique of collectively soldering the components to the printed circuit board by passing the board over a standing wave of molten solder that fixes the leads of the components. 6.7 REFERENCES AClS Technical Overview. 1999. ACIS geometric modeler. Programming manual. Boulder, CO: Spatial Technology Inc. Akella,J.,A. Dutoit, and D. P. Seiwiorek. 1992.A prototyping case study. In Proceedings of the 3Td IEEE InternationalWorkshop on Rapid System Prototyping. Research Triangle Park, NC: IEEE. Allen. W., D. Rosenthal, and K. Fiduk. 1991. The MCC CAD framework methodology man- agement system. In Proceedings of the 28th ACMlIEEE Design Automation Conference, 694-698. Amir B.,H. Balakrishnan,S. Seshan, and R. Katz.1995.EfficientTCP over networks with wire- less links. In Proceedings of the Fifth Workshop on Hot Topics in Operating Systems. Orcas Island,WA 6.7 References 265 Andrade,A. D.1996.Aceeptability of fabricated circuits. In Printed circuits handbook, 4th ed., edited by C. F. Coombs J"L, 35.3-35.41. New York: McGraw-Hill. Barnes, T., D. Harrison, A. Newton, and R. Spickelmier. 1992. Electronic CAD frameworks. Kluwer Academic Publishers. Bell, C. G. 1984. The mini and micro industries. IEEE Computer 17 (10): 14 30. Berners-Lee, T. 1989.lnfonnation management: A proposal. CERN Internal Proposal, March. Bohr, M.I998. Silicon trends and limits for advanced microprocessors. Communications of the ACM 41 (3):80-87. Brodersen, R. W.I997. The network computer and its future. In Proceedings of the IEEE Inter- national Solid-State Circuits Conference. San Francisco, CA. Buntein,A.,A. C Long, S.Narayanaswamy, et aI.I995. The lnfoPad user interface. In COMPeON '95, 159-162. Cho, T., G. Chien, F.Brianti, and P. R. Gray. 1996.A power-optimized CMOS baseband channel filter and ADC for cordless ••applications. VI W Cirruil Confl'rl'lIre nigl',~r 96, June Clark, R.H.1985.Handbook of printed circuit manufacturing. New York: VanNostrand Reinhold. Cole, R. E. 1999. Managing quality fads: How American business learned to play the quality game. New York and Oxford: Oxford University Press. Curry, I, and M. Kenney. 1999. Beating the clock: Corporate responses to rapid changes in the PC industry. California Management Review 42 (1): &-36. Duffek, E. F. 1996. Plating. In Printed circuits handbook, 4th ed, edited by C F. Coombs Jr., 19.1-19.55. New York: McGraw-Hili. Economist. 1994.A survey of the computer industry, 17 (suppl.): 1-22. Economist. 1999. A bad business, July, 53-54. Finger, S.,I Stivoric, and CAmon, et aI.1996. Reflection on a concurrent design methodology: A case study in wearable computer design. Computer Aided Design 28 (5): 393-404. Fulton, R. F._ 19R7. A framework for innovation. Computers in Mechanical Engineering, March. Gilleo, K., T. Cinque, and A. Silva. 1996.Flip chip 1,2,3: Bump bond and fill. Clrcuits Assembty; June,32-34. Green, H. D. 1996. Multichip modules. In Printed circuits handbook, 4th ed., edited by C F. Coombs Jr., 6.1-6.31. New York: McGraw-Hili. Groover, M. P. 1996. Fundamentals of modem manufacturing, 87&-906. Prentice-Hall. Guerra, M., M. Potkonjak, and 1. Rabaey.I994. System-level design guidance using algorithm properties. In VLSI Signal Processing VII, 73 82: IEEE Press. Gupta, R., et. al. 1989. An object-oriented VLSI CAD framework: A case study in rapid pro- totyping.IEEE Computer 22 (5): 28-37. Guy, E. T. 1992. An introduction to the CAD framework initiative. In Electro 1992 Conference Record. Boston, MA. Inside Read-Rite Corporation. 1993. (Informational brochure. Milpitas, CA: Read-Rite Cor- poration. Keller, K. H. 1984. An electronic circuit CAD framework. Ph.D Thesis, Department of Elec- trical Engineering and Computer Science, University of California, Berkeley. Lao,A.,1 Reason, and D. Messenchmitt.I994.Asynchronous video coding for wireless trans- port./EEE Workshop on Mobile Computing, December, Santa Cruz, CA. Le, M, T., F. Burghardt, S. Seshan, and J. Rabaey. 1995. InfoNet: The networking infrastructure of InfoPad. In Proceedings of Compean '95. 286 Computer Manufacturing Chap. 6 Leicht, H. W.1995. Reflew soldering and repair of BOAs. In 10th European Microelectronics Conference, 508-520. Long, A. c, S. Narayanaswamy, A. Burstein, R. Han, K. Lutz, B. Richards, S. Sheng, R. W. Brodersen, and 1.Rabaey. 1995. A prototype user interface for a mobile multimedia terminal. In Proceedings of the 1995 Computer Human Interface Conference. Mead, c., and L. Conway. 