[time-nuts] PCB design questions thread II

[SAIDJACK at aol.com]

Hi David,
 
for guaranteed product quality, including choice of material (FR4 choices,  
Getec, etc), tight impedance control, cleanliness (to reduce loss tangent  
especially for high-frequency performance), and documentation including  
solder-samples and cross-sections etc, try:
 
  _http://www.titanpcb.com/about_us/Titan_West.asp_ 
(http://www.titanpcb.com/about_us/Titan_West.asp) 
 
Not the cheapest, but great for "professional" proto's when quality trumps  
cost (above 1GHz, one source FR4 is totally different from another  sources 
FR4...)
 
expresspcb.com works well for low cost, quick-turn proto's.
 
bye,
Said
 
 
In a message dated 6/2/2008 11:42:01 Pacific Daylight Time,  
mccorkle at ptialaska.net writes:

David  and Patrick,
Check out the following two sites to get an idea of  the
current costs to have a custom made board  produced.

http://www.pcb123.com/
http://www.expresspcb.com/index.htm

Richard

>  Hi David and list
>
> I am quite interested in this post  too.
>
> I have wanted to fabricate my own PCBs for several years  now but I have
> never made an attempt. I am set up here to do silk  screening and I have
> ovens and a hot-air soldering iron. Has anyone  else tried to fabricate
> their own boards or is the price of farming  the work out just so low now?
>
> If anyone has farmed out work,  could you please feedback as to the entry
> level costs and if possible,  some suggested companies?
>
> P.S Many of the boards I want to  fabricate are replacements for obsolete
> ones. Is there a way to split  the layers of an old board apart to study
> them?
>
>  Thanks-Patrick
>
> David C. Partridge wrote:
>> I've been  working on the design for a frequency divider to complement the
>>  Thunderbolt I recently bought from TVB (thank you Tom, it's working  very
>> well as far as I can tell, though of course I've no other  standard to
>> compare against).
>>
>> Thanks to  lots of advice and guidance from Bruce Griffiths (many thanks
>>  again Bruce), I've got the design near completion.
>>
>> I'm  not aiming for NIST or equivalent perfection in terms on  minimising
>> jitter and other noise, but would like to at least make  a at least a
>> half-way decent job of this.
>>
>>  I'm now thinking ahead to the PCB requirements,with the caveat that  I've
>> only ever designed one PCB before and that was a single layer  board done
>> using double sized mylar and sticky black tape (Yes, it  was a good many
>> years ago).
>>
>> Now to  questions:
>>
>> 1. Surface mount or through hole?  I  don't have a re-flow oven (or even a
>> hot air soldering system), so  my inclination is to use through hole CMOS
>> (74HC163s with 74AC  glue logic and flip-flops), with the surface mount
>> restricted to  the clock shaper using a BAV99 and either an ADCMP600 or
>> MAX999  and surrounding components.   Will using through hole cause me  
grief?
>>
>> 2. How many layers?   In an ideal  world with money no object, if I
>> understand the current art  correctly, I think I'd probably aim for a five
>> layer board with  Vcc, Digital Ground and Power Ground being separate
>> internal  planes, and trace routing on the top and bottom of the board with
>>  as few vias between top and bottom as possible.  Does that sound  right?
>>
>> Do you think I can safely restrict myself to  two layers, and if so does it
>> make most sense to make one side of  the board digital ground, and route
>> everything else (Vcc,  Power/Analogue Ground, and signals) on the other 
side.
>> Or is there  a better approach (always assuming that a two layer board is a
>>  viable option).
>>
>> Cheers
>> Dave  Partridge
>>
>>
>>  _______________________________________________
>> time-nuts mailing  list -- time-nuts at febo.com
>> To unsubscribe, go to  
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow  the instructions there.
>>
>>
>
>
>  _______________________________________________
> time-nuts mailing list  -- time-nuts at febo.com
> To unsubscribe, go to  
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the  instructions  there.
>



_______________________________________________
time-nuts  mailing list -- time-nuts at febo.com
To unsubscribe, go to  https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the  instructions there.





**************Get trade secrets for amazing burgers. Watch "Cooking with 
Tyler Florence" on AOL Food.      
(http://food.aol.com/tyler-florence?video=4?&NCID=aolfod00030000000002)