Homebrew PCBs

On Mon, 14 Dec 2009 13:25:21 +0000, you wrote:

>Thanks for the responses. My reasons for asking are a mix really. I am 
>an engineer by trade but also I am just really being curious. I do not 
>have a specific need for a 4 layer board right now. I have laid out 4 
>layer boards in the past though and for some reason always fancied 
>making them myself. I have never tried yet.
>
>I like to make things smaller and smaller so 4 layer boards enable that. 
>For one company I worked at a few years ago I did the cad work for a 
>board that was 12mm x 10mm and needed to be 4 layers because of all the 
>tracks.
>
>Last year I quite fancied making a board based on the AVR32 and this 
>looked like it would have to be 4 layers at least. Getting a couple of 
>prototypes made would cost both time and money and well I did not have a 
>real need for the board. I just wanted to make one. So that project got 
>shelved.

I have a board design with a MEGA2560 and an epson graphics driver
chip, a 512K*8 RAM and assorted other parts.  Does well on a double
sided board.  4 layer would be nicer, but not needed by the design.  A
bit of careful layout has produced only one jumper on the board.

Harvey
>
>So I think I would probably use the skills in my work occassionally but 
>i am not sure if I was truely doing it for professional reasons it would 
>make financial sense. I certainly do not have cash to invest to prove 
>that. I think I just want to make more and more complex, small boards.
>
>Trev
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>
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>Andrew Mathison wrote:
>>
>> Dear Trevor White
>>
>> with regards to your question about 4 layer boards (which are easily 4 
>> times more expensive to have made,in my experience, than double sided 
>> ones....), are you a hobbyist or professional? Because if you are a 
>> professional, the price (almost !) does/should not matter.....
>>
>> If you are Hobbyist, then you should give some thought to redesigning 
>> the board for double layer, even if its a bit bigger because of 
>> that.... Fault finding on 4 layer PCBs is not for the faint hearted 
>> either and repairs can be a nightmare.....
>>
>> If you are developing something privately, for maybe later selling, 
>> may I still suggest that until the design is working perfectly, that 
>> you stay with double layer, get some experience with that and when you 
>> really go for "IT", do the 4 layer design. You may get some new 
>> problems but YOU WILL KNOW EXACTLY WHY!!! Which is like money in the 
>> bank!!!
>>
>> I would be most interested in learning why (if) you feel that a 4 
>> layer is the only way to go in your particular case......
>>
>> (I have to admit that my personal (not business I hasten to add, we 
>> used multilayer pcbs all the time there) PCB level is far less 
>> complicated than yours, I design using my PCB software at first double 
>> sided (my old software makes a mess/gives up when telling it to design 
>> single sided!) and then try and redesign by hand to fit a single sided 
>> PCB - it appears that I like wire links a lot!!! Or better said, they 
>> do not bother me at all......I can usually manage to get probably 90% 
>> of my designs (thats probably between 4 and 8 boards a year!!) onto 
>> single sided - not that I am anticipating you changing a 4 level 
>> design to ever fit single sided PCB, that was NOT my meaning!! Double 
>> at least I would still guess.....)
>>
>> Stay well and regards from
>>
>> Andy
>>
>> [Non-text portions of this message have been removed]
>>
>> 
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