MacDermid Technology

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MacDermid Technology

• Plated Additive Resistor Technology
• Plated - deposit is electroless nickel phosphorus
• Additive - plated only where desired on inner
  layers
• Resistor - common values from 25 to 100 ohms/sq.
• Technology dates to mid 1990s in development
  work for HADCO, Derry
• Prior to NIST program limited test vehicles were
  made - called TV-0 for this program
• Problems - consistency of product, change of
  resistor value in lamination, spread of
  resistance readings obtained

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Cross Section Diagram
MacDermid Plated Additive Resistors
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M-Pass? Plated Resistor Technology

• Type
• Resistance Range
• Process

• Thin-Film Resistive Metal(modified Ni/P)
• 25 - 100 ohm/square
• Selective/Additive Electroless Deposition
  Technique

MacDermid Resistor
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Current State of Technology

• Applications
• Large Number of Similar Value Resistors -
  Termination Resistors
• ex High Speed Digital, Fiber Optic Interface,
  Large Computational Requirements
• Existing Technology
• Electroplated Nickel/Phosphorus on Copper Foil
• Subtractive Process Technology
• Nickel Under All Copper Circuitry (High
  Frequency Applications?)
• PTF Type Compositions

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Fabrication Process Sequence

• Layer Preclean
• Apply Layer Resist
• Image
• Develop/Etch/Strip
• AOI
• Clean/Condition Layers
• Catalyze Surface
• Apply Plating Resist
• Image/Develop

• Accelerate Exposed Catalyst
• Plate Resistor Metal
• Strip Resist
• Laser Trim (if Required)
• Coat Resistor Areas
• Apply Oxide Alternative
• Laminate Multilayer Board

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M-Pass? Process Sequence
Clean/Condition Layers Catalyze Surface Apply
Plating Resist Image/Develop Accelerate Exposed
Catalyst Plate Resistor Metal Strip Resist Laser
Trim (if Required) Coat Resistor Areas
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M-Pass? Process Sequence
Clean/Condition Layers Catalyze Surface Apply
Plating Resist Image/Develop Accelerate Exposed
Catalyst Plate Resistor Metal Strip Resist Laser
Trim (if Required) Coat Resistor Areas
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M-Pass? Process Sequence
Clean/Condition Layers Catalyze Surface Apply
Plating Resist Image/Develop Accelerate Exposed
Catalyst Plate Resistor Metal Strip Resist Laser
Trim (if Required) Coat Resistor Areas
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M-Pass? Process Sequence
Clean/Condition Layers Catalyze Surface Apply
Plating Resist Image/Develop Accelerate Exposed
Catalyst Plate Resistor Metal Strip Resist Laser
Trim (if Required) Coat Resistor Areas
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M-Pass? Process Sequence
Clean/Condition Layers Catalyze Surface Apply
Plating Resist Image/Develop Accelerate Exposed
Catalyst Plate Resistor Metal Strip Resist Laser
Trim (if Required) Coat Resistor Areas
Typical L-cut in embedded resistor. Trim was
made in automated mode to 0.3 tolerance without
damaging the underlying substrate.
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M-Pass? Process Sequence
Clean/Condition Layers Catalyze Surface Apply
Plating Resist Image/Develop Accelerate Exposed
Catalyst Plate Resistor Metal Strip Resist Laser
Trim (if Required) Coat Resistor Areas
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AEPT TV1-R Test Vehicle
Test Vehicle Constructed at HADCO Tech Center in
Salem, NH. (Three times)
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AEPT Test Vehicle Results
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MacDermid Experience from TV-1

• Materials Compatibility
• Dry Film Used
• Developer Used for Imaging
• Catalyst Activity and Acceleration Sequence
• Dry Film Thickness and Application Method
• Dependent on Copper - 1.0 or 0.5 Ounce
• Vacuum or Wet Lamination
• Change in Resistance after Lamination
• Composition dependent
• Hard to anticipate with TV-1
• M-Pass Resistors trim easily to value

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MacDermid Experience from TV-1

• Keep scrap embedded resistor boards - there is
  some use for them
• Laser trim development
• Inkjet trim downward development
• Lamination studies
• Cover Coat studies

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MAC-2R Test Vehicle

• 12 x 12 format
• Individual Resistors Routed to Periphery
• 11 x 11 cap sheet laminated

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MAC-2R Test Vehicle
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M-Pass? Resistance Variation
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M-Pass? Resistance Variation
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Capability to Trim M-Pass Resistors
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Capability to Laminate M-Pass Resistors
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M-Pass? Values - Post Lamination
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M-Pass? Embedded Resistor Technology

• Selective Application - Lower Process Costs
• Completely Create Resistors at Board Fabrication
  Shop - No Selling Laminate
• Use Conventional PWB Processes - Laser Trim
  and/or Ink Jet Trim if Required
• Dwell Time Variation Allows Multiple Resistor
  Values per Layer (with Multiple Imaging Steps)

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Selective Inkjet Trimming Resistor Value Down
Courtesy of MicroFab - IPC Paper
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MacDermid Experience afterTV-2 and Nortel
Emulator

• Wide range of substrates can be used for M-Pass
  resistors
• Regular FR-4
• High Temperature Epoxy
• Flexible circuits
• Low dielectric constant materials
• M-Pass Process continues to produce useable parts
  quickly
• More development work needed to understand small
  resistor value changes upon lamination

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M-Pass? Development Status

• Deposition Process Routinely Operational in
  MacDermid Pilot Laboratory
• Hundreds of NIST/AEPT Test Parts Fabricated at
  Sanmina and Merix
• Current Lower Size Limit - 250 Microns on 0.5 oz.
  Copper Foil and Conventional Dry Film
• Resistance Demonstrated - 100 Ohms/Square or Less
• Demonstrated Attractive Laser Trim Properties

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M-Pass? Development Plan

• Make Process More Consistent
• Resistor value variability lt 5 (1 sigma)
• Demonstrate Chemical Consistency in Production
  Environment
• Demonstrate Higher Resistor Values (Ohms/Square)
  on Production Designs
• Solicit Partners for Additional Fabricator
  Testing and End-User Evaluations