barry
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This comment summed it up best (paraphrased): 'he's creating a solution in search of a problem'. QEDI see that this is not the only place Treez is going on about this.
A 1 man mission to get dumbed down instructions, even dumber than actually do exist.
T5400...now that is interesting QFN vs TQFP.
I had to squeeze some fets onto a part of a small board once, so I had to use these little QFN type fets....the clearance between the pads and the inner, large thermal pad is incredibly small.
-As much as I trust modern technology of component placement machines, I can only think that some of the QFN's will slide about on the solder and short out.
It seems now that most of the fets and led driver ic's have the QFN style now.......sometimes you can get them in like TQFP, but they don't tend to have the inner heat-removal pad.
Making the footprint for the QFNs is very critical, and i'd say for that kind of package, the PCB Layout guy needs a second pair of eyes to check out the footprints just to make sure they are optimal.
I reckon even the engineering manager him/herself should occasionally open up the component library now and then and check out the QFN pad sizing and spacing...its that critical.
Now, who doesn't think that the engineering manager doesn't need a dummy's guide to allow him/herself to learn how to inspect the component libraries of a complex pcb layout software package?......................in my H.O., the engineering manager should do this literally "behind the pcb layout guy's back", so that he can really check that things like footprints are being done right.
Thanks T5400, when you say stencil you mean the solder paste stencil?
Also, since you are in China, can you tell us which PCB Layout Software package that you use.
As far as I can see, the most successful Electronics design company in the world today is China, so youmust have some good ideas about PCB Layout too.
I hear that in China all the Electronics Companies are Government owned, which has definite advantages, because the government can get the various companies to pool their knowledge and skills and work toward the success of the Chinese Electronics industry altogether.
Since all the Chinese Electronics companys are closely Government controlled, is it true that the Government has instilled that only two different PCB Layout packages will be used?.......a simple one for simple pcbs, and amore complex one for the more complex stuff?
Can you say what are the pcb layout packages used in China? Can a Chinese company freely decide which pcb layout package to use, or must it seek Government advice?
I understand that you don't want dummy's guides produced for all the major PCB layout pakcages?
Supposing that they were payed for by a rich sponsor.
Do you still then object?
Supposing you want a junior apprentice to make a simple Test PCB (eg a load bank) etc.
Don't you think it would be helpful for him to have a dummy's guide?
Supposing he did it in a free one, say Eagle.....then suppose another technician uses diptrace, another KiCAD, another vutrax,etc etc
...none of them can modify each others schematic /pcb....do you think that's a problem?
Suppose someone can take a schematic to pcb in a major pcb package without problem because they have excellent IT skills, but supposing that they don't lay it out well , electrically, eg they make high power pulse current loops wide in area......do you think that's a problem?
Also, what percentage of people who use major cad packages do you think could identify say, the 'rectifier loop' and the 'power switch loop' in a switch mode power supply?
Also, do you believe that in some companies, the mechanical engineer uses the company's major pcb layout package, and doesn't even understand ohm's law?
Regarding TQFP's one of the biggest sources of solder bridging during assembly often due to the lack of solder dams between pads due to the pad sizes and pitch
..this sounds interesting, are you implying that solder bridging is more likely with TQFP than QFN?
Hi
it imply that anything fine pitch 0.5mm and down that have wrong pad design
may got to thin solder mask bethen pad , in that case pcb shop may remove it
or let it but so think that it broke ,then it will do solder bridge
that wly PCB designer need to work closely whit it PCB fab and assembly shop
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