SPECIFICATIONS AND PROPERTIES

OHMEGA-PLY^® RESISTOR-CONDUCTOR MATERIAL

SHEET RESISTIVITIES
Standard	10, 25, 50, 100, 250 ohms per square

TYPICAL PROPERTIES (EPOXY-GLASS DIELECTRIC)

ETCHED RESISTOR VARIATION (0.5" x 0.5" RESISTOR SIZE)
10 ohms per square	Plus or minus 3%
25, 50, 100 ohms per square	Plus or minus 5%
250 ohms per square	Plus or minus 10%

CURRENT NOISE (PER MIL-STD-202, METHOD 308)

Less than -15 db

MAXIMUM TEMPERATURE COEFFICIENT OF RESISTANCE (-65 ºC TO 125 ºC)
10 ohms per square	-20 ppm per degree C
25 ohms per square	-50 ppm per degree C
50 ohms per square	-80 ppm per degree C
100 ohms per square	+100 ppm per degree C
250 ohms per square	+100 ppm per degree C

RESISTANCE CHANGE AFTER 1000 HOURS 70 ºC AMBIENT TEMPERATURE
10 ohms per square	0.4% max (10 Watts/square load)
25 ohms per square	0.5% max (5 Watts/square load)
50 ohms per square	1.0% max (2.5 Watts/square load)
100 ohms per square	1.0% max (2.5 Watts/square load)
250 ohms per square	1.0% max (2.5 Watts/square load)

TCR TRACKING
25 ohms per square	Plus or minus 7 ppm per degree C max; Less than 2 ppm per degree C average
100 ohms per square	Plus or minus 15 ppm per degree C max; Less than 8 ppm per degree C average

RECOMMENDED POWER DISSIPATION

The figure shows the recommended power dissipation of small resistor area (less than 1100 mil²) at 25 °C ambient

FOR RESISTOR AREA LARGER THAN 1100 MIL2, THE RECOMMENDED POWER DISSIPATION AT 25°C AMBIENT IS AS FOLLOWS:
10 ohms per square	0.190+ MilliWatts/mil2
25 ohms per square	0.150+Milliwatts/mil2
50 ohms per square	0.138+Milliwatts/mil2
100 ohms per square	0.100+Milliwatts/mil2
250 ohms per square	0.090+Milliwatts/mil2

Maximum power dissipation depends on the ambient temperature, resistor element size and laminate/circuit board thermal properties. Dissipation improves with the use of natural heatsinks such as ground and power planes. Typical power dissipation for most Ohmega-Ply resistor designs operating at an ambient of less than 70 °C is approximately 1/10 to 1/8 Watt.

Note: Because of continuing product improvement, the above specifications and properties are subject to change. The information and data contained herein are based on tests to date, but no warranty thereof is given.

VII) RELIABILITY TEST DATA AND SPECIFICATIONS

Ohmega-Ply® has been used in numerous applications for over 25 years; exhibiting excellent performance and dependability. Due to its absolute long-term reliability under a variety of severe environmental conditions, Ohmega-Ply® is used in numerous critical products (space-base, aerospace, avionics, etc.) where the utmost in reliability is required. The estimated failure rate for Ohmega-Ply® resistors is less than 0.001 resistor elements per 1 million operating hours (this is based on test results where over 1 trillion component hour have been accumulated without a field failure. Field failure is defined as resistor failure that is caused by the resistive material itself, and not other sources of printed circuit board failure (opens, shorts, defective base material, excessive power surges, improper operating conditions, etc.). Ohmega-Ply® Specifications and Properties

Type of Test	Measured max./min. R (Alcatel Tested)	Ohmega Specifications	Thick film chip R (0805)
Humidity Test Temp: 40ºC Relative Humidity: 93%	After 21 days: 0.22% for 25 Ohm/sq. 0.07% for 100 Ohm/sq. 0.10% for 250 Ohm/sq. After 56 days: 0.74% for 25 Ohm/sq. 0.14% for 100 Ohm/sq. 0.22% for 250 Ohm/sq.	After 10 days: 0.5% for 25 Ohm/sq. 1.0% for 100 Ohm/sq.	After 56 days: < ± 1.50%
Thermal Cycling Hot Cycle Temp: 125ºC Cold Cycle: -25 ºC	After 100 Cycles -0.03% for 25 Ohm/sq. 0.03% for 100 Ohm/sq. -0.08 for 250 Ohm/sq.	After 25 Cycles -0.5% for 25 Ohm/sq. 1% for 100 Ohm/sq.	<± 0.25%
Aging Without Load Temp: 125ºC	After 100 Hours 0.10% for 25 Ohm/sq 0.08% for 100 Ohm/sq -0.13% for 250 Ohm/sq	Not specified	Not specified
Solder Heat/Float Temp: 260ºC Immersion: 20ºC	-0.02% for 25 Ohm/sq 0.01% for 100 Ohm/sq -0.01% for 250 Ohm/sq	0.5% for 25 Ohm/sq 1% for 100 Ohm/sq	<± 0.25%

