Die Attach & Thermal Interface Materials for CPU, GPU, & Memory

Paradigm Shifting Challenges for Computer Electronic Adhesives & Thermal Interface Materials:

“Improper thermal management and heat dissipation can result in dramatic failure in high performance computers”

 

While the functional aspects of the typical die-attach, component attach, substrate attach and thermal management are the same for all electronics, managing the ever evolving CPU and GPU die-attaches for power thermal management and stacking of large area chips for memory modules requires ever enhanced performance.

“AIT patented compressible phase-change thermal interface pads such as COOL-SILVER PAD and compressible pressure sensitive thermal adhesive tape such as COOL-BOND and COOL-GELFILM are some of the proven thermal solutions in some of the most stringent computer CPU and GPU module thermal management applications” http://www.ebay.com/itm/COOL-SILVER-Thermal-Pad-Phase-Change-Thermal-Compound-/230759985996?pt=US_Thermal_Compounds_Supplies&hash=item35ba5df34c

 

With over 30 years of experience in inventing and formulating specialty adhesives for electronic applications, AIT provides one of the most comprehensive die-attach film and paste adhesives and  thermal interface solutions that are engineered to facilitate manufacturability and throughput:

 

“The pressure sensitive thermal interface adhesive tapes such as COOL-BOND PSA-3NC have been extensively used in gaming computing industry for bonding heatsink for GPU and memory module without the need for mechanical fasteners”.http://www.ebay.com/itm/COOL-BOND-Thermal-Adhesive-Tape-Pad-Interface-TIM-/150802951348?pt=US_Thermal_Compounds_Supplies&hash=item231c8e6cb4

  • High thermal  and electrical conductivity die-attach pastes and film adhesives
  • 450mm and all size wafer DDAF
  • Compressible pressure sensitive thermal film that is industry best to provide instant bonding and lowest thermal resistance for GPU and memory modules
  • Conformal compressible phase change or pressure sensitive thermal interfaces for modules to heat-sink or board to casing

“Poor thermal dissipation increases the temperature and shortened the life of the high performance computers and lower the performance of the system”

 

Diamond-based and silver-based thermal adhesives from AI Technology, Inc. (AIT) have been used extensively for large area die-attach applications for over 20 years in supercomputers, mainframe computers and high performance gaming computers. Phase-change thermal interface pads pioneered by AIT and compressible phase-change thermal interface pads patented by AIT are now serving as the work horses in dissipating heat from multi-core CPU and GPU modules from super-computer and mainframe computer, server and desktop PC to laptop and tablet computers.

DIE ATTACH and THERMAL INTERFACE MATERIALS for CPU, GPU, MEMORY MODULE from LAPTOP and TABLET to MAINFRAME COMPUTER, SUPERCOMPUTER and MULTI-CORE SERVER AND DESKTOP COMPUTER

  • High Performance Electro-thermal Die-Attach for High Power CPU and GPU
  • Instant Bonding Pressure Sensitive Thermal Tape Adhesive for GPU Module
  • Compressible, Conformal Phase-Change Thermal Interface Material (TIM) Pad

PROVEN LOWEST POSSIBLE DIE-ATTACH THERMAL RESISTANCE DIE ATTACH ADHESIVES FOR OVER 20 YEARS:

Die-Attach thermal management is the first and most critical layer of the thermal stacks in a CPU and GPU modules. Highest thermal conductivity with thin and void-free bond-line of the die-attach adhesive is critical in dissipating the heat quickly to the broader module substrate.  AIT has more than 20 years of proven records in supporting highest performance super-computers, mainframe computers,  servers, desktop, laptop and tablet computer for high performance CPU and GPU modules with it high molecular flexibility and lowest thermal resistance die attach adhesives.

  • ME8512 is a popular choice of void-free die attach with low electrical and thermal resistance.
  • ME7519-LB is thermally conductive and electrically insulating die-attach adhesive.
  • ME7159-CD and ME8456-DA have been the workhorses for the most demanding CPU and GPU bonding of large dies.
  • MC7885 and MC8880 for high power applications with temperature operation of 250°C and beyond.

PROPERTY/PARAMETER ME 8512 ME 8456-DA MC8880 ME 7519-LB
Electrical Resistivity <0.0003 Ω-cm <0.0003 Ω-cm <0.003 Ω-cm >10¹⁴ Ω-cm
Viscosity @5.0 rpm/Thixotropic Index 10,000 cps/4.0 20,000 cps/4.0 10,000 cps/4.0 20,000cps/>3
Glass Transition Tg (°C) 52 -20 220 52
Device Push-off Strength (psi) >3000 >2000 >3000 >3000
Hardness (Type) ~ 80D ~ 80A ~ 99D ~ 85D
Cured Density of Conductive Adhesive Portion (gm/cc) 4.0 4.8 4.0 2.5
Thermal Conductivity > 12.0 W/m-°K > 12 W/m-°K > 8 W/m-°K > 12 W/m-°K
Linear Tab-Composite Thermal Expansion Coefficient  (ppm/°C) 40 (X-Y=Z,  Isotropic) 90 (X-Y=Z,  Isotropic) 26 (X-Y=Z,  Isotropic) 45 (X-Y=Z,  Isotropic)
Maximum Continuous Operation Temperature (°C) > 180 > 180 > 250 > 180
Decomposition Temperature @5% weight loss (°C) >450 >450 >500 >450
Recommended Curing Temperature/Time (°C/min.) >175/10 >175/10 >150/10 >175/10

