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On Sunday, January 15, 2023 at 12:10:54 AM UTC-4, John Larkin wrote:
On Sat, 14 Jan 2023 17:52:45 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Saturday, January 14, 2023 at 9:34:09 PM UTC-4, John Larkin wrote:
On Sat, 14 Jan 2023 16:20:53 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Saturday, January 14, 2023 at 3:17:24 PM UTC-4, John Larkin wrote:
On Sat, 14 Jan 2023 10:05:33 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Saturday, January 14, 2023 at 12:08:03 PM UTC-4, John Larkin wrote:
On Fri, 13 Jan 2023 21:20:50 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Saturday, January 14, 2023 at 12:39:49 AM UTC-4, John Larkin wrote:
On Sat, 7 Jan 2023 09:49:24 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
A small board with a 100QFP is being redesigned for a new FPGA due to obsolescence. Gowin makes a 100QFP device that would be a good fit, but my customer has said \"no\" to the 100% Chinese brand... US government customers, ya know!
So now I\'m looking at a BGA. I don\'t want to get into fine PCB design rules, so 1.0 mm ball pitch is my preference. The only devices I can find that fit on the board have 196 or 256 pins. But the real problem is availability.
Digikey has a few of the XC7S15-1FTGB196I and more a scheduled for delivery in April. Add in the various speed and temperature flavors trickling in (mostly in April) and I should be ok for the initial delivery in August... if I can get my hands on those. I don\'t know if Digikey factors in the backlog orders in these counts.
Mouser shows great inventory of Efinix parts, particularly the T13 and T20 in a 0.8 mm 256 pin BGA, 10s of thousands in stock. But I\'d rather work with a 1.0 mm BGA. Oddly enough, LCSC shows part numbers, but zero inventory.
Anyone work with 0.8 mm BGAs? What PWB feature dimensions did you use? Did this impact the PWB cost?
The 0.8 mm 256-ball T20 isn\'t bad...
https://www.dropbox.com/s/xjqgj2pz9mdhtma/P941_FPGA.jpg?raw=1
I can\'t really see much detail. It looks like there are virtually no pads on the vias under the BGA. What size are they?
The BGAVIAs are 12.5 mil OD with 8 mil drills. The other vias on the
board STANDARDVIA and POWERVIA are bigger.
2.25 mil (0.057 mm) is a pretty narrow via ring. Why not have a larger via pad?
I don\'t know. My PCB guy decides stuff like that. I\'d guess that he
wanted it to pass some design rule check, or maybe he started metric.
The board houses haven\'t complained as far as I know.
You should do your own thing and check with whoever will make your
boards.
Sounds good, but I\'ve never been able to get a board house to even discuss these issues. They always take the approach that they will work with what I give them, which means, if it gives poor results, it\'s my problem.
We always specify bare-board testing and warpage and tolerances, so we
don\'t get bad boards. What we can get is expensive boards.
There are a number of board companies with published capabilities, but they all vary, enough that there seems to be no consensus. Just like your via pad size. I\'ve never seen a board house that says that would be a standard board. I was just looking at one company who wants 10 mil annular ring on inner layers and 7 mil annular ring on surface layers. That\'s a huge difference from 2.25 mil. On the other hand, they will print 2.5 mil trace/space!
Zero annular ring seems to be OK on inners. That reduces capacitance.
5 or even 4 mil traces are usually standard price. I don\'t know why my
guy used 6 on the board that I posted.
We do email our board houses and often they answer!
You aren\'t paying attention.
That\'s because you\'re obnoxious.
Wow! Talk about sensitive. What is going on with you???
