Electro-Pyrotechnic Initiator Chip Resistor

EPIC

Vishay Sfernice

www.vishay.com

For technical questions, contact: sfer@vishay.com

Document Number: 53041

74

Revision: 03-Nov-08

Electro-pyrotechnic initiator resistors, also known as bridge

resistors, are resistive elements, which convert electrical

energy into heat energy in a precise electro-thermal profile

for the purpose of initiating a series of pyrotechnic events in

a controlled energetic reaction. In automotive applications

this effect is used to deploy automotive airbags and other

safety devices. These same devices are also used in military

applications for pilot ejection systems, explosive bolt

disengagement of airbone missiles, chaff dispensers,

artillery

projectile

activators,

anti-tank

mines,

etc.

Commercially, they are used in mining and de-constructions

applications.

FEATURES

Vishay has developed a special thin film resistor

chip specifically designed to provide pyrotechnic

engineers with a lot of advantages

• Firing energy down to 50 µJ

• Firing time down to 50 µs

• Ohmic range: 2R to 10R

• Compatibility with various pyrotechnic composition even

with no primer

• Joule effect ignition or flash ignition for very fast firing

• Easy set up by design of firing levels

• “No fire”/“all fire” ratio up to 70 %

• Very predictable, reproducible and reliable behaviour

• Size: 0603 preferred - other size available upon request

PRINCIPLE OF OPERATION

The two main parameters of an EPIC are “no fire” and “all

fire” conditions.

“No fire” represents the immunity of the resistor to the

environmental

electro-magnetic

pollution

and

electric

continuity test: Therefore customer will have to provide

Vishay/Sfernice with “no firing” conditions: Maximum current

and longest duration when part should not ignite the

explosive powder.

“All fire” represents the command pulse. Customer will have

to provide Vishay/Sfernice with “all firing” conditions:

Minimum current, duration necessary to ignite the explosive

powder.

DIMENSIONS in millimeters (inches)

MECHANICAL SPECIFICATIONS

• Substrate: Special alumina based substrate

• Resistive element: Fine line patterned Tantalum nitride thin

film layer

• Diffusion and conductive thin film layers

• Terminations: Wraparound over nickel barrier

TECHNOLOGY

This technology contributes to the stability of the heating element, the precise electro-thermal response profile and the ability to

design a precise activation energy.

All these features are perfectly controlled on high production volumes.

* Pb containing terminations are not RoHS compliant, exemptions may apply

Available

Pb-free

RoHS*

COMPLIANT

A

C

B

CASE

SIZE

DIMENSION

ABC

MAX. TOL. + 0.152 (0.006)

MIN. TOL. - 0.152 (0.006)

MAX. TOL. + 0.127 (0.005)

MIN. TOL. - 0.127 (0.005)

MAX. TOL. + 0.127 (0.005)

MIN. TOL. - 0.127 (0.005)

0603

1.52 (0.060)

0.75 (0.030)

0.5 (0.020)