IQD Frequency Products is a recognised market leader in Quartz Crystals, Clock Oscillators, Fast Make Oscillators, TCXOs, VCTCXOs, VCXOs, OCXOs, Rubidium Oscillators

1. Rugged Quartz Crystals &
Oscillators For High Shock
Applications
100,000G and more

2. History
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 Pre 1970 – High shock was a few 100g
 1970s – resonators could survive shock
levels of a few 1,000g
 1980s – 10,000g (HG products)
 2000s – 100,000g CX4HG and HGXO

3. Two basic failure mechanisms
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 Dismount
 Is the epoxy mount strong enough to hold
the resonator in place?
 Breakage
 Is the resonator design robust enough to
survive the stresses induced by high shock
events?

4. Keys to ruggedness
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 Small size
 Smaller devices typically experience lower
stresses under acceleration
 Stress  length2/thickness
 Maintain scale, then stress  size
 Fixed frequency, stress  (length)2
 Smaller size
 Lower stress
 Can withstand higher accelerations (shocks)
 Mechanical support
 Single end mount is good
 Dual end mount is better
 Lower stress
thickness
length
stress
2

Stress dual–end mounting = stress single–end mounting
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1

5. Avoiding dismount
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 Shorten resonator
 Shear dismount: Fixed frequency and
bonding area, 𝐴, (mass)∝(length),
so 𝐹 /𝐴∝ (length), so shorter resonator
is less likely to dismount
 Peel dismount: Torque τ ∝ (length) x
(mass) ∝ ( length)2, so shorter resonator
is less likely to dismount
 The right adhesive
 Strong
 Low outgassing
 Doesn’t de-Q the resonator
 Plenty of it
 Dual-end mount, for AT (introduces
other issues)
 Force distributed

6. Avoiding breakage
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 Simple geometry (avoiding weak structures)
 Fairly easy for ATs
 More challenging for tuning-forks
 Small resonator (Stress  length2/
thickness)
 Dual-end mount (reduces stress)

7. Where we are today
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 AT crystals
 Most products offer 10,000g or more
 Some offer up to 100,000g
 Could achieve 200,000g or more
 Would pursue if there were a market
demand for this
 Tuning-fork crystals
 Many offer up to 5,000g
 Up to 30,000g in preferred directions in some
cases
 More information can be found on our
website www.iqdfrequencyproducts.com

8. Standing out from the crowd
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