On Sat, 14 Jan 2023 21:04:55 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Sunday, January 15, 2023 at 12:10:54 AM UTC-4, John Larkin wrote:
On Sat, 14 Jan 2023 17:52:45 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Saturday, January 14, 2023 at 9:34:09 PM UTC-4, John Larkin wrote:
On Sat, 14 Jan 2023 16:20:53 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Saturday, January 14, 2023 at 3:17:24 PM UTC-4, John Larkin wrote:
On Sat, 14 Jan 2023 10:05:33 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Saturday, January 14, 2023 at 12:08:03 PM UTC-4, John Larkin wrote:
On Fri, 13 Jan 2023 21:20:50 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Saturday, January 14, 2023 at 12:39:49 AM UTC-4, John Larkin wrote:
On Sat, 7 Jan 2023 09:49:24 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
A small board with a 100QFP is being redesigned for a new FPGA due to obsolescence. Gowin makes a 100QFP device that would be a good fit, but my customer has said \"no\" to the 100% Chinese brand... US government customers, ya know!
So now I\'m looking at a BGA. I don\'t want to get into fine PCB design rules, so 1.0 mm ball pitch is my preference. The only devices I can find that fit on the board have 196 or 256 pins. But the real problem is availability.
Digikey has a few of the XC7S15-1FTGB196I and more a scheduled for delivery in April. Add in the various speed and temperature flavors trickling in (mostly in April) and I should be ok for the initial delivery in August... if I can get my hands on those. I don\'t know if Digikey factors in the backlog orders in these counts.
Mouser shows great inventory of Efinix parts, particularly the T13 and T20 in a 0.8 mm 256 pin BGA, 10s of thousands in stock. But I\'d rather work with a 1.0 mm BGA. Oddly enough, LCSC shows part numbers, but zero inventory.
Anyone work with 0.8 mm BGAs? What PWB feature dimensions did you use? Did this impact the PWB cost?
The 0.8 mm 256-ball T20 isn\'t bad...
https://www.dropbox.com/s/xjqgj2pz9mdhtma/P941_FPGA.jpg?raw=1
I can\'t really see much detail. It looks like there are virtually no pads on the vias under the BGA. What size are they?
The BGAVIAs are 12.5 mil OD with 8 mil drills. The other vias on the
board STANDARDVIA and POWERVIA are bigger.
2.25 mil (0.057 mm) is a pretty narrow via ring. Why not have a larger via pad?
I don\'t know. My PCB guy decides stuff like that. I\'d guess that he
wanted it to pass some design rule check, or maybe he started metric.
The board houses haven\'t complained as far as I know.
You should do your own thing and check with whoever will make your
boards.
Sounds good, but I\'ve never been able to get a board house to even discuss these issues. They always take the approach that they will work with what I give them, which means, if it gives poor results, it\'s my problem..
We always specify bare-board testing and warpage and tolerances, so we
don\'t get bad boards. What we can get is expensive boards.
There are a number of board companies with published capabilities, but they all vary, enough that there seems to be no consensus. Just like your via pad size. I\'ve never seen a board house that says that would be a standard board. I was just looking at one company who wants 10 mil annular ring on inner layers and 7 mil annular ring on surface layers. That\'s a huge difference from 2.25 mil. On the other hand, they will print 2.5 mil trace/space!
Zero annular ring seems to be OK on inners. That reduces capacitance.
5 or even 4 mil traces are usually standard price. I don\'t know why my
guy used 6 on the board that I posted.
We do email our board houses and often they answer!
You aren\'t paying attention.
That\'s because you\'re obnoxious.
Wow! Talk about sensitive. What is going on with you???
Just trying to help. My mistake.
On Sunday, January 15, 2023 at 2:37:04 PM UTC-4, John Larkin wrote:
On Sat, 14 Jan 2023 21:04:55 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Sunday, January 15, 2023 at 12:10:54 AM UTC-4, John Larkin wrote:
On Sat, 14 Jan 2023 17:52:45 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Saturday, January 14, 2023 at 9:34:09 PM UTC-4, John Larkin wrote:
On Sat, 14 Jan 2023 16:20:53 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Saturday, January 14, 2023 at 3:17:24 PM UTC-4, John Larkin wrote:
On Sat, 14 Jan 2023 10:05:33 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Saturday, January 14, 2023 at 12:08:03 PM UTC-4, John Larkin wrote:
On Fri, 13 Jan 2023 21:20:50 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Saturday, January 14, 2023 at 12:39:49 AM UTC-4, John Larkin wrote:
On Sat, 7 Jan 2023 09:49:24 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
A small board with a 100QFP is being redesigned for a new FPGA due to obsolescence. Gowin makes a 100QFP device that would be a good fit, but my customer has said \"no\" to the 100% Chinese brand... US government customers, ya know!
