Every Maxi, Mini and Micro H & M-Grade module 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.

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

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 No.	Baseplate Temperature	MTBF in 1000 hrs.
		G.B.	G.F.	A.I.C.	N.S.
V300C3V3M75BL	25°C	4,450	2,225	1,335	1,313
	50°C	2,714	1,357	814	801
	65°C	2,091	1,046	627	617
V300B5M200BL	25°C	4,064	2,032	1,219	1,199
	50°C	2,479	1,240	744	731
	65°C	1,910	995	573	564
V300A12M500BL	25°C	3,095	1,548	929	913
	50°C	1,188	944	566	557
	65°C	1,455	727	436	429

Fully encapsulated, Vicor Maxi, Mini and Micro modules utilize a proprietary spin fill process that assures complete, void free encapsulation making them suitable for the most harsh environments. In addition to providing mechanical rigidity, the encapsulant is thermally conductive to eliminate hot spots and aid in heat transfer to the baseplate. Two grades, H & M, are available with temperatures to -55°C operating and -65°C storage.

To verify the suitability of Vicor's Maxi, Mini and Micro H & M-Grade products for harsh environments, the H & M-Grade family of modules 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.

MIL-STD-810F, Method 500.2, Procedure I & II, 40,000 ft. and 70,000 ft. Operational.

MIL-STD-810F, Method 511.4, Procedure I, Operational.

• 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 grms for 4 hours per axis.
• MIL-STD-810F, Method 514.5C, General Minimum Integrity Curve per Figure 514.5C-17 with overall level of 7.7 grms for 1 hour per axis.

• MIL-STD-810-F, Method 516.5, Procedure I, Functional Shock, 40 G's.
• MIL-S-901D, Lightweight Hammer Shock, 3 impacts/axis, 1,3,5 ft.
• MIL-STD-202F, Method 213B, 60 G's, 9ms half sine.
• MIL-STD-202F, Method 213B, 75 G's, 11ms Saw Tooth Shock.

MIL-STD-810F, Method 513.5, Procedure II, table 513.5-II, Operational, 2-7 G's, 6 directions.

MIL-STD-810F, Method 507.4, Procedure I, Cycle I, 240 hrs, 95% RH.

MIL-STD-202F, Method 208, 8 hour aging.

MIL-STD-810F, Method 508.4, Section II.

MIL-STD-810F, Method 509.1.