Surface mount zero ohm jumpers?

[treez]

We wish to use zero ohm jumpers on LED MCPCB boards so we can track them up.
We don’t want to use 2010 resistors because they are thin and delicate and will *****. Do specific surface mount jumper components exist?

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I appreciate there's the harwin SMD jumper wires and the MMB0207 melf types, but these are expensive. You would think there would be a mass produced , cheap range of these things?

 

[barry]

Thin and delicate? What?? Why are you worried about a 2010 component, but not the rest of your components? What are you doing, smashing this board with a mallet?

 

[treez]

Thanks, i would imagine a MCPCB with lots of power leds expands quite a bit, and the 2010 may ***** due to this.?

 

[SLK001]

I've always used an 0805 or a 1206 0Ω resistor for this, depending on the size of trace that has to go under it. As for breakage, you have to try to break these.

Why are you using ***** (or is it the edaboard software being "big brother")?

 

[betwixt]

It's big brother!

The original word is obscured but I suspect Edaboard assumes a fractured zero ohm link is a banned mind-altering chemical.

Brian.

 

[treez]

Thanks, yes the word was c.r.a.c.k

 

[barry]

Thanks, i would imagine a MCPCB with lots of power leds expands quite a bit, and the 2010 may ***** due to this.?

My original comment stands: if you're concerned about the zero-ohm jumper, why aren't you concerned about everything else on that pcb? And instead of "imagining" the pcb is going to expand, why don't you try "analyzing" it?

 

[treez]

Thanks, a thin planar component such as a smd resistor is surely going to suffer shearing forces as the aluminium expands.
We need to lay the board out with the component which is least likely to fail.
I think the failure would come after months of expansion and contraction, so i doubt we could test this in the few days that we have to get into the market.

 

[dick_freebird]

A zero-ohm jumper constructed as a SMD resistor,
will have the same reliability attributes / issues as
any other so-constructed component. It is no worse
risk than the rest.

Smaller components are better since the thickness
is likely similar and "moment arm" is smaller. Since
there is zero resistance there is zero power dissipation
and no reason for a large body other than rated
terminal current (internal or external, land/trace size?).

If you want an early answer then you want accelerated
testing (you do not have to wait months for, say, 1K
temp cycles). But I'm guessing that along with "late
before you start" product development paradigm,
comes "spend no money" (because time is money and
having neither, seems to be a theme here).

Really, dude, you need a better class of customer
/ employer. It's just one thing after another and
none of it good.

 

[ads-ee]

Given the coefficient of thermal expansion between Alumina ~8E-6, aluminum ~23E-6, and FR4 ~14E-6. I'd think there would be more issues with the stress of the FR4 and aluminum as there is a larger discrepancy between FR4 and Al than between FR4 and the Alumina used in typical resistors.

I'm sure there is already stress on the package due to solder reflow and the cool down phase. The stress is likely to reduce as the temperature goes up as the working temp of the device is well below the point where the solder solidifies (freezes ~200C).

I think you are "stressing" about nothing.

 

[senilicus]

My original comment stands: if you're concerned about the zero-ohm jumper, why aren't you concerned about everything else on that pcb? And instead of "imagining" the pcb is going to expand, why don't you try "analyzing" it?

2010 components are "famous" on their risk off cracking during the assembly. I have worked at Lucent Technologies for a long time, and it was strongly discouraged to us 2010 components. We have had several designs were 2010 components were cracked after the soldering process. So still, I would not use them for that reason.

 

[treez]

We have had several designs were 2010 components were cracked after the soldering process. So still, I would not use them for that reason.

Thanks, this sounds like a nightmare. It doesnt surprise me, 2010's have the appearance of delicate little tiles. Im not surprised to hear they break.