Issue link: https://resources.ema-eda.com/i/1008704
12 I an was startled awake by a loud, repetitive dinging sound coming from his computer. He clicked to see an email message from the prototype supplier. YOUR JOB HAS BEEN PLACED ON HOLD FOR THE FOLLOWING REASON: TRACE WIDTH AND SPACING INCOMPATABLE WITH OUR PROCESSING CAPABILITY. DIAL 42 TO SPEAK WITH A MANUFACTURING ENGINEER WHO CAN HELP. Ian panicked. The layout software had made design seem so easy; why was this supplier having trouble? Ian dialed 42 and was connected to the Etch-O-Matronic Circuits' CAM department. He spoke with the CAM manager who turned out to be none other than Old Bob! He explained the nature of the disposition and helped Ian to see that just because his layout software allowed him to create one mil traces doesn't mean he should have. He went on to explain how to determine trace width with regards to performance and DFM. Very grateful for having established a manufacturing contact who could help, Ian hung up the phone. He then retraced his design steps after opening the layout on his computer. He checked the pre-set design rules to see the program was set to route all the lines at one mil width. After half-an-hour or so, Ian found out fortunately all default route spacing settings were set to a value of 14 mils. Ian was relieved to see this. Since the spacing between the two one mil lines was set so wide, Old Bob's CAM department at Etch-O-Matronic could increase the traces automatically to a more manufacturable width of seven mils and still allow eight mils space between traces and continue with fabrication. Immediately, another email popped up: YOUR JOB HAS BEEN PLACED ON HOLD FOR THE FOLLOWING REASON: DRILL SIZING IS INCOMPATABLE WITH PAD DIAM- ETER LEAVING INSUFFICIENT ANNULAR RING. DIAL 42 TO SPEAK WITH A MANUFACTURING ENGINEER WHO CAN HELP. Again, Ian dialed 42 and was connected to Old Bob who explained the design requirements and limitations of a plated through-hole and helped Ian adjust the design. Throughout the day, this notification shtick happened over and over. Each time, Old Bob patiently described a manufacturing problem caught by Etch-O-Matronic's CAM department and each time he helped Ian correct the layout. Finally after getting dinged on just about every aspect of the design (which had been set to the software's automated default settings), the PCB design files passed all Etch-O-Matronic's design rule checks, and the PCB design was fabricated and automatically shipped to Ian's selection for an electronic manufacturing services provider: RoHaws, EMS. Later, Ian received a tracking notification on his computer screen that the bare PCBs had just been delivered to RoHaws, EMS. Within the hour, Ian heard his computer ding repetitively, much like it did when he heard about manufacturing trouble from Etch-O-Matronic's CAM department. Ian received notifications the assembly job was on hold for numerous DFA reasons. Again, Ian was prompted to dial 42 to be connected with a manufacturing engineer who could help. Chapter 2 DFM, Not Just Another Acronym