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Electro-Pyrotechnic Initiator Chip Resistor EPIC Vishay Sfernice www.vishay.com For technical questions, contact: sfer@vishay.com Document Number: 53041 Electro-pyrotechnic initiator resistors, also known as bridge resistors, are resistive elem ents, 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 CB CASE SIZE DIMENSION ABC

Electro-Pyrotechnic Initiator Chip Resistor Vishay Sfernice Document Number: 53041 For technica l questions, contact: sfer@vishay.com www.vishay.com Revision: 03-Nov-08 75 EXAMPLE OF APPLICATION Chip: 0603 R: 2R ± 0R2 Energy: Around 1.5 mJ Response time: 0.2 ms Mounting Recommendations EPIC can be mounted either on a PCB or on a squib. Please refer to Application Note (http://www.vishay.com//doc?53044 ) to see Vishay/Sfernice recommendations. AIRBAGS INITIATORS A prerequisite to valid reliability estimation of an electro-explosive device (EED) is a sensitivity test program carefully chosen and properly perform. The Bruceton Method (or up and down method) of sensitivity testing was developed specifically for ordinance testing. Here under is an example of Bruceton’s test results. 2 customers: Customer A and customer B have equipped squibs of their own with 3 variants (Variant 1, 2 and 3) . Bruceton’s test results of Vishay heating elements are shown in Table 1 CONCLUSION Bruceton test results are self explanatory. They show that th e electro-thermal behavior of EPI C is predictable, precise and reproducible. For more information please read the Application Note (http://www.vishay.com/doc?53044 HOW TO GET THE RIGHT EPIC Each EPIC will have to be adapted to customer pyrotechnic el ement. To reach the right produ ct, Vishay/Sfernice works by “iteration”. Upon receipt of the EPIC Design Guide (http://www.vishay.com/doc?53045 ) duly filled, an initial sampling lot is given to customer (along with an EPIC reference) so he can provide Vishay/Sfernice with “no firing”/“all firing” conditions. Then Vishay/Sfernice will be able to provide a new set of samples (eventually tooling charges will be necessary). Ohmic value of samples will remain the same, but there will be a new compromise between the length, the width and the thickness of the filament so as to increase the sensitivity of the EPIC and adapt the firing conditions to the pyrotechnic element of the customer. When the right parameters are reached Vishay/Sfernice will design a final set of mask (with the participation of the customer). Notes (1) Tin/lead: Please consult  EPIC being a semi-custom product, please fill EPIC Design Guide (http://www.vishay.com/doc?53045 ) and send to sfer@vishay.com to get appropriate part number.  Per Vishay policy all the components de signed for automotive applications should be tested in accordance to AEC Q200 specification. As the EPIC is just part of an ignitor which is designed and qualified by each customer Vishay is not proceeding to any AEC Q200 test. HEATING ELEMENT CUSTOMER A CUSTOMER B NF (in mA) AF (in mA) NF (in mA) AF (in mA) Variant 1 546 766 538 776 Variant 2 571 839 577 859 Variant 3 619 891 612 875 ORDERING PROCEDURE New Global Part Numbering: EPICxxxxNT MODEL xxxx TERMINATION (1) PACKAGING EPIC Will be determined at time of design N: Tin/silver B: Tin/lead G: Gold W = Waffle pack T = Tape and reel PIC xxxx N T E

Document Number: 91000 www.vishay.com Revision: 18-Jul-08 1 Disclaimer Legal Disclaimer Notice Vishay All product specifications and data are subject to change without notice. Vishay Intertechnology, Inc., its affiliates, agents, and employees, and all persons acting on its or their behalf (collectively, “Vishay”), disclaim any and all liability for any errors, inaccuracies or incompleteness contained herein or in any other disclosure relating to any product. Vishay disclaims any and all li ability arising out of the use or application of any product described herein or of any information provided herein to the maximum extent permit ted by law. The product specifications do not expand or otherwise modify Vishay’s terms and conditions of purcha se, including but not limited to the warranty expressed therein, which apply to these products. No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted by this document or by any conduct of Vishay. The products shown herein are not designed for use in medi cal, life-saving, or life-sustaining applications unless otherwise expressly indicated. Customers using or selling Vishay products not expressly indicated for use in such applications do so entirely at their own risk and agree to fully indemnify Vishay for any damages arising or resulting from such use or sale. Please contact authorized Vishay personnel to obtain written terms and conditions regarding products designed for such applications. Product names and markings noted herein may be trademarks of their respective owners.