333 3 MEPIC www.vishay.com Vishay Sfernice Massive Electro-Pyrotechnic Initiator Chip Resistor FEATURES Surface mount design for standard assembly process Available SMD version only Available Active area designed upon performances Case size 0805 (1) Firing energy down to 1.0 mJ LINKS TO ADDITIONAL RESOURCES Firing time down to 250 s (2) Ohmic value: 2 to 8 10 % (typical) 3D Models Joule effect ignition The Massive Electro-Pyrotechnic Initiator Chips (MEPIC) are Easy set up by design of firing levels resistors dedicated to pyrotechnic applications. The MEPIC resistors are the Surface Mount Device (SMD) variants from Very predictable, reproducible and reliable behavior the established NiCr on FR type substrate technology from Compatibility with pyrotechnic element has to be tested in Vishay Sfernice. The standard case geometry (SMD) real environment enables the implementation of assembly process commonly used in the electronic component industry (pick and place, Material categorization: for definitions of compliance reflow soldering on flat PCB used as header) providing high please see www.vishay.com/doc 99912 productivity. The principle of MEPIC is to convert electrical Notes energy into heat in a precise electro-thermal profile for th e * This datasheet provides information about parts that ar e purpose of initiating a series of pyrotechnic events in a RoHS-compliant and / or parts that are non-RoHS-compliant. For controlled energetic reaction. In the mining industry this example, parts with lead (Pb) terminations are not RoHS-compliant. effect is commonly used for the ignition of electronic Please see the information / tables in this datasheet for details (1) detonators (digital blasting). Other industries such as Ignitor performances are dependent on both pyrotechnic primer chemistry and active areas geometry firework (e-match manufacturing) and demolition (various (2) For ohmic value < 3 the tolerance will be discussed with Vishay electric detonators) are also focused applications. Sfernice The MEPIC design has been developed specifically to offer an alternative to the Bridge Wire (BW) technology, insuring at least the same level of performances, while providing cost efficient assembly process and initiator design alternatives. TECHNOLOGY The MEPIC active area (heating zone) will be impregnated by the user with a primary pyrotechnic material (usually wet primer followed by drying) in such way to ensure an intimate contact for an optimum heat transfer of thermal energy. The geometry of the active area of the MEPIC, and both the primer chemistry and its impregnation method, will determine the global performances. Note that the active area of MEPIC shall not be put in direct contact with explosive powder as grain size will not ensure intimate contact and will induce non reproducible and non reliable performances. The two main characteristics of a MEPIC resistor are their All Fire (AF) and No Fire (NF) performances: - All Fire (AF) represents the command pulse where the major amount of the dissipated energy will be transferred to the primer to generate the ignition. Customer will have to provide Vishay Sfernice with All Fire conditions, usually with capacitance discharge parameters or with Minimum Current or Voltage and corresponding short pulse duration. - No Fire (NF) represents the immunity of the resistor with primer to the environmental electro-magnetic pollution and electric continuity test, where the major amount of the dissipated energy will be transferred to the substrate to ensure no ignition . Customer will have to provide Vishay Sfernice with No Fire conditions, usually maximum current or voltage and corresponding longest duration. In case of applicable capacitance discharge test the parameters shall also be provided. ASSEMBLY PRECAUTIONS In order to obtain reproducible ignition performances it is important that the assembly process fulfills the following criteria: - Do not use iron soldering method to mount the MEPIC on its header because uncontrolled amount of solder could impact the heat transfer (potential misfire or ignition delay) and local over heating may damage the MEPIC (deformation that may cause active area cracks). - Take specific precautions, such as no air bubble during preparation and application of primer, in order to ensure the intimate contact of pyrotechnic primer and MEPIC active area (potential misfire). - Take specific handling precaution in order not to damage MEPIC active area (ex: pickup head design for pick and place or specific fixing tools in the entire assembly process. - All along the assembly process, take specific care to extreme thermo-mechanic stress that could be applied to the MEPIC (such as stress induced during over molding) because the active area of MEPIC is subjected to crack (and generate unstable resistance value). - The MEPIC reliability is only guaranteed for one single reflow profile. - In case of necessity to dismantle a MEPIC, another MEPIC must be used (no rework is allowed). - Pay specific attention to the cleaning process after reflow soldering in order not to damage the active area and to keep it clean from various pollutions. Revision: 25-Nov-2021 Document Number: 53058 1 For technical questions, contact: sferthinfilm vishay.com THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc 91000 DDD D MEPIC www.vishay.com Vishay Sfernice STANDARD ELECTRICAL SPECIFICATIONS SIZE / CASE RESISTANCE RANGE RESISTANCE TOLERANCE MODEL (1) DESIGNATION % MEPIC (SMD) 0805 2 to 8 10 to 30 Note (1) Detailed dimensions are specified in Dimensions and Tolerances table RANGE OF IGNITION PERFORMANCES NO FIRE NO FIRE ALL FIRE IGNITION ALL FIRE MODEL CURRENT DURATION CURRENT TIME ENERGY A s A ms J MEPIC (SMD) 0.5 to 1.2 2 to 10 Down to 1 Down to 0.25 Down to 1000 Note Ignition performances are dependent on both pyrotechnic primer chemistry and active area geometry DIMENSIONS AND TOLERANCES in millimeters (inches) ACTIVE AREA INSULATION BACK SIDE SIZE / CASE WIDTH LENGTH THICKNESS WIDTH MODEL DISTANCE PADS DESIGNATION W L T TOLERANCE I P A 2.00 0.15 1.25 0.10 0.6 0.1 0.45 0.15 0.01 MEPIC (SMD) 0805 - (0.080 0.006) (0.050 0.004) (0.024 0.004) (0.018 0.006) ( 0.0004) CONSTRUCTION Substrate: epoxy based (FRx type) Resistive element: NiCr Terminations: SMD wraparound Tin plated copper or silver plated copper HOW TO GET THE RIGHT MEPIC Each MEPIC will have to be adapted to customer pyrotechnic primer chemistry (energetic material). To reach the right MEPIC design it is necessary to work by iterations. Upon receipt of the MEPIC Design Guide duly filled, an initial sampling lot is given to customer (along with a MEPIC reference) so he can provide No Firing / All Firing performances obtained after first testing. After the analysis of these first test results a new set of samples will be proposed (eventually tooling charges will be necessary) in order to get closer to the customer requirements. It may be several iterations until the right design is found. It may also happen that all requirements cannot be fulfilled simultaneously and then a compromise will be necessary between MEPIC design and customer pyrotechnic primer chemistry or ignition parameters. When the iterations are finished, which means that the design is validated with total or partial requirements fulfilled, Vishay Sfernice will design a final set of photomasks for serial production. Revision: 25-Nov-2021 Document Number: 53058 2 For technical questions, contact: sferthinfilm vishay.com THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc 91000