Compressible Phase-Change Thermal Interface Pads

  • Compressible and conformal couples with phase change to allow elimination of voids
  • Proven for most stringent and including military applications
  • Non-silicone and non-contaminating
  • US patented innovation
Thermal Interface Materials for Extreme Power GPU
FUNCTION AIT PART # THERMAL, ELECTRICAL AND OTHER RELEVANT PROPERTIES
Compressible Phase-Change COOL-SILVER™ PAD CPR8850-LB
  • Lowest thermal resistance, electrically non-conductive interface pad
  • Compressible, phase-change interface pad  (US patented)
Compressible Phase-Change COOL-SILVER™  G3 PAD
  • Lower cost version of the lowest thermal resistance pad
  • Compressible, phase-change interface pad  (US patented)
Compressible Phase-Change COOL-PAD™  CPR7159-LB
  • Modified diamond filled with one of the lowest thermal resistance
  • Compressible, electrically insulating phase-change pad (US patented)
Compressible Phase-Change COOL-PAD™  CPR7155-LB
  • Modified aluminum oxide filled with one of the lowest thermal resistance
  • Compressible, electrically insulating phase-change pad (US patented)
Gap-Filling Thermal Pad COOL-GAPFILL™

DT

  • Gap filling compressible  thermal pad with the lowest thermal resistance
  • One-side tacky (DT) with tacky side bonding to heat-sink surface
Gap-Filling Thermal Pad COOL-GAPFILL™

TT

  • Gap filling compressible  thermal pad with the lowest thermal resistance
  • Both side tacky (TT) for elimination of clips and/or fasteners
Thermal Gel COOL-SILVER™

G3 Gel

  • Non-curing, electrically non-conductive interface gel forming paste
  • Non-silicone grease, proven thermal stability similar to thermal pad

Compressible Thermal Gap Pad Thermal Interface

  • Compressible and conformal
  • Proven for large area requiring thermal filling into height gaps of different components
  • Ideal for large area module to device enclosure
  • Proven and used for most critical thermal challenges with military grade reliability
  • Non-silicone and non-contaminating
  • Available with different thickness with one-side or both side pressure sensitive

Thermal Interface for the Ever More Powerful Graphic Processor Unit (GPU) Module

  • Instant Bonding Compressible Pressure Sensitive Adhesive Tape and Pad
  • Compressible Phase-Change Interface Pad Proven for Performance
GPU and Other Module Mounting Thermal Adhesives
PROPERTY/PARAMETER RTC8550 RTK 7559-LB ME 7159-LB
Dielectric Strength (Volts/mil) Not Applicable >750 >750
Device Push-off Strength (psi) >1000 >1000 >1000
Cured Density (gm/cc) 4.5 2.5 2.5
Thermal Conductivity > 8.0 W/m-°C > 8.0 W/m-°C > 12 W/m-°C
Maximum Continuous Operation Temp. (°C) > 150 > 150 > 150
Electrical Resistivity <3x10-⁴ ohm-cm >10¹⁴ ohm-cm >10¹⁴ ohm-cm

What distinguishes AIT CPU, GPU and memory modules electronic adhesive and thermal management material solutions besides the unparalleled and proven low thermal resistance is it proven long-term reliability. In the die-attach, module mounting and heat-sink thermal interfaces, its patented compressible phase-change interface pads and the long-term reliability and consistent performance after years of thermal shock and cycling with the build-in stress relief with molecular flexible structures are the corner stones of the company products since its founding.

  1. Ultra-low electrical and thermal resistance between dies and substrate. Flexibility to produce camber-free, stress-free die mounting.
  2. For module mounting, molecular flexibility is specifically engineered in the thermal adhesive to provide stress absorption even in the most mis-matched CTE substrates and surfaces that extend to below -55°C.
  3. In the heat-sink interface layer, AIT provides the patented and proven compressible and conformable phase-change interface pad to eliminate trapped air and accommodate irregularity in gaps.
  4. Ultra-low thermal resistance gels and greases that are silicone free and free from drying and “pumped out”.
  5. Compressible and pressure sensitive thermal interface adhesive and/or pad for large area heat-spreading and heat-sinking for laptops and tablets.
  6. RoHS, REACH and WEEE compliant that meets UL94V-0 rating.

Comparison of Thermal Interface Materials Performance: Lower temperature rise represents a measurement of the efficiency of the thermal interface materials in transferring heat generated by the power electronic device to the heatsink (with fan) that dissipates heat to the environment by the forced circulating air. The thickness of the thermal interface material also contributes significantly to the efficiency of heat dissipation and should be minimized as much as the physcial configuration or construction permits. The effectiveness of a specific thermal interface material cannot be easily predicted by the claimed or even measured bulk thermal conductivity data or value: the thermal resistance at the thermal interface material to the substrates in their respective interfaces for thin bondline or interface thickness are significant and represents the “coupling efficiency” that cannot be predicted and must be measured.

The data in the comparison of thermal interface materials are collected by using an Intel CPU and forced air heatsink as represented in the above configuration. A thermocouple is drilled and embedded at the heatsink junction that interface with the thermal interface material to provide direct temperature data at the interface for measuring the “coupling” of the specific thermal interface materials to the heatsink.

For more information and recommendation assistance in managing die-attach reliability and module thermal interface management, 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