Blackfin PLCC

Started by csb June 30, 2003
Does anyone know if there are plans to release the 21535 blackfin in a PLCC
package instead of the BGA currently available.
Thanks

Chris Bradshaw


"csb" <skeeter1976@hotmail.com> wrote in message
news:3f00007d$0$938$9b0f33e3@clyde...
> Does anyone know if there are plans to release the 21535 blackfin in a
PLCC
> package instead of the BGA currently available.
ADI hasn't used PLCC for their DSPs for years. They simply have too many pins these days. Leon -- Leon Heller, G1HSM leon_heller@hotmail.com http://www.geocities.com/leon_heller
"Leon Heller" <leon_heller@hotmail.com> wrote in news:bdpkfm$2nt$1
@hercules.btinternet.com:

> > "csb" <skeeter1976@hotmail.com> wrote in message > news:3f00007d$0$938$9b0f33e3@clyde... >> Does anyone know if there are plans to release the 21535 blackfin in a > PLCC >> package instead of the BGA currently available. > > > ADI hasn't used PLCC for their DSPs for years. They simply have too
many
> pins these days. > > Leon
Leon is right that PLCCs have not been used in ADI DSPs since the 210x. PLCCs are evil! They are large, difficult to solder, sockets are crappy and often create their own problems, etc. The BF535 will probably be a BGA only part. It has 260 pins. There are plans for a BF531/2 in a 176 pin QFP. These are coming after the BGAs. The reality is that most new fast parts are going to be BGA. Some will be in QFP as well. BGAs are much more expensive to prototype but not necessarily more expensive in production. BGAs have the advantage that it is easier to remove heat from the part and that lead inductance is minimal compared to QFP. In production they tend to self align very nicely. The big disadvantage is that you don't hand solder them. -- Al Clark Danville Signal Processing, Inc. -------------------------------------------------------------------- Purveyors of Fine DSP Hardware and other Cool Stuff Available at http://www.danvillesignal.com
On Mon, 30 Jun 2003 17:36:31 GMT, Al Clark <dsp@danvillesignal.com>
wrote:

>"Leon Heller" <leon_heller@hotmail.com> wrote in news:bdpkfm$2nt$1 >@hercules.btinternet.com: > >> >> "csb" <skeeter1976@hotmail.com> wrote in message >> news:3f00007d$0$938$9b0f33e3@clyde... >>> Does anyone know if there are plans to release the 21535 blackfin in a >> PLCC >>> package instead of the BGA currently available. >> >> >> ADI hasn't used PLCC for their DSPs for years. They simply have too >many >> pins these days. >> >> Leon > >Leon is right that PLCCs have not been used in ADI DSPs since the 210x. >PLCCs are evil! They are large, difficult to solder, sockets are crappy >and often create their own problems, etc.
You prefer soldering BGAs to PLCCs? Actually, as long as the machine does it that part's not too bad, so let me rephrase: You prefer un-soldering BGAs to PLCCs? BGAs are maddening for rework... ...and inspection... PLCC sockets can be pretty nice if you don't abuse them. BGAs just make life difficult for everything but manufacturing, IMHO, but manufacturing is pretty important.
>The BF535 will probably be a BGA only part. It has 260 pins. > >There are plans for a BF531/2 in a 176 pin QFP. These are coming after >the BGAs. > >The reality is that most new fast parts are going to be BGA. Some will be >in QFP as well. BGAs are much more expensive to prototype but not >necessarily more expensive in production. > >BGAs have the advantage that it is easier to remove heat from the part >and that lead inductance is minimal compared to QFP. In production they >tend to self align very nicely. The big disadvantage is that you don't >hand solder them.
Or do much rework at all... :( I do agree that the speeds and line voltages of advanced parts pretty much preclude the use of PLCCs. TQFPs can be much better to work with than BGAs, but still have more lead inductance, etc. I miss the days of wire-wrap and DIPs...well, maybe not now that I think of it... At least with that stuff you could do almost as much at home as you could in a lab. Eric Jacobsen Minister of Algorithms, Intel Corp. My opinions may not be Intel's opinions. http://www.ericjacobsen.org
eric.jacobsen@ieee.org (Eric Jacobsen) wrote in
news:3f009aba.254965255@news.earthlink.net: 

