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Maximum Track Width for 0805 components Land

Dreamsniper

#17491

Maximum Track Width for 0805 components Land | 6 September, 2001

Hi,

What's the maximum track width that is allowed to be attached to a 0805 component land pattern. I have a 70 mil x 45 mil Land for my 0805 and is attached to a 50 mil wide track with a length of 300 mil to 1500 mil. Components affected are mostly ceramics capacitors. What will be the possible effect during soldering and on the life of the component ?

warm thanks regards,

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#17496

Maximum Track Width for 0805 components Land | 6 September, 2001

If your words imaged correctly, it seems a bit strange to have a trace that is wider than the pad where it connects, because we�re used to seeing a narrower trace connecting to a wider pad.

It�s tough to determine what the designer was thinking about, but here�s some shots at an answer. 1. The cross-sectional area of a trace determines its current handling capacity. All copper on the board is the same thickness, so the width of the copper trace or pad determines the current capacity. So as the trace necks down at the pad, there is less capacity. This lower capacity section has the potential for more local heating, wider temperature change of the solder connection during off-on cycles, etc. Bottom line: Less reliable connection than the trace in addition to it being inherently less reliable, due to the solder connection. 2. On the other hand, the designer may have designed the circuit so the pad width has ample capacity and the increase in trace width over the pad width is just �design tolerance�.

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