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4000g assembly

4000g assembly

4000g assembly

(OP)
I'm working to design a small (~8mm cube, <12grams) electronics package and assembly that can live in an environment with vibration producing accelerations up to 4000g.

Does anyone know if anything like this have ever been done before? The most robust assembly I've found is munitions guidance systems package, but they're not built for fatigue, and helpful details have been hard to find.

I would appreciate any other tips (ranging from preferred IC connection, to robust solder compounds, potting, PWB materials, and anything else) on how to keep this from falling apart.

MB

RE: 4000g assembly

Do you know the Shock Response Spectrum, or RMS or even how much time your design will see 4000g?

Here is some reference material:

www.stiweb.com
www.skfcm.com
www.bently.com
www.compsys.com
www.entek.com

Other references include app. notes and vibration analysis books on www.reliabilitydirect.com, ; and http://home.earthlink.net/~eaconcha/Main_page_frame.htm.


If you have specific questions then maybe we can give you specific answers.wink

Best Regards,

Heckler
Sr. Mechanical Engineer
SW2005 SP 5.0 & Pro/E 2001
Dell Precision 370
P4 3.6 GHz, 1GB RAM
XP Pro SP2.0
NVIDIA Quadro FX 1400
      o
  _`\(,_
(_)/ (_)

Never argue with an idiot. They'll bring you down to their level and beat you with experience every time.

RE: 4000g assembly

(OP)
I don't have an SRS, but I've measured some waveforms. However, I'm not sure if going into those details will be of much help in designing the PCB with appropriately robust connections.

Do you have any advice on bonding components under this loading so that they don't pop off the board?

Do you have any advice on supporting the board so it doesn't flex beyond it's limits?

RE: 4000g assembly

We use snubbers made from this material http://www.earsc.com/ for boards that will be required to operate in a high shock & vib environment.  Also, on custom designed boards we try to use through hole components verses surface mount but commerical boards are another story.  We sometime zip-tie components down or use some 3M goop.  Just be careful if this is a space qaulified component then outgasing will be an issue if you use silicon based products.

Best Regards,

Heckler
Sr. Mechanical Engineer
SW2005 SP 5.0 & Pro/E 2001
Dell Precision 370
P4 3.6 GHz, 1GB RAM
XP Pro SP2.0
NVIDIA Quadro FX 1400
      o
  _`\(,_
(_)/ (_)

Never argue with an idiot. They'll bring you down to their level and beat you with experience every time.

RE: 4000g assembly

You could always etch a piece of metal to be form fitting over the components then apply some thin electrical insulation film between the metal cover-form and the components. Screw the metal form down thru the circuit board to a rigid structure.

Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com

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