So now I\'m looking at a BGA. I don\'t want to get into fine PCB design rules, so 1.0 mm ball pitch is my preference. The only devices I can find that fit on the board have 196 or 256 pins. But the real problem is availability.
Digikey has a few of the XC7S15-1FTGB196I and more a scheduled for delivery in April. Add in the various speed and temperature flavors trickling in (mostly in April) and I should be ok for the initial delivery in August... if I can get my hands on those. I don\'t know if Digikey factors in the backlog orders in these counts.
Mouser shows great inventory of Efinix parts, particularly the T13 and T20 in a 0.8 mm 256 pin BGA, 10s of thousands in stock. But I\'d rather work with a 1.0 mm BGA. Oddly enough, LCSC shows part numbers, but zero inventory.
Anyone work with 0.8 mm BGAs? What PWB feature dimensions did you use? Did this impact the PWB cost?
The 0.8 mm 256-ball T20 isn\'t bad...
https://www.dropbox.com/s/xjqgj2pz9mdhtma/P941_FPGA.jpg?raw=1
I can\'t really see much detail. It looks like there are virtually no pads on the vias under the BGA. What size are they?
The BGAVIAs are 12.5 mil OD with 8 mil drills. The other vias on the
board STANDARDVIA and POWERVIA are bigger.
2.25 mil (0.057 mm) is a pretty narrow via ring. Why not have a larger via pad?
I don\'t know. My PCB guy decides stuff like that. I\'d guess that he
wanted it to pass some design rule check, or maybe he started metric.
The board houses haven\'t complained as far as I know.
You should do your own thing and check with whoever will make your
boards.
Sounds good, but I\'ve never been able to get a board house to even discuss these issues. They always take the approach that they will work with what I give them, which means, if it gives poor results, it\'s my problem.
We always specify bare-board testing and warpage and tolerances, so we
don\'t get bad boards. What we can get is expensive boards.
There are a number of board companies with published capabilities, but they all vary, enough that there seems to be no consensus. Just like your via pad size. I\'ve never seen a board house that says that would be a standard board. I was just looking at one company who wants 10 mil annular ring on inner layers and 7 mil annular ring on surface layers. That\'s a huge difference from 2.25 mil. On the other hand, they will print 2.5 mil trace/space!
Zero annular ring seems to be OK on inners. That reduces capacitance.
5 or even 4 mil traces are usually standard price. I don\'t know why my
guy used 6 on the board that I posted.
We do email our board houses and often they answer!
You aren\'t paying attention.
That\'s because you\'re obnoxious.
Wow! Talk about sensitive. What is going on with you???
Just trying to help. My mistake.
Dude, you are way too sensitive. Chillax! You\'ll live longer.
On Sun, 15 Jan 2023 20:11:34 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Sunday, January 15, 2023 at 2:37:04 PM UTC-4, John Larkin wrote:
On Sat, 14 Jan 2023 21:04:55 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Sunday, January 15, 2023 at 12:10:54 AM UTC-4, John Larkin wrote:
On Sat, 14 Jan 2023 17:52:45 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Saturday, January 14, 2023 at 9:34:09 PM UTC-4, John Larkin wrote:
On Sat, 14 Jan 2023 16:20:53 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Saturday, January 14, 2023 at 3:17:24 PM UTC-4, John Larkin wrote:
On Sat, 14 Jan 2023 10:05:33 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Saturday, January 14, 2023 at 12:08:03 PM UTC-4, John Larkin wrote:
On Fri, 13 Jan 2023 21:20:50 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Saturday, January 14, 2023 at 12:39:49 AM UTC-4, John Larkin wrote:
On Sat, 7 Jan 2023 09:49:24 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
A small board with a 100QFP is being redesigned for a new FPGA due to obsolescence. Gowin makes a 100QFP device that would be a good fit, but my customer has said \"no\" to the 100% Chinese brand... US government customers, ya know!
