Quality Testing

Environmental Stress Screening (ESS)   |     Mean Time Between Failure (MTBF)    |    Environmental Quality

 

Environmental Stress Screening (ESS)

Every H & M-Grade Maxi, Mini, and Micro as well as MI Family modules undergoes extensive post-production environmental stress screening (ESS) before shipment to verify compliance with Vicor's high quality and performance standards and to eliminate early life failures. To ensure the most effective routine for precipitating module failures, we continually evaluate our ESS program and make appropriate changes as new data become available or as product improvements occur. After burn-in and temperature cycling, each module undergoes final electrical testing over the specified temperature range. The program is outlined below.

 

   
MI Family Module Screening
 
Maxi, Mini and Micro Module Screening
                 
   
I-Grade
 
M-Grade
 
H-Grade
 
M-Grade
 
 
Operating Temperature
 
MI-200
-55 to +85°C
MI-J00
-40 to +100°C
 
MI-200
-55 to +85°C
MI-J00
-40 to +100°C
 
-40 to +100°C
 
-55 to +100°C
 
 
Storage Temperature
 
MI-200
-55 to +100°C
MI-J00
-55 to +125°C
 
MI-200
-65 to +100°C
MI-J00
-65 to +125°C
 
-55 to +125°C
 
-65 to +125°C
 
 
Temperature Cycling
17°C per minute nominal rate of change, dwell time until product stabilization.
 
12 cycles
-65 to +100°C
 
12 cycles
-65 to +100°C
 
12 cycles
-65 to +100°C
 
12 cycles
-65 to +100°C
 
 
Ambient Test @ 25°C
 
Yes
 
Yes
 
Yes
 
Yes
 
 
Power Cycling Burn-In
 
12 hours,
29 cycles
 
96 hours,
213 cycles
 
12 hours,
29 cycles
 
24 hours,
58 cycles
•
Power on 10 minutes,
off 15 minutes
•
Module temperature
cycling 35°C to 80°C
•
Load up to 100 W
•
Module output continuously monitored while enabled
 
 
Functional &
Parametric ATE Tests
Low & high temp.
 
-40 to +85°C
 
-55 to +85°C
 
-40 to +100°C
 
-55 to +100°C
 
 
AC Hi-Pot Test
 
Yes
 
Yes
 
Yes
 
Yes
 
 
Visual Inspection
Before packing
into ESD containers.
 
Yes
 
Yes
 
Yes
 
Yes
 

 

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Mean Time Between Failure (MTBF)

Because operating temperature is one of the most important factors in determining overall module reliability, it is imperative that the user's system design allow for efficient heat transfer from the baseplate to system ambient. Since temperature and failure rate are exponentially related, just a 10°C decrease in baseplate temperature can have a dramatic increase in MTBF. Due to patented zero-voltage/zero-current switching topology, Vicor converters are highly efficient compared to those with more traditional topologies. High efficiency translates into both smaller size and lower temperature rises. To minimize thermal impedance, all major power dissipating components are mounted directly to the baseplate.
Below are representative calculated MTBF values based on MIL-HDBK-217F. If you require information about a specific model, contact Vicor with the model number, expected baseplate temperature, and operating environment to obtain an individually prepared report.

 

Model Number
 
Baseplate Temperature
 
MTBF in 1000 Hours
     
   
G.B.
 
G.F.
 
A.I.C.
 
N.S.
 
 
MI-J71-MY
 
25°C
 
3,782
 
1,891
 
1,135
 
1,116
 
50°C
 
2,307
 
1,154
 
692
 
681
 
65°C
 
1,778
 
889
 
533
 
524
 
 
MI-274-MW
 
25°C
 
3,830
 
1,878
 
1,149
 
1,130
 
50°C
 
2,336
 
1,915
 
701
 
689
 
65°C
 
1,800
 
900
 
540
 
531
 
 
   
V24C3V3M75BL
(Micro)
 
25°C
 
6,235
 
3,117
 
1,870
 
1,839
 
50°C
 
3,803
 
1,902
 
1,141
 
1,122
 
65°C
 
2,930
 
1,465
 
879
 
864
 
 
V24B5M200BL
(Mini)
 
25°C
 
4,205
 
2,102
 
1,201
 
1,240
 
50°C
 
2,565
 
1,282
 
769
 
757
 
65°C
 
1,976
 
988
 
593
 
583
 
 
V24A12M400BL
(Maxi)
 