1980. Inrroducrion to VLSI systems. Reading, MA: Addison Wesley. Messner, G. 1996. Electronic packaging and interconnectivity. In Printed circuits handbook, 4th ed. edited by C. F. Coombs Jr., 1.3-1.22. New York: McGraw-Hill. Mitt,M .•G. Murakami, T. Kumakura, and N. Okabe.1995.Advanced interconnect and low cost micro stud BGAIn The 1995 JEEF.lCPMT Electronics Manufacturing Symposium, 428-521. Nakahara,H.l996.1)'pes of printed wiring boards. In Printed circuits handbook, 4th ed.,edited by C. F. Coombs Jr.,3.1-3.14. New York: McGraw-HilI. Narayanaswamy, S., S. Seshan, E. Brewer, R. Brodersen, F. Burghardt, A. Burstein, Y-C, Chang,A. Fox,I Gilbert, R. Han,R. Katz,A. C. Long,O. Messerschmitt,1. Rabaey.1996.Appli~ cation and network support for InfoPad. IEEE Personal Communications Magazine, March. Norman, D. A. 1998. The invisible computer. Cambridge, MA; MIT Press. Palmer, PI, D. I Williams, and CHughes. 1996. Assembly and packaging of conventional elec- tronics. Process Group Technical Report No. 96/13.1. England; Loughborough University. Patterson, D. A., and I L. Hennessy. 1996a. Computer architecture: A quantitative approach. San Francisco, CA: Morgan Kaufmann Publishers. Patterson, D. A., and I L. Hennessy. 19%b. Computer organization and design: The hardware! software interface. San Francisco, CA Morgan Kaufmann Publishers. Rabaey, J., L. Guerra, and R. Mehra. 1995. Design guidance in the power dimension. Paper presented at the International Conference on Acoustic, Speech and Signal Processing. Read-Rite Corporation. 1997.Thchnicalliterature available from 345 Los Caches St., Milpitas, CA. Red Herring. 1998. The post-PC world, December,50-66. Sarma S. E., S. Schofield, 1.A. Stori, 1.MacFarlane and P. K. Wright. 1996. Rapid product real- ization from detail design. Computer-Aided Design 28, (5); 383-392. Sheldahl Technical Staff. 1996. In Printed circuits handbook, 4th ed. edited by C. F. Coombs Jr., 40.1-40.31. New York: McGraw-Hili. Sheng, s., R.Allmon,L. Lynn, I. O'Donnell, K. Stone, and R. W. Brodersen. 1994. A monolithic CMOS radio system for wideband COMA communications. In Wireless '94 Conference Pro- ceedings. Calgary, Canada. Smailagic,A., and D. P Siewiorek. 1993.A case study in embedded-system design: The VuMan 2 Wearable Computer. IEEE Design and Test of Computers, September, 56 67. Stafford, 1. W. 1996. Semiconductor packaging technology. In Printed circuits handbook, 4th ed., edited by C. R Coombs Jr., 2.1-2.16. New York: McGraw-Hill. Stem, N. 1980. Who invented the first electronic judicial computer? Annals of the History of Computing 2 (4): 375-376. Sturges, R. H., and P. K. Wright. 1989. A quantification of dexterity. Journal of Robotics and Computer Aided Manufacturing 6 (1): 3-14. Wang, F c., B. Richards, and P. K. Wright. 1996. A multidisciplinary concurrent design envi- ronment for consumer electronic product design. Concurrent Engineering: Research and Applications 4 (4); 347-359. Wang, F c., P. K. Wright, B. A. Barsky, and D. C. H. Yang. 1999. Approximately arc-length parametrized C3 quintic interpolatory splines. Transactions of the AS ME, Journal of Mechan- ical DUign121 (3): 430-439. 6.8 Case Study on Computer Manufacturing 267 Weiss, P. 1999. Smart outfit. Science News 156 (21): 330-332. Yeh, C. P.1992.An integrated information framework for multidisciplinary PWB design. Ph.D Thesis, Georgia Institute of Technology. Yeh, C. P.,R. E. Fulton,and R. S.Peak. 1991. A prototype information integration framework for electronic packaging. Paper presented at the ASME 1991 Wmter Annual Meeting.Atlanta, GA. 6.8 CASE STUDY ON COMPUTER MANUFACTURING' 6.8.1 Overview This case study presents the product development process of the InfoPad shown in Figure 6.22. The InfoPad is a portable, wireless computer aimed at an approximate selling price of $300. It provides text and graphics, pen input, limited speech input, Fipn (j.2Z The InfoPad~a wireless "information appliance" (see <www.ua.bwu.be keJey.edu». >zhe InfoPad Wlill a large collaborative project, and particu.lar acknowledgmenu are made to the following colleagues: Professor Robert Brodersen,Professor Jan Rabaey, Dr. Frank Wang, Brian Richards, Susan MeYers, and many students at the Berkeley Wireless Research Center. 268 Computer Manufacturing Chap. 6 audio output, and full-motion color video. In a restricted classroom or home envi- ronment it can be used as a mobile communication device and a sketch pad (Brodersen, 1997). Twenty prototypes were produced as evaluation kits for mar- keting purposes and user testing in a college classroom. 