So now I\'m looking at a BGA. I don\'t want to get into fine PCB design rules, so 1.0 mm ball pitch is my preference. The only devices I can find that fit on the board have 196 or 256 pins. But the real problem is availability.
Digikey has a few of the XC7S15-1FTGB196I and more a scheduled for delivery in April. Add in the various speed and temperature flavors trickling in (mostly in April) and I should be ok for the initial delivery in August... if I can get my hands on those. I don\'t know if Digikey factors in the backlog orders in these counts.
Mouser shows great inventory of Efinix parts, particularly the T13 and T20 in a 0.8 mm 256 pin BGA, 10s of thousands in stock. But I\'d rather work with a 1.0 mm BGA. Oddly enough, LCSC shows part numbers, but zero inventory.
Anyone work with 0.8 mm BGAs? What PWB feature dimensions did you use? Did this impact the PWB cost?
The 0.8 mm 256-ball T20 isn\'t bad...
https://www.dropbox.com/s/xjqgj2pz9mdhtma/P941_FPGA.jpg?raw=1
I can\'t really see much detail. It looks like there are virtually no pads on the vias under the BGA. What size are they?
The BGAVIAs are 12.5 mil OD with 8 mil drills. The other vias on the
board STANDARDVIA and POWERVIA are bigger.
2.25 mil (0.057 mm) is a pretty narrow via ring. Why not have a larger via pad?
I don\'t know. My PCB guy decides stuff like that. I\'d guess that he
wanted it to pass some design rule check, or maybe he started metric.
The board houses haven\'t complained as far as I know.
You should do your own thing and check with whoever will make your
boards.
Sounds good, but I\'ve never been able to get a board house to even discuss these issues. They always take the approach that they will work with what I give them, which means, if it gives poor results, it\'s my problem.
We always specify bare-board testing and warpage and tolerances, so we
don\'t get bad boards. What we can get is expensive boards.
There are a number of board companies with published capabilities, but they all vary, enough that there seems to be no consensus. Just like your via pad size. I\'ve never seen a board house that says that would be a standard board. I was just looking at one company who wants 10 mil annular ring on inner layers and 7 mil annular ring on surface layers. That\'s a huge difference from 2.25 mil. On the other hand, they will print 2.5 mil trace/space!
Zero annular ring seems to be OK on inners. That reduces capacitance.
5 or even 4 mil traces are usually standard price. I don\'t know why my
guy used 6 on the board that I posted.
We do email our board houses and often they answer!
You aren\'t paying attention.
That\'s because you\'re obnoxious.
Wow! Talk about sensitive. What is going on with you???
Just trying to help. My mistake.
Dude, you are way too sensitive. Chillax! You\'ll live longer.
Stop being obnoxious and you\'ll get more help.
But not fom me.
