Issue link: https://iconnect007.uberflip.com/i/1398328
46 SMT007 MAGAZINE I AUGUST 2021 between the designer and the fab that builds this board. ere are several ways to approach this. Could the designer have used via-in-pad or HDI technology to break out from this 0.56 millimeter pitch BGA? e supplier could make those adjustments, but the supplier can't do outerlayer three mil, three-and-three spac- ing using the same stackup. e one ounce base copper is just too thick. ere are so many opportunities for dis- connect aer a design has been released for production and goes through change. Com- munication is the only way to see the proj- ect with success upfront. In other words, if the designer had access to the capability of the supplier building the board, the designer could have chosen the proper stackup and routing solution. Instead, because the designer chose a route without communica- tion, it forced the EMS supplier to go source the board with viable material thickness, which is going to shoot the cost, quoting, and timing all over the map. John Vaughan: Early alignment is critical in my view, so that it doesn't end up with purchasing driving the decision-making process. Had the designer aligned early on with the PCB fabri- cator, that would have solved the issue, right? Dack: Yes. Matties: How much time would that have saved? Dack: Everything is quick time to market; time is of the essence. So, when we discover that a chip is obsolete, or isn't accessible, the clock is still ticking on the project. Typically, it can take a week or two in a production environment just to receive all the quoting back, then to get commitment for availability of the new part. I wouldn't be surprised if it takes more than four to six weeks to implement a change like that. Matties: at's very costly. Nolan Johnson: And yet this is more prevalent than it has ever been historically in our indus- try—all these components on extended lead time. Designers must manage, redesign, and even completely reconfigure their vendor list in order to deliver on this new design. ere is so much to communicate. Vaughan: at's another opportunity for com- munication, you're exactly right. Lead times matter, particularly in this component mar- ket, because running at the typical rhythm in design, designers are typically under the gun and behind schedule before they've even begun. I'm sure Kelly can attest to that. If you're looking at the bill of materials for the components that are required as the design activity is launching, and you see items with 20-week lead times, there's really not a press- ing need to make some of those complex deci- sions without all the forethought that you typ- ically would find yourself having to make if you're a designer, in my opinion. Dack: Well said. Matties: Kelly, in your story, you may have known your capability, but if suddenly you can't get a component or you have to do some- thing on the fly, doesn't that mean that, at the end, all bets are off ? Dack: Yes. at's a time shi. Start with spec- ification. Start the design, from day one, with There are so many opportunities for discon- nect after a design has been released for production and goes through change.