Flip-Chip Underfills and Ball-Grid-Array Underfills

Traditional underfill and glob-top materials with anhydride curng epoxies have Tg around 100-150°C that may exert too high interfacial tensile stress when going through reflow soldering at 250°C. A new generation of AIT underfill and glob-top compounds with different chemistry enables a new paradigm of performance in ultra high Tg of 240°C and incorporating high thermal conductivity and low thermal interface resistance to power the transfer of heats from both the top and bottom sides of the flip-chip packages. Please CLICK HERE TO VIEW VIDEO for details of AI Technology’s Underfill And Glob-Top Encapsulant Products in enabling higher performance flip-chip and chip-on-board devices.

What distinguishes AIT’s Underfills  are  their unparalleled ability to manage stress while providing outstanding moisture barrier.  These capabilities are achieved with unconventional polymer engineering and designs.  AIT’s advanced microelectronic protection products are ideal for large high performance devices operating at high temperatures.

High Tg of 175-240C of the new generation of AIT thermally conductive underfill compounds coupling with molecular level stress absorption capability enables many high performance flip-chip packaging including power devices.

Traditional anhydride curing epoxies have limiting capability in stress absorption when undergoing reflow soldering of 250C for the new lead-free soldering.

  • Underfills and Glob-tops proven for use at high temperature of 150-300°C beyond, in addition to traditional 150°C applications.
  • Proven moisture insensitivity and low moisture absorption affords the possibility to meet up to the level 1 in JEDEC component reliability.
  • RoHS, REACH and WEEE compliant to meet UL94V-0 rating.

The same high Tg flip-chip underfill compounds with stress absorption capability are also available for use in managing stress in ball-grid-array packages on printed circuit board.

New Generation of Ultra High Tg Underfill

with Glass Transition of Over 240°C for Ultimate Flip-Chip and Component Stress Management

Liquid Underfills with Ultra-high Glass Transition (Tg):

  • Balancing these modified cyanate ester underfills that cure to much higher  glass transition temperatures and the stress absorption.
  • Outstanding thermal conductivity and low thermal resistance afford better thermal dissipation from powerful chip to both side of the microelectronic package.
  • Proven in use for the most stringent  military applications

High Melt-Flow Film Underfill for FOW:

  • Outstanding melt-flow and wetting to flow-over-wire for stack-chip applications
  • Ability to cure at lower temperature from 100-150°C for lower interfacial stresses
  • Ideal for large area stack-chip and module
  • Preform with specific thickness accommodates the flip-chip or ball-grid-array  parts with preformed cut-outs for interconnections allowing the film adhesive to flow  and encapsulate for protection

Flow-Over-Wire underfill film adhesive is available in DDAF format for large scale wafer level packaging

Underfill Liquids and Film Adhesives:

FUNCTION AIT PART# THERMAL, ELECTRICAL, & other RELEVANT PROPERTIES
Stress and Thermal Management MC7866-UF
  • Tg ~240°C to ensure minimal stress during lead-free soldering
  • Low curing temperature and low CTE to achieve lower stresses
  • Outstanding thermal conductivity and low interface resistance
Stress and Thermal Management MC7863-UF
  • Tg ~240°C to ensure minimal stress during lead-free soldering
  • Low curing temperature to achieve lower stresses
  • Lowest CTE for internal stress reduction
Stress Management MC7686-UF
  • Tg ~220°C to ensure minimal stress during lead-free soldering
  • Low curing temperature and low CTE to achieve lower stresses
  • Outstanding thermal conductivity and low interface resistance
Flow-Over-Wire Underfill Film Adhesive ESP7660-FOW
  • Tg ~175°C to ensure minimal stress during reflow soldering
  • High flow at low curing temperature of 100-150°C to achieve lower internal stresses
  • High flow at minimal pressure of less than 2 psi for flow-over-wire for stack-chip encapsulation and bonding
Flow-Over-Wire Underfill Film Adhesive CXP7860-FOW
  • Tg ~240°C to ensure minimal stress during reflow soldering
  • High flow at low curing temperature of 100-150°C to achieve lower internal stresses
  • High flow at minimal pressure of less than 2 psi for flow-over-wire for stack-chip encapsulation and bonding
Preform Underfill for Thermal and Stress Management CXP7686-UF
  • Tg ~220°C to ensure minimal stress during reflow soldering
  • High flow at minimal pressure of less than 2 psi for flow-over-wire for stack-chip at low curing temperature of 100-150°C to achieve lower internal stresses
  • Outstanding thermal conductivity and low thermal interface resistance
Preform Underfill for Thermal and Stress Management ESP7666-FOW
  • Tg ~175°C to ensure minimal stress during reflow soldering
  • High flow at minimal pressure of less than 2 psi for flow-over-wire for stack-chip at low curing temperature of 100-150°C to achieve lower internal stresses
  • Outstanding thermal conductivity and low thermal interface resistance

The ultra-high glass transition temperature (Tg) at 240C minimizes tensile stress induced failures when the flip-chip packages are going through the reflow soldering of lead-free solder.

For more information and recommendation assistance, please contact AIT sales and engineering:

AIT Solve My Problem

AIT technical sales and service department can also be reached at: 1-609-799-9388 or 1-800-735-5040 (EST) and Fax: 609-799-9308