typo "SPGA" should be FPGA... sorry. On Mar 22, 2018, at 2:36 PM, Yuan-chia Joyce Koo wrote: > besides ITRS outlined roadmap pin counts (which all industry tend > to bench mark and try to keep in line), there is a diminish of > return when you goes to too high pin counts - not only causes > layout problem, but also production yield issues - e.g. >1000 > interconnect better have very flat on both components and PWB... > you might need to go for LGA instead of BGA... as for prototype, > those components are killers to testing initial functionality of > the system (too complex). rather than block set of components > instead - that is why initial customer chip is SPGA, until the > funcationality are defined to set into ASIC to speed things up and > save the real estate... (more integrate on chip the better - > anything walk off chip is a problem... impedance, fan out, > etc.etc. you want as simple as possible - as lower pin count > as possibly, not more... IMHO... if you give designer max pin > count can be achieved for I/O, I bet he/she will used to max > +10%... leave you little or no room but many headache to try to > layout on PWB... )... By the way, you didn't say what PWB tech you > intende to use - 4/4? or 3/3? without knowing that, it is missing > half of the selection criteria... IMHO. One more thing, assume you > have deep pocket - e.g. you can custom make high density ACF if you > have enough volume or intend to use next gen pin count outlined in > ITRS... (although ITRS is no longer publish roadmap, I believe it > old version still cover next few years). > my 1.4 cents. > jk > On Mar 22, 2018, at 12:07 PM, Ahmad, Syed wrote: > >> We are trying to determine limits on solder or other interconnects >> for a high pin count prototype and need help in identifying >> suppliers for solders, stencil manufacturers, ACAs, ACFs and other >> options that may help us achieve lowest pitch interconnects. All >> help is welcome. Thank you for your assistance. Suppliers may >> contact me directly on my email. >> >> Syed Sajid Ahmad, >> Research Staff, ECE, NDSU >> Cell 701-200-1674