Pressure sensor, MP3H6115A at high altitudes

[stevetomporowsk]

We are using the MP3H6115A in a system that we have just tested to 40,000 feet.  We have had a failure (with no evidence of corona or arcing) which is traced to the same board as the pressure sensor.  The question is, how low in pressure can we do before the sensor self-destructs?    At 40,000 feet we are at 18.6 kPa, which is just barely in the range, but in testing, we might have dipped lower.

Thanks...Steve

[Joshevelle]

Hello Steve,

The absolute maximum temperature range for the MP3H6115A before is permanently damaged is -40°C and +125°C. The U.S. Standard Atmosphere Air Properties shows that the temperature at 40,000 ft is -69.7°F (~ -56.5°C).

So I won’t be concerned about the pressure, is the temperature that might damage the device.

As per suggestions, please provide detailed information regarding the application, perhaps you could mount the sensor in the warmer area in the system?

Hope it helps!

Josh

[stevetomporowsk]

Josh,

Thanks for the info. The actual application is a bomb fuze and the temperature requirements are down to -40°C for operation and -46°C for storage. Do we run the same risk of damage to the device if we store it at -46°C? We hadn't addressed the temperature spec yet, except to note that the altitude requirement (40,000 ft) did not match the max temp spec.

Thanks...Steve

Stephen Tomporowski

Kaman Precision Products

217 Smith St.

Middletown, CT 06457

steve.tomporowski@kaman.com<mailto:steve.tomporowski@kaman.com>

Phone: 860-632-4534

Fax: 860-632-4422

"We rely not upon management and trickery, but upon our own hearts and hands." --Pericles

"Never tell anyone HOW to do something. Tell them WHAT to do and they will surprise you with their ingenuity." --Gen. George S. Patton

"Never try to teach a pig to sing. It wastes your time and annoys the pig." --Samuel Clemens

[Joshevelle]

We usually perform the High and Low Temperature Storage Life test to simulate the potential shipping and storage conditions that the pressure sensor might encounter in actual usage. The test also evaluates the devices thermal integrity at worst case temperatures.

These tests are in accordance to MIL STD 750, Method 2056 Reference and following procedures.

• Pulsed Pressure Temperature Cycling with Bias (PPTCB)
• High Humidity, High Temperature with Bias (H3TB)
• High Temperature with Bias (HTB)
• High and Low Temperature Storage Life (HTSL, LTSL)
• Temperature Cycling (TC)
• Mechanical Shock - Variable Frequency Vibration
• Solderability
• Over Pressure

For detailed information about these topics (incl. Potential failure modes and mechanism) in our Sensor Data Book, page 1-5, "RELIABILITY ISSUES FOR SILICON PRESSURE SENSORS":

http://www.freescale.com/files/sensors/doc/data_lib/DL200.pdf

The MP3H6115A passed those tests; however its absolute minimum temperature is -40°C, below this temperature the inter molecular union between the silicon dice and the bonding wires will fail due to the different thermal dilation coefficients, making the unions break apart.

Unfortunately all our pressure sensors follow the same manufacturing process; therefore the absolute minimum temperature for all of them would be -40°C. We’re sorry for the inconveniences.

I hope you will find this information useful, please let me know if I can help any further.

-Josh

[stevetomporowsk]

Josh,

I guess another question. I went to look at Mil-Std 750 (Rev E) and method 2056 indicates vibration. Which method was used for high humidity? Or am I reading this wrong....;-)

Thanks...Steve

Stephen Tomporowski

Kaman Precision Products

217 Smith St.

Middletown, CT 06457

steve.tomporowski@kaman.com<mailto:steve.tomporowski@kaman.com>

Phone: 860-632-4534

Fax: 860-632-4422

"We rely not upon management and trickery, but upon our own hearts and hands." --Pericles

"Never tell anyone HOW to do something. Tell them WHAT to do and they will surprise you with their ingenuity." --Gen. George S. Patton

"Never try to teach a pig to sing. It wastes your time and annoys the pig." --Samuel Clemens

[Joshevelle]

Hello Steve,

Freescale has established semiconductor sensor reliability testing based on exercising to detect failures by the presence of the environmental stress. The method used for "High Humidity, High Temperature with Bias" is very similar to the JESD22-A101C:

http://www.jedec.org/sites/default/files/docs/22a101c.pdf

Test Conditions:

• Temperature between 60 and 85°C
• Relative humidity between 85 and 90%
• Rated voltage.
• test time = up to 1000 hours.

Please let me know if I can help any further.

-Josh

[stevetomporowsk]

Josh,

Thanks for the info. Although it wasn't what I wanted to hear, it's better to hear it now than in DVT or Qual.

Thanks again.....Steve

Stephen Tomporowski

Kaman Precision Products

217 Smith St.

Middletown, CT 06457

steve.tomporowski@kaman.com<mailto:steve.tomporowski@kaman.com>

Phone: 860-632-4534

Fax: 860-632-4422

"We rely not upon management and trickery, but upon our own hearts and hands." --Pericles

"Never tell anyone HOW to do something. Tell them WHAT to do and they will surprise you with their ingenuity." --Gen. George S. Patton

"Never try to teach a pig to sing. It wastes your time and annoys the pig." --Samuel Clemens