Hi Inge,

They are high performance electromechanical relays soldered to board (both 
sides of the board) that have a large ground pad that is soldered to the 
board with the signal pins sheared off to be coplanar to the bottom of the 
ground pad, and they are in turn soldered to the signal pads (more or less a 
butt joint). After soldering these things for a while, we have our soldering 
process down as far as stencil design and reflow. The solder joints look 
great. The relays are machine placed from a matrix tray.  So during 
cleaning, the board has stand-offs temporarily mounted to it so that it 
keeps it up it off the mesh conveyor while going through the cleaner (don't 
want to damage delicate components on the bottomside). There's a wash 
section, a rinse section, a final pure DI rinse, then a dry section that has 
three pairs of air knives. It's a vintage Stoelting washer (a CBW-318). The 
pumps in the rinse and wash section are 10hp, and I think the blower motor 
is 10-hp too. The spray bar manifold pressure is somewhere around 50-60 psi. 
Water temp is right around 130F. We run boards at 1ft per minute since it is 
such a short inline cleaner. Typical cleaning cycle is around 10-minutes. 
The board stays right where it's put on the conveyor until it's removed at 
the cleaner exit, it's not like it getting blowed and bounced around inside 
the cleaner. Just your typical inline cleaner...

I wouldn't expect something as robust as these relays are supposed to be, 
getting damaged just from getting washed?

Steve

-----Original Message----- h
From: Inge Hernefjord ?
Sent: Monday, March 26, 2012 5:19 PM
To: [log in to unmask]  a
Subject: Re: [TN] Quantify vibration

Says nothing, Guy,

they must specify shock waveform and time, and vibration waveform and
frequency range. There are tiny accelerators that you can put on the relays
and connect to a data recorder that follows the band through the washer.
Must be a hell of machine to create such impacts. PLace one accelerator to
the moving holder, whatever that is. As a reference.

What kind of relays?  And how are they mounted?  Do you clean them as free
individuals or are they soldered to a board?  I have shocked and vibrated
all kind of electronics long time back. Never, never heard of such things
as what you tell us.

/Inge

On 26 March 2012 21:51, Guy Ramsey <[log in to unmask]> wrote:

> We see a relay on many designs that has a vibration and shock
> specification.
>
> 30g shock, 10g vibration.
>
> If one was concerned about vibration or shock in an inline water wash. How
> might on quantify this?
>
> Guy
>
>
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