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
|