6.8.2 Goals of the Case Study Some key points that may be learned in the case study include the following: • Designing and fabricating a complex system like the InfoPad require collabo- ration between many engineering disciplines. Specifically, most consumer elec- tronic products are electromechanical systems. They consist of mechanical components such as structures, enclosures, and mechanisms, combined with electrical components such as printed circuit boards, power supplies, wires (harnesses), and switches. In spite of the advancements within each field- namely, the electrical CAD tools (BCAD) shown in Figure 5.9 and the mechanical CAD tools (MCAD) shown in Table 3.2-a gap still exists today for good communication between BCAD and MCAD. The cartoon of Figure 6.23 captures this struggle . • An environment called the domain unified computer aided design environ- ment (DUCADE) has thus been developed to address this need. It is a con- current engineering system for ECADIMCAD. The links from (a) conceptual design to (b) detail design to (c) fabrication are smooth and deterministic, cre- ating a fast link from the initial design to a fabricated product. This integration improves product quality and time-to-market. Flpre 6.13 DUCADE has the goal of reducing the wall between ECAD and MCAD. 6.8 Case Study on Computer Manufacturing 269 • A specific focus is on constraint resolution between electrical and mechanical issues.A central virtual-white-board environment is created to share and com- municate coupled design issues during the design process. • Various electrical and mechanical subsystems can be designed for modularity and reused in successive design generations. This further accelerates the design to production time. 6.8.3 Conceptual Design The conceptual design phase of the InfoPad involved a functional requirement tree. Figure 6.24 is a global overview of the product design space. Design constraints were specified for each functional requirement as hard (cannot be changed) or soft (can be changed) constraints. For example, a hard design constraint was the desired weight of less than 2 pounds, under the functional requirement of "portable." 6.8.4 Concurrent Detailed Design Using DUCADE The detailed designs for the InfoPad subsystems were conducted by various design teams. These included the pad group, the wireless communication (radios) group, the multimedia network group, the user interface group, and the mechanical design group. Each group used its own domain design tools to perform specific design tasks. However, at certain critical junctures. predetermined design data within each team's domain were shared with other teams in a collaborative way. For example, Figure 6.25 illustrates the collaboration between the "pad group" and "mechanical design group." The PCB of the pad was designed using the Racal PCB layout tools, and the InfoPad casing was designed using the MSCI ARIES mechanical design package. The domain unified computer aided design environment (DUCADE) then provided concurrent access to all the design tools of each team. Importantly, at crit- ical junctures. it specifically provided online checking and verification of the design issues that were predetermined as being coupled between design teams. Commercial CAD packages that were encapsulated in the DUCADE system included four MCAD packages and two ECAD packages: MSC/ARIES, 4 AutoCAD, 5 ProEngineer,6 ACIS, 7 Finesse, 8 and RacaWisula. 9 ARIES and AutoCADI ProEngineer were primarily used for mechanical component design and mechanical analyses such as interference and thermal analyses. ACIS was the solid modeling kernel and package for solid modeling. Racal/ Visula was the major electrical design tool for PCB layout design. 4MSCIARIESTMis a trademark of MacNeal Schwendler Corporation. 5AlltocADTh< is a trademark of Autodesk Inc. 6ProEngineerTl.t is a trademark of Parametric Technology Corporation. 7ACISn< is a trademark of Spatial Technology Inc. 8Finesse™ is a trademark of Harris EDA Inc. ~calIV'ISUalTM is a trademark of Racal-Redac. 