Thank you very much for your valuable suggestion! We will solve it as soon as possible!

PCB Design Rules

Group Administrators: 0 | Group Member: 189 | Group Threads: 284

Initially PCBs were designed manually by creating a photomask on a clear mylar sheet, usually at two or four times the true size. Starting from the schematic diagram the component pin pads were laid out on the mylar and then traces were routed to connect the pads. If you have many questions of PCB Design, please come here!

Community > Groups > PCB Design Rules > The reason of PCBs have big interfaces
The reason of PCBs have big interfaces
Alternate Text 305
Alternate Text 2
Alternate Text 12

Jeronimo F Atencio

Although the lines leaving the IC in the middle start fairly close to each other, they are significantly separated through the edge of the PCB. The width of and spacing between the leaving lines are determined according to a standard but I am not sure why they are decided to be this wide. Could you explain the reason behind?
Statement: This post is only the personal view of the author and does not represent the opinions of


0.100 was ubiquitous in through-hole and using a .100 edge connector also meant you could use a socket that connected to the mainboard with pins at a .100 spacing - that's what everyone had experience using, and it probably also was easiest to develop PCBs with .100 parts using the prototyping and design tools available then.


Mostly is because of mechanical tolerances. Fine pitch on edge pins is highly prone to shorting out or even being misaligned by an entire pin space due to tolerances required for insertion, and in some cases even thermal expansion could come into play.

Hot Threads

New Threads