In response to this recent post: 

We have considered implementing a jumper technique which does not 
actually use a jumper, but instead uses two pads, placed very close 
togather. Then solder paste is applied across the two pads, which will 
bridge when the board is reflowed. This could save substantial dollars 
in traditional component costs.

We have seen this technique used by some manufacturers, but there is 
some question as to what the people at IPC think about it.

Is this an acceptable technique? Is there a set of guidelines which we 
could follow in order to make this work properly? We appreciate any 
response.

don




Don,


There have a number of our customers use that technique on their 
assemblies..... from using them to enable and disable oscillators before 
and after ICT, to configuring the circuit on a video graphics board 
depending on the VRAM loaded....... 

Being with a Contract Assembly company, I can't provide any reliabilty info 
or anything of that sort, but it does work great on the assembly part of 
things. The customers that do use this have been doing it for as long as we 
have been building their products, which is over 2 years. I'm sure if there 
was a problem on the functional side of things, they would have changed it. 
 
You are right about saving money! It eliminates headers, shunts, the need 
for humans to stuff the items as well as all the associated defects....

The only thing that I can think of where there's been ANY problem, is if 
you need to have the jumper in place first, and then clear it later, one 
must be very diligent to be absolutely sure that the two pads are indeed 
clear when you perform that step....on the lay-outs that we have, the pads 
are pretty close together (but they have to be so they'll bridge) and it's 
fairly easy to leave a very fine solder bridge that can't be seen.....














































































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