270 Computer Manufacturing Chap. 6 Flcure 6.24 Design architecture of the InfoPad system. Readers who are interested in the electrical system design can refer to the litera- ture for radios in wireless communication development (Sheng et aI., 1994;Cho et aI., 1996), mobile multimedia networking and applications (I.e et al, 1995; Amir et el., 1995; Narayanaswamy at al., 1996), video aad graphic transport (Lao at al., 1994), user Proxim/Plessy radics XLink radio controls antenna -Plastic (ABS) casing - Color display module - Ribbons/connectors -Screws - 9V battery set (Sx9V) Mechanical subsystem -Enclosure -Structure -Conneceors - Power supply RFsubsystem -TI-ansmission -Receiving -Controt Text/graphics subsvstem Video subsystem Audio ~uhsvslem Handwritingreoog XIIserverf pen/audio servers! videoserverl GPIB LCDdillplays Central control -CPU -ROMIRAM Detail design mappin Medtev networl ARMsubsystern System evaluation InfoPad multimedia portable terminal Applications] . Constraint specification Multimedia access 'wireless communication Portable terminal InfoPad system design System specification Backbone network Protocols I Base stationIRadioIPeninoul I Audio 110 Graphics Video BW=1-2Mbps Power Sire Weight COOl System embodiment Backbone network -Infrastructure -Protccols 6.8 Case Study on Computer Manufacturing 27' Flpre 6.25 Detailed design of mechanical casing and PCB. interface applications (Long et al.,1995),and design tools and framework (Guerra et aI., 1994;Rabaey et el., 1995;Wang et al., 1996).Table 6.3 summarizes the implementation. 6.8.5 Coupled Design Constraints Figure 6.26 shows some of the coupling constraints that occurred between the mechan- ical and electrical domains. For clarity, only one arrow is shown for the coupling rela- tionship between the locations/orientations of the electronic components and the enclosure's shape. This coupling relationship usually required iterative design tasks with close communication between mechanical and electrical designers to achieve compact packaging. Because the lnfoPad wasdesigned to be alow-power device,many constraints focused on the compact packaging of ICs,devices, and displays. 6.8.6 Coupling Constraints Originating in the Mechanical Domain IC , J Several constraints originated on the "mechanical side" and had to be accommo- dated on the "electrical side."They are given the symbol em:> e They were as follows: • Given the 8 x 11 x 1 format-deliberately chosen to mimic the familiar engi- neers' clipboard the available space inside the terminal enclosure was lim- ited. It thus impacted the available area as well as the height for the display and the PCBs and their components. TABLE 6.3 Major Electrical Subsystems and Components of InfoPad Majorsubsystenu Functionality Major parts Source/part No PAL Commercial part/ATV 2500L EPROM Commercial part/AM27COlO Arm subsystem Central control Octal buffer Commercial partlHCfS74 SRAM CommercialpartffC551001 BFL-85 ARM60 Commercial partlGPS-P60ARMPR ARM interface chip Custom designed and fabricated Plesseydownlink Commercial part/GEC.DE6003 Proxirn uplink Commercial partlRDA.l00f200 Radio subsystem Wifeless Xilinix Commercial partlXC-4008 communications RXchip Custom designed and fabricated TXSRAM Commercial partffC551001 BFL·85 Antenna f x 2) Commercial partlEXC-VHF 902 SMJEXC-UHF 2400 Text/graphics LCD Commercial part/Sharp LM64k83 display Color video LCD Commercial partlSharp LQ4RAOI display Text/graphics chip set Custom designed and fabricated Multimedia Multimedia 110 (x 5) subsystem Color video chip set l.'ustomdesignedandfabricated (x 5) Audio control chip set Custom designed and fabricated (x5) Gazelle pen board Commercial part 110 subsystem Codec Commercial partlMCl45554 Speaker Commercial part Power subsystem Power supply 9VbatteryX 5 Commercial pan • Given the standard mechanical/UI features on the terminal casing-for example, the window for the LCD display on the top case, the access window fOTthe battery set-again, the shapes, dimensions, and positions of the PCBs and their components were limited to certain values. • Given the fact that the casing needed mechanical supporting structures. venti- lation grids, and antenna positioning relative to the user's body, certain restric- tions on placement of ICs were inevitable. To display these fOTthe electrical designers, DUCADE provided a simple "lay- ered" view of the (em> •.,) mechanical constraints. This was because the electrical design teams were familiar with 2.5~D layout tools (rather than 3-D tools) for ICs and PCBs. Figure 6.27shows the internal layout of the bottom casing. The maximum computer Manufacturing Chap. 6 272 Flture 6.26 Coupling mechanical/electrical design constraints, Figun- 6.27 Layout of the mechanical constraints, 273 ("Mechanical'" design constraints Ergonomic constraints Aesthetic (geometric) constraints I Thermal constraints Impact (stress) constraints Weight Material Enclosure ~ Enclosure ~ Mech.comp \Ioc. and orienl ~ ~ ~ ~~- SomeD •••.•gn Parameten Electrical design constraints Power constraints Electromagnetic constraints Proximity constraints .Routing area Etec.comp. loc. and orienl. Shielding Power ~ ~ [...]