On Monday, January 16, 2023 at 11:04:28 AM UTC-4, John Larkin wrote:
On Sun, 15 Jan 2023 20:11:34 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Sunday, January 15, 2023 at 2:37:04 PM UTC-4, John Larkin wrote:
On Sat, 14 Jan 2023 21:04:55 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Sunday, January 15, 2023 at 12:10:54 AM UTC-4, John Larkin wrote:
On Sat, 14 Jan 2023 17:52:45 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Saturday, January 14, 2023 at 9:34:09 PM UTC-4, John Larkin wrote:
On Sat, 14 Jan 2023 16:20:53 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Saturday, January 14, 2023 at 3:17:24 PM UTC-4, John Larkin wrote:
On Sat, 14 Jan 2023 10:05:33 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Saturday, January 14, 2023 at 12:08:03 PM UTC-4, John Larkin wrote:
On Fri, 13 Jan 2023 21:20:50 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
On Saturday, January 14, 2023 at 12:39:49 AM UTC-4, John Larkin wrote:
On Sat, 7 Jan 2023 09:49:24 -0800 (PST), \"gnuarm.del...@gmail.com\"
gnuarm.del...@gmail.com> wrote:
A small board with a 100QFP is being redesigned for a new FPGA due to obsolescence. Gowin makes a 100QFP device that would be a good fit, but my customer has said \"no\" to the 100% Chinese brand... US government customers, ya know!
So now I\'m looking at a BGA. I don\'t want to get into fine PCB design rules, so 1.0 mm ball pitch is my preference. The only devices I can find that fit on the board have 196 or 256 pins. But the real problem is availability.
Digikey has a few of the XC7S15-1FTGB196I and more a scheduled for delivery in April. Add in the various speed and temperature flavors trickling in (mostly in April) and I should be ok for the initial delivery in August... if I can get my hands on those. I don\'t know if Digikey factors in the backlog orders in these counts.
Mouser shows great inventory of Efinix parts, particularly the T13 and T20 in a 0.8 mm 256 pin BGA, 10s of thousands in stock. But I\'d rather work with a 1.0 mm BGA. Oddly enough, LCSC shows part numbers, but zero inventory.
Anyone work with 0.8 mm BGAs? What PWB feature dimensions did you use? Did this impact the PWB cost?
The 0.8 mm 256-ball T20 isn\'t bad...
https://www.dropbox.com/s/xjqgj2pz9mdhtma/P941_FPGA.jpg?raw=1
I can\'t really see much detail. It looks like there are virtually no pads on the vias under the BGA. What size are they?
The BGAVIAs are 12.5 mil OD with 8 mil drills. The other vias on the
board STANDARDVIA and POWERVIA are bigger.
2.25 mil (0.057 mm) is a pretty narrow via ring. Why not have a larger via pad?
I don\'t know. My PCB guy decides stuff like that. I\'d guess that he
wanted it to pass some design rule check, or maybe he started metric.
The board houses haven\'t complained as far as I know.
You should do your own thing and check with whoever will make your
boards.
Sounds good, but I\'ve never been able to get a board house to even discuss these issues. They always take the approach that they will work with what I give them, which means, if it gives poor results, it\'s my problem.
We always specify bare-board testing and warpage and tolerances, so we
don\'t get bad boards. What we can get is expensive boards.
There are a number of board companies with published capabilities, but they all vary, enough that there seems to be no consensus. Just like your via pad size. I\'ve never seen a board house that says that would be a standard board. I was just looking at one company who wants 10 mil annular ring on inner layers and 7 mil annular ring on surface layers. That\'s a huge difference from 2.25 mil. On the other hand, they will print 2.5 mil trace/space!
Zero annular ring seems to be OK on inners. That reduces capacitance.
5 or even 4 mil traces are usually standard price. I don\'t know why my
guy used 6 on the board that I posted.
We do email our board houses and often they answer!
You aren\'t paying attention.
That\'s because you\'re obnoxious.
Wow! Talk about sensitive. What is going on with you???
Just trying to help. My mistake.
Dude, you are way too sensitive. Chillax! You\'ll live longer.
Stop being obnoxious and you\'ll get more help.
But not fom me.
I\'m not going to continue to argue. Thank you for your opinions on using BGAs. But the price of your comments is too high. People have to walk on tiptoes around you to avoid insulting you. Sorry, but I left my ballet shoes in the car.
I would hope that someday, you might get some help with this issue. In the meantime, you are not the only electronic designer in the world. Other people design \"things that work\", every day.