Sheet Resistivity Ohm/sq.	Lmin (nH)	Lmax (nH)	Cmin (pF)	Cmax (pF)
25 100 250 Short	0.599 0.622 0.571 0.6	0.657 0.682 0.653	0.935 1.053 1.117 1	1.139 1.154 1.202

Minimum and maximum parasitic effects extracted from measured characteristic of integrated resistor   IBM3 IBM built and tested a numbers of evaluation boards that incorporated Ohmega-Ply® into number of internal layers of a multiplayer design. This effort was to see what effect, if any, there was on the assembly (and rework) process due to the embedded resistors. In addition, standard environmental stress tests were performed (including thermal cycling, thermal shock, vibration testing and torque testing). The findings of their published report showed “no significant resistance change on the resistors from the assembly process and stress test”. Unisys4 In evaluating the long term drift characteristics of Ohmega-Ply® on high Tg, low DC substrate, Unisys concluded that powered (22 mA), Ni-P buried resistors, fabricated using ammoniacal etch process and fully aqueous resist, when placed in a 55 °C cabinet environment, will drift < 2 % in 100,000 hours (11.4 years). Dassault5 Dassault Electronique did a 2 year study of Ohmega-Ply® for an active phased array antenna (X-band). The resistors were used in a stripline configuration a PTFE substrate (Rogers RT Duroid® 60002 and fusion bonded inside a multilayer package). The Ohmega-Ply® was compared to chip resistors and screen printed polymer inks. Ohmega-Ply® was selected for use due to superior tolerance and stability (compared to printed polymer inks) and space saving, parasitic reduction, and solder joint removal (compared to chip resistors). The results of testing are as follows:

Etching Tolerance	Minimum Resistor Width	Tolerance After Fusion Bonding	Influence of Ohmega-Ply Foil Layer on Microwave Properties	Shift of Resistor Values After 500 Thermal Cycles (-55ºC, +125ºC)	Thermal Coefficient of Resistance Within the Range (-55ºC, +125ºC)	Power Handling	No shift in microwave performance of two ports power divider, when Ohmega Foil Technology is tested under the following conditions:
5%	200 µ m	7%	NO	Microstrip: +2% Stripline: +3%	Microstrip: ±6% Stripline: ±7%	300 mW	500 thermal cycles (-55ºC, +125ºC) 500 hours at 125ºC 40 days 40ºC, 95% HR 48 hours salt spray

Rogers Corporation6 In an internal study, Rogers evaluated Ohmega-Ply® resistors on Kapton® /Pyralux®. They found the following change in a resistor that was 0.25” x 4.0” in size with a flex radius of 0.25” (the flex rate was 10 cycles/minute):

Number of Flex Cycles	% Change in Resistance
150 1,500 10,000	0.5 6.1 25.5

When a cover film or conformal coating was placed over the resistors (or, the resistors were multilayered on an internal plane of circuitry), and flexed up to 250,000 cycles, there was no significant change in resistance.   References Mahler, Bruce and Schroeder, Paul, “Planar Resistors in PCB Design”, Electronic Manufacturing, January 1989. Peeters, Joris et all., “Characterization of Integrated Resistors for Broadband Telecom Printed Circuit Boards”, IPC World Expo, June 1996. Martin, Cynthia, “Passive Devices Buried Resistors”, report from IBM, Austin, TX, 1998. Murphy, Tim, “Long Term Drift of Ni-P Buried Resistors on Cyanate Ester laminate”, IPC Printed Circuit Expo, 1994. Ledain, Bernard and Herblot, Jean, “Innovative Multilayer Technologies for Active Phased Array Antennas”, report from Dassault Electronique Saint-Cloud, France. Nguyen, Phong, “Shelf-Life and Flex-Life of Ohmega-Ply Materials”, Roger Microwave Conference, June 1989.