25°C
 
3,428
 
1,714
 
1,028
 
845
 
50°C
 
2,091
 
1,282
 
627
 
617
 
65°C
 
1,611
 
806
 
483
 
475
 

 

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Environmental Qualification

Fully encapsulated, Vicor Maxi, Mini, Micro, and MI family modules utilize a proprietary spin fill process that assures complete, void free encapsulation making them suitable for the harshest environments. In addition to providing mechanical rigidity, the encapsulant is thermally conductive to eliminate hot spots and aid in heat transfer to the baseplate. Modules are available with temperatures down to -55°C operating and -65°C storage.
To verify the suitability of Vicor's H & M-Grade Maxi, Mini, and Micro as well as MI Family modules for harsh environments, these products have been subjected to the environmental testing requirements of MIL-STD-810, MIL-S-901 and MIL-STD-202. These tests, listed below, are performed at an independent laboratory. Additional environmental tests can be done upon individual customer request.

 

Environment
 
Maxi, Mini and Micro Modules
 
MI Family Modules
 
 
Altitude   • MIL-STD-810F,
Method 500.4, Procedure I & II,
40,000 ft.and 70,000 ft. Operational		   • MIL-STD-810D,
Method 500.2, Procedure III,
explosive decompression (40 K ft.)
    • MIL-STD-810D,
Method 500.2, Procedure II,
40,000 ft., 1000 – 1500 ft./min.
to 70,000 ft., unit functioning
 
 
Explosive Atmosphere   • MIL-STD-810F,
Method 511.4, Procedure I, Operational		   • MIL-STD-810C,
Method 511.1, Procedure I
 
 
Vibration  

•

MIL-STD-810F,
Method 514.5, Procedure I,
category 14, sine and random
vibration per Table 514.5C
for helicopter AH-6J main rotor
with overall level of 5.6 g rms
for 4 hours per axis

  

•

 MIL-STD-810D,
Method 514.3, Procedure I,
category 6, helicopter, 20 g
• MIL-STD-810F,
Method 514.5C, general
minimum integrity curve
per Figure 514.5C-17
with overall level of 7.7 g rms
for 1 hr per axis		 • MIL-STD-810D,
Method 514.3 random:
10 – 300 Hz @ 0.02 g2/Hz,
2000 Hz @ 0.002 g2/Hz,
3.9 total g rms 3 hrs/axis
Sine: 30 Hz @ 20 g, 60 Hz @ 10 g,
90 Hz @ 6.6 g, 120 Hz @ 5.0 g,
16.0 total g rms, 3 axes
    • MIL-STD-810E, Method 514.4,
Table 514.4-VII, ±6 db/octave,
7.7 g rms, 1hr/axis
 
 
Shock   • MIL-STD-810F,
Method 516.5, Procedure I,
functional shock, 40 g		   • MIL-STD-810D,
Method 516.3, Procedure I,
functional shock, 40 g
• MIL-S-901D,
lightweight hammer shock,
3 impacts/axis,1, 3, 5 ft.		 • MIL-STD-202F,
Method 213B, 18 pulses, 60 g, 9 msec
• MIL-STD-202F,
Method 213B, 60 g,
9 ms half sine		 • MIL-STD-202F,
Method 213B, 75 g,
11 ms saw tooth shock
• MIL-STD-202F,
Method 213B, 75 g,
11 ms saw tooth shock		 • MIL-STD-202F,
Method 207A,
3 impacts / axis, 1, 3, 5 feet
 
 
Acceleration   • MIL-STD-810F,
Method 513.5, Procedure II,
Table 513.5-II, Operational,
2 – 7 g, 6 directions		   • MIL-STD-810D,
Method 513.3, Procedure II
Operational test, 9 g for 1 minute
along 3 mutually perpendicular axes
 
 
Humidity   • MIL-STD-810F,
Method 507.4,
95% Relative Humidity
 
 
Solder Test   • MIL-STD-202G,
Method 208H, 8 hr aging
 
 
Fungus   • MIL-STD-810F,
Method 508.5		   • MIL-STD-810C,
Method 508.1
 
 
Salt Fog   • MIL-STD-810F,
Method 509.4		   • MIL-STD-810C,
Method 509.1
 

 

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