... previous sections focus on small-batch manufacturing operations that generate a small number of parts, or even one-of-a-kind dies In other sectors of industry,largebatch manufacturing is more the normal situation Thus machining in all its formsturning, milling, drilling, and the like-can also be seen as a large-scale manufacturing process It supports mass-production manufacturing such as the auto and steel... Various switches,volume control knobs, and other 110were of course mounted on the side of PCBs and their precise dimensions were conveyed to the mechanical team Ultimately, this meant that they protruded through the plastic casing's boundary with user-friendly dimensions These components were a power connector, a power switch,serial/parallel ports, audio 110jacks, a keyboard jack, two volume control knobs,... it is of interest to note a ratio of $300 to Metal-Products 280 $7.5 to $2.5 billion cutting tools for labor costs to Manufacturing fixed machinery investments Chap 7 to disposable 7.1.5 Full-Scale Production Using Other Metal-Processing Operations Sheet rolling is also a large-batch manufacturing process in which a rolling mill continuously produces flat strip in coils Such strip is sold to a secondary... of single discrete into an ordinary soup can or filing cab- items, such as the hood of a car, is also a large-batch manufacturing process because many similar parts are produced on a continuous basis from one very expensive die This chapter considers these other examples of large-batch manufacturing, focusing as an example on sheet-metal forming The machines and dies for all these processes are extremely... programmer to achieve optimum cutting conditions The depth of cut is often fixed by the initial size of the bar and the required sfze of the product Metal-Products Manufacturing 284 Chap.7 Cutting speed is usually between 3 and 200 m min -1 (10 and 600 ft/min) However, in modem machining high-speed aluminum machining, speeds alloys The rotational may be as high as 3,500 m min-1 when speed (rpm) of the... per revolution Depth of cut may vary from o over part of the cycle to over 25 mrn (1 inch) It is possible to remove metal at a rate of more than 1,600 em' (100 inches") per minute, but such a rate would be very uncommon, and 80 to 160 em' (5 to 10 inches") per minute would normally be considered rapid As described, the surface of the tool over which the chip flows is known as the rake face The cutting... CSG, or DSG-to a physical component is critical to the success of quickly producing a quality part Ideally, the interchange from a design fonnat to a manufacturing format should preserve all the design information, plus it should be easy to Metal-Products Manufacturing 288 Chap 7 L fE-=-(i)-= =-=-=-3 =-=-(i)==L'·-=1 i Figure 7.9 Test part to be milled for G and M example Above: photograph of machined... process to predict The upper diagram in Figure 7 .10 represents the metal extrusion process-akin to squeezing out toothpaste The diameter of the undefonned material on the left is known, as is the diameter of the deformed material on the right, because it is all constrained to flow through a die of prescribed diameter However, in the lower sketch of Figure 7 .10, the free edge of the chip is unconstrained...Computer Manufacturing 274 Chap 6 internal height for the electrical subsystems is 0.78 inch Special features on the bottom case are the circular busses fur mounting the PCB, the through window for the battery... "dissect" several generations of the familiar Sony Walkman and see how the engineers have invented new ways of resolving the constraints (Cem)' For a first prototype there 6.8 Case Study on Computer 275 Manufacturing i Color di~playconnttlor Two volume controls Mounung holes Power connector AUdio~ Flpre 6.28 PCB layout and some electrical constraints is a limit to how much can be achieved in the first . InfoPad. In Proceedings of Compean '95. 286 Computer Manufacturing Chap. 6 Leicht, H. W.1995. Reflew soldering and repair of BOAs. In 10th European Microelectronics Conference, 508-520. Long,. stationIRadioIPeninoul I Audio 110 Graphics Video BW=1-2Mbps Power Sire Weight COOl System embodiment Backbone network -Infrastructure -Protccols 6.8 Case Study on Computer Manufacturing 27' Flpre. fabricated Multimedia Multimedia 110 (x 5) subsystem Color video chip set l.'ustomdesignedandfabricated (x 5) Audio control chip set Custom designed and fabricated (x5) Gazelle pen board Commercial part 110 subsystem Codec Commercial