MEPIC
www.vishay.com
Vishay Sfernice
Revision: 19-Dec-2018
1
Document Number: 53058
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
Massive Electro-Pyrotechnic Initiator Chip Resistor
DESIGN SUPPORT TOOLS
The Massive Electro-Pyrotechnic Initiator Chips (MEPIC) are
resistors dedicated to pyrotechnic applications. The MEPIC
resistors are the Surface Mount Device (SMD) variants from
the established NiCr on FR type substrate technology from
Vishay Sfernice. The standard case geometry (SMD)
enables the implementation of assembly process commonly
used in the electronic component industry (pick and place,
reflow soldering on flat PCB used as header) providing high
productivity. The principle of MEPIC is to convert electrical
energy into heat in a precise electro-thermal profile for the
purpose of initiating a series of pyrotechnic events in a
controlled energetic reaction. In the mining industry this
effect is commonly used for the ignition of electronic
detonators (digital blasting). Other industries such as
firework (e-match manufacturing) and demolition (various
electric detonators) are also focused applications.
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.
FEATURES
• Surface Mount Design for standard assembly
process
•SMD version only
• Active area designed upon performances
• Case size 0805
• Firing energy down to 1.0 mJ
(1)
• Firing time down to 250 μs
• Ohmic value: 2 to 8 ± 10 % (typical)
(2)
• Joule effect ignition
• Easy set up by design of firing levels
• Very predictable, reproducible and reliable behavior
• Compatibility with pyrotechnic element has to be tested in
real environment
• Material categorization: for definitions of compliance
please see www.vishay.com/doc?99912
Notes
* This datasheet provides information about parts that are
RoHS-compliant and / or parts that are non-RoHS-compliant. For
example, parts with lead (Pb) terminations are not RoHS-compliant.
Please see the information / tables in this datasheet for details
(1)
Ignitor performances are dependent on both pyrotechnic primer
chemistry and active areas geometry
(2)
For ohmic value < 3
the tolerance will be discussed with Vishay
Sfernice
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.
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Available
Models
Available
Available
MEPIC
www.vishay.com
Vishay Sfernice
Revision: 19-Dec-2018
2
Document Number: 53058
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
Note
(1)
Detailed dimensions are specified in Dimensions and Tolerances table
Note
• Ignition performances are dependent on both pyrotechnic primer chemistry and active area geometry
CONSTRUCTION
• Substrate: epoxy based (FRx type)
• Resistive element: NiCr
• Terminations: SMD wraparound
• Tin plated copper or silver plated copper
STANDARD ELECTRICAL SPECIFICATIONS
MODEL
SIZE / CASE
DESIGNATION
(1)
RESISTANCE RANGE
RESISTANCE TOLERANCE
%
MEPIC (SMD) 0805 2 to 8 10 to 30
RANGE OF IGNITION PERFORMANCES
MODEL
“NO FIRE”
CURRENT
A
“NO FIRE”
DURATION
s
“ALL FIRE”
CURRENT
A
IGNITION
TIME
ms
“ALL FIRE”
ENERGY
μJ
MEPIC (SMD) 0.5 to 1.2 2 to 10 Down to 1 Down to 0.25 Down to 1000
DIMENSIONS AND TOLERANCES in millimeters (inches)
MODEL
SIZE / CASE
DESIGNATION
WIDTH
W
LENGTH
L
THICKNESS
T
INSULATION
DISTANCE
I
BACK SIDE
PADS
P
ACTIVE AREA
WIDTH
TOLERANCE
A
MEPIC (SMD) 0805
2.00 ± 0.15
(0.080 ± 0.006)
1.25 ± 0.10
(0.050 ± 0.004)
0.6 ± 0.1
(0.024 ± 0.004)
-
0.45 ± 0.15
(0.018 ± 0.006)
± 0.01
(± 0.0004)
NiCr active area
Substrate
Tin or Silver
Copper
Substrate
NiCr
Copper
Tin or Silver