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28 The PCB Design Magazine • September 2017 THE HISTORY OF PREDICTIVE ENGINEERING rials and connection density (DEN), first pass yield (FPY) and the PCB Complexity Index (CI), the cost of any design as the Relative Cost Index (RCI); and 2. Cost (RCI) of different materials, layers, holes, final finishes, fabrication, density, and electrical test and performance (controlled impedance). 2. Design for Cost—Report Cards: using a report card of features for both PCB fab and as- sembly gives and indication of RCIs and if the cost will go up or how to get a discount. 3. First DFM design software tool, 1987: A lotus Spreadsheet was created for design plan- ning. a. Inputs: i. Board features: size, layers, traces, and holes b. Outputs: i. DDI, RCI, FPY and electrical performance 4. A second DFM design software tool, 1990: A more complex 55 Excel Spreadsheet was cre- ated over a number of years where not just the board and assembly measures are specified but also the system specs and more performance models. This became a virtual prototype called System Performance Analysis (SPA). a. Inputs: i. System inputs IC technology, lead attach tech, packaging tech, MCM, PCB technology, system interconnect tech, and cost models. b. Outputs: i. Electrical performance, power and power densities, crosstalk and power supply noise and costs. 5. MCC's Multichip Design Advisor, 1991: HP contributed its software and models to MCC for this predictive modeling software that later is spun out as SavanSys. 6. Wiring demand vs. wiring capability trade-offs. 7. HP-LABS Board Construction Advisor— IPDA, 1995: A board planning tool. 8. HP-LABS self-learning Expert System (Ex- plorer), 1996: An automatic search solution for PCB design goals. I believe that it's critical for today's PCB de- signers to have a better understanding of pre- dictive engineering. PE is not just for manufac- turers. Without predictive engineering, you re- ally can't have a true design for manufacturing process. PCBDESIGN Happy Holden has worked in printed circuit technology since 1970 with Hewlett Packard, NanYa/West- wood, Merix, Foxconn, and Gentex. He is currently a contributing editor with I-Connect007. To read past columns or contact Holden, click here. Fabricating hybrid semiconductor lasers on mate- rials other than silicon-on-insulator (SOI) substrates has proved challenging. Now, A*STAR researchers have developed an innovative technique that can in- tegrate the lasers on to a range of different materials. Hybrid lasers combine the light-emitting proper- ties of group III-V semiconductors like gallium arse- nide and indium phosphide, with conventional sili- con technologies. Doris Keh-Ting Ng and colleagues from the A*STAR Data Storage Institute have developed an innovative technique for bonding III-V lasers on to other substrates, be it silicon, quartz, or metal alloys. By using an ultrathin layer of silicon oxide to bond the lasers to a silicon substrate, the researchers developed a simpler, safer and more flexible tech- nique than direct bonding, which relies on chemical bonding between the surfaces. Integrated Lasers on Different Surfaces