Bye,
A small board with a 100QFP is being redesigned for a new FPGA due to obsolescence. Gowin makes a 100QFP device that would be a good fit, but my customer has said \"no\" to the 100% Chinese brand... US government customers, ya know!
So now I\'m looking at a BGA. I don\'t want to get into fine PCB design rules, so 1.0 mm ball pitch is my preference. The only devices I can find that fit on the board have 196 or 256 pins. But the real problem is availability.
Digikey has a few of the XC7S15-1FTGB196I and more a scheduled for delivery in April. Add in the various speed and temperature flavors trickling in (mostly in April) and I should be ok for the initial delivery in August... if I can get my hands on those. I don\'t know if Digikey factors in the backlog orders in these counts.
Mouser shows great inventory of Efinix parts, particularly the T13 and T20 in a 0.8 mm 256 pin BGA, 10s of thousands in stock. But I\'d rather work with a 1.0 mm BGA. Oddly enough, LCSC shows part numbers, but zero inventory.
Anyone work with 0.8 mm BGAs? What PWB feature dimensions did you use? Did this impact the PWB cost?
Am 07.01.2023 um 18:49 schrieb gnuarm.del...@gmail.com:
A small board with a 100QFP is being redesigned for a new FPGA due to obsolescence. Gowin makes a 100QFP device that would be a good fit, but my customer has said \"no\" to the 100% Chinese brand... US government customers, ya know!
So now I\'m looking at a BGA. I don\'t want to get into fine PCB design rules, so 1.0 mm ball pitch is my preference. The only devices I can find that fit on the board have 196 or 256 pins. But the real problem is availability.
Digikey has a few of the XC7S15-1FTGB196I and more a scheduled for delivery in April. Add in the various speed and temperature flavors trickling in (mostly in April) and I should be ok for the initial delivery in August.... if I can get my hands on those. I don\'t know if Digikey factors in the backlog orders in these counts.
Mouser shows great inventory of Efinix parts, particularly the T13 and T20 in a 0.8 mm 256 pin BGA, 10s of thousands in stock. But I\'d rather work with a 1.0 mm BGA. Oddly enough, LCSC shows part numbers, but zero inventory.
Anyone work with 0.8 mm BGAs? What PWB feature dimensions did you use? Did this impact the PWB cost?
I\'ve done a 324pin 0.8mm BGA recently.
My PCB fab is:
https://www.multi-circuit-boards.eu/en/index.html,
they also have a german office near my house.
I used all standard parameters like 0.2mm holes, 0.4mm via diameters and
0.1mm trace width and spaces on a 6-layer board, GND at layers 2 and 5.
Power planes are used on layer 3, as well as additional power and signal
routing.
All was manufactured perfectly fine and the board works as expected.
I was the schematics developer as well as the layouter.
There are some optimazations you can do if you do both.
You can try to join several pwr pins to one via and then get the space
for placing 0402 capacitors under the BGA.
(Recommended is max. 2 BGA-pads to one via)
Using 0201 caps saves you from doing tricky via omitting.
Using 0204 caps did\'t help in my case.
You can also ignore some I/Os for routing critical high speed nets.
There is lots of room for playing around optimizing and finally you can
use all BGA-pads.
I used Altium and partly it was a fun job as well as a mess with length
matching.
Doing 0.8mm is an easy job IMHO, also have done some 1mm BGAs, then used
0.5mm via diameter.
The advantage of using 2 tracks between 2 balls is not too big.
A 1mm 196ball FPGA has the same size as a 324pin 0.8mm chip, 15x15mm.
And now how to assemble a BGA pcb ?
Look here:
https://www.youtube.com/watch?v=EMCz0VsEbqc
Mike
PS:
Xilinx recommends lots of caps in power distribution network however on
the eval boards like SP701, AC701 and others these caps are placed
centimeters away from the chip...
--
Mike Randelzhofer, OHO-Elektronik
PS:
Xilinx recommends lots of caps in power distribution network however on
the eval boards like SP701, AC701 and others these caps are placed
centimeters away from the chip...