> You prefer soldering BGAs to PLCCs? Actually, as long as the machine > does it that part's not too bad, so let me rephrase: > > You prefer un-soldering BGAs to PLCCs?
I hate soldering PLCCs versus QFP. Obviously soldering & unsoldering BGAs is not practical without very special equipment. I don't buy into the toaster oven/ hot air gun theories. Reballing a BGA is usually too expensive. Of course, this depends on the cost of the original part.
> > BGAs are maddening for rework... > > ...and inspection...
Xrays
> > PLCC sockets can be pretty nice if you don't abuse them. BGAs just > make life difficult for everything but manufacturing, IMHO, but > manufacturing is pretty important.
My experience is that PLCC sockets are much much less reliable than the parts that are installed.
> >>The BF535 will probably be a BGA only part. It has 260 pins. >> >>There are plans for a BF531/2 in a 176 pin QFP. These are coming after >>the BGAs. >> >>The reality is that most new fast parts are going to be BGA. Some will >>be in QFP as well. BGAs are much more expensive to prototype but not >>necessarily more expensive in production. >> >>BGAs have the advantage that it is easier to remove heat from the part >>and that lead inductance is minimal compared to QFP. In production >>they tend to self align very nicely. The big disadvantage is that you >>don't hand solder them. > > Or do much rework at all... :(
REWORK SUCKS!
> > I do agree that the speeds and line voltages of advanced parts pretty > much preclude the use of PLCCs. TQFPs can be much better to work with > than BGAs, but still have more lead inductance, etc. > > I miss the days of wire-wrap and DIPs...well, maybe not now that I > think of it... > > At least with that stuff you could do almost as much at home as you > could in a lab. >
I hated wirewrap. I used mostly the perfboard prototying method. Today, I go right to PCBs. In the "olden" days I was primarily an analog guy (once the only one without gray hair) so soldered perf boards usually worked fine and I could avoid wirewrap. I think the worst thing about small parts (and BGAs certainly up the ante) is that the beginner (especially the kids) are less likely to pursue electronic hardware design, if for no other reason than that the tools cost too much. When I was a kid, I smoked things, now they just reboot ;-) -- Al Clark Danville Signal Processing, Inc. -------------------------------------------------------------------- Purveyors of Fine DSP Hardware and other Cool Stuff Available at http://www.danvillesignal.com
On Mon, 30 Jun 2003 21:35:33 GMT, Al Clark <dsp@danvillesignal.com>
wrote:

>eric.jacobsen@ieee.org (Eric Jacobsen) wrote in >news:3f009aba.254965255@news.earthlink.net: > >> BGAs are maddening for rework... >> >> ...and inspection... > >Xrays
Yeah, that's part of the maddening process...
>> PLCC sockets can be pretty nice if you don't abuse them. BGAs just >> make life difficult for everything but manufacturing, IMHO, but >> manufacturing is pretty important. > >My experience is that PLCC sockets are much much less reliable than the >parts that are installed.
That should be true of any socket, I think. We frequently used PLCC sockets with huge ugly expanders so we could hook a logic analyzer up to FPGAs and 210x DSPs. We'd occasionally have trouble with the debug expander, but seldom with the sockets. Even if the socket did flake out they were easy to change. I found those much easier to work with than the debug clips we used with the PQFPs for the 1610 DSPs. Maybe that stuff holds up better in the dry southwestern climate. ;)
>> I miss the days of wire-wrap and DIPs...well, maybe not now that I >> think of it... >> >> At least with that stuff you could do almost as much at home as you >> could in a lab. >> > >I hated wirewrap. I used mostly the perfboard prototying method. Today, I >go right to PCBs. In the "olden" days I was primarily an analog guy (once >the only one without gray hair) so soldered perf boards usually worked >fine and I could avoid wirewrap.
I would think wirewrap would suck for analog.
>I think the worst thing about small parts (and BGAs certainly up the >ante) is that the beginner (especially the kids) are less likely to >pursue electronic hardware design, if for no other reason than that the >tools cost too much.
I've thought that too. A weird thing I've observed is that the rf guys still have relatively easy prototyping tools that are convenient to work in a home lab. The test equipment is a little hairy, but other than that...
>When I was a kid, I smoked things, now they just >reboot ;-)
A lot of people smoked things in those days, not all of it failed electronics. ;) Eric Jacobsen Minister of Algorithms, Intel Corp. My opinions may not be Intel's opinions. http://www.ericjacobsen.org
In article <3f009aba.254965255@news.earthlink.net>, Eric Jacobsen wrote:
> On Mon, 30 Jun 2003 17:36:31 GMT, Al Clark <dsp@danvillesignal.com> > wrote: > >>"Leon Heller" <leon_heller@hotmail.com> wrote in news:bdpkfm$2nt$1 >>@hercules.btinternet.com: >> >>> >>> "csb" <skeeter1976@hotmail.com> wrote in message >>> news:3f00007d$0$938$9b0f33e3@clyde... >>>> Does anyone know if there are plans to release the 21535 blackfin in a >>> PLCC >>>> package instead of the BGA currently available. >>> >>> >>> ADI hasn't used PLCC for their DSPs for years. They simply have too >>many >>> pins these days. >>> >>> Leon >> >>Leon is right that PLCCs have not been used in ADI DSPs since the 210x. >>PLCCs are evil! They are large, difficult to solder, sockets are crappy >>and often create their own problems, etc. > > You prefer soldering BGAs to PLCCs? Actually, as long as the machine > does it that part's not too bad, so let me rephrase: > > You prefer un-soldering BGAs to PLCCs? > > BGAs are maddening for rework... > > ...and inspection...
yeah, it's all about the price of the board it's attached to... where I work, a 24-layer, $30,000 board can be saved by spending about $600 to put on a new chip...the diagnostic software I write pays for my salary very quickly! but, obviously there are many hobbyists on here...that's why you want to get dev boards!!!! rock and roll! -- different MP3 every day! http://gweep.net/~shifty/snackmaster . . . . . . . . ... . . . . . . "Maybe if you ever picked up a goddamn keyboard | Niente and compiler, you'd know yourself." -Matthew 7:1 | shifty@gweep.net
Leon Heller wrote:
> "csb" <skeeter1976@hotmail.com> wrote in message > news:3f00007d$0$938$9b0f33e3@clyde... > >>Does anyone know if there are plans to release the 21535 blackfin in a > > PLCC > >>package instead of the BGA currently available. > > ADI hasn't used PLCC for their DSPs for years. They simply have too many > pins these days.
I haven't seen any new device, small or large, in a PLCC for a long time. I think he really means QFP. Manufacturers don't really like PLCCs, as QFPs are smaller and easier to handle. On the other hand they have issues with those super fine QFPs, too - its not only the silicon that has super fine geometry these days. :-) Regards, Steve
Crackpot wrote:
> yeah, it's all about the price of the board it's attached to... > > where I work, a 24-layer, $30,000 board can be saved by spending > about $600 to put on a new chip...the diagnostic software > I write pays for my salary very quickly!
How thick are your 24 layer boards? Its years since I used that many layers, but the boards were really think and heavy then. Through hole ICs didn't actually reach all the way through. They had excellent rigidity, though. :-) I haven't seen BGAs being reworked, but they get swapped out quite freely by people who use them heavily. They must be less problematic than they appear to non IE types, like most of us. Regards, Steve
Steve Underwood <steveu@dis.org> wrote in news:bdtvt0$qeo$1
@hfc.pacific.net.hk:

> Crackpot wrote: >> yeah, it's all about the price of the board it's attached to... >> >> where I work, a 24-layer, $30,000 board can be saved by spending >> about $600 to put on a new chip...the diagnostic software >> I write pays for my salary very quickly! > > How thick are your 24 layer boards? Its years since I used that many > layers, but the boards were really think and heavy then. Through hole > ICs didn't actually reach all the way through. They had excellent > rigidity, though. :-) > > I haven't seen BGAs being reworked, but they get swapped out quite > freely by people who use them heavily. They must be less problematic > than they appear to non IE types, like most of us. > > Regards, > Steve > >
Reworking a BGA is not as easy as just removing and resoldering. The contacts are solder balls. Our supplier will place a BGA for $65 ea after the board was been profiled ($80). Reballing is $125 and this does not count replacing the reballed part on the board. If you are dealing with a very expensive part, you might want to reball the part, but usually we throw away the part and replace with a new one. Prototype BGA sockets are very expensive as well (maybe $1K). In production, BGAs are not difficult. They tend to self align very well. The biggest issue is PCB layout especially when the pitch is .8mm or smaller. This makes vias very small (often microvias are needed which is not something every pcb house can provide and they are definitely more expensive). BGAs are certainly a reality and if you want to build DSP boards you better get used to them. Of course, there are suppliers that would love to save you the trouble ;-) -- Al Clark Danville Signal Processing, Inc. -------------------------------------------------------------------- Purveyors of Fine DSP Hardware and other Cool Stuff Available at http://www.danvillesignal.com